Related Articles

Background

The Accreditation Council for Graduate Medical Education has mandated multisource feedback (MSF) in the ambulatory setting for internal medicine residents. Few published reports demonstrate actual MSF results for a residency class, and fewer still include clinical quality measures and knowledge-based testing performance in the data set.

Methods

Residents participating in a year-long group practice experience called the “long-block” received MSF that included self, peer, staff, attending physician, and patient evaluations, as well as concomitant clinical quality data and knowledge-based testing scores. Residents were given a rank for each data point compared with peers in the class, and these data were reviewed with the chief resident and program director over the course of the long-block.

Results

Multisource feedback identified residents who performed well on most measures compared with their peers (10%), residents who performed poorly on most measures compared with their peers (10%), and residents who performed well on some measures and poorly on others (80%). Each high-, intermediate-, and low-performing resident had a least one aspect of the MSF that was significantly lower than the other, and this served as the basis of formative feedback during the long-block.

Conclusion

Use of multi-source feedback in the ambulatory setting can identify high-, intermediate-, and low-performing residents and suggest specific formative feedback for each. More research needs to be done on the effect of such feedback, as well as the relationships between each of the components in the MSF data set.

Background

There is a global need to assess physicians' professional performance in actual clinical practice. Valid and reliable instruments are necessary to support these efforts. This study focuses on the reliability and validity, the influences of some sociodemographic biasing factors, associations between self and other evaluations, and the number of evaluations needed for reliable assessment of a physician based on the three instruments used for the multisource assessment of physicians' professional performance in the Netherlands.

Methods

This observational validation study of three instruments underlying multisource feedback (MSF) was set in 26 non-academic hospitals in the Netherlands. In total, 146 hospital-based physicians took part in the study. Each physician's professional performance was assessed by peers (physician colleagues), co-workers (including nurses, secretary assistants and other healthcare professionals) and patients. Physicians also completed a self-evaluation. Ratings of 864 peers, 894 co-workers and 1960 patients on MSF were available. We used principal components analysis and methods of classical test theory to evaluate the factor structure, reliability and validity of instruments. We used Pearson's correlation coefficient and linear mixed models to address other objectives.

Results

The peer, co-worker and patient instruments respectively had six factors, three factors and one factor with high internal consistencies (Cronbach's alpha 0.95 - 0.96). It appeared that only 2 percent of variance in the mean ratings could be attributed to biasing factors. Self-ratings were not correlated with peer, co-worker or patient ratings. However, ratings of peers, co-workers and patients were correlated. Five peer evaluations, five co-worker evaluations and 11 patient evaluations are required to achieve reliable results (reliability coefficient ≥ 0.70).

Conclusions

The study demonstrated that the three MSF instruments produced reliable and valid data for evaluating physicians' professional performance in the Netherlands. Scores from peers, co-workers and patients were not correlated with self-evaluations. Future research should examine improvement of performance when using MSF.

Background

While the Accreditation Council for Graduate Medical Education recommends multisource feedback (MSF) of resident performance, there is no uniformly accepted MSF tool for emergency medicine (EM) trainees, and the process of obtaining MSF in EM residencies is untested.

Objective

To determine the feasibility of an MSF program and evaluate the intraclass and interclass correlation of a previously reported resident professionalism evaluation, the Humanism Scale (HS).

Methods

To assess 10 third-year EM residents, we distributed an anonymous 9-item modified HS (EM-HS) to emergency department nursing staff, faculty physicians, and patients. The evaluators rated resident performance on a 1 to 9 scale (needs improvement to outstanding). Residents were asked to complete a self-evaluation of performance, using the same scale.

Analysis

Generalizability coefficients (Eρ2) were used to assess the reliability within evaluator classes. The mean score for each of the 9 questions provided by each evaluator class was calculated for each resident. Correlation coefficients were used to evaluate correlation between rater classes for each question on the EM-HS. Eρ2 and correlation values greater than 0.70 were deemed acceptable.

Results

EM-HSs were obtained from 44 nurses and 12 faculty physicians. The residents had an average of 13 evaluations by emergency department patients. Reliability within faculty and nurses was acceptable, with Eρ2 of 0.79 and 0.83, respectively. Interclass reliability was good between faculty and nurses.

Conclusions

An MSF program for EM residents is feasible. Intraclass reliability was acceptable for faculty and nurses. However, reliable feedback from patients requires a larger number of patient evaluations.

Background

Multisource feedback (MSF) is emerging as a central assessment method for several medical education competencies. Planning and resource requirements for a successful implementation can be significant. Our goal is to examine barriers and challenges to a successful multisite MSF implementation, and identify the benefits of MSF as perceived by participants.

Methods

We analyzed the 2007–2008 field trial implementation of the Assessment of Professional Behaviors, an MSF program of the National Board of Medical Examiners, conducted with 8 residency and fellowship programs at 4 institutions. We use a multimethod analysis that draws on quantitative process indicators and qualitative participant experience data. Process indicators include program attrition, completion of implementation milestones, number of participants at each site, number of MSF surveys assigned and completed, and adherence to an experimental rater training protocol. Qualitative data include communications with each program and semistructured interviews conducted with key field trial staff to elicit their experiences with implementation.

Results

Several implementation challenges are identified, including communication gaps and difficulty scheduling implementation and training workshops. Participant interviews indicate several program changes that should enhance feasibility, including increasing communication and streamlining the training process.

Conclusions

Multisource feedback is a complex educational intervention that has the potential to provide users with a better understanding of performance expectations in the graduate medical education environment. Standardization of the implementation processes and tools should reduce the burden on program administrators and participants. Further study is warranted to broaden our understanding of the resource requirements for a successful MSF implementation and to show how outcomes change as MSF gains broader acceptance.

Objective: To assess the internal validity and reliability of a multisource feedback (MSF) program by China Medical Board for resident physicians in China.

Method: Multisource feedback was used to assess professionalism, interpersonal and communication skills. 258 resident physicians were assessed by attending doctors, self-evaluation, resident peers, nurses, office staffs, and patients who completed a sealed questionnaire at 19 hospitals in China. Cronbach's alpha coefficient was used to assess reliability. Validity was assessed by exploratory factor analyses and by profile ratings.

Results: 4128 questionnaires were collected from this study. All responses had high internal consistency and reliability (Cronbach's α> 0.90), which suggests that both questions and form data were internally consistent. The exploratory factor analysis with varimax rotation for the evaluators' questionnaires was able to account for 70 to 74% of the total variance.

Conclusion: The current MSF assessment tools are internally valid and reliable for assessing resident physician professionalism and interpersonal and communication skills in China.

Karlijn Overeem, general practitioner and researcher, defended her thesis on 15 November 2011. The thesis concerns the development and implementation of a performance assessment system for medical specialists (consultants) in Dutch hospitals. Besides the use of multisource feedback, the assessments consist of a portfolio and an assessment interview with a trained colleague. The thesis comprises: a review, two qualitative studies and three quantitative studies.

Background

Chagas disease (American trypanosomiasis) is a zoonotic or anthropozoonotic disease caused by the parasite Trypanosoma cruzi. Predominantly affecting populations in poor areas of Latin America, medical care for this neglected disease is often lacking. Médecins Sans Frontières/Doctors Without Borders (MSF) has provided diagnostic and treatment services for Chagas disease since 1999. This report describes 10 years of field experience in four MSF programs in Honduras, Guatemala, and Bolivia, focusing on feasibility protocols, safety of drug therapy, and treatment effectiveness.

Methodology

From 1999 to 2008, MSF provided free diagnosis, etiological treatment, and follow-up care for patients <18 years of age seropositive for T. cruzi in Yoro, Honduras (1999–2002); Olopa, Guatemala (2003–2006); Entre Ríos, Bolivia (2002–2006); and Sucre, Bolivia (2005–2008). Essential program components guaranteeing feasibility of implementation were information, education, and communication (IEC) at the community and family level; vector control; health staff training; screening and diagnosis; treatment and compliance, including family-based strategies for early detection of adverse events; and logistics. Chagas disease diagnosis was confirmed by testing blood samples using two different diagnostic tests. T. cruzi-positive patients were treated with benznidazole as first-line treatment, with appropriate counseling, consent, and active participation from parents or guardians for daily administration of the drug, early detection of adverse events, and treatment withdrawal, when necessary. Weekly follow-up was conducted, with adverse events recorded to assess drug safety. Evaluations of serological conversion were carried out to measure treatment effectiveness. Vector control, entomological surveillance, and health education activities were carried out in all projects with close interaction with national and regional programs.

Results

Total numbers of children and adolescents tested for T. cruzi in Yoro, Olopa, Entre Ríos, and Sucre were 24,471, 8,927, 7,613, and 19,400, respectively. Of these, 232 (0.9%), 124 (1.4%), 1,475 (19.4%), and 1,145 (5.9%) patients, respectively, were diagnosed as seropositive. Patients were treated with benznidazole, and early findings of seroconversion varied widely between the Central and South American programs: 87.1% and 58.1% at 18 months post-treatment in Yoro and Olopa, respectively; 5.4% by up to 60 months in Entre Ríos; and 0% at an average of 18 months in Sucre. Benznidazole-related adverse events were observed in 50.2% and 50.8% of all patients treated in Yoro and Olopa, respectively, and 25.6% and 37.9% of patients in Entre Ríos and Sucre, respectively. Most adverse events were mild and manageable. No deaths occurred in the treatment population.

Conclusions

These results demonstrate the feasibility of implementing Chagas disease diagnosis and treatment programs in resource-limited settings, including remote rural areas, while addressing the limitations associated with drug-related adverse events. The variability in apparent treatment effectiveness may reflect differences in patient and parasite populations, and illustrates the limitations of current treatments and measures of efficacy. New treatments with improved safety profiles, pediatric formulations of existing and new drugs, and a faster, reliable test of cure are all urgently needed.

Author Summary

Chagas disease was discovered 100 years ago by the Brazilian physician Carlos Chagas. Predominantly affecting poor populations throughout Latin America, recognition and treatment of this parasitic disease are often neglected. Since 1999, the international medical humanitarian aid organization Médecins Sans Frontières (Doctors Without Borders) has offered diagnostic and therapeutic care for Chagas disease, and here we describe four of our programs in Honduras, Guatemala, and Bolivia, 1999–2008. The earliest programs focused on treating young children and in subsequent programs expanded up to 18 years of age. We identified six program components essential for project viability: information, education, and communication; vector control; health staff training; screening and diagnosis; treatment and compliance; and logistics. The number of children and adolescents screened for Chagas disease ranged from over 7,500 to nearly 25,000 in each program. Early analysis of cure rates ranged widely: from 87% and 58%, respectively, in Honduras and Guatemala, to 0%–5% in Bolivia. No deaths occurred in any of the programs, though drug-related side effects were observed in a quarter to half of all patients. Through our findings and experience, we discuss the feasibility, safety, and effectiveness of treatment programs for Chagas disease in resource-limited settings.

Médecins Sans Frontières (MSF) has been implementing medical assistance programs in Ethiopia since 1994, including the rehabilitation of health structures and the supply of drugs and medical equipment. In 1995, the serious shortage of surgeons in Ethiopia prompted MSF to add a programme to train general practitioners to perform surgery in the Woldya region. The results of the relevant feasibility study were encouraging. The programme's design is based on recent educational data and MSF's experience with introducing transcultural training in countries where unstable conditions prevail. The training programme is currently being studied by the Ethiopian Health Ministry for use as a model for training general practitioners in surgery throughout the country.

Background

Mediterranean spotted fever (MSF) is an acute febrile, zoonotic disease caused by Rickettsia conorii and transmitted to humans by the brown dogtick Rhipicephalus sanguineus. Nearly four hundred cases are reported every year (mainly from June to September) on the Italian island of Sicily. The aim of the study was to analyze the clinical and laboratory characteristics of patients with MSF and the efficacy of the drugs administered.

Methods

Our study was carried out on 415 children with MSF, during the period January 1997 – December 2004, at the "G. Di Cristina" Children's hospital in Palermo, Sicily, Italy. On admission patients' clinical history, physical and laboratory examination and indirect immunofluorescence antibody test (IFAT) for Rickettsia conorii were performed. Diagnosis was considered confirmed if the patients had an MSF diagnostic score greater than or equal to 25 according to the Raoult's scoring system. All patients were treated with chloramphenicol or with macrolides (clarithromycin or azithromycin).

Results

Fever, rash and tache noire were present in 386 (93%), 392 (94.5%) and 263 (63.4%) cases respectively. Eighteen (4.6%) children showed atypical exanthema. Chloramphenicol and newer macrolides all appeared to be effective and safe therapies.

Conclusion

Clinical features of 415 children with MSF were similar to those reported by other authors except for a lower incidence of headache, arthralgia and myalgia and a higher frequency of epato-splenomegaly. Concerning therapy, clarithromycin can be considered a valid alternative therapy to tetracyclines or chloramphenicol especially for children aged < eight years.

New findings in MSF epidemiology, clinical features, and severe forms have changed the general perception of MSF.

Mediterranean spotted fever (MSF) was first described in 1910. Twenty years later, it was recognized as a rickettsial disease transmitted by the brown dog tick. In contrast to Rocky Mountain spotted fever (RMSF), MSF was thought to be a benign disease; however, the first severe case that resulted in death was reported in France in the 1980s. We have noted important changes in the epidemiology of MSF in the last 10 years, with emergence and reemergence of MSF in several countries. Advanced molecular tools have allowed Rickettsia conorii conorii to be classified as a subspecies of R. conorii. New clinical features, such as multiple eschars, have been recently reported. Moreover, MSF has become more severe than RMSF; the mortality rate was as high as 32% in Portugal in 1997. Whether Rhipicephalus sanguineus is the only vector and reservoir for R. conorii conorii is a question not yet answered.

Objectives: To evaluate the utility of intrapartum amnioinfusion (AI) in reducing the infectious morbidity of patients with meconium-stained fluid (MSF). Previous studies have shown increased intraamniotic infection (IAI) and postpartum endometritis (PPE) rates in patients with MSF. Intraamniotic infection has been reduced with the prophylactic administration of ampicillin–sulbactam in MSF. Intraamniotic infection and PPE have been reduced with the use of AI in patients with clear fluid. No investigators have specifically examined the efficacy of AI in reducing meconium-stained, amniotic-fluid-associated infectious morbidity.

Methods: A retrospective cohort study of all cases of MSF was conducted and included patients who delivered at Louisiana State University Medical Center–Shreveport during the one-year period from January to December 1996. Patients were identified from the perinatal database by the diagnosis code of MSF. The medical records were reviewed to determine the consistency of MSF and the presence or absence of infectious morbidity. Patient demographics, labor characteristics, and various risk factors for infection were sought. The main outcome measures were the occurrence of clinical IAI or PPE. Statistical analysis included two-tailed unpaired t-test, X2, ANOVA, and Fisher exact test when appropriate.

Results: Two hundred seventy-three medical records of patients with MSF were studied. One hundred twenty nine patients received AI, and 144 did not receive AI. No significant differences in demographics, labor characteristics, or outcome variables were noted between the two groups. The incidences of IAI were 18.6% and 24.3%, P = 0.13, in the AI and non-AI groups, respectively. Postpartum endometritis occurred in 22.5% of AI patients and 21.5% of non-AI patients, P = 0.97.

Conclusions: The use of AI confers no benefit for the reduction of infectious morbidity in patients with MSF.

Background

Although a number of studies have shown good results in treating children with antiretroviral drugs (ARVs) in hospital settings, there is limited published information on results in pediatric programs that are nurse-centered and based in health centers, in particular on the psychosocial aspects of care.

Methods

Program treatment and outcome data were reported from two government-run health centers that were supported by Médecins Sans Frontières (MSF) in Kigali, Rwanda between October 2003 and June 2007. Interviews were held with health center staff and MSF program records were reviewed to describe the organization of the program. Important aspects included adequate training and supervision of nurses to manage ARV treatment. The program also emphasized family-centered care addressing the psychosocial needs of both caregivers and children to encourage early diagnosis, good adherence and follow-up.

Results

A total of 315 children (< 15 years) were started on ARVs, at a median age of 7.2 years (range: 0.7–14.9). Sixty percent were in WHO clinical stage I/II, with a median CD4% of 14%. Eighty-nine percent (n = 281) started a stavudine-containing regimen, mainly using the adult fixed-dose combination. The median follow-up time after ARV initiation was 2 years (interquartile range 1.2–2.6). Eighty-four percent (n = 265) of children were still on treatment in the program. Thirty (9.5%) were transferred out, eight (2.6%) died and 12 (3.8%) were lost to follow-up. An important feature of the study was that viral loads were done at a median time period of 18 months after starting ARVs and were available for 87% of the children. Of the 174 samples, VL was < 400 copies/ml in 82.8% (n = 144). Two children were started on second-line ARVs. Treatment was changed due to toxicity for 26 children (8.3%), mainly related to nevirapine.

Conclusion

This report suggests that providing ARVs to children in a health center/nurse-based program is both feasible and very effective. Adequate numbers and training of nursing staff and an emphasis on the psychosocial needs of caregivers and children have been key elements for the successful scaling-up of ARVs at this level of the health system.

The acute phase of Mediterranean spotted fever (MSF) is characterized by dramatic changes in cytokine production patterns, clearly indicating their role in the immunomodulation of the response against the microorganism, and the differences in cytokine production seem to influence the extent and severity of the disease. In this study, the single nucleotide polymorphisms (SNPs) of tumor necrosis factor alpha (TNF-α) −308G/A (rs1800629) and interleukin-10 (IL-10) −1087G/A (rs1800896), −824C/T (rs1800871), and −597C/A (rs1800872) and the gamma interferon (IFN-γ) T/A SNP at position +874 (rs2430561) were typed in 80 Sicilian patients affected by MSF and in 288 control subjects matched for age, gender, and geographic origin. No significant differences in TNF-α −308G/A genotype frequencies were observed. The +874TT genotype, associated with an increased production of IFN-γ, was found to be significantly less frequent in MSF patients than in the control group (odds ratio [OR], 0.18; 95% confidence interval [95% CI], 0.06 to 0.51; P corrected for the number of genotypes [Pc], 0.0021). In addition, when evaluating the IFN-γ and IL-10 genotype interaction, a significant increase of +874AA/−597CA (OR, 5.31; 95% CI, 2.37 to 11.88; Pc, 0.0027) combined genotypes was observed. In conclusion, our data strongly suggest that finely genetically tuned cytokine production may play a crucial role in the regulation of the immune response against rickettsial infection, therefore influencing the disease outcomes, ranging from nonapparent or subclinical condition to overt or fatal disease.

Objective:

To evaluate the status of fertility, developmental stages during gestation and teratological changes, if any, following oral administration of methanol sub-fraction (MSF) of the benzene chromatographic fraction of the chloroform extract of the seeds of Carica papaya in rats.

Materials and Methods:

The MSF was administered at the doses of 50 mg contraceptive dose (CD), 100 mg (2× CD), 250 mg (5× CD) and 500 mg (10× CD)/kg body wt/day along with vehicle-treated control using 10 male and 20 female Wistar rats in each group. Necropsies were performed one day before the expected parturition. Status of gravid/non-gravid uterus, the number of corpora lutea in the ovary, implantation status, fetal wellbeing, fetal resorption, fetal body weight, external, visceral and skeletal malformations were recorded.

Results:

Pregnancies were recorded in vehicle-treated control animals and in the animals treated with 50 mg/kg body wt/day. The animals treated with 2× CD, 5× CD and 10× CD did not get pregnant. The fetuses and the status of the ovary, uterus and implantation, fetal body weight, soft tissues and skeletal structures were recorded normal. Data were comparable to those of control.

Conclusion:

The results suggest that the test substance had no developmental toxicity and teratogenicity which could affect pregnancy, implantation and gestation.

Background

Significant adverse events (AE) have been reported in patients receiving medications for multidrug- and extensively-drug-resistant tuberculosis (MDR-TB & XDR-TB). However, there is little prospective data on AE in MDR- or XDR-TB/HIV co-infected patients on antituberculosis and antiretroviral therapy (ART) in programmatic settings.

Methods

Médecins Sans Frontières (MSF) is supporting a community-based treatment program for drug-resistant tuberculosis in HIV-infected patients in a slum setting in Mumbai, India since 2007. Patients are being treated for both diseases and the management of AE is done on an outpatient basis whenever possible. Prospective data were analysed to determine the occurrence and nature of AE.

Results

Between May 2007 and September 2011, 67 HIV/MDR-TB co-infected patients were being treated with anti-TB treatment and ART; 43.3% were female, median age was 35.5 years (Interquartile Range: 30.5–42) and the median duration of anti-TB treatment was 10 months (range 0.5–30). Overall, AE were common in this cohort: 71%, 63% and 40% of patients experienced one or more mild, moderate or severe AE, respectively. However, they were rarely life-threatening or debilitating. AE occurring most frequently included gastrointestinal symptoms (45% of patients), peripheral neuropathy (38%), hypothyroidism (32%), psychiatric symptoms (29%) and hypokalaemia (23%). Eleven patients were hospitalized for AE and one or more suspect drugs had to be permanently discontinued in 27 (40%). No AE led to indefinite suspension of an entire MDR-TB or ART regimen.

Conclusions

AE occurred frequently in this Mumbai HIV/MDR-TB cohort but not more frequently than in non-HIV patients on similar anti-TB treatment. Most AE can be successfully managed on an outpatient basis through a community-based treatment program, even in a resource-limited setting. Concerns about severe AE in the management of co-infected patients are justified, however, they should not cause delays in the urgently needed rapid scale-up of antiretroviral therapy and second-line anti-TB treatment.

Background

The World Health Organization (WHO) Global Program to Eliminate Lymphatic Filariasis relies on mass drug administration (MDA) of two drugs annually for 4 to 6 years. The goal is to reduce the reservoir of microfilariae in the blood to a level insufficient to maintain transmission by the mosquito vector. In 2008, the international medical aid organization Médecins Sans Frontières (MSF) performed the first round of a MDA in the high-burden area of Asmat district, in Papua, Indonesia. We report the challenges faced in this MDA on a remote Indonesian island and propose solutions to overcome these hurdles in similar future contexts.

Results

During the MDA, we encountered difficult challenges in accessing as well as persuading the patient population to take the antifilarial drugs. Health promotion activities supporting treatment need to be adapted and repetitive, with adequate time and resources allocated for accessing and communicating with local, seminomadic populations. Distribution of bednets resulted in an increase in MDA coverage, but it was still below the 80-85% target.

Conclusions

MDA for lymphatic filariasis is how the WHO has planned to eliminate the disease from endemic areas. Our programmatic experience will hopefully help inform future campaign planning in difficult-to-access, high-burden areas of the world to achieve target MDA coverage for elimination of lymphatic filariasis.

Background

Somalia is one of the most political unstable countries in the world. Ongoing insecurity has forced an inconsistent medical response by the international community, with little data collection. This paper describes the "remote" model of surgical care by Medecins Sans Frontieres, in Guri-El, Somalia. The challenges of providing the necessary prerequisites for safe surgery are discussed as well as the successes and limitations of task shifting in this resource-limited context.

Methods

In January 2006, MSF opened a project in Guri-El located between Mogadishu and Galcayo. The objectives were to reduce mortality due to complications of pregnancy and childbirth and from violent and non-violent trauma. At the start of the program, expatriate surgeons and anesthesiologists established safe surgical practices and performed surgical procedures. After January 2008, expatriates were evacuated due to insecurity and surgical care has been provided by local Somalian doctors and nurses with periodic supervisory visits from expatriate staff.

Results

Between October 2006 and December 2009, 2086 operations were performed on 1602 patients. The majority (1049, 65%) were male and the median age was 22 (interquartile range, 17-30). 1460 (70%) of interventions were emergent. Trauma accounted for 76% (1585) of all surgical pathology; gunshot wounds accounted for 89% (584) of violent injuries. Operative mortality (0.5% of all surgical interventions) was not higher when Somalian staff provided care compared to when expatriate surgeons and anesthesiologists.

Conclusions

The delivery of surgical care in any conflict-settings is difficult, but in situations where international support is limited, the challenges are more extreme. In this model, task shifting, or the provision of services by less trained cadres, was utilized and peri-operative mortality remained low demonstrating that safe surgical practices can be accomplished even without the presence of fully trained surgeon and anesthesiologists. If security improves in Somalia, on-site training by expatriate surgeons and anesthesiologists will be re-established. Until then, the best way MSF has found to support surgical care in Somalia is continue to support in a "remote" manner.

In 10 healthy subjects and 25 duodenal ulcer patients, gastric acid and pepsin and serum gastrin responses to cephalic-vagal stimulation induced by modified sham-feeding (MSF) were studied before and after vagotomy and atropinisation and compared with those to maximal stimulation with pentagastrin. When the MSF-induced peak acid output was normalised as a percentage of peak response to pentagastrin it was about 62% in healthy subjects and 66% in duodenal ulcer patients. Serum gastrin concentration was not changed significantly by modified sham-feeding either in normal subjects or in duodenal ulcer patients. Truncal vagotomy completely abolished gastric acid and pepsin responses to MSF in duodenal ulcer patients. Atropine almost completely suppressed gastric acid and pepsin responses to MSF in healthy subjects and reduced those in duodenal ulcer patients by about 62%. The combination of the modified sham-feeding and pentagastrin infusion resulted in augmentation of the acid output in duodenal ulcer patients but not in healthy subjects. This study shows that the cephalic phase results in a potent gastric acid and pepsin stimulation which is not accompanied by any change in serum gastrin concentration either in healthy subjects or duodenal ulcer patients and which is abolished by vagotomy and suppressed by atropine.

Migration stimulating factor (MSF) is a genetically truncated N-terminal isoform of fibronectin that is highly expressed during mammalian development in fetal fibroblasts, and during tumor formation in human cancer-associated myofibroblasts. However, its potential functional role in regulating tumor metabolism remains unexplored. Here, we generated an immortalized fibroblast cell line that recombinantly overexpresses MSF and studied their properties relative to vector-alone control fibroblasts. Our results indicate that overexpression of MSF is sufficient to confer myofibroblastic differentiation, likely via increased TGF-b signaling. In addition, MSF activates the inflammation-associated transcription factor NFκB, resulting in the onset of autophagy/mitophagy, thereby driving glycolytic metabolism (L-lactate production) in the tumor microenvironment. Consistent with the idea that glycolytic fibroblasts fuel tumor growth (via L-lactate, a high-energy mitochondrial fuel), MSF fibroblasts significantly increased tumor growth, by up to 4-fold. Mechanistic dissection of the MSF signaling pathway indicated that Cdc42 lies downstream of MSF and fibroblast activation. In accordance with this notion, Cdc42 overexpression in immortalized fibroblasts was sufficient to drive myofibroblast differentiation, to provoke a shift towards glycolytic metabolism and to promote tumor growth by up to 2-fold. In conclusion, the MSF/Cdc42/NFκB signaling cascade may be a critical druggable target in preventing “Warburg-like” cancer metabolism in tumor-associated fibroblasts. Thus, MSF functions in the metabolic remodeling of the tumor microenvironment by metabolically reprogramming cancer-associated fibroblasts toward glycolytic metabolism.

These experiments were performed to determine the importance of cephalic-vagal stimulation in the acid secretory response to eating in normal human subjects. Cephalic stimulation was induced by a modified sham feeding (MSF) technique, during which subjects chewed and expectorated appetizing food. The response to MSF was compared with that to gastric distention with 600 ml NaCl, glucose, or food. In addition, we measured the extent to which cephalic stimulation augments acid secretion that has been stimulated simultaneously by these other mechanisms. Our conclusions are as follows: (a) cephalic stimulation accounts for approximately one-third of the acid secreted when all mechanisms act simultaneously (food-distention plus MSF); (b) within the limits imposed by the maximal secretory capacity, the response to MSF is approximately the same, regardless of whether acid secretion is otherwise unstimulated or is stimulated simultaneously by gastric distention with NaCl, glucose, or food; and (c) gastric distention prolongs the response to cephalic stimulation.

Tumor necrosis factor alpha (TNF) is a key cytokine in the defense against many intracellular pathogens, including Rickettsia conorii, the causative agent of Mediterranean spotted fever (MSF). The levels of two soluble TNF receptors (sTNFR-p55 and sTNFR-p75), the extracellular domains of the two cell surface receptors for TNF, were elevated in the acute-stage plasma samples from 20 patients with serologically confirmed MSF. The median values were 3.1 and 7.8 ng/ml for sTNFR-p55 and sTNFR-p75, respectively. sTNFR values correlated significantly with plasma TNF concentrations. Patients with severe MSF had higher values for both receptor fragments than patients with nonsevere disease. The differences were statistically significant for sTNFR-p55 (median, 5.8 versus 2.0 ng/ml; P = 0.008). Given the proportionately higher values for both TNF and sTNFR-p55 in patients with severe MSF, the sTNFR-p55/TNF ratios for the two patient subgroups did not differ (P = 0.5), while the sTNFR-p75/TNF ratios were significantly different (P = 0.01), with disproportionately lower values in patients with severe disease.

Injection of rabbits with living Brucella melitensis Rev I induced the appearance of a macrophage-stimulating-factor (MSF) in the sera of these animals. MSF was involved in ingestion of bacilli, hastening the formation of protected loci as measured by the addition of lethal amounts of dihydrostreptomycin. When sufficient time had been allowed for effective ingestion, streptomycin had little effect. This in turn allowed for multiplication of bacilli intracellularly in the presence of 5 to 250 μg of drug per ml. MSF mediated more effective ingestion by both immune and normal macrophages. Under such conditions, there was little, if any, intracellular growth restriction by macrophages from immune animals. The activity appeared within the first 5 days after injection with 109 organisms and was present for several months. Three weeks after injection, the activity of serum was partially heat-labile. All activity was removed by absorption with heat-killed or living Rev I cells, suggesting that a specific globulin is concerned.

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Background

The complex characteristics and unclear biological fate of biomacromolecules (BMM), including colloidal and soluble microbial products (SMP), extracellular polymeric substances (EPS) and membrane surface foulants (MSF), are crucial factors that limit our understanding of membrane fouling in membrane bioreactors (MBRs).

Findings

In this study, the microbial transformation of BMM was investigated in a lab-scale MBR by well-controlled bioassay tests. The results of experimental measurements and mathematical modeling show that SMP, EPS, and MSF had different biodegradation behaviors and kinetic models. Based on the multi-exponential G models, SMP were mainly composed of slowly biodegradable polysaccharides (PS), proteins (PN), and non-biodegradable humic substances (HS). In contrast, EPS contained a large number of readily biodegradable PN, slowly biodegradable PS and HS. MSF were dominated by slowly biodegradable PS, which had a degradation rate constant similar to that of SMP-PS, while degradation behaviors of MSF-PN and MSF-HS were much more similar to those of EPS-PN and EPS-HS, respectively. In addition, the large-molecular weight (MW) compounds (>100 kDa) in BMM were found to have a faster microbial transformation rate compared to the small-MW compounds (<5 kDa). The parallel factor (PARAFAC) modeling of three-dimensional fluorescence excitation-emission matrix (EEM) spectra showed that the tryptophan-like PN were one of the major fractions in the BMM and they were more readily biodegradable than the HS. Besides microbial mineralization, humification and hydrolysis could be viewed as two important biotransformation mechanisms of large-MW compounds during the biodegradation process.

Significance

The results of this work can aid in tracking the origin of membrane foulants from the perspective of the biotransformation behaviors of SMP, EPS, and MSF.

There is increasing evidence that acetylcholinesterase (AChE) may have various specific developmental roles in brain development. Nevertheless, specific effects of AChE inhibition during early brain development have not been adequately described. Therefore, methanesulfonyl fluoride (MSF), an irreversible AChE inhibitor that shows high selectivity for the CNS was used to produce AChE inhibition in utero to study subsequent adult behaviors, sleep, and cholinergic markers. Rats exposed to MSF in utero showed a deficit in spatial learning tasks using appetitive motivation but, surprisingly, they performed equally well or better than controls when aversive motivation was used. One hypothesis was that MSF treatment in utero affected the response to stress. Tests of anxiety however showed no differences in basal levels of anxiety. Studies of sleep behavior, however, indicated a higher level of REM sleep which is only seen during the light phase of male rats exposed to MSF in utero as compared to controls. No differences in cholinergic markers in the brains of adults were found except that females exposed to MSF in utero had a higher level of ChAT activity in the synaptosomal fraction of the hippocampus. Even so, whether cholinergic alterations accompany the in utero MSF exposure remains to be determined. The failure to find widespread changes in cholinergic markers in the adult brains suggests changes in behaviors should be further investigated by testing the participation of postsynaptic mechanisms, measuring of cholinergic markers during earlier development periods and the possible participation of other neurotransmitter systems to clearly reveal the role of the cholinergic system following in utero MSF exposure.

Anorexia Nervosa (AN) is a disorder of self-starvation characterized by decreased meal size and food intake. While it is possible that reduced food intake in AN reflects an excess of inhibitory factors, e.g., cognitive inhibition related to fear of weight gain or abnormal postingestive negative feedback, it is also possible that decreased intake reflects diminished orosensory stimulation of food intake. This has been difficult to test directly because the amount of food ingested during a test meal by patients with AN reflects an integration of orosensory excitatory, and cognitive, learned, and postingestive inhibitory controls of eating. To begin to dissociate these controls, we adapted the modified sham feeding technique (MSF) to measure the intake of a series of sweetened solutions in the absence of postingestive stimulation. Subjects with AN (n=24) and normal controls (NC, n=10) were randomly presented with cherry Kool Aid® solutions sweetened with five concentrations of aspartame (0, 0.01, 0.03, 0.08 and 0.28%) in a closed opaque container fitted with a straw. They were instructed to sip as much as they wanted of the solution during 15 1-minute trials and to spit the fluid out into another opaque container. Subjects with AN sipped less unsweetened solution than NC (p<0.05). Because this difference appeared to account completely for the smaller intakes of sweetened solutions by AN, responsiveness of intake to sweet taste per se was not different in AN and NC. Since MSF eliminated postingestive and presumably cognitive inhibitory controls, and the orosensory response to sweet taste was not different in AN than NC, we conclude that decreased intake by AN subjects under these conditions reflects the increased inhibition characteristic of this disorder that is presumably learned, with a possible contribution of decreased potency of orosensory stimulation by the sipped solutions.