Human parainfluenza viruses (HPIV) are uncommon, yet high-risk pathogens after hematopoietic stem cell transplantation (HCT). We evaluated 5178 pediatric and adult patients undergoing HCT between 1974 and 2010 to determine the incidence, risk factors, response to treatment, and outcome of HPIV infection as well as any change in frequency or character of HPIV infection over time. HPIV was identified in 173 patients (3.3%); type 3 was most common (66%). HPIV involved the upper respiratory tract (URTI) (57%), lower respiratory tract (LRTI) (9%), and both (34%) areas of the respiratory tract, at a median of 62 days after transplant. In more recent years, HPIV has occurred later after HCT, while the proportion with nosocomial infection and mortality decreased. Over the last decade, HPIV was more common in older patients and in those receiving reduced intensity conditioning (RIC). RIC was a significant risk factor for later (beyond day +30) HPIV infections and this association was strongest in patients with URTI. HCT using a matched unrelated donor (MUD), mismatched related donor (MMRD), age 10-19 years, and graft-versus-host disease (GVHD) were all risk factors for HPIV infections. LRTI, early (<30 days) infections, age 10-19 years, MMRD, steroid use, and coinfection with other pathogens were risk factors for mortality. The survival of patients with LRTI, especially very early infections, was poor regardless of ribavirin treatment. HPIV incidence remains low, but may have delayed onset associated with RIC regimens and improving survival. Effective prophylaxis and treatment for HPIV are needed.
Human parainfluenza virus; Infection; Respiratory Virus; HCT (hematopoietic cell transplantation); Reduced Intensity Conditioning
Enterococcal bloodstream infections are associated with an increased risk of mortality during the first year after hematopoietic stem cell transplantation, especially in patients with vancomycin-resistant enterococci (VRE) strains. Colonization with VRE and delayed engraftment are significant risk factors for VRE bacteremia.
Background. Enterococci are an important cause of healthcare-associated infections. We retrospectively analyzed risk factors and outcome of vancomycin-resistant enterococci (VRE) and vancomycin-sensitive enterococci (VSE) infections.
Methods. Seven hundred fifty-two patients who received hematopoietic stem cell transplants from 2004 through 2008 at the University of Minnesota were included.
Results. Ninety-three patients had enterococcal bloodstream infection (BSI) during the first year after transplant. Vancomycin resistance was observed in 66% and 31% of isolates in adults and children, respectively. Cumulative incidence of VRE and VSE bacteremia was 6.6% (95% confidence interval [CI], 4.8%–8.4%) and 5.7% (95% CI, 4.0%–7.4%), respectively. Colonization with VRE before or after transplant was a risk factor for VRE bacteremia (odds ratio [OR], 3.3 [95% CI, 1.3–8.3] and 7.0 [95% CI, 4.0–14.8], respectively). Delay in engraftment increased the incidence of VRE bacteremia from 4.5% (95% CI, 2.9–6.6) if engrafted before day 21 and to 15% (95% CI, 3.2%–38%) if engrafted between days 36 and 42. In adults, mortality 30 days after infection was 38% for both VRE (95% CI, 25%–54%) and VSE cases (95% CI, 21%–62%). The hazard ratio for all-cause mortality up to 1 year after transplant was 4.2 (95% CI, 3.1–6.9) and 2.7 (95% CI, 1.4–5.1) for patients with VRE and VSE BSIs, respectively, compared to patients without enterococcal BSI. In pediatric patients, mortality 30 days after VRE and VSE bacteremia was 20% (95% CI, 5.4%–59%) and 4.5% (95% CI, .6%–28%), respectively.
Conclusion. High rates of vancomycin resistance and association of enterococcal infections with significant mortality warrant further efforts to optimize prevention and management of these infections.
Anterior cruciate ligament reconstruction (ACLR) is standard practice for athletes that wish to return to high-level activities; however functional outcomes after ACLR are poor. Quadriceps strength weakness, abnormal movement patterns and below normal knee function is reported in the months and years after ACLR. Second ACL injuries are common with even worse outcomes than primary ACLR. Modifiable limb-to-limb asymmetries have been identified in individuals who re-injure after primary ACLR, suggesting a neuromuscular training program is needed to improve post-operative outcomes. Pre-operative perturbation training, a neuromuscular training program, has been successful at improving limb symmetry prior to surgery, though benefits are not lasting after surgery. Implementing perturbation training after surgery may be successful in addressing post-operative deficits that contribute to poor functional outcomes and second ACL injury risk.
80 athletes that have undergone a unilateral ACLR and wish to return to level 1 or 2 activities will be recruited for this study and randomized to one of two treatment groups. A standard care group will receive prevention exercises, quadriceps strengthening and agility exercises, while the perturbation group will receive the same exercise program with the addition of perturbation training. The primary outcomes measures will include gait biomechanics, clinical and functional measures, and knee joint loading. Return to sport rates, return to pre-injury level of activity rates, and second injury rates will be secondary measures.
The results of this ACL-Specialized Post-Operative Return To Sports (ACL-SPORTS) Training program will help clinicians to better determine an effective post-operative treatment program that will improve modifiable impairments that influence outcomes after ACLR.
Randomized Control Trial NIH 5R01AR048212-07. ClinicalTrials.gov: NCT01773317
Anterior cruciate ligament reconstruction; Neuromuscular training; Return to Sport
Pulmonary cytolytic thrombi (PCT) is an uncommon complication after hematopoietic cell transplantation. Although the pathogenesis is unknown, patients typically respond to systemic corticosteroid treatment. Considering corticosteroids may impair graft versus leukemia reactions, we reviewed the records of 324 pediatric patients who received a transplant for leukemia and compared the outcomes of those with PCT (n=14) to those without PCT (n=310). PCT patients had a significantly more acute and chronic GVHD. Though 3 year non-relapse mortality and overall survival were similar, there was significantly less relapse in patients with PCT compared to those without PCT, regardless of the presence or absence of aGVHD (0% vs. 34% vs. 18%, p<0.01). In multivariate analysis, grade II–IV aGVHD (p=0.02), cGVHD (p=0.01) and development of PCT (p<0.01) were independently associated with less relapse. These data suggest that patients with PCT are at greater risk for GVHD, but a lower risk of leukemia relapse.
Pulmonary Cytolytic Thrombi; Stem Cell Transplantation; Leukemia; Relapse
The SMK box (SAM-III) translational riboswitches were identified in S-adenosyl-L-methionine (SAM) synthetase metK genes in members of the Lactobacillales. This riboswitch switches between two alternative conformations in response to the intracellular SAM concentration and controls metK expression at the level of translation initiation. We previously reported the crystal structure of the SAM-bound SMK box riboswitch. In this study we combined SHAPE chemical probing with mutagenesis to probe the ligand-induced conformational switching mechanism. We revealed that while the majority of the apo SMK box RNA molecules exist in an alternatively base paired (ON) conformation, a subset of them pre-organize into a SAM-bound-like (READY) conformation, which upon SAM exposure is selectively stabilized into the SAM-bound (OFF) conformation through an induced-fit mechanism. Mutagenesis showed that the ON state is only slightly more stable than the READY state, as several single-nucleotide substitutions in a hypervariable region outside the SAM-binding core can alter the folding landscape to favor the READY state. Such SMK variants display a “constitutively-OFF” behavior both in vitro and in vivo. Time-resolved and temperature-dependent SHAPE analyses revealed adaptation of the SMK box RNA to its mesothermal working environment. The latter analysis revealed that the SAM-bound SMK box RNA follows a two-step folding/unfolding process.
Three distinct classes of S-adenosyl-l-methionine (SAM)-responsive riboswitches have been identified that regulate bacterial gene expression at the levels of transcription attenuation or translation inhibition. The SMK box (SAM-III) translational riboswitch has been identified in the SAM synthetase gene in members of the Lactobacillales. Here we report the 2.2-Å crystal structure of the Enterococcus faecalis SMK box riboswitch. The Y-shaped riboswitch organizes its conserved nucleotides around a three-way junction for SAM recognition. The Shine-Dalgarno sequence, which is sequestered by base-pairing with the anti–Shine-Dalgarno sequence in response to SAM binding, also directly participates in SAM recognition. The riboswitch makes extensive interactions with the adenosine and sulfonium moieties of SAM but does not appear to recognize the tail of the methionine moiety. We captured a structural snapshot of the SMK box riboswitch sampling the near-cognate ligand S-adenosyl-l-homocysteine (SAH) in which SAH was found to adopt an alternative conformation and fails to make several key interactions.
Rapid lymphocyte recovery after bone marrow or peripheral blood transplantation is associated with improved survival. However, the impact of early lymphocyte recovery has not been examined after umbilical cord blood transplant (UCBT). We evaluated lymphocyte recovery in 360 consecutive patients with hematologic malignancy that underwent UCBT between 2001 and 2007. Uniform myeloablative (MA), reduced intensity conditioning (RIC) and graft vs. host disease prophylaxis regimens were used. In multivariate analysis, an ALC >200 ×106/L at day 30 (n=73) after MA conditioning was associated with superior 2-year overall survival (OS) (73% vs. 61%; p=0.02) [RR: 2.29; 95% CI: 1.15 – 4.56], progression-free survival (PFS) (68% vs. 54%; p=0.05) [RR: 1.96; 95% CI: 0.99 – 3.86] and less transplant related mortality (TRM) (8% vs. 28%, p<0.01) [RR: 4.38; 95% CI: 1.65 – 11.60] compared to ≤200×106/L (n=43). Similarly, an ALC >200 ×106/L at day 42 (n=105) after RIC was associated with superior 2-year OS (59% vs. 41%, p<0.01) [RR: 2.10; 95% CI: 1.3 – 3.41] and PFS (46% vs. 36%, p=0.05) [RR: 1.58; 95% CI: 1.01 – 2.49] compared to ≤200 ×106/L (n=55). There was no significant relationship between ALC and relapse. Rapid lymphocyte recovery early after UCBT predicts better survival in patients with hematologic malignancies.
ALL; AML; absolute lymphocyte count; allogeneic hematopoietic cell transplantation; umbilical cord blood; reduced intensity conditioning
Little is known about serum vitamin D levels following hematopoietic cell transplantation (HCT). Patients are instructed to avoid sun exposure due to an increased risk of skin cancers. Altered gastrointestinal absorptive capacity as a result of GVHD, bile acid or pancreatic enzyme insufficiency, or bacterial overgrowth may lead to difficulty absorbing the fat soluble vitamin D. This study was undertaken to determine the prevalence of serum 25-hydroxyvitamin D (25(OH)D) deficiency, and factors associated with 25(OH)D deficiency, among children and adults who were at least one year following HCT. A total of 95 participants (54 males, 41 females) completed a questionnaire on usual diet and lifestyle, and provided a blood sample for 25(OH)D determinations between November 2008 and July 2009. The majority of participants had serum 25(OH)D levels ≥75 nmol/L (n=62, 65%), 23 had insufficient levels (50–75 nmol/L), and 10 participants were deficient (<50 nmol/L). The majority of participants reported regular vitamin D supplement use (n=58, 61%). Prednisone use was significantly inversely associated with serum 25(OH)D concentrations. Total vitamin D intake was the strongest single predictor of 25(OH)D concentrations. These findings suggest that 400–600 IU vitamin D/day appear to be required to achieve optimal serum 25(OH)D concentrations following HCT.
hematopoietic cell transplantation; vitamin D; serum 25(OH)D; cancer survivors; diet; dietary supplements
The SMK box riboswitch, which represents one of three known classes of S-adenosylmethionine (SAM)-responsive riboswitches, regulates gene expression in bacteria at the level of translation initiation. In contrast to most riboswitches, which contain separate domains responsible for ligand recognition and gene regulation, the ligand-binding and regulatory domains of the SMK box riboswitch are coincident. This property was exploited to allow the first atomic-level characterization of a functionally intact riboswitch in both the ligand-bound and ligand-free states. NMR spectroscopy revealed distinct mutually exclusive RNA conformations that are differentially populated in the presence or absence of the effector metabolite. Isothermal titration calorimetry and in vivo reporter assay results revealed the thermodynamic and functional consequences of this conformational equilibrium. We present a comprehensive model of the structural, thermodynamic, and functional properties of this compact RNA regulatory element.
RNA; NMR spectroscopy; isothermal titration calorimetry; gene regulation; pre-existing equilibrium; riboswitch
The SMK (SAM-III) box is an S-adenosylmethionine (SAM)-responsive riboswitch found in the 5′ untranslated region of metK genes, encoding SAM synthetase, in many members of the Lactobacillales. SAM binding causes a structural rearrangement in the RNA that sequesters the Shine-Dalgarno (SD) sequence by pairing with a complementary anti-SD (ASD) sequence; sequestration of the SD sequence inhibits binding of the 30S ribosomal subunit and prevents translation initiation. We observed a slight increase in the half-life of the metK transcript in vivo when Enterococcus faecalis cells were depleted for SAM, but no significant change in overall transcript abundance, consistent with the model that this riboswitch regulates at the level of translation initiation. The half-life of the SAM-SMK box RNA complex in vitro is shorter than that of the metK transcript in vivo, raising the possibility of reversible binding of SAM. We used a fluorescence assay to directly visualize reversible switching between the SAM-free and SAM-bound conformations. We propose that the SMK box riboswitch can make multiple SAM-dependent regulatory decisions during the lifetime of the transcript in vivo, acting as a reversible switch that allows the cell to respond rapidly to fluctuations in SAM pools by modulating expression of the SAM synthetase gene.
riboswitch; RNA; translational regulation; bacteria; gene expression
Objective. A combination of intravenous clindamycin and oral tetracycline has been used for many years as a treatment for active rheumatoid arthritis (RA), despite the absence of good evidence for its efficacy. A single-blind pilot study of this therapy suggested that a double-blind placebo-controlled trial was warranted. Methods. Patients with active RA were randomised in a 2 : 1 ratio to receive active treatment or placebo for 25 weeks. The active treatment consisted of intravenous clindamycin in a reducing regime, and oral tetracycline twice daily three times a week. 50 patients were to be recruited. The primary outcome measure was the proportion of patients achieving an ACR20 response. Results. An interim statistical analysis was performed after 20 patients had completed the study. Two patients in the active group achieved an ACR20 response, with none in the placebo group (NS). There was a better ESR20 response in the placebo group (P = .02). There were no other significant differences between the groups. The results indicated that it was unlikely that a significant difference in ACR20 response would emerge if the remaining 30 patients were recruited. The trial was therefore halted. Conclusion. This antibiotic regime is unlikely to be a valuable therapy for active rheumatoid arthritis.
Umbilical cord blood has rapidly become a valuable alternative stem cell source for allogeneic hematopoietic stem cell transplantation. Extensive research over the last 20 years has established the safety and efficacy of umbilical cord blood transplantation in both children and adults with a variety of malignant and non-malignant diseases. This research has clearly shown that this stem cell source has several unique characteristics resulting in distinct advantages and disadvantages when compared to transplantation with unrelated bone marrow or peripheral blood stem cells. This article reviews the most recent literature comparing the outcomes after umbilical cord blood transplantation with other alternative stem cell sources.
stem cell transplantation; umbilical cord blood; alternative stem cell sources
To determine the antileukemic activity of weekly oral aminopterin in patients with refractory acute leukemia; to describe the pharmacodynamic properties of aminopterin; and to contrast the intracellular metabolism of aminopterin and methotrexate by patients’ blasts in vitro.
Forty-six patients were enrolled in three strata: children with acute lymphoblastic leukemia (ALL), adults with ALL, and patients with acute myeloid leukemia (AML).Aminopterin was given weekly, in two doses of 2mg/m2, 12 hours apart. Limited sampling pharmacokinetic analysis was done during the first week of therapy. Accumulation of [3H]aminopterin and [3H]methotrexate by leukemic blasts was studied in vitro.
Six of 22 children with ALL (27%; 95% confidence interval, 8–47%) had clinically significant responses. None of those with AML and only two of 11 adults with ALL had responses meeting protocol definitions, although peripheral blast counts tended to decrease with therapy in all groups. Mucosal toxicity was minimal, even with limited use of leucovorin rescue. Complete bioavailability of aminopterin was confirmed, with a mean area under the curve of 0.52 ± 0.03 µmol hour/L after oral dosing. No relationship between aminopterin pharmacokinetics and response was seen. In vitro, aminopterin showed more consistent metabolism by leukemic blasts to polyglutamates than methotrexate. Lineage-specific differences in the pattern of intracellular antifolylpolyglutamates were observed.
Weekly oral aminopterin has significant activity among children with refractory ALL. With greater cellular accumulation and metabolism, more reliable bioavailability than methotrexate, and tolerable toxicity at this dose and schedule, aminopterin deserves further study as a potent alternative to methotrexate.
Benign prostatic hyperplasia (BPH) is a complex and progressive disease common in aging men. While associated with bothersome lower urinary tract symptoms, it may also result in additional serious complications such as refractory hematuria, acute urinary retention, and BPH-related surgery. Medical therapy has been offered as an approach to halt this progression and perhaps reverse the pathophysiology of BPH. While alpha-blockers provide rapid relief in the form of improved flow rate, their effects may not reduce the overall risk of BPH-related complications. 5α-reductase inhibitors were therefore introduced to affect the underlying disease process by inhibiting the enzyme which converts testosterone to dihydrotesterone, the primary androgen involved in normal and abnormal prostate growth. Through this inhibition, prostate size is decreased, thereby reducing the risk of acute urinary retention and BPH-related surgery while providing symptom control. These effects are most pronounced in men with enlarged prostates (>25 mL) who are at the greatest risk of disease progression. This article reviews the literature for finasteride used in the treatment of BPH and provides evidence for its efficacy, safety and tolerability, applicability for combination therapy, and considerations of its effects on prostate cancer risk.
finasteride; 5α-reductase inhibitor; prostatic hyperplasia
Desmosomes are intercellular junctions responsible for strong cell-cell adhesion in epithelia and cardiac muscle. Numerous studies have shown that the other major type of epithelial cell adhesion, the adherens junction, is destabilized by src-induced tyrosine phosphorylation of two of its principal components, E-cadherin and β-catenin. Here we show that treatment of epithelial cells with the potent tyrosine phosphatase inhibitor sodium pervanadate causes tyrosine phosphorylation of the major desmosomal components desmoglein 2 and plakoglobin in both the non-ionic detergent soluble and insoluble cell fractions and, surprisingly, stabilizes desmosomal adhesion, inducing the hyper-adhesive form normally found in tissues and confluent cell sheets. Taken together with the few other studies on desmosomes these results suggest that the effects of tyrosine phosphorylation on desmosomal adhesion are complex.
desmosome; cell-cell adhesion; intercellular junction; tyrosine phosphorylation; pervanadate; desmoglein; plakoglobin
The genome sequence of a Bacillus anthracis-specific clear plaque mutant phage, AP50c, contains 31 open reading frames spanning 14,398 bp, has two mutations compared to wild-type AP50t, and has a colinear genome architecture highly similar to that of gram-positive Tectiviridae phages. Spontaneous AP50c-resistant B. anthracis mutants exhibit a mucoid colony phenotype.
The biosynthesis of hormones and neuropeptides involves post-translational cleavage of precursors at basic amino acids by prohormone convertases (PCs) predominantly in secretory granules that bud from the trans-Golgi Network. This study reports that the amino acid sequence of PC3 (aa617–638), previously identified as a novel transmembrane (TM) domain, confers lipid raft association and facilitates sorting of the enzyme to the secretory granules of Neuro2A cells for prohormone cleavage. Floatation analysis on sucrose density gradients showed that a proportion of full length (PC3-FL) and carboxyl terminus-truncated PC31–638 (PC3-638) containing the TM domain were associated with lipid rafts in Neuro2A cells, while PC31–616 (PC3-616) and PC3-ΔTM lacking the TM domain were not. Secondly, PC3-FL and PC3-638 underwent stimulated secretion and were shown to be colocalized with a secretory granule marker, chromogranin A, by immunocytochemistry. In contrast, PC3-616 and PC3-ΔTM were constitutively secreted and primarily localized in the Golgi. These data indicate that the transmembrane domain of PC3 plays a key role in sorting the enzyme to the regulated secretory pathway.
prohormone convertase; enzyme; sorting; lipid raft; transmembrane protein
Despite its increasing popularity, several recent studies comparing laparoscopic appendectomy (LA) with open appendectomy (OA) in children have failed to demonstrate significant improvements in patient outcomes. Many series include the “learning curve,” wherein surgeons inexperienced with laparoscopic techniques compare their results with results with OA with its extensive history. This study was designed to investigate outcomes in pediatric appendectomy patients managed by surgeons with extensive laparoscopic experience.
We preformed a retrospective review of 197 consecutive children undergoing appendectomy for presumed acute appendicitis from January 2002 through May 2004 at a university-affiliated community hospital by pediatric and general surgeons with extensive laparoscopic surgical experience.
The study included 117 patients who underwent LA and 80 who underwent OA. Of 122 acute appendicitis cases, mean operating times were 47 minutes (LA) and 48 minutes (OA). The LA group (n=71) had a faster return to full diet (17.6 h vs. 28.6 h, P=0.0008), and shorter postoperative length of stay (LOS) (1.06 d vs. 1.66 d, P<0.0001) compared with the OA group (n = 51). Complication rates, time on intravenous (IV) antibiotics, and IV opiates were similar among the 2 groups. Complicated appendicitis cases (LA, n=34; OA, n=26) were similar with regard to LOS, return to normal bowel function, complication rate and time on IV antibiotics and opiates, but was associated with an increased operation time (LA, 65 min; OA, 51 min, P=0.02).
Following the completion of the laparoscopic surgery learning curve, LA has a comparable operation time and results in a decreased postoperative LOS, and faster return to normal bowel function compared with OA in children with acute nongangrenous, nonperforated appendicitis.
Laparoscopic appendectomy; Open appendectomy; Learning curve; Children
Two companies, MRL and Meridian Diagnostics, have developed Food and Drug Administration-approved herpes simplex virus type 1 type-specific enzyme immunoassays. The sensitivity, specificity, and overall testing efficiency of these assays were 98.2, 93.8, and 96.6% for MRL and 98.8, 99.0, and 98.1% for Meridian, making both of these kits suitable for use in the clinical lab.
MRL Diagnostics and Meridian Diagnostics have recently designed herpes simplex virus type 2 (HSV-2)-specific enzyme immunoassays for HSV-2 antibody detection. Blood donor sera were assayed for HSV-2 antibodies by both methods. The sensitivity, specificity, and efficiency were 97.9, 95.4, and 95.9% for the MRL assay and 83.2, 98.2, and 95.5% for the Meridian assay, respectively.
Fatigue is a common and troubling symptom for people with multiple sclerosis (MS).
To evaluate the effectiveness and cost-effectiveness of a six-session group-based programme for managing MS-fatigue (Fatigue: Applying Cognitive behavioural and Energy effectiveness Techniques to lifeStyle (FACETS)).
Three-centre parallel arm randomised controlled trial with economic evaluation. Patients with MS and significant fatigue were randomised to FACETS plus current local practice (FACETS) or current local practice alone (CLP), using concealed computer-generated randomisation. Participant blinding was not possible. Primary outcomes were fatigue severity (Fatigue Assessment Instrument), self-efficacy (Multiple Sclerosis-Fatigue Self-Efficacy) and disease-specific quality of life (Multiple Sclerosis Impact Scale (MSIS-29)) at 1 and 4 months postintervention (follow-up 1 and 2). Quality adjusted life years (QALYs) were calculated (EuroQoL 5-Dimensions questionnaire and the Short-form 6-Dimensions questionnaire).
Between May 2008 and November 2009, 164 patients were randomised; primary outcome data were available for 146 (89%). Statistically significant differences favour the intervention group on fatigue self-efficacy at follow-up 1 (mean difference (MD) 9, 95% CI (4 to 14), standardised effect size (SES) 0.54, p=0.001) and follow-up 2 (MD 6, 95% CI (0 to 12), SES 0.36, p=0.05) and fatigue severity at follow-up 2 (MD −0.36, 95% CI (−0.63 to −0.08), SES −0.35, p=0.01) but no differences for MSIS-29 or QALYs. No adverse events reported. Estimated cost per person for FACETS is £453; findings suggest an incremental cost-effectiveness ratio of £2157 per additional person with a clinically significant improvement in fatigue.
FACETS is effective in reducing fatigue severity and increasing fatigue self-efficacy. However, it is difficult to assess the additional cost in terms of cost-effectiveness (ie, cost per QALY) as improvements in fatigue are not reflected in the QALY outcomes, with no significant differences between FACETS and CLP. The strengths of this trial are its pragmatic nature and high external validity.
Current Controlled Trials ISRCTN76517470.
MULTIPLE SCLEROSIS; RANDOMISED TRIALS; QUALITY OF LIFE; PSYCHOLOGY; INTERVENTIONAL