PMCC PMCC

Search tips
Search criteria

Advanced
Results 1-18 (18)
 

Clipboard (0)
None

Select a Filter Below

Journals
Year of Publication
more »
Document Types
1.  Enzyme Replacement Therapy Prevents Dental Defects in a Model of Hypophosphatasia 
Journal of Dental Research  2011;90(4):470-476.
Hypophosphatasia (HPP) occurs from loss-of-function mutation in the tissue-non-specific alkaline phosphatase (TNALP) gene, resulting in extracellular pyrophosphate accumulation that inhibits skeletal and dental mineralization. TNALP-null mice (Akp2-/-) phenocopy human infantile hypophosphatasia; they develop rickets at 1 week of age, and die before being weaned, having severe skeletal and dental hypomineralization and episodes of apnea and vitamin B6-responsive seizures. Delay and defects in dentin mineralization, together with a deficiency in acellular cementum, are characteristic. We report the prevention of these dental abnormalities in Akp2-/- mice receiving treatment from birth with daily injections of a mineral-targeting, human TNALP (sALP-FcD10). sALP-FcD10 prevented hypomineralization of alveolar bone, dentin, and cementum as assessed by micro-computed tomography and histology. Osteopontin – a marker of acellular cementum – was immuno-localized along root surfaces, confirming that acellular cementum, typically missing or reduced in Akp2-/- mice, formed normally. Our findings provide insight concerning how acellular cementum is formed on tooth surfaces to effect periodontal ligament attachment to retain teeth in their osseous alveolar sockets. Furthermore, they provide evidence that this enzyme-replacement therapy, applied early in post-natal life – where the majority of tooth root development occurs, including acellular cementum formation – could prevent the accelerated tooth loss seen in individuals with HPP.
doi:10.1177/0022034510393517
PMCID: PMC3144124  PMID: 21212313
tissue-non-specific alkaline phosphatase; tooth loss; cementum; dentin; osteopontin
2.  Infant morbidity in an Indian slum birth cohort 
Archives of disease in childhood  2007;93(6):479-484.
Objective
To establish incidence rates, clinic referrals, hospitalisations, mortality rates and baseline determinants of morbidity among infants in an Indian slum.
Design
A community-based birth cohort with twice-weekly surveillance.
Setting
Vellore, South India.
Subjects
452 newborns recruited over 18 months, followed through infancy.
Main outcome measures
Incidence rates of gastrointestinal illness, respiratory illness, undifferentiated fever, other infections and non-infectious morbidity; rates of community-based diagnoses, clinic visits and hospitalisation; and rate ratios of baseline factors for morbidity.
Results
Infants experienced 12 episodes (95% confidence interval (CI) 11 to 13) of illness, spending about one fifth of their infancy with an illness. Respiratory and gastrointestinal symptoms were most common with incidence rates (95% CI) of 7.4 (6.9 to 7.9) and 3.6 (3.3 to 3.9) episodes per child-year. Factors independently associated with a higher incidence of respiratory and gastrointestinal illness were age (3-5 months), male sex, cold/wet season and household involved in beedi work. The rate (95% CI) of hospitalisation, mainly for respiratory and gastrointestinal illness, was 0.28 (0.22 to 0.35) per child-year.
Conclusions
The morbidity burden due to respiratory and gastrointestinal illness is high in a South Indian urban slum, with children ill for approximately one fifth of infancy, mainly with respiratory and gastrointestinal illnesses. The risk factors identified were younger age, male sex, cold/wet season and household involvement in beedi work.
doi:10.1136/adc.2006.114546
PMCID: PMC2682775  PMID: 17916587
3.  Polymerase chain reaction in the detection of an ‘outbreak’ of asymptomatic viral infections in a community birth cohort in south India 
Epidemiology and infection  2007;136(3):399-405.
SUMMARY
Asymptomatic enteric infections are important where sequelae or protection from subsequent illness is an outcome measure. The use of reverse transcription–polymerase chain reaction (RT–PCR) to identify asymptomatic enteric infections in a birth cohort followed for rotaviral infections in a south Indian urban slum is reported. Of 1191 non-diarrhoeal samples from 371 children collected in May–June 2003, 22 (1·9%) were positive by ELISA. A total of 147 (40·6%) of 362 samples tested by VP6 RT–PCR were positive. In those samples that could be typed, a high diversity of G types including G1, G2, G4, G8, G9 and G10, and a high proportion (34·4%) of mixed infections were detected. Noroviruses were identified in 6/28 (21·4%) samples tested. The identification of infections undetectable by conventional techniques indicates the importance of the use of sensitive diagnostic techniques in research studies. Asymptomatically infected children may also act as a source of infection for other susceptible hosts.
doi:10.1017/S0950268807008709
PMCID: PMC2467457  PMID: 17521476
4.  Haemorrhagic colitis and haemolytic-uraemic syndrome: false positive reaction with a rotavirus latex agglutination test. 
Journal of Clinical Pathology  1991;44(7):609-610.
A stool sample from a child with haemorrhagic colitis and haemolytic-uraemic syndrome gave a positive reaction with the RotaScreen latex agglutination test in the absence of other evidence of rotavirus infection. When this test is performed on bloody specimens, positive reactions should be interpreted with caution and confirmed by other means.
PMCID: PMC496807  PMID: 1649843
5.  Serological reactivity against cyst and tachyzoite antigens of Toxoplasma gondii determined by FAST-ELISA. 
Journal of Clinical Pathology  1995;48(10):908-911.
AIMS--To obtain quantitative data on the human serological response to Toxoplasma gondii tachyzoite and bradyzoite antigens. METHODS--Serum samples from 30 patients who had positive antibody titres against T gondii and from 14 who were seronegative, together with sequential serum samples from four infected individuals, were screened by FAST-ELISA. RESULTS--Serum samples from the 30 seropositive patients showed high IgG and IgM titres against the T gondii tachyzoite antigen but very low responses to cyst antigen. This result was borne out in sequential serum samples from patients with toxoplasmosis. CONCLUSION--Antibody recognition of the cystic stage of T gondii is low, implying that either this stage is poorly immunogenic or that the antigen load is low.
PMCID: PMC502944  PMID: 8537487
6.  Detection of human papillomavirus DNA on the fingers of patients with genital warts 
Sexually Transmitted Infections  1999;75(5):317-319.
OBJECTIVE: To determine whether patients with genital warts carry human papillomavirus (HPV) DNA on their fingers. METHODS: 14 men and eight women with genital warts had cytobrush samples taken from genital lesions, finger tips, and tips of finger nails. Samples were examined for the presence of HPV DNA by the polymerase chain reaction. RESULTS: HPV DNA was detected in all female genital samples and in 13/14 male genital samples. HPV DNA was detected in the finger brush samples of three women and nine men. The same HPV type was identified in genital and hand samples in one woman and five men. CONCLUSION: This study has identified hand carriage of genital HPV types in patients with genital warts. Although sexual intercourse is considered the usual mode of transmitting genital HPV infection, our findings raise the possibility of transmission by finger-genital contact. 



PMCID: PMC1758241  PMID: 10616355
7.  Ocular herpes simplex virus infections: reduced sensitivity to acyclovir in primary disease. 
Forty isolates of herpes simplex virus (HSV) obtained from ocular herpetic infections were assayed for their sensitivity to five antiviral agents. There were wide ranges of sensitivity to foscarnet, idoxuridine, and vidarabine, but the majority were sensitive to acyclovir and ganciclovir. Reduced sensitivity to acyclovir was seen in four isolates, all of which were from primary infections acquired in the community and without a previous history of treatment with antiviral drugs.
PMCID: PMC1042100  PMID: 2162190
8.  Accuracy of serology for the diagnosis of Helicobacter pylori infection--a comparison of eight kits. 
Journal of Clinical Pathology  1996;49(5):373-376.
AIMS: To determine the accuracy of eight commercially available kits for the serological diagnosis of Helicobacter pylori infection, and hence whether a serology service could be introduced to reduce endoscopy workload. METHODS: Eighty four patients newly presenting to their general practitioners with dyspepsia were recruited. Gold standard diagnosis of H pylori infection was obtained both by a histological examination of gastroduodenal biopsy specimens and by the 14C-urea breath test (UBT). The performance of six quantitative and two qualitative enzyme linked immunosorbent assays for H pylori IgG, used according to the manufacturers' instructions, with serum samples obtained during the endoscopy visit, were compared. RESULTS: The study population had a median age of 45 years, and the prevalence of H pylori infection was 35%. With one exception, where the patient had received a course of anti-H pylori treatment between endoscopy and UBT, there was 100% concordance in the results of the two gold standard techniques. Discordant serology results were more common in patients aged > 50 years (42% of the total) than in younger patients (21%), and this was most noticeable in uninfected patients. The sensitivity of the kits was good (90-100%), but specificity was more variable (76-96%), and the rate of equivocal results was unacceptably high in some cases (0-12%). The overall accuracy of the kits ranged from 83 to 98%. Two kits in particular performed well (Pylori-Elisa II, Bio-Whitaker and Premier, Launch; qualitative) with 98% and 100% accuracy, respectively. CONCLUSIONS: In a symptomatic population with a prevalence of H pylori infection of 35%, particularly in patients aged < 50 years, some but not all serology kits may be used as a highly accurate and inexpensive alternative to the gold standard techniques.
PMCID: PMC500474  PMID: 8707949
9.  Internal quality assurance in a clinical virology laboratory. II. Internal quality control. 
Journal of Clinical Pathology  1995;48(3):198-202.
AIMS--In April 1991 additional quality control procedures were introduced into the virology section of the Clinical Microbiology and Public Health Laboratory, Cambridge. Internal quality control (IQC) samples were gradually included in the serological assays performed in the laboratory and supplemented kit controls and standard sera. METHODS--From April 1991 to December 1993, 2421 IQC procedures were carried out with reference sera. RESULTS--The IQC samples were evaluated according to the Westgard rules. Violations were recorded in 60 of 1808 (3.3%) controls and were highest in the IQC samples of complement fixation tests (25/312 (8%) of controls submitted for complement fixation tests). CONCLUSIONS--The inclusion of IQC samples in the serological assays performed in the laboratory has highlighted batch to batch variation in commercial assays. The setting of acceptable limits for the IQC samples has increased confidence in the validity of assay results.
PMCID: PMC502436  PMID: 7730475
10.  Internal quality assurance in a clinical virology laboratory. I. Internal quality assessment. 
Journal of Clinical Pathology  1995;48(2):168-173.
AIMS--In April 1991 an internal quality assessment scheme (IQAS) was introduced into the virology section of the Clinical Microbiology and Public Health Laboratory, Cambridge. The IQAS was established to identify recurring technical and procedural problems, to check the adequacy of current techniques, and to calculate the frequency of errors. METHODS--Between April 1991 and December 1993, 715 anonymous clinical serum samples were submitted to the laboratory to test 3245 individual procedures of diagnostic viral serology. RESULTS--A total of 485 (14.9%) procedural and 61 (1.9%) technical discrepancies were observed, the technical discrepancies mainly being recorded in complement fixation tests. Twenty two (0.7% of total procedures) of the technical discrepancies were diagnostically significant. CONCLUSIONS--Evaluation criteria developed with the introduction of IQAS to viral serology, and technical and procedural discrepancies are assessed. As yet, IQAS has not been introduced to other sections of the diagnostic virology laboratory (virus isolation, electron microscopy, immunofluorescence, and enzyme linked immunosorbent assays for viral and chlamydial antigens).
PMCID: PMC502399  PMID: 7745118
11.  Detection of immunoglobulin M (IgM), IgA, and IgG Norwalk virus-specific antibodies by indirect enzyme-linked immunosorbent assay with baculovirus-expressed Norwalk virus capsid antigen in adult volunteers challenged with Norwalk virus. 
Journal of Clinical Microbiology  1994;32(12):3059-3063.
Pre- and postexposure sera collected from 17 adult volunteers challenged with Norwalk virus as described previously (D. Y. Graham, X. Jiang, T. Tanaka, A. Opekun, P. Madore, and M. K. Estes, J. Infect. Dis. 170:34-43, 1994) were examined for Norwalk virus-specific immunoglobulin M (IgM), IgA, and IgG by indirect enzyme-linked immunosorbent assays with recombinant Norwalk virus antigen bound to the solid phase. Sixteen of the 17 volunteers had evidence of past infection, all presenting with preexisting IgG antibody of high avidity; only one volunteer had no evidence of previous infection. Virus infection was detected in 14 of the 16 volunteers with evidence of past infection, and 9 of the infected volunteers had symptomatic illness. A significant rise in both virus-specific IgA and IgG titers was detected after challenge in all of the volunteers who became ill. Five of the asymptomatic volunteers who were infected had rising titers of virus-specific IgG, but only two of the five had a concomitant rise in their virus-specific IgA antibody titers. Antibody rises were detectable in eight of nine ill volunteers 8 to 11 days after challenge but in the asymptomatic volunteers only after more than 15 days had elapsed. Virus-specific IgM was detected after challenge in all 14 infected volunteers. Between symptomatic and asymptomatic volunteers there were no significant differences in titers of virus-specific IgG and IgA in serum before challenge; however, there were significantly higher titers in symptomatic volunteers between 8 and > 90 days after challenge for virus-specific IgG and 8 and 24 days after challenge for virus-specific IgA.
PMCID: PMC264229  PMID: 7883902
12.  Prevalence of antibodies to Norwalk virus in England: detection by enzyme-linked immunosorbent assay using baculovirus-expressed Norwalk virus capsid antigen. 
Journal of Clinical Microbiology  1993;31(4):1022-1025.
A total of 3,250 serum specimens collected in England in 1991 and 1992 were tested by an indirect enzyme-linked immunosorbent assay for antibody to Norwalk virus using baculovirus-expressed capsid antigen, and 2,382 (73.3%) were positive. The prevalence of Norwalk virus antibody differed regionally. It was lowest (24.6%) in 6- to 11-month-old infants and increased to 89.7% in persons over 60 years old.
PMCID: PMC263611  PMID: 8385148
13.  Antibiotic resistant fever associated with herpes simplex virus infection in neutropenic patients with haematological malignancy. 
Journal of Clinical Pathology  1989;42(12):1255-1258.
The incidence of mucocutaneous herpes simplex virus infection confirmed by culture and occurring during febrile neutropenic episodes was determined in 43 patients with haematological malignancy. The outcome of 72 episodes of neutropenic fever was determined and correlated with the presence or absence of herpes simplex virus (HSV) infection. Twenty four patients had mucocutaneous HSV infection during at least one episode. In 24 episodes in which HSV was isolated only 12.5% of fevers responded to antibiotics and 75% of fevers were otherwise unexplained. Conversely, in 48 episodes of neutropenic fever in which HSV was not isolated 67% of fevers responded to antibiotics and only 8.3% were unexplained. The difference in incidence of antibiotic resistant fever in the two groups was significant. There was, therefore, a strong association between mucocutaneous HSV infection and antibiotic resistant fever in immunosuppressed neutropenic patients. As most HSV infections are the result of virus reactivation, establishing the HSV serological state of patients would identify those at risk of infection and hence those in whom the prophylactic use of acyclovir would be indicated.
PMCID: PMC502050  PMID: 2613919
15.  Serological Cross-Reaction between Legionella pneumophila and Citrobacter freundii in Indirect Immunofluorescence and Rapid Microagglutination Tests 
Journal of Clinical Microbiology  1991;29(1):200-201.
We describe the first case in which a diagnostic rise in titers of antibody to formalinized Legionella pneumophila serogroup 1 yolk sac antigen was shown to be caused by a cross-reaction between L. pneumophila and another organism, Citrobacter freundii.
PMCID: PMC269729  PMID: 1993758
16.  Toxoplasmosis in heart and heart and lung transplant recipients. 
Journal of Clinical Pathology  1989;42(2):194-199.
Of the first 250 heart and 35 heart and lung transplant recipients at Papworth Hospital, Cambridge, who survived for more than one month after transplantation, 217 heart and 33 heart and lung patients were investigated serologically for evidence of Toxoplasma gondii infection. Six patients acquired primary T gondii infection, most probably from the donor organ. Five patients experienced T gondii recrudescence, two of whom had recovered from primary infection a few years earlier. Two patients died from primary T gondii infection and the severity of symptoms in the other patients with primary infection was related to the amount of immunosuppressive treatment. Prophylaxis with pyrimethamine (25 mg a day for six weeks) was introduced for T gondii antibody negative transplant recipients who received a heart from a T gondii antibody positive donor after the first four cases of primary toxoplasmosis. Of the seven patients not given pyrimethamine, four (57%) acquired primary T gondii infection. This compared with two of the 14 patients (14%) given prophylaxis.
PMCID: PMC1141826  PMID: 2493490
17.  Cytomegalovirus infections in heart and heart and lung transplant recipients. 
Journal of Clinical Pathology  1988;41(6):660-667.
Of the first 166 heart and 15 heart and lung transplant recipients at Papworth Hospital, Cambridge, who survived for more than one month after transplantation, 162 were investigated for cytomegalovirus (CMV) infection by serological methods. Altogether, 73 (45%) developed CMV infection after transplantation: 30 (18.5%) had acquired primary infection and 43 (26.5%) reactivation or reinfection. Six patients died of primary infection, probably acquired from the donor organ. Recipients negative for CMV antibody who received an organ from an antibody positive donor had the most severe disease. Heart and lung transplant recipients experienced more severe primary CMV infection than those in whom the heart alone was transplanted. The most sensitive and rapid serological method was a mu-capture enzyme linked immunosorbent assay (ELISA) for detecting CMV specific IgM, the amount of which was often of prognostic value and influenced the management of patients.
PMCID: PMC1141547  PMID: 2838530
18.  Problems with serological diagnosis of Toxoplasma gondii infections in heart transplant recipients. 
Journal of Clinical Pathology  1986;39(10):1135-1139.
Of the first 128 patients to receive either heart or heart and lung transplants at Papworth Hospital, four developed Toxoplasma gondii infections acquired from the donor heart and two died. Six patients had passively acquired T gondii antibody as a result of blood transfusions around the time of transplantation. Eight patients developed antibodies against T gondii, which were detectable by changes in the latex agglutination test titres but not by those of the dye test. These false positive latex agglutination reactions occurred simultaneously with cytomegalovirus infection and were associated with the IgM serum fraction in the patients' sera. These reactions were not associated with cytomegalovirus specific IgM, Paul-Bunnell antibody, nor detectable rheumatoid factor. These findings emphasise the need for T gondii dye test confirmation of latex agglutination test titre rises in heart transplant recipients.
PMCID: PMC500237  PMID: 3023454

Results 1-18 (18)