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Biomedical subjects

P Ward

Publications and source records attributed to P Ward.

At least 127 records · Page 7Linked to original sources
PubMed1990

Production of IgM antibody to HHV6 in reactivation and primary infection.

The cross-reaction of HHV6 antibody with that to the other herpesviruses was studied in 96 blood donors whose sera were tested for IgG antibody to human herpesvirus type 6 (HHV6), cytomegalovirus (CMV), Epstein-Barr virus (EBV), varicella zostervirus (VZV) and herpes simplex virus (HSV). No correlation was found between IgG antibody to HHV6 and that to any of the other herpesviruses in these individuals. Antibodies to HHV6 and CMV were measured in patients undergoing documented serological responses to HHV6. Eleven cases of primary HHV6 infection associated with roseola infantum in babies, 1 of whom suffered from gastroenteritis as well as pyrexia and rash, are reported. Three cases of HHV6 reactivation, 1 in a 3-year-old child and 2 in adults, 1 of whom simultaneously underwent a primary CMV infection are also reported. Our results suggest that indirect immunofluorescence is a specific way of measuring HHV6 antibody, that HHV6 IgG and IgM can be detected in the absence of antibody to CMV and that HHV6 IgM is present both in primary HHV6 infections and in reactivations.

Adult↗
PubMed1990

Comparison between the polymerase chain reaction and slot blot hybridization for the detection of HPV sequences in cervical scrapes.

Sixty-four women presenting with a single mildly abnormal smear were investigated for infection with human papillomavirus (HPV) type 16 using both slot blot hybridization and polymerase chain reaction (PCR) amplification. PCR was nearly three times more sensitive for the detection of HPV 16 DNA than slot blot hybridization. HPV 16 was not significantly associated with a risk of progression to CIN if PCR was used to screen for infection. Women who smoked were at significantly greater risk of progression to CIN than non-smokers.

Adult↗
PubMed1990

Detection of Bifidobacterium species by enzymatic methods.

The properties of Bifidobacterium strains of human origin were examined by three enzymic tests and the amounts of acetic and lactic acids produced were also quantified. It was evident that two strains of the American Type Culture Collection (ATCC) did not belong to the genus. Moreover, at least one strain of Bifidobacterium added to some milk preparations did not show distinctive characteristics of the genus. It was also shown that most of bifidobacteria studied produced alpha-galactosidase (EC 3.2.1.22) and alpha-glucosidase (EC 3.2.1.20). The presence of alpha-galactosidase could afford a rapid differentiation of bifidobacteria used in some dairy products since this enzyme was not detected in Lactobacillus strains studied.

Acetates↗
PubMed1990

Paradoxical bone mineralisation in the twin to twin transfusion syndrome.

We report twin preterm infants with the twin to twin transfusion syndrome, exhibiting grossly different bone densities on chest radiographs. Photonabsorptiometry showed the polycythaemic twin was osteopenic and the anaemic twin osteosclerotic; bone mineral contents were 0.028 g/cm and 0.074 g/cm respectively (normal mean (SD) 0.041 (0.006) g/cm. We speculate that alterations in macrophage derived osteoclastic activity contribute to these previously unreported findings.

Absorptiometry, Photon↗
PubMed1989

Estimating the size of the dividing stem cell pool after allogeneic bone marrow transplantation.

Currently the problem of estimation of the number of pluripotent stem cells reconstituting marrow grafts following bone marrow transplantation, or studies looking at questions of clonal dominance in hematopoietic cell populations, rely on indirect measurement and a simple application of the formula for the sampling variation of a binomial proportion. This approach, from a statistical viewpoint, can be seen to be flawed. It is very easily remedied though and only requires appropriate use of variance stabilizing transformations. These lead to a very simple estimator for the number of hematopoietic stem cells involved in repopulating the marrow and require little in the way of additional calculation. We give the distribution theory for this estimator as well as simple approximations for practical application. As an illustration we rework data recently gathered to address the question as to whether or not reconstitution of marrow grafts in the clinical setting is oligoclonal.

Bone Marrow Transplantation↗
PubMed1989

Heterogeneity in mRNA of human papillomavirus type-6 subtypes in respiratory tract lesions.

We have analyzed the structure of viral transcripts in six HPV-6c-induced respiratory tract lesions, which included four benign laryngeal papilloma, one benign nasopapilloma, and one malignant tumor, in four benign laryngeal papilloma induced by HPV-6e, and in one benign laryngeal papilloma induced by HPV-6f. Northern analysis and S1 nuclease digestion with subgenomic RNA probes demonstrated that the major exon of 1050 bases had a 5' end in the E4 open reading frame and a 3' end in E5B. Primer extension from a synthetic oligonucleotide in E4 was used to examine sequences 5' to the major exon. Differences were found in length, start sites, and relative abundance of the first exon in transcripts produced in HPV-6c-induced infections as compared to HPV-6e- and HPV-6f-induced infections. Primer extension in the presence of dideoxynucleotides facilitated sequence analyses of the first exon. HPV-6c transcripts contained common sequences from E1 that in different transcripts extended farther upstream in the 5' direction into E7 resulting in different lengths. All of the mRNAs had the same splice junction at nucleotide 847 in E1 and 3325 in E4. Similarly, the HPV-6e transcripts shared common sequences in the first exon that differed in length as a result of different starting points and had the same splice junction as the HPV-6c transcripts. No differences were found in the structure of viral transcripts in a malignant vs benign lesions, nor in those of nasopapilloma vs laryngeal papilloma when induced by the same HPV-6 subtype.

Autoradiography↗
PubMed1988

Forearm mineral content in normal men: relationship to weight, height and plasma testosterone concentrations.

We measured forearm bone mineral content by single photon absorptiometry together with height, weight and the plasma concentrations of testosterone, free testosterone and sex steroid binding globulin in 66 normal Caucasian males aged 29-46 years. Multiple regression analysis suggests that bone mineral content in either the dominant or the nondominant arm is correlated with weight and sex steroid binding globulin (p less than 0.05 for both parameters). The partial negative correlation of bone mineral content (corrected for weight and sex steroid binding globulin) with plasma testosterone failed to reach statistical significance (p = 0.07). The parsimonious regression equation which best explained the bone mineral content measurements in the nondominant forearm in these men was bone mineral content = 29.1-0.374 (plasma testosterone) + 0.383 (weight) + 0.220 (sex steroid binding globulin) with an R2 value of 29.7%. A similar equation was generated for the dominant arm.

Adult↗
PubMed1988

Transcriptional activity of human papillomavirus type 6 in respiratory tract papillomata.

We have investigated the molecular basis for differences that we observed in the biological activities of genetically related but distinguishable human papillomavirus type 6 (HPV-6) subtypes. To analyse tissue-specific differences in replication and transcription, and to identify viral gene products important in the benign transformation of epithelial cells, we have modified procedures utilizing guanidinium isothiocyanate and density gradient centrifugation to facilitate the extraction of relatively undegraded DNA and RNA from 21 biopsy specimens of respiratory tract papillomata. Southern transfer analysis was used to characterize the viral genome, and to demonstrate that relative quantities of viral DNA in lesions varied but that the range was similar in lesions induced by HPV-6c, -6d, -6e and -6f. Dot blot analysis of the amount of viral RNA in comparison with the amount of 28S ribosomal RNA indicated that the relative level of viral RNA in each lesion varied considerably and that on average there was approximately twice as much viral RNA in HPV-6c-induced lesions as in HPV-6d-, -6e- or -6f-induced lesions. In dot blot and Northern analyses, hybridization of RNA from HPV-6c-induced lesions with HPV-6c DNA gave a stronger signal than hybridization of the same RNA with an HPV-6e probe, and vice versa. These differences in hybridization intensities with subtype-specific probes indicate that the most abundant RNA species are transcribed from parts of the genome that show sequence divergence between these two subtypes. Northern analysis demonstrated the predominant viral transcript to be about 1200 nucleotides in length in lesions induced by each of the four subtypes.

DNA, Neoplasm↗
PubMed1988

Blue rubber bleb naevus disease: an uncommon cause of gastrointestinal tract bleeding.

A 23 year old woman presented with facial pain, a right parotid tumour and iron deficiency anaemia. She had several cutaneous venous swellings and tumours with a similar appearance were found in the large bowel. Histological examination of the parotid tumour and angiography of the skin and gut lesions confirmed that they were venous in origin. The aetiology, classification, and complications of disorders of the venous system and the importance of using a tourniquet to examine the peripheral veins is discussed.

Adult↗