Biomedical subjects
B A Clark
Publications and source records attributed to B A Clark.
Histological types of carcinoma of the uterine cervix and the detectability of human papillomavirus DNA.
Using the Southern DNA hybridization technique, tissues from 17 cases of invasive carcinoma of the uterine cervix, including nine cases of squamous cell carcinoma, four cases of adenocarcinoma, one case of adenosquamous carcinoma, and three cases of undifferentiated carcinoma, were examined for the presence of human papillomavirus (HPV) DNA. None of the studied cases had histologically confirmed association of condyloma acuminatum or cervical intraepithelial neoplasia in the vicinity. HPV DNA was detected in two of 17 cases under low stringency conditions. One lesion was undifferentiated carcinoma, and another was squamous cell carcinoma. Hybridization under high stringency conditions with a variety of HPV DNA probes indicated the presence of HPV-16 in these two lesions. The other HPV-positive lesion was adenocarcinoma, demonstrating weak hybridizations with HPV-2 and HPV-16 DNA probes only under high stringency conditions. Altogether, three of 17 cases (17.6%) contained HPV DNA. This observation contrasts to the rate of HPV DNA present in 15 of 18 cases (83.3%) of the tissues of cervical intraepithelial neoplasia. Our data suggest that HPV was not consistently detected in invasive squamous cell carcinoma, despite the frequent association of HPV with its supposed precursor lesions of cervical intraepithelial neoplasia.
Accuracy of anthropometric equations for estimating body composition in female athletes.
Explore the source record for details and available documents.
Presence of human papillomavirus in verrucous carcinoma (Ackerman) of the vagina. Immunocytochemical, ultrastructural, and DNA hybridization studies.
Human papillomavirus (HPV) genomes were identified in two cases of verrucous carcinoma of the vagina, using Southern blot DNA hybridization under low-stringency conditions. Type (group) 6 HPV DNA (HPV-6) was identified, using molecularly cloned HPV-1 through HPV-6 DNA probes under high-stringency conditions in both cases. In addition, DNA extract in one case hybridized with HPV-1, HPV-3, and HPV-4 DNA probes. No HPV structural proteins were demonstrated in either case by immunocytochemical tests, using HPV antibodies. In one case viruslike intranuclear particles were observed by transmission electron microscopy. These two cases suggest a strong associative relationship between HPV and verrucous carcinoma (Ackerman) of the lower part of the genital tract.
Basal cell pseudopodia and the degree of maturation of squamous metaplasia of the uterine cervix: a morphometric quantification.
Application of morphometry to discrete processes was used to study the stroma-epithelial interface in benign proliferative processes of human cervical epithelium. This method with the use of two-dimensional transmission electron micrographs quantifies the number of pseudopodia and other features of the basal cell. The number of pseudopodia per basal cell and other basal cell features in reserve cell hyperplasia, immature squamous metaplasia, intermediate squamous metaplasia, and mature squamous metaplasia of human uterine cervix were measured. The number of pseudopodia per basal cell in reserve cell hyperplasia was 6.77 +/- 1.46 and comparable to that previously observed in advanced cervical intraepithelial neoplasia. The number of pseudopodia per basal cell in the three subtypes of squamous metaplasia ranged from 10.67 to 19.12 and was approximately half that observed in normal control epithelium. The concept of a continuum existing from reserve cell hyperplasia through immature squamous metaplasia to mature squamous metaplasia is supported with the demonstration of increasing numbers of pseudopodia per basal cell with cellular maturation.
Cytogenetic localization by variation in electrophoretic allozyme phenotype: Drosophila Odh.
A gene-dosage effect is characteristic of eukaryotic structural genes and is therefore useful in gene mapping. However, attributing quantitative variations in enzyme activity to a gene-dosage effect or other putative regulatory loci can be suspect when the locus in question may be inducible by variations in culture conditions. The problem of controlling for allele-specific variations in activity and regulation can be circumvented in Drosophila melanogaster by the use of synthetic duplications and deficiencies in conjunction with enzyme polymorphism. A method for constructing segmental aneupliods heterozygous for electrophoretic variants of octanol dehydrogenase (Odh) is presented which permitted variations in allozyme phenotype and enzyme activity--which show a strict dosage dependency--to be produced simultaneously. The structural gene region for Odh was identified using T(Y;A) stocks and the deficiency M(3)S31 was used to assign the locus to polytene band region 86D1-4. With this method a segmental aneuploid survey of Drosophila for purposes of gene localization can be accomplished in one generation with appropriate stocks.
Identification of human papillomavirus DNA in cervical and vaginal intraepithelial neoplasia with molecularly cloned virus-specific DNA probes.
The presence of human papillomavirus (HPV) DNA was identified in the tissues of cervical and vaginal intraepithelial neoplasia by Southern blot DNA hybridization under conditions of low stringency. The specific types of HPV present in the tissues were identified by using molecularly cloned types 1 through 6 (HPV-1 through HPV-6) HPV DNA probes under high-stringency conditions. All tissues of cervical and vaginal intraepithelial neoplasia analyzed contained HPV genomes. Fifteen of 19 samples (79%) contained HPV-6 DNA, and 10 of 19 samples (53%) HPV-3 DNA. Hybridization with HPV-1, HPV-2, HPV-4, and HPV-5 DNAs was also observed in several of the samples. Four of the samples did not hybridize with any of the probes tested (HPV-1 through HPV-6); yet, all showed hybridization with an HPV-EV DNA (a type 3-related DNA) probe under low-stringency conditions, indicating the presence of HPV types other than those belonging to HPV-1 through HPV-6.
Early invasive and in situ warty carcinoma of the vulva: clinical, histologic, and electron microscopic study with particular reference to viral association.
Cases of carcinoma of the vulva with a warty appearance were reviewed. Altogether, 27 cases of warty carcinoma of the vulva were treated at the University of Minnesota Hospitals between 1976 and 1980, which accounted for 22.4% of all vulvar epithelial malignancies. As compared to the previous experience between 1951 and 1970, this relative frequency increased fourfold. Clinical history indicated that warty carcinoma of the vulva was not necessarily preceded by long lead periods of in situ lesions. The lesions seemed to occur in all ages after adolescence, were multifocal in one third of the cases, were frequently locally recurring, and were relatively benign despite their often large size. Many of them were originally diagnosed as condyloma acuminatum. Virus-like particles were seen in eight of the 12 cases (67%) examined with transmission electron microscopy, which included six cases of invasive lesions. These observations suggest that human papillomavirus (HPV) may be the important etiologic agent of this group of tumors. Warty carcinoma of the vulva must be clearly separated from conventional invasive squamous cell carcinoma of the vulva, as its clinical behavior and a possible etiology appear unique.
Basal cell pseudopodia in cervical intraepithelial neoplasia; progressive reduction of number with severity: a morphometric quantification.
An application of a morphometric model is used to study the stroma epithelial interface in human cervical epithelium. This model derived by Okagaki and associates estimates from two dimensional transmission electron photomicrographs the number of basal cell pseudopodia per basal cell. The investigation of the full spectrum of cervical intraepithelial neoplasia (CIN) focusing on the basal cell-stroma interface with the "multiple cell-single section" model is discussed. Significant decreases in histopathologic grades of CIN are noted in the number of pseudopodia per basal cell (N) and the ratio (F) of the area of the stems of pseudopodia to the area of the base of the basal cell.
Semen studies on phenylketonurics.
Explore the source record for details and available documents.
Measurement of number and cross-sectional area of basal cell pseudopodia: a new morphometric method.
A method of morphometric quantitative of the number of pseudopodia per individual basal cell and the ratio of the total cross-sectional area of the pseudopodia to the base area of the basal cell, using the transmission electron microscope, was developed. The diameters and areas of the bases of basal cells and the pseudopodia were also obtained. The number of pseudopodia per basal cell (N) and the ratio of the areas (F) measured in normal human uterine cervical epithelium were 34.22 and 0.338, respectively. The values observed in reactive atypia were 23.62 and 0.188; and those in mild dysplasia of the cervical epithelium (the earliest premalignant condition of the cervical epithelium), 26.98 and 0.226. There were statistically significant reductions in the number of pseudopodia per cell (N) and the ratio of areas (F) in the latter two pathological conditions compared to the controls. This morphometric method provides higher sensitive means by which one can quantify the characteristics of pseudopodia in various premalignant epithelia.
Getting those blood samples right.
Explore the source record for details and available documents.
Immunoglobulin concentrations in duodenal fluid of infants and children.
The immunoglobulin content of duodenal fluid in children at different ages has not as yet been determined, while that of serum, feces, and saliva has been well established. In 92 normal infants, children, and young adults on whom duodenal intubation was performed, duodenal fluid IgA, IgM, and IgG levels were measured. From these data, a developmental profile of immunoglobulins in duodenal fluid from 2 weeks of life to 19 years was obtained. Duodenal fluid IgA, IgM, and IgG appeared to maintain rather constant levels. The grand mean IgA level was lower than the mean IgG level (12.7 +/- 0.8 vs 29.1 +/- 2.5 mg/g of protein). Secretory component was detected in all duodenal fluids. IgG concentrations were greater than those of IgM (29.1 +/- 2.5 vs 13.2 +/- 1.4 mg/g of protein) over all age ranges. The developmental patterns of all immunoglobulins appeared to be different from those observed in serum or saliva with the exception of duodenal fluid IgA, which has a pattern similar to that of salivary IgA.
An inexpensive method of determining body composition by underwater weighing.
A simple inexpensive densiometric method of determining body composition was compared to a more sophisticated one. Body density (Db), lean body mass (LBM), and relative fat content (%fat) were determined for 16 volunteers, 9 men and 7 women using a simple T-bar apparatus suspended in a swimming pool, and an electronic apparatus in conjunction with a metal tank. Residual volumes (RV) used in the determinations were estimated from age and height (RV-1), held constant at 1,300 ml for men and 1.000 ml for women (RV-2), and measured by the nitrogen washout method (RV-3). No significant difference was observed between the two methods of weighing, although significant differences did exist among the RV techniques. It was concluded that a simplified method of determining body composition is acceptable for screening purposes, but long term studies might require more sophisticated techniques with RV measured at the time of weighing.
Response of institutionalized geriatric mental patients to a twelve-week program of regular physical activity.
Twenty-three geriatric patients from a mental institution were randomly assigned to three groups-a social group, an exercise group, and a control group. Subjects participated in the study for 12 weeks. Heart rate at rest, exercise and recovery, balancing ability, total daily activity level (diary method), and a self-care inventory were recorded for analysis. Data were collected at the start, the 8th and 12th weeks of the study, and 4 weeks after the termination of treatment. A Groups X Sex X Measurement Period factorial design, using multivariate analysis of variance tested the effect of the three factors. The trials effect was significant, as were several univariate tests for the sex effect and group by sex interaction. Data were discussed in terms of programmed physical activity for geriatrics, its value, and the limitations of evaluating such behavior in geriatric populations.
Slitlamp measurement of anterior chamber geometry.
Explore the source record for details and available documents.
Letter: Comments on Donaldson's new instrument for keratography.
Explore the source record for details and available documents.
Posterior corneal curvature. Correlations in normal eyes and in eyes involved with primary angle-closure glaucoma.
Explore the source record for details and available documents.