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Biomedical subjects

J J Williams

Publications and source records attributed to J J Williams.

50 records · Page 3Linked to original sources
PubMed1979

Transient neuropathic bladder following herpes simplex genitalis.

A case of transient bladder dysfunction and urinary retention concomitant with herpes genitalis is presented. The protean manifestations of the herpes simplex virus, the similar neurotropic behavior of simplex and zoster, and the neurologic sequelae of the cutaneous simplex eruption are discussed. The possibility of sacral radiculopathy after herpes genitalis must be considered when evaluating acute or episodic neurogenic bladders.

Adult↗
PubMed1978

Inert gas a-A differences: a direct reflection of V/Q distribution.

A computer model was developed to study the relationship between ventilation-to-perfusion (V/Q) mismatch and the development of inert gas arterial-to-alveolar partial pressure differences (a-A differences). Increasing inhomogeneity of V/Q ratio is revealed directly as an increase in the a-A difference of each gas. The quantitative relationships between the Q vs. V/Q distribution and the fractional a-A difference solubility plot (a-A difference plot) were studied and described. These studies demonstrated that for log normally distributed V/Q ratios, the area under the a-A difference plot is linearly related to the log variance of the V/Q distribution and can be estimated directly from the values obtained from six gases. The maximum a-A difference occurs for a gas whose solubility is numerically equal to the mean V/Q. The effects of departure from log normality and multimodality are discussed. We conclude from these studies that quantitative information regarding the degree of inhomogeneity of V/Q for log normal distribution is available from direct calculations of inert gas retention and excretion data. Qualitative information is also available indicating the departure from log normality and the region toward which the distribution is skewed.

Biophysical Phenomena↗
PubMed1976

Progesterone metabolism by the ovary of the pregnant rat: discrepancies in the catabolic regulation model.

The intraovarian site of 20 alpha-hydroxysteroid dehydrogenase activity (20 alpha-OH-SDH) was determined biochemically by measuring enzyme activity in homogenates of the whole ovary, or of isolated ovarian compartments, during the last third segment of pregnancy in the rat. In agreement, with previously reported histochemical evidence, an increase in 20 alpha-OH-SDH activity was observed in isolated corpora lutea, but not in the non-luteal compartment of the ovary. Enzyme activity in corpora lutea was low between days 16 and 22 of pregnancy, but increased markedly (4-6 fold) on day 23. Between days 17 and 20 of pregnancy, serum concentrations of progesterone declined from 130 +/- 3 to 80 +/- 3 ng/ml, while 20 alpha-hydroxypregn-4-en-3-one (20 alpha-OH-P) concentrations declined from 34 +/- 3 to 18.5 +/- 3 ng/ml. Only later, between days 20 and 22 of pregnancy, was a significant decline in serum progesterone concentrations associated with an increase in serum 20 alpha-OH-P concentrations (50 +/- 15 ng/ml at 0800 h and 128.5 +/- 15 ng/ml at 1400 h on day 22). Thus the decline in progesterone concentration late in pregnancy can be explained only partially by conversion of progesterone to 20 alpha-OH-P. Further, a dissociation between changes in enzyme activity and in serum concentrations of 20 alpha-OH-P was also observed. A marked increase in serum levels of 20 alpha-OH-P on day 22 preceded any increase in enzyme activity by at least 10 h, and continued increases in enzyme activity on day 23 were not associated with any steady increase in peripheral 20 alpha-OH-P levels. We conclude from these observations that luteal regression is a more complex phenomenon than the regulation of a single enzyme, 20 alpha-hydroxysteroid dehydrogenase, and may involve regulation of both the synthesis and degradation of progesterone.

20-alpha-Dihydroprogesterone↗
PubMed1976

Luteal cell receptor content for prolactin (PRL) and luteinizing hormone (LH): regulation by LH and PRL.

The effect of LH and PRL during the differentiation of granulosa cells to luteal cells was examined by determining the ability of LH and PRL to regulate luteal cell receptor content for these hormones and to increase production of progesterone. Preovulatory follicles and corpora lutea were hormonally induced in immature hypophysectomized female rats by sequential treatment with estradiol, hFSH and oLH. The content of receptor for LH was high in granulosa cells of large antral follicles. Administration of LH caused receptor for LH to decrease markedly within 24 h and to remain low for 96 h. In contrast, granulosa cell content of receptor for PRL increased progressively for 48 h following LH stimulation and remained elevated in fully luteinized cells at 96 h. This increase in PRL receptor appears to be functionally related to the ability of luteal cells to respond to PRL. When PRL was given for 4 days after LH, both luteal cell progesterone production and LH receptor content increased progressively after, but not before, 48 h. Since these changes occurred in the absence of LH, the increase in LH receptor appears to be a consequence of, but not a requirement for, the PRL-induced increase in progesterone production. If daily injections of PRL were delayed for 72 or 96 h following LH induction of lutenization, luteolytic rather than luteotropic effects of PRL were observed. Since receptor for PRL remained elevated at 72 and 96 h, intracellular mechanisms and not receptor content, appear to be effecting the response of luteal cell to PRL.

20-alpha-Dihydroprogesterone↗
PubMedDate not supplied

Investigation of risk factors for porcine Taenia solium cysticercosis: a multiple regression analysis of a cross-sectional study in the Yucatan Peninsula, Mexico.

A cross-sectional survey for seropositivity to cysticercosis of pigs in the Yucatan Peninsula, Mexico, was carried out in 1996 together with a standardized questionnaire on predetermined individual pig and household risk factors for porcine infection. Serum samples from 697 pigs were analysed by immunoblot for antibodies to Taenia solium cysticercosis and questionnaires from 227 households in 18 villages were collected. All the data were analysed using multivariate analytical techniques taking household clustering into account. The overall porcine seroprevalence in the area was found to be 29%. The most important risk factors for seropositivity in pigs were presence versus absence of a toilet (adjusted odds ratio [adj. OR] 2.37, P = 0.005), crowded households (adj. OR 1.75, P = 0.034) and both corralling (adj. OR 2.14, P = 0.017) and letting pigs loose (adj. OR 2.32, P = 0.035) versus tying them up. There was evidence of clustering at household level and that possible risk factors at municipal or village level may also interact with higher risk management practices such as allowing pigs to run loose.

Animal Husbandry↗
PubMedDate not supplied

The lateral pillar classification of Legg-Calvé-Perthes disease.

To determine the predictive value of a new classification system for Legg-Perthes, 93 hips in 86 patients with radiographic follow-up to maturity were reviewed. All patients were treated by bracing at the Texas Scottish Rite Hospital from 1970 to 1980. Hips were classified during the fragmentation stage of disease into three groups based on radiolucency in the lateral pillar of the femoral head. Final radiographs were reviewed at skeletal maturity, and the outcome was determined according to the Stulberg classification. Group A had a uniformly good outcome (100% Stulberg I and II results); Group B had a good outcome in patients who were less than 9 years at onset (92% Stulberg I and II, 8% Stulberg III results), but a less favorable outcome in patients who were greater than 9 years at onset (30% Stulberg II, 50% Stulberg III, and 20% Stulberg IV results). In Group C, the majority of femoral heads became aspherical in both age groups (29% Stulberg II, 52% Stulberg III, and 19% Stulberg IV results). The group C hips also had a longer duration of fragmentation and reossification stages. Members of the Legg-Perthes study group agreed 78% of the time when applying the classification to unknown radiographs. The classification group was a stronger determinant than age of onset in predicting final outcome. This classification system is easy to apply during the active stage of the disease and has a high correlation in predicting the amount of flattening of the femoral head at skeletal maturity.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗
PubMedDate not supplied

Evolution of femoral head deformity during the healing phase of Legg-Calvé-Perthes disease.

Progressive changes in the roundness of the femoral head were noted during the healing phase of hips with Legg-Calvé-Perthes disease. Forty-nine of 136 hips studied became progressively rounder, and 15 hips became progressively flatter after onset of reossification of the femoral head. The femoral head was more likely to undergo progressive flattening in older patients, in those with more severe lateral pillar involvement, and in those with prolonged reossification. These changes occurred during a 3- to 4-year reossification period after cessation of treatment.

Adolescent↗
PubMedDate not supplied

Late knee problems in myelomeningocele.

This study was undertaken to assess the incidence and etiology of knee problems in a long-term follow-up of myelomeningocele patients. Of the 72 community ambulators reviewed, 17 (24%) had significant knee symptoms. A specific gait pattern was identified in symptomatic patients with low lumbar lesions, which may be explained on the basis of hip abductor and calf muscle weakness. These patients have a characteristic gait, which places abnormal stress on the knee, leading to medial and anteromedial rotary instability and eventual degenerative change. It is likely that disability resulting from knee symptoms will be the factor precluding independent ambulation in the patients reviewed in this study.

Adult↗