The Bacillus subtilis GroESL chaperonin was isolated by sucrose density gradient centrifugation and the constituent GroES and GroEL moieties were purified by electrophoresis in agarose. Electron microscopic images of negatively stained GroEL and GroES oligomers and GroESL complexes were averaged using a reference-free alignment method. The GroEL and GroES particles had the sevenfold symmetry characteristic of their Escherichia coli counterparts. GroESL complexes, reconstituted efficiently in vitro from GroEL and GroES in the absence of added ADP or ATP, had the characteristic bullet- and football-like shapes in side view. Purified bacteriophage phi 29 head-tail connectors having a mass in excess of 0.4 MDa were shown to bind to GroESL at the end opposite to the GroES. The same GroESL-connector complexes were isolated from phage-infected cells in which capsid assembly was blocked, and thus the complex may have functional significance in phi 29 morphogenesis.

Bacillus Phages↗

PubMedDate not supplied

Fluoroscopically guided transcervical fallopian tube recanalization of post-sterilization reversal mid-tubal obstructions.

PURPOSE: To assess the technical success and early outcome of fluoroscopically guided transcervical fallopian tube recanalization (FTR) in mid-tubal occlusion following sterilization reversal surgery. METHODS: From July 1995 to January 1998, patients with greater than 12 months secondary infertility underwent hysterosalpingography (HSG). FTR was performed in proximal or mid-tubal occlusion. Cases of FTR in mid-tubal occlusion were included in this study. Technical success (defined as complete tubal patency) using a standard guidewire and hydrophilic glidewire, the number of patients with at least one patent tube, and the intrauterine and ectopic pregnancy rates were determined. RESULTS: Twenty-six infertile patients with previous sterilization reversal underwent HSG. Eight of 26 (31%) patients (mean age 32 years, range 23-37 years), had attempted FTR for mid-tubal occlusion at the site of surgical anastomosis. Fourteen tubes were attempted as there were two previous salpingectomies. Technical success was achieved in eight of 14 (57%) tubes attempted, resulting in five of eight (62%) patients having at least one patent tube. At follow-up (mean 18 months, range 12-28 months) in these five patients there was one intrauterine pregnancy. There were no ectopic pregnancies. CONCLUSIONS: FTR in mid-tubal obstruction in infertile patients following sterilization reversal surgery is technically feasible and may result in intrauterine pregnancy. In this small group there was a lower technical success rate and lower pregnancy rate than in unselected proximal tubal occlusion.

Adult↗

PubMedDate not supplied

Examination of comorbid anxiety in psychiatric inpatients.

Seventy-three percent of 90 psychiatric inpatients had a coexisting anxiety disorder. There were few differences between patients with or without coexisting anxiety on more than 100 clinical and demographic variables that were tested. Patients who had an anxiety syndrome before the onset of their major psychiatric disorder also showed few differences when compared with patients whose anxiety started coincident to or after another DSM-III axis I disorder. The concept of primary/secondary anxiety disorder may not be useful when applied to a cross-section of psychiatric inpatients.

Adult↗

PubMedDate not supplied

High-performance liquid-chromatographic analysis of bases and nucleoside in mouse testes following in vivo thymidine administration.

In order to measure accurately bases and nucleosides in vivo, a method has been developed using high-performance liquid chromatography. This method is reproducible under conditions of constant pressure, temperature and pH and is rapid, requiring approximately 1 h for a complete chromatographic separation of bases and nucleosides. The method has been used to measure quantitatively the bases and nucleosides in mouse testes following in vivo administration of thymidine. Groups of male mice were given thymidine by intra-peritoneal injection and were killed at various time intervals and the testes removed for extraction procedures. There was a significant increase in the thymidine concentration in the testes 1 h after injection, which fairly quickly returned to the control value thereafter. There was a subsequent reduction in uridine concentration. This analytical method allows deoxyribonucleotide (dNTP) precursor pool sizes to be determined in germinal cells. It may also be useful for other tissues in vivo.

Animals↗

PubMedDate not supplied

Germ and somatic cell abnormalities following in vivo administration of thymidine and adenine.

It is known that an excess of or a depletion in bases and nucleosides produce genetic effects in vitro, and a similar effect has been found with the nucleoside thymidine in this laboratory in vivo. To confirm this effect and to see if this occurs with the base adenine, thymidine and adenine were administered to male mice by i.p. injection and the sperm examined for head-shape abnormalities 4 and 5 weeks later. Treated males also were mated to untreated females for the provision of an F1 generation. The F1 males were subjected to the sperm morphology assay when they reached 14 weeks of age. Amongst those F0 males given adenine, there was a dose-related increase in the frequency of abnormal sperm and the group given thymidine also showed increases, confirming the results of previous studies in this laboratory. In the F1 generation, the fraction of mice from treated males showing increases in numbers of abnormal sperm was greater than that of the controls. In a micronucleus test with mice treated with thymidine, mitosis was delayed and there was a marginal increase in micronuclei, suggesting that an imbalance in nucleoside pools may be responsible for chromosomal damage in somatic cells in vivo. Therefore it is considered that similar effects to those produced in vitro can be demonstrated in vivo. Furthermore, the results of the sperm morphology assay show that the damage is transmissible.

Adenine↗

PubMedDate not supplied

Chromosome aberrations (CA), sister-chromatid exchanges (SCE) and mitogen-induced blastogenesis in cultured peripheral lymphocytes from 48 control individuals sampled 8 times over 2 years.

Confidence in the measurement of positive effects determined by monitoring of environmentally or occupationally exposed individuals can be enhanced by a knowledge of the normal variability in these endpoints in the general population. Confounding effects can be determined and study interpretation improved by correlation of this variability with various lifestyle factors such as sex and age of donor, smoking and drinking habits, viral infections, exposure to diagnostic X-rays, etc. 8 blood samples were taken from each of 24 male and 24 female volunteers over a period of 2 years. Questionnaires pertaining to lifestyle were completed at the time of each sampling. Whole blood was cultured and slides prepared for CA or SCE analysis. Separated mononuclear cells were cultured with a range of phytohaemagglutinin concentrations and the maximum level of mitogen-induced blastogenesis was determined by measurements of [3H]thymidine uptake. There was a significant effect of both year and season of sampling for all 3 endpoints. No significant effects in any of the 3 endpoints were found with respect to sex or age of donor nor any of the other lifestyle factors, although SCE frequency and mitogen-induced blastogenesis were nearly always higher in females than males. These results point to the need for concurrent sampling of controls with exposed populations.

Adolescent↗

PubMedDate not supplied

Hypertrophic cardiomyopathy--therapy with slow channel inhibiting agents.

Slow channel inhibiting agents, particularly verapamil, appear to produce beneficial effects in relieving symptoms of dyspnea, chest pain, and syncope or presyncope in over 70% of patients with hypertrophic cardiomyopathy. Symptomatic relief occurs in patients with and without left ventricular outflow obstruction. Exercise hemodynamics, exercise tolerance, and cardiac performance during exercise tend to improve. The mechanisms for this symptomatic improvement, however, are not fully explained. Relief of symptoms is observed irrespective of any changes in the resting or provocable left ventricular outflow gradient. Similarly, changes in left ventricular systolic function, which in general remains unaffected, cannot be the basis for the beneficial response. Slow channel inhibiting agents, however, appear to improve left ventricular diastolic function, the mechanism of which is yet to be elucidated. Nevertheless, improved left ventricular diastolic function may provide an explanation for the relief of some symptoms in patients with hypertrophic cardiomyopathy. The influence of therapy with slow channel inhibiting agents on arrhythmias, sudden death, and on long-term prognosis of patients with hypertrophic cardiomyopathy remains uncertain at the present time and should be the subject of future investigations.

Angiocardiography↗

PubMedDate not supplied

Factors related to perineal trauma in childbirth.

We conducted an observational cohort study in three nurse-midwifery services to identify patient characteristics and clinical care measures related to perineal trauma at birth. Data were collected on all women who began care with a nurse-midwife in labor, using an adaptation of the Nurse-Midwifery Clinical Data Set (n = 3,049). Study variables included demographics, perineal management techniques and position for birth, and other intrapartum care and events. Univariate and multivariate analyses showed that episiotomy was strongly related to fetal bradycardia, prolonged second stage, ethnic status, and maternal education level. Warm compresses and flexion/counter-pressure to slow delivery were protective. Spontaneous lacerations were influenced by these factors as well. The lateral position for birth was protective, and use of oils or lubricants and the lithotomy position increased lacerations, Multisite studies in nurse-midwifery practices may provide an ideal means of determining effective care measures in healthy populations.

Adult↗

PubMedDate not supplied

The parallelogram approach in studies of genotoxic effects.

Over the past two decades mutagenicity tests have been used for the identification of potential human mutagens and have had an ancillary role, as supportive evidence in the assessment of human carcinogens. The demonstration of human germinal mutagens has been beyond the main scope of short-term testing strategies. However, just as mutagenicity tests have been useful in detecting potential carcinogens so should carcinogenicity tests assist the identification of presumptive germ cell mutagens. Cancer is an easily observable phenotype of mutation for genotoxic carcinogens and multi-site carcinogens or gonadal carcinogens logically could be germ cell mutagens. Thus carcinogenicity and mutagenicity data for a given genotoxic chemical should be considered together in the identification of putative germinal mutagens. Clearly, most classified human carcinogens are genotoxic thus helping to build the case for human germ cell mutagenicity. This paper describes the issues involved in such thinking and suggests an enhanced parallelogram approach incorporating the cancer endpoint. The enhanced parallelogram is explored using 1,3-butadiene and ethylene oxide as examples. The obvious lack of data for extrapolations using the parallelogram method suggests the need for targeted studies specifically designed for use in this approach.

Animals↗