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Biomedical subjects

J M Simpson

Publications and source records attributed to J M Simpson.

At least 37 records · Page 2Linked to original sources
PubMed2001

Use of complementary therapies in a sexual health clinic setting.

This prospective cohort study examined the health-seeking behaviour of patients diagnosed with genital warts and vulvodynia who presented to Manly Sexual Health Service from March to June 2000. A self-administered questionnaire was used to assess patients' perceptions of their condition and their use of complementary therapies. Thirty-seven patients with genital warts and 26 patients with vulvodynia participated in the study. The use of at least one complementary health product or method was reported by 59% of patients with genital warts and 96% of vulvodynia patients (P < 0.001). Having received conflicting information and being worried about the condition was significantly associated with visits to complementary health providers. Acknowledgement of this search for complementary therapies and open discussion can help patients make informed decisions and to avoid drug interactions, and should ultimately lead to better patient care.

Adolescent↗
PubMed2000

The Australian National Workplace Health Project: design and baseline findings.

BACKGROUND: This paper describes the study design, recruitment, measurement, and initial recruitment outcomes of Australia's largest workplace intervention trial, the National Workplace Health Project. METHODS: This was a cluster-randomized trial of socio-behavioral and environmental interventions focusing on key behaviors of physical activity, healthy food choices, cigarette smoking, and alcohol consumption, as well as motivational readiness for change. Twenty worksites were randomized separately for each intervention using a two-by-two factorial design. All participants underwent a health risk appraisal and measurements were made at baseline and at 1 and 2 years. RESULTS: The overall response rate for the baseline survey was 73% with 61% attending the health risk appraisal. The sample was predominantly male, English-speaking, married, blue-collar workers. Overall, 12% reported unsafe alcohol consumption, 26% were current smokers, 44% were physically inactive, 74% ate at most one piece of fruit per day, and 26% ate at most one serving of vegetables per day. Intervention and control conditions were similar at baseline for the primary outcomes, except that a higher proportion of the sociobehavioral intervention condition was more physically active (59%) than the corresponding control condition (53%). CONCLUSIONS: This study will permit the rigorous evaluation of the efficacy of sociobehavioral and environ mental intervention approaches to workplace health promotion. Although participants were randomized by worksite, intervention and control conditions were similar at baseline; any differences in the primary out come variables will be controlled for in the analysis.

Adult↗
PubMed2000

Hypoplastic left heart syndrome.

Hypoplastic left heart syndrome may be accurately diagnosed during fetal life. Prenatal diagnosis provides the opportunity for parents to make an informed choice about their options, including surgery, nonintervention postnatally or termination of pregnancy. Short to medium term survival continues to improve for a condition that was previously invariably lethal. There continues to be a significant mortality and morbidity associated with hypoplastic left heart syndrome, and the long-term prognosis is unknown. Knowledge of the condition prior to birth means that babies who are to undergo surgery present in optimal condition for such interventions. Parents who have had an affected fetus or child should be offered detailed fetal echocardiography to exclude a recurrence in subsequent pregnancies.

Aortic Coarctation↗
PubMed2000

Nuchal translucency and congenital heart defects: heart failure or not?

OBJECTIVE: To determine whether heart failure is the mechanism underlying the association between increased fetal nuchal translucency and congenital heart defects. METHODS: Retrospective analysis of the types of congenital heart defect observed in fetuses with increased nuchal translucency and those with normal nuchal scans. Retrospective quantitative analysis of cardiac size and left ventricular ejection fraction in fetuses with ventricular septal defects or the hypoplastic left heart syndrome. RESULTS: Eighty-three fetuses with congenital heart defects had undergone nuchal screening of which 51 had increased nuchal translucency and 32 had normal nuchal translucency. A wide variety of different congenital cardiac lesions with different hemodynamic effects were observed in fetuses with increased nuchal translucency and those with normal nuchal scans. Defects primarily characterized by left heart obstruction, right heart obstruction and septal defects occurred in both groups. All measurements of cardiothoracic ratio and left ventricular ejection fraction fell within the normal range and there was no significant difference between fetuses with increased nuchal translucency and those with normal nuchal scans. CONCLUSIONS: No specific type of congenital heart lesion is associated with increased nuchal translucency. The contention that heart failure explains the association between congenital heart defects and increased nuchal translucency is not supported by this study.

Heart Defects, Congenital↗
PubMed2000

A prospective comparison of the standard and reverse robinson cervical grafting techniques: radiographic and clinical analyses.

The authors performed a prospective study of 63 patients with cervical radiculopathy treated with Robinson anterior cervical discectomy and fusion and compared the traditional or standard and reverse graft techniques. Modifications of the standard Robinson grafting techniques have been proposed. The reverse graft technique has theoretical advantages, including limiting the deleterious effects of graft extrusion and maintaining rigid middle column support. A radiographic evaluation and an assessment of clinical outcome based on the criteria of Odom were performed prospectively for as long as 1 year after surgery. Thirty-one patients were treated with the standard grafting technique and 32 with the reverse graft orientation. The radiographic evaluation showed no significant differences between the two techniques with regard to sagittal alignment and disk heights. The overall fusion grade was higher in the reverse graft technique (p < 0.05). There were 93% and 96% good to excellent results in the standard graft and reverse graft groups, respectively. The authors report no significant differences associated with the standard or reverse anterior cervical grafting techniques in terms of radiographic alignment or disk height loss over time or at early clinical outcome. However, improved fusion grade was noted with the reverse graft technique, which may be related to end plate and intervertebral space preparation. The reverse grafting technique is an acceptable alternative to the standard graft orientation.

Adult↗
PubMed2000

Denaturing gradient gel electrophoresis analysis of 16S ribosomal DNA amplicons to monitor changes in fecal bacterial populations of weaning pigs after introduction of Lactobacillus reuteri strain MM53.

The diversity and stability of the fecal bacterial microbiota in weaning pigs was studied after introduction of an exogenous Lactobacillus reuteri strain, MM53, using a combination of cultivation and techniques based on genes encoding 16S rRNA (16S rDNA). Piglets (n = 9) were assigned to three treatment groups (control, daily dosed, and 4th-day dosed), and fresh fecal samples were collected daily. Dosed animals received 2.5 x 10(10) CFU of antibiotic-resistant L. reuteri MM53 daily or every 4th day. Mean Lactobacillus counts for the three groups ranged from 1 x 10(9) to 4 x 10(9) CFU/g of feces. Enumeration of strain L. reuteri MM53 on MRS agar (Difco) plates containing streptomycin and rifampin showed that the introduced strain fluctuated between 8 x 10(3) and 5 x 10(6) CFU/g of feces in the two dosed groups. Denaturing gradient gel electrophoresis (DGGE) of PCR-amplified 16S rDNA fragments, with primers specific for variable regions 1 and 3 (V1 and V3), was used to profile complexity of fecal bacterial populations. Analysis of DGGE banding profiles indicated that each individual maintained a unique fecal bacterial population that was stable over time, suggesting a strong host influence. In addition, individual DGGE patterns could be separated into distinct time-dependent clusters. Primers designed specifically to restrict DGGE analysis to a select group of lactobacilli allowed examination of interspecies relationships and abundance. Based on relative band migration distance and sequence determination, L. reuteri was distinguishable within the V1 region 16S rDNA gene patterns. Daily fluctuations in specific bands within these profiles were observed, which revealed an antagonistic relationship between L. reuteri MM53 (band V1-3) and another indigenous Lactobacillus assemblage (band V1-6).

Animals↗
PubMed1999

Application of denaturant gradient gel electrophoresis for the analysis of the porcine gastrointestinal microbiota.

The porcine gastrointestinal tract (GIT) microbiota has been studied to increase production efficiency, improve product quality, and help attempt to reduce disease. During the developmental period from birth through weaning, the intestinal microbiota undergoes a rapid ecological succession. There is interest in developing a monitoring technique that allows for analysis of bacterial population levels and shifts within the pig intestine. The objective of this study was to determine if denaturant gradient gel electrophoresis (DGGE) could be effectively applied to measure changes in bacterial populations of the pig GIT, as influenced by age, diet or compartment. Bacterial genetic diversity was determined using DGGE analysis of the V3 region of 16S rDNA PCR products (approximately 200 bp) obtained from primers specific for the domain Bacteria. Protocol development included optimization of: DNA extraction procedures, PCR amplification, removal of PCR artifacts, and optimization of gel preparation and image capture. DGGE analysis revealed diverse bacterial populations between pigs of different ages and among individual gut compartments. Comparison of fecal DNA from different aged pigs revealed several unique PCR product bands indicating the presence of unique bacterial populations. Comparison of different gut compartments demonstrated that bacterial populations were most similar (C, value > 50%) within a single compartment and between adjacent ones. Thus, DGGE can be used to examine bacterial diversity and population shifts in the pig GIT.

Aging↗
PubMed1999

Randomized double-blind trial of beta-carotene and vitamin C in women with minor cervical abnormalities.

A double-blind, placebo-controlled, randomized, factorial study using a daily oral administration of 30 mg beta-carotene and/or 500 mg vitamin C was conducted in 141 women with colposcopically and histologically confirmed minor squamous atypia or cervical intra-epithelial neoplasia (CIN) I. Over approximately 2 years of follow-up, 43 lesions regressed to normal and 13 progressed to CIN II. The regression rate was slightly higher, but not significantly so, in those randomized to beta-carotene compared to no beta-carotene (hazard ratio = 1.58, 95% CI: 0.86-2.93, P = 0.14) and slightly lower, but not statistically significant, for those randomized to vitamin C compared to no vitamin C (hazard ratio = 0.65, 95% CI: 0.35-1.21, P = 0.17). In a model with no interaction, the progression rate was slightly higher in those randomized to beta-carotene (hazard ratio = 1.75, 95% CI: 0.57-5.36, P = 0.32) and also in those randomized to vitamin C (hazard ratio = 2.40, 95% CI: 0.74-7.80, P = 0.13). Neither of these were statistically significant. However, there was some evidence of an interaction effect of the two compounds on the progression rate (P = 0.052), with seven of the progressed lesions occurring in those randomized to both vitamins compared to a total of six in the three other groups. The currently available evidence from this and other trials suggests that high doses of these compounds are unlikely to increase the regression or decrease the progression of minor atypia and CIN I.

Adult↗
PubMed1999

Attitudes of pharmacists and physicians to antibiotic policies in hospitals.

BACKGROUND: Antibiotic therapy in hospitals has substantial impact on patient outcome and the pharmacy drug budget. Antibiotic policies have been implemented by some hospitals to improve the quality of patient outcome and cost of antibiotic therapy. Antibiotic policies impose certain requirements on pharmacists and physicians. Pharmacists' and physicians' attitudes to and opinions about antibiotic policies are likely to affect the usefulness of such policies. AIM: To determine the attitudes of pharmacists and physicians to antibiotic policies in New South Wales (NSW) hospitals. METHODS: Pharmacists and physicians in NSW public hospitals were surveyed to determine their attitudes to and opinions on antibiotic policies. A simple one-stage cluster sample of 241 pharmacists and a two-stage cluster sample of 701 physicians were obtained. Factor analysis was used to identify the attitudinal dimensions. General linear modelling was used to investigate the effects of predictor variables on outcome variables. RESULTS: The response rates were 91% and 77% for pharmacists and physicians, respectively. Factor analysis identified three dimensions of attitude to antibiotic policies: that they encourage rational antibiotic use; that they improve the quality of antibiotic prescribing and that they are associated with some problems. The reliability of these factors (Cronbach's alpha) ranged from 0.71 to 0.74, and was 0.90 for the overall attitude scale. Pharmacists and physicians had a positive overall attitude to antibiotic policies. Whereas physicians recognize that antibiotic policies improve the quality of prescribing, this was highly correlated with identification of problems (alpha = 0.71). In urban hospitals, pharmacists were more likely than physicians to associate antibiotics with problems. CONCLUSION: There was a positive overall attitude to hospital antibiotic policies expressed by pharmacists and physicians.

Anti-Bacterial Agents↗
PubMed1999

A randomized phase II trial of interferon-alpha2b versus 5-fluorouracil after trabeculectomy.

PURPOSE: The aim of the present study was to investigate the safety and potential efficacy of subconjunctival interferon-alpha2b (IFN-alpha), either alone or in combination with 5-fluorouracil (5-FU), in reducing the risk of failure of glaucoma surgery METHODS: A prospective, masked randomized phase II study was undertaken in which patients received three subconjunctival injections per week for 3-4 weeks postoperatively. Three treatments were compared: (i) IFN-alpha (1 x 10(6)IU per dose); (ii) 5-FU (5 mg per dose); and (iii) alternating IFN-alpha and 5-FU (BOTH). The primary outcome measures were: (i) rate of successful control of intra-ocular pressure without further surgery; and (ii) the incidence of side effects. RESULTS: Fifty-seven patients undergoing glaucoma surgery with an increased risk of failure were evaluated, including 23 patients (40%) undergoing trabeculectomy combined with extracapsular cataract extraction as well as other conventional high-risk groups. With 53 patients (93%) completing 2 years follow up,there was no significant difference in success rates among the three groups. Intra-ocular pressure was controlled without further surgery in 79% of patients (95% confidence interval (CI): 61, 97%) receiving IFN-alpha, in 89% of patients (76, 100%) receiving 5-FU and in 89% of patients (76, 100% receiving BOTH. Side effects were similar among the three groups. CONCLUSIONS: These results are consistent with a beneficial effect of IFN-alpha2b given either alone or in combination with 5-FU after glaucoma filtering surgery. However, the lack of a clear and substantial benefit over conventional anti-fibrotic therapy does not support the further clinical evaluation of these treatments.

Adult↗
PubMed1999

Comparison of Adsol and CPDA-1 blood preservatives during simulated massive resuscitation after hemorrhage in swine.

BACKGROUND: In recent years, there has been a change from the use of blood stored in CPDA-1 to the use of red cells (RBCs) stored in electrolyte mixtures, such as Adsol (AS-1 RBCs). However, because Adsol contains mannitol, as well as increased amounts of glucose relative to CPD and CPDA-1, concerns have been expressed as to possible harmful effects (recipient hyperglycemia, inappropriate osmotic diuresis) that it might induce under conditions of massive RBC transfusion. STUDY DESIGN AND METHODS: A hemorrhagic shock animal model was used to evaluate the effects of large-volume infusion of CPDA-1 or Adsol on glucose homeostasis and on urinary output under conditions that were devoid of extensive surgical manipulation. Hemorrhage was induced in 10 female Pitman-Moore mini-pigs to maintain mean arterial blood pressure at 55 mmHg for 90 minutes. After the return of autologous RBCs plus 1 L of 0.9-percent sodium chloride, the animals were given solution equivalent to the solute load in either 20 units of CPDA-1 whole blood (63 mL x 20 = 1260 mL) or 20 units of AS-1 RBCs (100 mL x 20 = 2000 mL) over a period of 90 minutes. Animals were monitored to determine physiologic and blood chemical responses to infusion of the solutions and to determine if there was hyperglycemia or inappropriate diuresis in the Adsol-treated group. RESULTS: Animals that received CPDA-1 developed significant hypocalcemia, arterial hypotension, and elevated blood glucose concentrations; two of five animals died of circulatory collapse. In contrast, glucose metabolism in the Adsol recipients was well-regulated, serum ionized calcium concentration was not significantly altered, and all animals survived. No evidence of inappropriate diuresis was observed. CONCLUSION: Administration of large amounts of Adsol was not associated with hyperglycemia or inappropriate osmotic duiresis in hemorrhaged and resuscitated minipigs. These data suggest that fewer physiologic changes may be associated with the massive transfusion of AS-1 RBCs than with that of CPDA-1 whole blood.

Adenine↗
PubMed1999

Clinical outcomes of newborn screening for cystic fibrosis.

AIM: To determine how early diagnosis of cystic fibrosis, using neonatal screening, affects long term clinical outcome. METHODS: Fifty seven children with cystic fibrosis born before neonatal screening was introduced (1978 to mid 1981) and a further 60 children born during the first three years of the programme (mid 1981 to 1984), were followed up to the age of 10. The cohorts were compared on measures of clinical outcome, including height, weight, lung function tests, chest x-ray picture and Shwachman score. RESULTS: Age and sex adjusted standard deviation scores (SDS) for height and weight were consistently higher in children screened for cystic fibrosis than in those born before screening. At 10 years of age, average differences in SDS between groups were 0.4 (95% CI -0.1, 0.8) for weight and 0.3 (95% CI -0.1, 0.7) for height. This translates to an average difference of about 2.7 cm in height and 1.7 kg in weight. Mean FEV1 and FVC (as percentage predicted) were significantly higher in the screened cohort at 5 and 10 years of age, with an average difference of 9.4% FEV1 (95% CI 0.8, 17.9) and 8.4% FVC (95% CI 1.8, 15.0) at 10 years. Chest x-ray scores were not different between the groups at any age, but by 10 years screened patients scored an average 5.3 (95% CI 1.2, 9.4) points higher on the Shwachman score. CONCLUSION: Although not a randomised trial, this long term observational study indicates that early treatment made possible by neonatal screening may be important in determining subsequent clinical outcomes for children with cystic fibrosis. For countries contemplating the introduction of neonatal screening for cystic fibrosis, its introduction to some areas in a cluster randomised design will permit validation of studies performed to date.

Anti-Bacterial Agents↗
PubMed1999

Risk factors for the acquisition of genital warts: are condoms protective?

OBJECTIVES: To characterise risk factors for the acquisition of genital warts and specifically to determine whether condoms confer protection from infection. METHODS: A retrospective case-control study comparing demographic, behavioural, and sexual factors in men and women with and without newly diagnosed genital warts, who attended Sydney Sexual Health Centre (SSHC), an inner city public sexual health centre, in 1996. Data were extracted from the SSHC database. Crude odds ratios (OR) were calculated to compare cases and controls and significant factors were then controlled for using multivariate logistic regression to obtain adjusted odds ratios (ORs). RESULTS: 977 patients with warts and 977 controls matched by sex and date of attendance were included. In both sexes, univariate analysis revealed that younger age, more lifetime sexual partners, failure to use condoms, greater cigarette smoking and alcohol consumption were associated with warts, and there was a negative association with previous infection with Chlamydia trachomatis, Neisseria gonorrhoeae, hepatitis B, and genital herpes. In males, on multivariate analysis, factors which remained significant were younger age, more lifetime sexual partners; failure to use condoms, greater cigarette smoking, and previous chlamydia. In women, factors which remained significant were younger age, more lifetime sexual partners, condom use, marital status, and previous infections with Chlamydia trachomatis and herpes. CONCLUSIONS: Independent risk factors for genital warts include younger age, greater number of lifetime sexual partners, and smoking. Consistent condom use significantly reduces the risk of acquiring genital warts.

Adolescent↗
PubMed1999

Young working women utilise the after hours service at Sydney Sexual Health Centre.

OBJECTIVE: To analyse patterns of patient utilisation of the after hours service at Sydney Sexual Health Centre (SSHC). METHOD: A retrospective cross sectional database study compared all new daytime and after hours patients who registered for a medical consultation at SSHC between August 1994 and February 1995. Daytime and after hours attenders were compared using demographic and behavioural factors and for prevalence of STDs and HIV using logistic regression analysis. RESULTS: Of the 1662 eligible patients, 1362 (81.9%) attended during daytime hours, and 300 (18.1%) attended after hours. There was no significant difference in after hours attendance between patients living in inner compared with outer metropolitan zones. Using logistic regression analysis, being female (p = 0.0008), being between 20 and 39 years of age (p = 0.008), being employed (p < 0.001), and having no previous STD/genitourinary condition (p = 0.034) were the factors significantly associated with after hours attendance. CONCLUSIONS: The evening service was disproportionately utilised by a patient group not defined as "high risk" in the objectives of the service. This study challenges the assumption that evening clinics are always the way to reach high risk groups.

Adolescent↗
PubMed1999

Spermatogenesis without gonadotropins: maintenance has a lower testosterone threshold than initiation.

We showed previously that testosterone (T) alone could induce spermatogenesis and produce normally fertile spermatozoa in the absence of circulating gonadotropins. These studies used the hpg mouse, which is characterized by a congenital gonadotrophin deficiency due to a major deletion in the GnRH gene. Administering T by a subdermal implant of a SILASTIC brand tube impregnated with crystalline T showed that the androgenic requirement for full induction of spermatogenesis was a 1-cm length implant. Using this unique model of spermatogenesis without gonadotropins, we have now investigated the quantitative requirement for androgens to maintain spermatogenesis by testing the hypothesis that the androgenic threshold required for induction and maintenance of spermatogenesis are the same. Spermatogenesis was induced in homozygous hpg mice by T administration for 6 weeks. The first experiment determined the time-course of the regression of spermatogenesis after removal of the T-impregnated SILASTIC brand implant. Elongated spermatids were absent by 3 weeks and testicular weight regression was maximal by 4 weeks after androgen withdrawal. The second experiment examined the effects on maintenance of spermatogenesis of reducing the T dose. After full induction of spermatogenesis in homozygous hpg mice, the T implants were replaced with a range of smaller size T-impregnated SILASTIC brand implants for a further 4 weeks. All androgen-sensitive end-points (testis weight, tubular, and luminal diameters, round spermatids) were fully maintained with T implants of 0.06 cm and elongated spermatids with T implants of 0.25 cm. A further experiment showed that at very low T doses (0.06, 0.125 cm) the T effects observed at 4 weeks were maintained at 6 and 11 weeks duration. We conclude that the androgenic threshold to maintain spermatogenesis in the mouse is an order of magnitude lower than the threshold required for inducing spermatogenesis. This distinction suggests that the mechanism of action of testosterone in inducing spermatogenesis may involve regulation of a genetic switch to complete meiosis, whereas the maintenance involves a different locus of action. These findings suggest that further studies of androgen-dependent meiotic genes may be central to understanding the regulation and molecular basis of androgen-driven induction and maintenance of spermatogenesis.

Androgens↗
PubMed1999

Outpatient laminotomy and discectomy.

This is a prospective study of 61 consecutive patients undergoing lumbar laminotomy and discectomy on an outpatient basis. The purpose of this study was to report on the feasibility of performing lumbar laminotomy and discectomy as an outpatient procedure and to assess perioperative complications, patient satisfaction, cost, and clinical results. Conventional lumbar laminotomy and discectomy traditionally requires a 1-3-day hospital stay. Recent advances in anesthesia and surgical techniques, as well as observation of patient progress after this procedure, has led the authors to believe that that this procedure may be performed on an outpatient basis without compromising patient satisfaction, outcome, or complications. Sixty-one consecutive patients underwent surgery for herniated nucleus pulposus in the lumbar spine. The procedure was performed under loupe magnification without the use of a microscope. Clinical outcome and patient satisfaction were assessed at an average follow-up of 12.5 months. The results showed 62% excellent, 31% good, 7% fair, and there were no reports of a poor outcome. During the time of the study, four patients (7%) were admitted to the hospital after the procedure for reasons of pain control, inability to void, or lack of caregiver at home. Overall cost savings were reflected in the cost of inpatient stay when compared to a representative group of inpatients. Laminotomy and discectomy for a hemiated nucleus pulposus has 93% good or excellent results as shown by this study and previous studies. Laminotomy and discectomy, which remains the gold-standard procedure for herniated disc surgery, can be performed safely and effectively as an outpatient procedure in the majority of patients.

Adult↗
PubMed1998

Testing the gonadal regression-cytoprotection hypothesis.

Germinal damage is an almost universal accompaniment of cancer treatment as the result of bystander damage to the testis from cytotoxic drugs and/or irradiation. Cancer treatment for the most common cancers of the reproductive age group in men has improved such that most are now treated with curative intent, and many others are treated with likelihood of prolonged survival, so that the preservation of fertility is an important component of posttreatment quality of life. This has led to the consideration of developing adjuvant treatments that may reduce the gonadal toxicity of cancer therapy. One dominant hypothesis has been based on the supposition that the immature testis was resistant to cytotoxin damage. Hence, if hormonal treatment were able to cause spermatogenic regression to an immature state via an effective withdrawal of gonadotrophin secretion, the testis might be maintained temporarily in a protected state during cytotoxin exposure. However, clinical studies have been disappointing but have also been unable to test the hypothesis definitively thus far, due to the inability to completely suppress gonadotrophin secretion. Similarly, experimental models have also given conflicting results and, at best, a modest cytoprotection. To definitively test this hypothesis experimentally, we used the fact that the functionally hpg mouse has complete gonadotrophin deficiency but can undergo the induction of full spermatogenesis by testosterone. Thus, if complete gonadotrophin deficiency were an advantage during cytotoxin exposure, then the hpg mouse should exhibit some degree of germinal protection against cytotoxin-induced damage. We therefore administered three different cytotoxins (200 mg/kg procarbazine, 9 mg/kg doxorubicin, 8 Gy of X irradiation) to produce a range of severity in testicular damage and mechanism of action to either phenotypically normal or hpg mice. Testis weight and homogenization-resistant spermatid numbers were measured to evaluate the potential protective effects on spermatogenesis. Although the three cytotoxins produced a range of severity of spermatogenic damage, there was no evidence of cytoprotection in the hpg mice that were completely gonadotrophin deficient at the time of treatment. These findings cast doubt on the validity of the hypothesis that spermatogenic regression via gonadotrophin withdrawal can protect the mouse testis against cytotoxin-mediated spermatogenic damage.

Animals↗