The role of the androgen receptor in CNS masculinization

The medial posterior region of the bed nucleus of the stria terminalis (BSTMP) and the locus coeruleus (LC) show opposite patterns of sexual dimorphism. The BSTMP in males is greater in volume and number of neurons than in females (male > female) while in the LC, the opposite is true (female > male). To investigate the possible role of the androgen receptor (AR) in the masculinization of these two structures, males with the testicular feminization mutation (Tfm) were compared to their control littermate males. No differences were seen in the number of neurons of the BSTMP between Tfm and their control littermate males, while in the LC, Tfm males have a greater number of neurons than their control littermate males. These results show that the AR is involved in the control of neuron number in the LC but not in the BSTMP. Results based on the LC suggest that when females have a larger brain area than males, masculinization in males may be achieved through the AR, with androgens perhaps decreasing cell survival.     

The expression of brain sexual dimorphism in artificial selection of rat strains

Central nervous system sex differences have two morphological patterns. In one pattern, males show larger measurements (volume, number of neurons) than females (male > female; m > f) and, in the other, the opposite is true (female > male; f > m). The bed nucleus of the stria terminalis (BST) is a unique model for the study of sex differences because it has dimorphic and isomorphic subdivisions, with the former showing the two sexually differentiated morphological patterns. Meanwhile, other CNS structures, like the locus coeruleus (LC), present the f > m pattern. The philogenetic maintenance of the two patterns of sexual differentiation can help to disentangle the functional meaning of sex differences. Laboratory rat strains, whether albino or pigmented, descend from the Wistar strain through artificial selection. The present work compares the BST and LC of Wistar and Long-Evans rats. The medial posterior subdivision of the BST (BSTMP) is sexually dimorphic (m > f pattern) in the original (Wistar) and derived (Long-Evans) strains, while the lateral anterior and medial anterior subdivisions of the BST and the LC only present sex differences (f > m pattern) in the ancestor Wistar strain. Isomorphic BST regions are the same in both strains. The fact that the BSTMP, which is implicated in male copulatory behavior, is sexually dimorphic in both strains, as well as in other species, including humans, indicates the relevance of this structure in male sexual behavior in mammals.     

Ischemia-reperfusion injury during experimental heart transplantation. Evaluation of trimetazidine's cytoprotective effect

INTRODUCTION AND OBJECTIVES: The objectives of this study were to analyze the ischemia-reperfusion injury due to free radicals that occurs during heart transplantation and to determine the potential cytoprotective effect of trimetazidine. MATERIAL AND METHOD: A total of 21 orthotopic heart transplantations were performed in pigs. We divided the experimental animals into 2 groups: in group A (n=11),standard myocardial protection was used; in group B (n=10), trimetazidine was added to the cardioplegic solution used to protect the donor heart and to the solution administered to the recipient prior to release of the aortic clamp (trimetazidine, 10(-5) mol/L), and recipients were pretreated with trimetazidine, 2.5 mg/kg. Blood samples were taken from the recipients coronary sinus at three times: at baseline, during ischemia, and during reperfusion. We measured the levels of malondialdehyde, a marker of lipid peroxidation, and of several antioxidants: glutathione peroxidase, glutathione reductase, superoxide dismutase, alpha-tocopherol, and retinol. The total antioxidant status was also determined. RESULTS: Malondialdehyde production and enzymatic antioxidant activity rose during ischemia and reperfusion, while the retinol level decreased. The increases in malondialdehyde level and glutathione peroxidase activity that occurred between baseline and reperfusion were significantly higher in group A. CONCLUSIONS. The degree of lipid peroxidation and the level of activity of intracellular antioxidant mechanisms increased progressively throughout transplantation. Trimetazidine had a cytoprotective effect. It ameliorated free radical-induced reperfusion injury and modified the response pattern of several defense mechanisms.     

Treatment of uncomplicated hydatid cyst of the liver by closed marsupialization and fibrin glue obliteration

Treatment of hepatic echinococcosis remains a surgical problem not only in endemic countries. Between January 1983 and December 1999 a total of 29 patients underwent surgical treatment for hepatic hydatidosis at the Department of General Surgery at the University Hospital of Granada. The diagnosis was based on clinical criteria, serology, and imaging techniques. There were 16 male and 12 female patients (ages 7–67 and 30–74 years, respectively). Concomitant extrahepatic complications were found in seven patients. Among them, five had secondary parasitic cysts in the peritoneal cavity. In one case an intrathoracic rupture was found, and one patient suffered an intraabdominal rupture with anaphylactic shock. The right lobe was affected in 62% (18 patients). Hepatic cysts were multiple in 4 cases and calcified in 13. Conservative surgical procedures were performed in 23 patients (closed marsupialization with fibrin glue obliteration in 17 and drainage-marsupialization in 6), and radical surgical procedures were undertaken in 6 (pericystectomy in 5 and hemihepatectomy in 1). One patient underwent an explorative laparotomy with intraabdominal lavage followed by pericystectomy after primary resuscitation due to anaphylactic shock. The mean period of hospitalization was 15.9 days, and there were no serious postoperative complications or fatal outcomes. The perioperative morbidity rate was 2.5%. One patient suffered a recurrence of the disease following drainage marsupialization after an interval of 5 years. Our results indicate that the closed marsupialization technique is a safe, sparing method for treating uncomplicated hepatic hydatidosis. The results were also compared to those of a former study reported by our group in which the experience of another 19 years was presented.     

Pulmonary nocardiosis in heart transplant recipients: treatment and outcome

BACKGROUND: Nocardial infections typically affect patients receiving immunosuppressants, occurring early after surgery in 3% to 40% of heart transplant (HTx) recipients. The emergence of antibiotic resistance and occurrence of disease recurrences in AIDS population has engendered controversy about the treatment for immunodepressed HTx patients. METHODS: We present a retrospective study of the diagnosis, treatment and outcome of 560 HTx recipients between 1984 and 2002. RESULTS: Among the five cases of Nocardia infection (0.9%), three cases developed late after HTx (between 3.1 and 11 years follow-up). All patients had pulmonary disease and one in addition had subcutaneous nodules. Microbiological diagnosis required open lung biopsy in one case. All patients were treated primarily with trimethoprim-sulphamethoxazole, but evidence of resistance to sulfonamides led us to change the antimicrobial combination in two cases. Four patients who received one year of antibiogram-guided therapy showed complete healing without recidivism. Three patients died, all due to non-related causes, at follow-ups between 1 and 5 years. In one case a cutaneous recurrence of disease was attributed to noncompliance. CONCLUSIONS: Nocardiosis in current HTx is less common than previously reported. Its incidence seems to be delayed in time with modern immunosuppressants. Given the high incidence of sulfamide resistance, treatment must be guided by antibiotic sensitivity. We believe that maintenance therapy for a whole year is the appropriate option in order to avoid recidivism in this population.     

Asthenozoospermia: analysis of a large population

Spermatozoa travel a long distance to meet and fertilize the oocyte, so sperm motility is a requisite for normal fertilization. Asthenozoospermia, or low sperm motility, is a common cause of human male infertility. This is a retrospective study (1992-1999) to document the prevalence of this pathology in infertile men and to clarify the probable factors associated to its etiology. The prevalence was 18.71% for asthenozoospermia and 63.13% for asthenozoospermia associated with oligo- and/or teratozoo-spermia; thus, 81.84% of the studied samples had altered motility. Leukocytospermia, the ratio of germ cells/sperm, anti-sperm antibodies, consistency, biochemical markers of accessory sex glands, and sperm response after swim-up were studied in normospermic (N), asthenozoospermic (A), and combined asthenozoospermic (C) samples. No significant difference was found in the frequency of leukocytospermia among groups. The rate of germ cells/(spermatozoa + germ cells) between C and N (p < .01) and C and A (p < .01) was statistically different, while no difference was found on comparing N and A. MAR-test over 40% was found in 6% of the A samples and 7.6% of the C, while no positive values were observed in the N group. The percentage of hyperviscous samples was higher in the low sperm motility samples than in the normal group. Data on concentration of the biochemical markers seem to be decreased in asthenozoospermia. Pure and combined asthenozoo-spermia showed different behavior in sperm recovery after swim-up. Two different asthenozoospermias could be defined: the pure one where sperm environment is involved (immunological factor, hyperviscosity, and secretory gland function) and the combined, where the testis is comprised.     

Left atrial thrombosis after heart transplantation

Left atrial thrombosis in the absence of rheumatic heart disease and atrial fibrillation is a rare occurrence. We report two cases of left atrial pedunculated thrombus formation after orthotopic heart transplantation. Despite an uneventful post-operative course, sinus rhythm and normal contractility of the heart, large thrombi could be found several months following transplantation. Surgical thrombectomy was performed under cardiopulmonary bypass. Operative technique is proposed as one of the main factors that can contribute to left atrial thrombosis after heart transplantation.