Sexual dimorphism in accessory olfactory bulb mitral cells: a quantitative Golgi study.

The purpose of the present study was to identify the existence of sexual dimorphism in the dendritic field of accessory olfactory bulb mitral cells in rats and to investigate the effects of male orchidectomy and female androgenization on the day of birth upon this dendritic field. The rapid Golgi method was used to conduct a quantitative study of various characteristics of the dendritic field of accessory olfactory bulb mitral cells. The results indicated greater values for males than females for the following characteristics: (i) somatic area; (ii) degree of branching in the dendritic field; (iii) total dendritic length; and (iv) dendritic density around the neuronal soma. Orchidectomy of males, as well as androgenization of females, on the day of birth inverted these differences.     

Effects of early postnatal sex steroids on acquisition and extinction of a continuously reinforced lever-pressing response

The effects of early postnatal dihydrotestosterone (DHT) and estradiol on the sexually dimorphic continuously reinforced lever-pressing response were investigated. 90-day-old male rats postnatally treated (during the first eight days of postnatal life) with cyproterone acetate (CA), tamoxifen (TX) or vehicle, and 90-day-old females treated with estradiol benzoate (EB), DHT or vehicle in the same postnatal period, were studied during the acquisition and extinction of the continuously reinforced lever-pressing response using a free-operant procedure. During acquisition, the control males made more responses per minute than the control females, and also reached the extinction criterion significantly sooner than the females. CA treatment impaired the male's performance at the levels of that shown by females, whereas TX treatment affected neither acquisition nor extinction. Inversely, in both experimental phases females treated with DHT performed like control females, whereas the acquisition and extinction performances of the EB-females were similar to those obtained in the control or TX male groups.     

The distribution of glial fibrillary acidic protein in the adult rat brain is influenced by the neonatal levels of sex steroids

Sex steroids during the perinatal period are able to modify the postnatal development of neurons within steroid-sensitive areas in the rat brain. This study was designed to test the possible influence of the early postnatal levels of sex steroids on the morphology of the astrocytes. The experimental manipulation of the neonatal levels of sex steroids was performed by the androgenization of females with a single injection of testosterone propionate and by the orchidectomy of males on the day of birth. Control females received a single injection of vehicle and control males were sham operated. All the animals were sacrificed at 3 months of age postnatally. The immunohistochemical distribution of the glial fibrillary acidic protein (GFAP), a marker of astrocytic filaments, was studied on coronal sections of the dorsal hippocampus, the globus pallidus and the hypothalamic arcuate nucleus. The number of GFAP immunoreactive cells, the number of GFAP immunoreactive primary processes per cell and the surface density of the GFAP immunoreactive material were evaluated. This morphometric evaluation revealed a decreased surface density of GFAP immunoreactive material in the hippocampus, globus pallidus and the ventral part of the arcuate nucleus of orchidectomized males when compared to control males. Sex differences in the distribution of GFAP immunoreactivity were detected in the hippocampus and globus pallidus. These differences were abolished by the androgenization of females. The number of GFAP immunoreactive cells was similar in all the experimental groups, indicating that the differences in surface density represent an effect of sex steroids on the growth of astrocytic processes rather than on the proliferation of astrocytes.     

Oromandibular dystonia associated with fluoxetine

A 66 year old patient with major depression treated with fluoxetine developed persistent oromandibular dystonia and mild akathisia. She improved significantly after discontinuation of the drug and treatment with biperiden. The temporal relationship between the use of fluoxetine and the occurrence of dystonia and akathisia suggests that fluoxetine may have induced tardive dystonia in this patient possibly due to a serotonergically mediated inhibition of striatal dopaminergic neurotransmission. We believe that this is the first reported case of persistent or tardive dystonia associated with fluoxetine treatment     

Sex Differences in the Vomeronasal System

In the early eighties we found sex differences in the vomeronasal organ (VNO) and hypothesized that the vomeronasal system (VNS), a complex neural network involved in the control of reproductive behavior, might be sexually dimorphic. At that time sex differences had already been described for some structures that receive VNO input, such as the medial amygdala, the medial preoptic area, the ventromedial hypothalamic nucleus, and the ventral region of the premammillary nucleus. Since then, we have shown sex differences in the accessory olfactory bulb (AOB), the bed nucleus of the accessory olfactory tract (BAOT), and the bed nucleus of the stria terminalis (BST). When new VNS connections were found, all of them ended in nuclei that present sex differences. In general, sex differences in the olfactory system show two morphological patterns: one in which males present greater morphological measures than females, and just the opposite. To explain the morphometric measures of males in the latter, it has been hypothesized that androgens serve as inhibitors. Our work on the involvement of the GABA_A receptor in the development of AOB and maternal behavior sex differences also suggests that neonatal changes in neuronal membrane permeability to the ion Cl⁻ differences. This might be the first animal model to help us to understand the situation in which human genetic and gonadal sex do not agree with brain and behavioral sex. Finally, we stress that sex differences in the VNS constitute a neurofunctional model for understanding sex differences in reproductive behaviors.     

Intrahepatic cholestasis of pregnancy in twin pregnancies

To clarify whether the increase in estrogen levels occurring during twin pregnancies (TP) is associated with a greater risk of developing intrahepatic cholestasis of pregnancy (ICP), we followed up 62 consecutive patients with TP and compared them with single pregnancies delivered in our hospital during 1 year. The prevalence of ICP was significantly higher in twin than in single pregnancies (20.9% versus 4.7%, respectively; P less than 0.001). Urinary estriol excretion was also significantly higher in twin compared to single pregnancies, although no quantitative differences were detected in TP with or without ICP. In multiparous patients with a proband TP affected by ICP, the disease recurred only in further TP, emphasizing the important role that estrogens seem to play in the pathogenesis of ICP. In contrast, in multiparous patients with a proband single pregnancy affected by ICP, the disease occurred in 70.5% of their other single pregnancies, suggesting the presence of a metabolic predisposition in these cases. However, in both groups of multiparous women a notable number of single pregnancies were not affected by the disease, supporting the postulate that the pathogenesis of ICP is multifactorial and that some as yet unidentified environmental factor needs to be present in order to develop the disease and also to modulate its expressivity.     

A randomized multicenter comparison of basiliximab and muromonab (OKT3) in heart transplantation: SIMCOR study

BACKGROUND: Antilymphocytic antibodies have been long used for the prevention of acute rejection early after heart transplantation (HTx), but their adverse effects have limited their widespread use. Our aim was to evaluate the safety, tolerability, and efficacy of the novel anti-CD25 antibody basiliximab (BAS) compared with muromonab (OKT3). PATIENTS AND METHODS: In this multicenter study, 99 patients were randomly assigned to receive either BAS or OKT3 in the early post-HTx period. The primary endpoint was safety and tolerability. Specific safety variables were predefined for a better comparison of adverse effects. Secondary endpoints concerning anti-rejection efficacy were also evaluated. RESULTS: No adverse events related to study medication were found in the BAS group, whereas 23 were observed among patients receiving OKT3 (P<0.0001). The proportion of patients with predefined adverse events day 4 post-HTx was much higher with OKT3 than with BAS (43% vs. 4%; P<0.0001). Fever, acute pulmonary edema, hypotension, and other complications accounted for most of the difference. At 1-year follow-up, biopsy-proven rejection episodes grade>or=3A had occurred in 39.6% of BAS patients versus 40.4% of OKT3 patients (P=0.87). There were no differences in terms of severity and timing of acute rejection episodes. The number of infectious episodes, complications not related to study medication, and actuarial survival were similar in both groups. CONCLUSION: In this HTx study, induction therapy with BAS was safer and better tolerated than OKT3, without significant differences in efficacy outcomes.     

Colovesical fistula complicating diverticular disease: one-stage resection

Colonic diverticular disease is common in developed countries, and its prevalence increases with age. Most affected individuals remain asymptomatic throughout their lives, and relatively few patients require surgical intervention for obstructive or inflammatory complications. Colovesical fistula is the most common type (65%) of fistula associated with colonic diverticular disease. Primary resection of sigmoid colon with colorectal anastomosis performed as a one-stage procedure is its definitive treatment and can be performed safely--as simple closure, using an omental flap, or through resection and closure of bladder defect--in 90% of the patients. We report our experience with four patients suffering from colovesical fistula who were treated with primary resection of sigmoid colon and colorectal anastomosis performed as a one-step procedure. In our experience, diverting colostomy or Hartmann intervention is not recommended because of the lack of fistula definitive resolution and the possibility of additional complications.