Anxiety and hippocampus volume in the rat.

In depressed patients as well as healthy controls, a positive relationship between hippocampal volume and trait anxiety has been reported. This study sought to explore the possible inter-relation between hippocampal volume and trait anxiety further. Magnetic resonance imaging at 7 T was used to measure hippocampal volumes in a rat model of extremes in trait anxiety (experiment 1) and in a Wistar population with normal anxiety-related behavior (experiment 2). In addition to anxiety-related behavior, potentially confounding factors (depression-like, exploratory, and locomotor behavior) were assessed. Experiment 1 globally supported the hypothesis of a positive relationship between hippocampus volume and trait anxiety but did not allow for ruling out possible confounds arising from cosegregation of other behavioral traits. Experiment 2 yielded strong evidence for a negative relationship which was specific for trait anxiety. Thus, the relationship between hippocampal volume and anxiety may be more complex than expected. Interestingly, anxiety-related behavior in experiment 2 had a stronger influence on hippocampal volume than depression-like behavior. In the light of hippocampal volume loss in anxiety disorder and frequent comorbidity of anxiety and depression, this finding suggests that further research into the relationship between anxiety and hippocampal volume may be critical for understanding hippocampal contributions to normal and pathological behavior.     

Human xenoreactive natural antibodies of the IgM isotype activate pig endothelial cells

Abstract: Preformed, xenoreactive natural antibodies (XNA) and complement (C) are involved in the initiation of vascular rejection of organs transplanted between discordant species, presumably by stimulating donor organ endothelial cells (EC). Although C is known to play a role in the activation of EC, it has not been clear whether the antibodies serve only to anchor the initial components of C, and thus permit the C cascade to proceed, or whether the antibodies themselves deliver a signal to the EC. We have tested affinity-purified human IgM containing XNA (IgM-XNA) for its ability to stimulate in vitro the up-regulation of genes in pig EC. Northern blot analysis shows that IgM, which contains XNA, stimulates mRNA accumulation for certain genes (including IL-8, PAI-1, and ECI-7, a new gene that we have found is associated with EC activation), but not others known to be up-regulated in response to TNF, IL-1 or LPS. Our results show that XNA provide a signal to EC, and thus may themselves participate in activation of EC and consequent vascular rejection.     

Hypothalamic-pituitary-gonadal function in two infants with Smith-Lemli-Opitz syndrome

We report on the hypothalamic-pituitary-gonadal function in 2 male infants with the Smith-Lemli-Opitz (SLO or RSH) syndrome. Both infants had abnormal external genitalia. Basal and LHRH stimulated plasma gonadotropins were normal for age (1 month). Plasma testosterone, androstenedione, and dehydroepiandrosterone sulfate were normal for age and sex. Some forms of congenital adrenal hyperplasia (17,20-desmolase deficiency, 17α-hydroxylase deficiency, and 3β-hydroxysteroid dehydrogenase deficiency) were ruled out by hormonal studies. The endocrinological findings indicate a normal hypothalamic-pituitary-gonadal function and a normal adrenal steroid biosynthesis in these 2 patients. A partial androgen receptor defect causing the genital malformations seems possible in one patient. Whether 5α-reductase deficiency is the cause of the male pseudohermaphroditism in SLO syndrome remains the subject of future studies. © 1992 Wiley-Liss, Inc.     

Release of vasopressin from supraoptic neurons within the median eminence in vivo. A combined microdialysis and push-pull perfusion study in the rat

The present study was designed to investigate whether or not arginine vasopressin (AVP) is released from magnocellular neurons within the median eminence (ME) in vivo. Urethane-anesthetized adult male Wistar rats were equipped with a microdialysis probe aimed at the supraoptic (SON) or paraventricular nucleus (PVN), a push-pull perfusion probe resting in the ME, and a blood microdialysis probe within the jugular vein. Dialysis of the SON (but not the PVN) with Ringer's solution containing 56 mmol l⁻¹ K⁺ resulted in an increase in AVP release within the ME (to 492 ± 192% of release during basal conditions,P < 0.05) and into blood (to 138 ± 9%,P < 0.01) whereby the release probably occurred from axonal swellings and nerve terminals of supraoptic neurons which project through the internal zone of the ME to the posterior pituitary. The calculated amount of AVP released into the extracellular fluid of the ME was high enough (approximately 1 pg/μ1) to hypothesize that the neuropeptide could enter the portal blood capillaries in physiologically relevant concentrations. Taken together, the present study indicates that activation of magnocellular neurons is accompanied by release of AVP within the median eminence. We assume that AVP released in this way might mediate a communication between the hypothalamic-neurohypophysial system and the hypothalamic-pituitary-adrenal axis in response to selected stressful stimuli.     

Extraovarian Endometrioid Carcinoma Associated with Unopposed Oestrogen Replacement Therapy

EDITORIAL COMMENT: We accepted this case report for publication because, apart from being interesting, it raises the question of the appropriate hormone replacement therapy after bilateral oophorectomy (usually with hysterectomy) has been performed when there is evidence of endometriosis. Menopausal symptoms in these women can be relieved by oestrogen therapy without return of pelvic pain or dyspareunia. The authors report a case of endometrial-like carcinoma in a woman with known endometriosis after a hysterectomy and prolonged unopposed oestrogen therapy. Although this is a solitary case report, the authors explain that there are 8 others in the literature where malignancy occurred in extraovarian endometriosis after bilateral oophorectomy associated with unopposed oestrogen. One of our reviewers commented that a combination of oestrogen and progestogen should always be considered when prescribing hormone replacement therapy in women with a known history of endometriosis, following total hysterectomy and bilateral oophorectomy.     

Einsatz einer Mischkultur in Acetat-Fermentationen

Bacterial cultures were selected from the native flora of liquid manure in order to metabolize liquid manure substances. The mixed culture used in the growth experiments is characterized by low growth rates when maximum degradation of acetate occurs. The biomass concentration reached 2.2 g/l.     

Fusion and failure following anterior cervical plating with dynamic or rigid plates: 6-months results of a multi-centric, prospective, randomized, controlled study

Anterior cervical plate fixation is an approved surgical technique for cervical spine stabilization in the presence of anterior cervical instability. Rigid plate design with screws rigidly locked to the plate is widely used and is thought to provide a better fixation for the treated spinal segment than a dynamic design in which the screws may slide when the graft is settling. Recent biomechanical studies showed that dynamic anterior plates provide a better graft loading possibly leading to accelerated spinal fusion with a lower incidence of implant complications. This, however, was investigated in vitro and does not necessarily mean to be the case in vivo, as well. Thus, the two major aspects of this study were to compare the speed of bone fusion and the rate of implant complications using either rigid- or dynamic plates. The study design is prospective, randomized, controlled, and multi-centric, having been approved by respective ethic committees of all participating sites. One hundred and thirty-two patients were included in this study and randomly assigned to one of the two groups, both undergoing routine level-1- or level-2 anterior cervical discectomy with autograft fusion receiving either a dynamic plate with screws being locked in ap - position (ABC, Aesculap, Germany), or a rigid plate (CSLP, Synthes, Switzerland). Segmental mobility and implant complications were compared after 3- and 6 months, respectively. All measurements were performed by an independent radiologist. Mobility results after 6 months were available for 77 patients (43 ABC/34 CSLP). Mean segmental mobility for the ABC group was 1.7 mm at the time of discharge, 1.4 mm after 3 months, and 0.8 mm after 6 months. For the CSLP- group the measurements were 1.0, 1.8, and 1.7 mm, respectively. The differences of mean segmental mobility were statistically significant between both groups after 6 months (P = 0.02). Four patients of the CSLP-group demonstrated surgical hardware complications, whereas no implant complications were observed within the ABC-group (P = 0.0375). Dynamic plate designs provided a faster fusion of the cervical spine compared with rigid plate designs after prior spinal surgery. Moreover, the rate of implant complications was lower within the group of patients receiving a dynamic plate. These interim results refer to a follow-up period of 6 months after prior spinal surgery. Further investigations will be performed 2 years postoperatively.