Cutaneous fistulas to the vas deferens.

Cutaneous fistulas to the vas deferens are a rare occurrence. A careful review of the literature revealed only 16 cases reported within the last 70 years. We present a case of such a fistula occurring after inguinal orchiectomy for suppurative epididymo-orchitis and review the etiologies of all reported cases to provide recommendations for management.     

Habituation and dishabituation of human salivary response.

Habituation may be relevant for understanding how sensory stimuli influence factors related to ingestive behavior. In the first of three experiments in humans we showed that salivation and hedonic ratings to lemon or lime juice habituated within 10 presentations, and dishabituation of the salivation and hedonic ratings to the original juice were observed after a new juice was presented. Experiment 2 replicated the habituation and decrease in hedonics to lemon juice, and showed both dishabituation and a relative increase in hedonics when chocolate taste, rather than another juice, served as the dishabituating stimulus. In a third experiment we showed a video game, a nontaste stimulus, could serve as a distractor to prevent the development of habituation, as well as a dishabituator after habituation had occurred.     

Reassessment of a new model of complete cerebral ischemia in rats

Summary The present study was undertaken to ascertain the role of the microcirculation in the phenomenon of hypoperfusion following complete cerebral ischemia. The experiments were performed on rats under superficial ether anesthesia. Cerebral ischemia was induced by cardiac arrest for 3.5 or 10 min, with survival periods that lasted from 3 min to 7 days. A special metal hook-like device was inserted into the chest cavity at the third intercostal spaces for occluding the cardiac vessel bundle. The effect of this procedure was total cessation of systemic circulation, i.e., clinical death. In 52% of animals with 10-min clinical death, resuscitation (external heart massage and artificial ventilation) restored heart activity. When brain circulation was restored respiratory activity, pain reaction, corneal reflex, bioelectric activity of the cortex, and normal activities of the rats returned. Scanning electron microscopy was applied to study the effect of ischemia on the vessel wall and endothelial cells (EC). Ischemia produced a remarkable increase in the numbers of microvilli and pit-like invaginations on the luminal EC surface. The luminal wall surface of many of the microvessels (MV) formed ridges. Frequently, microthrombi of varying sizes were observed. The most prominent changes were noted from 3 min to 6 h of recirculation, and they correlated with hypoperfusion after ischemia. Seven days later, these changes completely disappeared. The data presented here indicate that progressive hypoperfusion after ischemia occurs with significant alterations fusion after ischemia occurs with significant alterations in the MV walls. These studies collectively suggest that the focal responses in select MVs may be associated with receptor molecule up-regulation of some, but not all, affected ECs. Our data provide further characterization of a new and unique chronic model of brain ischemia that can be applied to relevant clinical studies.This material was presented in part at the American Association of Neuropathologists, June, 1991 in Baltimore, MD and was supported in part by the NYS Office of Mental Retardation and Developmental Disabilities.     

Magnetic resonance imaging (MRI) effects on rat pineal neuroendocrine function

This study investigated the effects of MRI on receptor-mediated activation of pineal gland indole biosynthesis. Exposure of rats to MRI reduced the effects of isoproterenol on pineal serotonin and N-acetylserotonin levels suggesting that strong magnetic fields and/or radio-frequency pulsing used in MRI inhibited beta-adrenergic activation of the gland. There was no effect of MRI on saline controls.     

Head circumference of children with Down syndrome (0-36 months)

This study provides statistically appropriate head circumference reference curves for males and females with Down syndrome (DS) from birth to 36 months of age. A total of 239 males and 182 females from five study populations, yielding a combination of cross-sectional and longitudinal data, were used for the analysis. The method of least squares was used to test the fit of the growth model y = a+bx+c[log(x + 1)], where x is age in months. These standardized curves should provide information of value in the medical, physical, and developmental management of children with DS.     

Neurofibrillary tangles in Alzheimer's disease and progressive supranuclear palsy: antigenic similarities and differences

Summary The antigenic profile of neurofibrillary tangles (NFT) in Alzheimer's disease (AD), senile dementia of Alzheimer type (SDAT), progressive supranuclear palsy (PSP) and in non-demented aged humans was investigated by light and electron microscopic immunocytochemistry using antisera and monoclonal antibodies to tubulin, microtubule-associated proteins (MAP1, MAP2 and tau), neurofilament proteins and determinants unique to Alzheimer paired helical filaments (PHF). Antibodies to tau proteins labeled NFT in all cases investigated (AD, SDAT, PSP and non-demented aged humans). However, one monoclonal antibody to PHF recognized numerous tangles in AD/SDAT, but only a small minority of the PSP tangles. Antibodies to tubulin, MAP1, MAP2 and neurofilament proteins did not selectively stain NFT. Whereas pretreatment of sections with phosphatase was required for the detection of tangles with Tau-1 monoclonal antibody, digestion of sections with either phosphatase or pronase had no significant effect on the staining pattern obtained with the other antibodies. Our studies show that, as previously described for AD/SDAT, phosphorylated tau polypeptides are also a major antigenic determinant of tangles in PSP, indicating that tangle formation may follow a common pathogenetic pathway in neurofibrillary degenerations. There is, however, at least one epitope in AD/SDAT tangles which seems to be absent on, or at least inaccessible in, the 15-nm straight fibrils of PSP.Supported by a project of the Austrian Ministery of Science and Research     

Immunological and anti-chaperone therapeutic approaches for Alzheimer disease

Alzheimer disease (AD) is the most common cause of dementia. Currently available therapies only provide symptomatic relief. A number of therapeutic approaches are under development that aim to increase the clearance of brain Abeta peptides. These include immune mediated clearance of Abeta and the inhibition of the interaction between Abeta and its pathological chaperones. Both active and passive immunization has been shown to have robust effects in transgenic mouse models of AD on amyloid reduction and behavioral improvements. However, a human trial of active immunization has been associated with significant toxicity in a minority of patients. New generation vaccines are being developed which likely will reduce the potential for cell-mediated toxicity. In addition, the recent development of anti-chaperone therapy opens a new therapeutic avenue which is unlikely to be associated with toxicity.