Endogenous dopaminergic asymmetry affects development of seizures kindled in the rat amygdala

Cerebral dominance in 56 rats was determined by observing the direction of their turning behavior in response to injection of d-amphetamine (1.5 mg/kg, i.p.). Rats subsequently subjected to kindling of the amygdala developed full epileptic seizures after significantly fewer kindling sessions if the kindling electrodes were in the amygdala of the nondominant, rather than the dominant hemisphere. Kindling rate also showed a significant negative correlation with the total amount of turning after amphetamine. Rats kindled through electrodes in the ventral mesencephalon generally failed to develop full convulsive seizures, and did not show interhemispheric differences in the rate at which they developed preictal behaviors. As the dominant hemisphere of the rat, identified by rotational preference, contains a higher concentration of dopamine, we conclude that even small differences in dopaminergic activity, within the normal physiologic range, can affect the relative susceptibility of the two hemispheres to the development of kindled epilepsy.     

T2 hyperintense foci on magnetic resonance images of schizophrenic patients and controls.

High resolution magnetic resonance imaging (MRI) of the brain was performed on 18 male schizophrenic patients and 15 male normal control subjects using an identical imaging protocol. The number and size of T2 hyperintense foci were clinically quantified by an academic radiologist. Large foci (greater than or equal to 3 mm in diameter) were observed more frequently on patient images (7/18) than on control images (1/15). The imaging protocol detected high rates of focal hyperintensities, but no differences between patients and controls were noted in the total affected brain area (sum of focal areas) or in the presence or absence of foci.     

Unusual Physiologic Melanin Pigmentation of the Tongue

A patient had extensive congenital oral hyperpigmentation of the tongue. The clinical and histologic features set this case apart from any well-delineated disease. Clinically, the congenital onset, the appearance of large black-brownish lesions, the lack of associated systemic abnormalities, and the histologic findings of prominent deposition of melanin in the basal layer support the diagnosis of physiologic melanosis. The macular lesions of the tongue represent discrete depositions of melanin and exemplify soft tissue pigmentation of developmental origin.     

Evaluation of a multifaceted "Resident-as-Teacher" educational intervention to improve morning report

Background  

Resident-led morning report is an integral part of most residency programs and is ranked among the most valuable of educational experiences. The objectives of this study were to evaluate the effect of a resident-as-teacher educational intervention on the educational and teaching experience of morning report.     

Mapping of gene encoding mouse placental alkaline phosphatase to chromosome 4

The gene encoding the mouse placental alkaline phosphatase (ALP; orthophosphoric-monoester phosphohydrolase, alkaline optimum, EC 3.1.3.1) is mapped to chromosome 4, based on Southern blot hybridization of the mouse cDNA with DNAs from mouse-Chinese hamster somatic cell hybrids. This assignment is consistent with the genetic analysis of theAkp-2 locus, which is responsible for the genetic variation of alkaline phosphatase enzyme in placenta as well as in liver, kidney, and bone.     

Fibrin sealant: clinical use and the development of the University of Virginia Tissue Adhesive Center

The utilization of fibrin sealants to augment hemostasis, seal tissues, and facilitate targeted delivery of drugs is increasing. In 1985, a hospital-based program was established to provide autologous and allogeneic cryoprecipitate that serves as a fibrin sealant when combined with bovine thrombin. To date, more than 4,000 patients have been treated with this product at our institution, with an efficacy rate greater than 90%. Collaboration among surgical services and the blood bank fostered multispecialty expertise with this product that led, in 1997, to the establishment of the University of Virginia Tissue Adhesive Center. The Tissue Adhesive Center is a multidisciplinary center whose physician director and nursing and administrative support staff facilitate basic research, laboratory investigation, and preclinical and clinical trials with collaborators throughout the university. The Tissue Adhesive Center also provides educational programs and clinical consultation, and tracks and participates in peer review of sealant use. The licensure of a commercially produced, virally inactivated, pooled-plasma fibrin sealant in May 1998 provided an alternative source of adhesive. Utilization of the commercial product surpassed use of the blood bank product in April 1999. At present, use of the commercial product is approximately 3 times that of the blood bank-produced sealant. This report reviews the clinical uses of fibrin sealant, its regulatory history, the production of fibrin sealants, the evolution of a blood bank fibrin sealant program, the development of the Tissue Adhesive Center, and the utilization of commercial and blood bank-produced sealant at our university hospital.     

The incidence of T2-weighted MR imaging signal abnormalities in the brain of cocaine-dependent patients is age-related and region-specific.

BACKGROUND AND PURPOSE: Cocaine and its metabolites can produce vasospasm, and cocaine-dependent patients are at increased risk for stroke. Based on previous case reports, we hypothesized that the incidence of hyperintense brain lesions observed on T2-weighted MR images would also be increased in asymptomatic cocaine-dependent individuals. METHODS: Sixty-two male "crack" (smoked) cocaine-dependent participants ranging in age from 25 to 66 years were compared with 116 normal male control participants ranging in age from 25 to 80 years. Those with histories of neurologic symptoms or illnesses were excluded. The severity of hyperintense lesions was rated on a 0- to 3-point scale, and ratings of 3 were used in the data analysis as an indicator of a probable pathologic process. Three regions were separately rated: the cerebral white matter, insular subcortex white matter, and subcortical gray matter (basal ganglia and thalamus region). RESULTS: Significantly increased risk of severe lesions was observed in the two white matter regions of the cocaine-dependent group (odds ratio of 16.7 and 20.3) but not in the subcortial gray matter region (odds ratio of 1.4). In the insula subcortex white matter, the risk of lesions increased with age in the cocaine-dependant sample, but remained essentially absent among normal controls through the age of 80 years. In the cerebral white matter, the relationship of age and risk of lesion among normal participants was similar in shape to that in cocaine-dependent participants, but equivalent risk was seen 20 years earlier among cocaine-dependent participants. CONCLUSIONS: Cocaine-dependent participants had a significantly increased age-related risk of white matter damage. The possible clinical implications of this damage are discussed.