Experimental vitreous haemorrhage: Echographic appearances

Summary Vitreous haemorrhages were induced in rabbits and the echographic appearances on A and B scan were correlated with the gross and histologic appearances over a period of twenty weeks. In all cases, visible vitreous opacities produced distinct echo patterns. As the haemorrhages cleared, the echo amplitudes became progressively weaker. Several patterns of vitreous membranes on B scan were also observed. Pathological examination revealed that such membranes were composed of red cells, macrophages and condensed vitreous collagen. It is suggested that haematogenous vitreous membranes of this type are readily diagnosed by combined A- and B-scan ultrasonic examination, and are probably amenable to surgery.     

Effect of basal ganglia injury on central dopamine activity in Gulf War syndrome: correlation of proton magnetic resonance spectroscopy and plasma homovanillic acid levels

BACKGROUND: Many complaints of Gulf War veterans are compatible with a neurologic illness involving the basal ganglia. METHODS: In 12 veterans with Haley Gulf War syndrome 2 and in 15 healthy control veterans of similar age, sex, and educational level, we assessed functioning neuronal mass in both basal ganglia by measuring the ratio of N-acetyl-aspartate to creatine with proton magnetic resonance spectroscopy. Central dopamine activity was assessed by measuring the ratio of plasma homovanillic acid (HVA) and 3-methoxy-4-hydroxyphenlyglycol (MHPG). RESULTS: The logarithm of the age-standardized HVA/MHPG ratio was inversely associated with functioning neuronal mass in the left basal ganglia (R(2) = 0.56; F(1,27) = 33.82; P<.001) but not with that in the right (R(2) = 0. 04; F(1,26) = 1.09; P =.30). Controlling for age, renal clearances of creatinine and weak organic anions, handedness, and smoking did not substantially alter the associations. CONCLUSIONS: The reduction in functioning neuronal mass in the left basal ganglia of these veterans with Gulf War syndrome seems to have altered central dopamine production in a lateralized pattern. This finding supports the theory that Gulf War syndrome is a neurologic illness, in part related to injury to dopaminergic neurons in the basal ganglia.     

Posttraumatic stress two years after the Oklahoma City bombing in youths geographically distant from the explosion

This article describes Posttraumatic Stress Disorder (PTSD) symptomatology in 69 sixth-grade youths who resided within 100 miles of Oklahoma City at the time of the 1995 bombing of the Alfred P. Murrah Federal Building. These youths neither had any direct physical exposure nor personally knew anyone killed or injured in the explosion. A survey conducted two years after the bombing assessed exposure, PTSD symptoms, and functioning. PTSD symptom frequency was measured with the Impact of Event Scale--Revised. Our BCD criteria for defining PTSD caseness was modeled after DSM-IV B, C, and D criteria requiring one reexperiencing, three avoidance/numbing, and two arousal symptoms for diagnosis. Those who met our BCD criteria had significantly higher PTSD symptom scores than those who did not. Both increased mean PTSD symptom score and meeting our caseness definition were associated with increased functioning difficulties. Media exposure and indirect interpersonal exposure (having a friend who knew someone killed or injured) were significant predictors of symptomatology. These findings suggest that children geographically distant from disaster who have not directly experienced an interpersonal loss report PTSD symptoms and functional impairment associated with increased media exposure and indirect loss.     

Alcohol exposure and breast cancer: results of the women's contraceptive and reproductive experiences study.

OBJECTIVES: To explore associated biological outcomes and clarify the role of timing of exposure in the alcohol-breast cancer relationship.METHODS: In a population-based study of 4,575 women ages 35 to 64 years diagnosed with invasive breast cancer between 1994 and 1998 and 4,682 controls, we collected details of lifetime alcohol use and factors that could confound or modify the alcohol-breast cancer relationship. We used conditional logistic regression to compute the odds of breast cancer among drinkers relative to nondrinkers at all ages and at ages 35 to 49 and 50 to 64 years separately.RESULTS: Recent consumption (at reference age minus two) of >/=7 drinks per week was associated with increased risk [odds ratio (OR), 1.2; 95% CI, 1.01-1.3] and evidence of dose response was observed. Most of the excess was observed among women ages 50-64 years (OR 1.3; 95% CI, 1.1-1.6), although the test for age interaction was not statistically significant. Exposure later in life seemed more important than early exposure. Excess breast cancer associated with recent consumption was restricted to localized disease. When outcome was examined according to tumor hormone receptor status, highest risks were observed for estrogen receptor-positive/progesterone receptor-negative tumors (OR 1.6; 95% CI, 1.2-2.3).CONCLUSIONS: The effect of timing of alcohol exposure on breast cancer risk is complicated and will require additional study focused on this one issue. Further work is needed to explain how alcohol exposure, sex hormones, and tumor receptor status interact.     

Minority recruitment in hereditary breast cancer research.

Although recruitment of ethnic and racial minorities in medical research has been evaluated in several studies, much less is known about the methods used to recruit these populations to participate in cancer genetics research. This report reviews the resources that have been used to identify and recruit ethnic and racial minorities to participate in hereditary breast cancer research. Overall, hospital-based resources were used most often to identify potential subjects, and active recruitment methods were used most frequently to enroll eligible subjects. This review suggests that there appears to be a finite number of resources and strategies to identify and recruit potential subjects to participate in cancer genetics research; however, options for improving awareness about cancer genetics research among ethnic and racial minorities have not been extensively evaluated. To study ethnic and racial minority participation in cancer genetics research, stronger evaluation components will need to be integrated into research methods. Both observational and experimental studies are needed to determine resources that are most effective for identifying potential subjects who are ethnic and racial minorities and to evaluate the effects of different recruitment strategies on enrollment decisions among these populations.     

Evaluating fitness to drive after cerebral injury: basic issues and recommendations for medical and legal communities

Specialists in rehabilitation are typically called upon to evaluate and render an opinion about whether or not a person can be entrusted to resume driving. And, because driving is an individual privilege to be balanced against the public's right to safety and protection from the dangers of a driver whose residual deficits may impede ability to drive safely, these specialists have developed a number of methods to assess fitness to drive. Unfortunately, many evaluators remain unfamiliar with research used as basis for evaluations or lack understanding of the strengths and weaknesses of tests in use. Therefore, there may be unquestioning trust in tests and methods that leads to errors of significant consequence in decisions about fitness to drive as well as unawareness of expanding risks of litigation that can emanate from inappropriate recommendations. This article intends to draw attention to issues, considerations, and problems underlying the conduct of driver evaluations, including focus on ways in which the legal and medical communities approach question of fitness, legal and medical definitions and terminology, responsibility for assessment as well as tests and methods used in evaluations. Conclusions are drawn from discussion of these matters and recommendations are outlined for addressing identified problems at the interface between medical and legal communities.     

Prognostic Indicators for Squamous Cell Carcinoma of the Oral Cavity: A Clinicopathologic Correlation

Fifty-three patients with T1 squamous cell cancer of the floor of mouth and ventral surface of the tongue with a known clinical outcome were retrospectively analyzed and arbitrarily divided into “aggressive” and “nonaggressive” groups based on their clinical behavior. Various host and tumor factors were then evaluated in an attempt to determine whether the tumor behavior could have been predicted. The paraffin-embedded tumor specimens were evaluated for tumor differentiation, tumor thickness and tumor invasion, microvessel density, and p53 expression. In addition, a composite morphologic grading score was obtained by combining cell differentiation, nuclear polymorphism, mitosis activity, depth of infiltration, type of infiltration, and lymphatic infiltration. No single technique appeared capable of identifying “aggressive” behavior, although possibly an evaluation of composite factors might show promise in the future.     

Brainstem catecholaminergic neurons activated by hypoxemia express GR and are coordinately activated with fetal sheep hypothalamic paraventricular CRH neurons

In late gestation, challenges to fetal homeostasis are accompanied by increases in adrenocorticotropin (ACTH) concentrations in fetal peripheral plasma and Fos (c-fos protein) activation in corticotropin-releasing hormone (CRH) neurons of the fetal hypothalamic paraventricular nucleus (PVN). In adults, ventrolateral brainstem catecholaminergic (CA) neurons (A1/C1, A2/C2) project to the parvocellular neurons of the PVN, possess glucocorticoid receptors (GR) and are Fos activated in parallel with CRH neurons of the PVN during hypoxia. Such observations suggest a role for the aforementioned medullary neurons in the function of the hypothalamo-pituitary-adrenal axis. The present study utilized late gestation fetal sheep, stereotaxic methodology and retrograde axon tracing and immunocytochemical techniques to investigate the relationship between activation of fetal brainstem CA neurons and activation of fetal PVN CRH immunopositive neurons in response to hypoxemia. Results indicated that: (1) the largest brainstem CA projection to PVN CRH neurons is from A1/C1 neurons, (2) brainstem neurons exhibit GR immunostaining and (3) brainstem CA neurons show a strong correlation (A1/C1 - r(2)=0.894, P<0.005; A2/C2 - r(2)=0. 848; P<0.002) of Fos activation with Fos activation in PVN CRH cells. We conclude that in late gestation the brainstem A1/C1 and A2/C2 areas are in position to influence the function of the hypothalamo-pituitary-adrenal axis during hypoxemic challenges to homeostasis in a fashion similar to that which has been demonstrated in the adult rat.