Effects of isosorbide dinitrate on the response to atrial pacing in coronary heart disease.

To study the efficacy of isosorbide dinitrate in prevention of myocardial ischemia, 20 patients with angiographically proved coronary artery disease underwent atrial pacing (mean rate 138/min) before (P1), 10 minutes after (P2) and 65 minutes after (P3) sublingual administration of 5 mg of isosorbide dinitrate. The symptomatic, hemodynamic and metabolic responses were evaluated at rest and during each pacing period. Angina occurred in all subjects during P1. Angina did not recur or was less severe in 17 of 19 patients during P2 and in 19 of 20 patients during P3. Resting left ventricular end-diastolic pressure for the group was normal at 11 plus or minus 4 mm Hg (mean plus or minus standard deviation). On interruption of pacing at 4.5 minutes during P1, average end-diastolic pressure during sinus rhythm was abnormal (18 plus or minus 6 mm Hg). After administration of isosorbide dinitrate mean left ventricular end-diastolic pressure was significantly decreased at rest and remained normal when pacing was interrupted during P2 and P3. Brachial arterial pressure, cardiac index, tension-time index, left ventricular stroke work index and maximal rate of rise of left ventricular pressure were all diminished at rest before and during P2 and P3. S-T segment depression was less during P2 and P3 than during P1. Before isosorbide dinitrate was given, resting myocardial lactate extraction was 15 plus or minus 11 percent during P1 lactate extraction decreased to minus2 plus or minus 25 percent. Lactate extraction was significantly greater during P2 and P3 than during P1. This study demonstrates that sublingual administration of 5 mg of isosorbide dinitrate has a significant protective effect against pacing-induced myocardial ischemia at 10 and 65 minutes after administration.     

Microvascular basal lamina injury after experimental focal cerebral ischemia and reperfusion in the rat.

To define the location and extent of microvascular damage of the basal lamina after cerebral ischemia and reperfusion in rats, the authors subjected animals (n = 16) to 3 hours of focal cerebral ischemia and 24 hours of reperfusion using the suture middle cerebral artery occlusion model; sham-operated animals served as controls (n = 6). The Western blot technique was used to define the collagen type IV protein content in various brain regions, whereas immunohistochemistry identified microvascular basal lamina loss (anticollagen type IV staining). The extent of damage was quantified by automatic morphometric video-imaging analysis. Statistical analysis was based on the Mann-Whitney test and the paired Student's t-test. The ischemic hemisphere showed a reduction of the collagen type IV protein content after ischemia and reperfusion in the Western blot (reduction compared with the nonischemic side: total hemisphere, 33% +/- 6%; basal ganglia, 25% +/- 7%; cortex 49% +/- 4%; P < 0.01) [corrected]. There was also a decrease in the number of cerebral microvessels between the ischemic and nonischemic hemispheres (20% +/- 2%), cortical (8% +/- 3%), and basal ganglia areas (31% +/- 3%) (P < 0.001). Besides a reduction of the vessel number, there was also a loss in basal lamina antigen-positive stained area in ischemic areas (hemisphere, 16% +/- 3%; cortex, 14% +/- 3%; basal ganglia, 21% +/- 4%; P < 0.01) [corrected]. Cortical areas had a less pronounced basal lamina loss than basal ganglia (P < 0.05). For the first time, microvascular basal lamina damage, indicated by collagen type IV loss, is proven in rats by biochemical and morphometric analysis. These changes are comparable with those found in nonhuman primates. The authors report novel data regarding microvascular ischemic changes in the cortex. These data provide a basis for future experiments to determine the mechanisms of ischemic microvascular damage and to devise new therapeutic strategies.     

Effects of dextran infusion on left ventricular volume and pressure in man

The purpose of this investigation was to quantitate the changes in left ventricular volume and end-diastolic pressure that occur with rapid infusion of 500 ml of low molecular weight dextran, and thus to study left ventricular pressure-volume relationships. Left ventricular pressure and echocardiographic dimensions were recorded before, during, and following dextran infusion in eight patients with normal left ventricular function. With the infusion of dextran, left ventricular end-diastolic pressure rose progressively from 10 ± 3 mmHg (mean ± SD) to 24 ± 5 mmHg, whereas end-diastolic volume increased from 95 ± 23 ml to 118 ± 26 ml (24%). These results serve to emphasize the steepness of the left ventricular pressure-volume relationship at end-diastole in subjects with normal ventricular function when in the supine position.     

Mitral regurgitation due to lupus endocarditis treated with valve replacement.

A murmur of mitral regurgitation developed in a 20-year-old woman with a 2-year history of systemic lupus erythematosus. Echocardiography revealed thickening of both valve leaflets and abnormal diastolic motion of the posterior one, confirming the diagnosis of mitral endocarditis. The mitral regurgitation progressed to cause congestive heart failure, which was refractory to drug therapy but was effectively treated with mitral valve replacement.     

Cardiac tamponade secondary to haemophilus pericarditis: a case report.

Pyogenic pericarditis is encountered uncommonly in clinical practice. The majority of cases of clinically apparent pericarditis are viral in origin. When bacterial infection of the pericardial space does occur the causative organism is usually Staphylococcus or Streptococcus species. Isolation of an haemophilus organism from the pericardial space in this condition is distinctly unusual. There are only 10 previously reported cases in the literature of pericarditis secondary to Haemophilus influenzae. This report describes the case of a 36-year-old woman who presented with haemophilus empyema and purulent pericarditis progressing to cardiac tamponade. There are isolated reports of successful treatment of pyogenic pericarditis with closed drainage and antibiotics. In the absence of clear evidence demonstrating the efficacy of this approach the authors favour open exploration of the pericardial space.     

Chudley-McCullough syndrome: case report and review of the neuroimaging spectrum

We report on a child with Chudley-McCullough syndrome and re-evaluate the spectrum of imaging findings (in 15 previously reported patients) which appear to be variable and, to some extent, ambiguous in the literature. Magnetic resonance imaging of the brain revealed asymmetric colpocephaly with agenesis of the splenium corporis callosi, ribbon-like subcortical gray matter heterotopia along the cingulate gyri, malrotation of both hippocampi, and dysplasia of the cerebellum. Macrocrania together with sensorineural hearing loss, colpocephaly, and posterior or complete agenesis of the corpus callosum can be considered the hallmarks of the autosomal recessive Chudley-McCullough syndrome. These may be variably associated with interhemispheric arachnoid cyst, cortical dysplasia, gray matter heterotopia, and cerebellar dysplasia. While early support with hearing aids may lead to improved language and cognitive outcome, shunting of ventricular dilatation is not indicated in the Chudley-McCullough syndrome.     

The older woman: ethnicity and health

This article on minority women populations and health care seeks to address the economic impact of health care for such populations, discuss the scope of the problem surrounding women's health, address the health status of minority older women, identify ethnocultural strategies and nursing implications for the health care of older women from varying ethnic backgrounds, and provide resources to assist health care providers.     

Parallel interhemispheric processing in hemineglect: Relation to visual field defects

Parallel interhemispheric processing is required to explore our visual environment and to integrate visual information from both hemifields simultaneously. Damage to the right temporo-parietal cortex can disrupt such parallel processes and result in neglect and visual extinction of stimuli in the left contralesional visual space. Neglected or extinguished stimuli can still be processed, yet without reaching the patient's awareness. Such unconscious processing has been attributed to structurally intact primary visual areas in neglect. To study whether unconscious parallel processing depends on visual functional integrity, we compared the performance of neglect patients with visual field defects (VFDs) (n = 11) and hemianopic patients with partial or complete blindness of one visual hemifield (n = 11) on redundant targets effects (RTE). The RTE manifests as faster reaction times to redundant paired (two stimuli, one in each hemifield) than single stimulation (in one hemifield). We found RTEs, i.e., unconscious processing, in neglect patients but not in hemianopic patients. Furthermore, neglect patients showed large crossed–uncrossed differences (CUDs), i.e., faster response times to ipsi- than contralesional hemifield stimulation, reflecting a difference in processing speed for single stimuli in the two hemispheres that were correlated with VFDs and visual extinction. The finding that extinction, but not RTE, was correlated with the CUD suggests that under competitive bilateral stimulus conditions the delayed contralesional visual field input may not be detected by the intact left hemisphere, which presumably mediates the task given the impairment of the right hemisphere. By contrast, unconscious parallel processing of contralesional stimuli (RTE) occurred even when contralesional visual field input is lacking (VFD) or delayed (CUD) and is possibly mediated via subcortical visual pathways.