No abstract

To clarify the pathogenesis of chest pain in patients with cardiomyopathies, we compared coronary blood flow and other indicators of ischemia at rest and during pacing-induced tachycardia in nine patients with cardiomyopathy (four hypertrophic and five congestive) and in five control subjects. Coronary blood flow was reduced at rest and during pacing in cardiomyopathy patients compared with controls. In patients with hypertrophic cardiomyopathy, pacing induced chest pain in all, increased ST-segment depression in three patients and increased coronary venous lactate concentration. With pacing, two of five patients with congestive cardiomyopathy had chest discomfort and three had increased ST-segment depression, but coronary venous lactate concentration did not change significantly. In both groups of cardiomyopathies, the ratio of the systolic and diastolic pressure-time indexes tended to decrease more than in controls during pacing. Thus, myocardial perfusion is decreased in patients with cardiomyopathy, both at rest and during pacing. The changes detected during pacing point to subendocardial ischemia as the likely mechanism for angina in hypertrophic and possibly also in congestive cardiomyopathy.

Two new isolates of Ehrlichia chaffeensis (designated Jax and St. Vincent) were obtained from patients with fatal ehrlichial infections. Patients developed characteristic manifestations of severe disease due to E. chaffeensis, including marked thrombocytopenia, pulmonary insufficiency, and encephalopathy. Primary isolation was achieved in DH82 cells; the Jax and St. Vincent isolates were detected within 19 and 8 days postinoculation, respectively. The isolates were characterized by molecular evaluation of the 16S rRNA gene, the groESL heat shock operon, a 120-kDa immunodominant protein gene, and an incompletely characterized repetitive-motif sequence (variable-length PCR target [VLPT]). The sequences were compared with those of the corresponding molecular regions in the type isolate (Arkansas). St. Vincent contained one fewer repeat unit in both the 120-kDa protein gene and the VLPT compared with corresponding sequences of the Jax and Arkansas isolates. 16S rRNA gene sequences from the two new isolates had 100% identity to the corresponding sequences of the 91HE17 and Sapulpa isolates of E. chaffeensis, and to the corrected 16S rRNA gene sequence of the Arkansas isolate. The Jax isolate grew more slowly than the St. Vincent isolate in DH82 cells, and both of the new isolates grew more slowly than the extensively passaged Arkansas isolate. Although specific associations between ehrlichial pathogenicity and genotype were not identified from these comparisons, recovery of this organism from a spectrum of clinical presentations remains an integral step in understanding mechanisms of disease caused by E. chaffeensis.

Thirty-three outpatient epileptics with normal CT scans (group 1) and 31 patients with cerebellar and brain stem (CBS) atrophy (group 2) were randomly included in this study. There were no significant statistical differences between the groups with regard to age, education, and number of grand mal and other seizures. Statistical analyses showed that group 2 had a longer history of epilepsy with a consequently longer duration of phenytoin (PHT) consumption. Neuropsychological assessment revealed lower performance by this group on the following measures: full I.Q. scale, verbal I.Q. scale, performance I.Q. scale, information, arithmetic, block design, object assembly, digit symbol, Stroop test forms I and II, the B-M dexterity test, and the simple visual and auditory reaction time. No significant differences were observed between the two groups for the remaining 5 subtests from the WAIS scale, for the immediate recall and the delayed recall subtests belonging to Wechsler memory scale as well as for visual and auditory movement time. Analysis of the composite scores of neuropsychological performance showed that the cerebellum interferes with the following complex behavioral functions: (i) visuo-spatial organization for a concrete task, a function related to the cerebello-parietal loops' (ii) planning and programming of daily activities, a function related to the cerebello-frontal loops; and (iii) the speed of information processing, a mainly subcortical function.