Resting and exercise electrocardiographic abnormalities associated with sex hormone use in women. The Lipid Research Clinics Program Prevalence Study

Prevalence rates for resting and exercise electrocardiographic abnormalities were determined according to the use or nonuse of oral contraceptives and exogenous estrogens in 1,919 women participants from 10 defined North American study populations of the Lipid Research Clinics Program. Among women 30-49 years of age, no significant differences in the prevalence of resting electrocardiographic abnormalities between oral contraceptive users and nonusers were seen after adjustment for age, blood pressure, cigarette smoking, alcohol, and obesity. Abnormal graded exercise electrocardiograms, however, were more prevalent among the oral contraceptive users (odds ratio = 2.7, p less than 0.05). Among women 50 years and older, a significant deficit of abnormal Q waves on resting electrocardiogram and nonsignificant excess of abnormal S-T segment responses to exercise were noted in estrogen users compared with nonusers. Possible sources of bias and the pathophysiologic implications of these findings are discussed.     

Regional cerebral glucose metabolism and postmortem pathology in Alzheimer’s disease

In four patients with an antemortem diagnosis of probable Alzheimer's disease (AD) regional cerebral glucose metabolism (rCMRGl) was studied prospectively by positron emission tomography (PET) and compared with postmortem semiquantitative neuropathology. The interval between the last PET study and autopsy was 1.3±0.8 years. In comparison with age-matched controls, the AD patients showed predominant temporoparietal hypometabolism spreading to other cortical and subcortical regions during serial PET scans. All patients had neuropathological findings typical for AD. There was a significant relationship between rCMRGl and density of senile plaques (SP) in one patient (τ_b = –0.86, P < 0.05). SP were distributed quite homogeneously in all regions examined. Neurofibrillary tangles (NFT) were concentrated focally in the hippocampus-amygdala-entorhinal complex. In the context of widespread developing cortical hypometabolism, the predilection of NFT for involvement in limbic areas suggests a disruption of projection neurons as the pathogenetic process of cortical dysfunction. Received: 22 May 1995 / Revised, accepted: 13 October 1995     

Positive donor and negative recipient cytomegalovirus status is a detrimental factor for long-term renal allograft survival

Abstract In 524 allogeneic cadaveric kidney transplants, the impact of cytomegalovirus (CMV) donor/recipient status on the incidence of CMV infection, CMV disease, early and long-term graft, and patient survival have been analyzed with respect to rejection episodes. Most CMV infections (59%) and diseases (17%) were found in CMV-negative recipients of CMV-positive kidneys. The 1-year function rate of CMV-positive kidneys (75%) dropped about 10% below that of CMV-negative organs (85%), and in the case of CMV-negative recipients an additional graft loss of more than 10% happened within the 4th and 5th years (5-year graft survival pos./neg.: 56%). This detrimental effect was exaggerated if it coincided with antibody-treated rejection episodes.     

Evaluation of 75Br-labelled butyrophenone neuroleptics for imaging cerebral dopaminergic receptor areas using positron emission tomography

A comparative evaluation of three radiobrominated butyrophenone neuroleptics--bromospiperone (BSP), brombenperidol (BBP), and bromperidol (BP)--was made to assess the applicability of these compounds as radiopharmaceuticals labelled with the positron emitter 75Br (T1/2 = 1.6 h) for mapping cerebral dopaminergic receptor areas non-invasively with positron emission tomography (PET). BSP, BBP, and BP were prepared in high specific activities with high radiochemical yields, using electrophilic reactions with no-carrier-added 77Br- or 75Br-. Screening tests in rats using 77Br-labelled compounds indicated D2-specific localization for 77Br-BSP and 77Br-BBP, whereas PET experiments in baboons showed that only 75Br-BSP preferentially localized in cerebral tissues rich in dopaminergic receptors. The data suggest an inverse relationship between cerebral uptake and receptor-specific localization, which was attributed to a complicated interplay between the D2 receptor binding affinity, lipophilicity, % ionization and molecular weight of the radioligand, and the binding capacity of the cerebral tissues. 75Br-BSP gave a striatum-to-cerebellum ratio of 3 in baboon brain 5 h post-injection, which allowed visualization of dopaminergic-receptor-containing areas of the living brain using PET.     

Measurement of blood-brain hexose transport with dynamic PET: comparison of [18F]2-fluoro-2-deoxyglucose and [11C]O-methylglucose

Blood-to-tissue transport of [18F]2-fluoro-2-deoxyglucose (FDG) and [11C]O-methylglucose (CMG) was compared by dynamic positron emission tomography in four patients with recent ischemic infarcts and in three patients with intracerebral tumors. Local blood volume, tracer transport from tissue to blood, and FDG phosphorylation rates were also determined. A regional analysis of parametric images showed a close correlation of FDG and CMG transport rate constants in pathological tissue. Transport rates of FDG and CMG showed correspondingly less asymmetric remote effects than FDG phosphorylation rates. Transport rate constants were consistently higher for FDG than for CMG in pathological and normal tissue, in accordance with the higher affinity of carrier enzymes to FDG. There was a significant correlation between fitted regional blood volume values and correspondence of average absolute values with both tracers. It is concluded that dynamic FDG PET for measurement of cerebral glucose metabolism is also useful to measure alterations of hexose transport and local blood volume in pathological tissue.     

Impairment of language is related to left parieto-temporal glucose metabolism in aphasic stroke patients

Summary Twenty-six aphasic patients who had an ischaemic infarct in the territory of the left middle cerebral artery (MCA) were investigated. Cranial computed tomography (CT) showed various lesion sites: infarcts restricted to cortical structures in 12 patients, combined cortical and subcortical infarcts in 7 and isolated subcortical infarcts sparing the left cortex in another 7 cases. ¹⁸F-2-fluoro-2-deoxyglucose positron emission tomography revealed remote hypometabolism of the left convexity cortex and of the left basal ganglia, which was extended further than the morphological infarct zone in all cases. Types and degrees of aphasia were classified using the Aachener Aphasie Test (AAT): 10 patients had global aphasia, 2 Broca's, 5 Wernicke's, and 5 amnesic aphasia. Four patients suffered from minimal or residual aphasic symptoms. The AAT results were compared with the regional cerebral metabolic rates of glucose of the left hemisphere. Irrespective of the infarct location all five AAT subtests (Token test, repetition, written language, confrontation naming, auditory and reading comprehension) were closely correlated among each other and with left parieto-temporal metabolic rates, whereas left frontal and left basal ganglia metabolism showed no significant correlation. The close relation between left temporo-parietal functional activity and all five AAT subtests suggests that the different aspects of aphasia tested by AAT can be related to a common disorder of language processing in those areas.