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Biomedical subjects

E Meyer

Publications and source records attributed to E Meyer.

At least 199 records · Page 11Linked to original sources
PubMed1990

Blanching activities of betamethasone formulations. The effect of dosage form on topical drug availability.

The blanching activities of Betnovate cream, lotion, ointment and scalp application (each containing 0.1% betamethasone (as the 17-valerate] were determined using healthy human subjects over a 32 h period in both the occluded and unoccluded modes. Considering that all four formulation types contained the same label concentration of corticosteroid, it may be presumed that the formulations would show similar topical drug availability: this was, however, not found to be the case. The scalp application demonstrated the highest topical availability in both the occluded and unoccluded modes. The lotion formulation showed the greatest increase in topical availability on occlusion and the ointment formulation was the least sensitive to the effects of occlusion. These differences, due solely to the effects of the vehicle, may have important clinical implications.

Administration, Topical↗
PubMed1989

[Manifestation of AIDS in HIV infected homosexual males with lymphadenopathy syndrome].

26 homosexual men with HIV-infection and lymphadenopathy syndrome were examined between 1982 and 1984 and prospectively observed over a period of 58 months (median, range 53-69 months). 16 (61.5%) developed full blown AIDS within a median period of 41 months (23-63 months). 12 of them died 50 months (median, range 29-67 months) after the first examination. 10 patients showed no symptoms of AIDS after a median observation time of 57 months (54-63 months). A panel of clinical symptoms, signs of concomitant infections, chemical and immunological analyses, including a lymphnode biopsy were correlated to the course of the disease. A decreased proportion of CD4-cells and a lower CD4/CD8 ratio in the lymphnode suspensions at the first examination in patients with disease progression were the only parameter which correlated significantly with the development of AIDS.

AIDS-Related Complex↗
PubMed1989

Accuracy of ultrasonic evaluation of lumbar intervertebral discs by an anterior approach.

The aim of this investigation was to evaluate the diagnostic accuracy of sonography of the lower lumbar intervertebral discs. The results in 50 patients were compared to lumbar myelography. A short description of the sonographic appearance of the normal and pathological lumbar disc is given. The sonographic examination was inconclusive in 18% of the patients because of obesity, meteorism or diminution of the intervertebral disc space. In nearly half of these patients a herniation was found at myelography and confirmed at surgery. The study revealed a sensitivity varying from 0.63 to 0.77. Compared to lumbar myelography and CT scanning we find this too low to support its addition in lumbar disc disease because of non-invasiveness or lack of radiation alone.

Humans↗
PubMed1989

The effect of nimodipine on the evolution of human cerebral infarction studied by PET.

Fourteen patients were studied by positron emission tomography (PET) within 48 h of onset of a hemispheric ischemic stroke and again 7 days later. After the first set of PET scans, the patients were randomized to receive either nimodipine (n = 7) or a carrier solution (n = 7) by intravenous infusion. The infusions were maintained until the end of the second PET studies. CBF, cerebral blood volume (CBV), oxygen extraction ratio (OER), CMRO2, and CMRglc were measured each time. These metabolic and perfusion measurements were performed by standard methods. A surface map of each metabolic and perfusion measurement in the cortical mantle was generated by interpolating between the available slices. The various surface maps representing the physiological characteristics determined in the same or subsequent studies were aligned so that all data sets could be analyzed identically using an array of square regions of interest (ROIs). The functional status of each ROI was recorded at the two intervals following the cerebrovascular accident to characterize the evolution of the infarct, penumbra, and normal brain regions. We presumed the ischemic penumbra to be cortical regions in the proximity of the infarct and perfused at CBF values between 12 and 18 ml/100 g/min on the first PET scan, while densely ischemic regions had CBF of less than 12 nl/100 g/min and normally perfused brain greater than 18 ml/100 g/min. In the densely ischemic zone, CBF increased more in the nimodipine-treated group than in the carrier group. As well, in this region nimodipine reversed the decline in CMRO2 noted in the carrier group, the difference in the changes being significant. In the penumbra zone, comparable trends were noted in OER and CMRO2 but the difference in the changes between the two groups did not reach statistical significance. Changes in CMRglc and CBV were comparable between the two groups in both cortical regions.

Adult↗
PubMed1989

Myoclonus epilepsy and ragged-red fibres (MERRF). 1. A clinical, pathological, biochemical, magnetic resonance spectrographic and positron emission tomographic study.

Thirteen patients, including 6 from one family, with the syndrome of myoclonus epilepsy and ragged-red fibres (MERRF) were studied. There was considerable heterogeneity in the age of onset, severity and associated clinical features. Postmortem studies in 3 patients from the one family showed a particular system degeneration. In addition, the youngest and most severely affected family member showed the pathological changes of Leigh's syndrome. Cortical dysfunction is a prominent clinical feature in MERRF, but postmortem examination failed to reveal cortical abnormalities. Positron emission tomographic studies, however, showed decreased cortical metabolic rates for glucose and oxygen utilization, with normal cortical blood flow and cerebral pH. Analyses of kinetic rate constants for uptake and phosphorylation of the glucose analogue, fluorodeoxyglucose showed decreased hexokinase-mediated phosphorylation: normal K1 and k2 values but reduced k3. Phosphorus magnetic resonance spectroscopy studies suggested a normal cerebral intracellular pH. Biochemical studies on muscle homogenates in 6 patients showed partial deficiencies of the activities of certain mitochondrial enzymes in 4 cases, whereas in 2 patients no abnormality was found. Our data, combined with previous reports, show that MERRF is biochemically and genetically heterogeneous. Our experience, and analysis of the literature, suggests that many cases previously described as the Ramsay Hunt syndrome, as well as other hitherto unclassified system degenerations associated with myoclonus epilepsy, are examples of MERRF. These data permit the formulation of a hypothesis to explain the clinical, biochemical and genetic heterogeneity of MERRF, and its overlap with Leigh's syndrome. We suggest that different biochemical defects of the mitochondrial respiratory chain may cause similar cerebral metabolic effects, as measured by positron emission tomography, resulting in similar phenotypes. Reduced activity of one enzyme, however, may result in different phenotypes, depending on the severity of the defect and its tissue distribution. Moreover, the phenotypic expression of certain biochemical defects may be influenced by randomly occurring factors such as fever, which may increase metabolic demand and result in more deleterious cellular metabolic effects.

Adolescent↗
PubMed1989

Generalized decrease in brain glucose metabolism during fasting in humans studied by PET.

In prolonged fasting, the brain derives a large portion of its oxidative energy from the ketone bodies, beta-hydroxybutyrate and acetoacetate, thereby reducing whole body glucose consumption. Energy substrate utilization differs regionally in the brain of fasting rat, but comparable information has hitherto been unavailable in humans. We used positron emission tomography (PET) to study regional brain glucose and oxygen metabolism, blood flow, and blood volume in four obese subjects before and after a 3-wk total fast. Whole brain glucose utilization fell to 54% of control (postabsorptive) values (P less than 0.002). The whole brain rate constant for glucose tracer phosphorylation fell to 51% of control values (P less than 0.002). Both parameters decreased uniformly throughout the brain. The 2-fluoro-2-deoxy-D-glucose lumped constant decreased from a control value of 0.57 to 0.43 (P less than 0.01). Regional blood-brain barrier transfer coefficients for glucose tracer, regional oxygen utilization, blood flow, and blood volume were unchanged.

Adult↗
PubMed1989

Hemodynamic and metabolic effects of cerebral arteriovenous malformations studied by positron emission tomography.

Seventeen patients with an intracranial arteriovenous malformation were studied with positron emission tomography. Cerebral blood flow, cerebral blood volume, oxygen extraction fraction, and glucose and oxygen metabolism were evaluated in both hemispheres, excluding the area of the malformation itself. Patients were divided into three groups according to the size of their malformation, and results obtained were compared with studies in healthy volunteers. The glucose metabolism was significantly (p less than 0.01) decreased in the ipsilateral hemisphere in all patients. The cerebral blood volume was significantly increased (p less than 0.001) ipsilaterally in the three groups, and contralaterally in patients with medium- and large-sized arteriovenous malformations. The cerebral blood volume to cerebral blood flow ration, an index of vascular mean transit time, was significantly increased (p less than 0.005) ipsilaterally in patients with medium- and large-sized malformations and contralaterally in patients with large ones. Cerebral blood flow, oxygen extraction fraction, and oxygen metabolism were within the normal range bilaterally in all three groups, but oxygen extraction fraction tended to be higher in patients with larger lesions. The lack of significant change in oxygen metabolism suggests that oxygen metabolism in cortical areas remote from the arteriovenous malformation has been maintained by compensatory hemodynamic mechanisms. These data reveal widespread metabolic and hemodynamic consequences of arteriovenous malformations and suggest that they are associated with impairment of glucose metabolism, both in ipsilateral regions remote from the lesion and in the contralateral hemisphere in patients with large lesions.

Adult↗
PubMed1989

Automatic microdisc electrophoresis for urinary protein analysis: a comparison with standard analysis.

Molecular weight related urinary protein analysis is a very valuable diagnostic tool in modern nephrology. However, until recently urine had to be prepared for analysis by several procedures including concentration. Using a new micro-method it was demonstrated that the clinical significance of urinary disc-electrophoresis is much higher than with former systems. Thus, the use of microdisc electrophoresis (Phast system) is recommended for urinary protein analysis in the future.

Autoanalysis↗
PubMed1989

[Traumatic myopia due to ciliary body detachment].

A 20-year-old man developed myopia immediately after blunt trauma to the eye. The main finding was a shallow anterior chamber. Ultrasonography revealed anterior displacement of the iris lens diaphragm without change in lens thickness or axial length of the eye. After 1 week intraocular pressure decreased to a very low level, and edema of the optic disc and macula developed. Since hypotony and shallowness of the anterior chamber persisted for many months, we assume the cause to be detachment of the ciliary body. This is an uncommon mechanism for traumatic myopia, spasm of the ciliary body being more common.

Adult↗
PubMed1989

[Unusual manifestations of echinococcosis].

Hydatid disease is mostly located in the liver. It then has a characteristic appearance allowing a definite diagnosis by means of ultrasound and/or CT examination. Isolated extrahepatic infestation is much less common. We report a number of cases of hydatid cysts in the tail of the pancreas, the adrenal, the spleen, and in bones and muscles. With reference to these examples we discuss the potential usefulness of radiological examination for the diagnosis and also its limitations and the pitfalls that may be encountered.

Adult↗
PubMed1989

[Comparison of automated micro-disc electrophoresis for the analysis of urine proteins with a conventional system].

Recently a new system for analyzing urinary proteins due to their molecular weight distribution has been introduced. The whole system is automatically driven and uses a silver staining. Due to the small amount of protein necessary for analysis native urine samples can be used. The data presented here show that the automatic micro-disc-electrophoresis (Phast-system) is very useful for any routine testing due to the quick (2 hours) and easily obtainable results with a very high reproducibility. The clinical relevance of urinary protein analysis seems to be much higher using this system.

Electrophoresis, Disc↗
PubMed1989

Simultaneous correction for tracer arrival delay and dispersion in CBF measurements by the H215O autoradiographic method and dynamic PET.

The difference in tracer arrival times between the radial artery and the brain following i.v. injection of 15O-labeled water plus the difference in dispersion of the tracer bolus between these two sites have to be accounted for in order to quantify cerebral blood flow by the autoradiographic approach and positron emission tomography (PET). We describe a method that simultaneously corrects for these two effects by means of a four-parameter fit to the dynamically acquired data. Unlike with other methods, where the two corrections are performed sequentially, no additional measurement of the dispersion time constant is required. We have validated and tested the method by means of simulations and application to data from six human studies. The mean dispersion time constant of 4.0 +/- 1.2 sec, estimated by the new method for the six studies, is in fair agreement with estimates of 3 to 5 sec derived from cardiac PET.

Autoradiography↗