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Biomedical subjects

E Hirsch

Publications and source records attributed to E Hirsch.

At least 217 records · Page 12Linked to original sources

Dopaminergic and cholinergic lesions in progressive supranuclear palsy.

In 9 patients with progressive supranuclear palsy and in 27 controls, dopamine and homovanillic acid concentrations, choline acetyltransferase (CAT) activity, and the number of [3H]spiperone and [3H]quinuclidinyl benzilate binding sites were measured post mortem in the striatum (caudate nucleus, putamen, and nucleus accumbens), substantia innominata, and frontal cortex. Dopamine and homovanillic acid concentrations were reduced in the caudate nucleus and putamen but not in the nucleus accumbens or frontal cortex, indicating that the nigrostriatal dopaminergic system is lesioned in patients with progressive supranuclear palsy (as in those with Parkinson's disease) but not the mesocortical and mesolimbic dopaminergic systems, which are lesioned in parkinsonian patients. CAT activity and [3H]spiperone binding decreased in parallel fashion in all the structures. In the striatum, this suggests that the cholinergic neurons, which are target cells of the nigrostriatal system, also degenerate in this disease. This might explain the decrease in the number of dopamine receptors as well as the inefficacy of levodopa or anticholinergic therapy in these patients. The decrease in CAT activity in the substantia innominata and the frontal cortex indicates that the innominatocortical cholinergic system is lesioned in patients with progressive supranuclear palsy and may play a role in the intellectual deterioration observed. This lesion is also found in demented patients with Alzheimer's and Parkinson's diseases.

Aged↗

Decrease of valproate-induced hyperammonemia in normal subjects by lipid ingestion.

Sodium valproate (VPA), a branched short-chain fatty acid, always causes a hyperammonemia of renal origin in fasting man. The intake of medium-length, straight-chain fatty acids abolishes the VPA-induced hyperammonemia, and VPA free fraction increases concomitantly. Accordingly, fatty acids could be useful in preventing and treating hyperammonemia-accompanied stuporous states which are complications of VPA medication.

Ammonia↗

Survival from sepsis. The significance of altered protein metabolism regulated by proteolysis inducing factor, the circulating cleavage product of interleukin-1.

Amino acid (AA) arterial blood plasma concentrations, K1 (peripheral production + infusion rates), and central plasma clearance rates (K1 divided by arterial concentration) (CPCR-AA) were measured in 70 seriously septic patients. All of these people were in the "hyperdynamic" state at the time of observation. Thirty-seven recovered and 33 died. In addition, 10 noninfected, nontraumatized patients about to undergo laparotomy were studied. In 31 patients receiving parenteral alimentation, CPCR-AA was 326 +/- 38 in survivors and 160 +/- 17 ml/M2/min in the deaths (p less than 0.005). In 58 patients studied, while fasted with no intravenous amino acid infusion, values for CPCR-AA were: survivors 202 +/- 22 (28) and deaths 112 +/- 16 (30) ml/M2/min (p less than 0.002). The CPCR-AA in 10 noninfected patients was only 68 +/- 11 ml/M2/min. CPCR-AA in 19 patients correlated with hepatic protein synthetic rates in liver biopsies obtained simultaneously (r = 0.658, p less than 0.01), which shows that CPCR-AA is an indicator of visceral protein synthesis. To study the regulation of amino acid metabolism by synthesis. To study the regulation of amino acid metabolism by proteolysis inducing factor (PIF), the proteolysis inducing activity (PIA) of the plasma fraction (0-50,000 D) was measured 55 times in conjunction with metabolic studies. No significant differences existed in PIA between survivors and deaths. However, in those patients who recovered, PIA was significantly correlated to both peripheral amino acid production (r = 0.773, p less than 0.001) and to CPCR-AA (r = 0.721, p less than 0.001). This observation demonstrates the presence of one or more circulating agents affecting amino acid flux. PIA measured simultaneously in vivo correlated with in vitro protein synthetic rate in incubated liver biopsies (r = 0.653, p less than 0.01). PIF (4,000 D), isolated by chromatography, in patients without amino acid infusion was 35 +/- 3% in survivors and 33 +/- 6% in deaths (N.S.) and only 9 +/- 3% over control in noninfected patients. In patients who recovered, PIF titre was strongly correlated with peripheral amino acid production (r = 0.798, p less than 0.001) and with CPCR-AA (r = 0.835, p less than 0.001). However, values for patients who later died were significantly less for a given PIF titre. Thus, it is concluded that survival from sepsis is, in part, dependent on a significantly elevated CPCR-AA and hepatic protein synthesis, both of which appear to be related to the blood plasma PIF titre.

Amino Acids↗

Exchange of amino acids by muscle and liver in sepsis.

The amino acid "central fractional clearance rate" (CFCR), the ratio of the rate of amino acid entry into the extracellular pool to the size of the pool, is a measure of amino acid uptake and clearance by liver and other visceral tissues. In nine normal postabsorptive persons, the mean CFCR was 5%, compared with 21% in 31 seriously infected patients. For comparative purposes, biopsy specimens of liver and muscle were obtained for incubation. In infected patients, the rate of hepatic incorporation of tyrosine into protein was three times that in noninfected patients and correlated well with the CFCR. There was no significant difference in hepatic tyrosine oxidation. In muscle from infected patients, net protein degradation was six times that in noninfected patients. Incubated tissues from rats behaved similarly. Thus, accelerated transfer of amino acid from muscle to viscera for protein synthesis occurs in humans with sepsis, as it does in animals. The CFCR demonstrated the importance to survival of visceral amino acid uptake; it was 35% in surviving patients, and only 19% in those who died.

Amino Acids↗

Physician turnover in eight New England prepaid group practices: an analysis.

The objectives of this questionnaire study of all primary care physicians (N = 154) who had ever worked in eight New England prepaid group practices (PGPs) include 1) calculation of turnover rates, 2) comparison of those who stayed in (stayers) versus those who left (leavers) the PGPs, and 3) description of reasons given for leaving. An annual turnover rate of 3.9 to 6.3 per cent, depending upon the measure, was within the range reported by others. Factors associated with stayer-leaver status were experiences before and during the physician's PGP tenure. Leavers reported pre-PGP experience in fee-for-service, hospital-based, and academic positions, and while in the PGPs, they reported constraints on autonomy, independence, and professional development. Leavers reported higher incomes and longer working hours in their new practices. They cited the potential for greater autonomy as the reason for leaving. The findings and study limitations are discussed.

Attitude of Health Personnel↗

Necrotizing fasciitis following diagnostic laparoscopy.

A case of necrotizing fasciitis of the abdominal wall, following an uneventful diagnostic laparoscopy in an elderly, diabetic patient is reported. The patient recovered after extensive surgical debridement and antibiotic therapy. The possibility of a lethal infection in patients with impaired immune defense mechanisms is discussed.

Abdominal Muscles↗

Sex differences in the effects of voluntary activity on sucrose-induced obesity.

Sedentary, adult rats of both sexes fed Purina chow and a 32% sucrose solution overate, gained excess weight and had higher Lee Indexes of obesity than control animals fed only Purina chow. The magnitude of these effects was similar in the males and females. Animals of both sexes fed the sucrose diet showed a slower rate of weight loss during food deprivation than the chow controls. Access to an activity wheel led to a reduction in caloric intake and the elimination of obesity in male rats. In the chow fed male rats activity led to a smaller, transient suppression in caloric intake and a slightly lower level of body weight than the sedentary chow controls. Access to activity did not affect body weight in the female rats in either dietary condition. Rather, both active groups of female rats appeared to compensate for the energy cost of voluntary activity by a small increase in food consumption. Long-term exposure to activity was associated with more rapid weight loss during food deprivation in both males and females. These data reveal that high levels of activity and obesity can co-exist when normal female rats are fed a palatable diet but that activity eliminates this form of obesity in the male rat.

Animals↗

Overeating, dietary selection patterns and sucrose intake in growing rats.

Weaning rats were allowed access to food for either 5 hours or 24 hours per day. Within each food availability condition one group had access to a complete diet and one group had access to the complete diet and a 32% solution of sucrose. Caloric intake and rates of growth were considerably higher in the 24 hour access group. The availability of sucrose led to a small (10--15%) but consistent elevation in caloric intake in the ad lib condition but did not influence growth in either food availability condition. Absolute levels of sucrose intake and the proportion of calories taken from the sucrose solution were consistently higher in the ad lib group and increased with increases in body size for both groups. Dilution of the chow component or the sucrose component of the diet did not alter dietary selection patterns in either food availability condition. It appears that access to a palatable carbohydrate solution can lead to overeating in the rat but these solutions do not induce the rat to select imbalanced diets that compromise growth.

Age Factors↗

Effect of limited access to sucrose on overeating and patterns of feeding.

Four groups of adult rats, housed on a 12-12, light-dark cycle, were allowed access to a nutritionally complete diet and water. Three of these groups were also offered a 32% solution of sucrose. The sucrose was available for either the 24-hour period, the 12 hours of light or the 12 hours of dark. Access to sucrose led to overeating and excessive weight gain. These effects were more pronounced when the sucrose was available for the 24-hour period or during the dark. Limited access to sucrose produced a reversal of the rat's usual circadian pattern of feeding when the sucrose was available during the light and increased the rat's nocturnal hyperphagia when it was available during the dark. Sucrose intake and the proportion of calories taken from sucrose were higher in the 24-hour access group and the dark access group than the light access group. Access to sucrose did not induce a pattern of dietary selection that compromised growth or health. It appears that access to a palatable carbohydrate solution can lead to overeating and major changes in the circadian organization of feeding behavior. These data emphasize the potent role that external factors can play in the control of ingestive behavior.

Animals↗

[Investigations into mucous membrane compatibility using the Endorfer Jod-Thermalsole treatment of the conjunctivae of rabbits (author's transl)].

The conjunctivae of nine rabbits of the same breed were used to compare the local compatibility of the Endorfer Jod-Thermalsole with that of a physiological NaCl solution. The neuroleptanalgesics were administered using perfusion techniques. The reddening thus caused was used to measure the degree of inflammation. The reddening was assessed subjectively according to a points system and then photographed under the same conditions for greater objectivity. The slides are archived in the Institute for Balneology and Climatology of the University of Munich. After administering the Endorfer Jod-Thermalsole to the mucous membranes for 30 and 60 minutes there was no difference in compatibility as compares to a physiological NaCl solution. No appreciable irritation occurred.

Animals↗

[On the clinical picture of Purtscher's disease (author's transl)].

Case reports on patients suffering from traumatic retinal angiopathy (Purtscher's disease) and fat embolism in acute pancreatitis, respectively. Differential diagnostic comparison of the most important clinical findings with the aid of ophthalmoscopy, fluorescein angiography, computer perimetry and simultaneous fundus photography.

Adult↗

An analysis of the components of the pulmonary shunt equation: significance of the alveolar-arterial oxygen gradient, arterio-venous oxygen content difference, and mixed venous oxygen pressure.

Pulmonary shunt calculated by the Berggren method is commonly used as an indicator of pulmonary function. Although there is usually a good correlation between the shunt and the A-aDO2, other physiologic parameters involved in the shunt equation may significantly alter pulmonary function. The purpose of this study is to show the contribution of the PVO2 and a--v diff to the shunt equation. Data from eight selected patients with A--aDo2 values ranging from 300 to 395 torr and calculated shunts ranging from 6 to 35% were selected for this purpose. In patients with significant changes in PVO2 and a--v diff, the A--aDO2 is more reliable as an indicator of pulmonary function than is the calculated shunt.

Humans↗