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Biomedical subjects

J Lutz

Publications and source records attributed to J Lutz.

At least 109 records · Page 6Linked to original sources
PubMed1986

[Distribution in the body and functional effects of fluorocarbons used as oxygen carriers].

After the infusion of perfluorochemicals (PFC) given as artificial blood gas carriers a temporary storage of the inert substances in tissues of the organism occurs. The time course of this effect was investigated in longitudinal studies in the rat and compared with changes of different organ functions, expressed as changes in the levels of serum enzymes, in the elimination of indocyanine green and in the duration of pentobarbital sleeping time which are dependent on the excretory and detoxifying functions of the liver. The intensity of the elimination of colloidal carbon was used as a measure of the activity of the reticulo endothelial system. Observation of the time course of these functional tests in comparison with the storage of PFC and changes in organ weight of liver and spleen showed that diminutions in function had a distinctly shorter duration than PFC storage, whereas the longest lasting effects were seen in organ weight increase is regarded as a compensatory effect that is associated without functional loss at the maximum of its appearance.

Animals↗
PubMed1986

Bone mineral, serum calcium, and dietary intakes of mother/daughter pairs.

Data on factors potentially responsible for familial differences in the incidence of postmenopausal osteoporosis were obtained for 26 mother/daughter pairs. The factors were: bone mineral content of the radius (BMC); bone mineral content to bone width ratio (BMC/W); serum ionized (Ca++), ultrafiltrable (UF-Ca) and total calcium (T-Ca), ultrafiltrable and total magnesium, and 25-hydroxyvitamin D; and 7-day dietary intakes of selected nutrients. The BMC, BMC/W, and serum calcium fractions of the mothers were significantly correlated with those of the daughters. Although the BMC of the mothers was related to their caloric intakes, the interrelations between BMC and other variables of each group were not significant. Estimates of heritability, a measure of familial resemblance, were 0.724 for BMC; 0.570 for BMC/W; and 0.932, 0.916, and 0.668 for Ca++, UF-Ca, and T-Ca, respectively. Mothers with low BMC tended to have daughters with low BMC; there were also familial resemblances in serum calcium fractions.

Adult↗
PubMed1984

Perfluorochemicals as a treatment of decompression sickness in rats.

Perfluorodecalin and perfluorotripropylamine which have N2 solubility coefficients of 28.4 and 35.7 ml/dl, respectively, were used for treatment of decompression sickness in this study. Rats with chronically implanted venous catheters were held for 30 min at 800 kPa (7 bar, 8 ATA) by introducing compressed air into a chamber in which they were kept; a relatively short period of decompression followed (200 kPa/min). Immediately thereafter injections of the perfluorochemicals (PFCs) in a dose of 10 g/kg were given, controls received saline in the same volume or remained without treatment. An observation period of 2 h followed; after this time the incidence of death amongst the experimental animals (as compared with controls tested by the chi 2-test) showed that PFC treatment increased the likelihood of survival. Probit-log time relationship for the incidence of death also revealed a significant decrease in lethality in treated rats 30 min after the end of decompression. The mean lethal times Lt50 differed significantly, too. A still greater effect might be expected if the PFC emulsion were deprived of its normal nitrogen content by oxygenation before administration. Under the conditions of the present experiments PFCs produced an improvement in N2 exhalation at least in terms of the survival rate after compression followed by a very short decompression time.

Animals↗
PubMed1984

Calcium balance and acid-base status of women as affected by increased protein intake and by sodium bicarbonate ingestion.

Six women, aged 38 to 62 yr, participated in a 40-day metabolic study to investigate the effect of level of protein intake and of sodium bicarbonate ingestion on urinary calcium, net calcium balance, net renal acid excretion, and arterialized venous blood pH and bicarbonate ion concentration. The diet contained 44 g protein during the first 16 days and 102 g during the remaining 24 days. During the last 10 days of the study, 5.85 g of sodium bicarbonate was ingested concomitantly with the higher protein intake. Calcium, phosphorus, and magnesium intakes were held constant at 500, 900, and 300 mg, respectively. The increase in protein intake significantly increased urinary calcium and net renal acid excretion and the mean net calcium balance became negative. The ingestion of sodium bicarbonate alkalinized the urine and reversed the increase in urinary calcium associated with the higher protein intake; the mean net calcium balance became positive. The arterialized venous blood pH and bicarbonate ion concentrations were not significantly affected by dietary treatments. The results suggest that the ingestion of a small amount of sodium bicarbonate may be an effective way to increase calcium retention in women with protein-induced hypercalciuria.

Acid-Base Equilibrium↗
PubMed1984

Recovery from pentobarbital-induced sleep after administration of perfluorinated blood substitutes.

The sleeping time after administration of pentobarbital at 30 mg/kg body weight (BW) was used in rats as a simple, noninvasive screening test of liver function. In controls, repeated tests showed no shortening of the time and thus no signs of enzyme induction. After the injection of perfluorochemicals in the form of Fluosol-DA at doses of 4.4 and 10 g/kg BW, significant prolongations occurred that, in case of the higher dose, lasted only until the fourth day. The formerly observed liver cell proliferation thus seems to have a compensating effect, since the detoxifying function was restored when the maximum of increased liver mass was reached.

Animals↗
PubMed1983

Decreased release of lysosomal enzymes from peripheral leukocytes of patients with atopic dermatitis.

Peripheral blood leukocytes from fifteen patients with atopic dermatitis and ten normal nonatopic volunteers were incubated with various stimuli in vitro, and the release of the lysosomal beta-glucuronidase into the supernatant was measured. beta-Glucuronidase release was significantly reduced in patients with severe atopic dermatitis after stimulation with aggregated IgG, horse antihuman lymphocyte globulin (ALG), zymosan, and yeast-activated serum. There was an indirect correlation (r = -0.83) between aggregated IgG-induced beta-glucuronidase release and the intensity of clinical symptoms; however, there was no correlation with serum IgE levels. The enzyme release measured was not caused by cellular lysis, except for high concentrations of antilymphocyte globulin, as determined by lactic dehydrogenase (LDH) activity in the supernatant. It is concluded that lysosomal enzyme release defects might be involved in the well-known decreased resistance to infections in patients with atopic dermatitis.

Adolescent↗
PubMed1983

Hemodynamic consequences of severe pancreatitis.

Fifteen patients with severe pancreatitis underwent cardiovascular monitoring in an intensive care unit. The principal findings were a high cardiac index and a decrease in systemic vascular resistance. A significant negative correlation was found to exist between these two parameters (p less than 0.001). Severe pancreatitis apparently results in hemodynamic changes similar to those observed in sepsis. The mechanisms responsible for these observations are not known, although circulating vasoactive compounds resulting from pancreatic necrosis remain a strong possibility. Despite demonstrating a significant decrease in left ventricular stroke work index and an abnormal elevation in pulmonary capillary wedge pressure, the existence of a myocardial depressant factor could not be conclusively proved from these data.

Adult↗
PubMed1983

Effect of a first-trial cue on spontaneous recovery by moderately mentally retarded adults.

The effect of a distinctive first-trial cue on the degree of spontaneous recovery of moderately mentally retarded adults was investigated. The group given the cue showed more recovery of the operant response than did control groups for disinhibition on unextinguished discriminative stimulus. The group receiving the conventional procedure to produce spontaneous recovery, however, displayed significantly greater recovery than did any of the other groups. There was thus limited support for the hypothesis that cues associated with the first trial of a training session have greater significance for learners than do other cues.

Adolescent↗
PubMed1983

Studies on RES function in rats and mice after different doses of fluosol.

Changes in the activity of the RES were examined by: 1. the clearance of colloidal carbon in rats (expressed by the elimination constant K); 2. determination of the tolerance of endotoxin in mice and that of gram negative enterobacteria in rats (expressed in both methods by the lethality); 3. evaluation of the temporal course of weight and the amount of PFCs taken up by two chief organs of the RES--liver and spleen. The results revealed a distinct temporal action of PFCs on the function of the RES which was terminated before cellular responses ended.

Animals↗
PubMed1982

Variation in toxicity of Escherichia coli endotoxin after treatment with perfluorated blood substitutes in mice.

Treatment with perfluorochemicals (PFCs) shows a temporary decrease in phagocytic activity as measured by carbon clearance. The importance of this effect was checked by investigating the lethality after administrations of PFCs and Escherichia coli endotoxin in mice (NMRI strain). When endotoxin was applied simultaneously with PFC (4.4 g/kg body weight, a dose which could compensate a loss of a third of blood volume) the lethality rose 7.8-fold. If the challenge with endotoxin occurred later than 12 h after PFC injection, the increase of lethality was of a distinctly smaller degree. By means of pretreatment with various substances the increased lethality of endotoxin could be shifted in the direction of the control. C 48/80, aristolochic acid, and hydrocortisone were effective in this respect; zymosan remained ineffective. The results show a weakened resistance towards toxins from the intestinal tract under PFC administration; precaution in this regard should be taken during therapy with PFC.

Animals↗
PubMed1981

Calcium metabolism in postmenopausal and osteoporotic women consuming two levels of dietary protein.

Eight postmenopausal women, four with osteoporosis diagnosed by their physician and four without, participated in a metabolic study to investigate the effects of level of protein intake on calcium metabolism; renal acid excretion; plasma total and ultrafiltrable calcium; 1,25-dihydroxyvitamin D; and serum immunoreactive parathyroid hormone. Radial bone mineral content was evaluated. Protein intake was 50 g/day during the 1st 15-day experimental period and 110 g during the 2nd period. Calcium, magnesium, and phosphorus intakes were held constant at 713, 323, and 1078 mg/day. The increase in protein intake significantly increased net calcium absorption and urinary calcium. A calcium intake of 713 mg was not sufficient for calcium balance for most of the women studied. The calciuretic effect of increased protein intake was associated with increased renal acid excretion. None of the plasma and serum measurements mentioned above was significantly affected by the level of protein intake except for a slight increase in plasma total calcium. No significant differences in radial bone mineral content or in any of the other measurements were observed between the osteoporotic and the normal group of women.

Absorption↗
PubMed1981

The effect of a dual level word list on schizophrenic free recall.

Three-category dual level, three-category single level, and six-category single level word lists were presented for single trial free recall to 18 normals and 18 schizophrenics in remission. Schizophrenic recall was significantly inferior to that of normals across all three lists. Normals produced more clustering than schizophrenics, but the difference was not significant. Across both groups, the three-category dual level list produced significantly more recall than the other two lists. The three-category dual level list and the three-category single level list produced significantly more clustering than the six-category single level list. The results were interpreted as indicating that the schizophrenic's memory structure is similar to that of normals. It is suggested that the schizophrenic's recall deficit is not due to a lack of structure, or an inappropriate structure, but rather to a lessened tendency to utilize such structure.

Adolescent↗
PubMed1980

Effects of potential blood substitutes (perfluorochemicals) on rat liver and spleen.

The effect of an emulsion of perfluorochemicals (PFC) (7 parts perfluorodecalin and 3 parts perfluorotripropylamine, 4.4 g PFC/kg body weight) on organ function was determined. Whereas maximal storage of PFC was reached in the spleen as early as 12 h after PFC administration, the liver attained a maximal PFC content only after 2 days. The increase in weight also differed: a maximum occurred in the spleen on the 4th day, in the liver on the 8th day. Indocyanine green (ICG) clearance showed a small decrease, statistically significant after 12 and 24 h. Colloidal carbon clearance, used as a measure of the function of the reticuloendothelial system (RES) decreased instantly after PFC to less than half the control value; after full recovery a second decrease was seen which lasted till the 4th day after PFC. Pretreatment with C 48/80 or with increasing doses of E. coli endotoxin could largely obviate the depressive effect of PFC-loading on carbon clearance. Serum transaminases increased to about twice the control levels but were normal by the 2nd day, and thereafter. Alkaline phosphatase showed a 2.5 fold increase but returned to control level after the 2nd day. It is concluded that while a severe disturbance of liver function did not occur, the reduction in the capacity of the RES can become a serious factor in the defence against a simultaneously appearing infection if not compensated by activating the RES.

Animals↗