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Biomedical subjects

P Roth

Publications and source records attributed to P Roth.

At least 163 records · Page 9Linked to original sources
PubMed1980

Platelet-membrane fatty acids, platelet aggregation, and thromboxane formation during a mackerel diet.

Eicosapentaenoic acid (C20:5 omega 3), which is present in high concentration in certain salt-water fish, may reduce the incidence of cardiovascular disease in Greenland Eskimos by reducing platelet aggregation and adhesion. Changes in platelet and plasma fatty acids, platelet aggregation, and thromboxane (TX) formation were studied in 7 healthy White men who had been on a mackerel diet for 1 week. Platelet aggregation had TX synthesis after low-dose collagen stimulation in platelet-rich plasma were reduced. This could be due to the marked change of the ratio of C20:5 to arachidonic acid (C20:4 omega 6) in platelet membranes. When the men were on the mackerel diet, their C20:5 level in platelet membranes and in plasma increased and that of C20:4 dropped. Both fatty acids were released during platelet aggregation. The reduction in the amount of C20:4 liberated and/or a diminished conversion of C20:4 to TXA2 by competitive inhibition of the platelet cyclo-oxygenase by the released C20:5 could be responsible for the decreased platelet aggregation.

Animals↗
PubMed1980

[Synthesis and properties of carrier-bound enzymes. XI. Fixation of trypsin to various cellulose derivatives. Comparison of the kinetic properties of the trypsin-cellulose complexes].

Trypsin was covalently bound to carboxymethyl cellulose (CMC) azide and dialdehyde cellulose (DAC). Thereby the maximum protein binding capacity of CMC (420 mg/g) is 28 times that of DAC (15 mg/g). The high protein binding capacity of CMC is explained by a change in structure, i. e. by surface increase of the original cellulose powder due to chemical modification. By activation with sodium bisulfite solution we achieved an increase in protein binding capacity of DAC to values similar to those of CMC. The value of Vmax for all trypsin-DAC-complexes is about 38% of that of the free enzyme. With increasing protein content (from 1 to 12 mg/g) Km rises continuously from 0,14 to 0.36 mM. An analogous kinetic behaviour was found for trypsin-CMC-complexes only up to a protein content of 100 mg/g. Offering larger quantities of trypsin the enzyme is immobilized in an active form, so that all trypsin-CMC-complexes from 100 mg/g upwards have the same specific activity and the same Km; on the other hand the value of Vmax for the immobilized trypsin decreases to 17% of that for the free enzyme.

Cellulose↗
PubMed1979

[Selective aplasia of neutrophils: auto-immune origin].

Autoimmunity is a recognized factor in pure red cell aplasia and in some cases of aplastic anemia, but not in agranulocytosis. The case reported here demonstrated that pure neutrophilic aplasia of autoimmune origin may exist in man. A 75-year-old male is described who presented with complete agranulocytosis and absence of neutrophilic precursors in the bone marrow without thrombocytopenia or anemia. After 6 weeks, remission was induced by immunosuppressive treatment and 22 months later the patient is doing well without therapy. The absence of known cases of agranulocytosis, a good response to immunosuppressive therapy, and the demonstrated fact that the patient's peripheral blood mononuclear cells inhibit the growth of granulocytic colonies of normal human marrow in vitro allow the conclusion that this patient had pure neutropenic aplasia, probably due to autoimmune phenomena.

Aged↗
PubMed1979

Application of ferrokinetic investigation for differential diagnosis in bone marrow hypoplasia and their clinical relevance.

In this study, erythropoietic activity of bone marrow has been evaluated by ferrokinetics. For that purpose, the data of radioiron disappearance from plasma and its ultimate incorporation in red blood cells after the injection of about 10 muCi of 59Fe tagged autologous plasma, were analysed and fitted to the sum of three exponentials, using a non-linear least square SAAM-25 program on UNIVAC-1108 computer. A function representing time-activity relationship, was constructed. The functional physiological model of iron metabolism, proposed by Cavill and Ricketts, was used to calculate various ferrokinetic parameters in terms of coefficients and exponents of the time-activity function. After identifying the parameters that could be used as indices of erythropoietic activity of bone marrow, the study was repeated in six patients after they had undergone myelostimulative therapy. A distinct correlation was found between ferrokinetic observations and clinical and biochemical findings. It has been demonstrated that in histologically diagnosed cases with bone marrow hypoplasia, a further differentiation between pure aplasia and those with hypoplasia together with ineffective erythropoiesis was possible. This discrimination which is clinically very important, is only possible by means of kinetic investigations.

Adult↗
PubMed1979

Double-blind evaluation of the safety and hypnotic efficacy of temazepam in insomniac outpatients.

1 Efficacy of temazepam 30 mg at night as an hypnotic was compared with placebo in 55 out-patients with insomnia. The study was double blind, with two comparable groups of patients established by random allocation. Placebo and medication were taken for 4 consecutive nights and sleep questionnaires were completed the next day. 2 Patients reported that temazepam was more effective than placebo in reducing the difficulty of falling asleep and improving sleep maintenance. They also indicated that they awoke less and were less disturbed by early morning awakenings reported as a group that the average duration of sleep was increased by 1 hour. 3 The patients receiving temazepam reported being more alert in the morning and for the entire day than with placebo.

Anti-Anxiety Agents↗
PubMed1979

Hereditary myeloperoxidase deficiency.

The functional properties of granulocytes in a diabetic patient deficient in myeloperoxidase (MPO) were compared with those of granulocytes in healthy subjects. The granulocytes of this patient had normal phagocytic activity. The microbicidal activity of the granulocytes was partially diminished with regard to Staphylococcus aureus and was almost nil with regard to Candida albicans. Fungicidal activity of normal granulocytes was shown to be impaired during the in vitro artificial hyperglycemic condition. The relationship among diabetes mellitus, MPO deficiency, and serious C. albicans infection was examined. Genetic investigation was carried out in 28 members of the proband's family. In close relatives of the patient, MPO values were found to be diminshed to a greater or lesser degree, thus suggesting variable expressivity of the heterozygote state of MPO deficiency.

Adult↗
PubMed1979

[Interactions between macromolecular adjuvants and drugs. Part 16: Effects of human serum albumin and Mg2+ on oxytetracycline-polyvinylpyrrolidone interactions (author's transl)].

Equilibrium dialyses and fluorescent spectroscopic measurements demonstrated that human serum albumin (HSA) affects the oxytetracycline (OTC)--polyvinyl-pyrrolidone K 90 (PVP) interactions. The preferential binding of OTC with HSA, as compared to PVP, was evidenced by means of a three-compartment model. The binding values increased with the increase of the portion of PVP in the PVP-HSA mixture. Superadditive OTC bindings occurred at a ratio of 1:1 (by weight). The addition of Mg2+ to PVP-containing solutions, at a molar ratio of 1:1, also produced an increase of the interactions of this antibiotic with PVP, whereby maximal OTC-PVP bindings of 50--60% were reached.

Dialysis↗
PubMed1978

Postmitotic marrow neutrophils and neutrophil mobilization in man: role of the spleen.

The relationship between postmitotic marrow neutrophils (PMMN) and neutrophil increment in blood after an intravenous dose of 3 mg hydrocortisone/kg was studied in patients with normal-sized spleens and compared with splenectomized and splenomegalic patients. PMMN were quantified from the ferrokinetic measurement of the normoblast number and the PMMN/normoblast ratio in bone marrow biopsy sections. In 12 control patients with normal PMMN the increment was 3.50 +/- 1.13 X 10(9) neutrophils/liter. An excellent correlation was found between the number of PMMN and the maximal neutrophil increment (y = 826x - 1021, r = 0.93, p less than 0.001) among 24 patients with normal spleen size and a wide range of marrow cellularity. Significantly higher responses were observed in 10 splenectomized patients (y = 872x + 1429, r = 0.92, p less than 0.001). The two regression lines were shown to be parallel, indicating a diminution of the response by 2.5 X 10(9) neutrophils/liter in the presence of a normal spleen. In 11 hypersplenic patients the responses were further reduced and more variable. Peak neutrophilia occurred after median values of 2, 3, and 4 hr in the hypersplenic, the control, and the splenectomized group, respectively. These studies indicate that allowing for the different response curves neutrophil increments may be used as an index of PMMN in patients with normal spleen size and in splenectomized patients. They further suggest sequestration of the prematurely released cells by the spleen.

Bone Marrow Cells↗
PubMed1977

[Hereditary myeloperoxidase deficiency. Clinical, biological and genetic study].

A case is reported of hereditary myeloperoxidase deficiency in a diabetic patient suffering from a Candida albicans hepatic abscess. Myeloperoxidase (MPO) is completely absent from the neutrophils and monocytes, although it is present in the eosinophils. Functional granulocyte studies have revealed normalchemotactic and phagocytic activity, although the bacterial activity is partially diminished with regard to Staphylococcus aureus and is almost nil with regard to Candida albicans. The granulocytic metabolism, when stimulated by zymosan, is characterized by greatly increased oxygen consumption. Genetic investigations have been conducted in 28 members of the patient's family. Cyto- and biochemical determination of MPO is clearly diminished in close relatives of the patient. Genetic analysis indicates recessive autosomal transmission with variable expressivity of the gene for the heterozygote state.

Adult↗
PubMed1977

Muscle disease associated with renal failure.

A 54-year-old woman had muscle disease that terminated fatally with complete body paralysis. The patient had renal failure, which progressed concurrently with her muscle weakness. Myoglobinuria was not demonstrated during the active stage of her illness. Renal biopsy specimens demonstrated immune deposits in the glomeruli, and, at autopsy, there was a generalized glomerulonephritis. We believe the muscle disease was a consequence of acute rhabdomyolysis, hyperacute polymyositis, or virus infection. Regardless of the nature of the muscle disease, an immune mechanism may have been responsible for the associated renal failure.

Acute Kidney Injury↗
PubMed1977

[Synthesis and properties of carrier-fixed enzymes. VII. Linking of glucoamylase to dialdehyde cellulose, carboxymethylcellulose hydrazide and carboxymethylcellulose azide].

Glucoamylase (alpha-1,4-glucan glucohydrolase, EC 3.2.1.3) has been covalently linked to dialdehyde cellulose resulting in an immobilized enzyme containing 0.98% protein and an activity of 4.5 mg of the native enzyme per g of matrix, i.e. 46% relative activity. The complex lost its activity in continuous and batch hydrolysis of starch at 55 degrees C down to a limit of 18% of its original value. In contrast, the activity of the complex did not change when working at a temperature of 25 degrees C. Glucoamylase-carboxymethylcellulose complexes synthesized via carboxymethylcellulose hydrazide and azide, in contrast to MAEDA und SUZUKI [1], showed only an activity of 1 mg of the native enzyme per g of matrix. We did not succeed in coupling periodate-oxidized glucoamylase to carboxymethylcellulose hydrazide because the enzyme used lost nearly all of its activity already during periodate oxidation.

Azides↗
PubMed1977

[Synthesis and properties of carrier-fixed enzymes. VIII. Kinetic studies of the binding velocity of enzymes to macroporous carriers].

The kinetics of binding the enzymes glucose oxidase, trypsin, and peroxidase and also bovine gamma-globulin to the macroporous carriers dialdehyde cellulose, diazotized amino polystyrene, acrolein-acrylamide copolymer, and isothiocyanate groups carrying CPG-glass was studied. It was found empirically that the increase in protein content and--if there occurred no inactivation of enzyme during binding reaction--of enzymatic activity of the enzyme-carrier complex with the reaction time can be described by saturation curves (first order hyperbolas), which represent straight lines after suitable transformation. Thereby it is possible to calculate protein content or specific activity of the enzyme-carrier complex for any moment during binding reaction. From intercepts of the obtained straight lines with the ordinate and with the abscissa, respectively, one can determine the maximum binding capacity and the maximum specific activity and from their slope the reaction rate can be obtained. If there result no straight lines for plotting enzymatic activity of the enzyme-carrier complex against binding time after transformation, then this is an indication for partial inactivation of the free or already insolubilized enzyme. From kinetic measurements it is concluded that in all cases studied by use the preceding stage in chemical fixation of the enzyme to carrier is an adsorption equilibrium. Limitation of reaction rate by diffusion as in loading an ion exchanger could not be observed.

Glass↗