A simple and fast method for the determination of D-penicillamine in serum is described. The analysis is based o a fluorescence derivatization of the sulfhydryl group combined with a reversed-phase liquid chromatograhic separation and fluorescence detection. Before derivatization the serum proteins are precipitated with ethanol and removed by centrifugation. As derivatizing agent 5-dimethylaminonaphthaline-1-sulfonylaziridine is used which reacts selectively with thiols under defined reaction conditions. The detection limit is in the pmol range; 50-300 ng of D-penicillamine can be determined with a relative standard deviation of 7-8%. Thus the method permits a simple determination of D-penicillamine in serum at therapeutic levels.

Chromatography, Liquid↗

PubMed1981

Structural dimorphism of bile salt/lecithin mixed micelles. A possible regulatory mechanism for cholesterol solubility in bile? X-ray structure analysis.

The three-dimensional structure of bile salt/lecithin mixed micelles in 0.15 M saline was derived from X-ray small-angle scattering measurements under various conditions. Two essentially different types of micelles were detected. At bile salt:lecithin molar ratios lower than approximately 2:1, lamellar particles similar to a lecithin bilayer arrangement were found. The thickness of the bilayer is 5.1 nm for mixed micelles having a molar ratio of 1:1. The lateral dimensions of the micelle were found strongly dependent upon molar ratio, increasing as lecithin content increases. In addition, it appeared that under certain incompletely defined conditions vesicular particles having diameters in the region of more than 100 nm occur. A molecular model of this type of micelle has been derived by means of a thorough interpretation of the electron density distribution across the plane of the bilayer. This model is generally consistent with the "mixed-disk" model of Mazer et al. [Mazer, N. A., Kwasnick, R. F., Carey, M. C., & Benedek, G. B. (1977) Micellization, Solubilization, Microemulsions, Proc. Int. Symp. 1, 383-402] and thus differs from that proposed by Small [Small, D. M. (1967) Gastroenterology 52,607-610] and Dervichian [Dervichian, D. G. (1968) Adv. Chem. Ser. No. 84, 78-87]. At molar ratios exceeding 2:1, a different type of micelle structure was found. This is a highly isometrical particle of globular shape, probably having a centrosymmetric arrangement of the molecular constituents. At a 3:1 bile salt:lecithin molar ratio, the mean physiological ratio for human gallbladder bile, the diameter of this micelle is 6.2 nm. Provided that other bile constituents have no significant influence on the structure, it may reasonably be expected that native gallbladder bile contains micelles of this latter type. The prevalent balance between the two micellar forms may thus regulate the capacity of bile to transport cholesterol.

Bile Acids and Salts↗

PubMed1981

Pressure-dependent deactivation and reactivation of dimeric enzymes.

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Animals↗

PubMed1981

Pressure-induced structural changes of pig heart lactic dehydrogenase.

Lactic dehydrogenase from pig heart can be reversibly dissociated at hydrostatic pressures above 1000 bar. The breakdown of the native quaternary structure occurs at lower pressures compared to the isoenzyme from pig skeletal muscle. As shown by hybridization experiments of the two isoenzymes the final product of dissociation is the homogeneous monomer. Fluorescence emission spectra of the monomeric enzyme at elevated pressure are characterized by a decrease in fluorescence intensity without any red shift, indicating that no significant unfolding occurs upon high-pressure dissociation. The spectral changes are comparable to those observed after acid dissociation. The amount and rate of deactivation depend on pressure and on the conditions of the solvent. The presence of various anions (C1-, SO2-/4, HPO2-/4) has no effect on the stability of the enzyme towards pressure. High-pressure denaturation (as monitored by intrinsic protein fluorescence), and deactivation (measured immediately after decompression) run parallel; the pressure dependence of their first-order rate constants is characterized by an activation volume delta V not equal to De = - 140 +/- 10 cm3/mol. As taken from the yield of reconstitution, dissociation, denaturation and deactivation are found to be fully reversible provided the pressure does not exceed a limiting value (p = 1000 bar in Tris, pH 7.6; 24 h incubation at 20 degrees C). After extended incubation beyond the limiting pressure of 1000 bar, "irreversible high-pressure denaturation" occurs which is accompanied by partial aggregation after decompression. The coenzyme, NAD+, stabilizes the native tetramer shifting the dissociation equilibrium to higher pressures. The overall dissociation-association reaction can be quantitatively described by a consecutive dissociation/unfolding mechanism N in equilibrium 4 M' in equilibrium 4 M* (where N is the native tetramer, and M' and M* two different conformations of the monomer). The reaction volume of the dissociation reaction N in equilibrium 4 M' is found to be delta V Diss = - 360 +/- 30 cm3/mol; as indicated by the pressure dependence of the yield of reconstitution, the reaction volume of the equilibrium M' in equilibrium M* is also negative.

Animals↗

PubMed1981

Conditions relevant to the occurrence of acid-fast bacilli in sphagnum vegetation.

Biotopes with intact sphagnum vegetation were studied in Naustdal, West Norway: the health district with the former highest leprosy incidence rates in Norway. Concentration of acid-fast bacilli and concentration of non-cultivable acid-fast bacilli found in the vegetation fluid were compared with a series of variables related to the local environment and to the samples of vegetation. In bivariate analyses high concentrations were found in biotopes with orientation toward South, with a high coverage of vascular plants and with presence of Ericaceae. High concentrations were also found where dry weight of a vegetation was high, where pH in the fluid was low and where dry weight of the fluid was high. In a multivariate analysis, log-linear model, based on concentration of acid-fast bacilli as the dependent variable and orientation, pH, dry weight of vegetation and dry weight of fluid as the independent variables, all two-factor effects including the dependent variable were retained in the model. Furthermore, orientation versus dry weight of vegetation and dry weight of fluid versus dry weight of vegetation were retained.

Bacillus↗

PubMed1981

Mammalian spermatogenesis as a biologic dosimeter for radiation.

Mouse spermatogenesis was used as an in vivo test system obviously suitable as a biologic dosimeter. Ionizing irradiation induced changes in the frequency distribution of the cellular DNA content of whole testis preparations. These changes can be analysed by flow cytometry. Such measurements deliver information on: (1) an increase of the coefficient of variation of the DNA histograms of some spermatogenic cells, (2) induction of diploid mature sperm, and (3) the dose-depending inactivation of the highly sensitive differentiated spermatogonia. In this model especially No. 3 delivers quantitative information on the cytotoxic action of ionizing irradiation and chemical noxae as well, whereas Nos 1 and 2 may be used as qualitative criteria of mutagenic action of physical and chemical agents. No. 2 obviously being more sensitive than No. 1.

Animals↗

PubMed1981

[Rehabilitation potentials and limits with schizophrenic patients].

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Adult↗

PubMed1981

[Early postoperative discharge (author's transl)].

Early postoperative discharge is the most effective measure in establishing short stay surgery. In our clinic the data of discharge after standard operations have been defined empirically: appendectomy: 3rd to 4th day, cholecystectomy: 5th to 6th day, vagotomy: 5th to 6th day, inguinal hernia: 3rd to 4th day, struma resection: 3rd to 5th day. Early postoperative discharge presupposes no surgical complications and an undisturbed postoperative course. An early discharge cannot be recommended in patients older than 65 years, in patients living alone, in patients living in doubtful domestic conditions, and in alcoholics, No postoperative complications could be observed in any case of early discharge later on. 98.6% of all patients were satified with an early postoperative discharge.

Adult↗

PubMed1981

[Obstetric and neonatological aspects relating to incidence and importance of respiratory distress syndrome in prematurely born infants (author's transl)].

Morbidity and mortality due to respiratory distress syndrome (RDS) were analysed for 225 infants prematurely born between the 28th and 36th weeks of pregnancy in 1978. RDS morbidity accounted for 40 per cent, when based on enlarged clinical diagnosis, and for twelve per cent, when based only on radiographic thorax findings of phases II, III, and IV, according to Giedeon, and on histological post-mortem findings from the lungs. Early RDS mortality was found to be 7.5 per cent.--The rates of severe membrane syndromes and early deaths due to RDS were statistically reduced only in one pregnancy group, that is between the 31st and 32nd weeks, following prenatal Prednisolut prophylaxis. No death of infants occurred beyond the 33rd week of pregnancy, and no severe case of RDS was any longer recorded beyond the 34th week. Infants delivered by caesarean section were much more strongly exposed than others to hypoxia. Therefore, no valid information could be established about the impact of caesarean section on the development of RDS.--Conclusions are drawn from the above findings as to obstetric approach to imminent premature birth or to planned premature delivery.

Birth Weight↗

PubMed1980

[Unrecognized atypical tuberculosepsis in generalized hematologic neoplasms].

Differential diagnosis and therapy of 4 cases (3 of acute myelogenous leukemia and 1 of Hodgkin's disease, stage IVB) of septic exacerbation of febrile course in generalized hematologic neoplasms under intensive treatment are described. The infectious process of 3 cases was confirmed as generalized tuberculosis only at autopsy. The incidence in over 250 patients (1973-1979) was 1.6%.

Aged↗

PubMed1980

[Efficacy of intravenous gammaglobulin in bacterial infections in Surgical Patients. Results of a controlled, randomized clinical study (author's transl)].

The efficacy of intravenous gammaglobulin injections against postoperative bacterial infections was investigated in a prospective randomized, controlled clinical trial in 150 patients. It was found that after postoperative administration of 20 g i. v. gammaglobulin (Intraglobin) the preoperative serum levels had already been attained on the third day (without gammaglobulin they were lower than before operation on the 8th postoperative day). By means of this substitution it was possible to reduce the number of local infections (p less than 0.01) where moderate risk existed. With more persistent infections the incidence of septicemic complications were lower (p less than 0.05). On the basis of these results the application for certain indications of high doses of intravenous gammaglobulin discussed.

Clinical Trials as Topic↗

PubMed1980

[Does i.v. gamma globulin counteract postoperative bacterial infections? (authors's transl)].

A prospective, randomized clinical study investigated the effectiveness of IV gamma-globulin (GG) against bacterial infections after surgical procedures. As a result of 20 g GG IV, given postoperatively, the average concentration decrease for IgG (25% - 30%) could be balanced as soon as the third postoperative day, the local infection rate was decreased in the low-risk group, and, with the occurrence of long-lasting local infections, the number of patients with simultaneous septic complications was lowered.

Bacterial Infections↗