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H Götz

Publications and source records attributed to H Götz.

At least 19 recordsLinked to original sources
PubMed1992

Studies on human porin. VII. The channel properties of the human B-lymphocyte membrane-derived "Porin 31HL" are similar to those of mitochondrial porins.

Porin 31HL was isolated and purified from total membrane preparations of a human B-lymphocyte cell line. The protein showed a single band of apparent molecular mass 31 kDa on SDS-PAGE. Reconstitution of the protein into artificial lipid bilayer membranes defines its function as a channel-forming protein. The distribution of single-channel conductances had two maxima of 2.4 and 4.3 nS in 1M KCl. The channel formed by Porin 31HL of human B-lymphocytes was found to be voltage-dependent and switched to ion-permeable substates at membrane voltage larger than 20mV. In the open state the pore exhibited the characteristics of a general diffusion pore because the mobility sequence of the ions inside the pore was similar to that in the bulk aqueous phase. The effective diameter was estimated to be about 1.7 nm. The properties of the low conductance state of the channel were studied in detail. In this state the pore favored the passage of cations, in contrast to the open state which favored anions slightly. Monoclonal antibodies against the N-terminal end of Porin 31HL blocked its reconstitution but had otherwise no influence on the channel properties. This result suggested that the amphipathic alpha-helical structure at the N-terminal end is probably not involved in channel gating. The channel-forming properties of Porin 31HL were compared to those of porins isolated from mitochondrial outer membranes and to those of the "maxi chloride channel" observed in the cytoplasmic membrane of several eukaryotic cells.

Animals↗
PubMed1992

Studies on human porin. VIII. Expression of "Porin 31HL" channels in the plasmalemma of the acute-lymphoblastic-leukemia cell line KM3 as revealed by light- and electron-microscopy.

First electron microscopy data on the expression of the VDAC "Porin 31HL" in the plasmalemma of a eucaryotic cell are presented. In a light and electron microscopic study we demonstrate the expression of the porin channel in the outer cell membrane of the pre-B lymphocyte type acute-lymphoblastic-leukemia cell line KM3. Monoclonal mouse anti-"Porin 31HL" antibodies were applied in indirect immunofluorescence or immunogold labelling experiments. The results confirm our early topological data on the expression of porin channels in the cytoplasmic membrane of different human cell types as revealed on the light microscopy level. Interestingly, only a pre-embedding immunoreaction approach was successful for gold particle labelling of the plasmalemma. This again is in agreement with our recent data on the accessibility of the acetylated N-terminal part of "Porin 31HL" molecules on the outer cell surface.

Antibodies, Monoclonal↗
PubMed1991

Antagonistic effect of coryneform bacteria from red smear cheese against Listeria species.

A total of 187 coryneform bacteria were isolated from red smear and screened for inhibitory effects against 16 strains of Listeria species. Culture filtrates from Brevibacterium linens (16 strains), Arthrobacter nicotianae (4 strains) and Arthrobacter nucleogenes (3 strains) showed clear zones of inhibition. The antagonistic effect was seen against 26 to 87% of 91 Listeria strains tested. A. nicotianae and A. nucleogenes were more effective against Listeria innocua and Listeria ivanovii than against Listeria monocytogenes. No species specifically was observed for B. linens, but there was a difference regarding the inhibitory activity of individual culture filtrates. When culture filtrates of the test strains were added to Listeria broth cultures, the maximum growth level was not attained. Inhibition in broth cultures was dependent on the concentration of culture filtrates. Culture filtrates from the late stationary phase had a stronger inhibitory effect on the growth of L. monocytogenes. The nature of the inhibitory effects remained unclear. Attempts to characterize the nature of the antagonism showed that the culture filtrates lost their inhibitory activity upon heating, and the molecular size of the inhibitory substances were greater than 12-14 kDa.

Actinomycetales↗
PubMed1991

Quantitation of soluble HLA class II molecules by an enzyme-linked immunosorbent assay.

In order to quantify soluble HLA-DR,DQ,DP molecules (sHLA-RQP) an enzyme-linked immunosorbent assay was developed utilizing two monoclonal antibodies specific for HLA-DR,DP (Tü35) and HLA-DQ (Tü22) gene products, respectively. Highly purified HLA class II molecules isolated from a lymphoblastoid cell line were used for calculation of exact sHLA-RQP protein values. Circadian variations of sHLA-RQP plasma levels were studied in 7 healthy probands showing no significant deviations; measurements in 4 probands at intervals between 4 and 6 weeks revealed that sHLA-RQP levels remain relatively stable. The population analysis of 209 unrelated, HLA-typed healthy donors resulted in an average protein concentration of 1.53 +/- 2.44 micrograms/ml plasma for sHLA-RQP. Four out of 209 probands (= 1.9%) had no detectable sHLA-RQP. Significant associations of high or low sHLA-RQP levels to particular HLA-DR or -DQ specificities were not observed. However, plasma derived from HLA-DR9 positive had the highest and from HLA-DR8 positive donors the lowest mean sHLA-RQP values. By comparing HLA identical with two-haplotype-different siblings we found no evidence that sHLA-RQP plasma levels are under genetic control of the HLA complex or closely linked genes. Furthermore, soluble HLA class I plasma concentrations in 100 probands analyzed showed no correlation to those of sHLA-RQP.

Antibodies, Monoclonal↗
PubMed1991

Studies on human porin. VI. Production and characterization of eight monoclonal mouse antibodies against the human VDAC "Porin 31HL" and their application for histotopological studies in human skeletal muscle.

We report on the production and characterization of eight monoclonal mouse antibodies against the complete human VDAC "Porin 31HL". The antigen used was purified from a total membrane preparation of the transformed human B-lymphocyte cell line H2LCL. In Western blots all eight mAbs react with a single 31-kDa band in solubilized H2LCL membrane preparations thus demonstrating their specificity for the human VDAC "Porin 31HL". Concerning the epitope specificity we show that all eight mAbs equally react with the N-terminal part of human porin. Moreover, we demonstrate the expression of VDAC in the sarcolemma by indirect immunoenzyme labelling of cryosections of human skeletal muscle applying four of our mAbs. These data support our recent observations on the expression of porin channels in the plasmalemma of different normal and transformed human cell lines. VDAC in the plasmalemma is discussed as the molecular basis of the Blatz and Magleby channel.

Animals↗
PubMed1991

[Studies on human porin. V. The expression of "porin31HL" in the plasmalemma is not by cell transformation].

In recent papers we proved "Porin 31HL" to be located on the surface of human, EBV-transformed B lymphocytes. Here we present proof of "Porin 31HL" in the plasmalemma of normal human blood lymphocytes. For this purpose B and T lymphocytes were isolated from human heparinized blood and examined by indirect immunofluorescence techniques using different monoclonal antibodies against purified "Porin 31HL" and some B and T cell markers, respectively. For comparison a number of established cell lines of different origin were employed. Hence it followed that normal B and T cells as well as transformed and leukemic cells express "Porin 31HL" in their membrane. No significant quantitative differences could be seen. Consequently, the location of "Porin 31HL" in the plasmalemma is not a product of transformation.

Animals↗
PubMed1991

[Regional or general anesthesia in patients with pulmonary risks?].

Such partial functions of the respiratory system as ventilation, gas exchange, bronchomotor tone, respiratory regulation, secretion within the airways, mucociliary clearance, etc., are less impaired by such procedures as peridural or spinal anaesthesia than by general anaesthesia. As a result, it is often concluded that regional anaesthesia should always be used preferentially in the case of patients with a pulmonary risk. However, comparative studies have shown that pulmonary morbidity and mortality are little influenced by the anesthetic procedure. For, in the first instance, the incidence of post-operative complications affecting respiration are determined by previous lung pathologies, the age of the patient, and the location and duration of the surgical procedure. These are factors that cannot readily be influenced by anaesthesiological measures. For this reason, the pre-operative diagnostic evaluation and preparation, post-operative prophylaxis and treatment, including the components pain elimination, physiotherapy, respiratory therapy, broncholysis and secretolysis, are more important than the anaesthetic procedure itself.

Anesthesia, Conduction↗
PubMed1991

[The mechanism of the reduction of protein catabolism following trauma and during sepsis using xylitol].

Total parenteral nutrition (TPN) after trauma and sepsis has two major goals. One is the reduction of enhanced protein catabolism; the second is the avoidance of enhancement of whole-body glucose turnover. Glucose and xylitol differ in their quantitative utilization rate after trauma and sepsis. Maximal glucose utilization is reduced during such states, while the utilization of xylitol is more than doubled. In order to investigate whether these differences are associated with beneficial effects with regard to whole-body glucose turnover rate of gluconeogenesis and protein sparing, we conducted two studies using animal models and two clinical studies. METHODS. For the determination of glucose and protein turnover, radioactive and stable isotope techniques were applied. In an animal model a primed constant infusion of 3-H-6-glucose, 14-C-1-alanine and 13-C-3-alanine and 14-C-U-acetate was used to determine total glucose appearance, gluconeogenesis from 3-C-precursors and alanine flux. In the human studies hepatic glucose production was determined by using a primed constant infusion of 6.6-D-2-glucose and urea synthesis rate was determined by a primed constant infusion of 2-N-15-urea. RESULTS. In the first rat model we were able to show that hypocaloric xylitol compared to glucose significantly reduced whole-body glucose turnover from 1741 +/- 232 mumol/h during glucose infusion to 449 +/- 49 mumol/h during xylitol infusion and gluconeogenesis from C-3 carbons form 382 +/- 24 mumol/h during glucose infusion to 155 +/- 39 mumol/h during xylitol infusion after a burn trauma. In a second septic rat model the exchange of glucose calories by xylitol in a proportion of 1:1 was associated with a significantly ameliorated N-balance from +144 +/- 90 mgN/kg body weight per day during glucose infusion to +699 +/- 80 mgN/kg body weight per day during glucose-xylitol infusion and a reduced 3-methyl-histidine excretion from 7.14 +/- 0.61 mumol/kg body wt. per day during glucose infusion to 4.10 +/- 0.56 mumol/kg per day during glucose-xylitol infusion, respectively. In two studies with surgical intensive care patients we were able to confirm the nitrogen-sparing properties of xylitol infusion, together with amino acids during hypocaloric feeding or during TPN with a glucose/xylitol mixture in a proportion of 1:1. From a basal urea production rate of 9.2 +/- 1.6 mumol/kg min. xylitol led to a significant reduction with 6.4 +/- 1.5 mumol/kg per min. Hepatic glucose production was significantly reduced during xylitol infusion from basal 4.8 +/- 0.6 mg/kg per min to 3.1 +/- 0.7 mg/kg per min, respectively. Equicaloric glucose in a dosage of 3 g/kg per day had no effect. During TPN glucose/xylitol, in a proportion of 1:1 at a total dosage of 0.24 g/kg per h, significantly reduced whole-body glucose turnover, endogenous glucose production and lactate concentrations compared to an isocaloric glucose infusion. DISCUSSION. In animal as well as in human studies hypocaloric xylitol as well as a glucose-xylitol mixture were more efficient in preserving body protein than glucose alone. Whole-body glucose turnover was significantly reduced during hypocaloric xylitol or glucose-xylitol infusion compared to isocaloric glucose infusion. During the acute phase after trauma we therefore recommend a carbohydrate supplementation of 3 g/kg body wt. per day using xylitol. During long-term TPN, a glucose-xylitol mixture in a proportion of 1:1 in a dosage of 3 g/kg body wt. per day each is recommended as energy source, together with amino acids and, if necessary, lipids.

Animals↗
PubMed1991

[The effect of a thigh tourniquet on the pharmacokinetics of midazolam].

Although the general pharmacokinetics of midazolam (M) are well documented, little is known about the possible effects of a thigh tourniquet on the distribution and elimination of this drug. METHOD. Institutional approval for the study and individual informed consent were obtained. We studied 30 patients (ASA-I) without premedication who electively underwent a surgical procedure of the lower limb. Patients were divided into three groups of 10. The procedure was done in groups I and II with and in group III without tourniquet use. Anesthesia was induced in groups I and II with 0.1 mg/kg M, fentanyl 5 micrograms/kg, alcuronium-dichloride 0.15 mg/kg and etomidate 0.1-0.2 mg/kg i.v. and maintained with enflurane 0.3-1.0 vol.-%. About 20 min after midazolam injection and after exsanguination the tourniquet was applied on the proximal thigh in group I. In group II anesthesia was induced with etomidate 0.2 mg/kg and alcuronium-dichloride 0.15 mg/kg i.v., and maintained about 20 min with enflurane 1.0-1.5 vol.-% until exsanguination and tourniquet application. After this, these patients also received 0.1 mg/kg M and 5 micrograms/kg fentanyl i.v. Through an indwelling arterial line, blood samples were obtained prior to and 2, 15, 30, 45, 60, 75, 90, 105, 120, 135, 150, 165 and 180 min after M injection. Plasma M levels were measured by high-performance liquid chromatography with UV detection. These concentrations were fitted to a two-compartment open model. Comparison between groups was performed using the Kruskal-Wallis test and p less than 0.05 was considered to indicate significance. RESULTS. The groups were all comparable in age and weight, and groups I and II also in duration of thigh ischemia. Midazolam elimination half-time (t beta 1/2) was significantly shorter in group II than in groups III and I (52 min vs 126 min and 139 min; p less than 0.05). Of the calculated distribution volumes (volume of the central compartment, volume in the steady state and volume in the elimination phase), only the volume in the steady state was significantly smaller in group II than in groups III and I (p less than 0.05). Groups III and I did not differ significantly in the computed parameters. The measured initial midazolam mean concentrations in group II were twice those in groups III and I (655 ng/ml vs 323 ng/ml and 332 ng/ml). Since clearance was not significantly different between any two groups, the shorter t beta 1/2 in group II was probably due to the reduced distribution volume. CONCLUSION. These data demonstrate that in the presence of a thigh tourniquet the timing of the injection - before or after application of the tourniquet is of decisive importance. Injection after the application of a tourniquet leads to an higher plasma level and shortens the elimination half-life.

Adult↗
PubMed1990

[Famotidine dosage in children. The effect of different doses on the pH and volume of the gastric juice].

Children undergoing general anesthesia are at increased risk of severe aspiration pneumonitis. Cimetidine and ranitidine, specific histamine (H2-receptor) antagonists, when given 1-3 h preoperatively markedly reduce the acidity and volume of gastric content. A newer compound, famotidine, is a more specific antagonist with no inhibitory effect on the drug metabolizing microsomal enzyme systems of the liver (cytochrome P-450), in contrast to cimetidine. An additional clinical advantage is a possible longer duration of action. In order to evaluate these potential advantages we studied the effects of preanesthetic oral famotidine on gastric fluid pH and volume in 4 groups in a random manner. METHODS. With parental consent, 107 infants and children (ASA I status, 4 months to 14 years old, NPO for at least 6 h) received either no famotidine (n = 29) or 0.15 mg/kg (n = 27), 0.3 mg/kg (n = 25) or 0.6 mg/kg (n = 26) famotidine at 7.00 a.m. Following induction by mask with nitrous oxide/oxygen (N2O/O2) and enflurane (E) or i.v. thiopental, intubation was performed in all patients. Anesthesia was maintained with N2O/O2 and E. A orogastric double-lumen tube was passed into the stomach, and the gastric content was aspirated in a uniform manner. Gastric volume was recorded and pH values were measured with pH paper. RESULTS. In the control group, 28 of 29 patients (97%) had a pH less than 2.5, 18/29 (62%) had a gastric volume greater than 0.4 ml/kg and 17/29 (59%) had a pH less than 2.5 and gastric volume greater than 0.4 ml/kg, meaning an increased risk of pneumonitis if the child aspirates the gastric content. Famotidine administration was effective between 1.5 and 6 h after oral administration. Preoperative famotidine application produces pH values of gastric contents higher than 2.5 in all dosage groups (84%, 94%, 75%), and these differences were highly significant (P less than 0.001), whereas the gastric volume reduction with these doses was not significant. The incidence of pH less than 2.5 and volume of gastric contents exceeding 0.4 ml/kg did not vary with the different doses of famotidine. As there were no measurable differences in the effect of famotidine, we recommend that children at high risk of pulmonary aspiration receive 0.15 mg/kg famotidine orally at least 1.5 h but not later than 6 h before induction.

Administration, Oral↗
PubMed1989

[Identification of human porins. I. Purification of a porin from human B-lymphocytes (Porin 31HL) and the topochemical proof of its expression on the plasmalemma of the progenitor cell].

We describe for the first time a porin (Porin 31HL) on the plasmalemm of an eukaryontic cell line, where porins have been found only on the outer mitochondrial membranes. The expression of the porin on the plasmalemm of transformed human B-lymphocytes is demonstrated by cytotoxicity- and indirect immunofluorescence techniques with living and fixed cells. The rabbit xenoantisera used were directed against purified Porin 31HL and free or acetylated synthetic peptides of its nineteen N-terminal amino acids. The three-step purification procedure for Porin 31HL started from a total membrane fraction of the B-cell line, followed by ion-exchange chromatography on CM- and DEAE-cellulose and a final gel filtration in SDS on Sephacryl S-300.

Amino Acids↗
PubMed1989

[Identification of human porins. II. Characterization and primary structure of a 31-lDa porin from human B lymphocytes (Porin 31HL)].

We characterize and describe for the first time the primary structure of a human porin with the molecular mass of 31 kDa derived from the plasmalemm of B-lymphocytes (Porin 31HL). Porin 31HL is shown to be a basic, channel forming membrane protein. The protein chain is composed of 282 amino acids with a relative molecular mass of 30641 Da without derivatisation. It is not a glycoprotein. The N-terminus is acetylated. Altogether the amino-acid sequence shows 56% hydrophilic or charged amino acids arranged in alternating regions of hydrophilic or hydrophobic character as it is typical for porins. In addition the 18 N-terminal amino acids of Porin 31HL can be arranged to an amphilic alpha-helix like in other porins. Porin 31HL shows approx. 29% or 24% identity to the primary structure of mitochondrial porins of Neurospora crassa and Saccharomyces cerevisiae. Partial data on mitochondrial porins from rat kidney and beef heart show sequence identity of about 90% to the human B cell porin elaborated here.

Amino Acid Sequence↗
PubMed1986

Analysis by sequential immunoprecipitations of the specificities of the monoclonal antibodies TU22,34,35,36,37,39,43,58 and YD1/63.HLK directed against human HLA class II antigens.

The monoclonal antibodies (MOABs) TU22, TU34, TU35, TU36, TU37, TU39, TU43, TU58 and YD1/63.HLK were used to identify subpopulations of class II antigens encoded by the human major histocompatibility complex. Since all MOABs reacted with B lymphocytes of HLA-DR1-8 homozygous as well as all heterozygous cells tested, they recognize monomorphic determinants, with the possible exception of TU58 and YD1/63.HLK which do not fix complement. As shown by radioactive binding assays and immunoprecipitations of labeled chains, 3 MOABs reacted strongly and 3 others weakly with isolated beta-chains, and the former also bound alpha-chains, albeit very weakly. Immunoprecipitations with the MOABs from 125I-labeled KR3598 cells (Dw5, DR5, MT2, MB3 homozygous, SB2, SB4) demonstrated that at least 4 different subpopulations of class II antigens were present in the lysate. Possibilities to reconcile these biochemical data with the reactivity of the MOABs with HLA mutant cell lines and with functional as well as tissue distribution studies are discussed.

Animals↗
PubMed1986

[Rebound hypertension after controlled hypotension and its prevention by captopril].

In 27 patients undergoing ear, nose and throat surgery, the problem of post-hypotensive hypertension (rebound hypertension) following vasodilator-induced controlled hypotension was studied, together with prevention by the ACE inhibitor captopril. Hypotension was induced by sodium nitroprusside (SNP) in seven patients (group 1) and by nitroglycerin (NTG) in ten patients (group 3). Ten patients (group 2) received 25 mg captopril given orally, together with the preanaesthetic medication, as well as SNP. The degree and duration of the decrease in blood pressure did not differ significantly between groups. After discontinuation of the respective vasodilators, blood pressure had increased to above prehypotensive levels in both group 1 (SNP) and group 3 (NTG) 30 min afterward and, to a more marked extent, 60 min afterward. In these groups plasma renin activity (PRA) increased continuously during the hypotensive period up to 11.4 +/- 2.4 and 19.5 +/- 4.5 ng/ml/h, respectively, and had not yet reached its prehypotensive value 60 min after discontinuation. In group 2 (captopril/SNP) there was no overshoot hypertension on discontinuation of SNP, and the average infusion rate of SNP was reduced. PRA was markedly higher than in groups 1 and 3 (peak level 27.9 +/- 6.5 ng/ml/h) due to inhibition of the feedback mechanism in the renin-angiotensin system. From the results it may be concluded that both SNP and NTG can cause rebound hypertension, the extent of which depends on the level of hypotension previously achieved and the infusion rate of the vasodilator. Pretreatment with captopril prevents the rebound and reduces the dosage of vasodilator required and, therefore, may be considered an alternative to the well-documented beta-adrenergic blockers.

Adult↗
PubMed1986

Combined effects of high doses of rolitetracycline and testosterone on the liver of mice.

The effects of rolitetracycline (50 micrograms/g i.v.) and testosterone proprionate (4 X 1 micrograms/g s.c.) singly and combined on liver weight, serum GPT, SDH and bromsulfophthalein clearance have been measured in young mice. Pretreatment with testosterone tended to enhance the effects of rolitetracycline on the serum enzymes but was otherwise not effective.

Alanine Transaminase↗