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Biomedical subjects

J Groth

Publications and source records attributed to J Groth.

72 records · Page 4Linked to original sources
PubMed1980

Opiate binding sites in the retina: properties and distribution.

The presence of opiate binding sites in rat retina was confirmed and their properties and distribution were investigated. Etorphine, naloxone and methionine enkephalin exhibit high affinity, saturable binding to retinal membrane preparations. Scatchard analysis of the binding data yielded linear plots for each ligand. The P1 subcellular fraction contains the greatest density of sites per milligram of protein. The response of the binding of all ligands to sodium ions was similar in the retina to that observed in the brain. Competition experiments using naloxone and methionine enkephalin indicated that a homogeneous class of binding sites exists in the rat retina. Opiate binding sites were also demonstrated in the retina of cow, toad and skate. Methionine enkephalin-like immunoreactivity was not clearly detectable in rat retina but was present in toad retina. The physiological role of the opiate binding sites in the retina remains to be elucidated.

Animals↗
PubMed1980

[Antibody-dependent cell-mediated immune reactions--fundamentals and clinico-diagnostic relevance (author's transl)].

Antibody-dependent cell-mediated cytotoxicity is realized by means of humoral antibodies and unsensitized effector cells which interact with appropriate target structures inducing target cell destruction. Specificity of this immunological effector mechanism is mediated by immunoglobulins. Autologous, allogenic or xenogenic effector cells serve as efficient inductors of cell lysis. The in vivo relevance is still unclear. The present state of our knowledge has been surveyed and several samples are given showing the potential clinical importance of this immune mechanism in control of intracellular virus infections, bacterial and parasitological diseases, tumor and graft rejection, and autoimmune diseases. It has been attempted to interpret several apparently different immune phenomena (antibody-dependent cell-mediated cytotoxicity, "spontaneous" or "natural" cell-mediated cytotoxicity, mitogen-induced cell-mediated cytotoxicity and cytotoxic reactions of activated macrophages) under a common aspect.

Animals↗
PubMed1980

[Lymphocyturia following kidney transplantation].

Of 145 patients to whom was transferred a cadaver kidney in the Kidney Transplantation Centre Berlin from 1976 to 1978 we examined 4,638 fresh urines (on an average 32 urines per patient) for the existence of lymphocytes during the postoperative hospital stay. The following frequency distribution could be established: 3,377 tests without lymphocytes (72.8%), 1,093 tests with a slight-degree lymphocyturia (less than or equal to 10 lymphocytes/sediment, = 23.6%), 168 tests with a clear lymphocyturia (greater than 10 lymphocytes/sediment, = 3.6%). Here the appearance of a clear lymphocyturia could occasionally be proved at the beginning of rejection crises, in ruptures of the transplant, severe infections and transitory deteriorations of the transplant function, but also at the beginning of the function of the transplant and even at the moment of an undisturbed function of the transplant. According to these findings the determination of the lymphocyturia cannot be recommended for the rejection diagnostics.

Creatinine↗
PubMed1980

[Tissue typing and donor-recipient selection in dogs for experimental organ transplants].

About first results of a tissue typing for donor recipient selection in dog is reported on obtaining an optimum degree of histocompatibility. The modified NIH-test according to Brand and coworker was carried out. The sera for typing were prepared by means of artificial or natural immunisation. Serologic and genetic problems are discussed. Possibilities on perfection are shown for donor recipient selection in dogs.

Animals↗
PubMed1978

The effect of sexual hormones on skin graft survival, thymic morphology and serum levels of glycoproteins and albumin in mice.

Inbred mice of the B10LP strain were injected subcutaneously over a period of 28 days with chloromadinone acetate, mestranol, both hormones together, and the carrier alone. Treatment with the gestagen chloromadinone acetate alone or in combination with mestranol caused a significant prolongation of the H-2 different skin graft survival. This was not seen after mestranol treatment alone. All the hormone-treated mice developed characteristic cysts in the thymic medulla and changes in the concentration of some plasma proteins, e.g. a fall of albumin level and a simultaneous increase of glycoprotein level. Therefore, it is necessary to look for such side-effects in humans also to prevent or to notice early alterations of immunological surveillance.

Animals↗
PubMed1977

Mediastinoscopy in cancer of the oesophagus or cardia.

Fifty consecutive patients with verified squamous cell carcinoma in the oesophagus or adenocarcinoma had mediastinal metastases. One of 21 patients scopy. Seven of 29 patients with squamous cell carcinoma and mediastinal metastases. One of 21 patients with adenocarcinoma had this finding. It is concluded that patients with squamous cell carcinoma of the oesophagus should be mediastinoscopied and that it is also a worthwhile method in patients with adenocarcinoma.

Adenocarcinoma↗
PubMed1977

Pregnancy-associated increase of sialoglycoprotein level in serum of normal inbred mice.

The dynamics of the level of a fast migrating sialoglycoprotein (SGP) was studied in mice during pregnancy and the period of intensive nursing. A significant increase of the SGP concentration was established at the beginning of the third trimester only. Two days before delivery the SGP level declines markedly. Maximum values were attained shortly post partum. A relatively high SGP level is maintained for about 12 days post partum coinciding with the period of intensive nursing. Control values were attained at latest 18 days post partum.

Animals↗
PubMed1976

On the behaviour of murine lymphocytes after in vitro treatment with acid mucoproteins from human serum.

Seromucoproteins from human serum were isolated by perchloric acid extraction followed by DEAE-Sephadex A-50 ion exchange chromatography. The in vitro pretreatment of spleen leukocytes with this fraction caused a dose-dependent inhibition of graft-versus-host reaction as well as an increase of their electrophoretic mobility, the viability being maintained. On contrary, the pretreatment of mice (prospective spleen cell donors of recipients of sheep red blood cells) with human seromucoproteins had no effect on the gvh-reaction as well as on the agglutinin formation to sheep red blood cells under the given conditions. It is supposed that the suppressive effect after in vitro pretreatment may be attributed to a coating effect of seromucoproteins. The fact that spleen cells pretreated in vitro with seromucoproteins are lysed in presence of complement and antiseromucoprotein antiserum supports our opinion. These findings as well as data from the literature support the hypothesis that local concentrated mucoproteins in the skin graft bed in cases of protractedly surviving skin grafts, in the placenta, and on neoplastic tissues can influence unspecifically the immune response. We hope that the understanding of this mechanism may open new possibilities in prolonging allograft survival time.

Animals↗
PubMed1976

[Manufacture and possibilities of use of antisera against solubilized human erythrocyte membranes].

Antisera produced in rabbits against Triton X-100 solubilized human erythrocyte ghosts formed several several precipitation lines in immunoelectrophoresis and immunodiffusion tests against the solubilized ghosts. The antisera were used for detecting several membrane components during chromatographic separation. A membrane component was partially isolated using gel filtration on SEPHADEX G-200 (fraction F1/F2). Spectrin (Tektin A) was shown to be the main moiety of these fractions. Associated proteins (haemoglobin, GAPD) could not be detected by the antisera against whole ghost solubilisate.

Agglutinins↗
PubMed1975

Kinetics of opiate receptor inactivation by sulfhydryl reagents: evidence for conformational change in presence of sodium ions.

The role of SH groups in opiate-receptor interactions has been further examined. In activation by N-ethylmaleimide of sterospecific opiate binding by rat brain membrane fractions follows pseudo-first order kinetics and exhibits strong temperature dependence. The kinetics indicate that alkylation of a single SH group suffices to block opiate binding. Considerable protection from SH group inactivation is observed when treatment with N-ethylmaleimide is carried out in the presence of an opiate or an antagonist, suggesting close proximity of the SH group to the opiate binding site. The rate of inactivation of receptor binding by N-ethylmaleimide is markedly slower in buffers containing 100 mM NaCl (t1/2 equals 30 plus or minus 1.4 min) than in sodium-free buffers (t1/2 equals 10 plus or minus 1.0 min). Since the rate of alkylation of model SH compounds is unaffected by sodium ions, this protection seems best explained by a conformational change in the receptors that renders the SH groups less accessible to alkylation. The rate of inactivation is not affected by K+, Rb+, or Cs+ and only slightly by Li+. This cation specificity as well as the concentration-response to Na+ are remarkably similar to those previously shown to lead to increased antagonist and decreased agonist binding. We suggest that the same conformational change is involved in the two phenomena.

Alkylation↗
PubMed1975

Further properties of stereospecific opiate binding sites in rat brain: on the nature of the sodium effect.

Addition of sodium salts has been reported to enhance stereospecific binding of opiate antagonists while reducing binding of agonists to rat brain homogenate. We have tested, in addition to sodium and potassium, a number of organic cations. Our results support the suggestion that the ability to enhace antagonist binding is not a general characteristic of cations or high ionic strength, but a property of sodium ions. We have shown that the increase in antagonist binding results from an enhancement of binding affinity and not from unmasking of new binding sites. The reduction in etorphine binding in the presence of sodium is due to a decrease in binding affinity. This decrease is largely accounted for by an acceleration in the dissociation rate, while the greater affinity of naltrexone binding appears to be due to an increase in rate of association. Our results are consistent with the hypothesis of a conformational change in opiate binding sites in the presence of sodium, transformed sites exhibiting greater affinity for antagonists and reduced affinity for agonists. Preheating of rat brain P2 fraction at 50 degrees C results in gradual inactivation of stereospecific binding, but an increase in naltrexone binding is consistently observed after heating at 50 degrees C for 2 to 3 minutes, even at optimal concentrations of sodium.

Analgesics, Opioid↗
PubMedDate not supplied

Intensified ESWL of gallstones: dissociation of pulverisation, pain relief and stone-clearance.

BACKGROUND/AIMS: Recently, intensified shock wave lithotripsy for gallstone pulverisation and subsequent clearance without bile salt medication has been advocated. We report our first 44 patients treated by this regime: Patients with intact gallbladder function and symptomatic gallstones of any size, number and composition. METHODOLOGY: Forty-four consecutive patients who received intensified shock wave lithotripsy for gallstone pulverisation and clearance were included in this study. The patients all had intact gallbladder function and presented with symptomatic gallstones of any size, number and composition. RESULTS: Pulverisation was achieved in 75% of all cases (12 months), but only 34% were stone free. The proportion of patients with stone pulverisation compared to subsequent complete clearance was 93% versus 60% in small (</ = 20mm) solitary stones and 67% versus 15% in two or more stones. The pain intensity was markedly reduced within the first month of treatment, irrespective of complete pulverisation or definite stone clearance. CONCLUSIONS: The approach of stone pulverisation by multiple shockwave treatments is effective in solitary stones but does not achieve adequate stone clearance in multiple gallstones. Despite the low stone clearance rates in multiple stones, intensified ESWL used alone may be effective for these patients, if they are not eligible for surgery and the purpose of treatment is pain relief.

Cholelithiasis↗