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Biomedical subjects

G Wolf

Publications and source records attributed to G Wolf.

At least 505 records · Page 28Linked to original sources
PubMed1989

Glomerular and tubular membrane antigens reflecting cellular adaptation in human renal failure.

The excretion profiles of the following marker proteins of glomerular and tubular origin were studied in patients suffering from chronic renal disease (GN, N = 36, GFR: 8 to 120 ml/min/1.73 m2): angiotensinase A (ATA), a glomerular endothelial glycoprotein, tubular ala(-leu-gly)-amino-peptidase-M (APM), gamma-glutamyl transpeptidase (GGT), and the major brush border surface glycoprotein (SGP-antigen) of 240 kD. In addition, urinary excretion of proteins from kidney tissue and serum from 30 patients undergoing chronic hemodialysis (RCDT) were analyzed. Compared to the controls, ATA, APM and GGT activities were significantly higher in urine specimens of patients with GFR greater than 25 ml/min, whereas the urinary APM, GGT and SGP concentrations were decreased, and correlated with the GFR. Urinary GGT activity was negatively correlated with ATA activity but positively correlated with the decrease in GFR. Urine ATA activity of RCDT patients was higher compared to normal controls (2P = 0.001). Urinary excretion of serum proteins of RCDT patients, as assessed by SDS-polyacrylamide gel electrophoresis, disclosed heavy tubular proteinuria, indicating predominant tubular rather than glomerular alterations in handling of proteins. Histochemical evaluation of kidney sections from RCDT patients revealed clusters of hypertrophic nephrons with increased glomerular and tubular concentration of immunoreactive membrane proteins. However, there was a general decrease in renal cell-marker concentrations as observed by quantitative image analyses. These results indicate that renal injury is associated with a modulation in the synthesis of tubular and glomerular cell markers.

Adaptation, Physiological↗
PubMed1989

[PARTICLE--an expert system for microscopic image analysis].

The pathologist is usually not an expert in engineering or image analysis. Therefore an expert system was developed, entitled PARTICLE, to help pathologists producing image analysis programs in histological pathology. The PARTICLE expert system is based on karyometric data using the AMBA/R dialogue and programming system.

Expert Systems↗
PubMed1989

Expression of transforming growth factor-beta in wound healing of vitamin A-deficient rat corneas.

Transforming growth factor-beta (TGF-beta) is a multifunctional peptide that modulates cell proliferation and differentiation in many cell types and accelerates tissue repair response. In this study, expression of TGF-beta was investigated immunohistochemically in the healing of central 3 mm epithelial wounds of vitamin A-deficient (A-) rat and pair-fed controls. In control rat corneas, a positive reaction to TGF-beta was not evident during wound healing. In A- rat corneas at 4 hr post-abrasion, acute inflammatory cells showing high positivity to TGF-beta appeared in the peripheral stroma and gradually spread to the central cornea. By 24 hr, these cells accumulated and formed a pseudomembrane in the epithelial defect, which also showed an intense positivity to TGF-beta, suggesting that the peptide participates even in the acute inflammatory response. From about 16 hr post-injury, many fibroblasts revealing intense positivity to TGF-beta infiltrated the entire stroma and were part of the healing process. Reepithelialization occurred over the pseudomembrane and was completed by 48 hr. The central cornea showed remodeling of collagen structure and neovascularization. Fibroblasts containing TGF-beta were seen in the stroma, indicating that TGF-beta plays an important role in corneal wound healing. Indeed, in the absence of vitamin A, a common modulator of cell differentiation, TGF-beta may play a more important role in wound healing than in the normal state.

Animals↗
PubMed1988

Changes in the activity of gamma-glutamyl transpeptidase induced by kainic acid and surgical lesions of the hippocampal formation in young rats.

To study possible functional involvement of gamma-glutamyl transpeptidase (GGT) in glutamate transmitter metabolism we lesioned putative glutamatergic structures of the rat hippocampal formation by intracerebroventricular (i.c.v.) injection of kainic acid (KA) or by surgical CA3 axotomy. Unilateral injection of KA into the left lateral cerebral ventricle of 30-day-old rats resulted in decreased GGT activity in hippocampal areas CA3, Ca1 ipsilaterally, and in the contralateral area CA1, four hours after the induction of the chemical lesion. Four days after the injection, the enzyme activity was decreased in all hippocampal areas with the exception of the contralateral dentate gyrus. Four days after bilateral i.c.v. injection of KA, lower GGT levels were found than was seen after bilateral surgical lesion of the CA3 pyramidal cell axons (Schaffer's collaterals). The surgical lesion was followed by a decrease of GGT only in the stratum pyramidale and stratum radiatum of area CA1. In contrast to the effects in 30-day-old rats, unilateral i.c.v. injection of KA on postnatal day 12 did not alter the GGT activity in any studied hippocampal area presumably because of incomplete maturation of structures required for KA vulnerability.

Age Factors↗
PubMed1988

Histochemically demonstrable activity of phosphate-activated glutaminase in the postnatally developing rat hippocampus.

Phosphate-activated glutaminase (PAG) mediating the conversion of glutamine to glutamate and ammonia, appears to be the major glutamate metabolizing enzyme in brain. The functional relevance of PAG in postnatally maturing glutamatergic/aspartatergic structures of the rat hippocampus was studied by means of quantitative enzyme histochemistry as an alternative to immunocytochemical techniques. The calibration of the histochemical PAG reaction as well as several control experiments for specificity were carried out to ensure reliability of findings. PAG activity increased markedly during the first weeks of life with a drastic rise between postnatal days 12 and 15. On the other hand, activity of NADH diaphorase involved in the histochemical PAG assay as an auxiliary enzyme, showed a different distribution pattern as well as a different developmental sequence with high levels early in ontogenesis. The topographical and temporal parallelisms of PAG activity to several other parameters which are putatively associated with postnatally maturing glutamatergic/aspartatergic transmission processes, mutually indicate their significance in such a functional context.

Aging↗
PubMed1988

High-affinity uptake of L-[3H]glutamate and D-[3H]aspartate during postnatal development of the hippocampal formation: a quantitative autoradiographic study.

Quantitative autoradiography was used to determine the topographical and time patterns of L-[3H]glutamate and D-[3H]aspartate high-affinity uptake system in the hippocampal formation of the rat during postnatal development. Extended control experiments were performed to verify the specificity of labelling. For short incubation periods of 3-10 min, the data demonstrated a conspicuously low rate of glutamate accumulation in the hippocampal formation of newborn animals and a marked increase in labelling of hippocampal neuropil areas during the first weeks of postnatal life. Our autoradiographic data on developmental increase in glutamate high-affinity uptake levels are consistent, in terms of time and topography, in many ways with other parameters of maturation of glutamatergic and/or aspartatergic structures in the hippocampal formation.

Animals↗
PubMed1988

A comparative study of perineal ultrasound scanning and urethrocystography in patients with genuine stress incontinence.

Perineal scanning using linear array ultrasound was used as an alternative to radiologic urethrocystography in the investigation of female urinary incontinence. The posterior urethro-vesical angle (beta) and the angle of inclination (alpha) of 30 patients (age: 48 +/- 10.2 years) with genuine stress incontinence were measured by both procedures. In all cases the radiologic and ultrasound findings correlated well. Perineal scan provides similar information to that obtained by the radiographic procedure without exposure to X-rays. In contrast to urethrocystography perineal scan is fast, inexpensive, readily accessible and more acceptable to the patient.

Adult↗
PubMed1988

Fluoroscopic determination of NAD(P)H/NAD(P)+ ratios in brain slices under perifusion conditions.

The adaptation of a commercially available fluorescence microscope for continuous monitoring of endogenous NAD(P)H levels in brain slices is described. A specially designed self-stirring perifusion chamber was used to monitor a stable fluorescence signal for hours, indicating sufficient oxygen and substrate supply under measuring conditions. Profiles and reversibility of the fluorescence signals following changes in NAD(P)H levels in the picomolar range are demonstrated in slices of rat hippocampus. The degree of reduction obtained under normal metabolic conditions in the presence of 10 mM glucose was 29.9% +/- 1.3 (mean +/- S.D.; n = 12). The present technique allows convenient monitoring of the influence of various exogenous factors on metabolic conditions which are accompanied by changes in the redox state of brain nicotinamide nucleotides.

Animals↗
PubMed1988

Expert system for pathologists to generate an image analysis program for tumor grading.

The pathologist is usually not an expert in engineering or image analysis. We have, therefore, developed an expert system, entitled PARTICLE, to help pathologists producing image analysis programs by which to tackle problems in histological pathology, including tumor grading. The PARTICLE expert system is based on karyometric data, using the AMBA/R dialogue and programming system.

Diagnosis, Computer-Assisted↗
PubMed1988

The tumor-promoter-induced release of phosphorylated fibronectin from human lung fibroblasts.

The role of fibronectin (FN) phosphorylation was examined for its involvement in tumor-promoter-induced FN release from normal fibroblasts. We investigated phosphorylated FN in spent media and in cell layers of human lung fibroblasts (HLF) cultured in the presence and absence of the tumor-promoter 12-O-tetradecanoylphorbol-13-acetate (TPA). Our data, obtained by metabolic labeling of HLF with [32P]orthophosphate, revealed that 32P-labeled FN accumulated rapidly in the cell layer in the absence of TPA. With TPA present, accumulation of 32P-labeled FN at the cell layer of HLF was much slower than under control conditions. On the other hand, treatment of the cells with TPA caused a marked increase in the amount of medium-released FN. This increase in released FN, however, was caused by unlabeled FN and was not paralleled by an increase in 32P-labeled FN. We investigated the ability of FN from normal and TPA-treated cells to bind to normal HLF monolayers. We found no difference in re-binding ability, regardless of whether FN was derived from cell extracts of control cultures (showing highly phosphorylated FN) or from the medium of TPA-treated cultures with low phosphorylation of FN.

Cells, Cultured↗
PubMed1988

[Pharmacologic studies of cultivated human ciliated cells of the upper respiratory tract].

The ciliary frequency was measured in cultivated ciliated human cells of the upper respiratory tract. An attempt was made to influence this isolated system pharmacologically. Previously, contradictory results have been published regarding the effects of parasympathomimetic and sympathomimetic drugs. We investigated the muscarinic agonist carbachol and the beta 2-adrenoreceptor stimulating drug clenbuterol. Carbachol (10(-3) M) did not modify the ciliary frequency in 6 experiments neither at 37 degrees C nor at 24 degrees C, where the basal frequency was reduced. Spiropent (10(-5) M), a pharmaceutical preparation of clenbuterol and lactose, increased the ciliary frequency in 3 experiments. Clenbuterol, tested in the same concentration in 1 experiment, also caused an increase. Lactose was without effect. The secretolytic drug ambroxol did not influence the ciliary frequency. The neuropeptide substance P which causes an increase in ciliary frequency in the respiratory tract of rabbits in vivo, had no effect on isolated human ciliated cells indicating an indirect effect of this peptide. Calcitonin gene-related peptide which co-exists with substance P in sensory neurons of the airways, increased the ciliary frequency in 1 out of 6 experiments. In conclusion, our results indicate that ciliary activity can be directly modified via beta 2-adrenoreceptors. Other putative neuronal mediators did not reveal clearcut direct activity.

Ambroxol↗
PubMed1988

[New aspects in the pathogenesis and therapy of hyperreflexive rhinopathy].

Hyperreflectory rhinopathy (HR) is a non-specific hyperreactivity of the nasal mucosa. It causes hypersecretion, decreased nasal patency, sneezing and sometimes headache by local reflexes, which are beyond voluntary control. The synonymous name "vasomotor rhinitis" or "vasomotor rhinopathy" is no longer adequate with regard to our present state of knowledge of the autonomous innervation of the human nasal mucosa. Recent pharmacological investigations show the great importance of peptidergic neurons. In our own studies, the presence and the topical effects of the neuropeptide substance-P in human nasal mucosa are examined. A new concept of the autonomous innervation of the human nasal mucosa is presented. Apart from adrenergic and cholinergic neurons, it also includes peptidergic neurons (SP, CGRP, NKA, VIP, PHI, APP, GRP). According to this model, a hypothesis on the pathogenesis of HR is developed. A key position is occupied by the so-called "axon reflex" which is mediated by substance-P immunoreactive nerve fibers. It is released by a chemical, thermal or mechanical irritation. This axon reflex mediates pain, vasodilation and plasma extravasation (neurogenic oedema), hypersecretion such as smooth muscle contraction, and sneezing reflex. Capsaicin (8-methyl-N-vanillyl-6-nonenamid) leads to a selective degeneration of substance-P immunoreactive nerve fibres and desensitisation of its receptors after repeated topical or systemic application, thus blocking the axon reflex. The risk-free application of capsaicin was shown in self-experiments and in volunteers. Our hypothesis was confirmed by the good results of the treatment of a group of volunteer patients who suffered from HR.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Intranasal↗
PubMed1988

[A method of photometric measurement of the ciliary beat of cultivated ciliated cells of the upper respiratory tract in the human].

This study was based on a method of microphotometrical measurement of the ciliary beat of cells from the human upper respiratory tract. The ciliated cells were acquired by the tissue cultivation of small pieces of nasal mucosa obtained during surgical interventions in the paranasal sinuses. The experiments were performed in a chamber where the cells were superfused by a tyrode solution. The ciliary beat was measured by a microscope photometer built into an inverted microscope. During the measurements the diaphragm aperture of the photometer was positioned over the cilia in such a manner that the changes of light intensity resulting from the movement of the cilia could be registered. The frequency of the ciliary beat was estimated by counting the individual beats. The ciliary beat during control conditions was studied as well as the influence of temperature. Cooling of the experimental chamber resulted in a significant reduction of the frequency of the ciliary beat. The advantages of this single cell preparation of ciliated epithelia for pharmacological investigations are discussed.

Cells, Cultured↗
PubMed1988

[Parenteral or enteral hyperalimentation in the treatment of enterocutaneous fistulas?].

Occurrence of postoperative wound dehiscence with fistulae in stomach and small intestine is considered to be a severe surgical complication. The question has been raised, if the problem should be therapeutically tackled by means of surgery or medication in the context of intensive care. Retrospective and prospective analyses were made of the author's own cases at the Surgical Department of Graz University, between 1979 and 1985 (n = 31, with pancreas and colon fistulae uncounted). They were treated by two regimes. Group A (twelve patients) received purely parenteral substitution up to occlusion. Group B (19 patients) received a combination of enteral and parenteral nutrition, after their acute symptoms had vanished (ten gastroduodenal fistulae, eleven jejunal fistulae, ten ileum fistulae; seven elective and 24 emergency operations; 95 per cent being high-risk patients).

Combined Modality Therapy↗