PubMed Health⌕ Search

Biomedical subjects

K Kirsch

Publications and source records attributed to K Kirsch.

At least 55 records · Page 3Linked to original sources
PubMed1982

Long-term observations on plasma antidiuretic hormone levels during and after heat stress.

Eleven healthy subjects aged 18--26 years underwent intermittent heat stress in a sauna bath. Blood samples were taken immediately before, during and at various intervals after heat exposure for the measurement of antidiuretic hormone, osmolality and percentage change of plasma volume. Antidiuretic hormone was increased during, immediately after and 90 min after heat stress. Three hours after the heat stress period antidiuretic hormone returned to control values in spite of a significant increase in osmolality and a significant decrease in plasma volume. These results imply that other factors than ADH are responsible for the long-term homeostasis of water balance and plasma volume.

Adolescent↗
PubMed1981

Partial characterization of the carbohydrate units of rat intestinal sucrase--isomaltase.

Sucrase--isomaltase was purified from rat intestinal microvillus membranes after injection of D-[2-3H]mannose and L-[6-3H]fucose, using a column of monoclonal antibody-protein A-Sepharose. After Pronase digestion and gel filtration of the glycopeptides labelled from both precursors, a major part of the radioactivity was recovered in asparagine-linked complex oligosaccharides, and a smaller amount in partially alkali-labile high-molecular-weight glycopeptides. Only a small amount of [3H]mannose was found in endo-beta-N-acetylglucosaminidase H-sensitive high-mannose oligosaccharides.

Animals↗
PubMed1981

A villous cell-derived inhibitor of intestinal cell proliferation.

To test the hypothesis that the intestinal villous cell synthesizes a mitotic inhibitor that is specific for crypt cells, we have partially purified an extract from rat intestinal villous cells (VCE) and have demonstrated that it strongly and reversibly inhibits cell division and DNA synthesis in an intestinal epithelial cell line (IEC-6 cells). VCE produced a 60--70% inhibition of [3H]thymidine incorporation into DNA and a similar magnitude of inhibition of labeling of nuclei in autoradiographic studies. This inhibition was not associated with cytotoxicity as assessed by the effect of VCE on 51Cr release, hexose or amino acid uptake, and protein synthesis. VCE appears specific for IEC-6 cells because it did not affect DNA synthesis in 10 other cell lines, and extracts derived from other cell lines and from colonic mucosa did not affect DNA synthesis in IEC-6 cells. VCE may represent a villous cell factor involved in the control of intestinal epithelial cell turnover in vivo.

Animals↗
PubMed1980

Surface-membrane biogenesis in rat intestinal epithelial cells at different stages of maturation.

The biosynthesis of membrane proteins and glycoproteins has been studied in rat intestinal crypt and villus cells by measuring the incorporation of L-[5,6-3H] fucose, D-[2-3H] mannose and L-[3,4,5-3H] leucine, given intraperitoneally, into Golgi, lateral-basal and luminal membranes. Incorporation of leucine and mannose was approximately equal in crypt and villus cells, whereas fucose incorporation was markedly higher (3-4 times) in the differentiated villus cells. As previously reported [Quaroni, Kirsch & Weiser (1979) Biochem J. 182. 203-212] most of the fucosylated glyco-proteins synthesized in the villus cells and initially present in the Golgi and lateral-basal membranes were found re-distributed, within 3-4h of label administration, in the luminal membrane. A similar process appeared to occur in the crypt cells, where, however, only few fucose-labelled glycoproteins were identified. In contrast, most of the leucine-labelled and many mannose-labelled membrane components found in the lateral-basal membrane of both crypt and villus cells did not seen to undergo a similar re-distribution process. The fucosylated glycoproteins of the intestinal epithelial cells represent, therefore, a special class of membrane components, most of which appear with differentiation, that are selectively localized in the luminal portion of the plasmalemma. In contrast with the marked differences in protein and glycoprotein patterns between the luminal membrane of villus and crypt cells, only minor differences were found between their lateral-basal membrane components: their protein patterns on sodium dodecyl sulphate/polyacrylamide slab gels, and the patterns of fucose-, mannose- and leucine-labelled components (analysed 3-4h after label administration) were very similar. Although the minor differences detected may be of importance, it appears that most of the surface-membrane changes accompanying cell differentiation in the intestinal epithelial cells are localized in the luminal portion of their surface membrane.

Animals↗
PubMed1980

Characterization of glycopeptides labelled from D-[2-3H]mannose and L-[6-3H]fucose in intestinal epithelial cell membranes during differentiation.

The labelled glycopeptides obtained by Pronase digestion of rat intestinal epithelial cell membranes were examined by gel filtration after injection of D-[2-3H]mannose and L-[6-3H]fucose. Three labelled fraction were eluted in the following order from Bio-Gel P-6, Fraction I, which was excluded from the gel, was labelled mostly with [3H]fucose and slightly with [3H]mannose. Fraction II contained "complex" asparagine-linked oligosaccharides since it was labelled with [3H]mannose and [3H]fucose, was stable to mild alkali treatment, and resistant to endo-beta-N-acetyl-glucosaminidase H. Fraction III contained "high-mannose" asparagine-linked oligosaccharides, which were labelled with [3H]mannose, but not with [3H]fucose; these were sensitive to endo-beta-N-acetylglucosaminidase H, and were adsorbed on concanavalin A-Sepharose and subsequently eluted with methyl alpha-D-mannopyranoside. The time course of incorporation of [3H]mannose into these glycopeptides in microsomal fractions showed that high-mannose oligosaccharides were precursors of complex oligosaccharides. The rate of this processing was faster in rapidly dividing crypt cells than in differentiated villus cells. The ratio of radioactively labelled complex oligosaccharides to high-mannose oligosaccharides, 3h after [3H]mannose injection, was greater in crypt than in villus-cell lateral membranes. Luminal membranes of both crypt and villus cells were greatly enriched in labelled complex oligosaccharides compared with the labelling in lateral-basal membranes. These studies show that intestinal epithelial cells are polarized with respect to the structure of the asparagine-linked oligosaccharides on their membrane glycoproteins. During differentiation of these cells quantitative differences in labelled membrane glycopeptides, But no major qualitative change, were observed.

Animals↗
PubMed1980

Fluid volume distribution within superficial shell tissues along body axis during changes of body posture in man: the application of a new miniature plethysmographic method.

In up to six different sides along the body axis during tilting manoeuvres, volume shifts into or out off superficial tissues were followed with a newly developed miniature plethysmograph. It was possible to localize a region where no or only minor volume changes during the tilt table experiments occurred. This region is identical with the Hydrostatic Indifferent Point (HIP) being localized below the apex of the heart in the upper third of abdominal vena cava. Above the HIP fluid is drained out off the tissues during assumption of upright posture whereas below the HIP fluid volume is pooled. The volume changes occurred in two phases. Within the first 5 s in the cephalad parts of the body a rapid decrease occurred, thereafter the volume remained unchanged or even increased; below the HIP within the first 5 s a large volume increase was followed by a slow continuous volume increment. The functional peculiarities of the low pressure system as a whole were visible studying only superficial shell tissues of the body with the non invasive miniature plethysmographic technique.

Blood Circulation↗
PubMed1979

Synthesis of membrane glycoproteins in rat small-intestinal villus cells. Redistribution of L-[1,5,6-3H]fucose-labelled membrane glycoproteins among Golgi, lateral basal and microvillus membranes in vivo.

The biogenesis of plasmalemma glycoproteins of rat small-intestinal villus cells was studied by following the incorporation of l-[1,5,6-(3)H]fucose, given intraperitoneally with and without chase, into Golgi, lateral basal and microvillus membranes. Each membrane fraction showed distinct kinetics of incorporation of labelled fucose and was differently affected by the chase, which produced a much greater decrease in incorporation of label into Golgi and microvillus than into lateral basal membranes. The kinetic data suggest a redistribution of newly synthesized glycoproteins from the site of fucosylation, the Golgi complex, directly into both lateral basal and microvillus membranes. The observed biphasic pattern of label incorporation into the microvillus membrane fraction may be evidence for a second indirect route of incorporation. The selective effect of the chase suggests the presence of two different pools of radioactive fucose in the Golgi complex that differ in (1) their accessibility to dilution with non-radioactive fucose, and (2) their utilization for the biosynthesis of membrane glycoproteins subsequently destined for either the microvillus or the lateral basal parts of the plasmalemma. The radioactively labelled glycoproteins of the different membrane fractions were separated by sodium dodecyl sulphate/polyacrylamide-slab-gel electrophoresis and identified by fluorography. The patterns of labelled glycoproteins in Golgi and lateral basal membranes were identical at all times. At least 14 bands could be identified shortly after radioactive-fucose injection. Most seemed to disappear at later times, although one of them, which was never observed in microvillus membranes, increased in relative intensity. All but two of the labelled glycoproteins present in the microvillus membrane corresponded to those observed in Golgi and lateral basal membranes shortly after fucose injection. The patterns of labelled glycoproteins in all membrane fractions were little affected by the chase. These data support a flow concept for the insertion of most surface-membrane glycoproteins of the intestinal villus cells.

Animals↗
PubMed1979

Synthesis of membrane glycoproteins in rat small-intestinal villus cells. Effect of colchicine on the redistribution of L-[1,5,6-3H]fucose-labelled membrane glycoproteins among Golgi, lateral basal and microvillus membranes.

To define the role of cytoplasmic microtubules in the biogenesis of plasmalemma glycoproteins of rat small-intestinal villus cells, we studied the effect of colchicine on the incorporation of L-[1,5,6-3H]fucose into Golgi, lateral basal and microvillus membranes. Colchicine was administered intraperitoneally before or after injection of radioactive fucose. The incorporation of radioactivity into Golgi membranes was little affected by colchicine, which did not prevent the redistribution of most of the labelled glycoproteins from the Golgi complex into other parts of the villus cell. The incorporation of labelled glycoproteins into the microvillus membrane was greatly inhibited by colchicine given 2 h or 10 min before the radioactive fucose: all labelled glycoproteins present in this membrane were equally affected. In contrast, the administration of colchicine considerably increased the incorporation of radioactivity into the lateral basal part of the plasmalemma, and prevented the disappearance of most of the labelled glycoproteins from this membrane at late times after fucose injection. These results suggest that cytoplasmic microtubular structures are important for the polarization of the intestinal villus cell and the biogenesis of the microvillus membrane, although playing little or no role in the movement of membrane components from the Golgi complex to the lateral basal part of the plasmalemma.

Animals↗
PubMed1978

Synthesis of plasmalemmal glycoproteins in intestinal epithelial cells. Separation of Golgi membranes from villus and crypt cell surface membranes; glycosyltransferase activity of surface membrane.

The relationship between Golgi and cell surface membranes of intestinal cells was studied. These membranes were isolated from intestinal crypt cells and villus cells. The villus cell membranes consisted of microvillus membrane, a Golgi-rich fraction, and two membrane fractions interpreted as representing lateral-basal membranes. The villus cell microvillus membrane was purified by previously published techniques while the other membranes were obtained from isolated cells by differential centrifugation and density gradient velocity sedimentation. The two membrane fractions obtained from villus cells and considered to be lateral-basal membranes were enriched for Na+,K+-ATPase activity, but one also showed enrichment in glycosyltransferase activity. The Golgi membrane fraction was enriched for glycosyltransferase activity and had low to absent Na+,K+-ATPase activity. Adenylate cyclase activity was present in all membrane fractions except the microvillus membrane but co-purified with Golgi rather than lateral-basal membranes. Electron microscopy showed that the Golgi fraction consisted of variably sized vesicles and cisternalike structures. The two lateral-basal membrane fractions showed only vesicles of smaller, more uniform size. After 125I labeling of isolated intact cells, radioactivity was found associated with the lateral-basal and microvillus membrane fractions and not with the Golgi fraction. Antibody prepared against lateral-basal membrane fractions reacted with the surface membrane of isolated villus cells. The membrane fractions from isolated crypt cells demonstrated that all had high glycosyltransferase activity. The data show that glycosyltransferase activity, in addition to its Golgi location, may be a significant property of the lateral-basal portion of the intestinal villus cell plasma membrane. Data obtained with crypt cells support earlier data and show that the crypt cell surface membrane possesses glycosyltransferase activity.

Adenosine Triphosphatases↗
PubMed1978

[Avoidable surgical errors in hallux valgus surgery according to Brandes (author's transl)].

In postoperative follow-ups in a large number of patients who underwent Hallus valgus surgery according to Brandes, residual pain was found due to insufficient resection of the proximal phalanx. It is pointed out that the results of this frequent and beneficial Hallux valgus surgery can be improved by using a more subtile surgical technique. Figs. 1-5 show that errors continue to be made. If these errors can be avoided in the future this report will have fulfilled its purpose.

Hallux Valgus↗
PubMed1978

[The Sudeck-Leriche syndrome as a disturbance in distant regions of the body, clinical picture, and histology (author's transl)].

On the whole, every Sudeck-Leriche syndrome represents a serious complication. The causal noxae are various in nature. In a large case material during a period of observation extending over 26 years a Sudeck-Leriche syndrome was observed as a disturbance in distant regions of the body only in rare cases, for example after herpes zoster, apoplexy, and confusion of the cervical part of the medulla, with cervical and lumbal root irritations, etc. Histological findings in the case of Sudeck-Leriche syndrome are very rarely presented in literature. Histological investigations by the author carried out on muscle tissue in the case of Sudeck-Leriche syndrome yielded remarkable findings with a transition from functional to morphologically irreversible alterations. These alterations were present both in vessels and muscle fibers.

Autonomic Nervous System↗
PubMed1977

Extracellular fluid volume and central circulation after long lasting exercise and dehydration in conscious dogs.

Two aspects of the recovery period after endurance exercise were investigated: a) the fluid distribution between the intra- and extravascular parts of the extracellular fluid volume (ECFV) induced by exercise dehydration, b) the cardiovascular response pattern [blood pressure (BP), heart rate (HR), cardiac output (CO), total peripheral resistance (TPR), and central venous pressure (CVP)] to the heat load which results from the preceding exercise. Seven conscious dogs performed endurance exercise in a cool environment (16 degrees C) on a horizontal treadmill till 4% of the body weight was lost. It was found that about 70% of the total fluid loss of the body came from intracellular water. During exercise sodium and chloride concentrations rose by 6 mMol and 7 mMol respectively (P less than 0.005) and remained elevated throughout the early recovery period indicating a fluid loss of about 100-200 ml out of the ECFV. Direct measurements of the ECFV as sulfate space confirmed these values. Since the plasma volume remained unchanged, this fluid loss was carried totally by the interstitial fluid volume. Immediately after exercise body temperature was elevated by 1.5 degrees C and returned towards control within 90 min. Cardiac output was above control level for 2 h after the end of exercise, at first due to an increased HR and thereafter to an elevated stroke volume (SV) (P less than 0.02). CVP and TPR were below control levels for at least 2 h (P less than 0.01). A linear correlation was found between CVP and TPR. A close correlation existed between the body temperature and the cardiovascular parameters. It can be concluded that even long after exercise the cardiovascular system has to serve thermoregulatory needs.

Animals↗
PubMed1977

The influence of heat stress on plasma volume and intravascular proteins in sedentary females.

23 untrained femal subjects underwent a standardised thermal dehydration. Plasma volume (PV), hematocrit (HCT), total intravascular protein concentration (TPC), albumin concentration (AC), total globulin concentration (TGC) were determined before, immediately, 90 min and 180 min after the heat stress. The intravascular protein masses (IPM) were calculated from PV and protein concentration. In comparison to men the loss of body weight and PV was smaller. Consequently the TPC does not increase to the same amount in men. A tendency for a diminution of IPM could be observed but this shift was not significant, compared to males. According to these findings the colloid osmotic capacity remained on a relatively high level. Opposite to men the IPM of globulins increased in females after thermal dehydration.

Blood Proteins↗
PubMed1976

Intestinal lipoprotein formation: effect of cholchicine.

The possibility that microtubules might be involved in intestinal lipoprotein formation or secretion was studied by determining the effect of colchicine, a known microtubule inhibitor, on intestinal lipid absorption. The effect of colchicine (0.5 mg per 100 g) in the lymphatic absorption of [14C]oleic acid was studied in rats with indwelling mesenteric lymph cannulas. Colchicine-treated animals showed a marked delay as well as a decrease in the lympatic absorption of [14C]oleic acid. Chylomicrons from colchicine-treated animals showed no difference in apoprotein content when examined on sodium dodecyl sulfate polyacrylamide gels. Micellar lipid absorption was next studied from in situ jejunal loops in animals pretreated with colchicine. Colchicine administration was associated with a 3-fold increase in residual mucosal lipid when compared with controls. Thin layer chromatography of residual lipid demonstrated that residual lipid was largely present as triglyceride, suggesting that the impairment in lipid transport induced by colchicine was at a site distal to triglyceride resynthesis. Electron microscopic examination of intestine from colchicine-treated animals revealed that most residual lipid was present within the endoplasmic reticulum and Golgi in numerous particles the size of chylomicrons (0.2 to 0.4 mu). These results suggest that the impairment in lipid transport induced by colchicine is distal and, in part, may represent an "exit block". These results suggest a possible role for microtubules in intestinal lipid transport. However, further studies are required to demonstrate directly the participation of microtubules in chylomicron secretion.

Animals↗