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Biomedical subjects

M Langer

Publications and source records attributed to M Langer.

At least 469 records · Page 26Linked to original sources
PubMed1979

Peptide hormone-like immunoreactivity in the gastrointestinal tract and endocrine pancreas of eleven teleost species.

The distribution of peptide hormone-like immunostaining in the gastrointestinal tract of 11 teleost species was investigated by immunofluorescence. Cells immunoreactive for somatostatin were found in the glandular epithelium of the stomach of four species and in the epithelium of the pyloric appendage of one species. The mid-gut epithelium contained cells reactive with antibodies to glucagon (three species), gastrin (five species), pancreatic polypeptide (five species), and substance P (two species). Cells immunoreactive for met-enkephalin were found in the epithelium of both the mid-gut and the stomach of six species. In six species in which the endocrine pancreas was investigated, insulin-, glucagon-, and somatostatin-like immunoreactivity was observed. Pancreatic polypeptide was definitely localised by immunostaining in cells of the endocrine pancreas of only one out of three species examined. Vasocative intestinal polypeptide-, neurotensin-, bombesin-, and enkephalin-like immunoreactivity was identified in the gastrointestinal nerve fibres in various species. In view of the considerable species variation found, caution should be exercised in generalising about the peptides present in the gastrointestinal tract of fish.

Animals↗
PubMed1979

[Angiographic features of liver echinococcosis (author's transl)].

From 1973 to 1978 13 cases of cystic hydatid disease and 15 cases of alveolar hydatid disease of the liver were diagnosed by angiography. The main diagnostic features of cystic hydatid disease of the liver are the following: "rim-sign", avascular areas, curved displacement of the arteries and stretching of the intrahepatic arteries. Multilocular hydatid disease of the liver shows tumor-like angiographic signs, such as atypical vascular formations, distensions, vascular irregularities, arterial stenoses as well as hepatosplenomegaly. Differential diagnosis in malignant liver diseases is often impossible, but early venous filling and arteriovenous shunts are not characteristic of multilocular hydatid disease of the liver. Particularly difficult is the interpretation in patients who have had previous surgery.

Adult↗
PubMed1979

Free thyroxine (FT4) and free triiodothyronine (FT3) in autonomous thyroid nodules.

Total and free thyroid hormones (T3, T4, FT3 and FT4), TSH and its response to TRH were determined in sixty-three patients affected by autonomous thyroid nodules: mean concentrations of free T3 (FT3) were significantly higher in hot nodules (suppressing extranodular tissue on the scan) as compared to warm ones, even in those cases where total T3 and T4 were within normal ranges (hot nodules, group as a whole: 8.8 +/- 3.5 pg/ml; warm nodules: 5.3 +/- 1.2; hot nodules with normal total T3 and T4 concentrations: 7.5 +/- 3). Also the clinical condition of thyrotoxicosis appeared to be correlated with FT3 concentrations (toxic patients, group as a whole: 9.6 +/- 4.0 pg/ml; euthyroid patients: 6.8 +/- 3.1; toxic patients with normal values of T3 and T4; 8.3 +/- 2.8). On the contrary the correlation of total and free thyroid hormone concentrations with the response of TSH to TRH was not significant.

Adult↗
PubMed1979

[Histological study of the teleost liver. III. The system of biliary pathways].

In the liver of Haplochromis burtoni four divisions of the intrahepatic biliary pathways can be distinguished: canaliculus, canaliculus ductulus transition, ductulus biliferus, ductus biliferus. There are no transitional stages between the hepatocytes and biliary epithelial cells. The results of the investigation suggest that the ductules open into the ducts in two ways, directly and by graded transition of structure. The first part of the ductulus has a very narrow lumen and therefore is similar to the "Schaltstück" of salivary glands. Terminal ductulus cells can protrude into the canaliculus (= lumen of the liver tubulus), giving the appearance of centrotubular cells in cross-section. In the liver of most of the teleosts investigated here the canaliculi are intercellular. Tangentially cut diverticuli of the canaliculi appear to be unicellular ("intracellular") canaliculi, but are, however, merely unicellular ("intracellular") protrusions of the intercellular canaliculi. On the other hand the three cyprinid species (Barbus tetrazona, Idus idus, Carassius auratus) possess true unicellular ("intracellular") canaliculi. These can definitely be distinguished from the diverticuli of intercellular canaliculi by several criteria. Phylogenetically the unicellular ("intracellular") canaliculus must be regarded as derivative, and the intercellular canaliculus as the original form. The morphology of the wall of the gall-bladder of Haplochromis burtoni indicates that transfer of substances is increased together with transportation and drainage of fluids and variations in volume. The ultrastructure of the epithelial cells reveals a zonal arrangement.

Animals↗
PubMed1979

[Histologic study of the teleost liver. I. The structure of the liver parenchyma].

The liver parenchyma of the teleosts investigated in this study does not show a true lobular pattern. The finer arrangement of the hepatocytes corresponds to the classical conception that the structure of the liver parenchyma is tubular. On the other hand the laminar structure of parenchyma (ELIAS), as it is often described in the more recent literature, must be regarded as a predominantly descriptive perspective. Remnants of a tubular structure also appear in the liver of the cyprinids investigated here, which have no real liver tubules owing to the special feature of the canalicular region (unicellular or "intracellular" bile canaliculi). Compared to the liver of higher vertebrates eight of the nine teleost species investigated here possess a liver poor in connective tissue. The liver of Haplochromis burtoni also lacks a continuous tissue layer beneath the peritoneal mesothelium. In contrast the liver of Tetraodon leiurus is characterized by an abundance of connective tissue. This phenomenon can be attributed to the high proportion of sinusoids in the parenchyma, which confers a structure similar to that of mammalian liver. The resulting loss of mechanical stability is obviously compensated for by the enlarged contribution of the connective tissue to the structure of the parenchyma.

Animals↗
PubMed1979

[Histologic study of the teleost liver. II. The blood vessel system].

In the liver of the teleosts investigated in the present study the sinusoidal region shows a space of DISSE, which contains numerous microvilli originating from the hepatocytes. In some species, especially in Tetraodon leiurus, there are also bundles of collagenous fibrils. In the DISSE's space of larger sinusoids (transition sinusoids) sections of filament-rich cells are found. These are sometimes interconnected by desmosomes and can be interpreted as processes of smooth muscle cells from the region of the venae hepaticae. The endothelium of smaller sinusoids is fenestrated and shows micropinocytotic activity. The endothelia of the transition sinusoids and of the venae hepaticae are endowed with structures, which can be interpreted as macrovesicles. In the sinusoidal region true KUPFFER-cells and ITO-cells could not be observed. Nevertheless, the close location of granulocytes to the sinusoidal endothelium suggests that phagocytotic processes cannot be excluded for the sinusoidal region. Exceptionally, in Hemihaplochromis multicolor there were also signs of possible phagocytosis by sinusoidal endothelial cells. The chemomorphology of the sinusoidal region, above all the evidence of alkaline phosphatase, shows great differences between species. The examination of the larger blood-vessels in the liver of Haplochromis burtoni reveals venae portae with very thin walls and venae hepaticae with thick walls, which contain smooth muscle cells. Granulocytes and melanocytes are abundant in the wall of the venae hepaticae. This phenomenon indicates that the defence-functions, which in the liver of higher vertebrates are carried out by the sinusoids (KUPFFER-cells), are undertaken by the region of the venae hepaticae in the liver of Haplochromis burtoni, which is free of KUPFFER-cells. On their extrahepatic course the venae portae are surrounded by a sleeve of exocrine pancreatic tissue, which accompanies the vessels deep into the liver. The pancreatic cells bordering the thin-walled venae portae have sparse microvilli indicating a transfer of substances between venous blood and pancreas similar to the sinusoidal region of the liver. Furthermore, the investigation resulted in a clue to the innervation of the exocrine pancreas.

Animals↗
PubMed1978

[Ultrastructure of hepatocytes is teleost fishes following food deprivation].

Liver tissue of nine teleost species has been investigated electron microscopically after periods of fasting. Ultrastructural changes tn the hepatocytes are described mainly from Haplochromis burtoni. 70 days of food deprivation have the following effects: the intercellular spaces are widened; the size of the hepatocytes is reduced; lysosomes are enlarged and reach the diameter of the nucleus and have increased in number; the amount glycogen is reduced; the endoplasmatic reticulum bears less ribosomes. All alterations are reversible. The comparison of different species mainly shows differences conceming to the amount of lipid, which may be reduced or enlarged.

Animals↗