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J Chemnitz

Publications and source records attributed to J Chemnitz.

At least 37 records · Page 2Linked to original sources
PubMed1991

Preservation of rabbit kidneys using a solution containing hydrolyzed starch.

An organ preservation solution has been developed by combining some features of the hypertonic citrate formulation of Ross, Marshall, and Escott (RME) with some features of UW solution. Specifically the solution (HP16) contains a balance of cations similar to that in RME and the same concentration of citrate, but sulfate is replaced by chloride and mannitol by a starch hydrolysis product (SHP). A gelatin-derived polypeptide (Haemaccel) is included to provide colloid osmotic pressure. The objective was to increase the effectiveness of RME by using a higher-molecular-weight osmoticum than mannitol, but avoiding the expense of raffinose; reducing the osmolality to a more physiological level; and including a colloid to make the solution suitable for continuous perfusion. The effectiveness of the solution was tested by 48-hr hypothermic preservation of rabbit kidneys. The results were compared with those obtained using RME or UW. It was shown that simple hypothermic storage was more effective than continuous perfusion, and that HP16 was more effective than RME and as effective as UW. The improvement over RME was ascribed to the isotonic osmolality and the inclusion of a higher-molecular-weight osmoticum (the SHP), possibly supplemented by the colloid (Haemaccel). Two SHP preparations, both with dextrose-equivalent values of approximately 35, were equally effective. These materials contain a standardized mixture of dextrose, maltose, and tri- and oligosaccharides, and have the osmotic properties of a trisaccharide. The results provide a new, inexpensive preservation solution that is as effective as any so far tested with this model, and they support the importance of appropriate osmotic properties for solutions to be used in organ preservation.

Adenosine↗
PubMed1989

Injury and repair of smaller muscular and elastic arteries. Immunohistochemical demonstration of fibronectin and fibrinogen/fibrin and their degradation products in rabbit femoral and common carotid arteries following a dilatation injury.

Indirect immunoperoxidase staining for fibrinogen/fibrin and fibronectin was performed on normal and healing arterial tissue of muscular and smaller elastic arteries. Fibronectin was observed in the wall of the normal arteries, whereas fibrinogen/fibrin could not be demonstrated. Fibronectin was observed in the intima as well as the media deposited in a similar fashion in the femoral and carotid artery during repair. Apart from the early occurrence of fibrin/fibrinogen in the media of both arteries the distribution of fibrinogen/fibrin and degradation products differed. In the femoral artery a progressively weakening positive reaction for fibrinogen/fibrin and degradation products towards the lumen was observed in the intima and the media 7 and 14 days after the lesion. By 28 days the reaction in the media was negative. No thrombus formation was observed. In contrast, all the specimens examined from the common carotid arteries were obliterated by luminal thrombi 28 days after the lesion. The thrombus as well as the damaged intimal thickening and the compressed media were loaded with fibrinogen/fibrin and degradation products. The deposition of fibronectin, fibrinogen, and degradation products in the carotid artery was similar to that previously reported in experimental aortic arteriosclerosis in rabbits as well as in giant cell arteritis.

Animals↗
PubMed1989

Two fetal antigens (FA-1 and FA-2) and endometrial proteins (PP12 and PP14) isolated from amniotic fluid: localisation in the fetus and adult female genital tract.

Monospecific antisera against two fetal antigens (FA-1 and FA-2), alphafetoprotein (AFP) and two endometrial proteins (PP12 and PP14) were used to examine the distribution of these proteins and antigens in human trophoblast and gestational endometrium in first and third trimesters of pregnancy, normal human ovary and fetal tissues by indirect immunoperoxidase histochemical localisation techniques. Fetal liver stained exclusively for FA-1 and AFP which was used as a reference protein. Staining for FA-2 was seen in fetal connective tissue, in particular the basement membrane. FA-1 and FA-2 did not stain positively in decidua, trophoblast or ovarian tissue. Gestational endometrium stained positively for PP14 exclusively in the glandular epithelium, whilst staining for PP12 was seen only in the stromal cells. Trophoblast, both early and late, and ovarian tissue did not stain positively for any of the four substances tested.

Amniotic Fluid↗
PubMed1989

Localization of foetal antigen 2 (FA-2) in foetal and adult human skin.

Foetal antigen 2 (FA-2) is a connective-tissue-associated antigen isolated from second trimester human amniotic fluid. FA-2 has an alpha-electrophoretic mobility and is a single-chain molecule with a molecular weight of 26 kDa as determined by polyacrylamide gel electrophoresis (PAGE). Using indirect immunofluorescence and the immunoperoxidase technique, FA-2 was found to be in the lamina densa/sublamina densa region of the basement membrane zone (BMZ) in adult as well as in foetal skin. FA-2 was found throughout the dermis in foetal skin, whereas in adult skin it was found to be associated with the BMZ and around the blood vessels, hair follicles and eccrine glands. Intracellular FA-2 antigen was demonstrated in proliferating fibroblasts by the indirect immunoperoxidase technique and immunoelectron microscopy of the fibroblasts revealed staining of the antigen in the cisternae of the rough endoplasmatic reticulum at the trans-side of the Golgi complex as well as in vesicles close to the plasma membranes. FA-2, a hitherto undescribed antigen associated with human BMZ, is probably being synthesized by proliferating fibroblasts.

Adult↗
PubMed1987

Giant-cell arteritis. Histological, immunohistochemical and electronmicroscopic studies.

Biopsies from the temporal artery of 32 patients suspected of giant-cell arteritis were evaluated retrospectively by light microscopy, histochemical, and immunohistochemical methods, as well as by transmission electron microscopy (TEM). At the clinical follow-up the 32 patients included four clinical groups: temporal arteritis (8 patients), polymyalgia rheumatica (10 patients), rheumatoid arthritis (4 patients), and a group of miscellaneous diseases unrelated to inflammatory rheumatic diseases (10 patients). There were a number of similarities between age-related alterations in the arteries and the changes in giant-cell arteritis. The most important differences were the inflammatory cellular infiltration of the media, the perifocal accumulation of fibronectin, and the occurrence of deposits of fibrin/fibrinogen and fibrin/fibrinogen degradation products. In addition, alpha-2 macroglobulin, lysozyme and factor VIII were also noted in giant-cell arteritis. The alterations in giant-cell arteritis show a number of similarities to the changes following experimental vascular injury of the rabbit aorta. The nature of the findings in human giant-cell arteritis, as well as the similarity to the experimental arteritis, indicate that giant-cell arteritis may reflect a non-specific reaction to injury, independent of the cause of the disease.

Aged↗
PubMed1987

Placental proteins in peripheral blood and tissues of ectopic pregnancies.

Circulating human chorionic gonadotrophin (hCG), Schwangerschaftsprotein 1 (SP-1) and pregnancy-associated plasma protein A (PAPP-A) were examined in 10 women with ectopic gestation in relation to distribution and intensity of staining for these molecules using immunohistochemical techniques applied to matched trophoblastic and decidualized endometrial tissues. All 10 women revealed strong staining for hCG and SP-1 in the syncytiotrophoblast, which was apparently unrelated to maternal levels of hCG and SP-1, levels being less than the 10th centile of the normal range in 9/10 and 7/10 women, respectively. By contrast maternal PAPP-A levels seemed to correlate with the intensity and the distribution of staining for PAPP-A. Circulating PAPP-A was undetectable (less than 5 mIU/l) in 4 patients, and below the 10th centile in the remaining 6. Using immunohistochemical techniques hCG, SP-1 and PAPP-A could not be demonstrated in any of the decidualized endometrial tissues studied.

Chorionic Gonadotropin↗
PubMed1986

Immunohistochemical aspects of immunological cross-reaction and masking of epitopes for localization studies on pregnancy-associated plasma protein A.

The influence of antibody absorption procedures and proteolytic pre-treatment of formaldehyde-fixed placental tissue on the localization of pregnancy-associated plasma protein A by immunoperoxidase technique was examined. Apparently monospecific IgG fraction of the anti-plasma protein applied directly on fixed tissue resulted in staining of connective tissue and a thin apical rim of the syncytiotrophoblast. Further absorption of the antibody with foetal connective tissue abolished this staining reaction. Pre-treatment of the fixed placental tissue with trypsin prior to application of the antibody, which had been absorbed with connective tissue, resulted in staining within the cytoplasm of the syncytiotrophoblast exclusively. Identical staining was seen when this IgG preparation was used directly on frozen placental tissue. The results point to the importance of the specificity of the antibody preparations and of proteolytic unmasking of epitopes when fixed tissues are used for localization studies of pregnancy-associated plasma protein A by immunoperoxidase technique.

Epitopes↗
PubMed1986

Comparison of different antibody preparations against pregnancy-associated plasma protein-A (PAPP-A) for use in localization and immunoassay studies.

Four antibody preparations against pregnancy-associated plasma protein (PAPP-A) were compared in order to find an explanation for the contradictory results published on tissue localization, clinical usefulness and biological function of PAPP-A. One of the preparations studied was a rabbit anti-PAPP-A antiserum which has been offered for general scientific use (Bischof et al. 1979). Only the IgG fraction of anti-PAPP-A antisera which appeared to be monospecific and had been further absorbed with fetal connective tissue gave specific uniform staining of the cytoplasm of the syncytiotrophoblast exclusively. Circulating PAPP-A could not be detected by RIA employing this IgG preparation in the non-pregnant state, or before 18 days after conception. Circulating PAPP-A could be detected in all seven pregnant women studied within 4 weeks after conception. Identical results were obtained with a commercially available IgG fraction against PAPP-A.

Animals↗
PubMed1984

Repair in arterial tissue. Demonstration of fibrinogen/fibrin in the normal and healing rabbit thoracic aorta by the indirect immunoperoxidase technique.

The results of immunoperoxidase staining for fibrinogen/fibrin in ethanol- and formaldehyde-fixed, normal and healing arterial tissue are presented. Fibrinogen/fibrin was not observed in the normal aortic wall. The thoracic aorta damaged by a balloon catheter contained fibrinogen/fibrin in all layers of the wall. In the healing aortic wall there was a strong positive reaction in neo-intima, whereas the reaction in media was weak or absent. The staining reaction for fibrinogen/fibrin in formaldehyde-fixed neo-intima covered with aortic smooth muscle cells was strong and almost independent of proteolytic digestion, while such treatment increased the staining intensity for fibrinogen/fibrin in neo-intima covered with endothelium. Our results indicate that an extracellular matrix of fibrin and fibronectin may play a role in migration and proliferation of aortic smooth muscle cells.

Animals↗
PubMed1984

Effect of cooling and warming rate on glycerolized rabbit kidneys.

Cooling and warming rates are known to be important determinants of viability for cryopreserved cells, but optimal rates have not previously been determined for any whole organ. In this study, rabbit kidneys, permeated with 2 M glycerol were cooled to -80 degrees C at four rates varying from 1 degrees C/hr to 3.1 degrees C/min and then rewarmed at four rates from 1 degrees C/hr to 4.2 degrees C/min, giving 16 experimental treatments. After gradual deglycerolization at 10 degrees C, each kidney was autografted and observed for 30 min. Assessment was by measurement of vascular resistance, immediate post-thaw lactate dehydrogenase (LDH) release, gross appearance, light- and electron microscopy, and tissue K+/Na+ ratio 30 min after transplantation. The best results were obtained after cooling at 1 degrees C/hr; warming rate had little apparent influence on the criteria used to assess function with the exception of LDH release, which indicated a preferred warming rate around 1 degrees C/min. Histological studies revealed extensive vascular damage, notably to the glomerular capillaries, that was minimized by very slow cooling. Freeze substitution, carried out on samples removed at -80 degrees C, demonstrated extensive ice formation in the interstitial space and, at the faster cooling rates, in the glomerular capillaries. Intracapillary ice formation was reduced in the kidneys cooled at 1 degrees C/hr.

Animals↗
PubMed1984

Induction of murine alpha-foetoprotein synthesis by oestradiol.

The synthesis of murine alpha-foetoprotein (m-AFP) was induced in 43 out of 47 adult mice of both sexes by sc administration of 100 micrograms oestradiol-17 beta every second day. The m-AFP serum levels of the oestrogen treated male and female mice were 7 and 17%, respectively, of the levels in mice during late pregnancy. Immunohistochemical examination of liver tissue revealed the intracellular presence of m-AFP in less than 0.5% of the hepatocytes scattered throughout the liver of the oestrogen treated mice.

Animals↗
PubMed1983

Pregnancy-associated plasma protein A: a possible marker in the classification and prenatal diagnosis of Cornelia de Lange syndrome.

The concentration of human platelet lactogen (hPL), pregnancy specific beta-1 glycoprotein (SP-1) and pregnancy-associated plasma protein A (PAPP-A) were analysed in consecutive serum samples from a patient who gave birth to a child with Cornelia de Lange syndrome. HPL and SP-1 were present in normal concentrations from week 20 to week 35 of gestation whereas PAPP-A could not be detected in any of the samples examined. Immunohistochemical examination of two placentae from Cornelia de Lange syndrome revealed normal localization of hPL and SP-1 but the absence of PAPP-A from the syncytiotrophoblast. The significance of association between Cornelia de Lange syndrome and compromised synthesis of PAPP-A is discussed.

Adult↗
PubMed1983

Repair in arterial tissue. Demonstration of fibronectin in the normal and healing rabbit thoracic aorta by the indirect immunoperoxidase technique.

Immunoperoxidase staining for fibronectin in ethanol- and formaldehyde-fixed, normal and healing arterial tissue is presented. Proteolytic digestion of sections fixed in formaldehyde increased the staining intensity for fibronectin in media from normal thoracic aorta and in neo-intima covered with endothelium, and had a similar effect on media from thoracic aortae with an embolectomy catheter lesion. The staining reaction for fibronectin in formaldehyde-fixed neo-intima covered with aortic smooth muscle cells was strong and almost independent of proteolytic digestion. In re-endothelialized neo-intima with a high content of proteoglycans a masking effect was observed, probably depending on poor access of immunoglobulins to fibronectin. The masking effect observed in non-re-endothelialized neo-intima with a low content of proteoglycans was much weaker. The correlation between the choice of fixative and unmasking of antigenic determinants by proteases is discussed.

Animals↗
PubMed1983

The importance of the subendothelial connective tissue to the permeability of the neointimal barrier.

The thoracic aortas from two rabbits that had survived a single embolectomy catheter lesion for 2 years were studied by transmission electron microscopy after vital staining with Evans blue. An intimal thickening was formed inside the original internal elastic lamella in the re-endothelialized areas. Small blue areas in the ventral aortic wall showed intact endothelial cells covering an amorphous structureless subendothelial matrix. These observations indicate that endothelial cells do not form an effective barrier in the absence of differentiated subendothelial connective tissue.

Animals↗
PubMed1983

Intracellular and extracellular localization of fibronectin in primary cultures of aortic smooth muscle cells using immunoperoxidase cytochemistry in electron microscopy.

This report describes the intracellular and extracellular localization of fibronectin at the ultrastructural level in primary cultures of aortic smooth muscle cells. Fibronectin was present in all the cisternae of the rough endoplasmic reticulum except the perinuclear cisterna, in large vesicles associated with the trans side of the Golgi complex, and in single large vesicles in the cytoplasm often associated with microtubules. The extracellular microfibrils were heavily stained. In sections parallel to the plane of growth bundles of extracellular microfibrils in continuity with arrays of intracellular microfilaments were observed (fibronexus). The basement membrane around the aortic smooth muscle cells was discontinuous and diffusely stained. The results indicate that fibronectin is localized in the cytoplasmic membranous apparatus of protein synthesis, processing, and secretion. The lack of reaction product in the flat cisternae of the Golgi complex let suggest either that fibronection may not be present in significant amounts within the flattened cisternae or that the method is insufficient in detecting the glycoprotein in this subcompartment off the Golgi complex.

Animals↗
PubMed1983

D-penicillamine-induced angiopathy in rats. The effect of high dose D-penicillamine treatment on aortic permeability to albumin and on the ultrastructure of the vessel.

Male Sprague-Dawley rats were treated with D-penicillamine (D-pen) 500 mg/kg/day for 10 or 42 days. Pair fed rats served as controls. Changes in aortic morphology were examined by light- and transmission-electron microscopy (TEM). In addition, the endothelial permeability and the penetration through the aortic wall of albumin were studied 10 minutes, 24 and 48 hours after i. v. injection of human serum 131I-albumin (131I-HSA). TEM revealed extensive elastolysis in the arterial wall of D-pen-treated rats, consistent with an inhibitory effect on crosslink formation. In experimental animals excess deposition of collagen and glycoaminoglycans was observed in the subendothelial and medial layer of the aortic wall, together with prominent basal membrane substance around aortic smooth muscle cells. The aorta/serum-ratio and the radioactive build-up 24 and 48 hours after injection of 131I-HSA was reduced in animals treated with D-pen for 42 days, indicating an impeded transmural transport of tracer which may be caused by a steric exclusion effect of abundant hyaluronate. The endothelial ultrastructure was unaffected by D-pen, and no differences in aortic 131I-HSA radioactivity or aorta/serum-ratio were recorded between experimental and control groups 10 minutes after tracer injection, indicating that the permeability of the endothelial barrier to albumin remained unaffected by D-pen treatment. These observations support the hypothesis that treatment with high doses of D-pen may induce a fibroproliferative response in rat aorta, possibly by an inhibitory effect on the cross-linking of collagen and elastin.

Animals↗
PubMed1983

Repair in arterial tissue. An ultrastructural demonstration of proteoglycans in low temperature embedded normal and healing arterial tissue.

Low temperature embedded normal and healing arterial tissues were studied by transmission electron microscopy. The most conspicuous observation was the ultrastructurally well-preserved extracellular matrix of the arterial tissue. The proteoglycans were visible as rod-like structures (20-50 nm in width and about 200 nm in length) and radiating filaments connecting the granules to each other. The rod-like structures were removed after testicular hyaluronidase digestion. Chondroitinase ABC digestion removed most of the rod-like structures. Re-endothelialized neointima revealed a high content of rod-like structures forming a three-dimensional muralium joining together basal membrane microfibrils, collagen microfibrils and the microfibrillar component of elastin, whereas non-re-endothelialized neointima showed a reduced content of proteoglycans. The cylindrical granules may represent the proteoglycan monomer with condensed glycosaminoglycan chains.

Animals↗