| 1. |
- Agardh, Carl-David, et al.
(författare)
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The influence of plasma insulin concentrations on tissue insulin levels in rodents: a study of the diabetic Chinese hamster and the ob/ob mouse
- 1986
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Ingår i: Metabolism, Clinical and Experimental. - : Elsevier BV. - 1532-8600. ; 35:3, s. 244-249
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Tidskriftsartikel (refereegranskat)abstract
- Immunoreactive insulin was measured in acid-ethanol extracts of kidney, brain, liver, and heart from genetically diabetic Chinese hamsters and their nondiabetic controls and from obese (ob/ob) mice and their thin littermates. Selected samples were filtered on Sephadex G-50 columns and the insulin concentration determined. There was a good correlation between the insulin level measured in the acid-ethanol extracts of tissues and the insulin level after gel filtration, suggesting that the concentration measured in the whole extract is representative of the true insulin content. The present data demonstrate that different extrapancreatic organs contain characteristic amounts of insulin that are often (sometimes several-fold) higher than the insulin level of plasma. The tissue insulin concentrations also exhibit a wide range of values, with occasional high values. The data also show a direct correlation between plasma and kidney insulins but no relationship between plasma and brain insulins and a mixed correlation among plasma and liver and heart insulins.
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| 2. |
- Akerstrom, B., et al.
(författare)
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Structural relationship between α1-microglobulin from man, guinea-pig, rat and rabbit
- 1988
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Ingår i: European Journal of Biochemistry. - 0014-2956. ; 170:1-2, s. 143-148
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Tidskriftsartikel (refereegranskat)abstract
- Rabbit α1-microglobulin was purified from the urine of sodium-chromate-treated animals by the use of gel chromatography on Sephadex G-100 affinity chromatography on concanavalin-A - Sepharose and ion-exchange chromatography on DEAE-Sephadex. Rabbit α1-microglobulin had a molecular mass of 25.6 kDa on SDS/polyacrylamide gel electrophoresis. α1-microglobulin has previously been purified from the urine of humans, guinea-pigs and rats by similar methods, and the molecular masses of the four homologues were compared by SDS/polyacrylamide gel electrophoresis and gel chromatography in a denaturing medium. By these two methods the human homologue was 6 kDa and 3 kDa larger, respectively, than the other three proteins. Endoglycosidase F digestion of α1-microglobulin, followed by SDS/polyacrylamide gel electrophoresis, revealed three protein bands in the human α1-microglobulin sample, and only two bands in guinea-pig, rat and rabbit α1-microglobulin, with a gap between each band of 2.6-2.9 kDa. The amino-terminal amino acid sequences of the four homologues were determined and between 72% and 81% homology was seen. The five amino-terminal amino acids present in the other species were missing in guinea-pig α1-microglobulin. Our results indicate that human α1-microglobulin is substituted with two N-linked oligosaccharides, while only one is attached to each of the other α1-microglobulins, and that the extra glycosylamine-linked oligosaccharide in the human protein is attached to asparagine in position 17. Finally it is shown that all four homologues inhibit antigen stimulation of human lymphocytes, a finding which is consistent with our previous suggestion that the N-linked oligosaccharides carry the immunosuppressive activity of α1-microglobulin.
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| 3. |
- Alsheikhly, Abdul-Razzak
(författare)
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Virus mediated induction of antibody independent cytotoxicity (VDCC) and enhancement of antibody dependent cytotoxicity (ADCC) in human lymphocytes in vitro
- 1984
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Addition in vitro of small amounts of paramyxoviruses (Mumps or Sendai) to lymphocytes from healthy human donors induces a strong and non-selective cytotoxicity against a variety of target cells (VDCC, virus dependent cellular cytotoxicity). VDCC-like reactions are believed to play a role in vivo in the defense against virus infection and/or the causation of the tissue lesions associated with virus disease. The aim of this study was to investigate the mechanism of VDCC induction, its relationship to other lymphocyte mediated cytotoxic reactions and the nature of the effector cells involved.UV-inactivated virions induce VDCC as efficiently as live virus, indicating that it is not dependent on infection of either lymphocytes or target cells. Removal from the virions of the HN-surface glycoprotein carrying hemagglutination and neuraminidase activities abrogated VDCC. Removal of the F protein (F=fusion) was less efficient. When the lymphocytes were treated with solubilized HN- or F proteins, the HNprotein had full capacity to induce VDCC while the F protein was inactive. The importance of the HN-protein for VDCC was also supported by inhibition experiments with virus specific antibodies. Monoclonal anti-HN antibodies (mumps) inhibited VDCC whereas anti-F, anti-M (membrane) or anti-NP (nucleoprotein) antibodies did not. By using a panel of monoclonals directed to several distinct determinants of the HN-polypeptide, it was shown that at least 3 serologically defined structures of this protein were involved in VDCC induction. These structures appeared to be different from those involved in hemagglutination, hemolysis, neuraminidase activity and infectivity of the virus.When assayed at the level of the effector cell population (51Cr-release), VDCC was reflected by increased target cell lysis. At the effector cell level (single cell conjugate assay), VDCC was the expression of recruitment of both target-binding cells and target killing cells. In short term assays, virus treatment of the lymphocytes did not increase their recycling capacity, confirming that VDCC was primarily due to recruitment. Virus treatment of lymphocytes induces the release of interferon, known to enhance their cytotoxicity. VDCC induction appears to be independent of interferon. However, an activating effect of interferon in later phases of VDCC is not excluded.Cell fractionation experiments and single cell assays in combination with surface marker studies showed that VDCC effector cells were heterogeneous, including both large granular lymphocytes (LGL) and small to medium sized lymphocytes with Tcell characteristics. The cytotoxic effector cells recruited by virus comprised both lymphocytes bearing the LGL-associated HNK-1 antigen and lymphocytes bearing T-cell associated antigens. In absolute numbers, the majority of die effector cells had T-cell characteristics. However, the proportion of the latter differed for target cells of different types, suggesting that the target cells play a role in effector cell selection.VDCC is non-selective and is not MHC restricted, indicating that it is not mediated by specifically cytotoxic T-lymphocytes (CTL). Experiments with cord blood lymphocytes also showed that VDCC was not induced through specific or polyclonal activation by some viral material. VDCC induction is also independent of the participation of anti-target cell antibodies. However, virus treatment of the lymphocytes strongly enhanced their antibody dependent cytotoxicity (ADCC) both against VDCC susceptible tumor target cells and against VDCC resistant erythrocytic target cells. ADCC enhancement was a reflection of effector cell recruitment, primarily involving lymphocytes bearing T-cell markers. It was inhibited by monoclonal antibodies to the HN-protein. Taken together, these experiments showed that virus enhances ADCC by improving the effector cell target cell contacts necessary for cytotoxicity expression. This also results in a significant reduction in the amounts of antitarget cell antibodies required for the triggering of cytotoxicity.
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| 4. |
- Ayer-LeLievre, C, et al.
(författare)
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Nerve growth factor mRNA and protein in the testis and epididymis of mouse and rat.
- 1988
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - 0027-8424 .- 1091-6490. ; 85:8, s. 2628-32
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Tidskriftsartikel (refereegranskat)abstract
- In situ hybridization using beta-nerve growth factor (NGF) DNA probes was used to demonstrate NGF mRNA in spermatocytes and early spermatids of adult mouse. NGF mRNA-containing cells were also identified in the epithelium of convoluted ducts in mouse corpus epididymidis. Blot-hybridization analysis of RNA prepared from mouse testis and epididymis as well as from rat epididymis confirmed the presence of a 1.3-kilobase (kb) NGF mRNA in these tissues. In the rat testis, however, only a 1.5-kb NGF mRNA was found, corresponding in size to a minor NGF mRNA detected in the rat brain, heart, and epididymis. By using affinity-purified anti-NGF antibodies, NGF-like immunoreactivity was observed in germ cells of rat and mouse testis and in the lumen of epididymis. Extracts of both mouse epididymis and testis stimulated fiber outgrowth in cultured sympathetic ganglia, and the effect was blocked by antibodies to mouse NGF. A two-site enzyme immunoassay showed the presence of 10 and 70 ng of NGF per g of tissue in the mouse testis and epididymis, respectively. Furthermore, RNA blot analysis showed the presence of mRNA for the NGF receptor in mouse testis. These results suggest a nonneurotrophic role for NGF in the male reproductive system, possibly in survival maturation and/or motility of spermatozoa.
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| 5. |
- Bondeson, Lennart, et al.
(författare)
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Breast reductions: what to do with all the tissue specimens?
- 1985
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Ingår i: Histopathology. - : Wiley. - 0309-0167 .- 1365-2559. ; 9:3, s. 281-285
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Tidskriftsartikel (refereegranskat)abstract
- In order to find some guidelines for adequate examination of the often very large amount of tissue removed at reduction mammoplasties, a thorough macro- and microscopic study of a total of 400 specimens from 200 consecutive cases of bilateral breast reductions was done. The majority of patients were younger than 30 years of age. In these cases no abnormalities were found and a thorough macroscopic examination performed by an experienced pathologist is believed to be sufficient in this age group. In older women we encountered diverse findings, the most noteworthy being lobular carcinoma in situ in 8% of patients in this series who were over 40 years of age. This indicates the need for generous histological sampling in this age group. The potential value of roentgenological examination is also discussed.
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| 6. |
- Cöster, Lars, et al.
(författare)
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Structure of proteoheparan sulfates from fibroblasts. Confluent and proliferating fibroblasts produce at least three types of proteoheparan sulfates with functionally different core proteins
- 1986
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Ingår i: Journal of Biological Chemistry. - 1083-351X. ; 261:26, s. 12079-12088
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Tidskriftsartikel (refereegranskat)abstract
- [3H]Leucine- and [35S]sulfate-labeled proteoheparan sulfates were isolated from postconfluent or proliferating cultures of human skin fibroblasts. Cell layers were solubilized by Triton X-100, and transferrin-binding macromolecules were isolated by affinity chromatography. Proteoglycans with no affinity for transferrin were purified by using ion-exchange and gel permeation chromatography. Postconfluent cells synthesize a proteoheparan sulfate of Mr 350,000 (as determined by gel permeation chromatography) which has affinity for transferrin as well as for octyl-Sepharose. Its core protein (Mr 180,000) consists of two disulfide-bonded polypeptides of Mr 90,000. This species was not detected in cultures of proliferating cells. Proliferating and confluent cells also synthesize other forms of proteoheparan sulfates (Mr 200,000-400,000) which have no affinity for transferrin. However, most of them have affinity for octyl-Sepharose. The core protein of proteoheparan sulfates made by proliferating cells has Mr 50,000. A smaller form (Mr 250,000) of this proteoglycan was solubilized by Triton X-100, whereas a larger form (Mr 400,000) remained associated with the pericellular matrix. A third type of proteoheparan sulfate (Mr 200,000) without affinity for transferrin nor octyl-Sepharose was associated with postconfluent cell layers but not with proliferating ones. Its core protein has Mr 35,000. Heparan sulfate oligosaccharides (Mr 6,000 or higher) were found in proliferating cells but not in postconfluent ones.
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| 7. |
- Duan, R D, et al.
(författare)
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Stimulatory effects of human pancreatic polypeptide on rat pancreatic acini
- 1985
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Ingår i: Regulatory Peptides. - 0167-0115. ; 12:3, s. 215-222
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Tidskriftsartikel (refereegranskat)abstract
- The effect of human pancreatic polypeptide (HPP) on rat pancreatic acini has been studied. It was found that HPP stimulated amylase and lipase release from the acini. The secretory response of acini to HPP was dose-dependent in a sigmoidal fashion. Between 10(-9) M and 10(-8) M concentration of HPP there was a slow increase of enzyme release to about 40-60% over basal release. At concentrations of HPP above 10(-8) M there was a rapid increase of enzyme release, amounting to 4-6 times over basal release at 10(-6) M concentration of HPP. The potency of HPP compared to other secretagogues at 10(-7) M concentration was 45% of CCK, 60% of carbachol and 75% of secretin. HPP did not inhibit the effect of CCK, secretin and carbachol on amylase release. The amylase release stimulated by HPP was accompanied by an increase in 45Ca2+ efflux. Atropine or dibutyryl cyclic GMP did not influence the effect of HPP. It is concluded that HPP stimulates the release of enzymes from rat pancreatic acini and that Ca2+ may be a mediator for this secretion.
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| 8. |
- Ekström, Per A R, et al.
(författare)
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Impaired nerve regeneration in streptozotocin-diabetic rats. Effects of treatment with an aldose reductase inhibitor
- 1989
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Ingår i: Journal of the Neurological Sciences. - 0022-510X. ; 93:2-3, s. 231-237
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Forskningsöversikt (refereegranskat)abstract
- Rats with streptozotocin-induced diabetes have a decreased rate of sciatic nerve regeneration. We studied the effects on this defect of treatment with the aldose reductase inhibitor, ponalrestat (25 mg/kg per day via an endogastric tube). The nerves of diabetic rats were crush-injured at 5 weeks of diabetes and regeneration evaluated 7 days later with the pinch-reflex test. Ponalrestat treatment was started at day 3 after streptozotocin injection and was continued for the whole experimental period, i.e. until 6 weeks of diabetes. The treatment prevented effectively the accumulation of sorbitol and fructose in the nerves of diabetic rats, but was without effect on the sciatic nerve regeneration (controls 21.8 ± 1.2 mm/7 days (mean ± SEM, n = 6), untreated diabetics 15.8 ± 1.8 (n = 7), ponalrestat-treated diabetics 16.2 ± 1.0 (n = 10)). The results indicate that there is no connection between increased sorbitol pathway flux and impaired regeneration in streptozotocin diabetic rats.
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| 9. |
- Escribano, Julio, et al.
(författare)
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Identification of retinol as one of the protein HC chromophores
- 1988
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Ingår i: Biochemical and Biophysical Research Communications. - : Elsevier BV. - 0006-291X. ; 155:3, s. 1424-1429
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Tidskriftsartikel (refereegranskat)abstract
- Protein HC (alias alpha 1-microglobulin) contains so far unidentified yellow-brown fluorescent chromophores. Several preparations of human protein HC were extracted with hexane. Most of the extracts contained a substance which, upon reversed-phase HPLC, co-eluted with all-trans- retinol and had an absorption spectrum identical to that of retinol. The substance was also, like retinol, destroyed by exposure to ultraviolet light and acid pH. These observations strongly support the proposal that protein HC is a member of the newly defined lipocalin protein superfamily. The highest retinol-protein HC molar ratio of the investigated protein HC preparations was 1.6 x 10(-3) indicating that retinol is not the only ligand bound to protein HC. This was confirmed by comparing the absorption spectrum of protein HC before and after hexane extraction.
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| 10. |
- Fex, G, et al.
(författare)
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Isolation and partial characterization of a low molecular weight trypsin inhibitor from human urine
- 1981
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Ingår i: Biochimica et Biophysica Acta. - : Elsevier BV. - 0006-3002 .- 0005-2795. ; 667:2, s. 8-303
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Tidskriftsartikel (refereegranskat)abstract
- A low molecular weight glycoprotein which completely inhibited trypsin at a 1 : 1 molar ratio was isolated from human urine. It was generated from a precursor molecule which in turn derived from plasma inter-alpha-trypsin inhibitor. It had one polypeptide chain with a molecular weight of about 20 000 and a high content of half-cystine residues. Its amino-terminal amino-acid sequence was Val-Thr-Glu-Val-Thr-X-Leu-Glu-Asp-.
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