601
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Ghahary A, Chakrabarti S, Murphy LJ. Localization of the sites of synthesis and action of insulin-like growth factor-I in the rat uterus. Mol Endocrinol 1990; 4:191-5. [PMID: 2158621 DOI: 10.1210/mend-4-2-191] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
In this report we have used in situ hybridization to localize insulin-like growth factor-I (IGF-I) expression in the uterus and have examined the effects of exogenous IGF on 3H-methyl thymidine incorporation into DNA, in uterine sections in organ culture. IGF-I mRNA was detected in all layers of the uterus but was particularly abundant in the outer longitudinal smooth muscle layer. Although IGF-I mRNA was detectable in untreated, immature rat uteri, the abundance in each layer of the uterus was increased after 17 beta-estradiol (E2) administration. A similar increase was seen in uteri from ovariectomized, hypophysectomized rats treated with E2. IGF-I when added to uterine sections in organ culture had no significant effect on DNA synthesis in the absence of E2. However, a dose-dependent increase in DNA synthesis was seen in the presence of E2. The half-maximal and maximal responses required 1 and 10 ng IGF-I, respectively. Autoradiographic localization of 3H-methyl thymidine incorporation into DNA demonstrated that the majority of the DNA synthesis occurred in the stromal layer. These findings are consistent with the hypothesis that IGF-I may function as a paracrine growth factor, mediating stromal-myometrial cell interaction.
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602
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Chakrabarti S, Sima AA. The presence of anionic sites in basement membranes of cerebral capillaries. Microvasc Res 1990; 39:123-7. [PMID: 1690339 DOI: 10.1016/0026-2862(90)90064-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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603
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Chakrabarti S, Prashar S, Sima AA. Augmented polyol pathway activity and retinal pigment epithelial permeability in the diabetic BB rat. Diabetes Res Clin Pract 1990; 8:1-11. [PMID: 2105196 DOI: 10.1016/0168-8227(90)90089-c] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
In the present study we investigated the relationship between an augmented polyol pathway and the breakdown of the blood-retinal barrier in the spontaneously diabetic BB rat. Permeability experiments were performed in diabetic and age-matched non-diabetic BB rats in a longitudinal fashion using horseradish peroxidase. Increased permeability of horseradish peroxidase across the retinal pigment epithelium was noted after 6 months of diabetes. Abnormalities of the basal plasmalemmal infoldings of the retinal pigment epithelium were noted in the control animals and appeared to be exaggerated in diabetic rats. Simultaneous quantitative ultrastructural immunohistochemistry, using an affinity purified anti-BB rat aldose reductase antibody and protein-A gold, revealed a significant increase in the aldose reductase immunoreactivity of the retinal pigment epithelium in diabetic animals. These findings suggest that an augmented polyol pathway activity may play a role in the pathogenesis of the blood-retinal barrier breakdown at the level of the retinal pigment epithelium in the diabetic BB rat.
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604
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Berger EA, Clouse KA, Chaudhary VK, Chakrabarti S, FitzGerald DJ, Pastan I, Moss B. CD4-Pseudomonas exotoxin hybrid protein blocks the spread of human immunodeficiency virus infection in vitro and is active against cells expressing the envelope glycoproteins from diverse primate immunodeficiency retroviruses. Proc Natl Acad Sci U S A 1989; 86:9539-43. [PMID: 2480605 PMCID: PMC298532 DOI: 10.1073/pnas.86.23.9539] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
We previously described an unusual recombinant protein, designated CD4(178)-PE40, containing the gp120 binding region of human CD4 linked to active regions of Pseudomonas exotoxin A. The ability of this molecule to selectively inhibit protein synthesis in cells expressing the surface envelope glycoprotein of human immunodeficiency virus (HIV) suggested this molecule may be useful in treating infected individuals. To further evaluate its therapeutic potential, several in vitro properties of this hybrid toxin were examined. CD4(178)-PE40 was found to be an extremely potent cytotoxic agent, selectively killing HIV-infected cells with IC50 values around 100 pM. In a coculture system employing mixtures of HIV-infected and -uninfected cells, the hybrid toxin inhibited spread of the infection, as judged by a delay in HIV-induced cell killing and a dramatic suppression of free virus production. Experiments with control recombinant proteins indicated that this protective effect was primarily due to selective killing of the HIV-infected cells, rather than to a simple blocking effect of the CD4 moiety of the hybrid toxin. Using recombinant vaccinia viruses as expression vectors, we found the hybrid toxin to be active against cells expressing the envelope glycoproteins of divergent isolates of HIV-1, as well as HIV-2 and simian immunodeficiency virus. These results provide further support for the therapeutic potential of CD4(178)-PE40 in the treatment of HIV-infected individuals.
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605
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Chakrabarti S, Ma N, Sima AA. Reduced number of anionic sites is associated with glomerular basement membrane thickening in the diabetic BB-rat. Diabetologia 1989; 32:826-8. [PMID: 2591649 DOI: 10.1007/bf00264915] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Glomerular basement membranes of diabetic and age- and sex-matched non-diabetic BB rats were studied morphometrically and ultrastructurally using a quantitative histochemical technique employing the cationic dye cuprolinic blue. Six months of diabetes resulted in a significant reduction in the density of anionic sites associated with increased thickness of the glomerular basement membrane. These findings suggest that the loss of anionic sites may be an important mechanism in the genesis of glomerular basement membrane dysfunction in diabetes.
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606
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Chakrabarti S, Poddar MK. Effect of diazepam on electroacupuncture-induced changes in regional gamma-aminobutyric acid of the rat central nervous system. Neurosci Res 1989; 7:24-32. [PMID: 2812569 DOI: 10.1016/0168-0102(89)90034-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Electroacupuncture-induced analgesia (EAA), as assessed in terms of tail flick latency in adult male albino rats, was reduced or completely withdrawn by co-treatment of diazepam with electroacupuncture (EA) (10 Hz, 1 volt), although diazepam (5-20 mg/kg, i.p.) alone had no analgesic effect. Further, it was found that only the gamma-aminobutyric acid (GABA) system of thalamus and pons-medulla regions were involved in EAA. The EA-induced inhibition of GABAergic activity in the thalamus and pons-medulla was disinhibited when diazepam was pre-administered to rats treated with a single EA and reduced the EAA.
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607
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Dey D, Pradhan M, Das SB, Chakrabarti S. Precocious desynapsis of XY-bivalent in mouse germinal cells: influence of mitomycin C on tumour-bearing and normal mice. INDIAN JOURNAL OF EXPERIMENTAL BIOLOGY 1989; 27:757-60. [PMID: 2517268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
A comparative study on the cytotoxic potential of anticancer-antibiotic mitomycin C has been made on tumour-bearing and normal mice considering precocious desynapsis of sex bivalent as parameter. The study indicates a strikingly differential effect of the drug on the phenomenon in two different types of mice. The administration of mitomycin C at therapeutic dose although enhances the frequency of precocious desynapsis of XY-bivalent in non-tumour (normal) mice to a significant extent (compared to control), the same drug at the same dose fails to produce a similar effect on tumour-bearing specimens. Discussions have been made on: (i) the probable cause for this differential effect, (ii) the mechanism of mitomycin action on precocious desynapsis of sex bivalent and, (iii) the possible significance of the findings in relation to cancer chemotherapy.
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608
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Chakrabarti S, Sima AA. Effect of aldose reductase inhibition and insulin treatment on retinal capillary basement membrane thickening in BB rats. Diabetes 1989; 38:1181-6. [PMID: 2504638 DOI: 10.2337/diab.38.9.1181] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
This study compared the effect of glycemic control with insulin to that of the aldose reductase inhibitor ponalrestat on capillary basement membrane thickening in the retinas of diabetic BB rats. Diabetic animals with or without ponalrestat treatment were compared with diabetic rats subjected to vigorous insulin therapy or nondiabetic control rats with or without ponalrestat treatment after 6 mo of follow-up. Untreated diabetic animals showed the characteristic capillary basement membrane thickening in both the superficial and deep capillary beds of the retina. Vigorous blood glucose control with insulin therapy was accompanied by a complete prevention of capillary basement membrane thickening in both capillary beds, whereas aldose reductase inhibitor treatment achieved a complete prevention of basement membrane thickening in the deep capillary bed but not in the superficial capillary bed of the diabetic retina. These findings suggest that the mechanisms responsible for capillary basement membrane thickening in diabetes may be varied and modulated by topographical peculiarities in various capillary beds.
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609
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Ghahary A, Luo JM, Gong YW, Chakrabarti S, Sima AA, Murphy LJ. Increased renal aldose reductase activity, immunoreactivity, and mRNA in streptozocin-induced diabetic rats. Diabetes 1989; 38:1067-71. [PMID: 2526763 DOI: 10.2337/diab.38.8.1067] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Increased accumulation of renal sorbitol has been documented in the diabetic rat, and it has been suggested that this accumulation may be important in the pathogenesis of diabetic nephropathy. It is not clear whether sorbitol accumulation results from increases in substrate, activity of the aldose reductase (AR) protein molecule, or activity due to an increase in the amount of enzyme present. In this study, we have quantitated renal AR activity, immunoreactivity, and mRNA in rats 3 mo after induction of diabetes with streptozocin (STZ-D, 65 mg/kg body wt). Renal AR activity was significantly increased in diabetic rats compared with age-matched nondiabetic controls (0.95 +/- 0.05 vs. 0.51 +/- 0.03 U.mg-1.h-1, respectively, P less than .0005). Western blot analysis demonstrated that the antiserums recognized a single 40,000-Mr protein species in renal homogenates from both diabetic and nondiabetic rats. When quantitated in an immunodot assay, AR immunoreactivity was significantly increased in diabetic rats compared with nondiabetic controls (0.57 +/- 0.03 vs. 0.33 +/- 0.02 U, respectively, P less than .0005). Hybridization of Northern blots with a synthetic 36-nucleotide oligomer and an AR cDNA identified a 1.4-kilobase pair transcript; the abundance of the transcript was significantly increased in poly(A)+ RNA from the kidneys of diabetic compared with nondiabetic rats (P less than .005). This study demonstrates that renal AR activity is increased in the STZ-D rats and suggests that the increased AR activity can be in part explained by enhanced AR gene expression.
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610
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Décarie S, Chakrabarti S. Metabolism and hepatorenal toxicity due to repeated exposure to styrene in spontaneously hypertensive rats (SHR). JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH 1989; 27:455-65. [PMID: 2569538 DOI: 10.1080/15287398909531315] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Groups of adult male rats (5 rats per group), either normotensive (WKY) or spontaneously hypertensive (SHR), were exposed by inhalation to 0, 821, and 3018 ppm styrene, 5 h per day for 3 consecutive days. After the exposure, the urines were collected for 24 h and the animals were then sacrificed. The various biochemical parameters of hepatorenal toxicity due to styrene as well as its urinary metabolites were measured. Hepatotoxicity due to styrene was not further increased at any exposure level due to hypertension. However, repeated exposure of SHR rats to 3018 ppm styrene showed significant increases in the urinary excretion of gamma-glutamyl transpeptidase, proteins, and volume of urine, compared to WKY treated rats, whereas no such changes were observed due to repeated exposure to 821 ppm styrene. Studies of in vivo metabolism of styrene at higher exposure level showed significant decrease in the urinary excretion of mandelic, phenylglyoxylic, and hippuric acids in SHR rats compared to WKY-treated rats, suggesting an inhibition of deactivation of styrene reactive intermediate involving the epoxide hydrase pathway due to hypertension. At the same time, a significant increase in the urinary excretion of a potential nephrotoxic metabolite of styrene (e.g., mercapturates or thioethers) was observed in SHR-treated rats when compared to WKY-treated rats. These results demonstrate that spontaneous hypertension has the potential to further increase the nephrotoxicity due to repeated exposure to styrene, and the metabolism of styrene plays an important role in modifying such toxicity in the hypertensive state.
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611
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Chakrabarti S, Marchant WT, Kaplan GC, Dobson CA, Jernigan JG, Lampton ML, Malina RF. Telescience at the University of California, Berkeley. ACTA ASTRONAUTICA 1989; 19:467-472. [PMID: 11541164 DOI: 10.1016/0094-5765(89)90113-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The University of California at Berkeley (UCB) is a member of a university consortium involved in telescience testbed activities under the sponsorship of NASA. Our Telescience Testbed Project consists of three experiments using flight hardware being developed for the Extreme Ultraviolet Explorer project at UCB's Space Sciences Laboratory. The first one is a teleoperation experiment investigating remote instrument control using a computer network such as the Internet. The second experiment is an effort to develop a system for operation of a network of remote workstations allowing coordinated software development, evaluation, and use by widely dispersed groups. The final experiment concerns simulation as a method to facilitate the concurrent development of instrument hardware and support software. We describe our progress in these areas.
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612
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Chakrabarti S, Srinivasan J, Lall L, Rao LV, Talwar GP. Expression of biologically active human chorionic gonadotropin and its subunits by recombinant vaccinia virus. Gene 1989; 77:87-93. [PMID: 2473009 DOI: 10.1016/0378-1119(89)90362-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Vaccinia virus (VV) expression vector was used to clone the genes for coding alpha and beta subunits of human chorionic gonadotropin (hCG). Recombinant viruses VSL3 and VSS1 containing these genes were selected as blue coloured plaques on the basis of co-expression of Escherichia coli beta-galactosidase in the infected cells. CV-1 cells when infected with VSL3 or VSS1 secreted 2.4 and 1.8 micrograms of alpha and beta hCG subunits, respectively, per 3 x 10(6) cells after 24 h of infection. The subunit proteins expressed individually had immunoreactivity with monoclonal and polyclonal antibodies specific to hCG. The subunit hormonal peptides associated with each other during co-infection to form the complete hCG dimer, which was biologically active as evident from the induction of steroidogenesis in a mouse Leydig cell system.
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613
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Landriault H, Sirois G, Chakrabarti S, Cote MG. Effect of cimetidine on hepatic biochemical changes, liver toxicity and major urinary metabolite excretion of trichloroethylene in rats. J Appl Toxicol 1989; 9:75-81. [PMID: 2715569 DOI: 10.1002/jat.2550090202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The effects of cimetidine (CIM) (an inhibitor of the hepatic microsomal monooxygenase system) on the metabolism and hepatotoxicity of trichloroethylene (TRI) were studied in male Sprague-Dawley rats. Rats were given three doses of 120 mg/kg i.p. (low-dose regimen) of CIM at 0, 6 and 11 h for 1 day, or ten doses of 200 mg/kg (high-dose regimen) at 8, 11, 14 and 17 h for 2 days and 8 and 11 h on 3rd day. Trichloroethylene (0.5 or 0.65 ml/kg) was administered i.p. 1 h after 2nd dose (low-dose regimen) or 9th dose (high-dose regimen) of CIM. In the low-dose regimen study, the activity of hepatic microsomal aminopyrine N-demethylase was decreased 1 and 5 h after the second dose and 7 h after the third dose of CIM, but became normal 20 h after the last dose. The cytochrome P-450 content and the activities of aniline hydroxylase and epoxide hydratase remained unchanged. Trichloroethylene at both dose levels produced liver toxicity, as verified by increase in activities of SDH and SGPT as well as by liver histology. Cimetidine alone had no such effect. An apparent reduction in TRI toxicity by CIM (at both dose regimens) could be observed histologically. The biochemical tests (SDH and SGPT) corroborated the histological changes only when TRI was given at a dose of 0.5 ml/kg combined with a high-dose regimen of CIM. Cimetidine at both dose regimens had a tendency to decrease the in vivo metabolism of TRI.(ABSTRACT TRUNCATED AT 250 WORDS)
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614
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Banerjee SN, Chakrabarti S. Differential clastogenic sensitivity of heterochromatin and euchromatin: evidence from an in vivo study made on a submammalian vertebrate. In Vivo 1989; 3:55-60. [PMID: 2519833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
One of the properties often attributed to heterochromatin is its susceptibility to induced aberrations and exchanges. However, earlier studies made mostly on different mammalian in vitro cell lines on the distribution of aberrations within euchromatin and heterochromatin at metaphase chromosome level have given contradictory results. In the present study, an attempt has been made to evaluate the clastogenic sensitivity of heterochromatin and euchromatin using somatic chromosome complements of a submammalian vertebrate as experimental model and considering both chromosome aberrations and SCEs as end points.
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615
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Lall L, Srinivasan J, Rao LV, Jain SK, Talwar GP, Chakrabarti S. Recombinant vaccinia virus expresses immunoreactive alpha subunit of ovine luteinizing hormone which associates with beta-hCG to generate bioactive dimer. INDIAN JOURNAL OF BIOCHEMISTRY & BIOPHYSICS 1988; 25:510-4. [PMID: 2475429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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616
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Flexner C, Broyles SS, Earl P, Chakrabarti S, Moss B. Characterization of human immunodeficiency virus gag/pol gene products expressed by recombinant vaccinia viruses. Virology 1988; 166:339-49. [PMID: 2459842 DOI: 10.1016/0042-6822(88)90504-1] [Citation(s) in RCA: 62] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Recombinant vaccinia viruses containing either the entire gag/pol gene or the reverse transcriptase (RT) domain of the human immunodeficiency virus (HIV) were constructed. In mammalian cells infected with the recombinant vaccinia virus containing the gag/pol gene, major and minor polypeptides of 55 and 41 kDa were made, but processed gag products (p24/p17/p15) were not detected. In addition, none of the products of the pol open-reading frame were seen. Both the 55- and 41-kDa gag proteins were post-translationally modified by addition of myristic acid residues in recombinant vaccinia-infected cells, and were immunoprecipitated by antiserum to p24 gag, as well as by antisera from HIV-infected patients. These results indicate that neither proteolytic processing nor other HIV proteins are required for myristilation, and suggest that the 55- and 41-kDa gag precursors share the same amino terminus as p17. Cells infected with a separate vaccinia recombinant containing a truncated piece of the gag/pol gene with added start and stop codons at the 5' and 3' ends of the RT reading frame synthesized a major 61-kDa and a minor 51-kDa protein product which reacted immunologically with both a monoclonal antibody to native HIV p66/51 and antisera from HIV-infected patients. These proteins were purified from recombinant vaccinia-infected mammalian cells, and their enzyme activity was found to be similar to that of authentic HIV RT. Cells infected with the vaccinia/RT vector contained approximately 200-fold more RT per milligram of protein than cells infected with HIV. Recombinant RT was inhibited by dideoxynucleoside triphosphates and should be useful in screening for specific inhibitors of this enzyme. Mice inoculated intradermally with 10(8) plaque-forming units of the vaccinia/RT vector developed specific antibodies to the p66/51 proteins of HIV, but anti-HIV antibodies were not detected in mice inoculated with the vaccinia/gag vector.
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617
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Chakrabarti S, Ganguly A, Poddar MK. Possible involvement of the GABAergic system in dopaminergic-cholinergic interactions in electroacupuncture-induced analgesia. METHODS AND FINDINGS IN EXPERIMENTAL AND CLINICAL PHARMACOLOGY 1988; 10:545-9. [PMID: 3265752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The involvement of the GABA system in dopamine-acetylcholine interactions in electroacupuncture induced analgesia (EAA), measured in terms of tail flick latency (TFL) test, was studied with administration of the GABA receptor agonist, muscimol (1 mg/kg, i.p.); antagonist, bicuculline (2 mg/kg, i.p.); GABAmimetic drug, ethanolamine-O-sulfate (EOS) (2 mg/kg, s.c.) or the drugs stimulating or inhibiting acetylcholine and dopamine receptors activity to rats exposed to electroacupunture (EA). All the drugs were administered prior to EA (10 Hz, 1 volt) exposure (2-15 min). Results observed under the above conditions suggest that the cholinergic system has a direct inhibitory role on EAA and the dopaminergic system mediates its action via the cholinergic system. A decrease in EAA with both the GABA receptor agonist and antagonist and tremendous increase of EAA with the gabamimetic drug, EOS, showed that GABA receptors may not be directly involved in EAA. Further (a) gradual withdrawal of muscimol, bicuculline or physostigmine induced decrease in EAA with the increase in duration of EA exposure; (b) the characteristic changes in EAA observed with the coadministration of (i) L-DOPA + carbidopa + muscimol (ii) atropine + muscimol; and (c) no significant change in bicuculline + physostigmine induced inhibition of EAA with the increase in duration of EA exposure suggest that some inhibitory substance(s) may be released during EA which may inhibit the GABA system and finally cholinergic activity through the activation of dopaminergic neurone.
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618
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Glajchen N, Epstein S, Ismail F, Thomas S, Fallon M, Chakrabarti S. Bone mineral metabolism in experimental diabetes mellitus: osteocalcin as a measure of bone remodeling. Endocrinology 1988; 123:290-5. [PMID: 3133194 DOI: 10.1210/endo-123-1-290] [Citation(s) in RCA: 63] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The etiology of diabetic osteopenia has not been established. The value of serum osteocalcin (BGP) as a marker of the bone abnormalities and the possible role of the polyol pathway in diabetic osteopenia were investigated. Three groups of rats were studied over 7 weeks: group D (n = 12), rats with streptozotocin (55 mg/kg)-induced diabetes given saline by gavage; group DS (n = 12), rats with streptozotocin-induced diabetes given the aldose reductase inhibitor sorbinil (25 mg/kg) daily by gavage; and group C (n = 6), saline-injected controls. Circulating levels of ionized calcium, BGP, amino-terminal PTH, and glucose were measured on days 0, 7, 14, 28, and 49. Tibial bone specimens were examined for the presence of aldose reductase by immunocytochemistry and by histomorphometry after tetracycline labeling. Diabetic rats with or without sorbinil treatment failed to gain weight [group D, 234 +/- 26 g; group DS, 217.0 +/- 40 g; group C, 310 +/- 33 g (mean +/- SD)]. Serum BGP levels decreased significantly in the diabetic rats within 7 days and remained lower throughout the study. BGP values on day 7 were: group D, 47.7 +/- 4.9 ng/ml; group DS, 65.9 +/- 5.5 ng/ml; and group C, 90.4 +/- 4 ng/ml (mean +/- SEM). Serum PTH levels were similar in all groups, except for day 49, when an increase in the D group was observed. Bone histomorphometry showed decreased bone remodeling in the D group, which confirmed the serum BGP findings. Aldose reductase was detectable in the small blood vessels and in bone itself. Sorbinil failed to influence the biochemical or bone histomorphometric abnormalities associated with diabetes. Serum BGP may be a valuable marker for the decreased bone remodeling in insulinopenic diabetes.
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619
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Igarashi S, Myung SS, Chiba R, Hanaoka K, Miyashita M, Murata H, Yokota H, Bacala A, Imlay R, Kirk P, McNeil RR, Metcalf W, Cheng CP, Mao ZP, Yan Y, Xu YT, Zhou HS, Zhu YC, Abashian A, Gotow K, Kajino F, Naito F, Childers R, Darden C, Edwards J, Lusin S, Rosenfeld C, Wilson S, Johnson D, Frautschi M, Kagan H, Kass R, Trahern CG, Lee HY, Ko W, Lander RL, Maeshima K, Malchow RL, Sparks K, Williams MC, Abe K, Chakrabarti S, Fujii Y, Higashi T, Ishimoto S, Kurihara Y, Maki A, Nozaki T, Omori T, Perez P, Sagawa H, Sakai Y, Sugimoto Y, Takaiwa Y, Terada S, Tsuchiya K, Poling R, Aldritch A, Green J, Park IH, Sakamoto S, Sannes F, Schnetzer S, Stone R. Search for isolated leptons in low-thrust e+e- annihilation events at sqrt s =50 and 52 GeV. PHYSICAL REVIEW LETTERS 1988; 60:2359-2362. [PMID: 10038331 DOI: 10.1103/physrevlett.60.2359] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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620
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Shepp DH, Chakrabarti S, Moss B, Quinnan GV. Antibody-dependent cellular cytotoxicity specific for the envelope antigens of human immunodeficiency virus. J Infect Dis 1988; 157:1260-4. [PMID: 3163712 DOI: 10.1093/infdis/157.6.1260] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
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621
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Buller RM, Chakrabarti S, Moss B, Fredrickson T. Cell proliferative response to vaccinia virus is mediated by VGF. Virology 1988; 164:182-92. [PMID: 3363864 DOI: 10.1016/0042-6822(88)90635-6] [Citation(s) in RCA: 110] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
VGF, a polypeptide encoded by vaccinia virus, shares amino acid sequence homology and functional properties with cellular growth factors EGF and TGF-alpha. The availability of a VGF minus (VGF-) virus mutant has enabled us to examine the role of VGF in the replication of virus in vitro and in vivo. Studies in vitro with A431 cells (high EGF receptor density) showed that VGF+ wild-type virus induced the rapid formation of a focus of infection (not a plaque) which could be blocked by a monoclonal antibody to the EGF receptor. In vivo experiments with chicken embryos indicated that VGF+ virus stimulated the growth of ectodermal and entodermal cells of the chorioallantoic membrane. At early times, the majority of proliferating cells contained no detectable virus antigen, indicating that cell growth preceded infection and was a consequence of VGF secretion. Relative to VGF- virus, VGF+ virus produced lesions which contained more proliferating cells, more virus antigen, and increased amounts of infectious progeny. Secretion of VGF thus explains the conundrum of a nontransforming, strongly cytopathic virus inducing a hyperplastic cell response.
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622
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Chakrabarti S, Sen PC, Sinha NK. Purification and characterization of a low molecular weight basic protein from marine turtle egg white. Arch Biochem Biophys 1988; 262:286-92. [PMID: 2833172 DOI: 10.1016/0003-9861(88)90190-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The egg white of marine turtle (Caretta caretta Linn.) and one species of tortoise (Geomyda trijuga trijuga Schariggar) contain a low molecular weight basic protein. It has been purified to homogeneity from the egg white of marine turtle and characterized in terms of its major physicochemical and chemical properties. The molecular weight of this protein calculated from gel filtration, sodium dodecyl sulfate-gel electrophoresis in the presence of urea, sedimentation-diffusion data, and amino acid composition is 4300. Its isoelectric point is at pH 11.1 and intrinsic viscosity is 0.038 dl g-1 in 0.2 M NaCl. It has a Stokes radius of 12.6 A and a diffusion coefficient of 16.50 x 10(-7) cm2 s-1. Analysis of the far-ultraviolet circular dichroic spectrum has shown that the basic protein contains 27% beta-pleated sheet and little or no alpha-helix. It possesses a single polypeptide chain of 40 amino acid residues with three disulfide bonds. It lacks serine, methionine, phenylalanine and carbohydrate moiety. It binds to DNA and stimulates ATPase activity due to its strong basicity. The complex of DNA-basis protein is partially resistant to the action of DNase.
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623
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Buller RM, Chakrabarti S, Cooper JA, Twardzik DR, Moss B. Deletion of the vaccinia virus growth factor gene reduces virus virulence. J Virol 1988; 62:866-74. [PMID: 3339716 PMCID: PMC253644 DOI: 10.1128/jvi.62.3.866-874.1988] [Citation(s) in RCA: 167] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The vaccinia virus growth factor (VGF) gene encodes a polypeptide with amino acid sequence homology to epidermal growth factor (EGF) and transforming growth factor alpha and is present twice, once at each end of the virus genome within the inverted terminal repetition. Recombination procedures were used to replace more than half of both VGF genes with a beta-galactosidase cassette which served as a color indicator for isolating an unconditionally viable VGF- mutant. The VGF- mutant genotype and phenotype were confirmed by Southern blot analysis and assays for functional growth factor. The plaque-forming efficiencies of VGF- and wild-type (WT) viruses were similar in a variety of cell types containing low or high densities of EGF receptors, suggesting a lack of a specific requirement for either VGF or the EGF receptor in the initiation of virus infection. The yield of VGF- virus was similar to that of WT virus in growing BS-C-1 and Swiss 3T3 cells, but lower in resting Swiss 3T3 cells. The greatest differences between VGF- and WT virus occurred in vivo: higher doses of VGF- virus than WT virus were required for intracranial lethality in mice and for production of skin lesions in rabbits. Thus, expression of the VGF gene is important to the virulence of vaccinia virus.
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624
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Sima AA, Chakrabarti S, Tze WJ, Tai J. Pancreatic islet allograft prevents basement membrane thickening in the diabetic rat retina. Diabetologia 1988; 31:175-81. [PMID: 3131171 DOI: 10.1007/bf00276852] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Progressive basement membrane thickening is a characteristic structural abnormality in diabetic tissues including the retina. We examined the effect of pancreatic islet allotransplantation on basement membrane thickening and irregularities in retinal capillaries of the streptozotocin-diabetic rat. Diabetic animals received intraportal or intracerebral pancreatic islet allografts. Animals with functioning allografts demonstrated euglycaemia and a normal body weight gain during the 400-day post-transplantation period. The characteristic thickening of capillary basement membranes was completely prevented in animals with successful transplantation. The present findings suggest that islet allotransplantation may be a rational therapeutic approach in the treatment of diabetes mellitus and the prevention of ensuing secondary complications.
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625
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Sagawa H, Mori T, Abe K, Chakrabarti S, Fujii Y, Higashi Y, Ishimoto S, Kurihara Y, Maki A, Mani P, Nozaki T, Omori T, Perez P, Sakai Y, Sugimoto Y, Takaiwa Y, Terada S, Tsuchiya K, Bacala A, Imlay R, Kirk P, Marterer W, McNeil RR, Metcalf W, Cheng CP, Mao ZP, Yan Y, Xu YT, Zhou HS, Zhu YC, Abashian A, Gotow K, Kajino F, Naito F, Avignone F, Childers R, Darden C, Edwards J, Lusin S, Rosenfeld C, Wilson S, Johnson D, Frautschi M, Kagan H, Kass R, Trahern CG, Lee HY, Ko W, Lander RL, Maeshima K, Malchow RL, Saroff D, Sparks K, Williams MC, Aldritch A, Green J, Park IH, Sakamoto S, Sannes F, Schnetzer S, Stone R, Trentalange S, Zimmerman D, Miyano K. Measurements of R and a search for heavy-quark production in e+e- annihilation at sqrt s =50 and 52 GeV. PHYSICAL REVIEW LETTERS 1988; 60:93-96. [PMID: 10038207 DOI: 10.1103/physrevlett.60.93] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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