The participation of tumor necrosis factor in the pathogenesis of lung allograft rejection in the rat.

Tumor necrosis factor alpha and beta are polypeptide cytokines with a wide range of metabolic, immunologic, and inflammatory activities. TNF is known to participate in immune mediated injury of native lungs, but a role for TNF in mediating lung allograft rejection (AR) has not been established. In experiments reported here, we assessed the role of TNF in mediating lung AR in a rat model of lung transplantation (BN-->Lew) (RT1n-->RT1l).

Insulin-like growth factor-I stimulates the expression of 3 beta-hydroxysteroid dehydrogenase messenger ribonucleic acid in ovarian theca-interstitial cells.

Evidence accumulating in the literature supports the hypothesis that insulin-like growth factor-I (IGF-I) may play a role in stimulating differentiation of the ovarian theca-interstitial cells (TIC) during early follicular development. IGF-I has been shown to synergistically enhance the stimulation of androgen biosynthesis and to increase LH binding in TIC. The purpose of the present studies was to examine the role of IGF-I in TIC differentiation by determining the effects of IGF-I on 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD) mRNA expression in TIC stimulated to differentiate in vitro.

Interaction between insulin and thyroid hormone in rat pituitary tumour cells: insulin attenuates tri-iodothyronine-induced growth hormone mRNA levels.

Insulin has previously been shown to inhibit basal and stimulated rat GH (rGH) secretion as well as basal GH transcription in rat pituitary cells. The effect of physiological doses of insulin on tri-iodothyronine (T3)-stimulated GH mRNA levels in rat pituitary tumour cells was therefore examined. Insulin (7 nmol/l) suppressed T3-stimulated GH mRNA levels in GC and GH3 rat pituitary tumour cells by 58%.

Serum cytokine levels in heart allograft recipients: correlation with findings on endomyocardial biopsy.

The ability to detect rejection of human cardiac allografts depends on endomyocardial biopsy diagnosis. Because cytokines are known to mediate allograft rejection events, we chose to examine serum levels of specific cytokines and receptors (interleukin-2 [IL-2], IL-2 receptor [IL-2R], and tumor necrosis factor alpha [TNF-alpha]) and to correlate those levels with findings on endomyocardial biopsy. Sequential sera samples from 23 cardiac allograft recipients were examined for the cytokine levels mentioned, and data correlated with findings on endomyocardial biopsy.

Human insulin-like growth factor I receptor function in pituitary cells is suppressed by a dominant negative mutant.

Hybrid receptors were studied in GC rat pituitary cells overexpressing either wild-type 950Tyr (WT) human insulin-like growth factor I (IGF-I) receptors or mutant human IGF-I receptors truncated at position 952 in the beta subunit transmembrane region (952STOP). 125I-IGF-I binding was increased in both 950Tyr (WT) (14-fold) and truncated human IGF-I receptor (952STOP) stable transfectants (50-fold), when compared to untransfected cells that contained endogenous rat IGF-I receptors. Metabolic cell labeling followed by immunoprecipitation with monoclonal alpha and beta subunit-specific antibodies revealed the presence of hybrid rat/truncated human receptors, truncated transfected human receptors, and WT human IGF-I holotetramers.

Somatostatin analog induces insulin-like growth factor binding protein-1 (IGFBP-1) expression in human hepatoma cells.

As the somatostatin analog octreotide suppresses pituitary GH secretion and circulating IGF-1 levels, we examined its effects on human hepatoma (hep G2) cells which selectively express IGFBP-1. Octreotide (60 nM) stimulated IGFBP-1 up to 4.1-fold (p < 0.

Human insulin-like growth factor I receptor 950tyrosine is required for somatotroph growth factor signal transduction.

Insulin-like growth factor I (IGF-I), a growth hormone (GH)-dependent growth factor exerts feedback regulation of GH by inhibiting GH gene expression. IGF-I inhibition of GH secretion is enhanced 3-5-fold in GC rat pituitary cells overexpressing the wild type 950Tyr human IGF-I receptor which autophosphorylates appropriately. To determine the critical amino acid sequence responsible for IGF-I signaling, insertion, deletion, and site-directed mutants were constructed to substitute for 950Tyr in exon 16 of the human IGF-I receptor beta-subunit transmembrane domain.

Insulin-like growth factor binding proteins in ovarian follicles from women with polycystic ovarian disease: cellular source and levels in follicular fluid.

The follicular fluid (FF) of human ovaries contains insulin-like growth factor binding proteins (IGFBPs) which may regulate the bioavailability of the IGFs. Previously we showed discrete changes in IGFBP concentrations in FF which correlated with the physiological state of the follicle. The purpose of the present study was to test the hypothesis that IGFBPs in FF may be increased in polycystic ovarian disease (PCO).

Serum interleukin-2 levels in lung transplant recipients: correlation with findings on transbronchial biopsy.

Serum interleukin-2 (IL-2) levels were examined in the serum of 17 lung transplant recipients who underwent transbronchial biopsies to diagnose reasons for allograft dysfunction. Over 60 transbronchial biopsies were performed in these 17 patients in a 22-month observation period. Mean serum IL-2 levels were significantly elevated in patients experiencing allograft rejection (p less than 0.

Differential regulation of insulin-like growth factor I by growth hormone and thyroid hormone in the heart of juvenile hypophysectomized rats.

Recent data suggest that the heart can act as both a source and target for the actions of polypeptide growth factors. Insulin-like growth factor I (IGF-I) is a polypeptide that has both mitogenic and differentiation properties that function at the autocrine/paracrine level, and has recently been demonstrated to be expressed in the heart. This knowledge, coupled with the observation that thyroid hormone (T3) promotes relative cardiac growth compared to the proportional increases in body and heart growth evoked by growth hormone (GH), lead us to speculate whether differential induction of cardiac IGF-I may account for the specialized trophic effects of T3 on the heart.

Octreotide stimulates insulin-like growth factor binding protein-1 (IGFBP-1) levels in acromegaly.

Insulin-like growth factors (IGFs) circulate in a complexed state with several binding proteins (BPs). Of these, IGFBP-1 is regulated by hormonal and nutritional factors. The somatostatin analogue, octreotide, has been used to effectively control hypersomaototropism in acromegaly.

Binding and action of insulin-like growth factor I in pituitary tumor cells.

Insulin-like growth factor I (IGF-I), a target hormone mediating most of the growth effects of GH, suppresses GH gene expression in a feedback regulatory loop, which may be either endocrine or paracrine in nature. Although IGF-I has been shown to directly attenuate GH gene transcription, the relationship of IGF-I binding and action in the somatotroph cell remains unclear. Therefore, IGF-I binding and action were compared in two different pituitary cell lines both secreting GH.

Retinoic acid stimulates placental hormone secretion by choriocarcinoma cell lines in vitro.

Retinoic acid (RA), an active metabolite of vitamin A, is an important mediator of cellular differentiation and has been shown to stimulate human CG (hCG) secretion by JEG-3 choriocarcinoma cells in vitro. In order to determine whether RA stimulates the hCG secretion by other trophoblastic cell lines, we evaluated the effect of RA on hCG, hCG-alpha subunit (hCG-alpha), and progesterone secretion in three choriocarcinoma cell lines: JEG-3, JAR, and BeWo. RA stimulated hCG and hCG-alpha secretion in a dose-dependent fashion by each of the three cell lines.

Constitutive expression of a vitamin D 1-hydroxylase in a myelomonocytic cell line: a model for studying 1,25-dihydroxyvitamin D production in vitro.

The capacity of the v-myc-transformed, chicken myelomonocytic cell line HD-11 to metabolize 25-hydroxyvitamin D3 (25-OHD3) was examined. HD-11 cells produced and secreted a metabolite of 25-OHD3 that was bound with high affinity by receptor for 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3]. On normal-phase HPLC, this metabolite cochromatographed with authentic 1,25-(OH)2D3 in both hexane- and methylene chloride-based solvent systems.

Candidal pyarthrosis in an AIDS patient.

The unusual occurrence of a case of indolent Candida albicans pyarthrosis arising as a late complication in a 57-year-old male patient with AIDS, despite prior treatment with amphotericin B for candidemia, is reported. The case is discussed in the context of candidal pyarthrosis and of the rarely reported other fungal arthridites in AIDS patients.

Discordant secretion of placental protein hormones in differentiating trophoblasts in vitro.

The regulation of trophoblast secretion of the placental proteins CG (hCG), placental lactogen (hPL), and pregnancy specific-beta-1-glycoprotein (SP-1) has not been fully elucidated. We therefore studied the secretion of hCG, hCG-beta subunit, hCG-alpha subunit, hPL, and SP-1, both in the basal state and after exposure to 8-bromo-cAMP, during the in vitro differentiation of cytotrophoblasts to syncytiotrophoblasts. Term placental tissue was enzymatically digested and cytotrophoblasts purified by Percoll density gradient centrifugation.

Insulin regulates expression of the human growth hormone gene in transfected cells.

Insulin has been shown to inhibit rat growth hormone (GH) gene transcription. The effects of insulin were therefore tested on the expression of a transfected human GH gene. A 2.

Human chorionic gonadotropin expression in lung, breast, and renal carcinomas.

Conflicting results have emerged from studies that have examined nontrophoblastic tumor tissue for the presence of human chorionic gonadotropin (hCG) by immunoperoxidase techniques. We evaluated 11 lung carcinomas, ten breast carcinomas, and ten renal cell carcinomas for the presence of immunoreactive hCG by the avidin-biotin-horseradish peroxidase method. The hCG was found in 36% (4/11) of lung tissues, 10% (1/10) of breast tumors, and none of renal tumors.

Methods used to improve gamete efficiency.

Male factor infertility accounts for a significant percentage of problems in infertile couples. With clinical utilization of the technologies for selection of good-quality spermatozoa from the ejaculate, our ability to successfully treat the severely affected male factor couple has improved. However, it must be remembered that even with current technologies, fertilization success is reduced in these patients but remains above a 50% level.

Regulation of human growth hormone gene expression by insulin-like growth factor I in transfected cells.

Insulin-like growth factor I (IGF-I), a target hormone for growth hormone (GH) action, has been shown to regulate rat GH gene transcription. We further investigated its direct action on the human GH gene transfected in human choriocarcinoma cells (JEG3) which possess abundant IGF-I receptors. The 2.