bluuebunny/crossref_metadata_2025 huggingface dataset:
Hyperinnervation during Adrenal Regeneration Influences the Rate of Functional Recovery
Authors: Ulrich-Lai Yvonne M. , Engeland William C.
Published: April 2003

The rat adrenal cortex has the uncommon ability to demonstrate morphological and functional regeneration after injury-induced loss of cortical tissue. Peripheral nerves are involved in tissue regeneration and healing after injury, implying that nerves may also be involved in modulating the regeneration of the adrenal cortex. Studies were initiated to assess changes in adrenal innervation during cortical tissue regeneration subsequent to adrenal enucleation. Innervation of regenerating adrenals was assessed from 3 to 62 days postenucleation by immunohistofluorescent detection of neuronal markers for primary afferent, preganglionic sympathetic, and postganglionic sympathetic fibers. The regenerating adrenal contained few nerves at 3 days postenucleation, but became differentially innervated, with extensive innervation by nerve fibers positive for calcitonin gene-related peptide (CGRP), tyrosine hydroxylase (TH), neuropeptide Y (NPY), and neuronal nitric oxide synthase (nNOS). In contrast, there was only minimal innervation by nerve fibers positive for vasoactive intestinal peptide. By 14 days postenucleation, the CGRP-, TH-, and NPY-positive innervation included areas of hyperinnervation in the capsule, cortex, and central inflammatory site of the regenerating gland. In addition, many chromaffin cells were present at all time points postenucleation. Quantification of the regenerating gland content of CGRP, norepinephrine, epinephrine, and nNOS verified the immunohistofluorescent observations. The period of extensive innervation correlated temporally with the time (3–30 days) during which the regenerating glands recovered steroidogenic function. Moreover, splanchnic nerve transection at the time of adrenal enucleation decreased the innervation by CGRP-positive and vesicular acetylcholine transporter-positive fibers and delayed regeneration. These results support the hypothesis that adrenal innervation modulates tissue regeneration and functional recovery of the enucleated adrenal gland.
Dynorphin Stimulates Corticotropin Release from Mouse Anterior Pituitary AtT-20 Cells through Nonopioid Mechanisms
Authors: Cheng Peter Y. , Birk Alex V. , Gershengorn Marvin C. , Szeto Hazel H.
Published: April 2003

Dynorphin (Dyn) peptides were previously shown to increase plasma corticotropin (ACTH) in the ovine fetus, but the site of its action remains unclear. In the present study, Dyn A1-17 was found to stimulate ACTH release from mouse anterior pituitary tumor AtT-20 cells in a dose-dependent manner. Naloxone did not block the effect of Dyn A1-17 and the selective ĸ-opioid receptor agonist U50488H did not stimulate ACTH release. Dyn A2-17, a degradative peptide fragment that does not bind to opioid receptors, also stimulated ACTH release from AtT-20 cells. Although the nonopioid effects of Dyn have previously been attributed to N-methyl-D-aspartate (NMDA) receptors, the ACTH-releasing effects of Dyn A1-17 in AtT-20 cells were not affected by co-administration of NMDA receptor antagonist LY235959. The ACTH response to Dyn A1-17 could not be blocked by α-helical CRH (CRH antagonist) and was additive with a maximal stimulatory dose of CRH, suggesting different mechanisms of action. These results show that the release of ACTH by Dyn A1-17 in AtT-20 cells is not mediated by ĸ-opioid receptors or by the NMDA receptor.
Organization and Activation of Sexual and Agonistic Behavior in theLeopard Gecko, Eublepharis macularius
Authors: Rhen Turk , Crews David
Published: April 2003

Gonadal sex is determined by the temperature experienced during incubation in the leopard gecko (Eublepharis macularius). Furthermore, both factors, incubation temperature and gonadal sex, influence adult sexual and agonistic behavior in this species. Yet it is unclear whether such differences in behavior are irreversibly organized during development or are mediated by differences in hormone levels in adulthood. To address this question, we gonadectomized adult females and males generated from a female-biased (30°C) and a male-biased (32.5°C) incubation temperature and treated them with equivalent levels of various sex steroids. We found that 17β-estradiol (E2) activated sexual receptivity in females but not males, suggesting an organized sex difference in behavioral sensitivity to E2. There were also organized and activated sex differences in attractivity to stimulus males. Although females were more attractive than males when treated with E2, both sexes were equally unattractive when treated with dihydrotestosterone (DHT) or testosterone (T). Likewise, sex differences in aggressive and submissive behavior were organized and activated. Attacks on stimulus males were activated by T in males but not in females. In contrast, hormones did not influence flight behavior in males but did affect female submissiveness. Overall, males also evoked more attacks by stimulus males than did females. Nevertheless, females and males treated with androgens evoked more attacks than animals of the same sex that were treated with cholesterol or E2. Incubation temperature had some weak effects on certain behaviors and no effect on others. This suggests that temperature effects in gonadally intact geckos may be due primarily to differences in circulating levels of hormones in adulthood. We conclude that gonadal sex has both organizational and activational effects on various behaviors in the leopard gecko.
Differential Regulation of Prolactin Release and Lactotrope Proliferation during Pregnancy, Lactation and the Estrous Cycle
Authors: Yin Ping , Arita Jun
Published: April 2003

The proestrous surge of prolactin (PRL) secretion and subsequent proliferation of lactotropes at estrus have been suggested to be induced by a common hypothalamic hormone. We investigated changes in lactotrope proliferation at other reproductive stages of female rats when PRL secretion was stimulated. To assess proliferative activity of lactotropes, incorporation of 5-bromo-2′-deoxyuridine (BrdU) into DNA was measured by double immunostaining for PRL and BrdU. BrdU-labeling indices, determined by BrdU injections at 10.00 h, revealed low levels of proliferative activity of lactotropes at the reproductive stages including diestrus, days 6 and 13 of pregnancy, and day 6 of lactation while high levels were detected on estrus and the day of parturition. When BrdU-labeling indices were determined at 3-hour intervals through day 6 of pregnancy to find an increase in lactotrope proliferation which might occur at times other than 10.00 h, proliferative activity of lactotropes remained at low levels with a slight increase in the afternoon. Such a diurnal change as observed in early pregnancy was not detected on day 13 of pregnancy. In contrast, short-interval determinations of BrdU-labeling indices during a period from day 20 of pregnancy to day 2 of lactation revealed a marked increase in proliferative activity on the day of parturition with a peak at 18.00 h, which was comparable to that observed at estrus. To investigate involvement of ovarian steroids in suppression of lactotrope proliferation as observed during early pregnancy and lactation, ovariectomized and pup-removed lactating rats were given one of treatment combinations of estradiol and suckling. In pup-removed lactating rats, estradiol treatment alone induced neither a PRL surge nor an increase in BrdU-labeling indices. Suckling stimuli, which were effective in increasing serum PRL concentrations irrespective of estradiol treatment, elicited a marked increase in BrdU-labeling indices in the presence of estradiol but not in its absence. These results suggest that proliferative activity of rat lactotropes does not necessarily correlate with PRL secretion during pregnancy and lactation. In contrast to PRL release, lactotrope proliferation requires both a hypophysiotropic stimulatory input from the hypothalamus and a sensitizing action of estradiol, an observation which may account for the fact that proliferation does not occur during pregnancy and lactation in spite of elevated PRL release.
Differential Orexigenic Effects of Hexarelin and Its Analogs in the Rat Hypothalamus: Indication for Multiple Growth Hormone Secretagogue Receptor Subtypes
Authors: Torsello Antonio , Locatelli Vittorio , Melis Maria Rosaria , Succu Salvatora , Spano Maria Sabrina , Deghenghi Romano , Müller Eugenio E. , Argiolas Antonio
Published: April 2003

We have previously reported that hexarelin and some of its analogs, including EP 50885, stimulated GH secretion and feeding after systemic administration in the rat, whereas EP 40904 selectively stimulated food intake and EP 40737 only GH release. The precise mechanism of growth hormone-releasing peptides (GHRPs) actions is still unclear, but the integrity of the arcuate nucleus of the hypothalamus (ARC) appears crucial for their endocrine effects. To better characterize the site(s) and mechanisms(s) of the orexigenic action of GHRPs, we have investigated their effects after infusion into the arcuate, paraventricular, ventromedial and medial preoptic areas of the hypothalamus. Food intake was measured for 60 min following injection of the test compound (2 µg/rat). Hexarelin, EP 40904 and EP 50885 had significant orexigenic effects after injection into the ARC. A specific NPY antagonist significantly inhibited the effect of hexarelin, whereas a GHRH antagonist was ineffective. In the paraventricular nucleus, only EP 50885 stimulated feeding, whereas all peptides were ineffective in the ventromedial nucleus and medial preoptic area. Taken altogether, these results demonstrate that GHRPs are endowed with site-specific orexigenic actions and that endogenous NPY, but not GHRH, mediates these effects. The additional orexigenic action of EP 50885 in the paraventricular nucleus suggests the existence of a GHRP receptor subtype different from the already cloned one.
17β-Estradiol Stimulates Mouse Neuropeptide Y-Y1 Receptor Gene Transcription by Binding to Estrogen Receptor Alpha in Neuroblastoma Cells
Authors: Musso Rita , Maggi Adriana , Eva Carola
Published: April 2003

Several studies have shown that neuropeptide Y (NPY) is involved in the stimulation of gonadotropin hormone releasing hormone (GnRH) and luteinizing hormone (LH) secretion and that these effects are modulated by gonadal steroid feedback. The NPY regulation of GnRH release is probably mediated by the activation of the Y1 receptor subtype. In this study we examined the regulation of the Y1 receptor gene transcription by estrogens in transiently transfected NG108-15 neuroblastoma glioma cells. A chimeric plasmid containing the murine Y1 receptor promoter fused to the firefly luciferase reporter gene was induced by approximately 2-fold in response to 17β-estradiol treatment. The estrogen-mediated enhancement of luciferase activity was dose-dependent, blocked by the estrogen receptor (ER) antagonist ICI 182,780, and was strictly dependent on the presence of ERα, since it occurred only in NG108-15 cells cotransfected with an expression vector for the human ER. Mutational analysis was performed to investigate whether the hemipalindromic estrogen-responsive elements (EREs) flanking the Y1 receptor gene are responsible for conferring estradiol inducibility to the Y1 receptor gene promoter. Mutation of the ERE1 half site at position –932, or mutation of the ERE2 half site at position –809, relative to the ATG, failed to affect the 17β-estradiol-mediated enhancement of luciferase activity. Conversely, mutation of both ERE1 and ERE2 half sites completely abolished activation of luciferase activity induced by estrogen. We also examined whether 17β-estradiol stimulates the transcriptional activity of the Y1 receptor gene by binding to ERβ. Results demonstrated that luciferase activity was not modulated by estrogens when cells were transfected with the expression plasmid bearing the human ERβ. Moreover coexpression of both ERα and ERβ completely abolished the estrogen-induced activation of luciferase activity observed in the presence of ERα. Our data suggest that estrogens activate Y1 receptor gene transcription possibly via a direct interaction of ERα with the hemipalindromic EREs flanking the Y1 receptor gene.
Central 5-Hydroxytryptamine-2A Receptor Expression in Transgenic Mice Bearing a Glucocorticoid Receptor Antisense
Authors: Cyr Michel , Charbonneau Chantal , Morissette Marc , Rochford Joseph , Barden Nicholas , Di Paolo Thérèse
Published: April 2003

Transgenic mice bearing a transgene coding for a glucocorticoid receptor antisense mRNA that partially blocks glucocorticoid receptor expression were used to investigate the long-term effect of hypothalamic-pituitary-adrenal dysfunction on brain 5-hydroxytryptamine-2A (5-HT2A) receptor expression. The brain 5-HT2A receptor mRNA levels in transgenic mice were measured by in situ hybridization and compared to those in control mice. We also studied the effect of a 3-week treatment with fluoxetine on brain 5-HT2A receptor expression in the transgenic mice. No difference in 5-HT2A mRNA levels was observed between transgenic and control mice in cortical or striatal regions, and fluoxetine treatment was without effect. No difference in hypothalamic 5-HT2A mRNA levels was observed between transgenic and control mice, while fluoxetine treatment increased these levels in both transgenic as well as in the hypothalamic ventromedial and paraventricular nuclei of control mice. 5-HT2A receptor mRNA levels were similar in hippocampal CA1 and CA2 subregions of control and transgenic, but were lower in the CA3 and CA4 subregions of transgenic mice. Fluoxetine had no effect on 5-HT2A mRNA levels of transgenic mice but reduced control mouse 5-HT2A receptor mRNA levels in the CA3 subregion. These results suggest that impaired glucocorticoid receptor function can affect hippocampal 5-HT2A receptor expression in transgenic mice and that this is not corrected by fluoxetine treatment.
Dorsal and Ventral Medullary Catecholamine Cell Groups Contribute Differentially to Systemic Interleukin-1β-Induced Hypothalamic Pituitary Adrenal Axis Responses
Authors: Buller Kathryn , Xu Yangyang , Dayas Christopher , Day Trevor
Published: April 2003

Medial parvocellular paraventricular corticotropin-releasing hormone (mPVN CRH) cells are critical in generating hypothalamic-pituitary-adrenal (HPA) axis responses to systemic interleukin-1β (IL-1β). However, although it is understood that catecholamine inputs are important in initiating mPVN CRH cell responses to IL-1β, the contributions of distinct brainstem catecholamine cell groups are not known. We examined the role of nucleus tractus solitarius (NTS) and ventrolateral medulla (VLM) catecholamine cells in the activation of mPVN CRH, hypothalamic oxytocin (OT) and central amygdala cells in response to IL-1β (1 µg/kg, i.a.). Immunolabelling for the expression of c-fos was used as a marker of neuronal activation in combination with appropriate cytoplasmic phenotypic markers. First we confirmed that PVN 6-hydroxydopamine lesions, which selectively depleted catecholaminergic terminals, significantly reduced IL-1β-induced mPVN CRH cell activation. The contribution of VLM (A1/C1 cells) versus NTS (A2 cells) catecholamine cells to mPVN CRH cell responses was then examined by placing ibotenic acid lesions in either the VLM or NTS. The precise positioning of these lesions was guided by prior retrograde tracing studies in which we mapped the location of IL-1β-activated VLM and NTS cells that project to the mPVN. Both VLM and NTS lesions reduced the mPVN CRH and OT cell responses to IL-1β. Unlike VLM lesions, NTS lesions also suppressed the recruitment of central amygdala neurons. These studies provide novel evidence that both the NTS and VLM catecholamine cells have important, but differential, contributions to the generation of IL-1β-induced HPA axis responses.
Bidirectional Effects of Corticosterone on Splenic T-Cell Activation: Critical Role of Cell Density and Culture Time
Authors: Wiegers G. Jan , Stec Ilona E.M. , Klinkert Wolfgang E.F. , Linthorst Astrid C.E. , Reul Johannes M.H.M.
Published: April 2003

Glucocorticoids inhibit stimulus-induced T-cell proliferation, an early and essential parameter of cellular immunity. It was recently found however that physiological concentrations of glucocorticoids can also accelerate, not only inhibit, rat T-cell mitogenesis. We investigated mechanism(s) underlying mitogenic actions of glucocorticoids on anti-T-cell receptor (TCR)- and concanavalin A (Con A)-induced T-cell proliferation. Surprisingly, the ability of the glucocorticoid corticosterone (CORT) to either enhance or inhibit T-cell proliferation was found to depend primarily on the cell density and the timing of the cultures. At cell densities up to 1 × 105 cells/well (i.e. ‘low’ density), CORT inhibited T-cell proliferation irrespective of the culture time. In contrast, at cell densities of 2 × 105 cells/well and higher (‘high’ density), CORT potently stimulated T-cell mitogenesis during the first 2–3 culture days, but subsequently inhibited the proliferative response after 5–7 days. The glucocorticoid receptor antagonist RU486 completely abolished the effects of CORT. However, production of the main T cell growth factor interleukin (IL)-2 was inhibited by CORT at both ‘low’ and ‘high’ cell densities. In addition, irrespective of cell density, T-cell mitogenesis under either control conditions or in presence of CORT was completely blocked by an anti-IL-2-receptor-α-chain (IL-2Rα) antibody, indicating that T-cell proliferation was dependent on the IL-2 pathway. Immunofluorescence staining of IL-2Rα on CD4+ cells after 2–3 days in culture was increased by CORT, but only on cells cultured at ‘high’ density. Thus, glucocorticoids increase T-cell responsiveness to IL-2 under conditions of ‘high’ cell density only. We conclude that glucocorticoids may contribute to a more efficient early stage of cellular immune responses under conditions of intimate cell-to-cell contact (i.e. ‘high’ cell density), a situation likely to be present in vivo, for instance in lymph nodes. Thus, these findings are relevant to our understanding of the glucocorticoid control of immune function.
Regulation of Norepinephrine in the Medial Preoptic Area of Siberian Hamsters by Gonadal Steroids
Authors: Tomaselli Laura , Endoh Aya , Dodge James , Badura Lori L.
Published: April 2003

Photoperiod has profound effects upon the neuroendocrine axis underlying reproductive physiology in seasonally breeding mammals. For long-day (LD) breeders, such as the Siberian hamster, exposure to a short-day (SD) photoperiod results in declines in circulating levels of gonadal steroids, luteinizing hormone (LH), and prolactin (PRL). The current study sought to investigate the effects of photoperiod and steroid levels on norepinephrine (NE), one of the major neurochemical regulators of gonadotropin-releasing hormone (GnRH) function. Since NE release within the medial preoptic area (mPOA) has been shown to stimulate the activity of GnRH cells, it was hypothesized that exposure to a short photoperiod would decrease NE levels. Furthermore, since gonadal steroids show negative feedback on GnRH function, it was hypothesized that gonadectomy would result in increased levels of NE. Adult male and female Siberian hamsters were gonadectomized and implanted with silastic capsules containing either cholesterol (C) or a mixture of estradiol (E) or testosterone (T). Microdialysis sampling within the mPOA was conducted after 8 weeks of exposure to either an LD or an SD photoperiod. Blood samples were analyzed for LH and PRL, while dialysis samples were analyzed for NE and its major metabolite 3-methoxy-4-hydroxyphenylglycol (MHPG). The results revealed significant suppression of LH and PRL by exposure to the SD photoperiod in both males and females. For LH, the steroid implants suppressed circulating hormone levels under both photoperiods, whereas for PRL, steroid treatment facilitated circulating levels. In contrast, there were no significant effects of photoperiod on NE or MHPG release for either males or females, but there was a significant decrease in extracellular levels of these neurochemicals in steroid-treated animals. These data suggest that photoperiodic modulation of GnRH neuronal function by NE is achieved largely through the indirect effects of photoperiod on circulating gonadal steroids.
Vascular Endothelial Growth Factor Production and Regulation in Rodent and Human Pituitary Tumor Cells in vitro
Authors: Lohrer Penny , Gloddek Jutta , Hopfner Ursula , Losa Marco , Uhl Eberhard , Pagotto Uberto , Stalla Günter K. , Renner Ulrich
Published: April 2003

Angiogenesis, the formation of a new blood supply, is an essential step in tumorigenesis. Although vascular endothelial growth factor (VEGF) is known to be a very potent angiogenic factor in most solid tumors, little is known about its production and regulation in pituitary adenomas. We have investigated basal and stimulated VEGF production by rodent pituitary tumor cells (mouse corticotrope AtT20, rat lactosomatotrope GH3, mouse gonadotrope αT3-1 and mouse folliculostellate TtT/GF cells), and by hormone-inactive (27), corticotrope (9), lactotrope (3) and somatotrope (21) human pituitary adenoma cell cultures. All 4 pituitary cell lines secreted VEGF, which in the case of AtT20, GH3 and TtT/GF cells was inhibited by approximately 50% by dexamethasone. TtT/GF cells were the most responsive to the different stimuli used since basal values were augmented by pituitary adenylate cyclase activating polypeptide-38 (PACAP-38), interleukin-6 (IL-6), transforming growth factor-α (TGF-α), IGF-I and the somatostatin analogue ocreotide. However, in GH3, AtT20 and αT3-1 cells, basal VEGF levels where not enhanced with any of the stimuli tested. The majority of the human adenomas tested (92%) basally secreted measurable VEGF which was inhibited by dexamethasone in most cases (84%). VEGF levels were increased in hormone inactive adenomas, somatotrope tumors and prolactinomas by TGF-α, PACAP-38, and 17β-estradiol, respectively. In conclusion, pituitary tumor cells are capable of producing VEGF which may be involved in tumoral angiogenesis. Our results concerning the suppression of VEGF by dexamethasone suggest that glucocorticoids may have anti-angiogenic properties and therefore therapeutic relevance for the treatment of pituitary adenomas.
Expression of Functional Melanocortin-4 Receptor in the Hypothalamic GT1-1 Cell Line
Authors: Khong Kathy , Kurtz Stephen E. , Sykes Renee L. , Cone Roger D.
Published: April 2003

Mutations in the melanocortin-4 receptor (MC4-R) cause obesity in both mice and humans, and the receptor is presumed to have an important role in the regulation of energy homeostasis. The MC4-R is expressed in discrete sets of neurons in the central nervous system, and thus it has been technically difficult to study the regulation of expression and the signaling mechanisms of this receptor. We report here a neuronal cell line that exhibits endogenous functional expression for the MC4-R. Initially, RT-PCR analysis showed the presence of MC4-R RNA in the hypothalamic GT1-1 and GT1-7 cells. In addition, GT1-7 cells expressed melanocortin-3 receptor while the GT1-1 subclone specifically expressed predominantly the MC4-R RNA. High-affinity binding sites were demonstrated in the GT1-1 and GT1-7 cells for NDP-α melanocyte-stimulating hormone (MSH; Ki = 1.1 × 10–10 and 1.8 × 10–10M) and agouti-related protein (AGRP; Ki = 1.548 × 10–9 and 1.663–9M). α-MSH-stimulated cAMP production in GT1-1 cells with an EC50 of 2.2 × 10–8M, and cAMP production was inhibited in the presence of AGRP, an endogenous antagonist of the MC4-R. Stimulation of gonadotropin-releasing hormone (GnRH) secretion was achieved with 1 nM to 1µM concentrations of NDP-α-MSH while no GnRH secretion was observed when the GT1-1 cells were treated with AGRP. The data presented here show that GT1-1 cells specifically express a functional MC4-R that couples to GnRH release.
Functional Evidence for the Presence of Type II 5’-Deiodinase in Somatotropes and Its Adaptive Role in Hypothyroidism
Authors: Volpato Cláudia B. , Nunes Maria Tereza
Published: April 2003

The anterior pituitary contains abundant type II iodothyronine 5′-deiodinase (D2). The role of this enzyme in mediating thyroid hormone action in the pituitary has been proven only for thyrotropes, although there is evidence that it exists in other cell types, including somatotropes and lactotropes. Here we investigated the potential of D2 to mediate thyroid hormone regulation of growth hormone (GH). Using GH mRNA as an end point, we demonstrate that in hyperthyroid states GH mRNA levels are stimulated by triiodothyronine (T3) generated via D1, whereas in hypothyroidism, when D2 activity is markedly increased, GH mRNA is more responsive to tetraiodothyronine (T4) in a propylthiouracil-insensitive, reverse T3-suppressible manner. Under short-term hyperthyroid conditions, GH levels correlate with plasma T3; in contrast, the correlation is not observed in hypothyroidism, a condition in which plasma T3 levels are too low to account for the response. These results add support to the concept that D2 is present in the pituitary and that the enzyme plays an important role in mediating stimulation of GH by thyroid hormones, particularly in hypothyroid states in which they could alleviate the impact of hypothyroxinemia on GH secretion.
Pituitary Growth Hormone Secretion in the Turbot, a Phylogenetically Recent Teleost, Is Regulated by a Species-Specific Pattern of Neuropeptides
Authors: Rousseau Karine , Le Belle Nadine , Pichavant Karine , Marchelidon Jaques , Chow Billy K.C. , Boeuf Gilles , Dufour Sylvie
Published: April 2003

In mammals, growth hormone (GH) is under a dual hypothalamic control exerted by growth hormone-releasing hormone (GHRH) and somatostatin (SRIH). We investigated GH release in a pleuronectiform teleost, the turbot (Psetta maxima), using a serum-free primary culture of dispersed pituitary cells. Cells released GH for up to 12 days in culture, indicating that turbot somatotropes do not require releasing hormone for their regulation. SRIH dose-dependently inhibited GH release up to a maximal inhibitory effect of 95%. None of the potential stimulators tested induced any change in basal GH release. Also, neither forskolin, an activator of adenylate cyclase, nor phorbol ester (TPA), an activator of protein kinase C, were able to modify GH release, suggesting that spontaneous basal release already represents the maximal secretory capacity of turbot somatotropes. In contrast, forskolin and TPA were able to increase GH release in the presence of SRIH. In this condition (coincubation with SRIH), pituitary adenylate cyclase-activating polypeptide (PACAP) stimulated GH release, whereas none of the other neuropeptides tested (GHRHs; sea bream or salmon or chicken II GnRHs; TRH; CRH) had any significant effect. These data indicate that inhibitory control by SRIH may be the basic control of GH production in teleosts and lower vertebrates, while PACAP may represent the ancestral growth hormone-releasing factor in teleosts, a role taken over in higher vertebrates by GHRH.
Platelet GPIIb/IIIa Is Activated and Platelet-Leukocyte Coaggregates Formed in vivo during Hemodialysis
Authors: Kawabata Kenji , Nakai Shigeru , Miwa Masamiki , Sugiura Tatsuki , Otsuka Yuka , Shinzato Toru , Hiki Yoshiyuki , Tomimatsu Ikuko , Ushida Yumi , Hosono Fumiko , Maeda Kenji
Published: April 2003

Background/Aim: During hemodialysis, platelets and leukocytes are activated and form platelet-leukocyte coaggregates in which GPIIb/IIIa (CD41/CD61) and CD62P (P-selectin) are involved. However, it is still controversial whether platelet activation and platelet-leukocyte coaggregate formation are dependent on the dialyzer membrane material. Method: We examined the appearance of activation-dependent antibody on platelets as an index of platelet activation, and the appearance of platelet-specific antigen on leukocytes as an index of platelet-leukocyte coaggregation, during hemodialysis in 7 patients treated using regenerated cellulose (RC) membrane and next using polysulfone (PS) membrane. In order to reduce the influence of factors other than dialyzer membrane material, this study was conducted in a prospective crossover fashion using a pyrogen-free bicarbonate dialysate. Moreover, flow cytometric techniques with whole blood were employed, which reduce artificial cell activation during the cell or plasma separation procedure. The platelet-specific monoclonal antibodies used in this study were anti-CD61, PAC-1 (which recognizes only the conformationally activated GPIIb/IIIa) and anti-CD62P. Results: Changes in the percentage of PAC-1-positive platelets were significantly greater during hemodialysis with RC than with PS. However, changes in the percentage of CD62P-positive platelets were not significantly different between hemodialysis with RC and PS. Changes in the percentage of CD61- or CD62P-positive leukocytes were significantly greater during hemodialysis with RC than with PS. Although changes in percentage of PAC-1-positive platelets did not parallel those of CD62P-positive platelets during hemodialysis, there was a significant positive correlation between the percentage of CD61-positive leukocytes and the percentage of CD62P-positive leukocytes. Conclusion: This study, conducted in a prospective crossover fashion using a pyrogen-free bicarbonate dialysate in order to reduce the influence of factors other than the dialyzer membrane material, demonstrated that both the degrees of GPIIb/IIIa activation and platelet-leukocyte coaggregation were greater during hemodialysis with RC than PS.
Acute Renal Failure in Bone Marrow Transplant Patients Admitted to the Intensive Care Unit
Authors: Létourneau Isabelle , Dorval Marc , Bélanger Robert , Légaré Martin , Fortier Louise , Leblanc Martine
Published: April 2003

Background/Aims: Review of bone marrow transplant (BMT) cases admitted to our intensive care unit (ICU) and to compare co-morbidity and outcome of BMT patients developing or not developing acute renal failure (ARF). Methods: A case review of BMT patients admitted to the ICU (a 16-bed medico-surgical ICU in a tertiary care teaching institution) over a 4-year period. Results: Between January 1994 and December 1998, 57 among 441 BMT patients (12.9%) were admitted to the ICU, mainly for respiratory distress (58%) and hypotension (32%). Forty-two patients (73.7%) presented ARF as defined as a doubling of serum creatinine. Compared to the 15 other patients, ARF patients had a higher APACHE II score (30 ± 8 vs. 25 ± 7, p < 0.05). For ARF vs. non-ARF patients, there was no difference in age (43.8 ± 10.8 vs. 44.3 ± 11.1 years), in requirement for mechanical ventilation (76 vs. 73%) and vasopressors (69 vs. 60%), and in prevalence of graft-versus-host disease (19 vs. 13%) or neutropenia (69 vs. 67%), but the prevalence of sepsis (83 vs. 60%) and liver failure (69 vs. 40%) was higher. Maximum serum bilirubin was markedly increased in ARF compared to non-ARF patients (p < 0.005). For both subgroups, no difference in the administration of potential nephrotoxic agents was identified. Usually, ARF was considered multifactorial by clinicians, with ATN being the most frequent diagnosis (55%). Maximum serum creatinine reached a mean of 330 ± 130 µmol/l. In 74% of cases, ARF occurred concomitantly or after admission to the ICU. Oligoanuria was present in 38%, whereas polyuria was observed in 17%. Fourteen ARF patients (33%) required dialytic support. Mortality rates were significantly different in ARF vs. non-ARF patients (88 vs. 60%, p < 0.05). Predictive factors for the development of ARF were liver failure (odds ratio (OR) 5.9), low serum albumin (OR 1.2) and APACHE II score (OR 1.1), whereas variables predictive of mortality were mechanical ventilation (OR 14.8), ARF (OR 5.8), liver failure (OR 3.7), and APACHE II score (OR 1.2). Conclusions: This study confirms that ARF in BMT patients admitted to the ICU is frequent, multifactorial, related to liver failure, and that its development has a negative impact on outcome.
Sustained Expression of Thrombospondin-1 Is Associated with the Development of Glomerular and Tubulointerstitial Fibrosis in the Remnant Kidney Model
Authors: Hugo Christian , Kang Duk-Hee , Johnson Richard J.
Published: April 2003

Background/Aims: Transforming growth factor-β1 (TGF-β1) has been implicated in the development of progressive nephrosclerosis in the remnant kidney model of chronic renal insufficiency. Thrombospondin-1 (TSP-1) is an extracellular matrix protein which has been recently shown to be capable of converting TGF-β from its latent to its active form. We studied the expression of TSP-1 mRNA and protein during the development of glomerular and tubulointerstitial nephrosclerosis in the renal ablation model particularly in relation to TGF-β1 expression. Methods: The remnant kidney model in the rat was investigated 3 days, 1 week, 2 weeks, 3 weeks, 4 weeks, 7.5 weeks and 10 weeks after disease induction. Using single and double immunostaining techniques, renal tissues were examined for TSP-1 protein, TGF-β1, platelet-derived growth factor BB, extracellular matrix proteins, such as collagens and fibronectin, myofibroblast formation and macrophage influx. TSP-1 mRNA expression was investigated using a radioactive in situ hybridization technique. Results: De novo expression of TSP-1 mRNA and protein occurred in all glomerular cell types as well as in tubular cells, myofibroblasts and some macrophages in areas of tubulointerstitial injury. TSP-1 expression preceded and was sustained during the development of tubulointerstitial and glomerular fibrosis and was frequently localized at sites of increased expression of TGF-β1, but not of platelet-derived growth factor BB. Conclusion: In the remnant kidney model, the time course and localization of TSP-1 are consistent with its playing a role as a local activator of TGF-β1, thereby potentially participating in the development of nephrosclerosis.
Statistical versus Fuzzy Measures of Variable Interaction in Patients with Stroke
Authors: Helgason Cathy M. , Malik D.S. , Cheng Shih-Chuan , Jobe Thomas H. , Mordeson John N.
Published: April 2003

Evidence-based medicine, founded in probability-based statistics, applies what is the case for the collective to the individual patient. An intuitive approach, however, would define structure in the (physiologic) system of interest, the human being, directly relevant to other systems (patients) composed of similar variables. A difference in measure of variable interaction in the patient from that in the collective would show how extrapolation of information from the latter to the single patient is counterintuitive. Methods: We compare statistical to ‘fuzzy’ measures of variable interaction. Three diagnostic variables are considered in 30 stroke patients who underwent the same diagnostic tests. ‘Fit’ (fuzzy information) values [0, 1] for degree of variable severity were expertly assigned by 2 blinded raters for real and fabricated patients. Fabricated patients were composed of real-patient ‘fit’ values after shuffling. Real and fabricated patients were each numerically represented as a set . Three groups of fabricated patients and the real patient group were studied. Statistical [Pearson’s product-moment (regression analysis) and Spearman’s rank correlation] and three different fuzzy measures of variable interaction were applied to patient data. Results: Interaction for blood-vessel measured strong in real patients, and weak after one shuffle, using all fuzzy measures. By comparison, the same interaction was found in real patients by only 1 rater (Rater 2) using 1 statistical technique (Spearman’s rank correlation) which, as did Pearson product-moment correlation, found a ‘significant’ interaction between blood-heart in fabricated patients. Conclusion: Our study suggests that the measure of variable interaction in nature – as combined in the individual (real) patient – is captured robustly by fuzzy measures and not so by standard statistical measures.
A Genetic Epidemiological Study of Spinocerebellar Ataxias in Tottori Prefecture, Japan
Authors: Mori Masatada , Adachi Yoshiki , Kusumi Masayoshi , Nakashima Kenji
Published: April 2003

We investigated the genotype frequencies of patients with spinocerebellar ataxias (SCA), using a community-based prevalence study among 613,349 inhabitants in Tottori prefecture, Japan. Prevalence date was April 1, 1998. On this date, 109 SCA patients were identified in this community. The prevalence of SCA was 17.8 per 100,000 individuals. The most common cause of inherited SCA was a mutation at the SCA6 locus (25%), followed by mutation at the SCA1 locus (15%), SCA3 locus (5%) and dentatorubral-pallidoluysian atrophy locus (5%). None of the expanded alleles was found in SCA2, SCA7 or Friedreich’s ataxia. Mutation at SCA6 was also the most common form of sporadic SCA at 11%. Prevalences per 100,000 individuals were as follows: SCA6, 2.40; SCA1, 0.48; DRPLA, 0.32, and SCA3, 0.16.
Door-to-Door Prevalence Survey of Epilepsy in Three Sicilian Municipalities
Authors: Rocca W.A. , Savettieri G. , Anderson D.W. , Meneghini F. , Grigoletto F. , Morgante L. , Reggio A. , Salemi G. , Patti F. , Di Perri R.
Published: April 2003

A door-to-door prevalence survey of epilepsy was conducted in 3 Sicilian municipalities, as of November 1, 1987. In phase 1, the screening by questionnaire of 24,496 eligible subjects (participation = 92%) identified 544 suspected to have epilepsy. In phase 2, neurological evaluation of the 544 subjects yielded 111 with epilepsy. Of the 111 subjects, 103 (93%) had been previously diagnosed, 68 (61%) were taking antiepileptic medication, and 81 (73%) had active epilepsy. Referring to the 81 subjects with active epilepsy, the seizure type was generalized in 60 (74%), partial in 19 (23%) and undetermined in 2 (3%). The prevalence of active epilepsy (per 1,000 population) was 3.3 overall, 3.5 for men and 3.2 for women. The age-specific patterns for active epilepsy differed by sex, with higher figures for men at younger ages (5–19 years) and older ages (50–99 years). The age-specific prevalence figures for active epilepsy were lower than those from previous Italian surveys.
Association Study of a Nicotinic Receptor Variant with Schizophrenic Disorders
Authors: Lai I-Ching , Hong Chen-Jee , Tsai Shih-Jen
Published: April 2003

Nicotine acetylcholine receptors (nAChRs) are implicated in the pathogenesis of schizophrenia because the prevalence of smoking among schizophrenic patients is extraordinarily high, and nicotine has been demonstrated to improve some psychophysiological dysfunction in schizophrenics. In addition, recent studies have suggested linkage of the α7 nAChR gene region in families of schizophrenics. In a population-based association study, we tested the hypothesis that the allelic variant, with a 2-bp deletion, of the human α7 nAChR gene confers susceptibility to schizophrenic disorders. We genotyped α7 nAChR in 146 patients with schizophrenic disorders and 151 controls. The results showed no significant difference in genotype or allele frequencies between schizophrenic patients and control subjects. This suggests that α7 nAChR 2-bp deletion plays no major role in the pathogenesis of schizophrenic disorders. Other nAChR variants in schizophrenic disorders may need further investigation.
Cerebrospinal Fluid 5-Hydroxytryptamine and 5-Hydroxyindoleacetic Acid in HIV-1 Infection
Authors: Kumar Adarsh M. , Berger Joseph R. , Eisdorfer Carl , Fernandez J.B. , Goodkin Karl , Kumar Mahendra
Published: April 2003

Reduced level of serotonin (5-hydroxytryptamine, 5-HT) in humans has been associated with a number of mental health and behavioral problems including depression, aggression, violence, sexual dysfunctions, sleep and eating disorders. Even though among HIV-1-infected individuals, prevalence of mental health and behavioral problems are common, their relationship with central nervous system serotonin functions is not clearly understood. This investigation was carried out to study the status of CSF 5-HT in HIV-1+ subjects (n = 21), in the early stage of infection, and HIV-1– control subjects (n = 24). Samples of CSF were obtained by lumbar puncture and were analyzed for 5-HT and its metabolite 5-hydroxyindoleacetic acid (5-HIAA), using high-performance liquid chromatography equipped with electrochemical detector. Levels of CSF 5-HT were significantly lower in the HIV-1+ group compared to the HIV-1– group. There was no significant difference in the CSF 5-HIAA levels between the two groups. In both groups, however, there was a significant correlation between CSF 5-HT and 5-HIAA. In the HIV-1 + group, although CSF 5-HT level was significantly negatively correlated with serostatus, there was no correlation between either CSF 5-HT or 5-HIAA levels and CD4 cell number or any behavioral measures evaluated in this study, including Beck’s Depression Inventory and state/trait anxiety scores. These data suggest that HIV-1 infection affects the CNS 5-HT status with no significant association with measures of depression and anxiety, at least in the early stage of infection.
Association Study for a Functional Serotonin Transporter Gene Polymorphism and Late-Onset Alzheimer’s Disease for Chinese Patients
Authors: Tsai Shih-Jen , Hong Chen-Jee , Liu Tsung-Yun , Cheng Chih-Ya , Liu Hsiu-Chih
Published: April 2003

Two recent studies have demonstrated an association for a deletion/insertion polymorphism within the promoter region of the serotonin transporter gene (5-HTTLPR), and Alzheimer’s disease (AD). According to these studies, subjects with the short variant of the 5-HTTLPR gene are at increased risk for AD; however, this finding has not been confirmed by other workers. To evaluate the role of the 5-HTTLPR gene in susceptibility for AD, we conducted an association study for this polymorphism in a Chinese population. No significant differences were determined for genotype distribution or allele frequencies, comparing AD patients and normal controls. Even dividing the population into subgroups according to the presence of the APOE Ε4 allele, no differences for genotype or allele frequencies were determined, comparing patients and controls. These results suggest that it is unlikely that the 5-HTTLPR polymorphism plays a substantial role in conferring susceptibility to AD.
Differences in Substantia nigra Echogenicity of Nosological Subtypes within the Schizophrenic Spectrum
Authors: Jabs Burkhard Emanuel , Berg Daniela , Merschdorf Ursula , Bartsch Andreas Joachim , Pfuhlmann Bruno
Published: April 2003

Objective: Schizophrenic patients treated with neuroleptic drugs often develop neuroleptic-induced parkinsonism (NIP). Here, transcranial sonography (TCS) was used to test for differences in the susceptibility to NIP related to the echogenicity of the substantia nigra (SN) in different schizophrenic subforms. Methods: 79 patients with schizophrenic spectrum psychoses treated by neuroleptic drugs and diagnosed according to ICD-10 and Leonhard’s nosology were examined independently by TCS and, clinically, for NIP. Results: Patients with larger echogenic SN had more severe NIP (p < 0.05). Diagnostic categories according to ICD-10 did not differ significantly in SN echogenicity (p > 0.2), whereas Leonhard’s did (p < 0.05). Conclusions: These findings suggest altered SN echogenicity in subtypes of the schizophrenic spectrum. The putative role of the nigrostriatal system in the etiology of schizophrenic subtypes is discussed.
Evaluation of the Echographic Contribution to the Parasurgical Treatment of Melanomas of Small Dimensions
Authors: Specchia Giuseppe , Balestrazzi Emilio
Published: April 2003

In this work we underlined the contribution of echography in the parasurgical treatment (photocoagulative) of melanomas of small dimensions. Fourteen patients were examined; some of them were treated with argon laser, others with krypton laser. The echographic examination was performed with the A-B scan technique, naturally accompanied by fluorangiography before and after the operation. An accurate echographic and fluorangiographic follow-up makes it posible to control the evolution of the lesions efficaciously. From this work it is clear how echography gives highly reliable results which allow us, therefore, both to make an adequate therapeutic decision and to evaluate the efficaciousness of the treatment itself.
Effect of Topical Na-Hyaluronan on Hemidesmosome Formation in n-Heptanol-Induced Corneal Injury
Authors: Chung Jang-Hyun , Kim Won-Ki , Lee Jin-Sung , Pae Young-Sook , Kim Hyung-Jun
Published: April 2003

The present study investigated the effect of Na-hyaluronan (Na-HA) on the hemidesmosome morphogenesis in n-heptanol-induced corneal wounds. Central epithelial wounds were induced in the rabbit cornea by applying a 5.5-mm round filter paper, which was soaked in n-heptanol, for 60 s. 1% Na-HA in phosphate-buffered saline (PBS) or PBS alone were topically administered to the wounded cornea 4 times daily for up to 7 days. Epithelial healing rates during the first 2 days were not altered by Na-HA. The number of hemidesmosomes in the basement membrane of the central cornea was significantly increased in both 3- and 7-day groups after treatment with 1% Na-HA. The results suggest that topically applied 1% Na-HA may enhance the formation of hemidesmosomes during the early healing phase in n-heptanol-induced corneal wounds.
Lenticular Calcium, Magnesium, and Iron Levels in Diabetic Rats and Verapamil Effect
Authors: Cekic Osman , Bardak Yavuz
Published: April 2003

Lenticular calcium (Ca), magnesium (Mg), and iron (Fe) changes in diabetic rats and the effects of the Ca antagonist drug verapamil on this electrolyte imbalance were studied. Verapamil administration had no effect on the blood glucose values. Compared to the control group, a significant increase was observed in the lenticular Ca, Mg, and Fe content of the diabetic rats. Eight weeks of verapamil administration to the diabetic animals significantly reduced lenticular Ca, Mg, Fe values. Therefore it is suggested that verapamil might be a useful drug to prevent diabetic cataract formation.
Changes of the Inducible Heat Shock Protein 70 mRNA Level in Rat Retina After Ischemia and Reperfusion
Authors: Lewden O. , Garcher C. , Assem M. , Morales C. , Rochette L. , Bron A.M.
Published: April 2003

The heat shock protein 70 (HSP-70) mRNA level was evaluated in Long Evans rat retinas after ischemia and after reperfusion following ischemia. Retinal ischemia was induced by ligation of the optic nerve and vessels. Rats were sacrificed after 90 min of ischemia or 120 min of reperfusion following ischemia. Retinas were dissected. Total mRNA was extracted and inducible HSP-70 (iHSP-70) gene expression was analyzed by quantification of transcripts using an RT-PCR assay. Results were expressed in arbitrary units as a ratio of the optical density of iHSP-70/β-actin electrophoretic bands. iHSP-70 gene expression was 0.220 ± 0.027 (n = 5), 0.502 ± 0.045 (n = 5) and 0.468 ± 0.032 (n = 5) for the sham-operated, ischemia only and ischemia and reperfusion groups, respectively. There was a statistically significant difference between the control and ischemia groups, and between the control and ischemia and reperfusion groups (p < 0.001), suggesting a rapid HSP-70 mRNA expression of the retina due to an ischemic injury.
Expression of CD44 Isoforms in Cultured Human Trabecular Meshwork Cells
Authors: Jumper Michele D. , Stern Robert , Lui Gei-Ming , Formby Bent , Schwartz Daniel M.
Published: April 2003

Purpose: To determine the expression of CD44 isoforms in cultured human trabecular meshwork (HTM) and to discuss their possible relationship with outflow facility. Methods: CD44 isoform expression in cultured HTM was qualitatively examined using immunohistochemistry and RT-PCR analysis. Results: Immunohistochemistry of cultured HTM showed intense staining with a CD44s antibody, and with antibodies against CD44 exon 7, exon 11–12 and exon 14. By RT-PCR, at least three isoforms of CD44 were expressed in HTM: CD44s, CD44v-III and CD44v-I. Conclusions: At least three isoforms of CD44 are expressed in the HTM. CD44 may play a role in binding and turnover of hyaluronic acid in the trabecular meshwork, thereby regulating outflow facility.