Phytocontact dermatitis due to Ranunculus illyricus: two cases.
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Arthritis↗
Biomedical subjects
G Gur
Publications and source records attributed to G Gur.
The role of early colonoscopy in CMV colitis of transplant recipients.
Cytomegalovirus (CMV)-associated diseases remain a major problem in transplant recipients. Early diagnosis is critical. Presentation of early CMV colitis can be mild and nonspecific in transplant recipients. Although serology is helpful in the diagnosis, sometimes it is inadequate. Because the endoscopic features of CMV colitis are specific, colonoscopy facilitates the histopathologic examination. We present the clinical properties and advantages of early colonoscopy in transplant recipients with CMV colitis. The study group included seven patients (six men, one woman of mean age, 36.7 years (range, 22 to 64 years) whose mean transplant duration was 12.3 months (range, 1 to 72 months). Six of the seven patients experienced an acute graft rejection treated with high doses of steroids; one patient had a herpes simplex virus infection. All patients were on steroid treatment with a various combinations of immunosuppressive agents, including cyclosporine, mycophenolate mofetil, and tacrolimus. All patients presented with mild diarrhea without any blood or mucous discharge. Four patients had fever exceeding 38 degrees C; two had abdominal pain. Stool examinations revealed normal findings in six patients, while one patient had white blood cells and amoebic cysts. Serum CMV IgM and CMV pp65 antigenemia were negative in five of seven patients and two had positive results. All patients showed typical colonoscopic and histopathologic findings compatible with CMV colitis. Standard ganciclovir treatment was successful in all patients. Early and rapid colonoscopy is beneficial for the early diagnosis and management of CMV colitis in transplant recipients.
Adult↗
Acute pancreatitis due to ramipril therapy.
Few data exist about the incidence of drug induced acute pancreatitis in the general population. Drugs are related to the aetiology of pancreatitis in about 1.4%-2% of cases. Although angiotensin converting enzymes are generally well tolerated, acute pancreatitis has been reported in a few subjects treated with captopril, enalapril, and lisinopril. A 85 year old man with a long standing history of hypertension, who was treated with ramipril 5 mg once daily, presented with acute pancreatitis. Other causes of the disease were ruled out. After cessation of ramipril his condition improved and amylase level decreased. This was his third episode of acute pancreatitis since ramipril was started in 2000. To the authors' knowledge ramipril induced pancreatitis has not previously been reported.
Acute Disease↗
GnRH signaling pathways regulate differentially the tilapia gonadotropin subunit genes.
Exposure of tilapia pituitary cells in culture to salmon gonadotropin-releasing hormone (sGnRH; 0.01-100 nM) elevated the phosphorylated extracellular signal-regulated kinase (pERK) levels. sGnRH also elevated the alpha, FSHbeta and LHbeta subunit mRNA levels. The phorbol ester, 1-O-tetradecanoyl phorbol-13-acetate (TPA; 12.5 nM) increased pERK levels, whereas protein kinase C (PKC) depletion or inhibition by GF109203X (GF; 0.01-10 microM) suppressed GnRH-activated ERKs. GF too abated the GnRH-induced alpha and LHbeta mRNA levels, but had no effect on those of FSHbeta. Forskolin (0.001-100 microM) activated ERK, while inhibition of protein kinase A (PKA) by H89 (0.01-10 microM) suppressed pERK levels and all GnRH-stimulated gonadotropin subunit transcripts. Exposure of cells to the mitogen-activated protein kinase kinase (MAPK kinase; MEK) inhibitor (PD98059; PD 10, 25 and 50 microM) completely blocked GnRH-induced increase in ERKs activation. Furthermore, PD suppressed the alpha and LHbeta mRNA responses to GnRH, but had no effect on FSHbeta mRNA levels. It is suggested that in tilapia the differential regulation of gonadotropin subunit gene expression by GnRH results from a divergent recruitment of signal transduction pathways, activated upon GnRH binding; PKC-ERK cascade is involved in elevating alpha and LHbeta mRNAs, whereas induction of FSHbeta transcript is ERK-independent and is under direct cAMP-PKA regulation or through other MAPK cascades.
Animals↗
Gonadotropin response to GnRH during sexual ontogeny in the common carp, Cyprinus carpio.
This study was designed to reveal whether gonadotropic response to GnRH in the common carp (Cyprinus carpio) changes during sexual ontogeny and whether the response of FSHbeta and LHbeta subunits is uniform or differential. The study comprised fish at the following stages: juveniles (4-month-old females with primary oocytes and early spermatogenic males); maturing (9-month-old previtellogenic females and advanced spermatogenic males); and mature (16-month-old postvitellogenic females and spermiating males). Fish were injected with superactive salmon GnRH analogue (sGnRHa; 25 microg/kg) and blood was sampled 6, 12 and 24 h later for cGtH (LH) and sex steroid levels. Pituitaries were taken for determination of FSHbeta and LHbeta mRNA levels by slot-blot hybridization and for cGTH content in the same glands by radioimmunoassay (RIA). Values were compared with the levels prior to sGnRHa administration and with control fish sampled at the same intervals. Juvenile fish did not respond at all to sGnRHa. In maturing females, FSHbeta mRNA increased by >300%, while that of LHbeta increased by 200%. In maturing males, FSHbeta mRNA did not change and only a slight increase occurred in that of LHbeta. In 16-month-old postvitellogenic females, there was no response of FSHbeta mRNA, while that of LHbeta dramatically increased. In spermiating males of the same age, mRNA of both FSHbeta and LHbeta increased following sGnRHa injection. Immunoreactive cGtH was present in the pituitary and plasma of all fish examined, but in juveniles it did not change following sGnRHa injection. In maturing and mature fish of both genders, sGnRHa administration was followed by a marked increase in circulating cGtH, concomitant with a decrease in its pituitary content, indicating the limited amount of the hormone stored in the gland. In conclusion, the response of the gonadotropin subunit mRNAs in the common carp was found to be differential and dependent on the gender and the phase of sexual ontogeny.
Age Factors↗
Tilapia glycoprotein hormone alpha subunit: cDNA cloning and hypothalamic regulation.
The cDNA encoding the glycoprotein alpha (GPalpha) subunit of tilapia (Oreochromis mossambicus) was partially cloned using RACE-polymerase chain reaction (PCR) technique. The amplified cDNA was found to be 583 bases long, and to consist of a portion of the signal peptide, the full sequence encoding the mature peptide (94 amino acids) and the 3' untranslated region. Northern blot analysis revealed a single band of approximately 600 bp. Alignment of the deduced amino acids of the mature protein showed that the tilapia GPalpha subunit shares more than 80% identity with that of other perciform fish (i.e. striped bass, sea bream and yellowfin porgy) and less than 70% with that of more taxonomically remote fish and other vertebrates. Exposure of dispersed tilapia pituitary cells to salmon gonadotropin-releasing hormone (sGnRH) elevated GPalpha mRNA levels via both PKC and cAMP-protein kinase A (PKA) pathways. The transcript levels were also regulated by pituitary adenylate cyclase activating polypeptide (PACAP) and neuropeptide Y (NPY), both acting through PKC and PKA pathways. Moreover, a combined treatment of PACAP or NPY with GnRH seems to have an additive effect on the GPalpha subunit gene transcription. These results suggest that in tilapia the expression of GPalpha subunit is regulated by GnRH mainly via PKC and PKA pathways. Furthermore, PACAP and NPY can elevate the GnRH-stimulated GPalpha subunit transcription and can directly affect the subunit mRNA levels, via the same transduction pathways.
Animals↗
Characterization of tilapia FSHbeta gene and analysis of its 5' flanking region.
The objective of the current study was to unveil molecular mechanisms underlying transcriptional regulation of the FSHbeta gene expression in the pituitary of tilapia (Oreochromis mossambicus). The full-length sequence of tilapia FSHbeta (tFSHbeta) gene was determined. Its transcriptional unit (2.7 kb) exhibits the conserved genomic organization, i.e. three exons and two introns. Primer extension and RT-PCR analysis revealed heterogeneity of the tFSHbeta transcripts, due to alternate mRNA splicing and multiple initiation sites for transcription. Examination of the 5' flanking region (5'FR) of the tFSHbeta gene identified potential CAAT and TATA promoter proximal elements as well as several sequences of cis-acting motifs known to dictate inducible and tissue-specific transcriptional regulation in other gonadotropin genes. Chimeric constructs containing 1.7 kb of the tFSHbeta 5'FR fused to a luciferase (LUC) reporter gene were transiently transfected into primary culture of tilapia pituitary cells. The tFSHbeta-LUC construct was efficiently expressed under basal conditions and was rapidly induced by GnRH stimulation. Our data indicate that the 5'FR contains a functional promoter, which is responsive to GnRH treatment. In addition, 5' deletion analysis showed that the 1.7 kb, DNA sequence of the FSHbeta 5'FR encompasses both positive and negative regulatory elements.
Alternative Splicing↗
Regulation of gonadotropin subunit genes in tilapia.
A steroidogenic tilapia gonadotropin (taGtH=LH) was purified from pituitaries of hybrid tilapia (Oreochromis niloticus x O. aureus) and a homologous RIA was established. This RIA enabled the study of the endocrine regulation of GtH release, the transduction pathways involved in its secretion and its profile during the spawning cycle. Discrepancies between steroid and taGtH peaks during the cycle led to the conclusion that an additional gonadotropin similar to salmonid FSH operates early in the cycle. In order to identify this hormone and to study the endocrine control of synthesis of all gonadotropin (GtH) subunits, a molecular approach was taken. The cDNA sequences and the entire gene sequences encoding the FSHbeta and LHbeta subunits, as well as an incomplete sequence of the glycoprotein hormone alpha subunit (GPalpha), were cloned. Salmon gonadotropin-releasing hormone (sGnRH) elevated mRNA steady-state levels of all three GtH subunits in cultured pituitary cells. Pituitary adenylate cyclase-activating polypeptide (PACAP) and neuropeptide Y (NPY) also stimulated the expression of these subunits and potentiated the effect of GnRH, except that NPY did not affect FSHbeta. The GnRH and NPY effects were found to be mediated mainly through protein kinase C (PKC), while protein kinase A (PKA) cascade was involved to a lesser extent. Mitogen-activated protein kinase (MAPK) cascade takes part in mediating GnRH effects, possibly via PKC. Testosterone (T) and estradiol (E2), but not 11-ketotestosterone (KT), are able to elevate GPalpha and LHbeta mRNAs in pituitary cells of early maturing or regressing males. Low levels of T exposure are associated with elevated FSHbeta mRNA in cells of mature fish, while higher levels suppress it, but elevate LHbeta mRNA. In vivo observations also showed the association of low T levels with increased FSHbeta mRNA and high T levels with elevated LHbeta mRNA. In accordance with these findings, analysis of LHbeta and FSHbeta 5' gene-flanking regions revealed on both gene promoters a GtH-specific element (GSE), half site estrogen response elements (ERE), cAMP response element (CRE) and AP1. In vitro experiments showed that recombinant human activin-A leads to higher levels of GPalpha, FSHbeta and LHbeta mRNAs in pituitary cell culture. Porcine inhibin marginally decreased the mRNA levels of GPalpha and FSHbeta, but at a low level (1 ng/ml) it stimulated that of LHbeta. These results shed some light on certain hypothalamic and gonadal hormones regulating the expression of GtH subunit genes in tilapia. In addition, they provide evidence for their differential regulation, and insight into their mode of action.
Activins↗
GnRH receptor signaling in tilapia pituitary cells: role of mitogen-activated protein kinase (MAPK).
The role of mitogen-activated protein kinase (MAPK, also known as extracellular signal regulated kinase; ERK) stimulation in gonadotropin-releasing hormone (GnRH) signaling was investigated in cultured pituitary cells of tilapia hybrids (Oreochromis niloticus x O. aureus). Exposure of the cells to salmon GnRH (sGnRH) resulted in a dose- and time-dependent elevation in ERK levels. The PKC activator, 1-O-tetradecanoyl phorbol-13-acetate (TPA) increased kinase levels, while addition of GnRH had no further effect. However, chronic exposure to TPA resulted in reduction of basal and GnRH-induced ERK elevation. When PKC was inhibited by GF109203X, the GnRH-elevated ERK levels were totally abolished. The role of MAPK activation on GPalpha, FSHbeta and LHbeta gene expression was determined by administration of MAPK-kinase (MEK) inhibitor (PD98059; PD). This inhibitor completely blocked GnRH-induced increases in ERK activity. Furthermore, it suppressed GPalpha and LHbeta mRNA responses to GnRH, but had no effect on FSHbeta transcript levels. PD also decreased basal LHbeta mRNA levels. These results indicate that in tilapia pituitary cells, GnRH activates MAPK cascade in a PKC-dependent manner. ERK is involved in GnRH elevation of GPalpha and LHbeta, but not in FSHbeta genes transcription.
Animals↗
HASTE MRCP and MRI findings in alveolar echinococcosis of the liver.
Alveolar echinococcosis is a rare mass-producing inflammatory process of the liver. Experience with MRI, and particularly magnetic resonance cholangiopancreatography (MRCP), demonstrates that features of this disease are limited. The HASTE (half-Fourier acquisition single-shot turbo spin echo) MRCP and MRI findings of alveolar echinococcosis of the liver are presented in this report. HASTE MRCP was used to define the biliary system and the biliary system-mass relationship. It was found that results were comparable with those of invasive techniques such as endoscopic retrograde cholangiopancreatography and percutaneous transhepatic cholangiography.
Adolescent↗
Changes along the pituitary-gonadal axis during maturation of the black carp, Mylopharyngodon piceus.
The black carp, Mylopharyngodon piceus, is a late-maturing cyprinid reaching sexual maturity at the age of 6-7 years. The present work attempted to define nonfunctional sites along the pituitary-gonadal axis in immature fish utilizing in vivo and in vitro challenge experiments. Two- and 3-year old fish injected with salmon gonadotropin-releasing hormone analog (sGnRHa; 10 microg/kg) and metoclopramide (20 mg/kg) did not reveal any increase in circulating gonadotropin (cGtH) or estradiol (E(2)) level. Furthermore, cGtH release from cultured pituitary cells of fish at these ages did not increase in response to sGnRH (0.1 nM - 1 microM) but was augmented when exposed to TPA (12.5 nM). However, 4-year old female fish did respond to the above treatments both in vivo and in vitro. These results suggest the existence of nonfunctional site(s) proximal to the activation of PKC in the immature black carp gonadotrophs, probably at the level of GnRH receptors. These site(s) start to become functional in 4-year old fish. Two- and 3-year old fish injected with common carp pituitary extract (CPE) containing 350 microg cGtH/kg did not show any increase in circulating E(2). In addition, the estrogen secretion from fragments of the rudimentary gonads did not increase after exposure to CPE containing cGtH (0.5-4 microg/ml) but was elevated dose-dependently by exposure to dbcAMP (0.3-3 mM). However, the ovaries of 4-year old fish did respond to the gonadotropic stimulation, both in vivo and in vitro. These results suggest the existence of other non-functional site(s) in the immature black carp, proximal to the formation of cAMP in the gonads, probably at the level of GtH receptors. These site(s) start to become functional in 4-year old females. Another source of E(2) was discovered in the immature black carp: namely, the fat pad adjacent to the gonads. In contrast to the visceral adipose tissue, the fat pad secretes estrogen in response to cAMP elevation in 2- and 3-year old fish while in 4-year old fish it also responds to gonadotropic stimulation. Due to its large mass and high steroidogenic potency, it is assumed that the gonadal fat pad is involved in the process of puberty in the black carp. J. Exp. Zool. 286:405-413, 2000.
Adipose Tissue↗
Reproductive development of male and female tilapia hybrids (Oreochromis niloticus x O. aureus) and changes in mRNA levels of gonadotropin (GtH) Ibeta and IIbeta subunits.
A study was carried out in tilapia in order to see whether the gonadotropin (GtH) beta subunits show distinct patterns of expression at different stages of their reproductive development. Male and female tilapia hybrids (Oreochromis niloticus x O. aureus) were collected at various times of the year, and a number of parameters were measured in order to establish the reproductive state of the fish. Circulating testosterone (T), estradiol (E(2)) and 11 ketotestosterone (11KT) levels were assayed, gonads were removed for calculation of gonadosomatic index (GSI) values and histological studies, and RNA was extracted from the pituitaries for measurement of GtH Ibeta and IIbeta mRNA levels. In maturing fish of both sexes, the circulating steroid levels were positively correlated with each other (r(2) = 0.66-0.91) and in males, also with the GSI values (r(2) = 0.68). A positive correlation was also seen in these fish between GSI values and the prevalence of spermatocytes and spermatids (r(2) = 0.54). In maturing females, the maximal oocyte diameter was positively correlated with circulating E(2) levels (r(2) = 0.63), while GSI values showed no correlation; this presumably relates to the cycling nature of this asynchronous spawner. In regressing fish of both sexes, no clear correlation between these reproductive parameters was seen. In all fish, the GtH Ibeta mRNA levels were highest in fish with steroids ranging 1-10 ng T or E(2)/ml for males or females, respectively, and were lower in fish with steroids at higher or lower levels. In fish with high steroid levels, the IIbeta mRNA levels were also high, and in regressed males the increases were positively correlated. Exposure of cultured pituitary cells to either steroid (T at >10 nM, or E(2) at >1 nM) was followed by a decrease in the steady-state levels of the Ibeta transcript, while those of IIbeta were left unaltered. In situ hybridization studies revealed that in pituitaries of both sexes, the cells producing each of these mRNAs are located in a distinct location. These results suggest that gonadal steroids may exert differential feedback mechanisms at the level of the pituitary to control transcription of each GtH beta subunit in distinct cell types specific for each hormone.
Animals↗
Possible interactions between gonadotrophs and somatotrophs in the pituitary of tilapia: apparent roles for insulin-like growth factor I and estradiol.
The unique organization of the teleost pituitary, in which cells are grouped according to their characteristic hormone, makes this a suitable model for studying pituitary paracrine interactions. In a number of fish, including tilapia, there are variations in the circulating levels of the gonadotropins and GH, which are elevated during the reproductive season, suggesting interactions between the reproductive and growth axes. The aim of this study was to investigate paracrine interactions between the gonadotrophs and somatotrophs in the tilapia pituitary. Initially, dispersed pituitary cells were separated on a density gradient in which the gonadotrophs were found in the least dense fractions, and the somatotrophs were concentrated in the densest fraction. After 4 days in culture, cells in the least dense fractions showed characteristic cytoplasmic extensions not seen in the somatotrophs, which appeared small and failed to form aggregates; somatotrophs were found, however, attached to other non-GH cells. Staining of the nuclei with 4,6-diaminidino-2-phenyl-dihydrochloride revealed that the isolated somatotrophs had undergone nuclear condensation and fragmentation typical of apoptosis. Addition of either estradiol or human recombinant insulin-like growth factor I (IGF-I; 10 nM) to the somatotroph cultures increased the number of cell aggregates and reduced the number of condensed or fragmented nuclei. Immunocytochemical studies on pituitary sections revealed IGF-I immunoreactivity in regions of the proximal pars distalis that stain with gonadotropin IIbeta antisera and also in regions of the rostral pars distalis characteristic of corticotrophs; immunoreactive IGF-I was never seen in the region of the somatotrophs. Incubation of cells from the different fractions with testosterone (10 nM; 24 h) revealed that cells of the least dense fractions, which were rich in gonadotrophs, possessed aromatizing ability, which was absent in the somatotroph-enriched fraction. These results suggest that estradiol and IGF-I, both generated from cells other than the somatotrophs, may exert antiapoptotic effects and thus possibly control the size of this population of cells.
Animals↗
Recurrent GI hemorrhage following the use of silk sutures.
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Duodenal Ulcer↗
Differential effects of gonadotropin-releasing hormone, dopamine and somatostatin and their second messengers on the mRNA levels of gonadotropin II beta subunit and growth hormone in the teleost fish, tilapia.
In cultured pituitary cells of tilapia, gonadotropin-releasing hormone (GnRH; 10 nM 4-24 h), elevation of cyclic AMP (by 10 microM forskolin or 0.2 mM 3-isobutyl-1-methylxanthine: IBMX 0.5-36 h) or activation of protein kinase C (PKC; by 12.5 nM tetradecanoyl phorbol-13-acetate: TPA, 0.5-24 h) all increased gonadotropin (GtH) II beta steady state mRNA levels by three to four-fold. The involvement of PKA and PKC in the GnRH stimulatory effect on both GtH release and GtH II beta mRNA levels was corroborated by use of the PKA and PKC inhibitors, H89 and GF109203X, respectively (100 nM) which attenuated the GnRH effect. Incubation with actinomycin D (8 microM, 4-21 h) after preexposure for 24 h to either forskolin (10 microM) or TPA (12.5 nM), revealed that rates of transcript degradation were slower in forskolin-treated cells (T 1/2 = 14.1 h) than in control or TPA-treated cells (T 1/2 = 8.47 or 8.38 h), suggesting a stabilizing effect on the mRNA. Dopamine (DA; 10 microM, 4-36 h) had no apparent effect on steady state mRNA levels of GtH II beta, but reduced GtH release by as much as 75%. Steady state levels of growth hormone (GH) mRNA were not affected by exposure to GnRH (10 nM, 4-24 h), although GH release was more than doubled. Similarly, activation of PKC (by TPA 12.5 nM, 1.5-36 h), which was shown to be essential for the GnRH-stimulatory effect on GH release, did not alter levels of the GH transcript, but increased GH release by more than fivefold. DA (10 microM, 4-24 h) moderately increased GH transcript levels (160%) with similar kinetics but lower potency than direct elevation of cAMP (by 10 microM forskolin or 0.2 mM IBMX, 0.5-36 h) which increased transcript levels by more than fourfold. The involvement of PKA in the DA effect was confirmed when the PKA inhibitor H89 (100 nM, 15 min prior to DA exposure) attenuated the DA effect on GH mRNA levels. Exposure of cells to actinomycin D (8 microM, 2-16 h) after treatment with forskolin (10 microM, 24 h) led to a slower rate of transcript degradation than in control cells (T 1/2 = 6.5 h vs. T 1/2 = 4.36 h), suggesting that cAMP also elicits a stabilizing effect on GH mRNA. Somatostatin (100 nM, 0.5-36 h) had no clear effect on GH transcript levels, but reduced GH release by as much as 90%. These results suggest that activation of either cAMP-PKA or PKC pathways can, possibly by different mechanisms, stimulate mRNA levels of the GtH II beta gene, but that only the cAMP-PKA pathway stimulates GH mRNA levels. It would appear therefore that GnRH, although stimulating GH release, does not regulate GH transcription in this fish.
Animals↗
The importance of increasing the number of gastric biopsies in the diagnosis of Helicobacter pylori.
BACKGROUND/AIMS: The role of Helicobacter pylori in various gastroduodenal diseases is universally accepted. In this study, we aimed to determine the proper number and sites of the gastric biopsies in order to achieve the highest diagnostic yield through the use of a urease test and histopathology. We also compared the histological findings encountered in patients who had Helicobacter pylori (H. pylori) colonization. METHODOLOGY: Fifty patients referred for upper gastrointestinal endoscopy for dyspeptic complaints were included in the study. Our mapping protocol included 2 biopsies from antrum and 2 biopsies from corpus. We obtained 2 biopsies from each biopsy site for urease test and histopathological assessment. Golden standard positivity for the presence of H. pylori colonization was defined as concomitantly positive urease test and histologically detected bacteria found at the same biopsy site. RESULTS: Forty-three patients had H. pylori colonization. Colonization rates of H. pylori, sensitivities of urease testing, and histopathology in 4 biopsy sites were not statistically different. Sensitivity of urease testing was 81.4% for 1 biopsy and 100% for 4 cumulative biopsies. Sensitivities of histological assessment were 93% and 100% for 1 and 4 biopsies, respectively. CONCLUSIONS: Results of this study suggest that 2 biopsies for urease testing and 1 biopsy for histopathology obtained from the antrum or corpus of the stomach were sufficient to obtain the highest statistically significant diagnostic sensitivity.
Adult↗