Investigation of the effect of SRSF9 overexpression on HIV-1 production

Serine-arginine-rich splicing factors (SRSFs) are members of RNA processing proteins in the serine-arginine-rich (SR) family that could regulate the alternative splicing of the human immunodeficiency virus-1 (HIV-1). Whether SRSF9 has any effect on HIV-1 regulation requires elucidation. Here, we report for the first time the effects and mechanisms of SRSF9 on HIV-1 regulation. The overexpression of SRSF9 inhibits viral production and infectivity in both HEK293T and MT-4 cells. Deletion analysis of SRSF9 determined that the RNA regulation motif domain of SRSF9 is important for anti-HIV-1 effects. Furthermore, overexpression of SRSF9 increases multiple spliced forms of viral mRNA, such as Vpr mRNA. These data suggest that SRSF9 overexpression inhibits HIV-1 production by inducing the imbalanced HIV-1 mRNA splicing that could be exploited further for a novel HIV-1 therapeutic molecule. [BMB Reports 2022; 55(12): 639-644].

Identification of Novel Nucleocapsid Chimeric Proteins Inhibiting HIV-1 Replication

The positive transcription elongation factor b (P-TEFb) is an essential factor that induces transcription elongation and is also negatively regulated by the cellular factor HEXIM1. Previously, the chimeric protein HEXIM1-Tat (HT) was demonstrated to inhibit human immunodeficiency virus-1 (HIV)-1 transcription. In this study, we attempted to develop an improved antiviral protein that specifically binds viral RNA (vRNA) by fusing HT to HIV-1 nucleocapsid (NC). Thus, we synthesized NC-HEXIM1-Tat (NHT) and HEXIM1-Tat-NC (HTN). NHT and HTN inhibited virus proliferation more effectively than HT, and they did not attenuate the function of HT. Notably, NHT and HTN inhibited the infectivity of the progeny virus, whereas HT had no such effect. NHT and HTN selectively and effectively interacted with vRNA and inhibited the proper packaging of the HIV-1 genome. Taken together, our results illustrated that the novel NC-fused chimeric proteins NHT and HTN display novel mechanisms of anti-HIV effects by inhibiting both HIV-1 transcription and packaging.

Investigation of the effect of Staufen1 overexpression on the HIV-1 virus production

In this study, we investigated how Staufen1 influences the HIV-1 production. The overexpression of Staufen1 increased virus production without any negative affect on the viral infectivity. This increase was not caused by transcriptional activation; but by influencing post-transcriptional steps. Using multiple Gag protein derivatives, we confirmed that the zinc-finger domains of the HIV-1 nucleocapsid (NC) are important for its interaction with Staufen1. We also found that Staufen1 colocalized in stress granules with the mature form of the HIV-1 NC protein.

[Curative effect analysis of ultrasound-guided percutaneous radiofrequency ablation for caudate lobe hepatocellular carcinoma]

Objective: To investigate the safety and efficacy of ultrasound-guided percutaneous radiofrequency ablation (RFA) for caudate lobe hepatocellular carcinoma (HCC) and the failure factors of incomplete tumor ablation. Methods: Twenty-four cases with caudate lobe hepatocellular carcinoma who underwent ultrasound-guided percutaneous RFA in the Affiliated Tumor Hospital of Zhengzhou University from January 2017 to October 2019 were enrolled. The ablation effect and complications conditions were recorded, and the primary technical effectiveness and local tumor progression (LTP) were evaluated. Results: Among 24 cases, 20 cases had complete ablation at one session, 4 cases had incomplete ablation, and after supplementary radiofrequency ablation all cases had achieved complete ablation. There was no evidence of local tumor progression in 24 cases after one-month postoperative evaluation. The primary technical effectiveness rate was 100%. The postoperative follow-up was 2 to 29 months (median follow-up time was 18 months). Of the 24 cases after ablation, LTP were detected in 11 cases, of which only 3 cases had distant intrahepatic recurrence, 1 case had distant intrahepatic recurrence and distant metastasis, and 5 cases had only distant metastasis, 2 cases died, and 4 cases had SIR grade B complications related to ablation. Conclusion: Ultrasound-guided percutaneous radiofrequency ablation was safe and effective for caudate lobe hepatocellular carcinoma. In addition, the distance between the tumor and the inferior vena cava < 0.5cm is a suspected risk factor for incomplete ablation of caudate lobe hepatocellular carcinoma (P < 0.05).

Understanding of the functional role(s) of the Activating Transcription Factor 4(ATF4) in HIV regulation and production

The activating transcription factor (ATF) 4 belongs to the ATF/CREB (cAMP Response Element Binding bZIP [Basic Leucine Zipper]) transcription factor family, and plays a central role in the UPR (Unfolded Protein Response) process in cells. The induction of ATF4 expression has previously been shown to increase the replication of HIV-1. However, the detailed mechanism underlying this effect and the factors involved in the regulation of ATF4 function are still unknown. Here, we demonstrate first that knocking out ATF4 using siRNA shows a strong negative effect on HIV-1 production, indicating that ATF4 is a functional positive cellular factor in HIV-1 production. To determine the mechanism by which ATF4 regulates the HIV-1 life cycle, we assessed the effect of the overexpression of wild type ATF4 and its various derivatives on HIV-1 LTR-mediated transcriptional activation and the production of HIV-1 particles. This effect was studied through co-transfection experiments with either reporter vectors or proviral DNA. We found that the N-terminal domains of ATF4 are involved in HIV-1 LTR-mediated transcriptional activation, and thus in HIV-1 production. [BMB Reports 2018; 51(8): 388-393].

Investigation of function and regulation of the YB-1 cellular factor in HIV replication

Y-box binding protein 1 (YB-1) is a member of the cold-shock domain (CSD) protein superfamily. It participates in a wide variety of cellular events, including transcription, RNA splicing, translation, DNA repair, drug resistance, and stress responses. We investigated putative functions of YB-1 in HIV-1 replication. Functional studies using overexpression or knockdown of YB-1 in conjunction with transfection of proviral DNA showed that YB-1 enhances virus production. We found YB-1 regulates HIV-1 production by stimulating viral transcription using HIV-1 LTR sequence U3RU5 with Luciferase assay. We also identified a specific region from amino acids 1 to 324 of YB-1 as necessary for the participation of the protein in the production of virions.

Role of hysterectomy in chemoresistant gestational trophoblastic neoplasia

No abstract provided.

Investigation of functional roles of transcription termination factor-1 (TTF-I) in HIV-1 replication

Transcription termination factor-1 (TTF-I) is an RNA polymerase 1-mediated transcription terminator and consisting of a C-terminal DNA-binding domain, central domain, and N-terminal regulatory domain. This protein binds to a so-called ‘Sal box’ composed of an 11-base pair motif. The interaction of TTF-I with the ‘Sal box’ is important for many cellular events, including efficient termination of RNA polymerase-1 activity involved in pre-rRNA synthesis and formation of a chromatin loop. To further understand the role of TTF-I in human immunodeficiency virus (HIV)-I virus production, we generated various TTF-I mutant forms. Through a series of studies of the over-expression of TTF-I and its derivatives along with co-transfection with either proviral DNA or HIV-I long terminal repeat (LTR)-driven reporter vectors, we determined that wild-type TTF-I downregulates HIV-I LTR activity and virus production, while the TTF-I Myb-like domain alone upregulated virus production, suggesting that wild-type TTF-I inhibits virus production and trans-activation of the LTR sequence; the Myb-like domain of TTF-I increased virus production and trans-activated LTR activity.

Combined low-dose mycophenolate mofetil and tacrolimus for lupus nephritis with suboptimal response to standard therapy: a 12-month prospective study

OBJECTIVE

The objective of this paper is to evaluate the efficacy of combined mycophenolate mofetil (MMF) and tacrolimus (TAC) for lupus nephritis with suboptimal response to standard therapy.

METHODS

Inclusion criteria for patients: (1) biopsy-confirmed active lupus nephritis; and (2) inadequate response to ≥ 2 immunosuppressive regimens. While prednisolone (≤ 10 mg/day) and angiotensin-converting enzyme inhibitors were continued, immunosuppressive agents were replaced by combined MMF (1 g/day) and TAC (4 mg/day). Patients were followed every 2 months for the clinical response and adverse events at 12 months.

RESULTS

Twenty-one patients were recruited (20 women; age 35.8 ± 9.2 years; systemic lupus erythematosus (SLE) duration 111 ± 51 months). The histological classes of lupus nephritis were: IV/III (33%), V+III/IV (33%) and pure V (33%). The creatinine clearance (CrCl), urine protein-to-creatinine ratio (uP/Cr) and serum albumin was 82.4 ± 33 ml/min (<90 ml/min in 57%), 3.27 ± 1.5 and 30.1 ± 5.9 g/l, respectively. Thirteen (62%) patients had active urinary sediments and 17 (81%) patients had active lupus serology. At 12 months, eight (38%) patients had very good response, one (5%) patient had good response and five (24%) patients had partial response. Significant improvement in uP/Cr, albumin, complement C3 and anti-dsDNA titer, and stabilization of CrCl was observed in the responders. Thirty-three adverse events were reported in 18 patients: major infection requiring hospitalization (6%), infection not requiring hospitalization (27%), herpes infection (9%), diarrhea (12%), cramps (9%), dyspepsia (6%), transient increase in serum Cr (6%), alopecia (4%), facial twitching (3%), tremor (3%) and diabetes mellitus (3%). None of these had led to protocol withdrawal.

CONCLUSIONS

Combined low-dose MMF and TAC is an option for lupus nephritis that fails to respond adequately to standard regimens, with two-thirds of patients improving after 12 months. Longer-term observation is needed to confirm its efficacy and safety.

Variations in ventral root axon morphology and locomotor behavior components across different inbred strains of mice

Locomotion is a complex behavior affected by many different brain- and spinal cord systems, as well as by variations in the peripheral nervous system. Recently, we found increased gene expression for EphA4, a gene intricately involved in motor neuron development, between high-active parental strain C57BL/6J and the low-active chromosome substitution strain 1 (CSS1). CSS1 mice carry chromosome 1 from A/J mice in a C57BL/6J genetic background, allowing localization of quantitative trait loci (QTL) on chromosome 1. To find out whether differences in motor neuron anatomy, possibly related to the changes in EphA4 expression, are involved in the motor activity differences observed in these strains, motor performance in various behavioral paradigms and anatomical differences in the ventral roots were investigated. To correlate the behavioral profiles to the spinal motor neuron morphology, not only CSS1 and its parental strains C57BL/6J (host) and A/J (donor) were examined, but also a set of other mouse inbred strains (AKR/J, 129x1/SvJ and DBA/2J). Significant differences were found between inbred strains on home cage motor activity levels, the beam balance test, grip test performance, and on alternating versus synchronous hind limb movement (hind limb hopping). Also, considerable differences were found in spinal motor neuron morphology, with A/J and CSS1 showing smaller, possibly less developed, motor neuron axons compared to all other inbred strains. For CSS1 and C57BL/6J, only genetically different for chromosome 1, a correlation was found between motor activity levels, synchronous hind limb movement and neuro-anatomical differences in spinal motor neurons. Inclusion of the other inbred strains, however, did not show this direct correlation. These data verifies the complex nature of the mammalian motor system that may be further dissected using genetic mapping populations derived from these inbred strains.

Risk and predictors of work disability in Chinese patients with systemic lupus erythematosus

The aim of this study is to determine the risk and predictive factors for work disability in patients with SLE. A cross-sectional questionnaire study was performed to evaluate the employment status of a sample of consecutive Chinese patients with SLE. Demographic, socioeconomic data (age, gender, marital status, years of education and household income), employment status, self-reported fatigue score and disease characteristics (SLE duration, organ damage and disease activity) were collected. Work disability was defined by the failure to work due to SLE. The cumulative incidence of work disability since the time of SLE diagnosis was studied by a Kaplan Meier's plot, and factors predictive of work disability were studied by Cox regression. A total of 147 patients with SLE were studied (mean age = 39.4 +/- 11.3 years; 95% women). Among 105 patients who were working at the time of SLE diagnosis, 39 (37%) lost their ability to work as a result of SLE after a mean disease duration of 10.0 +/- 6.1 years. Twenty-two (56%) patients lost their work ability within 2 years of diagnosis of SLE. The self-reported reasons for job loss were musculoskeletal pain (87%), skin disease (26%), renal problem (21%), fatigue (85%), memory deterioration (51%), anxiety or depressive symptoms (74%), too frequent sick leave (10%) and long-term hospitalisation (10%). The cumulative risk of work disability was 36% at 5 years after SLE diagnosis. In a Cox regression model, age (HR = 1.06 [1.02-1.11] per year; P = 0.008), self-reported fatigue score (HR = 1.06 [1.01-1.10] per point; P = 0.01) and mean disease activity score in the preceding two years (HR = 1.20 [1.02-1.42] per point; P = 0.03) were independently associated with working disability. In all, 37% of this group of patients with SLE lost their work ability after having the disease for 10 years. More than 50% of these patients developed work disability within the first 2 years of SLE diagnosis. Older age, fatigue and more active disease were independent predictors of work disability.

San-Huang-Xie-Xin-Tang attenuates inflammatory responses in lipopolysaccharide-exposed rat lungs

In this study, the potential anti-inflammatory effect of San-Huang-Xie-Xin-Tang (SHXT) and its main component baicalin on LPS-induced lung injury were investigated and compared to the profile of dexamethasone (DEXA) in a pre-clinical animal model. Post-treatment with SHXT (75 mg/kg), baicalin (1.5 mg/kg) and DEXA (0.5 mg/kg), significantly inhibited LPS-induced hypotension, lung edema and acute survival rates. Western blotting analysis results indicated that all of them significantly inhibited LPS-induced iNOS, TGF-beta, p38MAPK, and ICAM-1 expressions in the lung tissues. Results from ELISA analysis showed that SHXT, baicalin and DEXA all decreased plasma levels of IL-1beta, TNF-alpha, and MCP-1 caused by LPS. Based on these findings, SHXT and baicalin decreased plasma concentrations of IL-1beta, TNF-alpha, MCP-1, and expressions of TGF-beta, ICAM-1, phosphorylated p38 MAPK, and iNOS, which were associated with lung injury and lethality. These evidences indicated that SHXT and baicalin showed strong anti-inflammatory activity, similar to that observed for DEXA, and therefore implicated that herbal SHXT might be therapeutically useful for the treatment of endotoxic lung injury.

Detection of mRNA expression of gonadotropin-releasing hormone and its receptor in normal and neoplastic rat prostates

Hypothalamic gonadotropin-releasing hormone (GnRH) plays a central role in the regulation of the mammalian reproductive systems as a releasing hormone of pituitary gonadotropins. However, a number of studies have shown that GnRH or its receptor are also expressed in some reproductive organs including prostate gland, mammary gland, ovary and placenta, tumors and tumor cell lines derived from these organs, suggesting that this peptide hormone may have other extrapituitary functions in addition to its role as a gonadotropin-releasing hormone. Moreover, it has been demonstrated that GnRH analogs exert some direct inhibitory effects on the proliferation of human and rat prostate cancer cells, probably mediated by its own specific receptors expressed in these tumor cells. In the present study, we investigated the mRNA expression of GnRH and its receptor in normal Noble rat prostate gland, and in three rat models of prostate cancer including the sex hormone-induced Noble rat model, an androgen-independent Noble rat prostatic tumor (AIT) and Dunning rat prostatic adenocarcinomas by RT-PCR and Southern blot analyses. The results showed that GnRH mRNA was expressed in the normal, hormone-treated and neoplastic rat prostates, in addition to its positive control expression in the hypothalamus, whereas its receptor was only detected in the androgen-dependent Dunning R3327H tumor. The detection of both GnRH and its receptor in the androgen-dependent Dunning R3327H tumor tissue suggests that this peptide hormone may have some autocrine and paracrine regulatory functions in this tumor. However, the gene expression of GnRH receptor was not detected in two androgen-independent Dunning tumor sublines and the Noble rat prostatic tumor, AIT, suggesting that the expression of GnRH receptor is lost or down-regulated in the prostatic tumors during the progression to a hormone-independent phenotype.

An approach to the identification of potent inhibitors of influenza virus fusion using parallel synthesis methodology

Structure-activity studies associated with the salicylic acid-derived inhibitor of influenza fusion, BMY-27709, were examined using a parallel synthesis approach. This SAR survey led to the discovery of potent influenza inhibitory activity in a series of aromatic amides and thioamides derived from 1,3,3-trimethyl-5-hydroxycyclohexylmethylamine. Select compounds were characterized as inhibitors of the H1 subtype of influenza A viruses that act by preventing the pH-induced fusion process, thereby blocking viral entry into host cells. In a plaque-reduction assay, the most potent inhibitors displayed EC(50) values of 0.02-0.14 microg/mL.

Real-time analysis of the activities of GnRH and GnRH analogs in alphaT3-1 cells by the Cytosensor microphysiometer

Gonadotropin-releasing hormone (GnRH), acting via the GnRH receptor, elicited rapid extracellular acidification responses in mouse gonadotrope-derived alphaT3-1 cells as measured by the Cytosensor microphysiometer, which indirectly monitors cellular metabolic rates. GnRH increased the extracellular acidification rate of the cells in a dose-dependent manner (EC(50) = 1.81 +/- 0.24 nM). The GnRH-stimulated acidification rate could be attenuated by protein kinase C (PKC) down-regulation, extracellular Ca2+ depletion, and the voltage-sensitive Ca2+ channel (VSCC) blocker nifedipine, indicating that the acidification response is activated by both Ca2+ and PKC-mediated pathways. Upon continuous exposure to 100 nM GnRH or periodic stimulation by 10 nM GnRH at 40 min intervals, homologous desensitization was more pronounced in the absence of extracellular Ca2+, suggesting that desensitization of GnRH activity may be mediated via depletion of intracellular Ca2+ stores. We have also compared the potency of eight GnRH analogs on alphaT3-1 cells. No acidification response was detected for GnRH free acid, consistent with the idea that the C-terminal amide is a critical structural determinant for GnRH activity. Replacement of Gly-NH(2) at the C-terminus by N-ethylamide dramatically reduced the EC(50) value, suggesting that substitution of the Gly-NH(2) moiety by N-ethylamide increases the potency of GnRH analogs. Substitution of Gly at position 6 by D-Trp significantly reduced the EC(50) value, whereas D-Lys at the same position slightly increased the EC(50) value, implying that either an aromatic amino acid or a non-basic amino acid at position 6 may be essential for potent GnRH agonists. In summary, our results demonstrate that the Cytosensor microphysiometer can be used to evaluate the actions of GnRH and GnRH analogs in alphaT3-1 cells in a real-time and noninvasive manner. This silicon-based microphysiometric system should provide new information on the structure-function studies of GnRH and is an invaluable tool for the screening of new GnRH agonists and antagonists in the future.

X-ray absorption spectroscopy study of Co structure in the epitaxial Co/Pt multilayers on Al2O3(11-20) substrates

In this study, five epitaxial [Co(t nm)/Pt(1 nm)]30, multilayer samples (t=0.16-1.07 nm) were studied using polarized X-ray absorption spectroscopy method. These samples were prepared on Mo(110)/ Al2O3(11-20) substrates by MBE technique. The results show that the Co layer is more like an fcc pseudomorphic structure for the Co thickness of less than 0.3 nm. For Co layer thickness of 1 nm, the first shell distance is 0.25 nm, which is very close to the Co-Co distance of bulk hcp Co. On the other hand, for Co layer of less than 0.3 nm, the in plane first shell distance is expanded by 4% and most of the neighboring atoms are Pt atoms. The fitting results of the Co/Pt multilayers seem to support a sharp boundary model rather than an interdiffusion model.

Transcriptional mRNA of bone morphogenetic proteins 2, 3, 4, and 5 in trigeminal nerve, benign and malignant peripheral nerve sheath tumors

Bone morphogenetic proteins (BMPs) have been shown to play an important role in cell growth and differentiation. BMPs, a rapidly expanding family closely related to transforming growth factor-beta (TGF-beta) superfamily, have been proven recently to possess a regulatory role and neurotrophic capacity in neurogenesis. The aim of the present study is to reveal the relationship among BMPs, peripheral nerve and neoplastic lesions of nerve sheath tumors. The mRNA transcriptions of BMP 2, 3, 4 and 5 in 12 cases of schwannoma, four cases of malignant schwannoma and three cases of trigeminal neuralgia were detected using an in situ hybridization technique. Our results demonstrated that the myelin sheaths of schwann cell from the peripheral neuroectomy of trigeminal neuralgia were positively expressing mRNA of BMP-2, 3, 4 and 5. However, the nerve fibers of trigeminal nerve showed only BMP-2 positive staining. All of the neoplastic lesions of nerve sheath showed a consistent but variant expression of BMP-2, 3, 4, and 5. Except for the BMP-4 mRNA, the expression signals of BMP-2, 3 and 5 mRNA in malignant schwannoma were relatively lower than in benign lesions. On the basis of the findings, we concluded that selected members of BMPs existed in the peripheral nerves and might contribute to the health maintenance, proliferation, regeneration and neoplastic transformation of the peripheral nerve system. Moreover, the effects of BMP-2, 3, 4 and 5 on peripheral nerve system and its neoplastic transformation might be widespread, diverse and antagonistic.

Salicylamide inhibitors of influenza virus fusion

Structural variation of the quinolizidine heterocycle of the influenza fusion inhibitor BMY-27709 was examined by several topological dissections in order to illuminate the critical features of the ring system. This exercise resulted in the identification of a series of synthetically more accessible decahydroquinolines that retained the structural elements of BMY-27709 important for antiviral activity. The 2-methyl-cis-decahydroquinoline 6f was the most potent influenza inhibitor identified that demonstrated an EC50 of 90 ng/mL in a plaque reduction assay.

A novel approach of intravenous electrocardiograph technique in correct position the long-term central venous catheter

Intravenous electrocardiograph (IVECG) can correctly positioning the catheter tip by enlarging p wave as it is moved toward right atrium, and it is a safe, reliable and accurate technique. To evaluate the efficacy of wire-conducted IVECG signal and IVECG signal from the port with sodium bicarbonate (NaHCO3) flushed catheter and to compare those with conventional anatomy landmark method was the propose of this study. This prospective study was carried out in 216 patients who suffered from malignant diseases. The correct position of the catheter tip among these groups was confirmed as follows. In group 1 (n = 80), the anatomy landmark method and portable chest radiograph recognized the correct position. In group 2 (n = 72), IVECG signal was conducted from guide wire to identify the tip position. In group 3 (n = 64), IVECG signal was conducted from the port with NaHCO3 (0.8 mEq/mL) flushed catheter to ascertain the tip position. The patient characteristics did not differ significantly among the groups. The duration of operation was significantly (P < 0.001) longer in group 1 than in group 2 and group 3 (45.4 +/- 9.3 minutes vs 35.7 +/- 8.0 minutes and 35.2 +/- 9.7 minutes, respectively). Catheter tip placement times were shorter in group 2 and group 3 than in group 1 (5.3 +/- 2.9 minutes and 6.4 +/- 3.0 minutes vs 16.7 +/- 5.7 minutes, respectively); there was a statistically significant difference between the group 1 and group 2 and group 3 (p < 0.001). Nonetheless, the duration of operation and catheter tip placement time was similar in group 2 and group 3. Early and late complications within the subsequent 3 months showed no significant difference among groups. We concluded that IVECG signal conducted from guide wire obtained a similar efficiency to that signal from the port with NaHCO3 flushed catheter on positioning the catheter tip of the venous Port-A-Cath system. It is recommended to use these methods to facilitate implanting long-term central venous devices.

Influences of tramadol on emergence characteristics from sevoflurane anesthesia in pediatric ambulatory surgery

Sevoflurane is used for pediatric ambulatory surgery due to its low blood solubility, rapid emergence, non-pungency and low airway irritability. Nevertheless, its tendency to induce agitation during emergence may offset its benefits. The following study was designed to evaluate the effects of intravenous (i.v.) tramadol (1 mg/kg) on the emergence from sevoflurane anesthesia. Forty ASA I children, ranging from 1 to 8 years old, scheduled for inguinal surgery, were randomized into two groups (Group S--control group, Group ST--i.v. tramadol, 20 in each group). The patients were first premedicated with oral atropine (0.01 mg/kg), then anesthesia was induced with i.v. application of thiamylal (3-4 mg/kg) and maintained with mask anesthesia with sevoflurane. Topical infiltration with 2-3 ml of 1% lidocaine was applied over skin incision area. I.v. tramadol (1 mg/kg) was given before the end of operation in Group ST. The emergence agitation was recorded on a visual analog scale (VAS, 0-10) by a blinded anesthesiologist in the PACU (postoperative anesthesia care unit), as well as the length of other recovery stages and complications after anesthesia. The age, weight, gender, and duration of surgery and anesthesia were similar in the two groups. The emergence agitation score (6.3 +/- 3.5 vs. 3.2 +/- 2.8, P < 0.05), incidences of agitation (VAS > 5, 55% vs 20%, P < 0.05), and postoperative pain (65% vs 30%, P < 0.05) were higher for the control group. I.v. Tramadol (1 mg/kg) before the end of operation reduced postoperative pain and the incidence and degree of emergence agitation from sevoflurane anesthesia in pediatric ambulatory surgery.

Molecular characterization of an additional shrimp hyperglycemic hormone: cDNA cloning, gene organization, expression and biological assay of recombinant proteins

The crustacean eyestalk CHH/MIH/GIH neurohormone gene family represents a unique group of neuropeptides identified mainly in crustaceans. In this study, we report the cloning and characterization of the cDNA and the gene encoding the hyperglycemic hormone (MeCHH-B) of the shrimp Metapenaeus ensis. The amino acid sequence of MeCHH-B shows 85% identity to that of MeCHH-A (formerly MeCHH-like neuropeptide). Two separate but identical MeCHH-B genes were identified in the genome of shrimp by library screening and they are located on different CHH gene clusters. The organization of the MeCHH-B gene is identical to other members of the CHH/MIH/GIH neurohormone family. MeCHH-B is expressed at a constant level in the eyestalks of juveniles and mature females. Unlike the MeCHH-A gene, a low level of MeCHH-B transcripts can also be detected in the central nervous system. Interestingly, the expression pattern of MeCHH-B in the eyestalk of vitellogenic females is reversed to that of the MeCHH-A gene. At the middle stage of gonad maturation, a minimum level of MeCHH-B transcript was recorded and a maximum level of MeCHH-A transcript was detected. Recombinant proteins for MeCHH-A and MeCHH-B were produced by a bacterial expression system. The hemolymph glucose level of bilaterally eyestalk-ablated shrimp increased two-fold 1 h after the rCHH injection and then returned to normal after 2 h. The hyperglycemic effect of these fusion proteins is comparable to that of de-stalked shrimp injected with crude extract from a single sinus gland.

cDNA cloning and expression of a novel estrogen receptor beta-subtype in goldfish (Carassius auratus)

We have isolated a second goldfish estrogen receptor (ER) beta-subtype (gfER-beta2) cDNA which is distinct from the liver-derived ER-beta (gfER-beta1) cDNA reported previously. The 2650-bp cDNA, isolated from a goldfish pituitary and brain cDNA library, encodes a 610 amino acid (aa) protein which shows only a 53% aa sequence identity with gfER-beta1 in overall structure. RT-PCR analysis showed that mRNA of gfER-beta2, in contrast to that of gfER-beta1, was predominantly expressed in pituitary, telencephalon and hypothalamus as well as in liver of female goldfish. The existence of a second distinct ER-beta subtype opens new dimensions for studying tissue-specific regulation of gene expression by estrogen in the tetraploid goldfish.

Estrogen receptor-mediated repression of gonadotropin-releasing hormone (gnRH) promoter activity in transfected CHO-K1 cells

To examine the transcriptional regulation of gonadotropin-releasing hormone (GnRH) gene in reproductive tissues, the expression of human GnRH gene promoter in cultured human granulosa cells and a Chinese hamster ovary-derived CHO-K1 tumor cells was studied. Transfection of luciferase reporter gene construct containing either upstream (hU) or downstream (hD) human GnRH gene promoter into both human granulosa and CHO-K1 cells showed that the upstream promoter, hU, was more active than hD in directing luciferase expression in these ovarian tissues. CHO-K1 cells transfected with either hU or hD construct showed insignificant changes in luciferase activity in response to 17beta-estradiol and GnRH. However, cotransfection of hU construct with a vector expressing a human estrogen receptor-alpha (ER-alpha) cDNA results in dose-dependent decreases in luciferase activity in response to both 17beta-estradiol and a GnRH agonist. By functional analysis of a series of deletion constructs, the ER-mediated suppression of GnRH promoter activity by 17beta-estradiol was localized to a region between -169 and -548 bp 5' of the upstream transcription start site of the human GnRH gene. Results of this study demonstrated that estrogen receptor can mediate the negative feedback regulation of human GnRH upstream promoter activity by both estrogen and GnRH in the ovary.

Cloning and characterization of goldfish activin betaA subunit

We have cloned a full-length cDNA coding for activin betaA subunit from a goldfish brain and pituitary cDNA library, which represents the first for activin betaA in fish. Sequence analysis of goldfish activin betaA shows that this peptide is highly conserved across vertebrates. The mature region of goldfish activin betaA shares 81% amino acid identity with that of humans. Messenger RNA of goldfish activin betaA is expressed in a variety of tissues including ovary, testis, brain and liver, suggesting a wide range of physiological roles for activin A in the goldfish. The identity of the cloned goldfish activin betaA was confirmed by expressing the protein in the Chinese hamster ovary (CHO) cells followed by detection of the specific activin activity in the culture medium using erythroid differentiation factor (EDF) assay with F5-5 cells. Stable CHO cell lines producing high level of recombinant goldfish activin A were established and characterized.

Novel quinolizidine salicylamide influenza fusion inhibitors

A novel series of quinolizidine salicylamides was synthesized as specific inhibitors of the H1 subtype of influenza A viruses. These inhibitors inhibit the pH-induced fusion process, thereby blocking viral entry into host cells. Compound 16 was the most active inhibitor in this series with an EC50 of 0.25 microg/mL in plaque reduction assay. The synthesis and the SAR of these compounds are discussed.

Solid-phase synthesis of benzisothiazolones as serine protease inhibitors

An efficient solid-phase synthesis of benzisothiazolone-1,1-dioxide-based serine protease inhibitors involving alkylation of carboxylic acids with N-(bromomethyl)benzisothiazolone-1,1-dioxide has been developed. An example using this procedure for preparation of a library of human mast cell tryptase inhibitors is described.

pH-dependent changes in photoaffinity labeling patterns of the H1 influenza virus hemagglutinin by using an inhibitor of viral fusion

The hemagglutinin (HA) protein undergoes a low-pH-induced conformational change in the acidic milieu of the endosome, resulting in fusion of viral and cellular membranes. A class of compounds that specifically interact with the HA protein of H1 and H2 subtype viruses and inhibit this conformational change was recently described (G. X. Luo et al., Virology 226:66-76, 1996, and J. Virol. 71:4062-4070, 1997). In this study, purified HA trimers (bromelain-cleaved HA [BHA]) are used to examine the properties and binding characteristics of these inhibitors. Compounds were able to inhibit the low-pH-induced change of isolated trimers, as detected by resistance to digestion with trypsin. Protection from digestion was extremely stable, as BHA-inhibitor complexes could be incubated for 24 h in low pH with almost no change in BHA structure. One inhibitor was prepared as a radiolabeled photoaffinity analog and used to probe for specific drug interactions with the HA protein. Analysis of BHA after photoaffinity analog binding and UV cross-linking revealed that the HA2 subunit of the HA was specifically radiolabeled. Cross-linking of the photoaffinity analog to BHA under neutral (native) pH conditions identified a stretch of amino acids within the alpha-helix of HA2 that interact with the inhibitor. Interestingly, cross-linking of the analog under acidic conditions identified a different region within the HA2 N terminus which interacts with the photoaffinity compound. These attachment sites help to delineate a potential binding pocket and suggest a model whereby the BHA is able to undergo a partial, reversible structural change in the presence of inhibitor compound.

mRNA expression of gonadotropin-releasing hormones (GnRHs) and GnRH receptor in goldfish

In goldfish (Carassius auratus), two distinct forms of gonadotropin-releasing hormone (GnRH), namely, salmon GnRH (sGnRH) and chicken GnRH-II (cGnRH-II), have been identified in the brain using chromatographic, immunological, and molecular cloning approaches. These two native GnRHs act on specific receptors in the anterior pituitary to stimulate the synthesis and release of gonadotropins and growth hormone in goldfish. To evaluate the potential roles of sGnRH and cGnRH-II in both neural and reproductive tissues in goldfish, we studied the mRNA expression of sGnRH, cGnRH-II, and GnRH receptor (GnRH-R) in discrete brain areas, pituitary, ovary, and testis by a combined reverse transcription-polymerase chain reaction (RT-PCR) and Southern blot analysis. Total RNA was extracted from various tissues of sexually recrudescent male and female goldfish and RT-PCR was performed with primers specific for GnRH-R complementary DNA (cDNA), sGnRH cDNA, cGnRH-II cDNA-1, and cDNA-2. Results showed that GnRHs and GnRH-R mRNAs are differentially distributed in the brain. In the goldfish brain, sGnRH mRNA was predominantly expressed in the forebrain areas (olfactory bulb, telencephalon, and hypothalamus) whereas cGnRH-II mRNA-1 were expressed in all brain areas including olfactory bulbs and optic tectum-thalamus. The expression level of cGnRH-II mRNA-2 was much lower than that of cGnRH-II mRNA-1 in the brain. On the other hand, GnRH-R mRNA was expressed in all brain regions and pituitary. In the ovary and testis, GnRH-R mRNA, sGnRH mRNA, and cGnRH-II mRNA-1, but not cGnRH-II mRNA-2, are expressed. Sequence analysis of the PCR products showed that nucleotide sequences of GnRH-R in gonads are identical with that in the brain and pituitary. The coexistence of GnRHs and GnRH-R mRNAs in both neural and gonadal tissues supports the notion that sGnRH and cGnRH-II may act as neurotransmitters and/or neuromodulators in the brain and as autocrine and/or paracrine hormones in gonadal tissues in addition to their established neuroendocrine roles at the pituitary of goldfish.

Injection pain with propofol: the effectiveness of thiopentone on induction

One hundred and twenty-seven children aged 3-6 years were allocated to four groups. All of them received venous cannulation on the dorsum of the hand. On induction, the group L1, L2 and L3 patients received propofol 3 mg/kg mixed with lignocaine 0.15 mg/kg, 0.3 mg/kg, 0.6 mg/kg, respectively. The group T patients received thiopentone 3 mg/kg, then propofol 1.5 mg/kg mixed with lignocaine 0.075 mg/kg. Pain on injection was categorized into two-assessment items (facial expression and limbs withdrawal). The facial expression category were subdivided into none, mild (knit of brows), moderate (grimace), and severe (crying). The withdrawal of limbs was categorized into none, mild (withdrawal of hand), moderate (withdrawal of fore-arm and arm), severe (withdrawal of arm and twisting of body). Patients were monitored using an electrocardiogram, pulse oximeter, autonomic noninvasive blood pressure measuring device and capnography. The patient characteristics did not differ significantly among the four groups. Pain on injection was significantly more frequent in the group L1 patients (81%) compared with the group T (27%) patients. Increasing lignocaine dose reduced the incidence of pain graded as "moderate" or "severe" though there was no significant difference. The incidences of excitatory effect on propofol injection were reduced with increasing lignocaine dose and prior administration of thiopentone but there were no obviously differences among groups. We concluded that thiopentone reduced injection pain on propofol and should be recommended.

Identification and characterization of a receptor from goldfish specific for a teleost growth hormone-releasing hormone-like peptide

In mammals, growth hormone-releasing hormone (GHRH), acting via the GHRH receptor, plays an important role in the regulation of growth hormone (GH) synthesis and secretion as well as the proliferation and differentiation of somatotropes in the pituitary. In fishes, information concerning the functional role of the characterized GHRHs is limited. For that reason, a putative goldfish GHRH receptor cDNA was characterized in this study. The receptor cDNA is 2,243 bp in length, encoding a 438-amino-acid-long polypeptide with 7 putative transmembrane-spanning regions, which is a characteristic of G-protein-coupled receptors. The receptor, when expressed in COS-7 cells, showed minimal responses (2-fold cAMP responses) when stimulated with 100 nM of human GHRH, pituitary adenylate cyclase-activating polypeptide (PACAP) and vasoactive intestinal polypeptide (VIP). However, this receptor was found to be specific for a carp GHRH-like peptide isolated from the brain of common carp (Cyprinus carpio); there was a significant and dose-dependent increase in intracellular cAMP (a maximum response of 22-fold increase with an EC50 of 0.1 nM) when the transfected cells were stimulated with this peptide. As a preliminary study to investigate the functional role of this receptor, the tissue distribution of the mRNA was analyzed by reverse-transcription-polymerase chain reaction. The receptor mRNA was found to be present in the brain, pituitary, gut, gill, heart, liver, skeletal muscle, spleen, ovary and testis. Together with a goldfish PACAP type 1 receptor and a VIP1 receptor recently isolated in our laboratory, characterization of this putative GHRH receptor provides the molecular basis for the future understanding of the neuroendocrine control of growth and reproduction by these neuropeptides in goldfish as well as other teleosts.

The commissioning of a flexible low-cost multipurpose X-ray beamline at SRRC

A low-cost multipurpose X-ray beamline has been commissioned at the bending magnet B15 of the Synchrotron Radiation Research Center (SRRC). The beamline is constructed in such a way to accommodate the various needs of small research consortia, from universities or research institutes, whose requirements of a beamline facility are quite diverse while under limited funding support. Flexibility is the special feature of this beamline. It is capable of performing quick test measurements without a prolonged reviewing process. Switching between different techniques, such as white-beam irradiation, EXAFS and X-ray scattering, can be achieved within 1 h. Novel experiments, such as energy-dispersive small-angle scattering experiments and energy-dispersive reflectivity measurements, can also be performed.

Serine 232 and methionine 272 define the ligand binding pocket in retinoic acid receptor subtypes

The transcriptional response mediated by retinoic acid involves a complex series of events beginning with ligand recognition by a nuclear receptor. To dissect the amino acid contacts important for receptor-specific ligand recognition, a series of retinoic acid receptor (RAR) mutants were constructed. Transcriptional studies revealed that serine 232 (Ser232) in RARalpha and methionine 272 (Met272) in RARgamma are critical residues for the recognition of their respective receptor-selective analogs. The identification of these key amino acids in the ligand binding pocket is confirmed by the reported crystal structure of RARgamma. Interestingly, the serine at position 232 in RARalpha gives an explanation for the observed differences in the affinity of the naturally occurring ligand, all-trans-retinoic acid (t-RA), in this receptor compared with that for the other receptors, since hydrogen bonding would not be permitted between the hydroxyl of serine and the hydrophobic linker of t-RA. Using this model, a molecular mechanism for the transcriptional antagonism of a synthetic analog is suggested that involves an alteration in the structure of the receptor protein in the region around the AF2 domain in helix 12.

Characterization of multiple promoters directing tissue-specific expression of the human gonadotropin-releasing hormone gene

Two promoters directing tissue-specific expression of GnRH gene in neuronal and reproductive tissues were characterized by functional analyses of GnRH promoter-luciferase (LUC) constructs in transfected placental cells (JEG) and hypothalamic neuronal cells (GT1-7). Results indicate that the downstream promoter directs the expression in a neuronal cell-specific manner, whereas the upstream promoter is fully active in the nonneural placental cell line. Transfection studies carried out in several tumor cell lines derived from human reproductive tissues verified that the upstream GnRH promoter construct was much more active in directing luciferase expression in reproductive tissue. The use of both upstream and downstream promoters in various human tumor cell lines derived from reproductive tissues were demonstrated by RT-PCR. Our studies also demonstrate that the reproductive tissue-specific messenger RNA transcribed from upstream promoter is capable of directing synthesis of preproGnRH protein. Serial deletion studies localized a cell-specific upstream promoter region that directs reproductive tissue expression. DNase I footprint analysis using nuclear extract obtained from the JEG cells indicated DNA/protein interactions in four specific sequence elements of the upstream promoter region. The interaction between nuclear binding proteins present in the JEG cells (but not the GT1-7 cells) and the four specific sequences in the upstream promoter region was confirmed by gel mobility shift analysis.

Molecular mechanism underlying the action of a novel fusion inhibitor of influenza A virus

In the initial stages of influenza virus infection, the hemagglutinin (HA) protein of influenza virus mediates both adsorption and penetration of the virus into the host cell. Recently, we identified and characterized BMY-27709 as an inhibitor of the H1 and H2 subtypes of influenza A virus that specifically inhibits the HA function necessary for virus-cell membrane fusion (G.-X. Luo, R. Colonno, and M. Krystal, Virology 226:66-76, 1996). Studies presented herein show that the inhibition is mediated through specific interaction with the HA protein. This binding represses the low-pH-induced conformational change of the HA protein which is a prerequisite for membrane fusion. In an attempt to define the binding pocket within the HA molecule, a number of drug-resistant viruses have been isolated and characterized. Sequence analyses of the HA gene of these drug-resistant viruses mapped amino acid changes responsible for drug resistance to a region located near the amino terminus of HA2. In addition, we have identified inactive analogs of BMY-27709 which are able to compete out the inhibitory activity of BMY-27709. This finding suggests that inhibition of the HA-mediated membrane fusion by this class of compounds is not solely the result of binding within the HA molecule but requires specific interactions.

Sequence of a cDNA clone encoding a novel somatolactin in goldfish, Carassius auratus

As a first step towards the development of a sensitive ribonuclease protection assay to study the regulation of somatolactin (SL) mRNA expression in pituitary cells of goldfish, we have isolated a complementary DNA (cDNA) clone encoding precursor sequence of SL from a cDNA library prepared from goldfish pituitary poly(A)+ RNA. The 843-bp goldfish SL (gfSL) cDNA has an open reading frame of 693 nucleotides with two possible start codons of AUG. Amino acid sequence alignment revealed that gfSL has the characteristics of four conserved domains (A, B, C and D) common to all SLs with the domain B being the most conserved region among all the characterized SLs. Similar to other teleost SLs, this gfSL is similarly related but clearly distinct from growth hormone and prolactin of goldfish and other teleosts. However, unlike most other known teleost SLs which have more than 70% amino acid sequence identity to each other, the overall amino acid sequence identity of this novel gfSL with other previously characterized SLs ranges from only 36% to 51%. Moreover, this gfSL contains only six cysteine residues, rather than seven in most other SLs, in conserved positions. Northern blot analysis revealed a single gfSL mRNA transcript of approximately 1 kb in the pituitaries of both sexually regressed and maturing male and female goldfish.

Retinoic acid receptor beta,gamma-selective ligands: synthesis and biological activity of 6-substituted 2-naphthoic acid retinoids

In search for retinoic acid receptor (RAR) selective ligands, a series of 6-substituted 2-naphthoic acid retinoids were synthesized and evaluated in vitro in a transactivation assay and a competition binding assay for all RARs. These derivatives, in general, showed RAR beta,gamma selectivity. Among these naphthoic acids, oxime derivative 12 was identified as a potent RAR gamma-selective retinoid, while olefinic derivative 11 was found to be comparable to retinoic acid and slightly RAR beta,gamma selective. For the bioassays, a general correlation was observed between the binding affinity of the ligand to the receptors and the potency of the compounds in the transactivation assay. The structure-activity relationship of these naphthoic acids will be discussed.

Identification of two prolactin cDNA sequences from a goldfish pituitary cDNA library

We have identified two different cDNA clones encoding for goldfish prolactin (gfPRL) from a pituitary cDNA library. The coding regions of these clones are predicted to encode for an identical amino acid (aa) sequence with four silent mutations. The 3'-untranslated regions (UTRs) of these clones show only 72% nucleotide (nt) sequence identity. The two genes each encoding gfPRL might have derived from recent gene duplication before the divergence of goldfish from other Cypriniforms. Genomic Southern blot analysis of goldfish DNA also demonstrated that there is a small family of two genes for prolactin in the genome of goldfish.

Isolation and characterization of two distinct growth hormone cDNAs from the goldfish, Carassius auratus

As a first step toward the development of a ribonuclease protection assay for studying the regulation of growth hormone (GH) gene expression in pituitary cells of the goldfish, Carassius auratus, we report the isolation of two cDNA clones encoding goldfish GH from a cDNA library prepared from pituitary poly(A)+ RNA. The complete nucleotide sequences of these two GH cDNA clones have been determined and both of them were predicted to encode a polypeptide of 210 amino acids (aa) including a putative signal peptide of 22 aa. One of the GH cDNAs encodes a polypeptide (gfGHI) with five cysteine residues (similar to other carp Ms), whereas another encodes a polypeptide (gfGHII) with four cysteine residues (similar to most teleostean GHs). Because these two GH cDNAs have distinct nucleotide sequences at their coding and 3' untranslated regions, they are likely to be encoded by two different genes.

Evidence for estrogen receptor-mediated regulation of human gonadotropin-releasing hormone promoter activity in human placental cells

Two fragments of the human gonadotropin-releasing hormone (GnRH) promoter, one containing 0.6 kb of the downstream promoter sequence (H-1) and another 1.8 kb fragment (H-2) containing the upstream promoter region with a deletion of the downstream promoter sequence, were fused to a promoterless luciferase (Luc) reporter construct and transfected into the human placental (JEG) cells. JEG cells transfected with both constructs showed insignificant changes in luciferase activity in response to estradiol. However, cotransfection of H-2-Luc construct with a vector expressing a human estrogen receptor (ER) cDNA results in dose-dependent decreases in luciferase activity in response to estradiol. This ER mediated down-regulation of promoter activity was retained in constructs with the GnRH promoter deleted to position 548 bp 5' to the upstream transcription start site. Further deletion of upstream promoter sequence to 169 bp reversed the estrogen responsiveness from inhibitory to stimulatory. Thus, this study demonstrated that the upstream GnRH promoter region can be regulated by estrogen in transfected JEG cells.

Sodium nonivamide acetate: a non-pungently antinociceptive capsaicin derivative with unusual anti-inflammatory properties

1. Bradykinin-induced vascular pain in conscious rats, hyperalgesia in the rat hind paw, rat hind paw edema induced by compound 48/80 and carrageenin and dye exudation induced by intraperitoneal injection of 0.7% acetic acid in mice were all inhibited by sodium nonivamide acetate (SNA). 2. Collagen and arachidonic acid-induced rabbit platelet aggregations were inhibited by SNA and capsaicin. In human platelet microsomes, prostaglandin E2 formation in arachidonic acid metabolite was not inhibited by SNA but was inhibited by capsaicin and indomethacin; thromboxane B2 formation and its synthetase activity were inhibited by SNA and capsaicin. 3. In the extracellular recording, SNA could not decrease the action potential amplitude of the vagus nerve. 4. The motor activity of mice induced by caffeine (1.0 mg/kg) was inhibited by SNA and capsaicin.

In-vivo activity of retinoid esters in skin is related to in-vitro hydrolysis rate

BMS-181163 (4-acetamidophenyl retinoate, previously reported as BMY-30123), the acetamidophenyl ester of all-trans-retinoic acid (tRA), is topically active in various retinoid-sensitive animal models, but was recently shown to be ineffective for the treatment of acne in patients. To determine whether BMS-181163 functions as a prodrug of tRA in mice but not in man, the relative rates of ester hydrolysis in mouse and human skin homogenates were determined. In-vitro hydrolysis assays showed that BMS-181163 was substantially hydrolysed in mouse skin homogenates and minimally in human skin preparations. In addition, a series of phenyl esters of tRA and several known active synthetic retinoids (Ch-80: (E)-4-[3-oxo-3-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthalenyl)-1 - propenyl] benzoic acid; CD-271: 6-[3-(1-adamantyl)-4-methyoxyphenyl]-2-naphthoic acid; and TTNPB: (E)-4-[2-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthalenyl)-1- propenyl] benzoic acid) was prepared and hydrolysis rates and in-vivo (rhino mouse utriculi reduction) activities were compared. The hydrolysis rates of the six test retinoid phenyl esters, ranging from 0.06 to 2.0 h-1 were found to correlate with the in-vivo activity. Those esters (BMS-181163 and acetamidophenyl esters of Ch-80 and TTNPB) with a higher hydrolysis rate exhibited in-vivo activity only slightly lower than their parent free acid retinoids. In contrast, the three phenyl esters with a hydrolysis rate less than 0.3 h-1 were inactive in-vivo.(ABSTRACT TRUNCATED AT 250 WORDS)

Retinoic acid receptor gamma mediates topical retinoid efficacy and irritation in animal models

Among retinoic acid receptors (RARs) alpha, beta, and gamma, the messenger RNA level of RAR-gamma is the most readily detectable by Northern blotting in human and mouse skin. This observation suggests that RAR-gamma may play a critical role in the modulation of the therapeutic benefits and side effects of retinoids in skin. To test this hypothesis, 11 RAR-gamma selective retinoids were synthesized based on three related structures. Each compound was found to prefer RAR-gamma when assessed by retinoid-induced transcriptional activity (RAR-gamma > RAR-beta > RAR-alpha). The apparent Kd for binding to recombinant receptor protein was found to follow a similar trend. To correlate this receptor selectivity with in vivo activity, the compounds were tested topically in the Rhino mouse utriculi reduction and rabbit irritation models, two assays widely used to screen retinoids for efficacy and side effects, respectively. The results indicated that for these compounds, both efficacy in the utriculi reduction assay and irritation potential in rabbits correlated positively with the RAR-gamma transactivation activity, with r2 of 0.9 and 0.8, respectively. These data suggest that RAR-gamma is an important regulator of retinoic acid efficacy in skin and further, that the irritation associated with the use of retinoids is most likely a receptor-mediated process.

Role of retinoic acid receptor gamma in the Rhino mouse and rabbit irritation models of retinoid activity

The three retinoic acid receptors (RAR alpha, RAR beta and RAR gamma) are known to modulate the transcription of target genes through interaction of the individual receptors with their naturally occurring ligand, retinoic acid (RA). Since RA has multiple effects in vivo, considerable effort has recently been devoted to finding selective compounds to elucidate the functions of individual receptors and to relate these functions to specific in vivo effects. The racemic synthetic retinoid 6-[(5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-2-naphthyl)hydroxy-methyl]-2- naphthalene carboxylic acid has recently been identified as an RAR gamma-selective agonist. A synthetic method involving lipase-mediated transformation has been developed to prepare the individual enantiomers. Discrimination between the two enantiomers is seen in both transcriptional activity and binding to recombinant receptors with the (S)-enantiomer being the more active. Differences between the two compounds are also seen in the Rhino mouse utriculi reduction assay and the rabbit irritation model. In both animal models, the (S)-enantiomer consistently gave a greater response. Taken together, these results suggest that the activity and irritation seen with RA and related compounds is receptor mediated. Further, the strong selectivity of the compounds reported here for RAR gamma suggests that this receptor plays an important role in these in vivo biological activities. The discrimination between these enantiomers may be useful in the design of novel retinoids with uniquely defined biological properties.

[The evaluation of the anti-shivering effect of tramadol during epidural anesthesia]

60 patients (except parturients) suffering from shivering after receiving epidural anesthesia were randomly divided into 2 equal groups. In order to evaluate the effect of Tramadol on the shivering, i.v. Tramadol (1 mg/Kg), in contrast to distilled water (20 ml) for the control group, was administered to the patients in the experimental group. We compared the arrest time between the two groups in addition to systolic blood pressure, diastolic blood pressure, heart rate, arterial O2 saturation, respiratory rate and body surface temperature. Furthermore, the degree of shivering was also compared sequentially. The systolic pressure of the control group declined significantly in the first 30 minutes (P < 0.05). The other data, including the diastolic pressure, heart rate, arterial O2 saturation, respiratory rate and body surface temperature, showed no significant difference (P > 0.05). The arrest time in the experimental group was 179 +/- 71.25 seconds in contrast to 2790 +/- 440.23 seconds in the control group, a large significant difference (P < 0.001). 10% of the patients in the experimental group experienced nausea or vomiting and 6.67% of the patients showed sedation which did not disturb consciousness level of psychomotor status. Since the exact mechanism of shivering during epidural anesthesia is not established, we sincerely hope more information about the effect to Tramadol on shivering can be uncovered.

Second messenger regulation of mouse gonadotropin-releasing hormone gene expression in immortalized mouse hypothalamic GT1-3 cells

Using a transgenic mouse derived GnRH expressing neuronal cell line, GT1-3, we studied the effects of activation of cAMP, Ca2+ and protein kinase C pathways by forskolin, ionomycin and the phorbol ester phorbol 12-myristate 13-acetate (PMA), respectively, upon gonadotropin-releasing hormone (GnRH) secretion, cellular peptide content, mRNA and RNA primary transcript levels. Forskolin, ionomycin and phorbol ester all caused an increase in GnRH secretion in GT1-3 cells in a time and dose-dependent manner during a short-term (1 h) static incubation. Prolonged treatment with forskolin (10 microM), ionomycin (1 microM) and PMA (10 nM) for 12 or 24 h resulted in significant decreases in GnRH mRNA levels. Time-course studies showed that the increases in GnRH secretion stimulated by forskolin, ionomycin and PMA were gradually attenuated over time in parallel with the decreases in mRNA expression. In contrast, there were only small and variable changes in the GnRH cellular content. Studies using a GnRH antagonist (100 microM) suggested that the released GnRH has a negative feedback effect on its own secretion. However, co-incubation with the GnRH antagonist did not alter the inhibitory effects on GnRH mRNA levels by the secretagogues. Further studies on the transcriptional effects of forskolin, ionomycin and PMA on GnRH gene expression in GT1-3 cells revealed that all three secretagogues suppressed GnRH RNA primary transcript levels, with forskolin having a slower time course of action. Thus, the inhibition of cytoplasmic GnRH mRNA, and presumably its synthesis, after 12-24 h of secretagogue treatment may be due at least in part to a suppression of GnRH gene transcription.(ABSTRACT TRUNCATED AT 250 WORDS)

Identification of a major up-stream transcription start site for the human progonadotropin-releasing hormone gene used in reproductive tissues and cell lines

Previous studies suggested that GnRH gene transcripts in human tissues may be derived from an upstream transcriptional start site in addition to the well characterized hypothalamic start site. To resolve this issue we characterized the transcriptional start sites of the human GnRH gene in a human placental tumor cell line (JEG) and a human breast tumor cell line (MDA). Using primer extension and reverse transcription-polymerase chain reaction (RT-PCR) assay, we identified a discrete upstream transcriptional start site 579 bases up-stream from the hypothalamic site in both JEG and MDA cell lines. The up-stream start site lacks the TATA and CAAT elements often present in RNA polymerase-II promoters, but contains the sequence GGTCTTGCT located 84 bases 5' to the up-stream start site similar to other genes that lack TATA/CAAT boxes. RT-PCR quantitation shows that the up-stream start site is the major transcriptional start site, representing 74% of the cytoplasmic transcripts in JEG cells and 67% in MDA cells. Supporting this observation, transfection assay using a human GnRH promoter/luciferase reporter gene construct containing only the up-stream transcription start site has a higher level of transcriptional activity than the human GnRH promoter/luciferase reporter construct containing only the down-stream start site. A high relative abundance (approximately 45%) of total GnRH mRNAs were also found in the nucleus of both cell lines, which did not appear to be a consequence of the nuclear/cytoplasmic fractionation procedure. To determine if this upstream start site was used in normal GnRH-expressing human tissues, we analyzed RNA from a variety of postmortem/surgical procedure tissue samples. RT-PCR analysis together with Southern blot analysis demonstrated the presence of GnRH mRNA in human pituitary, cerebral cortex, testes, ovary, and mammary gland for the first time as well as verified GnRH gene expression in hypothalamus and placenta. The up-stream transcriptional start site is used only in reproductive tissues, such as placenta, testes, ovary, and mammary gland, suggesting tissue-specific regulation at this site.