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Profiling impurities and degradants of butorphanol tartrate using liquid chromatography/mass spectrometry and liquid chromatography/tandem mass spectrometry substructural techniques.

A rapid and systemic strategy based on liquid chromatography/mass spectrometry (LC/MS) profiling and liquid chromatography/tandem mass spectrometry (LC/MS/MS) substructural techniques was utilized to elucidate the degradation products of butorphanol, the active ingredient in stadol NS. This strategy integrates, in a single instrumental approach, analytical HPLC, UV detection, full-scan electrospray mass spectrometry, and tandem mass spectrometry to rapidly and accurately elucidate structures of impurities and degradants. In these studies, several low-level degradation products were observed in long-term storage stability samples of bulk butorphanol. The resulting analytical profile includes information on five degradants including molecular structures, chromatographic behavior, molecular weight, UV data, and MS/MS substructural information. The degradation products formed during long-term storage of butorphanol tartrate included oxidative products proposed as 9-hydroxy-and 9-keto-butorphanol, norbutorphanol, a ring-contraction degradant, and delta 1, 10 a-butorphanol. These methodologies are applicable at any stage of the drug product cycle from discovery through to development. This library of butorphanol degradants provides a foundation for future development work regarding product monitoring, as well as a useful diagnostic tool for new degradation products.

Administration, Inhalation↗

Molecular cloning of cDNAs of mouse peptidylarginine deiminase type I, type III and type IV, and the expression pattern of type I in mouse.

Peptidylarginine deiminases (PADs), a group of post-translational enzymes, catalyze the conversion of protein-bound arginine residues to citrulline residues in a calcium ion-dependent manner and are widely distributed in various organs of vertebrates. Although the existence of four isoforms of PAD (types I, II, III, and IV) is reported in rodents, the relative functions of the isoforms with respect to their colocation in the tissues have yet to be explored. In this study, we cloned the full-length cDNA encoding mouse PAD type I by screening a uterine cDNA library and using the RACE method. This cDNA consists of an open reading frame of 1989 bases encoding 662 amino acids (73,823 Da), a 5'-untranslated region of 127 bases and a 3'-untranslated region of 1639 bases. Comparative reverse transcription-PCR and Northern-blot analyses detected PAD type I mRNA only in the epidermis and uterus. Administration of estrogen to adult ovariectomized mice increased the content of PAD type I mRNA in the uterus, providing evidence that its expression is under the control of the sex steroid hormone. We also cloned the full-length cDNAs of mouse PAD type III and type IV by the reverse transcription-PCR and RACE methods. The primary structure of PAD type III contains 664 amino acids (75,098 Da) deduced from the coding region of 1995 bases, and the primary structure of PAD type IV consists of 666 amino acids (74,475 Da) deduced from the coding region of 2001 bases. Comparison of the deduced amino acid sequences of all four isoforms of PAD showed about 50% identity with each other, the 3' regions being highly homologous compared with the 5' regions.

Amino Acid Sequence↗

Human domain antibodies against virulence traits of Candida albicans inhibit fungus adherence to vaginal epithelium and protect against experimental vaginal candidiasis.

Antibody variable domains (domain antibodies [DAbs]) are genetically engineered antibody fragments that include individual heavy-chain (VH) or kappa-chain (Vkappa) variable domains and lack the Fc region. Human DAbs against the 65-kDa mannoprotein (MP65) or the secretory aspartyl proteinase (SAP)-2 of Candida albicans (monospecific DAbs) or against both fungal antigens (heterodimeric, bispecific DAbs) were generated from phage expression libraries. Both monospecific and bispecific DAbs inhibited fungus adherence to the epithelial cells of rat vagina and accelerated the clearance of vaginal infection with the fungus. When heterodimeric DAbs were used, the clearance of infection was at least equivalent to treatment with fluconazole. The in vivo protective effects of DAbs were demonstrated by both pre- and postchallenge schedules of DAb administration and with both fluconazole-susceptible and fluconazole-resistant strains of C. albicans. This is the first demonstration that human DAbs lacking the Fc constituent can efficiently control an infection and can act largely by inhibiting adherence.

Animals↗

The optimal environment for socialization of the nurse-scientist.

Tangible elements or factors that contribute to the successful socialization of student scholars seeking the PhD degree in nursing are generally well known. Included among these are the university itself-its faculty, its resources, such as laboratories and libraries, and its research productivity. Less well known are some intangibles in the learning environment that make the difference between an acceptable learning environment and an optimal one, such as, the frequency and quality of informal interaction between faculty and students. The author identifies several characteristics of the pre-doctoral learning environment for nurse PhD students that faculty and administrators should seek to provide if they wish to support truly successful socialization of the scholar/scientist.

Education, Nursing, Graduate↗

Crossing the digital divide: the contribution of information technology to the professional performance of malaria researchers in Africa.

BACKGROUND: The US National Library of Medicine supports the Multilateral Initiative on Malaria (MIM) through the design, implementation, and operation of the Multilateral Initiative on Malaria Communications Network (MIMCom.) MIMCom makes possible enhanced access to the Internet and to medical literature. OBJECTIVES: The main objectives of the present study were to examine the use of MIMCom supported information technology (IT) by scientists, students, and administrative personnel to facilitate communication, retrieve information, obtain documents, write proposals, and prepare papers for publication; and to determine the contribution of this intervention to their professional performance. METHODS: The authors analyzed the contribution of enhanced Internet connectivity and access to electronic information resources to the performance of malaria research staff and their institutes through a cross-sectional questionnaire survey of 181 respondents at 14 health research centers in Africa. Separate reviews of bandwidth usage, requests for document delivery, and publications in peer reviewed journals support the data of the survey. RESULTS: The MIMCom network makes a positive contribution to the performance of malaria researchers and support staff at the sites reviewed by improving e-mail exchange, access to published literature, and research proposal development and submission. Implications of these findings are discussed. CONCLUSION: By providing full access to the Internet and the resources of the WorldWide Web, MIMCom has been shown to be invaluable to malaria researchers and their institutes in Africa. This access has increased visibility of scientists in their respective institutions and provided opportunities for stronger engagement with the international scientific community.

Access to Information↗

Use of the veterans history project to assess World War II veterans' perceptions of military experiences and health.

OBJECTIVE: This qualitative research study evaluated the attitudes, perceptions, and opinions of World War II veterans regarding the health impact of their military service. METHODS: The study design involved adding relevant health questions to the interview format developed by the ongoing Veterans History Project, a military oral history depository directed and maintained by the U.S. Library of Congress. Audiotaped interviews conducted with individuals and a focus group were coded and evaluated. Key informants provided background information. RESULTS: Findings included a general consensus among participants that military service during World War II was beneficial to their health. Preventive health practices were instilled as lifelong habits, as were feelings of self-confidence and independence. The Veterans Administration was viewed positively by respondents but was not used to any great extent. CONCLUSIONS: Current good health and feelings of patriotism, duty, and selflessness may underlie expressed positive attitudes about the health impact of service during World War II.

Aged↗

The CRISP system: an untapped resource for biomedical research project information.

CRISP (Computer Retrieval of Information on Scientific Projects) is a large database maintained and operated by the National Institutes of Health (NIH). It contains comprehensive scientific and selected administrative data on research carried out by the U.S. Public Health Service (PHS) or supported by PHS grants and contracts. Developed originally to meet the needs of NIH, it is an excellent, largely untapped resource for health information professionals at large, revealing new trends, methods, and techniques, often before they appear in the published literature. CRISP uses its own controlled vocabulary, developed to permit indexing of new and active research areas. Queries can combine subject headings with a great variety of administrative data elements (e.g., research category or principal investigator's name). Output is available in a variety of formats and media. While information professionals cannot directly access the CRISP system, abridged CRISP records are merged into the FEDRIP (Federal Research in Progress) database, and FEDRIP is publicly accessible through DIALOG. CRISP records in toxicology are also furnished to the National Library of Medicine's TOXLINE database. This paper discusses the indexing, information retrieval, publication products, and search services of the CRISP system, and how users of medical information can benefit from it.

Abstracting and Indexing↗

[Cloning and characterization of a specific cytokeratin-8 cDNA from rat prostatic epithelium].

In this study, we report the cloning and sequencing of a full-length cytokeratin-8 (CK-8) cDNA from a rat prostatic epithelial cDNA library. The effects of androgen on CK-8 expression in rat prostate were also studied. The data indicated that the steady-state level of CK-8 mRNA was elevated by about 5- to 10-fold in both prostate and seminal vesicles in castrated rats, and the elevated levels persisted during a 23-day experimental period. Androgen but not estrogen administration repressed the expression of CK-8 mRNA. This effect could be antagonized by the simultaneous administration of an antiandrogen, flutamide, indicating that CK-8 is a new class of androgen-repressed genes whose regulation is presumably mediated by androgen receptor mechanisms.

Androgens↗

Transcriptome response following administration of a live bacterial vaccine in Atlantic salmon (Salmo salar).

Antibacterial responses have been studied in Atlantic salmon following an acute intra peritoneal injection of a genetically attenuated (aroA(-)) strain of Aeromonas salmonicida known to elicit protective immunity. Three tissues were studied for transcriptional changes, the liver, head kidney and the gill. RNA was collected from fish 6, 12, 24 and 48 h following infection or at the same time points from fish injected with PBS as non-infected control. PCR-select cDNA subtraction libraries were constructed from pooled 24 and 48 h post infection RNA to identify up-regulated mRNAs. One thousand four hundred and eighty six cDNA clones were sequenced from enriched cDNA libraries, of which 71% had significant homologies to known functional proteins. Many of these clones have previously been un-characterised in Atlantic salmon. A salmonid cDNA microarray was used to further analyse the gene expression profile as the library construction in itself does not answer the dynamics of the response. The greatest increase in expression identified in the array analysis was a liver antibacterial peptide, hepcidin that was increased 11-fold following the challenge. A panel of clones were chosen for semiquantitative reverse transcriptase PCR from all time points sampled. These results indicated there were both temporal differences and tissue differences in the transcriptional response to bacterial exposure, potentially of relevance to the establishment of protection.

Aeromonas salmonicida↗

Zuclopenthixol acetate in the treatment of acute schizophrenia and similar serious mental illnesses.

BACKGROUND: People with schizophrenia or other psychotic illnesses may have delusions or hallucinations that may lead them to be aggressive or violent to themselves or others. Medication that is used in this context require the properties of rapid onset of effect (tranquillisation or at least initial sedation in order to quell aggressive or disorganised behaviour, but also antipsychotic effect), low frequency of administration and low levels of side effects, such as cardiological or neurological side effects, or pain at the injection site. Zuclopenthixol is the cis(Z)-isomer of clopenthixol, a neuroleptic of the thioxanthene group, used for treating people with psychotic symptoms. There is one oral preparation and two depot forms: zuclopenthixol acetate and zuclopenthixol decanoate. The acetate version does not stay in the body for very long (a single dose persists for only 72 hours) and is said to have these properties. OBJECTIVES: To estimate the effectiveness of zuclopenthixol acetate for the acute treatment of serious mental illnesses in comparison to other neuroleptic drugs. SEARCH STRATEGY: Searches of the Cochrane Schizophrenia Group's Register of Trials, The Cochrane Library, MEDLINE, abstracts of congresses and trial reference lists were performed. Appeals for unpublished data to the research community and to the Medical Information Department of Lundbeck Limited were also made. Attempts were made to contact relevant authors. SELECTION CRITERIA: Two reviewers independently assessed citations or papers and selected all randomised trials that included people with serious mental illnesses and compared zuclopenthixol acetate with other drug regimes. DATA COLLECTION AND ANALYSIS: Data were extracted independently by two reviewers. Attempts were made to contact authors for additional or missing information. Odds-ratios (OR) and 95% confidence intervals (CI) were estimated for binary data. Where possible, OR were pooled using Peto method and intention-to-treat analysis undertaken. Mean differences were used for continuous variables. MAIN RESULTS: Pooled data shows no difference for the outcome 'no important improvement' in psychotic symptoms at the end of the follow-up period (OR 0.84 CI 0. 34-2.05). Sedation was evaluated using different instruments. Only one study presented data which suggested an earlier and more intense sedation in zuclopenthixol acetate users at 4 hours (OR 0.18 CI 0. 04-0.93). Use of additional antipsychotic medication was not avoided in the zuclopentixol acetate group (OR 2.18, CI 0.64-7.42) and data on total number of administrations was not obtainable. Side effect data were poorly reported but there is no evidence of a consistent difference between zuclopenthixol acetate and other 'standard drugs' for either the pattern of side effects or the wish to leave the study early. Hospital and service outcomes, number of aggressive incidents, satisfaction with care and economic outcomes were not addressed by any study. REVIEWER'S CONCLUSIONS: Recommendations on the use of zuclopenthixol acetate for the management of psychiatric emergencies in preference to 'standard' treatment have to be viewed with caution. Most trials present important methodological flaws and findings are poorly reported. This review did not find any suggestion that zuclopenthixol acetate is more effective in controlling aggressive/disorganised behaviour, acute psychotic symptoms, or preventing side effects. There were no data directly related to tranquillisation, but it may produce more earlier and intense sedation than oral haloperidol. Well conducted randomized controlled trials are needed to confirm claims related to the use of zuclopenthixol acetate in emergency psychiatry.

Acute Disease↗

Identification of up-regulated Ras-like GTPase, Rap1b, by suppression subtractive hybridization.

BACKGROUND: Diabetic nephropathy accounts for over 30% of the end-stage renal disease (ESRD). A number of defined mechanisms and molecules that are involved in its pathogenesis are known, while others remain to be identified. METHODS: Suppression subtraction hybridization (SSH)-polymerase chain reaction (PCR) was employed to search for new genes that may be relevant to the pathogenesis of diabetic nephropathy during embryonic development, the time when the kidney is most susceptible to various forms of stress. A diabetic state was induced in pregnant mice at day-13 of gestation by administration of streptozotocin. The kidneys of newborn mice with blood glucose level> 200 mg/dL were harvested, mRNA isolated and subjected to SSH-PCR. Several differentially expressed cDNA fragments with up-regulated expression were isolated. One of the cDNA fragments had homology with human Ras-like guanine 5'-triphosphate (GTPase), Rap1b gene. By utilizing the lambdaZAP II mouse cDNA library and SMART RACE amplification, a full-length Rap1b cDNA was isolated. A recombinant protein was generated in pET15b bacterial expression system. An anti-Rap1b antibody was raised in rabbits by immunizing them with the fusion protein, and its specificity was confirmed by Western blot analysis. RESULTS: Rap1b cDNA had an open reading frame of 552 bp with a predicted putative protein size of approximately 21 kD. In vitro translation verified the authentication of the Rap1b cDNA clone. Northern blot analyses revealed a single approximately 2.3 kb Rap1b mRNA transcript. Its expression was up-regulated in several tissues, including the kidney of newborn diabetic mice. The degree of up-regulation of Rap1b mRNA expression was proportional to the blood glucose levels. Western blot analyses confirmed the hyperglycemia-induced up-regulation of the Rap1b expression. In situ hybridization and immunofluorescence studies revealed that Rap1b was expressed in the inner medullary collecting tubules. During hyperglycemia, its expression was accentuated and extended into the outer medullary and cortical collecting tubules. Similar up-regulation of Rap1b was observed when embryonic kidneys, harvested at day-13 of gestation, were exposed to high glucose ambience. CONCLUSION: The data suggest that Rap1b, a GTP-binding protein that plays a critical role in various signaling intracellular events, is another molecule that may be relevant to the pathobiology of diabetic nephropathy.

Amino Acid Sequence↗

Estrogen induction of cytochrome c oxidase subunit III in rat hippocampus.

Differential screening of a cDNA library prepared from mRNA of the hippocampus of estrogen-stimulated ovariectomized female rats led to the identification of a single estrogen-induced clone. Analysis of the sequence identified this cDNA as the gene coding for subunit III of the enzyme cytochrome c oxidase. Cytochrome c oxidase subunit III mRNA levels significantly increased as early as 3 h following the administration of a single dose of hormone. This effect was visible in the hippocampus and in the hypothalamus, but not in the other brain areas examined. Because subunit III of the cytochrome c oxidase is of mitochondrial origin, the mechanism involved in the estrogenic effect is still unknown. The observation that the activity of cytochrome c oxidase can also be induced by estrogens in the hippocampus indicates that this induction may be secondary to the increased expression of the other subunits of cytochrome c oxidase or to the general increase of neuronal activity.

Amino Acid Sequence↗

Document needs in a rural GRATEFUL MED outreach project.

An analysis of documents provided to eight rural Illinois hospital sites during a GRATEFUL MED outreach project involving end-user searching revealed significant patterns that have implications for collection development and information services in small, underserved hospitals. Document requests were analyzed by user groups making the requests, subject matter, inclusion on the Brandon/Hill lists and in Abridged Index Medicus, and publication date. Of the 359 documents requested, 86% came from health professional groups other than physicians and nurses. Eighty-five percent of all requests came from two sites that had active project-trained intermediaries, with most requests forwarded by the intermediaries. Subject analysis revealed a strong need for administrative and allied health information in addition to clinical information. Fewer than half of the titles on the recommended lists were requested during the project. Most documents requested had been published in the past five years. Introduction of end-user searching is not the complete answer to improved information access at small hospitals; the authors conclude that basic collections and library personnel are still needed locally to respond effectively to health professionals' information needs.

Documentation↗

Antidepressant plus benzodiazepine for major depression.

BACKGROUND: Anxiety frequently coexists with depression. There is no systematic review to show if adding benzodiazepines to antidepressants can bring about any advantage over antidepressants alone in the treatment of depression, although such a combination prescription appears to be widely practiced worldwide OBJECTIVES: To determine whether, among adult patients with major depression, adding benzodiazepines to antidepressants brings about any benefit in terms of symptomatic recovery or side-effects in the short term (less than 8 weeks) and long term (more than 2 months), in comparison with treatment by antidepressants alone. SEARCH STRATEGY: Electronic searches of MEDLINE, EMBASE, International Pharmaceutical Abstracts, Biological Abstracts, LILACS, PsycLit, the Cochrane Library and the trial register of the Cochrane Depression, Anxiety and Neurosis Group (January 1972 to December 1998), combined with hand searching, reference searching, SciSearch and personal contacts. SELECTION CRITERIA: All randomized controlled trials that compared combined antidepressant-benzodiazepine treatment with antidepressant alone for adult patients with major depression (Feighner criteria, RDC, DSM-III, DSM-III-R, DSM-IV or ICD-10). Exclusion criteria are: antidepressant dosage lower than 100 mg of imipramine or its equivalent daily and duration of trial shorter than 4 weeks. DATA COLLECTION AND ANALYSIS: Two reviewers independently assessed the eligibility and quality of the studies. Two reviewers independently extracted the data. Standardized weighted mean differences and relative risks were estimated with random effects model. The dropouts were assigned the least favorable outcome. Two sensitivity analyses examined the effect of this assumption as well as the effect of including medium quality studies. Three a priori subgroup analyses were performed with regard to the patients with or without comorbid anxiety and with regard to the types of benzodiazepines tested. MAIN RESULTS: Aggregating nine studies with a total of 679 patients, the combination therapy group was 37% (95%CI: 19 to 51%) less likely to drop out than the antidepressant alone group. The intention-to-treat analysis showed that the former were 63% (18 to 127%) to 38% (15 to 66%) more likely to show response (defined as 50% or greater reduction in the depression scale from baseline) up to 4 weeks. REVIEWER'S CONCLUSIONS: The potential benefits of adding a benzodiazepine to an antidepressant must be balanced judiciously against possible harms including development of dependence and accident proneness, on the one hand, and against continued suffering following no response and drop-out, on the other.

Adult↗

Antidepressants for cocaine dependence.

BACKGROUND: Cocaine dependence is a common and serious condition, which has become nowadays a substantial public health problem. The past decade has witnessed a sustained search for an effective pharmacotherapeutic agent for the treatment of cocaine dependence. While administration of cocaine acutely increases intercellular dopamine, serotonin, and norepinephrine levels by blocking their presynaptic reuptake, chronic cocaine abuse leads to down-regulation of monoamine systems. Post-cocaine use depression and cocaine craving may be linked to this down-regulation. Antidepressant pharmacotherapy, by augmenting monoamine levels, may alleviate cocaine abstinence symptomatology, as well as relieving dysphoria and associated craving by general antidepressant action. OBJECTIVES: To conduct a systematic review of all RCTs on the use of antidepressants for treating cocaine dependence. SEARCH STRATEGY: We searched the Cochrane Controlled Trials Register (Cochrane Library, issue 4, 2000), MEDLINE (from 1966 - 2000), EMBASE (from 1980 - 2000), LILACS (from 1982 - 2000), PsycLIT (from 1974 - 2000), Biological Abstracts (1982 to 2000). Other searches:reference searching; personal communication; conference abstracts; unpublished trials from pharmaceutical industry; book chapters on treatment of cocaine dependence. SELECTION CRITERIA: The inclusion criteria for all randomised controlled trials were that they should focus on the use of antidepressants on the treatment of cocaine dependence. Trials including patients with additional diagnosis such as opiate dependence were also eligible. DATA COLLECTION AND ANALYSIS: The reviewers extracted the data independently and Relative Risks, weighted mean difference and number needed to treat were estimated. The reviewers assumed that people who died or dropped out had no improvement and tested the sensitivity of the final results to this assumption. MAIN RESULTS: 18 studies were included in the review, with 1177 people randomised. Positive urine sample for cocaine metabolites was the main efficacy outcome, with no significant results obtained regardless the type of antidepressant. Compared to other drugs, desipramine performed better but showing just a non significant trend with heterogeneity present as revealed by the chi-square test (8.6, df=3; p=0.04). One single trial showed imipramine performed better than placebo in terms of clinical response according to patient's self-report. A similar rate of patients remaining in treatment was found for both patients taking desipramine or placebo. Results from one single trial suggest fluoxetine patients on SSRIs are less likely to dropout. Similar results were obtained for trials where patients had additional diagnosis of opioid dependence and/or were in methadone maintenance treatment. REVIEWER'S CONCLUSIONS: There is no current evidence supporting the clinical use of antidepressants in the treatment of cocaine dependence. Given the high rate of dropouts in this population, clinicians may consider adding psychotherapeutic supportive measures aiming to keep patients in treatment.

Antidepressive Agents↗

Molecular monitoring of bleomycin-induced pulmonary fibrosis by cDNA microarray-based gene expression profiling.

Pulmonary fibrosis is a progressive disorder whose molecular pathology is poorly understood. Here we developed an in-house cDNA microarray ("lung chip") originating from a lung-normalized cDNA library. By using this lung chip, we analyzed global gene expression in a murine model of bleomycin-induced fibrosis and selected 82 genes that differed by more than twofold intensity in at least one pairwise comparison with controls. Cluster analysis of these selected genes showed that the expression of genes associated with inflammation reached maximum levels at 5 days after bleomycin administration, while genes involved in the development of fibrosis increased gradually up to 14 days after bleomycin treatment. These changes in gene expression signature were well correlated with observed histopathological changes. The results show that microarray analysis of animal disease models is a powerful approach to understanding the gene expression programs that underlie these disorders.

Animals↗

Selection and optimization of proteolytically stable llama single-domain antibody fragments for oral immunotherapy.

We previously demonstrated that oral application of the recombinant single-domain antibody fragment (VHH) clone K609, directed against Escherichia coli F4 fimbriae, reduced E. coli-induced diarrhoea in piglets, but only at high VHH doses. We have now shown that a large portion of the orally applied K609 VHH is proteolytically degraded in the stomach. Stringent selection for proteolytic stability identified seven VHHs with 7- to 138-fold increased stability after in vitro incubation in gastric fluid. By DNA shuffling we obtained four clones with a further 1.5- to 3-fold increased in vitro stability. These VHHs differed by at most ten amino acid residues from each other and K609 that were scattered over the VHH sequence and did not overlap with predicted protease cleavage sites. The most stable clone, K922, retained 41% activity after incubation in gastric fluid and 90% in jejunal fluid. Oral application of K922 to piglets confirmed its improved proteolytic stability. In addition, K922 bound to F4 fimbriae with higher affinity and inhibited fimbrial adhesion at lower VHH concentrations. K922 is thus a promising candidate for prevention of piglet diarrhoea. Furthermore, our findings could guide selection and improvement by genetic engineering of other recombinant antibody fragments for oral use.

Administration, Oral↗

The structure of the rat amiloride-sensitive epithelial sodium channel gamma subunit gene and functional analysis of its promoter.

Prolonged dietary Na+ depletion and chronic administration of adrenal steroids increase steady-state mRNA levels of the gamma subunit of the epithelial sodium channel (gammaENaC) in rat colon. This increase correlates with a marked increase in transepithelial Na+ transport and is thought to occur via transcriptional regulation. To begin to evaluate these mechanisms in detail, we determined the organization of the rat gammaENaC gene. A rat genomic library was screened and overlapping lambda clones that together span the gene (approximately 36 kb) and contain at least 1 kb of 5' flanking genomic DNA were isolated. As in the human gene, the rat gammaENaC gene contains 13 exons and a CpG island at the 5' end of the gene. A single transcription start site was identified in rat kidney by nuclease protection assay defining a 5' untranslated region of 126 nt. The translation initiation codon was identified within the second exon and the entire 3' UTR (approximately 1 kb) was within the last exon. 800 bp of 5' flanking sequence, as well as the 3.4 kb first intron, were sequenced and analyzed for transcriptional regulatory motifs. Analogous to the human gammaENaC gene [Thomas, C.P., Doggett, N.A., Fisher, R., Stokes J.B., 1996. Genomic organization and the 5' flanking region of the gamma subunit of the human amiloride-sensitive epithelial sodium channel. J. Biol. Chem. 271, 26 062--26 066], two GC boxes were seen at -30 and -61 to the transcription start site. In addition, putative AP-1, AP-2, CRE, Sp1 and GATA-1 and GRE motifs were identified elsewhere in the 5' flanking region or the first intron. Two mammalian-wide interspersed repeats and a rodent-specific B1 repeat were also identified within the first intron. Fragments containing the putative GRE motifs coupled to luciferase did not confer a glucocorticoid-stimulated response in two cell lines that contained a functional glucocorticoid receptor. However, a 76 nt rat gammaENaC 5' flanking fragment (-76 to +68) directed expression of luciferase in the epithelial cell lines H441 and FRTL5, suggesting that this minimal region that contained both GC boxes was sufficient for promoter activity.

Animals↗