PubMed Health⌕ Search

Biomedical subjects

A Roman

Publications and source records attributed to A Roman.

At least 37 records · Page 2Linked to original sources
PubMed2000

Expression of 3 beta-hydroxysteroid dehydrogenase/isomerase in the female rat pituitary.

3 beta-Hydroxysteroid dehydrogenase/isomerase (3 beta-HSD) catalyses an essential step in the biosynthesis of steroid hormones and is widely distributed in peripheral steroid target organs. The present report describes for first time the expression of this enzyme in the pituitary of female rats. Immunohistochemistry at the light microscopic level was performed on pro-oestrous and ovariectomized rat pituitaries. Immunoreactive cells were scattered and randomly distributed throughout the anterior lobe, whereas cells located in the posterior lobe and pars intermedia were immunonegative. Differences were observed in cell morphology and in the number of 3 beta-HSD-immunopositive cells between ovariectomized and pro-oestrous female rat pituitaries, suggesting that steroidogenic activity is affected by ovarian endocrine function. Apart from adenohypophyseal immunoreactive cells, 3 beta-HSD immunopositivity was also noted in endothelial cells of almost all pituitary capillaries located in the anterior and posterior lobes.

3-Hydroxysteroid Dehydrogenases↗
PubMed1999

Overexpression of CCAAT displacement protein represses the promiscuously active proximal gp91(phox) promoter.

CCAAT displacement protein (CDP) is a transcriptional repressor that restricts expression of the gp91(phox) gene to mature myeloid cells. CDP interacts with multiple sites within the -450 to +12 bp human gp91(phox) promoter, and down-regulation of CDP DNA-binding activity is required for induction of gp91(phox) transcription in mature phagocytes. Truncation of the gp91(phox) promoter to -102 to +12 bp removes 4 CDP-binding sites and reveals a promiscuous promoter activity that is active in some nonphagocytic cells. A cis-element at -90 bp is required for derepressed transcription and serves as a binding site for multiple transcriptional activators. We now report that this element also serves as a binding site for CDP. The affinity of CDP for this element is relatively weak compared with upstream CDP-binding sites within the promoter, consistent with the promiscuous transcriptional activity exhibited by the -102 to +12 bp gp91(phox) promoter fragment. Further analysis of the proximal promoter reveals an additional weak-affinity CDP-binding site centered at approximately -20 bp. Overexpression of cloned CDP represses the -102 to +12 bp gp91(phox) promoter, indicating that these proximal CDP-binding sites are functionally significant. The constellation of transcriptional activators and a repressor that interacts with the -90 bp cis-element is identical to that observed for a promoter element at -220 bp, reflecting the highly modular organization of the gp91(phox) promoter. These studies illustrate the complex interplay between transcriptional activators and a repressor that contribute to the myeloid-restricted expression of the gp91(phox) gene.

Cell Differentiation↗
PubMed1999

Intravascular stents do not cause microangiopathic hemolysis or thrombotic microangiopathy.

An increased incidence of TTP has been noted among patients receiving intravascular stents to improve patency in diseased coronary, renal, and peripheral arteries. Placement of transjugular intrahepatic porto-systemic shunt stents is often associated with subsequent development of severe hemolysis. We have prospectively studied the development of microangiopathic hemolysis or TTP in patients undergoing intravascular stent placement for peripheral vascular or renal artery disease. Hemolysis was evaluated both before and after stent placement by measuring complete blood count, total bilirubin, lactate dehydrogenase (LDH), haptoglobin and reticulocyte count, and examining peripheral blood films of all patients. Coagulation parameters, blood urea nitrogen and creatinine were measured to exclude disseminated intravascular coagulation or thrombotic thrombocytopenic purpura as a potential cause of hemolysis. Seventeen patients (median age 69 years) were evaluated. One patient was on ticlopidine. Mean hematocrit fell from 41.8% pre-stenting to 35.5% post-stenting (P = 0.003) but without significant change in reticulocyte count (1.7 vs. 1.6%, P = 0.605), LDH (546 vs. 560 IU/l; P = 0.836), bilirubin (0.62 vs. 0.63 mg/dl; P = 1.0), or haptoglobin (183 vs. 158 mg/dl; P = 0.083). Thus, this drop in hematocrit could not be attributed to hemolysis. Peripheral blood films revealed fewer than 1% schistocytes before and after stent placement in all cases. Absence of significant changes in mean platelet count (240 vs. 210 x 10(9)/L; P = 0.088), fibrinogen (385 vs. 378 mg/dl; P = 0.789), BUN (24.5 vs. 16.8; P = 0.079), and creatinine (1.38 vs. 1.24; P = 0.757) argue against development of TTP or DIC resulting from stent placement. No patient developed new renal impairment, a neurological syndrome, or unexplained fever after stent placement. At a mean of 6 weeks follow-up after stent placement, patients have not developed signs of hemolytic anemia or worsening renal function. Our findings argue against a primary risk of microangiopathic hemolytic anemia or TTP due to intravascular stents in patients not receiving ticlopidine.

Aged↗
PubMed1999

CCAAT displacement protein binds to and negatively regulates human papillomavirus type 6 E6, E7, and E1 promoters.

Expression of human papillomavirus genes increases as the target cell, the keratinocyte, differentiates. CCAAT displacement protein (CDP) is a cellular protein which has been shown in other cell types to negatively regulate gene expression in undifferentiated cells but not in differentiated cells. We have previously shown that a 66-bp purine-thymidine-rich sequence (the 66-mer) binds CDP and negatively regulates the human papillomavirus type 6 (HPV-6) E6 promoter (S. Pattison, D. G. Skalnik, and A. Roman, J. Virol. 71:2013-2022, 1997). Cotransfection experiments with a plasmid expressing luciferase from the HPV-6 E6, E7, or E1 regulatory region and a plasmid carrying the CDP gene indicate that CDP represses transcription from all three HPV-6 promoters. Using electrophoretic mobility shift assays (EMSAs), we have shown that CDP binds HPV-6 both upstream and downstream of the E6, E7, and E1 transcription initiation start sites. Furthermore, when keratinocytes were induced to differentiate, all three promoter activities increased. Consistent with this, immunoblotting and EMSAs revealed that endogenous nucleus CDP and, correspondingly, DNA binding activity decreased when keratinocytes were induced to differentiate. The elevated promoter activities were abrogated by exogenously transfected CDP. Our data demonstrate that CDP fulfills the requirement of a differentiation-dependent negative regulator that could tie the HPV life cycle to keratinocyte differentiation.

3T3 Cells↗
PubMed1998

Amphotericin B determination in respiratory secretions by reversed-phase liquid chromatography.

Direct delivery of amphotericin B (AMB) to the respiratory tract may be an alternative to intravenous administration. The use of inhalation allows high AMB concentrations to be achieved at the site of infection. A reversed-phase high-performance liquid chromatographic method with a 30-mm-long column is described for assaying AMB in respiratory secretions obtained by bronchoaspiration (BAS) and bronchoalveolar lavage (BAL). Sample clean-up involved treatment with methanol (BAS) and solid-phase extraction onto Sep-Pak C18 cartridges (BAL). The mobile phase consisted of 2.5 mM Na2EDTA-acetonitrile (70:30, v/v). The retention time of AMB was 1.5 min. The range of the assay was from 0.1 to 5 micrograms/ml. The mean recovery was over 90% for both fluids. Within-day and between-day RSDs ranged from 3.10 to 11.87%. AMB in the BAS samples was stable for two days at 20-25 degrees C and for three months at -20 degrees C. The drug in the BAL fluid was stable for one day at 20-25 degrees C, seven days at 4 degrees C and for one month at -20 degrees C.

Amphotericin B↗
PubMed1998

Severe hyperthermia during tetrabenazine therapy for tardive dyskinesia.

We recently observed a 45-year-old patient with a history of psychiatric illness who presented with severe hyperthermia (rectal temperature above 41 degrees C) with intense rhabdomyolysis and liver cytolysis during tetrabenazine therapy for neuroleptic tardive dyskinesia. In addition to tetrabenazine, this patient took lorazepam and two antidepressant drugs: clomipramine, a potent serotonin-reuptake inhibitor, and mianserin. Hyperthermia responded to parenteral sodium dantrolene and oral bromocriptine administration. The significant role of tetrabenazine (a central nervous system dopamine-depleting drug) and the contribution of antidepressants to the mechanism of this neuroleptic malignant syndrome - like hyperthermia are discussed.

Anti-Anxiety Agents↗
PubMed1998

Effect of desipramine on immunological parameters in mice, and their reversal by stress.

Immunomodulation of cell-mediated immunity is demonstrated in mice, after administration of desipramine, a noradrenaline-reuptake inhibitor, with or without exposing the mice later to an acute swimming stress. A single i.p. injection of 10 mg/kg desipramine to naive mice increased the relative weight of their spleens, the response of their splenocytes to the mitogen concavaline-A and their ability to produce IL-10, as compared to saline controls. Exposing the desipramine-treated mice to a swimming stress significantly reduced these parameters, as well as the levels of IL-2 and IFN-gamma, as compared to desipramine-treated mice. Stress alone reduced the weight of the spleen, and the ability of splenocytes to produce IFN-gamma. As desipramine and acute stress have stimulatory effect on the sympathetic system, it is suggested that a concomitant administration of the drug and a stressful event of these mice, change the splenocytes' micro-environment of sympathetic transmitters, and inhibit their function. These results may be partially due to impairment in the T-helper cell function by a beta-adrenoreceptor-dependent mechanism.

Animals↗
PubMed1998

Effect of mild chronic stress, as a model of depression, on the immunoreactivity of C57BL/6 mice.

Numerous studies correlate the state of depression with some abnormalities in the immune response, such as increased numbers of white blood-cells, alterations in sub-populations of leucocytes, suppression of cytotoxic activity of natural-killer cells, increased levels of some autoantibodies and acute-phase proteins. Some of these changes have been attributed to autoimmunological reactions. While the possibilities to evaluate some reactions in depressed patients are limited, an animal model of depression could well simulate this clinical situation, and the chronic mild state of stress is a well accepted one. After undergoing stress for three-weeks, C57BL/6 mice demonstrate in the present study a decrease in thymus weight, as well as increased interleukin-1 and decreased interleukin-2 production. Splenocytes of the depressed mice exert a decrease in natural-killer-cell activity, in the proliferative response to Concanavalin-A, interleukin-1 and anti-CD3 monoclonal antibodies and an increase in the proliferative response to lipopolysaccharides and pokeweed mitogens. Our results also suggest that chronic stress-induced activation of suppressor cells in the spleen, due to elimination of CD8+ cells, increase the proliferation of splenocytes in response to mitogens of T cells.

Animals↗
PubMed1998

Community periodontal index and treatment needs values (CPITN) in a factory worker group in Cluj-Napoca, Romania.

The aim of the study was to determine the prevalence of periodontal disease and the treatment needs in a population of 214 factory workers in Romania. Of those examined, 9.34 per cent were in periodontal health (code 0), 21.49 per cent had gingival bleeding (code 1), 18.69 per cent had supra- or subgingival calculus (code 2), 32.71 per cent presented with pathological pockets 4-5 mm deep (code 3) and 17.76 per cent had pathological pockets 6 mm or deeper (code 4). The distribution of these subjects among the treatment need categories revealed that 30.83 per cent would need improvement in personal oral hygiene (I), 51.40 per cent from the subjects would need treatment (I) + scaling (II) and 17.76 per cent would need treatment (I + II) + complex treatment (III).

Adolescent↗
PubMed1998

State laws on youth access to tobacco in the United States: measuring their extensiveness with a new rating system.

OBJECTIVE: To develop and implement a rating system evaluating the extensiveness of state laws restricting youth access to tobacco. DESIGN: State laws on youth access to tobacco were analysed and assigned ratings on nine items. Six items addressed specific tobacco-control provisions, and three related to enforcement provisions. For each item, a target was specified reflecting public health objectives. Achieving the target resulted in a rating of +4 points; for three items, a rating of +5 was possible if the target was exceeded. Criteria for lower ratings were established for situations when the target was not met. SETTING: United States. RESULTS: State scores (sum of the ratings across all nine items) ranged from 0-18 in 1993, 2-21 in 1994, and 1-21 in 1995 and 1996, out of a possible total of 39. The average score across states was 7.2 in 1993, 7.9 in 1994, 8.2 in 1995, and 9.0 in 1996. The overall mean rating (per item) was 0.80 in 1993, 0.88 in 1994, 0.91 in 1995, and 1.00 in 1996, on a scale where 4.0 indicates that the target goals (per item) were met. From 1993 to 1996, scores increased for 20 states, decreased for one state, and remained unchanged for the others. The number of states for which state preemption of local tobacco regulation was a factor doubled from 10 states in 1993 to 20 states in 1996. CONCLUSIONS: Although all states have laws addressing youth access to tobacco, this analysis reveals that, as of the end of 1996, the progress towards meeting health policy targets is slow, and state legislation that preempts local tobacco regulation is becoming more common.

Adolescent↗
PubMed1997

The relative ability of human papillomavirus type 6 and human papillomavirus type 16 E7 proteins to transactivate E2F-responsive elements is promoter- and cell-dependent.

The human papillomavirus 16 E7 protein (HPV 16 E7) transactivates the adenovirus E2 promoter (AdE2) by altering interactions between retinoblastoma (pRb) family members and the transcription factor E2F. To understand factors limiting the oncogenic potential of HPV 6, the relative ability of HPV 6 E7 as compared to HPV 16 E7 to transactivate the AdE2 promoter was determined. In primary baby rat kidney cells and human foreskin keratinocytes, HPV 16 E7 transactivated the AdE2 promoter to a greater extent than HPV 6 E7, consistent with the observation that HPV 16 E7 binds pRb with greater affinity. HPV 6 E7 gain of function correlated with increasing the affinity of the HPV 6 E7 pRb binding site of conserved region 2 (CR2). In keratinocytes, in contrast to the AdE2 promoter, the abilities of the two E7 proteins to transactivate the B-myb promoter, a promoter regulated by E2F bound to p107/p130, were comparable. Introducing a negative charge into the N-terminus (CR1) and a high affinity pRb binding site into CR2 of HPV 6 E7 resulted in a transactivator with greater activity than HPV 16 E7 for both the AdE2 and B-myb promoters. Both of the promoters were negatively regulated by E2F and transactivation by the E7 proteins required an intact E2F site. In C33-A cells, which contain a mutated pRb, the two E7 proteins had comparable transactivating activity on both the AdE2 and B-myb promoters. The data are consistent with the interpretation that HPV 16 E7 affects interactions of pRb and p107/p130 with the E2F transcription factor, whereas HPV 6 E7 only affects interactions of p107/p130.

Amino Acid Sequence↗
PubMed1997

Cytogenetic and molecular studies of siblings with ataxia telangiectasia followed for 7 years.

We present cytogenetic, immunologic, and molecular data obtained over 7 years from a family with ataxia telangiectasia (AT) including 2 affected children and their unaffected sibling, and their obligate heterozygous parents. In a period of 3 years, the T lymphocytes from both AT patients showed clonal rearrangements of chromosomes 7 and 14 at specific bands (7p13, 7q35, 14q12, and 14q32), where loci for the Ig and TCH genes are located. A molecular study was carried out on peripheral blood and bone marrow samples from both patients using Southern blot and PCR for Ig and TCR genes. A monoclonal population for TCR gamma was observed in one of the two affected children, but only in peripheral blood.

Adolescent↗
PubMed1997

CCAAT displacement protein, a regulator of differentiation-specific gene expression, binds a negative regulatory element within the 5' end of the human papillomavirus type 6 long control region.

We have reported previously that a 636-bp fragment spanning the 5' two-thirds of the human papillomavirus type 6 (HPV6)-W50 long control region (LCR) functions as a transcriptional silencer (A. Farr, S. Pattison, B.-S. Youn, and A. Roman, J. Gen. Virol. 76:827-835, 1995). We have utilized nested deletion analyses to implicate a 66-bp sequence which appears to be critical for this activity. A comparison of the transcriptional regulatory activities of the LCRs of HPV6-W50 and HPV6b (which has a 94-bp deletion, resulting in the elimination of the 66-bp sequence) indicates that sequences within the 94-bp region negatively regulate the activity of the intact HPV6 LCR. Two sequence-specific DNA-protein interactions were visualized via electrophoretic mobility shift assays. One of the binding events is mediated by the transcriptional repressor CCAAT displacement protein (CDP), a factor which is active in undifferentiated cells but inactive in terminally differentiated cells. This conclusion is based on the following three lines of evidence: (i) a consensus CDP binding site oligonucleotide serves as a competitor in band shift assays, (ii) the band shift complex is not seen when a CDP-negative nuclear extract is used, and (iii) anti-CDP antiserum specifically inhibits the binding. These studies identify a DNA-protein interaction occurring within the 5' end of the LCR which may be important in maintaining the tight link between keratinocyte differentiation and HPV gene expression.

Base Sequence↗