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Biomedical subjects

M Moore

Publications and source records attributed to M Moore.

At least 163 records · Page 9Linked to original sources

Gastrointestinal endoscopy in patients taking antiplatelet agents and anticoagulants: survey of ASGE members. American Society for Gastrointestinal Endoscopy.

BACKGROUND: Gastrointestinal endoscopy is often required in patients taking aspirin, nonsteroidal anti-inflammatory drugs (NSAIDs), or anticoagulants. Because proper guidelines are lacking, we believe that most endoscopists use their own criteria and judgment for stopping and restarting these agents during the periendoscopic period, and the practice varies widely. The aim of our study was to identify these practices among ASGE members. METHODS: Questionnaires, each containing 22 questions with 157 responses, were sent to 3300 ASGE members, including all Gastroenterology Fellowship Program Directors. One thousand two hundred sixty-nine questionnaires were received and analyzed. RESULTS: Physicians stopped aspirin and NSAIDs more frequently before colonoscopy (81%) and ERCP (79%) than before upper endoscopy (51%) (p < 0.001). Ninety percent of physicians stopped aspirin and NSAIDs for 10 or fewer days. Only 20% of physicians performed sphincterotomy when aspirin and NSAIDs were not stopped compared with 88% and 85% (p < 0.001 for both) of physicians performing cold biopsies at esophagogastroduodenoscopy and colonoscopy, respectively, and 77% and 69% performing hot biopsies for the same procedures (p < 0.001 for all compared with sphincterotomy). Depending on the indication for anticoagulation, 51% to 60% of physicians stopped warfarin before upper endoscopy; 71% to 82% before colonoscopy; and 26% to 51% of physicians used a "heparin window." All physicians restarted warfarin immediately after diagnostic endoscopy, whereas 80% restarted it 7 or fewer days after therapeutic endoscopy. CONCLUSIONS: We conclude that a wide variation exists regarding the management of aspirin, NSAIDs, and anticoagulants in the periendoscopic period. There is a definite need for a consensus statement or guidelines for managing patients taking these agents.

Anti-Inflammatory Agents, Non-Steroidal↗

Effect of transient expression of the oestrogen receptor on constitutive and inducible CYP1A1 in Hs578T human breast cancer cells.

Hs578T human breast cancer cells are an oestrogen receptor (ER)-negative cell line. Treatment of these cells with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) resulted in formation of a 6.9 S nuclear aryl hydrocarbon (Ah) receptor complex, which bound to a [32P]dioxin-responsive element in a gel electrophoretic mobility shift assay. However, TCDD does not induce CYP1A1 gene expression or chloramphenicol acetyl transferase (CAT) activity in cells transiently transfected with pRNH11c or pMCAT5.12, which are Ah-responsive plasmids derived from the 5'-flanking region of the human and murine CYP1A1 genes respectively. Restoration of Ah responsiveness was investigated by co-transfecting Hs578T cells with pRNH11c or pMCAT5.12 and plasmids that express the ER (hER), Ah receptor (AhR) and AhR nuclear translocator (Arnt) proteins. ER expression resulted in significantly increased basal CAT activity; however, TCDD did not induce CAT activity in the transiently transfected cells. Expression of the AhR or Arnt proteins did not alter basal or inducible CAT activity. Expression of N- or C-terminal truncated ER in Hs578T resulted in differential regulation of Ah responsiveness. In Hs578T cells transiently expressing the ER, which contains C-terminal deletions (amino acids 282-595), basal CAT activity was also increased; however, Ah responsiveness was not restored. In contrast, transient expression of N-terminal-deleted (amino acids 1-178) ER resulted in a marked decrease in basal CAT activity but a restoration of Ah responsiveness. These results suggest that basal and inducible CAT activity in Hs578T cells transiently transfected with pRNH11c is modulated differentially by ER domains that are present in the N- and C-terminal regions of the ER.

Base Sequence↗

Purification and activities of the Rhodobacter capsulatus RpoN (sigma N) protein.

The rpoN-encoded sigma factors (sigma N) are a distinct class of bacterial sigma factors, with no obvious homology to the major sigma 70 class. The sigma N-containing RNA polymerase holoenzyme functions in enhancer-dependent transcription to allow expression of positively controlled genes. We have purified the Rhodobacter capsulatus sigma N protein, which is distinctive in lacking an acidic region implicated in the melting of promoter DNA by the Escherichia coll sigma N holoenzyme, and may represent a minor subclass of sigma N proteins. Assays of promoter recognition and holoenzyme formation and function showed that the purified R. capsulatus sigma N protein is distinct in activity compared to the enteric proteins, but retains the broad functions described for these proteins. As first described for the Klebsiella pneumoniae protein, promoter recognition in the absence of core RNA polymerase was detected, but contact of certain promoter bases by the R. capsulatus sigma N protein and its response to core RNA polymerase was clearly different from that determined for the K. pneumoniae and E. coli proteins. Results are discussed in the context of a requirement to modulate the activity of the DNA-binding surfaces of sigma N to regulate sigma N function. Circular dichroism was used to evaluate the structure of the R. capsulatus protein and revealed differences in the tertiary signals as compared to the K. pneumoniae protein, some of which are attributable to the DNA-binding domain of sigma N.

Amino Acid Sequence↗

Primary care physicians and their HIV prevention practices.

A national random-sample survey of 4011 primary care physicians was conducted to determine the extent to which they are providing HIV prevention and clinical services, and to learn what characteristics and attitudes might impede the provision of such services. Physicians were asked about their history-taking practices for new adult and adolescent patients, including asking about the use of illicit drugs (injection and noninjection), the number of sexual partners, use of condoms and contraceptives, past episodes of sexually transmitted diseases (STDs), sexual orientation, and sexual contact with partner(s) at high risk for HIV. A preliminary analysis was conducted and reported earlier by the Centers for Disease Control and Prevention (CDC), focusing on the HIV-prevention services being provided by primary care physicians. This report provides additional analyses from this study, focusing on characteristics and attitudes that may prevent physicians from providing these services. Male physicians and the physicians' belief that patients would be offended if asked questions about their sex behaviors were strongly predictive of not asking new patients about their sex and drug behaviors. The physician's specialty was also a strong predictor-OB/GYNs were predictive of asking these questions and GP/FPs were predictive of not asking the questions. Physicians who indicated that a majority of their patients were white were less likely to report asking patients about their sex and drug behaviors. The authors conclude that a substantial number of primary care physicians are missing important opportunities to prevent HIV transmission by not adequately assessing patients' risks and not providing necessary risk-reduction counseling during their physician-patient encounters. Physician's attitudes and beliefs about their patients, as well as their level of experience with HIV, may help to explain these observations.

Adolescent↗

Virologic and immunologic benefits of initial combination therapy with zidovudine and zalcitabine or didanosine compared with zidovudine monotherapy. Wellcome Resistance Study Collaborative Group.

A randomized controlled study was done to determine whether initial combination therapy with zidovudine and zalcitabine or zidovudine and didanosine would delay the emergence of zidovudine-resistant virus. Human immunodeficiency virus (HIV)-1-infected patients with <300 CD4 cells/mm3 and <4 weeks of prior zidovudine therapy were randomized to zidovudine, zidovudine plus zalcitabine, or zidovudine plus didanosine. Combination therapy did not delay the emergence of zidovudine-resistant virus isolates. However, combination therapy resulted in a significant increase in CD4 cells through 72 weeks compared with zidovudine monotherapy and a greater and more sustained decline in serum HIV-1 RNA. Although this trial was not designed as a clinical end-point study, patients assigned to zidovudine plus didanosine combination therapy experienced a significant delay in time to first AIDS-defining event or death compared with those assigned to zidovudine monotherapy.

Adult↗

Recognition and surgical management of the upper airway resistance syndrome.

Patients with upper airway resistance syndrome (UARS) have clinical signs and symptoms of excessive daytime somnolence (EDS) in the absence of obstructive sleep apnea. These patients have increased upper airway resistance, reflected by an elevated intrathoracic pressure measurement, despite a normal respiratory disturbance index (RDI). Physical findings often include excessive palatal tissue and narrowing of the oropharynx and hypopharynx. Nine patients with UARS who received surgical treatment were prospectively evaluated. The four men and five women had signs of EDS, with or without snoring. The mean (+/- standard deviation) RDI was 2.1 (+/- 1.2), and the mean esophageal pressure recording during polysomnography was -36.7 (+/- 16.2) cm H2O. The Epworth sleepiness scale was used to quantify EDS. The preoperative score of 12.0 (+/- 6.6) decreased to 3.4 (+/- 1.9) (P = .001) after surgical treatment. A variety of procedures, all including some type of palatal surgery, were performed. No treatment complications occurred. The recognition of UARS and an understanding of the mechanisms responsible for the progressive development of obstructive sleep apnea syndrome may facilitate the prompt identification and treatment of such patients. The pathophysiology of UARS and a preliminary report of its surgical treatment are discussed.

Adult↗

Prevention of postoperative abdominal adhesions by a sodium hyaluronate-based bioresorbable membrane: a prospective, randomized, double-blind multicenter study.

BACKGROUND: Postoperative abdominal adhesions are associated with numerous complications, including small bowel obstruction, difficult and dangerous reoperations, and infertility. A sodium hyaluronate and carboxymethylcellulose bioresorbable membrane (HA membrane) was developed to reduce formation of postoperative adhesions. The objectives of our prospective study were to assess the incidence of adhesions that recurred after a standardized major abdominal operation using direct laparoscopic peritoneal imaging and to determine the safety and effectiveness of HA membrane in preventing postoperative adhesions. STUDY DESIGN: Eleven centers enrolled 183 patients with ulcerative colitis or familial polyposis who were scheduled for colectomy and ileal pouch-anal anastomosis with diverting-loop ileostomy. Before abdominal closure, patients were randomly assigned to receive or not receive HA membrane placed under the midline incision. At ileostomy closure eight to 12 weeks later, laparoscopy was used to evaluate the incidence, extent, and severity of adhesion formation to the midline incision. RESULTS: Data were analyzed for 175 assessable patients. While only five (6 percent) of 90 control patients had no adhesions, 43 (51 percent) of 85 patients receiving HA membrane were free of adhesions (p < 0.00000000001). The mean percent of the incision length involved was 63 percent in the control group, significantly greater than the 23 percent observed in patients who received HA membrane (p < 0.001). Dense adhesions were observed in 52 (58 percent) of the 90 control patients, but in only 13 (15 percent) of the 85 receiving HA membrane (P < 0.0001). Comparison of the incidence of specific adverse events between the groups did not identify a difference (P > 0.05). CONCLUSIONS: This study represents the first controlled, prospective evaluation of postoperative abdominal adhesion formation and prevention after general abdominal surgery using standardized, direct peritoneal visualization. In this study, HA membrane was safe and significantly reduced the incidence, extent, and severity of postoperative abdominal adhesions.

Adenomatous Polyposis Coli↗

Effects of acepromazine maleate and phenoxybenzamine on urethral pressure profiles of anesthetized, healthy, sexually intact male cats.

OBJECTIVES: To evaluate the effects of 2 compounds with alpha adrenergic antagonist properties on the urethral pressures of anesthetized, healthy, sexually intact male cats, and to evaluate one of the compounds for effect on striated muscle. ANIMALS: 20 healthy, sexually intact male cats. PROCEDURE: Cats were anesthetized with halothane, and urethral pressure profilometry was performed before and after treatment. 125I-labeled alpha-bungarotoxin bound to nicotinic receptors of murine skeletal muscle was used in a competitive binding study with acepromazine maleate. RESULTS: Acepromazine maleate significantly decreased intraurethral pressures in the preprostatic (19%) and prostatic (21%) regions of the urethra. There was no effect on the postprostatic/penile segment. Acepromazine did not inhibit 125I-labeled alpha-bungarotoxin binding to nicotinic receptors in murine skeletal muscle. Phenoxybenzamine significantly decreased intraurethral pressures (14%) in the preprostatic region of the urethra only. CONCLUSIONS: Acepromazine maleate and phenoxybenzamine have effects on the smooth muscle of the urethra of healthy, male cats. Acepromazine has no effect on striated muscle. CLINICAL RELEVANCE: alpha-Adrenergic compounds may be used in the pharmacologic management of feline urinary tract disease.

Acepromazine↗

A passenger with pulmonary/laryngeal tuberculosis: no evidence of transmission on two short flights.

BACKGROUND: We investigated the likelihood of transmission of tuberculosis (TB) from a highly infectious passenger with pulmonary/laryngeal TB to other persons aboard two airline flights, each approximately 1.25 h in duration. METHODS: The 146 passengers with known U.S. residence and 15 flight crew were contacted and referred to their personal health care provider or local health department for a Mantoux tuberculin skin test (TST). Each person was asked to complete a risk factor questionnaire and return this form with TST information provided by the health care provider. RESULTS: Questionnaires and TST results were obtained for 110 passengers (75%) and 10 crew (67%). Twenty passenger TST's were excluded from the analysis: 10 were self-read; one was not read in millimeters of induration; 8 were read after 72 h of being placed; and 1 was performed on a person suspected of being anergic. A positive TST was defined as > or = 5 millimeters of induration. Five passengers were found to be TST positive. There were no positive TST's identified among flight crewmembers. Each of the TST positive individuals had a risk factor for a positive TST. The TST positive individuals were seated throughout the plane, and each was seated at least 5 rows away from the passenger with infectious TB. CONCLUSION: Although the possibility of transmission cannot be excluded, the findings of our investigation support a low likelihood of TB transmission during the study flights.

Adolescent↗

Core RNA polymerase and promoter DNA interactions of purified domains of sigma N: bipartite functions.

The sigma N class of sigma factors confer upon RNA polymerase the requirement for enhancer-binding activator proteins. The sigma-N (sigma N) protein of Klebsiella pneumoniae was analysed by the assay of purified peptides comprising domains or regions of sigma N defined by proteolysis or by homology alignment, respectively. The NH2-terminal Region I is required for the correct interaction of holoenzyme with the promoter, and promoter complexes forming with a truncated sigma N lacking Region I are not activatable. The complexes lack the DNA structure believed to represent nucleated strand separation but still make close contacts with this promoter part. Determinants of specific DNA recognition by sigma N were shown to reside in a C-terminal 16 kDa peptide, and core RNA polymerase binding determinants in an adjacent peptide. The latter contacts and appears to pack against the DNA-binding domain. Thus the DNA-binding and core-binding domains are bipartite in function, consistent with core functioning as an allosteric effector of the sigma DNA-binding activity. The DNA-binding and core-binding domains together include Region III of sigma N. Although not the primary determinant of core or DNA recognition, the acidic Region II of sigma N influenced both activities. Regions I and II in combination with core RNA polymerase thus appear to control the activity of C-terminal DNA contacting surfaces to allow formation of a closed promoter complex that is susceptible to activation.

Allosteric Regulation↗

No association between serum ferritin and asymptomatic carotid atherosclerosis. The Atherosclerosis Risk in Communities (ARIC) Study.

A possible association between body iron stores, measured as serum ferritin, and carotid arterial intima-media thickening was investigated in the Atherosclerosis Risk in Communities Study during 1990-1992 using a matched case-control design. For a 143-micrograms/liter greater serum ferritin concentration (the interquartile range), the odds ratio for cases with carotid intima-media thickening versus controls was 1.12 (95% confidence interval 0.97-1.30). However, there was no association (odds ratio = 1.00) after adjusting for major cardiovascular risk factors. This analysis of carotid arterial intima-media thickening, a measure of early atherosclerosis, in relation to serum ferritin does not support the hypothesis that increased body iron stores increase the risk of atherosclerotic cardiovascular disease.

Arteriosclerosis↗

Identification of close contacts between the sigma N (sigma 54) protein and promoter DNA in closed promoter complexes.

The complexes forming between the alternative sigma factor protein sigma N (sigma 54), its holoenzyme and promoter DNA were analysed using the hydroxyl radical probe and by photochemical footprinting of bromouridine-substituted DNA. Close contacts between the promoter, sigma N and its holoenzyme appear to be restricted predominantly to one face of the DNA helix, extending from -31 to -5. They all appear attributable to sigma N and no extra close contacts from the core RNA polymerase subunits in the holoenzyme-promoter DNA complex were detected. We suggest that the apparent absence of close core RNA polymerase contacts in the region of the promoter DNA to be melted during open complex formation is important for maintaining the closed complex. Results of the hydroxyl radical footprinting imply that sigma N makes multiple DNA backbone contacts across and beyond the -12, -24 consensus promoter elements, and the photochemical footprints indicate that consensus thymidine residues contribute important major groove contacts to sigma N. Formation of the open complex is shown to involve a major structural transition in the DNA contacted by sigma N, establishing a direct role for sigma N in formation of the activated promoter complex.

Base Sequence↗