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Biomedical subjects

J E Bailey

Publications and source records attributed to J E Bailey.

At least 91 records · Page 5Linked to original sources
PubMed1998

Diuretic-based treatment and cardiovascular events in patients with mild renal dysfunction enrolled in the systolic hypertension in the elderly program.

BACKGROUND: It is expected that the treatment of hypertension in patients with renal disease decreases the risk of cardiovascular events, but the evidence in these patients is lacking. OBJECTIVE: To assess the effect of diuretic-based treatment on cardiovascular events in patients with isolated systolic hypertension and renal dysfunction. METHODS: A total of 4336 persons aged 60 years and older with systolic blood pressures of 160 mm Hg and higher and diastolic blood pressures of less than 90 mm Hg were randomly assigned to receive either placebo or chlorthalidone (12.5-25.0 mg/d), with the addition of atenolol (25-50 mg/d) or reserpine (0.05-0.10 mg/d) if needed, and observed for 5 years. The risk of first-occurring cardiovascular events, including stroke, transient ischemic attack, myocardial infarction, heart failure, coronary artery bypass surgery, angioplasty, aneurysm, endarterectomy, sudden death, or rapid death, was stratified according to baseline serum creatinine levels (35.4-84.0, 84.1-101.6, 101.7-119.3, and 119.4-212.2 micromol/L [0.4-0.9, 1.0-1.1, 1.2-1.3, and 1.4-2.4 mg/dL]). RESULTS: Systolic blood pressure reduction was not affected by baseline serum creatinine levels. Active treatment did not affect the risk of serum creatinine levels becoming elevated during follow-up. The risk of hypokalemia with active treatment decreased significantly with increasing baseline serum creatinine levels. In the 4 baseline serum creatinine groups, the relative risk (95% confidence interval) of cardiovascular events developing with active treatment was 0.73 (0.54-0.97), 0.63 (0.49-0.82), 0.62 (0.44-0.87), and 0.59 (0.38-0.91). The results were similar for the outcomes of stroke or coronary artery events and in analyses stratified by sex or age. CONCLUSION: Diuretic-based treatment of patients with isolated systolic hypertension prevents the development of cardiovascular events in older persons with mild renal dysfunction.

Aged↗
PubMed1998

Tennessee's failed managed care program for mental health and substance abuse services.

In July 1996, Tennessee initiated a managed mental health and substance abuse program called TennCare Partners. This publicly funded "carve-out" experiment started chaotically and soon deteriorated into a crisis. Many patients did not receive care or lost continuity of care, and the traditional "safety net" mental health system nearly disintegrated. This qualitative case study sought to ascertain the impact of the TennCare Partners program. It points out that the program's difficulties stemmed directly from a flawed design that spread funds previously earmarked for severely mentally ill patients across the entire Medicaid population. States contemplating similar reforms should strive to protect vulnerable patients by risk-adjusting capitation payments and by focusing resources on care for severely mentally ill persons. States should also minimize program complexity and ensure the accountability of managed care networks for their patients' behavioral health care needs.

Adult↗
PubMed1998

Expression of the membrane protein glycophorin A as a fusion with the antibiotic resistance protein neomycin phosphotransferase II.

The gene for the integral membrane protein glycophorin A (GPA) was cloned in frame to the 5' end of the antibiotic resistance gene, neomycin phosphotransferase II (NPT). Protein expression was achieved in Escherichia coli as well as in mammalian cells. In case of Chinese hamster ovary cells (CHO) the resistant populations were analyzed 2 weeks after transfection; the amount of GPA-NPT fusion protein produced was constant from experiment to experiment. Neomycin resistance was directly correlated with GPA expression, thus allowing the direct selection for a stable GPA-expressing cell population without the need of a cloning step. The amount of GPA-NPT produced was further increased by weakening the specific NPT enzymatic activity via site-directed mutagenesis. Detection was simplified by the fact that all different fusion proteins could be detected by the same anti-NPT antibody. This approach may be also applicable to other membrane proteins.

Animals↗
PubMed1998

pTRIDENT, a novel vector family for tricistronic gene expression in mammalian cells.

We constructed tricistronic expression vectors for the simultaneous and coordinated expression of three independent genes in mammalian cells. One single promoter allows high level and, in some vectors, adjustable transcription of all three cistrons. Whereas the first cistron is translated in a cap-dependent manner, the subsequent ones utilize intercistronic regions of viral origin such as the internal ribosomal entry site of poliovirus or the cap-independent translation enhancer of encephalomyocarditis virus for enhanced translation. Three multiple cloning sites with a total of up to 18 unique restriction sites allow sequential cloning of the genes of interest. The modular structure of this pBluescript(R)-based high copy number vector system allows straightforward movement of individual cistrons among members of the pTRIDENT family, and facilitates their combination with existing expression vectors.

Animals↗
PubMed1998

Practical approach to acid-base disorders.

Acid-base balance is a general term for the way in which the body maintains a relatively constant pH despite continuous production of metabolic end products and is fundamental to physiologic homeostasis. Disease states of animals lead to irregularities of body fluid, electrolyte, and acid-base balance. With the advent of less expensive, accurate, as well as portable blood gas and electrolyte analyzers, acid-base assessment has become a standard of care in veterinary medicine. It is important that the veterinary practitioner understand acid-base pathophysiology to assure successful treatment of these disease states. The purpose of this article is to provide a simple and concise description of traditional and modern acid-base data interpretation and assist the practitioner with application of these methods.

Acid-Base Equilibrium↗
PubMed1998

Controlled proliferation by multigene metabolic engineering enhances the productivity of Chinese hamster ovary cells.

The eukaryotic cell cycle is regulated by a complex network of many proteins. Effective reprogramming of this complex regulatory apparatus to achieve bioprocess goals, such as cessation of proliferation at high cell density to allow an extended period of high production, can require coordinated manipulation of multiple genes. Previous efforts to establish inducible cell-cycle arrest of Chinese hamster ovary (CHO) cells by regulated expression of the cyclin-dependent kinase inhibitor (CDI) p21 failed. By tetracycline-regulated coexpression of p21 and the differentiation factor CCAAT/enhancer-binding protein alpha (which both stabilizes and induces p21), we have achieved effective cell-cycle arrest. Production of a model heterologous protein (secreted alkaline phosphatase; SEAP) has been increased 10-15 times, on a per cell basis, relative to an isogenic control cell line. Because activation of apoptosis response is a possible complication in a proliferation-arrested culture, the survival gene bcl-xL was coexpressed with another CDI, p27, found to enable CHO cell-cycle arrest predominantly in G1 phase. CHO cells stably transfected with a tricistronic construct containing the genes for these proteins and for SEAP showed 30-fold higher SEAP expression than controls.

Alkaline Phosphatase↗
PubMed1998

The prognostic significance of asymptomatic carotid bruits in the elderly.

OBJECTIVE: To determine the association between asymptomatic carotid bruits and the development of subsequent stroke in older adults with isolated systolic hypertension. DESIGN: Retrospective cohort study. SETTING: The Systolic Hypertension in the Elderly Program (SHEP), a 5-year randomized trial testing the efficacy of treating systolic hypertension in noninstitutionalized persons aged 60 years or older. From the original 4,736 SHEP participants, we identified a cohort of 4,442 persons who had no prior history of stroke, transient ischemic attack, or myocardial infarction at randomization. MEASUREMENTS AND MAIN RESULTS: The end point for this ancillary study was the development of a stroke. The average follow-up was 4.2 years. Carotid bruits were found in 284 (6.4%) of the participants at baseline. Strokes developed in 21 (7.4%) of those with carotid bruits and in 210 (5.0%) of those without carotid bruits. The unadjusted risk of stroke among persons with carotid bruits was 1.53 (95% confidence interval [CI] 0.98, 2.40). Adjusting for age, gender, race, blood pressure, smoking, lipid levels, self-reported aspirin use, and treatment group assignment, the relative risk of stroke among persons with asymptomatic carotid bruits was 1.29 (95% CI 0.80, 2.06). Among SHEP enrollees aged 60 to 69 years, there was a trend (p = .08) toward increased risk (relative risk [RR] 2.05; 95% CI 0.92, 4.68) of subsequent stroke in persons with, compared to those without, carotid bruits. However, among enrollees aged 70 years or over, there was no relation between carotid bruit and subsequent stroke (RR 0.98; 95% CI 0.55, 1.76). In no other subgroup of SHEP enrollees did the presence of carotid bruit independently predict stroke. CONCLUSIONS: Although we cannot rule out a small increased risk of stroke associated with bruits in asymptomatic SHEP enrollees aged 60 to 69 years, the utility of carotid bruits as a marker for increased risk of stroke among asymptomatic elderly with isolated systolic hypertension aged 70 years or older is limited.

Aged↗
PubMed1998

Physicians' experiences with Medicaid managed care: the Tennessee American College of physicians survey on TennCare.

Despite widespread introduction of Medicaid managed care (MMC), physicians have not been surveyed regarding its impact on patient care. This study documented physician experiences with MMC in Tennessee, where a statewide experimental managed care program (TennCare) delivers services through 12 capitated managed care organizations (MCOs). Practicing Tennessee American College of Physician (ACP) members (n = 1,181) were questioned regarding recent experience with the TennCare program, assessment of the program, and suggestions for improvement. The results, derived from 306 physician respondents (response rate 26%), were as expected, based on findings of a prior administrative focus group and independent surveys. Physicians' experiences were similar regardless of practice type. Most physicians rated the TennCare program as either fair (43%) or poor (42%) overall. The majority cited administrative complexity as a major problem that frequently adversely affected patient care. Physician experience suggests that administrative procedures and medication formularies should be streamlined and standardized to improve patient care.

Attitude of Health Personnel↗
PubMed1998

A methodologic issue for ophthalmic telemedicine: image quality and its effect on diagnostic accuracy and confidence.

BACKGROUND: The possibility of ophthalmic telemedicine raises questions as to the quality of images displayed on a video display terminal and its effect on a doctor's accuracy and confidence of diagnosis. This study compares diagnostic accuracy and confidence levels of subjects observing two formats of retinal imaging. METHODS: Test images included 90 conventional 4- x 6-inch retinal fundus photographs and the same set of photographs after they had been scanned, digitized, modified in brightness and contrast, and displayed on a video display terminal. Fifty-six of the images demonstrated one or more retinal anomalies; the remaining 34 were of normal fundi. Abnormalities were selected on the basis of estimates of prevalence in the general population. Twenty optometrists affiliated with the Southern California College of Optometry participated as subjects. One group of 10 was shown the photographs; the remaining ten subjects were shown the digitized images. Both groups were asked if the pictures were "healthy" or "unhealthy," how confident they were of their decision, and, if abnormal, what was the ocular disease. RESULT: T-tests were used to compare the results of the two groups. There was a statistically significant difference in the confidence of a specific diagnosis between the two groups (p = 0.018), as well as tendencies toward significance on other measures. CONCLUSION: Viewing digitally reconstructed photographic images of the retina on a video display caused doctors to lose confidence in making a diagnosis before they lost accuracy.

Adult↗
PubMed1997

Purification of the cardiac sarcoplasmic reticulum membrane protein phospholamban from recombinant Escherichia coli.

Phospholamban (PLN) was expressed in Escherichia coli as a protein fusion with glutathione S-transferase (GST). GST-PLN was mostly present in the insoluble protein fraction and accounted for approximately 50% of total insoluble protein. Attempts to suppress inclusion body formation or to use GST as an affinity-purification tag failed. A successful purification method is based on preparative SDS/PAGE and electrodialysis. From 1 g cells we typically purified 13.5 mg fusion protein with a PLN content of 2.8 mg. We genetically inserted an enterokinase (EK) protease site just in front of the PLN sequence and demonstrated the proteolytical liberation of PLN from the carrier protein. The approach described represents a substantial advancement in PLN expression and purification.

Animals↗
PubMed1997

Median effective dose of propofol required for induction of anaesthesia in goats.

OBJECTIVE: To determine the median effective dose (ED50) of propofol required for induction of anesthesia in goats and the frequency of myoclonic activity and apnea associated with propofol administration. DESIGN: Clinical trial. ANIMALS: 28 healthy mature goats. PROCEDURE: ED50 was determined by use of the up-and-down method. The first goat was given 4 mg of propofol/kg (1.8 mg/lb) of body weight, i.v. Dose was increased by 25% for the next goat if endotracheal intubation was not possible and decreased by 20% if it was. For each subsequent goat, dose was determined on the basis of response of the previous goat. The ED50 was calculated by use of probit analysis. Induction time, frequency and duration of apnea, frequency of myoclonus, and other adverse effects were recorded. RESULTS: ED50 was determined to be 5.1 mg/kg (2.3 mg/lb). Mean (+/- SD) induction time was 23.2 +/- 4.7 seconds. Apnea was observed in 27 of 28 goats; mean (+/- SD) duration of apnea was 72.9 +/- 38.3 seconds. dose did not correlate without duration of apnea. Myoclonic activity was observed in 16 of 28 goats; frequency of myoclonus was not associated with dose. Cyanosis, regurgitation, and signs of pain during injection were not observed. CLINICAL IMPLICATIONS: Administration of propofol at 5.1 mg/kg (2.3 mg/lb), i.v., should permit endotracheal intubation in half of unpremedicated, healthy, mature goats. Myoclonus and apnea were associated with propofol administration.

Anesthesia, Intravenous↗
PubMed1997

Risk factors for violent death of women in the home.

OBJECTIVES: To determine risk factors for violent death of women in the home, and particularly, to assess the strength and direction of any association between domestic violence or keeping firearms and homicide or suicide in the home. METHODS: Subgroup analysis of a large population-based case-control study database was performed, defining cases as all homicides and suicides occurring in the homes of female victims in 3 metropolitan counties: Shelby County, Tennessee; King County, Washington; and Cuyahoga County, Ohio. Randomly selected control subjects were matched to the victims by neighborhood, sex, race, and age range. Exposures to potential risk factors were ascertained by interviewing a proxy for the victim 3 to 6 weeks after the violent death occurred. These answers were compared with those obtained from controls using matched-pairs methods. RESULTS: All cases (n = 266) were identified in the 3-county area, including 143 homicides and 123 suicides, during a 5-year period. Matching controls (n = 266) were also identified. Firearms were involved in 46% of the homicides and 42% of the suicides. Independent risk factors for suicide in the home included a history of mental illness (odds ratio [OR], 258.8; 95% confidence interval [CI], 18.2-3679.8), living alone (OR, 13.4; 95% CI, 2.0-87.8), and having 1 or more guns in the home (OR, 4.6; 95% CI, 1.2-17.5). Independent risk factors for homicide included living alone (OR, 5.1; 95% CI, 2.0-13.2), illicit drug use by any member of the household (OR, 4.9; 95% CI, 1.3-15.9), prior domestic violence (OR, 4.0; 95% CI, 1.5-10.5), 1 or more guns in the home (OR, 3.4; 95% CI, 1.6-7.1), and previous arrest of any member of the household (OR, 3.0; 95% CI, 1.3-6.6). The increased risk of homicide associated with domestic violence, firearms, or illicit drugs was attributable to the homicides at the hands of a spouse, intimate acquaintance, or close relative. CONCLUSIONS: Among women, mental illness and living alone increase the risk of suicide in the home, and household use of illicit drugs and prior domestic violence increase the risk of homicide. Instead of conferring protection, keeping a gun in the home is associated with increased risk of both suicide and homicide of women. Household use of illicit drugs, domestic violence, and readily available firearms place women at particularly high risk of homicide at the hands of a spouse, an intimate acquaintance, or a close relative. Many factors place women at increased risk of violent death in the home. Community- and clinic-based interventions should target those with identifiable risk factors.

Domestic Violence↗
PubMed1997

Analysis of host-induced response in the rice blast fungus Magnaporthe grisea using two-dimensional polyacrylamide gel electrophoresis.

Two-dimensional (2-D) polyacrylamide gel electrophoresis of proteins was used to study the response of the rice blast fungus to extracts prepared from resistant and susceptible rice cultivars. A protein of molecular mass 31 kDa was induced by a susceptible host extract, while the fungus exposed to extract from the resistant cultivar and the untreated samples did not show the presence of this protein. Levels of this 31 kDa protein increased 30-fold, 72 h after treatment with plant extracts, with the concomitant appearance of at least sixteen other novel proteins. Fungus treated with extracts of resistant host or the untreated samples did not show any of these proteins while the proteins specific to different growth stages appeared as expected. Analysis of the extracellular samples showed induction of a 17 kDa protein after 72 h in the culture treated with susceptible host extract. Since the resistant host extract does not cause induction of any protein it is likely that the proteins induced in response to the susceptible host are expressed during the disease process and/or its establishment. Our study demonstrates usefulness of 2-D analysis in understanding host-pathogen interactions.

Ascomycota↗
PubMed1997

Transgenic tobacco expressing Vitreoscilla hemoglobin exhibits enhanced growth and altered metabolite production.

The gene for Vitreoscilla hemoglobin (VHb) has been introduced and expressed in Nicotiana tabaccum (tobacco). Transgenic tobacco plants expressing VHb exhibited enhanced growth, on average 80-100% more dry weight after 35 days of growth compared to wild-type controls. Furthermore, germination time is reduced from 6-8 days for wild-type tobacco to 3-4 days and the growth phase from germination to flowering was 3-5 days shorter for the VHb-expressing transgenes. Transgenic plants contained, on average, 30-40% more chlorophyll and 34% more nicotine than controls. VHb expression also resulted in an altered distribution of secondary metabolites: In the trangenic tobacco plants anabasine content was decreased 80% relative to control plants.

Anabasine↗
PubMed1997

Metabolic fluxes in riboflavin-producing Bacillus subtilis.

The pentose phosphate pathway and the pyruvate shunt were identified as major pathways of glucose catabolism in a recombinant, riboflavin-producing Bacillus subtilis strain. Reactions connecting the tricarboxylic acid cycle and glycolysis, catalyzed by the malic enzyme and phosphoenolpyruvate carboxykinase, consume up to 23% of the metabolized glucose. These are examples of important fluxes that can be accessed explicitly using a novel analysis based on synergistic application of flux balancing and recently introduced techniques of fractional 13C-labeling and two-dimensional nuclear magnetic resonance spectroscopy. The overall flux distribution also suggests that B. subtilis metabolism has an unusually high capacity for the reoxidation of NADPH. Under the conditions investigated, riboflavin formation in B. subtilis is limited by the fluxes through the biosynthetic rather than the central carbon pathways, which suggests a focus for future metabolic engineering of this system.

Bacillus subtilis↗
PubMed1997

Photoreceptor orientation and alignment in nasal fundus ectasia.

BACKGROUND: We investigated whether Stiles-Crawford (SCE) functions, a measure of photoreceptor orientation and alignment, are disturbed in patients with nasal fundus ectasia (tilted disc; Fuch's coloboma without apparent pupillary involvement). METHODS: SCE functions were obtained in three observers with nasal fundus ectasia, using psychophysical methods. RESULTS: In all cases, disruption of photoreceptor alignment can be inferred. Results include location of the SCE peaks outside the pupil in the direction of the lesion, differential alignment, and reduction of the magnitude of SCE at various retinal loci (reduced curvature or p factor). Additional results obtained with the selective adaptation technique imply that receptor disarray (splaying) may be responsible for loss of retinal directional sensitivity. CONCLUSIONS: From these results, it may be surmised that mechanical tractional forces can play a major role in defining photoreceptor orientation in the retina. Inferred anomalous photoreceptor alignment has heretofore not been specifically linked with Fuch's coloboma/tilted disc syndrome.

Adaptation, Ocular↗