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Biomedical subjects

J Douglas

Publications and source records attributed to J Douglas.

At least 73 records · Page 4Linked to original sources
PubMed1994

Prevalence of hypertension in rural west Africa.

The prevalence of hypertension in rural African communities has been reported previously to be relatively low, with prevalence rates ranging between 2.5% and 10.9%. The authors obtained blood pressure recordings in 3,588 adult residents (age > 20 years) of the Liberian Agricultural Company rubber plantation, located in rural Liberia, West Africa. Blood pressures were obtained using automated digital blood pressure machines in a house-to-house survey. Individuals with a systolic blood pressure greater than 139 mm Hg or a diastolic blood pressure greater than 89 mm Hg were referred to a central site, where three subsequent blood pressure determinations were made, the mean of which was used to determine whether people were hypertensive. The overall prevalence of hypertension (blood pressure > 139/89 mm Hg) was 12.5%. Hypertension was most common in the older women (prevalence 5.7% in women age 20-24 years old, 50% in women older than 55). Using more stringent criteria for hypertension, systolic blood pressure greater than 159 mm Hg or diastolic blood pressure greater than 94 mm Hg, 20% of women between 50-54 had hypertension and 26% of the women older than 55 had hypertension. In some ethnic groups, the prevalence of hypertension was as high as 25%. Based on these results, the prevalence of hypertension in some rural African communities may be higher than reported previously, particularly in older women and among certain ethnic groups, possibly suggesting a strong hereditary component.

Adult↗
PubMed1994

Low molecular weight heparin in prevention of restenosis after angioplasty. Results of Enoxaparin Restenosis (ERA) Trial.

BACKGROUND: Heparin, an anticoagulant, possesses antiproliferative effects and has been shown to reduce neointimal proliferation and restenosis following vascular injury in experimental studies. METHODS AND RESULTS: The primary aim of this double-blind multicenter study was to determine if 40 mg Enoxaparin, a low molecular weight heparin, administered subcutaneously once daily for 1 month after successful angioplasty would reduce the incidence of restenosis. Four hundred fifty-eight patients were randomized at nine clinical centers (231 to placebo and 227 to Enoxaparin). The primary end point was angiographic or clinical restenosis. Angiographic restenosis was defined as a loss of 50% of the initial gain as measured by quantitative coronary angiography (QCA) at a core laboratory. In the absence of QCA, clinical evidence of restenosis was defined as death, myocardial infarction, repeat revascularization, or worsening angina. Using the intention-to-treat analysis for all patients, restenosis occurred in 51% of the placebo group and 52% of the Enoxaparin group (relative risk, 1.07, P = .625). Likewise, no difference in restenosis was evident when the change in minimal lumen diameter or other angiographic definitions of restenosis were used. Adverse clinical events were infrequent and did not differ between the groups with the exception of minor bleeding complications, which were more common in the Enoxaparin group. CONCLUSIONS: Enoxaparin (40 mg/d SC for 1 month) following successful angioplasty did not reduce the incidence of angiographic restenosis or the occurrence of clinical events over 6 months. The treatment was well tolerated, although in-hospital minor bleeding was more common with active treatment.

Angioplasty, Balloon, Coronary↗
PubMed1994

Impressions of nursing in China.

This is the first of a series of reflections on a trip a group of nurses made to China in June 1994. John Douglas, a science writer who accompanied the group, wrote the first article in this series. He shares his reflections on the Chinese health care system and interviews conducted with several Chinese nurses. Dr. Grayce Roessler, an internationally known transcultural nursing leader, directed the tour. She has traveled extensively in China (some 30 trips over twenty years) and has worked with Chinese nurses to establish transcultural educational exchange programs between the United States and China. In a future issue of this journal, Dr. Roessler will present her reflections on nursing in China from a transcultural nursing leader's perspective. In the final article in this series Dr. Julianna Finn, a transcultural nurse educator who also made this trip, will present some reflections on nursing in China from a transcultural nursing theoretical perspective using Leininger's Culture Care Theory.

China↗
PubMed1994

Special report on health care delivery systems. Trends in the integrated delivery of health care and the corporate practice of medicine.

The prospects for federal legislation preempting state corporate practice restrictions are unclear. The health care reform bill originally introduced by President Clinton contained a provision that would have preempted "any state law related to the corporate practice of medicine" insofar as it applied to the arrangements between non-fee-for-service health plans and their participating providers. H.R. 3600/S. 1757, 103d Cong., 1st Sess. 1407(b) (1993). Whether and in what form a preemption provision may survive the legislative process and see a Presidential signature remains to be seen. The particular fate of the federal legislation notwithstanding, however, health care executives can nevertheless remain confident that the legal treatment of the "corporate practice" of medicine will continue to be of vital concern as the various forms of health care organizations evolve in the ongoing struggle to deliver quality medicine at affordable prices.

Commerce↗
PubMed1994

Aortic valve replacement in adults after balloon aortic valvuloplasty.

BACKGROUND: Percutaneous balloon aortic valvuloplasty is limited by a high risk of procedural morbidity, transient clinical benefit, and a high restenosis rate. The management of patients with symptomatic aortic valve restenosis after percutaneous balloon aortic valvuloplasty is unclear. We hypothesized that aortic valve replacement would produce superior midterm survival compared with repeat balloon aortic valvuloplasty or medication alone in patients with symptomatic aortic valve restenosis after prior balloon aortic valvuloplasty. METHODS AND RESULTS: Baseline clinical, echocardiographic, and hemodynamic data were collected on 165 patients who underwent percutaneous balloon aortic valvuloplasty as treatment for symptomatic degenerative calcific aortic stenosis. In 144 of these patients (87%), aortic valve replacement was originally considered to carry excessive risk. The survival of three subgroups was calculated during a median follow-up period of 3.9 years (range, 1 to 6 years). Ninety-four patients (57%) had no further mechanical intervention (subgroup 1-BAV), 31 patients (19%) developed symptomatic aortic valve restenosis and underwent a repeat balloon aortic valvuloplasty (subgroup 2-BAV), and 40 patients (24%) subsequently underwent aortic valve replacement (subgroup BAV+AVR). Follow-up was 99% complete. Patients in subgroup BAV+AVR tended to be younger and have a lower prevalence of coronary artery disease or mitral regurgitation. Only 1 patient (2.5%) suffered a perioperative death during aortic valve replacement. The probability of survival 3 years from the date of the last mechanical intervention was 13% for subgroup 1-BAV, 20% for subgroup 2-BAV, and 75% for subgroup BAV+AVR. At the conclusion of follow-up, only 2 patients had symptoms of congestive heart failure or angina after aortic valve replacement. CONCLUSIONS: Aortic valve replacement may be performed with a low mortality rate, excellent palliation of symptoms, and prolongation of survival in selected high-risk patients with a history of previous balloon aortic valvuloplasty.

Actuarial Analysis↗
PubMed1993

A short-term clinical evaluation of L-697,661, a non-nucleoside inhibitor of HIV-1 reverse transcriptase. L-697,661 Working Group.

BACKGROUND: The non-nucleoside reverse transcriptase inhibitors are novel antiretroviral agents with selective activity in vitro against human immunodeficiency virus type 1 (HIV-1). They act through direct inhibition of reverse transcriptase and are not incorporated into DNA. METHODS: We evaluated a pyridinone non-nucleoside reverse transcriptase inhibitor, L-697,661, in separate six-week double-blind trials in patients with HIV-1 infection whose CD4 counts ranged from 200 to 500 cells per cubic millimeter (68 patients) or less than 200 cells per cubic millimeter (67 patients). Eligible patients were randomly assigned to receive L-697,661 orally in one of three doses (25 mg twice a day, 100 mg three times a day, or 500 mg twice a day) or zidovudine (100 mg five times a day). Clinical and laboratory assessments were performed weekly. Viral isolates were obtained from a subgroup of patients before and after treatment and were evaluated for in vitro sensitivity to L-697,661. RESULTS: Both L-697,661 and zidovudine were well tolerated. Transient increases in CD4 counts were noted in the patients with fewer than 200 CD4 cells per cubic millimeter who received the two higher doses of L-697,661, but not in those who received the lowest dose or zidovudine. Patients who received L-697,661 had rapid, dose-related decreases in plasma p24 antigen levels. However, this response virtually disappeared after six weeks in some patients receiving L-697,661, coincidently with the emergence of resistant viruses. This change in susceptibility was more frequent among patients receiving the higher doses of L-697,661 and was associated with amino acid substitutions at positions 103 and 181 in the HIV-1 reverse transcriptase gene. CONCLUSIONS: L-697,661 is safe and well tolerated and has significant dose-related activity against HIV-1. However, resistant strains of the virus emerge rapidly and may limit the effectiveness of non-nucleoside reverse transcriptase inhibitors as monotherapy for HIV-1 infection.

Adult↗
PubMed1993

Biomechanical considerations in the treatment of navicular disease.

In recent years much attention has been paid to vascular studies of the navicular bone in health and disease; however, the relative importance of these studies has overshadowed biomechanical factors which may yet prove to be of importance. This paper outlines the pertinent anatomy, and discusses current concepts in the aetiology and pathogenesis of the disease. It describes the treatment regimens which are based on biomechanical considerations and compares the results of some currently employed techniques. All aspects of navicular disease remain controversial. This paper is not intended to review or debate all current information on the subject. It reviews information on only biomechanical considerations in an attempt to focus attention on these aspects of treatment.

Animals↗
PubMed1993

A prospective trial of subxiphoid pericardiotomy in the diagnosis and treatment of large pericardial effusion. A follow-up report.

OBJECTIVE: This study was designed to determine the cause of large pericardial effusions and evaluate the efficacy of subxiphoid pericardiotomy. SUMMARY BACKGROUND DATA: Despite great advances in the techniques used to diagnose pericardial effusions, much controversy remains concerning their cause and the optimal treatment of these effusions. METHODS: In a prospective consecutive case series, 57 patients underwent a thorough preoperative evaluation followed by a subxiphoid pericardiotomy. All tissue and fluid was exhaustively evaluated. Postoperatively, all patients were followed for a least 1 year. RESULTS: Surgery was performed under local anesthesia in 77% of patients, and the complications of surgery were minimal. Pericardial tissue and fluid established or aided in establishing a diagnosis in 81% of patients. Infection and malignancy were the leading causes; the condition in only 4 patients remained undiagnosed. Follow-up revealed recurrent effusion in nine (16%) patients, but only five (9%) required further surgery. The mortality rate at 30 days was 12%, and at 1 year, it was 37%. Fourteen of the 21 deaths occurred in patients with malignancies. CONCLUSIONS: These data show that the cause of most large pericardial effusions can be determined by a thorough evaluation accompanied by subxiphoid pericardiotomy. In addition, subxiphoid pericardial biopsy and window creation is safe and effective in the treatment of these effusions.

Biopsy↗
PubMed1992

Molecular characterization of a large homozygous deletion in the small cell lung cancer cell line U2020: a strategy for cloning the putative tumor suppressor gene.

Homozygous deletions are instrumental in the detection and cloning of tumor suppressor genes. We report the isolation and characterization of 39 new single-copy probes saturating a submicroscopic homozygous deletion detected in the DNA of the small cell lung cancer (SCLC) cell line U2020. The probes were selected from a large collection, covering the entire length of chromosome 3 with an estimated average spacing of 100-150 kb. Based on the number of probes in the deletion and the probe density, the size of the U2020 submicroscopic deletion was estimated to be in the range of 4-7 megabases. Among the deleted loci, 17 showed conservation across species, probably representing potential coding gene sequences. By genetic and physical mapping of a large randomly chosen fraction of the deleted probes, we defined the location of the U2020 deletion within chromosome band 3p12. Our cloning strategy is based on narrowing the region of interest by eliminating probes that retain heterozygosity in SCLC samples, thus selecting for probes in the region of common loss.

Blotting, Southern↗
PubMed1991

Chronic and severe eating problems in young children.

Children's eating problems are a common worry mentioned by parents. The severity of these can vary widely and the medical services seem to become concerned mostly when the child either starts to lose weight or fails to gain weight adequately. But low weight may not always be the only indicator of severe or chronic eating problems. Jo Douglas describes the children referred to the Day Centre in the Great Ormond Street department of psychological medicine where a based treatment programme is being carried out by a team of therapists to evaluate the most effective form of intervention.

Child↗
PubMed1990

A submicroscopic homozygous deletion at the D3S3 locus in a cell line isolated from a small cell lung carcinoma.

We have used 14 DNA probes, which detect 19 different restriction enzyme length polymorphisms, to search for heterozygosity on chromosome 3 in five cell lines isolated from patients with small cell lung carcinoma. The cell lines on karyotype analysis did not show the deletion in chromosome 3 characteristic of this disease. Our objective was to determine if allelic loss had occurred by some chromosomal mechanism other than deletion. Two of the cell lines are consistent with allelic loss having occurred by whole chromosome loss and reduplication. The third may have lost only the short arm due to i(3q) formation. The fourth cell line has an i(3q) chromosome, together with a translocation product involving the distal portion of the short arm of chromosome 3. Lack of evidence of heterozygosity for this distal portion of 3p suggests that a copy of the 3p homologue is involved in the translocation and therefore does not explain allelic loss of of the other homologue. The fifth, while also likely to have lost one chromosome homologue, has a submicroscopic deletion on all chromosome 3s, only detectable by RFLP analysis. Such homozygous deletions have recently proved useful in the isolation of tumour suppressor genes.

Alleles↗
PubMed1990

Evaluation of the clinical pharmacology of nilvadipine in patients with mild to moderate essential hypertension.

Eighty-four patients with diastolic blood pressure ranging from 100-115 mm Hg were randomized into a multicenter, parallel, double-blind, placebo-controlled, dose response study with nilvadipine (6 mg, 8 mg, 10 mg tid for 28 days). The hypotensive response pattern to nilvadipine was similar with all three doses although duration of response was dose dependent. Maximal decreases in diastolic blood pressure occurred at 1 hour when assessed on days 1 and 15 (16.0, 17.4, and 15.8 mm Hg, vs 17.2, 18.7, and 17.5 mm Hg, respectively). The hypotensive effect remained significant compared to placebo for at least 4 hours after dosing. The increase in heart rate associated with the maximal hypotensive response was minimal and not clinically significant (day 1: 7.6, 5.2, and 4.0 beats/min with 6, 8, and 10 mg; day 15: 4.0, 5.1, 2.6 beats/min with 6, 8, 9, and 10 mg, respectively). Finally, a correlation between plasma drug concentrations and nilvadipine-induced hypotensive response was observed (r = 0.48). Black and white hypertensive patients had similar hypotensive responses. Plasma nilvadipine concentrations on day 15 were similar to those on day 1 suggesting no accumulation of drug with a tid regimen. The most common drug related side effect was headache; less frequently seen were dizziness, edema, palpitations, and abdominal pain. Nilvadipine was well tolerated (only three patients were discontinued due to side effects). The efficacy, lack of tachycardia, and side effect profile observed in this study suggest that nilvadipine may be an important addition to the treatment of hypertension.

Blood Pressure↗
PubMed1990

Histopathology of endocervical infection caused by Chlamydia trachomatis, herpes simplex virus, Trichomonas vaginalis, and Neisseria gonorrhoeae.

We determined the histologic correlates of clinically identified mucopurulent cervicitis, culture-proven cervical infection with Chlamydia trachomatis, Neisseria gonorrhoeae, herpes simplex virus (HSV), and vaginal infection with Trichomonas vaginalis by examining cervical biopsies from 83 women. Clinical mucopurulent cervicitis and culture-documented infection with one or more of these pathogens correlated histologically with intraepithelial neutrophils, reactive endocervical cells, edema, luminal neutrophils, and with several deeper tissue changes such as extensive and dense subepithelial inflammation, granulation tissue, and necrotic ulceration. Focal loss of surface columnar cells and spongiosis were also correlated with culture-confirmed infection. Well-formed germinal centers were seen in biopsies from 14 of 21 patients (67%) with C trachomatis infection alone, but in none of 17 patients with infections other than C trachomatis (P less than 0.001). A predominantly plasmacytic infiltrate was also significantly associated with chlamydial infection. Necrotic ulcers overlying a predominantly lymphocytic infiltrate were seen in six of nine patients (67%) with HSV infection alone but in only two of 40 patients (5%) with other infections (P less than 0.001). Marked inflammatory changes were not seen in the patients infected with N gonorrhoeae. The organism T vaginalis was not associated with any endocervical pathology. If these results are confirmed by prospective studies, they suggest that pathologists should alert clinicians to the possibility of recent or current infection with C trachomatis or HSV when cervical biopsies show the above changes. The loss of surface columnar epithelium with HSV, chlamydial, and gonococcal infection offers a possible explanation for the reported association of these infections with increased risk of acquiring human immunodeficiency virus infection.

Adolescent↗
PubMed1990

Proximal tubular epithelial cells possess a novel 42-kilodalton guanine nucleotide-binding regulatory protein.

The proximal tubule of the kidney represents an important location where adenylate cyclase regulates salt and water transport; yet a detailed characterization of the distribution and classification of guanine nucleotide-binding protein (G protein) and adenylate cyclase is lacking. We used purified brush border (20-fold) and basolateral membranes (14-fold) to characterize parathyroid hormone- and G protein-regulated adenylate cyclase and G-protein distribution. Adenylate cyclase was predominantly localized to basolateral membranes, while the 46-kDa alpha subunit of the stimulatory G protein (Gs) was 2-fold higher in brush border membranes than in basolateral membranes. The alpha subunit of the inhibitory G protein (Gi; 41 kDa) was equally distributed on immunoblotting but was 2-fold higher in brush border membranes than in basolateral membranes on radiolabeling with pertussis toxin. A 42-kDa cholera toxin substrate that cross-reacted with antisera to the common alpha subunit of G proteins and to Gs on immunoblotting and that was not immunoprecipitated with two Gi antisera was the most abundant alpha subunit and comprised approximately 1% of the total membrane proteins. These observations suggest that G proteins are important regulators of proximal tubular transport independent of adenylate cyclase.

Adenosine Diphosphate Ribose↗