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Biomedical subjects

D Bell

Publications and source records attributed to D Bell.

At least 163 records · Page 9Linked to original sources
PubMed1988

Altered lung vascular permeability during intermittent haemodialysis.

Hypoxia is known to develop during intermittent haemodialysis. To investigate if increased pulmonary capillary permeability to protein contributes to this phenomenon, a dual-isotope technique using Indium-labelled transferrin and Technetium-labelled red blood cells was used. Lung vascular permeability was measured in eight patients with dialysis-dependent chronic renal failure immediately before and during intermittent haemodialysis with cuprophane membranes. As a group there was a significant increase in lung vascular permeability during the early stages of haemodialysis, compared to predialysis values (P less than 0.05) and this increase occurred during the period when the patients were leucopenic and maximally hypoxic. During the haemodialysis period, but not the predialysis period, the permeability index was also significantly increased compared to a group of eight controls (P less than 0.05). These results suggest that increased vascular permeability may contribute to dialysis-induced hypoxia and that this may relate to neutrophil activation within the pulmonary vascular bed.

Adolescent↗
PubMed1988

A phase II trial of oral 4'demethoxydaunorubicin in advanced colorectal carcinoma.

4'Demethoxydaunorubicin (DMDR), an orally active daunorubicin analogue, was administered to 22 patients with advanced colorectal carcinoma. Patients were stratified into good- and poor-risk categories and received doses of 45 mg/m2 and 40 mg/m2, respectively, at 28-day intervals. Twenty-one patients were evaluable for response. No tumour responses occurred, although six patients had stable disease. Therapy was well tolerated. Mild gastrointestinal toxicity occurred in 45% of patients. Marrow toxicity was common and usually mild. DMDR appears to have no useful activity in colorectal carcinoma.

Administration, Oral↗
PubMed1988

Reduced free radical activity detected by decreased diene conjugates in insulin-dependent diabetic patients.

Free radicals are unstable chemical species which react with and oxidize adjacent molecules, particularly polyunsaturated lipids. The diene-conjugated non-peroxide isomer of linoleic acid (PL-9,11-LA') has been identified as the main diene-conjugated compound in plasma, and is a probable marker of free radical activity. The aim of the current study was to determine whether the level of PL-9,11-LA', measured by HPLC, is altered in insulin-dependent diabetes, and to investigate whether any abnormality demonstrated correlated with microvascular disease in the form of retinopathy. There was no difference in the concentrations of linoleic acid between the diabetic and control groups (422(129) vs 402(81) (SD) mumol l-1). However, the concentration of PL-9,11-LA' was significantly reduced in the diabetic group compared with control group (15.6(6.7) vs 19.3(3.9) mumol l-1, p less than 0.01), with the molar ratio of PL-9,11-LA':linoleic acid x 100 similarly reduced (3.8(1.3) vs 5.0(1.6)%, p less than 0.005). This study does not support the concept that free radicals play a significant role in the development of diabetic vascular disease.

Adult↗
PubMed1988

Regional distribution of ventilation in chronic obstructive lung disease and the effect of salbutamol.

Regional distribution of ventilation was assessed in 5 normal volunteers, and 19 patients with symptomatic chronic obstructive lung disease (COAD) using the technique of gated lung ventilation imaging with 127Xe. The results of this technique were compared with the more conventional assessment of regional ventilation by analysis of 127Xe wash-out curves. Both techniques demonstrate loss of the normal gravitational distribution of ventilation in patients with severe COAD which is significantly reduced from normals in upper, middle and lower zones of each lung, being most marked in the lower zones (p less than 0.01). Gated lung imaging also shows a significant reduction of regional ventilation in patients with mild to moderate COAD compared to normals but only in the lower zones (p less than 0.05). Gated lung imaging provides a better quantitative method of assessing regional lung function than wash-out analysis and confirms loss of the normal gravitational distribution of ventilation in patients with obstructive lung disease and relates this to severity of disease. The distribution of ventilation was also assessed in 6 patients with severe COAD before and after placebo or salbutamol. There was a significant improvement of the distribution of ventilation to the lung bases after salbutamol (p less than 0.05).

Adult↗
PubMed1988

Are reduced lung volumes in IDDM due to defect in connective tissue?

Lung volumes were measured by spirometry and helium-dilution technique in 28 young adult men with insulin-dependent diabetes mellitus (IDDM) of long duration and compared with 16 age- and height-matched adult men without diabetes. Reduced values for forced expiratory volume at 1 s, vital capacity, functional residual capacity, total lung capacity, residual volume, and single-breath carbon monoxide transfer factor were found for the IDDM patients compared to the control subjects. The results are consistent with reduced lung volumes in IDDM patients and did not correlate with the presence or absence of mild cheiroarthropathy but may relate to duration of diabetes.

Adult↗
PubMed1987

Characterization in vitro and in vivo of progressively adriamycin-resistant B16-BL6 mouse melanoma cells.

Adriamycin (ADR)-resistant sublines of B16-BL6 mouse melanoma selected by exposure to increasing concentrations of ADR were characterized in vitro for growth properties and in vivo for tumorigenicity and pulmonary metastases. The progressively resistant sublines adapted to grow in the presence of 0.025, 0.05, 0.1, and 0.25 microgram/ml ADR in monolayer culture were found to be 5-, 10-, 20-, and 40-fold ADR-resistant, respectively, compared to the parental sensitive cells, using a soft-agar colony assay and continuous ADR treatment for 7 days. The doubling time in monolayer culture of the parent sensitive and progressively ADR-resistant sublines of B16-BL6 melanoma cells was approximately 16-18 h. Although the colony-forming efficiency in soft agar of parental sensitive cells was only 0.5-4%, the 5-, 10-, 20-, and 40-fold ADR-resistant sublines had colony-forming efficiencies of 15, 20, 30, and 77%, respectively. Tumorigenicity in C57BL/6 mice of progressively ADR-resistant sublines was similar to parental sensitive cells following s.c. and i.p. implantation of 10(5)-10(6) tumor cells. Experimental pulmonary metastases were significantly lower in ADR-resistant sublines with progressive resistance. Additionally, unlike the parental sensitive and 5-fold ADR-resistant B16-BL6 cells, the 10-, 20-, and 40-fold ADR-resistant sublines were spontaneously nonmetastatic. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunochemical detection of P-glycoprotein revealed the presence of a Mr 170,000 plasma membrane glycoprotein in the 40-fold ADR-resistant subline and its counterpart maintained for 1 year in ADR-free medium. Results from this study suggest that progressively ADR-resistant B16-BL6 mouse melanoma cells selected in vitro demonstrate a marked increase in colony formation in soft agar and a decrease in the ability to produce pulmonary metastases, without alterations in tumorigenicity.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1987

Fetus with asymmetric parietal encephalocele, and hydrops secondary to laryngeal atresia.

We describe a fetus with an asymmetric, nonmidline, parietal encephalocele that appeared to result from "expulsion" through the center of the membranous bone; the fetus also had laryngeal atresia, which caused pulmonary overdistension (fetal Valsalva maneuver) with consequent hydrops fetalis. A common cause and clear pathogenetic relationship between these anomalies is not apparent.

Abnormalities, Multiple↗
PubMed1987

Left ventricular preparation with an extrathoracically adjustable balloon occluder.

We developed a hydraulic occluder that could be adjusted percutaneously through a subcutaneous reservoir. Because of the potentially high pressures that may occur in preparing patients with transposition of the great vessels for an atrial switch procedure, the band on that hydrauler was modified to withstand arterial pressure and was subjected to studies involving banding of the aorta. Data indicate the suitability of this hydraulic occluder to withstand and maintain pressure in the systemic circulation.

Animals↗
PubMed1987

The acute inflammatory response to myocardial infarction: imaging with indium-111 labelled autologous neutrophils.

The uptake of indium-111 labelled neutrophils was examined in 30 patients with acute myocardial infarction by planar imaging and single photon emission computed tomography. The time from venepuncture to reinjection of the autologous labelled neutrophils was less than 2.5 hours and imaging was carried out 24 hours later. Twenty three patients had a positive uptake of neutrophils in the myocardium and imaging was improved by single photon emission computed tomography. There was a significant difference between the intervals from the onset of chest pain to injection of labelled neutrophils between patients with positive and negative images; early reinjection was more likely to produce a positive image. Indeed, all nine patients reinjected within 18 hours of the onset of symptoms had positive images. The results suggest that the stimulus for activation and migration of neutrophils is transient; this is an important factor if neutrophil release products play a role in cell damage after coronary occlusion.

Acute Disease↗
PubMed1987

Carbonated drinks, thiamine deficiency and right ventricular failure.

A 69 year old male presented with clinical features of right ventricular failure. A dilated poorly contracting right ventricle was confirmed by echocardiography and radionuclide ventriculography, with subsequent improvement following thiamine replacement. Wet beriberi is a result of thiamine deficiency and is uncommon in Europe and North America except in association with chronic alcohol abuse. We report a patient with beriberi presenting unusually with severe right-sided cardiac failure, with documented impairment of right ventricular function, which improved with thiamine replacement. His dietary intake of thiamine was low because of excess intake of carbonated drinks and carbohydrates.

Aged↗
PubMed1987

Home care in New York City: providers, payers, and clients.

Estimates based on 1980 data indicate that almost two-thirds of the disabled elderly in New York City receive care only from informal sources. Another one-fifth use a combination of informal and formal sources of care. Thus, only about 15 percent are exclusively dependent on various agencies and programs that constitute the formal home care system. Over 200 organizations in 1986 offered some form of home care service in New York City. Among these were at least 100 proprietary businesses, 61 nonprofit personal care agencies, and 36 nonprofit certified home health agencies. In 1984, 166,739 different New York City residents received home care services provided by the four largest types of formal providers of care: certified home health agencies; Long Term Home Health Care Programs; Human Resources Administration home attendant agencies and homemaker/housekeeper agencies; and Department for Aging homemaker/housekeeper programs. While women age 65 and older living alone are the largest client group for home care services, persons below age 65 account for approximately one-fourth of program caseloads of the four major home care providers in New York City. An estimate of one-day home care use in 1984 shows that the four major types of providers served 59,554 persons with total annual expenditures of $499.3 million, while nursing homes cared for 36,072 persons with annual expenditures of almost $1.4 billion. It is thus evident that more people are receiving organized, extended care at home on a given day in New York City than in nursing homes. Medicaid, the major payer for home care in New York City, spent $412.4 million on home care services in 1984, accounting for 82.6 percent of total publicly funded expenditures for home care services. Of this amount, 89 percent was for personal care services provided through the Human Resources Administration's personal care program. More details on home care in New York City follow, along with a discussion of policy perspectives surrounding the provision of and payment for home care services in the future.

Aged↗
PubMed1987

Recurrent cerebral ischemia and mitral valve vegetation in a patient with antiphospholipid antibodies.

A 37-year-old woman presented with a history of acute loss of vision in her left eye and a history of recurrent transient ischemic attacks. Subsequent investigations revealed a prolonged PTT. The lupus anticoagulant and anticardiolipin antibodies (aCL) were identified in her serum. A cardiac murmur was heard and echocardiography demonstrated a mass on the mitral valve. Extensive studies for infection were negative. Cardioembolic phenomena were considered a possible cause of her cerebral ischemic events. The occurrence of nonbacterial endocardial verrucae is well described in systemic lupus erythematosus. The pathogenesis of this lesion remains speculative, however, its occurrence in our patient, with a lupus anticoagulant and aCL suggests a possible association. The clinical manifestations of thrombosis in patients with antiphospholipid antibodies are varied, and may include the development of thrombotic endocardial lesions.

Adult↗
PubMed1987

The use of captopril and captopril plus frusemide as antihypertensive agents in non-insulin dependent diabetes.

After all previous antihypertensive treatment had been stopped, blood pressure and glucose tolerance were measured in 16 hypertensive non-insulin treated diabetics before and again six weeks after treatment with captopril, an angiotensin-converting enzyme inhibitor. Supine blood pressure fell from 184 +/- 4.1/103 +/- 2.6 to 165 +/- 5.2/88 +/- 2.1 mmHg (P less than 0.001) and erect from 179 +/- 5.2/102 +/- 3.2 to 158 +/- 5.6/87 +/- 2.6 mmHg (P less than 0.005). The area under the oral glucose tolerance curve fell from 2313.6 +/- 154 to 2192.8 +/- 146 mmol/min/l (P less than 0.02). There was no change in plasma insulin, total glycosylated haemoglobin or fructosamine. Four patients who failed to show lowering of supine diastolic pressure below 95 mmHg were additionally given oral frusemide with further improvement in blood pressure and no alteration in carbohydrate intolerance. It was concluded that captopril alone is usually an effective antihypertensive agent in non-insulin dependent diabetes with the addition of frusemide benefiting resistant cases. Glucose intolerance did not worsen with either captopril alone or captopril plus frusemide.

Blood Glucose↗