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Biomedical subjects

A Fink

Publications and source records attributed to A Fink.

At least 127 records · Page 7Linked to original sources
PubMed1985

Effect of size and density on canine gastric emptying of nondigestible solids.

Previous studies suggested that the food-containing canine stomach retains large, nondigestible spheres until all food has emptied; but it is not known whether there is a threshold size or a gradation of sizes that will empty along with food. Further, nothing is known of the effects of such parameters as density, shape, and surface energy on the emptying of nondigestible particles of any given size. To answer these questions 6 dogs with chronic duodenal fistulas were studied. Radiolabeled food and spheres were collected from the fistulas to compare the rate of gastric emptying of the spheres with that of the food. After a standard test meal of 99mTc-labeled liver, steak, and water, diverted chyme was collected over a stack of sieves in 30-min fractions over 5 postcibal hours. The percent of fed spheres and fed 99mTc-labeled liver in each collection was counted, and liquid chyme was returned to the distal duodenum. Spheres with a density of 1 emptied progressively faster as sphere diameters were decreased from 5 to 1 mm; but 0.015-mm spheres emptied at about the same rate as those with diameters of 1 mm. Emptying of the spheres became similar to emptying of the 99mTc-labeled liver at about 1.6 mm. Spheres with densities less than 1 or greater than 1 emptied more slowly than spheres of the same size with a density of 1, whereas paper squares emptied the same way as spheres of comparable size and density. Surface energy did not affect emptying. The findings indicated that both sphere size and density affect their emptying in the presence of food.

Animals↗
PubMed1985

Leukocyte adherence inhibition (LAI) for detecting specific tumor immunity in colorectal cancer.

Immunity to colorectal cancer antigen was tested by the tube leukocyte adherence inhibition (LAI) assay, using spent medium of human carcinoma cell lines as a source of antigen. The assay was positive in 18 out of 43 patients (41%) with colorectal tumor in comparison to only 2 out of 34 (5.8%) of colorectal cancer patients clinically free of disease, and to 4 out of 150 (2.6%) healthy subjects. The frequency of positive results correlated negatively with the tumor burden, 16 out of 29 (55.1%) patients with Dukes' A, B and C being positive compared to only 2 out of 14 (14.2%) patients with Dukes' stage D disease. Addition of PGE2 enhanced the sensitivity of the assay without affecting its specificity. The number of positive assays increased from 18 to 32 (41.8% to 74.4%) in the whole group of 43 colorectal cancer patients without altering significantly the frequency of positive results in the control group. The results with all groups of patients were influenced similarly by the addition of prostaglandins, the frequency of positive assays increasing from 55.1% to 82.7% and from 14.1% to 57.1% in early and advanced disease, respectively. These results lend further support to the value of the LAI assay in diagnosis and monitoring of the immune response in human colorectal cancer.

Antigens, Neoplasm↗
PubMed1985

Interferon modulates the leukotriene C4-induced non-adherence properties of leukocytes: acquisition of an asthmatic phenotype.

We have previously shown that peripheral blood leukocytes (PBL) of asthmatic patients acquire non-adherence properties after challenge with leukotriene C4 (LTC4), whereas PBL of normal individuals do not. Hence the use of the LTC4-induced leukocyte-adherence-inhibition (LAI) assay enables one to recognise an asthmatic phenotype on the basis of the ability of PBL to respond in vitro to LTC4. To examine the possibility that alpha interferon (IFN alpha) may have relevance to the pathogenesis of bronchial asthma, various concentrations of IFN were incubated with normal PBL and the acquisition of non-adhering properties was measured. We found that following 24 h incubation with 500 U/ml IFN, normal PBL were induced to respond to a standard dose of LTC4, and this reaction was abrogated by FPL 55712 and cyclohexamide.

Adult↗
PubMed1985

Leukotrienes (LTC4, LTD4) confer glass non-adherence on leukocytes of asthmatic individuals. Dependency on cyclooxygenase products and calcium ion.

It has been suggested that cysteinyl-containing leukotrienes (LT) are important mediators in bronchial asthma. Since leukotrienes have been shown to mediate the leukocyte adherence inhibition (LAI) phenomenon observed in cancer-bearing host we have devised a modified LAI assay which determines the acquisition of non-adherence properties of leukocytes following a challenge with pure synthetic LT. Our results demonstrate that peripheral blood leukocytes of asthmatic individuals acquire non-adherence properties when challenged with pure synthetic leukotriene C4 and D4, a property not shared by peripheral blood leukocytes of control healthy individuals. Furthermore, we demonstrate that LT activity as manifested by the LAI assay is dependent on cyclooxygenase products, since 2 X 10(-6) M Indomethacin abrogated the LT-induced LAI and is restored by the addition of 2 X 10(-6) M prostaglandin E2 which is also synergistic to LT activity. Our results further suggest the possibility that leukotriene activity is dependent on calcium ions since it was negated by known calcium antagonists. It is thus suggested that the LT-induced LAI may serve as a tool for the study of the interrelationship between the metabolic pathways of arachidonic acid and calcium ion homeostasis.

Asthma↗
PubMed1985

Physician and patient satisfaction as factors related to the organization of internal medicine group practices.

The present study compares patient satisfaction scores with job satisfaction scores of the physicians providing their care in 16 general internal medicine teaching hospital group practices. Practice sites with more satisfied patients were also more likely to have more satisfied housestaff and faculty physicians. Additionally, higher satisfaction scores for both physician groups and patients were consistently associated with a greater percentage of patients experiencing continuity of care, lower patient no-show rates, more efficient use of ancillary staff in providing direct patient care, and more reasonable charges for a routine follow-up visit. These findings suggest that improving physician and patient satisfaction may have economic as well as psychological and social benefits.

Consumer Behavior↗
PubMed1985

General medical care and the education of internists in university hospitals. An evaluation of the teaching hospital general medicine group practice program.

Fifteen general internal medicine group practices in university teaching hospitals were studied to evaluate their primary care services and education. Data were collected over 9 months from physicians, patients, and medical records, and by observation. All institutions had closed their general medical clinics. Many patients being treated in group practices were very sick; 57% had hypertension; 21% were diabetic; and 45% could not work. Most were satisfied with their care. Care for acute problems from a health care provider in the practice was available quickly; regular physicians were harder to see. House staff and faculty spent little time in the practices. Few practices used teams; most used traditional attending and house staff models. Practice physicians could not easily determine when patients were seen in the institution's emergency department or were hospitalized. Quality of care standards were not uniformly met. Finally, the structure of academic centers appeared to inhibit the practices' performance, suggesting a need for further appraisal of relationships between university hospitals and their ambulatory care units.

Appointments and Schedules↗
PubMed1985

A computerized tube leukocyte adherence inhibition assay in the diagnosis of human lung cancer.

A computerized tube LAI assay was used to determine the antitumor immune response in lung cancer patients. A standardized assay was established by the use of tumor antigen recovered from the spent medium of lung and colon adenocarcinoma cell lines. Furthermore, modulation of the assay by prostaglandin E2 (PGE2) was used to increase its sensitivity. Of 65 patients with epidermoid lung cancer, 34 (52.3%) had a positive nonadherence index (NAI). The NAI was inversely related to tumor burden, with 31 of 44 (70.6%) patients with lung cancer stages I and II and only 3 of 21 (14%.2%) patients with stage III having positive assays (greater than 30%). Addition of PGE2 to the as say increased the overall sensitivity so that a positive NAI was obtained in 88.6% of patients with lung cancer stages I and II, and 88.6% with stage III, respectively. Of 174 individuals from the control group, positive NAI was found in only 9 and 3.8% of patients with chronic obstructive pulmonary disease and normal controls, respectively. These results support previous observations on the specificity and sensitivity of the LAI assay in the diagnosis and study of human cancer.

Antigens, Neoplasm↗
PubMed1985

Is common variable hypogammaglobulinemia linked to HLA? A family study.

Two patients with common variable hypogammaglobulinemia (CVH) and their families, who came from different ethnic backgrounds, were surveyed for the level of immunoglobulins (Ig) and HLA genotypes. Six of 10 siblings and the mother in one family had a decreased level of one of the major classes of Ig (IgA in 5, IgM in 1 and IgG in the mother). A similar decrease was found in three of six siblings in the other family (IgG in one, IgA in one and IgM in one). HLA genotyping disclosed that affected and nonaffected family members had identical genotypes, suggesting that hypogammaglobulinemia in CVH is not linked to a specific HLA genotype.

Adolescent↗
PubMed1985

Cromolyn prevents bronchospastic attacks caused by Bacillus Calmette Geurin immunotherapy for malignant melanoma patient.

Bacillus Calmette Geurin (BCG) skin immunization is an adjuvant therapy for malignant melanoma patients. Adverse reactions to BCG skin immunization therapy are not uncommon and usually present as fever, influenza-like syndrome, pruritus skin rash, ulcers at the injection site, regional lymphadenopathy, and liver dysfunction. To our knowledge, a bronchospastic BCG immunotherapy-related attack has not yet been reported. We present a case of a patient with malignant melanoma who developed an unusual reaction during BCG immunotherapy. He developed asthma-like attacks after treatment, which could be prevented by inhalation of Cromolyn prior to and after therapy.

BCG Vaccine↗
PubMed1984

Consensus methods: characteristics and guidelines for use.

Consensus methods are being used increasingly to solve problems in medicine and health. Their main purpose is to define levels of agreement on controversial subjects. Advocates suggest that, when properly employed, consensus strategies can create structured environments in which experts are given the best available information, allowing their solutions to problems to be more justifiable and credible than otherwise. This paper surveys the characteristics of several major methods (Delphi, Nominal Group, and models developed by the National Institutes of Health and Glaser) and provides guidelines for those who want to use the techniques. Among the concerns these guidelines address are selecting problems, choosing members for consensus panels, specifying acceptable levels of agreement, properly using empirical data, obtaining professional and political support, and disseminating results.

Decision Making↗
PubMed1984

Exacerbation of asthmatic symptoms after cessation of nifedipine therapy.

Marked improvement in the respiratory status of two patients with chronic obstructive lung disease was observed during treatment with nifedipine for angina pectoris. Cessation of the drug led to an exacerbation of asthmatic symptoms in both patients which necessitated initiation of bronchodilator therapy. Nifedipine is a known calcium antagonist and as such it has been suggested that it diminishes the transmembrane penetration of calcium ion into bronchial smooth muscle cells and mast cells, thus leading to bronchial muscle relaxation and less mediator release. The complication of increased asthmatic symptoms after cessation of nifedipine therapy has not been previously emphasized and should be taken into account while treating patients with known obstructive airway disease.

Aged↗
PubMed1982

Modulation of antigen-induced leukocyte adherence inhibition by metabolites of arachidonic acid and intracellular nucleotides.

After binding a sensitizing tumor antigen, human leukocytes undergo a series of changes that lead to a loss of their glass-adherent properties; a phenomenon called leukocyte adherence inhibition (LAI). After surgery or when patients have a large tumor burden, their test results become negative. This study shows that in vitro incubation of the leukocytes for 5 min with PGE2 converted to positive the negative test, in an immunologically specific manner. The effect was critically dose-dependent, too little or too much did not alter the result. The same effect was achieved with PGE2, PGI2, aminophylline or other drugs that raise intracellular nucleotides, including dibutyryl cyclic AMP and dibutyryl cyclic GMP. Dibutyryl cyclic AMP stimulated a stronger response and 100 times less was needed than of dibutyryl cyclic GMP. Prostaglandins did not mediate LAI since Indomethacin failed to inhibit a positive test. Nonetheless, arachidonate metabolites were critical for the LAI phenomenon since BPB and mepacrine, inhibitors of phospholipase A2, negated the LAI response. Moreover, ETYA, phenidone and NDGA, inhibitors of the lipoxygenase metabolic pathway, all negated the positive LAI response. The positive response was especially sensitive to nullification by ETYA. Although the last-named drugs inhibit other arachidonate metabolic pathways too, conclusive evidence that the metabolites of the lipoxygenase pathway, and leukotrienes in particular, mediate the LAI response was the fact that FPL 55712, a competitive antagonist of SRS, nullified a positive response at levels as low as 10(-13) M. The results imply that prostaglandins were able to modulate the expression of LAI by affecting intracellular nucleotides, but leukotrienes, it seems, were the metabolites that mediated leukocyte nonadherence after monocytes recognized and bound tumor antigen.

Antigens, Neoplasm↗
PubMed1982

Studies in geriatric education: II. educational materials and programs.

There has recently been an increase in educational programs and materials in geriatrics, but their quality and content have not been adequately assessed. This study concerns important objectives and core contents in geriatric education, with a review of training programs, books, and audiovisual materials. Specific areas of need for printed and audiovisual materials are identified. Medical student and graduate level programs were found to address relatively few objectives. Geriatric fellowship programs, although having more extensive coverage, had some notable deficiencies. This information may be of use to those conducting training programs or preparing educational material in geriatrics.

Aged↗