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Biomedical subjects

S Davis

Publications and source records attributed to S Davis.

At least 451 records · Page 25Linked to original sources
PubMed1981

Lactic dehydrogenase in normal and leukemia lymphocyte subpopulations: evidence for the presence of abnormal T cells and B cells in chronic lymphocytic leukemia.

Lactic dehydrogenase (LDH) was quantitated and the isozyme pattern studied in lymphocyte subpopulations from normal people and patients with chronic lymphocytic leukemia (CLL). Normal T lymphocytes differed from normal B lymphocytes in having greater total LDH activity (597.2 versus 252.1). Total LDH activity in CLL T cells (347.1) was lower than normal T cells., but not significantly different than normal B cells. Total LDH activity in CLL B cells (124.6) was lower then normal B cells and normal T cells. The isozyme pattern of normal T lymphocytes showed a higher activity in the LDH-1 band (26.7% versus 5.4%) but showed a lower activity in LDH-5 band (4.3% versus 16.3%) compared to normal B cells. Chronic lymphocytic leukemia T cells could be distinguished from CLL B cells by a high LDH-5 band (22.3% versus 7.6%) and from normal T cells by a high LDH-5 band (22.3% versus 4.3%) and a low LDH-1 band (7.3% versus 26.7%). CLL B cells could be distinguished from normal B cells by a low LDH-5 band (7.6% versus 16.3%). Thus, the LDH isozyme pattern distinguishes normal T lymphocytes from normal B lymphocytes, and normal T and B lymphocytes from CLL T and B lymphocytes.

Adult↗
PubMed1981

Characterization of the phytohemagglutinin-induced proliferating lymphocyte subpopulations in chronic lymphocytic leukemia patients using a clonogenic agar technique and monoclonal antibodies.

Peripheral blood lymphocytes from normal donors and patients with chronic lymphocytic leukemia, B-cell type, were purified into T, helper T, and suppressor T lymphocytes by fluorescence-activated cell sorting using OKT3, OKT4, and OKT8 monoclonal antibodies. The maximum response of the purified subpopulations to stimulation by phytohemagglutinin (PHA) was determined by measuring the production of colonies when the stimulated cells were grown on agar. The helper T cells in normal and CLL patients were the most responsive to PHA stimulation, although the responsiveness of helper T cells to PHA was decreased in CLL. Purified CLL B cells responded minimally to PHA stimulation, but normal B lymphocytes did not. The abnormal response of CLL lymphocytes to PHA appears to be due abnormal helper T cells, and, to a smaller extent, to the ability of CLL B lymphocytes to respond.

Agar↗
PubMed1981

Pharmacology of Escherichia coli-L-asparaginase polyethylene glycol adduct.

The polyethylene glycol (PEG) adduct of Escherichia coli L-asparaginase was administered intravenously to 4 patients with chemotherapy refractory cancers. The PEG-enzyme in plasma exhibited a half-life of 16-25 days. Doses of 250IU/m2 or greater reduced plasma asparagine to undetectable levels for as long as enzyme was detectable in plasma. All doses of enzyme administered (250-1000 IU/m2) caused similar increases in plasma aspartate, i.e. no dose-response relationship. Pleural fluid and ascites contained detectable enzyme but at a value 10-15% of simultaneously drawn plasma levels. Toxicity in this small group of patients was minimal; nausea and transient fever predominated. There were no clinical signs of PEG-asparaginase-induced pancreatitis, renal dysfunction, hypocalcemia and hyperglycemia. No patient developed evidence of a PEG-asparaginase allergic reaction; no patient formed antibodies to asparaginase or PEG-asparaginase. Two patients with large cell lymphoma showed a partial response to treatment.

Antineoplastic Agents↗
PubMed1981

Knowledge and use of "alternative" cancer therapies in children.

Because of the increased interest in laetrile and other "alternative" cancer therapies among cancer patients and the lack of data concerning knowledge and use of such treatments in childhood cancer, parents of children diagnosed with cancer in 1977 and 1978 at a major pediatric oncology center were surveyed. Eight different "alternative" therapies or groups were known by 50% of parents. Seventeen of 106 children had received an "alternative" cancer treatment. News media were the most frequent initial information source. Accuracy of knowledge of toxic effects of laetrile was poor, with only 26.4% realizing poisoning was possible. Parents who felt desperation in their search for a cure and were looking for an easier treatment method, and those who were dissatisfied with their role in making treatment decisions, appeared at greatest risk of seeking "alternative" therapies. Over 56% of parents wanted more information about cancer and its treatment, with written information favored by almost 40%.

Adolescent↗
PubMed1981

Alteration of the circulating life and antigenic properties of bovine adenosine deaminase in mice by attachment of polyethylene glycol.

Polyethylene glycol was attached covalently to adenosine deaminase (ADA) using cyanuric chloride as the coupling agent. The modified adenosine deaminase (PEG-ADA) appears to lose its immunogenicity in mice following multiple intravenous injections. PEG-ADA does not react with antibodies raised against native ADA. The circulating half-life (T1/2) of PEG-ADA was increased to 28 hr. The lack of detectable antibody formation and long circulating life may make PEG-ADA suitable for treating human ADA deficiency.

Adenosine Deaminase↗
PubMed1981

Continuing education in cancer for the community physician: design and evaluation of a regional table of contents service.

The Arnold Library of the Fred Hutchinson Cancer Research Center offered two groups of practicing physicians in nonmetropolitan areas of the Pacific Northwest an opportunity to review regularly their choice of eighteen cancer journal tables of contents with the added provision (in compliance with federal copyright laws) of being able to receive any articles of interest at no charge from the library. Forty-nine (38.9%) of the 126 physicians selected chose to participate in the program. Of these, 20 (40.8%) actually requested articles from the service. After six months of the service, all of the original 126 physicians were queried by questionnaire. Those who used the service felt it helped in their practice of medicine and that it should be continued. Those who chose not to receive the service generally had access to the eighteen journals elsewhere or saw very few cancer patients. A majority of the articles which had been requested emphasized patient treatment. Approximately 25% of one library technician's time and $360 for photocopy and mailing costs were required to operate the service for forty-nine physicians for six months. The service seemed to identify a select audience of regular users who perceived a benefit from its use.

Community Medicine↗
PubMed1980

Incidence of retinoblastoma in the United States.

Data from the population-based Surveillance, Epidemiology, and End Results Program of the National Cancer Institute were used to calculate the incidence of retinoblastoma for the years 1974 through 1976. Each year 3.58 cases occurred for each million children under the age of 15 years. Incidence was markedly age related, with over 90% of the cases being diagnosed before the age of 5 years. Although no difference in incidence was found for whites and blacks, other nonwhites had rates greater than four times those of whites. Twenty percent of patients had bilateral disease. Treatment patterns revealed that surgery remains the most common treatment modality. Review of patterns of survival suggested that children in the other nonwhites category with unilateral disease had poorest survival rates.

Adolescent↗
PubMed1980

The plain abdominal radiograph in acute pancreatitis.

The radiographs of 100 patients with acute pancreatitis were reviewed and compared with 100 controls by two radiologists and a surgeon. Our aim was to assess the frequency and usefulness of the signs described in the literature. Calcification of the pancreas was seen in one case only. Abnormalities of the biliary tree (visible gallbaldder, biliary gas and gallstones) were seen in 10%. The left psoas shadow was more frequently absent in the pancreatitis series. Paucity of gastrointestinal gas although observed in 12 cases was ascribed to vomiting. A more important sign was the gaseous outline of an adynamic duodenal loop which was seen in half of the patients examined in the left lateral decubitus position. Dilated jejunum was seen in 31 cases, associated with sentinel loops in 10 and multiple fluid levels in 25 patients. Dilatation of thet ransverse colon was the most constant colonic sign (18%), but the colon 'cut-off' sign was not seen. It was concluded that the most prominent signs in order of importance are a gaseous distension of the duodenal loop, gas in the duodenal cap, a dilated transverse colon and the sentinel loop. The gasless abdomen is a striking but rare sign and in our series was always associated with severe pancreatitis.

Acute Disease↗
PubMed1980

A study of partial thiamin restriction in human volunteers.

A double blind study of partial thiamin restriction was undertaken in 19 volunteer male medical students for a period of 4 to 5 weeks. Each day the subjects followed a diet supplying 500 micrograms thiamin and took 1 capsule randomly assigned to contain 5 mg thiamin hydrochloride or thiamin placebo. This capsule also supplied physiological doses of other vitamins. At the end of the study all were repleted with thiamin hydrochloride. Ten thiamin-depleted subjects were correctly identified by low urinary thiamin excretion, decreasing erythrocyte transketolase activity, and elevation of the thiamin pyrophosphate effect. The remaining nine subjects were controls. The degree of thiamin depletion induced varied between individuals and had no measurable ill effect on health as assessed by subjective feelings, physical findings, psychological testing, nerve conduction studies, and work performance. Subclinical thiamin deficiency is defined from this study as the presence of a low urinary thiamin level (27 microgram thiamin/g creatinine) together with a thiamin pyrophosphate effect above 14.2% and below 35.4%. However, when urinary thiamin excretion is unknown, the data indicate that a thiamin pyrophosphate effect above 9% and below 41.6% is likely but not certain to represent subclinical thiamin deficiency. These guidelines, developed under experimental conditions, are a reference framework for assessment of thiamin status in population groups but should be applied with caution to individuals and to people with disease.

Adolescent↗
PubMed1980

Null cell (non-T, non-B) acute lymphoblastic leukemia terminating as malignant histiocytosis.

A case of null cell acute lymphoblastic leukemia (ALL) terminating in malignant histiocytosis (HMR) is discussed. The patient was a 22-year-old man who presented in January 1976 with ALL. Cell surface markers on the bone-marrow blasts showed that 1% formed rosettes with sheep erythrocytes (T cells) and 4% showed immunofluorescent staining for immunoglobulin; terminal transferase levels were elevated, confirming the diagnosis of null cell ALL. The patient was treated intensively with a combination of chemotherapy and cranial irradiation. One year after diagnosis, he was maintained in partial relapse (10-15% blasts). His terminal episode was characterized by pancytopenia. The bone marrow was replaced by malignant histiocytes. Cell surface membrane staining for cytophilic antibody was positive, whereas terminal transferase levels were in the range of nonlymphoid malignancies.

Acute Disease↗
PubMed1980

17 beta-hydroxysteroid dehydrogenase deficiency in malignant interstitial cell carcinoma of the testis.

A partial defect in testosterone (T) secretion due to a 17 beta-hydroxysteroid dehydrogenase deficiency has been documented in a patient with advanced metastatic interstitial cell carcinoma of the testis. Basal serum T was decreased (83 ng/ml), whereas androstenedione was markedly elevated (847 ng/ml). Dehydroepiandrosterone sulfate and estrone were moderately increased, while LH, FSH, and estradiol were minimally increased. After hCG administration, androstenedione rose to much greater degree than T. Fluoxymesterone failed to suppress circulating androgens and estrogens to below basal values, although LH and FSH were suppressed to immeasurable levels. These data support a partial enzyme deficiency within the tumor. They also suggest that although the tumor was autonomous, it still was capable of being stimulated by exogenous gonadotropins.

17-Hydroxysteroid Dehydrogenases↗