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Biomedical subjects

S Bates

Publications and source records attributed to S Bates.

At least 109 records · Page 6Linked to original sources
PubMed1986

Autocrine and paracrine growth regulation of human breast cancer.

Previous work from our laboratory has demonstrated that human breast cancer (BC) cells in culture can be stimulated by physiologic concentrations of estrogen. In an effort to further understand this process, we have examined the biochemical and biological properties of proteins secreted by human BC cells in vitro. We have developed a defined medium system which simultaneously allows the collection of factors secreted by the BC cells, facilitates their purification and allows for an unequivocal assay of their effect on other BC cells. By both biochemical and radioimmunoassay procedures, MCF-7 cells secrete large quantities of IGF-I-like activity. The cells contain receptors for IGF-I and are stimulated by physiologic concentrations of IGF-I. Multiple additional peaks of growth stimulatory activity can be obtained by partial purification of conditioned media from human BC cells by sequential dialysis, acid extraction and Biogel P60 chromatography. These peaks are induced up to 200-fold by physiologic concentrations of estrogen. Several of these peaks cross-react in a radioreceptor assay with EGF and are thus candidates for transforming growth factors. Monoclonal antibodies (MCA) have been prepared which react with secreted proteins from the MCF-7 cells. One of these MCAs binds to material from MCF-7 and ZR-75-1 hormone-dependent BC cells only when these two lines are treated with estrogen but reacts with conditioned medium from several other hormone-independent cell lines in the absence of estrogen stimulation. This MCA is currently undergoing further characterization and evaluation of its biological potency. We conclude that with estrogen stimulation, hormone-dependent human BC cells secrete peptides which when partially purified can replace estrogen as a mitogen. Their role as autocrine or paracrine growth factors and their effects on surrounding nonneoplastic stroma may suggest a means of interfering with tumor proliferation.

Animals↗
PubMed1985

Myelopathy following intrathecal chemotherapy in a patient with extensive Burkitt's lymphoma and altered immune status.

A 30-year-old homosexual man presented with widespread Burkitt's lymphoma. On the basis of immunologic and viral studies, he was suspected of having the acquired immune deficiency syndrome. Following chemotherapy that included intrathecal cytosine arabinoside and methotrexate, brain stem edema, paraplegia, and an elevated cerebrospinal fluid level of myelin basic protein developed. Autopsy revealed vacuolar demyelination of spinal cord, brain stem, and cerebellum. The pathologic findings were similar to those reported to occur in myelopathy associated with intrathecal chemotherapy, but far more extensive. The contribution of the suspected acquired immune deficiency syndrome is unknown.

Acquired Immunodeficiency Syndrome↗
PubMed1985

Dyspepsia. Definition and discussion of nomenclature.

Dyspepsia stands for a constellation of symptoms referrable to the upper gastrointestinal tract. However, the term dyspepsia is too vague to be useful in scientific work unless critically defined. In many cases dyspepsia coincides with the irritable bowel syndrome. An increased use of endoscopy and the possibility of prompt symptom relief in peptic ulcer by treatment with H2-receptor antagonists have focused the interest on patients with ulcer-like dyspepsia but in whom there is no evidence of ulcer disease. This large group of patients deserves further nosologic classification and there is a strong need of pathophysiologic and interventional studies.

Colonic Diseases, Functional↗
PubMed1985

Registration of pain in a psychological perspective.

Registration of pain must take into consideration the private nature of the pain experience while providing researcher and practitioner with measures which obtain satisfactory levels of compliance, reliability and sensitivity. A three-component model of pain based on social learning theory, comprised of physiological, cognitive/affective and overt behavioural dimensions has been shown to be a valuable tool in monitoring pain. Applications of the model show that it has satisfactory methodological characteristics when used in a study with continuous self-recording by patients, that it can accommodate discrepancies in physiological and affective dimensions and that it offers a variety of sensitive measures for evaluating treatment of pain.

Data Collection↗
PubMed1984

Two individuals with elliptocytic red cells apparently lack three minor erythrocyte membrane sialoglycoproteins.

We have studied the erythrocytes of two individuals (P. L. and K. W.) who lack the Gerbich (Ge) blood-group antigen. The erythrocytes of P. L. and K. W. were not reactive with two monoclonal antibodies (NBTS/BRIC 4 and NBTS/BRIC 10) which reacted with normal erythrocytes. The membranes of P. L. and K. W. erythrocytes appeared to lack three minor sialoglycoproteins (beta, beta 1 and gamma). These three minor sialoglycoproteins were found to be associated with the cytoskeletons of normal erythrocytes. Approx. 10% of the erythrocytes of P. L. and K. W. were frankly elliptocytic. We suggest that one or more of the minor sialoglycoproteins may play a part in maintaining the discoid shape of the human erythrocyte.

Blood Group Antigens↗
PubMedDate not supplied

Artifacts in functional magnetic resonance imaging from gaseous oxygen.

Unexpectedly large fluctuations in signal intensity were identified in the functional MRI (FMRI) of normal subjects breathing pure oxygen intermittently. To test the hypothesis that the signal changes were due to fluctuating concentrations of gaseous (paramagnetic) oxygen in the magnetic field, echo planar gradient echo images were acquired of a phantom contiguous to an oxygen mask through which pure oxygen was administered intermittently via plastic tubing. As a control, room air was administered intermittently or oxygen continuously in the same experimental protocol. Signal intensity changes of up to 60% temporally correlated with the administration of oxygen were produced in the phantom. In functional images prepared from the echo planar images, the signal intensity changes resulted in artifacts especially at interfaces in the phantom. The intermittent administration of pure oxygen during acquisition of data for FMRI may produce signal intensity changes that stimulate or obscure function.

Artifacts↗
PubMedDate not supplied

Childhood-onset depressive disorders. A follow-up study of rates of rehospitalization and out-of-home placement among child psychiatric inpatients.

This report describes preliminary outcome data for a sample of child psychiatric inpatients with diagnoses of major depression and/or dysthymic disorder at the time of their hospitalizations. Depressed children were compared with a contrast group of children with schizophrenia spectrum disorders. Results (based on semi-structured telephone interviews) indicate high rates of rehospitalization among our depressed cohort. Depressed children had rehospitalization rates of 35% and 45% respectively in the first and second years after discharge. Out-of-home placement was rarer in the depressed group, and significantly less likely than for children with schizophrenia spectrum disorders. However, 15% of the depressed cohort were placed out of their homes within the first year of discharge. There were no differences between children with major depressive and dysthymic disorders on these outcome variables, underscoring the serious long-term correlates of childhood dysthymic as well as major depressive disorders.

Antidepressive Agents↗
PubMedDate not supplied

Structural and functional changes of rhesus serum low density lipoproteins during cycles of diet-induced hypercholesterolemia.

Over the course of a 2-year study, two male rhesus monkeys underwent episodes of diet-induced hypercholesterolemia (from a diet supplemented with 25% coconut oil and 2% cholesterol) followed by regression phases in which the animals received a low fat Purina chow diet. During the induction of hypercholesterolemia, serum cholesterol, apo B, saturation of low density lipoprotein (LDL) cholesteryl ester fatty acyl chains, and the ability of the serum to stimulate cholesterol esterification by smooth muscle cells rose immediately and in parallel, whereas there was a lag period before the serum became mitogenic to smooth muscle cells. Concurrently, there were important changes in the density, size, chemistry, and concentration of the LDL species in the rhesus serum; induced LDL shifted from the LDL-II to the LDL-I density region with increasing cholesterol concentration. Both structural and functional changes were reversed upon return to a normal Purina chow diet, although at different rates. Serum cholesterol, apo B, and the rate of cholesterol esterification in smooth muscle cells promoted by the serum declined in parallel while the mitogenicity of the serum to smooth muscle cells and the degree of saturation of LDL cholesteryl ester fatty acids took longer to return to normal values. In fact, there was an immediate and dramatic rise in saturation upon reversal before the LDL cholesteryl ester fatty acyl chains returned to their normal composition. The Lp(a) particles did not increase in either concentration or size in response to the test diet, although the change in their lipid composition was similar to those of the other LDL species. The studies indicate that dietary manipulations affect the physicochemical properties of the LDL particles, and that the resultant structural alterations are accompanied by changed in vitro cellular response, suggestive of a greater atherogenicity.

Animals↗
PubMedDate not supplied

Cerebrovascular arteriopathy (arteriosclerosis) and ischemic childhood stroke.

The aim of this report is to describe the intracranial cerebrovascular abnormalities and clinical status of 8 children who had familial lipoprotein disorders and evidence of thromboembolic cerebrovascular disease. Six of the 8 children had low levels of plasma high density lipoprotein cholesterol, two had high triglyceride levels, and all came from kindreds characterized by familial lipoprotein abnormalities and premature cardio- and/or cerebrovascular atherosclerosis. Vascular occlusion, irregularities of the arterial lumen, beading, tortuosity, and evidence of collateralization were consistently noted. We speculate that cerebrovascular arteriosclerosis in pediatric ischemic stroke victims who have familial lipoprotein abnormalities may be related to lipoprotein-mediated endothelial damage and thrombosis formation, or to the failure to restore endothelial cells' integrity following damage. The apparent association of lipoproteins and strokes in children and their families merits further exploration, particularly when assessing cerebral angiograms in pediatric ischemic stroke victims. In children with unexplained ischemic cerebrovascular accidents, the diagnostic possibility of occlusive arteriosclerosis with thrombosis must be entertained.

Adolescent↗
PubMedDate not supplied

Plasma glucose response to recreational diving in novice teenage divers with insulin-requiring diabetes mellitus.

A growing number of individuals with insulin-requiring diabetes mellitus (IRDM) dive, but data on plasma glucose (PG) response to diving are limited, particularly for adolescents. We report on seven 16-17 year old novice divers with IRDM participating in a tropical diving camp who had recent at least moderate PG control (HbA1c 7.3 +/- 1.1%) (mean +/- SD). PG was measured at 60, 30 and 10 min pre-dive and immediately following 42 dives. Maximum depth (17 +/- 6 msw) and total underwater times (44 +/- 14 min) were not extreme. Pre-dive PG exceeded 16.7 mmol x L(-1) (300 mg x dL(-1)) in 22% of dives. Males had significantly higher pre-dive levels (15.4 +/- 5.6 mmol x L(-1) [277 +/- 100 mg x dL(-1)] vs. 12.8 +/- 2.9 mmol x L(-1) [230 +/- 52 mg x dL(-1)], respectively) and greater pre-post-dive changes (-4.3 +/- 4.4 mmol x L(-1) [-78 +/- 79 mg x dL(-1)] vs. -0.5 +/- 4.3 mmol x L(-1) [-9 +/- 77 mg x dL(-1)], respectively). Post-dive PG was < 4.4 mmol x L(-1) [< 80 mg x dL(-1)] in two dives by two different males (3.4 and 3.9 mmol x L(-1) [61 and 70 mg x dL(-1)]). No symptoms or complications of hypoglycemia were reported. These data show that in a closely monitored situation, and with benign diving conditions, some diabetic adolescents with good control and no secondary complications may be able to dive safely. The impact of purposeful elevation of PG to protect against hypoglycemia during diving remains to be determined.

Adolescent↗
PubMedDate not supplied

Optimal insulin delivery in adolescents with diabetes: impact of intensive treatment on psychosocial adjustment.

The psychosocial effects of recent advances in the management of diabetes mellitus are unknown and could conceivably be adverse, particularly during the critical period of adolescence. Seven teenagers were evaluated by standard psychosocial scales and a detailed questionnaire before and on completion of a 6-mo intensive management program utilizing home glucose monitoring and multiple injections or the insulin infusion pump. All achieved improved metabolic control with inpatient glucose values (during 24-h monitoring) falling from 244 +/- 58 to 108 +/- 10 mg/dl, glycosylated hemoglobin levels falling from 11.8 +/- 2.9% to 8.4 +/- 1.7%, and home glucose levels averaging 121 +/- 16 mg/dl. Standardized scales evaluating depression, diabetic adjustment, self-esteem, and social adjustment indicated no deterioration in psychosocial functioning. There was a statistically significant increase in locus of control scores, suggesting an improved sense of internal control of life events. The program questionnaire revealed a positive response to both the program and the control devices used. This study suggests that the positive metabolic benefits of intensive diabetic management during adolescence are not offset by adverse psychosocial effects and indeed positive psychosocial benefits may result.

Adaptation, Psychological↗