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Biomedical subjects

C Matthews

Publications and source records attributed to C Matthews.

At least 73 records · Page 4Linked to original sources
PubMed1987

Changes in transplanted kidney volume measured by ultrasound.

A simple ultrasonic method was used for measuring transplanted kidney volume in 29 patients. Five of these patients developed diabetes mellitus and six women became pregnant following transplantation. Serial measurements were performed over periods of 6-12 months after transplantation. The kidney volume became stable 6 months after transplantation and this volume correlated positively with the renal function. Renal hypertrophy was noted in those transplant patients who developed diabetes mellitus following transplantation and this hypertrophy was associated with improvement in graft function. Transplant volume also rose in acute rejection and returned to normal after appropriate treatment. During pregnancy following transplantation, the transplant volume increased early in pregnancy to return to normal before delivery. This volume increase was also associated with graft function improvement.

Diabetes Complications↗
PubMed1986

A human retinoblastoma cell line expressing the common acute lymphoblastic leukemia antigen and displaying an unusual chromosome abnormality.

A new continuous cell line derived from an untreated human retinoblastoma has been established. This cell line, FMC-RB1 is strongly positive for common acute lymphoblastic leukemia antigen and shows a number of ring chromosomes and two marker chromosomes considered to be derivations of chromosome #17; the nonrandom chromosomal changes associated with retinoblastoma, particularly the loss of a chromosome #13 or the deletion of 13q14 was not observed. The establishment of the cell line initially required the presence of bone marrow stromal cells. Morphologically, this cell line grew as a suspension of small round cells in grape-like clusters with periodic "shedding" of single cells. FMC-RB1 could be cloned in soft agar, even in the absence of bone marrow stromal cells as "feeders", making it suitable for a variety of biological studies.

Antigens, Neoplasm↗
PubMed1986

1,25-Dihydroxyvitamin D maintains bone cell activity, and parathyroid hormone modulates bone cell number in dogs.

The singular and combined effects of 1,25-dihydroxyvitamin D [1,25-(OH)2D] and PTH on bone were evaluated in a long term in vivo study in dogs. Dogs were rendered deficient in 1,25-(OH)2D and PTH by five sixths nephrectomy and parathyroidectomy. A control group was sham operated. Various combinations in status of 1,25-(OH)2D and PTH were produced by daily sc injections of 1,25-(OH)2D (1.25) and/or continuous infusion of 1-34 bovine PTH. These were 1.25+/PTH+, 1.25-/PTH-, 1.25+/PTH-, 1.25-/PTH+. Serum calcium levels were kept in the normal range by the administration of one or two of the hormones or by oral supplementation of calcium lactate. Histomorphometric evaluation of static and dynamic parameters of bone after 8 months of experimental observation revealed that deficiency in 1,25-(OH)2D and PTH resulted in decreased number and activity of bone-forming and resorbing cells. Administration of 1,25-(OH)2D increased the activity but not the number of bone cells. In contrast, administration of PTH increased the number but not the activity of bone cells. Tissue level activity was decreased when one or both hormones were deficient, and normal tissue level activity was found only when both hormones were given. These data are relevant for understanding and management of diseases with perturbations in vitamin D and/or PTH.

Animals↗
PubMed1985

Factors influencing return to work following cerebral infarction.

A study of 379 patients, employed before cerebral infarction and living one year afterward, was undertaken to determine what factors had influenced their returning to work. We found age, occupation, degree of disability, race, and hemisphere infarcted to be significant. Younger patients with less disability were more likely to return to work. Patients employed in professional-managerial positions were more likely to return to work than patients in blue-collar or farming positions. Although there were no racial differences following a left-hemisphere infarct, white patients were more likely to return to work following a right-hemisphere infarct. Sex, blood pressure, severity of stroke, educational level, consciousness level at admission, maximum weakness in extremities, first v repeated stroke, care by a specially trained stroke team, rehabilitation therapy, and speech did not additionally influence the probability of returning to work.

Age Factors↗
PubMed1985

FMC-HU-1-B: a lymphoma B-cell line with unusual characteristics.

A cell line (FMC-Hu-1-B) was established from a biopsy of an abdominal mass of a child with non-Burkitt's lymphoma. The establishment of the cell line initially required the presence of normal bone marrow stromal cells and phytohaemagglutinin stimulated leucocyte conditioned medium. The cell line lacked Epstein-Barr virus nuclear antigen and exhibited numerous chromosomal abnormalities. Cell-surface marker analysis using a panel of monoclonal antibodies revealed only markers of the B lineage. Within the B-cell lineage FMC-Hu-1-B seemed to occupy a level of maturation equivalent to normal mature B-cells (surface membrane IgM, secretion of immunoglobulin and FMC-1 positive). However, the cells also weakly expressed the common acute lymphoblastic leukaemia antigen, normally found on early precursors of B-cells. The cells appear to secrete auto-stimulatory growth factor(s).

B-Lymphocytes↗
PubMed1985

Age-dependent lidocaine disposition in patients with acute myocardial infarction.

To evaluate age-dependent changes in lidocaine disposition in patients with acute myocardial infarction, we measured plasma concentrations of lidocaine and its metabolites monoethylglycinexylidide and glycinexylidide after discontinuation of a maintenance lidocaine infusion. Plasma lidocaine clearance was calculated by dividing the lidocaine concentration at the end of the infusion into the maintenance infusion rate. Lidocaine clearance in 35 patients was related to body weight and was reduced by heart failure. Heart failure was more common in the elderly, occurring in 15 of 27 (56%) patients over 65 years old and seven of 29 (24%) patients under 65 years old. There was a reduction in lidocaine clearance with age due, in part, to lower body weight and a higher prevalence of heart failure in the elderly. Multilinear regression analysis showed that age and weight contributed to the prediction of lidocaine plasma clearance in patients with and without heart failure. Age was a particularly important predictor of lidocaine clearance in patients with heart failure. Adjustment of lidocaine maintenance doses based on age, weight, and heart failure may help control the frequency of lidocaine adverse reactions in the elderly.

Adult↗
PubMed1984

The effect of bone marrow stromal cells on the cloning of human leukemia/lymphoma cell lines.

The cloning of established human leukemia and lymphoma cell lines at limiting dilutions in microwells and soft agar is described. Growth of most cell lines was improved by the addition of human AB serum and irradiated human bone marrow stromal cells. In general, the cloning efficiency in microwells was greater than in soft agar. The effect of bone marrow stromal cells appeared to be caused by a diffusable factor(s), but close cellular interaction could not be excluded since cloning in microwells produced consistent and optimal cell growth compared to growth in soft agar. It was concluded that cloning of leukemia and lymphoma cell lines in microwells was the preferred method and that similar techniques could improve the cloning of fresh leukemia and lymphoma cells.

Bone Marrow Cells↗
PubMed1984

T-cell growth factor production by adult, but not childhood. Acute lymphoblastic leukaemic cells.

The production of T-cell growth factor (TCGF) by acute lymphoblastic leukaemia (ALL) cells was determined in seven children and in three adults. A significant production of TCGF by adult, but not childhood, ALL cells was observed. The adult ALL cells were classified as "non-T-non-B" by surface marker analysis. It is suggested that TCGF production may not be confined to the cells of T-lineage.

Acute Disease↗
PubMed1983

Reversal of decreased phosphorylation of sarcoplasmic reticulum calcium transport ATPase by 1,25-dihydroxycholecalciferol in experimental uremia.

When compared to that from sham-operated controls, sarcoplasmic reticulum isolated from skeletal muscle of uremic rabbits had a lower rate of calcium uptake and storing capacity. In vivo administration of 1,25-dihydroxycholecalciferol [1,25(OH)2D3] restored the values in uremic animals toward normal. To obtain information about the mechanisms responsible for these differences, phosphorylation of the calcium transport ATPase was studied. The steady-state levels of phosphoprotein in uremic membranes were lower and returned to normal when the secosteroid was administered. Electrophoresis of the membranes phosphorylated with 32P-inosine triphosphate (32P-ITP) showed that the differences were related to a 100,000 dalton protein. The rate of phosphoprotein formation, determined with 32P-ITP and at 0 degrees C, was considerably lower in uremic than in control animals. Pretreatment with 1,25(OH)2D3 prevented this change. The hypothesis is advanced that the vitamin D metabolite affects the steady-state concentration and rate constant of formation of active sites in the Ca-ATPase. These results may partly explain the altered Ca transport function of the sarcoplasmic reticulum in experimental uremia.

Animals↗
PubMed1983

Further studies on the hypernoradrenergic state of treated hypertensives: effect of captopril.

We investigated the effect of captopril on plasma norepinephrine concentration and blood pressure in two groups of hypertensive patients. One group consisted of five severely hypertensive patients rendered hypernoradrenergic by administration of a minoxidil-propranolol-diuretic regimen. The other group was ten untreated mildly hypertensive patients. Two hours after 12.5mg of captopril, blood pressure was lowered (p less than .05) in four of the five hypernoradrenergic patients from 180 +/- 8/102 +/- 8 to 132 +/- 7/77 +/- 8 mmHg. Chronic administration of 100-150mg of captopril tid caused no further blood pressure reduction. Precaptopril plasma norepinephrine concentration was 925 +/- 206 and two hours after the 12.5mg dose was 807 +/- 80 pg/ml. Three months later having advanced the dose to 300-450 mg/day it was lower (p less than .05) at 752 pg/ml. The acute blood pressure response correlated (r = -0.72, p less than .001) with the precaptopril plasma norepinephrine. Precaptopril blood pressure in the mild hypertensive patients was 146 +/- 4/98 +/- 1, after a 25-100mg dose it was 137 +/- 6/91 +/- 2 (diastolic p less than .05) and at two months with the same captopril dose bid it was 141 +/- 8/88 +/- 4 mmHg (diastolic p less than .01). Corresponding initial PNE was 425 +/- 72, two hours after captopril 405 +/- 47 and 310 +/- 63 pg/ml (p less than .05) with chronic administration. Thus, captopril lowers blood pressure in both hypernoradrenergic and eunoradrenergic hypertensive patients without increasing plasma norepinephrine suggesting some unique dampening effect of this drug on the sympathetic nervous system. Also, addition of captopril to triple therapy lowered blood pressure in proportion to plasma norepinephrine levels suggesting importance to its action on this sympathetic nervous system effector.

Blood Pressure↗
PubMed1977

Deuterolysis of amino acid precursors: evidence for hydrogen cyanide polymers as protein ancestors.

Deuterolysis experiments suggest that hydrogen cyanide polymers rather than aminoacetonitriles are major precursors of alpha-amino acids obtained from spark reactions and other studies on chemical evolution. These results are consistent with the hypothesis that the original heteropolypeptides on the earth were synthesized spontaneously from hydrogen cyanide and water without the intervening formation of alpha-amino acids.

Amino Acids↗
PubMed1977

Effect of 1,25-dihydroxycholecalciferol on impaired calcium transport by the sarcoplasmic reticulum in experimental uremia.

In the fragmented sarcoplasmic reticulum from skeletal muscle of rabbits with experimental uremia, defective calcium ion transport is found. An impairment of all parameters is observed (initial rate of uptake, storing capacity with and without oxalate, and concentrating ability). In vivo administration of 1,25-dihydroxycholecalciferol (1,25-(OH)2-vitamin D3)(2 X 27 ng X kg of body wt-1 X day-1 and 6 X 27 ng X kg-1 X day-1, respectively) improved the kinetic parameters. The low dose improved storing capacity, and the higher dose, in addition to the storing capacity, also corrected concentrating ability and the initial rate of uptake. It is concluded that active calcium transport in the sarcoplasmic reticulum is impaired by uremia and that this defect is responsive to the administration of 1,25-(OH)2-vitamin D3.

Animals↗
PubMed1976

Active Ca transport of sacroplasmic reticulum during experimental uremia. Changes in kinetics and lipid composition.

The Ca-transport system of sarcoplasmic vesicles of rabbits is altered by experimental uremia. 1. The influx rate constant of the experimental membranes decrease with a resulting decrease of the calcium influx rate. 2. The experimental membranes transport a smaller amount of Ca2+ per mol of ATP split than the controls, i.e. their transport ratio is discussed. 3. The calcium permeability of the experimental membranes increases with a resulting decreased concentrating ability. 4. The phosphatide content but not the cholesterol content of the experimental membranes decreases with a consequent increase of the cholesterol/phosphatide ratio. 5. The fatty acid pattern of total phosphatides of the experimental membranes changes. A relative decrease of palmitic acid and oleic acid occurs and a relative increase of stearic, arachidonic and higher unsaturated fatty acids. 6. The altered lipid composition of the membranes does not change the temperature dependence of the kinetics.

Adenosine Triphosphatases↗