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Biomedical subjects

C D Scott

Publications and source records attributed to C D Scott.

At least 73 records · Page 4Linked to original sources
PubMed1985

Identification of insulin-like growth factor-I and its receptors in the rat testis.

As part of a study of the testicular production and action of insulin-like growth factor-I (IGF-I), adult rat testes were extracted with acidified methanol, yielding an immunoreactive IGF-I fraction corresponding in size to human IGF-I. The mean IGF-I content (+/- SEM) of testes weighing approximately 1.1 g was 51.5 +/- 5.6 ng/testis, and was not due to serum contamination. After a 3-day fast testicular IGF-I decreased by 80%, whereas serum IGF-I levels declined by 90%. Testicular homogenates and isolated Leydig cells were shown to contain specific IGF-I receptors, Ka = 2 X 10(9) M-1, with 10% IGF-II cross-reactivity. The concentration of these receptors was 2 pmol binding sites per testis, or 3.3 fmol per 10(6) Leydig cells. However IGF-I at 250 ng/ml had no effect on basal or hCG-stimulated testosterone production by isolated Leydig cells, measured over 3 h. Although an effect of IGF-I over longer incubation periods cannot be excluded, it is also possible that testicular IGF-I has a mitogenic role, rather than acting on differentiated testicular functions.

Animals↗
PubMed1978

Automated system for fractionation of blood samples.

We describe a prototype system for preparing multiple fractions of blood components (plasma, washed erythrocytes, and hemolysates) by use of automated techniques. The procedure is based on centrifugal separation and sample transfer by induced pressure differentials in a blood-processing vessel (rotor) that has been designed to process 24 samples simultaneously. Erythrocytes are sedimented against the outer walls of individual sample chambers, and plasma is siphoned, by imposition of either a slight positive or negative pressure, into individual reservoirs in a collection ring. Cells are washed in situ; samples of washed cells, either packed or in saline solution, can be recovered. Cellular hemolysates are automatically prepared and transferred to individual, commercially available collection vials, ready for immediate analysis or for storage in liquid nitrogen. The system has potential application in any biomedical area in which many samples are to be expeditiously analyzed and in which one or more of the blood fractions will be used. A separate unit has been designed and developed for the semiautomated cleaning of the rotor.

Autoanalysis↗
PubMed1976

Use of a tapered fluidized bed as a continuous bioreactor.

Reactor systems based on tapered fluidized beds are being developed for aqueous bioprocesses in which adhering microorganisms or immobilized active biological fractions are used. The use of a fluidized bed prevents biomass buildup, accommodates particulates in the feed stream, is compatible with gas sparging, and allows easy removal or addition of the active materials. The tapered reactor tends to stabilize the fluidized bed, thus allowing a much wider range of operating conditions. Preliminary experimental results and an empirical mathematical model of the tapered bed indicate that bed stability is associated with a decreasing velocity and void-fraction profile up the bed and the pressure drop across the bed decreases with increasing flow rates. The tapered fluidized bed bioreactor is being evaluated for use in the enzymatic production of hydrogen, microbiological denitrification, and microbiological degradation of coal conversion aqueous waste streams. The enzyme catalyzed conversion of lactose to glucose and galactose was used in the evaluation of the reactor concept.

Biochemistry↗
PubMed1976

Premature chromosome condensation in human leukemia.

Premature chromosome condensation (PCC) has previously been observed in tissue culture and is believed to arise from asynchronous mitotic activity in multinucleated cells in which the affected nucleus is in interphase and at least one nucleus is in metaphase. Such cells have been noted following fusion induced by virus infection, spontaneously, and after treatment with cytochalasin B. The phenomenon has also been observed in malignant pleural effusions, but has not previously been described as a feature of hematologic disease. In this study, we report the observations of PCC in seven patients. Six of these patients had either acute myeloblastic leukemia or acute myelomonoblastic leukemia in association with the features of erythroleukemia, i.e., leukoerythroblastic reaction in the blood, and erythroid multinuclearity, "megaloblastoid" changes, and PAS-positive staining of erythroid precursor cells in the bone marrow. In all patients, erythroid multinuclearity has been noted. However, not all patients with erythroleukemia exhibit PCC. In this series, three additional patients have had similar bone marrow morphologic changes without PCC. The finding of PCC in erythroleukemia may have important implications as to etiology of this disorder.

Aged↗
PubMed1976

Centrifugal system for affinity chromatography with eluate monitoring.

A prototype centrifugal system has been developed that permits parallel photometric monitoring of eluate streams from a radial array of chromatographic columns. The modular rotor design consists of a discoidal center insert for eluent and sample apportionment, the chromatographic columns, and flow-through cuvetts-all mounted on an aluminum base plate. A common sample is introduced simultaneously to each column; a single eluent stream is used for all columns. The goal is to assay simultaneously for eight to 16 serum proteins separated by affinity chromatography from a single sample. The system is here exemplified by the use of immunosorbents (consisting of antibodies to human immunoglobulins covalently bound to alumina particles) to allow simultaneous determinations of IgG AND IgM from a single human serum sample in less than 16 min.

Blood Proteins↗
PubMed1975

Automated elution electrophoresis: a potential clinical tool.

An elution electrophoresis system in which a porous packed bed is used for separation and a flow photometer or colorimeter for continuous monitoring of the eluate may be capable of rapid, high-resolution analysis of serum proteins and other protein mixtures with very little manual labor. In a prototype of such a system we used a cooled separations column, 3 mm in diameter and 40 cm long, containing polyacrylamide beads. Samples are introduced, via a microsyringe, through a septum at the column midpoint. Typical analyses for serum proteins or serum isoenzymes require an electrophoresis time of about 30 min at 1200 V.

Autoanalysis↗
PubMed1973

Health care delivery and advanced technology.

Remedying the deficiencies in the current health care delivery system and effectively using advances in biomedical research require that a significant effort be organized to develop advanced technology in this field. The time is ripe and development personnel are available; hence, what are needed are simply a dedication to solving the problem, a commitment of resources toward this end, and an organizational mode that will allow the effective participation of developmental personnel.

Chromatography↗