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Biomedical subjects

M C Smith

Publications and source records attributed to M C Smith.

At least 163 records · Page 9Linked to original sources
PubMed1991

Selection of human consumables for future space missions.

Consumables for human spaceflight include oxygen, water, food and food packaging, personal hygiene items, and clothing. This paper deals with the requirements for food and water, and their impact on waste product generation. Just as urbanization of society has been made possible by improved food processing and packaging, manned spaceflight has benefitted from this technology. The downside of this technology is increased food package waste product. Since consumables make up a major portion of the vehicle onboard stowage and generate most of the waste products, selection of consumables is a very critical process. Food and package waste comprise the majority of the trash generated on the current shuttle orbiter missions. Plans for future missions must include accurate assessment of the waste products to be generated, and the methods for processing and disposing of these wastes.

Clothing↗
PubMed1991

Collection, compaction and storage of solid waste for space missions.

Efficient trash collection and volume reduction becomes very important during extended, manned space flight missions because of the high rate of crew member generated trash and the limited volume available to store this trash. Trash management in manned space flight vehicles requires that the following considerations be addressed: definition of the trash model including quantities/rates of generation and the physico-chemical characteristics of the trash; methods of collection and temporary stowage prior to treatment or processing; the methods of treatment/processing to affect biochemical stabilization and volume reduction; and storage of treated/processed trash prior to final disposition. This paper discusses trash management design approaches with focus on trash collection, compaction and storage. This paper also discusses the trash compactor design currently being developed for the Space Station Freedom program.

Ecological Systems, Closed↗
PubMed1991

Measurement of insulin-like growth factor-II in physiological fluids and tissues. II. Extraction quantification in rat tissues.

The tissue distribution and developmental patterns of insulin-like growth factor-II (IGF-II) have not been investigated in rat tissues, primarily because of the lack of an efficient extraction method for IGF-II and a sensitive RIA. IGF-II was extracted from rat tissues by formic acid, and the extract was heated at an acidic pH and treated with acetone. The removal of binding proteins was demonstrated by fast protein liquid chromatography size exclusion column and the elimination of a dilutional bias in the RIA. Using rat IGF-II as standard, we optimized a RIA for the quantification of IGF-II in rat tissues. In adult rats, IGF-II was found in all 15 tissues examined, with the highest concentration in the pituitary, followed by kidney, seminal vesicles, intestine, and serum. This distribution is not only different from that of IGF-I, but also differs from that reported for IGF-II mRNA and IGF-II receptors, suggesting that the rates of synthesis and/or metabolism of IGF-II are tissue dependent. Developmentally, IGF-II levels fell postnatally in most tissues, a pattern similar to that of IGF-II mRNA and IGF-II receptor. This developmental pattern supports the hypothesis that IGF-II is important in early growth and development. A relatively homogeneous distribution was observed in the adult rat brain, a distribution also different from that reported for IGF-II mRNA. In the pituitary, the highest concentration was found in the posterior pituitary, followed by the intermediate and anterior pituitary. In conclusion, IGF-II is found in many tissues of adult rats. This observation supports an autocrine and/or paracrine roles for IGF-II.

Animals↗
PubMed1991

Ethical ideology and product confidence: future pharmacists' attitudes toward generic drug substitution.

The impact of generic drugs on the prescription drug market has received widespread attention in the health care and marketing disciplines. Most research to date has focused solely on market factors' effect on pharmacists' attitudes toward generic drug substitution, and little attention has been given to individual factors. The present study extends previous research using Multiple Discriminant Analysis to ascertain the importance of ethical ideology and product confidence on pharmacists' attitudes toward future generic drug substitution across a salient set of market factors. The findings suggest that these individual factors are important in profiling pharmacists' disposition toward making a generic substitution in the future.

Attitude of Health Personnel↗
PubMed1991

Decision points in the integrative research review process: a flow-chart approach.

With the ever increasing volume of research information appearing in the literature, research syntheses are becoming more popular among researchers in various disciplines. This phenomenon demands application of rigorous and systematic review methodologies. Using Cooper's five-stage process for conducting an integrative research review, the authors have constructed a flow chart for health sciences librarians and others using this approach to identify decision points in this process. The accompanying narrative details the information that must be considered and analyzed. Included in the flow chart and text is an elaboration of meta-analysis and an integrative review to accommodate both quantitative and qualitative research results. A case is made for a collaborative relationship between the researcher and the librarian.

Data Collection↗
PubMed1991

The clinical use of barbiturates in neurological disorders.

Barbiturates retain an important place in clinical neurological practice. They are used as both diagnostic and therapeutic drugs, their most common uses being as anticonvulsant and anaesthetic agents. This article explores the current theories explaining the mechanism of action of the barbiturates, with special emphasis on their anaesthetic and anticonvulsant effects. The primary mechanism of action of barbiturates is to increase inhibition through the gamma-aminobutyric acid (GABA) system. Anaesthetic barbiturates also decrease excitation via a decrease in calcium conductance. Phenobarbital (phenobarbitone), the primary anticonvulsant barbiturate, is effective for partial, complex partial and secondarily generalised seizures. While no longer the drug of choice for all these seizure types, it remains an important and useful agent. Mysoline has been shown to be useful in the treatment of essential tremor and several other movement disorders, and as an anticonvulsant. Barbiturates are also used for their sedative-hypnotic properties. A relatively new use is in the evaluation of patients with medically intractable seizure disorders for possible surgical therapy. The roles of methohexital and amobarbital (amylobarbitone) are discussed in the section on barbiturates used as diagnostic agents. The experimental use of barbiturates is also commented on; the most important of these is perhaps the use of barbiturates in cerebral resuscitation.

Barbiturates↗
PubMed1991

A case-control study of the association between blood selenium and cystic ovaries in lactating dairy cattle.

We carried out a case-control study to investigate the association between the risk of developing cystic ovaries and the concentrations of Se in the blood of dairy cows. Cows were from dairy herds in the vicinity of Ithaca, NY. One hundred and thirty-two cystic ovary cases were identified; a similar number of herdmates who did not have cystic ovaries were selected as controls. Whole blood samples were collected from cystic cows and controls in which Se concentrations were determined. Milk samples also were collected and analyzed for concentrations of progesterone. Multivariate logistic regression analysis was used to identify the role of Se in the risk of developing cystic ovaries while controlling for other possible risk factors. Mean Se in blood concentration for cows with cystic ovaries (141 ng/ml) was similar to that of control cows without cystic ovaries (136 ng/ml). The concentration of progesterone in milk was significantly higher in controls than in cows with cystic ovaries. In the multivariate logistic regression analysis, cows with concentrations of Se in blood greater than 169 ng/ml had twice the risk of developing cystic ovaries compared with cows that had Se levels less than 108 ng/ml.

Age Factors↗
PubMed1990

An in vitro murine model of a penicillin specific IgE anamnestic response.

A new murine model system was developed to study hapten specific IgE anamnestic antibody forming cell (AFC) responses induced in vitro. BALB/c mice injected intraperitoneally with BPO-KLH (10 micrograms) in aluminum hydroxide gel (alum) on day 0 and 21 were killed on day 42. Spleen cells (4 X 10(7] were cultured for 0-8 days in the presence of BPO-KLH (0.25-2500 ng/ml), after which the numbers of BPO specific IgE AFC were enumerated in an ELISPOT assay at 37 degrees C using BPO-BSA coated plates. Peak BPO specific IgE anamnestic AFC responses (approximately 40 AFC/10(7) cultured cells) occurred when cells were cultured with 100 ng/ml BPO-KLH for 5 days; peak BPO specific IgG1 and IgA responses (approximately 3000 and approximately 280 AFC/10(7) cultured cells) were detected one day earlier with the same antigen concentration. No ELISPOTs of any isotype were detected if: cells were cultured in the absence of specific antigen; cells from alum treated or unsensitized mice were used; assay wells were coated with BSA alone; isotype specific antibodies were omitted; or assays were performed in the presence of cycloheximide or at 4 degrees C. Cellular interactions in IgE anamnestic AFC responses were studied using the newly developed model system. We found that these responses were partially T cell independent, and that spleens from sensitized and unsensitized adult mice, as well as neonatal mice, contained cells which suppressed these responses.

Animals↗
PubMed1990

Exclusion of infectious diseases from sheep and goat farms.

It is important for practitioners and owners to be aware of the risk associated with an open herd. This article has discussed some of the infectious diseases that might be inadvertently introduced. Many others--including most exotic diseases and some that are regulated by governmental agencies, such as tuberculosis and brucellosis--have been omitted. It should be obvious that a simple health certificate is an inadequate guarantee of freedom from infections. Instead, producers should be prepared to invest both time and money in evaluating the health status of the herd of origin. Some of the diseases discussed, such as foot rot, cause tremendous financial losses. Others, such as pinkeye, can be easily "lived with." The point to be made is that producers should consider all these and other diseases and then make informed decisions based on the probable cost of these diseases if they became established in the herd.

Animals↗
PubMed1990

Simple treatment for snoring also a means of prediction of uvulopalatopharyngoplasty success?

The old Indian literature describes a technique known as Sutra-Neti. That is, passing a catheter or similar material through the nose and out of the mouth as a means of clearing the airway. One of our patients adapted this method, tying the catheter end to end, in order to control his severe snoring and obstructive sleep apnoea. This was effective for several months. He subsequently responded well to a uvulopalatopharyngoplasty.

Adult↗