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Biomedical subjects

R D Smith

Publications and source records attributed to R D Smith.

At least 325 records · Page 18Linked to original sources
PubMed1989

Interrelationships between energy balance and postpartum reproductive function in dairy cattle.

Genetic improvement of dairy cows has markedly increased milk yield over the last three decades. Increased production has been associated with reduced conception rates (66% in 1951 versus 40 to 50% since 1975). Because conception rate in dairy heifers has remained higher, the metabolic demands of higher production may be related to the decline in reproductive performance in cows. During early lactation, increasing dietary intake fails to keep pace with rising milk production. The resultant negative energy balance and rate of mobilization of body reserves appear directly related to the postpartum interval to first ovulation and lower conception rate. Delays in the onset of normal ovarian activity, thus limiting the number of estrous cycles before breeding, may account for the observed decrease in fertility. Negative energy balance probably acts similarly to undernutrition and may manifest in delayed ovarian activity by impinging on pulsatile secretion of LH. Lower availability of glucose and insulin may also decrease LH pulsatility or limit ovarian responsiveness to gonadotropins. Alternatively, release of endogenous opioids in association with increasing feed intake or other lactational hormone responses may provide neural or pituitary inhibition of the pulsatile LH production that is requisite for ovarian follicular development.

Animal Nutritional Physiological Phenomena↗
PubMed1989

Collaboration in management development: health and education in Gwent.

Management development in the health service calls for collaboration between health authorities and educational bodies, but the two parties have different cultures and priorities. Ray Smith and Paul Thomas describe how collaboration is facilitated in Gwent, particularly for the Certificate in Management Studies, by the appointment of a management development adviser who is on the staff of both the health authority and the college of higher education.

Administrative Personnel↗
PubMed1989

Some characteristics of the community practice of pathology in the United States. National Manpower Survey of 1987.

An evaluation of 629 pathologists engaged in community hospital and private laboratory practice and representing 601 pathology practices of varying size shows surprising uniformity in the distribution of professional effort. On average, pathologists in community practice distribute their effort as follows: surgical pathology, 34.6%; autopsy pathology, 6.7%; cytology, 8.8%; clinical pathology, 18.0%; teaching, 6.0%; research and development, 2.3%; laboratory administration, 17.5%; hospital administration, 2.9%; and other, 3.2%. The average community pathologist is male, 52 years of age, and a graduate of an American medical school (60%). When surveyed in 1986, community pathologists worked an average of 50 hours per week and retired at an average age of 62 years.

Age Factors↗
PubMed1988

Prevention of acetaminophen-induced hepatotoxicity by dimethyl sulfoxide.

Dimethyl sulfoxide (DMSO) has previously been shown to protect against acetaminophen (APAP)-induced hepatotoxicity, but the mechanism of this effect was not clear. Treatment of mice with 1 mg/kg DMSO 4 h before 250 mg/kg APAP resulted in significantly less hepatotoxicity than with APAP alone, as measured by serum glutamic pyruvic transaminase (SGPT) content 24 h after APAP. Protection was also evident when 1 ml/kg DMSO was given 4, but not 8 h after 250 mg/kg APAP. The APAP-induced depletion of liver glutathione was prevented in mice pretreated with DMSO, although DMSO alone had no effect on liver glutathione levels. The hepatic concentration of cytochrome P-450 (P450) 4 h after treatment of mice with 1 ml/kg DMSO, was significantly decreased compared to saline-treated animals. However, while this DMSO pretreatment significantly decreased the activity of cytochrome P-450-linked aminopyrine-N-demethylase, it increased the activity of aniline hydroxylase. Covalent binding of [14C]APAP to hepatic protein in vivo was significantly decreased in mice pretreated with DMSO. Covalent binding of [14C]APAP to hepatic microsomal protein in vitro was not significantly altered after in vivo treatment with DMSO. However, the presence of DMSO in the in vitro incubation mixture significantly decreased covalent binding of [14C]APAP in a dose-dependent manner compared to microsomal fractions from untreated, saline-treated or DMSO pretreated animals. These data suggest that the DMSO-induced alterations in cytochrome P-450 content and activity may not be the cause of the observed protective action of this chemical. The ability to competitively inhibit APAP bioactivation or to directly scavenge free radicals produced during APAP metabolism, including the activated species which covalently binds to protein, may account for the hepatoprotection afforded by DMSO.

Acetaminophen↗
PubMed1988

Capillary zone electrophoresis-MS.

Coupling the separation capabilities of capillary zone electrophoresis with the analytical specificity of mass spectrometry yields a tool for detecting levels of substances down to 10 attomoles.

Electrophoresis↗
PubMed1988

Special report--National Manpower Survey of 1987. Manpower needs in community hospital and private laboratory practice of pathology.

A new survey of manpower requirements in the community hospital and private laboratory practice of pathology has been completed and analyzed. The survey used a new instrument, the National Pathology Manpower Database, which will be useful in conducting longitudinal surveys. This instrument will permit organized pathology to monitor changes in pathology manpower needs in the years ahead, which are likely to be fraught with change. The results of this survey foretell a significant deficit of pathologists in community hospital and private laboratory practice within the next five years.

American Medical Association↗
PubMed1988

Why not your pediatrician's office? A study of weekday pediatric emergency department use for minor illness care in a community hospital.

To determine the rationale for using a community hospital's emergency department for minor illness care on weekdays, we surveyed 150 parents of children 15 years of age or younger. Fifty (33.3%) participants had no identified source of routine pediatric care, and 31 (20.7%) had pediatric providers not locally available. For participants with local providers, major reasons for use of the emergency department included economic factors, parental knowledge, parent/provider communication, convenience, and insurance coverage. The results of this study demonstrate that the utilization pattern and sociodemographic profile of children seen in our emergency department on weekdays is more characteristic of an inner-city hospital than of a non-metropolitan setting. There are a number of feasible measures which could improve access to routine pediatric care for low socioeconomic families and reduce unnecessary emergency department utilization.

Adolescent↗
PubMed1988

Influence of protein intake and feeding strategy on reproductive performance of dairy cows.

A study was conducted to determine the impact of dietary CP concentration (13 vs. 20%) and feeding strategy (total mixed ration vs. separate feeding of the forage and concentrate) on reproductive performance of 57 early lactation dairy cows. Cows were assigned to one of four treatments in a 2 x 2 factorial arrangement. Rations composed of 40% forage (50% grass-legume silage:50% corn silage) and 60% concentrate (DM basis) were fed from d 5 to 100 postpartum. Cows fed a total mixed ration had lower ruminal ammonia and plasma urea N concentrations compared with cows fed separately. Feeding strategy groups showed no differences in reproductive performance. Cows fed a 20% CP ration had higher CP intake, higher ruminal ammonia, and higher urea N concentration in plasma and vaginal mucus. There were no differences between low and high CP groups in days to first observed estrus (24 vs. 27), days to first service (55 vs. 59), days open (72 vs 82) or services per conception (1.5 vs. 1.8). Days to first estimated ovulation were longer (22 vs. 17) in the high vs. low CP groups, and there was an interaction between protein intake and lactation number. Cows managed with an intensive program for detection of estrus and for reproductive health did not show differences in reproductive efficiency when fed 13 or 20% CP rations.

Animals↗
PubMed1988

Differential extraction of antigens of Anaplasma marginale.

Strain-, group-, and genus-specific antigens of the Florida isolate of Anaplasma marginale had different solubilities in zwitterionic, nonionic, and anionic detergents. On the basis of their solubility in nonionic detergent, antigens were grouped into 3 classes: (i) a 108-kilodalton (kD) group-specific antigen and a series of poorly defined antigens (70 to 100 kD) were completely soluble in nonionic detergent; (ii) 96 kD and 75 kD group-specific antigens, and a 91-kD strain-specific antigen were completely insoluble in nonionic detergent; and (iii) a 47-kD group-specific antigen and a 41-kD genus-specific antigen were partially soluble in nonionic detergent. A mercaptoethanol-sensitive antigen of 200 kD also was present in the insoluble fraction. Differences in solubility of taxonomic antigens of Anaplasma may reflect differences in function. Antigens totally insoluble in nonionic detergent were possibly integral membrane proteins, and those completely soluble in nonionic detergent were more likely peripheral membrane proteins that were less tightly bound to hydrophobic components of the membrane. Seemingly, all antigens were associated with membranes. Bovine preimmune and immune sera used did not react with any proteins of noninfected RBC.

Anaplasma↗
PubMed1988

Herpes zoster: a consideration in the differential diagnosis of radiculopathy.

Herpes zoster probably occurs more often than generally thought. Since it produces a radicular distribution of pain, it should be included in the differential diagnosis of radiculopathy. A case is presented in which evaluating the radicular low back pain before the characteristic rash appears was misleading. Careful history-taking concerning the exact nature of the pain and sensory changes is needed to differentiate between zoster and radiculopathy, if no rash is evident.

Back Pain↗
PubMed1988

Ecologic study of the risk factors for environmental mastitis in cows.

An index was developed to measure the proportion of intramammary infections caused by environmental microorganisms on dairy farms. This environmental index can be interpreted as the probability that an intramammary infection was caused by an environmental pathogen, rather than by a contagious pathogen. Using the environmental index as the outcome variable, risk factors for environmental mastitis were studied on 10 dairy farms in New York. Turning the cows outside was associated with lower environmental index, and having cows drink from a stream increased the environmental index. Selective (rather than uniform) nonlactating cow intramammary treatment was related to a lower environmental index (apparently because the farms practicing selective nonlactating cow treatment suffered from epizootics of contagious mastitis).

Animals↗
PubMed1987

Entamoeba histolytica: cytopathogenicity and lectin activity of avirulent mutants.

Three clones of Entamoeba histolytica (L-6, C93, C919) were isolated by mutagenesis with ethyl methanesulfonate from the axenic strain HM1:IMSS and were studied for adherence, cytolytic, and soluble galactose inhibitable lectin activity. Avirulent clones adhered to and killed fewer Chinese hamster ovary cells than HM1:IMSS (P less than 0.01). However, only C919 was deficient in adherence to red blood cells. Galactose (1.0 g) completely inhibited adherence of all the mutants to Chinese hamster ovary cells; however, adherence to erythrocytes was only partially inhibitable by galactose. Avirulent mutants were more susceptible to being killed by human neutrophils in vitro (P less than 0.01 compared to HM1:IMSS). Soluble protein preparations from all the avirulent mutants were markedly less mitogenic for human lymphocytes and had lower lectin activity for Chinese hamster ovary cells compared to the HM1:IMSS wild type (P less than 0.01 for each activity with each mutant). Indirect immunofluorescence with a monoclonal antibody (F-14) that recognizes the Gal/GalNAc lectin was positive for L-6 and C919. These findings utilizing avirulent mutants of E. histolytica further support a role for the amebic galactose inhibitable lectin in the in vivo pathogenesis of amebiasis.

Animals↗
PubMed1987

A survey of first-year pathology residents: factors in career choice.

Pathology has become less attractive to US medical graduates by every measure available to us. In 1981, 2.3 per cent of US medical school seniors planned a pathology career; by 1986, a steady decline had reached 1.6 per cent. In absolute numbers, adjusted for the response rate to the AAMC questionnaire, this means that the 290 seniors entering pathology in 1981 had fallen to 205 by 1986. FMGs enter pathology through the matching program in greater numbers than any other specialty. Our data show that slightly less than a third of current first-year pathology residents are FMGs, mainly from Caribbean and Mexican medical schools. The decline in US graduates entering pathology has resulted almost entirely from a drop in the number of men choosing the field. In 1984, 286 male US graduates matched in pathology, but this number dropped to 150 in 1985 and 149 in 1986. The group entering in 1985 was the first who will need 5 years to be eligible for certification in the anatomic pathology/clinical pathology programs. During the same years, the 116 women who matched in 1984 were followed by 111 in 1985 and 100 in 1986. The effect of the American Board of Pathology's change in requirements is not easily analyzed. The figures for residents entering, given above, would suggest that the requirements discouraged men, especially, from entering the field. This hypothesis is supported by our questionnaire data and by anecdote concerning the pressure felt by graduating seniors to finish their postgraduate training as fast as they can and start paying off their average debt of $33,650. Pathology still seems to attract people who like to teach, study interesting case material, and do research. The percentage of PhD/MDs entering pathology is almost 10 times as high as their percentage among graduating seniors. Discouragement against entering pathology came from a perceived shortage of job openings, negative statements from other physicians (including pathologists), the addition of a fifth-year requirement, and lack of patient contact. The last is hard to account for because pathology would obviously not offer the opportunities to see patients that exist in the clinical specialties, but it was prominent in the concerns of residents answering our questionnaire. The picture that emerges from our data is one of a specialty passing through a difficult period in attracting new talent into its ranks. The first step in dealing with the problem would seem to be recognizing its existence.(ABSTRACT TRUNCATED AT 400 WORDS)

Career Choice↗