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Biomedical subjects

G C Smith

Publications and source records attributed to G C Smith.

At least 19 recordsLinked to original sources
PubMed1992

Isolation of eastern equine encephalitis virus from Aedes albopictus in Florida.

Fourteen strains of eastern equine encephalitis (EEE) virus were isolated from Aedes albopictus mosquitoes collected in Polk County, Florida. These are the first isolations of an arbovirus of proven public health and veterinary importance from naturally infected Ae. albopictus in the United States since established populations of this introduced mosquito were first discovered in 1985. The widespread distribution of Ae. albopictus in Florida and in other areas of the United States where EEE is endemic raises concern that this species may become an epizootic and epidemic vector of EEE virus.

Aedes↗
PubMed1992

Successful parents of in vitro fertilization (IVF): the social repercussions.

A matched comparison was made of 157 parents of preschool twins conceived by one of the following: in vitro fertilization (IVF), infertility workup combined with infertility drug treatment, or spontaneously. The Interview Schedule for Social Interaction was used to examine systematically a comprehensive range of social relationships and the asymmetries therein. Overall, IVF parents reported having deficient social relationships compared with non-IVF parents, and this deficiency was both in size and in affective quality of their available relationships. As anticipated, mothers reported less adequate and available social relationships when compared with their spouses. In the event of a significant finding, mothers from the three groups always had lower mean scores than the fathers. The finding of the extent to which IVF parents were not as socially integrated, compared with the other families of preschool twins, highlights the need to strengthen through mutual aid IVF parents' social networks. The data also suggest the need for ongoing patient care by IVF teams and for support groups to be established exclusively for IVF parents of twins.

Adult↗
PubMed1992

Recovery of protein from urine specimens collected in cotton wool.

Cotton wool balls have been used to aid the collection of urine from infants. Concentrations of two urinary proteins, albumin and retinol binding protein, decreased by 40 and 80% respectively within 15 minutes of contact with the cotton wool. Cotton wool balls should not be used when investigating proteinuria.

Female↗
PubMed1992

Lean color characteristics of bullock and steer beef.

Twelve young bulls and 12 steers were slaughtered and the carcasses were fabricated at 48 h postmortem. Top rounds, bottom rounds, and rib eyes were vacuum-packaged and stored at 0 degrees C until 21 d postmortem. After subprimal storage, steaks were removed from each cut and displayed under simulated retail conditions for 3 d. Consumer panelists (n = 110) showed little difference in buying preference for top round, bottom round, and rib eye steaks from steers vs bullocks. Also, consumer panelists could not detect color differences between steaks from steers and bullocks. Experienced panelists (n = 6) detected brighter (P less than .05) muscle color for top round and rib eye steaks from steers but detected no difference in muscle color of bottom round steaks from bullocks and steers. Generally, overall desirability scores favored steaks from steer carcasses. This was particularly true of rib eye steaks. Sex-class of carcass did not affect aerobic plate counts of top round, bottom round, or rib eye steaks either before or after 3 d of retail display. Muscle pH was lower for top round and rib eye steaks from steer carcasses; however, the magnitude of this difference was not large enough to affect retail display stability. Muscle pH of bottom round steaks was not affected by sex-class. Although experienced panelists could detect differences in visual appearance of beef retail cuts from steers and bullocks, consumer panelists did not show a clear purchase preference for steer vs bullock beef. These data suggest that beef retail cuts from bullocks are acceptable in visual appearance.

Animals↗
PubMed1991

Rabies in urban foxes (Vulpes vulpes) in Britain: the use of a spatial stochastic simulation model to examine the pattern of spread and evaluate the efficacy of different control régimes.

The threat of rabies being reintroduced into Britain is probably greater now than at any time over the last 60 years. This threat is reviewed with particular regard to the problems that would be posed should rabies be introduced to the high-density fox populations found in many cities in southern England. Computer models can provide a valuable means of understanding the pattern of rabies spread in fox populations and the likely problems of control, so the construction of previous rabies models was reviewed. None were found to be suitable for analysing the particular problems posed by high-density, spatially heterogeneous, urban fox populations. Therefore, a new spatial stochastic simulation model was produced, based on demographic and other data collected during a long-term study on the urban fox population in Bristol, and fox density data collected from a number of cities in southern England. The simulation model was used to analyse the effects of spatial heterogeneity in the fox population on the pattern of rabies spread. Simulations were then used to evaluate the effects of: (i) varying levels of fox control; (ii) changing the size of the control zone; (iii) the onset of the rabies epizooty at different times of the year: and (iv) delay before the commencement of control on the chances of containing the disease. These simulations were run for four cities (Bournemouth and Poole, Bristol, Leicester and the West Midlands conurbation) with different mean fox population densities. It was found that the variance in the monthly velocity of the rabies front was greater for heterogeneous fox populations. In cities with high fox densities, low or moderate levels of control were unsuccessful in containing the disease, but these urban areas had the highest rates of success with the highest levels of control. A three-month delay in the commencement of a rabies control campaign on average reduced the chance of successfully controlling the disease by 10-20%, although this was higher in lower-density fox populations. Rabies outbreaks in the dispersal period were on average 10% less likely to be contained. Increasing the size of the control zone increased the chances of successfully containing the disease, although this effect was density dependent, so the effect was less in low-density fox populations. These results are discussed in relation to the current rabies contingency plans for British urban areas.

Animals↗
PubMed1991

The brain and higher mental function.

Critical evaluation of biological theories of psychiatric disorder requires an understanding of current concepts of higher mental function and its related biology. Both the nature of the topic and the rapidity of advances in the field make it difficult to obtain an updated synthesis. Part I of this paper attempts to provide that by reviewing current concepts of the mind/body relationship, emotion, arousal, attention, consciousness and motivation. Part II considers those concepts in relation to recent work on the structure and function of the reticular, limbic and anterior cerebral systems. It is concluded that the model of the limbic system as subserving emotional life could now perhaps be set aside in favour of the model of a core set of chemically identified neurons in the reticular system being necessary but not sufficient to subserve higher mental function whilst also subserving other integrating functions for which no mental terminology is required. The problem of developing an eclectic theory of higher mental function that will embrace these concepts is discussed.

Animals↗
PubMed1991

Concordance with recommendations in a consultation-liaison psychiatry service.

We studied the concordance of physicians with the recommendations of psychiatric consultants in a sample of 270 consultations in a 400-bed general hospital. Of the patients about whom a consultation was sought, 37% had a past psychiatric history, and 67% were on psychotropic drugs. Twelve percent had Organic Mental Disorder, 35% Affective Disorder, and for 24% no DSM-III diagnosis could be made. The psychiatrist made psychotropic drug recommendations in 62%, and the physicians' concordance with this recommendation was 86%. The physician's discharge summary included a diagnosis which concorded with the psychiatrist's diagnosis in 53% of files. The psychiatrist recommended further investigations in only 5.2% of files.

Adolescent↗
PubMed1991

Problems identified by family caregivers in counseling.

Content analysis of the problems that caregiving daughters and daughters-in-law (N = 51) elected to work on during counseling yielded seven categories: improving coping skills, meeting elder's care needs, responding to family issues, concern over the caregiver-recipient relationship, eliciting formal and informal supports, feelings of inadequacy and guilt, and planning for elder's future. Two global themes of maintaining control and increasing responsibility within the caregiver role were also evident. Case examples illustrate problems, and practice implications are considered.

Counseling↗
PubMed1991

Prostaglandin E2 and fetal oxygen tension synergistically inhibit response of isolated fetal rabbit ductus arteriosus to norepinephrine.

We wished to determine the effect of prostaglandin E2 (PGE2) on the response of the ductus arteriosus to norepinephrine (NE) and whether any effect of PGE2 was influenced by O2 tension. The vessel was isolated from fetal New Zealand White rabbits and studied in vitro. The response to NE was assessed in terms of both sensitivity (pEC50) and maximum contractile response (MCR) as determined from cumulative concentration-response curves. PGE2 caused a concentration-dependent inhibition of ductal sensitivity to NE. This was maximal in nanomolar concentrations of PGE2, in which ductal sensitivity to NE was decreased by approximately 50 times. This action was only minimally potentiated by 3% O2 (simulating fetal O2 tension, PO2). PGE2 could also inhibit the MCR to NE, but this was entirely dependent on PO2. In 95% O2, PGE2 had no effect on the MCR to NE, whereas in fetal PO2, PGE2 decreased the MCR. This decrease was maximal in 1 nM PGE2, in which the MCR in 3% O2 was about one fifth the size of the MCR in 95% O2. In 1 nM nM PGE2, 10% O2 also largely abolished the inhibitory effect of PGE2 on ductal MCR to NE, indicating that this effect of O2 is also observed in the range of the physiologic increase of arterial PO2, tension that occurs at birth. PGE2 also inhibited ductal sensitivity to 5-hydroxytryptamine, histamine, and potassium. We conclude that physiologic and therapeutic concentrations of PGE2 inhibit sensitivity of the ductus arteriosus to certain vasoconstrictors and can inhibit the maximum response to NE in fetal but not increased PO2.

Animals↗
PubMed1991

Relationships between pork loin palatability traits and physical characteristics of cooked chops.

Pork loins (n = 72) were selected so that marbling scores would range from "practically devoid" to "abundant" in the longissimus muscle. Loin chops were cooked and rated by a trained six-member sensory panel. Physical and chemical characteristics were stratified according to marbling level (divided into 10 subclasses), muscle structure, shear force, overall palatability, and juiciness (each divided into three subclasses). The highest ratings for overall palatability were assigned to chops with high reflectance (685 nm), low moisture (70.1%), high i.m. fat (9.1%; or, high marbling score), low protein (19.4%), and low cooking loss (25.9%). Chops with the highest percentage of cooking loss were high in moisture content (75.59%), low in i.m. fat (1.78%), and high in protein content (21.54%). Differences in muscle structure, shear force, overall palatability, and juiciness were associated with differences in percentages of protein, moisture (whole tissue basis [WTB]) and fat (WTB). Pork loins with marbling between "practically devoid-plus" and "small" had (P less than .05) more protein and less fat (WTB) than loins with marbling scores between "modest" and "abundant." Loins with overall palatability ratings between 4.0 and 6.0 had more moisture and protein (P less than .05) than did loins with palatability ratings of 6.1 to 8.0. Selecting pork loins with "small" or less marbling, extremely open structure, a juicy rating of "slightly juicy," and an overall palatability rating of "like slightly" would identify fresh loins that had lower fat and(or) higher protein content.

Animals↗
PubMed1991

Laboratory studies of a Brazilian strain of Aedes albopictus as a potential vector of Mayaro and Oropouche viruses.

The vector efficiency of colonized Aedes albopictus from Brazil was assessed for Mayaro (MAY) and Oropouche (ORO) viruses. Female mosquitoes, 3-4 days old, were fed on a MAY-infected hamster with a viremia level of 5.3 log10 Vero cell plaque-forming units (PFU) of virus/ml or an ORO-infected hamster circulating 7.3 log10 PFU/ml. Mayaro infection rates among fed mosquitoes were 16.9 and 11% at 6, 13 and 20 days postfeeding, respectively, and 1/2 and 2/2 infected mosquitoes transmitted virus on days 13 and 20, respectively. Only 13, 5 and 3% of mosquitoes were infected with ORO virus at 6, 13 and 20 days, respectively, and no transmission occurred. Mosquitoes were also fed on 3 dilutions of MAY virus-blood suspensions in membrane feeders. The infection rate among mosquitoes fed the highest concentration (7.7 log10 PFU/ml) was 11/13 (85%), and 5/11 (46%) infected mosquitoes transmitted virus.

Aedes↗
PubMed1990

Psychiatric morbidity in parents of twins born after in vitro fertilization (IVF) techniques.

A matched comparison was made of 158 parents of preschool twins conceived under three conditions; spontaneously, after infertility workup including drug treatment, and after in vitro fertilization (IVF). Indications of probable psychiatric caseness were obtained using the 60-item General Health Questionnaire. IVF parents' mean scores were similar to those of parents who spontaneously conceived, and both were significantly greater than those who conceived after an infertility workup. Mothers and fathers overall had similar scores, contrary to previous community findings of higher rates of psychiatric disorder among females. The prevalence of probable psychiatric caseness was less for IVF and spontaneously conceiving mothers, but greater for the respective fathers, than in an English community sample and greater than in an Australian community sample. The extent to which the self-reports of current psychiatric disturbance can be ascribed to any preexisting psychopathology is unknown. Indications of increased psychiatric disturbance found in this investigation warrant further prospective investigations, especially of the difficulties of rearing twins when couples are vulnerable in having this degree of psychiatric morbidity.

Australia↗
PubMed1990

Post-extrasystolic potentiation in a human fetus detected during measurement of systolic time intervals in labour.

Measurement of the pre-ejection period (PEP), a non-invasive index of cardiac function, was made in a human fetus with a disturbance of cardiac rhythm manifested by: (i) intermittent mechanically ineffective extrasystoles (ventricular premature beats) and (ii) pauses. The mean interval between the sinus beats before and following extrasystoles was virtually the same as that before and following pauses. The PEP was shortened at the first sinus beat following both extrasystoles and pauses, but to a greater extent following extrasystoles. The PEP was still shortened at the second sinus beat following extrasystoles, but prolonged at the same cardiac cycle following pauses. These data demonstrate that fetal cardiac post-extrasystolic potentiation was taking place and that this was due in part to inotropic potentiation of the post-extrasystolic beats. Inotropic potentiation of post-extrasystolic beats is due to a fundamental property of cardiac muscle relating frequency of stimulation to strength of contraction (the so-called 'force-interval' relationship). Our data present the first evidence, to our knowledge, that the inotropic state of the human fetal heart in vivo is modulated by this mechanism.

Cardiac Complexes, Premature↗
PubMed1990

Effectiveness of individual counseling by professional and peer helpers for family caregivers of the elderly.

This study of the effectiveness of individual counseling for daughters and daughters-in-law (N = 87) who were the primary caregivers for frail elderly parents revealed that participants who received professional counseling demonstrated significantly better outcomes than a no-treatment control group in regard to subjective well-being, level of psychiatric symptomatology, and perceived change in aspects of the caregiver-care-receiver relationship. Participants who received peer counseling demonstrated similar gains but did not improve significantly more than did control subjects in subjective well-being. Both forms of counseling had no significant effect on caregivers' formal and informal social support networks.

Aging↗
PubMed1990

The five year school medical--time for change.

School medical records of 1000 children born in 1981 were studied retrospectively. They showed that once known medical problems and those screened for by the school nurse (hearing, vision, growth) were excluded, only 17 problems requiring treatment were discovered: speech (n = 10), development (n = 3), undescended testes (n = 3), and phimosis (n = 1). This indicates that routine screening by a nurse, backed up by selective medical examination by the school doctor, is efficient and effective.

Child, Preschool↗
PubMed1990

Vector competence of Aedes albopictus for a newly recognized Bunyavirus from mosquitoes collected in Potosi, Missouri.

The vector competence of a Kentucky strain of Aedes albopictus was assessed for a newly recognized Bunyavirus isolated from Ae. albopictus collected in Potosi, Missouri. Females are susceptible to peroral infection and 44.7% became infected after ingesting about 15 Vero cell plaque-forming units (PFU) of virus. Virus replicated and reached average titers of 10(5.4)-10(6.0) PFU/mosquito by day 7 postfeeding. Fourteen (40%) of 35 females tested in an in vitro virus transmission experiment were infected, and 3 (21.4%) of the infected females transmitted virus. There was no evidence of vertical transmission among 1,196 progeny of a group of mothers exposed to infection perorally or among 6,635 progeny of mothers infected by parenteral inoculation. The absence or infrequency of vertical transmission suggests that the virus was not introduced into Missouri via infected Ae. albopictus eggs. Nonetheless, Ae. albopictus is a competent vector of this virus and we provide the first experimental evidence for incriminating Ae. albopictus as a vector in a natural arbovirus transmission cycle in the United States.

Aedes↗