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Biomedical subjects

G C Smith

Publications and source records attributed to G C Smith.

At least 163 records · Page 9Linked to original sources

Detecting bunyaviruses of the Bunyamwera and California serogroups by a PCR technique.

Many bunyaviruses of the Bunyamwera and California serogroups are medically important human pathogens. The development of an effective technique to detect the viruses by using molecular biologic tools, such as PCR, improves not only clinical diagnosis but also virologic surveillance of mosquito vectors in the field. In this study, we evaluated eight pairs of primers for reactivity with 44 viruses of the genus Bunyavirus, using a reverse transcriptase PCR technique. With a pair of serogroup-specific primers we designed, all viruses of the serogroups tested could be detected. Further, virus-specific primer pairs were identified for California encephalitis virus, Jamestown Canyon virus, La Crosse virus, and snowshoe hare virus for use in North America. Using this technique, we could detect one La Crosse virus-infected mosquito in a pool of 100 mosquitoes with undetectable plaque titers.

Animals↗

Genetic influences on beef longissimus palatability in charolais- and limousin-sired steers and heifers.

Random matings of 10 Charolais sires and eight Limousin sires to crossbred cows produced 392 steers and heifers that were used to evaluate genetic influences on beef palatability. Longissimus lumborum steaks were measured for shear force at 1, 4, 7, 14, 21, and 35 d postmortem and for taste panel attributes at 14 d postmortem. Longer postmortem aging periods resulted in lower (P < .05) shear force values for progeny from all 18 sires. Shear force variation among sires did not diminish during postmortem aging; however, shear force variation among progeny within a sire decreased during postmortem aging. Median within-breed heritability estimates from Method-R were .33 for shear force, .49 for 24-h calpastatin activity, and .18 for marbling score. All taste panel attribute heritability estimates were very low. Solid evidence existed for a very high within-breed genetic correlation between calpastatin activity and shear force. However, the across-breed genetic correlation between marbling and shear force seemed to be higher than the correlation between calpastatin activity and shear force. Very few antagonistic genetic relationships existed between production/carcass traits and palatability traits.

Aging↗

Growth and fresh meat quality characteristics of pigs supplemented with vitamin E.

Crossbred pigs (n = 30) were fed to determine the influence of supplementation with vitamin E on growth and slaughter characteristics of swine and on the quality characteristics of fresh pork. Pigs received either a control diet containing no vitamin E (CON) or a diet formulated to contain 100 mg of vitamin E/kg feed (VITE). During 84 d of feeding, feed intake and weight gain were measured every 2 wk. After the feeding period, pigs were slaughtered and the loin from the left side of each carcass was removed 4 d after death. Alpha-Tocopherol concentration and proximate composition of the longissimus muscle were determined. Loins were sliced into 10-cm sections and stored under vacuum (2 degrees C) for 0, 14, 28, and 56 d. After storage, loins were sliced into 2.54-cm chops, wrapped in polyvinyl chloride film and stored in a retail case (2 to 4 degrees C) for 5 d. Thiobarbituric acid (TBA) values, Hunter L, a, and b values, total plate counts, pH, purge loss, drip loss, cook loss, taste panel characteristics, and visual panel characteristics were evaluated. Growth traits, slaughter characteristics, and proximate composition did not differ (P > .05) between dietary treatment groups. Alpha-Tocopherol concentrations were greater (P < .05) and TBA values during extended retail display were less (P < .05) for VITE chops than for CON chops. Overall palatability ratings were more desirable (P < .05, at 14 d of vacuum storage) for VITE chops than for CON chops. Color measurements, sensory characteristics, total plate counts, pH, purge loss, drip loss, and cook loss were not influenced (P > .05) by vitamin E supplementation. These results indicated that at the tissue alpha-tocopherol concentrations of the present study, vitamin E supplementation of the growing-finishing diet of hogs reduced lipid oxidation in fresh pork but did not influence pork color or tissue drip loss.

Analysis of Variance↗

Effect of phenotypic expression of Brahman breeding on marbling and tenderness traits.

Steers with known proportions of Brahman and Hereford breeding (80 quarter-bloods, 25% Brahman x 75% Hereford and 79 half-bloods, 50% Brahman x 50% Hereford) were used to determine the effect of phenotype on marbling and beef tenderness characteristics. Three experienced evaluators independently classified each live steer according to estimated proportion of Brahman breeding based on phenotypic evidence of Brahman breed characteristics. The steers were slaughtered, their carcasses were graded, and a carcass. Samples of longissimus muscle were obtained for measurement of 24-h calpastatin activity, sensory panel evaluation, and Warner-Bratzler shear (WBS) force measurements. Paired steaks were aged (6 and 18 d postmortem) and palatability determinations were completed. Estimates of live animal phenotype ranged from 0/16 to 9/16 for quarter-blood Brahman steers and from 1/14 to 13/16 for half-blood Brahman steers. Neither live animal phenotype nor carcass hump height was correlated with marbling score. Live animal phenotype was correlated (P < .01) with taste panel tenderness ratings (rd6 = -.36; rd18 = .36) and shear force values (rd6 = .36; rd18 = .30). Moreover, carcass hump height exhibited low, negative correlations (P < .05) with panel tenderness scores (rd6 = -.16; rd18 = -.28) and low, positive correlations (P < .10) with shear force (rd6 = .13; rd18 = .16). Steaks from steers classified as more than 3/8 Brahman were tougher (P < .05) than steaks from steers classified as 3/8 or less Brahman. Steaks from carcasses with hump height measurements of 7.60 cm or greater had lower panel tenderness ratings and higher WBS values (P < .05) than steaks from carcasses with hump heights less than 6.35 cm. Quarter-blood and half-blood Brahman steers that were similar in phenotype produced steaks that were similar in tenderness. Results of this study suggest that as phenotypic evidence of Brahman breeding increases the tenderness of cooked steaks from Brahman crossbred steers decreases.

Animals↗

Effects of animal age, marbling score, calpastatin activity, subprimal cut, calcium injection, and degree of doneness on the palatability of steaks from limousin steers.

Strip loin (longissimus lumborum), sirloin (gluteus medius) and round (semimembranosus) subprimals from 114 purebred and crossbred Limousin steers were used to identify main effects and interactions of animal age, marbling score, calpastatin activity, subprimal cut, calcium injection (5% wt/wt with a 200 mM CaCl2 solution at 48 h postmortem), and degree of doneness on the palatability of cooked beef steaks. Steaks were aged for 14 d, frozen, thawed, cooked to different internal temperature end points, visually scored for degree of doneness, sheared on a Warner-Bratzler shear machine, and evaluated by a trained taste panel. Raw and cooked steaks from carcasses of higher USDA quality grades had higher fat and lower moisture percentages (P < .05). Higher degrees of doneness resulted in lower moisture percentages (P < .05). Lower shear force values were associated with less variation in shear force. Younger slaughter age and lower calpastatin activity both resulted in greater tenderness (P < .05). Shear force was lowest between "medium rare" and "medium" and increased toward both ends of the degree of doneness scale for round and sirloin steaks; however, shear force increased linearly with degree of doneness in strip loin steaks (P < .05). Subprimal cut had the largest effect on taste panel tenderness ratings, and degree of doneness had the largest effect on taste panel juiciness ratings. The improvement in shear force due to CaCl2 injection was greater for strip loin and sirloin steaks than for round steaks (P < .05 for the interaction). Injection with CaCl2 improved all taste panel attributes. In addition, CaCl2 injection reduced the toughening effects of cooking (P < .05).

Aging↗

Modification of early-postmortem muscle pH and use of postmortem aging to improve beef tenderness.

This study was conducted to determine whether modification of early-postmortem muscle pH and(or) control of postmortem aging time could be used to improve tenderness of strip loin (longissimus, LM), top sirloin (GM), and top round (SM) steaks. Muscle pH, at 1.5 and 3 h postmortem, was modified using three 60-Hz electrical stimulation (ES) treatments (240 V, 35 V, or combined use of 240 and 35 V). Vacuum-packaged sections of the LM, GM, and SM were aged for 6, 12, 18, or 24 d postmortem. Use of ES increased rate of postmortem muscle pH decline and decreased shear force of LM steaks but had no effect on tenderness of GM or SM steaks. Reducing 3-h pH of the LM reduced variability in LM shear force but had little effect on tenderness of GM or SM steaks. However, lower values for 24-h pH of the LM were associated with increased tenderness of all three cuts. Tenderness of all cuts also improved as length of the postmortem aging period was increased. For LM and SM steaks, the greatest improvements in tenderness were achieved by 12 d; however, tenderness of GM steaks continued to increase up to 24 d postmortem.

Animals↗

Implant program effects on performance and carcass quality of steer calves finished for 212 days.

We compared the effects of seven implant treatments combining use of Ralgro (RAL), Synovex-S (SYN), and Revalor-S (REV) on performance and beef quality traits of crossbred steer calves (n = 560) finished for 212 d. A randomized complete block design was used to compare treatments consisting of 1) non-implanted control (CON); 2) RAL on d 0, SYN on d 60, and REV on d 130 (RALSYNREV); 3) RAL on d 0, REV on d 60, and REV on d 130 (RALREVREV); 4) SYN on d 30 and REV on d 130 (SYNREV); 5) REV on d 30 and REV on d 130 (REVREV); 6) REV on d 0, REV on d 75, and REV on d 150, 12.5% crude protein diet (REV3X-12.5); and 7) REV on d 0, REV on d 75, and REV on d 150, 14.5% crude protein diet (REV3X-14.5). All implant groups had higher ADG and gained more efficiently (ADG: feed intake) than the CON group. No distinct performance advantages were noted for particular implant schemes. Implant treatments did not (P > .05) affect dressing percentage, carcass weight, or KPH fat percentage. Fat thickness did not differ (P > .05) for implanted vs CON steers; however, REVREV, SYNREV, and RALREVREV steers produced fatter carcasses than did REV3X-12.5 and RALSYNREV steers. The REV3X-12.5 and REV3X-14.5 treatments increased longissimus muscle area compared with CON; longissimus muscle areas for all other treatments did not differ (P > .05) from CON. No reduction in percentage of Choice and Prime carcasses occurred with use of SYNREV or REVREV; however, all treatments receiving three successive implants had lower (P < .05) percentages of Choice and Prime carcasses than the CON group. Increasing dietary crude protein seemed to lessen the detrimental effect of three successive REV implants on percentages of Choice and Prime carcasses. Loin steaks from REVREV, REV3X-12.5, and REV3X-14.5 steers had higher (P < .05) shear force values than steaks from CON steers.

Anabolic Agents↗

Incidence and sensory evaluation of injection-site lesions in beef top sirloin butts.

The effects of ongoing quality assurance initiatives on the national incidence of injection-site lesions and the impact of these lesions on the sensory characteristics of top sirloin butts were examined by a series of audits and two experiments. The national incidence of injection-site lesions in top sirloin butts (n = 98,192) has not changed between July 1993 (10.91%) and July 1995 (10.19%). However, during this same period, the mean weight of injection-site lesion trim increased (P < .05) from 102.63 +/- 12.56 g to 152.81 +/- 13.24 g. Eighty percent of lesions examined during this period were classified as chronologically "older," originating from injections given either during preweaning, stocking, or in the early feeding period; however, there was an increase (P < .01) in the incidence of nodular scars during the audit period, likely created by intramuscular injections during the mid- to late-feeding periods. Warner-Bratzler shear measurements of lesion-afflicted steaks taken near the site of lesions and in areas up to 7.62 cm from the lesion center were significantly greater than similar measurements on control top sirloin steaks. Panelist tenderness scores for mildly lesioned steaks were lower (P < .05) and had greater within-(P < .01) and among- (P < .05) steak variation than control (normal) steaks. Mean juiciness ratings were higher (P < .001) for lesioned steaks; however, steak flavor intensity variation was greater within injection-site lesioned vs control top sirloin steaks, with undesirable flavors reported by panelists. Injection-site lesions still occur at an unacceptable frequency in the top sirloin butt, and those lesions, if not removed entirely, can dramatically reduce the desirability of top sirloin steaks.

Animals↗

Consultation-liaison psychiatry in an Australian oncology unit.

OBJECTIVE: To provide an overview of the work of a consultation-liaison (C-L) psychiatry service to an oncology unit in a university affiliated teaching hospital, with the aid of a comprehensive clinical database. METHOD: The MICROCARES prospective clinical database system was used to record data on all oncology inpatients referred to C-L psychiatry, and the hospital clinical database was used to compare referred inpatients with all oncology inpatients. RESULTS: Two hundred and seventy-one referrals were made in the 3 years from 1991 to 1993, a referral rate of 10.4%. The referred patients were younger but there was no bias in sex and marital status. The mean length of stay was twice that for all other oncology admissions, day cases excluded. The most frequent reasons for referral were coping problems, depression, terminal illness issues and anxiety. The most common psychiatric diagnoses were Systemic Family Problems (V codes, 24%), Mood Disorders (23%), Adjustment Disorders (16%) and Organic Mental Disorders (10%). Management involved family conferences in half of the patients and antidepressant medication in one-quarter. Concordance with pharmacological recommendations was 98%. Existential issues and family-centred care are discussed. CONCLUSIONS: Both individual and family-centred care is required in an oncology service; a dedicated liaison attachment offers considerable staff support. Psycho-oncology is underdeveloped in Australia compared to many overseas services; there is scope for substantial growth in preventive and supportive work.

Adaptation, Psychological↗

Consultation-liaison psychiatry in an obstetric service.

OBJECTIVE: The aim of this paper is to provide an overview of the work of a consultation-liaison (C-L) psychiatry service to an obstetric inpatient unit in a university affiliated teaching hospital, with the aid of a comprehensive clinical database. METHOD: The MICRO-CARES clinical database system was used for prospective recording of data on all obstetric inpatients referred to the C-L psychiatry service and the hospital clinical database was used to compare referred inpatients with all obstetric inpatients. RESULTS: Ninety patients were referred in 3 years, a referral rate of 1.2% of obstetric admissions. There was no bias in referral on age, but there were significantly more unmarried patients in the referred group (p < 0.001). Referred patients had a significantly prolonged length of stay: a mean of 9 days for referred patients, with 6 days for all obstetric patients (p < 0.001). The most frequent reasons for referral were: coping problems, depression, anxiety/fear and past history of major psychiatric illness. The most common DMS-III-R psychiatric diagnoses were: Personality Disorders (19%), Mood Disorders (17%), Schizophrenic Disorders (15%) and Adjustment Disorders (13%). At least one confirmed diagnosis was made in 77% of patients, but 42% of diagnoses remained differential. There were significantly more patients with diseases of the nervous system, endocrine and circulatory disorders in the referred group (p < 0.001). Recommendations of psychosocial interventions predominated over psychopharmacological interventions, and concordance with these was 97% and 98%, respectively. Issues in the relationship of obstetrics and psychiatric C-L services are discussed and future directions indicated. CONCLUSIONS: The referral rate was low compared with other specialty units. This is probably due to factors inherent in obstetric practice. A wide spectrum of psychiatric disorders was referred, including a higher than expected number of women with postpartum psychotic disorders, the majority of whom were managed successfully in the obstetric ward. There is a need for increased liaison with obstetric and community services and for collaborative research, with a particular emphasis on the prevention of psychiatric morbidity associated with pregnancy.

Adaptation, Psychological↗

Consultation-liaison psychiatry to renal medicine: work with an inpatient unit.

OBJECTIVE: To provide an overview of the work of a liaison psychiatry service to a renal medicine inpatient unit, based on a comprehensive clinical database, in order to provide a basis for comparison with similar units and to identify issues of concern. METHOD: The MICRO-CARES prospective clinical database system was used to obtain data on all patients referred to the Liaison Psychiatry Service, and the hospital clinical database was used to compare referred patients with total Renal Unit admissions in a large, suburban, university-affiliated hospital. RESULTS: Two hundred and ninety-nine inpatient referrals were made in the three years from 1990 to 1992: a referral rate of 17%. There was no bias in referral on age, sex or marital status. Coping problems (27%), depression (20%) and noncompliance (11%) were the most frequent reasons cited. Forty-five per cent of referrals required a pre-dialysis assessment. There was good agreement between consultee and consultant about noncompliance, but poorer agreement about organic brain syndromes, depression, anxiety and alcohol problems. The highest prevalence of DSM-III-R diagnoses was for V Codes (35% of Mental Disorders (23%). Referred patients had a length of stay significantly longer than that of the total admissions (20.5 days +/- 20.6 SD compared with 8.7 +2- 12.5 SD, p < .001). Psychotropic drugs were prescribed in 25% of referrals, and liaison psychiatry staff spent a mean of 181 +/- 148 SD minutes per patient, reflecting the emphasis on psychological management. The systems issues are discussed. CONCLUSIONS: The high level of complex physical/psychiatric comorbidity present and the systemic issues involved suggest that the management of patients in a renal medicine inpatient unit requires a dedicated attachment of a consultant psychiatrist-led, multidisciplinary, liaison psychiatry team which is well trained in psychodynamic issues and is comfortable with the complexity of biological issues which arise. The data provide a reliable basis for comparison with other services.

Adaptation, Psychological↗

Mineral values of selected plant foods common to southern Burkina Faso and to Niamey, Niger, west Africa.

Wild and cultivated fruits, leaves, nuts, seeds, spices and vegetables from southern Burkina Faso and Niamey, Niger, were analysed for their copper, iron, magnesium, manganese and zinc concentrations and compared to imported, exotic reference foods found within the study area. The species analysed covered a broad spectrum of local diet; 33 were wild and 16 were cultivated. The edible wild plants were often the highest in mineral concentrations. Five species analysed, exhibited consistently high mineral values, specifically, Adansonia digitata, Boerhavia diffusa, Cerathoteca sesamoides, Sclerocarya birrea and Xylopia sp. The latter was particularly high in zinc, an observation which suggests that there may be a solid rationale for local traditions which recommended its consumption during pregnancy and lactation. Respondents indicated that during times of drought, wild plants were not consumed in the volume they once were, due to changes of infrastructure and in famine relief programmes.

Adult↗

Assessment of arthropod vectors of infectious diseases in areas of U.S. troop deployment in the Persian Gulf.

Beginning in August 1990, approximately 800,000 coalition troops were deployed to the Persian Gulf during Operations Desert Shield and Desert Storm. There was substantial concern about arthropod-borne diseases, particularly sand fly fever and cutaneous leishmaniasis, because of high morbidity rates in the Persian Gulf during World War II (WWII). In sharp contrast to WWII, there was no report of sand fly fever among coalition forces and only 31 cases of leishmaniasis among 697,000 U.S. troops. To further evaluate the risk of arthropod-borne diseases, an entomologic survey was conducted in 12 areas of Kuwait and Saudi Arabia. A total of 1,556 arthropods was collected during four survey periods in 1992. The suspected vectors of cutaneous Leishmania major infection, sand fly fever, West Nile fever, Rift Valley fever, and Crimean-Congo hemorrhagic fever were identified; however, there was no evidence of arboviruses or Leishmania among collected specimens nor from 51 trapped rodents. There are several possible reasons for the low risk of arthropod-borne infectious diseases among Desert Shield/Storm troops in an area where suspected vectors frequently were found: the use of insecticides and repellents, and the deployment of most ground troops to the open desert during the cooler, winter period--conditions least favorable for the transmission of arthropod-borne diseases.

Animals↗

Psychoeducational support groups for aging parents: development and preliminary outcomes.

A psychoeducational support group program for aging parents (mean age = 65.3) of adult offspring with developmental disabilities was established with assistance from a focus group of practitioners and parents. We reported on the program's development, parents' self-reported objectives for participating in the program, as well as appraisals made by the parents and professional group leaders regarding process and outcome issues. We were also interested in whether parents who resided with their offspring (n = 17) experienced support groups differently than did parents with offspring who lived away (n = 13). Implications for developing and evaluating future interventions with this target population were discussed.

Activities of Daily Living↗

Isolations of Potosi virus from mosquitoes collected in the United States, 1989-94.

Potosi (POT) virus, a recently characterized Bunyamwera serogroup virus, was discovered when it was isolated from Aedes albopictus collected at a waste-tire site in Potosi, Washington County, Missouri, during 1989. During the following year, POT virus was not isolated from 39,048 mosquitoes, including 17,519 Ae. albopictus, collected in Washington County. In 1991, mosquito collections from South Carolina, Ohio, and Michigan yielded 8 strains of POT virus: 6 from Coquillettidia perturbans and one each from Culex restuans and Psorophora columbiae. Additional collections of Ae. albopictus from several states during 1990-93 failed to yield further isolates of POT virus. In 1994, POT virus was isolated from Ae. albopictus and Anopheles punctipennis in North Carolina and from Ae. albopictus in Illinois. These represent the first virus isolations of any type for Ae. albopictus in those states. Thus far, POT virus has been isolated from 5 mosquito species in different genera in 6 states. The known geographic range of POT virus, based on virus isolations, has been extended from Missouri to the upper Midwest and the Atlantic seaboard. Potential vector relationships and possible transmission cycles of POT virus are discussed.

Animals↗

Arboviruses associated with mosquitoes from nine Florida counties during 1993.

Mosquitoes were collected for virus isolation tests from 36 sites in Bradford, Lake, Leon, Manatee, Orange, Osceola, Pasco, Putnam, and Sarasota counties, FL, from April 6 through October 11, 1993. A total of 158,129 adult specimens were collected in 726 trap nights using CDC light traps, usually baited with dry ice. At least 35 species were represented, although 60% of the collections was made up of 3 species (Aedes infirmatus, 6.5%; Anopheles crucians, 14.4%; and Culex nigripalpus, 39.4%). Four of the 36 collecting sites were located at waste-tire sites, where 254 trap nights yielded 27,455 specimens (17.4% of 9-county total). Forty-three virus strains were isolated from 2,812 mosquito pools consisting of 158,129 specimens. The viruses isolated include eastern equine encephalitis (EEE), 5 strains; Everglades (EVE), 2 strains; Keystone (KEY), 6 strains; Tensaw (TEN), 21 strains; trivittatus (TVT), one strain; Shark River (SR), one strain; and Flanders (FLA), one strain. In addition, 2 strains that are either KEY or Jamestown Canyon (JC) virus, and 4 ungrouped viruses remain to be identified. Twenty-one (48.8%) of the 43 virus strains were isolated from mosquitoes collected at waste-tire sites as follows: EEE (1), KEY (5), KEY/JC (1), TEN (13), and one ungrouped virus. The vector relations of the viruses are discussed and the potential importance of waste-tire sites as breeding habitats and harborages for vector and nuisance species is emphasized.

Aedes↗

Recognising drug and alcohol problems in patients referred to consultation-liaison psychiatry.

OBJECTIVE: To study the extent of recognition by referring doctors of drug and alcohol problems in patients referred to consultation-liaison psychiatry for any reason, and the factors associated with non-recognition. DESIGN: Comparison of referring doctors' reasons for referral and psychiatrists' DSM-III-R diagnoses in 2347 inpatients referred consecutively over three years, by means of the prospective MICROCARES clinical database used by the consultation-liaison psychiatry service of each hospital involved. SETTING: Four general teaching hospitals of Monash University. RESULTS: Psychiatrists considered a psychoactive substance use disorder diagnosis likely in 336 (14%) of the referred patients; referring doctors missed 188 (56%) of these, referring instead for "depression", "anxiety" and "suicide attempt evaluation". The factors correlating with this discordance included younger age, male sex, having a personality disorder diagnosed, and having attempted self-harm. CONCLUSIONS: The extent of the failure to identify drug and alcohol problems in patients in whom some psychological problem worthy of referral to psychiatry had been detected is symptomatic of the extent of this failure in medicine generally. Education and the use of screening procedures may lead to development of coherent drug and alcohol protocols in individual institutions.

Alcoholism↗

DNA-dependent protein kinase catalytic subunit: a relative of phosphatidylinositol 3-kinase and the ataxia telangiectasia gene product.

DNA-dependent protein kinase (DNA-PK), which is involved in DNA double-stranded break repair and V(D)J recombination, comprises a DNA-targeting component called Ku and an approximately 460 kDa catalytic subunit, DNA-PKcs. Here, we describe the cloning of the DNA-PKcs cDNA and show that DNA-PKcs falls into the phosphatidylinositol (PI) 3-kinase family. Biochemical assays, however, indicate that DNA-PK phosphorylates proteins but has no detectable activity toward lipids. Strikingly, DNA-PKcs is most similar to PI kinase family members involved in cell cycle control, DNA repair, and DNA damage responses. These include the FKBP12-rapamycin-binding proteins Tor1p, Tor2p, and FRAP, S. pombe rad3, and the product of the ataxia telangiectasia gene, mutations in which lead to genomic instability and predisposition to cancer. The relationship of these proteins to DNA-PKcs provides important clues to their mechanisms of action.

Ataxia Telangiectasia↗