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Biomedical subjects

V M Thomas

Publications and source records attributed to V M Thomas.

At least 19 recordsLinked to original sources

Assessing elemental mercury vapor exposure from cultural and religious practices.

Use of elemental mercury in certain cultural and religious practices can cause high exposures to mercury vapor. Uses include sprinkling mercury on the floor of a home or car, burning it in a candle, and mixing it with perfume. Some uses can produce indoor air mercury concentrations one or two orders of magnitude above occupational exposure limits. Exposures resulting from other uses, such as infrequent use of a small bead of mercury, could be well below currently recognized risk levels. Metallic mercury is available at almost all of the 15 botanicas visited in New York, New Jersey, and Pennsylvania, but botanica personnel often deny having mercury for sale when approached by outsiders to these religious and cultural traditions. Actions by public health authorities have driven the mercury trade underground in some locations. Interviews indicate that mercury users are aware that mercury is hazardous, but are not aware of the inhalation exposure risk. We argue against a crackdown by health authorities because it could drive the practices further underground, because high-risk practices may be rare, and because uninformed government intervention could have unfortunate political and civic side effects for some Caribbean and Latin American immigrant groups. We recommend an outreach and education program involving religious and community leaders, botanica personnel, and other mercury users.

Adult↗

Soviet and post-Soviet environmental management: lessons from a case study on lead pollution.

Through a case study on lead pollution in the former Soviet Union, the linkage of policy, environmental science, and environmental management is explored, and compared with the US experience. Soviet bans on leaded gasoline and lead-based paint appear to have been effective. Regional governments, in cooperation with the petroleum industry, are taking the initiative in phasing out leaded gasoline, to some extent in defiance of federal policy. Problems with management of lead-acid batteries have been worsened by the collapse of the political system. Lack of reliable environmental data impedes reliable environmental assessment. The types of environmental measurements reflect an emphasis on multipollutant environmental contamination, rather than on human exposure to single pollutants.

Air Pollutants↗

Effects of dietary vitamin E supplementation during late pregnancy on lamb mortality and ewe productivity.

OBJECTIVE: To determine the effect of feeding vitamin E to ewes during late pregnancy on lamb mortality and ewe productivity. DESIGN: Prospective study. ANIMALS: 1,302 mature Rambouillet and Targhee ewes. PROCEDURE: During a 3-year period, approximately 430 ewes/y were randomly allocated to 2 groups; supplement-group ewes were fed additional vitamin E and control-group ewes were not. Beginning approximately 3 weeks before the first expected lambing date, ewes were fed 2.3 kg (5 lb) of alfalfa-grass hay/d and 0.23 kg (0.5 lb) of barley-based pellets/d with or without supplemental vitamin E. Pellets that were supplemented contained 1,450 mg of DL-alpha-tocopherol acetate/kg (658 mg/lb) of feed and provided an additional 330 IU of vitamin E/ewe/d. Selenium was incorporated into a trace mineral salt and fed free choice to all ewes throughout pregnancy. RESULTS: Supplemental vitamin E had no effect on ewe weight, body condition score, fertility, or prolificacy. In ewes that lambed in the early part of the lambing season, vitamin E supplementation significantly reduced lamb mortality, compared with no supplementation (12 vs 17%, respectively). Consequently, supplement-group ewes had significantly greater total body weight of lambs per ewe at the time of weaning, compared with control-group ewes. Differences were not observed between ewe groups in lamb mortality or total body weight of lambs per ewe at the time of weaning when ewes lambed during the late part of the lambing season. CLINICAL IMPLICATIONS: If ewes are fed additional vitamin E3 weeks before parturition, those that lamb in the early part of the lambing season may have low lamb mortality and, thus, higher total body weight of lambs per ewe at the time of weaning.

Animals↗

Influence of energy or protein supplementation during midpregnancy on forage intake of ewes grazing Montana winter range.

A 2-yr winter experiment was conducted to determine the influence of either energy or protein supplementation during midpregnancy on fecal output (FO), forage intake, blood metabolite profiles, and BW changes of ewes grazing winter range. Thirty-two Targhee ewes were selected for uniformity in age and BW and assigned randomly to one of four dietary treatments 1) no supplement (NONE); 2) 150 g of barley supplement (BAR); 3) 75 of feather g meal, blood supplement (FM/BM); and 4) 75 g of FM, BM, urea supplement (FM/BU/U). Two 5-d experimental periods were conducted during each winter (January and February). Forage FO (P = 0.9), total FO (P = 0.7), and subsequent forage intake (P < .01) were higher during Yr 1 than during Yr 2. Supplement type did not affect forage DMI when expressed either as grams/day (P = .57) or as a percentage of BW (P = .52). Body weight changes and body condition scores were not affected (P > .10) by year but were affected (P < .01) by treatment; unsupplemented ewes lost more (P < .01) BW and body condition than supplemented ewes. Serum urea N (SUN) concentrations were affected (P < .03) by a year x treatment interaction. Unsupplemented, FM/ BM, and FM/BM/U ewes had higher (P < .10) SUN concentrations during Yr 1 than during Yr 2, averaging 9.8 ml/dL and 7.5 mg/dL, respectively. Barley-supplemented ewes had similar (P > .10) SUN concentrations both years, averaging 7.4 mg/dL. Alternate-day supplementation during midpregnancy with energy of protein had no effect on forage DMI of ewes grazing winter range.

Animal Feed↗

Effects of substituting feather meal for soybean meal on ruminal fiber fermentation and lamb and wool growth.

Our objective was to evaluate the effects of substituting feather meal (FM) for soybean meal (SBM) on ruminal fiber fermentation, lamb gain, blood metabolite profiles, and wool growth. A SBM supplement was formulated, and FM replaced either 33% (33FM), 66% (66FM), or 100% (FMS) of the SBM protein. Four ruminally cannulated wethers were used in a 4 x 4 Latin square design to study in situ ruminal digestion. Wethers were limit-fed barley straw and fed the supplements once daily. Ruminal NH3 N concentrations reflected a sampling time x protein source interaction (P < .01). Within sampling times, ruminal NH3 N concentrations decreased linearly (P < .05) as FM replaced soybean meal. Cubic (0 h; P < .10) and quadratic (24 h; P < .05) responses also were noted for ruminal NH3 N concentration. Substitution of FM for SBM had no effect (P > .10) on rate and extent of straw NDF disappearance. A 56-d feeding trial was conducted using 28 wether lambs (n = 7 per treatment; initial BW 32.3 kg). Wethers were individually fed chopped barley straw and one of the four supplements described previously. Linear increases (P < .05) in BW gain and serum total protein concentration were observed as FM replaced SBM. Wool fiber diameter and sulfur content did not differ (P > .10) among treatments. These data suggest that FM can be substituted for SBM in protein supplements fed to sheep consuming low-quality roughages at a maintenance level of ME intake.

Ammonia↗

Effects of supplemental protein source on passage of nitrogen to the small intestine, nutritional status of pregnant ewes, and wool follicle development of progeny.

Rambouillet wethers, surgically fitted with ruminal and duodenal cannulas, were used to determine the influence of substituting soybean meal (SBM) with blood meal (BM) in grass hay diets (8.0% CP) on N flow to the small intestine. Treatments were arranged in a 3 x 4 Latin square design and included diets (10.6% CP) supplemented with SBM; 2/3 SBM:1/3 BM; 1/3 SBM:2/3 BM; or BM. Ruminal NH3 N concentration decreased linearly (P = .03) as BM replaced SBM; however, feeding BM did not affect (P > .10) the total N, microbial N, or nonammonia N flows to the small intestine. A second experiment was conducted to determine the influence of substituting SBM with BM on ewe BW and condition score changes, blood metabolite profiles, wool growth, and progeny wool follicle development. Thirty-two pregnant Targhee ewes fed a grass hay diet were allotted randomly to four groups (n = 8) and supplemented with either SBM; 2/3 SBM:1/3 BM; 1/3 SBM:2/3 BM; or BM. Soybean meal, BM, or their combinations provided 22 g of dietary CP daily. Dietary treatments had no influence on ewe BW (P = .40) or body condition score (P = .77) changes, and ewes gained 7.6 kg of BW during the 84-d experiment. Protein source did not influence (P > .10) serum protein, urea N, creatinine, glucose, or nonesterified fatty acid concentrations. Lamb wool follicle density per square millimeter and secondary:primary follicle ratios were 22.4 and 10.8, respectively, and were not different (P > .10) among dietary treatments. Compared with SBM, no advantages were detected for BM supplementation of grass hay diets in these studies.

Animal Feed↗

Effects of supplemental protein source and metabolizable energy intake on nutritional status in pregnant ewes.

Two experiments were conducted to evaluate effects of supplemental protein source and ME intake (Exp. 1) on ewe nutritional status during pregnancy. Forty-two mature Targhee ewes were allotted randomly in Exp. 1 to one of six treatments (n = 7) using a 2 x 3 factorial arrangement. Ewes were individually fed chopped barley straw and supplements containing either urea (U), soybean meal (SBM), or blood meal (BM) plus SBM during the 84-d experiment. Straw and supplement intakes were adjusted to meet either 80 or 100% of ME requirements. In Exp. 2, 30 pregnant Targhee ewes that were allotted randomly to one of three groups (n = 10) were individually fed protein supplements similar to those in Exp. 1 and had group access to long-stem barley straw. In Exp. 1, ewes fed BM + SBM gained more (P less than .05) weight, lost less (P less than .05) body condition, and had increased (P less than .05) wool fiber length compared with ewes fed U; SBM ewes were intermediate (P less than .05) in response. Ewes fed BW + SBM had increased (P less than .05) blood urea N and albumin concentrations compared with ewes fed U. Metabolizable energy intake did not affect (P greater than .05) ewe performance or serum metabolite concentrations. Ewes fed BM + SBM in Exp. 2 gained more (P less than .05) weight than ewes fed either SBM or U, and ewes fed SBM lost less weight (P less than .05) than ewes fed U.(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Feed↗

Effects of skirting on processing characteristics of Targhee wool.

Ninety mature Targhee ewes were randomly allocated to nine lots. Lots were randomly assigned to three fleece preparation treatments: 1) nonskirted (control); 2) bellies removed, in which bellies and topknots were removed on the shearing floor; and 3) skirted, in which bellies and topknots were removed and remaining fleece was thrown on a table and lightly skirted. Bellies and topknots composed about 6 to 7% of the fleece weight. An additional 6.6% was removed when fleeces were skirted. Top fiber diameters were not affected (P greater than .10) by skirting. Although not significant (P greater than .10), percentage yield, vegetable content, percentage of noilage, top fiber length, and yellowness indexes tended to be most desirable for skirted lots and least desirable for unskirted lots. Lots with bellies removed were intermediate. Removal of bellies reduced vegetable contamination by 8.4%, with an additional reduction of about .5% by further skirting. Skirting reduced the number of fibers less than 25.4 mm (P less than .10) by 42%. Minimal colored fiber contamination of top was observed. One colored fiber per 15 g of top was detected in two lots of the treatment with bellies removed. All other lots contained no colored fibers. All wools evaluated were well below industry limits set for use in high-quality white or pastel fabrics. All skirted lots of wool evaluated in this study had improved processing characteristics for all processing traits evaluated.

Animal Husbandry↗

Caring for the person receiving ventilatory support at home: care givers' needs and involvement.

Little is known of the needs of family members who provide home care to persons receiving ventilatory support (VS). In a structured interview of 44 care givers of 29 persons receiving VS, finances, provisions for emergencies, information, family relationships, and continuity of care were ranked as the most important needs. Needs for support services were ranked highest in importance to the care givers of persons receiving continuous VS, care givers who did not live in, and children of persons receiving VS. Parents of persons receiving VS ranked educational needs and attention to other family members of highest importance. Handling emergencies was most important to less experienced care givers, whereas financial and respite needs were more important to experienced and full-time care givers. Findings suggest the need for early participation of community health care professionals in care giver preparation, negotiations with third-party payers, 24-hour support services, information networks, and long-term, comprehensive coverage of services.

Activities of Daily Living↗

Influence of lasalocid and supplement level on productivity of gestating ewes grazing winter range.

Two winter feeding trials (1985-86; 1986-87) were conducted to evaluate the productivity of gestating ewes fed lasalocid (L) and two supplement levels while grazing Montana winter range. Five hundred range ewes were randomized within age and breed each year and allotted to .15 or .23 kg hd-1.d-1 of a 20% CP supplement and either no L or L at 70 mg hd-1.d-1. Feed treatments began on 18 Dec. approximately 100 d before the first expected lambing date and continued for 84 d. Ewes fed .23 kg of supplement per day gained more (P less than .01) total weight (4.9 vs 4.0 kg) during the 84-d experiment and had higher (P less than .05) grease fleece weights (4.2 vs 4.0 kg) than those fed .15 kg of supplement. Lasalocid had no effect (P greater than .05) on ewe weight change or grease fleece weights. Supplement level had no effect (P greater than .05) on reproduction, lamb mortality and lamb performance. Ewes fed L had a greater (P less than .05) percentage of lambs born per ewe than those not fed L (120.7 vs 112.1%); lamb performance was similar (P greater than .05) between treatments. However, because a greater percentage of lambs were born per ewe starting the experiment, ewes fed L produced more (P less than .05) kilograms of weaned lamb than those not fed L (25.9 vs 23.4 kg). In conclusion, ewes fed L and grazing winter range weaned more kg of lamb than did controls because of an improved lambing percentage.(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Feed↗

Relationships between Brucella ovis semen culture and various semen and serology parameters.

Semen and blood samples from 154 rams from two Montana range flocks (Flock A, vaccinated for Brucella ovis ; Flock B, nonvaccinated) were evaluated to determine the relationship between Brucella ovis (B. ovis ) semen culture results and various semen and blood parameters. All rams utilized in this study exhibited no palpable ram epididymitis lesions. Thirteen and 25.6% of the rams tested in Flocks A and B, respectively, had positive B. ovis semen cultures. Only age of ram and ram condition scores differed (P<0.05) between flocks. No flock by semen culture interactions were detected (P>0.05) for any of the parameters evaluated. Age of ram, ram condition score, and spermatozoa rate from forward movement were unrelated (P>0.05) to B. ovis culture results. Rams with positive B. ovis semen cultures had lower sperm motility (P<0.05), higher percentage of abnormal spermatozoa cells (P<0.05), higher percentage of spermatozoa head abnormalities (P<0.01), lower percentage of live-normal cells (P<0.05), higher incidence of white blood cells in semen (P<0.01) and higher complement fixation (CF) titers (P<0.01).

Journal Article↗

Influence of body condition and lasalocid during late gestation on blood metabolites, lamb birth weight and colostrum composition and production in Finn-cross ewes.

The objective of this experiment was to examine the effects of body condition (BC) and of lasalocid (L) the last 4 wk of gestation on blood metabolite profiles, lamb birth weight and colostrum composition and production. Twenty-eight 3-yr-old Finn-Targhee ewes (73 kg) were assigned randomly within BC grouping (2.5 or 3.5) and individually fed a diet of 90% alfalfa pellets and 10% of a supplement containing either no L (C = control) or L. Gestation and 24-h postlambing weights were higher (P less than .05) for 3.5 BC versus 2.5 BC ewes. Lasalocid had no effect (P greater than .05) on ewe weight. Average number of lambs born within treatment groups were similar (P greater than .05). Total kilograms of lamb born were greater (P less than .10) for 3.5 BC ewes. Body condition 3.5 ewes had greater concentrations of total protein (P less than .10) and albumin (P less than .05) the last 4 wk of gestation than those in the 2.5 BC group. Feeding L decreased (P less than .05) blood urea-N in comparison with C ewes. Colostrum composition and production were not influenced (P greater than .05) by BC, L or number of lambs born. Serum 3-hydroxybutyrate seemed to be a good indicator of energy metabolism; albumin and blood urea-N concentrations reflected dietary protein intake. Lasalocid had a minimal effect on nutrient metabolism and productivity of ewes fed in excess of the NRC (1985) protein and energy requirements.

Animals↗

The degradation of [14C]molinate in soil under flooded and nonflooded conditions.

The degradation of [14C]molinate in soil under flooded and nonflooded conditions was investigated. In laboratory studies, 50 percent of the applied molinate was lost in 3 weeks under moist soil conditions, while under flooded conditions, dissipation was reduced to 50 percent loss in 10 weeks. Analysis for molinate and its degradation products in the soil and flood water showed that under flooded conditions very little breakdown of molinate occurred, and volatilization was the primary mode of dissipation. However, under nonflooded conditions, hydroxylation of the azepine ring and further oxidation to the respective ketones occurs. Oxidation to form the sulfoxide, cleavage to yield the imine, and acetylation of the imine are also proposed. Other pathways appear to involve desethylation to produce a free thiocarbamic acid derivative followed by S-methylation as well as carboxylation of the S-ethyl group.

Azepines↗