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Biomedical subjects

S R Lowry

Publications and source records attributed to S R Lowry.

At least 19 recordsLinked to original sources
PubMed2001

Use of FT-NIR transmission spectroscopy for the quantitative analysis of an active ingredient in a translucent pharmaceutical topical gel formulation.

The objective of this study was to demonstrate the use of transmission Fourier transform near-infrared (FT-NIR) spectroscopy for quantitative analysis of an active ingredient in a translucent gel formulation. Gels were prepared using Carbopol 980 with 0%, 1%, 2%, 4%, 6%, and 8% ketoprofen and analyzed with an FT-NIR spectrophotometer operated in the transmission mode. The correlation coefficient of the calibration was 0.9996, and the root mean squared error of calibration was 0.0775%. The percent relative standard deviation for multiple measurements was 0.10%. The results prove that FT-NIR can be a good alternative to other, more time-consuming means of analysis for these types of formulations.

Administration, Topical↗
PubMed2001

Effects of dietary fat and L-carnitine on plasma and whole blood taurine concentrations and cardiac function in healthy dogs fed protein-restricted diets.

OBJECTIVE: To evaluate plasma taurine concentrations (PTC), whole blood taurine concentrations (WBTC), and echocardiographic findings in dogs fed 1 of 3 protein-restricted diets that varied in fat and L-carnitine content. ANIMALS: 17 healthy Beagles. DESIGN: Baseline PTC and WBTC were determined, and echocardiography was performed in all dogs consuming a maintenance diet. Dogs were then fed 1 of 3 protein-restricted diets for 48 months: a low-fat (LF) diet, a high-fat and L-carnitine supplemented (HF + C) diet, or a high-fat (HF) diet. All diets contained methionine and cystine concentrations at or above recommended Association of American Feed Control Officials (AAFCO) minimum requirements. Echocardiographic findings, PTC, and WBTC were evaluated every 6 months. RESULTS: The PTC and WBTC were not significantly different among the 3 groups after 12 months. All groups had significant decreases in WBTC from baseline concentrations, and the HF group also had a significant decrease in PTC. One dog with PT and WBT deficiency developed dilated cardiomyopathy (DCM). Taurine supplementation resulted in significant improvement in cardiac function. Another dog with decreased WBTC developed changes compatible with early DCM. CONCLUSIONS AND CLINICAL RELEVANCE: Results revealed that dogs fed protein-restricted diets can develop decreased taurine concentrations; therefore, protein-restricted diets should be supplemented with taurine. Dietary methionine and cystine concentrations at or above AAFCO recommended minimum requirements did not prevent decreased taurine concentrations. The possibility exists that AAFCO recommended minimum requirements are not adequate for dogs consuming protein-restricted diets. Our results also revealed that, similar to cats, dogs can develop DCM secondary to taurine deficiency, and taurine supplementation can result in substantial improvement in cardiac function.

Animals↗
PubMed1998

The analysis of exfoliated cervical cells by infrared microscopy.

The screening technique developed by Dr. Papanicolau for cervical cancer has significantly increased opportunities for early detection and treatment of this disease. Recently there has been a great deal of concern related to the accuracy of the Pap smear screening technique for cervical cancer and the need for highly skilled technologists to reliably examine the prepared samples. The use of infrared spectroscopy as a technique to discriminate between normal and malignant cervical cell samples has been reported by several research groups. Samples of cervical cells can be prepared for spectroscopic diagnosis by centrifuging cells obtained by the normal Pap smear technique and applying them to an infrared transparent window. A major concern with diagnosis by infrared spectroscopy is the homogeneity of the sample and whether the spectral features used in the analysis are caused by localized groups of cells or can be attributed to the majority of the cells in the sample. In this paper we report on the use of automated infrared microscopic mapping techniques to measure the infrared spectra at fixed intervals across the sample covering a 5 mm spot. Various post processing techniques have been applied to the spectral results to create images revealing specific features of the sample. The techniques applied to the data include: 1) Baseline corrected peak height; 2) Band ratioing to compensate for thickness; 3) Correlation metrics; 4) Similarity matching, and 5) Mahalanobis distance classification algorithm.

Algorithms↗
PubMed1997

Improved osseointeraction of calcium phosphate-coated external fixation pins. Studies in calves.

We investigated osseointeraction of solution-precipitated calcium phosphate (SPCP)-coated transfixation pins used in external skeletal fixation of a calf stable fracture model. One group (SPCP) received centrally-threaded transfixation pins which had SPCP coating; the other group (control) received identical, but not coated, pins. Radiographs were obtained 1 and 40 days after surgery and examined for evidence of osteolysis. Bone phase 99mTc-MDP studies were performed 6 and 28 days after surgery. Calves were killed 40 days after surgery and mechanical tests performed. Dual-energy x-ray absorptiometry (DEXA) and histomorphometric analyses were done. A smaller proportion of SPCP pins (5/24) had evidence of discharge during the study compared with control pins (21/24). A smaller proportion of SPCP pins (4%) had radiographic evidence of osteolysis compared with control pins (42%). Uptake of 99mTc-MDP was similar for SPCP and control calves. Uptake was significantly greater in bone segments showing radiographic evidence of osteolysis than in bone segments not having osteolysis. Yield stress (MPa) for axial displacement was similar in the treatment groups. Bone mineral density was less in SPCP pins. Affinity index and interface histologic score were greater and osteoclastic index less in SPCP calves. Coating of transfixation pins with solution-precipitated calcium phosphate improved the osseointeraction of pin and bone during this 40-day study.

Absorptiometry, Photon↗
PubMed1994

Identification, characterization, and physical mapping of 14 polymorphic simple sequence repeat markers on human chromosome 21.

Fourteen new dinucleotide repeat polymorphisms specific for human chromosome 21 have been identified, mapped, and characterized. The average heterozygosity of all markers was 0.66. The average PIC value was 0.61. The markers were mapped by STS content mapping of YACs previously assigned to chromosome 21. The correlation of polymorphic genetic markers with substantially complete physical maps should facilitate the identification of loci of interest on chromosome 21.

Base Sequence↗
PubMed1994

Effects of chemical restraint on the endoscopic appearance of laryngeal and pharyngeal anatomy and sensation in adult cattle.

Effects of 2 drugs commonly used for chemical restraint of cattle were evaluated for their effect on laryngeal and pharyngeal anatomy, function, and response to stimuli. Eighteen adult Jersey cows, free of respiratory tract disease, were studied. Cows were assigned at random to 1 of 3 treatment groups. Endoscopic evaluations were performed before and at a predetermined time interval after administration of each drug. Responses to stimuli were evaluated by stimulating 7 preselected sites (epiglottis, left and right arytenoid cartilages, left and right vocal folds, and left and right dorsolateral pharyngeal walls) with a closed, transendoscopic biopsy probe. Xylazine HCl (0.05 mg/kg of body weight, i.v.) was administered to group-1 cows (n = 6), and endoscopy was repeated 5 minutes after administration of the drug. Xylazine (0.07 mg/kg, i.v.) was administered to group-2 cows (n = 6), and endoscopy was repeated 5 minutes after administration of the drug. Acepromazine maleate (0.035 mg/kg, i.v.) was administered to group-3 cows (n = 6), and endoscopy was repeated 10 minutes after administration of the drug. Responses to stimuli were scored as brisk (0), moderate (1), slow (2), and absent (3). Scores for responses to stimuli were compared, using the Wilcoxon signed-rank test for data within groups, and a general linear models procedure, using the Kruskal-Wallis test between groups. Interobserver agreement rates were generated for each group. A value of P < 0.05 was considered significant. Xylazine profoundly changed laryngeal sensitivity and function at both dosages. The corniculate processes of the arytenoid cartilages were observed to be in a markedly adducted position after sedation.(ABSTRACT TRUNCATED AT 250 WORDS)

Acepromazine↗
PubMed1993

Cloning and characterization of EagI YACs from human chromosome 21.

Yeast artificial chromosomes (YACs) were made from a total EagI digest of DNA from a mouse-human chromosome 21 hybrid cell line. Approximately 3750 YACs, corresponding to 75-125 human YACs, with an average size of approximately 100 kb were recovered. Southern hybridization indicates that the chimera frequency in this library may be less than 3%. Thirty-four of the human EagI YACs were regionally assigned by a number of methods. Some YACs were regionally assigned to one of six chromosome regions by hybridization of Alu-PCR products from the YAC against Alu-PCR-amplified DNA from a panel of hybrid cell lines that contain various parts of chromosome 21. Additional YACs were regionally assigned by fluorescence in situ hybridization using either biotinylated Alu-PCR products or yeast genomic DNA from the YAC-containing strains as probes. The regionally assigned EagI YACs are located preferentially in two regions of the chromosome: near the q telomere and in the p-arm ribosomal gene region.

Animals↗
PubMed1993

A fluorescence in situ hybridization map of human chromosome 21 consisting of 30 genetic and physical markers on the chromosome: localization of 137 additional YAC and cosmid clones with respect to this map.

A fluorescence in situ hybridization (FISH) map of human chromosome 21 was compiled using yeast artificial chromosome (YAC) DNA probes that encode 28 markers physically and/or genetically mapped on the chromosome. Probes that recognize the centromere and rDNA repeat sequences in the p arm were also placed as reference markers on the FISH map. For each probe, the location of the fluorescence hybridization signal was measured on metaphase chromosomes with respect to fractional chromosome length (FL) from p-ter. The location of the markers was established with a standard error of +/- 1.9 Mb using from 9 to 63 FL measurements for each probe. The relative order and separation of the markers as determined by FISH are shown to correspond well to those of other maps of the chromosome. Fifty-one additional YAC and 86 cosmid clones were also localized by FISH with respect to the 30 markers on the chromosome. The cosmids, chosen at random from a flow-sorter chromosome 21 cosmid library, show some biases in chromosome distribution.

Chromosome Mapping↗
PubMed1992

Voluntary intake and ingestive behavior of steers grazing Johnstone or endophyte-infected Kentucky-31 tall fescue.

Effects of grazing low-endophyte (Acremonium coenophialum Morgan-Jones and Gams, less than 1% infection) Johnstone (J) or high-endophyte (60% infection) Kentucky-31 (K) tall fescue (Festuca arundinacea Schreb.) on grazing behavior and voluntary intake were studied. Six Angus steers (average initial BW = 326 kg) grazed 1.21-ha plots of each forage cultivar (three steers per cultivar) in four 28-d periods beginning May 27. Daytime observations (0630 until 2130) revealed that J steers spent more (P less than .10) time grazing and lying down and took more (P less than .05) prehensile bites than K steers did; conversely, steers grazing K spent more (P less than .10) time standing and idling than J steers did. Idling time showed a forage x period interaction (P less than .10). Mean OM bite size (grams per bite) was not affected (P greater than .10) by forage but differed (P less than .10) among periods. Limited nighttime observations (2130 until 0630) revealed no effects (P greater than .10) of forage on grazing time or number of prehensile bites taken. Voluntary intakes of OM and NDF did not differ (P greater than .10) between steers grazing J and K; however, a forage x period interaction (P less than .10) existed such that, during Period 1, steers grazing J had greater (P less than .01) OM and NDF intakes than did steers grazing K. These data suggest that cattle grazing endophyte-infected tall fescue display altered daytime grazing behavior and that reduction of voluntary intake attributable to endophyte infection may be less severe under free-grazing than has been reported for controlled environmental conditions.

Acremonium↗
PubMed1992

Use and misuse of multiple comparisons in animal experiments.

The objective of many animal experiments is to detect meaningful relationships among treatments and associated responses. Types of comparisons of means include pairwise multiple comparisons, planned orthogonal or nonorthogonal contrasts, and orthogonal polynomials. Some procedures are appropriate only for specific types of treatment designs and specific types of objectives. Pairwise, multiple comparisons are appropriate only for comparing unstructured, qualitative treatments. Planned comparisons partition the overall set of treatment effects into independent or nonindependent subsets, with special application to factorials. Orthogonal polynomial (regression) procedures assess relationships between quantitative treatments and response when a full range of responses or an optimal dose is of interest. Recommendations for appropriate use of each mean comparison procedure are illustrated using data from three Journal of Animal Science articles. Also mentioned are a number of computer graphics packages that provide creative ways to display biological relationships and can be linked to statistical packages for input and to word processors or 35-mm cameras for output.

Analysis of Variance↗
PubMed1990

Effects of nutrition, sex of calf and breed type on response to zeranol: preweaning growth.

An experiment was conducted to evaluate the effects of breed, sex and plane of nutrition on the growth response to zeranol in Angus and crossbred calves prior to weaning. Eighty-eight heifers and 118 steers received either a high or low plane of nutrition using a first and last grazing technique. Half of the calves in each nutrition group received a zeranol implant (36 mg) at an average age of 3.4 mo. Both zeranol and the higher level of nutrition increased (P less than .001) growth rate prior to weaning (7.4 mo of age). Zeranol did not affect hip height at weaning (P greater than .1), but calves on the higher plane of nutrition were taller (P less than .01) than calves on the lower plane of nutrition. The zeranol x nutrition interaction was not significant (P greater than .1) for growth rate or hip height. Steers grew faster (P less than .01) preweaning and were taller (P less than .01) at weaning than heifers. Crossbred calves gained more rapidly (P less than .001) preweaning and were taller (P less than .001) at weaning than Angus calves were. Neither sex nor breed interacted with zeranol to influence any of the traits examined. Based on these results we conclude that preweaning growth was affected by zeranol and this effect was consistent across sexes, breeds and planes of nutrition tested.

Animal Nutritional Physiological Phenomena↗
PubMed1990

Severity of liver abscesses and efficiency of feed utilization of feedlot cattle.

Relationships of gain, intake, feed efficiency and severity of liver abscesses were evaluated in 12 experiments involving 566 head of individually fed cattle. Concentrate level in the diets ranged from 64 to 95%. In all experiments, livers were scored as unabscessed (0), one or two small abscesses (A-), two to four small active abscesses (A) or one or more large, active abscesses (A+). Based on homogeneity of variances, nine of the experiments were divided into two groups. In one group (four experiments) the incidence of liver abscesses was 32.1% and no significant (P greater than .25) effects of liver abscess severity score on feedlot performance variables were found. In the second group (five experiments), the incidence of liver abscesses was 77.7%. In the second group, liver abscess severity score affected final live weight (P less than .10), hot carcass weight (P less than .0001), dry matter intake (P less than .10), daily gain based on live weight recorded 24 h prior to slaughter (P less than .10), daily gain based on live weight estimated from hot carcass weight with a 62% dressing percentage (P less than .0001), feed efficiency using final live weight estimated from hot carcass weight (P less than .0001) and dressing percentage (P less than .01). In all cases, performance means for cattle with A+ liver scores were the only ones that differed significantly from those of non-abscessed cattle.

Analysis of Variance↗
PubMed1989

Corn gluten meal and blood meal mixture for dairy cows in midlactation.

Twelve midlactation Holstein cows were assigned to a switchback design with 4-wk periods to compare a corn gluten meal and blood meal mixture with soybean meal as supplemental protein sources. All experimental diets contained 60% ammoniated corn silage, on a dry basis, and a corn and oats (2:1) basal concentrate mixture. Diets were: urea control (12.5% CP); soybean meal (16.1% CP); low protein (14.3% CP) corn gluten and blood meal mixture; and high protein (16.8% CP) corn gluten and blood meal mixture. Cows fed the control diet consumed less DM, and produced less milk containing a lower percentage of protein than cows fed other diets. Protein efficiency and milk fat percentage were higher for cows fed the control diet than for cows fed the natural protein diets. Fat-corrected milk and fat yields did not differ among diets. The high protein diets (16.1 and 16.8% CP) decreased protein efficiency and increased SNF percentage. Milk yield per unit of DM intake was higher when cows fed the lower degradable protein source (corn gluten-blood meal) than when they were fed soybean meal. The low degradable protein mixture produced a similar lactation response to soybean meal at both the high and low concentrations of total dietary protein. This study indicates that the dietary protein and undegradable protein concentration needed by midlactation Holstein fed complete mixed diets may be lower than generally recommended.

Amino Acids↗
PubMed1989

Role of parathyroid hormone in the anemia of chronic terminal renal dysfunction in dogs.

Terminal renal dysfunction (TRD) was induced in 2 groups of dogs by partial surgical ablation of the kidney. Dogs of a control group and of 1 of the TRD groups were maintained on a diet containing normal phosphorus concentration, whereas dogs of the other TRD group were maintained on a low-phosphorus diet. Mild anemia developed in dogs of both TRD groups and could not be attributed to iron deficiency, increased erythrocyte concentration of 2,3-diphosphoglycerate, or absolute deficiency of erythropoietin (EP). Subsequently, all dogs were acutely depleted of approximately 25% of their blood volume. Erythropoietin concentration in dogs of the TRD groups was lower than that of controls, however, erythroid regenerative capacity was comparable with that of control dogs when plasma parathyroid hormone (PTH) concentration was lowered by reduced dietary intake of phosphorus. The PCV in dogs of the chronic TRD groups had a slight positive correlation with serum EP concentration, and a significant (P less than 0.05) negative correlation with plasma PTH and serum phosphorus and creatinine concentrations, using a correlation matrix. There was no longer a significant correlation between plasma PTH concentration and PCV after controlling for serum creatinine concentration by use of a multiple linear regression analysis. A significant (P less than 0.05) negative correlation also was observed between plasma PTH and serum EP concentrations, but not between serum EP and phosphorus or creatinine concentrations. Significance of the EP and PTH association was reduced when analyzed, using a multiple linear regression analysis that included serum creatinine values.(ABSTRACT TRUNCATED AT 250 WORDS)

Anemia↗
PubMed1988

Piperazine resistance in population-B equine strongyles: a study of selection in Thoroughbreds in Kentucky from 1966 through 1983.

Observations were completed over an 18-year period (1966 through 1983) in Thoroughbred mares (15/year) and yearlings (11 to 24/year) on a farm where benzimidazole-resistant small strongyles had emerged previously (1962 to 1965). This farm was operated as a closed, nonboarding type, which included a racing stable for its home-bred foals. At 2-week intervals, counts of worm eggs per gram of feces (EPG) and larvae per gram of feces were done to monitor strongyle infections and efficacies of bimonthly (every 8 weeks) antiparasitic treatments that were administered by stomach tube or were fed (dichlorvos pellets) to 1 group of yearlings during a 7-year period (1970 through 1976). The study included several drugs or mixtures, including thiabendazole (TBZ), phenothiazine (PTZ) + piperazine (PPZ)-carbon disulfide (CS2) complex, PTZ + PPZ + trichlorfon (TCF), dichlorvos, and pyrantel pamoate. These were used selectively in treated subgroups (usually 3/year) of mares and yearlings. The horses in drug treatment subgroups grazed together on common pastures; thus, efficacy comparisons between drugs were limited or nullified. However, annual mean EPG and larvae per gram of feces counts of mares and yearlings tended to increase over time, and for the yearlings treated with TBZ + PPZ and PTZ + PPZ-CS2, the buildup of these mean counts was statistically significant (P less than 0.05 for regression coefficients).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗