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Biomedical subjects

J A Patterson

Publications and source records attributed to J A Patterson.

At least 37 records · Page 2Linked to original sources
PubMed1993

Effect of galactan on selected microbial populations and pH and volatile fatty acids in the ileum of the weanling pig.

Studies were conducted to determine the effect of galactan on the colonization of E. coli and lactobacilli and ileal pH and volatile fatty acid production in the digestive tract of the weanling pig. In each of two replicate trials, eight 21-d-old nursing pigs were cannulated in the terminal ileum. After a 7-d recovery period, the pigs were weaned and randomly assigned to two test diets: 1) a corn-soybean meal-based control diet and 2) a similar diet containing 1% galactan. On d 1 after weaning, all pigs were orally subjected to K88+ E. coli (2 x 10(9) colony forming units). Ileal digesta samples were collected on d 0, 2, 4, 6, 8, and 10 after weaning and assayed for total E. coli, K88+ E. coli, lactobacilli, pH, and VFA. At the end of the trials, the pigs were killed and digesta samples were collected from the stomach, duodenum, cecum, and colon. Assays similar to those performed on the digesta samples collected from ileal cannulas were performed. Pigs fed 1% galactan had lower (P < .10) ileal pH, lower (P < .05) total E. coli on d 6 and 8, and lower (P < .05) K88+ E. coli concentrations in the ileum than pigs fed the control diet. There were no differences in ADG or gain:feed ratio between diets. The VFA concentrations were not different in the ileum between diets. The VFA were higher (P < .10) on d 0 than on any other day of the study. Acetate and isobutyrate concentrations were lower (P < .10) in the cecum in pigs fed 1% galactan.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Anaerobic Production of Extracellular Polysaccharide by Butyrivibrio fibrisolvens nyx.

Anaerobic production of extracellular polysaccharide (EP) was examined, using a previously uncharacterized, obligately anaerobic rumen isolate, Butyrivibrio fibrisolvens nyx, which produced an EP that was rheologically similar to xanthan gum. The main objectives were to determine the nutritional requirements and conditions which promoted EP production by strain nyx. Strain nyx was grown anaerobically in defined and semidefined media. In addition to carbohydrate and nitrogen sources, strain nyx required acetic acid, folic acid, biotin, and pyridoxamine. Strain nyx produced similar amounts of EP at 35 to 40 degrees C. Conditions that improved growth usually improved EP production. Of the carbohydrates tested, glucose supported the fastest growth and most EP production, followed by sucrose, xylose, and lactose. Strain nyx utilized ammonium sulfate, urea, or vitamin-free casein hydrolysate as nitrogen sources for growth and EP production. At 2 and 20 g/liter, respectively, ammonium sulfate and vitamin-free casein hydrolysate supported about the same rates of growth and EP production. EP was not produced in the lag or stationary phases, and EP production was exponential during exponential cell growth. Based on the results of this work, anaerobic EP production with B. fibrisolvens nyx could reduce energy costs for industrial EP production compared with the cost of aerated systems. Finally, this work demonstrated that, under appropriate growth conditions, a gastrointestinal tract (ruminal) microorganism produced high levels of EP.

Journal Article↗
PubMed1990

Digestibility and feeding value of pearl millet as influenced by the brown-midrib, low-lignin trait.

Our objectives were to determine the intake and digestibility of pearl millet as influenced by the brown-midrib (BMR), low-lignin trait and to determine the relative acceptability of BMR pearl millet in relation to its normal counterpart. Two field replicates of brown-midrib pearl millet and its normal counterpart were harvested as hay at the boot to heading stage twice during the growing season (2 genotypes x 2 cuttings x 2 field replicates). Twenty-four wethers had ad libitum access to a total forage diet (pearl millet forage), water and trace mineralized salt. The experimental period was 21 d (14 d for adjustment and 7 d for sample collection). Lignin was 23% lower (P less than or equal to .01) and in vitro DM digestibility (IVDMD) was 4% higher (P less than or equal to .01) in BMR vs normal genotype forages. Wethers preferred first-cutting millet to second-cutting millet, as evidenced by 62% higher (P less than or equal to .01) DMI for first-cutting forages. Dry matter intake of second-cutting forages was higher (P less than or equal to .10) for BMR pearl millet forage than for normal pearl millet (2.0 vs 1.5% of BW), but first-cutting forages were similar in DMI (2.9% of BW). In an acceptability trial of pearl millet regrowth (4 wk), grazing lambs with access to both genotypes displayed a marked preference (P less than .01) for the BMR genotype, spending an average of 2.6 min on plots containing the brown-midrib pearl millet for every minute spent on the normal genotype.(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Feed↗
PubMed1989

Use of 2-ethoxyethanol and alpha-amylase in the neutral detergent fiber method of feed analysis.

Use of 2-ethoxyethanol in the NDF procedure for feed analysis was reevaluated, because justification for its use in the NDF procedure has diminished and 2-ethoxyethanol poses potential health hazards. Initial rationale for addition of 2-ethoxyethanol was to minimize inhibitory effects of decalin on filtration and to facilitate starch solubilization. Decalin is no longer recommended in the procedure; alpha-amylase is commonly used to facilitate starch solubilization. Objectives of this study were to evaluate effects on NDF values of: 1) eliminating 2-ethoxyethanol from the procedure and 2) addition of and timing of addition of alpha-amylase. Deletion of 2-ethoxyethanol resulted in lower NDF values than neutral detergent solution with 2-ethoxyethanol (61.95 and 62.06%, respectively). Neutral detergent fiber values were lower for samples treated with alpha-amylase just prior to filtration (61.86%) than for samples not treated with alpha-amylase (62.13%). Addition of alpha-amylase 30 min after onset of boiling resulted in lower values (62.07%) than with no alpha-amylase addition (62.29%) in solutions containing 2-ethoxyethanol but not in solutions without 2-ethoxyethanol. Observed treatment differences were small, however, and probably not of practical significance. No differences in NDF values were noted due to timing of alpha-amylase addition. Inclusion of samples requiring alpha-amylase to filter increased overall mean CV and resulted in no statistical differences between neutral detergent solutions or alpha-amylase treatments. Suggested modifications to the NDF procedure include elimination of 2-ethoxyethanol and addition of alpha-amylase just prior to filtering.

Animal Feed↗
PubMed1989

Sertoli-Leydig cell tumor associated with a mature cystic teratoma in a single ovary.

Sertoli-Leydig cell tumors of the ovary are rare neoplasms of young women and are best known for their frequent virilizing effects. They have very rarely been reported in association with other ovarian neoplasms. We report such a tumor associated with a mature cystic teratoma in the same ovary. The wide variety of histologic patterns seen in many Sertoli-Leydig cell tumors including the present case, often causing difficulty in diagnosis, is reviewed.

Adult↗
PubMed1988

Threshold recovery functions following impulse noise trauma.

An analysis of the pure-tone threshold recovery functions obtained from 118 chinchillas exposed to high-level impulse noise showed that there are at least three distinctly different types of recovery function: type I--a recovery function for which the initial threshold shift recovers monotonically with increasing postexposure time; type II--a delayed recovery; i.e., for a period as long as 6 h following removal from noise, the pure-tone threshold remains elevated and stable before thresholds begin to follow a monotonic course of recovery; and type III--the growth function; i.e., over a period of at least 6 h following removal from the noise, pure-tone thresholds continue to get worse before they begin to follow a monotonic course of recovery. There is more permanent threshold shift (PTS), more sensory cell loss, and predictions of PTS and cell loss based upon initial measures of threshold shift are less accurate at those frequencies characterized by a type III recovery process than at those frequencies characterized by a type I recovery process.

Acoustic Stimulation↗
PubMed1988

Effect of dietary energy source and concentration on performance of dairy cows during early lactation.

Eighteen Holstein heifers were placed into groups of 3 according to projected calving date, prepartum BW, and prepartum condition score. Following parturition, animals within each group were assigned randomly to one of three diets and remained on the experiment for 45 d. Diets consisted of forage:concentrate ratios of 72:28, 53:47, or 73:27 (isocaloric to the 53:47 ratio by addition of 8% soybean oil). Diets were fed twice daily as total mixed rations. Blood, rumen fluid, and adipose tissue were sampled at -7, 5, 20, and 45 d of lactation. Performance means were, respectively: DM intake (kg/d) 13.9, 14.9, and 12.4; milk (kg/d) 24.5, 25.8, and 18.6; milk fat (%) 3.77, 3.59, and 3.62; milk protein (%) 3.03, 2.99, and 3.11; body condition score (0 = thin, 5 = fat) 1.53, 1.87, and 1.99; and BW (kg) 514, 523, and 505. Cows fed soybean oil had higher ruminal isoacids than those fed the other diets and higher acetate than cows on the 53:47 diet. Diets had no effect on blood metabolites or activity of adipose glycerol-P dehydrogenase (EC 1.1.1.8). The soybean oil diet reduced short-chain fatty acids and increased long-chain fatty acids in milk. Feed intake and milk production were highest for cows receiving the 53:47 diet. As expected, animals on the 72:28 diet did not consume adequate energy to maintain high production which concurrently resulted in lower body condition scores.

Animal Nutritional Physiological Phenomena↗
PubMed1988

Metabolism of DL-methionine and methionine analogs by rumen microorganisms.

Rates of degradation of DL-methionine and a number of methionine derivatives by rumen microorganisms were studied in vitro. Methionine hydroxy analog, the ammonium salt, and the amide derivative of methionine hydroxy analog were degraded more slowly than was methionine. Methyl and ethyl esters of methionine hydroxy analog were rapidly converted to methionine hydroxy analog, which was then degraded. Whole rumen contents were separated into protozoal and bacterial fractions, and rates of disappearance of [14C]carboxyl-labeled methionine and methionine hydroxy analog were determined. Disappearance of the label tended to be slower in the bacterial fraction; however, incorporation into cellular material tended to be higher for the bacterial than for the protozoal fraction. Disappearance of labeled methionine hydroxy analog was slower than labeled methionine in all fractions. Addition of unlabeled methionine inhibited disappearance of labeled methionine hydroxy analog, but unlabeled methionine hydroxy analog did not affect disappearance of labeled methionine. The effect of either Na2SO4, methionine, or methionine hydroxy analog on neutral detergent fiber digestion was related to amount of sulfur in the medium and not source of sulfur.

Animals↗
PubMed1988

Comparison of Maxon suture with Vicryl, chromic catgut, and PDS sutures in fascial closure in rats.

Two hundred ten rats were randomized into one of five study groups to compare standard absorbable sutures with a new synthetic absorbable suture. We evaluated Maxon (polyglyconate), Vicryl (polyglactin), chromic catgut (catgut), and PDS (polydioxanone) with respect to tissue inflammatory reaction, knot security, suture tensile strength, and suture absorption. The results indicate that Maxon and PDS elicited a lower degree of chronic inflammation when compared with Vicryl and chromic catgut. The tensile strengths of Maxon and Vicryl significantly exceeded those of PDS and chromic catgut during the critical period of wound healing. Maxon and PDS retained a larger percentage of tensile strength during the long postoperative period, whereas Vicryl and chromic catgut were mostly absorbed. Maxon is an excellent addition to the armamentarium of the gynecologic surgeon.

Absorption↗
PubMed1986

Correlation of cellular atypia and human papillomavirus deoxyribonucleic acid sequences in exfoliated cells of the uterine cervix.

Restriction enzyme digestion and Southern blot hybridization were used to analyze deoxyribonucleic acid (DNA) extracted from exfoliated cervical cells for the presence of human papillomavirus sequences and these results were correlated with cytologic findings on Papanicolaou smears. Specimens (N = 204) were obtained from a nonselected population of women undergoing routine cytologic screening and human papillomavirus DNA sequences were detected in 33 (16%) women. Thirteen smears contained atypical squamous cells, ranging from very mild dysplasia to moderate dysplasia; all showed associated morphologic evidence of human papillomavirus infection characterized by koilocytosis, nuclear enlargement, wrinkling, and hyperchromasia, and human papillomavirus DNA was demonstrable in 12 (92%) smears. Of the remaining 191 samples with normal cytology, 21 (11%) also contained human papillomavirus DNA sequences. Reevaluation of the smears from these women resulted in a revision of the cytologic diagnosis to very mild dysplasia in four cases. These data suggest that human papillomavirus infection occurs more frequently than predicted by cytologic screening.

Base Sequence↗
PubMed1985

A modified, prefixed, Golgi-rapid technique for the cephalopod retina.

A quick and simple method for Golgi staining of neurons and glia in the cephalopod retina is described. The main difference between this method and other Golgi-rapid protocols is that tissue is placed in sachets constructed from dialysis membrane prior to chromation and impregnation. This greatly reduces the amount of surface deposition of silver chromate and can reduce the number of elements impregnated. Together these effects produce improved Golgi staining of the cephalopod retina. Given some modifications to the osmolarity of the solutions employed, the method should be applicable to other, non-cephalopod tissues where superficial structures are obscured by surface precipitation, or neurons are arranged in thin sheets of tissue. The method employs prefixation of tissue in a fixative suitable for light or electron microscopy.

Animals↗
PubMed1985

Glutamine synthetase activity in the ruminal bacterium Succinivibrio dextrinosolvens.

Succinivibrio dextrinosolvens C18 was found to possess glutamine synthetase (GS), urease, glutamate dehydrogenase, and several other nitrogen assimilation enzymes. When grown in continuous culture under ammonia limitation, both GS and urease activities were high and glutamate dehydrogenase activity was low, but the opposite activity pattern was observed for growth in the presence of ample ammonia. The addition of high-level (15 mM) ammonium chloride to ammonia-limited cultures resulted in a rapid loss of GS activity as measured by either the gamma-glutamyl transferase or forward assay method with cells or extracts. No similar activity losses occurred for urease, glutamate dehydrogenase, or pyruvate kinase. The GS activity loss was not prevented by the addition of chloramphenicol and rifampin. The GS activity could be recovered by washing or incubating cells in buffer or by the addition of snake venom phosphodiesterase to cell extracts. Manganese inhibited the GS activity (forward assay) of untreated cells but stimulated the GS activity in ammonia-treated cells. Alanine, glycine, and possibly serine were inhibitory to GS activity. Optimal pH values for GS activity were 7.3 and 7.4 for the forward and gamma-glutamyl transferase assays, respectively. The glutamate dehydrogenase activity was NADPH linked and optimal in the presence of KCl. The data are consistent with an adenylylation-deadenylylation control mechanism for GS activity in S. dextrinosolvens, and the GS pathway is a major route for ammonia assimilation under low environmental ammonia levels. The rapid regulation of the ATP-requiring GS activity may be of ecological importance to this strictly anaerobic ruminal bacterium.

Ammonia↗
PubMed1984

Monoclonal antibody 4F2 reactive with basal layer keratinocytes: studies in the normal and a hyperproliferative state.

To establish a method for separating different keratinocyte subpopulations in the epidermis, we studied the specificity of monoclonal antibody 4F2 for keratinocytes. Preliminary screening experiments had previously demonstrated 4F2 reactivity with the epidermis. 4F2 reacted with a subpopulation (19.29 +/- 5.23%) of human epidermal cells in suspension. The membrane antigen identified by 4F2 continues to be expressed by cultured keratinocytes. In frozen tissue section using an indirect immunofluorescence technique, the 4F2-positive cells in the basal layer are sharply demarcated from the negative suprabasilar layers. Even in the hyperproliferative state of psoriasis, the 4F2 reactivity is confined to the basal layer. Cell suspensions of psoriatic epidermis demonstrated a greater percentage of reactivity with 4F2 (49.51% +/- 6.50%), probably reflecting the expanded population of basal layer cells. Monoclonal 4F2, therefore, reacts with a membrane antigen present on basal keratinocytes, and provides a probe for use in the isolation of the basal keratinocyte subpopulation. Thus, this antibody should be useful in studies of normal and aberrant differentiation of the epidermis.

Antibodies, Monoclonal↗