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Biomedical subjects

D R Zimmerman

Publications and source records attributed to D R Zimmerman.

At least 73 records · Page 4Linked to original sources
PubMed1988

Periodontal surgery for a patient with paroxysmal nocturnal hemoglobinuria.

Paroxysmal nocturnal hemoglobinuria (PNH) is an uncommon blood stem cell disorder. The acquired defect is in the cell membrane of the precursor of the affected clone, which renders erythrocytes, platelets and granulocytes unusually sensitive to the hemolytic effects of complement. It is characterized by chronic hemolysis, intermittent hemoglobinuria, thrombotic events and bone marrow hypoplasia. Hemolysis is precipitated by infection, strenuous exercise, surgery or menstruation. The dilemma of managing a PNH patient is that both the periodontal infection and the surgical treatment are precipitating factors. Management is further complicated by the fact that the patient is receiving corticosteroids. The treatment of the PNH patient is complex and potentially hazardous. It requires close cooperation between the periodontist and the hematologist. This paper describes the management of one such case.

Adult↗
PubMed1988

Characterization of antral follicle populations during the estrous cycle in pigs selected for ovulation rate.

The objectives of this study were to characterize and compare ovarian follicular populations in Gene Pool Control (GPC, randomly selected) and Relax Select line (RS, nine generations of selection for high ovulation rate followed by six generations of random selection) gilts during different stages of the estrous cycle. Thirty-five RS and 23 GPC gilts were allotted randomly within litter for ovary recovery on either d 3, 15 or 19 of the estrous cycle. Surface follicles on the ovaries were classified by size (small, less than 3 mm; medium, 3 to 6.9 mm; large, 7 to 12 mm), and counts were recorded for each ovary. Ovarian weight (OW), number of corpora lutea (CL), follicular fluid volume (FFV) from small, medium and large follicles, residual ovarian weight and follicular fluid weight (FFW) also were recorded. Total numbers of small and medium follicles were greatest on d 15, whereas total number of large follicles and FFW were greatest on d 19. The OW, FFW and follicle numbers of all classes were lowest on d 3. The RS gilts expressed longer interestrous intervals (21.9 vs 20.4 d, P less than .05) and higher ovulation rates (18.5 vs 15.3 CL, P less than .01) than GPC gilts. The left ovary of RS gilts was responsible for most of the ovulation rate advantage (10.3 vs 7.4 CL, P less than .01) Overall, GPC gilts had more total small follicles than RS gilts (P less than .01). The advantage was due primarily to higher numbers of small follicles at d 15.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Characterization of gonadotropic and ovarian steroid hormones during the periovulatory period in high ovulating select and control line gilts.

Cyclic gilts from Control (C, randomly selected, n = 11) and Relax Select (RS, nine generations of selection for increased ovulation rate followed by seven generations of relaxed or random selection, n = 9) lines of the University of Nebraska Gene Pool population (derived from 14 different breeds) were utilized to characterize differences in gonadotropic and ovarian steroid hormones during preovulatory and postovulatory phases of the estrous cycle. Blood samples were collected during four periods (0500, 1100, 1700 and 2300) daily beginning 2 d prior to anticipated estrus (d -2, d 18 of a 20-d estrous cycle), and continuing through d 4 postestrus (d 0 = 1st of standing estrus). Sampling within a period consisted of five blood samples at 15-min intervals. All plasma samples were analyzed for concentrations of follicle stimulating hormone (FSH) and luteinizing hormone (LH). Neither mean LH nor peak concentration of LH during the preovulatory surge differed between genetic lines (P greater than .10). Concentrations of FSH increased faster (line X period, P less than .05) and tended (P less than .1) to peak at a higher concentration in RS (.88 ng/ml) than in C (.54 ng/ml) gilts (P less than .05) during the 12 h preceding the FSH and LH preovulatory peaks. The second FSH surge began approximately 24 h after the preovulatory FSH peak. Peak FSH concentrations were observed at 42 h in both lines (1.46 vs 1.74 ng/ml for C and RS gilts, respectively). The higher FSH concentration in RS gilts established during the preovulatory surge was maintained through the second FSH surge (P less than .01). No line differences were detected in plasma concentrations of estradiol-17 beta and progesterone.

Animals↗
PubMed1987

Health maintenance organizations and physicians: impact and response.

The considerable growth of health maintenance organizations is significantly changing the traditional systems under which physicians have historically practiced medicine. Allowable cost reimbursement, fee-for-service payment, and private practice are being confronted with the spread of HMOs and the shift of physicians to capitated payment systems or salaried employment status. The disruption in physicians' work lives has led to a number of collective responses including militant resistance to HMOs, the creation of physician-controlled HMOs, affiliation with union-like mutual benefit organizations, and the establishment of physician labor unions. This paper examines the impact of these changes on physicians and the nature and likely success of the responses being made.

Health Maintenance Organizations↗
PubMed1985

Nutritive value of D-tryptophan for the growing pig.

The replacement value of D-tryptophan (D-TRP) for L-tryptophan (L-TRP) was estimated in four 28-d experiments with weanling pigs. In all experiments, supplementing TRP-deficient diets with D- and L-TRP significantly increased feed intake, rate and efficiency of gain and decreased plasma urea N (PUN). In Exp. 1, the performance responses to added D-TRP were similar to those with added L-TRP. Relative responses (D-TRP/L-TRP) for average daily feed intake (ADF), weight gain (ADG) and gain/feed (G/F) on percentage added TRP, and ADG on daily TRP intake were 1.2, 1.1, 1.0 and .9, respectively. In Exp. 2, pigs fed added L-TRP consumed more feed (P less than .05) and gained weight faster (P less than .05) than those fed added D-TRP. Relative responses of D- to L-TRP for ADF, ADG and G/F on percentage added TRP and ADG on daily TRP intake were .7, .7, .8 and 1.0. In Exp. 3, a 2 X 3 treatment arrangement was used. Pigs were fed two basal diets (.10% TRP) or basal diets with .05% added D- or L-TRP. The basal diets were formulated at two levels of large neutral amino acids (LNAA). The addition of L-TRP, as compared with D-TRP, increased ADF (P less than .01), ADG (P less than .01), G/F (P less than .05) and plasma TRP (P less than .01). Added LNAA decreased (P less than .05) ADF and added TRP increased G/F more in pigs fed high-LNAA diets than in those fed low-LNAA diets (interaction, P less than .05).(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Feed↗
PubMed1985

Threonine requirement of pigs weighing 5 to 15 kg and the effect of excess methionine in diets marginal in threonine.

Experiments were conducted to estimate the threonine requirement of pigs weighing 5 to 15 kg and to determine whether excess methionine increased the threonine requirement. Feeding .70% dietary threonine in Exp. 1 maximized (P less than .01) gain/feed and minimized (P less than .01) plasma urea N. Plasma threonine was increased (P less than .01) by threonine supplementation and the rate of increase accelerated above .65% dietary threonine. Threonine supplementation did not affect plasma methionine, tryptophan and(or) lysine, but it increased leucine (P less than .01) and isoleucine (P less than .05). In Exp. 2, additions of .40% methionine and(or) .30% threonine to a 16% crude protein diet that had calculated concentrations of .57% sulfur amino acids and .68% threonine did not affect (P less than .10) pig performance or plasma urea N. In Exp. 3, a 15% crude protein diet that had calculated concentrations of .54% sulfur amino acids and .61% threonine was supplemented with .40% methionine and(or) .15% threonine. Amino acid additions did not affect performance of pigs, but pigs fed supplemental threonine had the least plasma urea N, indicating that .61% dietary threonine was marginally deficient for pigs weighing 5 to 15 kg.

Animal Feed↗
PubMed1985

Influencing prolificacy of sows by selection for physiological factors.

The potential to improve prolificacy, with major emphasis on selection for components of litter size, ovulation rate and prenatal survival, and selection for physiological factors are reviewed. Response to selection for physiological factors is superior to direct selection if physiological factors have moderate heritabilities and moderate to high genetic correlations with the trait to be improved. There are very few estimates of the genetic parameters needed to calculate the relative efficiency of direct and indirect selection. Testis size is highly heritable and positively correlated genetically with ovulation rate in both mice and pigs and may be potentially useful in an index with litter size to improve ovulation rate and prenatal survival. Selection for growth, ovulation rate or litter size has increased ovulation rate in mice, but the physiological explanations are different. Selection for litter size in a line of pigs previously selected for ovulation rate was effective; the realized heritability was 0.18 +/- 0.06. Potential improvements in litter size from index selection for ovulation rate and prenatal survival are discussed and compared to direct selection for litter size.

Animals↗
PubMed1984

Effects of graded levels of lysine and excess arginine and threonine on young pigs fed practical diets.

Three experiments were conducted to estimate the lysine requirement of the weanling pig and the effects of excess arginine and threonine on that estimate. Feeding 1.15% dietary lysine in Exp. 1 and 1.20% in Exp. 2 maximized feed efficiency and resulted in the lowest plasma urea N values. Adding .15% threonine to the diets in Exp. 2 did not affect (P greater than .10) performance of the pigs, but increased (P less than .01) plasma urea N and decreased (P less than .01) plasma lysine concentrations. Supplemental arginine (.22%) did not affect performance of the growing pigs in Exp. 3, but it increased (P less than .01) plasma urea N. Pigs fed a corn-soybean meal diet utilized feed more efficiently (P less than .05) than those fed a corn-fish meal-dried whey diet. The most likely cause for this response was that the corn-soybean diet contained more lysine (.82%) than expected, whereas the corn-fish meal-dried whey diet had close to the expected content of lysine (.72%). From these results, it was concluded that the lysine requirement of the weanling pig fed practical diets is at least 1.15 or 1.20% of the diet. Also, added arginine or threonine did not adversely affect the performance of pigs.

Amino Acids, Essential↗
PubMed1983

Pubertal development of the boar: age-related changes in testicular morphology and in vitro production of testosterone and estradiol-17 beta.

The responsiveness of testicular tissue, in terms of testosterone (T) and estradiol-17 beta (E2) production, to human chorionic gonadotropin (hCG) stimulation in vitro was assessed during pubertal development of the boar. A morphometric investigation was conducted concurrently to quantitate Leydig cell and seminiferous tubule changes in the testes of developing boars. Testicular volume percentage of seminiferous tubules increased from 36% at 40 days of age to a maximum of 72% at 190 days of age. Increases in tubular diameter were from 65 micrometers at 40 days of age to 236 micrometers at 250 days of age. Testicular volume percentage of Leydig cells decreased from 40% at 40 days of age to 10% at 250 days of age. Leydig cell number increased rapidly to 130 days of age, remained constant through 160 days, and then increased steadily to 220 days of age. Volume per Leydig cell changed little from 40 to 130 days of age, increased by 75% at 160 days, and declined thereafter. Total Leydig cell weight increased steadily from 40 to 160 days of age and then declined slightly. The capacity of Leydig cells for T production and testicular tissue for E2 production was greatest (P less than 0.05) after hCG stimulation in boars that were 130 and 160 days of age. In addition, sensitivity, as judged by the regression coefficient of T or E2 production per Leydig cell on log dosage of hCG was greater (p less than 0.05) for T at 130 days of age and for E2 at 160 days of age. The data presented support the hypothesis that one factor in pubertal development of boars is an increased capacity and sensitivity of the testes to gonadotropin stimulation.

Aging↗
PubMed1983

Testicular growth in boars of different genetic lines and its relationship to reproductive performance.

Testicular growth of 377 boars was compared by obtaining in situ measurements of testes width and length and excised tissue weights. Two experiments involved a line selected nine generations for ovulation rate (OR) and a control line (CL), and two experiments contained boars of the OR line and two other lines; WL, a Large White-Landrace cross, and a line founded by crossing lines OR and CL and selected six generations for increased average daily gain and decreased backfat (LG line). In situ testes measurements were similar for the OR and CL lines and were curvilinearly related to age. The LG line had smaller in situ measurements than the OR line (P less than .05) when both unadjusted means and means adjusted for body weight were compared. The OR line had 10.5% heavier testes than the CL line at 90.8 kg and a 9 to 15% advantage at 120, 141, 162 and 183 d of age. The OR line had more rapid testicular development from 120 to 183 d of age (P less than .05) than the CL line. The LG line had significantly lower excised testes weights (17 to 50% less), a lower percentage of tubules that showed active spermatogenesis and lower mean diameter of the seminiferous tubules (P less than .05) than the OR line. The relative differences between lines OR, CL and LG suggest that selection for lean growth rate has resulted in less rapid testicular development and increased age at puberty. The correlations of testes weights and in situ testes measurements taken at the time of castration were between .76 and .93. The correlations of testes width and testes length with epididymides weights were slightly lower, and correlations of body weight and testes weight ranged from .51 to .70. Mean diameter of the seminiferous tubules and percentage of tubules with active spermatogenesis were correlated with measurements of testes size (r = .50 to .61) and body weight at the time of castration (r = .29 to .36). Correlations of excised testes weights with number born in the boar's contemporary litter and ovulation rate of full sibs were uniformly positive. The correlations of measurements of testes size and backfat (r = -.09 to .20) suggest that the phenotypic relationship between testes growth and body composition is small. However, the response found in the LG line suggests a negative genetic relationship between lean growth rate and testicular growth rate.

Animals↗
PubMed1982

Influence of energy intake during lactation on the interval from weaning to first estrus in sows.

A total of 191 crossbred sows were used to determine the effect of energy intake during one lactation on (1) sow and pig performance and (2) the percentage of sows in estrus by 7, 14, 21 and 70 d postweaning. Sows received 8 (Lo) or 16 (Hi) Mcal of metabolizable energy (ME)/d (Exp. 1 and 2) and 8 (Lo), 12 (Md) or 16 (Hi) Mcal of Me/d (Exp. 3) during a 28-d lactation period. All sows were fed an equal amount of crude protein, vitamins and minerals that met or exceeded the recommendations of the National Research Council. Each day after weaning, sows were fed 1.8 kg of a 14% crude protein diet and checked for estrus using boars. Serum samples were obtained weekly from sows not detected in estrus by 15 d postweaning for progesterone analysis. In Exp. 1 sows fed Lo lost more (P less than .01) weight and backfat, and weaned lighter weight (P less than .01) pigs than sows fed Hi. Fewer sows fed Lo exhibited estrus (P less than .01) by 7, 14, 12 and 70 d postweaning than sows fed Hi. In Exp. 2, sows fed Lo lost more (P less than .01) weight and backfat than sows fed Hi, but pig weaning weights did not differ. Fewer sows fed Lo expressed estrus by 7 d (P less than .01) postweaning than those fed Hi. In Exp. 3 sow weight and backfat loss decreased (P less than .01) linearly as energy intake increased. Pig weaning weights were not affected by energy intake. Fewer sows fed Lo expressed estrus (P less than or equal to .05) by 7, 14, 21 and 70 d postweaning than those fed Md and Hi. There was no difference in the percentage of sows fed Md or Hi that exhibited estrus by these time periods. Blood samples collected on d 110 of gestation and d 14 and 26 of lactation, indicated that energy intake did not influence hematocrit values, total serum protein or albumin concentrations. A significant energy intake by time interaction was observed for serum blood urea N. Three of the 25 sows bled for progesterone analysis had luteal tissue activity suggesting ovulation had occurred even in the absence of a detected behavioral estrus.

Animals↗
PubMed1982

Pubertal development of the boar: testosterone, estradiol-17 beta, cortisol and LH concentrations before and after castration at various ages.

Forty-eight Landrace x Duroc boars were assigned at weaning to eight castration ages (40, 70, 100, 130, 160, 190, 220 and 250 d). Catheterization of the external jugular vein was performed 5 d before scheduled castration. Blood samples were collected every .5 h between 0800 and 1200 h, 2 d before (-2) and on d +1, +2, +3, +4, +8 and +16 after castration. Testosterone (T) was determined in serum samples collected every .5 h on d -2. Serum concentrations of estradiol-17 beta (E2), cortisol (C) and luteinizing hormone (LH) were quantified by radioimmunoassays in pooled (within boar) samples collected on d -2. In addition, LH was determined in pooled (within boar) samples collected on d +1, +2, +3, +4, +8 and +16 after castration. Mean concentrations of T and E2 (d -2) increased in a near linear (P less than .01) fashion with age of boar. However, T concentrations at 250 d of age had declined (P less than .01) to values similar to concentrations of boars at 130 d of age. Serum C concentrations (d -2) were lower (P less than .01) at 100, 130 and 160 d of age compared with an average C concentration of 19 ng/ml for all other age groups. Mean concentrations of LH (d -2) did not differ among any of the ages. Luteinizing hormone concentrations were elevated (P less than .01) within 1 to 2 d following castration at 40, 70, 100, 130 and 160 d of age. Serum T concentrations of individual boars varied greatly at all ages as determined by half-hourly sampling over a 4-h period. The results indicate that in the boar: (1) T concentrations increase as pubertal development progresses and decline as maturity nears; (2) E2 concentrations increase steadily through pubertal development; (3) C concentrations are depressed at 100, 130 and 160 d of age relative to concentrations before and after that period; (4) LH concentrations are constant during pubertal development, and (5) a decrease in the sensitivity of the negative feedback mechanism controlling LH occurs after 160 d of age.

Aging↗
PubMed1980

Inheritance of teat number and its relationship to maternal traits in swine.

The relationship of teat number to seven measures of female reproduction was evaluated in the University of Nebraska Gene Pool population. Teat number was recorded for 7,513 pigs, ovulation rate for 2,794 gilts and litter size and weight at birth and weaning (42 days) for 789 gilts. Paternal half-sib and full-sib analyses were used to estimate heritabilities for each trait and to estimate the genetic and phenotypic correlations of teat number with the measures of reproduction. The direct response to selection for ovulation rate and the correlated response in teat number were also evaluated from the regressions of line differences (Select-Control) on generation number (10 generations of selection) and cumulative selection differential for ovulation rate. The paternal half-sib heritabililty for teat number was .32, and the paternal half-sib heritabilities for ovulation rate and the litter traits were similar to previous estimates from this population. Most of the genetic and phenotypic correlations with teat number were negative and all were nonsignificant. The realized heritability for ovulation rate was .46 +/- .10. The regression of response in teat number on generation number number was .08 +/- .03 (P < .10). An estimate of .44 was obtained for the realized genetic correlation of teat number with ovulation rate.

Animals↗
PubMed1980

Effects of dietary cellulose and neomycin on function of the cecum of pigs.

Six crossbred male pigs (40 kg) with cecal cannulas were randomly allotted to three treatments for evaluation of the effect of three levels of dietary Solka-floc (2, 10 and 18%) on cecal functionality. Samples were collected every fourth day for 40 days. Blood was obtained 4 hr after the morning feeding, and cecal contents were sampled at 3-hr intervals during the 12-hr period between the morning and evening meals. Blood urea nitrogen was not affected by dietary cellulose, and it remained constant throughout the experiment. Dry matter and cellulose digestibilities were reduced (P < .05) by the increase in dietary cellulose, suggesting a maximum cellulose digestion capability of about 35 g/pig daily. A definite daily pattern was observed for cecal ammonia nitrogen. It reached a maximum 6 hr after feeding. Cecal volatile fatty acid (VFA) concentrations were not affected by dietary cellulose. After 40 days, 150 mg/kg body weight of neomycin sulfate was administered daily for 8 days, 100 mg in the feed and 50 mg into the cecum via the cannula. The antibiotic resulted in a decrease (P < .01) in cecal VFA concentrations, an increase (P < .01) in cecal ammonia N level and a complete arrest of cellulose digestion.

Ammonia↗
PubMed1980

Scorpion envenomation.

A potentially lethal neurotoxin-producing scorpion, Centruroides sculpturatus, exists in the southwestern United States. The most common symptoms of envenomation of 24 patients included local pain, restlessness, and roving eye movements. In this series 80% of cases were in children less than 10 years of age. Pain at the site of the sting was a predominant symptom in the patient more than 10 years of age; however, extreme and perpetual restlessness was the most common symptom in the younger patient. The diagnosis in children is usually made by clinical presentation alone since the site of the sting cannot be identified and children may not communicate the history of the sting. The most commonly used chemotherapeutic agent is phenobarbital. There is no evidence, however, that this drug decreases morbidity or mortality, and massive doses of phenobarbital were associated with two respiratory arrests in this series. The nature of scorpions and their venoms is discussed. Research is needed regarding the use of sympathetic blocking agents in scorpion envenomation.

Animals↗
PubMed1980

A simple intestinal cannula for swine.

A T-cannula was designed for placement in the gastrointestinal tract of pigs used for nutritional studies. It was made from available and inexpensive polyvinylchloride plumbing fittings. The main advantages of the cannula are (1) light weight (32 g), (2) good tolerance by the animals, (3) short projection from the body wall, (4) minimal leakae, and (5) patency for several months. The caudal part of the ilea of ten pigs was cannulated with satisfactory results. Macroscopic alterations of the gastrointestinal tract were not observed when the animals were euthanatized.

Animals↗