Biomedical subjects
Publications and source records attributed to R J Harmon.
A fluorogenic assay for the detection of beta-glucosidase was developed as part of a simplified conventional method to distinguish Staphylococcus warneri and Staphylococcus hominis isolated from bovine body sites. The assay is based on the fact that strains of S. warneri produce beta-glucosidase, while strains of S. hominis do not.
Twenty-one, middle to late lactation Holstein cows were assigned to one of three treatments in a completely randomized design to examine physiological changes associated with intramammary or intravenous administration of Escherichia coli endotoxin. Treatments were 1) Hank's balanced salt solution infusion in two contralateral quarters (control), 2) E. coli endotoxin infusion in two contralateral quarters, and 3) intravenous infusion of E. coli endotoxin. Blood was sampled and rectal temperature was measured at 30-min intervals. Endotoxin treatment was at 0900 h and sampling continued until 1700 h. Serum prolactin, cortisol, and 13,14-dihydro-15-keto-prostaglandin F2 alpha were measured. A pyretic response was observed in intravenous and intramammary treatment groups after endotoxin treatment. Response peak was higher (41.1 vs. 40.3 degrees C) and occurred later (6 vs. 4.5 h posttreatment) in the intramammary than the intravenous treatment group. Significant prolactin peaks were observed also in intravenous and intramammary endotoxin treatment groups. Prolactin peaked higher (288 vs. 112 ng/ml) and occurred sooner (1 vs. 4 h posttreatment) in the intravenous than in the intramammary treatment group. Cortisol followed a trend similar to prolactin. Cortisol peaked higher (100 vs. 82 ng/ml) and sooner (2.5 vs. 4.5 h posttreatment) in the intravenous than in the intramammary treatment group. Concentrations of 13,14-dihydro-15-keto-prostaglandin F2 alpha increased rapidly posttreatment in the intravenous group only.
Bovine mammary secretions from individual quarters were collected from five cows at 0, 14, and 28 d of involution, at parturition, and 14 d after parturition and used in a microassay to evaluate growth of several Staphylococcus species. All Staphylococcus species evaluated followed similar growth patterns in secretions. Mammary secretions obtained at 14 and 28 d of involution were poor media for growth of Staphylococcus species. Conversely, mammary secretions collected at cessation of milking, parturition, and early lactation supported growth of all species evaluated. Growth of Staphylococcus species in mammary secretions differed slightly among cows but was similar among quarters of a cow. Results suggested that the ability of bovine mammary secretions to support or inhibit growth of Staphylococcus species was related to functional states of the mammary gland.
The susceptibility of uninfected or Staphylococcus chromogenes-infected quarters to challenge with Staphylococcus aureus was measured. Seventeen S. chromogenes-infected quarters were challenged by infusion of S. aureus into the teat sinus; 47% (8 of 17) became infected and all 18 uninfected quarters challenged similarly with S. aureus became infected. No differences in daily milk yield were seen between uninfected quarters and S. chromogenes-infected quarters prior to S. aureus infusion. Postinfusion, milk yield for S. aureus-infected, S. chromogenes-infected, and S. chromogenes- and S. aureus-infected quarters differed. Somatic cell counts were elevated in S. chromogenes-infected quarters compared with uninfected quarters prior to S. aureus infusion. Somatic cell counts were not different between S. aureus- and S. chromogenes- and S. aureus-infected quarters postinfusion, but were different for S. chromogenes-infected quarters. Chloride concentrations in S. chromogenes- and S. aureus-infected quarters were different from either S. aureus-infected or S. chromogenes-infected quarters. Staphylococcus aureus colony forming units in quarters with preexisting S. chromogenes infections were lower than S. aureus colony-forming units in previously uninfected quarters. Possible protective mechanisms induced by S. chromogenes against superinfection by S. aureus are discussed.
The Perinatal Loss Interview was administered to 24 mothers who had experienced perinatal loss and were raising a child born subsequent to the loss; mothers were asked about postponing subsequent pregnancy, including what their doctors advised. Mothers were dissatisfied with doctor advice, reporting that the timing of a subsequent pregnancy was a personal decision and many factors influenced their decision. Furthermore, regardless of timing, most mothers reported overprotective and replacement feelings toward the subsequent child. These results imply that physicians may be most effective by educating mothers about advantages and disadvantages of postponing pregnancy so that an informed decision can be made.
This study examined the effectiveness of intervening with parents of premature infants by showing them examples of newborns' sensory, perceptual, and social capabilities. Fourteen couples and their premature infants, divided into an intervention group and a nonintervention group, were studied. Parents in the intervention group observed an assessment of premature infant behavior (APIB) examination and received feedback from the examiner prior to completing a parental assessment battery; the nonintervention group did not observe the APIB examination until after they completed the assessment battery. The assessment battery measured parental anxiety, perceptions, and awareness of neonatal behavior. Comparisons between the two groups revealed (a) intervention fathers reported significantly lower anxiety than did nonintervention fathers, (b) intervention mothers and fathers had significantly more realistic perceptions of their newborn compared to nonintervention parents, and (c) intervention mothers had significantly more accurate awareness of their newborns' abilities than nonintervention mothers, and intervention fathers had higher, but nonsignificant, awareness scores compared to nonintervention fathers. Having parents observe the administration of the APIB may be an effective way to educate them about their premature infant's behavior.
A greater percentage of DNase-positive strains was detected with DNase test agar than with DNase test agar containing 0.005% methyl green or 0.005% toluidine blue (P less than 0.01). No significant differences were obtained in the percentage of phosphatase-positive strains with the four methods compared. On the basis of ease of use, P agar containing para-nitrophenylphosphate disodium (0.495 mg/ml) would be the preferred method for determining phosphatase activity of staphylococci.
Responses to prepartum injection of sows with Se and vitamin E (E) were evaluated by determining immunoglobulin (IgA, IgM, IgG) levels in the colostrum and serum of the sows and the serum of their offspring. Fifty-four sows (40 multiparous, 14 primiparous) receiving diets adequate in E and Se according to current NRC (1988) standards were randomly allotted to four treatment groups in which a single i.m. injection of saline (controls), 5 mg of Se, 1,000 IU of E, or both Se and E were given on d 100 of gestation. Sows were bled prior to and 7 d after injection, at farrowing and on d 14 and 28 of lactation. Colostral samples were collected at the initiation of farrowing. Pigs were bled 20 h postpartum and at 14 and 28 d of age. Major immunoglobulin changes in the serum of the sows due to treatment were not seen prior to parturition. Injections of Se and(or) E resulted in higher colostral IgM levels (8.4, 10.7, 9.8 and 9.6 mg/ml, respectively), but only the response from Se was significant (P less than .05). Concentrations of colostral IgA or IgG were not affected by treatment (P greater than .30). Compared with controls, all three treatments increased (P less than .10) IgM concentrations in serum from pigs at birth (28.3, 33.3, 36.0 and 33.5 mg/ml, respectively), whereas IgA and IgG concentrations were not affected (P greater than .30).(ABSTRACT TRUNCATED AT 250 WORDS)
Heifers (n = 103) ranging in age from 1d to 2 yr were sampled to determine the coagulase-negative staphylococcal flora of haircoat, nares, vagina, teat skin, and streak canal. A total of 2706 staphylococal strains were identified from 3612 bacterial isolates. Other genera or groups identified included Bacillus, Micrococcus, Corynebacterium, and coliforms. Staphylococci were identified utilizing a simplified biochemical scheme. Staphylococcus xylosus, S. chromogenes, and S. warneri were the predominant species recovered from anatomic sites and streak canal. Staphylococcal strains identified from specific body sites (expressed as percentage of heifers harboring these species) were: nares 74% S. xylosus and 48% S. warneri; haircoat, 70% S. xylosus and 57% S. chromogenes; vagina, 60% S. chromogenes and 54% S. xylosus; teat skin 62% S. chromogenes and 61% S. warneri; streak canal 53% S. chromogenes, and 43% S. warneri. The prevalent staphylococcal strains identified differed from heifers in confined housing compared with heifers on pasture. Differences observed in distribution of Staphylococcus species among body sites, particularly those between teat skin and streak canal, suggest that establishment of staphylococcal microflora depends on the ability of a species to adapt to and colonize anatomic sites as well as on environmental conditions present.
Explore the source record for details and available documents.
A phage typing set composed of 13 phages is described for characterizing Staphylococcus epidermidis. Isolates (372) from cases of bovine mastitis were used in this study. Of these, 350 or 94% were successfully delineated, and 63 phage types were observed. Twenty two cultures were not typeable.
Forty-four first lactation heifers were fed NaCl (23 and 136 g/d) or KHCO3 (0 and 272 g/d) beginning 42 d prepartum and continuing to 10 d postpartum to study the influence of these salts on udder edema and selected blood parameters. Addition of NaCl or KHCO3 singly to the diet significantly increased the severity of udder edema, but the addition of both salts did not increase edema. Blood samples were collected from the jugular vein at 42 d prepartum and at 1, 3, and 10 d postpartum. Hematocrit and pH were measured on whole blood and osmolarity on serum samples. Concentrations of protein, Ca, Na, K, and Cl in serum were also determined. Serum total proteins were reduced and serum osmolarity was increased in the cows fed NaCl. Blood pH was elevated in the group receiving KHCO3. Serum K was higher in groups receiving supplemental KHCO3. No differences across dietary treatments were observed in the other parameters. Although addition of NaCl or KHCO3 to the diet increased the severity of udder edema, the exact mechanism causing edema could not be determined.
Four primiparous, ruminally fistulated, lactating Holstein cows were assigned to a 4 X 4 Latin square to study the effects of NaHCO3 infusion time on ruminal milieu and systemic acid-base balance. Sodium bicarbonate, approximating .8% of diet DM, was mixed with water and infused into the rumen for 1, 2, 4, or 6 h postfeeding to simulate different timed-release rates of NaHCO3. All cows received a corn silage and concentrate diet mixed at a 40:60 ratio on a DM basis and fed in amounts that were consumed within 1 h. Ruminal fluid, blood, and urine samples were collected at 0, 1, 2, 3, 4, 5, 6, 8, and 10 h postfeeding. Length of infusion time did not alter ruminal, blood, or urine pH, but all three variables were affected by sampling time, with the 5, 1, and 3-h sampling intervals yielding the lowest values for the three measurements, respectively. Ruminal VFA molar percentages of acetate, propionate, butyrate, isovalerate, and valerate were not influenced by infusion interval but were all different due to time of sampling. Blood pCO2 and HCO3 were affected by sampling time but not by infusion interval. With the exception of blood HCO3, all treatment X sampling time interactions were nonsignificant. It appears that timed release of NaHCO3 does not alter ruminal function or acid-base balance.
The efficacy of an acrylic latex barrier teat dip with germicide on new infections at parturition was tested on 113 cows and heifers during the prepartum period. A split udder design was used in which right quarters were undipped controls and left quarters were dipped with latex dip once daily for approximately 14 d prior to parturition. Distal streak canal swabs were taken from all quarters prior to the beginning of dipping, and all cows were quarter sampled in duplicate at drying off, parturition, and the first 5 consecutive wk of lactation. All quarters received antibiotic therapy at drying off. Excluding infections detected by distal streak canal swabs, the number of new infections at parturition in control and dipped quarters was 32 and 36. New infections at parturition in control and dipped quarters were Staphylococcus aureus, 2 and 2; coagulase-negative staphylococci, 8 and 9; stretptococci, 10 and 12; coliforms, 8 and 8; and others, 4 and 5. Differences were not significant. These results suggest no benefit to use of prepartum latex teat dip with germicide on new infections at parturition.
Six ruminally fistulated Holstein cows were utilized in a randomized block design to examine effects of yeast culture supplement on ruminal metabolism and apparent digestibility. Cows were fed a diet of 40% corn silage and 60% concentrate (DM basis). Treatments were control (supplement without yeast cells) and yeast culture supplement. Treatment periods were 6 wk. Ruminal pH, ammonia, molar proportions of acetate and isovalerate, and acetate: propionate ratio were lower and molar proportions of propionate and valerate higher in cows receiving yeast. The concentration of anaerobic bacteria tended to be higher and cellulolytic bacteria concentrations were greater in cows fed yeast than in cows receiving control diet. Supplemental yeast did not affect molar proportions of isobutyrate or butyrate, total VFA, or viable yeast concentrations in ruminal fluid. Ruminal liquid dilution rate and total tract apparent digestibilities were not different between treatments. Rate of disappearance of cellulose in vitro was lower in cows receiving yeast. Less variation in ammonia concentrations and microbial numbers suggest that ruminal fermentation was more stable in cows receiving yeast culture supplement.
Eleven unselected 47,XXX girls, now 15 to 22 years of age, have been observed from birth in a prospective study of children with sex chromosome anomalies. A description of their growth and development is presented. The 47,XXX infants were not generally distinguishable from chromosomally normal children in the first year of life, even though there was a slight delay in neuromotor development. By 2 years of age, developmental delays in speech and language often became evident, and speech therapy was often necessitated in the preschool years. Early school problems included speech and language deficiencies, lack of coordination, poor academic performance, and immature behavior; these persisted throughout the school years. By high school age, a 47,XXX girl was generally tall and often subject to somatic complaints. Sexual development was generally normal. Seven of the 11 propositae had a diagnosed psychiatric disorder or disturbance at some time during adolescence. Variability within this syndrome is great; one proposita is in college and another is mentally retarded. The frequency of the diagnosis of the 47,XXX karyotype by genetic amniocentesis is estimated to be 1/1000, the same incidence as in the newborn population. Expectant parents must be counseled as to the significance of this karyotype and prognostic information must be given. Suggested guidelines are included.
Explore the source record for details and available documents.
The purpose of this study was to examine the effects of endophyte (Acremonium coenophialium) toxic tall fescue seed on serum prolactin, daily feed intake, and average daily weight gain in male rats. Thirty Sprague-Dawley male rats (218 g) were randomly assigned to treatments of (I) rat chow (50%) plus an endophyte-free tall fescue seed (50%), (II) same as I only restricted feed intake as III, (III) rat chow (50%) plus endophyte infected tall fescue seed (50%) and (IV) rat chow (50%) plus endophyte infected tall fescue seed (25%) plus endophyte free tall fescue seed (25%). Dry matter intake and average daily gain were lower (P less than .05) for rats fed treatment II and III than for those fed treatment I and IV, with treatment IV being lower (P less than .05) than treatment I. Body weights on days 4, 11 and 21 followed the same trend with the rats fed treatment I having higher weights at each weigh period than those on treatments II, III and IV; and those fed treatment IV having higher weights at each period than those on treatment II and III. Baseline concentrations of serum prolactin were similar among treatments. Serum prolactin concentrations were lower (P less than .05) in rats fed treatment III and IV than in those fed treatment II, and those fed treatment I were not different from all others on day 4. On day 11, rats fed treatment I, III and IV had lower (P less than .05) serum prolactin concentrations than those fed treatment II.(ABSTRACT TRUNCATED AT 250 WORDS)