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Biomedical subjects

J P Reynolds

Publications and source records attributed to J P Reynolds.

9 recordsLinked to original sources
PubMed1997

Effects of antimicrobial treatment at the end of lactation on milk yield, somatic cell count, and incidence of clinical mastitis during the subsequent lactation in a dairy herd with a low prevalence of contagious mastitis.

OBJECTIVE: To determine whether treating cows with antimicrobials at the end of lactation would lower the incidence of clinical mastitis, improve milk production, and decrease somatic cell count (SCC) in the subsequent lactation. DESIGN: Randomized blind field trial. ANIMALS: 233 Holstein cows from a single herd. All cows were in lactation 2 or greater. PROCEDURE: Cows were randomly assigned to treatment groups. Treated cows were given procaine penicillin G and novobiocin by intramammary infusion. Control cows were not treated. Farm personnel recorded cases of clinical mastitis. Milk yield and SCC were recorded during the subsequent lactation. RESULTS: Treatment did not significantly reduce the incidence of clinical mastitis when data for all cows were grouped or when data were stratified by lactation groups (lactation 2 vs lactation > or = 3) or by last SCC (< or = 500,000 cells/ml vs > 500,000 cells/ml). Somatic cell counts (first, mean of first 5, maximum of first 5) for treated and control cows were similar, and proportions of treated and control cows with SCC > 500,000 cells/ml at least once were not significantly different. Treated cows produced 179 kg (394 lb) more milk during the first 17 weeks of lactation than did control cows. CLINICAL IMPLICATIONS: Treating cows with antimicrobials at the end of lactation increased 17-week milk production during the subsequent lactation and, at current milk prices, was financially preferable to not treating them.

Analysis of Variance↗
PubMed1997

Evidence of vertical transmission of Neospora sp infection in dairy cattle.

OBJECTIVE: To determine whether heifers with naturally acquired congenital exposure to Neospora sp would transmit the infection to their offspring during gestation. DESIGN: Prospective cohort study. ANIMALS: Neonatal heifers on a dairy with a history of Neospora sp infections were selected for the study on the basis of their serum titers to Neospora sp, as determined by the use of indirect fluorescent antibody testing. Seropositive heifers (n = 25) had titers > or = 1:5,120 and seronegative heifers (25) had titers < or = 1:80. All heifers were raised and bred on the dairy, and samples were obtained from heifers and their calves at the time of calving. PROCEDURE: Blood samples were tested for Neospora sp antibodies. Histologic evaluations, Neospora sp immunohistochemical examinations, and protozoal culturing were performed on samples obtained from selected offspring (second-generation calves). RESULTS: Seropositive heifers gave birth to calves with titers > or = 1:1,280 to Neospora sp. All offspring from seropositive heifers that were necropsied had evidence of Neospora sp infection. All seronegative heifers and their offspring had titers < 1:80 to Neospora sp. CLINICAL IMPLICATIONS: Congenitally acquired Neospora sp infection can persist in clinically normal heifers and be transmitted transplacentally to their offspring. Vertical transmission can be a way by which neosporosis is maintained in herds.

Animals↗
PubMed1996

Sensitivity and specificity analysis for somatic cell count (SCC) used to predict bacteriologically positive subclinical mastitis at calving in a dairy herd with low SCC.

OBJECTIVE: Validate, by sensitivity and specificity analyses, use of somatic cell count (SCC) to predict bacteriologically positive subclinical mastitis in a California dairy herd with low SCC. DESIGN: Study of monthly dairy herd improvement SCC obtained from the immediate preceding lactation and individual cow composite milk sample microbiologic isolates collected at calving. ANIMALS: 515 California dairy cows with SCC and culture data. PROCEDURE: Somatic cell count sensitivity and specificity analyses with combinations of SCC parameter and at various thresholds were done, using the bacterial isolates as the standard. RESULTS: Combination of SCC threshold and SCC parameters could not be developed that had sufficient sensitivity and specificity to be a useful predictor of cows that would calve with subclinical mastitis. CLINICAL IMPLICATIONS: Under the conditions at this particular dairy, SCC could not be used as a basis of prediction of cows that would calve with bacteriologically positive subclinical mastitis or require selective nonlactating-cow antibiotic treatment.

Animals↗
PubMed1996

Preservative efficacy tests in formulated nasal products: reproducibility and factors affecting preservative activity.

Preservative efficacy tests were performed in triplicate on each of three batches of three formulated nasal spray preparations to assess the inter- and intra-batch variation in preservative performance which typically results from these procedures, and to assess the relative importance of factors influencing preservative performance in nasal products. Tests were conducted using procedures conforming, as far as possible, to both the European and the US pharmacopoeias and the results interpreted using the performance criteria of both. Despite the adoption of practices designed to maximize reproducibility, a marked variation in the degree of microbial inactivation was observed, both within and between batches of product. A preservative system comprising benzalkonium chloride and phenylethyl alcohol was found to be far superior to combinations of either benzalkonium chloride plus disodium edetate or potassium sorbate plus disodium edetate, both of which failed to satisfy the EP performance criteria on a number of occasions. Proposals are made for the adoption of inactivation criteria which incorporate realistic error limits reflecting the inherent problems of reproducibility of the viable counting procedures involved.

Administration, Intranasal↗
PubMed1990

Patterns of uterine prolapse in dairy cows and prognosis after treatment.

A 12-month study was undertaken in a 9-veterinarian dairy practice to determine patterns of uterine prolapse and factors associated with posttreatment survival. Of 220,000 cows in herds visited by veterinarians from the practice, 200 (0.09%) developed prolapses mostly (155/169 with data) in the first 24 hours after calving. Most cows (130/200) had prolapses during fall and winter months, and assistance was required in 47 of 200 calvings that resulted in prolapses. Treatment of affected cows (n = 196) consisted of cleansing and replacement of the uterus, insertion of perivulvar retention sutures, local and systemic administration of antibiotics, and parenteral administration of dexamethasone and oxytocin. Calcium was administered to cows with milk fever (n = 117) and to multiparous cows without milk fever attended by veterinarian 9 (n = 8). Crude recovery rate after 2 weeks was 72.4%, but recovery was significantly better if the calf was born alive (P = 0.001), the cow was primiparous (P = 0.03), the cow did not have stage-3 milk fever (P = 0.003), or if the cow was attended by veterinarian 9 (P = 0.01). Time to treatment was not significantly associated with recovery, but affected cows were treated mostly (127/156) within 2 hours of occurrence of the prolapse. By multivariable analysis, presence of a liveborn calf, parity, and lack of stage-3 milk fever, but not attending veterinarian, were significant (P less than 0.05) prognostic indicators of 2-week survival.

Animals↗
PubMed1984

Uterine prolapse and hypocalcemia in dairy cows.

Blood samples were collected from 53 dairy cows with uterine prolapse and from 53 cows with normal parturition (no uterine prolapse) matched by dairy as controls for various management programs among dairies. Cows with uterine prolapse had significantly lower total serum calcium content than did controls (P less than 0.01). Mean (+/- SEM) serum calcium content (mg/dl) for affected cows and controls were 6.08 (+/- 0.25) and 6.96 (+/- 0.20), respectively. Severe hypocalcemia (less than 4 mg/dl) was found in 10 (19%) of the affected cows, compared with 1 (1.8%) of the controls. Fifteen (28%) of the affected cows had moderate hypocalcemia (4.1 to 6.0 mg/dl), compared with 14 (26%) of the controls; 19 (36%) of the affected cows were mildly hypocalcemic (6.1 to 7.9 mg/dl), compared with 25 (47%) of the controls. Nine (17%) of the affected cows and 13 (25%) of the controls were within the normal range of calcium content (greater than 8 mg/dl). Nine of the affected cows were first-calf cows. The serum of these animals did not have significantly lower calcium concentrations, compared with controls matched by parity. Serum calcium values (mg/dl) for 9 first-calf cows and the 9 matched controls were 7.24 (+/- 0.42) and 7.00 (+/- 0.39), respectively. It was concluded that hypocalcemia was associated with uterine prolapse in multiparous dairy cows and, along with other factors, is involved as an etiologic factor for this puerperal condition.

Animals↗
PubMed1976

Clot retraction: evaluation in dilute suspensions of platelet-rich plasma and gel-separated platelets.

Suspensions of platelet-rich plasma (PRP) or gel-separated platelets (GSP) can be used to evaluate clot retraction subsequent to platelet aggregation and fibrin formation. PRP (200,000 per cubic millimeter) or GSP (200,000 or 100,000 per cubic millimeter) are diluted 1:10 (PRP) or 1:8 (GSP) in phosphate buffer, pH 7.4, and clotted with a high concentration (2.5 U. per milliliter) of thrombin. Human fibrinogen (25 mg. per cent) is added to GSP prior to dilution. Clot retraction is 91 to 100 per cent completed in 1 hour and is quantified by measurement of residual fluid volume. Test conditions are unfavorable for fibrinolysis. Very low concentrations of fibrin/fibrinogen degradation products D and E are detected in residual fluid, and no erythrocyte fall-out occurs. Furthermore, the extent of retraction in the dilute systems is related only to platelet numbers and platelet function. The dilute PRP and GSP methods allow evaluation of clot retraction in the presence of PGE1, the most potent inhibitor of platelet aggregation induced by conventional concentrations of collagen, ADP, epinephrine, and thrombin (0.1 to 0.5 U. per milliliter). High concentrations of PGE1 (to 6 x 10(-6) M) do not inhibit aggregation of GSP, fibrin formation, or platelet-fibrin interaction induced by 2.5 U. per milliliter of thrombin. In contrast, PGE1 concentrations as low as 1.5 to 3.0 x 10(-8) M inhibit clot retraction in both the dilute PRP and GSP systems. Thus, using dilute PRP or GSP the effects of platelet aggregation inhibitors on clot retraction can be determined independently of effects on platelet aggregation.

Blood Cell Count↗
PubMed1972

The variable prevalence of junctional-complex-associated bodies in the human sweat gland.

Sweat gland biopsies have been examined for their content of junctional-complex-associated (JCA) bodies. These bodies have been observed at the lumen of the gland as well as the intercellular canaliculi. A JCA body was encountered in each of two dark cells with uncondensed secretory granules; one of these cells was from a specimen in which no other bodies could be found after an extensive search. All other JCA bodies occurred in either clear or undifferentiated cells. Junctional-complex-associated bodies occupied pairs of adjacent cells rather frequently, but no cell revealed more than one body. The prevalence of JCA bodies varied widely among specimens. Glands lacking morphologic abnormalities, and others with some atypical features, disclosed few or no such bodies. Some glands that contained JCA bodies also contained coil cells with extensive vacuolization, which occurred as a manifestation of Hurler's disease or on an unexplained basis. Glands from a patient with cystic fibrosis exhibited the highest prevalence of JCA bodies. Some of the coil profiles in glands near a scar in one specimen were composed of undifferentiated cells with rare mitotic figures and no identifiable clear or dark cells. Numerous JCA bodies, particularly at the lumen, were found in sweat glands in this and another specimen containing frequent undifferentiated cells.

Biopsy↗