Factors influencing prescribing habits.
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Biomedical subjects
R D Walker
Publications and source records attributed to R D Walker.
Serratia marcescens mastitis in a dairy herd.
Serratia marcescens caused clinical mastitis in 5 cows and nonclinical mastitis in 21 cows of a 190-cow herd. Repeated bacteriologic culture of specimens from the cows, postmilking teat dip, environment, and equipment was performed. Serratia marcescens was not isolated from the dip, environment, or equipment. Progress of the infection in cows was monitored for 10 months. Some cows remained infected with S marcescens for at least 10 months. Economic loss estimates were based on Dairy Herd Improvement Association linear score reports. The average nonclinical loss was about $22/cow.
Animals↗
Growth in children following kidney transplantation.
Growth was assessed in children following 128 separate kidney transplants using a generalized growth curve multivariate analysis. The height standard deviation score was the dependent variable. Time since transplant, prednisone dosage, and creatinine clearance were the independent variables. For the purposes of comparison patients were grouped according to sex, race, age at transplantation, initial allograft function, acute rejection episodes and the use of cyclosporin A. Patient's height standard deviation scores tended to increase negatively after transplantation. However, children who received transplants before their 7th birthday, with initial allograft function greater than 60 ml/min per 1.73 m2, exhibited "catch-up" growth. Height standard deviation scores positively improved in males but not in females, as prednisone dosage was decreased. Height standard deviation scores became more negative as renal function decreased after transplantation. Changes in renal function produced the greatest effect upon height in black children, children less than 7 years, and males.
Adolescent↗
The management of posterior urethral valves by initial vesicostomy and delayed valve ablation.
We managed 32 neonates and infants with temporary vesicostomy and delayed valve ablation. The criterion on which successful management was gauged was estimated creatinine clearance. Renal failure or death occurred in 30% of the patients and 7% required transplantation. There was no apparent difference between our patients managed initially with vesicostomy and other series managed initially with valve ablation in preventing the complications of posterior urethral valves.
Cystostomy↗
Time and temperature dependence of granulocyte damage by leucotoxic supernatants from Pasteurella haemolytica A1.
Bacterial exotoxins may contribute to the pathogenic potential of micro-organisms through interactions with cells of the host defence system as well as by directly damaging host tissue. The present studies were designed to explore mechanisms of interaction between bovine granulocytes and the leucotoxin produced by Pasteurella haemolytica, a major cause of bovine respiratory disease. Leucotoxin-containing supernatant from P. haemolytica A1 caused rapid cell death in isolated bovine granulocytes that was close to half-maximal by 5 min and nearly 90% complete after 30 min at 37 degrees C. Maintaining granulocytes at ice-water temperature markedly attenuated or prevented the toxic effect; furthermore, if exposed to supernatants at ice-water temperature and then washed, most cells remained viable even after rewarming to room temperature. However, even a very brief exposure (about 5 s) at 37 degrees C led to extensive cell death even after immediate cold dilution and washing. Granule enzymes such as arylsulphatase were released far more slowly than cytosol contents. Leucotoxin purified by column chromatography showed temperature dependence and divergence between cytosol and granule marker release similar to those observed with the crude supernatant preparation. These findings indicate that irreversible interaction between P. haemolytica leucotoxin and bovine granulocytes is initiated very rapidly at 37 degrees C but markedly impeded at low temperature, while granule enzyme release follows cytosol marker release over a much longer period. The results suggest either a requirement for target cell metabolic activity to initiate toxin effects or a temperature-dependent receptor conformation, with granule enzyme release following as a secondary consequence of granulocyte death.
Animals↗
A tracheoscopic technique for obtaining uncontaminated lower airway secretions for bacterial culture in the horse.
Transtracheal aspirate (TTA) aerobic microbiology culture results from 30 ponies were compared to protected catheter brush (PCB) culture results obtained from the same ponies. The PCB procedure resulted in significantly fewer (P less than 0.05) isolates than those obtained by the TTA procedure and the PCB procedure resulted in significantly more samples with no bacteria growth than the TTA procedure. To address the possibility that the volume of tracheobronchial secretion obtained by PCB was insufficient as a microbiological sample, a sterile, double-sheathed, protected aspiration catheter (PAC) was developed. Comparisons were made between TTA and PAC aerobic microbiology culture results from 18 pneumonic foals and weanlings. There were no significant differences between the PAC and TTA procedures with respect to the number of bacteria isolates. It was concluded that the PAC technique may be used as an alternative to TTA for isolation of equine pulmonary bacteria and may be the preferred procedure because of the reduced risk of complications associated with the TTA.
Animals↗
Isolation of Gardnerella vaginalis from the reproductive tract of four mares.
A gram-variable pleomorphic bacillus was isolated from the reproductive tracts of 4 mares during routine prebreeding soundness examinations. Using a commercial bacterial identification system, these organisms were identified as Streptococcus acidominimus. However, colonial and Gram-staining characteristics did not support this identification. Subsequent testing indicated the organism was similar to Gardnerella vaginalis. Additional growth and biochemical analysis performed in our laboratory and at the Michigan Department of Public Health and by the Center for Disease Control, Atlanta, Georgia, confirmed the identification of G. vaginalis.
Animals↗
Drug preferences of alcoholic polydrug abusers with and without panic.
Manifestations of anxiety, including panic disorder, are more common in the alcoholic population than in the general population. Alcoholics frequently abuse other drugs. The authors hypothesized that alcoholic subjects with panic attacks would abuse anxiolytic drugs more and panic-inducing drugs less frequently than nonanxious alcoholic subjects, and that their abuse of panic-inducing drugs would predate the age at panic onset. Findings indicate that alcoholic subjects with panic attacks (but not panic disorder) abused opiates and sedatives to a greater degree than nonanxious alcoholic subjects and abused marijuana, a panic-inducing drug, at a younger age. More alcoholic subjects with panic disorder than with panic attacks abused cocaine. The prevalence of abuse and the ages at onset of abuse of other drugs were similar for both the panic and the nonpanic group.
Adult↗
Renal functional changes associated with vesicoureteral reflux.
The data cited have been intended to show that renal functional abnormalities are commonly associated with reflux. Tubular abnormalities, particularly concentrating defects, probably occur early, and glomerular dysfunction is a late manifestation. Problems with acid-base balance are uncommonly examined but may be more relevant clinically, because such abnormalities could affect bone growth. Fractional excretion studies are less sensitive than concentrating ability in indicating dysfunction. Associated pyelonephritis hastens renal damage and exacerbates any functional abnormality. Renal functional abnormalities are more common in patients with renal scarring and indeed may be predictive of a process that is not yet apparent pathologically.
Acid-Base Equilibrium↗
Serum and tissue cage fluid concentrations of ciprofloxacin after oral administration of the drug to healthy dogs.
Ciprofloxacin, a fluoroquinolone antimicrobial agent, was administered orally to 4 healthy dogs at dosage of approximately 11 and 23 mg/kg of body weight, every 12 hours for 4 days, with a 4-week interval between dosing regimens. Serum and tissue cage fluid (TCF) concentrations of ciprofloxacin were measured after the first and seventh dose of each dosing regimen. The peak concentration was greatest in the serum after multiple doses of 23 mg/kg (mean +/- SEM; 5.68 +/- 0.54 micrograms/ml) and least in the TCF after a single dose of 11 mg/kg (0.43 +/- 0.54 micrograms/ml). The time to peak concentration was not influenced by multiple dosing or drug dose, but was longer for TCF (6.41 +/- 0.52 hour) than for serum (1.53 +/- 0.52 hour). Accumulation of ciprofloxacin was reflected by the area under the concentration curve from 0 to 12 hours after administration (AUC0----12). The AUC0----12 was greatest in the serum after multiple doses of 23 mg/kg (31.95 +/- 1.90 micrograms.h/ml) and least in the TCF after a single dose of 11 mg/kg (3.87 +/- 1.90 micrograms.h/ml). The elimination half-life was not influenced by multiple dosing or dose concentration, but was greater for TCF (14.59 +/- 1.91 hours) than for serum (5.14 +/- 1.91 hours). The percentage of TCF penetration (AUCTCF/AUCserum) was greater after multiple doses (95.76 +/- 6.79%) than after a single dose (55.55 +/- 6.79%) and was not different between doses of 11 and 23 mg/kg. Both dosing regimens of ciprofloxacin resulted in continuous serum and TCF concentrations greater than 90% of the minimal inhibitory concentration for the aerobic and facultative anaerobic clinical isolates tested, including Pseudomonas aeruginosa.
Administration, Oral↗
Hematological changes in calves exposed to a mixture of lipopolysaccharide and crude leukotoxin of Pasteurella haemolytica.
The purpose of this investigation was to determine if culture supernatants of Pasteurella haemolytica containing crude leukotoxin and lipopolysaccharide (CLCL) causes disseminated intravascular coagulopathy (DIC) when injected into calves. The effect of intraduodenal (ID) exposure followed by a subsequent subcutaneous (SC) inoculation of either heat-treated or untreated CLCL was evaluated. The relative contribution of the crude leukotoxin and lipopolysaccharide (LPS) to the virulence of P. haemolytica was evaluated. One group of calves received an ID inoculation of CLCL followed two weeks later by a SC inoculation of CLCL; one group received an ID inoculation of tissue culture medium followed two weeks later by a SC inoculation of CLCL; and a third group received an ID inoculation of CLCL followed two weeks later by a SC inoculation of heat-treated CLCL. Hematological parameters used to evaluate DIC included white cell count, platelet count, neutrophil number, fibrinogen, fibrin degradation products, one stage prothrombin time (OSPT), activated partial thromboplastin time, body temperature and clinical signs. Each parameter was measured in calves at 0, 2, 4, 6, 12 and 24 h following the SC inoculation of CLCL. Each group had significant changes over time in all parameters except body temperature. Calves that received a SC inoculation of heat-treated CLCL had smaller changes in all parameters except OSPT compared to the other groups. Results suggest that the LPS and leukotoxin of P. haemolytica exert additive effects on the coagulation cascade and number of peripheral leukocytes, and that the ID inoculation of CLCL does not affect the response of calves to a SC inoculation of toxin.
Animals↗
Granulocyte plasma membrane damage by leukotoxic supernatant from Pasteurella haemolytica A1 and protection by immune serum.
Bovine respiratory disease caused by Pasteurella haemolytica may be partially mediated by a leukotoxin secreted by the microorganism. We examined the effect of leukotoxic Pasteurella supernatants on leakage of the cytosol enzyme lactate dehydrogenase and the lysosomal enzyme arylsulfatase from bovine granulocytes. Lactate dehydrogenase release (94%) was much higher than arylsulfatase release (38%) over 30 minutes of incubation. The Pasteurella supernatants inhibited superoxide production by stimulated granulocytes at concentrations which also caused substantial cell death as measured by failure to exclude trypan blue. Both toxic effects were prevented by serum from aerosol-immunized calves, and protection appeared to be antibody-specific by comparison with fetal bovine serum or with serum absorbed against intact P. haemolytica. These findings suggest that the leukotoxin may selectively disrupt the granulocyte plasma membrane, and that antibody directed against a surface component of the microorganism is also capable of protecting against the leukotoxin effect.
Animals↗
Urinary prostaglandin E2 in patients with vesicoureteral reflux.
The urinary prostaglandin E2 (PGE2) excretion of children with various grades of vesicoureteral reflux who were undergoing reimplant surgery was compared to those of age- and sex-matched controls. Urinary PGE2 excretions were significantly increased in patients with vesicoureteral reflux (p = 0.001). Furthermore, the PGE2 excretion correlated positively with the grade of reflux. Because of the interaction between vasopressin, sodium excretion, and PGE2, elevated urinary PGE2 may partially explain the decreased concentrating capacity seen in children with vesicoureteral reflux.
Child↗
New concepts in the treatment of genitourinary cancer in childhood.
The treatment of Wilms' tumor is based on initial surgical removal followed by clinical and histologic staging. Chemotherapy provides the major adjunctive therapy in virtually all Wilms' tumors, radiotherapy being used in some situations. Exceptions to this are the treatment of bilateral Wilms' tumors and large intracaval extension. Bilateral Wilms' tumor is treated with initial biopsy and staging, adjunctive chemotherapy, and/or radiation therapy and bilateral partial nephrectomy after there is maximum resolution of tumor. Similarly, extensive caval extension of tumor may be treated preoperatively with chemotherapy and radiotherapy followed by resection. Nephroblastomatosis, a precursor of Wilms' tumor, is a common associated finding at exploration. It requires alteration in management and may change the prognosis. Sarcomas of the kidney and congenital mesoblastic nephroma represent the spectrum of severity of solid renal masses in children. Neuroblastoma is the most common solid tumor in children, and its prognosis is largely dependent on the age of the patient and the stage of disease. Chemotherapy and radiotherapy is adjunctive treatments have been disappointing. Immunotherapy holds some promise for the future. Testicular tumors are unusual in children. Those that occur in infancy are most often benign teratomas that require orchiectomy alone. Malignant germ cell tumors in children are most often yolk sac tumors and respond to surgery and chemotherapy. Lymph node dissection is indicated only in paratesticular rhabdomyasarcoma. Other genitourinary rhabdomyasarcomas occur in the bladder, prostate, vagina, and uterus. After maximum decrease in tumor volume with chemotherapy and radiotherapy, surgical exploration and resection of remaining tumor probably represent the best form of treatment. Organ-sparing procedures should be carefully selected in that they may worsen the prognosis.
Antineoplastic Combined Chemotherapy Protocols↗
Calcium ion involvement in the action of Pasteurella haemolytica leukotoxin.
The influence of Ca2+ ions on the cytotoxic activity of Pasteurella haemolytica leukotoxin was investigated. The divalent cation influenced the cytotoxic effect of the leukotoxin for sensitive BL-3 target cells, but its absence did not eliminate cytotoxicity. In short-term 1-h assays using neutral red uptake as a measure of cell viability, depletion of Ca2+ either by exhaustive dialysis or by addition of the Ca2+ chelators EDTA and EGTA eliminated the cytolytic effect of low doses of the toxin. Addition of Ca2+ to target cell cultures depleted of the divalent cation restored the cytolytic effect of the leukotoxin. Prolonged exposure of the BL-3 cells to the toxin abrogated the protective effect of EDTA and EGTA. Cell death measured by uptake of neutral red, exclusion of trypan blue and 51Cr release indicated that protection observed in the absence of free Ca2+ was temporary. Toxin-induced cytolysis equivalent to that observed in the presence of Ca2+ occurred following the initial 2-h exposure. In addition, verapamil, a Ca2+ channel blocker, prevented cell death during 1-h cytotoxicity assays. The protection afforded by verapamil was dose-dependent and was influenced by the concentration of Ca2+ in the buffer medium. The results suggest that Ca2+ positively influences the rapid initial phase of cell death resulting from exposure to the toxin, but is not required for the entirety of the cytolytic process.
Animals↗
Response to sodium lactate infusion in alcoholics with panic attacks.
The authors studied the response to sodium lactate infusion of 12 alcoholics with a history of panic attacks, 10 alcoholics without a history of panic attacks, and 16 nonalcoholic patients with panic disorder. The rate of lactate-induced panic was significantly higher in alcoholics with panic attacks than in alcoholics without panic attacks. Alcoholics with panic attacks were similar to nonalcoholic patients with panic disorder in their response to lactate. These findings support the specificity of lactate-induced panic for panic states and suggest that panic attacks in alcoholics resemble those in nonalcoholics. Lactate infusion may prove useful in the diagnosis of panic disorder in alcoholics.
Adult↗
Prevalence, onset, and clinical recognition of panic states in hospitalized male alcoholics.
Alcoholism has been associated with a high prevalence of anxiety and phobic disorders. The authors ascertained the current prevalence of panic disorder and the lifetime prevalence of infrequent panic attacks in 154 male alcoholics in an inpatient alcohol treatment program. Thirteen percent (N = 20) gave a lifetime history of panic attacks and 45% (N = 9) of these had current panic disorder. Panic attacks preceded or coincided with the onset of problem drinking in 50% (N = 9) of the 18 patients with both diagnoses. Only two patients with histories of panic had been previously diagnosed, and none had been treated. Clinical implications of these findings are discussed.
Adult↗
Drinking-related locus of control and the drinking status of urban Native Americans.
Although promising, the available data concerning drinking-related locus of control have been almost entirely limited to treatment samples of white men. The major purpose of this study was to extend our understanding by comparing the drinking-related expectancies of three groups of Native Americans: problem drinkers, nonproblem drinkers and recovered alcoholics. Multivariate analyses were employed to control statistically for important sociodemographic differences between groups and included a test of the possibility that sex moderated the relationship between drinking status and drinking expectancies. As predicted, problem drinkers reported significantly less personal control of alcohol use than either nonproblem drinkers or recovered alcoholics. There were no significant differences between nonproblem drinkers and recovered alcoholics. Native American men were found to hold significantly more external orientations towards drinking than did women. The results were discussed in terms of comparisons with the available literature, and future research needs were identified. The findings provide indirect support for current treatment philosophies that seek to modify patient perceptions of the controllability of drinking behavior in a more internal direction.
Adult↗