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Biomedical subjects

R D Walker

Publications and source records attributed to R D Walker.

At least 73 records · Page 4Linked to original sources
PubMed1996

Clinical issues related to the costs of alcoholism.

Alcohol (ethanol) use disorders are prevalent in many countries and are associated with significant social and health costs. Little is known, however, about the comparative cost effectiveness of treatments for alcoholism. Pharmacoeconomic evaluations are largely (if not wholly) absent from the alcoholism treatment outcome database. We discuss pharmacological approaches to the treatment of alcohol withdrawal and dependence, describing agents that ameliorate withdrawal symptoms, deter alcohol consumption, reduce alcohol craving and produce conditioned alcohol aversion. Cost-relevant clinical considerations are elucidated and recommendations for cost-conscious pharmacological treatment of alcohol dependence are proffered.

Alcohol Deterrents↗
PubMed1996

Valine requirement of the high-producing lactating sow.

Two hundred three (40 or 41/treatment, average parity 4.3) Large White x Landrace or Large White x Chester White x Landrace sows were used to determine the valine requirement of sows with a genetic capacity for high milk production. All diets were formulated to contain .90% total lysine, with all amino acids other than valine formulated to be at least 110% of their suggested estimates relative to lysine based on ratios derived from the National and Agricultural Research Councils. The control diet was formulated to .75% total valine, and crystalline valine replaced cornstarch to provide additional treatments containing .85, .95, 1.05, and 1.15% total dietary valine. Corresponding valine:lysine ratios were 83, 94, 106, 117, and 128%. Mean litter size after adjustment was 10.3 pigs across treatments, and average lactation length was 26 d. Number of pigs weaned was not affected by dietary valine (mean = 10.2 pigs), nor was daily sow feed (mean = 6.24 kg) or lysine (mean = 56 g) intake. Valine intake increased (linear, P < .001) as dietary valine increased. Litter weight at d 21 and at weaning (d 26) increased (linear, P < .02) with increasing dietary valine (62.4 to 65.5 kg and 76.1 to 79.9 kg, respectively). Litter weight gain increased from d 0 to 7 (linear, P < .06) and from d 0 to 21 and d 0 to weaning (linear, P < .02) as dietary valine increased. Dietary valine had no effect (P > .10) on sow weight change, 10th rib, or last lumbar backfat change from d 0 to 21 or d 0 to weaning or on days from weaning to estrus. These results demonstrate that increasing dietary valine for high-producing sows (21-d litter weights > 60 kg) results in improved litter weight gain. Based on the linear responses observed, the requirement is at least 1.15% of the diet (72 g/d of valine intake) to maximize litter weaning weight and litter weight gain, much greater than recommended currently by the National Research Council (100% of lysine, 36.5 g/d) or the Agricultural Research Council (70% of lysine, 25.5 g/d).

Amino Acids↗
PubMed1996

Substance-use and psychiatric disorders among American Indian veterans.

Native American (NA) veterans have rarely been the focus of investigational efforts. We review studies relevant to an assessment of NA substance-use disorders, and discuss findings of the Drug Abuse Treatment Services Evaluation Project pertaining specifically to NA veterans. A larger proportion of NA veterans discharged from VA inpatient care in FY93 were diagnosed with a substance-use disorder compared to the total population of veterans discharged that year. Substance-dependent NAs were more likely to be diagnosed with alcohol-use disorders and posttraumatic stress disorder, and less likely to be diagnosed with drug-use disorders and other psychiatric disorders than substance-dependent veterans generally.

Adult↗
PubMed1996

Alcohol abuse in urban Indian adolescents and women: a longitudinal study for assessment and risk evaluation.

Empirical studies of American Indian health and mental health have focused primarily on reservation samples or small cross-sectional school-based or treatment samples. Few studies have addressed these issues among urban American Indian populations. This paper introduces an ongoing ten-year prospective longitudinal study of alcohol abuse, drug abuse, and mental health status in a community sample of urban American Indian adolescents and women. The study uses structured interviews and diagnostic assessments to identify risk factors for, and measure prevalence of, alcohol abuse, drug abuse, and psychopathology in 523 Indian youth and 276 Indian women. Study aims, rationale, research design, methods, sample characteristics, assessment instruments, and substance use prevalence are described, and methodological issues related to conducting longitudinal research are discussed.

Adolescent↗
PubMed1996

Common sheath reimplantation yields excellent results in the treatment of vesicoureteral reflux in duplicated collecting systems.

PURPOSE: We evaluated our 10-year experience with the surgical treatment of vesicoureteral reflux in uncomplicated duplicated collecting systems. MATERIALS AND METHODS: Between 1984 and 1994, 54 refluxing renal units (8 bilateral) in 37 female and 9 male patients required surgery. Patient age ranged from 7 months to 17 years (average 4.9 at surgery). Postoperative followup (average 14.2 months) included voiding cystourethrography and renal sonography or excretory urography. RESULTS: Common sheath ureteral reimplantation via an intravesical approach was performed in 48 of the 54 refluxing renal units. Of the remaining 6 renal units detrussorrhaphy was performed in 4, and ureteroureterostomy combined with ureteral reimplantation and partial lower pole nephrectomy were done in 1 each. Two treated renal units had persistent postoperative vesicoureteral reflux, which resolved after subureteral polytetrafluoroethylene (Teflon) injection. No renal had postoperative hydronephrosis. Contralateral reflux was identified in 1 patient who underwent unilateral reimplantation. Our overall success rate was 96% for the surgical correction of vesicoureteral reflux in uncomplicated duplicated collecting systems. Common sheath reimplantation had a 98% success rate. CONCLUSIONS: Although a duplicated collecting system increases the risk for surgical treatment, the presence of a duplication anomaly does not adversely affect surgical outcome. Modifications of procedures commonly performed in the surgical treatment of single system reflux to accommodate common sheath reimplantation have excellent surgical results with minimal morbidity.

Adolescent↗
PubMed1995

Onlay-tube-onlay urethroplasty technique in primary perineal hypospadias surgery.

We extended the principles of the onlay flap to the most severe hypospadias cases. Four patients with perineal hypospadias required central division of the urethral plate to correct chordee despite dorsal plication. The urethra was reconstructed in 1 stage by proximally and distally onlaying to the remaining urethral plate a flap with its central portion tubularized to fill the gap where there was no longer a urethral plate. All patients have good cosmetic and functional results at 1 year of followup. There were no strictures or diverticula but 1 fistula developed. This technique extends the principles and advantages of an onlay flap to those severe hypospadias cases that require division of the urethral plate to correct chordee.

Humans↗
PubMed1995

Diagnosis and hospital readmission rates of female veterans with substance-related disorders.

OBJECTIVES: The study examined the prevalence of substance use, psychiatric, and medical disorders in female veterans discharged from VA hospitals. METHODS: The VA discharge abstract database was used to identify women discharged in fiscal year 1991 who received a diagnosis of substance abuse or dependence or substance-induced psychosis (N = 1,698). They were compared with female veterans who did not receive a substance-related diagnosis (N = 12,037). RESULTS: Alcohol and cocaine use disorders were the most prevalent substance use disorders. Women with substance use disorders were more frequently diagnosed as having personality disorders, depression, and posttraumatic stress disorder than women without substance use disorders. Skin and subcutaneous tissue diseases, infectious and parasitic diseases, and digestive diseases were more prevalent among women with substance use disorders than among women in the same age group who did not have substance use disorders. Approximately 44 percent of women with substance use disorders who were discharged during the first six months of fiscal year 1991 were rehospitalized within that year. CONCLUSIONS: Substance use disorders and associated comorbidities are endemic among women treated in VA hospitals. Additional studies examining characteristics of indigent women with substance use disorders are needed.

Adult↗
PubMed1995

Characteristics of substance-abusing veterans attempting suicide: a national study.

Demographic, diagnostic, and service utilization characteristics of veterans diagnosed with suicide attempt, substance dependence, both, or neither at discharge from Department of Veterans Affairs (DVA) hospitals in fiscal year 1994 (FY94) were compared using the DVA's discharge abstract database. Four groups of veterans were studied: (1) substance-abusing suicidal inpatients (n = 1,459), (2) substance-abusing nonsuicidal inpatients (n = 123,808), (3) nonsubstance-abusing suicidal inpatients (n = 632), and (4) nonsubstance-abusing nonsuicidal inpatients (n = 402,906). Substance-abusing suicidal veterans had higher rates of substance abuse than substance-abusing nonsuicidal veterans. Substance-abusing suicidal veterans had a higher mean number of inpatient treatment episodes and a larger proportion of discharges against medical advice than the other three inpatient groups. Psychiatric and substance use disorders are more prevalent among substance-abusing suicidal veterans than among veterans with only substance use disorders or suicidal conduct.

Adult↗
PubMed1995

Dust suppression in swine feed using soybean oil.

Dust generation from swine feed (corn-soybean meal diet) treated with soybean oil was investigated using a cement mixer in a plywood box. Airborne total dust concentrations in the box were measured gravimetrically using a vacuum pump and filters while 12-kg feed samples were constantly mixed. The treatment factors were soybean oil concentration (0, 1, and 3%), corn bulk density (normal, 730 kg/m3 and low, 600 kg/m3), time of oil addition (before vs after grinding the corn), and storage time (0, 7, and 14 d). The feed was a mixture of soybean meal, base mix, and adjusted amounts of ground corn and soybean oil. Adding soybean oil after grinding at 1 and 3% levels to feed made with normal-bulk density corn suppressed total dust generation (3.39 and .99 mg/m3, respectively) (P < .001) compared with the no oil treatment (29.1 mg/m3). The 3% soybean oil treatment suppressed dust generation (.99 mg/m3) more than the 1% soybean oil treatment (3.39 mg/m3) (P < .001). Adding soybean oil after grinding the corn suppressed dust generation more than adding the oil to the corn before grinding for every oil level (P < .001). More dust was generated by feed made from low-bulk density corn than by feed made with normal-bulk density corn at every oil level (P < .001). There was no evidence of any storage time or treatment x storage time interactions.

Animal Feed↗
PubMed1995

Rectus fascial wrap: early results of a modification of the rectus fascial sling.

We describe an operation that increases bladder neck resistance in patients with urinary incontinence. It is a modification of the rectus fascial sling that was designed as an adjunct to augmentation cystoplasty and is used in association with clean intermittent catheterization. The operation is performed by circumferentially wrapping a rectus fascial defatted free graft around the bladder neck and suturing it to appose the bladder neck. The procedure was done in 17 patients, including 10 with myelodysplasia, 3 with sacral lipoma, 3 with bladder exstrophy and 1 with nonneurogenic neurogenic bladder. Leak point pressure improved in patients in whom it was measured preoperatively and postoperatively. Complications developed in 5 patients, including difficulty with catheterization in 2, ventral hernia at the graft harvest site in 1, bladder calculus in 1 and detrusor hyperreflexia in 1. Early results with the bladder fascial wrap indicate that it has the ability to improve continence in patients with a dysfunctional bladder neck who have undergone augmentation.

Adolescent↗
PubMed1995

Pharmacokinetics, nephrotoxicosis, and in vitro antibacterial activity associated with single versus multiple (three times) daily gentamicin treatments in horses.

Once-daily administration of aminoglycosides may be a safe and effective therapeutic regimen, on the basis of the microbiologic and pharmacokinetic characteristics of these antibiotics. This study was designed to determine serum and tissue concentrations following i.v. administration of gentamicin, at dosages of 6.6 mg/kg of body weight, every 24 hours, and 2.2 mg/kg, every 8 hours, for 10 days in adult horses. Nephrotoxicosis from these dosage regimens also was compared, and microbiologic effects, including postantibiotic effects, were determined with various concentrations of gentamicin against an equine clinical isolate of Pseudomonas aeruginosa. Treatment at the 6.6-mg/kg dosage resulted in maximal serum concentrations (77.93 +/- 19.90 micrograms/ml, mean +/- SEM) and area under the concentration-vs-time curves (83.79 +/- 14.97 micrograms.h/ml) that were significantly (P < 0.05) greater than those following treatment at the 2.2-mg/kg dosage (5.05 +/- 0.50 micrograms/ml and 6.03 +/- 0.66 micrograms.h/ml, respectively). Nephrotoxicosis was not induced with either dosage regimen, and postantibiotic effects were prolonged with a higher gentamicin concentration. This study provided evidence to support the use of once-daily gentamicin treatment in adult horses.

Animals↗
PubMed1994

Psychiatric and medical comorbidities of veterans with substance use disorders.

OBJECTIVE: The authors examined patterns of substance use disorders and psychiatric and medical comorbidity in all male veterans treated in Veterans Affairs (VA) medical centers during a one-year period. METHODS: A national discharge abstract data base was used to derive point prevalence rates of psychiatric and medical disorders for 539,557 inpatients treated in VA medical centers in fiscal year 1991. RESULTS: Nearly one-quarter of all male veterans treated in the study year had a substance-related diagnosis. The most prevalent substance use disorders were alcohol dependence (87.7 percent) and cocaine dependence (17.5 percent), and the most frequent psychiatric diagnoses among veterans with substance-related diagnoses were depression and personality disorders. Digestive disorders were more prevalent among veterans who abused substances than among veterans who did not, and veterans who abused substances were also more likely to have multiple hospitalizations and longer index hospital stays. CONCLUSIONS: Substance use disorders and comorbid psychiatric syndromes are common in male veterans treated in VA hospitals. Veterans with substance-related diagnoses may have longer hospital stays and more frequent hospitalizations than veterans without substance use disorders.

Adult↗