Search PubMed⌕ Search

Biomedical subjects

T Barnes

Publications and source records attributed to T Barnes.

70 records · Page 4Linked to original sources
PubMed1986

Angiotensin and salt appetite: physiological amounts of angiotensin given peripherally increase salt appetite in the rat.

Two experiments were conducted in which adrenalectomized male Sprague-Dawley rats were maintained ad lib on distilled water, 3% saline, and sodium-free food. In Experiment 1, 45 rats were given 100, 200, 400, 800, and 1,000 micrograms/kg/day desoxycorticosterone acetate (DOCA) im for 5 days to determine the dose of DOCA that would produce the lowest voluntary saline intake, and 800 micrograms/kg/day was found to produce the nadir in saline intake. In Experiment 2, 40 rats were placed ad lib on distilled water, saline, and sodium-free food as described above, maintained on 800 micrograms/kg/day DOCA, and infused with 4, 25, 100 micrograms/kg/day angiotensin II (A II) or 0.9% saline. The three A II groups showed significant percentage changes in their saline intake above pre-A II levels; the saline control group showed no change in saline intake from pre-A II level. These results are interpreted to demonstrate the production of salt appetite in rats by peripheral administration of physiological doses of angiotensin II.

Angiotensin II↗
PubMed1984

Oxygen at 2 atmospheres absolute pressure does not increase the radiation sensitivity of normal brain in rats.

Cranial radiation was administered to CD Fisher rats at 1.0, 1.5 and 2.0 atmospheres absolute oxygen pressure. Life span following radiation was recorded. Surviving animals were killed at 28 weeks and the brains were examined independently by two neuropathologists. Survival time was significantly less in animals receiving higher doses of radiation but showed no relationship to the oxygen pressure in the environment of the animal at the time radiation was administered. Microscopic examination of the brain did not reveal any differences in animals radiated in a normobaric or hyperbaric oxygen environment. It is concluded that hyperbaric oxygen does not sensitize the normal brain to the effects of ionizing radiation.

Animals↗
PubMed1984

Dialysate flow rate and peritoneal clearance.

We evaluated the influence of dialysate flow rates upon peritoneal clearance of urea, creatine, protein losses into dialysate, glucose disappearance from dialysate, sodium removal from the patient during dialysis, and ultrafiltration rate in 64 patients undergoing intermittent peritoneal dialysis. We evaluated three dialysate flow rates: 2 L/h, 3 L/h, and 4 L/h. All dialysate contained 1.5% glucose. The clearance of urea in milliliters per minute (2-L series 14.0, 3-L series 15.1, 4-L series 17.6) and creatinine in milliliters per minute (2-L series 9.3, 3-L series 10.6, 4-L series 11.6) determined at a dialysate flow rate of 4 L/h was significantly greater than the clearances determined at 3 and 2 L/h of dialysate flow (P less than 0.05). The clearance of glucose from the peritoneal cavity in milliliters per minute (2-L series 6.9, 3-L series 7.9, 4-L series 8.9) was significantly greater for the 4-L series as compared with the 2-L series (P less than 0.05). There were no other significant differences. Neither sex, race, previous episodes of peritonitis, nor etiology of renal failure influenced the results. Given the high cost of dialysate, we recommend dialysate flows of 2 L/h if a patient has a residual renal clearance of 2.5 mL/min. Although increasing dialysate flow rate may compensate for renal clearances significantly less than this, we believe the patient should be offered hemodialysis, continuous cyclic peritoneal dialysis (CCPD), or continuous ambulatory peritoneal dialysis (CAPD).

Creatinine↗
PubMed1983

Peritonitis in continuous ambulatory peritoneal dialysis patients.

Peritonitis is the most important complication of continuous ambulatory peritoneal dialysis (CAPD). We reviewed our experience with peritonitis over a 2 1/2-year period. Our patients spent 4% of their total time on dialysis in hospital due to peritonitis. Thirty-eight percent of the episodes of peritonitis were treated without hospitalization. We evaluated the dialysate bag change technique as commonly performed with currently available devices (extension tubing and titanium Luerlock Tenckhoff catheter adapter). The aseptic techniques described for dialysis extension tubing changes appear adequate (with no increased incidence of peritonitis demonstrated shortly after an extension tubing set change). Long-term sterility is maintained at the dialysate bag puncture port and at the orifice of the dialysis catheter adapter (no positive cultures from the bag port and orifice of the titanium adapter). Etiologic diagnosis of uremia was not a risk factor predisposing to peritonitis. The incidence of peritonitis was greater among patients with less formal education and lower income. Out data suggest that patients with less formal education and of lower economic status be carefully evaluated before commencing CAPD.

Bicarbonates↗
PubMed1983

Evaluation of continuous ambulatory peritoneal dialysis.

This study was undertaken to ascertain whether 19 patients maintained on continuous ambulatory peritoneal dialysis (CAPD) for at least 1 year experienced any deterioration in peritoneal membrane function. Selected serum chemistries and skinfold measurements were also evaluated to determine whether patients dialyzed by CAPD could maintain a normal nutritional status. This study demonstrates that patients maintained on CAPD had stable dialysate protein losses, glucose absorption from the dialysate, and constant urea, creatinine, and sodium removal. When these patients were subdivided by incidence of peritonitis, the group with a lower incidence of peritonitis (one episode every 349 +/- 155 SEM days) showed stable serum protein concentration and improvement in upper arm area whereas the group with a high incidence of peritonitis (one episode every 95 +/- 7 SEM days) showed a reduction in upper arm muscle area. Thus, our data suggest that over a 1-year period, there is no deterioration in peritoneal membrane characteristics and CAPD is effective in maintaining the nutritional status of the patient. However, both membrane function and nutritional status may be impaired by frequent episodes of infection.

Adolescent↗
PubMed1983

Comparison of home hemodialysis to continuous ambulatory peritoneal dialysis.

We evaluated prospectively various outcome measurements of patients assigned initially to continuous ambulatory peritoneal dialysis (CAPD) and home hemodialysis (HHD) from February 1979 to August 1981 and the causes for failures of the techniques. Morbidity was assessed by time in hospital/time on dialysis. Fifty-six patients were trained for CAPD and 37 for HHD. Those assigned to CAPD experienced an increased frequency of hospitalization (7.5% CAPD, 2.8% HHD, respectively) primarily due to episodes of peritonitis. There was also a higher modality failure rate (43% vs. 16%). However, the groups were not comparable in all respects. For example, the CAPD population included 21 patients with major cardiovascular diseases versus only three in the HHD group. The demographic characteristics of both populations including race, sex, age, income, place of residence, marital status, and education were similar. At the time of this study there is no direct evidence showing that healthy patients otherwise able to perform HHD may be maintained with less morbidity for a prolonged period utilizing CAPD. Therefore, we suggest that HHD is the home method of choice for patients able to proceed with this technique. CAPD may be indicated for patients in whom the period of home dialysis is expected to be relatively short and who would be otherwise unable to carry out home dialysis, for example, patients awaiting transplantation and those unable to be maintained on hemodialysis because of impaired cardiac function. To fully evaluate CAPD as a long-term maintenance therapy, a prospective trial must be performed.

Adult↗
PubMed1982

Augmentation of peritoneal clearance by dipyridamole.

We performed a double blind crossover trial in which dipyridamole was administered to ten patients undergoing intermittent peritoneal dialysis at 2 liters/hour (10 min infusion, 30 min intraperitoneal dwell of dialysate and 20 min drainage of dialysate). After the patients received the drug for 3 days at a dose of 75 mg three times daily, peritoneal inulin clearance increased by 1.2 ml/min (P less than 0.05), and glucose absorption increased by 12.1 g (P less than 0.05). The mechanism of the observed drug-induced effects is unknown.

Adult↗
PubMed1981

Intraperitoneal coagulation in chronic liver disease ascites.

Twenty patients with the ascites of chronic liver disease were investigated for in vivo evidence of active coagulation within ascites by detection of fibrin monomer. Increased levels of fibrin monomer, increased fibrin/fibrinogen degradation products, and absent or low levels of fibrinogen in the ascites of all patients tested confirmed the presence of intraperitoneal coagulation when ascites is present.

Ascites↗
PubMed1981

Peritoneal abnormalities during infectious episodes of continuous ambulatory peritoneal dialysis.

Exchanges were performed in 1-hour and 3- to 5-hour cycles when patients were noninfected and during episodes of peritonitis. The hourly exchange dialysate effluent volume decreased with the occurrence of peritonitis. These exchanges were associated with increased glucose absorption from dialysate, diminished sodium removal and augmented clearances of urea and creatinine. Protein losses were increased in the dialysate effluent of patients during an episode of peritonitis during the hourly exchanges. In the long-dwell exchanges obtained after clinical improvements of peritonitis, only protein losses were increased over control. Clearances, sodium loss in dialysate and glucose absorption were not altered from control.

Adult↗
PubMedDate not supplied

Evaluation of hysterectomized women seen at a clinic for treatment of sexually transmitted diseases.

Thirty-one women who had had total hysterectomies, seen in a venereal disease clinic, were interviewed and examined. Thirteen (31%) of the 31 women had acquired one or more venereal infections after hysterectomy. The diseases, listed in order of decreasing frequency, were trichomoniasis (four cases), gonorrhea (three), early latent syphilis (three), vaginal candidiasis (three), secondary syphilis (two), late latent syphilis (two), and condyloma acuminatum (one). These results indicate that clinicians working in venereal disease clinics must maintain as high an index of suspicion of sexually transmissible diseases for women with hysterectomies as for all other women.

Adult↗
PubMedDate not supplied

Evaluation of the limulus amebocyte lysate assay for presumptive diagnosis of gonorrhea in men at a clinic for sexually transmitted diseases.

Specimens of urethral exudate from 200 men with uncomplicated urethritis were tested for Neisseria gonorrhoeae by the limulus amebocyte lysate assay, culture on modified Thayer-Martin medium, and gram-stained smear. As compared with cultures, the sensitivity and specificity of the limulus assay were 94.8% and 89.3%, respectively, while the sensitivity and specificity of the gram stain were 98.8% and 100.0%, respectively. The accuracy of prediction of the presence of N. gonorrhoeae was significantly better by gram-stained smear than by the limulus assay. Unless the limulus assay is modified, as it was in this study, it does not appear to have a role in the presumptive diagnosis of the gonorrhea in men at a clinic for sexually transmitted diseases.

Adolescent↗