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Biomedical subjects

C Barnett

Publications and source records attributed to C Barnett.

13 recordsLinked to original sources
PubMed1992

Enteric-coated charcoal as a means of blinding studies comparing bismuth and H2-receptor antagonists.

Clinical trials comparing H2-receptor antagonists and bismuth-containing regimens in ulcer healing, ulcer relapse, or dyspepsia have not been double-blind, because bismuth darkens stools. This study was designed to determine whether enteric-coated charcoal could darken stools of subjects taking an H2-receptor antagonist without interfering with absorption of the drug. Twelve healthy volunteers participated in a randomized, double-blind, crossover trial of oral ranitidine (300 mg at bedtime) alone, ranitidine plus bismuth (30 ml Pepto-Bismol four times daily), and ranitidine plus enteric-coated charcoal (four tablets daily). Mean stool colors both with ranitidine plus charcoal and with ranitidine plus bismuth were significantly darker than with ranitidine alone, but were not significantly different from each other. Blood levels of ranitidine during the 10 h after its administration did not differ significantly among the three regimens. We conclude that enteric-coated charcoal can be used to blind clinical trials comparing an H2-receptor antagonist (e.g., ranitidine) and a bismuth regimen.

Administration, Oral↗
PubMed1991

Fasting gastric pH and its relationship to true hypochlorhydria in humans.

Abnormally low rates of gastric acid secretion (hypochlorhydria) are associated with bacterial overgrowth, enteric infection, and with hypergastrinemia and an increased risk of gastric neoplasms. In the present study, we evaluated the ability of fasting gastric juice pH measurements to detect true hypochlorhydria. True hypochlorhydria was defined as a peak acid output in response to a maximally effective stimulant of acid secretion that was below the lower limit of normal for 365 consecutive healthy subjects. In these healthy subjects, average basal pH was 2.16 +/- 0.09 in men and 2.79 +/- 0.18 in women. In 109 consecutive experiments in 28 subjects with true hypochlorhydria, fasting gastric pH averaged 7.44 +/- 0.11 in men and 7.65 +/- 0.33 in women. Fasting pH exceeded the upper 95% confidence limit of normal (5.09 in men and 6.81 in women) in 102 of the 109 experiments (94%). Thus, fasting pH measurement was a sensitive method for diagnosing bona fide hypochlorhydria.

Achlorhydria↗
PubMed1989

Computer assisted treatment planning for 125I ophthalmic plaque radiotherapy.

This paper describes a computer program for planning the treatment of ocular tumors with 125I plaques. The program permits the input of the tumor configuration into a model eye and facilitates the viewing of the relative geometry of the tumor and various eye structures in different perspectives. Custom-designed 125I plaques can be localized onto the globe, and dose distributions can be calculated and superimposed on the eye structures in any plane or on the inner eye surface. The program allows efficient evaluation of the plaque design in terms of radiation dose distribution relative to the tumor and critical structures.

Brachytherapy↗
PubMed1989

Survival and quality of life after interstitial implantation of removable high-activity iodine-125 sources for the treatment of patients with recurrent malignant gliomas.

Between January 1980 and January 1988, 95 evaluable patients with recurrent, unifocal, supratentorial malignant gliomas were reirradiated with high-activity iodine-125 sources implanted directly into tumor in afterloaded, removable catheters using computerized tomography-directed stereotaxy. A tumor dose of 5270-15,000 cGy was delivered at a maximum distance of 0.5 cm from the rim of the contrast-enhancing mass seen on CT scans. The median survival for the 50 patients with anaplastic astrocytoma was 81 weeks and for 45 patients with glioblastoma multiforme it was 54 weeks. The 18- and 36-month survival rates for patients with anaplastic astrocytoma were 46% and 28%, respectively; the 18- and 36-month survival rates for patients with glioblastoma multiforme were 22% and 8%, respectively. Because of clinical deterioration, increasing steroid dependency, and increasing mass effect at the implantation site seen on CT scans, necrotic tissue was excised from 47 patients (49%) at craniotomy; in some patients, tumor was mixed with necrotic tissue. The survival of reoperated patients was significantly longer compared with patients who did not undergo this procedure. Serial determination of the Karnofsky Performance Score (KPS) showed that there was no significant deterioration for the group as a whole during the 6 months immediately after implantation. At 18 months, 33 of the patients were alive; KPS ranged between 50 to 90 (mean 79) and 67% were steroid dependent. At 36 months, 18 patients were alive; 17 patients were evaluable with KPS that ranged between 40 to 90 (mean 76) and 53% were steroid dependent. Eleven of the 17 evaluable long-term survivors had a KPS of 80 or higher with a mean of 87. Interstitial brachytherapy may provide long-term survival in selected patients with recurrent malignant gliomas who have been irradiated previously with conventional teletherapy. The quality of life in the majority of long-term survivors appears to be quite satisfactory. Further attempts to control tumor growth using this modality appear to be warranted.

Adolescent↗
PubMed1988

Improved dose distribution with customized I-125 source loading in temporary interstitial implants.

I-125 sources are being used in temporary interstitial implants of various sites. Radiation safety considerations favor its use over other available radioisotopes. Cost containment is achieved by using the same sources for a number of patients. Loading I-125 seeds into implant catheters at our institutions permit customized source arrangement to optimize the implant dose patterns. Clinical examples are given for which the dose distributions achieved with customized source loading are superior to those achievable with standard Ir-192 ribbons.

Brachytherapy↗
PubMed1987

Detailed comparison of basal and food-stimulated gastric acid secretion rates and serum gastrin concentrations in duodenal ulcer patients and normal subjects.

We measured basal and peak acid outputs, food-stimulated acid secretion, and basal and food-stimulated serum gastrin concentrations in a large group of duodenal ulcer patients and normal subjects. Basal and peak acid outputs were significantly higher in ulcer patients. In contrast, acid secretion was similar in the groups when food was infused into the stomach and when sham feeding was combined with meal infusion to simulate normal eating. Meal-stimulated acid secretion, expressed as a percentage of peak acid output to correct for differences in secretory capacity, was lower in ulcer patients (P less than 0.002). Basal serum gastrin concentrations were higher in ulcer patients, which may have contributed to higher basal acid output. However, increases in serum gastrin after food were similar in the groups. Duodenal ulcer patients, as a group, have increased basal and maximal acid secretion, but the amount of acid secreted and gastrin released after eating is normal.

Adult↗
PubMed1986

Effect of intragastric infusions of ethanol and wine on serum gastrin concentration and gastric acid secretion.

The effects of ethanol and wine on serum gastrin concentration and gastric acid secretion were evaluated in 13 normal volunteers. Solutions studied were pure ethanol (5%, 12%, and 36%), red wine, and white wine. Each solution contained 28 g of ethanol and each was administered as a slow, steady intragastric infusion to simulate normal ingestion of beverages. When compared to saline (control), none of the pure ethanol solutions increased serum gastrin concentration or gastric acid secretion significantly. In contrast, red and white wine (12% ethanol vol/vol) were potent stimulants of gastrin release and acid secretion when compared either to saline or pure 12% ethanol. Mean (+/- SEM) peak serum gastrin increases with 300 ml of red wine, white wine, saline, and pure 12% ethanol were 253 +/- 125, 182 +/- 91, 13 +/- 2, and 11 +/- 3 pg/ml, respectively (p less than 0.05 for red and white wine versus saline or 12% ethanol), and the mean peak acid outputs were 28.6 +/- 2.8, 27.9 +/- 1.9, 9.3 +/- 2.0, and 11.9 +/- 1.3 mmol/h, respectively (p less than 0.05 for red and white wine versus saline or 12% ethanol). We conclude that red and white wine stimulate gastric acid secretion, probably by enhanced release of gastrin, and that this effect is not due to the ethanol content of wine.

Adult↗
PubMed1986

Retention of knowledge and self-care skills after an intensive in-patient diabetes education program.

Diabetes knowledge and self-care skills were studied in 35 adults with IDDM and NIDDM before and after an intensive in-patient education program and 6-12 months after discharge. Knowledge and skills were compared to fasting serum glucose levels and percent ideal body weight (%IBW). Although knowledge improved during hospitalization and knowledge and skills were maintained at follow-up, there was not a significant relationship between fasting serum glucose levels and knowledge or self-care skills or %IBW.

Adult↗
PubMed1979

Reduction of twenty-four-hour gastric acidity with combination drug therapy in patients with duodenal ulcer.

Four "extra-effort" drug regimens were tested to determine which most nearly eliminated 24-hr gastric acidity in 8 patients with duodenal ulcer. The regimens included two 300 mg cimetidine tablets with meals and at bedtime; one 300 mg cimetidine tablet plus an anticholinergic drug with meals and at bedtime; 300 mg cimetidine with meals and at bedtime plus liquid antacid 1 and 3 hr after meals and at bedtime; and 300 mg cimetidine, an anticholinergic drug, and antacid, taken simultaneously as each meal was finished and at bedtime. No regimen completely eliminated gastric acidity. However, compared to standard cimetidine therapy (300 mg four times daily) which led to a median 24-hr pH of 2.6, each "extra-effort" regimen except cimetidine plus an anticholinergic was significantly better in reducing gastric acidity. During the daytime hours, cimetidine with meals plus antacid 1 and 3 hr after meals was most effective (median pH 5.0). However, the more convenient regimen of cimetidine, an anticholinergic drug, and antacid was almost as effective (median pH 4.3). None of the "extra-effort" regimens was significantly more effective than standard cimetidine therapy during the hours of sleep.

Adult↗
PubMedDate not supplied

Dose parameters of 125I and 192Ir seed sources.

As mandated by an NCI brachytherapy contract, we measured dosimetric parameters for 192Ir seeds and two models of 125I seeds. Measurements were with LiF powder in a water-equivalent phantom. Data were corrected for background, sample mass, and finite detector volume. Selected parameters were also investigated through Monte Carlo calculations. Results are presented in terms of a dose parametrization that is described in detail, and are compared to published data. Our results agreed well with published data for relative quantities such as radial and angular dose dependence. Our measured value for the 192Ir dose factor was 4.55 cGy(H2O) cm2 mCi-1 h-1, also in good agreement with commonly used values. However, the measured dose factors for 125I seed models 6702 and 6711 were 1.18 and 1.06 cGy(H2O) cm2 mCi-1 h-1, values well below those in general use.

Brachytherapy↗
PubMedDate not supplied

Nursing faculty's knowledge and attitudes toward persons with AIDS.

The research examined knowledge, fear, homophobia, and the willingness to care for persons with AIDS. The subjects were 45 faculty members from nursing programs in a mid-southern state. The study was an extension of an earlier study by Lester and Beard (1988). A 56-item questionnaire consisting of knowledge and attitude questions was used. Attitude questions were categorized into fear, homophobia, and the intent to give care. With the level of significance set at (p less than .01), homophobia and fear were significantly correlated positively. Knowledge was not significantly correlated with any of the variables. Findings suggest that AIDS education should be directed toward changing attitudes and values by promoting learning in the affective domain.

Acquired Immunodeficiency Syndrome↗