Search PubMed⌕ Search

Biomedical subjects

J K Dunn

Publications and source records attributed to J K Dunn.

At least 73 records · Page 4Linked to original sources
PubMed1988

Withholding medical treatment from the severely demented patient. Decisional processes and cost implications.

We performed an observational study to determine the prevalence of severe dementia in a general medicine unit, the categories of acute medical care provided to these patients, the process by which treatment decisions are made, and their cost implications. The prevalence of severe dementia was 4.4%. The patients from whom some form of acute medical care was withheld (26 [45.6%] of 57) were more severely ill at admission and had a mortality rate five times higher than those who received full care. Physicians cited family wishes in 75.9% of the decisions to limit care but in only 10.9% of the decisions to give full care. The only differences in charges incurred were due to differential mortality rates in individuals from whom care was withheld. We recommend that hospitals develop and implement protocols for decision making in the care of the severely demented to promote open discussions among providers and families and to increase family contributions to decision making. We believe that the extension of this consultative approach to decisions involving severely demented patients may have the virtue of combining more humane care with more cost-effective care.

Acute Disease↗
PubMed1986

The accuracy of children's self-reports of diet: Family Health Project.

This study was designed to test the accuracy of four different methods for enabling children in the third to sixth grades to record their frequency of consumption of foods high in any of four targeted nutrients. The forms varied in two ways: recording the whole day or a segment of the day (morning, afternoon, or evening) or use or non-use of pictures of the food items. The accuracy of the children's recording of food consumption was validated by observation of their behavior for 2 continuous 12-hour days. Twenty-four children in the third to sixth grades were observed for each of the 2 days. An 82.9% agreement was obtained between the child's self-reported food frequency and the observer's record of the child's consumption. Ethnicity slightly affected the accuracy of form completion, while gender and grade level of the children did not. The results of this study validate the accuracy with which children record diet using a food frequency of consumption method.

Child↗
PubMed1985

Differential response of urinary N-acetyl-beta-D-glucosaminidase to two osmotic diuretics in the dog.

Urinary N-acetyl-beta-D-glucosaminidase (NAG), a lysosomal hydrolase located the proximal tubule of the kidney, has been used as a marker for subtle renal injury. In humans and other animals with diabetes mellitus, urinary NAG activity has been shown to increase within 12 hours of the onset of hyperglycemia and glycosuria. Whether the rise in urinary NAG activity is in response to the hyperglycemia or to the osmotic diuresis associated with glycosuria is not known, nor has the time course of the rise in enzyme activity been determined. A study was designed using four groups of dogs to examine these possibilities: group 1 (n = 5), control dogs; group 2 (n = 5), mannitol-infused dogs; group 3 (n = 5), low-glucose dogs; and group 4 (n = 5), high-glucose dogs. In groups 2 and 4, mannitol and glucose, respectively, were infused at a rate to double urine flow from the left ureter without altering the contralateral urine volume. In group 3, sufficient glucose was infused to elevate left renal vein glucose level without producing glycosuria. In the control dogs infused with normal saline solution at a constant rate throughout the control and study periods, no differences were found in urinary NAG excretion when data from individual clearance periods were compared for the right and left kidneys. In the low-glucose dogs, urinary NAG/creatinine ratios were significantly increased (P less than 0.01) when the left and right kidneys were compared for the duration of the infusion.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylglucosaminidase↗
PubMed1984

The diagnostic significance of a positive direct antiglobulin test in anemic cats.

The preparation of a feline Coombs serum (rabbit antifeline gamma globulin) is described. The direct antiglobulin test using this serum was performed on 20 anemic and 20 healthy control cats. Red cell membrane antibodies were detected in cats with feline leukemia virus infection and in others with inflammatory and neoplastic diseases. A low titre of cold agglutinating antibody was present in a high proportion of the control cats. Positive direct antiglobulin tests were noted in cats without overt hemolytic disease. It was concluded that the direct antiglobulin test in anemic cats has certain diagnostic limitations. A positive reaction should be interpreted cautiously especially when there is no clinical or laboratory evidence to support a diagnosis of autoimmune hemolytic anemia.

Anaplasmataceae Infections↗
PubMed1982

Control of upper gastrointestinal bleeding with a microcrystalline collagen hemostat.

A microcrystalline collagen hemostat (MCH) widely used in general surgery was tested in the control of bleeding from experimentally produced gastric ulcers. Five dogs had a gastrotomy and were given heparin. Using the standard "ulcer maker," three sets of three ulcers were made in the gastric mucosa of each animal. Blood from each ulcer was collected for a 5-min period to allow for stabilization of bleeding. MCH powder or slurry or no MCH was placed directly on one ulcer of each set in random order. The bleeding rate for the next 10 min was measured. Mean decrements in the bleeding rate for slurry MCH and dry MCH-treated ulcers were 87% and 81%, respectively, compared with 51% for controls, P less than 0.05. Twelve MCH-treated ulcers, but no control ulcer, stopped bleeding completely, P less than 0.01. Preliminary observations show that MCH slurry can be applied through an endoscope and may be hemostatically effective in man. MCH may have a role in the endoscopic control of gastrointestinal bleeding.

Animals↗
PubMed1981

Cancers of the breast and female genital system: search for recessive genetic factors through analysis of human isolate.

To investigate the importance of recessive genes in female breast and genital cancers, we have conducted investigations in the Hutterites, a highly inbred genetic isolate in North America. The homogeneous life style of this group, which lives on communal farms, also facilitates distinction between shared environmental and genetic factors. We ascertained 177 cases of cancer (all organ systems) through Canadian and United States cancer registries, field trips, and searches of death certificates. Breast cancer and endometrial cancer mortalities were those expected for 1970 United States whites, but no deaths due to squamous cervical carcinoma were ascertained in this monogamous population. Inbreeding coefficients (F) for cases were higher than means for matched controls for each of the four cases of breast cancers that occurred in younger women (less than 45 years of age), for four of five cases of endometrial cancer, and for the single cases of uterine leiomyosarcoma, dysgerminoma, and ovarian adenocarcinoma. By contrast, in cases of breast cancer that occurred in women 45 years of age or older, only four of 15 F's were above those for controls. There is a significant difference between the two breast cancer age groups with respect to the likelihood that the F of cases was higher than the F of controls (chi 2 = 6.99, p less than 0.01). However, grouping cases by type, none of the F distributions were significantly different from those of their matched controls. These preliminary genetic investigations thus conform certain concepts concerning breast and female genital cancer but also suggest the desirability of further studies to elucidate the role of genetic factors in premenopausal breast cancer.

Adult↗
PubMed1981

Association of in vitro Escherichia coli adherence to vaginal and buccal epithelial cells with susceptibility of women to recurrent urinary-tract infections.

To identify changes in epithelial cells that were associated with susceptibility to recurrent urinary-tract infections, we investigated the adherence of Escherichia coli to vaginal and buccal cells obtained from 11 healthy controls and 24 patients who had had at least three such infections in the preceding year. Adherence to vaginal cells was greater in patients than in controls (10.1 +/- 0.92 vs. 3.8 +/- 0.47 bacteria per cell [mean +/- S.E.], P less than 0.001), as was adherence to buccal cells (11.7 +/- 1.29 vs. 7.1 +/- 0.49, P = 0.002). This increased adherence in patients persisted despite temporary remission of the infection. Vaginal cells from patients not receiving antimicrobial prophylaxis had greater adherence than cells from patients given prophylactic therapy (11.7 +/- 1.34 vs. 8.3 +/- 1.0; P = 0.027). The range and rapidity of change in adherence as well as in vivo colonization of the vaginal mucosa were greater in patients than controls. Our data suggest that susceptibility to urinary-tract infections in women is associated with changes in the adhesive characteristics of epithelial cells.

Adhesiveness↗
PubMed1980

The colon influences ileal resection diarrhea.

Fecal mass and electrolyte concentrations from 25 ileectomy and/or colectomy patients on known diets were used to assess those factors most responsible for their diarrhea. In 18 ileectomy patients the severity of diarrhea, expressed as a fecal weight, was a function of both percent of colon and centimeters of ileum removed. Linear regression analysis, however, showed that the extent of missing colon had three times the effect of missing ileum on fecal weight. Patients who lost the ileocecal valve and part of the right colon had more diarrhea than those who lost comparable lengths of ileum but had this area preserved. Fecal ion concentrations seemed independent of diet but were related to fecal weight and the amount of colon and ileum removed. Potassium concentration was strongly dependent on the amount of colon lost, while sodium concentration was more influenced by the length of resected ileum. Choloride was most dependent on fecal weight. As expected, fecal fat correlated strongly with the extent of ileum removed. Regresison equations were constructed from the electrolyte data which described and predicted the extent of lost ileum or colon. Our data were also used to separate patients with less than 100 cm of ileum removed from those with more extensive resections. The severity of diarrhea following ileal resection depends primarily on the amount of contiguous colon removed. Varying loss of ileum and colon produced predictable effects on fecal weight and electrolyte composition. Surgeons should preserve the maximum amount of colon possible to reduce the severity of diarrhea in these patients.

Adult↗
PubMed1980

Cancer mortality in a human isolate.

Cancer mortality (1965--77) among 12,652 members of an inbred human religious isolate, the Hutterites, was compared with expectations based on mortality rates for the U.S. white population in 1970. Overall, Hutterites had significantly fewer deaths from cancer than expected (P < 0.01), due primarily to fewer lung cancers among males. Smoking is prohibited for this religious group. The most frequent types of cancers were leukemia and cancers of the digestive system, the prostate gland, and the female breast. Preliminary results suggest an association between recessive alleles and childhood leukemia. More stomach and rectal cancers were observed than expected, but differences were generally not significant. Familial aggregates of cancers of the stomach and breast are being investigated. The low frequency of cervical cancer is consistent with current evidence for an association of cervical cancer with early age at first intercourse and promiscuity, neither of which is characteristic of this population.

Canada↗
PubMed1980

A stochastic model for the occurrence of transient ischemic attacks.

This paper presents the development, application and evaluation of a stochastic model of the frequency of occurrence of transient ischemic attacks (TIAs). TIAs occur during periods of abnormal arterial activity. The TIAs which occur during a single period of abnormal activity are called a cluster of TIAs. Thus, the number of TIAs occurring in a time interval is determined by the number of clusters of TIAs occurring and the number of TIAs per cluster. The distribution of the number of clusters, which is a modification of the Poisson distribution, is obtained through the use of infinitesimal probabilities and the method of generating function. The number of TIAs per cluster follows the logarithmic series distribution. The distribution of the number of TIAs is then a modification of the negative binomial distribution, which allows for censoring of the data that may be related to the occurrence of the clusters of TIAs. Estimates for the parameters, based on observed frequencies, are obtained, which allow the model to be applied to data from the Aspirin in Transient Ischemic Attacks Study.

Aspirin↗
PubMedDate not supplied

Smoking, smoking cessation, and understanding of the role of multiple cardiac risk factors among the urban poor.

OBJECTIVE: To determine in a population of low socioeconomic status (SES) patients: (a) rates of current smoking and smoking cessation, (b) persons' understanding of the adverse health impact of multiple cardiovascular disease (CVD) risk factors, and (c) if the diagnosis of other CVD risk factors, specifically hypertension or hypercholesterolemia, was related to smoking cessation. DESIGN: Cross-sectional interview survey. SETTING: Community clinics and eligibility centers of the Harris County Hospital District (HD), which provides primary care to over 166,000 indigent persons in Houston, Texas. SUBJECTS: Randomly selected adults attending an HD setting for eligibility screening or primary care. RESULTS: Over 93% of subjects approached participated (n = 547). Their mean age was 40.7 years, 55% were female, and 39% had > 9 years of education. The ethnic distribution was 54% Hispanic, 28% black, and 14% non-Hispanic white. Current smoking ranged from 10% among Hispanic females to 56% among black males. The percentage of ever smokers who had quit was 24% among black males, 44% among black females, 43% among Hispanic males, and 70% among Hispanic females. The majority recognized the increase in danger from smoking in the presence of hypertension or hypercholesterolemia. Among patients who were smokers when they found out they had hypertension (n = 70), 65% reported it increased their desire to quit. After adjustment for other variables including age and known CVD, predictors of being an ex-smoker were being female (OR 2.1, 95% CI 1.3-3.5), being Hispanic (OR 2.8 95% CI 1.5-5.7), and having hypertension (OR 2.3, 95% CI 1.3-4.2). CONCLUSION: In this low SES population, there was substantial smoking cessation, widespread acknowledgment of the cumulative effect of smoking and other CVD risk factors, and some evidence that smoking cessation increased after the diagnosis of hypertension.

Adult↗
PubMedDate not supplied

Chronic donepezil treatment is associated with slowed cognitive decline in Alzheimer's disease.

OBJECTIVE: To compare rates of cognitive decline between probable Alzheimer's disease (AD) patients treated with long-duration cholinesterase inhibitors (ChE-Is) and those who remained untreated. BACKGROUND: ChE-Is, including donepezil and tracrine, have shown beneficial effects on cognition and global functioning in patients with AD. The duration of these benefits is unknown because the longest double-blind placebo-controlled studies reported were only approximately 6 months long. Ethical concerns regarding randomization of patients to placebo for long periods make it difficult to undertake trials of longer duration. METHODS: We identified patients in 4 AD centers who were or were not consistently treated with ChE-Is and who had demographic, psychometric and follow-up data. We compared 205 ChE-I-treated and 218 untreated AD patients on baseline variables hypothesized to differ between these groups, on baseline Mini Mental Status Examination (MMSE) scores and on rates of MMSE change at 1 year. The analysis was performed initially with all ChE-I-treated patients as a single group versus untreated subjects, and then with donepezil versus untreated subjects and tacrine versus untreated subjects. RESULTS: As expected, treated and untreated patients differed with respect to age, education, ethnicity, percentage of community dwelling and exact days of follow-up (ANOVA and chi2) in several comparisons, but did not differ on baseline MMSE score. These baseline variables were highly intercorrelated. MMSE scores declined significantly more slowly after 1 year of ChE-I treatment compared to untreated patients (p = 0.05) after controlling for baseline differences in age, education, ethnicity and percentage of community dwelling. Slowing of decline was significant in the donepezil-treated patients (p = 0.007) but not in the tacrine-treated group (p = 0.33). CONCLUSIONS: This study, utilizing concurrent, nonrandomized controls, suggests that donepezil continues to have efficacy over at least the first year of therapy. Other studies are needed to determine whether the benefits are maintained beyond 1 year.

Aged↗