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Biomedical subjects

R L Nelson

Publications and source records attributed to R L Nelson.

At least 37 records · Page 2Linked to original sources
PubMed1999

Stoma complications: the Cook County Hospital experience.

PURPOSE: A retrospective analysis of enteric stomas performed at Cook County Hospital was undertaken to evaluate stoma complications per stoma type and configuration and operating service. In addition, we attempted to identify factors predictive of increased enteric stoma complications. METHODS: From 1976 to 1995, data cards on 1,616 patients with stomas were compiled by Cook County Hospital enteric stomal therapists. Data card information included age, gender, weight, early and late stoma complications, emergency status, operating service, type and configuration of the stoma, and whether the patient was seen preoperatively by an enteric stomal therapist. Data were then analyzed using a logistic regression model to identify those variables that influenced the rate of complications. RESULTS: There were 553 (34 percent) patients with complications. Among the total complications, 448 (28 percent) occurred early (<1 month postoperative), and 105 (6 percent) occurred late (>1 month). The most common early complications were skin irritation (12 percent), pain associated with poor stoma location (7 percent), and partial necrosis (5 percent). The most common late complications were skin irritation (6 percent), prolapse (2 percent), and stenosis (2 percent). The enteric stoma with the most complications was the loop ileostomy (75 percent). The enteric stoma with the least complications was the end transverse colostomy (6 percent). The general surgery service had the most complications (47 percent), followed by gynecology (44 percent), surgical oncology (37 percent), colorectal (32 percent), pediatric surgery (29 percent), and trauma (25 percent). Age, operating service, enteric stoma type and configuration, and preoperative enteric stomal therapist marking were found to be variables that influenced stoma complications. CONCLUSIONS: Complications from enteric stoma construction are common. Preoperative enteric stoma site marking, especially in older patients, and avoiding the ileostomy, particularly in the loop configuration, can help minimize complications.

Adolescent↗
PubMed1999

Determination of factors responsible for the declining incidence of colorectal cancer.

INTRODUCTION: After rising for 13 years in the United States, the incidence of colorectal cancer began to fall in 1986 and has continued to drop since then. This report contains an analysis of the pattern of declining colorectal cancer risk by colorectal subsite, race, and gender and a time trend investigation of suspected risk modifiers of colorectal cancer. METHOD: Colorectal cancer incidence data were obtained from the Surveillance, Epidemiology, and End Results Public Use Files from 1973 to 1994. The following exposure variables were assessed, focussing principally on the period 1970 to 1980: dietary fat, fiber, ethanolic beverages, vitamin A, vitamin C, iron, calcium, estrogen, aspirin, energy intake, body mass index, serum cholesterol, body iron stores, cholecystectomy, constipation, cigarette use, physical activity, and colonoscopic polypectomy. Data sources used in these analyses were principally National Health and Nutrition Examination Surveys I, II, and III. RESULTS: After 1985 colorectal cancer incidence declined predominantly in the distal colorectum almost equally in both white males and white females. Some exposures remained unchanged or trended in the wrong direction (dietary fat, calcium, ethanol, energy intake, physical activity, overweight prevalence, and cholecystectomy). Others did not apply equally to both genders (estrogen, aspirin, ethanol, calcium, and cholecystectomy). Others may become significant in the future, such as aspirin, estrogen, or calcium, because their supplementation is now prevalent, but were not in 1970 to 1975. Of all the risk factors or interventions assessed, the one most consistent with the observed pattern of change is increased use of colonoscopic polypectomy. CONCLUSION: The best method to diminish the incidence of colorectal cancer today may be to increase the use of screening colonoscopy and polypectomy.

Colorectal Neoplasms↗
PubMed1999

Universal versus selective gestational diabetes screening: application of 1997 American Diabetes Association recommendations.

OBJECTIVE: We sought to evaluate the impact of the 1997 American Diabetes Association gestational diabetes mellitus screening guidelines applied to a universally screened population. STUDY DESIGN: A retrospective analysis of 18,504 women universally screened for gestational diabetes mellitus at Mayo Clinic, Rochester, between January 1, 1986, and December 31, 1997, was performed. Diabetic screening consisted of plasma glucose determination 1 hour after a 50-g oral glucose challenge. Diagnosis of gestational diabetes mellitus was based on National Diabetes Data Group criteria. RESULTS: Of 564 cases of gestational diabetes mellitus diagnosed during the study period, 17 (3.0%) would have been missed under the 1997 American Diabetes Association selective screening guidelines while exempting only 10% of this predominantly white population from screening. Screening only women >/=25 years old would have detected 90.4% of gestational diabetes mellitus cases, whereas the addition of the remaining 3 screening criteria combined would have detected only an additional 6.6% of cases. CONCLUSIONS: The proportion of patients with gestational diabetes mellitus that would remain undiagnosed under the 1997 American Diabetes Association screening guidelines would be relatively small in our population. However, implementation of these guidelines would decrease the number of screens by only 10% while adding significant complexity to the screening process. Youth appears to be the most significant protective factor for gestational diabetes mellitus in our population.

Adult↗
PubMed1998

Time trends in distal colorectal cancer subsite location related to age and how it affects choice of screening modality.

BACKGROUND AND OBJECTIVES: A time trend analysis of colorectal cancer (CRC) incidence in the distal colorectum as a proportion of total CRC is presented for the period 1977-1994 as a function of age, to determine the age at which Americans might best be served by screening fiberoptic sigmoidoscopy. METHODS: CRC incidence rates were obtained for each anatomic subsite from SEER Public Use Files for 1977, 1986, and 1994. The colorectum was divided anatomically for these analyses at the junction of the descending colon and sigmoid colon. Incidence in the distal colorectum was divided by total CRC incidence to determine the proportion of CRC in that age/race/gender/year cohort located in the distal colorectum. RESULTS: The proportion of distal CRC among African Americans was without a clear trend as they grew older in each of the years of observation and in both genders. However, in whites, with increasing age, the proportion of distal disease declined progressively in both genders, with the greatest decline in 1994. Distal CRC became less prevalent than proximal at about age 72 years in white women and at age 82 in white men in 1994. CONCLUSIONS: As the white population becomes older, and for African Americans of all ages, more total colon screening modalities are needed, although at the onset of recommended screening, among 50- to 60-year-olds, fiberoptic sigmoidoscopy would appear efficacious.

Age Factors↗
PubMed1998

Sequelae of unrecognized gestational diabetes.

OBJECTIVE: Prior studies have suggested that macrosomia is the only morbid condition associated with gestational diabetes and that this association is the result of confounding by maternal obesity rather than a result of gestational diabetes itself. We sought to determine whether unrecognized gestational diabetes is an independent predictor of macrosomia and other perinatal morbid conditions after controlling for confounding variables. STUDY DESIGN: A retrospective analysis of 472 consecutive cases of gestational diabetes diagnosed between 24 and 30 weeks' gestation was undertaken including 16 prospectively identified but clinically unrecognized cases, 297 cases treated with diet alone, and 76 treated with diet plus insulin. Unrecognized cases were matched to 64 nondiabetic controls for race, age, body mass index, parity, pregnancy weight gain, and gestational age at delivery. RESULTS: In the unrecognized gestational diabetes group versus the nondiabetic control versus gestational diabetes diet groups rates of large for gestational age infants (44% vs 5% vs 9%, p < 0.0005), macrosomia (44% vs 8% vs 15%, p < 0.01), shoulder dystocia (19% vs 3% vs 3%, p < 0.05), and birth trauma (25% vs 0% vs 0.3%, p < 0.001) were all significantly increased. These differences remained significant after controlling for maternal age, race, parity, body mass index, pregnancy weight gain, and gestational age at delivery. CONCLUSIONS: This study suggests that unrecognized gestational diabetes increases risks of large for gestational age infants, macrosomia, shoulder dystocia, and birth trauma independent of maternal obesity and other confounding variables. Clinical recognition and dietary control of gestational diabetes are associated with a reduction in these perinatal morbid conditions.

Adult↗
PubMed1997

The relation of age, race, and gender to the subsite location of colorectal carcinoma.

BACKGROUND: Characteristics that determine the anatomic site within the colorectum where carcinoma is most likely to occur would be useful in choosing optimal modalities for cancer screening and in the study of etiology. The aim of this study was to identify any association of gender, race, or age with colorectal carcinoma in the proximal or distal colorectum. METHODS: A descriptive, population-based epidemiologic study was conducted on colorectal carcinoma (CRC) cases identified through the Illinois Tumor Registry. Among CRC patients diagnosed between 1986 and 1991, age at diagnosis (40-90 years), gender, white or African American race, and subsite of CRC location were identified. Incidence rates were determined with demographic data from the 1990 Illinois census. Logistic regression was used to identify significant subsite specific risk factors for CRC. RESULTS: During the study period, 38,931 cases of CRC occurred in Illinois among whites and African Americans between the ages of 40 and 90 years. Age, race, and gender were independently significantly associated with both proximal and distal CRC risk (P < 0.0001). The greatest risk for white males was for distal CRC, followed by the risk for African American males of developing CRC in the distal colorectum. African Americans were more likely than whites to develop proximal CRC (odds ratio [OR] = 1.19), whereas whites were more likely to have distal CRC than African Americans (OR = 1.26). Regarding the development of CRC anywhere in the colorectum, male incidence rates adjusted for age and race were greater than rates for females (OR = 1.32 for proximal and 1.68 for distal). CONCLUSIONS: The division of the colorectum anatomically in these analyses at the junction of the descending and sigmoid colon, and including the rectum above the anal canal with "distal" CRC, demonstrated a predominance of African Americans among those at risk for proximal colon carcinoma and a predominance of white males among those at risk for distal CRC; these predominances were clearer than in previous reports. These findings may have a role in the selection of optimal CRC screening strategies for each gender or racial group.

Adult↗
PubMed1997

Zinc-bis-histidinate preserves cardiac function in a porcine model of cardioplegic arrest.

BACKGROUND: We examined the ability of zinc-bis-histidinate to preserve postarrest myocardial function when added to a standard crystalloid cardioplegic solution. METHODS: Domestic pigs (35 to 50 kg) on left-sided cardiopulmonary bypass were subjected to 90 minutes of regional ischemia followed by 60 minutes of hypothermic cardioplegic arrest induced by antegrade infusion of 20 mL/kg cold St. Thomas' #2 cardioplegic solution with or without 100 mumol/L of zinc-bis-histidinate and maintained by infusion of 10 mL/kg of the same every 20 minutes. During reperfusion function was assessed at 1 and 3 hours over increasing preloads using the right-sided bypass method. RESULTS: At roller pump flows up to 2,000 mL/min, stroke work index-end-diastolic pressure curves were significantly (p < 0.05) higher and shifted to the left in treated hearts. In a series of pigs, echocardiography was used to determine end-diastolic and end-systolic volumes. At roller pump flows up to 3,500 mL/min, end-systolic pressure-end-systolic volume curves were significantly higher and shifted to the left in treated hearts. Left ventricular ejection fraction, fractional shortening, stroke volume, and cardiac output were significantly (p < 0.05) higher in treated hearts. Electron microscopy revealed that mitochondria in tissue not at risk appeared more swollen in control hearts. CONCLUSIONS: The results of this study support the conclusion that zinc-bis-histidinate is effective as a myocardial preservative when added to a crystalloid cardioplegic solution.

Animals↗
PubMed1996

Island flap anoplasty for treatment of transsphincteric fistula-in-ano.

BACKGROUND: Treatment of fistula-in-ano often replaces one problem, risk of persistent anal sepsis, with another, either incontinence after fistulotomy or mucosal ectropion after rectal flap advancement. A new technique for treatment of transsphincteric fistulas is described that could eliminate risk of both complications. TECHNIQUE: Island flap anoplasty, previously used in management of anal strictures or ectropion, is modified to treat transsphincteric fistulas. RESULTS: The operation has been performed in 11 patients, 3 of whom had Crohn's disease. Follow-up varied from one to ten months. Early recurrences have occurred in three patients, two with Crohn's disease and one without. Remaining patients have done well. CONCLUSION: This procedure is technically easy to perform and appears to cure transsphincteric fistulas while preserving anal sphincter. In the event of persistence of fistula, other operative options are not eliminated by this procedure. We feel that further experience and longer follow-up is needed to define precise indications for this procedure and to determine if continence is improved more so than with standard fistulotomy.

Humans↗
PubMed1996

The effect of dietary selenium deficiency on acute colorectal mucosal nucleotoxicity induced by several carcinogens in the rodent.

BACKGROUND: Selenium (SE) has been inversely associated with colon cancer risk. Two potential mechanisms of this effect were examined in a rodent short-term carcinogenesis assay: whether dietary SE deficiency altered the initiation aspect of carcinogenesis in the colon, and whether SE altered carcinogen metabolism. SETTING: Animal laboratory. SUBJECTS: 52 Sprague-Dawley rats, divided into a SE diet deficient group (0.002 parts per million; ppm) and a SE sufficient (0.2 ppm) group. ENDPOINTS: Weight, serum SE concentration, and karryorhectic index (KI), which is a measure of acute carcinogen induced nuclear toxicity in the colonic mucosa. METHODS: After three weeks of acclimation to the diets, eight animals from each dietary group were injected with one of the following: dimethylhydrazine (DMH), a colon specific carcinogen, its metabolite, methylazoxymethanol (MAM), or 0.9% sodium chloride. Twenty-four hours after injection the colons were removed, blood drawn, and the stained colons assayed for nuclear aberrations. RESULTS: No weight differences were generated by the dietary variations. Low-dietary SE resulted in serum SE declining markedly in the study period to 6 ng/ml versus 33 ng/ml in the SE sufficient group. Diet alone, and variations in weight gain, did not alter the KI. Both carcinogens greatly increased the KI in both the left and right colon. A SE-deficient diet was associated with a higher KI in both carcinogen groups in the right colon, with statistical significance for both the left and right colon in the MAM injection group. CONCLUSIONS: Dietary SE deficiency is associated with increased KI of the colon in MAM treated rats. SE, therefore, has a protective effect in the initiation phase of carcinogenesis.

Animals↗
PubMed1996

Pharmacologic treatment options for non-insulin-dependent diabetes mellitus.

Non-insulin-dependent diabetes mellitus (NIDDM) is a major health concern for clinicians who are responsible for the care of an aging population. The relationship between hyperglycemia and the chronic complications of retinopathy, nephropathy, and neuropathy has been established in patients with insulin-dependent diabetes mellitus, and it is extremely likely that such a relationship exists in patients with NIDDM as well. Diet and exercise are the cornerstone for the management of NIDDM. The assessment of glycemic control should determine which patients with NIDDM need more aggressive intervention to control hyperglycemia. Pharmacologic treatment options include oral administration of the sulfonylureas, a biguanide, and an alpha-glucosidase inhibitor and subcutaneous administration of insulin. Extensive education about diabetes and self-monitoring of blood glucose levels are important components in maximizing glycemic control. Additional pharmacologic treatment options are necessary when adequate individualized treatment goals are not attained. The goal of therapy is to prevent the onset or progression of long-term microvascular and macrovascular complications. In this review, we present the therapeutic options and outline our approach to the pharmacologic treatment of NIDDM. Relevant medical literature on each treatment modality is reviewed, and the cost of therapy with use of each medication is provided.

Acarbose↗
PubMed1996

Screening of average-risk individuals for colorectal cancer and postoperative evaluation of patients with colorectal cancer.

Screening of the average-risk individual for disease creates a different relationship between practitioner and subject than the normal doctor-patient relationship. Screened individuals are asymptomatic, have a whole range of motivations from denial to neurosis, and, for the most part, derive no benefit from the screen, as they are destined never to contract the disease. Rewards to the few must clearly outweigh the risks to the many. The screening strategy must be economical when applied to a large population, safe, and effective in achieving the ultimate goal, which, in the case of colorectal cancer, is reduction in the mortality rate. Prediagnostic screening of asymptomatic adults over the age of 45 years for primary disease has been shown to fulfill all of these criteria. Postoperative screening of asymptomatic individuals after curative resection of colorectal cancer for recurrence has been shown to fulfill none of them.

Adult↗
PubMed1995

Risk of neoplastic and other diseases among people with heterozygosity for hereditary hemochromatosis.

BACKGROUND: Increased body iron stores have been associated with risk of heart attack in men and risk of cancer and colonic adenoma in both sexes. Because heterozygous carriers of hereditary hemochromatosis (HH) have on the average increased iron stores compared with noncarriers of the HH gene and comprise as much as 15% of the American population, disease risk in HH heterozygotes was investigated. METHODS: A community-based cohort was defined, in which the exposure variable was heterozygosity for HH. Heterozygotes were identified by mailing individuals homozygous for HH questionnaires concerning the health histories of their parents (predominantly heterozygotes or exposed). Spouses of the HH homozygotes were asked to complete accompanying questionnaires concerning their parents (unexposed). The frequencies for exposed and unexposed, age-adjusted relative risks (RR), and 95% confidence intervals (CI), of cancer, heart disease, and stroke as causes of death as well as the cumulative incidence of heart attack, diabetes, stroke, hypertension, colonic adenoma, and cancers of the lung, colorectum, breast, cervix, pancreas, stomach, and blood were estimated. RESULTS: Data were available for 1950 HH heterozygotes and 1656 unexposed subjects. Elevated RR were observed in HH heterozygotes in males for diabetes (RR, 1.16; 95% CI, 1.01-1.33), colorectal cancer (RR, 1.28; CI, 1.07-1.53), and hematologic malignancy (RR, 1.30; CI, 1.30-1.63), for colonic adenoma in females (RR, 1.29; CI, 1.08-1.53) and males (RR, 1.24; CI, 1.05-1.46), and for stomach cancer in females (RR, 1.37; CI, 1.04-1.79). CONCLUSIONS: Heterozygosity for HH is associated with increased risk for colorectal neoplasia, diabetes, hematologic malignancy, and gastric cancer. No increased risk of heart disease, cancer death, or cancers of the lung, breast, or cervix were demonstrated.

Adult↗