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Biomedical subjects

Naomi M Gades

Publications and source records attributed to Naomi M Gades.

8 recordsLinked to original sources

Dropout in a longitudinal, cohort study of urologic disease in community men.

BACKGROUND: Reasons for attrition in studies vary, but may be a major concern in long-term studies if those who drop out differ systematically from those who continue to participate. Factors associated with dropout were evaluated in a twelve-year community-based, prospective cohort study of urologic disease in men. METHODS: During 1989-1991, 2,115 randomly selected Caucasian men, ages 40-79 years from Olmsted County, Minnesota were enrolled and followed with questionnaires biennially; 332 men were added in follow-up. A random subset (approximately 25%) received a urologic examination. Baseline characteristics including age, benign prostatic hyperplasia (BPH) symptoms, comorbidities, and socioeconomic factors were compared between subjects who did and did not participate after the twelfth year of follow-up. RESULTS: Of the 2,447 men, 195 died and were excluded; 682 did not participate in 2002. Compared with men in the 40-49 year age group, men > or = 70 years of age at baseline had a greater relative odds of dropout, 2.65 (95% CI: 1.93, 3.63). In age-adjusted analyses, relative to men without stroke, men who had suffered a stroke had a higher odds of dropout, age-adjusted OR 3.07 (95% CI: 1.49, 6.33). Presence of at least one BPH symptom was not associated with dropout, (age-adjusted OR 1.12 (95% CI: 0.93, 1.36)). CONCLUSION: These results provide assurance that dropout was not related to primary study outcomes. However, factors associated with dropout should be taken into account in analyses where they may be potential confounders.

Adult↗

Association between smoking and erectile dysfunction: a population-based study.

The association between smoking and erectile dysfunction was evaluated in a cohort of 2,115 Caucasian men, aged 40-79 years, randomly selected from Olmsted County, Minnesota. Smoking status was assessed by questionnaire; during the fourth biennial examination, erectile dysfunction was assessed with the Brief Male Sexual Function Inventory. Of the 1,329 men with a regular sexual partner, 173 were current smokers, 836 had previously smoked, and 203 reported erectile dysfunction. Compared with former and never smokers, current smokers in their forties had the greatest relative odds of erectile dysfunction, 2.74 (95% confidence interval (CI): 0.44, 16.89), compared with 1.38 (95% CI: 0.51, 3.74), 1.70 (95% CI: 0.82, 3.51), and 0.77 (95% CI: 0.27, 2.21) for men in their fifties, sixties, and seventies, respectively. Compared with men who never smoked, men who smoked at some time had a greater likelihood of erectile dysfunction (age-adjusted odds ratio = 1.42, 95% CI: 1.00, 2.02), and there was a dose response. Although the causal pathway underlying this association is not clear, this study contributes to the growing literature describing an association between smoking and erectile dysfunction.

Adult↗

Prevalence of conditions potentially associated with lower urinary tract symptoms in men.

OBJECTIVE: To estimate the frequency of conditions associated with lower urinary tract symptoms (LUTS, typically included when assessing benign prostatic hyperplasia, BPH), as other causes of LUTS should be excluded when diagnosing BPH, using data from the Olmsted County Study of Urinary Symptoms and Health Status among Men. SUBJECTS AND METHODS: During 1989-91, Caucasian men aged 40-79 years were randomly selected from the Olmsted County population. Before contact, eligibility was determined by reviewing the community medical records. Baseline exclusion criteria included comorbid pre-existing conditions or treatments, e.g. prostate, bladder or lower back surgery, bladder neck contracture or cancer, diabetes with lower extremity amputation, and neurological diseases, including Parkinson's disease, amyotrophic lateral sclerosis, multiple sclerosis, tabes dorsalis and stroke. Men with these conditions were excluded from the Olmsted County Study at baseline, because these conditions are potentially associated with LUTS. RESULTS: Of the 5100 randomly sampled men, 13.4% met at least one of the pre-existing exclusion criteria. Individually, the frequency of exclusions was 7.8% for prostate cancer or surgery, 4.8% for back surgery, 1.3% for bladder surgery and 1.4% for neurological conditions. All other conditions represented <1.0% of the study exclusions. Older men were more likely to meet at least one of the exclusion criteria, with men in their fifth to eighth decade having a total exclusion frequency of 1.4%, 5.4%, 8.5% and 32.8%, respectively. The most common reason for men in their fifth decade to be excluded was lower back surgery (0.9%), whereas the most common reason in the eighth was prostate surgery (21.8%). CONCLUSIONS: In men, conditions that may contribute to LUTS, other than BPH, are prevalent in the community and increase in frequency with age. It is important that other conditions associated with LUTS be excluded before a definitive diagnosis of BPH. Any oversight in this initial evaluation can potentially result in misclassification bias, misdiagnosis and incorrect treatment of patients.

Adult↗

Cocaethylene metabolism and interaction with cocaine and ethanol: role of carboxylesterases.

Carboxylesterases are important in the metabolism of cocaine, catalyzing the hydrolysis of cocaine to its two major metabolites, benzoylecgonine and ecgonine methyl ester. In the presence of ethanol, some cocaine undergoes transesterification with ethanol instead of hydrolysis with water producing the active metabolite, cocaethylene. The metabolic fate of cocaethylene is unknown, but given its structural similarity to cocaine, it was hypothesized that cocaethylene would also be metabolized by carboxylesterases and its elimination decreased in the presence of ethanol, as is cocaine's. Dogs were given cocaine alone, cocaethylene alone, cocaine and ethanol, cocaethylene and ethanol, and cocaine and cocaethylene on separate study days and sequential blood samples drawn. Plasma concentrations of cocaine, benzoylecgonine, and cocaethylene were determined by high-performance liquid chromatography. The pharmacokinetic dispositions of cocaine and cocaethylene were similar with clearance values of 0.91 +/- 0.22 and 0.79 +/- 0.16 l/min, and volumes of distribution of 2.6 +/- 0.82 and 2.7 +/- 0.47 l/kg, respectively. Both cocaine and cocaethylene clearances were decreased about 20% when given with ethanol. Following administration of cocaethylene alone, benzoylecgonine achieved similar plasma concentrations as those attained following cocaine alone, which indicates that benzoylecgonine is a major metabolite of cocaethylene. Carboxylesterases play an important role in the elimination of both cocaine and cocaethylene.

Animals↗

Activated charcoal and the absorption of ferrous sulfate in rats.

The treatment of iron poisoning has typically not included the administration of activated charcoal due to the lack of evidence supporting its efficacy. Several in vitro studies have demonstrated good adsorption of iron in a variety of pH ranges that were comparable to those found with other drugs for which activated charcoal is clinically used. This study was designed to determine whether activated charcoal altered the gastrointestinal absorption of toxic doses of iron as ferrous sulfate in an in vivo model. Seventy-five male Sprague-Dawley rats were randomly assigned into 5 groups: control given only distilled water; 100 mg elemental Iron and water; 1:1 charcoal to iron; 2:1 charcoal to iron; and 4:1 charcoal to iron. All treatments were administered consecutively by gavage within 5 min. Physiological measurements and blood samples were taken at 0, 1, 4 and 8 h after treatment. There were no consistent differences in physiological measurements among the 5 groups. Mean serum iron concentrations did not differ among Groups 2, 3, 4 and 5 at the 4 sampling times except at I h between Groups 4 and 5. The area under the curve for serum iron concentrations did not differ among the treatment groups. Activated charcoal did not alter the extent of iron absorption in the experimental model.

Animals↗

A novel ultrasound technique to estimate right ventricular geometry during fibrillation.

Finite element modelling of the heart for the purpose of studying the electric fields of defibrillation shocks requires knowledge of the geometry of the heart during fibrillation. However, the standard method of measuring this geometry, MRI. cannot be used during fibrillation because the heart geometry changes rapidly and perhaps unpredictably. We present a new ultrasound approach to measuring the right ventricular geometry during fibrillation and preliminary data using this technique. In six anaesthetized pigs, we find that a short axis cross-sectional area of the right ventricle increases by 38% during a 30 s episode of ventricular fibrillation. A long axis cross-sectional area increases by 19% during this same time. By fitting parameters of a simple geometric model to the experimental data, we estimate that the volume of blood in the right ventricular cavity increases by approximately 30% during the episode of ventricular fibrillation. We present the first study of the RV area during-fibrillation with the estimated volume. Our data suggest changes in defibrillation threshold may be linked to current shunting through the increased blood volume.

Animals↗

Chronic restraint via tail immobilization of mice: effects on corticosterone levels and other physiologic indices of stress.

Chronic venous cannulation in mice is an acceptable and useful technique for repeated blood sampling or continuous intravenous administration of substances, for which mild restraint of the animal may be necessary. Because chronic restraint has drawn considerable attention in the animal welfare community, the purpose of this study was to evaluate physiologic indices of stress in mice restrained by using an established tail restraint method. Serum corticosterone levels and body, thymus, adrenal, and spleen weights on days 2, 5, 8, and 12 were compared between tail-restrained and unrestrained mice. There were no significant differences between the two groups at the time points evaluated. Corticosterone levels were highest on day 8 for both groups and were significantly different from those on days 2 (P<0.009) and 5 (P<0.04) for restrained mice and on day 2 (P<0.02) for unrestrained mice. Levels in both groups declined by day 12, suggesting habitation. Weight loss was observed in all mice whether restrained or unrestrained. Significant differences in body, thymus, adrenal, and spleen weights were not evident between restrained and unrestrained mice. This study provides important information for balancing issues of prolonged restraint, animal well-being, and research goals.

Adrenal Glands↗