Joint effects of smoking, noise exposure and age on hearing loss

BACKGROUND: Smoking has been shown to have adverse effects on hearing, but it's unclear whether smoking interacts with known causes of hearing loss such as noise exposure and ageing. AIMS: To examine the hypothesis that smoking, noise and age jointly affect hearing acuity. METHODS: This cross-sectional study was carried out in 535 male adult workers of a metal processing factory. Pure-tone audiometric tests were utilized to assess hearing loss. Noise exposure assessment was based on a job exposure matrix constructed with industrial hygienist scoring and job titles. Each participant answered questionnaires about socio-demographic, life-style, occupational and health-related data. Analysis of the possible underlying biological model was undertaken assessing departures from additivity using measures of the size of the interaction present. RESULTS: Age and occupational noise exposures were, separately, positively associated with hearing loss. For all the factors combined the estimated effect on hearing loss was higher than the sum of the effects from each isolated variable, especially for smoking and noise among those 20-40 years of age, and for smoking and age among those non-exposed to occupational noise. CONCLUSIONS: The synergistic effect of smoking, noise exposure and age on hearing loss, found in this study, is consistent with the biological interaction. Furthermore, it is possible that distinct ototoxic substances in the chemical composition of mainstream smoke may synergistically affect hearing when in combination with noise exposure, which needs to be examined in future studies.     

Incidence, clinical features and subtypes of delirium in elderly patients treated for hip fractures

OBJECTIVE: To describe the incidence, risk factors and clinical features (subtypes) of delirium during the postoperative period after hip fracture surgery in elderly patients. DESIGN: Prospective study. METHODS: Thirty-four consecutive patients (9 men and 25 women) were included in this study between June 16 to July 14, 2003. All patients underwent surgery for a fractured neck of femur and were pre- and postoperatively cared for at a combined geriatric/orthopedic ward. ASSESSMENT: The diagnosis of delirium was based on the criteria of the DSM-IV and the Confusion Assessment Method Scale. Subtypes of delirium were classified according to the criteria proposed by Lipowski: hyperactive-hyperalert (or agitated), hypoactive-hypoalert (somnolent) and mixed delirium. Results: Fifty-five percent (n = 19) of the 34 patients developed delirium after surgery. The development of delirium was associated with the medication midazolam taken perioperatively. Nine (47%) of the delirious patients had a hyperactive type of delirium; 5 (26%) developed a hypoactive delirium, and 5 (26%) had a mixed type. We did not find any association among subtypes of delirium and clinical features. CONCLUSIONS: Delirium is a common complication in the postoperative period of elderly patients treated for hip fractures. The use of midazolam in the perioperative period increased the risk of developing postoperative delirium. The hyperactive type of delirium was the most common subtype of delirium.     

Radiographic assessment of resectability of locoregional disease in children with high-risk neuroblastoma during neoadjuvant chemotherapy

BACKGROUND: The optimal timing for attempting removal of the primary tumor and regional disease in patients with high-risk neuroblastoma is uncertain. The purpose of this study was to evaluate resectability of the primary tumor and regional disease, as determined radiographically, in children with high-risk neuroblastoma during neoadjuvant chemotherapy. PROCEDURE: Patients enrolled in our institutional high-risk neuroblastoma protocol were evaluated prospectively by CT scan and/or MRI to determine the resectability of their primary tumor and regional disease at diagnosis, after two cycles of experimental therapy and after standard induction therapy. Tumors were considered to be unresectable if there was significant involvement with major vascular structures or contiguous organs, or would likely require nephrectomy to remove the entire tumor. RESULTS: Twenty-four patients were referred prior to surgery for treatment of high-risk neuroblastoma. Seven of 24 (29%) patients were felt to be resectable at diagnosis, with an additional 9 patients becoming resectable after the initial experimental therapy. Thus, overall, 16 of 24 (67%) patients were felt to be resectable by the completion of the initial therapy. Only four additional patients of the remaining eight were considered resectable after the completion of standard induction therapy. CONCLUSIONS: Based on these data, we conclude that complete resection of the primary tumor and regional disease in children with high-risk neuroblastoma can be performed after an initial phase therapy in the majority of patients. Since earlier tumor removal may decrease the chance for the subsequent development of chemotherapy-resistant disease, we are recommending surgical resection as soon as the locoregional disease appears to be resectable.     

Available pharmacological treatments for anorexia nervosa

Currently, no medications are approved by the FDA for the treatment of anorexia nervosa (AN). However, there are several promising pharmacological targets. Treatment includes a weight restoration and a weight maintenance phase and different pharmacological treatments may be useful in one phase, but not the other. Although cyproheptadine has some modest benefit during the weight restoration phase, it is not widely used. Fluoxetine administered during the weight maintenance phase decreases relapse rate. The medications currently being most widely studied are the atypical antipsychotics, particularly olanzapine. Emerging evidence suggests that some AN patients have psychotic symptoms that may respond to antipsychotic agents. There are promising case reports and open-label studies of the atypical antipsychotics, but as yet, no randomised, placebo-controlled, double-blind studies have been reported. Additional novel treatment approaches are urgently needed for this group of severely ill patients who have a high premature mortality rate.     

Phentolamine bioequivalence study

OBJECTIVE: To assess the bioequivalence of 2 tablet formulations of phentolamine (Regitine phentolamine 40 mg tablet formulation by Novartis, Brazil, as test formulation, and Vasomax, phentolamine 40 mg tablet formulation by Schering Plough S.A., Brazil, as reference formulation). METHODS: A single 40 mg oral dose of each formulation was administered to 36 male healthy volunteers. The study was conducted after screening, using an open, randomized, 2-period crossover design, a 7-day interval between doses, and wash-out period of at least 4 weeks. Plasma samples for determination of phentolamine were obtained predose and at intervals over 720 min postdose. Plasma concentrations were quantified by reversed-phase liquid chromatography coupled to tandem mass spectrometry (LC-MS-MS) with positive ion electrospray ionization using multiple reactions monitoring (MRM) method. Precision of the method was evaluated using calibration curves and plasma quality control samples. The subjects were monitored throughout the study. Systolic and diastolic blood pressure and pulse rate measurement were taken predose and at intervals up to 720 min. Tolerance of both products was good. No serious adverse reactions were reported. The pharmacokinetic parameters calculated for both compounds included: AUC(0-720 min), AUC(0-infinity), C(max), Ca and k(e). RESULTS: The maximum concentrations reached (C(max)) were compared. Regitine 40 mg formulation C(max) geometric mean ratio was 108.29% (90% CI = 98.58-118.96) of Vasomax 40 mg formulation. The areas under the curve (AUC(0-720 min)) were compared. Regitine 40 formulation (AUC(0-720 min)) geometric mean ratio was 102.33% (90% CI = 97.21-107.72) of Vasomax 40 mg formulation. CONCLUSION: Since the 90% CI for both C(max) and AUC ratio where inside the 80 to 125% interval proposed by the Food and Drug Administration, it is concluded that Regitine 40 mg tablet is bioequivalent to Vasomax for the rate and extent of absorption.     

Measuring risk perception among low-income minority primary care patients

Studying patients' risk perceptions by ascertaining the probabilities of developing a disease is suboptimal, as patients might have difficulty using numerical expressions to depict the probabilities/chances of developing a disease. We surveyed patients at 2 community health centers and assessed risk perception by patients' self-reported chance of developing a disease (expressed in percentages), patients' relative chance of developing a disease compared to others' chance of developing a disease, and patients' ranked chances of developing different diseases. Many patients had difficulties understanding percentages and most patients overestimated their absolute risk. However, most patients indicated that they had a lower chance of developing diseases when compared to others. Patients with known risk factors (smoking) indicated a higher relative risk of developing an associated disease (lung cancer). Patients' ranked chances of developing different diseases were consistent with the actual frequency of developing a disease. Although patients had difficulty expressing risk in percentages, they estimated their risks well through comparisons with others and by ranking of disease frequencies.     

Differential effects of aging on the distribution of calcium-binding proteins in a pretectal nucleus of the chicken brain

The nucleus pretectalis (PT) of birds is an ovoid-shaped visuomotor cell group of the pretectum that receives tectal input and projects back to the optic tectum. We performed immunohistochemical single- and double-labeling to determine the distribution and abundance of neurons containing three calcium-binding proteins, parvalbumin (PV), calretinin (CR), and calbindin (CB), in the PT in chickens at three ages. We found that PV-positive and CR-positive cells co-localize and are largely found in the outer part of PT at all ages. The GluR4 subunit of the AMPA-type glutamate receptor was selectively localized to these neurons. CB-positive neurons, however, were largely absent from the PT in young and adult chickens. The abundance of PV-positive and CR-positive neurons in PT in old birds was indistinguishable from that in the younger birds, but CB-positive perikarya were 10-20-fold more common than in young birds, and were again mainly found in the outer part of PT. The overall abundance of neurons in PT was reduced to about 50% of its former abundance in the old birds, with this loss restricted to the central part of the nucleus. These data indicate that a cell loss process develops in PT as birds age, that parvalbuminergic and calretinergic neurons resist this process, and that this process is associated with increased expression of CB.