Mitochondrial mutations associated with hearing and balance disorders.

Hearing and balance disorders are related to the inner ear and are among the major cause of falls in older adults. Hearing loss that commonly occurs with aging (aka presbyacusis) can result from noise exposure, smoking, ototoxic drugs and genetic factors such as mutations in nuclear and mitochondrial genes. Mutations in mitochondrial DNA (mtDNA) have been reported to play an important role in cell function by providing energy, as well as, cell death (apoptosis). This study aims to systematically review mitochondrial mutations associated with presbyacusis and suggests preventive measurements to improve the quality of life in older adults.

Social transition in the north: comparisons of drug-taking behavior among Alaska and Russian natives.

OBJECTIVES: This study represents a continuation of the work initiated by the "Social Transition in the North" (STN) project. This research extends the findings from earlier reports, specifically focusing on comparisons of drug-taking behavior among Alaska and Siberian Eskimos; it is one of the first studies that obtained substance abuse data from Russian Natives in eastern Russian. STUDY DESIGN: The data were taken from the STN study was collected in two regions of Alaska (Northwest Arctic and the Aleutian Islands) and in two regions of the Russian Far East (Kamchatka and Chukotka). The health questionnaire included questions about the drug taking behavior of the study populations. METHODS: The methodology employed was responses to a questionnaire, administered by the initial Social Transitions team. Imbedded in the interview protocols were questions (in a quantitative format) that inquired about drinking and other drug use. Seven-hundred interviews, conducted the first year, formed the database for the findings reported herein. Of these respondents, 45% are Alaska Native; 55% are Russian Natives. Ages ranged from 13 to 60, with a mean of 38 years. Among the Alaskan group, 35% were male, 65% female; of the Russians, 25% were female, 75% were male. RESULTS: The Russian cohort consumed significantly higher levels of alcohol, while the Alaskan group reported higher levels of marijuana, cocaine, inhalants and chewing tobacco. CONCLUSIONS: The differences found were attributable to cultural practices, reflected by the traditional drinking practices in Russian and to the rising substance abuse problem in the U.S.

Effect of cochlear implant surgery on vestibular function: meta-analysis study.

IMPORTANCE: Vestibular disorders have been reported following cochlear implant (CI) surgery, but the literature shows a wide discrepancy in the reported clinical impact. The aim of this meta-analysis is to quantify the effect of CI before and after surgery on the outcomes of vestibular tests, postural stability, and subjective perception of dizziness. OBJECTIVE: To evaluate the effects of CI surgery on vestibular function in adult patients (≥18 years) with sensorineural hearing loss who underwent unilateral or bilateral implantation. DATA SOURCES: MEDLINE, PubMed, Web of Science and Cochrane Library from January 1, 1995, through July 12, 2016. STUDY SELECTION: Published studies of adult patients who received unilateral or bilateral CIs and whose vestibular function or postural stability was assessed before and after surgery. DATA EXTRACTION: From each study, test results before and after surgery were compared, for the following five tests: clinical head impulse test (HIT); bi-thermal caloric irrigation of the horizontal semicircular canal; vestibular evoked myogenic potential (VEMP); dizziness handicap inventory (DHI); and computerized dynamic posturography (CDP). RESULTS: Twenty-seven studies met all inclusion criteria. Most studies performed either bi-thermal caloric irrigation and/or VEMP, with fewer studies investigating changes in HIT, posturography or DHI. CI surgery significantly affected the results of caloric and VEMP testing. However, HIT results, posturography, and DHI, scores were not significantly affected after CI surgery. CONCLUSIONS AND RELEVANCE: CI surgery has a significant negative effect on the results of caloric as well as VEMP tests. No significant effect of CI surgery was detected in HIT, posturography, or DHI scores. Overall, the clinical effect of CI surgery on the vestibular function was found to be insignificant. Nonetheless, the potential effects of surgery on the vestibular system should be discussed with CI candidates before surgery.

Assessing the impact of clinical information-retrieval technology in a family practice residency.

RATIONALE AND OBJECTIVE: Evidence-based sources of information do not integrate self-assessment tools to assess the impact of a users' search for clinical information. We present a method to evaluate evidence-based sources of information, by systematically assessing the impact of searches for clinical information in everyday practice. METHODS: We integrated an information management tool (InfoRetriever 2003) with an educational intervention in a cohort of 26 family medicine residents. An electronic impact assessment scale was used by these doctors to report the perceived impact of each item of information (each hit) retrieved on hand-held computer. We compared the types of impact associated with hits in two distinct categories: clinical decision support systems (CDSS) vs. clinical information-retrieval technology (CIRT). Information hits in CDSS were defined as any hit in the following InfoRetriever databases: Clinical Prediction Rules, History and Physical Exam diagnostic calculator and Diagnostic Test calculator. CIRT information hits were defined as any hit in: Abstracts of Cochrane Reviews, InfoPOEMs, evidence-based practice guideline summaries and the Griffith's 5 Minute Clinical Consult. RESULTS: The impact assessment questionnaire was linked to 5160 information hits. 4946 impact assessment questionnaires were answered (95.9%), and 2495 contained reports of impact (48.4%). Reports of positive impact on doctors were most frequently in the areas of learning and practice improvement. In comparison to CDSS, CIRT hits were more frequently associated with learning and recall. CDSS hits were more frequently associated with reports of practice improvement. CONCLUSIONS: Our new method permits systematic and comparative assessment of impact associated with distinct categories of information.

Multiplane Transesophageal and Intracardiac Echocardiography in Large Swine: Imaging Technique, Normal Values, and Research Applications.

Transthoracic echocardiographic imaging has been difficult to attain in the swine model. This study: (1) compares multiplane transesophageal echocardiography (TEE) with single plane TEE and intracardiac catheter echocardiography (ICE) for imaging of the swine cardiovascular system; and (2) defines normal values using these techniques in a closed chest large swine model (n = 24, body weight 50-114 kg). Multiplane TEE increased success rate over the single plane (the variable plane array only at 0 degrees ) TEE (P < 0.01) for imaging the left ventricular (LV) long-axis view (100% vs 50%), LV outflow tract (100% vs 33%), right atrium and its appendage (79% vs 33%), ascending aorta (100% vs 58%), and aortic arch (100% vs 17%). TEE-derived normal values at end-diastole (ED) and end-systole (ES) were: LV internal diameter (ID) = 49 +/- 3 mm (ED) and 33 +/- 4 mm (ES); LV wall thickness = 7 +/- 1 mm (ED); right ventricular (RV) ID = 24 +/- 4 mm (ED); RV wall thickness = 4 +/- 2 mm (ED); left atrial ID = 48 +/- 6 mm (ES); aortic root ID = 26 +/- 3 mm (ES); LV volume = 157 +/- 49 ml (ED) and 57 +/- 22 ml (ES). Baseline LV ejection fraction (64% +/- 6%), Doppler-derived stroke volume (86 +/- 14 ml), and cardiac index (107 ml/min per kg) were determined. Basal normal values, except for an elevated cardiac index in swine, are comparable to those reported for human adults. Multiplane TEE provided better overall cardiac imaging than did single plane TEE. ICE provided higher resolution imaging of individual cardiac chambers and structures when the ultrasound catheter was introduced into the right or left heart, but whole heart imaging was limited by ultrasound penetration at 12.5 MHz. Normal indices of chamber size and function provide a reference for the physiological significance of induced pathological states in this relevant animal model.

Valvular heart disease, Part 2. Mitral valve disease in older adults.

Mitral valve disease is a common cause of morbidity and mortality in patients over age 65. The etiology, physical findings, and natural history of rheumatic mitral stenosis, rheumatic mitral regurgitation, chronic non-rheumatic mitral regurgitation, and acute mitral regurgitation may differ in older and younger patients. In addition, symptoms of mitral valve disease may be masked or exacerbated by coexistent coronary artery disease, pulmonary disease, hypertension, and other systemic disorders that commonly occur in older adults. The clinical evaluation, along with various non-invasive cardiac procedures, is important for identifying mitral valve disease as the cause of abnormal signs and symptoms in older patients. Recognition of mitral valve abnormalities has important implications, because mitral valve repair or replacement is usually associated with favorable short- and long-term results, even in patients over age 65.

Valvular heart disease, Part 1. Diagnosis and surgical management of aortic valve disease in older adults.

Aortic valve disease is a common cause of morbidity and mortality in older patients. The etiology, physical findings, and natural history of aortic stenosis and aortic regurgitation may differ in older patients compared with younger patients. In addition, symptoms of aortic valve disease may be masked or exacerbated by co-existent coronary artery disease, hypertension, pulmonary diseases, and other systemic disorders that commonly occur in the geriatric population. Clinical assessment, along with various non-invasive cardiac techniques including ECG, chest x-ray, and echocardiogram are important in identifying aortic valve disease as the cause of abnormal signs and symptoms in these patients. Recognition of aortic valve abnormalities has important therapeutic implications because aortic valve replacement is usually associated with favorable short- and long-term results, even in patients over age 65.

Heat generation during ablation of porcine skin with erbium:YAG laser vs a novel picosecond infrared laser.

IMPORTANCE: Despite significant advances in surgery, most surgical tools remain basic. Lasers provide a means of precise surgical ablation, but their clinical use has remained limited because of undesired thermal, ionizing, or acoustic stress effects leading to tissue injury. A novel ultrafast, nonionizing, picosecond infrared laser (PIRL) system has recently been developed and is capable, in theory, of ablation with negligible thermal or acoustic stress effects. OBJECTIVE: To measure and compare heat generation by means of thermography during ablation of ex vivo porcine skin by conventional microsecond-pulsed erbium:YAG (Er:YAG) laser and picosecond infrared laser (PIRL). DESIGN AND SETTING: This study was conducted in an optics laboratory and used a pretest-posttest experimental design comparing 2 methods of laser ablation of tissue with each sample acting as its own control. INTERVENTION: Ex vivo porcine skin was ablated in a 5-mm line pattern with both Er:YAG laser and PIRL at fluence levels marginally above ablation threshold (2 J/cm² and 0.6 J/cm², respectively). MAIN OUTCOMES AND MEASURES: Peaks and maxima of skin temperature rises were determined using a thermography camera. Means of peak temperature rises were compared using the paired sample t test. Ablation craters were assessed by means of digital microscopy. RESULTS Mean peak rise in skin surface temperature for the Er:YAG laser and PIRL was 15.0°C and 1.68°C, respectively (P < .001). Maximum peak rise in skin surface temperature was 18.85°C for the Er:YAG laser and 2.05°C for the PIRL. Ablation craters were confirmed on digital microscopy. CONCLUSIONS AND RELEVANCE: Picosecond infrared laser ablation results in negligible heat generation, considerably less than Er:YAG laser ablation, which confirms the potential of this novel technology in minimizing undesirable thermal injury associated with lasers currently in clinical use.

Multiple substance dependence and course of alcoholism among Alaska native men and women.

Alcohol dependence among Native Americans and Alaska Natives is twice that found in the general population. Alaska Natives are 7 times more likely to die of alcohol-related problems. This study investigated differences in the course and consequences of alcoholism and co-occurring polysubstance dependence in a sample of 582 alcohol-dependent Alaska Natives undergoing inpatient lifetime treatment in Anchorage between 1994 and 1999. Mean age was 33.9 years. Information on lifetime psychiatric symptoms and disorders was collected by using the Semi-Structured Assessment for the Genetics of Alcoholism (SSAGA), a research diagnostic interview. Results indicate that in addition to alcohol dependence, the majority of subjects were dependent on other substances. Marijuana dependence was most common, followed by dependence on cocaine and opiates. Compared with subjects not dependent on any other drugs, subjects with co-occurring alcohol and opiate dependence showed significant differences in relation to age of first regular drink, intoxication, tolerance and withdrawal symptoms, number of medical problems, and number of psychological problems. More research and specific clinical interventions are needed for alcohol- and opiate-dependent Alaska Natives. Findings indicate the need for prevention and interventions in alcohol and illicit drug abuse in this population at an early age.

Ethnicity and psychiatric comorbidity among alcohol-dependent persons who receive inpatient treatment: African Americans, Alaska natives, Caucasians, and Hispanics.

This study examined ethnic and gender differences of psychiatric comorbidity among alcohol dependent men and women from four ethnic groups: Alaska Native, Caucasians, African Americans, and Hispanics. The data were obtained through individual standardized interview; DSM-III-R diagnoses were obtained via a computer algorithm. The subjects included 1177 Caucasians, 361 African Americans, 93 Hispanics and 486 Alaska Natives. Significant ethnic differences were found in relation to age of onset of alcohol and multiple substance dependence and psychiatric comorbidity. Ethnic differences were also noted with regard to the health care utilization.