Research on excess deaths among American Indians and Alaska Natives: a critical review

American Indians and Alaska Natives die younger and at higher rates proportionately than members of the general United States population. Causes of death among Native peoples in the U.S. have been the subject of numerous studies by health care professionals and social scientists. Many of these deaths are considered excess deaths, that is, deaths that occur statistically beyond the rate of incidence of the larger population. This paper examines 46 studies of excess deaths published within five years (1987 to 1993) and based on data gathered within ten years (1982 to 1992) and critiques the studies for methodology and context. Existing studies of excess death among Native peoples are limited by a lack of definitional clarity, ethnic misclassifications, lack of multidisciplinary and Native representation on research terms, superficial analysis of statistical findings, overrepresentation of data for some tribes and underrepresentation for others, bias for quantitative research methods and unbalanced prioritization.     

Shaping ability of Lightspeed rotary nickel-titanium instruments in simulated root canals. Part 1

Dextran sulphate sodium (DSS) is an oral agent capable of inducing chronic diarrhoea and colonic inflammation and necrosis in rats. The role of the afferent nerves in this model of colonic mucosal damage is not known. The hypothesis that functional ablation of the capsaicin-sensitive afferent nerves will aggravate DSS-induced colonic damage in rats was tested. Capsaicin pretreatment was used to ablate afferent nerve function and DSS was administered in the drinking water. Control rats received vehicle pretreatment and water without DSS. There were significant correlations between diarrhoea score, mucosal neutrophil infiltration, mucosal necrosis, and anaemia. Capsaicin pretreatment increased diarrhoea score and colonic mucosal neutrophil infiltration in the rats with colonic damage after 2 or 14 days of DSS. In addition, it induced anaemia and mortality in rats after 14 days of DSS. The data supports the hypothesis that functional ablation of the capsaicin-sensitive afferent nerves aggravates the colonic damage induced by DSS.     

Empirical evaluation of DSM-IV generalized anxiety disorder criteria in children and adolescents

Evaluated the Diagnostic and Statistical Manual of Mental Disorders (4th ed. [DSM-IV], American Psychiatric Association, 1994) generalized anxiety disorder (GAD) criteria in children and adolescents. Clinic-referred children meeting criteria for DSM-IV GAD, those meeting criteria for another DSM-IV anxiety disorder, and normal children participated in a structured interview and completed self-report questionnaires. Groups were compared in terms of interview and self-report measures to examine convergent and discriminant validity. In addition, developmental differences, cross-informant symptom and syndrome agreement, and validity of parent and child report were determined. Finally, the symptoms comprising the GAD associated symptom criterion (Criterion C) were examined in terms of rate of endorsement and predictive power. Results showed that parameters of worry differentiated children with GAD from those with other anxiety disorders and controls. Developmental differences in the sample did not appear to necessitate a separate criteria set for the classification of generalized anxiety in children of this age. Symptoms from GAD Criterion C evidenced moderately high rates of endorsement and acceptable predictive power. Overall, the DSM-IV GAD criteria for children and adolescents are supported, but further evaluation is necessary before firm conclusions can be drawn.     

Chorea caused by lithium intoxication: a case report and literature review

We report a patient who developed an acute, reversible, generalized choreiform disorder from lithium (Li) intoxication. This medication was prescribed for manic-depressive disorder, and serum levels became elevated after the addition of a diuretic for the treatment of hypertension. There were no other apparent causes for the movement disorder, and it was associated with other known features of Li intoxication, including ataxia and encephalopathy. There was a delay between the initial symptoms of Li intoxication and the onset of chorea. The chorea improved as serum Li levels diminished, with some lag time. This represents the eleventh case report of Li-induced chorea, but only the sixth in a patient without concomitant neuroleptic therapy, and the first presented with videotape confirmation. A review of these other cases is included, and possible mechanisms are discussed.     

Re-examination of the mutagenicity of ethylene glycol monobutyl ether to Salmonella tester strain TA97a

Widespread use of implantable cardioverter defibrillators (ICDs) for the treatment of ventricular tachycardia (VT) and ventricular fibrillation (VF) occurred in the late 1980s and early 1990s. Additionally, there has been increasing appreciation during this time for both the lack of efficacy and proarrhythmic activity of antiarrhythmic drugs to treat these cardiac arrhythmias. We evaluated the use of antiarrhythmic drugs from 1987 to 1991 (5-year period) at the time of ICD implantation in 25,450 patients. The use of all classes of antiarrhythmic agents decreased from 61% to 24% during this time period (P < 0.05). In addition, there was a significant reduction in antiarrhythmic agent use for each drug class (P < 0.05) with the exception of Class II agents (beta blockers). These changes in drug use occurred independent of any changes in age, sex, ejection fraction, prevalence of coronary artery disease, or type of ventricular arrhythmia (VT vs VF).     

Systematic relationships among pocket gopher chewing lice (Phthiraptera: Trichodectidae) inferred from electrophoretic data

This study was designed to explore the efficacy of gonadotrophin-releasing hormone (GnRH) to antagonize the effect of gonadotrophin surge-inhibiting factor (GnSIF) on the timing of the induction by GnRH of the maximal self-priming effect on pituitary LH responsiveness. The GnSIF levels were increased by FSH treatment and reduced after gonadectomy. Female rats were injected s.c. with 10 IU FSH or saline (control) on three occasions during the 4-day cycle. Serial i.v. injections of GnRH (500 pmol/kg body weight) were administered to intact rats on the afternoon of pro-oestrus or 15-30 min after ovariectomy. Intact male rats were given 10 IU FSH and 500 or 2000 pmol GnRH/kg body weight on an equivalent time-schedule. Endogenous GnRH release was suppressed with phenobarbital. In intact female control rats, the timing of the maximally primed LH response was delayed as the GnRH pulse-interval increased. FSH treatment of female rats induced a suppression of the initial unprimed LH response and delayed the maximally primed LH response, which showed further delay as the GnRH pulse-interval was increased. When the pulsatile administration of GnRH was started 15-30 min after ovariectomy, the priming effect of GnRH did not change as the GnRH pulse-interval was increased in the saline-treated rats. However, FSH treatment caused a suppression of the unprimed LH response, a delay in the primed LH response and decreased the delay of the maximally primed LH response to GnRH when the GnRH pulse-interval was decreased. Increasing the interval between ovariectomy and the first GnRH pulse to 4 h diminished the efficacy of the FSH treatment: GnRH-induced priming was delayed by only one pulse instead of the two pulses in control rats. In intact males but not in orchidectomized rats, a self-priming effect was demonstrated during GnRH pulses which were 1 h apart. The effect of 2 nmol GnRH/kg body weight was the most pronounced. Compared with intact female rats, the timing of the maximally primed LH response was delayed by 1 h. FSH treatment did not affect the pituitary LH response to both dose levels of GnRH. It is concluded that FSH treatment increased the release of GnSIF by the ovary, then induced a state of low responsiveness of the pituitary gland to GnRH and subsequently delayed GnRH-induced maximal self-priming. The efficacy of GnRH to prime the pituitary gland was higher when GnSIF levels were decreasing after removal of the ovaries.(ABSTRACT TRUNCATED AT 400 WORDS)