Euthanasia.
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Biomedical subjects
Publications and source records attributed to M Irwin.
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A multicenter study was undertaken to determine the failure rate of a specific bipolar tined polyurethane ventricular pacing lead, the Medtronic 4004/4004M pacing lead. Seven centers in the United States and Canada implanted 586 Medtronic 4004/4004M pacing leads. The study was designed to determine the probability and clinical manifestations of lead failure. Only failures compatible with an insulation problem were included. The Kaplan-Meier estimate of the percentage of 4004/4004M lead failures within 4 years after implantation was 14.1% (95% confidence interval: 8.5%-19.3%). Failures were manifested as sensing abnormalities, failure to capture, early battery depletion, and significant decrease in measured impedance compared with previous impedance measurements. The observed rate of failure is unacceptable, and strong consideration should be given to replacing the 4004/4004M pacing lead in pacemaker dependent patients and closely monitoring nondependent patients.
AIM/BACKGROUND: This study aimed to determine the feasibility of objective compliance monitoring of amblyopia therapy in clinical research. Occlusion has been the mainstay of amblyopia therapy for over 250 years, yet it has never been subjected to rigorous evaluation. Treatment regimens range arbitrarily from a few minutes to most of the waking hours of the day. Compliance is problematic and as, hitherto, accurate objective monitoring has been impossible it is not known how much occlusion is required to effect an improvement in vision. METHODS: An occlusion dose monitor (ODM) has been developed. The ODM consists of a modified occlusion patch and a miniature battery driven datalogger which periodically monitors patch skin contact. The patch is a standard disposable item with two miniature electrocardiogram electrodes attached to its undersurface. The datalogger comprises a high speed static RAM and a clock driven address counter. Data are retrieved using an IBM PC/AT computer. Fifteen child amblyopes were randomly allocated unilateral occlusion of 1, 4, or 8 hours per day for 4 weeks. Owing to data loss, presumed because of accumulation and discharge of static electricity, an additional child was included in the 8 hour group. Outcome measures were objective (ODM) and subjective (diary) compliance with treatment, logMAR visual acuity, and contrast sensitivity. RESULTS: Objective monitoring of occlusion is technically feasible and clinically informative. CONCLUSION: Objective monitoring of occlusion has opened up new research opportunities which, it is hoped, will enable the dose-effect relation of occlusion therapy in the various types of amblyopia to be investigated objectively, and facilitate the design of effective therapeutic regimens.
OBJECTIVE: The relationship between drinking relapse and family history for alcoholism to cognitive functioning was investigated in alcoholics who completed a 28-day inpatient treatment program. METHOD: The current study examined 144 primary alcoholics who completed a battery of cognitive tests on admission to treatment and at a 3-4 month follow-up visit. Participants were classified as either family history positive (FH+) (n = 86) or family history negative (FH-) (n = 58) based on information on alcohol dependence in first degree relatives. The subjects were further classified as drinkers (n = 56) or abstainers (n = 88) at follow-up, based upon information gathered about their drinking practices during the interval. RESULTS: There were no differences between the groups based on family history status at admission to treatment. Comparisons made at follow-up revealed that the abstainers' (both FH+ and FH-) performance improved. The FH+ drinkers' performance was worse than that of both the FH- drinkers and the FH+ abstainers at follow-up. The poor performance of the FH+ drinkers relative to the FH- drinkers was not attributable to differences in drinking consumption during the test-retest interval. CONCLUSIONS: These results suggest that alcoholics who maintain abstinence following treatment show improvement on cognitive testing at follow-up; both FH+ and FH- abstainers showed improvement, indicating that a positive family history of alcoholism does not impede recovery that occurs with abstinence. The most important finding, however, is that the FH+ drinkers show greater deterioration at follow-up compared to the other groups.(ABSTRACT TRUNCATED AT 250 WORDS)
A Monte Carlo method called sequential imputation is proposed for multilocus likelihood computations. This method is most useful in mapping situations where the data consist of large pedigrees with substantial missing information and it is desirable to perform linkage analysis utilizing data from many polymorphic markers simultaneously. A pedigree example with 155 individuals, 9 loci, and 155,520 haplotypes is used for illustration.
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OBJECTIVE: To evaluate the utility of the Vineland Social Adaptive Scale (Vineland) in measuring social adaptive functioning in children with attention-deficit hyperactivity disorder (ADHD). DESIGN: Cross-sectional group comparison. SETTING: Multidisciplinary hyperactivity and learning problem clinic at a tertiary referral center in Chicago, Ill. PARTICIPANTS: One hundred four school-age children with ADHD. INTERVENTION: None. MEASUREMENTS/MAIN RESULTS: The Vineland was administered to the study population. Despite average full-scale IQ scores (mean [+/- SD], 101 +/- 6), the children with ADHD had Vineland standard scores in the borderline to low-average range (73 +/- 14). The discrepancy between the Vineland standard scores and the full-scale IQ scores increased with increasing age and IQ. CONCLUSIONS: Children with ADHD referred to a tertiary attention problem clinic displayed significant social adaptive dysfunctioning on the Vineland. The evaluation of children with ADHD should include assessment of adaptive skills, and treatment planning for children with ADHD should include the identification of social and adaptive deficiencies when therapeutic goals are established.
OBJECTIVE: To determine whether polygraphic sleep recordings, obtained at the time of admission to an inpatient alcohol treatment program, predict abstinence and relapse 3 months following hospital discharge in nondepressed patients with primary alcoholism. DESIGN: Two independent, consecutive cohorts of patients (group 1, n = 28; group 2, n = 17) underwent all-night polygraphic sleep recordings and other clinical evaluations during the first and fourth weeks of a 1-month inpatient treatment program within a Veteran Affairs Medical Center. They were reevaluated 3 months following discharge to the community. None were treated with disulfiram or other medications during or after hospitalization. PATIENTS: All subjects were male veterans with primary alcoholism and without significant preexisting, secondary, or comorbid diagnoses such as major medical problems, depression, antisocial personality, or drug addiction. OUTCOME MEASURES: Relapse was defined as any alcohol consumption between discharge from the hospital and 3-month follow-up. RESULTS: Ten (36%) of 28 patients in group 1 were Relapsers at 3-month follow-up. Relapsers in group 1 showed significantly shorter Rapid Eye Movement (REM) latency, increased Rapid Eye Movement percent (REM%), and increased REM Density during their admission sleep studies compared with Abstainers. To replicate these observations, group 2 was then studied as a validation sample. Six (35%) of 17 patients relapsed. As in group 1, Relapsers had significantly shorter REM latency and increased REM% compared with Abstainers; REM Density was not significantly different in the Relapsers as compared with Abstainers in group 2. Using a principal components analysis based on these three REM sleep measures to determine "REM pressure," three separate discriminant function analyses (DFAs) were calculated: one for each group and one for all patients (n = 45) together. The DFA from group 1 correctly classified 22 (78.6%) of the 28 patients in group 1 and 13 (76.5%) of the 17 patients in group 2 as Relapsers or Abstainers. The DFA from group 2 correctly classified 13 (76.5%) of the 17 patients in group 2 and 23 (82.1%) of the 28 patients in group 1. The DFA formed from both groups together correctly classified 36 (80%) of the 45 patients. When the REM sleep measures at hospital admission and discharge were compared, no statistically significant effect of time was observed. Abstinence and relapse were not consistently related to other clinical measures at the time of hospital admission such as age, duration and severity of alcoholism, marital status, employment, hepatic enzyme levels, cognitive performance, or depression ratings. CONCLUSION: Short REM latency, increased REM%, and, possibly, increased REM Density at the time of admission to a 1-month inpatient alcohol treatment program predict relapse in nondepressed patients with primary alcoholism by 3 months following hospital discharge.
Depressed patients show a reduction of natural killer (NK) cell activity which may be associated with specific depressive symptoms. The present study demonstrated that sleep disturbance and retardation, but not other depressive symptoms, were negatively correlated with NK activity in 38 depressed patients. Specific behavioral changes in depression such as sleep disturbance and retardation were found to predict 16% of the variance of cytotoxicity levels in depression.
This study evaluates whether recently widowed women who fulfill criteria for a depressive syndrome differ in their immune responses from widows who do not. Twenty-one middle-aged widows who had lost their spouses 2 months before the initial evaluation and 21 demographically matched married women were evaluated at approximately 6-month intervals for 13 months. Evaluations consisted of diagnostic interviews using the Schedule for Affective Disorders and Schizophrenia, Hamilton Rating Scale for Depression, and Beck Depression Inventory. Immune function was measured by total lymphocyte counts, natural killer (NK) cell activity, mitogen responsiveness to concanavalin A, and T-cell subsets. There were no statistically significant differences on any of the immune measures between the entire cohort of widows and control subjects. However, the subset of widows who met DSM-III-R criteria for major depressive syndromes demonstrated impaired immune function (lower NK cell activity and lower mitogen stimulation) compared with those who did not meet criteria for major depression. This study suggests a relationship between impaired immune function and depression in women experiencing the stress of bereavement.
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The rate of depressive symptoms among alcoholics is high, but many of these syndromes appear to be alcohol-induced mood disorders and might not represent major depressive episodes independent of heavy drinking. The present study examines one aspect of the relationship between alcoholism and depression by evaluating the incidence of new episodes of major depressive disorders among alcohol-dependent men during the year following treatment. One year following discharge from an alcohol treatment program, structured face-to-face interviews were carried out with 239 primary alcoholic men, as well as additional informants. Approximately 4% of the men developed depressive episodes while drinking heavily, but only 2.1% demonstrated major depressions independent of heavy alcohol intake. There was no evidence of an increased incidence of any other major psychiatric disorder during the year of follow-up. These results are consistent with prospective studies of children of alcoholics and of longitudinal evaluations of general population samples. They do not indicate that in the present sample most primary alcohol-dependent men have elevated rates for major depressive disorders independent of alcohol-induced mood syndromes. However, it is likely that in the context of heavy drinking severe, although temporary, depressive episodes are likely to be observed.
The DDI mode of pacing that permits noncompetitive atrioventricular sequential bradycardia support was chosen in 65 of 480 (14%) patients selected for dual chamber pacing between February 1985 and March 1990. All patients were implanted with Pacesetter 283 or 285 pulse generators and programmed to DDI. The indications for pacing were sick sinus syndrome (n = 52), combined sinus node dysfunction and AV block (n = 13). Forty-two of these patients had a history of paroxysmal atrial arrhythmias. All patients received passive fixation atrial and ventricular leads. Follow-up thereafter was performed predischarge, and at 6 weeks, 3 and 6 months after discharge. The duration of follow-up ranged from 1-61 months (mean 31 months). Fifty-four of 65 (83%) patients chosen for DDI remain programmed in the DDI mode. Three patients were reprogrammed to VVI and eight to DDD. During the course of follow-up, six patients presented with effective VVI pacing with consistent ventriculoatrial conduction that was appropriately sensed by the atrial circuit with atrial output inhibition. A further four patients presented with "functional undersensing" due to ventricular blanking period (VBP) characteristics in these pulse generators and in this mode. Functional undersensing was eliminated in all but one patient by reprogramming the VBP to 13 msec with no subsequent episodes of provoked crosstalk inhibition. Effective VVI pacing was observed in patients with AV block during times of sinus acceleration.(ABSTRACT TRUNCATED AT 250 WORDS)
Two studies are reported which explore the possible relationship between academic failure, as measured by grade retention, and the capacity to sustain attention on a computerized continuous performance task. In a nonreferred sample, 89 children who had been retained at some point in their academic careers showed a higher frequency of abnormal scores on an index of sustained attention than did 93 children who had never repeated a grade. In a sample of children who had been referred for an evaluation of Attention-Deficit Hyperactivity Disorder, children with a history of grade retention had significantly lower scores on the same measure of sustained attention. Results are discussed in terms of the possible contribution of attention deficits to over-all academic achievement, even for children who have not necessarily been referred for a clinical evaluation.
Benzodiazepines have anxiolytic properties and attenuate behavioral stress responses induced by corticotropin releasing hormone (CRH). To evaluate the effect of benzodiazepines on CRH-induced immune suppression, potent centrally acting benzodiazepines were administered prior to central infusion of CRH (i.c.v.; 1.0 microgram). CRH induced a significant (P < 0.01) reduction of splenic natural killer cell activity which was completely antagonized by pretreatment with either diazepam or alprazolam.
Experimental data together with clinical studies have generated information about the association between sympathetic nervous system activity and immunity as measured by in vitro correlates of cellular immune function. In addition, studies on the in vivo role of central CRF in coordinating sympathetic outflow and modulating immune function have provided an opportunity to examine central mechanisms important in the link between brain, behavior, and immune function. Finally, use of CRF as a neuropeptide probe will likely continue to give information about the central mechanisms relevant to the abnormal regulation of sympathetic nervous activity and immune function in stress and possibly in aging.
A novel Monte Carlo method for linkage analyses involving large pedigrees and many polymorphic loci is introduced. Issues related to the efficiency of the method are discussed.