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Biomedical subjects

S M Davis

Publications and source records attributed to S M Davis.

At least 73 records · Page 4Linked to original sources
PubMed1998

Health-related quality of life for rural American Indians in New Mexico.

OBJECTIVES: To determine health-related quality of life for rural American Indians using an economical telephone surveillance system. DESIGN: We interviewed 618 American Indians by telephone about health-related quality of life using an adaptation of the Behavioral Risk Factor Surveillance System questionnaire. RESULTS: A smaller proportion of rural New Mexico American Indians (50.7%) reported their general health as 'excellent' or 'very good' compared to the overall New Mexico (58.2%) and US populations (57.9%). American Indians reported a mental health limitation more frequently than the New Mexico and the US populations. However, 13% fewer rural New Mexico American Indians reported a limitation in usual activities. Most limitations were due to musculoskeletal conditions or diabetes mellitus. Survey respondents were found to be representative of the rural American Indian population as reported by the 1990 US Census Bureau by tribal group affiliation and age, but were not representative by income, education, and gender. CONCLUSIONS: Health-related quality of life for rural American Indians differs little from that of other New Mexicans and the general US population; however, when physical and mental health was rated as poor, fewer American Indians reported a limitation in usual activities. A telephone survey focusing on New Mexico American Indians is an efficient method by which to conduct surveillance of health-related quality of life.

Adolescent↗
PubMed1998

Non-ceremonial tobacco use among southwestern rural American Indians: the New Mexico American Indian Behavioural Risk Factor Survey.

OBJECTIVES: To ascertain non-ceremonial tobacco use among rural American Indians in New Mexico (United States). DESIGN: A geographically targeted telephone survey. SETTING: Rural New Mexico. PARTICIPANTS: American Indian residents aged 18 years and older. MAIN OUTCOME MEASURES: Prevalence of ever-smokers and current smokers of cigarettes and ever-users and current users of smokeless tobacco, number of cigarettes smoked, and prevalence of cigarette smoking quitting behaviour. RESULTS: Of the 1266 respondents, 38.5% (95% confidence interval (CI) = 34.5% to 42.1%) reported ever smoking, and 16.3% (95% CI = 13.5% to 19.0%) reported being current smokers. Current smokers averaged 7.6 (95% CI = 6.0 to 9.3) cigarettes per day. Current smoking prevalence was highest among men and lowest among college graduates. Prevalence of smokeless tobacco use was 24.1% for ever-use and 7.2% for current use and showed a strong male predominance of use. CONCLUSIONS: The prevalence of current smokers among rural American Indians in New Mexico was lower than among American Indians of other regions in the United States, all New Mexicans, and the national population as a whole. Although smoking prevalence was lower among American Indians in New Mexico, variation by sex and education followed the same patterns as reported among American Indians of other regions.

Adolescent↗
PubMed1998

Transcranial Doppler detection of microemboli during percutaneous transluminal coronary angioplasty.

BACKGROUND AND PURPOSE: The use of percutaneous transluminal coronary angioplasty (PTCA) to treat coronary artery disease is now commonplace. The occurrence of microemboli during invasive procedures such as cardiac angiography and bypass surgery is well documented, although neurological complications are relatively uncommon. To date, no investigation has been undertaken of the frequency or nature of microemboli occurring during PTCA or of the correlation with aortic atheroma. METHODS: Twenty patients having elective PTCA underwent examination by transcranial Doppler ultrasonography (TCD) to detect left middle cerebral artery microemboli occurring during the procedure. Blinded off-line analysis correlated microembolic signal counts on TCD with the components of each stage of the PTCA. Patients later underwent transesophageal (TEE) echocardiography, with measurements made of the thickness of the intima and atheroma in the ascending and descending thoracic aortic arch by cardiologists blinded to the TCD results. RESULTS: A total of 973 microembolic signals were detected (mean+/-SD, 48.7+/-36.7 per patient); 196 (20%) occurred on movement of the PTCA catheter and wire around the aortic arch, 84 (9%) with other PTCA catheter-associated movements, and 679 (70%) in association with injection of solutions (eg, saline and contrast). Mean signal counts during contrast injection were significantly greater than during the other 3 phases (P<0.001). No neurological events occurred in the study. Although not statistically significant, there was a trend toward greater microembolic signal counts with the number of times the catheter was passed around the aortic arch and the amount of arch atheroma detected by transesophageal echocardiography. CONCLUSIONS: Microemboli detected on TCD are a common occurrence during PTCA but are largely asymptomatic. The majority of microembolic signals are most probably gaseous in origin and do not appear to be related to the extent of aortic atheroma or to clinical events.

Aged↗
PubMed1998

Spontaneous reperfusion after ischemic stroke is associated with improved outcome.

BACKGROUND AND PURPOSE: The rationale behind thrombolytic therapy in acute ischemic stroke is penumbral salvage by rapid restoration of cerebral blood flow. The relationship, however, between early reperfusion (potentially composed of both nutritional and nonnutritional components) and outcome remains unclear. METHODS: To establish the relationship between reperfusion parameters and outcome variables (Canadian Neurological Scale, Barthel Index, outcome CT scans), we used 99Tc-hexamethylpropyleneamine oxime (99Tc-HMPAO) single-photon emission CT (SPECT) to examine 41 acute ischemic stroke patients. All patients had at least 2 SPECT studies (24 with 3 studies), and none had been treated with thrombolytic or other acute investigational drugs. RESULTS: A total of 106 studies were performed. Mean time to acute study was 9.2 hours; that for subacute study was 42 hours and for outcome study was 150 days. Hypoperfusion (HP) volumes at each of the 3 time points correlated with outcome clinical state and final infarct size. Both early reperfusion (61% of patients) and nutritional reperfusion alone (56%), which is early reperfusion maintained at outcome, were associated with improvement in clinical state and better functional outcome. Early HP volume change (acute minus subacute HP volume) and total HP volume change (acute minus outcome HP volume) also correlated with clinical improvement and better outcome. CONCLUSIONS: This study establishes the benefit of spontaneous reperfusion after ischemic stroke and emphasizes the prognostic value of HP deficit volumes. 99Tc-HMPAO SPECT may be used to screen patients and group them according to perfusion deficit in acute stroke trials, thereby decreasing patient numbers required to show drug effect.

Adult↗
PubMed1998

Streptokinase in acute stroke: effect on reperfusion and recanalization. Australian Streptokinase Trial Study Group.

The Australian Streptokinase Trial was a randomized, double-blind, placebo-controlled trial, in which streptokinase (SK, 1.5 million IU I.V.) was given within 4 hours of stroke onset. In a subset of 37 patients, 99mTc-labeled D,L-hexamethylpropylene amine oxime single-photon emission computed tomography (SPECT) and/or transcranial Doppler (TCD) studies were performed before and after therapy to test the hypothesis that SK may improve the hemodynamic measures of reperfusion/recanalization rates (TCD parameter) within 24 hours. Eighteen patients received SK and 19 placebo. Baseline characteristics were similar in both groups, and there were no differences in clinical outcomes assessed at 3 months after stroke. Although there was no increase in the group mean perfusion defect or volume on SPECT after thrombolytic therapy, a larger number of patients demonstrating the combined end point of reperfusion or recanalization was seen in the SK group (13/14, 93%) than in the placebo group (7/14, 50%; p = 0.01). Although SK given within 4 hours of acute ischemic stroke appears to improve arterial patency/tissue reperfusion, this effect is neither early nor extensive enough to influence overall clinical outcome.

Acute Disease↗
PubMed1998

Prediction of stroke outcome with echoplanar perfusion- and diffusion-weighted MRI.

OBJECTIVES: We examined the utility of echoplanar magnetic resonance perfusion imaging and diffusion-weighted imaging (DWI) in predicting stroke evolution and outcome in 18 patients with acute hemispheric infarction. METHODS: Patients were studied within 24 hours (mean, 12.2 hours), subacutely (mean, 4.7 days), and at outcome (mean, 84 days). Comparisons were made between infarction volumes as measured on perfusion imaging (PI) and isotropic DWI maps, clinical assessment scales (Canadian Neurological Scale, Barthel Index, and Rankin Scale), and final infarct volume (T2-weighted MRI). RESULTS: Acute PI lesion volumes correlated with acute neurologic state, clinical outcome, and final infarct volume. Acute DWI lesions correlated less robustly with acute neurologic state, but correlated well with clinical outcome and final infarct volume. Three of six possible patterns of abnormalities were seen: PI lesion larger than DWI lesion (65%), PI lesion smaller than DWI lesion (12%), and DWI lesion but no PI lesion (23%). A pattern of a PI lesion larger than the DWI lesion predicted DWI expansion into surrounding hypoperfused tissue (p < 0.05). In the other two patterns, DWI lesions did not enlarge, suggesting that no significant increase in ischemic lesion size occurs in the absence of a larger perfusion deficit. CONCLUSIONS: Combined early PI and DWI can define different acute infarct patterns, which may allow the selection of rational therapeutic strategies based on the presence or absence of potentially salvageable ischemic tissue.

Adult↗
PubMed1998

MSQ: Migraine-Specific Quality-of-Life Questionnaire. Further investigation of the factor structure.

MSQ, the 16-item Migraine-Specific Quality-of-Life Questionnaire (Version 1.0), was developed by Glaxo Wellcome Inc. to assess the effect of migraine and its treatment on patients' health-related quality of life (HR-QOL). The MSQ was hypothesised to measure 3 meaningful dimensions: (i) Role Function-Restrictive; (ii) Role Function-Preventive; and (iii) Emotional Function. The objective of this research was to further investigate the number of dimensions as well as the items contained in each dimension through principal components factor analysis of clinical trial data. Secondary objectives were to determine whether the factor structure changed in post-treatment visits compared with screening visits, to make recommendations for coding the MSQ when the patient did not have a migraine in the previous 4 weeks, and to modify the MSQ if so indicated by this research. Results supported the existence of 3 distinct factors which agreed strongly with the hypothesised dimensions. The analysis of post-treatment data suggested that the underlying factor structure of the MSQ varies as a result of treatment. Based on evaluations of the 'did not have a migraine' response, it was concluded that it be dropped from the MSQ. All these changes have been incorporated into MSQ (Version 2.0) which is being evaluated in studies to determine if its psychometric properties are different than the properties of the previous version.

Adult↗
PubMed1998

Adaptation of the Dartmouth COOP Charts for use among American Indian people with diabetes.

OBJECTIVE: To adapt the Dartmouth COOP Charts for use among American Indians with diabetes and to evaluate the operating characteristics of the adapted charts because measures of health status have not been evaluated for use among American Indians with diabetes. RESEARCH DESIGN AND METHODS: American Indian adults participated in focus group conferences to adapt and review the Dartmouth COOP Charts for use in American Indian communities. American Indian participants with diabetes were interviewed and administered the adapted charts. The operating characteristics of the charts were evaluated by measuring internal and external consistency, reliability, and acceptability. RESULTS: Some of the wording and pictures were considered to be offensive and culturally inappropriate in American Indian communities. The adapted charts showed internal consistency in a comparison of interchart variables. CONCLUSIONS: The adapted Dartmouth COOP Charts are more culturally acceptable than the original charts and appear to measure constructs adequately.

Adolescent↗
PubMed1998

The treatment of chronic depression, part 2: a double-blind, randomized trial of sertraline and imipramine.

BACKGROUND: Chronic depression appears to be a common, frequently disabling illness that is often inadequately treated. Unlike episodic depressions with shorter illness duration, neither acute nor long-term treatment approaches for chronic depression have been well studied. METHOD: 635 outpatients at 12 sites who met DSM-III-R criteria for chronic major depression or double depression were randomly assigned to 12 weeks of double-blind treatment with either sertraline (in daily doses of 50-200 mg) or imipramine (in daily doses of 50-300 mg). Efficacy and safety were assessed either weekly or every 2 weeks during the 12 weeks of acute treatment. RESULTS: Despite high rates of chronicity (mean duration of major depression = 8.9+/-9.1 years; mean duration of dysthymia = 23+/-13 years) and high rates of comorbidity, 52% of patients achieved a satisfactory therapeutic response to sertraline or imipramine (by a conservative, intent-to-treat analysis). Approximately 21% of the patients who had achieved a therapeutic response at week 12 had not done so at week 8, confirming the longer time to response in depressions with high chronicity. Patients treated with sertraline reported significantly fewer adverse events and were significantly less likely to discontinue treatment due to side effects than imipramine-treated patients (6.3% vs. 12.0%). CONCLUSION: These results indicate that patients suffering from depression with high chronicity can achieve a good therapeutic response to acute treatment with either sertraline or imipramine, although sertraline is better tolerated.

Adult↗
PubMed1998

The treatment of chronic depression, part 3: psychosocial functioning before and after treatment with sertraline or imipramine.

BACKGROUND: Previous research has suggested that depressed patients, and particularly chronically depressed patients, have significant impairments in many areas of their lives. While previous studies suggested that these "psychosocial" impairments improve following pharmacologic treatment, no large scale definitive study using multiple measures of psychosocial functioning has been reported. METHOD: We assessed multiple domains of psychosocial functioning using interviewer-rated and self-report measures within the context of a 12-week acute treatment trial of sertraline and imipramine for patients with chronic depression (double depression and chronic major depression). We also compared the psychosocial functioning data of this sample before and after treatment with normative data available from published community samples. RESULTS: Chronically depressed patients manifested severe impairments in psychosocial functioning at baseline. After treatment with sertraline or imipramine, psychosocial functioning improved significantly. Significant improvements appeared relatively early in treatment (week 4). Despite these highly significant improvements in functioning during acute treatment, the study sample as a whole did not achieve levels of psychosocial functioning comparable to a comparator nondepressed community sample. However, patients who reached full symptomatic response (remission) during acute treatment did have levels of psychosocial functioning in most areas at endpoint that approached or equaled those of community samples. CONCLUSION: These results indicate that successful antidepressant treatment with sertraline or imipramine can alleviate the severe psychosocial impairments found in chronic depression.

Adaptation, Psychological↗
PubMed1997

Risk factors for stroke due to cerebral infarction in young adults.

BACKGROUND AND PURPOSE: Stroke in the young is particularly tragic because of the potential for a lifetime of disablement. More than 10% of patients with stroke due to cerebral infarction are aged 55 years or younger. While a number of studies have addressed the issue of stroke mechanism in the young, quantitation of risk factors has rarely been undertaken. Given the importance of risk factor assessment in primary prevention, we aimed to assess this using case-control methodology in a hospital-based series and community-based control subjects. METHODS: A total of 201 consecutive patients with first-onset stroke due to cerebral infarction aged 15 to 55 years (mean, 45.5 years) were accrued from four teaching hospitals during 1985 to 1992 and compared with their age- and sex-matched neighborhood controls. Information concerning potential risk factor exposure status was collected by structured questionnaire at interview. Stroke risks were estimated by calculating the odds ratios with multivariate logistic regression. RESULTS: Significantly increased risk of stroke was found among those with diabetes (odds ratio, 11.6 [95% confidence intervals, 1.2 to 115.2]), hypertension (6.8 [3.3 to 13.9]), heart disease (2.7 [1.1 to 6.4]), current cigarette smoking (2.5 [1.3, 5.0]), and long-term heavy alcohol consumption (> or = 60 g/d) (15.3 [1.0 to 232.0]). However, heavy alcohol ingestion (> or = 60 g) within 24 hours preceding stroke onset was not a risk factor (0.9 [0.3 to 3.4]). CONCLUSIONS: Diabetes, hypertension, heart disease, current smoking, and long-term heavy alcohol consumption are major risk factors for stroke in young adults. Given that the majority of these factors are either correctable or modifiable, prevention strategies may have the potential to reduce the impact of stroke in this age group.

Adolescent↗
PubMed1997

Suspected lamotrigine-induced toxic epidermal necrolysis.

OBJECTIVE: To describe a patient who developed toxic epidermal necrolysis (TEN) possibly secondary to lamotrigine use. CASE SUMMARY: A 74-year-old white man with a history of probable complex partial seizures was admitted to the neurology service for a prolonged postictal state. His antiepileptic regimen was changed while he was in the hospital to include lamotrigine. After 19 days of hospitalization and 14 days of lamotrigine therapy, the patient became febrile. The next day he developed a rash which progressed within 4 days to TEN, diagnosed by skin biopsy. All suspected drugs were discontinued, including lamotrigine. The patient was treated with hydrotherapy in the burn unit. His symptoms improved and he was discharged from the hospital 26 days after the rash developed. DISCUSSION: During lamotrigine's premarketing clinical trials, the manufacturer reported several cases of Stevens-Johnson syndrome and TEN. There are several published case reports of lamotrigine-induced severe skin reactions. All of these reports included patients being treated with both valproic acid and lamotrigine. Our patient was exposed to phenytoin, carbamazepine, clindamycin, and lamotrigine, but not valproic acid. The patient reported prior use of phenytoin with no skin rash. Carbamazepine was the antiepileptic drug the patient was maintained on prior to his hospital admission, and the symptoms of TEN resolved while he was still receiving carbamazepine. The patient received only two doses of clindamycin, which makes this agent an unlikely cause of TEN. CONCLUSIONS: Because of the temporal relationship of the onset of the patient's rash and several drugs that are known to cause severe rashes, it is not certain which drug was the definite culprit. However, based on the evidence from the literature, lamotrigine appears to be the causative agent.

Aged↗
PubMed1997

Lung volume reduction surgery at a community hospital: program development and outcomes.

STUDY OBJECTIVES: Description of the development and results of a program in lung volume reduction surgery (LVRS) at a community hospital. DESIGN: Prospective data collection. SETTING: A 320-bed community hospital. PATIENTS: Fifty-five patients consecutively discharged from the hospital following LVRS. The mean preoperative FEV1 averaged 28% (+/-8%) of predicted values, while the preoperative PaCO2 averaged 49 mm Hg (+/-11.5 mm Hg). Forty-eight patients completed a preoperative conditioning regimen and underwent the procedure on an elective basis. Seven patients underwent the procedure during a hospital admission for a COPD exacerbation. Eight patients required mechanical ventilation preoperatively, including three who had required long-term mechanical ventilatory support. RESULTS: Three patients (5%) died in the hospital following surgery. One patient developed chronic ventilator dependence. All three of the patients who required long-term mechanical ventilation preoperatively were weaned from the ventilator and returned home. Follow-up pulmonary function testing is available for 42 patients 3 months after surgery, and for 20 patients 6 months after the operation. At 3 months, the mean FEV1 improved 0.19 L (p=0.0002), the mean improvement for FVC was 0.37 L (p=0.0001), and the mean drop in residual volume was 0.97 L (p=0.0001). Similar changes are seen at 6 months. Highly significant improvements were also seen in quality of life measurements and exercise performance. The benefits of surgical treatment of emphysema seemed similar in both elective and urgent groups. CONCLUSIONS: LVRS can be done safely and effectively at a community hospital, with significant improvement in pulmonary function and quality of life.

Adult↗