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Biomedical subjects

M E Miller

Publications and source records attributed to M E Miller.

At least 55 records · Page 3Linked to original sources
PubMed1999

Validation of the PASE in older adults with knee pain and physical disability.

PURPOSE: To examine the validity of the Physical Activity Scale for the Elderly (PASE) among individuals with disability. METHODS: A sample of 471 participants (mean age = 71.36) in an epidemiological study of chronic knee pain completed the PASE and self-report measures of knee pain, perceived physical function, satisfaction with physical function, and importance of physical function. A 6-min walk test and an isokinetic assessment of knee strength were also administered. RESULTS: PASE scores were significantly correlated in expected directions with performance on the 6-min walk, knee strength, frequency of knee pain during transfer, and perceived difficulty with physical functioning. Gender and age were identified as significant moderators of PASE scores and the scale's construct validity was supported by testing a conceptually driven hypothesis regarding patterns of physical activity. CONCLUSIONS: These results support the PASE's validity for the assessment of physical activity among older adults with pain and disability.

Aged↗
PubMed1999

Multi-method assessment of access to primary medical care in rural Colorado.

The objectives of this study include conducting an analysis of access to primary medical care in rural Colorado through simultaneous consideration of primary care physician-to-population and distance-to-nearest provider indices. Analyses examined the potential development and implications of excessively large, perhaps unmanageable patient caseloads that might result from every rural Coloradoan's exclusive use of the nearest generalist physician as a regular source of care. Using American Medical Association Physician Masterfile data for 1995 and coordinates for latitude and longitude from U.S. Census files (Census of Population and Housing, 1990), the authors calculated distance to the nearest primary care physician for residents of each of the 1,317 block groups in Colorado's 52 rural counties. Caseloads for each generalist physician were computed assuming the population used the nearest provider for care. Straight-line mileage to primary medical care was modest for rural Coloradoans--a median distance of 2.5 miles. Almost two-thirds (65 percent) of the population resided within 5 miles, and virtually all residents (99 percent) were within 30 miles of a generalist physician. However, had everyone traveled the shortest possible distance to care, demand for service from many of the 343 primary care doctors in rural regions of the state would have been overwhelming. The results of simultaneous application of distance-to-care and provider-to-population techniques unrestricted by geographic boundaries depict access to primary medical care and corresponding consumer difficulty more fully than in previous studies. Further combination of methods of needs assessment such as those used in this analysis may better inform the future efforts of organizations mandated to address health care underservice in rural areas.

Colorado↗
PubMed1999

Is diabetic nephropathy inherited? Studies of glomerular structure in type 1 diabetic sibling pairs.

Only a minority of patients with type 1 diabetes develop diabetic nephropathy (DN). Poor glycemic control cannot fully explain DN risk, and family studies suggest genetic susceptibility factors. To understand familial DN concordance, we evaluated glomerular structure in families with type 1 diabetic sibling pairs. Kidney function and biopsy studies were performed in 21 probands (P) (first to develop diabetes) and 21 siblings (S) (second to develop diabetes), most with normal urinary albumin excretion rates (UAER). Glomerular structure was measured by morphometry. Intrafamilial correlation was estimated by one-way random-effects ANOVA and by mixed-effects ANOVA, adjusting for age and duration of diabetes. Diabetes duration was, by definition, longer in P than in S, while age and sex were similar. HbA1c over 5 years and blood pressure were not different in P and S and were without familial effect. UAER was greater in P than in S (P < 0.05), with strong familial effect (P = 0.03). A strong concordance among siblings for mesangial fractional volume (P < or = 0.01) remained significant after adjustment for diabetes duration and age (P = 0.04). Results were similar for mesangial cell (P = 0.01; adjusted P = 0.04) and mesangial matrix fractional volumes (P < 0.01; adjusted P = 0.06). There was also clustering of the patterns of glomerular lesions. For example, if P had relatively marked glomerular basement membrane thickening compared with mesangial matrix expansion, S had a similar pattern (chi2, P < 0.025). Strong concordance in severity and patterns of glomerular lesions in type 1 diabetic siblings, despite lack of concordance in glycemia, supports an important role for genetic factors in DN risk.

Adult↗
PubMed1999

Evaluation of the malaria threat at the multipurpose range complex, Yongp'yong, Republic of Korea.

As part of an operational effort to control the transmission of malaria after its reemergence in the Republic of Korea, a number of U.S. military and Korean civilian health workers assessed the situation at a large training site where two cases had been transmitted. The vector mosquitoes (Anopheles sinensis) probably had a limited flight range (< 1 km) in this situation based on low numbers in permanent light traps and biting collections at the billeting area compared with collections from light traps and larval surveys where the mosquito was abundant. The threat of malaria was proven by the presence of infected local Korean residents (13 of 105 sampled). However, only a small proportion of U.S. soldiers (39 of 78 surveyed) at the training site used personal protective measures. Further efforts should include improved techniques for informing and motivating soldiers to use personal protective measures and cooperation with Korean authorities to perform vector control in civilian areas bordering the training area.

Animals↗
PubMed1998

Occupational injuries among adolescents in Washington State, 1988-1991.

BACKGROUND: To characterize work-related injuries and illnesses in minors. METHODS: We analyzed Washington State workers' compensation claims from 1988 through 1991. RESULTS: There were 17,800 claims among adolescents from age 11 through 17 years accepted in the 4-year period, including three occupational fatalities, 22 amputations, and 464 fractures; 89% of all injuries occurred among the 16- and 17-year-olds. Claims were most frequent in restaurants, food stores, service industry, other retail and wholesale trade, and agriculture. Washington State census data were used for denominator in calculating injury rates for adolescents and adults. The crude injury rate for 16- and 17-year-olds employed at the time of the census was similar to that seen among adults (9.0 vs 10.4 per 100 workers), despite that minors work fewer hours per year. The rate among boys was almost twice that seen among girls (11.7 vs. 6.4 per 100 workers). Highest rates, per 100 workers, were in public administration (27.0), construction (21.1), agriculture (11.4), and restaurants (11.0). Using census data for those working anytime over the course of the year and adjusted for the number of hours worked, the injury rate for 16- and 17-year-olds was 19.4/100 full time equivalents compared with 10.6 of 100 full-time equivalents for adults. Most injuries were lacerations, sprains and strains, contusions, and burns. CONCLUSIONS: Public health policy and injury prevention strategies for working adolescents should be developed and implemented.

Accidents, Occupational↗
PubMed1998

Perceived importance and satisfaction with physical function in patients with knee osteoarthritis.

This investigation examined the determinants of satisfaction with physical function for participants in an Observational Arthritis Study in Seniors (OASIS). The sample consisted of 480 men (51%) and women (49%) over the age of 65 years who had difficulty performing activities of daily living due to knee pain. As part of baseline testing for OASIS, participants completed a measure that assessed satisfaction with function for six physical activities. After controlling for relevant covariates, scores on the satisfaction index were regressed on seven conceptually relevant predictor variables. The results revealed that satisfaction with physical function is a distinct construct from level of function, irrespective of whether the latter variable is measured objectively or subjectively. When entered into a hierarchical regression model, 6-minute walk test data accounted for 11% of the variance in satisfaction scores, whereas perceived difficulty accounted for an additional 22%. Moreover, a significant interaction term between importance and perceived difficulty revealed that patients who rated the activities as important and who had high levels of perceived difficulty had the lowest satisfaction scores. Discussion focuses on the determinants of satisfaction with physical function with emphasis on the interaction between perceived difficulty and importance.

Activities of Daily Living↗
PubMed1998

The timing of change: patterns in transitions in functional status among elderly persons.

Data from the Longitudinal Study on Aging (LSOA) were analyzed to describe the heterogeneity of functional status transitions over 2-years (single-state model), and to explore whether changes in status in the previous two to four year period enhance the prediction of a subsequent transition (two-state model). Multivariate logistic regression with a robust estimate of variance was used to analyze a 7-category nominal response of: functional status (4 levels), institutionalization, death, and missing. Weighted percentages for functional status transitions and stability (unchanged status) showed that unchanged or improved functioning were at least as common as death or worsened functional status. Initial disability level, morbidities, and self-rated health were the strongest predictors of disability status after 2-years. The two-state model revealed that a previous transition (positive or negative) increases the risk for a subsequent transition, independent of initial disability level. The predictive and explanatory quality of the two-state model is substantially improved over single-state models, particularly from its ability to identify subgroups of individuals with marked functional status instability.

Activities of Daily Living↗
PubMed1998

Laparoscopic placement of electrodes for diaphragm pacing using stimulation to locate the phrenic nerve motor points.

Laparoscopic mapping of the phrenic nerve motor points using test stimulation was conducted for the implant of epimysial electrodes for diaphragm pacing in dogs. Both visual assessment of muscle activation and measurements of recruitment were useful for identifying an implant location resulting in a mean electrode placement approximately 14 mm from the phrenic nerve motor points in 16 dogs. Postmortem analysis of the stimulus test site locations and corresponding recruitment curves suggested that the phrenic nerve motor points could be predicted during the laparoscopic procedure to within 4.5 mm of the anatomical motor point.

Animals↗
PubMed1998

The relative weighting of acoustic properties in the perception of [s] + stop clusters by children and adults.

We examined the perceptual weighting by children and adults of the acoustic properties specifying complete closure of the vocal tract following a syllable-initial [s]. Experiment 1 was a novel manipulation of previously examined acoustic properties (duration of a silent gap and first formant transition) and showed that children weight the first formant transition more than adults. Experiment 2, an acoustic analysis of naturally produced say and stay, revealed that, contrary to expectations, a burst can be present in stay and that first formant transitions do not necessarily distinguish say and stay in natural tokens. Experiment 3 manipulated natural speech portions to create stimuli that varied primarily in the duration of the silent gap and in the presence or absence of a stop burst, and showed that children weight these stop bursts less than adults. Taken together, the perception experiments support claims that children integrate multiple acoustic properties as adults do, but that they weight dynamic properties of the signal more than adults and weight static properties less.

Adult↗
PubMed1997

Rationale, design, and baseline characteristics of the Prospective Randomized Evaluation of the Vascular Effects of Norvasc Trial (PREVENT).

The Prospective Randomized Evaluation of the Vascular Effects of Norvasc Trial is the first angiographic clinical trial to be designed to test whether an agent can slow or even reverse the progression of early coronary atherosclerosis in patients with documented disease. In addition, a subset of patients are undergoing carotid ultrasound examinations, providing a unique opportunity to assess and correlate disease progression in 2 arterial beds.

Aged↗
PubMed1997

Alkaline pH and internal calcium increase Na+ and K+ effluxes in LK sheep red blood cells in Cl--free solutions.

We examined the effects of pH, internal ionized Ca (Ca2+i), cellular ATP, external divalent cations and quinine on Cl-independent ouabain-resistant K+ efflux in volume-clamped sheep red blood cells (SRBCs) of normal high (HK) and low (LK) intracellular K+ phenotypes. In LK SRBCs the K+ efflux was higher at pH 9.0 (350%) than at pHs 7. 4 and 6.5, and was inhibited by external divalent cations, quinine, and cellular ATP depletion. The above findings suggest that the increased K+ efflux at alkaline pH is due to the opening of ion channels or specific transporters in the cell membrane. In addition, K+ efflux was activated (100%) when Ca2+i was increased (+A23187, +Ca2+o) into the microm range. However, in comparison to human red blood cells, the Ca2+i-induced increase in K+ efflux in LK SRBCs was fourfold smaller and insensitive to quinine and charybdotoxin. The Na+ efflux was also higher at pH 9.0 than at pH 7.4, and activated (about 40%) by increasing Ca2+i. In contrast, in HK SRBCs the K+ efflux at pH 9.0 was neither inhibited by quinine nor activated by Ca2+i. These studies suggest the presence in LK SRBCs, of at least two pathways for Cl--independent K+ and Na+ transport, of which one is unmasked by alkalinization, and the other by a rise in Ca2+i.

Adenosine Triphosphate↗
PubMed1997

Time course analysis of the discriminative stimulus effects of the optical isomers of 3,4-methylenedioxymethamphetamine (MDMA).

The present study examined the discriminative stimulus effects of the MDMA optical isomers administered at different presession injection intervals. In the first experiment, male Sprague-Dawley rats were trained in a two-lever, food-reinforced operant procedure to discriminate either (+)-MDMA (1.25 mg/kg) or (-)-MDMA (3.50 mg kg) at either 20 or 90 min following injection. Animals administered (+)-MDMA or saline 90 min before training sessions failed to attain the discrimination criteria after 73 training sessions, whereas (-)-MDMA successfully established discriminative stimulus control at both the 20 min and the 90 min postinjection intervals. (+)-Amphetamine did not substitute for either isomer, although a significant amount of drug-appropriate responding occurred in animals trained to discriminate (+)-MDMA at 20 min and (-)-MDMA at 90 min. Sch 39166 partially reduced the discrimination of (+)-MDMA at 20 min and (-)-MDMA at 90 min, although this effect was not dose dependent. Sch 39166 had no effect on animals trained to discriminate (-)-MDMA at 20 min. Haloperidol did not alter the discrimination of (+)-MDMA at 20 min but partially reduced the discriminative stimulus control of (-)-MDMA at 20 min and (-)-MDMA at 90 min. Fenfluramine substituted for both isomers of MDMA. Pirenpirone completely blocked the discriminative stimulus effects of (-)-MDMA at 20 min, although (+)-MDMA at 20 min and (-)-MDMA at 90 min were only partly blocked. WAY 100,135 had little effect on drug-appropriate responding; however, the discrimination of (+)-MDMA at 20 min was partly reduced by this 5-HT1A antagonist. In a second experiment, rats trained to discriminate (+)-MDMA (1.5 mg/kg) or (-)-MDMA (3.0 mg/kg) from saline were administered substitution tests with both isomers 20, 60, 90 and 120 min after injection. Results confirmed those of the first experiment that (+)-MDMA appears to have a shorter duration of action than (-)-MDMA. These results are discussed in light of the training doses employed.

Amphetamine↗
PubMed1997

Exploring the relationship between inpatient facility and physician services.

OBJECTIVES: Medicare hospitalizations involve both facility and physician services. Although several studies analyze hospital-level variations in Medicare inpatient facility and inpatient physician services per admission, few studies directly explore the relationship between these services. Theoretically, inpatient facility and physician services may be complements or substitutes. That is, an increase in facility services may lead to an increase or decrease in physician services and vice versa. This article contributes to the existing literature by exploring directly the relationship between facility and physician services. METHODS: Medicare physician claims were linked to inpatient hospital stays using data from the Medicare hospital cost reports, the Medicare Patient Analysis and Review file, and the Medicare National Claims History System. RESULTS: In multivariate regression analyses, the (partial) correlations between facility and physician services were positive, which is consistent with complementarity. Standardized regression coefficients indicate that physician services are the single most important determinant of facility services; however, facility services are a less important determinant of physician services. A 10% increase in physician services is associated with at least a 3.0% increase in facility services. CONCLUSIONS: Proposals that reduce inpatient physician expenditures also would reduce facility expenditures in the long-run.

Aged↗
PubMed1997

Predicting developmental shifts in perceptual weighting schemes.

Recent models of developmental changes in speech perception suggest that the weights assigned to acoustic properties change as children gain experience with a native language. Empirical evidence supports this position, but few suggestions have been offered as to what guides this shift. These three experiments were designed to improve our ability to predict how perceptual weighting schemes change with development. The specific hypothesis explored was twofold: (1) the weight assigned by adults to any one acoustic property differs across phonetic environments according to how informative that property is in each environment; and (2) the weight assigned by children to any one acoustic property differs less across phonetic environments because children have not fully learned the patterns of covariation between phonetic informativeness and environment for each property. Experiment 1 replicated previous findings of age-related differences in the weights assigned to noise spectra and formant transitions in labeling of syllable-initial fricatives (/s/ or /[symbol: see text]/). In experiment 2 the variation in F3-onset frequency associated with place of fricative constriction was eliminated. This property differs more (i.e., is more informative) in /u/ than in /a/. Accordingly adults' transition effect was reduced more for /u/ than for /a/ from experiment 1. Children's transition effect was similarly reduced across vowel environments. In experiment 3, F3-onset frequency was appropriately manipulated for both vowels, and adults transition effect increased more for /u/ than for /a/ from experiment 2. The increase in children's transition effect was more similar across vowels. We conclude that the children had not fully learned how information provided by F3 transitions varies across /a/ and /u/ environments, and suggest that developmental weighting shifts may be guided by children learning the relation between phonetic informativeness and environment.

Adult↗
PubMed1997

Developmental weighting shifts for noise components of fricative-vowel syllables.

Previous studies have convincingly shown that the weight assigned to vocalic formant transitions in decisions of fricative identity for fricative-vowel syllables decreases with development. Although these same studies suggested a developmental increase in the weight assigned to the noise spectrum, the role of the aperiodic-noise portions of the signals in these fricative decisions have not been as well-studied. The purpose of these experiments was to examine more closely developmental shifts in the weight assigned to the aperiodic-noise components of the signals in decisions of syllable-initial fricative identity. Two experiments used noises varying along continua from a clear /s/ percept to a clear /[symbol: see text]/ percept. In experiment 1, these noises were created by combining /s/ and /[symbol: see text]/ noises produced by a human vocal tract at different amplitude ratios, a process that resulted in stimuli differing primarily in the amplitude of a relatively low-frequency (roughly 2.2-kHz) peak. In experiment 2, noises that varied only in the amplitude of a similar low-frequency peak were created with a software synthesizer. Both experiments used synthetic /a/ and /u/ portions, and efforts were made to minimize possible contributions of vocalic formant transitions to fricative labeling. Children and adults labeled the resulting stimuli as /s/ vowel or /[symbol: see text]/ vowel. Combined results of the two experiments showed that children's responses were less influenced than those of adults by the amplitude of the low-frequency peak of fricative noises.

Adult↗