Long-period gratings for selective monitoring of loads on a wind turbine blade.

An optical fiber sensor based on long-period gratings (LPG) for selective measurements of flap- and edge-wise bending of a wind turbine blade is presented. Two consecutive LPGs separated by 40 mm interfere to improve resolution and reduce noise in a D-shaped fiber. The mode profile of the device was characterized experimentally to provide a model describing the mode couplings. The sensor was tested on a wind turbine blade.

Comparing Differences in ADL Outcomes for the STOMP Intervention for Dementia in the Natural Home Environment Versus a Clinic Environment.

BACKGROUND: Few studies have examined structured rehabilitation techniques for improving activities of daily living in people with mild-moderate dementia. We sought to examine the advantages to delivering the Skill-building through Task-Oriented Motor Practice (STOMP) intervention in the home environment (versus the clinic), hypothesizing that ADL improvement would be significantly better, time to meeting goals would be faster and fewer displays of behavior would be noted. METHODS: Compared results of two quasi-experimental studies of STOMP, one completed in the home, one completed previously in a clinic. Participants were English-speaking; community dwelling adults aged 50-90 diagnosed with mild-moderate dementia who could participate in an intensive rehabilitation program (5 days/week, 3 hours/day, for 2 weeks). Outcome measurements include examiner-observation of performance and proxy-report of performance and satisfaction with performance in patient-selected goals. RESULTS: No differences existed in the sociodemographic characteristics between the home and clinic groups where the groups were primarily white, married, had > high school education and had mild-moderate dementia. Results from the home group indicate that participants made significant improvement in ADL which was generally retained at the 90 day follow-up. These results were not significantly different than the clinic group. No significant advantages were noted for the home group in terms of time to meeting goals or exhibition of fewer behaviors. DISCUSSION: The STOMP intervention appeared to work equally as well in the home and in the clinic. Future studies should continue to examine the benefits of massed practice using high-dose regimens.

Comparison of the clock test and a questionnaire-based test for screening for cognitive impairment in Nigerians.

BACKGROUND: Since it is projected that by 2020 seventy percent of the elderly will reside in developing countries, a reliable screening method for dementia and cognitive impairment in general in populations with diverse languages, culture, education and literacy will be needed. We sought to determine if the Clock Test, a screening test for dementia, was suitable for use in a Nigerian population. STUDY DESIGN: Cross-sectional survey of 54 men and 12 women from Northern Nigeria. Researchers administered two dementia screening tools: a questionnaire-based test adapted for use in a Nigerian population and the Clock Test. RESULTS: Overall, 53.0% of the subjects had an abnormal Clock Test whereas 10.6% of the subjects had an abnormal questionnaire score. Only 9.1% of the subjects had abnormal scores on both tests. Subjects with more schooling had a greater probability of having a positive clock concept (understanding that a circle represented a clock). Of those with more than 6 years of schooling, 91.0% had a positive clock concept. Subjects with a negative clock concept were more likely to have an abnormal Clock Test (93.3%) than a questionnaire (26.6%). CONCLUSIONS: The main finding of our study was the discrepancy between the results of the Clock Test and the questionnaire. Performance on the Clock Test appeared to have been heavily influenced by education level, indicating the test is not universally applicable across cultures. The questionnaire-based test appears to reduce the effects of illiteracy on assessing dementia in a Nigerian population. Larger studies should be done to control for how education affects the assessment of dementia.

Comparison of the clock test and a questionnaire - based test for screening for cognitive impairment in Nigerians

Background: Since it is projected that by 2020 seventy percent of the elderly will reside in developing countries; a reliable screening method for dementia and cognitive impairment in general in populations with diverse languages; culture; education and literacy will be needed. We sought to determine if the Clock Test; a screening test for dementia; was suitable for use in a Nigerian population. Study design: Cross-sectional survey of 54 men and 12 women from Northern Nigeria. Researchers administered two dementia screening tools: a questionnaire-based test adapted for use in a Nigerian population and the Clock Test. Results: Overall; 53.0of the subjects had an abnormal Clock Test whereas 10.6of the subjects had an abnormal questionnaire score. Only 9.1of the subjects had abnormal scores on both tests. Subjects with more schooling had a greater probability of having a positive clock concept (understanding that a circle represented a clock). Of those with more than 6 years of schooling; 91.0had a positive clock concept. Subjects with a negative clock concept were more likely to have an abnormal Clock Test (93.3) than a questionnaire (26.6). Conclusions: The main finding of our study was the discrepancy between the results of the Clock Test and the questionnaire. Performance on the Clock Test appeared to have been heavily influenced by education level; indicating the test is not universally applicable across cultures. The questionnaire-based test appears to reduce the effects of illiteracy on assessing dementia in a Nigerian population. Larger studies should be done to control for how education affects the assessment of dementia

Intracardiac expression of neutral endopeptidase.

Neutral endopeptidase (NEP), a proteolytic enzyme, is known to degrade several peptides which control cardiovascular homeostasis. This is a preliminary study of the pattern of the intracardiac regional expression of the NEP gene in the normal heart, and the age-related changes in this expression in the cardiac regions. The relative abundance of NEP mRNA was determined by RT-PCR in the right atrium (RA), right ventricle (RV), left atrium (LA), left ventricle (LV) and interventricular septum (IVS) in 2-month-old (young) and 12-month-old (advanced-age adult) Wistar Kyoto (WKY) rats. The NEP gene was expressed in all 5 cardiac regions in both age groups. In young rats, the NEP expression level was lowest in the RA; this level was significantly lower than in the septum (p < 0.05). In the advanced-age adult rats, the level was lowest in the LA; this level also was significantly lower than in the septum (p < 0.05). The level in the RA in advanced-age rats was higher than that in the young rats (p < 0.01), but the levels in other regions were not significantly different between the young rats and advanced-age adult rats. Our study showed that the NEP gene was expressed in all cardiac regions of both young rats and advanced-age adult rats. However, the regional distribution of the gene was different in each age group. The region-specific expression of the NEP gene and the age-related regional changes in the expression may be due to the structural and functional characteristics of the various regions.

Prevalence of psychiatric disorders among persons convicted of driving while impaired.

BACKGROUND: Large numbers of convicted drunk drivers are entering alcohol treatment programs, yet little information is available about their need for psychiatric treatment. This study of convicted drunk drivers estimates lifetime and 12-month prevalence of DSM-III-R psychiatric disorders (alcohol and drug abuse and dependence, major depressive disorder, dysthymic disorder, generalized anxiety disorder, posttraumatic stress disorder, and antisocial personality disorder) and compares rates with estimates from a US population-based survey. METHODS: Six hundred twelve women and 493 men, aged 23 to 54 years, convicted of driving while impaired, who had been referred to a screening program in Bernalillo County, New Mexico, were located and interviewed using the Diagnostic Interview Schedule between January 25, 1994, and June 30, 1997. Psychiatric diagnoses were compared with findings from the National Comorbidity Survey for the western region of the United States, conducted between September 14, 1990, and February 6, 1992. RESULTS: Eighty-five percent of female and 91% of male offenders reported a lifetime alcohol-use disorder, compared with 22% and 44%, respectively, in the National Comorbidity Survey sample. Thirty-two percent of female and 38% of male offenders had a drug-use disorder, compared with 16% and 21%, respectively, in the National Comorbidity Survey sample. For offenders with alcohol-use disorders, 50% of women and 33% of men had at least 1 additional psychiatric disorder other than drug abuse or dependence, mainly posttraumatic stress disorder or major depression. CONCLUSION: Drunk-driving offenders need assessment and treatment services not only for alcohol problems but also for drug use and the other psychiatric disorders that commonly accompany alcohol-related problems.

Victim impact panels: do they impact drunk drivers? A follow-up of female and male, first-time and repeat offenders.

OBJECTIVE: To examine gender differences and re-arrest rates of first-time and repeat offenders following referral to Victim Impact Panels (VIPs). METHOD: Study participants (N = 6,702; 79% men) were first-time and repeat driving-while-impaired offenders who were referred to and completed a screening program in Bernalillo County, New Mexico, from 1989 to 1994. Whether subjects were mandated to attend a VIP was self-reported in a personal interview. Multivariate Cox proportional hazards analysis was used to test the effects of VIP referral and other predictors of recidivism. Separate models were developed for female and male first-time and repeat offenders. RESULTS: After controlling for multiple risk factors, VIP referral was not statistically associated with recidivism for female or male first offenders. However, female repeat offenders referred to VIPs were significantly more likely to be re-arrested compared with those not referred, with an odds of rearrest more than twice that of females not referred. CONCLUSIONS: Although many factors influence recidivism, this study raises the possibility that VIPs may have a negative impact on female repeat offenders.

Effect of literacy on breast-feeding outcomes.

BACKGROUND: We studied the effect of functional health literacy on the initiation and continuance of breast-feeding in women at a public health clinic. METHODS: Subjects were 61 first-time mothers aged 18 years or older who spoke English as their first language. They were divided into two groups, one who exclusively breast-fed for at least the first 2 months and one who never initiated breast-feeding or did not exclusively breast-feed for at least 2 months. The Rapid Estimate of Adult Literacy in Medicine (REALM) was administered, providing reading grade-level estimates for each subject. RESULTS: An association between functional health literacy and breast-feeding was seen, with only 23% of the women in the lower literacy group exclusively breast-feeding during the first 2 months compared with 54% of women in the higher literacy group. CONCLUSION: Many patients need simpler health education materials encouraging breastfeeding. These materials are needed both before and during pregnancy.

Applying the diabetes quality improvement project indicators in the Indian Health Service primary care setting.

OBJECTIVE: With publication of the Diabetes Quality Improvement Project (DQIP) measures, the Indian Health Service National Diabetes Program applied the DQIP format to its IHS Diabetes Care and Outcomes Audit for comparison and benchmarks. RESEARCH DESIGN AND METHODS: Since 1986 the IHS Diabetes Care and Outcomes Audit has been conducted by medical record review in >75% of IHS and tribal facilities. Each year systematic random sample of charts is drawn from local diabetes registries. Chart reviews are conducted by, trained professionals according to standard definitions and instructions. Abstracted data are entered into a microcomputer-based epidemiologic software package. Local, regional, and national rates are constructed for each item. During the period 1995-1997, 150 facilities submitted data for compilation, representing participation from all 12 IHS administrative regions. The IHS Diabetes Care and Outcomes Audit collected virtually all of the DQIP measures, with the exception of LDL cholesterol (which was added to the record review in 1998). RESULTS: In 1995, 1996, and 1997, a total of 9,557, 9,985, and 9,626 individuals, respectively, were included in the total IHS audit sample. The reviews for 1995, 1996, and 1997 revealed that of all subjects: 55, 65, and 80%, respectively, had more than one HbA1c test during the year (P < 0.001); 42, 38, and 34%, respectively; had a high-risk HbA1c (>9.5%) (P < 0.001); 83, 81, and 84%, respectively, were tested for macroproteinuria (P < 0.11) and 16, 17, and 23%, respectively were tested for microproteinuria (P < 0.001); total cholesterol was assessed in 80, 81, and 85%, respectively (P < 0.001), and corresponding proportions of those with values <5.17 mmol/l were 48, 50, and 52%, respectively; triglyceride values were measured for 75,75, and 80%, respectively (P < 0.001), and the corresponding median triglyceride levels were 199, 198, and 193 mg/dl, respectively (P < 0.001); the proportion of clients with a blood pressure <140/90 mmHg was 64, 64, and 66%, respectively (P < 0.05); 55, 56, and 55%, respectively, had a dilated eye exam (P < 0.053); and the proportion of clients who had a comprehensive foot exam were 59, 59, and 61%, respectively (P < 0.05). CONCLUSIONS: The DQIP accountability and quality improvement measures could be easily applied to the IHS Diabetes Care and Outcomes Audit, and the process can prove to be practical. However, data alone are not sufficient to effect change. Use of the measures to ensure that the quality of care improves must also be stressed, because measuring alone will not guarantee such improvement.

Do risk factors for re-arrest differ for female and male drunk-driving offenders?

BACKGROUND: The present study investigated gender differences in factors affecting recidivism among 628 female and 659 male drunk-driving offenders. The study population included residents from New Mexico who completed a screening program for offenders and who were still residents when contacted 5 years later. METHOD: Risk factors for re-arrest in the 5-year period after screening referral were examined using multiple logistic regression models. Predictor variables included gender, age, ethnicity, education, marital status, blood alcohol concentration at arrest, parental alcohol problems, spousal alcohol problems, lifetime use of cannabis, cocaine, or amphetamines, abusive behavior toward spouse, and scores on two standardized assessments. RESULTS: Risk factors for re-arrest were similar for males and females except that young age predicted higher recidivism among males but not females. The overall 5-year re-arrest rate was 26%-20% for women, 38% for males age 30 and under, and 24% for males age 31 and older. CONCLUSIONS: Young age predicts re-arrest for males but not for females. Neither the type of risk factors nor the number of risk factors fully explained female offenders' disproportionately lower recidivism rates, compared with young males.

Public health and clinical implications of high hemoglobin A1c levels and weight in younger adult Native American people with diabetes.

BACKGROUND: Type 2 diabetes mellitus is a major public health issue for Native American people. Because glycemic levels are predictive of diabetes outcome, understanding determinants of high hemoglobin A(1c) (HbA(1c)) levels may provide targets for prevention efforts. OBJECTIVES: To investigate determinants of high HbA(1c) levels in Native American people. METHODS: We conducted a population-based, cross-sectional study of 206 participants with diabetes from 8 Native American communities in New Mexico. We used linear regression to assess the relationship of HbA(1c) level with age, body mass index (BMI), treatment type, duration of diabetes, physical activity, and diet. RESULTS: Age, dietary pattern, and treatment type were determinants of HbA(1c) levels. Participants younger than 55 years had the highest adjusted HbA(1c) levels at 9.5% and those 65 years and older had the lowest levels at 7.8%. According to a participant's dietary intake, HbA(1c) levels were highest for those who consumed the most fat and sugar, and high consumption of fat and sugar affected HbA(1c) levels most among those younger than 55 years. Participants treated with insulin had the highest hemoglobin A(1c) levels. Physical activity was not associated with HbA(1c) level. CONCLUSIONS: We found an increasing severity of diabetes among younger people. To avoid increased morbidity and mortality in the future, young Native American adults with diabetes need vigorous therapy to maintain tight glucose control. Arch Intern Med. 2000;160:3471-3476.

Attrition in a follow-up study of driving while impaired offenders: who is lost?

High attrition rates seriously threaten the validity of follow-up studies of criminal justice populations. This study examines attrition from a follow-up study of drink-driving offenders referred 5 years earlier to a screening programme. The aim of the study was to determine which factors are most closely associated with: (1) inability to locate subjects, (2) subjects' refusal to participate; (3) the manner in which subjects refuse. Logistic regression models compared the following groups of subjects: located vs not located; interviewed vs not interviewed; type of refusal (direct vs indirect). Independent variables included gender, age group, ethnicity, whether the subject had a telephone, compliance with and completion of the screening programme, alcohol dependence or abuse diagnosis vs no diagnosis, breath-alcohol level (BAL) at the time of arrest, and whether the subject had an outstanding arrest warrant. Some factors (younger age, screening compliance, Mexican national ethnicity, and having an outstanding arrest warrant) predicted both inability to locate and type of refusal. Hispanic ethnicity and having a telephone predicted better success with locating subjects. Among refusers, non-Hispanic whites were more likely than other ethnic groups to refuse directly, and those with warrants were more likely to refuse indirectly. Non-compliance with the screening programme was also associated with differential follow-up rates. Neither arrest BAL nor alcohol diagnoses was associated with differential rates of follow-up. We conclude that alcohol diagnosis does not appear to influence successful follow-up in this criminal justice population. Rather, tracking and interviewing challenges differed among ethnic groups, suggesting a need for culturally sensitive recruitment strategies in these populations.

Victim impact panels: who is sentenced to attend? Does attendance affect recidivism of first-time DWI offenders?

BACKGROUND: Victim Impact Panels (VIPs) have been implemented widely in the United States by judges as a deterrent to drinking and driving, but there is little evidence of their utility in preventing recidivism. OBJECTIVES: The objectives of this study were to examine judges' referral patterns to the VIPs among a multiethnic population of convicted first-time driving while impaired (DWI) offenders and to compare 5-year recidivism rates of those mandated and not mandated to attend the VIP. METHODS: Study participants included 5,238 convicted first-time DWI offenders who were referred to a screening program in Bernalillo County, New Mexico, and who completed a personal interview with a master's-level counselor between April 1989 and October 1995. Logistic regression analysis was used to evaluate judges' preferences in mandating offenders to attend a VIP. The percent of subjects reoffending in the 5 years following their referral for screening was calculated by standard life-table analyses. Cox proportional hazards analysis was used to test the effects of known independent predictors for recidivism. Separate models were developed for the entire population, non-Hispanic offenders, and Hispanic/Mexican national subgroups. RESULTS: Female judges who regularly adjudicated DWI offenders were more likely to refer offenders to a VIP. Judges were less likely to refer men and offenders with less than 12 years of education and an unknown arrest blood alcohol concentration (BAC), and of Hispanic/Mexican national or other race/ ethnicity. Judges were more likely to refer unmarried offenders to a VIP. After controlling for multiple risk factors, referral to VIP was not a strong predictor of recidivism in Hispanic and non-Hispanic ethnic groups, with 95% confidence limits ranging from 0.8 to 1.0, compared to those not referred. CONCLUSIONS: Female judges were more likely than male judges to refer offenders to a VIP, and referral patterns varied by offender characteristics. The VIP referral did not increase rearrest rates but lowered them marginally to not at all. This study should be followed up with a randomized design to control for referral patterns and to further define the impact of mandating offenders to the VIP.

The influence of ethnicity on use of herbal remedies in elderly Hispanics and non-Hispanic whites.

OBJECTIVE: To compare the use of herbal remedies between elderly, self-identified Hispanics and non-Hispanic whites (NHW). DESIGN: Cross-sectional, interviewer-administered survey. PATIENTS/SETTING: 186 patients, 65 years and older, at a university-based, ambulatory, senior health center. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Differences in herbal use patterns between Hispanic and NHW participants. Main outcome measures were participants' use of herbal remedies, types of remedies used, medical reason for use, age, sex, Hispanic or NHW ethnicity, income, and education. RESULTS: Overall, 61% of patients had used an herbal remedy at some time in their lives. A larger proportion of Hispanic subjects used herbal remedies than did NHW subjects (77% versus 47%, respectively). Hispanic subjects preferred to use the raw herb in a tea, whereas NHW subjects preferred processed herbs in a capsule or tablet form. Significantly more Hispanic subjects grew or gathered their own herbs and received their information about herbs from a family member than did NHW subjects. Few subjects in either ethnic group received their information about herbal remedies from an allopathic provider. For both groups, the herbs most often used were yerba buena, manzanilla, poleo, osha, and alhucema. The top perceived medical problems that herbs were used for were health care maintenance, dyspepsia, upper respiratory infection, skin problems, and anxiety/nerves/insomnia. CONCLUSION: Ethnicity was related to the frequency of herbal use, the choice and preferred form of herb, and the source of knowledge of herbal remedies. Hispanic culture may account for the observed differences.

Assessing food selection in a health promotion program: validation of a brief instrument for American Indian children in the southwest United States.

OBJECTIVE: Brief dietary assessment instruments are needed to evaluate behavior changes of participants in dietary intervention programs. The purpose of this project was to design and validate an instrument for children participating in Pathways to Health, a culturally appropriate, cancer prevention curriculum. DESIGN: Validation of a brief food selection instrument, Yesterday's Food Choices (YFC), which contained 33 questions about foods eaten the previous day with response choices of yes, no, or not sure. Reference data for validation were 24-hour dietary recalls administered individually to 120 students selected randomly. SUBJECTS: The YFC and 24-hour dietary recalls were administered to American Indian children in fifth- and seventh-grade classes in the Southwest United States. STATISTICAL ANALYSES PERFORMED: Dietary recalls were coded for food items in the YFC and results were compared for each item using percentage agreement and the kappa statistic. RESULTS: Percentage agreement for all items was greater than 60%; for most items it was greater than 70%, and for several items it was greater than 80%. The amount of agreement beyond that explained by chance (kappa statistic) was generally small. Three items showed substantial agreement beyond chance (kappa > or = 0.6); 2 items showed moderate agreement (kappa = 0.40 to 0.59) most items showed fair agreement (kappa = 0.20 to 0.39). The food items showing substantial agreement were hot or cold cereal, low-fat milk, and mutton or chile stew. Fried or scrambled eggs and deep-fried foods showed moderate agreement beyond chances. CONCLUSIONS: Previous development and validation of brief food selection instruments for children participating in health promotion programs has had limited success. In this study, instrument-related factors that apparently contributed to poor agreement between data from the YFC and 24-hour dietary recall were inclusion of categories of foods vs specific foods; food knowledge, preparation, and vocabulary, item length, and overreporting of attractive foods. Collecting and scoring the 24-hour recall data may also have contributed to poor agreement. Further development of brief instruments for evaluating changes in children's behavior in dietary programs is necessary. Factors related to the YFC that need further development may be issues that are also important in the development of effective, brief dietary assessments for children as individual clients or patients.

Use of AUDIT for alcohol screening among emergency room patients in Thailand. Alcohol Use Disorders Identification Test.

This study evaluated the Alcohol Use Disorders Identification Test (AUDIT) against blood alcohol levels and medical diagnoses. The population under study included 695 current drinkers admitted to emergency rooms of four regional Thailand hospitals. The AUDIT positivity rate was 61% among 343 patients who drank prior to admission and 32% among 352 patients who did not drink alcohol before admission. Breath alcohol levels were positively associated with AUDIT scores. The sensitivity against a previous or current alcohol-related medical diagnosis was 89%. We concluded that the AUDIT is a satisfactory instrument for alcohol screening in this population.

Shortening deactivation of cardiac muscle: physiological mechanisms and clinical implications.

UNLABELLED: PHYSIOLOGICAL MECHANISM: A rapid change of length applied during isometric contraction of skeletal or cardiac muscle may result in redeveloped tension less than appropriate for the new length because of "deactivation" of the contractile system. The amount of shortening deactivation is directly related to both the time during the contraction when the length change occurs and to the extent of muscle shortening. If the muscle is permitted to shorten early in the contraction, the redeveloped tension will be appropriate to the new length as predicted from the classic Frank-Starling relationship. However, the same length change, which is imposed later in the contraction, results in a redeveloped tension that is less than predicted. Furthermore, a greater change in length results in less tension being redeveloped than if a smaller length decrement is applied at the same time during the contraction. It has been demonstrated that the reduced tension during active muscle shortening is associated with reduced affinity of troponin C for Ca2+. The free Ca2+ is then picked up by the SR, with less Ca2+ available for tension development until the subsequent contraction. CLINICAL SIGNIFICANCE: Although the clinical significance of shortening deactivation remains speculative, it seems likely that in the intact heart deactivation would affect myocardial O2 consumption. The decreased efficiency with which the heart maintains a given stroke work against a high afterload might be related to the lesser degree of fiber shortening and, therefore, less shortening deactivation. Conversely, it is well-known that the same level of stroke work accomplished by an increase in end-diastolic volume requires much less O2. This may be related, at least in part, to the greater degree of shortening with an accompanying increase in deactivation under the latter conditions. For example, in congestive heart failure where ejection fraction and fiber shortening are minimal, the maintenance of the longer fiber lengths could significantly increase the MVO2. Ford has suggested that the deactivating effect of shortening produced by afterload reduction would limit energy expenditure, therefore, exerting a favorable effect on the failing myocardium. It would also seem that an inotropic agent that increased shortening deactivation might compensate for the increased MVO2 caused by the inotrope and have a favorable effect on cardiac work. From most of the studies we have reviewed, it appears likely that shortening deactivation acts as a physiological "feedback" mechanism that affects afterload and in turn, myocardial oxygen consumption. Pathological situations such as acidosis and ischemia have been associated with reduced myofilament Ca2+ sensitivity or affinity and depressed cardiac contractility. Is it then possible that interventions that increase Ca2+ sensitivity might favorably alter ventricular pressure-volume relations during ejection and improve myocardial function by reducing the magnitude of shortening deactivation? Whatever the mechanism and clinical significance, future investigations will help to define the role of shortening deactivation in modifying ventricular function.

Age-related difference in cardiac adaptation to chronic hypertension in rats, with and without nifedipine treatment.

UNLABELLED: Three myosin isozymes, V1 (alphaalpha MHC = Myosin Heavy Chain gene), V2 (alphabeta MHC) and V3 (betaalpha MHC) that are identified in the cardiac ventricles of most mammals have been shown to shift to a V3 predominance pattern during cardiac growth and in response to left ventricular pressure overload, and to V1 predominance following anti hypertensive treatment. This study examined whether long-term hypertension impairs the ability of the adult heart to restructure myosin isozyme proportions. Using pyrophosphate gel electrophoresis, we studied proportions of cardiac myosin isozymes (V1 and V3) in young (16 weeks) and adult (36 weeks) spontaneously hypertensive rats (SHR), and following 12 weeks of nifedipine (N) treatment in age-matched SHR rats (SHR-N). The values of V1 and V3 myosin isozymes were derived by adding half of the value of V2 to each isozyme proportion. The V3 proportion in the young SHR control (SHR-C) group (49%) was 34% higher (p < 0.05) than in the young Wistar Kyoto control (WKY-C) group (37%). However, the proportion was similarly high, though not statistically significant, in both the adult SHRC (73%) and WKY-C (71%) groups. The proportion in the young SHR-N group (29%) was 41% lower (p < 0.05) than in the young SHR-C group (49%), and the proportion in the adult SHR-N group (47%) was 34% lower (p < 0.05) than in the adult SHR-C group (73%). The ratio of left ventricular weight to body weight (LVW/BW), which determines left ventricular hypertrophy (LVH), was higher in both young and adult SHR-C (26%, p < 0.05, and 42%, p < 0.05, respectively) than in WKY-C groups. The mean LVW/BW was 27% (p < 0.05) greater in adult than in young SHR-C rats. The LVW/BW in both age groups of treated SHR-N was similar to that in age matched WKY-C rats. CONCLUSION: Our study showed that a rise in the V3 level occurs in young hypertensive rats, but no rise occurs in the V3 level in adult hypertensive rats. High blood pressure seems to contribute to the high V3 level in young hypertensive rats, but in adult hypertensive rats, high blood pressure does not accentuate the V3 rise already acquired due to the aging process. Nifedipine treatment in both young and adult hypertensive rats prevented the V3 rise due to hypertension and to the aging process. This effect of nifedipine seems to be through its antihypertensive action.