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Biomedical subjects

S T Miller

Publications and source records attributed to S T Miller.

At least 19 recordsLinked to original sources
PubMed1992

Transient aplastic crisis in patients with sickle cell disease. B19 parvovirus studies during a 7-year period.

OBJECTIVE: To determine (1) the proportion of cases of transient aplastic crisis (TAC) in patients with sickle cell disease due to B19 parvovirus infection in several years, (2) longitudinally, the immune response to B19 parvovirus infection, and (3) whether patients with sickle cell disease experience recurrent or chronic B19 parvovirus infection. DESIGN: Prospective evaluation of patients with sickle cell disease and TAC to find evidence of B19 parvovirus infection and, if present, to document the pattern of serologic response with time. SETTING: Large urban teaching hospital. PATIENTS: Patients younger than 18 years with sickle cell disease who were admitted to the hospital with a diagnosis of TAC or who developed TAC while in the hospital for other reasons. Follow-up serologic studies of B19 parvovirus infection were done in eight patients. MEASUREMENTS/MAIN RESULTS: Serum was tested for B19 parvovirus DNA/viral particles and specific anti-B19 parvovirus IgM and IgG antibodies. B19 parvovirus DNA/viral particles were detected in 11 (21%) of 53 patients with TAC. Specific anti-B19 parvovirus IgM antibodies were detected in 34 (64%) of the 53 patients. Overall, 36 (68%) of 53 patients with TAC had evidence of acute B19 parvovirus infection as shown by the detection of B19 DNA parvovirus and/or specific anti-B19 parvovirus IgM antibodies in acute-phase serum. Follow-up serologic studies in eight patients with acute infection revealed disappearance of B19 parvovirus DNA/viral particles and anti-B19 parvovirus IgM antibodies and persistence of anti-B19 parvovirus IgG antibodies for up to 3 1/2 years after the diagnosis of acute B19 parvovirus infection. No patient had evidence of recurrent or chronic B19 parvovirus infection. CONCLUSIONS: Approximately 70% of cases of TAC in patients with sickle cell disease identified in a 7-year period were caused by acute B19 parvovirus infection. Once detected, anti-B19 parvovirus IgG antibodies remain detectable for several years. There was no evidence of chronic or recurrent B19 parvovirus infection in patients with sickle cell disease.

Adolescent↗
PubMed1992

Less intensive long-term transfusion therapy for sickle cell anemia and cerebrovascular accident.

To determine the efficacy of a less intensive transfusion regimen in preventing recurrent cerebrovascular accidents and reducing transfusion requirements in patients with sickle cell anemia, we offered to 14 patients who had been undergoing aggressive transfusion therapy (sickle hemoglobin concentration kept less than 30% of total) for a mean of 9 years the option of either diminishing or stopping transfusion therapy. Thirteen patients chose to continue a modified transfusion regimen to maintain sickle hemoglobin concentration less than 60%; 10 of these patients have now been followed for 1 year or more (12 to 27 months, mean 15.5 months). There have been no recurrent neurologic events, although two patients have died of complications of hemochromatosis. All patients had a reduction in donor exposure, and there was a mean reduction in net transfusion requirement of 31.4% during the first year after modification. The greatest reduction was achieved in the single patient managed by small-volume (5 ml/kg) simple transfusion rather than partial packed cell exchange. We conclude that although long-term consequences of less aggressive transfusion therapy are unknown, the use of such a regimen may be reasonable, particularly in patients with significant transfusional hemochromatosis.

Adolescent↗
PubMed1992

Discrepancies in recording systolic blood pressure of elderly persons by ambulatory blood pressure monitor.

Agreements between auscultatory blood pressure measurements and recordings of the Suntech Accutracker II ambulatory blood pressure monitor (ABPM) were examined in 103 participants ages 23 through 91 to estimate influence of age on accuracy of automated recordings. Simultaneous auscultation by two technicians and recording by the ABPM were compared. Technicians demonstrated close agreement in auscultation of blood pressure. Mean systolic blood pressure measured by ABPM was 5.6 mm Hg lower and mean ABPM diastolic blood pressure was 6.3 mm Hg lower than average auscultatory blood pressure measured by technicians (P less than .0001). Discrepancies in systolic blood pressure measurements between technicians and ABPM were associated with age and systolic blood pressure. The age effect, controlled for gender and race, was a 0.15 mm Hg increase in systolic blood pressure discrepancy per year of age. Discrepancies in diastolic blood pressure measurements were associated with race but not with age or body size measurements. Automated recordings of blood pressure by this ABPM may have systematic bias compared to auscultation which exceeds current standards for ABPM instrumentation. For systolic blood pressure, this bias increases with age and may affect interpretation of ABPM recordings in elderly persons.

Adult↗
PubMed1992

MIDAS: hypertension and atherosclerosis. A trial of the effects of antihypertensive drug treatment on atherosclerosis. MIDAS Research Group.

Although clinical trials of the efficacy of antihypertensive treatment have demonstrated impressive reductions in the incidence of stroke, the reduction in coronary artery disease mortality has been less impressive. It may be that the antihypertensive drugs used in these trials induced metabolic disturbances, or produced inadequate regression of left ventricular hypertrophy, thus blunting the reduction in risk of coronary artery disease expected with blood pressure-lowering. Isradipine, a dihydropyridine calcium antagonist known to be an effective antihypertensive agent, has also displayed pronounced antiatherogenic effects in animals. Thus, a reasonable hypothesis could be that isradipine not only reduces the level of blood pressure, but also may have a positive effect on the evolution of atherosclerotic plaque in coronary and carotid arteries, thereby leading to prevention of clinical sequelae of atherosclerosis. On this basis, a 3-year clinical trial is being carried out in the United States--the Multicenter Isradipine/Diuretic Atherosclerosis Study (MIDAS)--to establish the efficacy of isradipine in inhibiting atherogenesis and retarding the progression of atherosclerosis in carotid arteries of hypertensive patients. The primary end point of the study is intima-media thickness and the extent of atherosclerotic plaque in the carotid arteries, as measured by B-mode ultrasonography.

Antihypertensive Agents↗
PubMed1992

Nonpharmacologic intervention to reduce blood pressure in older patients with mild hypertension.

BACKGROUND: Although nonpharmacologic interventions are widely recommended in the therapy of high blood pressure in older adults, surprisingly little data exist to confirm the efficacy of these interventions in older persons. METHODS: We conducted a randomized, controlled clinical trial in persons aged 60 to 85 years with a diastolic blood pressure of 85 to 100 mm Hg. The experimental arm was a nonpharmacologic intervention combining weight reduction, sodium restriction, and increased physical activity. The nonpharmacologic intervention consisted of eight weekly group and two individual sessions during the intensive phase, followed by four monthly group sessions during the maintenance phase. The control group received no treatment during the study. Blood pressure was assessed by certified technicians (blinded to group assignment) using random zero sphygmomanometers. RESULTS: Of 56 participants randomized, 47 completed the entire 6-month trial (21 in the intervention group and 26 in the control group). Attendance at the intervention sessions was excellent. The intervention group lost more weight (-2.1 kg) over 6 months than the control group (+0.3 kg). Trends for decreasing 24-hour urine sodium excretion in both the intervention and control groups, with greater trend in the intervention group, were not statistically significant. The intervention group experienced more reduction in systolic and diastolic blood pressure than did the control group (mean differences between groups at 6 months, 4.2/4.9 mm Hg, respectively). CONCLUSIONS: Our data indicate that a nonpharmacologic intervention will lower systolic and diastolic blood pressure levels in older people with borderline or mild elevations of diastolic blood pressure.

Aged↗
PubMed1991

Assessing emotional distress at the internist's office.

At their first visits to a clinic, 102 outpatients rated the severity of their presenting complaint, of 12 possible body problems including 6 nonspecific symptoms, of a set of adjustment difficulties, and answered the Welsh A and the Beck Depression inventories. Then, an internist 'blind' to the foregoing answers performed a routine history and physical exam, afterward rating the patient for degree of organic and of psychosomatic involvement. Significant correlations were found between clinician judgments of psychosomatic involvement and patients' self-reported complaints on all assessment measures (smallest r = 0.25, P less than 0.01). Substantial intercorrelations were found among the assessment measures, especially between Welsh A (Anxiety) and Beck Depression scores (r = 0.73).

Affective Symptoms↗
PubMed1991

Role of Chlamydia pneumoniae in acute chest syndrome of sickle cell disease.

Children with sickle cell disease and acute chest syndrome were investigated for infection with Chlamydia pneumoniae and Mycoplasma pneumoniae. Of 30 patients who had 32 episodes of acute chest syndrome, four (13%) had C. pneumoniae isolated from the nasopharynx; two of these also had serologic evidence of acute infection, and one had positive nasopharyngeal isolates on two subsequent occasions during the course of 1 year with stable, elevated titers of anti-C. pneumoniae IgG, suggesting chronic infection. Two patients with negative cultures had serologic evidence of infection with C. pneumoniae. None of 32 cultures for M. pneumoniae were positive, and although anti-M. pneumoniae IgM developed in two patients, one of these patients had evidence of C. pneumoniae infection (positive culture and seroconversion). We conclude that C. pneumoniae infection is prevalent in our sickle cell population with acute chest syndrome. Until further studies clarify the pathophysiologic significance of C. pneumoniae infection, we believe that early inclusion of erythromycin as antimicrobial therapy for acute chest syndrome seems reasonable.

Adolescent↗
PubMed1991

Prevalence of postural hypotension at baseline in the Systolic Hypertension in the Elderly Program (SHEP) cohort.

OBJECTIVE: The objective of this study was to examine the prevalence and correlates of postural hypotension (defined as a drop in systolic blood pressure of greater than or equal to 20 mm Hg) in a cohort of elderly persons with isolated systolic hypertension (ISH). DESIGN: Baseline cross-sectional analysis of the 4,736 persons randomized in the Systolic Hypertension in the Elderly Program (SHEP). SETTING: A randomized multi-center double-blind outpatient clinical trial of the impact of treating ISH. PARTICIPANTS: Men and women age greater than or equal to 60 years with the systolic blood pressure (SBP) greater than or equal to 160 mm Hg and diastolic blood pressure (DBP) less than 90 mm Hg. MEASURES: Medical histories were obtained using interviewer-administered, standardized clinical history forms. At entry into the study, seated and standing BP was measured by certified BP technicians using a random zero sphygmomanometer. Postural hypotension (PH) was assessed at 1 and 3 minutes after the participant arose from a seated position. MAIN RESULTS: PH was found in 10.4% of participants at 1 minute and in 12.0% of participants at 3 minutes. 5.3% of participants demonstrated PH at both time intervals while 17.3% demonstrated PH at either or both of the time intervals. Factors significantly (P less than 0.05) associated with the presence of PH were higher mean SBP and a lower mean body mass index. CONCLUSIONS: Somewhat different persons were defined as having PH based upon the 1 minute and 3 minute standing measures of BP, and prevalence estimates of PH can vary depending on whether one or more intervals of measurement are used. Cross-sectional data analysis indicated that PH, in healthy community-dwelling older persons with ISH, may not be associated with a history of disorders or problems usually thought to be related to PH. However, prospective data are needed to determine the prognostic significance of PH, and whether one or multiple measurements carry more significance.

Aged↗
PubMed1991

Impact of a geriatric assessment unit on subsequent health care charges.

BACKGROUND: In a recent randomized controlled trial assessing the efficacy of an inpatient geriatric assessment unit (GAU), we demonstrated that patients assigned to the unit were less likely than those in the usual care group to be admitted to a nursing home and more likely to remain living in the community. Despite evidence of benefits of GAU care, questions remain about its cost. We examine the impact of GAU treatment on subsequent health care charges. METHODS: Sequential referrals of elderly disabled patients considered at risk for institutionalization or likely to improve with rehabilitation were randomized to the GAU or to usual care. Charge data were collected on utilization of a wide variety of health care services starting at the point of randomization. RESULTS: The group randomized to the GAU experienced significantly higher rehabilitation charges per participant ($10,583 vs $2066, P = .0001), but lower mean nursing home charges ($1798 vs $3426, P = .004). Total health care charges per participant over the 1 year follow-up were greater for the GAU group ($28,406 vs $16,444, P = .004). When charges were adjusted per year of life survived, the GAU group still showed a substantial (but nonsignificant, P = .10) increase in total charges. However, when charges were adjusted per day subsequently spent residing in the community, adjusted total charges were similar between the two groups. CONCLUSIONS: Our results indicated that improved outcomes from GAU care require an investment in rehabilitation that is not totally offset by decreased institutional charges in the following year.

Aged↗
PubMed1991

Comparison of subjective ratings of function with observed functional ability of frail older persons.

BACKGROUND: Important clinical decisions often hinge on patients' functional status. Previous studies have shown disagreement among sources of ratings of patients' functional status. This study compared patient self-ratings, family member ratings, and physician ratings of patient function to performance-based functional testing criteria. METHODS: Five activities of daily living of 73 older patients were studied at admission to a rehabilitation unit following discharge from an acute care community hospital. Data were collected from patients, family members, and physicians and were compared with performance-based function testing. RESULTS: Patient ratings were significantly more accurate than physician ratings for walking, transferring, and telephoning. Patients were significantly more accurate than family members for rating walking and telephoning, but patients were not significantly more accurate than family members or physicians for rating eating or dressing. CONCLUSIONS: We conclude that decisions about patients' functional level should be based on performance testing. If performance testing is unavailable, patients' own ratings are most accurate, followed by family ratings. Physicians' ratings are least accurate.

Activities of Daily Living↗
PubMed1990

A comparison of two automated monitors in the measurement of blood pressure reactivity. Trials of Hypertension Prevention Collaborative Research Group.

Cardiovascular reactivity is the change in blood pressure, pulse, and other parameters of cardiovascular function in response to a challenging task. During the conduct of cardiovascular reactivity protocols, researchers frequently use automated blood pressure devices to measure blood pressure reactivity. However, the accuracy of automated devices in measuring blood pressure reactivity is unknown. To investigate the accuracy and precision of the Dinamap 1846 SXP and the VitaStat 2600B in the measurement of blood pressure reactivity, we compared blood pressure reactivity recorded by the VitaStat and Dinamap with that obtained by observers using a conventional mercury sphygmomanometer. At three sites, 159 normotensive subjects performed the same task twice, once with blood pressure reactivity measured by the manual observers and once by the VitaStat (n = 79) or Dinamap (n = 80), with the order determined at random. Ratios (VitaStat/Dinamap) of aggregate within-person variance for baseline and task, systolic and diastolic blood pressures ranged from 1.53 to 4.93 (all P < 0.01), suggesting that the Dinamap has better precision than the VitaStat. For both diastolic and systolic blood pressure reactivity and for both types of automated devices, the mean differences in blood pressure reactivity between manual and automated measurements were small (range, -1.8 to 0.8 mm Hg). However, the VitaStat versus manual scatter plot of diastolic blood pressure reactivity showed greater dispersion (correlation coefficient r = 0.16, P = 0.15) than the Dinamap versus manual scatter plot (r = 0.36, P = 0.001). For systolic blood pressure reactivity, the VitaStat versus manual and Dinamap versus manual scatter plots were similar. Our data indicate that the Dinamap is superior to the VitaStat in the measurement of blood pressure reactivity. The substantial performance differences between the VitaStat and Dinamap suggest that other automated blood pressure monitors must be evaluated prior to use in cardiovascular reactivity studies.

Adult↗
PubMed1979

Administration of human somatotropin in levodopa-treated patients with Parkinsonism.

To investigate further the role of growth hormone (GH) on the cerebral effects of levodopa, human somatotropin (human growth hormone) was administered to four patients with parkinsonism with varying response to chronic levodopa therapy. The doses of somatotropin (5 IU) were administered on alternate days for four days, and the effects of this hormone on the patient's symptomatic control, dyskinesia, plasma GH, and dopa levels were evaluated and compared with those of patients receiving saline injections. We have demonstrated that administration of exogenous human somatotropin, even during marked and sustained elevations of plasma GH levels, does not alter the therapeutic or side effects of levodopa therapy. With one exception, plasma dopa levels after human somatotropin administration remained unchanged. We conclude that neither the endogenous increases of GH in response to levodopa nor those attained following human somatotropin administration modify in any consistent way the therapeutic and side effects of chronic levodopa therapy, and that the episodic releases of GH in response to levodopa occur independently of its cerebral effects.

Aged↗
PubMed1979

Seizure disorders and trace metals: manganese tissue levels in treated epileptics.

We determined the concentrations of manganese in whole blood and hair in 52 epileptics, 6 blood relatives, and 24 normal controls. Blood, and possibly hair manganese content, was significantly lower in treated epileptics than in controls (p less than 0.002). Although not all patients showed reduced tissue manganese levels, most of those with frequent seizures had manganese levels falling below the lowest control level, suggesting a relationship between manganese tissue levels and high seizure activity. These differences in manganese levels were not correlated with the type, dose, or plasma levels of anticonvulsant medication. Reduced manganese availability at the neuronal level, where Mn++ stabilizes membrane excitability, may affect epileptogenic lesions to increase the likelihood of seizure activity.

Adolescent↗