Variations in circadian rhythms of activity, sleep, and light exposure related to dementia in nursing-home patients

We measured 24-hour circadian-rhythm patterns of activity and sleep/wake activity in a group of nursing-home patients (58 women and 19 men with a mean age of 85.7 years). Severely demented patients were contrasted with a composite group of moderate y, mild, or not-demented patients. Sleep/wake activity and light exposure were recorded with the Actillume recorder. Cosinor analyses were computed to determine the mesor, amplitude, acrophase, and circadian quotient of the activity rhythms. The diagnosis of dementia was based on the Mini Mental Examination and on examination of medical records. Sleep was extremely fragmented in both groups of nursing-home patients. Severely demented patients slept more both at night and during the day, but there were no significant differences in the number of awakenings during the night or in the number of naps during the day when compared to the composite group of moderate, mild, or no-dementia patients. The severely demented group had lower activity mesor, more blunted amplitude, and were more phase delayed (i.e. had later acrophases) than the other group. In addition, the severely demented patients spent less time exposed to bright light. These results confirm that circadian rhythms in nursing-home patients are disturbed with more disturbance in the severely demented. Much of the disturbance may be related not just to age but to mental status.

An improved method for rapid and efficient radioiodination of iodine-123-IQNB

The SPECT radioligand, 3-quinuclidinyl-4-[123I]iodobenzilate ([123I]IQNB), binds to muscarinic receptors and has generated interest as a potential agent for clinical SPECT. Unfortunately, cumbersome and inefficient radioiodination procedures have limited the practicality of [123I]IQNB SPECT imaging.

METHODS

We report a rapid (5 min) and simple radioiodination procedure for preparing [123I]IQNB from a tri-n-butylstannyl precursor in a no-carrier-added reaction that yields high specific activity with radiochemical yield exceeding 60%. The radiochemical purity of the final product exceeds 95%.

RESULTS

We have used this procedure to radioiodinate the four stereoisomers of [123I]IQNB. The procedure is highly reliable and reproducible. SPECT studies on a healthy human volunteer at 1, 2, 6 and 24 hr after injection of each of the four stereoisomers reveal expected differences in the kinetic and binding characteristics of the four stereoisomers. (R,S)-[123I]IQNB appears to be the SPECT agent of choice.

CONCLUSION

Radioiodination of [123I]IQNB from our tri-n-butylstannyl precursor is simpler, more efficient and less expensive than previous techniques. The potential exists for a "kit" which would be practical in a typical clinical setting.

Cortical gyral anatomy and gross brain dimensions in monozygotic twins discordant for schizophrenia

BACKGROUND

This study combines recent advances in three-dimensional neuroimaging technology and the genetic constraints inherent in monozygotic (MZ) twins to examine surface gyral anatomy and gross brain dimensions in monozygotic twin pairs discordant for schizophrenia. Results are presented and evaluated with respect to prior observations of cortical anomalies in schizophrenia and the hypothesis that schizophrenia involves cortical maldevelopment.

DESIGN

Three-dimensional renderings from volumetric magnetic resonance imaging (MRI) data of 13 MZ twin pairs discordant for schizophrenia and nine normal MZ pairs were studied. Qualitative assessments of left and right hemisphere surfaces were made by raters blind to diagnosis in an effect to identify developmental gyral abnormalities such as vertical temporal gyri or microgyria. Measurement of brain hemisphere length, area, and volume were also determined. These data were compared within discordant MZ schizophrenia pairs, within normal MZ pairs, and between matched unaffected discordant and normal MZ groups.

RESULTS

Raters did not identify qualitatively abnormal gyri in the schizophrenia subjects to enable distinction from their unaffected co-twins or from normal controls. Brain hemisphere volumes in the affected DS were significantly smaller bilaterally by about 3% compared with their unaffected DS co-twins, who did not differ from normals on this measure.

CONCLUSIONS

We were unable to confirm previous reports of vertical gyri or localized gyral thinning as being characteristic of the cortical anatomy of schizophrenia. If cortical maldevelopment is associated with schizophrenia it does not appear to disrupt gross gyral pattern formation in these ways. The quantitative results of diminished hemisphere volume and length in the twins with schizophrenia are consistent with previous reports of smaller brain size in schizophrenia. Our results suggest that this is a bilateral phenomenon that may be dependent, at least in part, on environmental factors.

Crystallization of experimental bioactive glass compositions

Crystallization kinetics studies for six experimental glass formulations in the system Na2O-CaO-SiO2-P2O5 synthesized by wet chemistry were conducted by means of differential thermal analysis. These glasses had CaO/P2O5 and SiO2/ (CaO + Na2O) ratios ranging from 8.74-3.38 and 0.92-3.03, respectively. Samples of each glass (n = 30 were heated from 23 to 1250 degrees C under N2 atmosphere at heating rates ranging from 10 to 50 degrees C/min. Glass-ceramics were obtained after heat treating the initial glasses at temperatures determined from their DTA exotherms. The activation energy of crystallization for each glass composition was calculated from an expression-relating log-heating rate and the reciprocal of the exothermic peak temperature. The compositions of the six glasses were significantly different (p = 0.05). The activation energy of crystallization (Q) values ranged from 196 to 782 kJ/mole. A correlation was obtained between Q and CaO/P2O5 and between Q and the Young's modulus (P < 0.001). Two of the six glasses exhibited bulk crystallization. X-ray diffraction studies showed that four of the six glasses exhibited different proportions of crystalline phases following heat treatment. These phases were wollastonite (CaSiO3), Na2CaSi3O9, combeite [Na4Ca3SI6O16(OH)2], and some unidentifiable phases. Two of the six bioceramic materials had a mixture of unknown crystalline phases.

Hypertension awareness, treatment and control rates for an Asian population: results from a national survey in Korea

OBJECTIVE

This observational study was performed in order to determine the hypertension awareness, treatment, and control rates for the country of Korea.

METHODS

Rates were determined in conjunction with a national blood pressure survey in Korea in 1990. Through cluster sampling, individuals aged > 30 in 190/146,944 districts were selected for study. Among 25,567 eligible individuals, 21,242 had measurement of blood pressure (BP) and answered a standard questionnaire. BP was recorded as the mean of two measurements with a standard mercury manometer. Hypertension was defined either as BP > or = 160/95 mm Hg or on treatment (n = 2628), or as BP > or = 140/90 mm Hg or on treatment (n = 4219). Treatment was defined as any method of BP treatment, including dietary, traditional, or medication.

RESULTS

Rates for BP > or = 160/95 mm Hg or on treatment: aware 1057 (40%), treated 696 (27%), controlled 367 (14%). Rates for BP > or = 140/90 mm Hg or on treatment: aware 1069 (25%), treated 696 (16%), controlled 221 (5%).

CONCLUSIONS

Hypertension awareness, treatment, and control rates are relatively low in Korea. Blood-pressure control programs, including detection strategies, are needed here and worldwide.

Tourette syndrome: prediction of phenotypic variation in monozygotic twins by caudate nucleus D2 receptor binding

Tourette syndrome, a chronic tic disorder with autosomal dominant inheritance, exhibits considerable phenotypic variability even within monozygotic twin pairs. The origins of this variability remain unclear. Recent findings have implicated the caudate nucleus as a locus of pathology, and pharmacological evidence supports dopaminergic involvement. Within monozygotic twins discordant for Tourette syndrome severity, differences in D2 dopamine receptor binding in the head of the caudate nucleus predicted differences in phenotypic severity (r = 0.99); this relation was not observed in putamen. These data may link Tourette syndrome with a spectrum of neuropsychiatric disorders that involve associative striatal circuitry.

Body weight and blood pressure. Effects of weight reduction on hypertension

A substudy of the Hypertension Optimal Treatment study, conducted in the Jackson Mississippi Center, set out to determine the link between obesity and hypertension and to determine the effects of weight loss in hypertensive individuals. An analysis of the relationship between body mass index and diastolic blood pressure for another study showed that increasing body mass indices were associated with increases in blood pressure. This indicates that not only is there a strong relationship between obesity and hypertension, but that there is also a close association between the continuous variables of body mass index and blood pressure. The purpose of the present study was to determine the effectiveness of a weight loss regimen in reducing the amount of medication required to achieve the target blood pressure in 228 patients at the Jackson center. Subjects were randomized to a dietary intervention group or to a control group. Preliminary 3 month observational data showed that subjects who lost the appropriate amount of weight were three times more likely to achieve their target blood pressure at 3 months. These observations suggest that weight reduction regimens can reduce elevated blood pressure and can probably promote further blood pressure reductions when combined with drug therapy in the treatment of hypertension.

Computerized Wisconsin Card Sorting Test: comparison with manual administration

Computer-based testing in neuropsychology potentially offers important advantages. These include improvement in reliability and more efficient use of resources. For tests such as the Wisconsin Card Sorting Test (WCST) in which examiners must provide on-going feedback to subjects, reliability may be decreased by variability and errors in test presentation, errors in response recording and feedback, and errors in scoring. In addition, an important aspects of neuropsychological assessment is qualitative, that is, observations of the processes by which the subject responds to the test situation. The mechanics of administering the WCST hinder the examiner from allocating attention for observing these processes. Accordingly, we have automated both the administration and the scoring of the WCST. Although potential benefits of computerizing the WCST seem likely, it is possible that factors which cannot at present be duplicated by a computer may effect performance. This study compared performance between the standard manual Heaton version of the WCST and the computerized version. In a group of 33 normal and psychiatric subjects, there were significant differences in the number of Errors and the number of Correct responses, but no significant differences in performance were found for Perseverative Responses, Perseverative Errors, and Set Breaks. The mean number of Categories achieved was 2.0 for the computer administered version and 2.4 for the manual version: this difference was only marginally significant (p = 0.065). The computerized form of the WCST appears to yield similar quantitative results on scores which are most specifically affected by brain injuries in testing with the manual form. Lower variance was seen in the computer scores. This result is consistent with more reliable administration and accuracy in data acquisition and scoring in the computer version. The results overall indicate that the computer version is not a substitute for a human examiner, rather, the computer can function as a reliable partner, carrying out the mechanics of test presentation and scoring, freeing the examiner to more fully support the subject in taking the test and to observe the non-quantitative aspects of test performance.

Effect of ranitidine on theophylline metabolism in healthy Koreans living in China

OBJECTIVE

To evaluate the effect of concurrent ranitidine therapy on theophylline metabolism in healthy Koreans.

DESIGN

A 4-week, double-blind, randomized, placebo-controlled, crossover study.

SETTING

The Clinical Research Unit, Department of Pharmaceutical Sciences, Yanbian Medical College, Yanji, China.

SUBJECTS

Six young, healthy, nonsmoking Korean volunteers residing in China with no known factors that would alter theophylline metabolism.

INTERVENTIONS

Subjects received extended-release oral theophylline at a constant dosage over 4 weeks to yield a serum concentration (Cp) between 5 and 10 micrograms/mL. Week 1 was the dosage titration phase. During week 2 subjects randomly received either ranitidine or a matching placebo. Week 3 was a washout phase, and during week 4 subjects were crossed over to receive either placebo or ranitidine. At the end of each treatment week, serum and urinary metabolite concentrations were measured.

OUTCOME MEASURES

Theophylline serum concentrations and urinary concentrations of 1-methylxanthine, 1-methyluric acid, 3-methylxanthine, and 1,3-dimethyluric acid were measured. Estimates of clearance (Cl), volume of distribution (Vd), and half-life (t1/2) were determined.

RESULTS

Concurrent administration of ranitidine with theophylline did not significantly alter theophylline Cp, Cl, Vd, or t1/2. Urinary concentrations of major theophylline metabolites also were not changed.

CONCLUSIONS

Ranitidine does not significantly alter the metabolism of theophylline in healthy Koreans residing in China.

Cardiovascular effects of cocaine in neonates exposed prenatally

This blinded cross-sectional study was to determine whether chronic cocaine exposure in utero produces abnormalities in left ventricular function (shortening fraction), heart rate, rhythm, and conduction in term neonates. Three groups of neonates were evaluated by two-dimensional echo Doppler and 24 hour Holter monitor, with studies initiated in the first 24 hours of life. Group A (n = 32) neonates had a positive history of chronic maternal cocaine use in pregnancy (MCU+) and a positive neonatal urine cocaine test (NUC+). Group B (n = 23) neonates were MCU+ but NUC-. Group C (n = 32) neonates were MCU- and NUC-. Measured parameters were compared statistically by analysis of variance. p < 0.05 was regarded as significant. Echocardiography showed no significant difference between groups A, B, and C for left ventricular shortening fraction. Holter monitor likewise revealed no significant difference between groups in minimal, maximal, and average heart rate, or in the incidence of supraventricular and ventricular arrhythmias greater than 20 beats/h in the 24-hour period. None of the patients had atrioventricular or bundle branch block. It is possible that the developmental state of the newborn heart makes it less responsive to the adverse effects of cocaine.

Superior temporal gyrus volume in schizophrenia: a study using MRI morphometry assisted by surface rendering

OBJECTIVE

Interpretation of the literature concerning superior temporal gyrus volume in patients with schizophrenia is complicated by methodological variation between studies and by the difficulty of identifying gyral boundaries in serial sections.

METHOD

With the aid of three-dimensional cortical renderings, the authors developed a morphometric approach in which information from the cortical surface is incorporated into gyral boundary decisions. Using this technique, they assessed superior temporal gyrus volume in young, right-handed male patients with schizophrenia and in right-handed male comparison subjects. They also compared their technique with existing slice-based morphometric methods by using previously reported subcortical landmarks to define the gyral boundaries.

RESULTS

There was no significant main effect of diagnosis and no significant diagnosis-by-hemisphere interaction. Significant leftward laterality was present only among comparison subjects. Leftward superior temporal gyrus laterality did not correlate with leftward laterality of the planum temporale. No significant reduction in superior temporal gyrus volume was revealed in the patients. No significant leftward laterality was detected with the slice-based technique, suggesting that a significant portion of superior temporal gyrus tissue is omitted with this approach. The lack of findings could not be explained by a general absence of morphometric abnormalities in this group of subjects because the patients had significantly larger lateral ventricles.

CONCLUSIONS

Significant reduction in the superior temporal gyrus volume was not confirmed in this group of patients with schizophrenia, probably because of the small effect size of this finding. Methodological variation is an important factor in determining superior temporal gyrus volume on magnetic resonance imaging scans.

Characterization of experimental composite biomaterials

A comparison was made among the elastic moduli of various combinations of dimethacrylates that may be used as matrix resins in dental restorative composite biomaterials systems. Two ceramic filler materials with contrasting shape and size were synthesized by wet chemistry; these were used to produce a range of experimental composite systems. Dynamic elastic moduli determinations were used to study the influence of filler volume, filler size/shape, use of silane coupling agents, and storage in water. The filler was varied from 0 to 59% by volume for filler A and from 0 to 48% volume for filler B. Silane treatment was found to have a significant effect on modulus. Moduli for composite materials containing silane-treated filler were higher compared to materials containing the same volume loading of non-silane-treated filler. Using a light curing resin as a matrix gave a significantly higher modulus for a filler loading of 38% by volume. Storage in water for 29 days was found to have only a slight effect on moduli for composite systems containing in excess of 20% by volume of filler. The experimental composite systems produced slightly higher values for moduli than were predicted by the theoretical Reuse constant stress model.

Hypertension in East Asia

Asians comprise the largest single ethnic group in the world and the fastest growing minority ethnic group within the United States. The prevalence of hypertension in most Asian groups is similar to that of non-Asians. The associations with hypertension are similar to those seen in Western populations. Body mass index is a surprisingly strong predictor of blood pressure, even in very lean Asian populations. Studies in Asian groups suggest that the prevalence of target organ disease as related to hypertension are dependent on other cardiovascular disease risk factors. Stroke is more common than heart disease in Asia. Hypertension treatment data in East Asia is sparse, and treatment methods vary widely. Hypertension control among the world's largest ethnic group remains a challenge.

Differential cholinergic regulation in Alzheimer's patients compared to controls following chronic blockade with scopolamine: a SPECT study

The effects of low-dose chronic scopolamine on measures of cerebral perfusion and muscarinic receptors were tested in eight Alzheimer's disease (AD) subjects and eight elderly controls. Single photon emission computed tomography (SPECT) scans using technetium-labelled hexamethypropylene amine oxide (99mTc-HMPAO) to measure cerebral perfusion before and after chronic scopolamine revealed a significant 12% increase in the normal controls (P < 0.01) while the AD subjects showed no significant change. In contrast, the controls showed decreased muscarinic binding as evidenced by 123I-quinuclidinyl-4-iodobenzilate (123I-QNB) labelling after chronic drug (-10%, P < 0.01) whereas the AD subjects showed increased 123I-QNB labelling (+8%, P < 0.05). The difference between AD and control subjects was even more marked when the ratio of I-QNB to HMPAO uptake was compared, pointing to a double dissociation in the SPECT results. These data cannot be explained by group differences in cerebral perfusion alone and suggest a differential sensitivity between AD and elderly controls to chronic cholinergic blockade.

Lateralized differences in iodine-123-IBZM uptake in the basal ganglia in asymmetric Parkinson's disease

We used equilibrium analysis of SPECT data from patients with asymmetric Parkinson's disease to determine if lateralized differences in the striatal uptake of [123I]IBZM correlate with asymmetry in clinical findings and, by inference, with lateralized differences in the concentration of extracellular dopamine.

METHODS

Twelve patients with asymmetric clinical signs of idiopathic Parkinson's disease were injected with a bolus of [123I]IBZM, and multiple SPECT scans recorded the time course of radioligand uptake. The time integral method was used to estimate peak specific binding, so that a ratio of specific-to-nonspecific binding in the left and right striatum of each subject at equilibrium could be determined. Nine patients also had 99mTc-HMPAO SPECT scans which were examined for evidence of blood flow asymmetries.

RESULTS

Paired t-tests comparing [123I]IBZM uptake revealed significantly greater (mean = 7.3%) availability of dopamine-D2 receptors in the basal ganglia contralateral to maximal clinical signs. Differences in receptor availability correlated significantly with differences in every measure of the clinical assessment. No significant differences in regional cerebral blood flow between the two sides were observed with 99mTc-HMPAO.

CONCLUSION

These results demonstrate the ability of [123I]IBZM SPECT to reveal clinically meaningful variations in striatal dopamine receptor availability in patients with asymmetric Parkinson's disease. The equilibrium analysis technique used to determine these findings is a simple and robust method of measuring relative receptor availability and may be useful in studying other illnesses where dysfunction of dopaminergic neurotransmission is suspected.

Normal asymmetry of the planum temporale in patients with schizophrenia. Three-dimensional cortical morphometry with MRI

BACKGROUND

Abnormal cerebral anatomical lateralisation has been reported in schizophrenia and may implicate anomalous neurodevelopment in the aetiology of this disease. A popular recent hypothesis has predicted that such disturbances in normal lateralisation should be especially apparent in the morphology of the temporal lobes.

METHOD

A temporal cortical region lying in the plane of the Sylvian fissure--known as the planum temporale--exhibits pronounced leftward asymmetry in normal right-handed males. We compared lateralisation of the planum temporale in schizophrenic and control males using MRI surface-rendering morphometry of the supratemporal cortex.

RESULTS

Contrary to the lateralisation hypothesis, normal patterns of leftward planum asymmetry were detected in both the schizophrenic and control groups. Schizophrenics and controls also exhibited a predicted symmetry in the bilateral areas of Heschl's gyrus, a supratemporal cortical structure immediately anterior to the planum.

CONCLUSION

These data do not support the notion that neurodevelopmental mechanisms of cerebral asymmetry are abnormal in schizophrenia.

Body mass index and blood pressure in Korean men and women: the Korean National Blood Pressure Survey

AIMS AND METHODS

The association between body mass index (BMI) and blood pressure is well known in relatively obese populations. The purpose of the present study was to investigate the relationship between BMI and blood pressure in a lean population. Through cluster sampling, individuals aged > 30 years in 190 out of 154,082 districts were selected for study. Among 25,567 eligible individuals, measurements of blood pressure and BMI were made in 22,354.

RESULTS

The BMI for males was 22.8 +/- 2.7 kg/m2 and for females was 23.4 +/- 3.2 kg/m2 (means +/- SD). Over a BMI range from 16 to 31 kg/m2 the relationships between BMI and systolic and diastolic blood pressure were almost linear. Over the BMI range 25-31 kg/m2 (overweight-to-obese) each BMI unit was associated with a difference of 1.0 mmHg in diastolic blood pressure. Over the BMI range 16-25 kg/m2 (normal-to-lean) each BMI unit was associated with a difference of 0.89 mmHg in diastolic blood pressure.

CONCLUSION

We conclude that a strong association between BMI and blood pressure exists for lean as well as for obese subjects.

Mercury vapour suppression by various liquid media

Fresh and used photographic fixer, Merconvap and water were evaluated for their ability to suppress the vapourization of mercury. Mercury vapour concentration above the four test storage liquids was measured at various times between 10 min and 335 days, using a mercury vapour measuring instrument. The data were analysed using a Student-Newman-Keuls multiple comparison test (P = 0.05). The results showed that fresh and used fixer and Merconvap suppressed the vapourization of mercury to below the detection limit of the measuring instrument (0.01 mg/m3). Water was much less effective compared with the other liquids and showed an increase in mercury vapour concentration with log t.

Lack of effect of hydrocholorthiazide on total cholesterol

To determine the effect of hydrochlorothiazide on total cholesterol, baseline total cholesterol and blood pressure were determined in 618 hypertensive subjects in a hypertension clinic in Pusan, Korea. After 12-24 months (mean follow-up time 14 months), total cholesterol and blood pressure measurements were repeated. In the group whose therapy included hydrochlorothiazide (n = 436), total cholesterol fell by 8 +/- 39 mg/dL. Those not treated with a diuretic (n = 182) had an identical fall in total cholesterol of 8 +/- 42 mg/dL (P < 0.001 for change from baseline). Patients with a baseline total cholesterol > 200 mg/dL were asked to reduce intake of saturated fat. Change in total cholesterol for 180 patients on this diet and hydrochlorothiazide was -24 +/- 31 mg/dL (P < 0.0001); for 71 patients on the diet and non-diuretic therapy, change was -22 +/- 35 mg/dL (P < 0.0001). There was no change in total cholesterol in either drug group for those with a baseline value < or = 200 mg/dL. It is concluded that in this group of Korean patients on a relatively low-fat diet, a low dose of hydrochlorothiazide had no adverse effect on total cholesterol at 14 months, and hydrochlorothiazide nor other agents prevented a beneficial effect of further reduction of saturated fat on total cholesterol.

Hypertension in Korea: a national survey

To determine the prevalence of hypertension (HTN) and its risk factors, we performed a population-based national cross-sectional blood pressure (BP) survey in Korea in 1990. Through cluster sampling, we selected for study individuals older than 30 years of age in 190 of 154,082 districts. Among 25,567 eligible individuals, 21,242 subjects had measurements of BP and body mass index (BMI) and underwent a standard interview. BP was recorded as the mean of two measurements on a standard mercury manometer. The prevalence of HTN varied widely by area of residence. Overall prevalence was 19.8% for HTN defined as BP > or = 140/90 mm Hg or subject on medication, and 12.4% for BP > or = 160/95 mm Hg or subject on medication. Correlates for HTN identified by logistic regression analysis included positive family history of HTN (odds ratio [OR] = 2.2,), age (10 years); OR = 1.9), alcohol intake (500 cc; OR = 1.4), urban location (versus rural; OR = 1.3), and BMI (1 BMI unit; OR = 1.2). [Am J Prev Med 1994;10:200-4]

Bioavailability of digoxin tablets in healthy volunteers

The bioavailability of digoxin generic tablets manufactured in Korea (formulations A & B) were compared to a standard (formulation C; Lanoxin brand digoxin, Burroughs Wellcome, USA) in 12 healthy Korean male volunteers (mean age 31.4 years) in a single dose, randomized, complete block crossover study. Using a Latin square design, each of the subjects was randomized to the order number and allocated to each of the three treatments of 0.5 mg oral digoxin. Digoxin concentrations in serum and urine samples collected for 48 hours after dosing were measured by fluorescence polarization immunoassay and radioimmunoassay, respectively. Treatments were compared by using nonlinear least squares regression analysis to evaluate the following pharmacokinetic parameters: maximum serum concentration (Cmax); time of maximum serum concentration (Tmax); area under the serum concentration-time curve for 0-12 hours (AUC0-12); and cummulative urinary excretion for 0-48 hours (CUE0-48). Mean AUC0-12, Cmax, and CUE0-48 values for formulations B and C were significantly different from formulation A (p < 0.001), but not significantly different from each other. Based on AUC0-12 and CUE0-48, respectively, the relative availability of formulation B was 87.5% and 89.6% and the relative availability of formulation A was 43% and 35% when compared to formulation C (the standard).

Theophylline disposition in Korean patients with congestive heart failure

OBJECTIVE

This study proposed to determine the systemic disposition of theophylline in Korean adult patients during decompensated congestive heart failure compared with disposition after recovery.

DESIGN

An experimental, prospective, self-controlled, nonrandomized design was used.

SETTING

The study was performed in a general community hospital located in Pusan, Korea.

PATIENTS

Eight nonsmoking elderly Korean patients with decompensated congestive heart failure presenting to the emergency department were included in the study. Consecutive patients who met entrance criteria were selected. All patients completed the study.

INTERVENTIONS

A single dose of aminophylline 6 mg/kg was administered by intravenous infusion over 30 minutes. Standard methods of congestive heart failure therapy were used in each patient, including bed rest, restriction of sodium, and drug therapy including digoxin. After compensation of congestive heart failure was achieved, the theophylline infusion was repeated.

OUTCOME MEASURES

Serum theophylline concentrations were measured at 2, 6, 12, and 18 hours after completion of the dose at baseline and following treatment.

RESULTS

A clinically and statistically significant improvement in mean theophylline total body clearance was demonstrated following treatment (from 21.7 +/- 2.8 to 43.4 +/- 4.7 mL/kg/h [mean +/- SEM]; p < 0.01). Comparison of these results with a computer model based on literature averages of peoples of all nationalities showed significant underprediction of theophylline clearance both before (p < 0.05) and after (p < 0.01) treatment. The theophylline elimination half-life prior to treatment was 18.2 +/- 2.2 hours and decreased to 9.1 +/- 0.8 hours following treatment (p < 0.01). There was no statistical difference between the computer-model predicted initial theophylline half-life and the measured value, but the model significantly underpredicted the improvement following treatment.

CONCLUSIONS

The improvement in theophylline clearance demonstrated in this study appears to be greater than that reported for Western patients. This has practical application to the calculation of appropriate theophylline maintenance dosage regimens in Korean patients with cardiac failure. These data support the need for consideration of racial differences in individualizing dosage regimens. We suggest that all kinetic models, whether software supported or not, should consider incorporating ethnic origin as a demographic factor that helps select the proper model for individual patients.

Gender differences in the normal lateralization of the supratemporal cortex: MRI surface-rendering morphometry of Heschl's gyrus and the planum temporale

Gender differences in hemispheric asymmetry for language functioning have been reported in the neuropsychological literature. Despite numerous reports of anatomic asymmetries in corresponding cortical regions, the possibility of gender dimorphism in the putative neuroanatomical substrate of language has not been systematically examined in vivo. We assessed asymmetry of the planum temporale (PT), a supratemporal region of auditory association cortex, in 12 normal, right-handed females and 12 age-matched right-handed males with the aid of MRI surface-rendering morphometry. Bilateral areas were also assessed for Heschl's gyrus (HG), a supratemporal region of primary auditory cortex where no asymmetry was anticipated. We found a significant interaction between gender and hemisphere for the PT, with males having significantly larger left versus right PTs. Left-right differences in PT area were not significant among females (10 of 12 males showed leftward lateralization of the PT, vs 5 of 12 females). No main effect of gender was found for total (left + right) PT area, and no asymmetries or gender effects were detected for HG. This finding of gender dimorphism in PT area is consistent with evidence for reduced asymmetry among females in the lateralization of language functions attributable to the supratemporal cortex. The implications for theories about interactions between sex hormones and the development of brain asymmetries are discussed.