Should factor XII assays be included in thrombophilia screening?
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Disease Susceptibility↗
Biomedical subjects
D W Jones
Publications and source records attributed to D W Jones.
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.
Adult↗
Lateralized differences in iodine-123-IBZM uptake in the basal ganglia in asymmetric Parkinson's disease.
UNLABELLED: 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.
Adult↗
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.
Adult↗
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.
Copper↗
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.
Adult↗
Sylvian fissure asymmetries in monozygotic twins: a test of laterality in schizophrenia.
To address prior reports that schizophrenia is associated with loss of normal brain asymmetry and that it might be linked to a defect of a gene controlling cerebral lateralization, we measured on three-dimensional cortical renderings from magnetic resonance imaging (MRI) scans the lengths and angles of the sylvian fissures in 10 normal monozygotic (MZ) twin pairs (n = 10 pairs) and in 10 MZ pairs discordant for schizophrenia (n = 10 pairs). We confirmed in both sets of twins the expected normal asymmetries of length and angle of the sylvian fissure. We also confirmed that the length asymmetry occurs solely in the region of the planum temporale. In the discordant twins, affected and unaffected twins did not differ in asymmetry measures, thus failing to support an association between illness per se and diminished asymmetry. Moreover, the discordant twins as a group did not differ from the normal twins as a group, thus failing to confirm the hypothesis of a genetic association with abnormal asymmetry. The implications of variations in methodology and patient samples are discussed.
Adult↗
Effects of doxazosin and hydrochlorothiazide on lipid levels in Korean patients with essential hypertension.
Because none of the major studies used to document adverse or beneficial metabolic effects of antihypertensive drugs were made of non-Western patients with a non-Western diet, we compared doxazosin and hydrochlorothiazide in Korean patients receiving a Korean diet to determine if one regimen is superior to the other in terms of efficacy, adverse metabolic effects, or both. The randomized, double-blind, parallel study of Korean hypertensive patients compared the effects of oral doxazosin (mean +/- SD dose, 10.3 +/- 6.3 mg/day) and oral hydrochlorothiazide (44.0 + 11.0 mg/day) on blood pressure (BP) and lipid metabolism. The results of 48 patients treated for 20 weeks are reported here. Systolic (p < 0.001) and diastolic (p < 0.001) BP (SBP, DBP) were significantly lower in both groups at the end of the treatment period. Doxazosin significantly increased high-density-lipoprotein (HDL) cholesterol from a baseline of 1.10 +/- 0.31 to 1.27 +/- 0.30 mM (p < 0.05) and HDL/total cholesterol from 0.25 +/- 0.1 to 0.28 +/- 0.1 mM (p < 0.01). Hydrochlorothiazide significantly increased triglyceride from a baseline of 1.63 +/- 0.71 to 2.02 +/- 0.87 mM (p < 0.05). In contrast to Western studies, hydrochlorothiazide demonstrated no adverse effect on total, low-density-lipoprotein (LDL), or HDL cholesterol, or on HDL/total cholesterol. Indeed, HDL cholesterol was increased by 0.16 mM (p < 0.01). As in Western patients, doxazosin is effective for treatment of essential hypertension in Koreans and has no adverse effects but some beneficial effects on lipids.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
The usefulness of echocardiography in the surgical management of infants with congenital heart disease.
Between January 1988 and August 1991, at The Children's Heart Center, Atlanta, 83 infants with congenital heart defects were diagnosed by echocardiography and underwent surgery without cardiac catheterization. The diagnostic categories included 46 infants with left heart obstructive lesions, 19 infants with cyanotic heart lesions, and 18 infants with miscellaneous lesions. Forty-five infants (55%) underwent surgery under cardiopulmonary bypass. There were three errors in diagnosis, yielding a diagnostic accuracy of 95%. Many infants with congenital heart disease can be accurately and completely diagnosed by echocardiography and can safely undergo surgery without cardiac catheterization.
Aortic Coarctation↗
Anatomical abnormalities in the brains of monozygotic twins discordant and concordant for schizophrenia.
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Brain↗
In vivo imaging of cerebral muscarinic receptors with I-123 QNB and SPECT: studies in normal subjects and patients with dementia.
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Alzheimer Disease↗
A comparison of xenon-133 and xenon-127 for the determination of regional cerebral blood flow measured by dynamic SPECT.
Phantom studies and cerebral blood flow (CBF) measurements in 11 normal subjects at rest were performed by single photon emission tomography (SPECT) with Xe-133 (16 mm full-width at half-maximum [FWHM] collimation) and Xe-127 (16 mm, 12 mm, and 9 mm FWHM collimation). The phantom results clearly illustrated the feasibility of Xe-127 studies and the advantage of Xe-127 over Xe-133 for equivalent patient dose exposures. CBF values obtained with Xe-127 were comparable to those of Xe-133 for the 16 mm collimator, although higher flow values were found with the better resolution, probably because of reduced partial volume effects. The correlations between the various groups of examinations were high, except for the Xe-133 and Xe-127 16 mm collimator groups. Xe-127 allows a considerable increase in the resolution of the images, while exposing the patient to a lower radiation dose. Potential limitations because of higher energy penetrating photons from Xe-127 were not observed in this specially shielded equipment.
Adolescent↗
Effect of phenylpropanolamine hydrochloride on blood pressure in Korean patients with hypertension controlled by hydrochlorothiazide.
The effect of 10 oral doses of phenylpropanolamine hydrochloride 25 mg four times a day on blood pressure and heart rate in Korean patients with hypertension controlled by hydrochlorothiazide was studied. A randomized, placebo-controlled, crossover, double-blind study design was used. Twenty Korean patients with mild hypertension controlled by hydrochlorothiazide were recruited from an ambulatory-care clinic. Blood pressure and heart rate were measured in triplicate before treatment, after a five-day washout period between phases of treatment, and two hours after the last dose in each phase of treatment. Eighteen patients completed both phases of treatment, and one patient completed only the placebo phase. Mean baseline values for systolic and diastolic blood pressures and heart rate before the placebo phase did not significantly differ from mean baseline values before the phenylpropanolamine phase. Comparison of mean baseline values for systolic and diastolic blood pressures and heart rate with mean after-treatment values showed no clinically relevant or statistically significant changes for the 19 patients who completed the placebo phase or the 18 patients who completed the phenylpropanolamine phase. There was no significant difference between the mean change in systolic blood pressure, diastolic blood pressure, or heart rate when the phenylpropanolamine phase was compared with the placebo phase. Phenylpropanolamine hydrochloride 25 mg p.o. four times a day (total, 10 doses) given to Korean patients with hypertension controlled by hydrochlorothiazide did not affect blood pressure or heart rate according to single-point outcome measurements.
Administration, Oral↗
Captopril versus captopril plus hydrochlorothiazide for essential hypertension in Koreans.
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Antihypertensive Agents↗
The distribution of cerebral muscarinic acetylcholine receptors in vivo in patients with dementia. A controlled study with 123IQNB and single photon emission computed tomography.
A high-affinity muscarinic receptor antagonist, 123IQNB (3-quinuclidinyl-4-iodobenzilate labeled with iodine 123), was used with single photon emission computed tomography to image muscarinic acetylcholine receptors in 14 patients with dementia and in 11 healthy controls. High-resolution single photon emission computed tomographic scanning was performed 21 hours after the intravenous administration of approximately 5 mCi of IQNB. In normal subjects, the images of retained ligand showed a consistent regional pattern that correlated with postmortem studies of the relative distribution of muscarinic receptors in the normal human brain, having high radioactivity counts in the basal ganglia, occipital cortex, and insular cortex, low counts in the thalamus, and virtually no counts in the cerebellum. Eight of 12 patients with a clinical diagnosis of Alzheimer's disease had obvious focal cortical defects in either frontal or posterior temporal cortex. Both patients with a clinical diagnosis of Pick's disease had obvious frontal and anterior temporal defects. A region of interest statistical analysis of relative regional activity revealed a significant reduction bilaterally in the posterior temporal cortex of the patients with Alzheimer's disease compared with controls. This study demonstrates the practicability of acetylcholine receptor imaging with 123IQNB and single photon emission computed tomography. The data suggest that focal abnormalities in muscarinic binding in vivo may characterize some patients with Alzheimer's disease and Pick's disease, but further studies are needed to address questions about partial volume artifacts and receptor quantification.
Adult↗
Clinical implications of resilient denture lining material research. Part II: Gelation and flow properties of tissue conditioners.
The clinical effectiveness of tissue conditioners and functional impression materials is influenced by their gelation and flow properties. Laboratory tests were previously conducted that simulated the conditions of clinical use to the extent possible on six commercial intraoral-gelling resilient denture liners. The liners were found to vary significantly in their gelation times and to flow throughout the 7-day study. Their initial flow after mixing was influenced most by the time of loading. While extrapolations to the clinical environment require caution, the results of this study imply that the dentist should (1) adapt clinical techniques to the gelation times of particular materials, (2) reduce the initial flow of some materials by delaying denture placement on the supporting mucosa, and (3) expect the materials to be effective tissue conditioners for at least 7 days.
Acrylic Resins↗
In vivo fungal presence and growth on two resilient denture liners.
To determine whether two intraoral-setting resilient denture liners supported the in vivo presence or growth of oral commensal fungi, the liners were randomly placed in the mandibular complete dentures of 14 patients. Cytologic smears were made from the liner surfaces at 1 hour and 1, 2, 7, 14 and 30 days after intraoral placement. Yeast forms were observed in six patient trials of material A and in two trials of material B. Hyphae were observed in only one patient trial of material A and in two trials of material B. When yeast forms and hyphae findings were combined and were considered as indicative of fungal presence or growth, the prevalence up to 30 days was seven for material A and four for material B. Statistical analysis revealed no significant difference in the prevalence of fungal presence or growth between the two resilient denture liners tested.
Acrylic Resins↗
Gel strength and rate of gelation of soft polymers.
A rheometer was used to characterize the gelation rate of six commercial short- to medium-term (chairside intra-oral gelation) denture soft-lining materials. Shear puncture force was measured from one to 60 days for six short- to medium-term materials as well as for three heat-cured (polymerizable) materials. The observed increase in puncture force with age of the specimen was considered to be a function of increased polymer chain entanglement and/or loss of plasticizer. Reduction in puncture force with age occurred for some materials as a result of hydration of the polymer gel. Rheometer setting time (gelation rate) and puncture force values for the intra-oral gelation materials were influenced by the quantity of ethyl alcohol present in the mixing liquid. In general, the higher the level of ethyl alcohol, the shorter the gelation time and the stronger the gel. The characterization of the properties may help develop improved prosthodontic treatment procedures, and allow better management of soft-tissue recovery following trauma.
Denture Liners↗