Distribution and cardiovascular risk correlates of hemoglobin A(1c) in nondiabetic younger adults: the Bogalusa Heart Study

Excess glycated hemoglobin (HbA(1c)), an indicator of long-term glucose homeostasis, is recognized as a risk factor for cardiovascular (CV) disease and mortality even among persons without diabetes. However, information is scant regarding its distribution and correlates of CV risk in nondiabetic younger adults. This aspect was examined in a biracial (black-white) community-based sample of 1111 younger adults (mean age: 36.2 years; 71% white, 43% male) enrolled in the Bogalusa Heart Study. Blacks vs whites and women vs men had higher HbA(1c) values (P < .0001). In bivariate analysis adjusted for age, race, sex, and smoking status, significant adverse trends were noted for body mass index, waist circumference, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol (HDL-C), total cholesterol to HDL-C ratio, insulin, glucose, and homeostasis model assessment of insulin resistance across HbA(1c) quartiles; trends were not significant for mean arterial blood pressure, triglycerides, C-reactive protein, adiponectin, and estimated glomerular filtration rate. In multivariate analysis, besides race and sex, total cholesterol to HDL-C ratio and waist circumference were independent correlates of HbA(1c). Furthermore, the prevalence of excess (top decile) HbA(1c) was 1.6-fold (P < .05) higher among those with metabolic syndrome defined by the National Cholesterol Education Program Adult Treatment Panel III and 2.1-fold (P < .01) and 1.5-fold (P < .05) higher, respectively, among those with positive parental history of CV disease and type 2 diabetes mellitus. These findings underscore the potential value of HbA(1c) in risk assessments of CV disease and type 2 diabetes mellitus in nondiabetic, apparently "healthy" younger adults.

Microfluidic approach for rapid interfacial tension measurement

A novel microfluidic approach to measure interfacial tension of immiscible fluids rapidly is reported. This method rests upon quantitative force balance analysis of drop formation dynamics in a coaxial microfluidic device. The values of interfacial tension for several two liquids without/with surfactants are measured. These measurements compare well with those measured by the commercial interfacial tensiometry. The viscosity of water phase fluid can also be accurately measured in the same microfluidic device. Several model systems with interfacial tension from 1.0 to 10.0 mN/m and water phase viscosity from 1.0 to 10.0 mPa.s are tested in this work.

Changes in risk variables of metabolic syndrome since childhood in pre-diabetic and type 2 diabetic subjects: the Bogalusa Heart Study

OBJECTIVE

That type 2 diabetes is associated with the metabolic syndrome is known. However, information is lacking regarding the long-term and adverse changes of metabolic syndrome variables in the development of type 2 diabetes from childhood to adulthood.

RESEARCH DESIGN AND METHODS

Observations were examined, retrospectively, in a community-based cohort of normoglycemic (n = 1,838), pre-diabetic (n = 90), and type 2 diabetic (n = 60) subjects followed serially for cardiovascular risk factors during childhood (4-11 years), adolescence (12-18 years), and adulthood (19-44 years).

RESULTS

Diabetic subjects versus normoglycemic subjects had significantly higher levels of subscapular skinfold, BMI, triglycerides, glucose, insulin, and homeostasis model assessment of insulin resistance and lower levels of HDL cholesterol beginning in childhood and higher levels of mean arterial pressure (MAP) in adolescence and adulthood. In a multivariate model including BMI, MAP, HDL cholesterol, LDL cholesterol, triglycerides, glucose, and insulin, adjusted for age, age(2), race, sex, and race x sex interaction, adverse changes in glucose and LDL cholesterol were independently associated with pre-diabetic subjects, whereas adverse changes in BMI, glucose, and HDL cholesterol were associated with diabetic subjects. As young adults, pre-diabetic and diabetic groups displayed a significantly higher prevalence of obesity, hypertension, dyslipidemia, hyperinsulinemia, and metabolic syndrome.

CONCLUSIONS

These findings indicate that adverse levels of risk variables of metabolic syndrome, adiposity, and measures of glucose homeostasis accelerating since childhood characterize the early natural history of type 2 diabetes and underscore the importance of early prevention and intervention on risk factors beginning in childhood.

Linguiform rotation flap for amputations of the fingertip

The aim of all treatments for fingertip amputation is to reconstruct the defects and meet the patient's needs. Sometimes an easy and versatile one-step procedure is needed. Between July 2005 and June 2006, 23 patients with amputated fingertips were treated with the linguiform rotation flap. It is a rotation advancement flap with the pedicle and a skin bridge usually on the volar side near the margin of the stump, and is based on one of the neurovascular bundles, the dorsal branches of the palmar digital arteries, the dorsal digital arteries, and the network among them. The follow-up period was 3 months to 1.5 years (mean 7.5 months), with relatively good results. The linguiform flap can be used for amputations at any level from the nailfold to the proximal interphalangeal joint to cover the exposed bone and tendon. The technique is simple and safe, and provides good protective padding. It is a good alternative for the reconstruction of fingertip amputations, particularly transverse, dorsal, and lateral oblique ones.

The profile of gene expression and role of nuclear factor kappa B on glomerular injury in rats with Thy-1 nephritis

Mesangioproliferative glomerulonephritis (MsPGN) is a disease of high incidence in humans. Rats with Thy-1 nephritis (Thy-1 N) are used as an animal model for studying MsPGN. Although several studies have demonstrated that many pathological factors could cause the injury of glomerular mesangial cells (GMCs) in Thy-1 N, changes of profile and the molecular mechanism of the disease (i.e. the role of transcription factors) at intervals remain unclear. The purpose of this study was to identify the changes in gene expression profile and to observe the role of nuclear factor kappa B (NF-kappaB) on the pathological change of renal tissue in Thy-1 N rats. Our results showed that the pathological changes of GMCs in Thy-1 N included three phases: apoptosis (40 min), necrosis (24 h) and proliferation (7 days). Concomitantly, at 40 min and on day 7, the up-regulation of 341 genes and 250 genes were observed, while 392 genes and 119 genes were down-regulated in Thy-1 N. Expression of interleukin (IL)-1beta, IL-6, proliferating cell nuclear antigen, alpha-smooth muscle actin, collagen type IV and excretion of urinary protein was increased in rats with Thy-1 N and decreased in pyrrolidine dithiocarbamate-treated rats with Thy-1 N. These data indicated that the significant changes in the gene profile were coupled with the pathological changes of Thy-1 N, and activation of NF-kappaB may contribute to the pathogenesis of GMCs apoptosis, proliferation, extracelluar matrix accumulation and proteinuria in Thy-1 N.

Identification of a novel HLA-A allele, HLA-A*9216

The new human leukocyte antigen (HLA)-A*9216 differs from A*02010101 by a nonsynonymous nucleotide change at condon 76 (GTG>CTG).

Effects of hydrostatic pressure on microtubule organization and cell cycle in gynogenetically activated eggs of olive flounder (Paralichthys olivaceus)

Indirect immunofluorescence staining was used to detect cytological changes of isolated blastodisks during mitosis of flounder haploid eggs treated with hydrostatic pressure. Changes in microtubule structure and expected cleavage suppression were observed from blastodisk formation to the third cell cycle, with obvious differences between treated and control eggs. In most eggs, microtubules were disassembled and the nucleation capacity of the centrosome was temporarily inhibited after pressure treatment. Within 15-20 min after treatment, the nucleation capacity of the centrosome began to gradually recover, with slow regeneration of microtubules; approximately 25 min after treatment, the nucleation capacity of the centrosome recovered completely, regenerated distinct bipolar spindles, and the first mitosis ensued. During the second cell cycle, approximately 61% of the embryos were at the two-cell stage, with a monopolar spindle in each blastomere; that treatment was effective was based on second cleavage blockage. Approximately 15% of the eggs still remained at the one-cell stage and had a monopolar spindle (treatment was effective, according to the general model of first cleavage blockage). However, treatment was ineffective in approximately 15% of the embryos (bipolar spindle in each blastomeres) and in another 8% (bipolar spindle in one of the two blastomeres and a monopolar spindle in the other; both mechanisms operating in different parts of the embryo). This is the first report elucidating mitotic gynogenetic diploid induction by hydrostatic pressure in marine fishes and provides a cytological basis for developing an efficient method of inducing mitotic gynogenesis in olive flounder.

Utility of non-high-density lipoprotein cholesterol versus other lipoprotein measures in detecting subclinical atherosclerosis in young adults (The Bogalusa Heart Study)

Direct comparative data on the utility of non-high-density lipoprotein (HDL) cholesterol versus low-density lipoprotein cholesterol, HDL cholesterol, triglycerides, apolipoprotein (apo) B, apo A-I, ratio to total cholesterol to HDL cholesterol, and ratio of apo B to apo A-I in detecting increased carotid intima-media thickness (IMT), a validated measurement of subclinical atherosclerosis, in asymptomatic younger adults are scant. This aspect was examined in 1,203 black and white subjects (71% white, 43% men) 24 to 43 years of age. In multivariate logistic regression analysis of each lipoprotein measurement (top quartile vs lower 3 quartiles specific for age, race, and gender) for detecting increased carotid IMT (top decile vs lower 9 deciles specific for age, race, and gender), only non-HDL cholesterol, total cholesterol/HDL cholesterol, and apo B emerged as significant correlates with respective odds ratios of 1.75 (95% confidence interval [CI] 1.10 to 2.78), 2.02 (95% CI 1.27 to 3.19), and 2.13 (95% CI 1.38 3.29), after adjusting for body mass index, systolic blood pressure, and other lipoprotein measurements. Regarding discriminating values of different lipoprotein measurements in detecting increased carotid IMT, area (c-value) under the receiver operating characteristic curve analysis for each lipoprotein measurement adjusted for age, race, gender, body mass index, and systolic blood pressure indicated that the c-value for non-HDL cholesterol (0.73) was similar to those for low-density lipoprotein cholesterol (0.76), total cholesterol/HDL cholesterol (0.72), apo B/apo A-I (0.71), and HDL cholesterol (0.70), but significantly (p <0.001) higher than that for apo A-I (0.69), triglycerides (0.64), and apo B (0.64). In conclusion, non-HDL cholesterol is as good as or better than other widely recommended lipoprotein measurements in the identification of subclinical atherosclerosis in young adults.

Persistent elevation of liver function enzymes within the reference range is associated with increased cardiovascular risk in young adults: the Bogalusa Heart Study

Elevations in alanine aminotransferase (ALT) and gamma-glutamyl transferase (GGT), markers of liver dysfunction and nonalcoholic fatty liver, are considered as part of the metabolic syndrome and related diseases. However, information is limited regarding the persistence (tracking) in levels of these enzymes over time and their influence on cardiovascular (CV) risk in young adults. The study sample consisted of white and black subjects (N = 489, 40% male, 73% white; baseline age, 18-32 years) followed over a period of 12 years as part of the Bogalusa Heart Study, with repeat measurements of CV risk factor variables and liver enzymes. Both at baseline and follow-up, males vs females had higher ALT (P < .01 to .0001) and GGT (P < .0001); blacks vs whites had higher GGT (P < .0001). With respect to persistence in enzyme levels over time, of those individuals who had ALT and GGT at the top quintile specific for age, race, and sex at baseline, about 50% of them continued to remain so with high values after 12 years. Individuals with levels persistently in the highest quintile vs those in the lowest quintile showed higher (P < .0001) body mass index, waist circumference, triglycerides, low-density lipoprotein cholesterol, glucose, insulin, insulin resistance index, and systolic and diastolic blood pressures; lower (P < .0001) high-density lipoprotein cholesterol; and higher (P < .05 to .001) prevalence of obesity, hypertension, dyslipidemia, metabolic syndrome as defined by the National Cholesterol Education Program Adult Treatment Panel III, positive parental history of type 2 diabetes, and coronary heart disease. In addition, based on a multivariate analysis using 2 separate models for ALT and GGT, baseline levels of both enzymes were independent predictors of follow-up; insulin resistance index and baseline GGT were also predictive of follow-up systolic blood pressure. Elevations in liver enzymes ALT and GGT, within "reference" range, persist over time and relate to clinically relevant adverse CV risk profile in young adults.

Adiponectin and its correlates of cardiovascular risk in young adults: the Bogalusa Heart Study

Adiponectin, a novel adipocytokine produced exclusively in the adipose tissue, plays a major role in the development of metabolic syndrome, type 2 diabetes mellitus, and related cardiovascular (CV) diseases. However, information is scant regarding the association of adiponectin with measures of CV risk in young adults. This aspect was examined in a biracial (black-white) community-based sample of 1153 individuals (mean age, 36.2 years; 70% white, 43% male) who participated in the Bogalusa Heart Study. Adiponectin levels showed race (white > black, P < .0001) and sex (female > male, P < .0001) differences, and correlated significantly in a beneficial manner to measures of obesity (body mass index, waist circumference, and abdominal height), mean arterial blood pressure, lipoprotein variables (low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and triglycerides), measures of glucose homeostasis (insulin, glucose, homeostasis model assessment of insulin resistance [HOMA-IR]), and uric acid, after adjusting for age, race, sex, and cigarette smoking. In multivariate analysis that used either body mass index or abdominal height as a measure of general and visceral adiposity in 2 separate models, HOMA-IR was the major contributor explaining 18.4% and 18.1% of the variance, respectively. There was a significant interaction between abdominal height and HOMA-IR on adiponectin level in that the inverse association between adiponectin and insulin resistance was pronounced at higher level of visceral adiposity. Furthermore, adiponectin levels decreased with increasing number of metabolic syndrome risk factors defined by the National Cholesterol Education Program Adult Treatment Panel III (P for trend <.0001). Moreover, adiponectin levels were low among those with positive parental histories of coronary heart disease (P = .03), hypertension (P = .04), and type 2 diabetes mellitus (P = .01), considered as surrogate measures of risk. These findings, by showing an inverse association of adiponectin with insulin resistance, visceral adiposity, and related metabolic syndrome, and also with positive parental histories of coronary heart disease, hypertension, and type 2 diabetes mellitus, underscore the value of adiponectin in CV and type 2 diabetes mellitus risk assessments in young adults.

Controllable preparation of monodisperse O/W and W/O emulsions in the same microfluidic device

This letter presents a simple way to prepare monodisperse O/W and W/O emulsions in the same T-junction microfluidic device just by changing the wetting properties of the microchannel wall with different surfactants. Highly uniform droplets ranging from 50 to 400 mum with a polydispersity index (sigma) value of less than 2% were successfully prepared. With the change in surfactants and surfactant concentrations, the interfacial tension and the wetting properties varied, and disordered or ordered two-phase flow patterns could be controllable. Monodisperse O/W and W/O emulsions were prepared under the action of a cross-flowing shear force or a perpendicular shear force by using an oil solution with 0.1-2.0 wt % Span 80 and an aqueous solution with 0.1-2.0 wt % Tween 20 as a continuous-phase flow, respectively. It gives a controllable method of preparing O/W and W/O emulsions in the same microfluidic device.

Distribution and metabolic syndrome correlates of plasma C-reactive protein in biracial (black-white) younger adults: the Bogalusa Heart Study

The association between plasma C-reactive protein (CRP), a marker of systemic inflammation, and the metabolic syndrome is well recognized. However, information is scant regarding the component of metabolic syndrome that is critical in modulating CRP levels in younger adults. This aspect was examined in a biracial (black-white) community-based sample of 1083 younger adults (mean age, 36.1 years; 71% white, 45% male) enrolled in the Bogalusa Heart Study. Plasma CRP along with metabolic syndrome variables were measured. CRP levels showed a significant race (black>white, P=.01) and sex (female>male, P=.0001) differences, and related to measures of obesity (body mass index [BMI], waist circumference, and sagittal diameter), blood pressure (systolic, diastolic, and mean arterial blood pressure), lipoproteins (low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglycerides, total cholesterol-high-density lipoprotein cholesterol ratio), glucose homeostasis (insulin, glucose, homeostasis model assessment of insulin resistance), and uric acid, after adjusting for age, race, sex, and cigarette smoking. Furthermore, CRP levels increased with increasing number of metabolic syndrome risk factors, as defined by the National Cholesterol Education Program Adult Treatment Panel III, regardless of race and sex (P for trend<0001). In multivariate analysis, using 3 separate models for different obesity measures, obesity was the major contributor to the explained variance in each model with BMI, waist, and sagittal diameter contributing 17.0%, 13.4%, and 17.1% of the variance, respectively. In contrast, homeostasis model assessment of insulin resistance contributed 1.2%, 0.3%, and 0% to the explained variance in the models with BMI, waist, and sagittal diameter, respectively. In conclusion, CRP levels differ among race and sex groups and correlate to metabolic syndrome variables in younger adults. In addition, these findings strongly suggest that although obesity and insulin resistance are the main underlying features of the metabolic syndrome, the former appears to be the major mediator of CRP levels, which has important health implications.

Shear force induced monodisperse droplet formation in a microfluidic device by controlling wetting properties

Perpendicular flow is used to induce oil droplet breakup by using a capillary as water phase flow channel. It is a new route to produce monodisperse emulsions. The wetting properties of the fluids on the walls are exceedingly important parameters. Depending on the oil and water flow rates, different spatial distributions of the two phases as laminar, plugs, cobbles and drops, are obtained. The effects of two-phase flow rates on plugs and drop size are studied, and the different droplet formation mechanisms of plug flow and drop flow are discussed. Two quantitative equations utilized to predict the droplet size are developed.

Ultrafast all optical switching via tunable Fano interference

Tunneling induced quantum interference experienced by an incident probe in asymmetric double quantum wells can easily be modulated by means of an external control light beam. This phenomenon, which is here examined within the dressed-state picture, can be exploited to devise a novel all-optical ultrafast switch. For a suitably designed semiconductor heterostructure, the switch is found to exhibit frequency bandwidths of the order of 0.1 THz and response and recovery times of about 1 ps.

Vascular abnormalities in asymptomatic, healthy young adult smokers without other major cardiovascular risk factors: the Bogalusa Heart Study

Cigarette smoking, an established cardiovascular (CV) disease risk factor, is known to impair pulsatile arterial function in middle-aged and older adults. However, information is scant in healthy young adults for whom smoking is the only CV risk factor, at current guidelines. Nonsmokers (n = 145) and smokers (n = 142) aged on average 36 years were selected for not having obesity, hypertension, dyslipidemia, diabetes, or clinically manifest CV disease. Pulsatile arterial function was measured in terms of large artery compliance (C1), small artery compliance (C2), and systemic vascular resistance (SVR) by noninvasively recorded radial artery waveforms. Smokers versus nonsmokers had significantly lower measures of adiposity and LDL-cholesterol; and higher systolic blood pressure and triglycerides. In addition, smokers versus nonsmokers had lower C2 (5.09 v 6.63 mL/mm Hg x 100, P = .0009) and higher SVR (1399.0 v 1325.5 dyn . sec . cm(-5), P = .006), after adjustment for race, sex, and age. Decreases in C2 (P for trend = .001) and increases in SVR (P for trend = .01) were noted with increasing years of smoking. Multivariate analysis revealed that duration of smoking was associated adversely with C2 (P = .004), independent of race, sex, age, systolic and diastolic blood pressures, HDL-cholesterol, triglycerides, glucose, and insulin. The odds of having adverse C2 (bottom 10 percentile) and SVR (top 10 percentile) were, respectively, 2.9 (P = .01) and 2.6 (P = .07) times higher in smokers versus nonsmokers. The observed deleterious effects of cigarette smoking on arterial wall dynamics in otherwise healthy young adults underscore the need for aggressive early prevention and intervention strategies to control smoking behavior.

Isolation of an esterase-producing Trichosporon brassicae and its catalytic performance in kinetic resolution of ketoprofen

A yeast strain CGMCC 0574, identified as Trichosporon brassicae, was selected from 92 strains for its high (S) selectivity in the hydrolysis of ketoprofen ethyl ester. The effective strains of the microorganisms were isolated from soil samples with the ester as the sole carbon source. The ethyl ester proved to be the best substrate for resolution of ketoprofen among several ketoprofen esters examined. The resting cells of CGMCC 0574 could catalyze the hydrolysis of ketoprofen ethyl ester with an enantiomeric ratio of 44.9, giving (S)-ketoprofen an enantiomeric excess of 91.5% at 42% conversion.

1-acetyl-3-[benzoyl(4-methoxyphenyl)methylene]-2,3-dihydro-1H-indol-2-one

In the title compound, C25H19NO4, the indole moiety is not completely planar, the heterocyclic ring being distorted very slightly towards a half-chair conformation. The benzoyl and 4-methoxyphenyl substituents are individually almost planar and are in a bisecting and nearly perpendicular configuration, respectively, with respect to the plane of the indole moiety. The molecular and packing structures in the crystal are stabilized by intramolecular and intermolecular C-H...O interactions.

[Investigation on the excited state dynamics properties of hemicyanine molecules]

In this paper, the excited state dynamics properties of hemicynine were investigated by using time-resolved fluorescence and 3D fluorescence spectra techniques. The interaction of hemicyanine molecules caused formation of H-aggregates and a blue shift of the 3D fluorescence spectra in interleaving hemicyanine/arachidic acid multilayers. The peak of fluorescence was a red shift along with the time decay. The lifetime of the LB fluorescence was much shorter and the difference of beginning luminescence was less than that of the hemicyanine solution due to the stronger intermolecule interactions in the aggregates.

Efficient preparation of (R)-alpha-monobenzoyl glycerol by lipase catalyzed asymmetric esterification: optimization and operation in packed bed reactor

Optically active (R)-alpha-monobenzoyl glycerol (MBG) was synthesized by Candida antarctica lipase B (CHIRAZYME L-2) catalyzed asymmetric esterification of glycerol with benzoic anhydride in organic solvents. Various conditions, such as the type and composition of the organic solvent, water content of the system, reaction temperature, and concentrations of the substrates were systematically examined and optimized in screw-capped test tubes with respect to both the reaction rate and the enzyme selectivity. 1,4-Dioxane was found to be the best solvent and no additional water was needed for the system. The optimum temperature was around 30 degrees C, while the most suitable substrate concentrations were 100 mM each for glycerol and benzoic anhydride, respectively. However, when excessive anhydride (e.g., 200 mM) was used, the produced MBG could be further transformed into 1,3-dibenzoyl glycerol (DBG) by the same enzyme with a priority to (S)-MBG, resulting in a significant improvement of the product optical purity from ca. 50-70% e.e. Under optimal conditions (100 mM glycerol, 100-200 mM benzoic anhydride, dioxane, 25-30 degrees C), the enzymatic synthesis of (R)-MBG was successfully operated in a packed-bed reactor for about 1 week, with an average productivity of 0.79 g MBG/day/g biocatalyst in the case of continuous operation and 0.94 g MBG/day/g biocatalyst in the case of semicontinuous operation. After refinement and preferential crystallization of the crude product, (R)-MBG could be obtained in an almost optically pure form (>98% e.e.).

Dynamics of 'Technegas' deposited in the lung

In tomographic Technegas ventilation studies, the deposited aerosol should be stable. The aim of this study was to investigate the stability of deposited Technegas in severely obstructed patients and in healthy volunteers. Six emphysematous patients and five healthy volunteers were studied. Anterioposterior (AP) and posterioanterior (PA) dynamic images of ventilation (120 frames, 1 frame.min-1) were acquired after inhalation of 99mTc-Technegas' in the supine position. The time-activity curve of the whole lung showed two phases in the emphysematous patients as well as in the healthy volunteers. The activity decreased rapidly in the first phase, then reached almost a constant level (the second phase) after approximately 50 min. The logarithms of both the first phase and the second phase were close to straight lines. The half-time of the first phase was approximately 9 min. No systematic differences in 'Technegas' clearance rate were found between central regions and peripheral regions and between high count rate regions and normal count rate regions. Pertechnegas contamination was subsequently detected, and we conclude that the rapid first phase is probably due to clearance of Pertechnegas. When stable Technegas is required, we suggest that data acquisition should start about 50 min after inhalation.

Photoinduced reactions of 1-acetylisatin with phenylacetylenes

[reaction: see text]Photoinduced reactions of 1-acetylisatin 1 with diphenylacetylenes 2a-2c afforded the corresponding 3-methylene-2-indolones 4a-4e and 5a-5e in 80-90% yields via a spirooxetene intermediate. Similar irradiation of 1 with phenylacetylene, on the other hand, resulted in efficient formation of two diastereoisomeric dispiro[3H-indole-3,2'-furan-3',3"-(3H)-indole]-2,5',2"(2H,5'H,2"H )triones 6 and 7 via a reaction sequence with initial formation of the spirooxetene intermediate. The regioselectivity in the photocycloaddition of 1 with phenylacetylene and the reaction mechanism for the formation of 6 and 7 are discussed.

Distribution of ventilation-to-perfusion ratios analysed in planar scintigrams of emphysematous patients

The aim of the present study was to develop and evaluate a method for semi-quantification of ventilation-to-perfusion ratios in small regions in planar pulmonary scintigrams using 99mTc-Technegas (Tetley Manufacturing Ltd, Sydney, Australia) and 99mTc-macro-aggregated human albumin. Eight emphysematous patients and eight healthy volunteers were investigated in the supine position. Anterio-posterior and posterio-anterior images of ventilation and ventilation-and-perfusion were acquired consecutively. Perfusion images were obtained by subtracting the corrected ventilation images from ventilation-and-perfusion images. Lung regions of interest were divided into 2.03 x 2.03 cm regions. The ratio of normalized counts of ventilation-to-perfusion (V/Q) was calculated in each square region. The log (V/Q)s of healthy volunteers were distributed symmetrically and similarly around 0, whereas the corresponding ratios in patients distributed unevenly. The standard deviations of log (V/Q)s were significantly higher in patients than in healthy volunteers. Parametric images of V/Q distribution were constructed to visualize the magnitude and location of 'waste ventilation' and 'shunt' effects. In conclusion, the present semi-quantitative method is validated by confirming the expected dispersed V/Q distribution in emphysematous patients compared to healthy volunteers.

[A method for preparation of carbon fiber electrode]

Carbon fiber electrode (CFE) can be used in detection of exocytosis of single neuron or endocrine cell. A simplified method for preparation of CFE, as described in the present paper, greatly ensures the coordination and success of the preparation. Such CFEs have a low noise level. Exocytosis of rat adrenal chromaffin cells was investigated in the clarification of the effect of MPP+ on transmitter release. It is found that exocytosis was not stimulated by MPP+ and the high K+ induced secretion was not changed by MPP+. These observations suggest that the previously reported elevation of dopamine content in the surrounding histosolution of DA neuron is probably resulted from blockage of the re-uptake of DA by MPP+.

[Role of M-type receptor in internal calcium release and quantal secretion in rat adrenal chromaffin cells]

In rat single adrenal chromaffin cells, the effects of methacholine (MCh) on [Ca2+]i and catecholamine secretion were studied with fura-2 fluorescence and carbon fiber electrodes. In the presence of 2 mmol/L Ca2+ in the bath, locally applying 1 mmol/L MCh, either containing or not containing Ca2+, evoked both [Ca2+]i and secretion signals. In the absence of Ca2+ in the bath, MCh could still evoke [Ca2+]i and secretion. These results suggest that MCh causes release of Ca2+ from Ca2+ stores, which is sufficient to yield the evoked secretion. The Ca2+ store can be depleted by single MCh puff in the absence of Ca2+ in the bath.