Determinants of post-ischaemic reactive hyperaemia in patients with diabetes mellitus type II.

Dysfunction of resistance arteries is thought to be an early reversible stage in the development of atherosclerosis. Dynamics of post-ischaemic reactive hyperaemia are believed to constitute a useful tool for monitoring resistance vessel function. Patient characteristics influencing reactive hyperaemia, however, need to be defined more precisely. Since reactive hyperaemia is a dynamic process, yielding submaximal peak values after 5 min of ischaemia, this period was chosen to investigate the determinants of reactive hyperaemia in 100 type II diabetic patients as well as in 61 control subjects. Reactive hyperaemia was measured by venous-occlusion plethysmography; clinical and laboratory data were acquired by routine methods. Statistical comparison was performed with SYSTAT 5.0 for Apple Macintosh. Overall, no significant differences between diabetic patients and controls were observed by group comparison. In control subjects, only gender showed an influence on peak reactive hyperaemia (females 40.5 +/- 15.3; males 51.8 +/- 17.7 ml min-1 100 ml-1, P < 0.01). In diabetic patients, in addition to gender, actual blood glucose (r = 0.377, P < 0.05) and meal intake (non-fasting 42.8 +/- 19.2; fasting 51.2 +/- 19.5 ml min-1 100 ml-1, P < 0.05) were found to influence reactive hyperaemia. Further investigation revealed a loss of the correlation between peak reactive hyperaemia and actual blood glucose observed in the fasting state (P < 0.001) in non-fasting diabetic patients, indicating an influence of meal intake on resistance vessel reactivity. Our results suggest that, in diabetic subjects, in addition to gender actual blood glucose and the postprandial situation impacts on peak reactive hyperaemia.     

Effect of local warming on forearm reactive hyperaemia

Measurement of minimal vascular resistance has proved useful in quantifying structural changes in regional circulations. Accurate measurement of minimal vascular resistance requires full relaxation of all resistance vessels within the region under examination. The usual procedure in humans involves the measurement of maximal forearm blood-flow following 6-10 min of forearm ischaemia. We conducted this study to find whether forearm skin was fully vasodilated by this procedure. Peak forearm blood-flow was measured by plethysmography in six healthy subjects following 10 min of ischaemia while the arm was at a neutral temperature (33 degrees C) and while the arm was locally warmed to 42 degrees C. Peak reactive hyperaemia blood-flow was significantly elevated by local heating (P less than 0.001) to 79.6 ml 100 ml-1 min-1 from a value of 50.2 ml 100 ml-1 min-1 during normothermia. Peak reactive hyperaemia blood-flow in the contralateral unheated forearm showed no significant change between the two periods of ischaemia (P greater than 0.05). These findings were confirmed in four subjects by laser Doppler velocimetry, which gives a linear index of skin blood-flow. In normothermic conditions, this index rose to 0.89 V following 10 min of ischaemia and to 1.26 V with local warming to 42 degrees C (P less than 0.001). Ischaemia plus local warming did not cause a further significant rise in this index of skin blood-flow (1.35 V, P greater than 0.05). These data suggest that 10 min of ischaemia during normothermia is insufficient to relax fully cutaneous resistance vessels and that maximal forearm blood-flow is underestimated by this procedure.     

Comparison of levels of human immunodeficiency virus type 1 RNA in plasma as measured by the NucliSens nucleic acid sequence-based amplification and Quantiplex branched-DNA assays

This study compared levels of human immunodeficiency virus type 1 RNA in plasma as measured by the Quantiplex branched-DNA and NucliSens nucleic acid sequence-based amplification assays. RNA was detectable in 118 of 184 samples (64.13%) by the Quantiplex assay and in 171 of 184 samples (92.94%) by the NucliSens assay. Regression analysis indicated that a linear relationship existed between the two sets of values (P < 0.0001), although the Quantiplex and NucliSens values were significantly different (P < 0.001), with the NucliSens values being approximately 0.323 log higher. Spearman correlation analysis indicated that the overall changes in patient viral load patterns were highly correlative between the two assays: r = 0.912, P < 0.0001. The lower limits of sensitivity were determined to be approximately 100 copies/ml and 1,200 to 1,400 copies/ml for the NucliSens and Quantiplex assays, respectively.     

Depressed activation of the lectin pathway of complement in hereditary angioedema

The possibility of simultaneous measurement of the classical pathway (CP), mannan-binding lectin (MBL)--lectin pathway (LP) and alternative pathway (AP) of complement activation by the recently developed Wielisa method allowed us to investigate the in vivo significance of the C1-inhibitor (C1INH) in three complement activation pathways. Functional activity of the CP, LP and AP were measured in the sera of 68 adult patients with hereditary angioedema (HAE) and 64 healthy controls. In addition, the level of C1q, MBL, MBL-associated serine protease-2 (MASP-2), C4-, C3- and C1INH was measured by standard laboratory methods. MBL-2 genotypes were determined by polymerase chain reaction. Besides the complement alterations (low CP and C1INH activity, low C4-, C1INH concentrations), which characterize HAE, the level of MASP-2 was also lower (P = 0.0001) in patients compared with controls. Depressed LP activity was found in patients compared with controls (P = 0.0008) in homozygous carriers of the normal MBL genotype (A/A), but not in carriers of variant genotypes (A/O, O/O). Activity of CP correlated with LP in patients (Spearman's r = 0.64; P < 0.0001), but no significant correlation was found in the control group and no correlation with AP was observed. In contrast, the activity of CP and AP correlated (Spearman's r = 0.47; P < 0.0001) in healthy controls, but there was no significant correlation in the HAE patients. We conclude that the activation of LP might also occur in subjects with C1INH deficiency, which is reflected by the low MASP-2 and C4 levels.     

Postprandial impairment of resistance vessel function in insulin treated patients with diabetes mellitus type-2.

Reduced postischaemic reactive hyperaemia, is considered a marker of impaired resistance vessel function. Acute postprandial hyperlipidaemia has been shown to induce vascular dysfunction. In the present study, the impact of postprandial hyperglycaemia on resistance vessel reactivity was investigated in insulin treated type-2 diabetic patients. The study was performed in 16 insulin treated type-2 diabetics (eight male/eight female, age 47 +/- 3 years, HbA1c 7.2 +/- 0.2) and 16 controls. Reactive hyperaemia was measured in the forearm by venous occlusion plethysmography after 5 min of ischaemia in the fasting state and 90 min after a test meal. In diabetics, blood glucose increased from 8.7 +/- 1.1 to 15.3 +/- 1.0 mmol l-1 (P<0.001) postprandially. This resulted in (i) a significant increase of resting blood flow (3.4 +/- 0.3 to 4.8 +/- 0.4 ml min-1 100 ml-1, P<0.01) and (ii) in a reduced peak reactive hyperaemia (52.3 +/- 7.4 to 36.8 +/- 4.3 ml min-1 100 ml-1, P<0.005). In controls, a similar effect of the meal on resting flow was observed but reactive hyperaemia was unaltered. In the absence of a test meal, basal flow as well as peak reactive hyperaemia remained unchanged in diabetic as well as in non-diabetic subjects. Our data provide evidence that in the postprandial state resistance vessel reactivity becomes reduced in insulin treated type-2 diabetic patients.     

Large capillary fluid permeability in skeletal muscle and skin of man as a basis for rapid beneficial fluid transfer between tissue and blood.

Our previous studies strongly indicate that the capillary filtration coefficient (CFC) in skeletal muscle and skin of man is much larger than previously believed, or about 0.050 ml min-1 100 ml-1 mmHg-1. The hypothesis that this large capillary fluid permeability is a factor of primary importance for plasma volume control was approached. Experimental hypovolaemia induced by lower body negative pressure (LBNP of 70-95 cmH2O) was associated with a rapid net fluid gain from the studied upper arm into the circulation of 0.17 ml min-1 100 ml-1 tissue. The transcapillary driving force for this fluid transfer, probably caused by adrenergic adjustment of vascular resistance, with a decline of capillary pressure, was relatively small, or 1.7 mmHg on average. CFC was instead very high during LBNP, increasing from a control value of 0.054 +/- 0.004 (SE) to no less than 0.097 +/- 0.007 ml min-1 100 ml-1 mmHg-1, probably reflecting an increased number of effectively perfused capillaries. It is suggested that the large capillary fluid permeability in skeletal muscle and skin of man, with large tissue mass and fluid reservoir, may be of great functional importance for plasma volume control after blood loss and also in other (patho)physiological situations. As demonstrated, it can thus permit rapid transfer of large fluid volumes into the circulation and, perhaps of special importance, with only small transcapillary driving force (capillary pressure decline).(ABSTRACT TRUNCATED AT 250 WORDS)     

HPLC法同时测定对乙酰氨基酚、咖啡因、盐酸麻黄碱和维生素C的含量

目的：建立同一色谱条件下对乙酰氨基酚、咖啡因、盐酸麻黄碱和维生素C含量的HPLC测定法。方法：采用高效液相色谱法,以Capcell-pak C18为色谱柱,流动相为乙晴/庚烷磺酸钠溶液缓冲液（30/70）,检测波长为210nm,流速1.0ml.min-1,采用外标法计算含量。结果：对乙酰氨基酚、咖啡因、盐酸麻黄碱和维生素C的分离度好,乙酰氨基酚在15mg.100ml-1～120mg.100ml-1范围内线性关系良好（r=0.9999）;咖啡因在6.25mg.100ml-1～50mg.100ml-1范围内线性关系良好（r=0.9994）;盐酸麻黄碱在6.25mg.100ml-1～50mg.100ml-1范围内线性关系良好（r=0.9998）;维生素C在40mg.100ml-1～320mg.100ml-1范围内线性关系良好（r=0.9994）。实验的精确度和稳定性良好,样品回收率高。结论：本方法操作简单,结果准确,可以有效地控制该类制剂的质量。     

Controlled twitch mouth pressure reliably predicts twitch esophageal pressure

The present study hypothesized that twitch mouth pressure (TwPmo) can reliably predict intrathoracic pressure swings reflected by twitch esophageal pressure (TwPes) using a controlled and automated trigger technique. TwPmo, TwPes, and transdiaphragmatic pressure (TwPdi) following bilateral anterior magnetic phrenic nerve stimulation were measured in 21 healthy subjects using an inspiratory pressure trigger (0.5kPa, experiment 1), an expiratory pressure trigger (0.5kPa, experiment 2), an inspiratory flow trigger (40ml/s, experiment 3), and no trigger at relaxed functional residual capacity (experiment 4). TwPmo and TwPes were correlated as follows: r=0.99, p<0.0001 (experiment 1); r=0.67, p=0.001 (experiment 2); r=0.96, p<0.0001 (experiment 3); no correlation (experiment 4). Bland and Altman analysis revealed most narrow limits of agreement for TwPmo and TwPes in experiment 1: bias (range) 0.15kPa (-0.03 to 0.32). TwPmo is an excellent predictor for TwPes when using a fully automated and controlled inspiratory pressure trigger. Thus, measurement of TwPmo could become a standard means assessing inspiratory muscle strength.     

Semen granulocyte elastase: its relevance for the diagnosis and prognosis of silent genital tract inflammation

Elastase-inhibitor complex was assessed by immunoassay in the seminal plasma of 312 men attending the outpatient infertility clinic. Using receiver operating characteristic (ROC) curve analysis, elastase at the cut-off value of > or =290 ng/ml was shown to be efficient (sensitivity 79.5%, specificity 74.4%) in the detection of genital tract inflammation as defined by leukocytospermia (>1x10(6) leukocytes/ml). The prevalence of increased elastase in 292 infertile men was significantly higher (34%) as compared with that (5%) observed in 20 fertile men (P: = 0.02). Moreover, high elastase concentration (> or =290 ng/ml) was observed in 66 of the 264 men (25%) without leukocytospermia. A significant positive correlation was found between elastase concentration and patient age (r = 0.202, P: < 0.0001) and the number of leukocytes (r = 0.330, P: < 0.0001). A negative correlation was found between elastase concentration and semen volume (r = -0.146, P: = 0.01) and the percentage of spermatozoa with single-stranded DNA (r = -0.194, P: = 0.024), but there was no correlation between elastase and sperm reactive oxygen species production. A higher seminal elastase concentration was significantly associated with tubal damage in female partners (P: < 0.001). After norfloxacine antibiotic therapy, decrease in elastase concentration was observed in 15 (25%) of the 60 treated patients. Tubal damage in the partner negatively affected the response to antibiotic therapy. In conclusion, granulocyte elastase is a reliable screening test for silent genital tract inflammation of the couple. The elastase-inhibitor complex may have a protective effect in reducing sperm DNA denaturation.     

Relationship between hyperglycaemia and aerobic power in men with newly diagnosed type 2 (non insulin-dependent) diabetes.

The aim of the study described here was to evaluate aerobic function during exercise and its determinants in middle-aged men with newly diagnosed Type 2 (non insulin-dependent) diabetes. Using breath-by-breath technique, we measured O2 uptake at anaerobic (ventilatory) threshold and at peak exercise in a group of diabetic men (n = 19; fasting blood glucose 8.6 +/- 0.7 mmol l-1, mean +/- SEM) without any disease or medication that could have had an influence on exercise performance, and compared the results to those observed in non-diabetic healthy control men (n = 18). There were no differences in physical activity or smoking habits between the groups. Oxygen uptake was lower in the diabetic men than in the control men both at anaerobic threshold (15.0 +/- 0.8 vs. 18.8 +/- 1.0 ml min-1 kg-1, P < 0.01) and at peak exercise (25.3 +/- 1.5 vs. 31.1 +/- 1.4 ml min-1 kg-1, P < 0.01). In the diabetic men peak O2 uptake showed an inverse linear correlation with age (r = -0.71, P < or = 0.001), fasting blood glucose (r = -0.49, P < 0.05) and glucose response in an oral glucose tolerance test (r = -0.43, P < 0.05). In addition, long-term smoking was associated with impaired peak O2 uptake. In a stepwise multiple regression procedure 75% of the total variance of peak O2 uptake in the diabetic men was explained by age, post-load blood glucose response and smoking history. Thus, in addition to ageing and smoking, hyperglycaemia is correlated with impaired aerobic power in men with newly diagnosed Type 2 diabetes.     

Detection and quantification of antibodies to Newcastle disease virus in ostrich and rhea sera using a liquid phase blocking enzyme-linked immunosorbent assay

A liquid phase blocking ELISA (LPB-ELISA) was adapted for the detection and quantification of antibodies to Newcastle disease virus. Sera from vaccinated and unvaccinated commercial flocks of ostriches (Struthio camelus) and rheas (Rhea americana) were tested. The purified and nonpurified virus used as the antigen and the capture and detector antibodies were prepared and standardized for this purpose. The hemagglutination-inhibition (HI) test was regarded as the reference method. The cutoff point for the LPB-ELISA was determined by a two-graph receiver operating characteristic analysis. The LPB-ELISA titers regressed significantly (P < 0.0001) on the HI titers with a high correlation coefficient (r = 0.875). The two tests showed good agreement (kappa = 0.82; P < 0.0001), relative sensitivity (90.91%) and specificity (91.18%), and accuracy (91.02%), suggesting that they are interchangeable.     

Estimation of extracellular space and blood volume using bioelectrical impedance measurements

Summary The bromide-82 dilution space (extracellular space, ECS) and blood volume (BV) were measured in 21 patients with esophageal and gastric cancer and in 27 patients 18–96 months after total gastrectomy. Resistance (R) and reactance (X_c) from bioelectrical impedance measurements were used to obtain multiple regression equations for ECS and BV. The variables weight, gender, and height ²/X_c were independent predictors of ECS (r = 0.767; P < 0.0001). Height 2/R and gender were predictors of blood volume (r = 0.856; P < 0.0001). The mean difference between the Br space and the ECS predicted from impedance measurements was 0 ± 1.54 (mean ± SD). The limits of agreement (± 2 SD) were therefore ±3.081 or 19.6% of the mean Br space of 15.71. The limits of agreement for BV were ±789 ml or ±19.7% of the average BV of 4008 ml. It is concluded that bioelectrical impedance plethysmography using a single frequency can be used for the estimation of ECS and BV The wide limits of agreement, however, may limit its used in clinical practice.Abbreviations ECS extracellular space - BV blood volume - R resistance - X_c reactance - SD standard deviation - LBM lean body mass - TBW total body water - RCM red blood cell mass - cAMA corrected arm muscle area - Z impedance - ANOVA analysis of variance - NS not significant - Na_e/K_c exchangeable sodium to exchangeable potassium ratio - p specific resistivity - PV plasma volume     

Transcapillary clearance of albumin in rat skeletal muscle monitored by external detection. Effects of alterations in capillary surface area

The effects of noradrenaline (NA)-induced vasoconstriction on the transcapillary passage of albumin was evaluated by an external detection technique, allowing repetitive measurements of albumin clearance (Cl) during various conditions (in the same animal). Six isolated rat hindquarters were perfused with serum-albumin solutions during maximal vasodilation (papaverine 90 microM) and Cl was determined at different net filtration rates (Fv) induced by elevations of venous pressure. Then, the perfusate was changed to one of similar composition but containing noradrenaline (2-4 microM), and the procedure of determining Cl vs. Fv was repeated. Tissue accumulation of [99mTc]albumin was expressed in terms of clearance, using the isogravimetric Cl of defined muscle samples during maximum vasodilation in separate experiments as reference, the latter being 0.0246 +/- 0.0012 ml min-1 per 100 g. Noradrenaline caused an increase in vascular resistance from 2 to 14 mmHg min 100 g ml-1, while the Cl vs. Fv relationship was shifted downwards in a fashion parallel with the control Cl vs. Fv curve. For Fv = 0, Cl was 0.0101 +/- 0.0014 ml min-1 per 100 g during NA challenge. The average reflection coefficient for albumin (sigma tot) was 0.92 +/- 0.01 irrespective of vascular tone. Thus, both albumin clearance and the capillary filtration coefficient (CFC) seem to vary in direct proportion to the capillary surface area available for exchange.     

狼疮性肾炎患者外周血IL-18水平及其基因表达

为了探讨白细胞介素 18(IL 18)在狼疮性肾炎 (LN )发生、发展中的作用。我们采用逆转录多聚酶链反应 (RT PCR )及酶联免疫吸附 (ELISA )法测定 16例正常人及 18例LN患者外周血单个核细胞 (PBMC )IL 18mRNA表达量及其血浆水平。结果提示LN患者PBMCIL 18mRNA表达量及血浆IL 18水平均较正常对照组显著增高 [IL 18mRNA表达量为 :1 2 6 2± 0 189vs0 84 4± 0 15 5 ,P <0 0 0 1;IL 18血浆水平为 :(82 2 0 9± 5 32 77)pg/mlvs (2 39 5 7± 75 0 6 )pg/ml,P <0 0 0 1]。且WHOIV型LN增高较非IV型LN更为显著 [IL 18mRNA表达量为 :1 32 9± 0 2 1vs 1 138± 0 15 2 3,P <0 0 5 ;IL 18血浆水平为 :(1135 5 4± 5 15 34)pg/mlvs (5 0 8 6 5± 341 36 )pg/ml,P <0 0 1]。另外 ,血浆IL 18水平与肾组织活动指数 ,肾小管间质损害程度呈等级相关 (r分别为 :0 6 10和 0 4 99,P均 <0 0 5 ) ,也与血清肌酐 (Scr) ,血清内生肌酐清除率 (Ccr)及 2 4h尿蛋白排泄量 (2 4hUPQ )呈直线相关 (r分别为 :0 898、 0 6 2 8和 0 5 37,P均 <0 0 5 )。本研究认为循环IL 18表达和分泌增高可能参与LN的免疫发病过程 ,并与狼疮活动有一定的关系     

Thoracic electrical bioimpedance versus thermodilution in patients post open-heart surgery

Thoracic electrical bioimpedance cardiography is a non-invasive, continuous and low-cost method of estimation of cardiac output and other haemodynamic parameters. Though subject to continuous technological refinement controversial opinions exist on its validity in subsets of critically ill patients, patients with heart disease or after cardiac surgery. A comparison study between thermodilution (TD) and bioimpedance (TEB) was performed in 28 patients undergoing elective cardiac surgery (CABG, aortic or mitral valve replacement or combined procedures). 128 pairs of cardiac index estimates at specific time points during 20 hours at the postoperative ICU were evaluated. A poor correlation (r = 0.26, p < 0.05, bias -0.07 l.min-1.m2, precision + 1.1 l.min-1.m-2, 95% limits of agreement -2.27-2.13 l.min-1.m-2) between TD and TEB cannot support the routine use of TEB monitoring in early postoperative period after open-heart surgery. Possible reasons of lack of agreement in this population are discussed. Further studies with technically improved bioimpedance cardiographs will be needed.     

Significance of brain natriuretic peptides in patients on continuous ambulatory peritoneal dialysis

It is well known that plasma brain natriuretic peptide (BNP) concentration is elevated in cardiovascular diseases such as congestive heart failure. However, although it has been reported to increase in hemodialysis (HD) patients, little is known about plasma BNP in patients undergoing continuous ambulatory peritoneal dialysis (CAPD). Plasma BNP concentrations were measured and compared among CAPD patients (n=32), HD patients (n=63) and healthy volunteers (n=14) as well as those patients without cardiovascular disease. In addition, the correlation between plasma BNP concentration and parameters of echocardiography was examined. Plasma BNP concentration was significantly higher in CAPD patients without cardiovascular disease (n=23) than in healthy volunteers (n=14) (62.1+/-60.6 pg/ml versus 9.7+/-9.7 pg/ml, mean +/- SD, P<0.0001). Furthermore, it had a positive correlation with LVMI (CAPD: r=0.37, P=0.0354; HD: r=0.49, P<0.0001) but a negative correlation with LVEF (CAPD: r=-0.39, P=0.0277; HD: r=-0.40, P=0.0010) in both CAPD and HD patients. When all patients were compared, plasma BNP concentration was significantly lower in CAPD patients (n=32) than in HD patients (n=63) (114.8+/-142.7 pg/ml versus 296.8+/-430.4 pg/ml, P<0.0001). When those patients without cardiovascular disease was compared, it was also significantly lower in CAPD patients (n=23) than in HD patients (n=40) (62.1+/-60.6 pg/ml versus 151.8+/-102.2 pg/ml, P<0.0001). In conclusion, plasma BNP concentration was elevated in CAPD patients and correlated with LVMI and LVEF, suggesting that plasma BNP in CAPD patients may be associated with left ventricular hypertrophy (LVH) and left ventricular systolic dysfunction. In addition, plasma BNP concentration was significantly lower in CAPD patients than in HD patients, suggesting that cardiac load in CAPD patients may be lower than that of HD patients.     

Increased levels of vascular endothelial growth factor in induced sputum in asthmatic patients

BACKGROUND: Vascular endothelial growth factor (VEGF) is highly expressed in the airway of asthmatic patients. As VEGF increases airway vascular permeability, consequent thickening of the airway wall mucosa may lead to narrowing of the airway lumen. OBJECTIVE: We evaluated the relationship between VEGF levels in induced sputum and eosinophilic inflammatory profiles, and the degree of airway vascular permeability in asthmatic patients and we evaluated the effect of inhaled corticosteroids on VEGF levels in induced sputum. METHODS: Induced sputum specimens were obtained from 28 glucocorticosteroids free asthmatics and 11 healthy control subjects. We examined VEGF levels and airway vascular permeability index in induced sputum. After the initial sputum induction, 21 asthmatics received 8-week inhaled beclomethasone dipropionate (BDP, 800 micro g/day) therapy, then sputum induction was repeated. RESULTS: The VEGF levels in asthmatics were significantly higher than in healthy control subjects (P < 0.0001). The VEGF levels were negatively correlated with forced expiratory volume of 1 s (FEV1, % predicted, r = - 0.68, P < 0.001), the percentage of eosinophils (r = 0.51, P < 0.01) and ECP levels (r = 0.39, P < 0.05). Moreover, the VEGF levels were significantly correlated with airway vascular permeability index (r = 0.61, P < 0.001). After 8-week inhaled BDP therapy, the VEGF levels were significantly decreased compared to pretreatment levels (P < 0.0001) and the VEGF levels were significantly correlated with airway vascular permeability index even in post-treatment asthmatics (r = 0.62, P < 0.01). CONCLUSION: The VEGF levels in induced sputum were increased in asthmatics and its levels were associated with degree of airway narrowing and airway vascular permeability. These findings provide strong evidence that VEGF may play an important role in the pathogenesis of bronchial asthma.     

Adipokines in children with sleep disordered breathing

STUDY OBJECTIVE: Associations between SDB, the metabolic syndrome, and circulating levels of adipokines have emerged in adults but have not been examined in snoring children, who, in contradistinction to adults, display insulin resistance and lipid abnormalities as a function of adiposity rather than SDB. Therefore, we aimed to examine associations between circulating adipokines levels, insulin resistance, and measures of SDB in children. DESIGN: Prospective study. SETTING: Polysomnographic evaluation and assessment of plasma levels of leptin, adiponectin, resistin, glucose, insulin, and CRP. PARTICIPANTS: 130 children (mean age 8.2 +/- 2.8 years; 39% obese) were studied. MEASUREMENTS AND RESULTS: Log adiponectin levels were lower in obese than nonobese children (3.8 +/- 0.31 vs 4.0 +/- 0.30 corresponding to 8,381.4 +/- 5,841.0 vs 12,853.2 +/- 7,780.2 ng/ml, P < 0.0001) and were inversely correlated with BMI Z scores (r = -0.47, P < 0.0001) but not with log AHI. Log leptin concentrations were higher in the obese group than the nonobese group (4.2 +/- 0.32 vs 3.4 +/- 0.57 corresponding to 19,542.6 +/- 13,643.6 vs 5,875.5 +/- 8,425.7 pg/ml, P < 0.0001), correlated with BMI Z scores (r = 0.64, P < 0.0001), and were significantly lower in children with AHI < or = 1/hr than children with AHI > 1/hr (P = 0.006) and in children with SpO2 nadir > or = 90% than children with SpO2 nadir < 90%, even after controlling for BMI Z score (P < 0.03). No significant differences were found in log resistin levels as a function of obesity or AHI. Significant correlations between log adiponectin levels and log Insulin/Glucose (I/G) ratios (-0.28, P = 0.006) and between log leptin levels and log I/G ratios (r = 0.66, P < 0.0001) emerged. CONCLUSIONS: In close agreement with the absence of a measurable effect of SDB on insulin resistance in children, circulating adipokines levels are primarily attributable to the ponderal index. However, SDB and associated hypoxemia may contribute to the elevation of leptin levels.     

The influence of Atriopeptins I and II on the relationship between glomerular filtration and natriuresis

The effects of two pure synthetic atrial natriuretic factors, Atriopeptin (AP) I and AP II, on the whole kidney glomerular filtration rate (GFR), sodium and potassium excretion (UNaV, UKV), urine flow rate (V) and arterial blood pressure (BP) were studied in adult male Sprague-Dawley rats. The variables were measured during a control period and during 70 min of continuous intravenous infusion of AP I or AP II at a rate of 10 micrograms h-1 kg-1 body wt. A time control group was studied in parallel to see whether the variables under study changed with time. The AP I infusion did not affect GFR (change from 1.34 +/- 0.10 to 1.24 +/- 0.04 ml min-1 g-1 kidney wt), but was clearly natriuretic (UNaV changed from 0.071 +/- 0.011 to 0.229 +/- 0.038 mumol min-1 g-1 kidney wt, P less than 0.01). The UKV increased from 0.504 +/- 0.073 to 1.138 +/- 0.121 mumol min-1 g-1 kidney wt, (P less than 0.001) and V from 1.88 +/- 0.10 to 2.94 +/- 0.15 microliter min-1 g-1 kidney wt, (P less than 0.001). Urine osmolality (Uosm) and BP were unaffected. During AP II infusion GFR remained unchanged but was slightly below the pre-infusion level during the last infusion period (1.05 +/- 0.07 as against 1.37 +/- 0.09 ml min-1 g-1 kidney wt, P less than 0.05). Despite this fact, UNaV was significantly elevated throughout the infusion period.(ABSTRACT TRUNCATED AT 250 WORDS)     

Empirically derived new equations for calculating body fat percentage based on skinfold thickness and midarm circumference in preschool Indian children.

We wanted to develop and apply new equations based on skinfold and midarm measurements for estimating %fat in preschool children suitable for field use. Prediction equations were developed on preschool-aged urban boys (n = 100) and girls (n = 84). Skinfolds at four sites and midarm measurements were regressed on %fat derived from equations based on height and weight and from bioelectrical impedance analysis (BIA; resistance at 50 kHz). These equations were applied: 1) to 12 children in whom the %fat was determined using D2O dilution, and 2) to 50 children in whom their %fat was derived using height-weight and BIA equations. The 95% limits of agreement (mean +/- 2 SD) for %fat derived by anthropometry and by new equations were within 1.7% in boys (r = 0.85; P < 0.001) and girls (r = 0.90; P < 0.001) and by BIA and new equations were within 1.5% in boys (r = 0.82; P < 0.001) and 2% in girls (r = 0.88; P < 0.001). For %fat measured by D2O dilution and new equations, 95% limits of agreement was within 1.3% (r = 0.98; P < 0.001). In 50 children 95% limits of agreement between anthropometry and new equations were within 1.8% in boys (r = 0.88; P < 0.001) and 1.4% in girls (r = 0.92; P < 0.001) and between BIA and new equations were within 1% in boys (r = 0.91; P < 0.001) and 1.5% in girls (r = 0.89; P < 0.001). The new equations for measuring %fat based on midarm circumference and skinfold measurements are rapid and accurate for South Asian children and should be useful for prediction of body composition and nutritional survey in field studies.