Accuracy and Reliability of Whole Blood Bilirubin Measurements Using a Roche Blood Gas Analyzer for Neonatal Hyperbilirubinemia Screening and Risk Stratification.

Background: Accurate bilirubin measurements are essential for appropriate management of neonatal hyperbilirubinemia. This study aimed to evaluate the accuracy and reliability of whole blood bilirubin measurements obtained using a Roche blood gas analyzer (Roche TBiL), with total serum bilirubin (TSB) measurements determined by the Ortho VITROS 4600 chemistry system (Ortho TSB) serving as a reference. Materials and Methods: Medical records of hospitalized neonates that underwent simultaneous Roche TBiL and Ortho TSB measurements were reviewed for eligibility selection and data collection. The correlations and differences between two sets of results were determined using Passing-Bablok regression analysis and a Bland-Altman plot, respectively. For eligible newborns, the risk of developing severe hyperbilirubinemia was assessed using the Bhutani nomogram. Weighted kappa analysis was used to evaluate the agreement between risk prediction by the two methods. Results: We obtained 618 paired Roche TBiL and Ortho TSB results from 309 neonates. Roche TBiL and Ortho TSB measurements showed a good correlation (r = 0.923; 95% CI: 0.905-0.938). Passing-Bablok regression analysis yielded the following equation: Roche TBiL = 0.794 × Ortho TSB + 1.255 mg/dL, with a slope of 0.794 (95% CI: 0.763-0.825) and intercept of 1.255 (95% CI: 1.042-1.417). The average difference between the two methods was 0.1 ± 1.448 mg/dL. A total of 207 neonates were eligible for evaluation of the agreement between the risk-grading methods. Although kappa analysis showed good agreement between the methods, with a weighted kappa of 0.681 (95% CI: 0.610-0.751) across all populations, the values for approximately half of the neonates at intermediate and high risk of hyperbilirubinemia (33/72) were underestimated by Roche TBiL. Conclusion: Our results indicate that Roche TBiL and Ortho TSB measurements in the neonatal population are not consistent. As a point-of-care and trace blood assay, Roche blood gas bilirubin measurements can facilitate primary screening of neonatal hyperbilirubinemia, but it seems to lack accuracy regarding risk stratification, particularly for high-risk newborn individuals.

Renin-angiotensin system modulates neurotransmitters in the paraventricular nucleus and contributes to angiotensin II-induced hypertensive response.

Angiotensin II (ANG II)-induced inflammatory and oxidative stress responses contribute to the pathogenesis of hypertension. In this study, we determined whether renin-angiotensin system (RAS) activation in the hypothalamic paraventricular nucleus (PVN) contributes to the ANG II-induced hypertensive response via interaction with neurotransmitters in the PVN. Rats underwent subcutaneous infusion of ANG II or saline for 4 weeks. These rats were treated for 4 weeks through bilateral PVN infusion with either vehicle or losartan (LOS), an angiotensin II type 1 receptor (AT1-R) antagonist, via osmotic minipump. ANG II infusion resulted in higher levels of glutamate, norepinephrine (NE), AT1-R and pro-inflammatory cytokines (PIC), and lower level of gamma-aminobutyric acid (GABA) in the PVN. Rats receiving ANG II also had higher levels of mean arterial pressure, plasma PIC, NE and aldosterone than control animals. PVN treatment with LOS attenuated these ANG II-induced hypertensive responses. In conclusion, these findings suggest that the RAS activation in the PVN contributes to the ANG II-induced hypertensive response via interaction with PIC and neurotransmitters (glutamate, NE and GABA) in the PVN.

Apocynin attenuates pressure overload-induced cardiac hypertrophy in rats by reducing levels of reactive oxygen species.

It has been shown that angiotensin II (Ang II) is involved in cardiac remodeling mediated by NADPH oxidase-dependent reactive oxygen species (ROS). Accordingly, NADPH oxidase-dependent ROS may play a role in cardiac hypertrophy induced by pressure overload. In the present study, we sought to determine whether inhibition of NADPH oxidase prevents cardiac hypertrophy. After abdominal aorta banding to induce cardiac hypertrophy, rats were treated for 8 weeks with apocynin (Apo) or captopril (Cap). Measures of cardiac hypertrophy were evaluated. Treatment with Cap or Apo reduced the left ventricle/body weight ratio (LV/BW), LV transnuclear myocyte diameter, and atrial natriuretic factor (ANF) mRNA expression relative to those of untreated rats subjected to aorta banding. The activity of NADPH oxidase and the ROS levels were decreased in treated animals. Cap, but not Apo, decreased Ang II levels and inhibited expression of p22phox and p67phox in LVs. In conclusion, local expression of Ang II appears to contribute to pressure overload-induced cardiac hypertrophy by upregulating NADPH oxidase expression and promoting ROS synthesis. Inhibition of NADPH oxidase and elimination of ROS may prevent or repair damage due to cardiac hypertrophy.

[Effects of selenium and/or iodine deficiency on chondrocyte apoptosis in rats].

OBJECTIVE: To explore the effects of selenium and/or iodine deficiency on chondrocyte apoptosis in articular cartilage in rats. METHODS: Forty-eight Sprague-Dawley rats were randomly divided into selenium deficiency group, iodine deficiency group, combined selenium and iodine deficiency group, and control group. Chondrocyte apoptosis was detected by terminal deoxynucleotidyl transferase biotin-dUTP nick end labeling (TUNEL) method, and Bcl-2 and Bax in articular cartilage were stained by immunohistochemistry in F3 generation of rats. RESULTS: In articular cartilage, the positive rate of apoptotic chondrocytes stained by TUNEL in the upper and middle zones in selenium deficiency group, iodine deficiency group, and combined selenium and iodine deficiency group (all P < 0.05) were significantly higher than that in control group. The apoptotic chondrocytes were prominent in the middle zone. The positive percentage of chondrocytes apoptosis was not significantly different among these three groups (P > 0.05). Compared with the control group, the expressions of both Bcl-2 and Bax were significantly higher in the upper and middle zone in the selenium deficiency group, iodine deficiency group, and combined selenium and iodine deficiency group (all P < 0.05); however, the expressions of Bcl-2 and Bax were not significantly different among these three groups (P > 0.05). CONCLUSION: Selenium and/or iodine deficiency may induce chondrocyte apoptosis.

[Angiotensin II increases ROS production in cardiac fibroblasts by inducing p22phox over-expression].

OBJECTIVE: To investigate the changes in the reactive oxygen species (ROS) in rat cardiac fibroblasts exposed to angiotensin II (Ang II) treatment and explore the possible pathways that mediate ROS production. METHODS: In vitro cultured fetal rat cardiac fibroblasts treated with apocynin (APO, 100 micromol/L), Ang II (10(-7) mol/L), or APO+Ang II (10(-7) mol/L Ang II was added 1 h after 100 micromol/L APO), and the ROS levels and p22phox expression in the cells were detected using fluorescent microscope and immunohistochemistry, respectively. RESULTS: Compared with the normal control cells, Ang II treatment of the cardiac fibroblasts resulted in significantly increased ROS production, the effect of which was inhibited by the application of APO. p22phox expression was hardly detected by immunohistochemistry in the control cells, but over-expressed in AngII-treated cells. APO substantially decreased the over-expression of p22phox induced by Ang II. CONCLUSION: Ang II increases ROS production in fetal rat cardiac fibroblasts probably by inducing p22phox over-expression.

[Angiotensin II type 2 receptors participate in the regulation of inflammatory cytokine secretion in adult rat hypertrophied cardiomyocytes].

OBJECTIVE: To investigate the effect of angiotensin II (AngII) type 2 (AT2) receptors on pressure overload-induced inflammatory cytokine secretion in adult rat hypertrophied cadiomyocytes. METHODS: Rat models of left ventricular hypertrophy induced by pressure overload was established by placing a band around the abdominal aortic of the rats, from which the hypertrophied cadiomyocytes were isolated and purified 8 weeks later. The isolated cardiomyocytes were treated with AngII plus losartan or AngII plus PD123319, and 36 h after the treatments, the expression levels of tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta) and IL-6 in the supernatant were detected using radioimmunoassay. RESULTS: AngII induced TNF-alpha and IL-1beta secretion from the hypertrophied cardiomyocyets, and pretreatment of the cells with PD123319, but not losartan, decreased their secretion. IL-6 level was not detected in the supernatant. CONCLUSION: AngII-induced the expression of inflammatory cytokines in adult rat hypertrophied cardiomyocytes is mediated mainly by AT2, not by AT1 receptors.

[Epimedium alleviates chemotherapy-induced damage to the ultrastructure and function of rat epididymides].

OBJECTIVE: To investigate the protective action of Epimedium against chemotherapy-induced damage to rat epididymides. METHODS: Fifty 60-day-old male rats were divided into a control, a model and a treatment group. Procarbazine was injected into the abdominal cavity of the model rats at the dose of 30 mg/(kg x d). In addition to procarbazine, Epimedium was given intragastrically to the treatment group. The changes in the ultrastructure of the epididymis were observed after 10 and 20 days. RESULTS: Electron microscopy showed that the chemotherapy-induced damages to the epididymal epithelia mainly included cell swelling, local cavitation of mitochondria, tumor-like change in nucleoli, agglutination of marginal translocation of heterochromatin and cell apoptosis. The damage to the epithelial ultrastructure was slight in the treatment group as compared with the model rats. Chemotherapy significantly affected sperm concentration, sperm viability and sialic acid (SA), which were (15.59 +/- 4.01) x 10(6)/ml, (76.71 +/- 10.11)% and (19.38 +/- 9.34) g/mg prot in the model group in comparison with (10.63 +/- 3.82) x 10(6)/ml (P < 0.01), (60.03 +/- 7.54)% (P < 0.01) and (13.62 +/- 7.81) g/g prot (P < 0.05) in the control. Epimedium significantly increased sperm viability in the treatment group (60.03 +/- 7.54)% as compared with the model rats (69.90 +/- 12.58)% (P < 0.05). CONCLUSION: Epimedium can lessen chemotherapy-induced damage to the epididymis and protect the reproductive function of rats.

Angiotensin II receptors subtypes mediate diverse gene expression profile in adult hypertrophic cardiomyocytes.

1. Although the systemic and cardiac renin-angiotensin systems are known to be activated in the setting of pressure overload, the actions and signaling mechanisms of angiotensin (Ang) II via AT(1) and AT(2) receptors in hypertrophic cardiomyocytes (CM) remain largely unclear. 2. Hypertrophic CM were prepared from rats with aortic banding for 8 weeks, cultured and then treated as follows: (i) 1 micromol/L AngII for 24 h; (ii) 10 micromol/L losartan (an AT(1) receptor antagonist) for 1 h followed by 1 micromol/L AngII for 24 h; and (iii) 10 micromol/L PD123319 (an AT(2) receptor antagonist) for 1 h followed by 1 micromol/L AngII for 24 h. Changes in the expression of genes following stimulation of AT(1) and AT(2) receptors specific to G-protein-coupled receptor (GPCR) signaling pathways were tested using GEArray (Superarray, Bethesda, MD, USA). The effects of AngII, acting via AT(1) and AT(2) receptors, on the expression of tumour necrosis factor (TNF)-alpha, interleukin (IL)-1beta and IL-6 were confirmed by reverse transcription-polymerase chain reaction and radioimmunoassay. 3. The genes regulated via stimulation of AT(1) receptors were mainly restricted to the signaling pathways including cAMP/protein kinase (PK) A, Ca(2+), PKC, protein tyrosine kinase, mitogen-activated protein kinases, phosphatidylinositol 3-kinase and nuclear factor-kappaB. In addition to these pathways related to activation of AT(1) receptors, four additional signaling pathways were found to be associated with stimulation of AT(2) receptors, including phospholipase C, nitric oxide/cGMP, Rho and Janus kinase/signal transducer and activator of transcription. Blockade of AT(2) receptors decreased the mRNA and protein expression of TNF-alpha and IL-1beta, whereas blockade of AT(1) receptors had no such effect. 4. In conclusion, in hypertrophic CM, AngII leads to distinct signaling responses mediated by AT(1) and AT(2) receptors. Stimulation of AT(2) receptors appears to have a greater influence on GPCR-signaling than stimulation of AT(1) receptors. Angiotensin II enhances the synthesis and secretion of TNF-alpha and IL-1beta in hypertrophic CM, which is mediated by AT(2), but not AT(1), receptors.

[Alteration of signal transduction-associated gene expression in rat cardiac fibroblasts induced by blocking angiotensin II receptors].

To investigate the molecular mechanism of angiotensin II (Ang II) receptor activation in adult rat cardiac fibroblasts, the expressions of cell signal transduction-associated genes were studied by using cDNA microarray. Cardiac fibroblasts of adult Sprague-Dawley rats (230~250 g) were isolated and cultured. The cells were divided into 4 groups: Ang II, Ang II + losartan, Ang II + PD123319, Ang II + losartan + PD123319. The expressions of Ang II receptors were studied by immunohistochemical staining. Total RNA was extracted and purified. After cDNA synthesis and biotin-16-dUTP labeling, the probes were denatured and hybridized with GEArray Q Series mouse G Protein-coupled Receptors Signaling Pathway Finder Gene Array (MM-025) containing 96 genes associated with 11 pathways. The arrays were scanned with a Uniscand1000 scanner and further analyzed with GEArray Analyzer software. RT-PCR was used to further confirm the results of gene microarray. The results of immunohistochemical staining showed that the expression of Ang II type 2 (AT2) receptor was evidently induced by Ang II stimulation when Ang II type 1 (AT1) receptor was blocked. The results of gene array indicated that blocking AT1 receptor changed 34 genes (more than 2 folds), 30 were down-regulated and 4 were up-regulated. The maximum change was not beyond 20 folds. The following 9 pathways were activated: cAMP/PKA, Ca2+, PKC, PLC, MAPK, PI-3 kinase, NO-cGMP, Rho, NF-kappaB pathways. Blockade of AT2 receptor caused 64 genes changing more than 2 folds (48 were down-regulated and 16 were up-regulated). Eleven pathways were basically activated. The change of the following 7 genes was over 30 folds: Cyp19a1 (37 folds), Il1r2 (42 folds), Cflar (53 folds), Bcl21 (31 folds), Pik3cg (278 folds), Cdkn1a (90 folds), Agt (162 folds). According to the activated extent, the signal transduction pathways in turn were PI-3 kinase, NF-kappaB and JAK-STAT pathways. Blocking both AT1 and AT2 receptors changed 46 genes more than 2 folds (36 were down-regulated and 10 were up-regulated). Eleven pathways were basically activated. The results of RT-PCR of IL-1beta and TNF-alpha confirmed the observations in gene microarray. Our results show that Ang II can induce a high expression of AT2 receptor in adult rat cardiac fibroblasts when AT1 receptor is blocked, and the signal mechanism of AT2 receptor is clearly different from that of AT1 receptor.

The protective effect of captopril on nicotine-induced endothelial dysfunction in rat.

This study was designed to examine the in vivo and in vitro effects of captopril, an angiotensin-converting enzyme inhibitor, on nicotine-induced endothelial dysfunction in rats. Endothelial dysfunction was induced by exposing isolated rat mesenteric arteries to nicotine (0.01, 0.1, or 1 mM) for 24 hr using an organ culture system, or by treating rats with nicotine (2 mg/kg/day, intraperitoneally) for 4 weeks. The protective effects of captopril were tested by exposing isolated mesenteric arteries to captopril (0.01, 0.03, or 0.1 mM) + nicotine (0.1 mM) for 24 hr, or by treating rats with captopril (3 mg/kg/day, intravenously) + nicotine (2 mg/kg/day, intraperitoneally) for 4 weeks. Exposure of the isolated mesenteric arteries to nicotine induced a significant concentration -dependent inhibition of endothelium-dependent relaxation. Co-culture of segments of mesenteric artery with captopril (0.03 or 0.1 mM) attenuated the nicotine-induced impairment of vasorelaxation in a dose-dependent manner. Administration of nicotine to rats for 4 weeks significantly impaired endothelium-dependent relaxation compared with control rats. This impairment was accompanied by a reduction in nitrite/nitrate, nitric oxide (NO) synthase (NOS), and superoxide dismutase (SOD) activities in the serum and aorta. Chronic captopril treatment not only improved the impairment of endothelium-dependent relaxation, but also prevented the reduction of nitrite/nitrate contents and of NOS and SOD activities in the serum and aorta. However, there were no significant differences in serum angiotensin-converting enzyme activity among the three groups. These results indicate that captopril can be used to attenuate nicotine-induced endothelial dysfunction, an effect that may be related not only to antioxidation, but also to enhancing NO production by preventing the decrease in NOS.