Effect of hypothermia on bilirubin-induced alterations in brain cell membrane function and energy metabolism in newborn piglets

The aim of this study was to evaluate the effects of hypothermia on bilirubin-induced alterations in brain cell membrane function and energy metabolism in the developing brain. Thirty-seven newborn piglets were divided randomly into four groups: normothermic control (NC, n=9); hypothermic control (HC, n=7); normothermic bilirubin infusion (NB, n=11); and hypothermic bilirubin infusion (HB, n=10) groups. In bilirubin infusion groups (NB and HB), a loading dose of bilirubin (35 mg/kg) was given over 5 min, followed by a continuous infusion (25 mg/kg/h) for 4 h. The control groups (NC, HC) received a bilirubin-free buffer solution. Sulfadimethoxine was administered to animals in all experimental groups. Rectal temperature was maintained between 38.0 and 39.0 degrees C in normothermic groups, and between 34.0 and 35.0 degrees C in hypothermic groups for 4 h after the start of bilirubin infusion. The final blood and brain bilirubin concentrations in the bilirubin infusion groups (NB and HB) were not significantly different. Decreased cerebral cortical cell membrane Na(+),K(+)-ATPase activity and increased lipid peroxidation products observed in the NB group, indicative of bilirubin-induced brain damage, were significantly attenuated in the HB group. Hypothermia also significantly improved the bilirubin-induced reduction in brain ATP and phosphocreatine levels and increase in blood and brain lactate levels. In summary, hypothermia significantly attenuated the bilirubin-induced alterations in brain cell membrane function and energy metabolism in the newborn piglet. These findings suggest the possibility that hypothermia could be a good neuroprotective therapeutic modality in neonatal bilirubin encephalopathy.

A case of hereditary angioedema associated with idiopathic hypoparathyroidism

Hereditary angioedema is a rare autosomal dominant disease characterized by the edema of subcutaneous tissues, respiratory tract and bowel. It is caused by the deficiency of C1 esterase inhibitor. Hereditary angioedema may be associated with autoimmune diseases, such as systemic lupus erythematosus, rheumatoid arthritis, autoimmune thyroiditis and glomerulonephritis. We report a 34-year-old male patient with hereditary angioedema who developed idiopathic hypoparathyroidism. Autoimmunity seems to be an important basis of this association and it might be caused by the immune dysfunction due to decreased level of complements; nevertheless, a casual association could not be excluded. To our knowledge, this is the first report of hereditary angioedema in association with idiopathic hypoparathyroidism in the medical literature.

Analysis of three lupane type triterpenoids in Helicteres angustifolia by high-performance liquid chromatography

Kang-chih-ma is the dried roots and stems of Helicteres angustifolia (Sterculiaceae) and a commonly used folk herbal drug in Taiwan. It possesses antidotal, analgesic, anti-inflammatory and anti-bacterial effects and is also known as a kind of tumor inhibitory plant. To evaluate the quality of H. angustifolia, a simple, rapid and accurate high-performance liquid chromatographic (HPLC) method was developed for the assay of three lupane type triterpenes: 3beta-acetoxy-27-benzoyloxylup-20(29)-en-28-oic acid methyl ester (methyl helicterate), 3beta-acetoxy-27-benzoyloxylup-20(29)-en-28-oic acid, and 3beta-acetoxy-27-(p-hydroxyl) benzoyloxylup-20(29)-en-28-oic acid methyl ester. The present HPLC system used an Inertsil ODS-2 column by gradient elution with acetonitrile and water as the mobile phase and detected at UV 230 nm. Regression equations revealed good linear relationships (correlation coefficients: 0.9922-0.9997). The relative standard deviations of these three constituents ranged between 1.05-3.14% (intraday) and 2.12-4.38% (interday). The contents of these three constituents of the heartwood and the bark of the roots of H. angustifolia in five different samples have also been determined.

N(omega) -nitro-L-arginine methyl ester (L-NAME) attenuates the acute inflammatory responses and brain injury during the early phase of experimental Escherichia coli meningitis in the newborn piglet

We evaluated the anti-inflammatory and neuroprotective effect of nonselective NOS inhibitor, N(omega)-nitro-L-arginine methyl ester (L-NAME), in experimental bacterial meningitis in the newborn piglet. Meningitis was induced by intracisternal injection of 10(8) colony forming units of Escherichia coli. L-NAME 10 mg kg(-1) was given intravenously 30 min before induction of meningitis. L-NAME significantly attenuated the increase in intracranial pressure and decrease in cerebrospinal fluid glucose concentration observed in the meningitis group. Systemic and cerebral perfusion pressure were even higher compared to the control and meningitis groups. However, the meningitis-induced increase in tumor necrosis factor-alpha level, leukocyte numbers and lactate level in the cerebrospinal fluid was not significantly attenuated with L-NAME administration. Reduced cerebral cortical cell membrane Na+, K+ -ATPase activity and increased lipid peroxidation products, indicative of meningitis-induced brain cell membrane dysfunction, were significantly improved with L-NAME treatment. Decreased brain glucose and ATP levels were also significantly improved with L-NAME treatment. These findings suggest that L-NAME was effective in attenuating the acute inflammatory responses and brain injury in neonatal bacterial meningitis.

Helicobacter pylori prevalence and CagA status among children in two counties of China with high and low risks of gastric cancer

BACKGROUND

Studies in adult populations in selected countries with widely varying rates of gastric cancer have shown a weak correlation between gastric cancer mortality rates and the prevalence of CagA+ strains of H. pylori. However, only limited data are available in ethnically homogenous populations with varying rates in the same region. METHODS; We compared the prevalence of H. pylori in general and of CagA+ strains in particular among children in Shandong Province, China in areas at high (Linqu County) and low risk (Cangshan County) of gastric cancer. H. pylori status among children aged 3 to 12 years was determined by 13C-UBT, and CagA status was determined by enzyme-linked immunosorbent assay (ELISA). Because of the difficulty in obtaining blood from young children aged 3 to 4 years and from some children aged 5 years, CagA status was determined among part of children 5 years old and children 6 to 12 years old. RESULTS; Among 98 children aged 3 to 12 years in Linqu, 68 (69.4%) was H. pylori-positive, as compared with 29 (28.7%) among 101 children in Cangshan. Among children positive for 13C-UBT, the proportion of the CagA+ strains were identified was 46 (88.5%) of 52 in Linqu and 13 (81.3%) of 16 in Cangshan, respectively.

CONCLUSIONS

The prevalence of H. pylori was nearly three times higher among children in Linqu than in Cangshan, which may contribute to the large differential in gastric cancer rates for two neighboring populations in Shandong Province.

Cloning, characterization, and phylogenetic analysis of a shrimp white spot syndrome virus gene that encodes a protein kinase

An open reading frame (ORF) that encodes a 715-amino-acid polypeptide was found in an 8421-bp EcoRI fragment of the shrimp white spot syndrome virus (WSSV) genome. The polypeptide shows significant homology to eukaryotic serine/threonine protein kinase (PK) and contains the major conserved subdomains for eukaryotic protein kinases. Coupled in vitro transcription and translation generated a protein having an apparent molecular mass of about 87 kDa according to sodium dodecyl sulfate-polyacrylamide gel electrophoresis. For transcriptional analysis of the pk gene, total RNA was isolated from WSSV-infected shrimp at different times after infection. Northern blot analysis with pk-specific riboprobe found a major and a minor transcript of 2.7 and 5.7 kb, respectively. Rapid amplification of the 5' cDNA ends of the major 2.7-kb pk transcript showed that there were two transcriptional initiation sites located at nucleotide residues -38(G) and -39(G) relative to the ATG translational start codon. Temporal expression analysis by RT-PCR indicated that the transcription of the pk gene started 2 h after infection and continued for at least 60 h. Phylogenetic analysis showed that WSSV protein kinase does not have any close relatives and does not fall into any of the major protein kinase groups.

Performance of WSSV-infected and WSSV-negative Penaeus monodon postlarvae in culture ponds

In a survey of 27 Penaeus monodon culture ponds stocked with postlarvae (approximately PL10) at medium density (approximately 40 shrimp m(-2)), single-step nested white spot syndrome virus (WSSV) PCR was used to measure the WSSV infection rates in the shrimp populations within 1 mo after stocking. Seven ponds were initially WSSV-free, and the shrimp in 5 of these were harvested successfully. In the ponds (n = 6) where detection rates were higher than 50%, mass mortality occurred during the growth period, and none of these ponds was harvested successfully. In a subsequent study, P. monodon brooders were classified into 3 groups according to their WSSV infection status before and after spawning: brooders that were WSSV-positive before spawning were assigned to group A; spawners that became WSSV-positive only after spawning were assigned to group B; and group C consisted of brooders that were still WSSV-negative after spawning. WSSV screening showed that 75, 44 and 14%, respectively, of group A, B and C brooders produced nauplii that were WSSV-positive. Most (57%; 16/28) of the brooders in group A produced nauplii in which the WSSV prevalence was high (>50%). When a pond was stocked with high-prevalence nauplii from 1 of these group A brooders, an outbreak of white spot syndrome occurred within 3 wk and only approximately 20% of the initial population survived through to harvest (after 174 d). By contrast, 2 other ponds stocked with low-prevalence and WSSV-negative nauplii (derived respectively from 2 brooders in group B), both had much higher survival rates (70 to 80%) and yielded much larger (approximately 3x by weight) total harvests. We conclude that testing the nauplii is an effective and practical screening strategy for commercially cultured P. monodon.

The enhanced effect of a hexameric deoxyriboguanosine run conjugation to CpG oligodeoxynucleotides on protection against allergic asthma

BACKGROUND

Oligodeoxynucleotides containing a CpG motif (CpG ODNs), as potent inducers of T(H)1 immunity, are considered promising candidates for immune modulation in asthma. We have previously demonstrated that conjugation of a hexameric deoxyriboguanosine run to the 3' terminus (3' dG(6)-run) of phosphodiester (PE) CpG ODNs enhanced their immuno-stimulatory activities in vitro.

OBJECTIVE

This study aimed to evaluate the effect of a 3' dG(6)-run conjugation to PE or phosphorothioate (PS) CpG ODNs on protection against murine allergic asthma in vivo.

METHODS

Balb/c mice were sensitized to ovalbumin by intraperitoneal injection with or without CpG ODNs (PS CpG ODNs, PE CpG ODNs, and those with 3' dG(6)-run) and subsequently challenged with ovalbumin. We evaluated airway hyperresponsiveness, eosinophil proportion in bronchoalveolar lavage fluid, airway inflammation, and ovalbumin-specific antibody responses.

RESULTS

The conjugation of a 3' dG(6)-run to PE CpG ODNs enhanced the production of IFN-gamma from ovalbumin-specific T(H) cells and prevented the development of asthma in terms of airway hyperresponsiveness, airway eosinophilia, and ovalbumin-specific IgE responses; these effects were comparable to those of PS CpG ODNs. Enhanced effects of the 3' dG(6)-run were also observed in PS CpG ODNs, though they were lower than those in PE CpG ODNs.

CONCLUSION

This study suggests that conjugation of a 3' dG(6)-run to CpG ODNs might provide an effective method for immune modulation of allergic asthma.

Thyroxine treatment induces upregulation of renin-angiotensin-aldosterone system due to decreasing effective plasma volume in patients with primary myxoedema

BACKGROUND

In experimental animals and humans, hypothyroidism is associated with fluid retention and generalized oedema, increased antidiuretic hormone (ADH), decreased atrial natriuretic hormone (ANH), and decreased renin-angiotensin-aldosterone system (RAAS), which subsequently can be corrected by thyroid hormone replacement. The purpose of this study was to determine the effect of thyroxine therapy on RAAS and neurohormones affecting water and electrolyte metabolism and the reason for these changes in patients with primary myxoedema.

METHODS

We measured changes in the plasma renin activity (PRA), serum aldosterone (Aldo), ADH, ANH levels, serum and 24 h urinary electrolytes and osmolalities, and cardiac function in 22 female patients with primary myxoedema before and after correction of hypothyroidism. We also evaluated age-, sex-, and BMI-matched 15 healthy control subjects (Cont).

RESULTS

It took an average of 4.3 months (range, 3-9 months) to normalize thyroid function. The mean reductions of body weight and estimated plasma volume were 1.8+/-1.0 kg (P=0.002) and 8.5% (P<0.001), respectively. In addition, serum Na+ and osmolality and the haematocrit were significantly elevated after correction of hypothyroidism (P<0.01 and P<0.001, respectively). Increased F(E)Na and C(OSM) (P<0.05) levels in patients with hypothyroidism (Ho) compared with those in Cont did not change after thyroxine therapy (Eu). However, C(H(2)O), U(E)K, F(E)K, and TTKG levels as well as creatinine clearance (Ccr) were markedly increased in Eu compared with Ho and Cont (P<0.01, respectively). Increased plasma ADH concentration and decreased plasma ANH concentration were normalized compared to Cont after thyroxine therapy (P<0.001 and P<0.01, respectively). Low PRA and serum Aldo concentration in Ho were significantly increased in Eu (P<0.001 and P<0.01, respectively). In addition, increased left ventricular mass index and decreased cardiac output in Ho were normalized compared to Cont after thyroxine therapy (P<0.01, respectively)

CONCLUSIONS

These findings suggest that the exaggerated upregulation of RAAS after correction of hypothyroidism in patients with primary myxoedema is associated with an increase in Ccr and a decrease in plasma volume resulting from water diuresis, natriuresis, osmotic diuresis and inappropriate changes in plasma ADH and ANH levels. The improved renal function coincided with an amelioration of cardiac function. These changes seem to be an adaptive response for preventing excessive plasma volume and weight loss after thyroxine therapy.

Effects of hyperglycemia or hypoglycemia on brain cell membrane function and energy metabolism during the immediate reoxygenation-reperfusion period after acute transient global hypoxia-ischemia in the newborn piglet

This study was done to determine the effects of hyperglycemia or hypoglycemia on brain cell membrane function and energy metabolism during the immediate reoxygenation-reperfusion period after hypoxia-ischemia (HI). Forty-five newborn piglets were divided randomly into four experimental groups: normoxia control (NC, n=9); HI/reoxygenation-reperfusion (RR) control (HC, n=11); HI/RR hyperglycemia (HE, n=12); and HI/RR hypoglycemia (HO, n=13) group. Animals were subjected to transient HI for 30 min followed by 2 h of RR. Cerebral HI was induced by temporary but complete occlusion of bilateral common carotid arteries with surgical clips and simultaneous breathing with 8% oxygen. Glucose was unregulated in HC group, and controlled by modified glucose clamp technique immediately after HI in HE (350 mg/dl) and HO (50 mg/dl) groups. During HI, heart rate, base deficit, glucose and lactate level in the blood and cerebrospinal fluid increased, and arterial pH, oxygen saturation and blood pressure decreased significantly in HC, HE and HO groups. During RR, these abnormalities returned to normal values, but lactic acidosis persisted especially in HO group. Cerebral Na(+),K(+)-ATPase activity decreased, and lipid peroxidation products increased significantly in HC group than in NC group, and these abnormalities were significantly aggravated in HE, but not in HO, group. Brain ATP and phosphocreatine levels in HE group were significantly reduced compared to the corresponding values in NC, HC and HO groups. In summary, hyperglycemia, but not hypoglycemia immediately after HI interfered with the recovery of brain cell membrane function and energy metabolism. These findings suggest that post-hypoxic-ischemic hyperglycemia is not beneficial and might even be harmful in neonatal hypoxic-ischemic encephalopathy.

Isolation and characterization of a cell-associated protein of Bacillus pumilus PH-01

A cell-associated protein released from Bacillus pumilus PH-01 showed an affinity for some dioxins, like 1,2,3,4-tetrachlorodibenzo-p-dioxin (TCDD) and 1,2,3,4-tetrachlorodibenzofuran (TCDF), and the concentration of the protein increased when B. pumilus PH-01 was boiled in minimal salts medium. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and matrix-assisted laser desorption ionization-mass spectrometry revealed that the boiled culture supernatant contained a major protein with a molecular mass of 5,313.4 Da. The adsorption behavior of the protein for 1,2,3,4-TCDD and 1,2,3,4-TCDF was examined by digesting it with proteinase K and trypsin, showing that the proteolyzed protein lost the ability to adsorb the compounds. The amino acid sequence of the protein was determined by automated Edman degradation and tandem mass spectrometry. A search of the protein databases showed no existence of proteins with an homologous sequence.

7-Nitroindazole, but not aminoguanidine, attenuates the acute inflammatory responses and brain injury during the early phase of Escherichia coli meningitis in the newborn piglet

We evaluated the anti-inflammatory and neuroprotective effects of the selective neuronal nitric oxide synthase inhibitor 7-nitroindazole and aminoguanidine, which predominantly inhibits inducible nitric oxide synthase, during the early phase of experimental bacterial meningitis in the newborn piglet. Meningitis was induced by intracisternal injection of 10(8) colony-forming units of Escherichia coli in 100 microl of saline. 7-Nitroindazole significantly attenuated the meningitis-induced acute inflammatory responses such as increased intracranial pressure, decreased cerebrospinal fluid (CSF) glucose concentration, and CSF leukocytosis at 2 h. However, meningitis-induced CSF leukocytosis at 4 h and increased CSF lactate and tumor necrosis factor alpha levels were not significantly attenuated. Reduced cerebral cortical cell membrane Na(+),K(+)-ATPase activity and increased lipid peroxidation products, indicative of meningitis-induced brain cell membrane dysfunction, were also significantly improved with 7-nitroindazole treatment. In contrast, although aminoguanidine significantly attenuated the increase in the CSF tumor necrosis factor alpha level, it failed to attenuate the acute inflammation and the ensuing brain injury in bacterial meningitis. In summary, 7-nitroindazole, but not aminoguanidine, significantly attenuated the acute inflammatory responses and brain injury during the early phase of neonatal bacterial meningitis.

Shear stress regulates occludin content and phosphorylation

Previous studies determined that shear stress imposed on bovine aortic endothelial cell (BAEC) monolayers increased the hydraulic conductivity (L(P)); however, the mechanism by which shear stress increases L(P) remains unknown. This study tested the hypothesis that shear stress regulates paracellular transport by altering the expression and phosphorylation state of the tight junction protein occludin. The effect of shear stress on occludin content was examined by Western blot analysis. Ten dyn/cm(2) significantly reduced occludin content in a time-dependent manner such that after a 3 h exposure to shear, occludin content decreased to 44% of control. Twenty dyn/cm(2) decreased occludin content to 50% of control and increased L(P) by 4.7-fold after 3 h. Occludin expression and L(P) depend on tyrosine kinase activity because erbstatin A (10 microM) attenuated both the shear-induced decrease in occludin content and increase in L(P). Shear stress increased occludin phosphorylation after 5 min, 15 min, and 3 h exposures. The shear-induced increase in occludin phosphorylation was attenuated with dibutyryl (DB) cAMP (1 mM), a reagent previously shown to reverse the shear-induced increase in L(P). We conclude that shear stress rapidly (< or = 5 min) increases occludin phosphorylation and significantly decreases the expression of occludin over 1-4 h. Alterations in the occludin phosphorylation state and occludin total content are potential mechanisms by which shear stress increases L(P).

3-Aminobenzamide, a poly (ADP-ribose) synthetase inhibitor, attenuates the acute inflammatory responses and brain injury in experimental Escherichia coli meningitis in the newborn piglet

The aim of the present study was to evaluate the anti-inflammatory and neuroprotective effects of a poly (ADP-ribose) synthetase inhibitor 3-aminobenzamide during the early phase of experimental bacterial meningitis in the newborn piglet. Meningitis was induced by intracisternal injection of 10(8) colony forming units of Escherichia coli in 100 microl of saline. 3-Aminobenzamide, given 30 mg kg(-1) as a bolus i.v. injection 30 min before induction of meningitis, significantly attenuated the meningitis-induced acute inflammatory responses such as increased cerebrospinal fluid (CSF) lactate concentration, CSF leukocytosis and increased CSF tumor necrosis factor-alpha level. However, meningitis-induced increase in intracranial pressure and decrease in CSF glucose level were not significantly improved. Increased cerebral cortical cell membrane lipid peroxidation products (conjugated dienes) and decreased brain ATP/phosphocreatine levels observed in the meningitis group were also significantly improved with 3-aminobenzamide treatment. However, the improvement of reduced Na+, K+-ATPase activity did not reach a statistical significance (p = 0.06). In summary, 3-aminobenzamide significantly attenuated the acute inflammatory responses and the ensuing brain injury during the early phase of neonatal bacterial meningitis. These findings suggest that poly (ADP-ribose) synthetase inhibitors such as 3-aminobenzamide might be a promising novel anti-inflammatory and neuroprotective adjuvant therapy in neonatal bacterial meningitis.

Effect of hypothermia on brain cell membrane function and energy metabolism after transient global hypoxia-ischemia in the newborn piglet

This study was done to determine the effects of hypothermia on brain cell membrane function and energy metabolism after transient hypoxia-ischemia (HI) in the newborn piglet. Cerebral HI was induced by temporarily complete occlusion of bilateral common carotid arteries with surgical clips and simultaneous breathing with 8% oxygen for 30 min, followed by release of carotid occlusion and normoxic ventilation for 4 hr. Rectal temperature was maintained between 38.0 and 39.0 degrees C in normothermic groups, and between 34.0 and 35.0 degrees C in hypothermic groups for 4 hr after HI. During HI, heart rate, glucose and lactate level in the blood and cerebrospinal fluid increased, and base excess, pH and blood pressure decreased significantly in both normothermic and hypothermic groups. After HI, these abnormalities returned to normal in normothermic group, but lactic acidosis persisted in hypothermic group. Decreased cerebral Na+,K+- ATPase activity and increased lipid peroxidation products, indicative of HI- induced brain injury, were more profound in hypothermic group than in normothermic group. Brain ATP and phosphocreatine levels were not different between normothermic and hypothermic groups. In summary, hypothermia applied immediately after HI for 4 hr did not improve the recovery of brain cell membrane function and energy metabolism in the newborn piglet.

An intervention trial to inhibit the progression of precancerous gastric lesions: compliance, serum micronutrients and S-allyl cysteine levels, and toxicity

Gastric cancer is the second most frequent cause of death from cancer in the world and the leading cause of death from cancer in China. In September 1995, we launched a randomized multi-intervention trial to inhibit the progression of precancerous gastric lesions in Linqu County, Shandong Province, an area of China with one of the world's highest rates of gastric cancer. Treatment compliance was measured by pill counts and quarterly serum concentrations of vitamin C, vitamin E and S-allyl cysteine. In 1999, toxicity information was collected from each trial participant to evaluate treatment-related side-effects during the trial. Compliance rates were 93% and 92.9% for 39 months of treatment with the vitamins/mineral and garlic preparation, respectively. The means for serum concentrations of vitamins C and E were 7.2 microg/ml and 1695 microg/dl among subjects in the active treatment groups compared with 3.1 microg/ml and 752 microg/dl among subjects in the placebo treatment group, respectively. No significant differences in side-effects were observed between the placebo treatment group and the vitamins/mineral and garlic preparation treatment groups during the 39-month trial period.

The evaluation of the therapeutic effect of tao-shang-tsao on alpha-naphthylisothiocyanate and carbon tetrachloride-induced acute liver damage in rats

The hepatoprotective effects of Tao-shang-tsao, Ixeris laevigata Sch.-Bip. var. oldhami Kitam., were studied on cholestatic hepatitis induced by alpha-naphthylisothiocyanate (ANIT, 100 mg/10 ml/kg, in olive oil, i.p.) and acute hepatitis induced by carbon tetrachloride (20% CCl4/olive oil, 1.5 ml/kg, i.p.) in rats by post-treatment with the crude methanolic extracts of I. laevigata (0.3, 1.0, and 2.0 g/kg) orally in the therapeutic model. Hepatoprotective activity was monitored by estimating the serum transaminases concentrations and histopathological changes in the livers of experimental rats. It was found that the I. laevigata extract significantly decreased the acute elevation of serum transaminases by biochemical examination. According to pathohistological studies in the liver of experimental rats, the crude I. laevigata extract ameliorates the central necrosis, fatty change or proliferation of bile duct epithelium focal necrosis caused by ANIT or CCl4-induced hepatitis rats.

Access blood flow as a predictor of early failures of native arteriovenous fistulas in hemodialysis patients

Blood flow imaging using color doppler has proven effective in predicting graft failures in hemodialysis patients, but its effect on native arteriovenous fistulas (AVF) is not well known. This study was performed to investigate whether measurements of the access blood flow can be used as predictors of an early failure of a native AVF in hemodialysis patients. Fifty-three consecutive patients who received native AVF operations were included in this study. Access blood flow was measured at 1 week after operations, and AVF function was followed for 4 months. During the follow-up, access failures developed in 10 patients at 9.8 +/- 3.5 weeks. AVF blood flow was significantly lower in the failure group (n = 10) than in the patent group (n = 43) (450 +/- 214 vs. 814 +/- 348 ml/min, p = 0.003). The incidence of access failures was higher in the patients with a flow <350 ml/min (n = 9) compared to the patients with a flow >350 ml/min (n = 44) (55.5 vs. 11.3%, p = 0.008). The diameters of veins were significantly smaller in the failure group than in the patent group (3.5 +/- 0.5 vs. 4.1 +/- 0.7 mm, p = 0.018). The incidence of diabetes mellitus was higher in the failure group than in the patent group (90 vs. 51%, p = 0.025). However, age, sex, duration from an operation to first cannulation, and different AVF sites did not make a significant difference between the two groups. Our data suggest that access blood flow measurements using color doppler ultrasound during early postoperative periods are useful parameters in predicting an early failure of a native AVF in hemodialysis patients.

Efficient regional ozone control strategies for the eastern United States

When environmental regulatory bodies formulate control plans, it is incumbent upon them to try to achieve the stated goals in an economically efficient manner. The US Environmental Protection Agency (EPA) is presently developing regulations to limit the influence of transported ozone on areas that are having difficulty meeting the ambient air quality standard. EPA has proposed stringent control measures for emissions of nitrogen oxides (NOx) in 22 states of the eastern US. The strategy would necessitate the use of selective catalytic reduction or similar high-performance technology on almost all major power plants in the region, as well as extensive controls on industrial sources. This paper suggests several alternative approaches that would achieve equal or better environmental improvement at lower cost. These include focusing control efforts on sources closer to the North-east Corridor, pushing controls on close-in sources to a higher level of technology performance, and relaxing the stringency of requirements for states remote from ozone problem areas. All the approaches examined are two to three times more cost-effective than EPA's proposed approach in the North-east Corridor.

Juxtaglomerular cell tumor of the kidney: a case report

We report a case of renin-secreting juxtaglomerular cell tumor which developed in a hypertensive 47-yr-old Korean man. Presumptive clinical diagnosis was made before surgery based on the high level of plasma renin and the radiologic evidence of renal mass. Grossly, a round, bulging, well-encapsulated mass of 3 x 3 cm was located in the mid-portion of the right kidney. On microscopic examination, the tumor was composed of ovoid to polyhedral cells with bland nuclei, indistinct nucleoli and light eosinophilic cytoplasm. The immunostaining for renin showed strong positivity in the cytoplasm of tumor cells. The characteristic rhomboid shaped renin protogranules were observed in ultrastructural analysis.

Effect of hypothermia on brain cell membrane function and energy metabolism in experimental Escherichia coli meningitis in the newborn piglet

We evaluated the anti-inflammatory and neuroprotective effects of hypothermia during the early phase of experimental Escherichia coli meningitis in the newborn piglet. Hypothermia significantly attenuated the meningitis-induced acute inflammatory responses such as increased intracranial pressure, decreased glucose level, increased lactate concentration, increased tumor necrosis factor-alpha level and leukocytosis in the cerebrospinal fluid. Decreased cerebral cortical cell membrane Na+,K+-ATPase activity and increased lipid peroxidation products, indicative of meningitis-induced brain damage, were significantly improved with hypothermia. Hypothermia also significantly improved the meningitis-induced reduction in brain ATP and phosphocreatine levels. In summary, hypothermia significantly attenuated the acute inflammatory responses and the ensuing brain injury in experimental neonatal bacterial meningitis.

Clinical significance of anti-endothelial cell antibody in renal transplant recipients

In order to evaluate the role of anti-endothelial cell antibody (AECA) in acute rejection in renal transplantation, serum AECA IgG titers were measured in 68 healthy controls, 111 chronic hemodialysis (HD) patients and 58 first renal transplant recipients. The AECA titer in hemodialysis patients was higher than in healthy controls (13.9 +/- 5.0 vs. 4.8 +/- 2.3 U/mL, p < 0.01). In transplant recipients, AECA titers were not affected by dialysis mode (HD vs. CAPD vs. non-dialysis; 9.6 +/- 7.6 vs. 7.9 +/- 3.9 vs. 11.9 +/- 3.1 U/mL, p > 0.05). After renal transplantation, AECA titer was decreased significantly (vs. 4.7 +/- 3.6 U/mL. p < 0.01). The serum AECA IgG titers increased significantly in recipients with acute rejection (6.9 +/- 3.1 vs. 13.5 +/- 9.9 U/mL, p < 0.01), but decreased to 5.6 +/- 3.0 U/mL (p < 0.01) after formal rejection therapy. In the recipients with acute rejection (n = 27), the pre-renal transplant AECA titer was higher than in that without acute rejection (14.0 +/- 8.6 vs. 7.7 +/- 3.8 U/mL, p < 0.01). The results of this study lead us to conclude that pre- and post-renal transplant AECA titer might be a useful predictor for acute rejection and useful for monitoring acute rejection in renal transplant recipients.

Kinetics of placenta growth factor/vascular endothelial growth factor synergy in endothelial hydraulic conductivity and proliferation

Vascular endothelial growth factor (VEGF) was originally discovered as vascular permeability factor because of its ability to increase microvascular permeability to plasma proteins. Since then, it has been shown to induce proliferation and migration in endothelial cells. Placenta growth factor (PlGF) is a member of the VEGF family of growth factors, but has little or undetectable mitogenic activity on endothelial cells. Intriguingly, however, PlGF was able to potentiate the action of low concentrations of VEGF on endothelial cell growth and macromolecule permeability in vitro. Here we show that PlGF can potentiate the effects of VEGF on the hydraulic conductivity of certain endothelial cells and that the duration of pretreatment with PlGF determines the resulting response. Hydraulic conductivity (Lp) was calculated from the water flux across the monolayer of human umbilical vein endothelial cells (HUVECs) or bovine aortic endothelial cells (BAECs). After 2 h of exposure to VEGF(165), the Lp of BAEC monolayers increased threefold, but the Lp of HUVEC monolayers did not increase. PlGF alone induced a small (63%) increase in Lp in BAECs, but not in HUVECs. BAEC, but not HUVEC, monolayers exposed first to PlGF and then to VEGF exhibited a seven- to eightfold increase in Lp. This enhancement in BAEC Lp could be observed for 4 h after the administration of PlGF. PlGF also potentiated the effect of VEGF on BAEC proliferation. Thus, augmentation of VEGF action by PlGF depends on the duration of PlGF exposure and on the origin of endothelial cells.

Sequencing and amplified restriction fragment length polymorphism analysis of ribonucleotide reductase large subunit gene of the white spot syndrome virus in blue crab (Callinectes sapidus) from American Coastal Waters

In the present study, the existence of white spot syndrome virus (WSSV) in blue crab (Callinectes sapidus) collected from 3 different American coastal waters (New York, New Jersey, and Texas) was confirmed by 2-step diagnostic polymerase chain reaction and in situ hybridization analysis. When geographic isolates were also compared using a gene that encodes the WSSV ribonucleotide reductase large subunit RR1 (WSSV rr1), a C(1661)-to-T point mutation was found in the New Jersey WSSV isolated. This point mutation, which resulted in the creation of an additional RsaI endonuclease recognition site, was not found in the WSSV from the New York and Texas blue crab samples, or in the WSSV Taiwan isolate, or in any of the other WSSV geographical isolates for which data are available. WSSV rr1-specific RsaI amplified restriction fragment length polymorphism of an amplified 1156-bp fragment thus distinguished the New Jersey blue crab samples from the other WSSV isolates.