[The clinical effect of ultrasonic bone curette-assisted "zoning" style laminectomy for the treatment of severe ossification of thoracic ligamentum flavum]

Objective: To investigate the safety and clinical efficacy of "zoning" style laminectomy by ultrasonic bone curette in patients with severe thoracic ossification of the ligamentum flavum(TOLF). Methods: The clinical data of 36 patients with severe TOLF treated by "zoning" style laminectomy at Department of Spinal Surgery,Zhengzhou Orthopaedic Hospital from October 2015 to October 2018 were respectively analyzed.There were 17 males and 19 females,aged(57.3±10.2)years(range:43 to 80 years).According to the anatomical characteristics of the thoracic ligamentum flavum and the pathological process of ossionization,each decompression segment was divided into the upper 1/3 area of the lamina,the bilateral area of the ossionum flavum,the transitional area,and the area of close contact between the ossionum flavum and the spinal cord.Different surgical strategies were used for decompression in turn.The modified Japanese Orthopedic Association (mJOA) was used to evaluate the neurological function status before and after surgery,to evaluate the surgical effect of patients,and to observe the surgical complications.Paired sample T test was used for data analysis. Results: All 36 patients successfully completed the operation,the operation time was (88.6±24.6) minutes(range:60 to 150 minutes).The intraoperative blood loss was (426.7±167.4) ml(range:250 to 800 ml).Follow-up time was (27.2±7.7) months(range:12 to 48 months).The mJOA score at the last follow-up was 9.0±1.5,which was statistically significant compared with the preoperative score 5.4±1.8 (t=13.59,P<0.01).The improvement rate of mJOA score was (65.7±22.1) %,of which 17 cases were excellent (47.2%),13 cases were good (36.1%),4 cases were normal (11.1%),2 cases were ineffective (5.6%).Ten patients had cerebrospinal fluid leakage during the separation or removal of dural ossification and were cured after a series of comprehensive conservative treatment.Two patients showed transient neurological deterioration,and the neurological function gradually recovered to the preoperative state after comprehensive treatment such as increasing the mean arterial pressure and using neurotrophic drugs.During the follow-up,no aggravation of neurological dysfunction and segmental kyphosis were found. Conclusions: The ultrasonic bone curette-assisted "zoning" style laminectomy for the treatment of severe TOLF can directly observed the position relationship between ossification of the ligamentum flavum and the spinal canal structure during the operation,and accurately guide the surgical decompression.It has the advantages of safe operation and complete decompression,which provides an important reference for the selection of clinical surgery.

[Anterior retropharyngeal debridement combined with posterior atlantoaxial fusion for atlantoaxial Tuberculosis]

OBJECTIVE

To evaluate the clinical efficacy of anterior debridement combined with posterior atlantoaxial fusion for atlantoaxial Tuberculosis.

METHODS

From February 2005 to February 2013, 7 patients, 3 males and 4 females, with atlantoaxial Tuberculosis underwent anterior debridement combined with posterior atlantoaxial fusion in Department of Orthopedics Zhengzhou University People's Hospital were selected.In the preoperative and final follow-up, Japanese Orthopaedic Association score (JOA), neck disability index (NDI) and Frankel Classification were used to evaluate neurological function and calculate improvement rate.At final follow-up, clinical efficacy was evaluated by Odom's grade.Situation of internal fixation, fusion of upper cervical were assessed by X-ray, CT scan and MRI scan.

RESULTS

Bony fusion were achieved in 7 cases after operation in 12 months. Tuberculosis were reached clinical cure between 17 and 21 months. At follow The JOA score increased from (11.1±0.7) preoperatively to (15.3±0.5) in final follow-up(P<0.05), and the NDI decreased from (34.0±4.6) preoperatively to (10.1±1.3) in final follow-up (P<0.05). At last follow-up, according to Odom's standard, excellent were obtained in 5 cases, good 1 cases and ordinary 1 case. Frankel Classification of all cases improved from D class to E.

CONCLUSIONS

The treatment of anterior retropharyngeal debridement combine with atlantoaxial fusion, and local anti-tuberculosis drug using intraoperative, not only could obtain reliable clinical efficacy, completly removal of lesions, but also obtain strong stability, which plays an important role in the treatment of atlantoaxial Tuberculosis.

Fibroblast growth factor 21 improves insulin resistance and ameliorates renal injury in db/db mice

Despite the emerging importance of fibroblast growth factor 21 (FGF21) as a metabolic hormone regulating energy balance, its direct effects on renal function remain unexplored. FGF21 was injected ip daily for 12 weeks into db/db mice. Compared with control vehicle injection, FGF21 treatment significantly improved lipid profiles and insulin resistance and resulted in significantly higher serum adiponectin levels. In contrast, serum insulin and 8-isoprostane levels were significantly decreased. Interestingly, FGF21 and its receptor components in the kidneys were found to be significantly up-regulated in db/db mice, which suggests an FGF21-resistant state. FGF21 treatment significantly down-regulated FGF21 receptor components and activated ERK phosphorylation. FGF21 administration also markedly decreased urinary albumin excretion and mesangial expansion and suppressed profibrotic molecule synthesis. Furthermore, FGF21 improved renal lipid metabolism and oxidative stress injury. In cultured renal cells, FGF21 was mainly expressed in mesangial cells, and knockdown of FGF21 expression by stealth small interfering RNA further aggravated high-glucose-induced profibrotic cytokine synthesis in mesangial cells. Our results suggest that FGF21 improves insulin resistance and protects against renal injury through both improvement of systemic metabolic alterations and antifibrotic effects in type 2 diabetic nephropathy. Targeting FGF21 could therefore provide a potential candidate approach for a therapeutic strategy in type 2 diabetic nephropathy.

Renal protective effects of toll-like receptor 4 signaling blockade in type 2 diabetic mice

Chronic inflammation caused by high glucose and high free fatty acid (FFA) concentrations is a major contributor to the pathogenesis of type 2 diabetes. Recent evidence suggests that activation of Toll-like receptor (TLR) signaling induces peripheral insulin resistance and mediates central insulin and leptin resistance. In this study, we investigated the renal effects of TLR4 signaling blockade in type 2 diabetic mice. Eight-week-old db/db mice were treated for 12 weeks with (S,R)-3-phenyl-4,5-dihydro-5-isoxasole acetic acid (GIT27), which targets macrophages through the inhibition of TLR4- and TLR2/6-mediated signaling pathways. Although GIT27 treatment improved glycemic control and insulin tolerance, which is associated with a lower lipid profile, it did not impact body weight or food consumption. GIT27 treatment also markedly decreased urinary albumin excretion, decreased proinflammatory cytokine synthesis, improved tissue lipid metabolism, induced oxidative stress, and improved glomerulosclerosis compared with the control db/db group. In cultured podocytes and adipocytes, high glucose levels with FFA stimulation increased TLR4 expression and proinflammatory cytokine synthesis, but the effects were abolished by GIT27 treatment. In addition, knockdown of TLR4 expression by stealth small interfering RNA abolished FFA-induced proinflammatory cytokine synthesis in cultured podocytes. In conclusion, our results suggest that GIT27 treatment improves insulin resistance and protects against the renal injury that occurs in type 2 diabetic nephropathy through both metabolic and antiglomerulosclerotic mechanisms. These results suggest that TLR pathway inhibition might play a direct protective role in diabetic kidney disease.

Microbial diversity and prevalence of foodborne pathogens in cheap and junk foods consumed by primary schoolchildren

Aerobic plate counts (APC), coliforms, Bacillus cereus, Escherichia coli and eight foodborne pathogens were tested in 1008 cheap and junk foods, including candies, dried cakes, chewing gum, chocolate, dried and seasoned seafood, ice cream, and sugary foods. APCs were positive for 342 samples (33·9%), and the majority of the counts were 2-3 log CFU g(-1) or ml(-1) (average: 1·10 log CFU g(-1) or ml(-1) ). Most samples (97·3%) contained no coliforms (average: 0·07 log CFU g(-1) or ml(-1) ). Bacillus cereus was detected in 68 samples (average: 0·14 log CFU g(-1) or ml(-1) ). Escherichia coli and Listeria monocytogenes were detected in 6 and 1 samples, respectively, whereas other foodborne pathogens were not isolated. The highest bacterial counts were associated with dried and seasoned seafood products and dried cakes, suggesting that appropriate regulations of these food types should be considered. Cheap and junk foods were produced mainly in developing countries, but there were no significant differences in the bacterial counts among different countries of origin. The presence of foodborne pathogens may pose a risk for children. These results suggest that there is cause for deeper concern about the safety of these foods and that effective countermeasures should be established to improve their microbiological safety.

SIGNIFICANCE AND IMPACT OF THE STUDY

Food safety is especially important for children, but only limited information is available about the microbiological quality of cheap and junk foods that are consumed frequently by primary schoolchildren (e.g. dried cakes, candies and chocolates). The present study investigated the microbial quality of cheap and junk foods, and our results indicate that these foods are a potential health risk for children, therefore, deeper concern about the safety of these foods and effective countermeasures should be established to improve their microbiological safety. The present study may contribute to the development of an appropriate child food safety management system.

Effects of surface chemical structure on the mechanical properties of Si(1-x)Ge(x) nanowires

The Young's modulus and fracture strength of Si(1-x)Ge(x) nanowires (NWs) as a function of Ge concentration were measured from tensile stress measurements. The Young's modulus of the NWs decreased linearly with increasing Ge content. No evidence was found for a linear relationship between the fracture strength of the NWs and Ge content, which is closely related to the quantity of interstitial Ge atoms contained in the wire. However, by removing some of the interstitial Ge atoms through rapid thermal annealing, a linear relationship could be produced. The discrepancy in the reported strength of Si and Ge NWs between calculated and experimented results could be related to SiO(2-x)/Si interfacial defects that are found in Si(1-x)Ge(x) NWs. It was also possible to significantly decrease the number of interfacial defects in the NWs by incorporating a surface passivated Al2O3 layer, which resulted in a substantial increase in fracture strength.

18F half-life measurement using a high-purity germanium detector

The half-life of (18)F has been measured using HPGe detectors with a (137)Cs reference source. The counting ratio of 511 keV γ-rays from (18)F to 622 keV γ-rays from (137)Cs was fitted for the half-life with a weighted least-square method. Uncertainties due to the systematic effects arising from the measurement of a high activity (18)F source were studied in detail. The half-life of (18)F was found to be (109.72±0.19) min. The result is in a good agreement with the recommended value of (109.728±0.019) min evaluated at the Laborotaire National Henri Becquerel (LNHB).

Blockade of cannabinoid receptor 1 improves insulin resistance, lipid metabolism, and diabetic nephropathy in db/db mice

The endocannabinoid system is important in the pathogenesis of obesity-related metabolic disorders. However, the effect of inhibiting the endocannabinoid system in type 2 diabetic nephropathy is unclear. Therefore, we examined the effect of the cannabinoid (CB)1 receptor antagonist, SR141716, on insulin resistance and diabetic nephropathy in db/db mice. Six-week-old db/db mice were treated with the CB1-specific antagonist SR141716 (10 mg/kg · d) for 3 months. Treatment with SR141716 significantly improved insulin resistance and lipid abnormalities. Concomitantly, CB1 antagonism improved cardiac functional and morphological abnormality, hepatic steatosis, and phenotypic changes of adipocytes into small differentiated forms, associated with increased adiponectin expression and decreased lipid hydroperoxide levels. CB1 receptor was overexpressed in diabetic kidneys, especially in podocytes. Treatment with the SR141716 markedly decreased urinary albumin excretion and mesangial expansion and suppressed profibrotic and proinflammatory cytokine synthesis. Furthermore, SR141716 improved renal lipid metabolism and decreased urinary 8-isoprostane levels, renal lipid hydroperoxide content, and renal lipid content. In cultured podocytes, high-glucose stimulation increased CB1 receptor expression, and SR141716 treatment abolished high-glucose-induced up-regulation of collagen and plasminogen activator inhibitor-1 synthesis. Additionally, knockdown of CB1 receptor expression by stealth small interfering RNA abolished high-glucose-induced sterol-regulatory element-binding protein-1 expression in podocytes. These findings suggest that CB1 blockade improves insulin resistance and protect against renal injury through both metabolic and antifibrotic effects in type 2 diabetic nephropathy. Targeting CB1 blockade could therefore provide a new therapeutic target to prevent type 2 diabetic nephropathy.

Measurement limits to 134Cs concentration in soil

We investigate the caesium concentrations in soils in mountain areas near Gori nuclear power plant in Korea, focusing on the measurement limits to the (134)Cs. In order to lower the minimum detectable amount (MDA) of activity for the (134)Cs, we have used the ammonium molybdophosphate (AMP) precipitation method to get rid of the (40)K existing in natural radioactivity, which reduces the MDA activity about 10 times smaller than those without the AMP precipitation method. The MDA results for the (134)Cs were found to be in the range between 0.015 and 0.044 Bq/kg-dry weight. In order to diminish the background, we also have measured a part of the soil samples in Yangyang, a small town in the east coast of Korea. However, it turns out that in order to detect the (134)Cs in the samples the MDA should be reduced to the level of mBq/kg-dry weight.

6-Mercaptopurine transport by equilibrative nucleoside transporters in conditionally immortalized rat syncytiotrophoblast cell lines TR-TBTs

Recently, more women were provided with 6-mercaptopurine (6-MP) during pregnancy. Therefore, we attempted to clarify the transport mechanisms of 6-MP through blood-placenta barrier using rat conditionally immortalized syncytiotrophoblast cell lines (TR-TBTs). The uptake of 6-MP was time- and ATP dependent, but sodium independent in TR-TBTs. 6-MP was eliminated over 50% from the cells within 30 min. The uptake of 6-MP was saturable with Michaelis-Menten constant values of 198 μM and 250 μM in TR-TBT 18d-1 and TR-TBT 18d-2, respectively. 6-Thioguanine, azathioprine, and hypoxantine, structural analogues of 6-MP, strongly inhibited [(14) C]6-MP uptake. Equilibrative nucleoside transporter (ENT) inhibitors, adenosine and uridine, significantly inhibited [(14) C]6-MP uptake. However, several organic anions and cations had no effect on [(14) C]6-MP uptake in TR-TBTs. These results suggest that sodium-independent transporters, ENTs, may be involved in 6-MP uptake at the placenta. In addition, multidrug resistance protein (MRP) inhibitors, methotrexate, probenecid, cefmetazole, and sulfinpyrazone, significantly increased the accumulation of [(14) C]6-MP in the cells. It is indicated that 6-MP may be eliminated across the blood-placental barrier via MRPs. TR-TBTs expressed mRNA of ENT1, ENT2, MRP4, and MRP5. These findings are important for the therapy of acute lymphoblastic leukemia and autoimmune diseases of pregnant women, and should be useful data in elucidating teratogenicity of 6-MP during pregnancy.

Synthesis of poly(methyl urethane) acrylate oligomer using 2-isocyanatoethyl methacrylate for UV curable coating

The poly(methyl urethane) acrylate oligomer was obtained by the reaction of methyl acrylate oligomer and 2-isocyanatoethyl methacrylate. Synthesis of poly(methyl urethane) acrylate oligomer was done with 2-mercaptoethanol (2-MEOH), methyl acrylate, 2,2'-azobisisobutyronitrile (AIBN, initiator) and dibutyltin dilaurate as a catalyst. Then 2-MEOH was used for functional chain transfer agent. The structure and property of the synthesized oligomers were characterized by FT-IR, FT-NMR, rheometer, and DSC. In this study, by synthetic method including the addition of 2-isocyanatoethyl methacrylate, thermal behavior of synthesized material was improved more than that reported in the previous study. Poly(methyl urethane) oligomer can be used for UV curable coatings, inks and adhesives. UV curable coating have high resistance against weather, ozone, aging, frictional wear, and heat. Besides they can absorb the shock and resist rust according to the thickness of film. It is used as an adhesive, paint, optical fiber coating agent, and waterproof agent because of these advantages at the present time.

Frequencies of CYP3A5 genotypes and haplotypes in a Korean population

BACKGROUND AND OBJECTIVE

CYP3A, the drug-metabolizing enzyme is an important factor in the pharmacokinetics of many drugs. Polymorphism of the CYP3A5 gene is known to influence the functionality of the CYP3A5 enzymes. The full extent of CYP3A5 genetic polymorphism was analysed in a Korean population.

METHODS

Specific polymerase chain reaction-restriction fragment length polymorphism tests for CYP 3AP1 through CYP3A5*7 or direct sequencing were used to identify reported CYP3A5 variant alleles, using 194 unrelated samples.

RESULTS AND DISCUSSION

The most frequent single nucleotide polymorphism (SNP) was 6986A>G (CYP3A5*3). The next most frequent SNP was 31611C>T. Haplotype analysis using detected SNPs revealed that the most frequent haplotype was *3A (frequency: 0.724), followed by *1E (frequency: 0.211), *3C (frequency: 0.034) and *1A (frequency: 0.023). We did not find CYP3AP1*3, CYP3A5*6, or *7 in this Korean sample.

CONCLUSION

A large proportion of Koreans may have relatively low levels of metabolically active CYP3A5 protein and therefore may be at risk of high levels of drugs metabolized by this enzyme, after administration of conventional doses.

Spironolactone ameliorates renal injury and connective tissue growth factor expression in type II diabetic rats

Administration of spironolactone provides a beneficial effect in various animal models of renal injury. In this study, we investigated whether spironolactone prevents the progression of diabetic nephropathy through reduction of connective tissue growth factor (CTGF) synthesis in type II diabetic rats. In addition, we evaluated the effect of aldosterone and spironolactone on CTGF and collagen production in cultured cells. Renal functional and morphologic changes were examined in Otsuka Long-Evans Tokushima Fatty rats with or without spironolactone treatment (20 mg/kg/day) for 8 months, as well as in non-diabetic age-matched Long-Evans Tokushima Otsuka rats. Spironolactone treatment did not induce any significant differences in body weight, kidney/body weight ratio, serum creatinine concentration, blood glucose levels, or systolic blood pressure. However, urinary protein and albumin excretion were significantly decreased in the spironolactone treatment group, which was associated with amelioration of glomerulosclerosis. In addition, renal CTGF, collagen synthesis demonstrated marked decreases in the spironolactone treatment group. In cultured MC and PTC, aldosterone induced significant increases in CTGF gene expression and protein synthesis associated with increased collagen synthesis, which was abolished by prior treatment with spironolactone. However, aldosterone treatment did not induce transforming growth factor (TGF)-beta1 overproduction, and inhibition of TGF-beta1 by neutralization of TGF-beta1 protein did not significantly prevent aldosterone-induced CTGF production. These results suggest that the antifibrotic effects of spironolactone may be mediated by CTGF through a TGF-beta1-independent pathway in this animal model of diabetic nephropathy.

Characteristics of population with normal serum creatinine impaired renal function and: The validation of a MDRD formula in a healthy general population

BACKGROUND AND AIMS

Glomerular filtration rate (GFR) provides the most accurate estimation of renal function. This study investigated the clinical characteristics of patients with impaired renal function having a normal serum creatinine level. We also validated whether the new Modification of Diet in Renal Disease (MDRD) formula can be applied in a healthy general population.

MATERIAL AND METHODS

A total 393 participants who had serum creatinine concentration below 132.6 micromol/L without underlying diseases were randomly selected on an address basis in Ansan City. According to the level of GFR, they were divided into 3 groups and we analyzed their clinical characteristics. In 75 subjects, who were randomly selected 25 cases in each group based on GFR estimated by Cockcroft-Gault (C-G) formula, true GFR was measured using the 99mTc-DTPA renal clearance method.

RESULTS

A total 393 (male: 106, female: 287) participants were as follows: GFR < 60 ml/min/1.73 m2; 4% (n = 25); 60 < or = GFR < 90 ml/min/1.73 m2; 26.2% (n = 103); GFR > or = 90 ml/min/1.73 m2; 67.4% (n = 265). In the group of decreased GFR, the mean age was older (67.4+/-10.7 vs. 48.7+/-12.8 vs. 39.4+/-8.2 years, p < 0.001), the gender was male (90.33+/-28.77 vs. 110.55+/-31.64, p < 0.001), and amount of proteinuria more increased (0.61 (0.56) vs. 0.33 (0.34) vs. 0.38 (0.33) gm/day, p = 0.007). The accuracy and precision of each formula were assessed by the difference in GFR measured by the 99mTc-DTPA renal clearance method--estimated GFR by each formula (deltaGFR), and the coefficient of determination (r2) of different predictive equations. The results were as follows: deltaGFR = -14.78+/-46.03, r2 = 0.79 (24-hour urinary creatinine clearance), deltaGFR=-16.79+/-57.32, r2 = 0.66 (100/serum creatinine), deltaGFR = 9.54+/-39.18, r2 = 0.87 (C-G formula), deltaGFR = -12.30+/-54.31, r2 = 0.66 (AASK formula), deltaGFR = 8.70+/-37.62, r2 = 0.79 (MDRD formula). Multiple linear regression analysis and logistic regression analysis showed that age, serum creatinine, total cholesterol and 24-hour urinary protein excretion were independently related to GFR and associated with a significant increase in the risk of decrement of GFR.

CONCLUSIONS

From these results, a more accurate assessment of renal function should be required in a population characterized by older age, male gender and more proteinuria. The MDRD study formula and Cockcroft-Gault formula have greater accuracy and precision with true GFR, and this equation can be applied in subjects with healthy general population.

Urinary concentration of transforming growth factor-beta-inducible gene-h3(beta ig-h3) in patients with Type 2 diabetes mellitus

AIMS

The expression of TGF beta-inducible gene h3(beta ig-h3) has been used to assess the biological activity of TGF beta in the kidney. In this study, we investigated whether the urinary concentration of beta ig-h3 is associated with diabetic nephropathy in patients with Type 2 diabetes mellitus. We also evaluated the relationship between the urinary concentration of beta ig-3 and proteinuria and microalbuminuria (AER) in a normal healthy population and in Type 2 diabetes patients.

METHODS

Four hundred and seventy-nine Type 2 diabetic patients without non-diabetic kidney diseases and 528 healthy control subjects were enrolled. The study subjects were divided into five groups: a non-diabetic healthy control group with normal ACR (n = 443), a non-diabetic healthy control group with microalbuminuria (n = 85), a normoalbuminuric diabetic group (n = 198), a microalbuminuric diabetic group (n = 155) and an overt proteinuria group (n = 126). Urinary levels of beta ig-h3 were measured by enzyme-linked immunosorbent assay.

RESULTS

(i) Urinary excretion of beta ig-h3 was significantly higher in the diabetic groups than in the controls, even in the normoalbuminuric stage (25.02 +/- 8.84 vs. 18.67 +/- 6.56, P = 0.03). In diabetic patients, urinary beta ig-h3 levels increased significantly as diabetic nephropathy advanced (25.02 +/- 8.84 vs. 34.06 +/- 24.55 vs. 169.63 +/- 57.33, P < 0.001). (ii) Proteinuria was found to be significantly correlated with urinary beta ig-h3 (healthy control; r = 0.137, P = 0.019, diabetic patients; r = 0.604, P < 0.001). ACR was also found to be significantly related with urinary beta ig-h3 in diabetic patients (r = 0.383, P = 0.006). (iii) In diabetic patients, urinary beta ig-h3 was significantly related with systolic and diastolic blood pressure (systolic blood pressure: r = 0.436, P = 0.024; diastolic blood pressure, r = 0.365, P = 0.042), total cholesterol and HbA(1c) (cholesterol: r = 0.169, P = 0.03, HbA(1c); r = 0.387, P = 0.044). Logistic regression analyses showed that urinary beta ig-h3 was associated with a significant increase in the risk of microalbuminuria and proteinuria in diabetic patients.

CONCLUSIONS

Longitudinal monitoring of urinary beta ig-h3 may improve the likelihood of detecting diabetic nephropathy at an earlier stage and beta ig-h3 could be a sensitive marker of diabetic kidney disease progression.

Plasma and urinary vascular endothelial growth factor and diabetic nephropathy in Type 2 diabetes mellitus

AIMS

Vascular endothelial growth factor (VEGF) has been implicated in the pathogenesis of diabetes mellitus. We determined whether alterations of plasma and urinary VEGF levels are related to diabetic nephropathy in Type 2 diabetic patients.

METHODS

One hundred and seven patients and 47 healthy controls were studied. Study subjects were divided into four groups using urinary albumin-to-creatinine ratio (ACR): a non-diabetic healthy control group (n = 47), a normoalbuminuric diabetic group (n = 37), a microalbuminuric diabetic group (n = 37) and an overt proteinuric diabetic group (n = 33). VEGF levels were measured by enzyme-linked immunosorbent assay.

RESULTS

(i) Urinary VEGF concentrations were significantly higher in the diabetic groups, even at the normoalbuminuric stage (log VEGF/Cr, normoalbuminuria; 4.33 +/- 1.06 vs. control; 3.53 +/- 0.79, P = 0.009). Urinary VEGF excretions increased as diabetic nephropathy advanced. (ii) Plasma and urinary VEGF levels were higher in hypertensive diabetic patients than in the normotensive individuals with diabetes. (iii) In those with diabetes, plasma VEGF levels were found to be positively correlated with plasma urea (r = 0.398, P = 0.039) and urinary ACR (r = 0.251, P = 0.044), and urinary VEGF to be positively correlated with urinary ACR (r = 0.645, P < 0.001), and creatinine (r = 0.336, P = 0.009), and to be negatively correlated with serum albumin (r = -0.557, P < 0.001). Urinary VEGF and serum creatinine were independently correlated with urinary ACR.

CONCLUSIONS

Urinary excretion of VEGF increased during the earlier stage of diabetic nephropathy and was significantly correlated with urinary albumin excretion. This suggests that urinary VEGF might be used as a sensitive marker of diabetic nephropathy and for predicting disease progression.

Plasma and urinary vascular endothelial growth factor and diabetic nephropathy in Type 2 diabetes mellitus

AIMS

Vascular endothelial growth factor (VEGF) has been implicated in the pathogenesis of diabetes mellitus. We determined whether alterations of plasma and urinary VEGF levels are related to diabetic nephropathy in Type 2 diabetic patients.

METHODS

One hundred and seven patients and 47 healthy controls were studied. Study subjects were divided into four groups using urinary albumin-to-creatinine ratio (ACR): a non-diabetic healthy control group (n = 47), a normoalbuminuric diabetic group (n = 37), a microalbuminuric diabetic group (n = 37) and an overt proteinuric diabetic group (n = 33). VEGF levels were measured by enzyme-linked immunosorbent assay.

RESULTS

(i) Urinary VEGF concentrations were significantly higher in the diabetic groups, even at the normoalbuminuric stage (log VEGF/Cr, normoalbuminuria; 4.33 +/- 1.06 vs. control; 3.53 +/- 0.79, P = 0.009). Urinary VEGF excretions increased as diabetic nephropathy advanced. (ii) Plasma and urinary VEGF levels were higher in hypertensive diabetic patients than in the normotensive individuals with diabetes. (iii) In those with diabetes, plasma VEGF levels were found to be positively correlated with plasma urea (r = 0.398, P = 0.039) and urinary ACR (r = 0.251, P = 0.044), and urinary VEGF to be positively correlated with urinary ACR (r = 0.645, P < 0.001), and creatinine (r = 0.336, P = 0.009), and to be negatively correlated with serum albumin (r = -0.557, P < 0.001). Urinary VEGF and serum creatinine were independently correlated with urinary ACR.

CONCLUSIONS

Urinary excretion of VEGF increased during the earlier stage of diabetic nephropathy and was significantly correlated with urinary albumin excretion. This suggests that urinary VEGF might be used as a sensitive marker of diabetic nephropathy and for predicting disease progression.

Taurine transport mechanism through the blood-brain barrier in spontaneously hypertensive rats

Taurine levels in the brain decrease when an animal is subjected to pathological conditions, such as ischemia-anoxia and seizure, but they tend to increase in hypertension. The present study investigated the blood-brain barrier (BBB) transport of [3H]-labelled taurine in spontaneously hypertensive rats (SHR) using internal artery carotid perfusion (ICAP) at a rate of 4 ml/min for 10, 15 and 30 seconds. The volume of distribution in brain (VD) and the permeability surface area product (PS) of [3H]-taurine through the BBB in SHR were calculated. The PS value for taurine at 15 s was higher than at the longer perfusion times. This could result from taurine efflux back into blood occurring after 15 s. As in the case of normotensive rats, taurine was shown to enter the brain via the sodium and chloride ion dependent carrier system.

Role of reactive oxygen species in apoptosis induced by N-ethylmaleimide in HepG2 human hepatoblastoma cells

We have previously reported that N-ethylmaleimide induces apoptosis through activation of K(+), Cl(-)-cotransport in HepG2 human hepatoblastoma cells. In this study, we investigated the role for reactive oxygen species as a mediator of the apoptosis induced by N-ethylmaleimide. N-ethylmaleimide induced a significant elevation of intracellular level of reactive oxygen species. Treatment with antioxidants (N-acetyl cysteine, N,N'-diphenyl-p-phenylenediamine) which markedly suppressed generation of reactive oxygen species, significantly inhibited the N-ethylmaleimide-induced activation of K(+), Cl(-)-cotransport and apoptosis. Inhibitors of NADPH oxidase (diphenylene iodonium, apocynin, D-(+)-neopterine) also significantly blunted the generation of reactive oxygen species, activation of K(+), Cl(-)-cotransport and apoptosis induced by N-ethylmaleimide. These results suggest that reactive oxygen species generated through activation of NADPH oxidase may play a role in the N-ethylmaleimide-induced stimulation of K(+), Cl(-)-cotransport and apoptosis in HepG2 cells.

Characterization of dioxin-like activity of sediments from a Czech river basin

Synthetic organic chemicals are present in environmental compartments as complex mixtures and therefore their potential effects are difficult to predict. In this study, in vitro bioassays using wild-type fish and rat hepatoma cell lines and their corresponding recombinant cell systems were used to evaluate 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-like activity in extracts of sediments collected from rivers of the Czech Republic. All the sediment extracts elicited statistically significant responses in all the cell lines tested. For most sediment extracts, a complete dose-response relationship was obtained. The maximal efficacy of the samples was between 57 and 143% of the maximal induction elicited by TCDD. Greater responsiveness, sensitivity, and reproducibility were observed for recombinant than wild-type cells. Cell line-specific differences in the sensitivity to compounds present in the complex sediment extracts were observed. The TCDD equivalents (TCDD-EQs) determined from the different cell bioassays were correlated. Greater concentrations of TCDD-EQs were obtained with fish cell lines. The TCDD-EQs calculated from the results of chemical analysis of toxic equivalents (TEQs) were in good agreement with those determined by bioassays; the arly hydrocaron receptor (AhR)-effects of the identified chemicals appear to be generally additive. This indicates that most of the TCDD-like activity was accounted for by the compounds identified and quantified by instrumental analysis. Fractionation along with mass-balance calculations allowed identification of the active fractions and classes of compounds. Polycyclic aromatic hydrocarbons (PAHs) were found to be responsible for most of the AhR-mediated activity in sediments.

Deflazacort increases osteoclast formation in mouse bone marrow culture and the ratio of RANKL/OPG mRNA expression in marrow stromal cells

Information on precise effects of deflazacort on bone cell function, especially osteoclasts, is quite limited. Therefore, the present study was undertaken to test effects of deflazacort on osteoclast-like cell formation in mouse bone marrow cultures and on the regulation of osteoprotegerin (OPG) and its ligand (RANKL) mRNA expressions by RT-PCR in the ST2 marrow stromal cells. TRAP-positive mononuclear cells increased after the treatment of deflazacort at 10(-9) to 10(-7) M alone for 6 days in a dose-dependent manner. Number of TRAP-positive multi-nucleated cells (MNCs) increased significantly with combined treatment of deflazacort at 10(-7) M and 1,25-(OH)2D3 at 10(-9) M compared to that of cultures treated with 1,25-(OH)2D3 alone (p<0.05). Exposure to deflazacort at 10(-7) M in the presence of 1,25-(OH)2D3 at 10(-9) M in the last 3-day culture had greater stimulatory effect on osteoclast-like cell formation than that of the first 3-day culture did. Deflazacort at 10(-10) -10(-6) M downregulated OPG and upregulated RANKL in mRNA levels in a dose-dependent manner. These observations suggest that deflazacort stimulate osteoclast precursor in the absence of 1,25-(OH)2D3 and enhance differentiation of osteoclasts in the presence of 1,25-(OH)2D3. These effects are, in part, thought to be mediated by the regulation of the expression of OPG and RANKL mRNA in marrow stromal cells.

Effect of phthalates on the stability and performance of AgBF4-PVP membranes for olefin/paraffin separation

The presence of a phthalate in dry polymer membranes consisting of polyvinylpyrrolidone (PVP) and AgBF4, AgBF4-PVP, provides long-term stability and better performance for the separation of propylene/propane gas mixtures.

Apoptosis signal-regulating kinase 1 controls the proapoptotic function of death-associated protein (Daxx) in the cytoplasm

Although Daxx (death-associated protein) was first reported to mediate the apoptotic signal from Fas to JNK in the cytoplasm, other data suggested that Daxx is mainly located in the nucleus as a transcriptional regulator. Here, we demonstrated that cellular localization of Daxx could be determined by the relative concentration of a proapoptotic kinase, apoptosis signal-regulating kinase 1 (ASK1) by using immunofluorescence and transcriptional reporter assay. ASK1 sequestered Daxx in the cytoplasm and inhibited the repressive activity of Daxx in transcription. In addition, Daxx was bound to the activated Fas only in the presence of ASK1, accelerating the Fas-mediated apoptosis. These results suggest that Daxx requires ASK1 for its cytoplasmic localization and Fas-mediated signaling. Taken together, we could conclude that ASK1 controls the dual function of Daxx as a transcriptional repressor in the nucleus and as a proapoptotic signal mediator in the cytoplasm.

Identification of a mutation in the human raloxifene response element of the transforming growth factor-beta 3 gene

The human transforming growth factor-beta 3 (TGF-beta 3) is an important cytokine to maintain bone mass by inhibiting osteoclast differentiation. Recently raloxifene response element (RRE), a new enhancer with a polypurine sequence for estrogen receptor (ER)-mediated gene activation, was identified on the TGF-beta 3 gene. Functional analysis of the RRE-mediated pathway has shown that this would be an important pathway for bone preserving effect. We found a novel mutation in the RRE sequence by single-strand conformational polymorphism analysis in one of 200 Korean women. Cloning and sequencing revealed a heterozygote in which one allele had an insertion of 20 nucleotides (AGAGAGGGAGAGGGAGA GGG) between nucleotide +71 and +72 and a point mutation at nucleotide +75 (G-A transition), and the other allele had normal sequence. The insertion was a nearly perfect tandem duplication of the wild type DNA sequence. The bone mineral density of the affected woman was not much lower than that of age-matched controls. Transient transfection of the mutant allele showed no significantly different activity compared with that of the wild type allele. These observations suggest that the heterozygote variation of the RRE sequence seems not to be operative in determination of bone mass.

Polychlorinated naphthalenes, biphenyls, dibenzo-p-dioxins, and dibenzofurans as well as polycyclic aromatic hydrocarbons and alkylphenols in sediment from the Detroit and Rouge Rivers, Michigan, USA

Sediment from the upper Detroit and lower Rouge Rivers in southeastern Michigan, USA, were analyzed to examine the distribution of polychlorinated naphthalenes (PCNs), biphenyls (PCBs), dibenzo-p-dioxins (PCDDs), and dibenzofurans (PCDFs) as well as polycyclic aromatic hydrocarbons (PAHs) and alkylphenolic compounds such as butylphenol, octylphenol, and nonylphenol (NP). Sediments from a non-point source location in Lake Michigan were also analyzed for target compounds. Concentrations of target compounds in the upper Detroit and lower Rouge Rivers varied considerably among locations, and notable spatial variation existed. Concentrations of PCNs and PCDDs/PCDFs in sediments from the upper Detroit and lower Rouge Rivers ranged from 0.08 to 187 ng/g and 69 to 1420 pg/g dry weight, respectively. Total PCBs, PAHs, and NP concentrations ranged from 8 to 25,000, 17 to 44,000, and < 10 to 60,000 ng/g dry weight, respectively. Concentrations of all target compounds except PCNs were significantly correlated with total organic carbon content of sediments. Similarly, concentrations of PCBs, PCDDs, and PCDFs were significantly correlated with each other. The distribution of organic contaminants in the upper reaches of the Detroit River and lower Rouge River suggested the presence of localized, but multiple, sources of contamination for each compound class. Conners Creek combined sewer overflow has been identified as one of the potential sources for the upper Detroit River, where the highest concentrations PCBs and PCDDs/PCDFs were found. Polycyclic aromatic hydrocarbon and NP concentrations were consistently high in sediment from the lower Rouge River. Analysis of data from selected locations suggested that PCNs contributed a greater proportion of the dioxin-like activity than PCBs and PCDDs/PCDFs contributed.

Stability of the disulfide bond in an avidin-biotin linked chimeric peptide during in vivo transcytosis through brain endothelial cells

Drug delivery of potential neuropharmaceuticals with poor intrinsic permeability through the blood-brain barrier (BBB), such as peptides, is facilitated by coupling to a vector that undergoes receptor-mediated transcytosis through the endothelial cells of brain microvessels. When cleavable disulfide linkers are used in the synthesis of such "chimeric peptides", it is crucial that the S-S-bridge is stable during transcytosis. Cleavage within endothelial cells could result in sequestration of the drug moiety instead of passage through the BBB. In the present study the metabolically stable opioid peptide [3 H]DALDA ([3 H]Tyr-DArg-Phe-Lys-NH2 ) was used as a model drug. It was monobiotinylated with the cleavable biotin reagent sulfosuccinimidyl 2-(biotinamido)ethyl-1,3'-dithiopropionate (NHS-SS-biotin) to obtain bio-[3 H]DALDA. The biotinylated peptide was then bound to a vector for brain delivery after intravenous injection in rats, a covalent conjugate of streptavidin and the transferrin receptor monoclonal antibody, OX26. Compared to peptide without vector, brain uptake of bio-[3 H]DALDA after was increased 18-fold to reach 0.12% of the injected dose per g tissue. Transcranial microdialysis was performed for 60 min after an intravenous bolus of chimeric peptide, followed by reverse phase HPLC of dialysate. Stability of the chimeric peptide during transport through the BBB into brain extracellular fluid was concluded from the absence of a peptide peak generated by disulfide cleavage.

Role of pertussis toxin-sensitive G-proteins in intracellular Ca2+ release and apoptosis induced by inhibiting cystic fibrosis transmembrane conductance regulator (CFTR) Cl- channels in HepG2 human hepatoblastoma cells

Previously, we have reported that inhibition of cystic fibrosis transmembrane conductance regulator (CFTR) Cl- channels by glibenclamide induced intracellular Ca2+ release from IP(3)-sensitive stores and apoptosis in HepG2 human hepatoblastoma cells (Kim JA, Kang YS, Lee SH, Lee EH, Yoo BH, Lee YS. 1999. Biochem Biophys Res Commun 261:682-688). In this study we investigated the upstream signals involved in the mechanism of these actions of glibenclamide. Treatment with glibenclamide initiated production of inositol 1,4,5-trisphosphate (IP(3)) in a dose- and time-dependent manner. The glibenclamide-induced formation of IP(3) was significantly inhibited by CFTR activators (levamisole and bromotetramisole). The intracellular Ca2+ release and apoptosis induced by glibenclamide were significantly suppressed by treatment with phospholipase C (PLC) inhibitors (U-73122 and manoalide) or by pretreatment with pertussis toxin (PTx). In addition, PTx-catalyzed ADP-ribosylation of GTP-binding proteins (G-proteins) was markedly enhanced by treatment with glibenclamide in a time-dependent manner. Taken together, these results suggest that PTx-sensitive G-proteins coupled to PLCbeta may mediate the intracellular Ca2+ release and apoptosis induced by inhibiting CFTR Cl- channels in HepG2 cells. These results further suggest that the PTx-sensitive G-proteins may be a valuable target for the therapeutic intervention of human hepatomas.

Involvement of K(+)-Cl(-)-cotransport in the apoptosis induced by N-ethylmaleimide in HepG2 human hepatoblastoma cells

The role of K(+)-Cl(-)-cotransport in apoptosis in human cancer cells was investigated. N-Ethylmaleimide, a K(+)-Cl(-)-cotransport activator, induced apoptosis in a dose-dependent manner in HepG2 human hepatoblastoma cells. N-Ethylmaleimide induced Cl(-)-dependent K(+) efflux, indicating that K(+)-Cl(-)-cotransport is functionally present in HepG2 cells. Calyculin-A and genistein, inhibitors of K(+)-Cl(-)-cotransport, significantly prevented both K(+)-Cl(-)-cotransport activation and apoptosis induced by N-ethylmaleimide. These results demonstrate, for the first time, a novel role for K(+)-Cl(-)-cotransport in apoptosis in human hepatoma cells. These results further suggest that K(+)-Cl(-)-cotransport may be a valuable target for therapeutic interventions for human hepatoma.

Facilitated olefin transport by reversible olefin coordination to silver ions in a dry cellulose acetate membrane

The highly selective dry complex membrane AgBF4-cellulose acetate (CA) was prepared and tested for the separation of ethylene/ethane and propylene/propane mixtures. The maximum selectivity for olefin over paraffin was found to be 280 for the ethylene/ethane mixture and 200 for the propylene/propane mixture. Solid-state interactions of AgBF4 with cellulose acetate (CA) and/or olefins have been investigated by using FT-IR, UV, and X-ray photoelectron spectroscopy (XPS). FT-IR and XPS studies clearly show that the silver ions are coordinated by carbonyl oxygen atoms among three different types of oxygen atoms present in CA-two in the acetate group and one in the ether linkage. Upon incorporation of AgBF4 into CA, the carbonyl stretching frequency of the free cellulose acetate at 1750 cm(-1) shifts to a lower frequency by about 41 cm(-1). The binding energy corresponding to a carbonyl oxygen atom in the O 1s XPS spectrum shifts to a more positive binding energy by the incorporation of AgBF4. Reversible olefin coordination to silver ions has been observed by FT-IR and UV studies. Treatment of the AgBF4-CA membrane placed in a gas cell with propylene produces a propylene-coordinated membrane in which coordinated propylene is easily replaced by other olefins such as 1,3-butadiene.

Role of NAD(P)H oxidase in the tamoxifen-induced generation of reactive oxygen species and apoptosis in HepG2 human hepatoblastoma cells

Previously, tamoxifen (TAM) has been shown to induce apoptosis through elevation of intracellular Ca2+ in HepG2 human hepatoblastoma cells. In this study we investigated the role of reactive oxygen species (ROS) in the TAM-induced apoptosis, and interrelationship between intracellular Ca2+ and ROS. TAM induced a slow and sustained increase in intracellular ROS level. An antioxidant, N-acetylcysteine significantly inhibited both ROS production and apoptosis induced by TAM, suggesting that ROS may play an essential role in the TAM-induced apoptosis. In a time frame ROS generation followed intracellular Ca2+ increase, and the extracellular and intracellular Ca2+ chelation with EGTA and BAPTA/AM, respectively, completely inhibited the TAM-induced ROS production, indicating that intracellular Ca2+ may mediate the ROS generation. Inhibitors of NAD(P)H oxidase, diphenylene iodonium, phenylarsine oxide and neopterine, significantly blocked the TAM-induced ROS generation and apoptosis, implying that this oxidase may act as a source enzyme for the production of ROS. These results suggest that non-phagocytic NAD(P)H oxidase may play a novel role as a mediator of the apoptosis associated with intracellular Ca2+ in HepG2 cells.

Transanally injected triamcinolone acetonide in levator syndrome

PURPOSE

Several treatments are used for the treatment of levator syndrome, such as rectal massage, biofeedback, and galvanic stimulation. But their effects are inconsistent, and multiple treatment sessions are usually required. Triamcinolone acetonide and lidocaine mixture was injected locally into the tenderest point in levator syndrome under the hypothesis that levator syndrome is caused by tendinitis of pelvic floor musculature.

METHODS

A mixture of 40 mg of triamcinolone acetonide and 1 ml of 2 percent lidocaine was injected into the tenderest point transanally in 104 patients (33 males; mean age, 51 years) with levator syndrome from December 1996 to May 1998 at Daehang Clinic. Additional injections were repeated at two-week intervals to a maximum of three injections in cases of poor response. Follow-up was performed prospectively concerning patient's perception of pain level using a visual analog scale. Depending on the response, the patients were classified into four groups: pain-free, good, fair, and no response. More than 50 percent pain reduction was classified as "good," and less than 49 percent reduction as "fair."

RESULTS

The injection regions, where the tenderest points were identified on digital rectal compression, were left anterior anal canal in 71.2 percent of patients, right anterior in 3.8 percent of patients, and posterior in 25 percent of patients. The results of treatment were as follows: at three months after injection, response was classified as pain-free in 36.8 percent of patients, good in 35 percent of patients, fair in 19.5 percent of patients, and no response in 8.7 percent of patients; at six months the response was pain-free in 30.1 percent of patients, good in 46.5 percent of patients, fair in 18.2 percent of patients, and no response in 5.2 percent of patients. Most patients, except 8.7 percent at three months and 5.2 percent at six months, experienced treatment benefits. There were no complications during the follow-up periods.

CONCLUSION

Transanal injection of triamcinolone acetonide and lidocaine mixture into the tenderest point is such a simple, safe, and very effective modality that it can be recommended as a primary therapy for levator syndrome.

Inhibitors of Na+/Ca2+ exchanger prevent oxidant-induced intracellular Ca2+ increase and apoptosis in a human hepatoma cell line

Oxidative stress appears to be implicated in the pathogenesis of various diseases including hepatotoxicity. Although intracellular Ca2+ signals have been suggested to play a role in the oxidative damage of hepatocytes, the sources and effects of oxidant-induced intracellular Ca2+ increases are currently debatable. Thus, in this study we investigated the exact source and mechanism of oxidant-induced liver cell damage using HepG2 human hepatoma cells as a model liver cellular system. Treatment with 200 microM of tert-butyl hydroperoxide (tBOOH) induced a sustained increase in the level of intracellular reactive oxygen intermediates (ROI) and apoptosis, assessed by 2',7'-dichlorofluorescein fluorescence and flow cytometry, respectively. Antioxidants, N-acetyl cysteine (NAC) or N,N'-diphenyl-p-phenylenediamine significantly inhibited both the ROI generation and apoptosis. In addition, tBOOH induced a slow and sustained increase in intracellular Ca2+ concentration, which was completely prevented by the antioxidants. An intracellular Ca2+ chelator, bis-(o-aminophenoxy)-ethane-N,N,N',N'-tetraacetic acid/cetoxymethyl ester significantly suppressed the tBOOH-induced apoptosis. These results imply that activation of an intracellular Ca2+ signal triggered by increased ROI may mediate the tBOOH-induced apoptosis. Both intracellular Ca2+ increase and induction of apoptosis were significantly inhibited by an extracellular Ca2+ chelator or Na+/Ca2+ exchanger blockers (bepridil and benzamil), whereas neither Ca2+ channel antagonists (verapamil and nifedipine) nor a nonselective cation channel blocker (flufenamic acid) had an effect. These results suggest that tBOOH may increase intracellular Ca2+ through the activation of reverse mode of Na+/Ca2+ exchanger. However, tBOOH decreased intracellular Na+ concentration, which was completely prevented by NAC. These results indicate that ROI generated by tBOOH may increase intracellular Ca2+ concentration by direct activation of the reverse mode of Na+/Ca2+ exchanger, rather than indirect elevation of intracellular Na+ levels. Taken together, these results suggest that the oxidant, tBOOH induced apoptosis in human HepG2 cells and that intracellular Ca2+ may mediate this action of tBOOH. These results further suggest that Na+/Ca2+ exchanger may be a target for the management of oxidative hepatotoxicity.

Brain uptake and the analgesic effect of oxytocin--its usefulness as an analgesic agent

To establish the usefulness of oxytocin (OT) as an analgesic for women in delivery, the pharmacokinetic parameters and blood-brain barrier (BBB) permeability of [3H]OT were obtained using an intravenous injection technique or the internal carotid artery perfusion/capillary depletion (ICAP/CDM) method. Brain uptake of OT was similar to that of sucrose, plasma space marker, indicating that OT has a poor BBB permeability. Moreover, the analgesic effects of OT injected through the jugular vein on nociception were evaluated by the tail-flick method. The antinociceptive effects of OT injected at a dose of 0.2 mg/kg or 2 mg/kg were dose-dependent. In addition, the analgesic effects of OT on the CNS were unaffected by naloxone, a m-receptor antagonist. In a similar manner to the opioid system, OT may play a modulatory role in antinociception.

Caveolin internalization by heat shock or hyperosmotic shock

We investigated the cellular localization of caveolin, a landmark protein of caveolae, by indirect immunofluorescence after heat shock or hyperosmotic shock. Caveolin was internalized to the perinucleus by heat shock (43 degrees C) and relocalized in the plasma membrane after recovery of NIH3T3 cells at 37 degrees C for 4 h. The caveolin internalization was also observed after cells were exposed to hyperosmotic shock. Caveolin disappeared from detergent-insoluble complexes in the heat-shocked cells, but alkaline phosphatase was still there, suggesting that their responses to heat shock are quite different even though both of them were enriched in detergent-insoluble complexes of normal cells. Caveolin was internalized by the actin depolymerizer cytochalasin D, but not by the tubulin depolymerizer nocodazole. In addition, cellular exposure to hydrogen peroxide caused caveolin internalization along with disintegrated microfilaments and intact microtubules. Since cellular exposure to heat shock showed disintegrated microfilaments but intact microtubules, caveolin internalization might be due to depolymerized microfilaments. When cells were exposed to heat shock and allowed to recover for 4 h, actin depolymerization and caveolin internalization were not induced by a second heat shock, suggesting that some heat shock protein(s) might prevent actin depolymerization and caveolin internalization.

Ca2+ influx mediates apoptosis induced by 4-aminopyridine, a K+ channel blocker, in HepG2 human hepatoblastoma cells

Apoptosis appears to be implicated in the pathogenesis and therapeutic applications of cancer. In this study we investigated the induction of apoptosis by 4-aminopyridine (4-AP), a K(+) channel blocker, and its mechanism in HepG2 human hepatoblastoma cells. 4-AP reduced cell viability and induced DNA fragmentation, a hallmark of apoptosis, in a dose-dependent manner. In addition, 4-AP induced a sustained increase in intracellular Ca(2+) concentration, which was completely inhibited by the extracellular Ca(2+) chelation with EGTA. 4-AP also induced Mn(2+) influx, indicating that the 4-AP-induced increased intracellular Ca(2+) levels were due to activation of Ca(2+) influx pathway. 4-AP also depolarized membrane potential that was measured by using di-O-C(5)(3), a voltage-sensitive fluorescent dye. 4-AP-induced Ca(2+) influx was significantly inhibited not by voltage-operative Ca(2+) channel blockers (nifedipine or verapamil), but by flufenamic acid (FA), a known nonselective cation channel blocker. Quantitative analysis of apoptosis by the flow cytometry revealed that treatment with either FA or BAPTA, an intracellular Ca(2+) chelator, significantly inhibited the 4-AP-induced apoptosis. Taken together, these results suggest that the observed 4-AP-induced apoptosis in the HepG2 cells may result from Ca(2+) influx through the activation of voltage-sensitive Ca(2+)-permeable non-selective cation channels. These results further suggest that membrane potential change by modulation of K(+) channel activity may be involved in the mechanism of apoptosis in human hepatoma cells.

Involvement of Ca2+ influx in the mechanism of tamoxifen-induced apoptosis in HepG2 human hepatoblastoma cells

The signaling mechanism of tamoxifen (TAM)-induced apoptosis was investigated in HepG2 human hepatoblastoma cells which do not express the estrogen receptor (ER). TAM induced cytotoxicity and DNA fragmentation, a hallmark of apoptosis, in a dose-dependent manner. TAM increased the intracellular concentration of Ca2+. This effect was completely inhibited by the extracellular Ca2+ chelation with EGTA. TAM also induced a Mn2+ influx, indicating that TAM activated Ca2+ influx pathways. This action of TAM was significantly inhibited by flufenamic acid (FA), a known non-selective cation channel blocker. Quantitative analysis of apoptosis by flow cytometry revealed that treatment with either FA or BAPTA, an intracellular Ca2+ chelator, significantly inhibited TAM-induced apoptosis. These results suggest that intracellular Ca2+ signals may play a central role in the mechanism of the TAM-induced apoptotic cell death in ER-negative HepG2 cells.

An antibody-avidin fusion protein specific for the transferrin receptor serves as a delivery vehicle for effective brain targeting: initial applications in anti-HIV antisense drug delivery to the brain

In the present study a novel Ab-avidin fusion protein has been constructed to deliver biotinylated compounds across the blood brain barrier. This fusion molecule consists of an Ab specific for the transferrin receptor genetically fused to avidin. The Ab-avidin fusion protein (anti-TfR IgG3-CH3-Av) expressed in murine myeloma cells was correctly assembled and secreted and showed both Ab- and avidin-related activities. In animal models, it showed much longer serum half-life than the chemical conjugate between OX-26 and avidin. Most importantly, this fusion protein demonstrated superior [3H]biotin uptake into brain parenchyma in comparison with the chemical conjugate. We also delivered a biotinylated 18-mer antisense peptide-nucleic acid specific for the rev gene of HIV-1 to the brain. Brain uptake of the HIV antisense drug was increased at least 15-fold when it was bound to the anti-TfR IgG3-CH3-Av, suggesting its potential use in neurologic AIDS. This novel Ab fusion protein should have general utility as a universal vehicle to effectively deliver biotinylated compounds across the blood-brain barrier for diagnosis and/or therapy of a broad range of CNS disorders such as infectious diseases, brain tumors as well as Parkinson's and Huntington's diseases.

Chromosomal localization of ESTs obtained from human fetal liver via BAC-mediated FISH mapping

A total of 55 expressed sequence tags (ESTs) randomly chosen from our collection of fetal liver ESTs were mapped to chromosomes by fluorescence in situ hybridization (FISH) mapping techniques. To generate FISH mapping probes, the genomic DNAs for each EST were selected by screening an arrayed human bacterial artificial chromosome (BAC) library. In total, 73 BACs were used for mapping of the 55 ESTs. Among them, 70 BACs representing 52 ESTs unequivocally mapped to single chromosomal regions. The remaining 3 BACs representing 3 ESTs were localized to multiple regions, suggesting that BACs may have very low chimerism. Our mapping results were compared with EST mapping databases deposited in NCBI. Thirty-six of 55 ESTs corresponded to previously mapped positions of ESTs, 2 ESTs mapped to different positions from previously determined ones, and it was found that 17 ESTs have been mapped on new locations from this study. These mapping data may be used for completing the framework of the human physical map, and also for providing a good starting point for searching disease-related genes.

Glibenclamide induces apoptosis through inhibition of cystic fibrosis transmembrane conductance regulator (CFTR) Cl(-) channels and intracellular Ca(2+) release in HepG2 human hepatoblastoma cells

Glibenclamide, an inhibitor of cystic fibrosis transmembrane conductance regulator (CFTR) Cl(-) channels, induced apoptosis in a dose- and time-dependent manner in HepG2 human hepatoblastoma cells. Glibenclamide increased intracellular Ca(2+) concentration, which was significantly inhibited by Ca(2+) release blockers dantrolene and TMB-8. BAPTA/AM, an intracellular Ca(2+) chelator, and the Ca(2+) release blockers significantly inhibited glibenclamide-induced apoptosis. Glibanclamide also increased intracellular Cl(-) concentration, which was significantly blocked by CFTR Cl(-) channel activators levamisole and bromotetramisole. These activators also significantly inhibited both intracellular Ca(2+) release and apoptosis induced by glibenclamide. The expression of CFTR protein in the cells was confirmed by Western blot analysis. These results suggest that glibenclamide induced apoptosis through inhibition of CFTR Cl(-) channels and intracellular Ca(2+) release and that this protein may be a good target for treatment of human hepatomas.

Inhibitory effects of constituents of Gastrodia elata Bl. on glutamate-induced apoptosis in IMR-32 human neuroblastoma cells

The inhibitory effects of the constituents of Gastrodia elata Bl. (GE) on glutamate-induced apoptosis in human neuronal cells were investigated using IMR32 human neuroblastoma cells. Glutamate (GLU) induced DNA fragmentation, a hallmark of apoptosis, in a dose-dependent manner. GLU also induced a slow and sustained increase in intracellular Ca2+ concentration. Treatment with EGTA, an extracellular Ca2+ chelator, in a nominal Ca2+-free buffer solution abolished the GLU-induced intracellular Ca2+ increase, indicating that GLU stimulated Ca2+ influx pathway in the IMR32 cells. BAPTA, an intracellular Ca2+ chelator, significantly inhibited the GLU-induced apoptosis assessed by the flow cytometry measuring hypodiploid DNA content indicative of apoptosis, implying that intracellular Ca2+ rise may mediate the apoptotic action of GLU. Vanillin (VAN) and p-hydroxybenzaldehyde (p-HB), known constituents of GE, significantly inhibited both intracellular Ca2+ rise and apoptosis induced by GLU. These results suggest that the apoptosis-inhibitory actions of the constituents of GE may account, at least in part, for the basis of their antiepileptic activities. These results further suggest that intracellular Ca2+ signaling pathway may be a molecular target of the constituents of GE.

TNF-alpha-mediated apoptosis is initiated in caveolae-like domains

Caveolae-like domains (CLDs) have been hypothesized to mediate apoptosis, since they contain sphingomyelin and initiate the conversion of sphingomyelin to ceramide. To address whether CLDs are directly involved in apoptosis, CLDs from U937 cells were isolated, taking advantage of their detergent insolubility and low density. The CLDs contained alkaline phosphatase as well as many signaling molecules, including Fyn, protein kinase Calpha, Raf-1, phospholipase Cgamma1, and tyrosine phosphoproteins. Immunoblotting and immunofluorescent data showed that TNF receptor 1 colocalized with CD36 in CLDs, suggesting that TNF-alpha-initiated apoptosis occurs in CLDs. When cells were incubated with lipoprotein-deficient medium, the cholesterol concentration was greatly decreased in CLDs but not in other fractions, implying that the CLDs were selectively disrupted. In the CLD-disrupted cells, the surface expression of TNF receptor 1 and CD36 was significantly reduced. Analysis of cellular morphology, percent DNA fragmentation, DNA laddering, and caspase-3 activity showed that TNF-alpha-mediated apoptosis was blocked in CLD-disrupted cells, whereas anti-Fas-mediated apoptosis was not. Since Fas was not found in CLDs of Jurkat cells, apoptosis by Fas ligation might not require CLDs. Taken together, these data strongly imply that TNF-alpha-mediated apoptosis is initiated in CLDs.

Suppression of ceramide-mediated apoptosis by HSP70

Ceramide has been known as an important second messenger in programmed cell death (apoptosis) which is induced by various stimuli such as the tumor necrosis factor-alpha (TNF-alpha), Fas ligand, and environmental stresses such as UV-irradiation and heat shock. Although the precise molecular mechanism of apoptosis is not fully understood, ceramide generated by sphingomyelinase (SMase) mediates the activation of several downstream molecules that are implicated in the regulation of apoptosis. Here, we show that stress-inducible heat shock protein 70 (Hsp70) prevents apoptosis induced by increased level of intracellular ceramide. In T-cell hybridoma DO11.10, we examined the effect of Hsp70 on apoptosis mediated by TNF-alpha, Fas ligation, SMase, and C2-ceramide, all of which elevate intracellular ceramide levels. Hsp70 not only markedly reduced internucleosomal DNA fragmentation, but also enhanced cell viability measured by the Trypan blue dye exclusion test. Similarly, the ceramide-induced c-jun amino-terminal kinase (JNK/SAPK) activation is impaired in cells overexpressing Hsp70. These data strongly suggest that hsp70 functions as a regulator of apoptosis downstream of ceramide.

Permeability of a capsaicin derivative, [14C]DA-5018 to blood-brain barrier corrected with HPLC method

In the present work, the transport mechanism of a capsaicin derivative, DA-5018, through blood-brain barrier (BBB) has been investigated to evaluate the feasibility of potential drug development. The result of pharmacokinetic parameters obtained from the intravenous injection of plasma volume marker, [3H]RSA and [14C]DA-5018, indicated that both AUC, area under the plasma concentration curve and VD, volume of distribution in brain of [3H]RSA agreed with those reported (1620 +/- 10 percentage injected dose minute per milliliter (%IDmin/ml) and 12.0 +/- 0.1 microliters/g, respectively). Elimination half-life and AUC of [14C]DA-5018 is corrected by the HPLC analysis, 19.6 +/- 1.2 min and 7.69 +/- 0.85% IDmin/ml, respectively. The metabolic rate of [14C] DA-5018 was very rapid. The blood-brain barrier permeability surface area (PS) product of [14C]DA-5018 was calculated to be 0.24 +/- 0.05 microliter/min/g. The result of internal carotid artery perfusion and capillary depletion suggested that [14C]DA-5018 pass through BBB with the time increasingly. Investigation of transport mechanism of [14C]DA-5018 using agonist and antagonist suggested that vanilloid (capsaicin) receptor did not exist in the BBB, and nutrient carrier system in the BBB has no effect on the transport of DA-5018. In conclusion, despite the fact that penetration of DA-5018 through BBB is significant, the intact drug found in the brain tissue is small because of a rapid metabolism. Therefore, for the central analgesic effect of DA-5018, the method to increase the metabolic stability in plasma and the brain permeability should be considered.

Role of Ca2+ influx in the tert-butyl hydroperoxide-induced apoptosis of HepG2 human hepatoblastoma cells

Oxidative stress appears to be implicated in the pathogenesis of various diseases including alcoholic liver injury. In this study we investigated the mechanism of apoptosis induced by tert-butyl hydroperoxide (TBHP) in HepG2 human hepatoblastoma cells. Treatment with TBHP significantly reduced glutathione content and glutathione reductase activity, and increased glutathione peroxidase activity, indicating that TBHP induced oxidative stress in the HepG2 cells. TBHP also induced reduction of cell viability and DNA fragmentation, a hallmark of apoptosis, in a dose-dependent manner. In addition, TBHP induced a sustained increase in intracellular Ca2+ concentration, which was completely prevented by the extracellular Ca2+ chelation with EGTA. TBHP also induced Mn2+ influx. These results indicate that the intracellular Ca2+ increase by TBHP is exclusively due to Ca2+ influx from the extracellular site. Treatment with either an extracellular (EGTA) or an intracellular Ca2+ chelator (BAPTA/AM) significantly suppressed the TBHP-induced apoptosis. Taken together, these results suggest that TBHP induced the apoptotic cell death in the HepG2 cells and that Ca2+ influx may play an important role in the apoptosis induced by TBHP.

Electroretinographic evaluation in adult diabetics

In cross-sectional fashion, we recorded the maximal combined response and 30-Hz flicker responses in 178 adult diabetics and 40 normal controls according to the recommendations of the International Society of Clinical Electrophysiology of Vision. The oscillatory potentials were extracted from the maximal combined response by high-pass filtering. The clear media and attached retina were criteria for inclusion in this study. The data were statistically analyzed with the expectation that this procedure may provide a new feature that could have some clinical significance. Timing delays occurred more frequently than amplitude reductions in the maximal combined response and flicker responses, while amplitude reductions were more common in the first and second oscillatory potentials. The hypernormal b-wave amplitude was rare. The summed amplitude of the oscillatory potentials was highly correlated with the total power of the oscillatory potentials (the frequency domain). A reduction of the second oscillatory potential amplitude was more common than a reduction of the summed amplitude or total power. The electroretinographic component that demonstrates retinal dysfunction in the earlier stage may be a valuable indicator. In the early stage, a delay in the a-wave time and a reduction in the second oscillatory potential amplitude were the most frequent abnormalities: analysis of variance demonstrated that the summed amplitude of the oscillatory potentials and second oscillatory potential amplitude and time were the most sensitive measures of the diabetic retina. Hence, the second oscillatory potential amplitude may be the most sensitive and valuable indicator representing a quantitative measure of overall retinal dysfunction.

No increase in blood-brain barrier permeability after intraperitoneal injection of endotoxin in the rat

Reactions mediated by the brain are part of the response to intraperitoneal administration of endotoxin, a model of gram-negative bacterial infection. To test the hypothesis that a compromised blood-brain barrier (BBB) may contribute to these reactions, the integrity of the BBB was measured following lipopolysaccharide administration. Rats received intraperitoneal injections of 50 microg/kg or 2 mg/kg of endotoxin. Brain uptake of a macromolecular vascular marker, 3H-labelled rat serum albumin, and of a poorly permeable low molecular weight substance, [14C]sucrose, was then measured with the intravenous bolus injection method. Compared to controls, neither dose of endotoxin affected the BBB permeability for these tracers. This was true when brain uptake was measured 5 min or 2 h after lipopolysaccharide injection. It is concluded that intraperitoneal endotoxin even at a high dose does not acutely disrupt the BBB.