A novel mechanism in maggot debridement therapy: protease in excretion/secretion promotes hepatocyte growth factor production

Maggot debridement therapy (MDT) is effective for treating intractable wounds, but its precise molecular mechanism, including the association between MDT and growth factors, remains unknown. We administered MDT to nine patients (66.3 ± 11.8 yr, 5 male and 4 female) with intractable wounds of lower extremities because they did not respond to conventional therapies. Significant increases of hepatocyte growth factor (HGF) levels were observed in femoral vein blood during 48 h of MDT (P < 0.05), but no significant change was found for vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), transforming growth factor-β1 (TGF-β1), or tumor necrosis factor-α (TNF-α). We conducted NIH-3T3 cell stimulation assay to evaluate the relation between HGF and protease activity in excretion/secretion (ES) derived from maggots. Compared with the control group, HGF was significantly higher in the 0.05 μg/ml ES group (P < 0.01). Furthermore, protease inhibitors suppressed the increase of HGF (P < 0.05). The HGF expression was increased in proportion to the ES protein concentration of 0.025 to 0.5 μg/ml. In fact, ES showed stronger capability of promoting HGF production and less cytotoxicity than chymotrypsin or bromelain. HGF is an important factor involved in cutaneous wound healing. Therefore, these results suggest that formation of healthy granulation tissue observed during MDT results from the increased HGF. Further investigation to identify molecules enhancing HGF expression by MDT will contribute greatly to drug target discovery for intractable wound healing therapy.

Serum biological antioxidant potential predicts the prognosis of hemodialysis patients

BACKGROUND

It is well known that oxidative stress is enhanced in patients with end-stage renal disease. However, little is known about the relationship between serum antioxidant capacity and clinical outcome in hemodialysis (HD) patients.

METHODS

We examined the relationship between serum biomarkers of oxidative stress and clinical outcomes including all-cause mortality, hospitalization rate and incidence of cardiovascular events in HD patients. As biomarkers of oxidative stress, we measured serum levels of coenzyme Q10 (CoQ10) and biological antioxidant potential (BAP).

RESULTS

108 patients were observed for 30 months as the follow-up periods. The survival group (n = 83) showed significantly higher BAP values compared with those in death groups (n = 25; p < 0.05). When serum BAP levels were divided into two groups by their median value, the group with higher BAP values had a better survival rate than that with lower BAP values on the Kaplan-Meier survival analysis (p = 0.05). Although serum levels of CoQ10 did not show any association with clinical outcomes, lower BAP was selected as an independent risk factor for all-cause mortality as well as the absence of angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers therapy by age-adjusted Cox regression analysis.

CONCLUSIONS

This study indicated that BAP could predict the prognosis of HD patients.

Effects of kaempferol on the mechanisms of drug resistance in the human glioblastoma cell line T98G

Food contains components that may either increase or decrease the bioavailability of a drug. In particular, it is known that grapefruit juice and St. John's Wort induce drug interactions via an effect on the drug-metabolizing enzyme cytochrome P450 (CYP). However, interactions with membrane transporters, such as P-glycoprotein and multidrug resistance-related protein (MRP), may also influence drug bioavailability. The objective of the present study was to investigate the effects of kaempferol, a flavonoid present in food, on the cytotoxicity of anticancer drugs and the mechanisms of drug resistance in the human glioblastoma cell line T98G. Acute exposure to kaempferol inhibited the efflux of calcein, a substrate of MRP; however, chronic exposure caused no apparent effect on calcein efflux. The cytotoxicity of doxorubicin was not influenced by chronic exposure of cells to kaempferol, although that of cisplatin was significantly reduced. Multidrug resistance is often associated with increased levels of MRP1, glutathione S-transferase (GST) and activity by chronic exposure to kaempferol, although MRP2 protein levels are decreased. Accordingly, we hypothesized that the cytotoxicity of anticancer drugs that conjugate with glutathione and the substrate of MRPs may be influenced by long-term intake of drugs such as kaempferol, which are substrates of MRPs and GST.

Differences in associated factors between aortic and mitral valve calcification in hemodialysis

Increased prevalence of aortic and mitral valve calcification has been reported in patients on hemodialysis, but it remains unknown whether aortic and mitral valve calcification arise from similar pathogenesis. We detected heart valve calcification using two-dimensional echocardiography, and we related valve calcification to various clinical parameters in patients treated with hemodialysis three times a week for more than 1 year. In 112 patients (77 men and 35 women, age 67+/-10 years, duration on hemodialysis 95+/-67 months), aortic and mitral valve calcification were observed in 84 (75.0%) and 58 (51.7%) patients, respectively. Aortic valve calcification was associated with increased age, higher serum calcium, lower serum albumin, lower total cholesterol and higher high-sensitivity C-reactive protein. Multivariate analysis showed that increased age and higher serum calcium were independently associated with aortic valve calcification. Conversely, mitral valve calcification was associated with increased age, higher high-sensitivity C-reactive protein and higher serum beta(2)-microglobulin, but not with higher serum calcium. In multivariate analysis, increased age and higher serum beta(2)-microglobulin were independently associated with mitral valve calcification. Serum beta(2)-microglobulin was associated with longer duration on hemodialysis, malnutrition inflammation (lower serum albumin and higher high-sensitivity C-reactive protein) and dyslipidemia. Considering the results in previous studies showing that the distribution of beta(2)-microglobulin amyloid deposition was consistent with that of tissue calcification in patients on hemodialysis, beta(2)-microglobulin may have pathogenic roles in valve calcification.

Neutrophil elastase inhibitor (sivelestat) reduces the levels of inflammatory mediators by inhibiting NF-kB

OBJECTIVE

Sivelestat sodium hydrate (sivelestat) is a specific synthetic inhibitor of neutrophil elastase (NE). Various studies suggest that sivelestat treatment reduces inflammation. In this study, we tested the hypothesis that sivelestat acts as an inhibitor of inflammatory mediators and prevents nuclear factor-kB (NF-kB) activation.

METHODS

In the presence and absence of sivelestat, the mouse macrophage cell line RAW 264.7 was stimulated with lipopolysaccharide (LPS) and the levels of inflammatory mediators (TNF-alpha, IL-6 and high mobility group box 1 (HMGB1)) and nitrite in the cell supernatant were measured, along with inducible nitric oxide synthase (iNOS) expression.

RESULTS

While LPS administration increased the secretion of inflammatory mediators and nitric oxide (NO), sivelestat decreased the secretion of these mediators. Cell signaling studies demonstrated that sivelestat decreased NF-kB activation by inhibiting IkB phosphorylation.

CONCLUSION

Sivelestat may inhibit the various inflammatory mediators through NF-kB inhibition.

Relationship between period of survival and clinicopathological characteristics in patients with colorectal liver metastasis

AIM

Cancer death in the early period after hepatectomy still occurs in patients with colorectal liver metastasis (CLM). We examined the relationship between clinicopathological parameters and survival periods in 130 CLM patients who underwent hepatectomy.

PATIENTS/METHODS

Patients were divided into four groups: Group 1 (5-year survivors without tumor relapse), Group 2 (survivors at 2-5 years), Group 3 (cancer death at 2-5 years), and Group 4 (cancer death within 2 years).

RESULTS

A short surgical margin was frequent in Group 4 compared to Group 1 (31 vs. 78%, P<0.05). Primary node-positive status, absence of fibrous pseudo-capsular formation, higher Clinical Risk Score, and tumor recurrence within 12 months were frequent in Group 4 (P<0.05). Multivariate analysis revealed a short surgical margin (HR; 3.5) and early tumor relapse (HR; 5.9) as independently significant related parameters (P<0.05).

CONCLUSIONS

Sufficient surgical margins and careful follow-up for early tumor relapse may be important for improving postoperative outcomes for CLM patients.

Comparison of survival between anatomic and non-anatomic liver resection in patients with hepatocellular carcinoma: significance of surgical margin in non-anatomic resection

AIMS

Anatomic resection, i.e., systematic removal of a liver segment confined by portal branches, is theoretically effective in eradicating intrahepatic metastasis of hepatocellular carcinoma (HCC). The procedure may reduce tumour recurrence and enhance survival of HCC patients. To determine the significance of anatomic resection for HCC patients, we retrospectively conducted a comparative analysis between anatomic (AR) and non-anatomic liver resection (NAR) in 113 Japanese HCC patients with a solitary tumour, a tumour located within one segment, absence or invasion of distal to second order branches of the portal vein, and absence or invasion of peripheral branches of the hepatic vein.

METHODS

Patients were divided into two groups, AR group (n = 49) and NAR group (n = 64).

RESULTS

The prevalence of liver damage Grade B in the NAR group was significantly greater than in the AR group (p < 0.05). Tumour-free and overall survival following liver resection was not significantly different between AR and NAR groups. In the NAR group, tumour-free and overall survival in patients with tumour exposure at the surgical margin was significantly lower than with a surgical margin greater than 0 mm (not exposed) (p < 0.05). Survival between the AR and NAR groups without tumour exposure at the surgical margin was similar.

CONCLUSIONS

Anatomic resection is the theoretical aim. In HCC patients with impaired liver functions, limited liver resection without tumour exposure may provide longer tumour-free and overall survival.

Trisectionectomy for large hepatocellular carcinoma using the liver hanging maneuver

BACKGROUND/PURPOSE

Large liver tumors often expand and severely compress intrahepatic vessels. In cases of the trisectionectomy for such tumors, however, it is difficult to adequately expose the transection planes. The liver hanging maneuver (LHM) is a useful technique for hemihepatectomy and an adequate transection plane might be also required in trisectionectomy.

METHODS

LHM procedure is basically followed by the Belghiti's method. A nasogastric tube was used for hanging. At the hepatic hilum, the tube was placed between the liver and Glisson's pedicle.

RESULTS

We report here the application of LHM for right and left trisectionectomy in patients with a large hepatoma in two cases. In case of a right trisectionectomy for a large tumor compressing the umbilical Glisson's pedicle, an adequate transection plane was obtained using the LHM because the resected and remnant livers rotated to the other side upon lifting the tube during transection. In case of a left trisectionectomy for a large hepatic tumor compressing the right hepatic vein, an adequate transection plane along the right hepatic vein was obtained using LHM as well.

CONCLUSIONS

LHM is a useful surgical application for right and left trisectionectomy in patients with large liver tumors compressing the cut plane.

Genetic parameters for image analysis traits on M. longissimus thoracis and M. trapezius of carcass cross section in Japanese Black steers

In Japan, the degree of marbling in ribeye (M. longissimus thoracis) is evaluated in the beef meat grading process. However, other muscles (e.g., M. trapezius) are also important in determining the meat quality and carcass market prices. The purpose of this study was to estimate genetic parameters for M. longissimus thoracis (M-LONG) and M. trapezius (M-TRAP) of carcass cross section of Japanese Black steers by computer image analysis. The number of records of Japanese Black steers and the number of pedigree records were 2,925 and 10,889, respectively. Digital images of the carcass cross section were taken between the sixth and seventh ribs by photographing equipment. Muscle area (MA), fat area ratio (FAR), overall coarseness of marbling particles (OCM), and coarseness of maximum marbling particle (MMC) in M-LONG and M-TRAP were calculated by image analysis. Genetic parameters for these traits were estimated using the AIREMLF90 program with an animal model. Fixed effects that were included in the model were dates of arrival at the carcass market and slaughter age (mo), and random effects of fattening farms, additive genetic effects and residuals were included in the model. For M-LONG, heritability estimates (+/-SE) were 0.46 +/- 0.06, 0.59 +/- 0.06, 0.47 +/- 0.06, and 0.20 +/- 0.05 for MA, FAR, OCM, and MMC, respectively. Heritability estimates (+/-SE) in M-TRAP were 0.47 +/- 0.06, 0.57 +/- 0.07, 0.49 +/- 0.07, and 0.13 +/- 0.04 for the same traits. Genetic correlations between subcutaneous fat thickness and FAR for M-LONG and M-TRAP were negative (-0.21 and -0.19, respectively). Those correlations between M-LONG and M-TRAP were moderate to high for MA, FAR, OCM, and MMC (0.38, 0.52, 0.39, and 0.60, respectively). These results indicate that other muscles including M-LONG should be evaluated for more efficient genetic improvement.

An in vitro study of the effect of some dietary components on calculus formation: regulation of calcium phosphate precipitation

OBJECTIVE

We studied the effects of food components on the in vitro formation of calcium phosphate precipitates.

MATERIALS AND METHODS

The effects of food components, such as starch, soybean flour, fish meal, rapeseed oil, and coconut oil, on calcium phosphate precipitation were studied using a pH drop method.

RESULTS

Although the addition of starch had no effect on the rate of precipitation of amorphous calcium phosphate (ACP), it increased both the rate of transformation of ACP to hydroxyapatite (HAP) and the induction time (i.e. time for the initiation of transformation of ACP to HAP to occur); this was irrespective of the heat treatment of the starch. Amylopectin (insoluble constituent of starch) was effective in increasing the rate of HAP transformation, but amylose (soluble constituent of starch) was not. Oil specimen obtained from rapeseed (400 microl ml(-1)) increased the entire reaction of calcium phosphate precipitation, but that from coconut did not. Protein food, such as soybean flour and fish meal, decreased the rate of transformation of ACP to HAP and increased the induction time, while they had no effect on the rate of ACP precipitation.

CONCLUSION

These results suggest that carbohydrate and oil (both are staple diets for the humans) enhance oral calcification (dental calculus formation or re-mineralization of tooth enamel), while side dishes of protein food would decrease it.