Study of the Mechanism Underlying the Onset of Diabetic Xeroderma Focusing on an Aquaporin-3 in a Streptozotocin-Induced Diabetic Mouse Model

Xeroderma is a frequent complication in diabetic patients. In this study, we investigated the mechanism underlying the onset of diabetic xeroderma, focusing on aquaporin-3 (AQP3), which plays an important role in water transport in the skin. Dermal water content in diabetic mice was significantly lower than that in control mice. The expression level of AQP3 in the skin was significantly lower in diabetic mice than in control mice. One week after streptozotocin (STZ) treatment, despite their increased blood glucose levels, mice showed no changes in the expression levels of AQP3, Bmal1, Clock, and D site-binding protein (Dbp) in the skin and 8-hydroxydeoxyguanosine (8-OHdG) in the urine. In contrast, two weeks after STZ treatment, mice showed increases in the blood glucose level, decreases in AQP3, Bmal1, Clock, and Dbp levels, and increases in the urinary levels of 8-OHdG. The results of this study suggest that skin AQP3 expression decreases in diabetes, which may limit water transport from the vessel side to the corneum side, causing dry skin. In addition, in diabetic mice, increased oxidative stress triggered decreases in the expression levels of Bmal1 and Clock in the skin, thereby inhibiting the transcription of Aqp3 by Dbp, which resulted in decreased AQP3 expression.

Anti-Hypertensive Effects of Acacia Polyphenol in Spontaneously Hypertensive Rats

We have previously demonstrated that acacia polyphenol (AP) exerts strong anti-obesity, anti-diabetic, and anti-atopic dermatitis effects. In the present study, we investigated the anti-hypertensive effects of AP. Spontaneously hypertensive rats (SHR) with hypertension and control Wistar Kyoto rats (WKY) were used. WKY and SHR were fed AP-containing food or AP-free food (control group) ad libitum for 4 weeks, and their blood pressures were measured. After AP administration, both systolic and diastolic blood pressures were significantly lower in the SHR group than in the control group. There were no differences in the systolic or diastolic blood pressure of WKY between the AP group and the control group. Angiotensin-converting enzyme (ACE) activity, nicotinamide adenine dinucleotide phosphate (NADPH) oxidase expression, and superoxide dismutase (SOD) activity in SHR kidneys were not altered by AP administration. Blood SOD activity in SHR was significantly higher in the AP group than in the control group. AP exerts anti-hypertensive effects on hypertension but has almost no effect on normal blood pressure. The anti-hypertensive effects of AP may be related to the anti-oxidative effects of increased blood SOD activity.

Changes in the Pharmacokinetics of Phenytoin in Dextran Sulfate Sodium–Induced Ulcerative Colitis in Mice

We previously demonstrated that the expression levels of drug-metabolizing enzymes, cytochrome P450 (CYP) enzymes, in the liver are significantly decreased in a murine model of ulcerative colitis (UC). In this study, we investigated changes in the pharmacokinetics of phenytoin, a CYP2C substrate drug, in the presence of UC. Colitis was induced by feeding male mice 3.5% dextran sulfate sodium (DSS) dissolved in drinking water for 10 days. The messenger RNA (mRNA) expression of CYP2C29 and CYP2C37 and the protein expression of CYP2C in the liver were evaluated via real-time reverse transcription–polymerase chain reaction and Western blotting, respectively. In DSS-treated animals, both mRNA and protein expression levels of CYP2C in the liver were significantly reduced relative to those in control animals (by 20%-40%). Phenytoin (30 mg/kg) was administered orally in a single dose to mice, and plasma concentrations were measured. Plasma concentrations of phenytoin were higher in the DSS-treated group than in the control group at 12, 24, and 36 hours after administration. Animals given DSS also exhibited a higher area under the plasma concentration–time curve extrapolated to infinity (AUCinf, 315 μg·h/mL), a delayed elimination half-life ( T1/2, 8.1 hours), and a decreased body clearance (CL/F, 3.52 mL/h) compared with that of control animals (AUCinf, 215 μg·h/mL; T1/2, 3.6 h; CL/F, 5.58 mL/h). This study indicated that the presence of UC decreases CYP2C expression levels in the liver, thereby delaying the metabolism of CYP2C substrates, including phenytoin, and increasing blood concentrations of these substrates.

Epigallocatechin gallate induces a hepatospecific decrease in the CYP3A expression level by altering intestinal flora

In previous studies, we showed that a high-dose intake of green tea polyphenol (GP) induced a hepatospecific decrease in the expression and activity of the drug-metabolizing enzyme cytochrome P450 3A (CYP3A). In this study, we examined whether this decrease in CYP3A expression is induced by epigallocatechin gallate (EGCG), which is the main component of GP. After a diet containing 1.5% EGCG was given to mice, the hepatic CYP3A expression was measured. The level of intestinal bacteria of Clostridium spp., the concentration of lithocholic acid (LCA) in the feces, and the level of the translocation of pregnane X receptor (PXR) to the nucleus in the liver were examined. A decrease in the CYP3A expression level was observed beginning on the second day of the treatment with EGCG. The level of translocation of PXR to the nucleus was significantly lower in the EGCG group. The fecal level of LCA was clearly decreased by the EGCG treatment. The level of intestinal bacteria of Clostridium spp. was also decreased by the EGCG treatment. It is clear that the hepatospecific decrease in the CYP3A expression level observed after a high-dose intake of GP was caused by EGCG. Because EGCG, which is not absorbed from the intestine, causes a decrease in the level of LCA-producing bacteria in the colon, the level of LCA in the liver decreases, resulting in a decrease in the nuclear translocation of PXR, which in turn leads to the observed decrease in the expression level of CYP3A.

Intra-arterial therapy with cisplatin suspension in lipiodol and 5-fluorouracil for hepatocellular carcinoma with portal vein tumour thrombosis

BACKGROUND

Portal vein tumour thrombosis is a negative prognostic factor for hepatocellular carcinoma (HCC).

AIM

To assess the efficacy of cisplatin in lipiodol emulsion combined with 5-fluorouracil (5-FU) for patients with HCC and portal vein tumour thrombosis.

METHODS

The study subjects were 51 patients with the above-specified criteria who received injection of cisplatin suspension in lipiodol emulsion followed by intra-arterial infusion of 5-FU. The primary objective was to determine tumour response to the treatment, while the secondary objectives were safety and tolerability. Independent factors for survival were also assessed.

RESULTS

Ten patients had complete response and 34 patients had partial response (response rate, 86.3%). The median survival for all 51 patients was 33 months, while that for 10 complete response patients and 21 patients who showed disappearance of HCC following additional therapies was 39 months. The single factor that significantly influenced survival was therapeutic effect. Treatment was well tolerated and severe toxicity was infrequent, with only grade 3 toxicity (thrombocytopenia) in one patient.

CONCLUSIONS

The present study demonstrated the efficacy of hepatic arterial infusion chemotherapy using cisplatin-lipiodol emulsion and 5-FU without serious adverse effects in patients with unresectable HCC and portal vein tumour thrombosis.

Randomized Comparison of Intra-Arterial Chemotherapy Versus Intra-Arterial Chemotherapy and Gelfoam Embolization for Treatment of Advanced Cervical Carcinoma

PURPOSE

We evaluated the effects of intra-arterial infusion therapy by comparing the results obtained with a combination of intra-arterial anticancer drugs with and without transcatheter arterial embolization (TAE) in patients with cervical cancer.

METHODS

Between April 1999 and March 2003, intra-arterial therapy was administered to 45 patients (mean age 49 years) with cervical cancer. Of these, 18 had stage IIb , 4 had stage IIIa, 19 had stage IIIb, and 4 had stage IVb cancer; the histopathologic types were squamous cell carcinoma (n = 35), adenocarcinoma (n = 8), and adenosquamous carcinoma (n = 2). A total of 45 patients gave their informed consent and were randomized on a continuous basis into one of three groups according to the therapeutic protocols: group A consisted of 15 patients who received cisplatin, group B consisted of 17 patients who received cisplatin, mitomycin, doxorubicin hydrochloride, and 5-fluorouracil, and group C consisted of 13 patients who received cisplatin and TAE. Each protocol was administered twice with a 3 week interval between treatments. The efficacy of treatment was evaluated on the basis of the tumor reduction ratio (%) using MR imaging and the side effects were analyzed.

RESULTS

In groups A, B, and C, the tumor reduction ratio was 54%, 84%, and 86%, respectively; it was significantly greater in groups B and C than in group A (p < 0.01). The difference between groups B and C was not statistically significant. Although all group C patients developed severe pain after TAE, the pain was controlled with analgesics. Thrombocytopenia occurred in 6 of 17 (35%) group B patients.

CONCLUSION

Group B and C patients had better tumor reduction than those in group A. Fewer hematologic complications occurred in group C patients compared with group B.

[Transthoracic Doppler echocardiographic detection of intramyocardial coronary artery flow in humans using high frequency transducer]

The use of transthoracic color and pulsed Doppler echocardiography to detect intramyocardial coronary artery flow in humans was evaluated in 18 normal healthy subjects (mean age 54 years) and in 16 patients with hypertrophic cardiomyopathy (HCM; mean age 59 years) to measure the intramyocardial coronary artery flow velocity at the ventricular septum and the apex using a 10-5 or 7-4 MHz transducer. Linear inflow color Doppler signals which passed the interventricular septum were demonstrated in 15 of 18 normal subjects (83%) and 15 of 16 patients with HCM (94%). The phasic flow velocities measured by pulsed Doppler echocardiography consisted of two forward flow signals in mid-systole (S-wave) and holodiastole (D-wave), and were obtained in 11 of 18 in normal subjects (61%) and 14 of 16 patients with HCM (88%). The mean peak velocities of the S- and D-waves in patients with HCM (mean [+/-SD] 27 +/- 9 and 86 +/- 23 cm/sec, respectively) were significantly (p < 0.05) higher than those in normal subjects (18 +/- 4 and 54 +/- 11 cm/sec, respectively). At the apex, linear inflow color Doppler signals which passed the myocardium perpendicularly during the whole diastole were demonstrated in 14 of 18 normal subjects (78%) and all 16 patients with HCM (100%). The phasic flow velocities were measured by pulsed Doppler echocardiography in 10 of 18 normal subjects (56%) and 15 of 16 patients with HCM (94%). The mean peak velocities in patients with HCM (74 +/- 27 cm/sec) were significantly (p < 0.05) higher than those in normal subjects (33 +/- 13 cm/sec). Transthoracic color and pulsed Doppler echocardiography can detect intramyocardial coronary artery flow in humans at the interventricular septum and the apex noninvasively.