A novel entecavir analogue constructing with a spiro[2.4]heptane core structure in the aglycon moiety: Its synthesis and evaluation for anti-hepatitis B virus activity

Synthesis of a novel 2'-deoxy-guanine carbocyclic nucleoside 4 constructed with spiro[2.4]heptane core structure in the aglycon moiety was carried out. Radical-mediated 5-exo-dig mode cyclization and following cyclopropanation proceeded efficiently to furnish the spiro alcohol 10. Subsequent Mitsunobu-type glycosylation between 13 and 14, deoxygenation of the 2'-hydroxyl group of 16 and deprotection of 17 gave the title compound 4. Compound 4 demonstrated moderate anti-HBV activity (EC₅₀ value of 0.12 ± 0.02 µM) and no cytotoxicity against HepG2 cells was observed up to 100 µM.

Diastereoselective Synthesis of 6″-(Z)- and 6″-(E)-Fluoro Analogues of Anti-hepatitis B Virus Agent Entecavir and Its Evaluation of the Activity and Toxicity Profile of the Diastereomers

A method for the diastereoselective synthesis of 6″-(Z)- and 6″-(E)-fluorinated analogues of the anti-HBV agent entecavir has been developed. Construction of the methylenecyclopentane skeleton of the target molecules has been accomplished by radical-mediated 5-exo-dig cyclization of the selenides 6 and 15 having the phenylsulfanylethynyl structure as a radical accepting moiety. In the radical reaction of the TBS-protected precursor 6, (Z)-anti-12 was formed as a major product. On the other hand, TIPS-protected 15 gave (E)-anti-12. The sulfur-extrusive stannylation of anti-12 furnished a mixture of geometric isomers of the respective vinylstannane, whereas benzoyl-protected 17 underwent the stannylation in the manner of retention of configuration. Following XeF2-mediated fluorination, introduction of the purine base and deoxygenation of the resulting carbocyclic guanosine gave the target (E)- and (Z)-3 after deprotection. Evaluation of the anti-HBV activity of 3 revealed that fluorine-substitution at the 6″-position of entecavir gave rise to a reduction in the cytotoxicity in HepG2 cells with retention of the antiviral activity.

Subacute hepatic failure associated with a new antidiabetic agent, troglitazone: a case report with autopsy examination

An autopsy case of fatal subacute hepatic failure after administration of troglitazone is described. The liver dysfunction developed about five months after the patient, a sixty-three-year-old woman, had been initially treated with troglitazone. The patient developed hepatic failure and died despite various hepatic auxiliary treatments such as plasmapheresis. Autopsy findings revealed focal liver cell necrosis, cholestasis and steatosis with infiltration of lymphocytes and neutrophils and lack of regenerative activity. The causative mechanism of liver dysfunction may be metabolite aberration, as a result of accumulation of hepatotoxic metabolite(s), in a category of idiosyncratic liver injury. It is proposed to monitor liver function strictly and periodically for the diabetic patients prescribed troglitazone.

Analysis of bilirubin uridine 5'-diphosphate (UDP)-glucuronosyltransferase gene mutations in seven patients with Crigler-Najjar syndrome type II

Crigler-Najjar syndrome (CN) type II is caused by a reduction in hepatic bilirubin uridine 5'-diphosphate (UDP)-glucuronosyltransferase activity. Recently, there has been progress in mutation analysis of patients with CN type II. Here, we analyzed both the coding and the promoter regions of the gene in seven Japanese patients with CN type II from five unrelated families. The mutations found in this study were classified into three types. The first type was composed of double homozygous missense mutations (Gly71Arg and Tyr486Asp) in exons 1 and 5. These mutations, which were detected in five patients from three unrelated families, were the commonest. The second type, which was detected in one patient, consisted of a single homozygous missense mutation (Arg209Trp) in exon 1. The third type, which was detected in one patient and was a new type of mutation combination, was composed of a homozygous insertion mutation of the TATAA element and a heterozygous missense mutation (Pro229Gln) in exon 1. Although the first and the second type of mutations are recessive, the third type appears to be dominant with incomplete penetrance, since the allele frequency of the insertion mutation of the TATAA element is very high (40%).

[A case of hepatocellular carcinoma with reduction of primary tumor and disappearance of multiple lung metastasis]

A 56-year-old male had suffered from hepatocellular carcinoma treated by operation, PHoT and TAE since 1994. In December 1995, he had multiple metastases of lung in addition to recurrence of primary hepatic lesions. We discontinued treatment of TAE and decided to administer UFT (400 mg/day) orally as an outpatient. After seven months, the primary hepatic lesions were decreased in size, and metastatic lesions of lung were completely eliminated with reduction of AFP level. Generally, hepatocellular carcinoma with metastasis is refractory to treatment. However, this result suggests that UFT is one of the effective treatments for such advanced cases as having lung metastasis.

[A case of early gastric cancer with Virchow's node metastasis, effectively treated by high dose of UFT]

We report a case of early gastric cancer with Virchow's node metastasis. The patient underwent partial gastrectomy and postoperative immunochemotherapy using MMC, 5'-DFUR and PSK, which reduced the Virchow's node. Three years after surgery, we found metastases to the left subclavicular and axillary nodes other than the Virchow's node. Then UFT was administered orally at 600 mg/day, and the metastatic nodes diminished, then vanished. The patient is alive nearly five years after surgery.

[Expression of c-erbB-2 protein and vessel invasion in colorectal cancer]

Using sections of formalin-fixed, paraffin-embedded tissues from 64 colorectal cancer patients, the expression of c-erbB-2 oncoprotein was studied immunohistochemically. Twenty-seven percent of the cases with liver metastasis showed positive staining. On the other hand, only 3% of cases without liver metastasis were positive. Expression rates of c-erbB-2 protein in liver metastasis cases showed no significant difference between primary operation (26%) and recurrence (27%). Of all c-erbB-2 positive patients, 90% (9/10) had liver metastasis. Secondly, vessel invasions of 45 rectal cancer patients were studied using Victoria Blue (VB) elastic staining and endothelial staining by factor VIII-related antigen and Ulex europaeus agglutinin I (UEA-I) lectin. VB-HE double stain was efficacious to detect vascular invasion, but endothelial staining was not. There were statistically more vascular invasions in 30 patients with liver or lymph node metastases than in those without metastasis. And in cases with metastasis, many vascular invasions into the extra-muscular layer were seen. Both vascular invasions and c-erbB-2 protein were valuable indicators of possible liver metastasis.

[Effects and complications of continuous hepatic arterial infusion chemotherapy using implantable reservoir for liver metastases from colorectal cancer]

Continuous arterial infusion chemotherapy using implantable reservoir was performed for unresectable liver metastases from colorectal cancer and the therapeutic effects, side effects and complications were evaluated. Eleven patients were treated with four kinds of arterial infusion courses that mainly consisted of 5-FU. The arterial infusion courses were discontinued in 2 patients because of nausea and vomiting, and in one patient because of diarrhea. The catheters were dislocated in 2 patients and another 2 developed fistulous between the hepatic artery and bile duct. Three patients developed duodenal ulcer. Serum CEA was reduced in 4 patients (36%). After all, response rate was 9% (1/11). The one-year survival rates of all cases and cases treated with more than 4 courses were 36.3% and 80.0%, respectively.

[Continuous hepatic arterial infusion chemotherapy using implantable reservoir in liver metastases from colorectal cancer]

Continuous hepatic arterial infusion chemotherapy using implantable reservoir was performed for liver metastases from colorectal cancer, and the therapeutic effects, side effects, and complications were evaluated. 9 patients with unresectable liver metastases were as follows, 1. Group A; 3 patients, MMC 2 mg.one shot + 5-FU 250 mg/day.continuous infusion x 14 days, and then 5-FU tablets 150 mg/day.p.o. x 14 days, 2. Group B; 4 patients, MMC 2 mg.one shot + 5-FU 500 mg/day.continuous infusion x 7 days, and then 5-FU tablets 150 mg/day.p.o. x 14 days, 3. Group C; 2 patients, 5-FU 500 mg/day.continuous infusion x 14 days, and then free from agents for 14 days. In 2 of 3 group A patients, the catheters became dislocated and one died of perforation of duodenum. In group A and group B, no severe side effects were noted. But both of group C patients showed nausea, vomiting and diarrhea. In 8 of 9 patients (89%), serum CEA level fell below the preoperative level. In 4 of 7 patients who underwent CT scan, the size of the tumor regressed. Total infused dose of 5-FU was 8.17 +/- 7.56 g in group A, 16.9 +/- 2.88 g in group B, and 21.0 +/- 9.90 g in group C on average. In 2 patients of group B, therapy was repeated seven times.