Treatment of elderly patients with hepatocellular carcinomas with mitomycin C and 5-fluorouracil

Twenty elderly patients with hepatocellular carcinoma were treated with 5-fluorouracil (5-FU) at a daily dose of 200-300 mg per os, and with a combination of 0.3-0.35 mg/kg of mitomycin C (MMC) iv on day 1 and 8-10 mg/kg of 5-FU iv daily starting on day 1 for 5 consecutive days, repeating at 4 week intervals. According to the Koyama-Saito's criteria, there was no response in the 5-FU treatment, while a 20% (2/10) of response rate (2 partial responses) was obtained in the combination regimen. The durations of response in 2 partial responses were 7.3 and 4.0 months, respectively. The median survival with MMC and 5-FU was 3.4 months compared with 1.5 months with 5-FU alone, and the survival was correlated with tumor response. The combination produced more gastrointestinal toxicities and myelotoxicities compared to a single drug, but they were well tolerated. These results support the superiority of the combination of MMC and 5-FU over 5-FU alone in the treatment of elderly hepatocellular carcinoma.     

Molded bone augmentation by a combination of barrier membrane and recombinant human bone morphogenetic protein-2

OBJECTIVES: To provide the histological background to a new method of local bone augmentation, we examined the events occurring beneath a barrier membrane applied with recombinant human bone morphogenetic protein-2 (rhBMP-2). MATERIALS AND METHODS: The effects on bone augmentation of rhBMP-2, applied with a membrane mold (BMP-Memb), over surgically-induced bone defects in rat calvaria were examined histologically, and the results compared with those from application of rhBMP-2 (BMP) alone, or of a molded membrane (Memb) alone. RESULTS: At postoperative week 2, the BMP group showed the most marked bone formation. However, the bone diminished in size by week 8. The Memb group showed slow but continuous bone formation by week 8. In the BMP-Memb group, bone filled the space in the mold at week 2, and this was maintained until week 8. Moreover, the soft tissue that had intervened between newly formed bone and the membrane in the Memb group was not evident in the BMP-Memb group, in which bone had formed directly on the membrane. CONCLUSIONS: The results suggest that the combination of rhBMP-2 and barrier membrane has advantages in producing and maintaining bone in the intended shape by inducing osteoblasts directly on the inner surface of the membrane.     

Lack of favorable effect of immunomodulators on outbred syngeneic rodent islet transplantation

We studied the effect of two immunomodulators, lobenzarit disodium and OK-432, on outbred syngeneic islet transplantation. Six hundred fresh islets taken from two male Wistar rats were transplanted intraportally into other male Wistar rats that had been made diabetic with streptozotocin. Lobenzarit was given to 12 recipients and OK-432 to seven recipients intraperitoneally for 1 month, while nine controls received only intraperitoneal saline. Both drug-treated groups could not maintain lower fasting plasma glucose levels or higher fasting body weights at each time as compared with controls. The islet survival time in lobenzarit-treated (23.5 +/- 8.0 days) and OK-432-treated (25.3 +/- 13.4 days) groups was not longer than that (21.6 +/- 9.4 days) of the control group. All the pancreatic insulin contents of the seven surviving controls, ten surviving lobenzarit and five surviving OK-432 recipients were less than 0.8% of the mean insulin content obtained from 12 normal male rats. The hepatic insulin content of both drug-treated groups was not higher than that of the control group. These results suggest that lobenzarit disodium and OK-432 cannot protect outbred syngeneic islet grafts.     

Possible involvement of cholinergic nicotinic receptor in insulin release from isolated rat islets

Insulin release is influenced by the autonomic nervous system. Regarding parasympathetic control, previous reports have shown that regulation of insulin release is executed exclusively through muscarinic receptors in the pancreatic islets. In the present study, however, we examined the effect on insulin release at the islet level of various agents affecting the parasympathetic nervous system, especially nicotinic receptor blockers. Pancreatic islets isolated from adult Wistar male rats were incubated with these agents and insulin release in the media was measured. Acetylcholine chloride (10(-5) M), as well as distigmine bromide (10(-6), 10(-5) M), both of which are cholinesterase inhibitors, stimulated insulin release, whereas atropine (5 x 10(-6), 5 x 10(-5) M) suppressed it. On the other hand, serum and IgG from myasthenia gravis patients, containing anti-acetylcholine receptor antibodies, affected insulin release, and alpha-bungarotoxin (10(-9)-10(-7) M), a nicotinic receptor blocker, stimulated insulin release dose-dependently. The present observations suggest that insulin release is influenced by the parasympathetic nervous system, mediated via not only muscarinic but also nicotinic receptors.     

Islet function after storage at -2 degrees C and -196 degrees C

The radical treatment of type 1 diabetes by transplantation requires the extracorporeal storage of islets, and this has frequently been studied. Damage from ice formation, however, has prevented the development of any satisfactory method for preservation. We compared islet function after frozen storage with that after non-frozen storage. Isolated rat islets immersed in 10% dimethyl sulfoxide were kept at -2 degrees C (group A) and -196 degrees C (group B) for 7 days. After one day of culture, some of the islets were incubated in 3.3 and 16.7 mM glucose-containing Krebs--Henseleit bicarbonate buffer for 60 min. The other islets were incubated with 3H-leucine for 2 h. The radioactivity of whole-islet homogenate and the insulin extracted from it were measured. We also counted the number of islets before and after the 7-day storage. The islets thus preserved were transplanted into streptozotocin-induced diabetic rats and the fasting plasma glucose was determined weekly. Non-cooled islets were used as controls (group C). Insulin release in the presence of 16.7 mM glucose did not significantly differ between groups C and A, whereas it was lower in group B than in groups A or C. The islet uptake of 3H-leucine was lower in A and B compared with C, but the insulin synthesis was similar in all three groups. More islets were recovered from A than B. Fasting plasma glucose was lowered similarly in the diabetic rats after transplantation of islets from A and B. The relative ease of preservation at -2 degrees C, and the positive results of this experiment, favor this method of preservation.     

Vacor inhibits insulin release from islets in vitro

It has been reported that Vacor, a rodenticide containing N-3-pyridylmethyl-N'-p-nitrophenyl urea, causes insulin-dependent diabetes mellitus. The pathomechanism of Vacor-induced diabetes mellitus has not been clarified yet. The effect of Vacor, therefore, was studied in terms of insulin release from isolated rat pancreatic islets. Vacor suppressed glucose-stimulated insulin release, but did not affect the insulin release induced by theophylline or 12-o-tetra-decanoylphorbol 13-acetate. It is suspected that the suppression of insulin release from pancreatic islets by Vacor may contribute to the pathogenesis of Vacor-induced diabetes mellitus and that this suppression might not be related to cAMP and C-kinase.     

Factor VII Morioka (FVII L-26P): a homozygous missense mutation in the signal sequence identified in a patient with factor VII deficiency

We investigated the molecular basis of factor VII deficiency in a Japanese patient and identified a novel missense mutation in the signal sequence of the gene. Factor VII activity and antigen level measured in the patient were 10.7% and 11% of normal, respectively. All exons except 1B and the 5'-flanking region containing promoter region were amplified by polymerase chain reaction (PCR) from genomic DNA. Sequencing analysis of the PCR fragments revealed that the patient was a homozygote for a T to C substitution at nucleotide position 38. This mutation predicts an amino acid replacement of leucine to proline at codon −26 in the hydrophobic core of the signal peptide, which probably affects translocation of the protein into endoplasmic reticulum and subsequently causes reduction in plasma factor VII level.