Responsiveness of human gastric tumors implanted in nude mice to clinically equivalent doses of various antitumor agents

To reproduce clinical effects of various antitumor agents in the human tumor/nude mouse model, we investigated the responsiveness of 11 lines of human gastric tumor xenografts to doses of the agents pharmacokinetically equivalent to the respective clinical doses, which we designated the "rational dose" (RD). We found that the response rates to mitomycin C, 3-[(4-amino-2-methyl-5-pyrimidinyl]methyl-1-[2-chloroethyl]-1- nitrosourea (ACNU), adriamycin, 5-fluorouracil were 18%, and that to vinblastine was 30%; on the other hand, those to vincristine, methotrexate, and cyclophosphamide were poor. In contrast, in our previous study using the maximum tolerated doses, response rates to mitomycin C, ACNU, and vinblastine were as high as 64-82%, and those to adriamycin and 5-fluorouracil were 18%. When these results were compared with the clinical response rates of gastric tumors, as a whole, the results with RD's exhibited much better coincidence with the clinical data in terms of relative therapeutic potency, indicating the validity of the use of clinically equivalent doses instead of maximum tolerated doses in the human tumor model.     

Potentiation of allergic bronchoconstriction by repeated exposure to formaldehyde in guinea-pigs in vivo

BACKGROUND: Indoor formaldehyde (FA) might worsen allergies and be an underlying factor for the increasing incidence and severity of asthma; the exact mechanism, however, remains unclear. OBJECTIVE: The present study examined the effects of repeated exposure to FA on methacholine- and antigen-induced bronchoconstriction in guinea-pigs in vivo. METHODS: First, non-sensitized guinea-pigs were transnasally treated with 0.1 or 1.0% FA or saline three times a week for 6 weeks, and increasing concentrations of methacholine (50, 100, and 200 microg/mL) were inhaled at 5-min intervals. Second, guinea-pigs pre-treated with transnasal administration of FA or saline using the same protocol were passively sensitized with anti-ovalbumin (OA) serum 7 days before antigen challenge. Third, guinea-pigs were actively sensitized with OA and pre-treated with transnasal administration of FA or saline using the same protocol. The lateral pressure of the tracheal tube (Pao) was measured under anesthesia and artificial ventilation. RESULTS: The antigen-induced increase in Pao in actively sensitized guinea-pigs was significantly potentiated by FA exposure in a dose-dependent manner. The dose-response curve of the methacholine-induced increase in Pao in non-sensitized guinea-pigs or of the antigen-induced increase in Pao in passively sensitized guinea-pigs was not altered by FA exposure. Transnasal administration of FA significantly increased the serum anti-OA homocytotropic antibody titre (IgG) as measured by the passive cutaneous anaphylaxis reaction in actively sensitized guinea-pigs. CONCLUSION: The results suggest that repeated exposure to FA worsens allergic bronchoconstriction through enhancing antigen sensitization.     

Relationship between HLA-D and in vitro and in vivo responsiveness to Candida allergen.

In vitro reaction to Candida allergen was studied in 100 normal healthy Japanese and related to HLA. A significant association was found between the low responder group (< 7,000 c.p.m.) and HLA-B15 and the high responder group (> 7,000 c.p.m.) and HLA-B7, as well as Dwl. Four HLA-D homozygote cells of types HLA-Dwl and DHO, were tested; these fitted in the high responder group. HLA-DYT and DEn fitted into the low responder group. Responsiveness to Candida allergen corresponded to skin test (r = 0.884, P < 0.01). From these results, in vitro lymphocyte reaction to Candida allergen and skin tests showed close correlation and an association with HLA antigens, HLA-D in particular.     

A nonsynonymous polymorphism in the human fatty acid amide hydrolase gene did not associate with either methamphetamine dependence or schizophrenia

Genetic contributions to the etiology of substance abuse and dependence are topics of major interest. Acute and chronic cannabis use can produce drug-induced psychosis resembling schizophrenia and worsen positive symptoms of schizophrenia. The endocannabinoid system is one of the most important neural signaling pathways implicated in substance abuse and dependence. The fatty acid amide hydrolase (FAAH) is a primary catabolic enzyme of endocannabinoids. To clarify a possible involvement of FAAH in the etiology of methamphetamine dependence/psychosis or schizophrenia, we examined the genetic association of a nonsynonymous polymorphism of the FAAH gene (Pro129Thr) by a case-control study. We found no significant association in allele and genotype frequencies of the polymorphism with either disorder. Because the Pro129Thr polymorphism reduces enzyme instability, it is unlikely that dysfunction of FAAH and enhanced endocannabinoid system induce susceptibility to either methamphetamine dependence/psychosis or schizophrenia.     

Development of a diagnostic PCR assay targeting the Mn-dependent superoxide dismutase gene (sodA) for identification of Streptococcus gallolyticus

A PCR-based assay to identify Streptococcus gallolyticus has been developed. The assay uses an oligonucleotide primer pair targeting a partial sequence of the manganese-dependent superoxide dismutase gene (sodA). The assay distinguished members of the S. gallolyticus group from other, closely related taxa successfully by yielding a 408-bp specific amplicon.     

Modified PCR-RFLP method for HLA-DPB1 and -DQA1 genotyping.

We previously developed a new technique for HLA class II genotyping by digestion of polymerase chain reaction-amplified genes with restriction endonucleases (PCR-RFLP method). This PCR-RFLP method is an efficient and convenient typing technique for class II alleles. However, small fragments or bands located close to each other on polyacrylamide gels sometimes prevent precise analysis of the RFLP bands. Furthermore, the restriction enzymes we have reported in the previous papers are not sufficient to identify the genotypes of all heterozygous individuals. Here, we report an improved PCR-RFLP method using some informative restriction enzymes which have either a single cleavage site or, alternatively, no cleavage site in the amplified DNA region, depending on the HLA alleles, making reading of RFLP band patterns much easier. Each second exon of the HLA-DQA1 or -DPB1 gene was selectively amplified from genomic DNAs of 70 HLA-homozygous B-cell lines and 100 healthy Japanese by PCR. Amplified DNAs were digested with restriction endonucleases and then subjected to electrophoresis assaying simply for cutting, or no cutting, of the DNA. ApaLI, HphI, BsaJI, FokI, MboII and Mn1I can discriminate eight alleles of the DQA1 gene. Similarly 19 alleles of the DPB1 gene can be discriminated with Bsp1286I, FokI, DdeI, BsaJI, BssHII, Cfr13I, RsaI, EcoNI, and AvaII enzymes. This modified PCR-RFLP method can be successfully applied to heterozygotes. Thus, the method is technically simpler and more practical for routine HLA typing work than our previous PCR-RFLP method.     

Histological evaluation of medial patellofemoral ligament reconstructed using the Leeds-Keio ligament prosthesis

In a total of 15 knees from 15 patients undergoing medial patellofemoral ligament reconstruction using an artificial substitute and a medial retinaculum slip coverage for recurrent patellar dislocation, the reconstructed ligaments were histologically evaluated using hematoxilin-eosin and elastic van Gieson stains. The artificial substitute was a mesh-type Leeds-Keio ligament. The mean age of the patients at the time of surgery was 20 years (range; 13-38 years). The mean interval from initial reconstruction to gathering was 53 months (range; 11-109 months). In the tissue over the artificial ligament, longitudinally aligned collagen fiber bundles with spindle-shaped nuclei were formed in all specimens except one specimen of 11 months postsurgery, but it seemed to be mature ligament only in specimens more than 60 months postsurgery. The tissue inside the artificial ligament was immature as a whole in all specimens, although 13 out of the 15 specimens had regularly aligned collagen fiber bundles slightly or in some portions.     

Existence of phenol oxidase in the argasid tick Ornithodoros moubata

Phenol oxidase (PO, EC 1.10.3.1) activity was detected in the hemolymph of the fourth instar nymphs of the argasid tick, Ornithodoros moubata, with peak levels corresponding to the days before the majority of the nymphs had molted, suggestive of a protective role of PO during the ecdysial phase. Higher PO activity was detected in plasma relative to the hemolymph and was negligible in hemocytes. The concentration of the hemolymph and plasma assayed clearly influenced the level of PO activity, and was significantly reduced ( P<0.005) after treatment with 1-phenyl-2 thiourea, a specific PO inhibitor. This is the first report of the existence of PO in the hemolymph and plasma of a soft tick species. The regulation of PO activity and its precise role in soft tick immunity, particularly during the ecdysial phase, are interesting and need to be examined further.     

Polyglutamine aggregates stimulate ER stress signals and caspase-12 activation

Accumulation of unfolded and malfolded proteins causes endoplasmic reticulum (ER) stress, stimulating unfolded protein response (UPR) and c-Jun N-terminal kinase (JNK) activation and activating caspase-12 located on the ER. Little is known about the relationship between the ER stress and polyglutamine [poly(Q)] aggregates. Poly(Q)72 repeats [poly(Q)(72)] induced the stimulation of ER stress signals such as JNK activation, upregulation of Grp78/Bip and caspase-12 activation in C2C5 cells. We prepared antiserum against the cleavage site of mouse caspase-12 at D(318) (anti-m12D318), and showed that poly(Q)(72) with perinuclear aggregates, cytoplasmic inclusions and nuclear inclusions stimulated JNK activation and anti-m12D318 immunoreactivity, but poly(Q)(72) with dispersed aggregates and small nuclear aggregates showed a significantly less effect. Poly(Q)(72) and poly(Q)(11) dispersed in cytoplasm did not. Anti-m12D318-positive cells showed apoptotic features. Unlike anti-m8D387 immunoreactivity, the anti-m12D318 immunoreactivity was not coaggregated with poly(Q). Ac-IETD-fmk (caspase-8 inhibitor) and Ac-DEVD-CHO (caspase-3 inhibitor) did not prevent the anti-m12D318 immunoreactivity induced by poly(Q)(72) aggregates. Anti-m12D318 immunoreactivity was detected in caspase-8(-/-) and caspase-3(-/-) mouse embryonic fibroblasts expressing poly(Q)(72) aggregates. Thus, caspase-12 was activated by poly(Q)(72) aggregates via a pathway independent of caspase-8 and caspase-3 activation, and caspase-12 activation was closely associated with poly(Q) aggregate-mediated cell death. Stimulation of ER stress signals may be involved in the pathogenesis of neurodegenerative disorders with poly(Q) expansion.