Ulcerous change decreases the accuracy of endoscopic ultrasonography diagnosis for the invasive depth of early gastric cancer.

BACKGROUND: With the development of endoscopic submucosal dissection, an expansion of the criteria for local treatment was suggested for lesions with ulcerous changes or undifferentiated-type adenocarcinoma. AIM OF THE STUDY: To determine the efficacy of endoscopic ultrasonography for such lesions, we retrospectively analyzed factors that influenced accurate diagnosis by endoscopic ultrasonography of the depth of tumor invasion. METHODS: We investigated 267 gastric adenocarcinomas for which histopathological results were obtained by endoscopic mucosal resection or gastrectomy. The lesions were divided into four groups by histological type and the presence of ulcerous changes. Five clinicopathological factors were assessed for their possible associations with incorrect diagnosis. RESULTS: The positive predictive value (PPV) for cancer limited within the mucosa (endoscopic ultrasonography, EUS-M) and cancer invaded into the submucosal layer (EUS-SM) were 88.0% (125 of 142 lesions) and 60.0% (30 of 50 lesions), respectively. The lesions diagnosed as EUS-M/SM borderline (37 lesions) included 19 lesions (51.4%) of M cancer and 17 lesions (45.9%) of SM cancer. In logistic analysis, ulcerous changes (p < 0.0001) and macroscopic classification (p = 0.0284) were factors that caused incorrect diagnosis by endoscopic ultrasonography. In the group having differentiated-type adenocarcinoma with ulcerous changes, the PPV of EUS-SM was 25% (3 of 12), and there was a significant difference (p < 0.05) between the EUS-SM of this group and that of the differentiated-type adenocarcinoma without ulcerous changes. CONCLUSION: The accuracy of endoscopic ultrasonography tumor staging was not sufficient for the lesions with ulcerous changes in our study. Therefore, we should be careful to perform endoscopic submucosal dissection for lesions with ulcerous changes.

Screening and production of arylsulfatases for target therapy with etoposide 4'-sulfate, an antitumor prodrug.

Two arylsulfatase-producing streptomycetes that desulfated etoposide 4'-sulfate were isolated from soil samples. Taxonomical study identified one soil isolate as Streptomyces griseorubiginosus S980-14 (Es-1 arylsulfatase producer), while the other was considered new and tentatively designated Streptomyces sp. T109-3 (Es-2 arylsulfatase producer). Both strains produced extracellular arylsulfatase activities, provided that cultivation media were prepared with distilled water. Unlike the two known types of arylsulfatases, which had significant activity on p-nitrophenyl sulfate but none on etoposide 4'-sulfate, the crude streptomycete arylsulfatases efficiently desulfated etoposide 4'-sulfate and p-nitrophenyl sulfate, which supports the establishment of a new type of arylsulfatases.

A new type of Streptomycete arylsulfatase with high affinity to the sulfuryl moiety of the substrate.

Streptomyces sp. T109-3 arylsulfatase (Es-2), which desulfated p-nitrophenyl sulfate as well as etoposide 4'-sulfate, was purified to protein homogeneity by sulfated cellulose affinity and DEAE-cellulose column chromatographies. Es-2 required calcium for enzyme activity and was severely inhibited by SH and chelating reagents. Comparative characterization showed that, although distinct in recognition of the binding moiety of substrate, Es-1 (Streptomyces griseorubiginosus S980-14 arylsulfatase) and Es-2 shared high desulfating activity on etoposide 4'-sulfate and many other common enzymological characteristics, which suggested they would be acceptable as the enzyme component of antitumor antibody-enzyme conjugates for target chemotherapy.

Studies on the mode of antifungal action of pradimicin antibiotics. II. D-mannopyranoside-binding site and calcium-binding site.

Based on the structure-activity relationship data of BMY-28864 and related pradimicin derivatives, the calcium salt-forming ability and the D-mannopyranoside-specific visible absorption maximum shift of BMY-28864 were analysed in the ternary complex formation of BMY-28864 with D-mannopyranoside and calcium. The free C-18 carboxyl group of BMY-28864 was proved to be the sole site for binding to calcium, while no hydroxyl groups of the aglycone were involved in calcium salt formation. The stereospecific D-mannopyranoside-recognizing ability of BMY-28864 was completely abolished by removal of the C-5 disaccharide moiety, and, more particularly, of the C-5 thomosamine moiety. Close relationship of these findings with the antifungal action was also supported by the in vitro antifungal assay and the potassium leakage induction test.

Studies on the mode of antifungal action of pradimicin antibiotics. III. Spectrophotometric sequence analysis of the ternary complex formation of BMY-28864 with D-mannopyranoside and calcium.

Sequence of reactions in the process of ternary complex formation of BMY-28864 with D-mannopyranoside and calcium was spectrophotometrically determined under more strict analytical conditions using metal-free preparations of sugars and the pradimicin derivative at a bandpass slit width of 1 nm. In the first phase of ternary complex formation, BMY-28864 stereospecifically recognized and bound to D-mannopyranoside in the absence of calcium, which was revealed by a visible absorption maximum shift of ca. 8 nm. Subsequently, the BMY-28864-D-mannopyranoside conjugate reacted with calcium to yield the ternary complex, which was detected by an additional visible absorption maximum shift of ca. 8 nm. When the three components were mixed at the same time, both phases simultaneously occurred to produce the ternary complex which was accompanied by a visible absorption maximum shift of 16 nm in total. Based on this two-phased reaction sequence, the mechanism of ternary complex formation of BMY-28864 with D-mannopyranoside and calcium was reexamined in details. Terminal D-mannopyranoside was confirmed to be essential as BMY-28864-specific sugar receptor by in vitro analysis and animal cell experiments. While calcium, strontium and cadmium behaved similar in the in vitro ternary complex formation, the yeast and animal cell experiments showed that only calcium played a dual role as a base in the ternary complex formation and as an effector in physiological disturbances leading to cell death.

Studies on the mode of antifungal action of pradimicin antibiotics. I. Lectin-mimic binding of BMY-28864 to yeast mannan in the presence of calcium.

BMY-28864 (BMS-181184), a water-soluble pradimicin derivative, specifically bound on the yeast cell surface in the presence of calcium, which was considered to be the initial step that triggered chain reactions leading to the fungicidal action. Close cause-effect relationships of the cell wall binding of BMY-28864 with its antifungal activity and potassium leakage induction were observed by Candida albicans and Saccharomyces cerevisiae in the presence and absence of calcium. Using mannan and methyl alpha-D-mannopyranoside as specific sugars, the mode of binding of BMY-28864 to sugar was examined in vitro in the presence of calcium. Quantitative component analysis revealed that the precipitate of BMY-28864 with methyl alpha-D-mannopyranoside and calcium was a ternary complex possessing a molar component ratio of 2.1:4.3:1.0. These findings altogether proved that BMY-28864, although not protein, recognized specific sugars such as mannose in the same manner as lectin, and that the ternary complex formation of BMY-28864 with specific sugar and calcium was the first step for expression of the selective antifungal action of the pradimicin.

[Effects of dietary proteins on analgesic activity of tolerance and physical dependence on morphine in rats].

Effects of dietary proteins such as casein and egg albumin on analgesic activity of, tolerance to and physical dependence on morphine in rats were examined. There was no difference in analgesic activity after acute administration of morphine 10 mg/kg, s.c. between rats treated with casein food or egg albumin food and normal food for 5 or 21 days. The development of tolerance to morphine analgesia in rats treated with albumin food but not with casein food was suppressed during daily morphine 10 mg/kg, s.c. on 5 consecutive days. Rats were treated with casein or albumin food mixed with morphine (0.5 mg/g of food) for 5 days. Morphine intake in rats treated with albumin food was significantly decreased as compared to that with morphine admixed casein or normal food. Body weight loss by naloxone in morphine-dependent rats was significantly less in both casein food and albumin food groups than in the normal food group. These results suggest that chronic dietary treatment with albumin may produce a partial inhibition of development of tolerance to morphine analgesia and that with casein may attenuate morphine withdrawal manifestation in rats.

Syntheses and biological properties of new 8-fluorocarbapenem derivatives.

8-Fluorocarbapenem derivatives having various C-3 side chains were synthesized to study for the structure-activity relationship of carbapenems by in vitro biological evaluation. The introduction of fluorine at C-8 of racemic PS-5 led to slight improvements of the antimicrobial activity and the stability to renal dehydropeptidase-I. When D-cysteine was additionally introduced to the C-3 position of (+/-)-8-fluorocarbapenem, the diastereomeric separation of the 8-fluorocarbapenems became feasible. As expected from penicillins and cephalosporins, (+)-8-fluoro-3-D-cysteinylcarbapenem (+)-7a was antimicrobially active, whereas (-)-7b was inactive. It is worth noting, however, that (+)-7a was significantly more sensitive to renal dehydropeptidase-I than (-)-7b. Irrespective of the presence of fluorine at C-8, basic S-side chains at C-3, such as the pyridyl and pyrrolidyl groups, significantly improved in antimicrobial activity and dehydropeptidase-I stability. The combination of 8-fluorination with C-3 basic side chains in 7c--g resulted in a marked improvement of antimicrobial activity and dehydropeptidase-I stability.

Kinetic analysis of dehydropeptidase-I and comparative in vitro and in vivo stabilities of PS-5 derivatives modified at the C-3 side chain.

With partially purified kidney dehydropeptidase-I (DHP-I) preparations, the hydrolysis kinetics of glycyldehydrophenylalanine (Gly-dPh) by DHP-I were found to be completely non-Michaelian, whereas those of PS-5 and imipenem were composed of at least two-phase reactions which were also observed using Bacillus cereus type II beta-lactamase. Thus the DHP-I stabilities of 34 PS-5 carbapenem derivatives which were synthesized by chemical modification at the C-3 side chain of PS-5 were examined in vitro using fresh mouse, dog and human DHP-I preparations, and are tentatively expressed in reference to the DHP-I stabilities of PS-5. The in vitro DHP-I stability of PS-5 was significantly improved by introduction of basic side chains and cysteines at C-3. More particularly, the D-cysteinyl side chain was more stable relative to DHP-I than the L-cysteinyl. In vivo, however, the degree of improvement of the DHP-I-stability by chemical modification at C-3 was not sufficient enough to establish therapeutically effective levels of serum concentrations and urinary recoveries of the carbapenem derivatives after parenteral administration.

[The effects of constituents of an antitussive and expectorant preparation on physical dependence on and antitussive activity of dihydrocodeine].

The effects of constituents of an antitussive and expectorant preparation on physical dependence potential and antitussive activity of dihydrocodeine (DC) were studied. Rats were treated with DC, methylephedrine (ME), chlorpheniramine (CP), and caffeine (CA) singly or simultaneously admixed with food (DC 0.125, ME: 0.25, CP: 0.05, CA: 0.25 mg /g of food) for 7 days. Subsequently, rats were treated with naloxone (0.5 mg/kg, sc) and withdrawal signs produced were observed. Naloxone-precipitated body weight loss in DC-treated rats was suppressed by simultaneous administration of the three drugs (ME, CP and CA) or CP, which is a H1-receptor antagonist. In abrupt withdrawal, the withdrawal signs were also suppressed by CP. Moreover, tripelennamine, the same kind of H1-receptor antagonist, suppressed naloxone-precipitated withdrawal signs, but cimetidine H2-receptor antagonist, did not suppress them. These results may suggest that H1-receptor antagonists suppress the development of physical dependence on DC, and that H1-receptors play an important role in the physical dependence. On the other hand, the cough reflex was induced by electric stimulation in order to evaluate the influence of ME, CP, and CA on antitussive effect of DC in guinea pigs. ME enhanced the effect of DC. These experimental findings suggest that the constituents of the antitussive and expectorant preparation suppress the development of physical dependence on DC, though they increase the antitussive effect of DC.

Antibacterial activity and chemical modifications of PS-5 at the C-3 side chain.

Using PS-5 as starting material, the effects of chemical modification at the C-3 side chain were studied on the antibacterial activity against Gram-positive and Gram-negative bacteria including beta-lactamase-producers. Among 35 side chains tested, 4-pyridylthio showed the highest antibacterial activity against the Gram-positive bacteria, and D-cysteinyl against the Gram-negative microbes. In general, compared with acetamidoethylthio in PS-5, basic side chains showed improved antibacterial activity against the staphylococci and pseudomonads, whereas the antibiotic activity against the Gram-negative bacteria decreased with bulky side chains. The introduction of 6-aminopenicillanate and 7-aminocephalosporanate to the C-3 side chain of carbapenem significantly reduced the antibacterial activity against the beta-lactamase-producing microbes.

[Pharmacogenetic studies on analgesic activity of and physical dependence on morphine in BALB/c, C57BL/6 inbred mice and these recombinant CBF1 mice].

Mice of the BALB/c, C57BL/6, and CBF1 strains were studied with respect to analgesic activity of and physical dependence on morphine. The acute administration of morphine resulted in analgesic response in the three strains with the following ranking orders: BALB/c greater than C57BL/6 = CBF1 for 5 mg/kg, and C57BL/6 greater than BALB/c greater than CBF1 for 10 and 20 mg/kg. Mice were treated with morphine-admixed food (1-3 mg/g of food) for 9 days. During the treatment, morphine intake in BALB/c was lower than those in C57BL/6 and CBF1. Thus, we examined the degree of physical dependence in three mouse strains after chronic morphine injections for 10 days. There was significant difference in naloxone-precipitated body weight loss among strains, the ranking being as follows: BALB/c greater than CBF1 greater than C57BL/6. However, there was no difference in appearance rate of naloxone-precipitated jumping, but a difference in body shakes and body weight loss, among strains. These results suggest that analgesia of and preference for morphine, and naloxone-precipitated weight loss and body shakes may be influenced by genetic factors.