[Clinical evaluation of cefmetazole in the dermatologic field]

The therapeutic efficacy and safety of cefmetazole, a cephamycin-derived antibiotic in an injectable form were evaluated in patients with pyogenic infection in the dermatological field. Especially, it was found to be extremely effective for the skin diseases due to staphylococci or streptococci. The results obtained were the following; marked improvement in 18 cases and moderate improvement in 34 cases out of 61 cases, attaining efficacy of 86.7%. Side effects were noted as the rise of GOT and GPT in 3 cases, which were normalized by ceasing its further administration. The MIC of cefmetazole against Staphylococcus aureus isolated out of foci was 0.39-6.25 microgram/ml, while those of CEZ, CXM and ABPC used as the controls exceeded 50 microgram/ml in some cases. It is considered thus, that cefmetazole, is superior to these other antibiotics also in terms of MIC.

Stereochemistry of proton abstraction catalyzed by lysine and ornithine omega-aminotransferases

(6R)-L-[6-3H]Lysine and (6S)-L-[6]3H]lysine were prepared to investigate the stereochemical aspects of the reaction catalyzed by bacterial L-lysine epsilon-aminotransferase. When (6R)-L-[6-3H]lysine was used as a substrate, the tritium label was retained in the product, delta 1-piperideine-6-carboxylate. In contrast, the radioactivity from (6S)-L-[6-3H]lysine was found in the solvent. Thus, the pro-S hydrogen at the prochiral C-6 carbon of L-lysine is specifically abstracted by L-lysine epsilon-aminotransferase. The proton exchange was observed by proton nuclear magnetic resonance analysis in the reaction of bacterial L-ornithine delta-aminotransferase with L-ornithine in 2H2O. The isolated L-[5-2H]ornithine was converted to dextrorotatory 4-phthalimido[4-2H]butyrate. This indicates that L-ornithine delta-aminotransferase catalyzes the stereospecific exchange of the pro-S hydrogen at the prochiral C-5 carbon of L-ornithine with the solvent.

Stereochemistry of meso-alpha,epsilon-diaminopimelate decarboxylase reaction: the first evidence for pyridoxal 5'-phosphate dependent decarboxylation with inversion of configuration

The stereochemistry of the decarboxylation of meso-alpha,epsilon-diaminopimelate catalyzed by meso-alpha,epsilon-diaminopimelate decarboxylase (EC 4.1.1.20) of Bacillus sphaericus was determined by stereochemical analyses of [6-2H]-L-lysine produced by the reaction in D2O. The product [6-2H]-L-lysine was converted to levorotatory methyl 5-phthalimido[5-2H]valerate by the reactions not affecting the absolute configuration of the asymmetric carbon atom. By contrast, methyl 5-phthalimido[5-2H]valerate derived from [2,6-2H2]-L-lysine, which was produced from [2,6-2H2]diaminopimelate by decarboxylation in H2O, was dextrorotatory. The authentic methyl (R)-5-phthalimido[5-2H]valerate prepared from L-glutamate with glutamate decarboxylase was levorotatory. These results indicate that the meso-alpha,epsilon-diaminopimelate decarboxylase reaction proceeds in an inversion mode. The deuterium label in [6-2H]-L-lysine was fully conserved during the conversion into pelletierine through [1-2H]cadaverine by the stereospecific diamine oxidase reaction. Thus, the enzymatic decarboxylation of meso-alpha,epsilon-diaminopimelate occurs with inversion of configuration in contrast to the other amino acid decarboxylase reported so far.

CArcinogenic activity of clivorine, a pyrrolizidine alkaloid isolated from Ligularia dentata

The carcinogenic activity of clivorine, a pyrrolizidine alkaloid isolated from Ligularia dentata, was studied in inbred ACI rats. Twelve animals in the experimental group received a 0.005% solution of clivorine in drinking water for 340 days and survived beyond 440 days after the beginning of the experiment. Of this group, 8 developed tumors in the liver; 2 developed hemangioendothelial sarcomas, and 6 developed neoplastic nodules. The hemangioendothelial sarcoma showed metastasis in the lung of one rat. No tumors were observed in the liver of the control animals.

The existence of three types of acetohydroxy acid synthetase in an isoleucine-requiring mutant of Aerobacter aerogenes

The synthesis of the three types of acetolactate synthase (EC 4.1.3.18) which are responsible for the biosynthesis os isoleucine and valine, was observed in Aerobacter aerogenes I-12, an isoleucine-requiring mutant, when grown on the four kinds of media. When the cells were grown on isoleucine-rich medium, acetolactate synthase sensitive to feedback inhibition and having an optimum pH at 8.0 was formed. By increasing the amount of potassium phosphate in the medium, the catabolite repression of the enzyme having an optimum pH at 6.0 and which is insensitive to feedback inhibition, was released. In contrast, acetolactate synthase having an optimum pH at 8.0 and insensitive to feedback inhibition was formd when isoleucine was limited, irrespective of phosphate concentrations. Two insensitive enzymes were not regulated by isoleucine, leucine and valine, although sensitive pH 8.0 enzyme was repressed by them. Thus, it may be assumed that the synthesis of insensitive pH 8.0 enzyme were repressed by limiting the amount of isoleucine is still open.

License Limitation Regulations: The Japanese System

Fishery regulations in Japan derive from the "Old Fisheries Law" of 1901. This law recognized and legalized traditional institutions and practices. In 1949 a new law replaced the "Old Fisheries Law" and this in turn was amended substantially in 1962.From the legal viewpoint fisheries are divided into three categories, "Fishing Rights Fisheries," "License Fisheries," and "Other Fisheries." License Fisheries produce 60% of catches and this proportion has gradually increased over many years. Coastal Fisheries are controlled by the Fishing Rights system. "Common Fishing Rights" are those that enable fishermen to exploit a certain area of water in order to harvest shellfish and seaweeds and to operate small types of fixed gear and small mobile gears such as beach seines set from nonmotorized craft. "Set Net Fishing Rights" are granted for gears fixed in water shallower than 27 m. "Demarcated Fishing Rights" enable holders to engage in fish culture within a given coastal area. Fishing Rights are monopolistic rights to engage in certain fisheries in certain areas of public waters. They are thus property rights, and in legal transactions most of the same provisions concerning land apply to them.The major fisheries are controlled by licenses. A fishing license legally exempts an individual from general prohibitions declared for the purpose of conservation or the maintenance of order in the exploitation of fishing grounds. There are two categories, licenses granted by the Minister of Agriculture and Forestry, and licenses granted by Prefectural Governors. The former licenses are required to engage in fisheries for which national control is considered necessary because of the large size of the vessels engaged, the wide area of fishing operation, the existence of international fishery agreements, and the nature of the fishing grounds, etc. Seventeen fisheries come under these licenses. Prefectural Governors issue licenses to vessels engaged in fisheries next in importance to the above group. The number of vessels to be licensed in each fishery is determined in consultation with Fisheries Coordination Committees by size-class of vessels, fishing area, and periods of operation. Licenses are subject to restrictions in respect to areas fished, closed seasons, vessel tonnage, equipment and power, minimum size of fish caught, and other things.All Japanese fisheries are controlled as a unit. Almost all are limited in the number of vessels that may take part. In recent years there have been few fisheries where the number of licenses issued has increased, but there has been a rise in the size of vessels and the quality of their equipment. Since fishing effort is controlled by the limitation on the number of licenses, in several instances their number has been reduced when exploitation seemed too high. In some cases vessels have been transferred to other fisheries; in others those forced out have been compensated by those remaining. But since renewal is nearly assured the license acquires value, and investments and loans are made taking the license as security. There is no fee charged for the licenses. It would have been better if one were, and the income used to compensate those who are forced out.A "tonnage supplement system" is used to reduce the effects of increase in fishing power resulting from the use of larger and more efficient vessels within the licensing system. To replace a vessel with another of larger size, the equivalent extra tonnage must be retired by purchase of a license or some other means.The system used in Japan arose in response to conditions in that country, and is regarded as successful. Other countries considering license limitations should consider their special problems to judge whether such a system is appropriate.

Morphological correlates of increased coupling resistance at an electrotonic synapse

Close appositions between axonal membranes are present in the septum between adjacent axonal segments of the septate or lateral giant axons of the crayfish Procambarus. In sections the closely apposed membranes appear separated by a space or gap. The use of lanthanum indicates that there may be structures connecting the apposed membranes. The apparent gap is actually a network of channels continuous with the extracellular space. Adjacent axonal segments are electrotonically coupled at the septa. The coupling resistance is increased by mechanical injury of an axon, immersion in low Cl(-) solutions, and immersion in low Ca(++) solutions, followed by a return to normal physiological solution. Septa at which coupling resistance had been measured were examined in the electron microscope. The induced increases in coupling resistance are associated with separation of the junctional membranes (with the exception of the moderate increases during immersion in low Ca(++) solutions). Schwann cell processes are present between the separated axonal membranes. When nerve cords in low Cl(-) solutions are returned to normal physiological solution, coupling, i.e., electrotonic synapses. A model of an electrotonic synapse is proposed in which tween axonal membranes are again found. The association between the morphological and physiological findings provides further evidence that the junctions are the sites of electrotonic coupling, i.e., electrotonic, synapses. A model of an electrotonic synapse is proposed in which intercytoplasmic channels not open to the extracellular space are interlaced with a hexagonal network of extracellular channels between the apposed junctional membranes.

Experimental alteration of coupling resistance at an electrotonic synapse

Adjacent segments of the septate axon of the crayfish Procambarus are electrotonically coupled by junction located in the septa between them (see Pappas et al. 1970. J. Cell Biol.49:173). The coupling resistance at the septa was changed by several experimental treatments. Mechanical injury to an axon increased coupling resistance (more than 7-fold); no recovery of coupling resistance was observed, although the resting potential and resistance of the injured axon could return to near normal levels. Immersion in salines with Na propionate substituted for NaCl increased coupling resistance (mean: 6.1-fold). On return of the preparation to normal saline, coupling resistance recovered virtually completely. Immersion in low Ca(++) solutions moderately increased coupling resistance (3.5-fold or less), but return to normal saline was followed by large increases in coupling resistance (5-100-fold). 60 nM Ca(++) is near the maximum concentration that leads to increased coupling resistance on return to normal saline. Large increases in coupling resistance are associated with separation of junctional membranes (Pappas et al. 1970. Ibid.); calculations show that the separated membranes greatly increase in resistance. Increase in coupling resistance is probably an important response to injury. Mechanisms underlying changes reported here may be relevant to normal physiological processes of coupling and decoupling.