Tracheoplasty with palatal mucoperiosteal graft

A case of tracheal reconstruction with a palatal mucoperiosteal graft is reported. The patient is a 75-year-old woman who had the anterior wall of her trachea resected for invading thyroid carcinoma. Palatal mucoperiosteum, which is easy to handle, provided both the lining and supporting tissue for the trachea. Local neck skin was used for covering. This procedure proved very successful.     

Enzyme complex structure and location of enzymes in the phthalate degradative pathway in Rhodococcus erythropolis

A. SUEMORI, K. NAKAJIMA, R. KURANE AND Y. NAKAMURA. 1996. Rhodococcus erythropolis strain S1 formed enzymes essential to the degradation of phthalate when grown in phthalate-minimal medium. The reaction responsible for the dihydroxylation of the phthalate-benzene ring was concluded to be catalysed by membrane-associated phthalate 3,4-dioxygenase (PO). Of the other enzymes involved, 3,4-dihydro-3,4-dihydroxyphthalate 3,4-dehydrogenase (PH) and 3,4-dihydroxyphthalate 2-decarboxylase (PC) appeared likely to be membrane-bound, while protocatechuate 3,4-dioxygenase appeared to be present in the cytoplasm. Based on the data, the membrane-bound PO and PH apparently form an enzyme complex, which is associated with the NADH-regenerating system.     

Effect of penicillin G on the electroporation of Rhodococcus rhodochrous CF222

M. SUNAIRI, N. IWABUCHI, K. MURAKAMI, F. WATANABE, Y. OGAWA, H. MUROOKA AND M. NAKAJIMA. 1996. Suitable conditions for the introduction of bacteriophage DNA into cells of Rhodococcus rhodochrous CF222 by electroporation were established, and penicillin G was found to enhance the transfection frequency. When conditions optimal for the parental strain were applied to its colony-morphological mutants, different transfection frequencies were observed. Penicillin G enhanced the transfection frequency of smooth and mucoidal mutants but not of rough mutants.     

Induction and Repair of Damage to DNA in Cucumber Cotyledons Irradiated with UV-B

Photoinduced lesions in DNA, namely, cyclobutane pyrimidinedimers (CPDs) and pyrimidine-(6-4)-pyrimidone photoproducts[(6-4)photoproducts], in cucumber cotyledons that had been irradiatedwith naturally occurring levels of UV-B (290–320 nm) werequantitated by enzyme-linked immunosorbent assays with monoclonalantibodies specific to each type of photolesion. Induction ofthese photolesions was dependent on temperature and their extentwas reduced by simultaneous irradiation with white light. Thedark repair of both types of photolesion was undetectable. Light-dependentremoval of (6-4)photoproducts was very slow, with 50% removalin 4 h. By contrast, 50% of initial CPDs were removed within15 min. Both photorepair processes were dependent on the intensityof white light and were sensitive to temperature. These resultsindicate that high photolyase activity is present in cucumbercotyledons and that repair activities in cucumber cotyledonsare different from those reported in Arabidopsis, in which (6-4)photoproductsare photorepaired more rapidly than CPDs. (Received October 13, 1995; Accepted December 28, 1995)     

An on-line advisory control system for the lactic acid fermentation process

A fuzzy expert system was developed for online diagnosing and controlling of bioprocesses. The system was constructed in object-oriented Smalltalk/V for diagnosing and controlling of bioprocesses. Lactic acid fermentation with an industrial strain ofLactobacillus casei was chosen as the model system. The performance of the fuzzy expert system and the knowledge base utilizing experts' knowledge and several facts obtained from the experiments were successfully validated with on-line fermentations. The fuzzy expert system could diagnose a fault on-line and give reasonable advice to the process operator. In order to achieve the diagnosing faculty, a database, a knowledge base, and both backward and forward chaining procedures were implemented employing the object-oriented programming environment. A defuzzifier was implemented in the system to achieve on-line control. In order to realize a decision-making system with a human operator and a fuzzy expert system, a new control strategy namedAdvice was also introduced. Several cultivations were carried out in order to collect knowledge on the effects concerned with inoculum properties to the process and to construct a database including standard time-course profiles. The performance of the fuzzy expert control system was successfully tested with on-line experiments.Visiting scientist from HUT at RIKEN     

Neuroeffector actions of prostaglandin D2 on isolated dog mesenteric arteries

Treatment with prostaglandin (PG) D2 in concentrations (10(-8) to 10(-7) M) insufficient to alter the basal tone potentiated the contractile response of helical strips of dog mesenteric arteries to transmural electrical stimulation but did not influence the response to norepinephrine. The potentiating effect of PGD2 was not prevented by treatment with diphloretin phosphate, a PG antagonist, whereas contractions of dog cerebral arteries induced by PGD2 were suppressed. The 3H-overflow evoked by transmural stimulation in superfused mesenteric arterial strips previously soaked in 3H-norepinephrine containing media was significantly increased in PGD2. It is concluded that PGD2 increases the stimulation-evoked release of norepinephrine from adrenergic nerves innervating the arterial wall. PGD2 appears to act differently on receptive sites responsible for increasing the release of norepinephrine and for producing arterial contraction.