Presence of Cell Wall Lytic Enzyme in Stable Staphylococcal L-Form

The stable L-form cells derived from Staphylococcus aureus 209P were examined for the presence of cell wall lytic enzymes. The enzyme preparations from cells and culture fluid of the parent strain lysed both Micrococcus lysodeikticus cells and S. aureus cells, whereas the enzyme preparations from the L-form lysed M. lysodeikticus cells but not S. aureus cells. Lipoteichoic acid, which has been reported to be a regulator of the lytic enzyme, inhibited both enzyme preparations from the parent strain and the L-form. However, the susceptibility of the enzyme preparation from the L-form to lipoteichoic acid was lower than that from the parent strain

Production of Insect Toxin Beauvericin From Entomopathogenic Fungi Cordyceps Militaris by Heterologous Expression of Global Regulator

Cordyceps militaris is one of entomopathogenic fungi species that is well known to be a traditional medicine in China for decades. Although the pharmaceutical and/or toxic properties of C. militaris has attracted attention as a promising resource for finding bioactive compounds, only a few substances including cordycepin have been reported so far. In the previous report heterologous expression of LaeA, a global regulator for secondary metabolites production in fungi, has been succeeded in C. militaris. The LaeA-engineered transformants are proved to produce new and/or elevated production of secondary metabolites, as detected by HPLC analysis. In order to further characterize the secondary metabolites that were being significantly produced by LaeA transformant, HPLC profiling and structure elucidation by proton NMR were conducted in two target compounds, designated as compound 1 and compound 2. Compound 1 possessed the highly similar characters to insect toxin beauvericin in UV spectrum, molecular weight, and retention time in HPLC analysis. Proton NMR analysis revealed that compound 1 had the same proton signals as beauvericin

Penicillin Resistance of Pseudomonas aeruginosa Clinical Isolates from Urinary Tract Infections

One hundred and thirteen clinical isolates of Pseudomonas aeruginosa from urinary tract infections were tested for their mechanisms of resistance to penicillins. Ninety-eight percent and 100.0% of the strains were resistant (MIC≧100 μg/ml) to ampicillin and penicillin G, respectively, while only 5.3% were resistant to piperacillin. Low permeability of the outer membrane, and penicillinase production were involved in their resistance mechanisms. Peptidoglycan synthesis in ether-treated cells of two representative strains was inhibited by ampicillin and piperacillin at the concentrations markedly lower than that for penicillin G

Bilateral Renal Cell Carcinoma and its Treatment

A report is presented on two cases of bilateral renal cell carcinoma together with a review of the literature. Bilateral renal cell carcinoma is rare and there is much controversy concerning its treatment. Our current experience supports conservative therapy for bilateral renal cell carcinoma

Trapping of CDC42 C-terminal variants in the Golgi drives pyrin inflammasome hyperactivation

CDC42-C末端異常症に於ける炎症病態を解明 --ゴルジ体への異常蓄積がパイリンインフラマソーム形成を過剰促進--. 京都大学プレスリリース. 2022-05-02.Mutations in the C-terminal region of the CDC42 gene cause severe neonatal-onset autoinflammation. Effectiveness of IL-1β–blocking therapy indicates that the pathology involves abnormal inflammasome activation; however, the mechanism underlying autoinflammation remains to be elucidated. Using induced-pluripotent stem cells established from patients carrying CDC42[R186C], we found that patient-derived cells secreted larger amounts of IL-1β in response to pyrin-activating stimuli. Aberrant palmitoylation and localization of CDC42[R186C] protein to the Golgi apparatus promoted pyrin inflammasome assembly downstream of pyrin dephosphorylation. Aberrant subcellular localization was the common pathological feature shared by CDC42 C-terminal variants with inflammatory phenotypes, including CDC42[*192C*24] that also localizes to the Golgi apparatus. Furthermore, the level of pyrin inflammasome overactivation paralleled that of mutant protein accumulation in the Golgi apparatus, but not that of the mutant GTPase activity. These results reveal an unexpected association between CDC42 subcellular localization and pyrin inflammasome activation that could pave the way for elucidating the mechanism of pyrin inflammasome formation

日本人ADA2欠損症患者における詳細な発現解析によりII型インターフェロンシグネチャーの特異的上昇とSTAT1過剰活性化が明らかとなった

京都大学新制・課程博士博士(医学)甲第23796号医博第4842号新制||医||1058(附属図書館)京都大学大学院医学研究科医学専攻(主査)教授 森信 暁雄, 教授 椛島 健治, 教授 杉田 昌彦学位規則第4条第1項該当Doctor of Medical ScienceKyoto UniversityDFA

Adherence of Candida albicans to Urinary Catheters

The occurrence of Candida albicans in patients with urinary tract infections, and in vitro of C. albicans to a urinary catheter were studied. C. albicans was more adherent to latex rubber than to silicon, whereas C. tropicalis adherence was the reverse. The relationship between the adherence and the change in interfacial free energy which corresponds to the process of adherence, suggests that hydrophobic interactions are involved in candidal adherence to catheter materials. Among five N-acyl-phenylalanines, N-octyl-phenylalanine showed outstanding ability in removing adherent fungi on catheter surfaces

Production of Insect Toxin Beauvericin from Entomopathogenic Fungi Cordyceps militaris by Heterologous Expression of Global Regulator

Cordyceps militaris is one of entomopathogenic fungi species that is well known to be a traditional medicine in China for decades. Although the pharmaceutical and/or toxic properties of C. militaris has attracted attention as a promising resource for finding bioactive compounds, only a few substances including cordycepin have been reported so far. In the previous report heterologous expression of LaeA, a global regulator for secondary metabolites production in fungi, has been succeeded in C. militaris. The LaeA-engineered transformants are proved to produce new and/or elevated production of secondary metabolites, as detected by HPLC analysis. In order to further characterize the secondary metabolites that were being significantly produced by LaeA transformant, HPLC profiling and structure elucidation by proton NMR were conducted in two target compounds, designated as compound 1 and compound 2. Compound 1 possessed the highly similar characters to insect toxin beauvericin in UV spectrum, molecular weight, and retention time in HPLC analysis. Proton NMR analysis revealed that compound 1 had the same proton signals as beauvericin

Identification by Heterologous Expression and Gene Disruption of VisA as l-Lysine 2-Aminotransferase Essential for Virginiamycin S Biosynthesis in Streptomyces virginiae

The visA gene of Streptomyces virginiae has been thought to be a part of the virginiamycin S (VS) biosynthetic gene cluster based on its location in the middle of genes that encode enzymes highly similar to those participating in the biosynthesis of streptogramin-type antibiotics. Heterologous expression of the visA gene was achieved in Escherichia coli by an N-terminal fusion with thioredoxin (TrxA), and the intact recombinant VisA protein (rVisA) was purified after cleavage with enterokinase to remove the TrxA moiety. The purified rVisA showed clear l-lysine 2-aminotransferase activity with an optimum pH of around 8.0 and an optimum temperature at 35°C, with 2-oxohexanoate as the best amino acceptor, indicating that VisA converts l-lysine into Δ(1)-piperidine 2-carboxylic acid. A visA deletion mutant of S. virginiae was created by homologous recombination, and the in vivo function of the visA gene was studied by phenotypic comparison between the wild type and the visA deletion mutant. No differences in growth in liquid media or in morphological behavior on solid media were observed, indicating that visA is not involved in primary metabolism or morphological differentiation. However, the visA mutant failed to produce VS while maintaining the production of virginiamycin M(1) at a level comparable to that of the parental wild-type strain, demonstrating that visA is essential to VS biosynthesis. These results, together with the observed recovery of the defect in VS production by the external addition of 3-hydroxypicolinic acid (3-HPA), a starter molecule in VS biosynthesis, suggest that VisA is the first enzyme of the VS biosynthetic pathway and that it supplies 3-HPA from l-lysine