The potential of a polyglycolic acid sheet for preventing intrathoracic sleeve migration

INTRODUCTION

Postoperative gastroesophageal reflux disease (GERD) can be a consequence of laparoscopic sleeve gastrectomy (LSG). Intrathoracic sleeve migration (ITSM) is a factor contributing to its development. This study aimed to investigate whether the occurrence of ITSM can be prevented by applying a polyglycolic acid (PGA) sheet around the His angle.

MATERIAL AND METHODS

In this retrospective analysis, 46 consecutive patients who underwent LSG were divided into two groups: Group A - our standard LSG in the first half (n = 23) and Group B - our standard LSG with PGA sheet covering the angle of His in the second half (n = 23). We compared the two groups for one-year postoperative GERD and the incidence of ITSM.

RESULTS

No significant differences were found between the two groups in terms of patient background, operation time, and one-year postoperative total body weight loss, and no adverse effects related to the PGA sheet were observed. Group B had a significantly lower incidence of ITSM than Group A, and the rate of acid-reducing medicine usage was less pronounced in Group B during follow-up (p < .05).

CONCLUSION

This study suggests that applying a PGA sheet can be safe and effective in reducing postoperative ITSM and preventing exacerbations of postoperative GERD.

Piriform Fossa Injury during Calibration Tube Insertion in Laparoscopic Sleeve Gastrectomy

Piriform fossa and/or esophageal injuries caused by calibration tubes are relatively rare and remain unelucidated. Herein, we report the case of a 36-year-old woman with morbid obesity, sleep apnea, and menstrual abnormalities who was scheduled to undergo laparoscopic sleeve gastrectomy (LSG). We inserted a 36-Fr Nelaton catheter made of natural rubber as a calibration tube during the surgery. However, excessive resistance was observed. We confirmed a submucosal layer detachment approximately 5 cm from the left piriform fossa to the esophagus using intraoperative endoscopy. Additionally, LSG was performed using an endoscope as the guiding calibration tube. We inserted a nasogastric tube under endoscopy with a guidewire before completing the surgery, hoping for a guiding effect on the saliva flow. After 17 months, the patient had successfully lost weight postoperatively without complaints of neck pain or discomfort during swallowing. Therefore, in cases where the damage is limited to the submucosal layer, as in this case, conservative therapy should be considered; this is similar to the concept of endoscopic submucosal dissection not requiring suture closure. This case highlights the risk of iatrogenic injuries to the piriform fossa and/or esophagus during LSG and the importance of careful calibration tube insertion to prevent them.

Treatments for Staple Line Leakage after Laparoscopic Sleeve Gastrectomy

The number of laparoscopic sleeve gastrectomies (LSGs) performed in patients with obesity who are eligible for bariatric and metabolic surgery is currently much lower in Japan than in other countries. Considering the large number of potential patients with obesity and type 2 diabetes and the unique Japanese national health insurance system that guarantees fair healthcare delivery, there is room to increase the number of LSGs in Japan in the near future. However, strict health insurance regulations may limit access to mandatory devices needed to treat postoperative complications, such as staple line leakage, which can cause severe morbidity and even mortality. Therefore, understanding the pathogenesis and treatment options for this complication is crucial. This article examined the current situation in Japan and its impact on staple line leakage management, including the role of endoscopic treatment in reducing reoperation. The authors suggest increasing education and collaboration between healthcare professionals to optimize management and improve patient outcomes.

Feasibility of Laparoscopic Sleeve Gastrectomy for Patients with Obesity and Disorders of Intellectual Development: a Single Institutional Experience

BACKGROUND

Owing to their difficulty following clinical advice for procedural safety and ideal surgical outcomes, bariatric and metabolic surgery (BMS) for patients with disorders of intellectual development (DID) is concerning. Studies reporting the feasibility of BMS for this population remain scarce. This study aims to clarify the feasibility of laparoscopic sleeve gastrectomy (LSG) for patients with clinically severe obesity and DID.

METHODS

A retrospective analysis of a single institutional prospective database collected from 2010 to 2022 was performed. The Wechsler Adult Intelligence Scale (WAIS) was used to measure intellectual ability before LSG. A multidisciplinary team approach was implemented to give special support and care to patients with DID. Patients were categorized into groups according to their WAIS scores. LSG outcomes were statistically compared between the DID and average intellectual ability groups.

RESULTS

Using the WAIS to measure intellectual ability among patients who underwent LSG, we identified 14 patients with DID (IQ score: < 69, mean IQ: 63.4) and 71 with average intellectual ability (IQ score: 90-109, mean IQ: 98.9). Operative outcomes were comparable between the groups as follows: operation time (DID: 163 ± 41 min, average intelligence: 162 ± 30 min), hospital stay (DID: 4 [4-5] days, average intelligence: 5 [4-6] days), and total comorbidities (DID: 7.1%, average intelligence: 8.4%). No reoperations were performed, and no mortalities were observed.

CONCLUSIONS

With medical and social support and care, performing LSG on patients with clinically severe obesity and DID is safe, with good short-term results.

Surgical treatment for non-tuberculous mycobacterial pulmonary disease: analysis of prognostic factors

BACKGROUND: The surgical treatment for non-tuberculous mycobacterial pulmonary disease (NTM-PD) has an important adjunctive role and reported outcomes have been generally good; however, the prognostic factors remain unclear.METHODS: Sixty-one patients with NTM-PD who underwent surgical resection for a therapeutic purpose from January 2000 to March 2017 at five affiliated institutions were enrolled. We explored the factors that influence complications and prognosis by retrospectively referring to the medical records.RESULTS: The mean age of the present cohort was 61.8 ± 11.4 years. The pathogen was Mycobacterium avium complex in 49 patients, M. abscessus in 5. The most common indications were refractory to medication in 39. The surgical techniques employed were lobectomy or further resection in 49, sublobar resection in 8, with video-assisted thoracoscopic surgery in 21. Sputum culture conversion rate was 95.1%. Univariate analysis of factors associated with deterioration revealed significant differences related to age (P = 0.025), pre-operative albumin level (P = 0.001) and development of postoperative complications (P = 0.037), while pre-operative albumin level alone was a significant factor in multivariate analysis (P = 0.009).CONCLUSION: Outcomes after resection were generally good in the present cases. Nutritional status, as indicated by albumin level, may affect prognosis after surgical treatment.

Self Control and Server-Supervisory Control for Multiple Mobile Robots and its Applicability to Intelligent DNC System

Multiple mobile robots with six PSD (Position Sensitive Detector) sensors are designed for experimentally evaluating the performance of two control systems. They are self-control mode and server-supervisory control mode. The control systems are considered to realize swarm behaviors such as Ligia exotica. This is done by using only information of PSD sensors. Experimental results show basic but important behaviors for multiple mobile robots. They are following, avoidance, and schooling behaviors. The collective behaviors such as following, avoidance, and schooling emerge from the local interactions among the robots and/or between the robots and the environment. The objective of the study is to design an actual system for multiple mobile robots, to systematically simulate the behaviors of various creatures who form groups such as a school of fish or a swarm of insect. Further, the applicability of the server-supervisory control scheme to an intelligent DNC (Direct Numerical Control) system is briefly considered for future development. DNC system is an important peripheral apparatus, which can directly control NC machine tools. However, conventional DNC systems can neither deal with various information transmitted from different kinds of sensors through wireless communication nor output suitable G-codes by analyzing the sensors information in real time. The intelligent DNC system proposed at the end of the chapter aims to realize such a novel and flexible function with low cost.

Polypoid type of laryngeal sarcoidosis--case report and review of the literature

A 45-year-old mentally retarded woman was discovered to produce a stridor upon inhalation. Fiberoptic laryngoscopic study revealed a smooth-surfaced, wide, and pedunculated tumor on the right arytenoid and the right aryepiglottic fold. Histopathological study revealed that the tumor was characterized by granulomatous inflammation. The condition was diagnosed as laryngeal sarcoidosis. The tumor was resected surgically. Surgical resection of the tumor and injection of corticosteroid should be performed for polypoid-type laryngeal sarcoidosis. The case is discussed in detail, along with a review of the literature pertaining to sarcoidosis of the larynx.

Diagnosis and physiopathology of laryngeal deposits in autoimmune disease

We report the clinical features and pathology of a previously unreported form of vocal fold disease seen in 4 patients, 3 of whom were diagnosed as autoimmune disease. The characteristic features of these lesions were found as bilateral transverse lesions in the mid portion of the vocal folds. The patients had dysphonia and diplophonia. Stroboscopic examinations showed 180-degree phase shifts between the anterior and posterior portion of the vocal folds. Case 1 had systemic lupus erythematosus, case 2 had Hashimoto's thyroiditis, and case 3 had progressive systemic sclerosis. Prior to the onset of hoarseness, autoimmune antibody titers were increased. These cases need differential diagnosis from vocal fold nodules and cysts. Two cases were recurrent after endoscopic surgery, 1 recurring 3 times. Glucocorticoid was effective in preventing the recurrence in the early phase. Recurrence may have occurred because the surgical strategy was the same as that used for vocal fold nodules or cysts.

Auditory brainstem responses in leptomeningeal metastatic spread. Presentation of 2 cases

Auditory brainstem responses (ABRs) were recorded in 2 patients with hearing loss caused by leptomeningeal metastatic spread. These recordings showed similar characteristic findings. The absolute latencies of wave V and interwave latencies I-V were exceedingly increased. Definite effects on the wave morphology and latency of wave V were observed with the use of high repetition rates. It is surmised that the hearing loss caused by leptomeningeal metastatic spread is mainly an effect on the auditory nerve and/or the cochlear nucleus. ABR examination is of clinical value in detecting functional abnormalities resulting from leptomeningeal metastatic spread.

[Surgical approach to the nasal valve stenosis]

Nasal valve, originally defined by Mink (1903), has changed its concept and is now regarded as slit-like opening between the caudal end of the upper lateral cartilage and the septum. Contrary to Caucasians whose smallest area of the nose lies at the nasal valve, the narrowest part of Japanese nose situates at the area between the anterior portion of the inferior turbinate and the septum. Thus, we have fewer chance to experience patients with stenotic nasal valve. Six patients complaining nasal obstruction resulted from nasal valve stenosis, mainly due to dislocated or collapsed upper lateral cartilage, underwent surgery during the last 2 years and a half. Cases of septal deformity, even it it produced valve stenosis, were excluded in this study. Surgical intervention was directed toward reconstruction of normal anatomic relationships, usually by widening the nasal valve angle and preventing collapsibility. Three underwent open rhinoplasty with gull-wing columellar skin incision, whereas 3 others were operated on via transnostril approach. History of midfacial trauma caused us to choose open rhinoplasty for restoring the function and structure. Immediate postoperative result was excellent in the aspect of appearance and subjective data regardless of surgical approach. Open rhinoplasty provided a splendid long-term result without remarkable complications. On the other hand, 2 cases operated via transnostril approach complained recurrence of stuffy nose.

[Blow-out fractures of the orbit--imaging modalities and therapeutic results]

Thirty-four cases of blow-out fracture were evaluated by high-resolution CT, Hess test for red and green color and synoptophore. The results of these tests were compared with the final outcome of the fractures. The fractures were classified on the basis of the location (floor, medial wall or roof), extent (total, partial or linear) and type of fragments (punched-out or trapdoor). The medial wall type included many cases (33%) with no complaint of double vision, and many cases with a combination of disturbances in ocular mobility in both the horizontal and vertical directions. The floor type showed a low incidence of disturbances in ocular movement in the horizontal directions. Regarding the extent of the fracture, all cases with the total type showed disappearance of double vision within three months. Many of the partial and linear types had a poor outcome. With regard to the type of fragments, all of the trapdoor type cases showed a favorable result with disappearance of double vision within three months. Some of the punched-out type cases, however, showed a poor outcome.

[Practical value of LDH-X determination for the detection of sperm traces]

The examination of 38 stains collected in sexual offences provided spermatozoa-positive, LDH-X-negative results in 4 samples and spermatozoa-negative, LDH-X-positive results in 6 samples. The results suggest that besides the microscopic detection of spermatozoa the demonstration of LDH-X should be performed in medicolegal identification of seminal stains.

[B-modes ultrasonic diagnosis of the maxillary sinus]

As a routine preoperative evaluation for chronic sinusitis and postoperative maxillary cyst (mucocele and pyocele), CT scans and B-mode ultrasonic diagnosis including three methods, linear, sector, and convex scans, were performed. By chronic sinusitis, 112 sides by linear scans, 43 sides by sector scans, and 29 sides by convex scans were included in the study. By the postoperative cyst, 43 sides by linear scans, 24 sides by sector scans, and 12 sides by convex scans were included. The positive diagnostic finding by ultrasonography is defined as the depicted echo of the posterior wall. In chronic sinusitis, positive diagnostic rates were as follows: linear scans, 73.2%, sector scans, 88.2%, and convex scans, 77.8%. As for the scan planes, horizontal plane yielded more positive than sagittal one. In postoperative cyst similarly, linear, 86.0%, sector, 95.8%, and convex, 83.3%. Horizontal more positive than sagittal also. The negative findings were caused, in chronic sinusitis, by attenuation by the air in the sinus, thick anterior wall, and artifacts. In postoperative cysts, the negative findings were caused by specific location of the cysts (lateral or posterior). Our results recommend the use of sector scan because of its easy manipulation and higher positive diagnostic rates due to the radial beam conforming to the curvature of the posterior wall. Especially, the sector scan was higher diagnostic rate than linear scan, because the sector scan transmitted radial beam, and received its reflective wave easily from a curved posterior wall of the maxillary sinus. The sector scan, its manipulation is easy, and its diagnostic rate is higher than any other scans.

[Types and treatments of blow-out fractures]

A total of ten cases of blow-out fractures of the orbit was investigated as to the signs and symptoms, image findings of conventional views of Caldwell and Waters' and of coronal CT. According to the locations of fractures, medial, floor and medial-floor types were classified. Fractured bone tips were classified to depressive and trapdoor types. Fractures often occur posterior to the eyeball, the inferior rectus muscle showed dislocation and cylinder-like hypertrophy. Contrary to the reports in the past, the inferior rectus muscle did not show entrapment in the herniated portion. Caldwell view is superior to Waters' view in demonstrating fractures at the medial orbital wall. As to the choice of treatment in the majority of cases, conservative methods are indicated. Images by CT are used in determining surgical methods, the depressive type without clinical improvement after two weeks is the indication for the surgical treatments.

[C7 typing of blood stains using isoelectric focusing and immunoblotting]

By means of isoelectric focusing and immunoblotting C7 types were clearly demonstrated from bloodstains which had been stored at 37 degrees C for up to three weeks, at room temperature for up to six weeks and at 4 degrees C for over ten weeks. The C7 typing is practically useful in medicolegal individualization of unknown bloodstains.

Age-related occurrence of simple renal cysts studied by ultrasonography

Three hundred forty-eight outpatients without evidence of renal disease were examined by ultrasound. Their ages ranged from 18 to 83 years. Unexpected renal cysts of more than 1 cm were found in 47 patients (13.5%). No cysts were demonstrated in patients less than 23 years old; thereafter the number of patients with cysts increased significantly with age. The cyst diameter also tended to increase with age, but the correlation with age was not significant. There was no statistical difference of cyst occurrence between the right and left kidney, or between males and females. The upper portion of the kidney was most often affected in the equally divided three portions along the long axis. These results confirm that the development of simple renal cysts is age-related.

Absence of a gamma-melanocyte-stimulating hormone sequence in proopiomelanocortin mRNA of chum salmon Oncorhynchus keta

1. Complete nucleotide sequence of one of the salmon proopiomelanocortin mRNAs (POMC mRNAs) was determined. 2. The region corresponding to gamma-melanocyte-stimulating hormone (gamma-MSH) was lacking in salmon POMC mRNA, although overall organization of the multi-hormone structure was exactly the same as that of mammalian POMC mRNAs. 3. The possible evolutional history of POMC mRNA in mammalian species may be revealed from the finding of this characteristic that salmon POMC mRNA lacks the region corresponding to gamma-MSH.

Primary structure of two mRNAs encoding putative salmon alpha-subunits of pituitary glycoprotein hormone

1. By random sequence analyses, we isolated from the cDNA library of salmon pituitary glands two clones, the deduced amino acid sequences corresponding to the C-terminal region of which are almost the same as those of the alpha subunits of mammalian glycoprotein hormones. 2. Comparison of the nucleotide sequences and deduced amino acid sequences from these two clones with those of mammalian species revealed that the two newly-isolated cDNAs corresponded to mRNAs encoding the putative salmon pre-alpha subunit of glycoprotein hormones. 3. Homology in the nucleotide sequences of these two clones suggested that corresponding mRNAs may be encoded by separate genes which probably evolved from a common ancestral gene.

Improvement of cytotoxicity of tumor necrosis factor (TNF) by increase in basicity of its N-terminal region

Two new recombinant TNFs (named rTNF-Scw1 and -Scw2) with higher basicity than conventional recombinant human TNF-alpha (rTNF-alpha) in the N-terminal region were constructed. Their sequences were constructed based on those of partially purified cytotoxic factors from the culture supernatant of acute monocytic leukemia cells THP-1, which unlike rTNF-alpha are cytotoxic to T24 bladder carcinoma cells in vitro. These new rTNF-Ss showed a broader cytotoxicity to tumor cells than rTNF-alpha. This increase in the basicity of the N-terminal region over that of conventional TNF significantly increased the cytotoxicity on tumor cells in vivo as well as in vitro.

Detection of a countertranscript in promyelocytic leukemia cells HL60 during early differentiation by TPA

We have isolated several cDNA clones corresponding to the mRNAs expressed during early phase of differentiation of promyelocytic leukemia cells HL60 by TPA. Two interrelated clones were examined, one pHH81 and the other pHH58 possessing inserts of 180 and 730 base pairs, respectively. Northern blot analyses of poly(A) RNAs from induced cells revealed that the clone pHH81 hybridized with 4.3kb RNA, while the clone pHH58 hybridized with 4.3kb and, in addition 0.7kb RNA. Sequence determination of those cDNA clones and extensive Northern blot analyses revealed that the inserts of these clones were derived from 4.3kb mRNAs. 0.7kb RNA was hybridized with only 5' upstream region of the clone pHH58, especially with the strand designed to detect anti-sense RNA. Thus we concluded that 0.7kb RNA is a countertranscript of 4.3kb RNA expressed during early differentiation of HL60 cells.

Nucleotide sequence of a cloned cDNA for proopiomelanocortin precursor of chum salmon, Onchorynchus keta

We have isolated a cDNA clone encoding salmon proopiomelanocortin precursor. Polyadenylated RNA was isolated from pituitary neurointermediate lobes and used to construct a cDNA library. The library was screened with 17 mer of oligodeoxyribonucleotides specific for the hexapeptide sequence in salmon beta-endorphin I, Phe-Met-Lys-Pro-Tyr-Thr at positions 4-9 excluding the third nucleotide. One positive clone, pSSM17 containing an insert of 1303 base pairs (bp) was characterized. Sequence determination revealed that it possessed sequences covering the entire regions encoding ACTH and beta-lipotropin and that the mRNA had the same overall organization as those of other mammalian species, i.e., the following peptide hormones were arranged in order from 5' upstream, ACTH including alpha-melanotropin and corticotropin-like intermediate lobe peptide, beta-lipotropin including gamma-lipotropin, beta-melanotropin and beta-endorphin. Amino acid sequences for putative salmon ACTH, beta-, and gamma-lipotropin were predicted. Comparison of the salmon mRNA sequence with those of mammals showed that the regions of alpha- and beta-MSH are relatively homologous, but other regions are much less so, especially in the 3' nontranslated region where it is much longer and completely heterologous.

Molecular cloning and characterization of a cDNA clone for a protein specifically expressed in embryo as well as in a chemically induced pancreatic B cell tumor of rat

cDNAs were molecularly cloned for proteins specifically expressed in embryo as well as in a chemically induced rat pancreatic B cell tumor in which virally related oncogenes such as v-myc, v-src, v-yes, v-mos and v-kis were previously demonstrated not to be expressed. A plasmid cDNA library consisting of 48,000 independent colonies was constructed from poly(A) containing cytoplasmic RNA isolated from 12 day rat embryo. The library was screened by hybridization with 32p-labelled cDNA synthesized from poly(A) containing RNA of rat pancreatic B cell tumor or normal islet B cells. Two clones were obtained which showed a clearly positive reaction only with tumor probe. Nucleotide sequence of one of them harboring insert of 615 nucleotides was determined and its amino acid sequence of 119 residues was deduced, which showed that the protein encoded by this mRNA is highly basic, basic residues/acidic residues being 1.63.

Heterogeneity of 3' nontranslated regions in proopiomelanocortin (POMC) precursor mRNA of chum salmon Onchorynchus keta: polymorphism of the gene

Heterogeneity of salmon pituitary proopiomelanocortin (POMC) mRNA was shown by comparison of the nucleotide sequence of independently isolated cDNA clones encoding POMC, pSSM90, pSSM53 and pSSM17, the last of which was previously characterized. Newly isolated clones pSSM90 and pSSM53 contained inserts of 1228 and 666 base pairs, respectively (excluding poly(A)). Sequence analysis revealed that the former contained sequences coding for the carboxy half of putative corticotropin (ACTH), the whole region of beta-lipotropin (beta-LPH), and the entire 3' nontranslated region, while the latter contained only the 3' nontranslated region. Sequence comparison of the three clones revealed that there are some definite nucleotide changes in the 3' nontranslated regions, i.e., base replacements and base additions at multiple sites, whereas no single change was observed in the coding regions, thus demonstrating heterogeneity and hence polymorphism of the gene in the salmon genome.

Translation in vitro and regulation of mouse liver S-adenosylmethionine synthetase messenger RNA

Total RNA was isolated from adult mouse liver tissues. The alpha- and beta-form isozymes of S-adenosylmethionine synthetase existing in liver were synthesized in a reticulocyte lysate cell-free system under the direction of total RNA and were immunoprecipitated with antibody to the beta-form. The newly synthesized and the in vivo labeled S-adenosylmethionine synthetase subunits were compared by SDS-polyacrylamide gel electrophoresis. Both the alpha- and beta-forms consist of the same size Mr 48 000 subunit. The level of the beta-form mRNA activity in mouse liver was shown to increase following intraperitoneal transplantation of Ehrlich ascites tumor cells and the changes in the mRNA activity parallel those in the cellular level of S-adenosylmethionine synthetase beta.

Effect of ribonuclease H from chick embryo on the covalent-linked poly(A)--poly(dA) complementary to poly(dT) template

In vitro poly(dA) synthesis on poly(dT) template can be initiated by poly(A) primer. Poly(A) chains are covalently extended by DNA polymerase. The reaction product consists of poly(dA) chain with poly(A) at their 5'-ends, hydrogen bonded to the template poly(dT). The primer poly(A) is linked to the product poly(dA) via a 3':5'-phosphodiester bond, and can be specifically removed by ribonuclease H from chick embryos, leaving a 5'-phosphate end of poly(dA). Poly- or oligoriboadenylate longer than the (pA)5 could serve as a priming activity to synthesize poly(A) covalently linked to poly(dA).

Purification and properties of magnesium- and manganese-dependent ribonucleases H from chick embryo

Two RNases H, Mg2+- and Mn2+-dependent RNases H, are present in extracts of chick embryo. These RNases H can be separated by phosphocellulose column chromatography. Mg2+-dependent RNase H was purified over 900-fold and Mn2+-dependent RNase H over 1,700-fold from chick embryo extracts. The molecular weight of the purified Mg2+-dependent RNase H was about 40,000 and of the Mn2+-dependent RNase H about 120,000, when estimated by gel filtration. Mg2+-dependent RNase H exhibits maximal activity at pH 9.5, and requires 15 to 20 mM Mg2+ for maximal activity, whereas Mn2+-dependent RNase H is most active at pH 8.5, and is maximally active at the concentration of 0.4 mM Mn2+, and has some activity with Mg2+. Both enzymes require a sulfhydryl reagent for maximal activity. Mn2+-dependent RNase H was inhibited by o-phenanthroline, pyrophosphate, and those polyamines tested, whereas Mg2+-dependent enzyme was not, although it was inhibited by NaF. Both RNases H liberate a mixture of oligonucleotides with 5'-phosphate and 3'-hydroxyl termini endonucleolytically.

Depside as potent inhibitor of prostaglandin biosynthesis: a new active site model for fatty acid cyclooxygenase

Forty depsides and depsidones, the esters of phenolcarboxylic acids, were examined for their inhibitory effect against prostaglandin biosynthesis with rabbit renal microsomes. 4-0-Methylcryptochlorophaeic acid was the most active inhibitor so far tested and its IC50 value was 0.34 muM. Kinetic investigation has shown that this depside acts competitively with respect to arachidonic acid as most of the non - steroidal antiinflammatory drugs. X-Ray analysis has revealed that 4-0-methylcryptochlorophaeic acid maintains its rigid conformation by forming a strong hydrogen bond between the hydroxyl and methoxyl groups. Comparison of CPK models between 4-0-methylcryptochlorophaeic acid and non-steroidal antiinflammatory drugs revealed that the carboxyl group and the two rings of these drugs are almost superimposable to those of the depside. This finding led us to propose a new active site model based on the three dimentional structure of the depside.

Xanthocillin X monomethyl ether, a potent inhibitor of prostaglandin biosynthesis

Xanthocillin X monomethyl ether, known as an antiviral antibiotic, was isolated as a potent inhibitor of Dichotomomyces cejpii. The compound inhibited prostaglandin synthesis from 14C-arachidonic acid in rabbit kidney microsomes by 50% at a concentration of 0.2 microM, while prostaglandin synthesis by microsomes of ram seminal vesicle was inhibited by 50% at 20 microM. The inhibition of xanthocillin X monomethyl ether was reversible. Of the enzymatic steps involved in the synthesis of prostaglandins and thromboxanes tested, conversion of arachidonic acid into prostaglandin H2 was specifically inhibited by xanthocillin X monomethyl ether. Anti-inflammatory activity of this antibiotic on carrageenan-induced oedema in the rat foot was, however, not detectable.

Thielavin A and B, new inhibitors of prostaglandin biosynthesis produced by Thielavia terricola

Two potent inhibitors of prostaglandin biosynthesis, thielavin A (C31H34O10) and B (C29H30O10), were isolated from cultures of Thielavia terricola. Both of these compounds were shown to be structurally related to depsides, thus consisting of three hydroxybenzoic acid groups. Concentrations required for 50% inhibition of the conversion of 14C-arachidonic acid into prostaglandins F2 alpha plus E2 by microsomes of ram seminal vesicles were 12 microM for thielavin A and 9 microM for thielavin B, respectively. Of the enzymatic steps involved in prostaglandin synthesis, thielavin A specifically inhibited the conversion of arachidonic acid into prostaglandin H2, while prostaglandin E2 synthesis from the endoperoxide was the most sensitive to thielavin B. Thromboxane A2 synthesis from prostaglandin H2 in bovine platelet microsomes were inhibited by 50% at concentrations of 150 and 350 microM of thielavin A and B, respectively. Thielavin B was significantly effective on carrageenan-induced oedema of rats when administered intravenously but on on oral administration. The anti-inflammatory activity was not detectable with thielavin A either on intravenous injection or on oral administration.

Inhibition of brain glutamate decarboxylase by 4,5-dihydroxyisophthalic acid and related compounds

Hydroxybenzoic and phthalic acids and their related compounds were tested for inhibitory activity to brain glutamate decarboxylase. Of mono-, di-, and trihydroxybenzoic acids, gallic acid was the most inhibitory, giving 50% inhibition at a concentration of 0.17 mM. Dihydroxybenzoic acids were less inhibitory than the trihydroxyacids but more than monohydroxybenzoic acids. Of the phthalic acid-related compounds tested, 4,5-dihydroxyisophthalic acid was the most potent inhibitor, producing 50% inhibition at 0.61 microM. The inhibition of these compounds was competitive with respect to L-glutamate. The Ki values were 0.02, 1.2 and 4.9 microM for 4,5-dihydroxyisophthalic acid, 5-hydroxyisophthalic acid and gallic acid, respectively. When administered intraventricularly to mice, 4,5-dihydroxyisophthalic acid produced a significant decrease in the gamma-aminobutyric acid content of the brain, resulting in induction of convulsions.

Nuclear location of ribonuclease H and increased level of magnesium-dependent ribonuclease H in rat liver on thioacetamide treatment

Rat liver nuclei were isolated in aqueous solutions of low ionic strength or anhydrous glycerol. The presence of ribonuclease H (RNase H) [EC 3.1.4.34] activity in the cytoplasm is due to extraction of the nuclear enzyme by buffer and inorganic salts. Two forms of RNase H were separated from rat liver nuclei by affinity chromatography using a DNA-cellulose column. When the RNase H in the wash solution of nuclei with 0.3 M sucrose and in nuclear solution extracted with 0.15 M NaCl were fractionated on a single-stranded DNA-cellulose column, two peaks corresponding to Mn2+- and Mg2+-dependent RNases H were eluted at 0.1 M and 0.2 M NaCl, respectively, and a peak having both RNase H activities was recovered in the wash-through fraction from the column. Among the enzymes from these two fractions in the nuclei, the activity of the Mg2+-dependent RNase H which binds to DNA-cellulose increased several-fold within 24 h of a single injection of thioacetamide. The activities of Mg2+-dependent RNase H extracted with higher-salt solution from the nuclei and recovered in the flow-through fraction from the DNA-cellulose column and the Mn2+-dependent RNase H activities were relatively unaffected by an injection of thioacetamide.

Isolation of 4.5-dihydroxyisophthalic acid an inhibitor of brain glutamate decarboxylase, produced by a Streptomyces species

A potent inhibitor of brain glutamate decarboxylase (L-glutamate 1-carboxy-lyase, EC 4.1.1.15) was isolated from cultures of a Streptomyces species, and its structure was found to be 4,5-dihydroxyisophthalic acid. The metabolite inhibited beef brain glutamate decarboxylase 50% at a concentration of 0.12 microgram/ml (0.61 micron). The kinetic analysis indicated that 4,5-dihydroxyisophthalic acid was a competitive inhibitor having a Ki value of 0.18 micron.

Herbicidins A and B, two new antibiotics with herbicidal activity. I. Producing organism and biological activities

Herbicidins A and B, two new antibiotics with selective and contact herbicidal activity, were produced by a new species of Streptomyces designated as S. sagononensis. Among tested microorganisms, herbicidins indicated some activity against fungi in vitro and Xanthomonas oryzae in vivo. Their characteristic features were brought into relief by their selective and contact killing effect on many dicotyledonous plant as well as their inhibition of germination of the plant seeds, such as Chinese cabbage.