Purification and Some Properties of a Haim-sensitiveα-Amylase from Newly IsolatedBacillussp. No. 195

Newly isolated Bacillus sp. No. 195 produced an extracellular alpha-amylase sensitive to Haim which was found to inhibit specifically animal alpha-amylases. The enzyme was purified easily by two steps of starch adsorption and gel filtration using Sephacryl S-200. The purified enzyme, which showed a single band on native-PAGE or SDS-PAGE, had a molecular weight of 60,000 as judged on SDS-PAGE. The optimum pH value for activity and the isoelectric point were around 7.0 and 4.5, respectively. The sensitivity of the amylase to Haim was similar to that of animal amylase rather than bacterial amylase. It was suggested that a Haim-amylase complex might be formed at the molar ratio of 1:1. The amino acid sequence F-S-W similar to the triplet F-E-W highly conserved among alpha-amylases sensitive to proteinaceous inhibitors, such as Hoe 467-A or Haim, was found in the amino-terminal part of the No. 195 amylase.

Oral intake of γ-aminobutyric acid affects mood and activities of central nervous system during stressed condition induced by mental tasks

γ-Aminobutyric acid (GABA) is a kind of amino acid contained in green tea leaves and other foods. Several reports have shown that GABA might affect brain protein synthesis, improve many brain functions such as memory and study capability, lower the blood pressure of spontaneously hypertensive rats, and may also have a relaxation effect in humans. However, the evidence for its mood-improving function is still not sufficient. In this study, we investigated how the oral intake of GABA influences human adults psychologically and physiologically under a condition of mental stress. Sixty-three adults (28 males, 35 females) participated in a randomized, single blind, placebo-controlled, crossover-designed study over two experiment days. Capsules containing 100 mg of GABA or dextrin as a placebo were used as test samples. The results showed that EEG activities including alpha band and beta band brain waves decreased depending on the mental stress task loads, and the condition of 30 min after GABA intake diminished this decrease compared with the placebo condition. That is to say, GABA might have alleviated the stress induced by the mental tasks. This effect also corresponded with the results of the POMS scores.

A primary retroperitoneal serous cystadenocarcinoma with clinically aggressive behavior

CASE REPORT

We describe a 44-year-old woman with a primary retroperitoneal serous cystadenocarcinoma as the fourth report in the world literature. A contrast-enhanced computed tomographic scan of the abdomen demonstrated a mass with enhanced solid mural nodules and septa in the left retroperitoneum. Serum CA19-9 was elevated at 181 U/ml. The patient underwent a complete resection of the retroperitoneal tumor with a partial resection of the psoas major muscle and its fascia. Pathological examination showed a well-differentiated papillary serous cystadenocarcinoma of ovarian type and locoregional lymph node metastases. Seven months after surgery, the patient developed a pelvic recurrence, and underwent a total hysterectomy, a left salpingo-oophorectomy and a resection of the metastatic mesenteric mass. Two months after the second surgery, serum CA19-9 and CA125 increased to 1,114 U/ml and 218 U/ml, respectively. A solitary liver metastasis was confirmed on a computed tomographic scan. The patient is now being treated with weekly docetaxel and carboplatin.

CONCLUSION

The present case illustrates the clinically aggressive nature of a primary retroperitoneal serous cystadenocarcinoma.

Ossifying luteinized thecoma of the ovary

A 51-year-old woman presented with lumbar backache leading to the preoperative diagnosis of a right solid adnexal mass with calcification on computed tomographic scan. Histological examination revealed a right ovarian luteinized thecoma characterized by extensive calcification and metaplastic ossification. Osteoblasts and osteoclasts surrounded the surface of the heterotopic bone. Haversian canals were occasionally identified in the bony trabeculae. Ossifying ovarian neoplasms are extremely rare and this case is the first to demonstrate the osseous metaplasia in ovarian luteinized thecoma.

Focal enhancement of expression of c-Met/hepatocyte growth factor receptor in the myocardium in human myocardial infarction

To determine the distribution and expression level of hepatocyte growth factor (HGF) specific receptor, c-Met, in human myocardial infarction. Autopsies of 13 patients who died without heart diseases (control) and 13 patients with a history of myocardial infarction (2 h to 10 years before death). The harvested myocardial tissues were stained with hematoxylin-eosin (H&E) and immunohistochemically stained for c-Met expression by the avidin-biotin-horseradish peroxidase complex method using an antibody to c-Met. C-Met expression was only slightly increased in control subjects and in noninfarcted myocardium of the test group. In contrast, high expression was noted in the peripheral region of the myocardial infarction and in some hypertrophic myocardial cells. C-Met was not expressed in the infarcted myocardium, but overexpression was noted in the surrounding myocardial cells of blood vessels and in the subendocardium and subepicardium in a band-like pattern. The expression level of c-Met was most enhanced at the time of appearance of coagulative necrosis and least in the myocardium of subjects with old infarcts. Our results indicate that HGF preferentially reaches the ischemic regions of the myocardium and has local and direct effects on the myocardium in patients with myocardial infarction.

Extensive myocardial stunning showing transient regression of prolonged T wave inversion and prolonged sympathetic denervation

A 69-year-old woman was admitted to the hospital with palpitations. Although left ventriculography showed extensive akinesis except in the basal hyperkinetic segment, coronary angiography showed normal coronary arteries. 123I-metaiodobenzylguanidine (MIBG) accumulation was obviously reduced in the anteroseptal, apical and inferior areas. Inverted T waves developed on day 3 and disappeared on day 104 after transient regression. Echocardiography showed normal left ventricular motion two weeks later. Ergonovine provocation test showed no vasospasm and thallium-201 showed no perfusion defect on day 46. Electrocardiography and MIBG returned to normal on day 216. These findings suggest prolonged sympathetic nerve injury in extensive myocardial stunning.

A simultaneous assay method for L-glutamate and L-pyroglutamate contents in soy sauce using a 5-oxoprolinase (without ATP hydrolyzing activity)

L-Glutamine and L-glutamate, which are important flavor components in soy sauce, are converted to L-pyroglutamate during brewing. Therefore, it is necessary that the L-glutamate and L-pyroglutamate contents can be measured accurately. We developed a simultaneous assay method for L-glutamate and L-pyroglutamate by using 5-oxoprolinase (without ATP hydrolyzing activity) and glutamate oxidase. By this method, the L-pyroglutamate could be measured accurately in a range of 0.05 to 1.0 mM in the presence of 1.0 mM L-glutamate. This system is effective for process and quality controls.

Histological changes of the pancreas in an elderly diabetic patient positive for GAD antibody

We examined the histological changes of the pancreas in a 75-year-old diabetic woman who was treated with sulphonylurea for 10 years and required insulin treatment for the subsequant 10 years. She was positive for antiglutamic acid decarboxylase antibody (GAD Ab) 20 years after the diagnosis of diabetes. Her autopsied pancreas revealed disfigured islets and no beta cells. These changes were indistinguishable from those of the long-sustained type 1 diabetes mellitus, and insulitis was not found. This case suggests that diabetic patients positive for the GAD Ab, even if oral hypoglycemic agents are effective, may develop complete beta cell destruction over a long period.

Co-expression of p53 and bcl-2 may correlate to the presence of epstein-barr virus genome and the expression of proliferating cell nuclear antigen in nasopharyngeal carcinoma

Epstein-Barr virus (EBV) has been well documented in the aetiology of nasopharyngeal carcinoma (NPC), although its role as well as the genetic basis in the genesis of NPC have not been elucidated. The p53 gene mutations are infrequently found in NPC, but the expression of p53 protein, as well as bcl-2 oncoprotein, has been reported in a high percentage of cases, and also in association with EBV. Proliferating cell nuclear antigen (PCNA) has also been shown to be increased in NPC, suggesting its association among the overexpression of p53 and bcl-2 oncoprotein. We undertook this study to evaluate the correlation among these abnormalities in the development of NPC. The expression of p53 protein, bcl-2 oncoprotein, and the level of PCNA were investigated by immunohistochemistry in 53 patients with NPC. Twenty tissue samples from these patients were studied for p53 gene mutations by single strand conformation polymorphism (SSCP) and DNA sequencing as well as EBV genomes by polymerase chain reaction. Among the 53 specimens, 42 (79%) showed expression of p53 protein and 40 (75%) gave positive result for bcl-2 oncoprotein. A significant association was found between p53 expression and bcl-2 oncoprotein (P=0.002; Fisher's exact test) with 68% of the patients showing coexpression of both markers. The PCNA labelling index in the 53 patients varied from 5% to 80%. High PCNA labelling index was frequently found in the patients with overexpression of p53 protein and bcl-2 oncoprotein. The PCNA index in patients with p53 expression was significant higher than in those without p53 expression (P=0.002). Of the 20 patients, p53 mutations were found in four cases. EBV genomes were detected in 14 cases of which 12 cases showed overexpression of both p53 and bcl-2 and one case with only p53 expression and one case with bcl-2 expression. EBV genomes were detected in two cases with p53 mutations. We conclude that EBV is the important etiologic factor in NPC which may be involved in p53 and bcl-2 overexpression. The mutant p53 protein is correlated to deregulation of PCNA. p53 mutations participate in a small proportion of the tumorigenesis.

The role of S100A4 gene encoding an S100-related calcium-binding protein in human bile duct adenocarcinoma cell lines: correlation of S100A4 expression and invasive growth in Matrigel Matrix

S100A4, one of the tandemly arranged S100 genes at chromosome 1q21, has been suggested to play a functional role in cell motility and invasiveness of tumor cell growth. We investigated the expression of S100A4 and the in vitro invasiveness of 4 human bile duct adenocarcinoma cell lines by the Matrigel assay. S100A4 was abundantly expressed in 2 adenocarcinoma cell lines whose growth pattern was highly invasive. Induction of antisense S100A4 into one of the cell lines decreased S100A4 mRNA levels and reduced invasiveness. In contrast, induction of sense S100A4 expression into non-invasive KMBC adenocarcinoma cells, which originally lacked S100A4 expression, resulted in apparent invasive potential in the transfected cells compared with the cells with the vector alone. These results suggest that S100A4 expression is well correlated with the invasiveness of human bile duct adenocarcinomas.

Molecular cloning, sequencing, and expression in Escherichia coli of the gene encoding a novel 5-oxoprolinase without ATP-hydrolyzing activity from Alcaligenes faecalis N-38A

The gene encoding a novel 5-oxoprolinase without ATP-hydrolyzing activity from Alcaligenes faecalis N-38A was cloned and characterized. The coding region of this gene is 1,299 bp long. The predicted primary protein is composed of 433 amino acid residues, with a 31-amino-acid signal peptide. The mature protein is composed of 402 amino acid residues with a molecular mass of 46,163 Da. The derived amino acid sequence of the enzyme showed no significant sequence similarity to any other proteins reported so far. The 5-oxoprolinase gene was expressed in Escherichia coli by using a regulatory expression system with an isopropyl-beta-D-thiogalactopyranoside-inducible tac promoter, and its expression level was approximately 16 mg per liter. The purified enzyme has the same characteristics as the authentic enzyme, except for the amino terminus, which has three additional amino acids. The enzyme was markedly inhibited by p-chloromercuribenzoic acid, EDTA, o-phenanthroline, HgCl(2), and CuSO(4). The EDTA-inactivated enzyme was completely restored by the addition of Zn(2+) or Co(2+). In addition, the enzyme was found to contain 1 g-atom of zinc per mol of protein. These results suggest that the 5-oxoprolinase produced by A. faecalis N-38A is a zinc metalloenzyme.

Isoproterenol-induced myocardial injury resulting in altered S100A4 and S100A11 protein expression in the rat

S-100 proteins (S100) are characterized by calcium-binding ability with two structural EF hands. Several S100 are expressed in cardiomyocytes and thought to play a crucial role in calcium signaling. To examine whether the expression of S100 is a response to detectable myocardial damage or regeneration, we investigated, immunohistochemically, the expression of S100A4 and S100A11 in the isoproterenol (ISP)-treated rat heart. Definite expression of S100A4 and S100A11 was demonstrated in normal cardiomyocytes, and their staining patterns were enhanced in the ISP-treated rat heart, suggesting the possible involvement of S1-A4 and S100A11 in ISP-induced myocardial damage.

Activation of the TCL1 protein in B cell lymphomas

The TCL1 gene, localized near the break point of chromosome 14q32.1 often involved in T cell leukemias, is also expressed in normal precursor T and B cells, and B cell lymphoma cell lines. We investigated the expression of the TCL1 protein in various types of B cell lymphomas according to the Revised European-American Classification of Lymphoid neoplasms. Paraffin-embedded tissue sections of lymphoma specimens were subjected to TCL1 immunohistochemistry, and positivity was scored on a three-tiered scale: - (< 25% cells), + (25-50% cells), and ++ (> 50% cells). The TCL1 protein was expressed in low-grade B cell lymphomas including mucosa-associated lymphoid tissue type in ocular adnexa (18/20, 90%). It was also expressed in follicular, lymphoplasmacytic, and mantle cell lymphoma, but not in high-grade diffuse large B cell lymphoma (2/11, 18%). These data suggest that the expression of the TCL1 gene characterizes low-grade B cell lymphomas, and may be involved in certain processes of lymphomatogenesis.

Induction of S100A4 gene expression inhibits in vitro invasiveness of human squamous cell carcinoma, KOSC-3 cells

S100A4 is considered functionally involved in metastasis and invasiveness of rodent and human mammary tumors. We screened the expression of S100A4 in human squamous cell carcinoma cell lines, and found 2 cell lines which were highly invasive, but did not express any noticeable extent of S100A4. To examine whether the expression of S100A4 regulated invasiveness of squamous cell carcinoma, we transfected S100A4 cDNA into KOCS-3 and HSC-4 squamous cell carcinoma cells. The transfectants from KOSC-3 cells expressing sense S100A4 decreased invasiveness by 80% compared with cells of the wild type or those with the vector only.

Sequential changes of hepatocyte growth factor in the serum and enhanced c-Met expression in the myocardium in acute myocardial infarction

A 68-year-old male with acute myocardial infarction (AMI) was admitted to the hospital with chest pain that had started 1 day earlier. The serum levels (ng/ml) of hepatocyte growth factor (HGF) were 1.06, 1.22, 1.05, 0.72 and 0.64 on days 2, 3, 4, 5 and 6 postinfarction, respectively. He died suddenly due to cardiopulmonary arrest on day 6. At autopsy, approximately 400 ml of bloody pericardial fluid, caused by rupture of the left ventricle, was detected and the c-Met expression in the myocardium was immunohistochemically found to be most intense in the border zone of the infarcted and non-infarcted region. Although there was no c-Met expression in the infarcted myocardium, it was increased in the myocardial cells surrounding the blood vessels. This is the first report to show sequential changes of HGF in the serum, as well as c-Met expression in the myocardium, in a patient with AMI.

Prognostic value of serum hepatocyte growth factor in patients with acute coronary syndromes

The present study examined whether or not hepatocyte growth factor (HGF), an endothelium-specific growth factor that stimulates regeneration of the endothelium, is increased or has a prognostic significance in patients with acute coronary syndromes. HGF was measured in 106 patients with coronary artery disease (20 stable effort angina, 12 unstable angina without adverse events, 24 unstable angina with adverse events and 50 acute myocardial infarction) on admission and 21 normal volunteers. The measurements in all patients were recorded before administration of heparin, and in acute myocardial infarction patients they were recorded from days 2 to 6 after heparin discontinuation on day 1. HGF levels (ng/ml) were 0.30+/-0.06 for the controls, 0.31+/-0.08 for stable effort angina patients, 0.31+/-0.08 for unstable angina patients without adverse events, 0.40+/-0.20 for unstable angina patients with adverse events and in acute myocardial infarction patients they were 0.45+/-0.18 on day 0, 0.57+/-0.45 on day 2, 0.50+/-0.35 on day 3, 0.48+/-0.32 on day 4, 0.44+/-0.20 on day 5, and 0.38+/-0.14 on day 6. HGF plays a crucial role in the restoration of injured endothelial cells and is a predictor of adverse events in patients with acute coronary syndromes.

Purification and characterization of a novel 5-oxoprolinase (without ATP-hydrolyzing activity) from Alcaligenes faecalis N-38A

A novel type of 5-oxoprolinase was found in a cell extract of strain N-38A, which was later identified as Alcaligenes faecalis. The enzyme in the cell extract was purified to a homogeneous state with a yield of 16.6%. The molecular weight of the purified enzyme was estimated to be 47,000 by both sodium dodecyl sulfate-polyacrylamide gel electrophoresis and gel filtration, suggesting that the enzyme is a monomeric protein. The enzyme specifically catalyzed a decyclization of L-pyroglutamate without hydrolyzing ATP and also without any requirements for metal ions such as Mg2+ and K+. The optimal pH for the decyclization was 7.4. The reaction was reversible. The equilibrium constant of the reaction, Keq = [L-glutamate]/[L-pyroglutamate], was evaluated to be approximately 0. 035, which indicates that the reaction tends to form L-pyroglutamate. The amino-terminal amino acid sequence of the enzyme was H-Glu-Pro-Arg-Leu-Asp-Thr-Ser-Gln-Leu-Tyr-Ala-Asp-Val-His-Phe-. No protein with a similar sequence was found in the DNASIS database. Based on these data, it was strongly suggested that the enzyme described here is a novel type of 5-oxoprolinase.

Regional left ventricular dysfunction in a patient with severe prolonged anemia

A 47-year-old woman with severe prolonged anemia developed heart failure. After treatment of the heart failure and anemia, she showed regional dysfunction of the left ventricular wall and myocardial fatty acid metabolism was disturbed in these sites. Coronary arteriography showed normal images. It took about 4 months to recover both left ventricular wall motion and fatty acid metabolism. Prolonged decrease of oxygen supply to the myocardium, which is caused by severe prolonged anemia, seemed to affect the myocardial function in this case, which could be another model of anemia-related myocardial dysfunction.

Lipoatrophy induced by recombinant human insulin injection

A 79-year-old man had been treated with recombinant human insulin since the age of 77. He developed subcutaneous fat atrophy around the injection site 16 months after induction of insulin therapy. Skin biopsy of the atrophic site revealed inflammatory changes and adipocyte atrophy. Changing the type of insulin and injection site relieved the fat atrophy. Although insulin-induced lipoatrophy was a common complication before the development of human insulin, it is now rare. The immunological reaction to the insulin product, as in conventional impure insulin-induced lipoatrophy, seemed to be involved in the etiology of lipoatrophy in this case.

Cloning of a thermostable ascorbate oxidase gene from Acremonium sp. HI-25 and modification of the azide sensitivity of the enzyme by site-directed mutagenesis

A gene encoding a thermostable ascorbate oxidase (ASOM) was cloned from Acremonium sp. HI-25 and sequenced. The gene comprised 1709 bp and was interrupted by a single intron of 57 bp. ASOM consisted of 551 amino acids including a signal peptide with a molecular mass of 61200, and contained four histidine-rich regions with high sequence homology to the corresponding regions of other multicopper oxidases. The ASOM gene was expressed in Aspergillus nidulans under the Aspergillus oryzae Taka-amylase A gene promoter. The recombinant enzyme (An-ASOM) exhibited almost the same enzymatic properties as ASOM. The ASOM gene was mutated by site-directed mutagenesis with reference to the amino acid sequences of plant enzymes to generate enzymes with altered azide sensitivity. Site-directed mutagenesis at the trinuclear active copper site resulted in an increase in azide resistance; the Ala465Leu and Phe463Trp/Ala465Leu mutants exhibited approximately 10 and 20% increases in azide resistance, respectively.

Nucleotide sequence of the gene encoding the precursor protein of pepstatin insensitive acid protease B, scytalidopepsin B, from Scytalidium lignicolum

A chromosomal DNA of Scytalidium lignicolum was digested with Sau3AI. The digest was self-ligated and amplified by inverse PCR procedure using primers designed based on the nucleotide sequences of up- and down-stream regions of an intron present in the scytalidopepsin B gene. Analysis of the nucleotide sequence of PCR product (700 bp) showed that the enzyme is synthesized as a precursor protein consisting of the prepro- and mature enzyme regions. The deduced amino acid sequence was highly similar to those of aspergillopepsin A and recently reported endothiapepsins B and C, but quite different from those of pepstatin-insensitive bacterial acid proteases and the pepstatin-sensitive aspartic protease family.

Comparative studies of suidatrestin, a specific inhibitor of trehalases

Suidatrestin, isolated from a Streptomyces strain, was characterized as a new trehalase inhibitor. Its inhibitory potential was 7 to 50-fold higher than that of validamycin when tested against insect, fungal and mammalian trehalases. The kinetic properties of suidatrestin were studied in vitro with trehalases from flight muscle mitochondria of the fly, Protophormia terraenovae, from larval midgut of the moth, Spodoptera littoralis, and from porcine kidney, as well as with maltase from yeast. Suidatrestin was inactive on maltase but inhibited all trehalases with IC50 values of 0.08-0.1 microM; Ki values ranged from 0.02 to 0.05 microM. The very low Ki/K(m) ratios (3.9 x 10(-6) -4.9 x 10(-6)) indicated excellent in vitro inhibitory action of suidatrestin. When injected into larvae of S. littoralis, suidatrestin required high and repetitive doses which lead to reversible inhibition of larval growth only. Consecutive omission of the inhibitor even stimulated weight increase above that of controls. Significant mortality was achieved at a rather high dose only. Injection of a growth-inhibiting dose of suidatrestin did not change hemolymph osmolality as a measure of sugar concentration. The discrepancy between in vitro and in vivo potency of suidatrestin may be understood once its chemical structure is fully known.

[Significance of hepatocyte growth factor measurement in patients with acute myocardial infarction]

The use of hepatocyte growth factor for acute myocardial infarction was investigated. Several other biochemical markers are already used for noninvasive detection of acute myocardial infarction. Hepatocyte growth factor, creatine phosphokinase (CK) and CK isozyme (CK-MB) levels were measured in 10 patients with stable effort angina after diagnostic catheterization, and in 21 patients with acute myocardial infarction twice a day for the first 3 days and once a day for the next 4 days. The time to reach the maximum level and the time to decline to less than half of the maximum level for each patient was also measured. Hepatocyte growth factor levels (ng/ml) were 0.3 +/- 0.1 for patients with angina pectoris, and 10.4 +/- 8.8 within 6 hours and 6.7 +/- 4.5 within 12 hours after the onset for patients with acute myocardial infarction. The time to reach the maximum (hours) and the time to decline to less than half of the maximum level (days) were 9.2 +/- 5.2 and 1.1 +/- 0.3 for hepatocyte growth factor, 19.5 +/- 7.2 and 2.3 +/- 1.1 for CK and 16.3 +/- 7.2 and 1.5 +/- 0.4 for CK-MB, respectively. The correlation coefficients between the maximum level of hepatocyte growth factor and the maximum levels of CK and CK-MB were 0.64 and 0.70, respectively. Hepatocyte growth factor is useful as a prognostic indicator and reflects the clinical course in patients with acute myocardial infarction.

Silent thyroiditis after excision of a thymoma

A 61-year-old man developed thyrotoxicosis after excision of a thymoma. His laboratory examination showed an increased level of thyroid hormone and a low thyroidal iodine uptake. No thyroidal autoantibody was detected. With the diagnosis of silent thyroiditis, he was treated with propranolol. He became euthyroid after 2 months. Thymoma often accompanies an autoimmune disease as a paraneoplastic syndrome, and an immunological mechanism is thought to be involved in the onset of silent thyroiditis. This case suggests the involvement of an immunological mechanism in the pathogenesis of silent thyroiditis.

Discitis, infectious arthritis, and bacterial meningitis in a patient with pancreatic diabetes

A 63-year-old woman with pancreatic diabetes after a total pancreatectomy and splenectomy developed discitis of the L2/3 intervertebral disk. Rapidly she also developed infectious arthritis of the left knee joint and bacterial meningitis. Aspirate from the left knee contained Enterococcus faecalis. The diagnosis of discitis is generally difficult in the initial period of disease, and patients with diabetes or splenectomy are susceptible to rapid progression of the infection. Early diagnosis of discitis using magnetic resonance imaging of the spine and treatment with antibiotics might have altered her clinical course.

Modulation of S-100 genes response to growth conditions in human epithelial tumor cells

Many new members of the S-100 genes are known to be associated with cell differentiation, malignant transformation, and cell cycle. Of the S-100 genes examined in the present study, calcyclin, calpactin I light chain and calvasculin were expressed in most human epithelial tumor cells, and their expression levels differed according to various growth conditions. Their transcribed levels differed depending on each cell line, but their expression patterns were similarly changed under growth-modulatory conditions. Their messenger RNA levels increased parallel to the S phase population of cells, and decreased at G1/G2 phases. In contrast, this expression diminished in tumor cells under growth-inhibitory conditions, such as treatment with topoisomerase II inhibitor VP-16 or phorbol 12-myristate 13-acetate.

Isolation of propioxatin A from Actinosynnema sp. SI-23 during a screening for Serratia piscatorum metalloproteinase inhibitors

An inhibitor of Serratia metalloproteinase was found in the cultured broth of strain SI-23, which was identified to be Actinosynnema sp. The inhibitor had a potent inhibitory effect on Serratia metalloproteinase and a weak effect on thermolysin, but no effect on other groups of proteinases. The structure of the inhibitor was deduced to be propioxatin A, reported as an enkephalinase B inhibitor.

Hepatocyte growth factor(HGF): a new biochemical marker for acute myocardial infarction

The purpose of this study was to investigate the use of hepatocyte growth factor as a biochemical marker for acute myocardial infarction. Several biochemical markers are used for noninvasive detection of acute myocardial infarction. However, hepatocyte growth factor has not been used previously for this purpose. We measured hepatocyte growth factor, creatine phosphokinase, and MB isoenzyme (CK-MB) levels in 6 patients with stable effort angina after diagnostic catheterization (controls) and in 12 patients with acute myocardial infarction (AMI). The measurements in the AMI patients were recorded twice a day for the first 3 days after onset of chest pain and once a day for the next 4 days. Furthermore, in each patient we evaluated the time to reach the maximum level and the time for the level to decline to less than half the maximum. Hepatocyte growth factor levels (ng/ml) were 0.3+/-0.1 for angina pectoris patients, and 15.7+/-9.1 within 6h and 12.5+/-4.6 within 12h after the onset for AMI patients, respectively. The correlation coefficients between hepatocyte growth factor and creatine phosphokinase and between hepatocyte growth factor and CK-MB were 0.68 and 0.74, respectively. The time to reach the maximum (h) and the time to decline to less than half of the maximum level (days) were 6.6+/-2.6 and 1.2 +/-0.2 for hepatocyte growth factor, 19.4+/-8.7 and 2.5+/-1.4 for creatine phosphokinase, and 16.6+/-7.7 and 1.5+/-0.4 for CK-MB, respectively. Hepatocyte growth factor is useful as a prognostic indicator and reflects the clinical course in patients with acute myocardial infarction.

Allelic loss of chromosome 16q in endometrial cancer: correlation with poor prognosis of patients and less differentiated histology

Deletion of certain chromosomal regions can be demonstrated in malignant cells. Chromosome 16q is one of the regions where allelic loss is frequently detected in carcinoma of the breast and many other tumors, suggesting that gene(s) which retard tumor growth may exist here. To elucidate the clinicopathological significance of chromosome 16q, loss of heterozygosity (LOH) was investigated using microsatellite polymorphism analysis in 58 patients with endometrial lesions (50 with endometrial carcinoma and 8 who had hyperplasia with or without atypia). When 11 regions of chromosome 16q were examined, LOH was found in 20 patients with carcinoma (40%) and none of the patients with hyperplasia. The tumors of 9 of the 20 patients (45%) showed total loss of 16q, while the others (55%) showed partial deletion. Tumors with LOH were histologically less differentiated than those without LOH (P = 0.038, chi2 test). Patients with tumors showing LOH of 16q had a worse prognosis than those without LOH according to Kaplan-Meier survival analysis (P=0.0158, log-rank test). In addition, LOH of 16q showed a significant relationship to prognosis by Cox regression analysis. Deletion mapping of 16q demonstrated that two regions (16q22.1 and 16q22.2-23.1) were frequently involved. Patients with 16q22.1 LOH had a poorer prognosis than those with intact 16q22.1 (P=0.0003, log-rank test). These findings suggest that gene(s) of which defect is possibly related to the aggressiveness of endometrial cancer are localized on a limited region of 16q that includes 16q22.1.

Incidence of p53 and Ha-ras gene mutations in chemically induced rat mammary carcinomas

To determine whether p53 alterations, which are frequent in human breast cancers, are also common in rat mammary tumors, we examined 40 tumors from 24 rats treated with 7,12-dimethylbenz[a]anthracene (DMBA) and 34 tumors from 14 rats treated with N-nitroso-N-methylurea (NMU) (an N-nitroso compound). DMBA and NMU are known genotoxic mutagens. The entire coding regions of the p53 and Ha-ras genes were examined for mutations by polymerase chain reaction single-strand conformational polymorphism analysis and by direct sequencing. One of the 40 DMBA-induced mammary tumors had a p53 mutation, a single-base substitution (AGC-->GGC) at codon 307, resulting in an amino-acid change from Ser to Gly. No mutations were found in NMU-induced tumors. The incidence of Ha-ras gene mutation was 79% (27 of 34) at codon 12 in the NMU group and 23% (nine of 40) at codon 61 in the DMBA group. Thus, p53 mutation, in contrast to Ha-ras mutation, did not seem to be a prerequisite for carcinogenesis in chemically induced rat mammary tumors.

Immunohistochemical detection of truncated APC protein in sporadic human colorectal adenomas and adenocarcinomas

Mutations of the APC gene frequently occur in sporadic forms of colorectal adenomas and adenocarcinomas. Phenotypically, the vast majority of these mutations result in the truncation of the APC protein. To demonstrate the defective APC gene product in human colorectal tumors, rabbit region-specific antisera raised against the APC protein of amino acid sequences between 371 and 390 (SPI) and between 1821 and 1840 (SP3) were used to exhibit the truncated APC protein. In all, 86 lesions from 67 cases of sporadic adenoma and adenocarcinoma were examined; abnormal staining patterns were distinguished in 43 lesions (50%); the incidence of abnormalities was not significantly different between adenomas and carcinomas. The majority, 75% exhibited epitopic change with the SPI-positive and SP3-negative phenotype (type P1), and 25% exhibited neither of these phenotypes (type P2). The staining pattern in all lesions was uniform, and studies of carcinomas arising in adenomas showed the same pattern of staining. These findings supported the view that the APC lesion is a very early event in colorectal carcinogenesis. Furthermore, this simple immunohistochemical approach demonstrated that different adenomas from the same patient showed different staining patterns.

Novel beta-D-galactofuranose-containing high-mannose type oligosaccharides in ascorbate oxidase from Acremonium sp. HI-25

Ascorbate oxidase from the fungus Acremonium sp. HI-25 is a copper-containing glycoprotein that catalyzes the oxidation of ascorbic acid to dehydroascorbic acid. Monosaccharide composition analysis showed that the enzyme contains exclusively N-linked oligosaccharide chains. Following liberation by hydrazinolysis/re-N-acetylation, and fractionation by HPLC on anion exchange. Amide-80 and/or octadecyl silica columns after derivatization with p-aminobenzoic ethyl ester, the structures of the twelve major neutral oligosaccharides were identified by FAB-MS, 400 MHz 1H-NMR, methylation analysis, mild acid hydrolysis, and/or sequential exoglycosidase digestions. Acremonium sp. ascorbate oxidase was found to consist of high-mannose type oligosaccharides (76.3%) having 4 to 9 mannose residues and a series of novel D-galactofuranose-containing high-mannose type oligosaccharides (18.6%) with the following structure.

Nucleotide sequence of the gene encoding pepstatin-insensitive acid protease B, scytalidopepsin B, of Scytalidium lignicolum

A chromosomal DNA fragment of Scytalidium lignicolum that encodes the mature enzyme region of acid protease B (Scytalidopepsin B), was cloned and its nucleotides sequenced. The fragment contained a 76-bp intron at the middle of the mature enzyme-coding region. The mature enzyme was composed of 206 amino acid residues with a molecular weight of 21,550. There were some discrepancies between the amino acid sequence deduced from these results and that previously established by protein sequencing.

Altered carbohydrate composition in colorectal adenomas and carcinomas: histochemical characterization of N-acetylgalactosamine, L-fucose, and o-acetylated sialic acid

Changes of surface sugar residues in the large intestinal mucosa may be associated with malignant transformation and may be of importance in differentiating borderline lesions. To compare these changes in normal mucosa, adenomas, and carcinomas of the large intestine, we investigated modifications of carbohydrate composition, such as those of N-acetyl-galactosamine (GalNac), L-fucose, and o-acetylated sialic acid, by histochemical staining with Dolichos biflorus agglutinin (DBA) and Ulex europaeus agglutinin-1 (UEA-1) lectins, and with Culling's periodic acid-thionin Schiff/potassium hydroxide/periodic acid-Schiff (PAT/KOH/PAS), respectively. For stable staining, the sections stained with DBA and UEA-1 were pretreated with potassium hydroxide and neuraminidase. We conclude that the pattern of the two lectin stainings in carcinomas is quite different from that in normal mucosa and adenomas, and that it shows the carcinomatous features in some cases of adenoma with severe atypia (borderline lesions). In contrast, PAT/KOH/PAS staining demonstrates differences between normal mucosa and adenomas rather than differences between adenomas and carcinomas.

Isolation and characterization of a novel 5-oxoprolinase (without ATP-hydrolyzing) from Alcaligenes faecalis N-38A

A screening test was undertaken to isolate a microorganism that produced 5-oxoprolinase (without ATP-hydrolyzing). The 5-oxoprolinase (without ATP-hydrolyzing) activity (decyclization activity toward L-pyroglutamate) was found in a cell-free extract of Alcaligenes faecalis N-38A, newly isolated from a soil sample. The enzyme was purified as a homogeneous preparation. The molecular weight of the enzyme was estimated to be 47,000. The decyclization activity was specific for L-pyroglutamate, and independent of ATP and metal ions. The reaction was a reversible one, i.e., cyclization reaction of L-glutamate to yield pyroglutamate was identified.

Suppression of episodic growth hormone secretion in streptozotocin-induced diabetic mice: time-course studies on the hypothalamic pituitary axis

To elucidate the roles of the hypothalamic peptides, GH-releasing hormone (GRH) and somatostatin (SRIH), potentially responsible for altered GH dynamics in diabetes, we studied the time courses of their changes in level associated with altered GH secretion in streptozotocin (STZ)-induced diabetic mice. Diabetic mice were used at 4, 7, and 14 days after STZ injection for analyses of 1) GH secretion in vivo, 2) hypothalamic GRH and SRIH messenger RNA (mRNA) levels, 3) pituitary GH mRNA and protein contents, and 4) pituitary GH response to GRH in vitro. GH secretion was completely suppressed 7 and 14 days after STZ injection. The hypothalamic GRH mRNA level was reduced to 59.8%, 61.2%, and 48.5% of control values at 4, 7, and 14 days, respectively. In contrast, the hypothalamic SRIH mRNA level was not altered at all of these time points. Pituitary GH mRNA and protein contents were significantly reduced to 70.2% and 61.5% of those in controls, respectively, only at 14 days. Pituitary GH responses to GRH at three doses (10, 50, and 250 nM) in vitro were remarkably increased at 4, 7, and 14 days. These findings indicate that the diabetic state rapidly and primarily inhibits hypothalamic GRH gene expression without affecting SRIH. A persistent decrease in hypothalamic GRH tone has been suggested to result in inhibition of GH synthesis in the pituitary. Enhancement of GH responsiveness to GRH may be due to the up-regulation of GRH receptors in the pituitary.

Gene expression of hypothalamic growth hormone (GH)-releasing hormone and somatostatin does not correlate with pulsatile secretion of GH in the adult mouse

The secretion of growth hormone (GH) shows a pulsatile pattern in many mammalian species, and depends on the interaction of two hypothalamic hormones, GH-releasing hormone (GHRH) and somatostatin (SRIH). A surge of GHRH secretion into the hypophysial portal blood induces peak secretion of GH from the anterior pituitary. To study whether the rhythmic and reciprocal oscillation in secretion of GHRH and SRIH are associated with changes in synthesis of these peptides, we examined the expression of hypothalamic GHRH and SRIH mRNA by Northern blotting during trough and peak phases of GH secretion in male mice. Hypothalamic GHRH and SRIH mRNA levels did not differ between trough and peak phases of GH secretion. This result suggests that changes in GHRH and SRIH secretion have little association with changes in the synthesis of these peptides at the hypothalamus in the male mouse.

Mutation and allelic loss of the p53 gene in endometrial carcinoma. Incidence and outcome in 92 surgical patients

BACKGROUND

Alterations of the p53 gene are involved in the development of diverse human malignancies, but their incidence and clinicopathologic features are still not well characterized for endometrial carcinoma.

METHODS

To investigate the clinicopathologic significance of p53, mutations and loss of heterozygosity (LOH) in endometrial carcinoma in 92 patients with this disease were examined.

RESULTS

Mutations of p53 were detected in 20 (22%) of the 92 patients with carcinoma, and LOH was detected in 23 (32%) of the 72 patients in whom heterozygosity of the gene was available. There was a significant correlation between the occurrence of mutation and LOH. Mutations and LOH were more frequent in patients with Grade 3 tumors than in those with Grades 1 and 2 tumors (P = 0.0498, P = 0.0051, respectively). Patients with LOH had a poorer postoperative survival than those without LOH (P = 0.0022, log-rank test), and patients with both LOH and mutation showed the worst prognosis (P < 0.0001, log rank test). Loss of heterozygosity of the p53 gene showed a significant relation to prognosis that was independent of tumor stage, histologic grade, and muscular invasion.

CONCLUSIONS

Mutation and LOH of the p53 gene are prognostic indicators in patients with endometrial carcinoma, suggesting that alterations of p53 may play an important role in the development of this cancer.

Effects of alpha- and beta-arbutin on activity of tyrosinases from mushroom and mouse melanoma

The effects of alpha- and beta-arbutin on the activity of tyrosinases from mushroom and mouse melanoma were examined. alpha-Arbutin was synthesized from hydroquinone and starch using glucoside synthetase (GSase). beta-Arbutin inhibited both tyrosinase activities from mushroom and mouse melanoma. alpha-Arbutin inhibited only the tyrosinase from mouse melanoma, 10 times as strongly as beta-arbutin. The IC50 of alpha-arbutin was 0.48 mM and its inhibitory mechanism was speculated to be mixed type inhibition, while that of beta-arbutin was noncompetitive.

Isolation and characterization of a dipeptidyl aminopeptidase from Streptomyces sp. WM-23

A screening test was undertaken to isolate microorganisms that produced dipeptidyl aminopeptidase. The hydrolytic activity toward alanyl-phenylalanine p-nitroanilide was found in a culture filtrate of a actinomyces strain (WM-23), newly isolated from a soil sample. The enzyme (WM-23 dipeptidyl aminopeptidase) was isolated from the culture filtrate as a homogeneous preparation. The WM-23 enzyme, inhibited by phenylmethylsulfonyl fluoride, may be classified to mammalian dipeptidyl aminopeptidase II. The enzymatic characteristics were investigated.