Vascular invasion and potential for tumor angiogenesis and metastasis in gastric carcinoma

BACKGROUND

Hematogenous metastasis occurs when cancer cells released from the primary site enter blood vessels and are transported to distant organs, where they attach and proliferate. Angiogenesis is essential for tumor growth and metastasis and depends on the production of angiogenic factors by tumor cells.

METHODS

We analyzed data on 1184 Japanese adult men and women with gastric cancer with respect to the relation between vascular invasion and the potential for tumor angiogenesis and metastasis. All these patients were treated from 1976 to 1995 in the Department of Surgery II, Kyushu University. In 300 patients, the expression of vascular endothelial growth factor (VEGF) and p53 protein in tumor tissues was examined by using an immunohistochemical staining method or Northern blotting or both. Intratumoral microvessels were stained with anti-CD31 monoclonal antibody.

RESULTS

Vascular invasion was evident in 254 patients (21.5%), and in these patients lymphatic invasion was more frequent and the rate of lymph node metastasis was higher in relation to the extent of vascular invasion. The positive findings were directly related to the depth of invasion and the presence of lymph node and liver metastasis. Tumor invasive and metastatic rates increased in relation to the extent of vascular invasion. Expressions of VEGF and p53 protein were higher and microvessel density was more prominent in tumor tissues in relation to the extent of vascular invasion. A close relation between VEGF and p53 protein expressions was also noted in tumors that showed vascular invasion. The expression of VEGF is one of the independent risk factors for vascular invasion. The postoperative outcome was poorer in patients with vascular invasion in relation to the extent of vascular invasion.

CONCLUSIONS

Our findings show that gastric cancers with characteristics of vascular invasion have greater intratumoral angiogenesis and that VEGF and p53 overexpression is associated with intratumoral angiogenesis and metastases to distant organs.

A case of noninflammatory corneal edema following anterior-posterior radial keratotomy (Sato's operation) successfully treated by topical corticosteroid

BACKGROUND

Corticosteroids seem to affect the functions of corneal endothelial cells directly in addition to their anti-inflammatory effect.

CASE

A 69-year-old man presented with blurred vision in his left eye and decreased visual acuity in both eyes. He had received anterior-posterior radial keratotomy for myopia in both eyes 40 years earlier.

OBSERVATIONS

Both eyes showed mild corneal stromal edema in the pupil area. We diagnosed the condition as corneal edema secondary to cell loss and dysfunction of corneal endothelium after surgery. One month later, the stromal edema was further advanced in the left eye. Corneal thickness had increased from the initial value of 619 microm to 631 microm, and corrected visual acuity had decreased from 0.5 to 0.06. There were no signs suggesting inflammatory reaction. The left eye was then treated with topical corticosteroid eyedrops and subconjunctival corticosteroid injection. Two months later, corneal thickness had decreased to 546 microm and visual acuity had improved to 0.5.

CONCLUSIONS

This case shows that topical corticosteroids may be effective in treating corneal edema by producing an anti-inflammatory effect and possibly activating the endothelium.

Chemopreventive effect of curcumin on N-nitrosomethylbenzylamine-induced esophageal carcinogenesis in rats

Modifying effects of curcumin (derived from the rhizome of Curcuma longa L.) during the initiation or post-initiation phase of N-nitrosomethylbenzylamine (NMBA)-induced esophageal carcinogenesis were investigated in male F344 rats. Five-week-old rats were divided into 5 groups, and groups 1, 2 and 3 were given intraperitoneal injections of NMBA (0.5 mg / kg body weight / injection 15 times) for 5 weeks from 7 weeks old to induce esophageal neoplasms. Groups 2 and 3 were fed the diet containing 500 ppm curcumin during the initiation and post-initiation phases, respectively. Group 4 was given the diet containing curcumin throughout the experiment, and group 5 was kept on the basal diet alone and served as an untreated control. Incidence and multiplicity of esophageal neoplasms of group 1 (NMBA alone) were 66.7% and 0.83 +/- 0.70, respectively. Those of groups 2 and 3 were significantly less than those of group 1 (39.3%, 0.46 +/- 0.64, P < 0.05; 33.3%, 0.36 +/- 0.56, P < 0.05, respectively). Furthermore, the incidence and multiplicity of esophageal preneoplastic lesions (moderate or severe epithelial dysplasia) of group 2 (57.1%, 0.61 +/- 0.57; 40%, 0.29 +/- 0.46) or 3 (56.7%, 0.67 +/- 0.66; 23.3%, 0.23 +/- 0.43) were less than those of group 1 (100%, 1.67 +/- 0.70; 70.8%, 0.92 +/- 0.72) (P < 0.05). In this experiment, feeding of curcumin significantly decreased the expression of cell proliferation biomarkers (5-bromo-2'-deoxyuridine labeling index) in the non-lesional esophageal epithelium (P < 0.01). These findings indicate that curcumin inhibits NMBA-induced esophageal carcinogenesis when given during the post initiation as well as initiation phase. This inhibition may be related to suppression of the increased cell proliferation induced by NMBA in the esophageal epithelium.

Serum immunosuppressive acidic protein and natural killer cell activity in patients with metastatic renal cell carcinoma before and after nephrectomy

PURPOSE

To our knowledge the impact of nephrectomy on stage M1 renal cell carcinoma remains to be determined. We previously reported that nephrectomy is beneficial in patients with elevated serum C-reactive protein before treatment, and those in whom nadir C-reactive protein decreases postoperatively to within the normal range may expect longer survival when surgery is combined with postoperative immunotherapy. In this study we determine the effect of nephrectomy on the immune response in patients with metastatic renal cell carcinoma.

MATERIALS AND METHODS

We retrospectively reviewed the records of 40 patients with metastatic renal cell carcinoma diagnosed at our institution between 1986 and 1999. These patients underwent nephrectomy before cytokine therapy with interferon. Before and after nephrectomy we measured serum C-reactive protein, serum immunosuppressive acidic protein and peripheral blood natural killer cell activity.

RESULTS

In 15 patients with pretreatment serum C-reactive protein within the normal range (less than 1 ng./ml.) there was no significant difference before and after nephrectomy in the serum immunosuppressive acidic protein level or natural killer cell activity (p = 0.4587 and 0.3892, respectively). On the other hand, in 25 patients with serum C-reactive protein elevated before treatment to 1 ng./ml. or greater serum immunosuppressive acidic protein decreased significantly and natural killer cell activity increased significantly after cytoreductive surgery (p = 0.0002 and 0.0286, respectively).

CONCLUSIONS

Our study implies that nephrectomy may be beneficial in patients with elevated serum C-reactive protein before treatment. Further evaluation by a prospective study is needed to make a definitive conclusion.

Polymer coating of liposomes with a modified polyvinyl alcohol and their systemic circulation and RES uptake in rats

The objective of this study was to evaluate the in vivo characteristics of liposomes coated with a polyvinyl alcohol having a long alkyl chain at the end of the molecule (PVA-R) as an injectable drug carrier for passive targeting of drugs. A fluorescence marker, cholesteryl-anthracene-9-carboxylate, was incorporated into the liposomes to detect their concentration in the plasma and organs. The small unilamellar liposomes (100 nm in diameter) with various lipid compositions, such as the different cholesterol contents or the different charges, were prepared by the hydration method followed by sonication and coated with PVA or PVA-R by just mixing the resultant liposomal suspensions with the polymer solutions. The circulation and distribution of the liposomes were tested with their intravenous administration in rats. The PVA-R-coated liposomes showed significantly higher circulation compared to that of non-coated ones in any liposomal formulation tested. The prolonged circulation of PVA-R-coated liposomes was attributed to their fewer uptake in liver and spleen. The extent in improvement in the in vivo characteristics were well interpreted by the hydrophobicity of liposomes and their coating amount of PVA-R. It was also demonstrated that the liposomes having a positive and a negative charge, which showed the completely different circulating profiles, showed almost the same profile by coating with PVA-R. When the liposomes were coated with PVA the improvement in blood circulation was much less in any cases, although coating layer of PVA was detected. These results confirm that not only the hydrophilic property but the sterically stabilizing effect of the coating layer is important to prolong the circulation of the particulate drug carriers with less RES uptake, and the PVA-R having a hydrophobic moiety at the end of the molecule of PVA is a suitable material for the coating of liposomes.

The role of volume weighted mean nuclear volume in predicting the prognosis of patients with primary transitional cell carcinoma of the upper urinary tract: a report of 102 new cases

PURPOSE

We compare estimates of volume weighted mean nuclear volume (MNV) with histological grading to determine the prognosis of primary transitional cell carcinoma of the upper urinary tract using a Cox proportional hazards model.

MATERIALS AND METHODS

We retrospectively reviewed 102 patients who underwent nephroureterectomy for primary transitional cell carcinoma of the upper urinary tract at our hospital between April 1981 and March 1997. Traditional prognostic factors, such as patient age, sex, stage and grade, multiplicity and unbiased estimates of MNV were analyzed with respect to disease recurrence and survival.

RESULTS

Estimates of mean nuclear volume were significantly larger for patients with than without lymph node metastasis (p = 0.0031). No prognostic factor significantly correlated with recurrence of transitional cell carcinoma of the bladder. For pTxN0M0 cases univariate analysis revealed that histological grade (p = 0.0018), pathological T stage (p = 0.0030) and estimates of MNV (p = 0.0001) correlated significantly with disease specific survival, and multivariate stepwise regression analysis revealed that estimate of MNV was the only powerful predictor of prognosis (p = 0.0007).

CONCLUSIONS

Our results indicate that estimate of MNV is an important predictor of prognosis for transitional cell carcinoma of the upper urinary tract. We recommend MNV estimate as a supportive method for subjective histological grading.

Quinochalcones and flavonoids from fresh florets in different cultivars of Carthamus tinctorius L

The flavonoid constituents in fresh florets of the three distinctive cultivars of Carthamus tinctorius L. were purified and identified to investigate flavonoid biosynthesis in the petals. From the orange flower of cv. Kenba (K.), four new compounds, anhydrosafflor yellow B (1), two kaempferols, 9 and 13, and a quercetin, 17, were isolated, as well as the twelve known compounds, and their structures were determined by spectral data, chemical reactions, and molecular mechanics calculations. From the yellow flower of cv. Ogon-hanagasa (O.), two flavonols and two quinochalcones, and from the white flower of cv. Shiro-bana (S.), three flavonois were isolated. These compounds were the same as those contained in cv. K. To compare the flavonoid constituents among the three cultivars, crude extracts were analyzed by a LC/PDA/MS system. In cv. K., six quinochalcones and eleven flavonols were identified. In cv. O., three quinochalcones and nine flavonols were identified, but the red pigment, carthamin (4), and its precursor, precarthamin (3), were not detected. In cv. S., four flavonols without a 6-hydroxyl group were identified. On the basis of a comparative study on the constituents among these three cultivars, a possible biosynthetic pathway to form quinochalcones via the intermediate, pentahydroxychalcone (19), is proposed.

Accelerative effect of olive oil on adrenal corticosterone secretion in rats loaded with single or repetitive immersion-restraint stress

The present study was performed to clarify the effects of dietary oils on physiological and metabolic changes induced by a stress, using one-time or repetitive water-immersion of restrained rats (single or repetitive stress) as an experimental stress load. In rats fed any test diets containing 20%) of the mixture of tripalmitin, tristearin, and corn oil (PSC), olive oil (OLI). safflower oil (SAF), and linseed oil (LIS) with repetitive stress loading, body weight gains and food intakes were generally reduced. The weights of the thymus and spleen also declined, but the adrenal weights were enhanced. Particularly, the increase in the adrenal weight of rats given the OLI diet was greater than of rats supplied with other diets. When the rats were loaded with the single or repetitive stress, the concentrations of urea, lipid peroxide, and corticosterone in the plasma were increased in rats fed any of dietary oils. The rise of plasma corticosterone level was especially great in rats fed the OLI diet. The concentrations of total cholesterol (T-CHOL) and triglyceride (TG) in the plasma and liver generally tended to be higher in rats fed the OLI diet than in rats given the other diets with and without stress exposure. Plasma corticosterone concentration was correlated to the adrenal weight (r=0.87, p<0.05). This study showed that OLI especially enhanced the adrenal weight in rats exposed to the repetitive stress and further raised the increased secretion of adrenal corticosterone in rats loaded with the single or repetitive stress compared with the other oils. The mechanism explaining these actions of OLI was inferred to be related to the levels of T-CHOL and TG in the plasma and liver generally enhanced by stress.

[Bacteria isolated from surgical infections and their susceptibilities to antimicrobial agents. Special references to bacteria isolated between April 1997 and March 1998]

The annual multicenter studies on isolated bacteria from infections in general surgery and their antimicrobial susceptibility have been conducted in 19 facilities in Japan since July 1982. This paper describes the results obtained during the period from April 1997 to March 1998. The number of cases investigated as objectives was 215 for one year. A total of 420 strains (170 strains from primary infections and 250 strains from postoperative infections) were isolated from 174 cases (80.9% of total cases). In primary infections, the isolation rate of anaerobic bacteria was higher than in postoperative infections, while in postoperative infections, those of aerobic Gram-positive bacteria and Pseudomonas aeruginosa were higher than in primary infections. Among aerobic Gram-positive bacteria, the isolation rate of Enterococcus faecalis was the highest, followed by Staphylococcus aureus, which was frequently isolated from postoperative infections. Among anaerobic Gram-positive bacteria, Peptostreptococcus spp. and Streptococcus spp. were commonly isolated from both types of infections. Among aerobic Gram-negative bacteria, Escherichia coli was most predominantly isolated from primary infections, followed by P. aeruginosa, Klebsiella pneumoniae in this order, and from postoperative infections, P. aeruginosa was most predominantly isolated, followed by E. coli and K. pneumoniae. Among anaerobic Gram-negative bacteria, Bacteroides fragilis group was the majority of isolates from both types of infections. We found neither vancomycin nor arbekacin resistant strains of S. aureus, and found no vancomycin resistant strains of Enterococcus spp. The susceptibility of P. aeruginosa against carbapenems did not decline in the year 1997, while resistance of B. fragilis group against cephems advanced increasingly.

A comparison of prednisolone and methylprednisolone for renal transplantation

A large difference in immunosuppressive potency between methylprednisolone and prednisolone has been suggested in vitro. However, the selection of the best glucocorticoid for renal transplantation has been seldom considered so far. Thus, the present study was undertaken to compare therapeutic efficacy between prednisolone and methylprednisolone in renal transplantation. We studied 42 renal transplant recipients who were operated on between 1990 and 1994. The patients were divided into two treatment groups: a methylprednisolone/ cyclosporine group (n = 19) and a prednisolone/cyclosporine group (n = 23). Clinical outcome and drug side effects were compared retrospectively between the treatment groups 24-84 months after transplantation. The overall graft survival time in patients treated with methylprednisolone/cyclosporine was superior to that in patients treated with prednisolone/cyclosporine (p < 0.05). Among the recipients from cadaver donors, 5/16 (31.3%) treated with prednisolone required nephrectomy, whereas none of the 10 patients treated with methylprednisolone received nephrectomy (p < 0.01). An examination of the recipients from living related donors revealed that serum creatinine levels 24-36 months after operation were significantly lower in the methylprednisolone group (p < 0.05). Cyclosporine trough levels and glucocorticoid side effects were similar between the treatment groups. The results raised the possibility that methylprednisolone is superior to prednisolone when combined with cyclosporine for maintenance immunosuppressive therapy in renal transplantation.

Development of an HIV-1-dependent expression vector with the Cre/loxP system

Previously, we used the human methionine tRNA promoter as an expression cassette for hammerhead ribozymes. The tRNA promoter driven ribozyme was targeted against the LTR portion of the HIV-1 NL4-3 strain. We constructed VSV-G-pseudotyped MuLV-based vectors expressing the ribozyme. The ribozyme expressing retrovirus vector strongly suppressed gag p24 antigen production in freshly HIV-1 infected MT-4 cells. In this study, the potential of such a molecular genetic intervention was examined by using the Cre-loxP recombination system. Site-specific excision of HIV-1 was achieved by using this model system with an acute infection. These studies represent one step toward the development of a novel antiviral strategy for the treatment of AIDS.

Phosphorothioate G3T4G3 motifs inhibits the early stage of HIV-1 infection

It is well known that G-rich phosphorothioate oligonucleotides (G-rich PS) bind to the V3 loop of HIV-1 gp120 and inhibit HIV-1 infection. In this study, we investigated the inhibitory mechanism of a new type of G-rich PS (PS-G3T4G3) on the replication cycle of HIV-1. PS-G3T4G3 inhibits both cell to cell and cell free infections. Binding and entry assays revealed that the inhibitory step of PS-G3T4G3 occurs at the early stage of HIV-1 infection. V3 loop-specific mAb test showed that PS-G3T4G3 binds to the V3 loop and prevents its interaction with chemokine receptors. These results suggest that PS-G3T4G3 may be a novel candidate for an HIV-1 inhibitor.

[A new decision tree method for statistical analysis of quantitative data obtained in toxicity studies on rodents]

Regarding the statistical analysis of the quantitative data obtained in control and dosage groups in toxicity studies, we tried to simplify the decision tree method. In a new decision tree presented in this article, one-way analysis of variance and Kruskal-Wallis nonparametric analysis of variance are excluded from the traditional decision tree: (1) Bartlett's test is used as a test for the equality of k variances: (2) Then, if the k sampled populations have equal variances (p > 0.05 by the Bartlett's test), Dunnett's multiple comparison test is performed: otherwise, Steel's test is used. This new method, which increases the power in some conditions, may serve as an alternative to the traditional decision tree method.

Correlation between plasma and hepatic phosphatidylcholine hydroperoxide, energy charge, and total glutathione content in ischemia reperfusion injury of rat liver

BACKGROUND/AIMS

Oxygen-derived free radicals are believed to be responsible for the hepatocellular injury leading to liver failure following ischemia-reperfusion in liver, endotoxemia and many other life-threatening illnesses. This study was designed to investigate the reactive oxygen species interaction in lipid peroxidation, the adenosine and energy charge levels of liver cells, and total glutathione content in ischemic-reperfusion injury of liver in rat.

METHODOLOGY

To prevent intestinal congestion during the clamping of vascular structures, subcutaneous transposition of the spleen was done beforehand. Four to six weeks later, after the development of natural portal-systemic shunts, occlusion of the portal vein, hepatic artery and bile duct was performed for different periods; blood and liver samples were taken at different intervals after the release. On the basis of the ischemia-reperfusion time, the rats were divided into the following 9 groups: 30/0, 30/30, 30/60, 60/0, 60/30, 60/60, 90/0, 90/30, and 90/60. The following parameters were measured: total hepatic glutathione content, adenosine values (ATP, ADP, AMP), energy charge, phosphatidylcholine hydroperoxide (PCOOH) concentrations in liver and plasma, and serum transaminases (AST, ALT). Decreased liver glutathione stores (an indicator of increased oxidative stress), increased serum hepatic transaminases (an indicator of hepatocellular injury), and increased PCOOH (an indicator of cellular-membrane lipid peroxidation) were noted.

RESULTS

The ATP level and energy charge diminished significantly with the increase in duration of ischemia and reperfusion. A close correlation between the PCOOH levels in plasma and liver was observed. Extreme damage was noted in the 90-minute ischemia with 60-minute reperfusion group. The hepatic total glutathione level was reduced to the lowest level in the 90/60 group and it correlated with the energy charge level, denoting the highest degree of oxidative stress sustained by the liver cells in this group.

CONCLUSIONS

These results indicated that prolonged hepatic ischemia with reperfusion produced bursts of oxygen-derived free radicals which overwhelmed the defense mechanisms of the cells, with a resultant decrease in energy charge associated with an increase in membrane lipid peroxidation. These findings not only provide confirmation of previously reported hepatocellular injury by free radicals generated after reperfusion, but they also establish the use of PCOOH analysis in liver and plasma as a sensitive and specific indicator of the injury process in time. The plasma PCOOH level may be a useful indicator of free radical induced hepatic membrane lipid peroxidation during ischemia-reperfusion, and might be employed in clinical studies of the therapeutic effects of drugs in various liver diseases, as well as for determining the prognosis after different kinds of hepatic operations.

Vinca alkaloids induce granulocyte-macrophage colony stimulating factor in human peripheral blood mononuclear cells

Several anti-cancer drugs are known to have proliferation-related effects on various cells, such as an activation of some transcription factors and an induction of some cytokines. We examined the effect of anti-cancer drugs on granulocyte-macrophage colony stimulating factor (GM-CSF) induction in human peripheral blood mononuclear cells (PBMC). Increase of GM-CSF protein and mRNA were observed in PBMC after exposure to vindesine sulfate (VDS). Induction of GM-CSF protein was dose-dependent and detectable at VDS concentrations of 0.1 microgram/ml. This effect was also observed in response to treatment with other microtuble-depolymerizing agents, vincristine sulfate and vinorelbine ditartrate, but not with cisplatin, etoposide, or paclitaxel. In order to elucidate the mechanism of this phenomenon, we examined the effects of cyclohexamide and actinomycin D on the expression of GM-CSF mRNA. Both of these drugs completely inhibited GM-CSF mRNA expression after VDS exposure, implying that VDS induces de novo GM-CSF synthesis in an indirect manner. As a candidate for the initial signaling, we next examined the role of the IL-1 beta autocrine or paracrine pathways in GM-CSF induction by VDS. IL-1 beta protein and mRNA expression were induced after VDS exposure more rapidly (from 4 hours) than expression of GM-CSF (protein from 12 hours and mRNA from 8 hours). Addition of anti-IL-1 beta antibody partially inhibited induction of GM-CSF by VDS. These results suggest that GM-CSF induction by VDS is partially mediated through the initial generation of IL-1 beta in PBMC.

Inhibition of Ca(2+) signalling by p130, a phospholipase-C-related catalytically inactive protein: critical role of the p130 pleckstrin homology domain

p130 was originally identified as an Ins(1,4,5)P(3)-binding protein similar to phospholipase C-delta but lacking any phospholipase activity. In the present study we have further analysed the interactions of p130 with inositol compounds in vitro. To determine which of the potential ligands interacts with p130 in cells, we performed an analysis of the cellular localization of this protein, the isolation of a protein-ligand complex from cell lysates and studied the effects of p130 on Ins(1,4,5)P(3)-mediated Ca(2+) signalling by using permeabilized and transiently or stably transfected COS-1 cells (COS-1(p130)). In vitro, p130 bound Ins(1,4,5)P(3) with a higher affinity than that for phosphoinositides. When the protein was isolated from COS-1(p130) cells by immunoprecipitation, it was found to be associated with Ins(1,4,5)P(3). Localization studies demonstrated the presence of the full-length p130 in the cytoplasm of living cells, not at the plasma membrane. In cell-based assays, p130 had an inhibitory effect on Ca(2+) signalling. When fura-2-loaded COS-1(p130) cells were stimulated with bradykinin, epidermal growth factor or ATP, it was found that the agonist-induced increase in free Ca(2+) concentration, observed in control cells, was inhibited in COS-1(p130). This inhibition was not accompanied by the decreased production of Ins(1,4,5)P(3); the intact p130 pleckstrin homology domain, known to be the ligand-binding site in vitro, was required for this effect in cells. These results suggest that Ins(1,4,5)P(3) could be the main p130 ligand in cells and that this binding has the potential to inhibit Ins(1,4,5)P(3)-mediated Ca(2+) signalling.

Supratentorial desmoplastic ependymoma with giant ependymal rosettes

We report a case of a 22-year-old female who presented with a solid tumor in the frontal lobe having no continuity with the wall of the lateral ventricle. The tumor was excised. The patient has been free from clinical symptoms and tumor recurrence for over nine years. Microscopically, the tumor was composed of extremely large ependymal true rosettes, resembling medulloepithelioma, and thick fibrous septa, which were surrounded by thick reactive gliosis. There were no histological signs of malignancy. In our case, the tumor is assumed to be a variant of gliofibroma for which we propose the term "desmoplastic ependymoma".

Regulation of ecdysteroid signalling: molecular cloning, characterization and expression of 3-dehydroecdysone 3 alpha-reductase, a novel eukaryotic member of the short-chain dehydrogenases/reductases superfamily from the cotton leafworm, Spodoptera littoralis

One route of inactivation of ecdysteroids in insects involves ecdysone oxidase-catalysed conversion into 3-dehydroecdysone (3DE), followed by irreversible reduction by 3DE 3 alpha-reductase to 3-epiecdysone. The 3DE 3 alpha-reductase has been purified and subjected to limited amino acid sequencing. It occurs as two distinct forms, including a probable trimer of subunit molecular mass of approx. 26 kDa. A reverse-transcriptase PCR-based approach has been used to clone the cDNA (1.2 kb) encoding the 26 kDa protein. Northern blotting showed that the mRNA transcript was expressed in Malpighian tubules during the early stage of the last larval instar. Conceptual translation of the 3DE 3 alpha-reductase cDNA and database searching revealed that the enzyme belongs to the short-chain dehydrogenases/reductases superfamily. Furthermore, the enzyme is a novel eukaryotic 3-dehydrosteroid 3 alpha-reductase member of that family, whereas vertebrate 3-dehydrosteroid 3 alpha-reductases belong to the aldo-keto reductase (AKR) superfamily. Enzymically active recombinant 3DE 3 alpha-reductase has been produced using a baculovirus expression system. Surprisingly, we observed no similarity between this 3DE 3 alpha-reductase and a previously reported 3DE 3 beta-reductase, which acts on the same substrate and belongs to the AKR family.

Effects of pH and chloride concentration on resonance Raman spectra of human myeloperoxidase and Raman microspectroscopic analysis of enzyme state in azurophilic granules

Resonance Raman spectra of human myeloperoxidase were examined at pH 3.3-10.5 in the absence and presence of chloride ions. Among the porphyrin vibrational bands, the core-size marker bands showed particularly large wavenumber downshifts on going from pH 8.7 to 5.3 with a transition midpoint at pH 6.5 in the absence of chloride ions. The chloride ions did not affect the spectrum at a pH below 5.3 and above 8.7 whereas an increase of chloride concentration at neutral pH caused spectral changes similar to those observed upon pH lowering. Analogous effects were also observed on the Raman intensity. In addition, the stretching mode of the bond between the heme Fe and proximal histidine shifted by -2 cm(-1) on going from pH 8.7 to 5.3. Decomposition of the nu(3) band revealed the presence of two components, which was confirmed by an isosbestic point in the absorption spectra. The observed spectral changes indicated the existence of alkaline and acidic forms of the enzyme. The pK of interconversion was 6.5, and it was increased by binding of chloride ions. The porphyrin core was slightly expanded in the acidic form compared to that in the alkaline form. A molecular mechanism of the porphyrin core expansion was proposed on the basis of the X-ray crystal structure. The pH-spectrum relationships obtained for the isolated enzyme were applied to in situ analysis of the state of myeloperoxidase in azurophilic granules of living neutrophils. The enzyme was stored in the acidic form and kept inactive in catalyzing HOCl production.

Utilization of poly(DL-lactide-co-glycolide) nanoparticles for preparation of mini-depot tablets by direct compression

PURPOSE

The objectives of this study were to prepare the long-acting matrix tablets by direct compression of the mixture of drug and poly(DL-lactide-co-glycolide) (PLGA) nanoparticles and to clarify the effects of such factors as polymer species, mixing ratio of nanoparticles with different molecular weights, and the tablet weight on the drug release and to discuss the mechanism of drug release from matrix tablets. In addition, mini-matrix tablets were prepared to investigate the possibility of application as an implantable dosage form.

METHODS

PLGA nanoparticles were prepared by the modified spontaneous emulsion solvent diffusion method. The matrix tablets were prepared by direct compression of mixtures of drug and nanoparticles, and then the release properties, swelling properties and changes in molecular weight of PLGA during the release test were evaluated.

RESULTS

The drug showed the biphasic release patterns from all matrix tablets; i.e. a portion of the drug was released rapidly (the initial release phase), the release stopped for a long period (the lag time), and then the residual drug was released (the second release phase). Matrix tablets with various biphasic release patterns could be prepared by altering the molecular weight or copolymer ratio of PLGA. The addition of nanoparticles of low molecular weight PLGA to those of high molecular weight reduced the release rate at the initial release phase, but that at the second release phase was almost entirely unaffected by mixing ratio. Also, the release patterns could be changed by altering the tablet weight and size, but the amounts released per unit of surface area were the same. Hydration analysis suggested that the initial release rates were correlated well with the swelling properties of tablets.

CONCLUSION

This system had advantages in terms of simplicity in design and predictability of drug release rate and may be useful as an implantable dosage form.

Metal binding modes of Alzheimer's amyloid beta-peptide in insoluble aggregates and soluble complexes

Aggregation of the amyloid beta-peptide (Abeta) into insoluble fibrils is a key pathological event in Alzheimer's disease. Zn(II) induces the Abeta aggregation at acidic-to-neutral pH, while Cu(II) is an effective inducer only at mildly acidic pH. We have examined Zn(II) and Cu(II) binding modes of Abeta and their pH dependence by Raman spectroscopy. The Raman spectra clearly demonstrate that three histidine residues in the N-terminal hydrophilic region provide primary metal binding sites and the solubility of the metal-Abeta complex is correlated with the metal binding mode. Zn(II) binds to the N(tau) atom of the histidine imidazole ring and the peptide aggregates through intermolecular His(N(tau))-Zn(II)-His(N(tau)) bridges. The N(tau)-metal ligation also occurs in Cu(II)-induced Abeta aggregation at mildly acidic pH. At neutral pH, however, Cu(II) binds to N(pi), the other nitrogen of the histidine imidazole ring, and to deprotonated amide nitrogens of the peptide main chain. The chelation of Cu(II) by histidine and main-chain amide groups results in soluble Cu(II)-Abeta complexes. Under normal physiological conditions, Cu(II) is expected to protect Abeta against Zn(II)-induced aggregation by competing with Zn(II) for histidine residues of Abeta.

Splenic vein occlusion secondary to tuberculous lymphadenitis at the splenic hilum: report of a case

We report a patient with splenic vein occlusion (SVO) secondary to tuberculosis. A 17-year-old male patient with mild epigastric pain and splenomegaly was found to have gastric varices by gastroscopy, and SVO by selective angiography. At operation, the splenic vein was occluded by hard fibrous tissue at the splenic hilum, and thus a splenectomy was performed. A microscopic examination of the tissue revealed caseous necrosis surrounded by epithelioid cells and Langhans-type giant cells. Although there were no other findings suggesting intestinal tuberculosis, it seemed that tuberculous lymphadenitis of the splenic hilum most likely caused the occlusion of the splenic vein. Because specific tests for tuberculosis were negative in both immunohistochemical staining for bacille Calmette-Guérin and polymerase chain reaction of DNA for Mycobacterium tuberculosis, the time of infection was assumed to have occurred a long time before. SVO can sometimes be seen in pancreatic diseases, but this patient with tuberculosis appears to be the first such reported case in the English literature.

Enantioselective determination of bromoisovalerylurea by liquid chromatography on chiral stationary phase in reversed- or normal-phase partition mode

Bromoisovalerylurea (bromvalerylurea) is a sedative-hypnotic given orally as a racemate. Enantiomers of this drug could be separated by high-performance liquid chromatography on the three chiral stationary phases (a vancomycin-bonded, beta-cyclodextrin derivative-bonded, or urea derivative-bonded phase). Biological fluids of human subjects who had ingested toxic or therapeutic doses of the racemate were chromatographed after liquid-liquid extraction. The (+)-enantiomer concentration was almost equal to the (-)-enantiomer concentration in the serum of one overdosed patient. In all the other subjects, the (+)-enantiomer was less than the (-)-enantiomer in their sera and saliva. The data suggest that the drug is absorbed non-stereoselectively from the gastrointestinal tract and eliminated from the blood stereoselectively.

Comparison of outer membrane protein genes omp and pmp in the whole genome sequences of Chlamydia pneumoniae isolates from Japan and the United States

Chlamydia pneumoniae is a widespread pathogen of the respiratory tract that is also associated with atherosclerosis. The whole genome sequence was determined for a Japanese isolate, C. pneumoniae strain J138. The sequence predicted a variety of genes encoding outer membrane proteins (OMPs) including ompA and porB, another 10 predicted omp genes, and 27 pmp genes. All were detected in the whole genome sequence of strain CWL029, a strain isolated and sequenced in the United States. A comparative study of the OMPs of the two strains revealed a nucleotide sequence identity of 89.6%-100% (deduced amino acid sequence identity, 71.1%-100%). The overall genomic organization and location of genes are identical in both strains. Thus, a few unique sequences of the OMPs may be essential for specific attributes that define the differential biology of two C. pneumoniae strains.