l-cysteine as a regulator for arsenic-mediated cancer-promoting and anti-cancer effects

Previous studies have shown that activities of tyrosine kinases and secretion of the active form of matrix metalloproteinase-2 (MMP-2) are correlated with promotion of tumor growth, while apoptotic cell death in cancer cells is correlated with anti-cancer effects. Although arsenic has been reported to have both cancer-promoting and anti-cancer effects, the mechanisms of the arsenic-mediated bidirectional effects remain unknown. We examined the effects of arsenic on both proto-oncogene c-RET-transfected NIH3T3 cells with benign characters and oncogenic RET-MEN2A-transfected NIH3T3 cells with malignant characters. Arsenic promoted not only c-RET tyrosine kinase activity but also genetically activated RET-MEN2A kinase activity with promotion of dimer formation of RET proteins. Arsenic also increased secretion of the active form of MMP-2 in both RET-MEN2A-transfectants and c-RET-transfectants. On the other hand, arsenic promoted poly-(ADP-ribose) polymerase (PARP) degradation and cell death in both malignant and non-malignant cells. Interestingly, l-cysteine inhibited the arsenic-mediated tumor-promoting effects (activation of kinases and MMP-2 secretion) but not arsenic-mediated anti-cancer effects (PARP degradation and cell death). Our results suggest redox-linked regulation of arsenic-mediated activities of kinases and MMP-2 secretion but not arsenic-mediated cell death. Our results also suggest that l-cysteine is an ideal supplement that inhibits arsenic-mediated tumor-promoting effects without affecting arsenic-mediated anti-cancer effects.     

A scalable controlled-release device for transscleral drug delivery to the retina

A transscleral drug-delivery device, designed for the administration of protein-type drugs, that consists of a drug reservoir covered with a controlled-release membrane was manufactured and tested. The controlled-release membrane is made of photopolymerized polyethylene glycol dimethacrylate (PEGDM) that contains interconnected collagen microparticles (COLs), which are the routes for drug permeation. The results showed that the release of 40-kDa FITC-dextran (FD40) was dependent on the COL concentration, which indicated that FD40 travelled through the membrane-embedded COLs. Additionally, the sustained-release drug formulations, FD40-loaded COLs and FD40-loaded COLs pelletized with PEGDM, fine-tuned the release of FD40. Capsules filled with COLs that contained recombinant human brain-derived neurotrophic factor (rhBDNF) released bioactive rhBDNF in a manner dependent on the membrane COL concentration, as was found for FD40 release. When capsules were sutured onto sclerae of rabbit eyes, FD40 was found to spread to the retinal pigment epithelium. Implantation of the device was easy, and it did not damage the eye tissues. In conclusion, our capsule is easily modified to accommodate different release rates for protein-type drugs by altering the membrane COL composition and/or drug formulation and can be implanted and removed with minor surgery. The device thus has great potential as a conduit for continuous, controlled drug release.     

Microbiological tests and the reimbursement of medical fees in Japan

Microbiological tests are important for the diagnosis of infectious diseases and their follow-ups. Under the medical reimbursement system, Gram staining has been approved as a fast laboratory test for outpatients, and remuneration for the management of laboratory testing is also applied to it. On the other hand, a serious problem in conducting microbiological testing is unprofitability, including high personnel costs and expenses for reagents. We conducted a survey involving eight medical institutions of the costs for Gram staining, bacterial culture and identification, anaerobic culture, antimicrobial susceptibility testing, isolation culture of acid-fast bacteria, and testing for susceptibility to antimycobacterial agents. The mean costs for all these items were higher than medical service fees. Even after the previous revision of the medical fee and increases in service fees, the operations of the above-mentioned tests still remain unprofitable. The Japanese Promotion Council for Laboratory Testing has been involved in ensuring appropriate reimbursement of medical fees. The council conducted surveys and assessments of costs for laboratory tests and their clinical values, and submitted a request to the Ministry of Health, Labour and Welfare for an improvement in the medical treatment fees. In response to our request, there were increases in some medical service fees, including the increase from 170 to 400 yen for Gram staining. It is important to continue to ask relevant government agencies to ensure appropriate remuneration for microbiological testing based on objective data.     

Osteopontin expression in pulmonary tumor thrombotic microangiopathy caused by gastric carcinoma

Pulmonary tumor thrombotic microangiopathy (PTTM) is characterized by fibrocellular intimal proliferation and thrombus formation in small pulmonary arteries and arterioles in patients with metastatic carcinoma. Osteopontin (OPN) is a multifunctional cytokine and adhesive protein, and has been demonstrated to be implicated in fibrosis, neointima formation, arterial occlusion by thrombus, and tumor metastases in cooperation with platelet-derived growth factor (PDGF) and vascular endothelial growth factor (VEGF). Herein is described an autopsy case of gastric adenocarcinoma with severe pulmonary hypertension due to PTTM. Histologically, tumor cell emboli markedly induced both fibromuscular intimal thickening and thrombosis, resulting in luminal stenosis and occlusion of small pulmonary arteries and arterioles. Tumor cells, both in the PTTM lesions and primary gastric carcinoma, had positive immunoreactivity for OPN, PDGF, and VEGF. In addition, proliferating fibromuscular intimal cells also showed expression of OPN, PDGF, and VEGF. These findings suggest that OPN may be involved in fibrocellular intimal proliferation and thrombus formation in PTTM together with PDGF and VEGF. To the best of the authors' knowledge this is the first report to demonstrate the possible involvement of OPN in PTTM. It is postulated that OPN is one of the candidate molecules for the development of PTTM.     

Deletion of the core-H region in mice abolishes the expression of three proximal odorant receptor genes in cis

We have previously reported that a 2.1-kb homology (H) sequence, conserved between mouse and human, regulates the odorant receptor (OR) gene MOR28 in transgenic mice. Here, we narrowed down the essential sequences of the H to a core of 124 bp by using a transient expression system in zebrafish embryos. Transgenic experiments in mice demonstrated that the core-H sequence is sufficient to endow expression of the MOR28 minigene. Deletion and mutation analyses of the core-H region revealed two homeodomain sequences to be essential for the H enhancer activity. Targeted deletion of the core-H abolished expression of three proximal OR genes, MOR28, MOR10, and MOR83, in cis, indicating the presence of another locus control region/enhancer in the downstream region, that regulates four distal OR genes in the same MOR28 cluster. In the heterozygous mice, the H(-) phenotype of the mutant allele was not rescued by the wild-type H(+) allele in trans.     

Anticonflict action of tandospirone in a modified Geller-Seifter conflict test in rats.

Tandospirone is a novel non-benzodiazepine compound possessing potent anxiolytic properties in a water lick conflict paradigm in rats and a high affinity for central 5-HT1A receptors. In the present study, tandospirone was evaluated for anxiolytic activity in a modified Geller-Seifter conflict paradigm in rats. Tandospirone produced significant increases in the punished responding at doses of 1.25, 2.5 and 5.0 mg/kg, i.p. or 20 mg/kg, p.o., although it decreased unpunished responding at doses of 2.5 and 5.0 mg/kg, i.p. or 20 mg/kg, p.o. Likewise, diazepam was also effective after i.p.-administration in this test, and its minimum effective dose was slightly higher than that of tandospirone. This suggests that tandospirone might be as effective in the treatment of anxiety as diazepam. The anticonflict action of tandospirone was not inhibited by Ro-15-1788, a benzodiazepine antagonist, although that of diazepam was completely inhibited. 8-OH-DPAT, a full agonist of 5-HT1A receptors, was also effective in this test with a high potency. Therefore, the possibility exists that the anticonflict action of tandospirone is related to its agonist action on 5-HT1A receptors, not on benzodiazepine receptors.     

Effects of the putative anxiolytic SM-3997 on central monoaminergic systems

The effects of SM-3997 on central monoaminergic systems were evaluated by ex vivo measurement of monoamines and their metabolite levels in rat brain after intraperitoneal treatment of drugs and by in vitro measurement of monoamine uptake into rat brain slices. The effects of SM-3997 were also compared with those of other new nonbenzodiazepine anxiolytic compounds. SM-3997, buspirone, gepirone and ipsapirone showed no effects on serotonin uptake and dopamine uptake, and a weak inhibition of norepinephrine uptake at the concentration of 100 microM. SM-3997 decreased the serotonin metabolite (5-hydroxyindole-3-acetic acid) level without changing the serotonin level in hippocampus and increased dopamine metabolite (3,4-dihydroxyphenylacetic acid, homovanillic acid) level with no effect on the dopamine level in striatum. SM-3997 also produced an increase in the norepinephrine metabolite (3-methoxy-4-hydroxyphenylglycol) level with a decrease in the norepinephrine levels in hippocampus. Similar effects on serotonin metabolites and norepinephrine metabolites were observed in several other regions. Although the serotonergic effect of SM-3997 was similar to that of buspirone, gepirone and ipsapirone, the dopaminergic effect of SM-3997 was much weaker than that of buspirone.     

Analysis of multiple primary cancers in patients with urologic cancer

Background The study of the clinical features of multiple primary cancers (MPC) may provide insight into the pathogenesis of specific cancers, as well as the issue of treatment-related induction of second tumors. Methods Between 1972 and 1995, 94 of 765 patients with urologic cancer treated at our hospital had MPC. We retrospectively analyzed the clinical features of these patients, and compared them with those of the 671 patients with single primary cancers (SPC). Results The frequency of MPC among all 765 patients was 12.3%. The average age at diagnosis of urologic cancer in the male patients was significantly higher in the MPC group than in the SPC group. In the MPC group, the organs most commonly involved were the bladder and prostate (urologic cancers), and the stomach and lung (nonurologic cancers). Adenocarcinoma was the most common tumor in the MPC group. The interval between the first and second cancer diagnoses was significantly longer in female patients with MPC than in male patients. No significant difference between the MPC and SPC groups was observed in the distribution of ABO blood groups or in the frequency of history of tobacco or alcohol use. Four MPC patients had second cancers considered to have been induced by the treatment for the first cancer. The prognoses were significantly poorer for the patients with MPC. The rate of death due to urologic cancer was much lower in the patients with MPC than in those with SPC. Conclusions We found that more than 10% of the 765 patients with urologic cancer whose cases we reviewed had another primary cancer. Because the number of cases of MPC is increasing, it is important to be aware of the possibility of the development of MPC and to therefore carefully follow up cancer patients.     

Endocrine evaluation of induction of ovulation with pulsatile and continuous administration of human menopausal gonadotropin (hMG) in anovulatory women

To evaluate the endocrine profiles during induction of ovulation with pulsatile and continuous administration of hMG (Pergonal), 3 patients with polycystic ovarian disease (PCO) and 4 patients with hypothalamic amenorrhea were selected as the subjects. The total dose of hMG per day was 150 IU in each patient. hMG pulse was administered intravenously via a portable infusion pump every 90 min in 4 patients including 3 PCO cases (9.375 IU/pulse) and every 18 min in one patient (1.875 IU/pulse). The remaining 2 patients received continuous subcutaneous infusion of hMG (150 IU/day). Following hMG treatment, 8,000 to 10,000 IU of hCG was used to induce ovulation. All 7 patients ovulated and 4 of them conceived. Pregnancy resulted in 2 patients following pulsatile (every 90 min) administration and in 2 patients after continuous infusion. The duration of hMG treatment needed to induce ovulation was similar among the three modes of administration and within the range of 7 to 10 days. A sustained elevation of circulating FSH levels was observed in all patients and serum estradiol increased more than 3,000 pg/ml in 6 of 7 patients during the course of treatment. Mean (+/- SE) midluteal progesterone level was 107.1 +/- 20.9 ng/ml. Moderate to severe ovarian hyperstimulation occurred in all patients. These results indicate that both pulsatile and continuous administration of hMG are similarly effective in inducing ovulation. They also appear to indicate that the hMG-induced follicular development is profoundly affected by the maintenance of high levels of FSH in the circulation rather than by the mode of administering hMG, whether pulsatile or continuous.     

Activated perilobular, not periacinar, pancreatic stellate cells contribute to fibrogenesis in chronic alcoholic pancreatitis

The authors investigated the role of activated perilobular, not periacinar, pancreatic stellate cells, in fibrogenesis in chronic pancreatitis, based on the distribution of myofibroblasts. Twenty-four patients with clinically diagnosed chronic alcoholic pancreatitis were studied histopathologically, immunohistochemically and quantitatively. In all cases, fibrosis was patchily distributed in the perilobular, or interlobular, areas, accompanied by a cirrhosis-like appearance; it had extended into the intralobular area in advanced cases. Seven patients had a massive or confluent loss of exocrine tissue, resulting in extensive interlobular fibrosis; the more extensive the interlobular fibrosis, the smaller the lobules. Immunoreactivity to alpha-smooth muscle actin, a myofibroblast marker, was found mostly in the same areas of the fibrosis, mainly the interlobular, and less often the periacinar, areas; the average percentage area of perilobular myofibroblasts was significantly higher than that of periacinar myofibroblasts in 20 randomly selected lobules (P > 0.001), in which the average value for the former was 38.03% (range: 13.54-61.32%; SD, 13.8%) and that for the latter was 4.85% (range 0.90-9.57%; SD, 2.22%). Fibrosis also immunostained positive for collagen types I and III. In conclusion, activated perilobular, not periacinar, pancreatic stellate cell contribute to fibrogenesis in chronic pancreatitis.