Protein carbonyl accumulation in aging dauer formation-defective (daf) mutants of Caenorhabditis elegans

It is known that a dauer-constitutive gene, daf-2, controls both larval development and adult life span in Caenorhabditis elegans. The increased life span caused by the daf-2 mutation can be enhanced by a daf-12 mutation and suppressed by a daf-16 mutation. In order to determine the correlation between longevity and oxidative stress in these mutants, protein carbonyl (a good indicator of oxidative damage during aging) was measured. Mean life spans of these mutants were in the order of daf-16 < daf-2; daf-16 approximately equal to wild type < daf-2 < daf-2;daf-12. Accumulations of protein carbonyl in these wild-type and daf mutants were in a mirror image of the order of their life spans. These results strongly support the notion that oxidative damage is one of the major causal factors for life-span determination in C. elegans.

Sunlight mutagenesis: changes in mutational specificity during the irradiation of phage M13mp2

We reported previously that the mutations in phage M13mp2, a single-stranded DNA phage, induced by sunlight exposure are predominated by G-to-C transversions. We have now made an unexpected observation that an exposure to sunlight for a short period of time results in induction mainly of C-to-T transitions while a longer exposure results in the induction of G-to-C transversions. This peculiar phenomenon suggests that DNA damage formed by initial sunlight exposure can be transformed during an elongated exposure. 7, 8-Dihydro-8-oxoguanine (8-oxoG) in DNA might be involved in the shift of the mutational specificity, as 8-oxoG was formed in the phage DNA upon the sunlight exposure. We also compared the mutagenic activity of UVB irradiation with that of sunlight exposure. The results demonstrate that the genotoxic properties of sunlight and UVB in phage M13mp2 mutagenesis are different. The shift in the mutational specificity associated with the dose of the sunlight may call for general cautions in the studies of agent-induced mutagenesis.

Prostaglandins in the stomach: an update

Prostaglandins (PGs) are responsible for regulation of various physiologic activities in many tissues and organs, including the stomach. Recent studies have shown new crucial roles of PGs in the stomach. Activation of inflammatory cytokines and neutrophils may cause acute gastric mucosal lesions and recurrence of ulcers, which are induced by noxious stimuli such as nonsteroidal antiinflammatory drugs (NSAIDs), stress and Helicobacter pylori (H. pylori). These phenomena are PG-dependent because exogenous PGs reverse them. PG deficiency and H. pylori may worsen the quality of ulcer healing in terms of inflammatory responses, which are related to future ulcer recurrence. Neutrophils, monocytes/macrophages, and adhesion molecules are involved in the mechanism of recurrence caused by inflammatory cytokines. PGs accelerate ulcer healing, possibly via angiogenesis, epithelial cell proliferation, production of growth factors such as hepatocyte growth factor and transforming growth factor beta, reconstruction of extracellular matrices, and suppression of inflammatory cell infiltration, in addition to gastroprotective mechanisms. The PG synthase cyclooxygenase (COX) has two forms, COX-1 and COX-2. COX-2, but not COX-1, contributes to ulcer healing. Moreover, recent studies suggest the involvement of COX-2 in development of gastric and colon carcinoma. This may be linked to the chemopreventive effect of NSAIDs.

[Review process of new oncology drug application in Japan--role of MD reviewer]

On the basis of discussion by the Committee for Drug Safety Ensuring Measures, the Japanese Ministry of Health and Welfare (MHW) has amended the Pharmaceutical Affairs Law and related laws, and is reforming its review system for approving new drugs. One of the most important changes in the review system is the establishment of Pharmaceuticals and Medical Devices Evaluation Center (PMDEC) in July, 1997 under the National Institute of Health Sciences, a research institute under MHW. PMDEC, the Evaluation and Licensing Division at MHW and the Organization for Drug ADR Relief, R&D Promotion and Product Review (the Drug Organization) are in charge of drug approval, and reexamination and reevaluation applications. Before the reform new drug application reviews had been conducted mainly by the Central Pharmaceutical Affairs Council (CPAC). After the reform PMDEC, employing technical officials who have expertise in pharmacology, toxicology, biostatistics, clinical medicine, or other scientific fields, jointly review the applications with CPAC. The Evaluation and Licensing Division takes charge of administrative matters, such as final decisions on approvals, developing guidelines concerning the review process, international affairs, and regulatory instructions. During the early part of review the Drug Organization conducts a compliance review on the documents, which a sponsor submits with the approval application, and GCP inspection.

Algorithm for the treatment of mood disorders in Japan

In order to establish algorithms for mood disorders in Japan, over 300 psychiatrists completed a questionnaire. They were asked to recommend various drug treatments for particular cases. The order in which the drugs were recommended was taken into consideration. References were made to the randomized double blind study conducted by the working group. Evidence was ranked according to its probability, with the addition of case reports and medical opinions, since conclusions derived from the randomized double blind study alone did not give a full representation. Japanese documentation was referred to as much as possible in order to represent Japanese characteristics. Algorithms were made for eight subtypes; acute mania, bipolar depression, mild or moderate, severe major depression, psychotic depression, rapid cycling bipolar disorder, dysthymic disorder and major depression with advanced cancer. Major depression and bipolar disorder algorithms are discussed in this paper. Clinical psychopharmacological evidence in Japan was insufficient to generate these algorithms for mood disorders. These algorithms may need revision according to future advances in clinical psychopharmacology. (Int J Psych Clin Pract 1999; 3: 277-285).

Massive pleural effusion and ascites resulting from esophagectomy with extensive lymphadenectomy for cancer of the abdominal esophagus

Chylothorax is an uncommon but well recognized complication of esophagectomy. We present the case of a 57 year-old man with squamous cell carcinoma of the abdominal esophagus who underwent subtotal esophagectomy by right thoracotomy. Post-operatively, the volume of pleural effusion from the right chest was increased (1600-2000 ml/day). The effusion was straw colored, not changing to milky after meals. The characteristics and composition of the pleural fluid were similar to those of chyle. We therefore treated this patient using methods for treatment of chylothorax, conservatively, by administration of OK-432 and minocycline/hydrochloride into the pleural cavity from the chest tube with success. We discuss the pathophysiology of this unusual condition and its treatment.

Algorithm for the treatment of schizophrenia in Japan

Evidence-based psychopharmacological algorithms for the treatment of patients with schizophrenia have been developed in many countries in the last decade. While it would be of interest to consider a common algorithm based on international consensus, algorithms and information on antipsychotics available in each country are limited. Inspired by the algorithm generated by the International Psychopharmacology Algorithm (IPA) Project, this algorithm for the treatment of schizophrenia has been developed by the Japan Psychophamacology Algorithm (JPA) Project. New antipsychotics, such as clozapine, olanzapine and quetiapine, are excluded from this algorithm, being currently unavailable in Japan. In the end there was no essential difference between the algorithms for the treatment of acute schizophrenic episodes. However, combined use of antipsychotics appears to be more common in Japan and the adjunctive use of L-DOPS or thyrotropin-releasing hormone is included in the JPA algorithm for the treatment of drug-refractory schizophrenia.

The relationship between carboplatin AUC and serum thrombopoietin kinetics in patients with lung cancer

To clarify the relationship between the carboplatin AUC and the extent of damage to thrombopoiesis, we monitored both endogenous serum TPO kinetics and carboplatin pharmacokinetics after single-agent carboplatin administration. Previously untreated 12 patients with stage IV non-small-cell lung cancer were enrolled. The actual carboplatin AUC showed a significant positive correlation with the maximum increase ratio of TPO (TPOmax/TPOday1) (r = 0.74, p = 0.014). Furthermore, the increase ratio of TPO at one week after administration of carboplatin (TPOday8/TPOday1) showed a significant negative correlation with the following platelet nadir around day 19 (r = -0.84, p = 0.005). By monitoring the changes in endogenous TPO concentration, we could estimate the degree of thrombocytopenia and determine the indication, and thus the optimal timing of prophylactic administration of TPO before platelets are markedly reduced.

A rare case of a thyrotropin-secreting pituitary tumor which responded to methimazole

A 52-year-old Japanese male complained of palpitations and excessive sweating. He showed evidence of hyperthyroidism, but without suppression of the serum thyroid-stimulating hormone (TSH). On admission, the serum level of the alpha-subunit of TSH was elevated, but tests for thyroid autoantibodies were negative. The TSH response to thyrotropin-releasing hormone (TRH) was blunted. Imaging studies revealed a pituitary tumor 2 cm in diameter. Administration of methimazole lowered the serum levels of thyroid hormones, and elevated the serum level of TSH. These findings led to the diagnosis of a thyrotropin-secreting pituitary tumor. Immunohistochemical analysis and electron microscopic findings verified the diagnosis.

A critical role for DNA end-joining proteins in both lymphogenesis and neurogenesis

XRCC4 was identified via a complementation cloning method that employed an ionizing radiation (IR)-sensitive hamster cell line. By gene-targeted mutation, we show that XRCC4 deficiency in primary murine cells causes growth defects, premature senescence, IR sensitivity, and inability to support V(D)J recombination. In mice, XRCC4 deficiency causes late embryonic lethality accompanied by defective lymphogenesis and defective neurogenesis manifested by extensive apoptotic death of newly generated postmitotic neuronal cells. We find similar neuronal developmental defects in embryos that lack DNA ligase IV, an XRCC4-associated protein. Our findings demonstrate that differentiating lymphocytes and neurons strictly require the XRCC4 and DNA ligase IV end-joining proteins and point to the general stage of neuronal development in which these proteins are necessary.

Expression of lung-resistance protein gene is not associated with platinum drug exposure in lung cancer

BACKGROUND

Platinum drug resistance is an important problem in lung cancer chemotherapy. In this study, we examined lung-resistance protein (LRP) gene expression in vivo and in vitro in relation to platinum drug exposure.

MATERIALS AND METHODS

The expression levels of the LRP gene were assessed by the reverse transcription polymerase chain reaction, in 80 autopsy samples (40 lung tumors and 40 corresponding normal lung tissues), two lung cancer cell lines and in peripheral mononuclear cells collected from 8 lung cancer patients before and after platinum drug administration.

RESULTS

The LRP gene expression levels of autopsy specimens exposed antemortem to platinum drugs were not significantly different to those of specimens without platinum drug exposure, for both lung tumors and normal lung tissues. Our results also demonstrate that LRP gene expression was not induced by platinum drugs either in vitro or in vivo.

CONCLUSIONS

The present results indicate that LRP gene expression is not associated with platinum drug exposure in lung cancer.

A candidate high density lipoprotein (HDL) receptor, HB2, with possible multiple functions shows sequence homology with adhesion molecules

High density lipoprotein (HDL), an antiatherogenic lipoprotein comprises several subclasses differing in composition and metabolic function. This physiological complexity appears to be matched with the growing number of candidate HDL receptors, since several HDL binding proteins have recently been identified in various tissues. Because these putative receptors may signal different pathways it is important to identify their structure and potential role in HDL metabolism. We review recent progress in the cloning and characterization of HB2, one of a pair of HDL binding proteins (HB1 and HB2) first purified from rat liver. The structure of HB2 is consistent with a receptor role for this membrane protein and when expressed in cells, increases HDL binding 2 fold. HB2, minimally present in THP-1 cells, is substantially upregulated in macrophages and appears sensitive to cholesterol loading of these cells. The protein shows high homology with adhesion molecules ALCAM and BEN and the possibility that HDL by binding to HB2, reduces adhesion induced arterial wall injury, is discussed in the context of the known protective role of HDL against atherosclerosis. The possible functions of HB2 are also compared with other recently cloned HDL receptors.

Protective effect of rebamipide against ammonia-induced gastric mucosal lesions

We investigated the protective effect of rebamipide against ammonia-induced gastric mucosal lesions. Participation of prostaglandin E2 and nitric oxide in the action of rebamipide was also examined. Rebamipide was administered intraperitoneally (10-100 mg/kg) to male Wistar/ST rats (150-325 g) fasted for 24 hr. Thirty minutes later, 1% NH4OH (1 ml) solution was given intragastrically. One hour later, the length of the mucosal lesions was measured (lesion index), and prostaglandin E2 (PGE2) was determined by radioimmunoassay. A 1% NH4OH solution caused gastric mucosal lesions with hemorrhagic necrosis and submucosal edema. PGE2 synthesis was not affected by NH4OH but was significantly increased by rebamipide. Rebamipide decreased the severity of NH4OH-induced gastric mucosal lesions in a dose-dependent manner. Pretreatment with indomethacin (5 mg/kg, subcutaneously) did not affect the protective effect of rebamipide; however, pretreatment with N(omega)-nitro-L-arginine (L-NNA, 1-10 mg/kg, intravenously), an inhibitor of nitric oxide synthase, attenuated the protective effect of rebamipide in a dose-dependent manner. Simultaneous administration of L-arginine (100 mg/kg) and L-NNA completely restored the protective effect of rebamipide, whereas D-arginine was inactive. These results suggest that nitric oxide contributes significantly to the protective effect of rebamipide against ammonia-induced gastric mucosal lesions.

Ulcer recurrence: cytokines and inflammatory response-dependent process

H. pylori and nonsteroidal antiinflammatory drugs (NSAIDs) are important factors in the recurrence of peptic ulcer diseases. However, H. pylori-negative recurring ulcers can also be found in nonusers of NSAIDs. The aim of this paper is to review recent data pertaining to mechanisms of ulcer recurrence. Prostaglandin E2 generation is impaired in the tissues of the ulcer scar site and prostaglandin depletion induced by administration of indomethacin during the healing of experimental gastric ulcer predisposes to future ulcer recurrence. Therefore, the prostaglandin deficiency may impair the quality of ulcer healing and thus increase the likelihood of future ulcer recurrence. Persistent infiltration of polymorphonuclear cells is the most prominent finding in the gastric ulcer scar in rats treated with indomethacin. Concomitant administration of prostaglandin E1-analog with indomethacin attenuates inflammatory infiltration and reduces future ulcer recurrence. Therefore, the inflammatory responses at the ulcer scar site may be a key to the quality of ulcer healing. Recent clinical findings suggest a close relationship between the quality of ulcer healing, infiltration of neutrophils and mononuclear cells, and future ulcer recurrence. Gastroprotective drugs such as prostaglandin analogs and prostaglandin inducers improve the quality of ulcer healing and reduce future recurrence. Production of inflammatory cytokines is stimulated by ulcerogenic factors such as NSAIDs, stress, and H. pylori infection. Inflammatory cytokines such as interleukin-1beta and tumor necrosis factor-alpha cause recurrence of healed ulcer. Synthetic prostaglandin E2 inhibits recurrence as well as the production of the cytokines.

[Gastrointestinal lesions in liver cirrhosis]

The gastrointestinal bleeding commonly observed in patients with liver cirrhosis is usually from esophageal and gastric varices, gastroduodenal ulcer, and congestive gastropathy. Portal hypertension is the major causative factor of pathogenesis of GI lesions. In the present review, we focus in gastric mucosal defense and Helicobacter pylori infection in liver cirrhosis. Gastric mucosal defense is reduced in liver cirrhosis, especially prostaglandins which play a role in the gastric mucosal defense decreased in the gastric mucosal of patients with liver cirrhosis and rat portal hypertension model. Although H. pylori is strongly associated with peptic ulcer disease and chronic gastritis, several studies showed no relationship between H. pylori infection and gastroduodenal ulcer or the infection and congestive gastropathy in liver cirrhosis. Reduced gastric mucosal defense may account for the pathogenesis of GI lesions in liver cirrhosis.

Rebamipide prevents recurrence of gastric ulcers without affecting Helicobacter pylori status

Rebamipide, a gastroprotective drug developed in Japan, accelerates ulcer healing and reduces recurrence of experimental gastric ulcers. We examined the effects of rebamipide, given during healing of human gastric ulcers infected with Helicobacter pylori, on the quality of ulcer healing and ulcer recurrence. Sixty H. pylori-positive patients with gastric ulcers were randomly allocated to three treatment groups: group O (N = 20) received 20 mg of omeprazole every day for eight weeks, group OR (N = 20) received the same dose of omeprazole and 300 mg of rebamipide three times a day for eight weeks, and group OA (N = 20) received the same dose of omeprazole for eight weeks and 1500 mg of amoxicillin three times a day for the first two weeks. After this treatment was completed no other medication was given. Endoscopic examinations were performed at the end of therapy (for healing rate), one month later (for rate of H. pylori eradication) and every three months for follow-up (for ulcer recurrence rate). At the end of therapy, biopsy specimens were taken from the gastric ulcer scar and examined under the microscope for neutrophil and mononuclear cell infiltration. The ulcer healing rate of the three groups was almost the same; H. pylori in group OA was 65% and that of the other two groups was 0%. The number of patients with a flat ulcer scar pattern (good quality of ulcer healing) was increased and the neutrophil infiltration was significantly improved in groups OR and OA compared to group O. The ulcer recurrence rate was significantly lower in group OA and group OR than in group O. In conclusion, rebamipide is almost equipotent to amoxicillin plus omeprazole for the reduction of ulcer recurrence. The decreased recurrence rate by rebamipide may be due to improvement of the quality of ulcer healing, reflected as in the suppression of inflammatory cell infiltration in the scar, which results from either cure of H. pylori infection and/or treatment with a gastroprotective drug such as rebamipide.

Increased mRNA levels of transforming growth factor-beta1 and monocyte chemoattractant protein-1 in ulcer relapse caused by interleukin-1beta in rats

This study investigated the mRNA expression of transforming growth factor-beta1 (TGF-beta1) and monocyte chemoattractant protein-1 (MCP-1) in rat gastric tissues in which ulcers had relapsed due to interleukin-1beta (IL-1beta) administration. Rats with healed ulcers were administered IL-1beta (1 microg/kg) and killed after 0, 12, 24, or 48 hr. Both TGF-beta1 and MCP-1 mRNA levels were increased in the scarred gastric tissues at 24 hr (fourfold), when ulcers had not relapsed. Furthermore, the expression of these genes also increased in the ulcerated gastric tissues at 48 hr (fivefold), when 90% of healed ulcers had relapsed. On the other hand, the number of macrophages that had infiltrated the scarred gastric tissues at 24 hr was two times higher than that at 0 hr. At 48 hr, the number of macrophages that had infiltrated gastric tissues in which ulcers had relapsed was similar to that at 24 hr. Thus, TGF-beta1 and MCP-1 may be implicated in the macrophage infiltration, thereby leading to ulcer relapse due to IL-1beta.

ZK1, a novel Krüppel-type zinc finger gene, is induced following exposure to ionizing radiation and enhances apoptotic cell death on hematopoietic cells

To identify and early response factor by exposure to ionizing radiation, we cloned the cDNA of a novel Krüppel-type zinc finger (ZNF) gene, ZK1, from a cDNA library constructed from the human leukemia cell line, CMK86, using degenerate primers. This cDNA encoded a protein of 671 amino acids with an A box of Krüppel-associated box (KRAB) domain at the N-terminus, followed by 15 ZNF motifs. The expression level of the ZK1 mRNA in human leukemia cells lines, CMK86 and U937, was increased after exposure to ionizing radiation. Furthermore, murine myeloid precursor 32D cells that were stably transfected with ZK1 cDNA had higher sensitivity to ionizing radiation than the 32D parent cells. These data suggest that the ZK1 gene is one of early response genes by exposure to ionizing radiation, and may have some functions on radiation-induced apoptotic cell death on hematopoietic cells.

Propranolol attenuates haloperidol-induced Fos expression in discrete regions of rat brain: possible brain regions responsible for akathisia

Neuroleptics induce several extra-pyramidal side effects, such as akathisia, acute dystonia and parkinsonism. Although recently developed atypical neuroleptics ameliorate some of these side effects, akathisia remains a common and severely distressing adverse reaction. Several drugs are reported to be of clinical use for the pharmacological treatment of akathisia. In particular, the beta-adrenoceptor blocker, propranolol, has been widely used for the treatment of akathisia, but it does not ameliorate other extra-pyramidal side effects. To identify the neural substrates of akathisia, we investigated the effects of propranolol on haloperidol-induced Fos expression in rat brain. Haloperidol (1 mg/kg) induced Fos-positive nuclei in several regions of the brain, including the cingulate cortex area 3, piriform cortex nucleus accumbens, caudate-putamen, ventral lateral septum and parietal cortex. Pretreatment with propranolol (5 mg/kg) reduced the number of Fos-positive nuclei in the cingulate cortex area 3, the piriform cortex and area 1 of the parietal cortex. Injection of vehicle by itself tended to increase Fos expression in the cingulate cortex area 3 and the piriform cortex. Considering the functions of these brain regions, we speculate that the most plausible neural framework for haloperidol-induced akathisia involves area I of the parietal cortex, but possible roles for the cingulate cortex area 3 and the piriform cortex cannot be ruled out.

Comparison of early- and late-onset rapid cycling affective disorders: clinical course and response to pharmacotherapy

This study compared the clinical course and response to pharmacotherapy of patients with rapid cycling affective disorder (RCAD). A retrospective study was conducted on outpatients with affective disorder from 1991 to 1992 at Okayama University Medical School to select cases of RCAD. The subjects were 35 patients who fulfilled DSM-III-R criteria for mood disorder and had experienced at least four episodes of illness during the previous year. The subjects were divided into two groups according to their age at the first phase of affective illness: an early-onset group, consisting of patients aged 25 years or younger, and a late-onset group, consisting of patients aged 26 or older. There were 14 patients in the early-onset group and 21 in the late-onset group. Both the mean duration from onset to rapid cycling and the mean duration of each phase were shorter in the early-onset group than in the late-onset group. There were no significant differences between the groups in period of remission, character of the first episode, heredity, or thyroid function. Lithium carbonate therapy was more effective for reducing manic symptoms in the late-onset group than in the early-onset group, without maintaining a prophylactic effect in either group, whereas carbamazepine was more effective in the early-onset group. Antidepressants used in the depressive phase had a tendency to be more effective in the late-onset than in the early-onset group. However, rapid cycling induced by antidepressants was more evident in the late-onset than in the early-onset group. These findings supported the differentiation of RCAD into two groups based on age at onset, the early-onset group showing a rapid cycling course at an early stage and a good response to carbamazepine, the late-onset group having a relatively long disease duration until the appearance of a rapid cycling course and a good response to lithium carbonate in the manic phase and to antidepressants in the depressive phase.

Differential expression of DNA topoisomerase II alpha and II beta genes between small cell and non-small cell lung cancer

DNA topoisomerase II (Topo II) inhibitors are widely used in lung cancer chemotherapy, but small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC) show different sensitivity to them. In this study, we examined the gene expression levels of both isoforms of Topo II (II alpha and II beta) in lung cancer specimens to investigate the differential expression between SCLC and NSCLC. The expression levels of the Topo II alpha and Topo II beta genes were assessed in 80 autopsy samples (40 primary tumors and 40 corresponding normal lung tissues) by using the reverse transcription polymerase chain reaction. We found that the expression levels of the Topo II alpha gene in tumors were significantly higher than those in normal lung tissues, and that those in SCLC were significantly higher than those in NSCLC. There were no significant differences in Topo II beta gene expression between tumors and normal lung tissues and between SCLC and NSCLC. Further-more, correlation analysis revealed that Topo II alpha expression was correlated with Topo II beta expression in both tumor and normal lung tissues. These results indicate that a difference exists in the regulation of the Topo II gene between lung tumors and normal lung tissues. Our finding of differential expression of Topo II alpha between SCLC and NSCLC also suggests that the Topo II alpha expression level is associated with sensitivity to Topo II inhibitors.

The TEL/ETV6 gene is required specifically for hematopoiesis in the bone marrow

The TEL (translocation-Ets-leukemia or ETV6) locus, which encodes an Ets family transcription factor, is frequently rearranged in human leukemias of myeloid or lymphoid origins. By gene targeting in mice, we previously showed that TEL-/- mice are embryonic lethal because of a yolk sac angiogenic defect. TEL also appears essential for the survival of selected neural and mesenchymal populations within the embryo proper. Here, we have generated mouse chimeras with TEL-/- ES cells to examine a possible requirement in adult hematopoiesis. Although not required for the intrinsic proliferation and/or differentiation of adult-type hematopoietic lineages in the yolk sac and fetal liver, TEL function is essential for the establishment of hematopoiesis of all lineages in the bone marrow. This defect is manifest within the first week of postnatal life. Our data pinpoint a critical role for TEL in the normal transition of hematopoietic activity from fetal liver to bone marrow. This might reflect an inability of TEL-/- hematopoietic stem cells or progenitors to migrate or home to the bone marrow or, more likely, the failure of these cells to respond appropriately and/or survive within the bone marrow microenvironment. These data establish TEL as the first transcription factor required specifically for hematopoiesis within the bone marrow, as opposed to other sites of hematopoietic activity during development.