Pathogenesis of Hirschsprung's disease and its variants: recent progress

The enteric nervous system (ENS) is a complex network of interconnected neurons within the wall of the intestine that controls intestinal motility, regulates mucosal secretion and blood flow, and also modulates sensation from the gut. The cells that form the ENS in mammals are derived primarily from vagal neural crest cells. During the past decade there has been an explosion of information about genes that control the development of neural crest. Molecular-genetic analysis has identified several genes that have a role in the development of Hirschsprung's disease. The major susceptibility gene is RET, which is also involved in multiple endocrine neoplasia type 2. Recently, genetic studies have provided strong evidence in animal models that intestinal neuronal dysplasia (IND) is a real entity. HOX11L1 knockout mice and endothelin B receptor-deficient rats demonstrated abnormalities of the ENS resembling IND type B in humans. These findings support the concept that IND may be linked to a genetic defect.

Phase I/II trial of weekly cisplatin, etoposide, and irinotecan chemotherapy for metastatic lung cancer: JCOG 9507

Combinations of cisplatin-irinotecan and cisplatin-etoposide are active and well tolerated in patients with both small-cell lung cancer (SCLC) and nonsmall-cell lung cancer (NSCLC). To define the recommended dose for phase II trials of irinotecan combined with cisplatin and etoposide in chemonaive patients with stage IV disease, 56 patients (11 having SCLC and 45 NSCLC) received cisplatin 25 mg m(-2) weekly for 9 weeks, etoposide 60 mg m(-2) for 3 days on weeks 1, 3, 5, 7 and 9, and irinotecan 20-100 mg m(-2) (levels 1-8) on weeks 2, 4, 6 and 8, together with a prophylactical granulocyte colony-stimulating factor support (50 microg m(-2) on days 4-7 on weeks 1, 3, 5, 7 and 9, and on days 2-7 on weeks 2, 4, 6 and 8). Grade 3-4 leukocytopenia, neutropenia and thrombocytopenia were noted in 20 (36%), 28 (50%) and nine (16%) patients, respectively. Grade 3 diarrhoea, grade 3 cardiac toxicity, and grade 4 transaminase elevation developed in one (1.8%) patient each. Totally, four of 56 patients were removed from the study because of toxicity and recovered, and two other patients died in situations where drug toxicity might contribute to their death. Dose-limiting toxicity was noted in less than one-third of patients at dose levels 1-7, but in all patients at dose level 8. Thus, the recommended dose was determined to be level 7 (irinotecan 90 mg m(-2)). The response rates for SCLC and NSCLC were 91% (10/11) and 38% (17/45), respectively. The median survival time and 1-year survival rate were 11.9 months and 46% for SCLC and 10.1 months and 40% for NSCLC, respectively. This regimen was considered to be feasible and promising for the treatment of stage IV SCLC and NSCLC.

Allelic association of the neuronal nitric oxide synthase (NOS1) gene with schizophrenia

Nitric oxide (NO) has been identified as a widespread and multifunctional biological messenger molecule in the central nervous system (CNS), with possible roles in neurotransmission, neurosecretion, synaptic plasticity, and tissue injury in many neurological disorders, including schizophrenia. Neuronal NO is widely produced in the brain from L-arginine catalyzed by neuronal NO synthase (NOS1). We therefore hypothesized that the NOS1 gene may play a role in the pathophysiology of schizophrenia. In the present study, we examined the genetic association between a novel single nucleotide polymorphism (SNP: a C-->T transition located 276 base pairs downstream from the translation termination site) of the human NOS1 gene, which is located in chromosome 12q24, and schizophrenia (215 Japanese patients with schizophrenia and 182 healthy controls). The allele frequencies of the polymorphism in exon 29 of the NOS1 gene differed significantly between patients with schizophrenia and controls (chi(2) = 20.10, df = 1, P = 0.000007; relative risk = 1.92; 95% confidence interval = 1.44-2.55). Our results suggest that the NOS1 gene polymorphism may confer increased susceptibility to schizophrenia.

Association between three functional polymorphisms of dopamine D2 receptor gene and tardive dyskinesia in schizophrenia

The dopamine D2 receptor (DRD2) gene is considered one of the candidate genes contributing to the development of tardive dyskinesia (TD). In the present study, we investigated the genetic association between three functional polymorphisms (Ser311Cys, -141C Ins/Del and TaqI A) in the DRD2 gene and TD (200 patients with schizophrenia: 44 with TD and 156 without TD). No significant difference in the allelic and genotypic distribution between patients with TD and those without TD was observed. However, we found a slightly significant association between the -141C Ins/Del polymorphism and the total Abnormal Involuntary Movement Scale (AIMS) score (P = 0.037). The significant association between the -141C Ins/Del polymorphism and the total AIMS score did not remain after the regression analysis was taken into account (P = 0.14). Our results suggest that that three functional polymorphisms in DRD2 may not play a major role in the occurrence of TD.

[Tumor markers in lung cancer]

Carcinoembryonic antigen (CEA), squamous cell carcinoma antigen (SCC), neuron-specific enolase (NSE), cytokeratin 19 fragment (CYFRA), and pro-gastrin-releasing peptide (proGRP) can be used as tumor markers for lung cancer. CEA is sensitive for adenocarcinoma, SCC and CYFRA for squamous cell carcinoma, and NSE and proGRP for small cell carcinoma. A tumor marker is generally used as a marker to monitor the clinical course. Serum levels of pro-GRP, reflect the disease course of patients with small cell lung cancer more accurately than NSE or CEA. Among the patients with clinical N0-1 non-small cell lung cancer high serum CEA levels, adenocarcinoma histology, and large tumor dimension were significant predictors of pathologic N2 disease. CEA played a new role in predicting metastasis to mediastinal lymph nodes A more effective treatment may enhance the value of tumor markers to predict relapse.

Novel polymorphism in the 5'-upstream region of the human 5-HT6 receptor gene and schizophrenia

The localization of 5-hydroxytryptamine6 (5-HT6) receptor in the limbic and cortical regions, and the high affinity of atypical antipsychotic drugs such as clozapine for the receptor, suggest the possible involvement of the receptor in the pathogenesis of schizophrenia. In this study, we searched systematically for polymorphisms in the 5'-upstream region of the human 5-HT6 receptor gene. We identified a trinucleotide repeat polymorphism, (GCC)2/3, at a nucleotide position between -1093 and -1085 bp upstream from the translation start site. Subsequent case-control association study did not demonstrate significant differences of genotype and allele frequency between 206 controls and 246 patients with schizophrenia. Our results suggest that the 5-HT6 receptor gene polymorphism does not confer increased susceptibility to schizophrenia.

Retrospective study of hyponatremia in gastric cancer patients treated with a combination chemotherapy of 5-fluorouracil and cisplatin: a possible warning sign of severe hematological toxicities?

BACKGROUND

Some anti-neoplastic agents induce hyponatremia. The relationship between hyponatremia and other toxicities in gastric cancer patients treated with 5-fluorouracil and cisplatin (FP) was investigated retrospectively to clarify its clinical significance.

METHODS

The subjects were 50 advanced gastric cancer patients treated with FP. Patients' performance status, oral intake, nausea/vomiting, diarrhea, fever, urine volume, presence of ascites or pleural effusion, laboratory data and administration of diuretics, corticosteroid and contents and volume of hydration before and during the first 5 days after chemotherapy were reviewed.

RESULTS

The serum sodium level decreased after initiation of chemotherapy in all patients and the lowest level (nadir) was most frequently observed on day 8 (range, days 2-14), which preceded hematological toxicities. In 10 patients (20%) the nadir of serum sodium was lower than 125 mEq/l. We classified these 10 patients as a low-sodium group and the others into a normal-sodium group. Six (60%) and seven (70%) of the 10 patients in the low-sodium group had complications with grade 3 or 4 leukopenia and thrombocytopenia, whereas only one (3%) and two (5%) were seen in the normal-sodium group (p < 0.0001). Stomatitis and diarrhea were also slightly more severe in the former than the latter group. With respect to sensitivity and probability, receiver operating characteristic curves showed the nadir ((> or = ) or <125 mEq/l) of the serum sodium level was the best marker for both leukopenia and thrombocytopenia.

CONCLUSION

Hyponatremia after initiation of chemotherapy with FP may be a warning sign of subsequent severe hematological toxicity.

A phase I/II trial of cisplatin, docetaxel and ifosfamide in advanced or recurrent non-small cell lung cancer

This trial was initiated to evaluate the toxicity and activity of combination chemotherapy employing cisplatin (CDDP), docetaxel (DCT) and ifosfamide (IFX) in non-small cell lung cancer (NSCLC), and to determine the maximum tolerated dose (MTD) of IFX. Chemotherapy-naive patients with advanced or recurrent NSCLC received 60 mg/m(2) DCT followed after a 3-h interval by 60 mg/m(2) CDDP on chemotherapy day 1, and IFX at an escalating dose with mesna protection on days 2-4. The chemotherapy was repeated every 3 weeks. Granulocyte colony-stimulating factor (GCSF) was administered in the event of grade 3 leukopenia/neutropenia. The patients tolerated the treatment well up to level 4 of IFX dosing 1.5 g/day, but not the IFX dose at level 6 (2.0 g/day). Additional patients were enrolled in level 5 (IFX 1.7 g/day) to evaluate the toxicity of the drugs around the MTD. Level 5 was also judged as having exceeded the MTD, with febrile neutropenia and hepatic toxicity being observed as the dose-limiting toxicities. No toxicity-related deaths occurred. The majority of the chemotherapy courses were supported by GCSF administration. A total of 33 eligible patients were entered into the trial; the overall response rate was 10/33 or 30% among all eligible cases, and the rate for patients treated with the MTD or higher (levels 4-6) was 8/24, or 33% (90% confidence limit: 18-52%). The MTD of IFX was 1.5 g/m(2) administered for 3 days in this triplet combination. The clinical activity does not seem to justify the toxicity profile.

Japanese experience of telemedicine in oncology

We started telemedicine projects from 1990 with a telepathology system within Tsukiji Campus of National Cancer Center. In 1994, we connected Tsukiji Campus and Kashiwa Campus by 6 Mbps optical fiber leased line using IP protocol for data transmission, for teleconference, telepathology, and teleradiology projects. We also started connection of regional cancer centers and are now forming a cancer center network of 14 cancer centers. We are at present organizing 130 teleconferences per year with an attendance of more than 16000 people as summary. We have also used a high-resolution image transferring system, such as SHD (2000 pixelsx2000 pixels resolution) system on one side, and an economical telemedicine system using JAVA and a WWW browser (NCC_image) on the other side. We think that providing information is another field of telemedicine. We began the experimental gopher and WWW service in 1993. We are now providing official up-to-date cancer information for patients and healthcare professionals. We are getting more than 400000 hits per month. We are also providing a teleconference video session which is held every week on the Internet using a Real Video system with synchronized slide presentation on the WWW browser. We are also organizing a Cancer Image Reference Database System including DICOM images with viewer software. This paper is a summary of the telemedicine projects performed at the National Cancer Center.

Impairment of learning and memory in rats caused by oxidative stress and aging, and changes in antioxidative defense systems

To elucidate the influence of oxidative stress on the brain functions during aging, the cognitive performance ability of rats was assessed by using the water-maze test as an oxidative stress before and after hyperoxia. Young rats showed significantly greater learning ability than both old rats and vitamin-E-deficient rats. Although the memory functions of all rats were Impaired after oxidative stress, the memory retention of young rats was greater than those of other groups. After the stress, none of the rats recovered their learning ability. During aging and through hyperoxia, the release of acetylcholine from nerve terminals was remarkably decreased. Instead, thiobarbituric acid reactive substance (TBARS) contents in rat hippocampus and cebral cortex, and their synaptic membranes, were significantly increased during aging and by oxidative stress. The antioxidative defense system in rat brain was also changed by the stress. These results suggest that oxidative stress may contribute to learning and memory deficits following oxidative brain damage during aging.

Association analysis between two functional dopamine D2 receptor gene polymorphisms and schizophrenia

The dopamine D2 receptor (DRD2) gene has been listed as one of the candidate genes for susceptibility to schizophrenia. To date, a significant association between schizophrenia and two functional DRD2 gene polymorphisms, Ser311Cys and -141C Ins/Del, in Japanese samples, has been reported by Arinami et al. [1994: Lancet 343:703-704; 1997: Hum Mol Genet 6:577-582]. In the present study, we replicated the findings of Arinami et al. [1994: Lancet 343:703-704; 1997: Hum Mol Genet 6:577-582] in the same ethnic groups (Japanese samples) with the same polymorphisms (Ser311Cys and -141C Ins/Del). We genotyped these two polymorphisms for 241 patients and for 201 controls. Neither polymorphism was associated with schizophrenia. Moreover, in a haplotype analysis of the present sample, combined pairs of two polymorphisms provided no evidence for the association of either haplotype with schizophrenia. Our findings indicate that an association between the two functional DRD2 gene polymorphisms, Ser311Cys and -141C Ins/Del, and schizophrenia is unlikely.

Phase I and pharmacological study of paclitaxel given over 3 h with cisplatin for advanced non-small cell lung cancer

BACKGROUND

To establish the toxicities and maximum tolerated dose of paclitaxel given over 3 h in combination with cisplatin, to determine the pharmacokinetic profiles of these two drugs and to observe their antitumor activity, we conducted a combination phase I study in non-small cell lung cancer.

METHODS

Patients received paclitaxel doses of 150-210 mg/m2 given over 3 h and cisplatin doses of 60-80 mg/m2 as a 1 h infusion 2 h after the end of the paclitaxel infusion.

RESULTS

A total of 25 patients with previously untreated non-small cell lung cancer were enrolled. Granulocytopenia was the most frequent hematological toxicity and the most prominent non-hematological toxicity was sensory dominant neuropathy. Two of six patients experienced dose limiting toxicities (leukopenia, infection and neuropathy) at a dose of paclitaxel 210 mg/m2 and cisplatin 60 mg/m2, which was considered the maximum tolerated dose. There were seven partial responses among 24 evaluable patients, for an overall response rate of 29%. The median survival time was 341 days and the 1 year survival rate was 45.8%. As the paclitaxel pharmacokinetic parameters in this study were consistent with those of our previous single agent study, we found no significant drug-drug interaction between the 3 h infusion paclitaxel and cisplatin.

CONCLUSION

The recommended doses for further study are determined to be paclitaxel 180 mg/m2 and cisplatin 80 mg/m2. This is a well-tolerated and active regimen for non-small cell lung cancer. In view of the promising survival outcome, further evaluation in prospective randomized trials versus other regimens is warranted.

Clara cell secretory protein (CC16) gene polymorphism and schizophrenia in humans

An increasing amount of evidence suggests that the pathophysiology of schizophrenia is associated with activation of the inflammatory response system, as indicated by lower serum concentrations of Clara cell secretory protein (CC16), an endogenous anti-inflammatory protein in patients with schizophrenia. In the present study, we investigated the genetic association between a functional polymorphism (A38G) in human CC16 gene and schizophrenia (248 Japanese schizophrenic patients and 206 healthy controls). No significant positive association between the CC16 gene polymorphism and schizophrenia was observed. In addition, even when schizophrenic patients were divided into those with a positive family history for schizophrenia and with a negative family history for schizophrenia, no significant association with A38G polymorphism of the CC16 gene was observed. Our results suggest that the CC16 gene polymorphism do not confer increased susceptibility for schizophrenia.

The metabolism of plasma glucose and catecholamines in Alzheimer's disease

Several lines of evidence suggest that the cholinergic system in the hippocampus plays a pivotal roll in regulating the peripheral metabolism of glucose and catecholamines. The injection of cholinergic stimulators including neostigmine, the acetylcholine esterase inhibitor, into the third ventricle or the hippocampus induces the elevation of glucose or catecholamines in plasma in rats. Under stress conditions, release of acetylcholine in the hippocampus increases, which coincides with the elevation of plasma glucose and catecholamines. Age-related reduction in responsivity of the cholinergic system in the hippocampus has been well documented. The intrahippocampal neostigmine injection induces significantly attenuated responses in plasma glucose and catecholamines in rats, the finding suggested that changes in cholinergic system activity in the hippocampus could result in alteration of the peripheral metabolism of glucose and catecholamines. In Alzheimer's disease (AD), the most common type of dementia, degeneration of the hippocampal cholinergic system is one of the most robust pathological features. Measurement of plasma catecholamines during a fasting state in the groups of AD subjects, vascular dementia subjects, and non-demented control subjects showed significantly lower plasma epinephrine levels in the AD subjects.

Polymorphisms of tryptophan hydroxylase gene and the symptomatology of schizophrenia: an association study

Serotonergic neurotransmission may be involved in the etiology of schizophrenia. We systematically searched for human tryptophan hydroxylase (TPH) coding polymorphisms, and detected a novel pentanucleotide repeat deletion polymorphism (GTTTT)4/5 in TPH intron 1b. We also confirmed A779C intron 7. Neither polymorphism showed a significant association with schizophrenia (182 patients with schizophrenia, 148 controls). A significant association, however, between A779C genotypes and the total Manchester Scale (MS) scores was found in male patients (P = 0.045). Subsequently, a significant association was also found between A779C genotypes and the MS negative symptoms scores in male patients (P = 0.030). These results suggest that the TPH gene may play a role in the negative symptoms in male patients with schizophrenia.

Phase I study of a weekly infusion of irinotecan hydrochloride (CPT-11) and a 14-day continuous infusion of etoposide in patients with lung cancer: JCOG trial 9408

BACKGROUND

The aim was to determine the maximum tolerated dose (MTD) and recommended dose of irinotecan hydrochloride (CPT-11) in combination with a 14-day continuous infusion of etoposide in patients with refractory advanced lung cancer (LC), especially small cell lung cancer (SCLC).

METHODS

Etoposide was administered continuously at 25 mg/m2/day for 14 days. The initial dose of CPT-11 was 40 mg/m2 given as a 90 min intravenous infusion on days 1, 8 and 15 and the dose escalation of CPT-11 was planned in increments of 20 mg/m2 until severe or life-threatening toxic effects were observed.

RESULTS

Nine refractory or advanced LC patients (eight at level 1, one at level 2) were entered in this study, of whom two at level 1 were not assessable for toxicity because of patient's refusal and progressive disease. One treatment-related death due to pulmonary toxicity and one patient with hypotension who needed catecholamine for more than 48 h were observed at level 1, a CPT-11 dose of 40 mg/m2. The MTD of CPT-11 was 40 mg/m2. Therapeutic efficacy could be assessed in seven patients, of whom two achieved a partial response.

CONCLUSIONS

This regimen was too toxic and the recommended dose was outside the levels in this study. One has to consider pulmonary toxicity when using CPT-11, especially for patients previously treated with cytotoxic agents for which pulmonary toxicity has been reported.

Relationship between serum cholesterol levels and meta-chlorophenylpiperazine-induced cortisol responses in healthy men and women

We investigated the effect of cholesterol on serotonergic receptor function in 20 healthy male and 10 healthy female subjects using cortisol responses to meta-chlorophenylpiperazine (m-CPP) neuroendocrine challenge tests. M-CPP, a metabolite of the antidepressant trazodone, has been widely used in psychopharmacology research as a probe of serotonin function. In the human brain, m-CPP binds both to various serotonergic receptors, mainly 5-HT(2C), and to alpha(2)-adrenoceptors. After an overnight fast, the subjects received m-CPP (0.5 mg/kg) or identical placebo capsules orally in a randomized, double blind, crossover design. Blood was obtained for measurement of cholesterol and cortisol. In some analyses, especially in males, there were significant positive correlations between serum cholesterol levels and cortisol responses. These findings suggest the possibility that serum cholesterol levels may be positively associated with serotonergic receptor function. The existence of such an association may provide an explanation for reported increases in depression, suicide and violence in individuals with low or lowered cholesterol.