Enhancement of metastatic properties of pancreatic cancer cells by MUC1 gene encoding an anti-adhesion molecule

MUC1 mucin expression has been shown to be associated clinicopathologically with metastasis and poor clinical outcome in a variety of tumors. To further investigate this finding experimentally, human pancreatic cancer S2-013 cells overexpressing MUC1 were used for spontaneous metastatic potential in nude mice. It was found that the number of lung metastases of MUC1 transfectants was significantly higher than that of control cells. To analyze the molecular mechanisms that underlie the increased metastatic activity, in vitro adhesion assays were performed. MUC1 mucin expression enhancedin vitro invasiveness and motility of S2-013 cells, and decreased the binding of S2-013 cells to type I collagen, Type IV collagen and laminin. Similar effects were not observed for cells expressing tandem repeat-deleted MUC1 cDNA. Adhesion properties were abolished by benzyl-alpha-GalNAc treatment, indicating that glycosylation of the extracellular domain of MUC1 was essential for these biological adhesive functions. Our data support the hypothesis that MUC1 expression contributes to the metastatic ability of pancreatic cancer cells.

Dehydroepiandrosterone suppresses elevated hepatic glucose-6-phosphatase mRNA level in C57BL/KsJ-db/db mice: comparison with troglitazone

Dehydroepiandrosterone (DHEA) is known to improve hyperglycemia of diabetic C57BL/KsJ-db/db mice that are obese and insulin resistant. In a previous study, we reported that DHEA as well as troglitazone suppresses the elevated hepatic gluconeogenic enzymes, glucose-6-phosphatase (G6Pase) and fructose-1,6-bisphosphatase (FBPase) activities in C57BL/KsJ-db/db mice. In the present study, we evaluated the changes in mRNA of G6Pase and FBPase in db/db mice. Despite hyperinsulinemia, the G6Pase mRNA level of db/db mice was elevated as compared to their heterozygote littermate db/+m mice. In contrast, the FBPase mRNA level was not elevated in db/db mice. Administration of DHEA for two weeks significantly decreased the blood glucose level and the elevated G6Pase mRNA level in db/db mice. No significant changes were seen in the FBPase mRNA level after the administration of DHEA. Administration of troglitazone also decreased the blood glucose and G6Pase mRNA level in db/db mice although no changes were seen in the FBPase mRNA level. These results suggest that the elevation of G6Pase mRNA is important in elucidating the cause of insulin resistance, and that the G6Pase gene is at least one target for the hypoglycemic effects of DHEA as an insulin sensitizing agent in db/db mice.

[Consultation and survey for drug interaction in outpatients taking the medicines potentially interact with St. John's Wort]

Ministry Health Welfare of Japan announced the caution for drug interaction of St. John's Wort (SJW), a herbal supplement occasionally used for depression, on May, 2000. Immediately after the announcement, we conducted drug consultation for outpatients prescribed the medicines potentially interacting with SJW. We provided information concerning possible drug interaction with SJW for 741 outpatients (except for pediatrics) during the period of May 22-June 16, 2000. The potential drugs prescribed frequently were warfarin (28.0%), theophylline (19.7%), digitalis (18.4%), carbamazepine (7.2%), disopyramide (6.9%) and cyclosporin (6.3%). Of the patients, 401 subjects were surveyed by collecting the questionnaires to clarify the background of SJW drug interaction. Twenty-two subjects (5.5%) have known commercially available SJW products, 5 subjects (1.2%) have ever taken SJW products before and 2 subjects (0.5%) have taken SJW products concomitant with prescribed medicines. Gender difference was observed in paying attention to SJW products; female subjects (8.6%) tended to have more interest in SJW products than male subjects (2.8%). Two subjects taking SJW have realized for the first time that the supplements they took were SJW products when their package photographs were shown at the consultation. Showing the package photographs might be helpful for making the patients easy to identify the SJW products, because most patients do not pay attention to whether the supplements contain SJW or not. It is recommended that drug consultation should be provided to avoid serious drug interaction with SJW while the outpatients are taking potential medicines prescribed.

Assessment of renal toxicity by analysis of regeneration of tubular epithelium in rats given low-dose cadmium chloride or cadmium-polluted rice for 22 months

To determine whether low-dose oral administration of cadmium (Cd) induces renal toxicity, six groups of female Sprague-Dawley rats were fed a diet containing low amounts of CdCl2 or Cd-polluted rice at concentrations up to 40 ppm, and were killed after 12, 18, and 22 months (experiment 1). In addition to the determination of cortical Cd levels and histopathological assessment of kidneys, labeling indices (LIs) for proliferating cell nuclear antigen (PCNA) in the renal cortical tubular epithelium of Cd-treated rats were determined as a measure of regenerative activity. For comparison, the kidneys of rats given diets containing small to large amounts of CdCl2 up to 600 ppm for 4 months were similarly examined (experiment 2). Animals in experiment 1 demonstrated spontaneous chronic nephropathy and fluctuation in the tubular PCNA LI, but these findings were not correlated with renal Cd levels at 22 months. PCNA LI on the other hand, appeared to be linked to the severity of chronic nephropathy. In experiment 2, levels of CdCl2 of 200 ppm or more clearly induced degeneration and apoptosis of proximal tubules with high correlations between renal Cd levels, PCNA LI, and the severity of tubular degeneration. The results demonstrated that, in contrast to high-dose Cd administration, treatment with 40 ppm or less for 22 months did not influence tubular regeneration as a component of nonspecific chronic nephropathy, suggesting that long-term oral administration of low levels of Cd does not injure renal tubules in female rats.

Transmission electron microscopic study of hepatocytes in bioartificial liver

A bioartificial liver (BAL) was prepared by simple inoculation of hepatocytes into the inner space of hollow fibers of a hemodialyzer and it was maintained in a closed circuit for in vitro culture. Morphology of hepatocytes in the hollow fibers was studied in detail using transmission electron microscopy (TEM). The hepatocytes formed three-dimensional, rod-shaped aggregates of 200 microm in diameter throughout the whole dimension of the hollow fibers after 1 day of culture. Approximately five hepatocyte layers existed from the surface to the center of the aggregate. The hepatocytes in the aggregate displayed mostly polygonal shapes and were surrounded by five to six cells. Abundant bile canaliculi were formed between the hepatocytes and were sealed by tight junctions. The distance between the adjacent hepatocytes except the bile canaliculus domain was approximately 20 nm, and interdigitation was observed between some hepatocytes. These observations indicate that the hepatocytes formed functionally associated aggregates, that is, organoids. Although the cells facing the inner surface of the hollow fiber lost their polygonal shape and became flattened during the following several-day culture, no drastic change was observed in the morphology of the hepatocytes located inside the aggregate. After 14 days of culture, the number of living cells decreased and most of these had a deformed nucleus, few numbers of organelles, and intermittent lipid droplets.

Participation of angiotensin II in pressor response and norepinephrine release to spinal nerve stimulation in pithed rats

Experiments were carried out to examine whether endogenous angiotensin II (A-II) is involved in the regulation of release of norepinephrine (NE) elicited by the stimulation of spinal sympathetic nerves in pithed rats. It was assessed in terms of the alterations in concentrations of arterial blood plasma A-II and NE elicited by nerve stimulation (5 Hz, 50 V, 1 msec for 45 s) in pithed rats under vehicle or captopril (3 mg/kg, i.v.) treatment. Comparative study with pentobarbital anesthetized rats showed that pithing rats have the characteristics of lower basal blood pressure and lower NE level, whereas they have higher basal A-II level. In pithed rats treated with vehicle, pressor response to nerve stimulation was accompanied by increases in both A-II and NE level. In rats treated with captopril, the nerve stimulation caused about 40% lower increases in pressor response and NE level than those observed in rats treated with vehicle. These results suggest that the sympathetic nerve-induced NE release is facilitated by endogenous A-II in pithed rats, and that captopril exerts its inhibitory effect on the pressor response to nerve stimulation through the suppression of this interaction.

Reminiscence therapy using odor in alcohol-dependent patients--psychophysiological evaluation and psychological evaluation; power spectral analysis of heart rate variability

OBJECTIVE

This research was based on the hypothesis that when alcohol-dependent patients describe themselves, awakening of emotion by affirmative odor stimulation may facilitate memory reframing focusing on more affirmative emotion and memories. To prove the hypothesis, physiological changes accompanied by emotional awakening were evaluated by measuring the autonomic activity. In addition, subjective evaluation by a self-report manner was examined to investigate the effectiveness of Reminiscence Therapy (RT) using odor in alcohol-dependent patients.

SUBJECTS

Thirty-four patients who met the DSM-IV criteria of alcohol-related disorders and were hospitalized in a ward specialized to alcohol dependence therapy.

METHODS

Each patient underwent a one-to-one interview twice. For counterbalance, one interview was performed with odor stimulation using an odor with a relaxing effect that recall pleasant emotion, and the other was without odor stimulation. As the evaluation indices of physiological changes accompanied by emotional awakening, index of autonomic function (HRV; Heart rate variability) for objective evaluation and psychological indices (STAI; State-Trait Anxiety Inventory VAS; Visual Analog Scale) for subjective evaluation were measured.

RESULTS

1) Objective evaluation: Regarding the evaluation index of the autonomic function, the sympathetic nervous system activity (LF/HF; low frequency component/high frequency component ratio) was significantly inhibited by odor stimulation (p < 0.05). 2) Subjective evaluation: Compared to the state prior to interview, state anxiety judged by STAI was significantly decreased after interview (p < 0.01). The VAS score was significantly decreased after interview regardless of the presence or absence of odor stimulation (p < 0.0001).

CONCLUSIONS

A reduction in state anxiety was observed. The effect of odor was not significant on the subjective evaluation, but the objective evaluation suggested that the odor inhibited the sympathetic nervous system. Thus, it was suggested that odor can be used in RT, that is, emotional changes due to stimulation of odor may be applicable in RT.

Site-specific accumulation of a LINE-like retrotransposon in a sex chromosome of the dioecious plant Cannabis sativa

Male-associated DNA sequences were analysed in hemp (Cannabis sativa L.), a dioecious plant with heteromorphic sex chromosomes. A male-associated DNA sequence in C. sativa (MADC1) and its flanking sequence encoded a reverse transcriptase that was strongly homologous to those of LINE-like retrotransposons from various plants and other organisms, as well as another open reading frame (ORF). Fluorescence in situ hybridization (FISH) with MADC1 as probe, which yielded strong signals specific for male genomic DNA in gel blot analysis, generated a clear doublet signal at the end of the long arm of the Y chromosome. FISH using pachytene chromosomes of pollen mother cells at meiotic prophase I revealed that pairing of X and Y chromosomes occurred at the short arm of the Y chromosome where MADC1 was not present. Furthermore, FISH using extended DNA fibers, with MADC1 and its flanking DNA as probes, revealed that 100 to 200 copies of the retrotransposon were located in tandem on the Y chromosome. These results support the hypothesis that accumulation of a specific LINE-like retrotransposon at the terminal region of the long arm of the Y chromosome might be one cause of heteromorphism of sex chromosomes.

Role of the gynoecium in natural senescence of carnation (Dianthus caryophyllus L.) flowers

Although the role of the gynoecium in natural senescence of the carnation flower has long been suggested, it has remained a matter of dispute because petal senescence in the cut carnation flower was not delayed by the removal of gynoecium. In this study, the gynoecium was snapped off by hand, in contrast to previous investigations where removal was achieved by forceps or scissors. The removal of the gynoecium by hand prevented the onset of ethylene production and prolonged the vase life of the flower, demonstrating a decisive role of the gynoecium in controlling natural senescence of the carnation flower. Abscisic acid (ABA) and indole-3-acetic acid (IAA), which induced ethylene production and accelerated petal senescence in carnation flowers, did not stimulate ethylene production in the flowers with gynoecia removed (-Gyn flowers). Application of 1-aminocyclopropane-1-carboxylate (ACC), the ethylene precursor, induced substantial ethylene production and petal wilting in the flowers with gynoecia left intact, but was less effective at stimulating ethylene production in the -Gyn flowers and negligible petal in-rolling was observed. Exogenous ethylene induced autocatalytic production of the gas and petal wilting in the -Gyn flowers. These results indicated that ethylene generated in the gynoecium triggers the onset of ethylene production in the petals of carnation during natural senescence.

Enhancement of metastatic properties of pancreatic cancer cells by MUC1 gene encoding an anti-adhesion molecule

MUC1 mucin expression has been shown to be associated clinicopathologically with metastasis and poor clinical outcome in a variety of tumors. To further investigate this finding experimentally, human pancreatic cancer S2-013 cells overexpressing MUC1 were used for spontaneous metastatic potential in nude mice. It was found that the number of lung metastases of MUC1 transfectants was significantly higher than that of control cells. To analyze the molecular mechanisms that underlie the increased metastatic activity, in vitro adhesion assays were performed. MUC1 mucin expression enhancedin vitro invasiveness and motility of S2-013 cells, and decreased the binding of S2-013 cells to type I collagen, Type IV collagen and laminin. Similar effects were not observed for cells expressing tandem repeat-deleted MUC1 cDNA. Adhesion properties were abolished by benzyl-alpha-GalNAc treatment, indicating that glycosylation of the extracellular domain of MUC1 was essential for these biological adhesive functions. Our data support the hypothesis that MUC1 expression contributes to the metastatic ability of pancreatic cancer cells.

[Successful treatment for descending necrotizing mediastinitis: a case report]

A 21-year-old female was admitted to our hospital because of high fever, neck swelling, and dyspnea. She was diagnosed as descending necrotizing mediastinitis (DNM) extended from odontogenic infection. On the day of admission, she underwent cervical drainage. Next day, the CT scan showed an abscess below the tracheal bifurcation and bilateral pleural effusion. Mediastinal drainage was performed through a right thoracotomy, and a left thoracic tube was inserted. Anaerobic Peptostreptococcus was found with bacteriological culture. After the mediastinal drainage, bilateral thoracic irrigation was performed through the thoracic tubes. Left thoracic tube was removed on the 8th day and right one was removed on the 20th day after the thoracotomy. She was discharged on the 42nd day. DNM is relatively rare, but it is lethal disease with high mortality. Immediate and sufficient mediastinal drainage is indispensable for the disease.

Disruption of insulin receptor substrate 2 causes type 2 diabetes because of liver insulin resistance and lack of compensatory beta-cell hyperplasia

To investigate the role of insulin receptor substrate (IRS)-2 in vivo, we generated IRS-2-deficient mice by gene targeting. Although homozygous IRS-2-deficient mice (IRS-2-/- mice) had a body weight similar to wild-type mice, they progressively developed type 2 diabetes at 10 weeks. IRS-2-/- mice showed insulin resistance and a defect in the insulin-stimulated signaling pathway in liver but not in skeletal muscle. Despite insulin resistance, the amount of beta-cells was reduced to 83% of that in wild-type mice, which was in marked contrast to the 85% increase in the amount of beta-cells in IRS-1-deficient mice (IRS-1-/- mice) to compensate for insulin resistance. Thus, IRS-2 plays a crucial role in the regulation of beta-cell mass. On the other hand, insulin secretion by the same number of cells in response to glucose measured ex vivo was significantly increased in IRS-2-/- mice compared with wild-type mice but was decreased in IRS-1-/- mice. These results suggest that IRS-1 and IRS-2 may play different roles in the regulation of beta-cell mass and the function of individual beta-cells.

Interaction of SK(Ca) channels and L-type Ca(2+) channels in catecholamine secretion in the rat adrenal gland

We elucidated the interaction of small-conductance Ca(2+)-activated K(+) (SK(Ca)) channels and L-type Ca(2+) channels in muscarinic receptor-mediated control of catecholamine secretion in the isolated perfused rat adrenal gland. The muscarinic agonist methacholine (10-300 microM) produced concentration-dependent increases in adrenal output of epinephrine and norepinephrine. The SK(Ca) channel blocker apamin (1 microM) enhanced the methacholine-induced catecholamine responses. The facilitatory effect of apamin on the methacholine-induced catecholamine responses was not observed during treatment with the L-type Ca(2+) channel blocker nifedipine (3 microM) or Ca(2+)-free solution. Nifedipine did not affect the methacholine-induced catecholamine responses, but it inhibited the responses during treatment with apamin. The L-type Ca(2+) channel activator Bay k 8644 (1 microM) enhanced the methacholine-induced catecholamine responses, whereas the enhancement of the methacholine-induced epinephrine and norepinephrine responses were prevented and attenuated by apamin, respectively. These results suggest that SK(Ca) channels are activated by muscarinic receptor stimulation, which inhibits the opening of L-type Ca(2+) channels and thereby attenuates adrenal catecholamine secretion.

Posterior sagittal anorectoplasty for failed imperforate anus surgery: lessons learned from secondary repairs

PURPOSE

The aim of this study was to evaluate secondary operations using a posterior sagittal approach in patients with fecal incontinence and impaction after primary repair of anorectal malformations.

METHODS

Twenty patients (14 boys, 6 girls) who had previous failed surgery for imperforate anus underwent secondary operations. The indications for surgery included fecal incontinence (n = 16) and fecal impaction (n = 4). Patients ranged in age from 2 to 30 years (mean, 11 years), with 4 over the age of 20 years. The primary procedures included abdominosacroperineal (n = 7), sacroperineal (n = 10), and perineal (n = 3) pull-throughs. At surgery, none of the patients underwent a diverting colostomy. The rectum was mobilized from the surrounding structures through a posterior sagittal approach. The surgical findings included anteriorly displaced anus (n = 17), laterally displaced anus (n = 3), mesenteric fat surrounding the rectum (n = 4), mega-rectosigmoid (n = 2), and others (n = 3). The rectum underwent reconstruction, which involved relocation of the rectum and anus to surround them with the muscle complex.

RESULTS

Patients underwent follow-up for periods ranging from 8 months to 6 years after surgery (mean, 3 years). To evaluate the functional results, fecal continence scores (Templeton and Ditesheim) were calculated for incontinent patients. Of the 16 incontinent patients, 12 achieved continence and 4 some improvement. Of the 4 patients with fecal impaction, 2 achieved daily voluntary bowel movement, whereas the other 2 have mild constipation and need occasional enemas.

CONCLUSIONS

Our study suggests that (1) a secondary operation through a posterior sagittal approach can restore fecal continence and is efficacious even in adolescents and adults and (2) a posterior sagittal procedure can be safely performed without a diverting colostomy.

Clinicopathologic evaluation of hepatocellular carcinoma with bile duct thrombi

BACKGROUND

The aim of this study was to evaluate the clinicopathologic characteristics of patients with hepatocellular carcinoma (HCC) and bile duct thrombi (BDT).

PATIENTS

Seventeen patients with HCC and BDT among 671 patients with HCC who underwent hepatic resection were enrolled in this study.

RESULTS

There were no significant differences in the survival rates between patients with and those without BDT, although the rate of stage IV or portal vein invasion was significantly higher in patients with HCC and BDT than in those with HCC but without BDT. In 9 of 17 patients with BDT, preoperative jaundice was observed. Five of the 17 patients underwent a bile duct resection combined with hepatic resection, and 12 patients underwent hepatic resection with removal of the BDT without bile duct resection. None of the patients had histopathologic evidence of direct tumor invasion into the bile duct wall or of any tumor recurrence related to the BDT. There were no significant differences in the survival rates between patients who underwent bile duct resection and those who did not.

CONCLUSION

Hepatic resection and the removal of BDT without bile duct resection were sufficient surgical interventions to treat patients with HCC and BDT.

Increased risk of prostate cancer and benign prostatic hyperplasia associated with a CYP17 gene polymorphism with a gene dosage effect

The CYP17 gene (CYP17) codes for the cytochrome P450c17alpha enzyme, which mediates two key steps in the sex steroid synthesis. There is a polymorphism (a T-to-C substitution) in the 5'-untranslated region, which may influence the transcription level of CYP17 mRNA. There is a continuing controversy as to whether the variant allele is associated with a subset of breast cancer or polycystic ovary syndrome. In prostate cancer research, there are contradictory data concerning the CYP17 risk allele. We explored the association between CYP17 polymorphism and a risk of prostate cancer or benign prostatic hyperplasia (BPH) in a Japanese population. This study included 252 prostate cancer patients, 202 BPH patients, and 131 male controls. A 451-bp fragment encompassing the polymorphic site was amplified by PCR, treated with restriction enzyme MspA1, and electrophoresed on an agarose gel. The MspA1-undigested allele with the published sequence and the MspA1-digested variant allele were designated as A1 and A2, respectively. There was a significant difference (P < 0.05) in the genotypes between prostate cancer patients and male controls, and between BPH patients and male controls. Men with the A1/A1 CYP17 genotype had an increased risk of prostate cancer [odds ratio (OR), 2.57; 95% confidence interval (CI) = 1.39-4.78] and BPH (OR, 2.44; 95% CI = 1.26-4.72) compared with those with the A2/A2 genotype. Men with the A1/A2 genotype had an intermediate increased risk of prostate cancer (OR, 1.45; 95% CI = 0.84-2.54) and BPH (OR, 1.60; 95% CI = 0.89-2.87) compared with those with the A2/A2 genotype. The trend of an increasing risk of prostate cancer and BPH with an increasing number of the A1 allele was statistically significant (prostate cancer versus male control, P = 0.003; OR, 1.57; 95% CI = 1.16-2.12; BPH versus male control, P = 0.008; OR, 1.55; 95% CI = 1.12-2.13). There was no significant association between the CYP17 genotype and the tumor status (grade and stage) of prostate cancer. Our results suggest that the A1 allele of the CYP17 polymorphism is associated with an increased risk of prostate cancer and BPH, with a gene dosage effect. However, the CYP17 genotype does not seem to influence the disease status in prostate cancer.

Role of endogenous endothelins in catecholamine secretion in the rat adrenal gland

We investigated the role of endogenous endothelins in catecholamine secretion in response to transmural electrical stimulation in the retrogradely perfused rat adrenal gland. (R)2-[(R)-2-[(S)-2-[[1-(hexahydro-1H-azepinyl)]carbonyl]amino-4-++ +methy l-pentanoyl]amino-3-[3-(1-methyl-1H-indoyl)]propionyl]amino-3-(2-+ ++pyridyl) propionic acid (FR139317; 0.03-3 microM), an endothelin ET(A) receptor antagonist, inhibited the electrical stimulation-induced epinephrine and norepinephrine output. Neither N-cis-2, 6-dimethylpiperidinocarbonyl-L-gamma-methylleucyl-D-1- methoxycarbonyl tryptophanyl-D-norleucine (BQ-788; 0.03-3 microM), an endothelin ET(B) receptor antagonist, nor phosphoramidon (1-100 mM), an endothelin-converting enzyme inhibitor, affected the catecholamine output responses. However, the inhibition by FR139317 of the catecholamine output responses was abolished by pretreatment with phosphoramidon (100 mM) or BQ-788 (3 microM). These results indicate that activation of endothelin ET(B) receptors by endogenous endothelins inhibits the catecholamine output responses under the condition in which endothelin ET(A) receptors are blocked. Exogenous endothelin-1 (1-100 nM) did not affect the catecholamine output responses, but it inhibited the responses under treatment with phosphoramidon and FR139317. Activation of endothelin ET(A) receptors may interfere with the endothelin ET(B) receptor-mediated inhibitory action on the neuronally evoked secretion of adrenal catecholamines.

Prevalence of dementia of Alzheimer type and apolipoprotein E phenotypes in aged patients with Down's syndrome

We investigated the exact prevalence of dementia of Alzheimer type (DAT) and apolipoprotein E (ApoE) phenotypes in 106 Japanese Down's syndrome (DS) patients. Among these patients 16 were diagnosed as having DAT. The prevalence of DAT was 0% in the 30- to 39-year-old group, 16% in the 40- to 49-year-old group, and 38% in those over 50 years old. The frequency of the epsilon4 allele in DS patients with DAT was 18.8%, which was considerably higher than that of nondemented DS patients (4.5%) and Japanese nondemented controls (6.7%). Especially, the frequency of the epsilon4 allele in DS patients who developed DAT under 50 years was significantly higher (28.6%). DS patients certainly develop DAT at earlier ages but the prevalence of DAT in each group of patients was lower than previously recognized. It is very likely that the ApoE epsilon4 is a risk factor for DAT even in DS patients with a genetic predisposition to Alzheimer's disease.

High frequency of tetraploidy detected in malignant melanoma of Japanese patients by fluorescence in situ hybridization

Aneuploidy and hyperploidy are often detected in malignant melanoma by cytogenetic analysis and flow cytometric analysis of DNA content. To determine the ploidy of cells in surgical specimens of melanin-producing tumors of Japanese patients, we performed fluorescence in situ hybridization (FISH) using touch smear technique to count the number of chromosomes 18 and X + Y in interphase nuclei using alpha-satellite DNA probes, D18Z1, DXZ1 and DYZ3. A normal melanocyte strain showed two D18Z1 and two [DXZ1+DYZ3] signals per nucleus, indicating 2N, and a malignant melanoma cell line showed 4 per nucleus, indicating 4N, consistent with results of cytogenetic and flow cytometric analyses. Therefore we employed this FISH method to analyze ploidy of surgical specimens. Specimens obtained from 8 patients with nevus cell nevus showed 2 FISH signals per nucleus. On the other hand, in all specimens obtained from 8 patients with malignant melanoma (6 primary and 2 metastatic melanoma), 65-90% of cells exhibited 4 signals per nucleus, indicating 4N. Histopathologically, 50-70% of cells were identified as malignant melanoma cells, indicating that our FISH method is effective to detect melanoma cells in tissue. We also analyzed allelic loss of the p53 gene by FISH with a p53 locus-specific probe and mutation of the p53 gene by immunostaining since mutation and deletion of the p53 gene may cause hyperploidy. All specimens except one obtained from a case with young-onset metastatic melanoma exhibited no allelic losses or negative p53 staining, showing the p53 gene was intact. These results indicate that tetraploidy, not caused by p53 mutation or deletion, is commonly found in malignant melanoma of Japanese patients. It is also suggested that there is no positive relationship between tetraploidy and poorer prognosis, and mutation and allelic loss of the p53 gene might be markers of aggressive form of malignant melanoma.

Cardioprotective effect of TY-12533, a novel Na(+)/H(+) exchange inhibitor, on ischemia/reperfusion injury

The effects of 6,7,8, 9-tetrahydro-2-methyl-5H-cyclohepta[b]pyridine-3-carbonylguanidine maleate (TY-12533) on myocardial ischemia/reperfusion injury were evaluated in rats. Inhibitory effects of TY-12533, TY-50893 (the 9-chloro derivative of TY-12533) and cariporide on the platelet Na(+)/H(+) exchanger in vitro were almost equal at pH 6.2 and decreased at pH 6.7; but TY-12533 was four times more potent than TY-50893 and cariporide at pH 6.7. TY-12533, TY-50893 and cariporide administered before ischemia (0.01-1 mg/kg, i.v.) suppressed the ischemia/reperfusion-induced arrhythmias to the same extent in vivo; but TY-12533 was more effective than cariporide and TY-50893 when they were administered during ischemia (0.1-1 mg/kg). Similar results were obtained for the inhibitory effects of these drugs administered before ischemia (0.03-0.1 mg/kg, i.v.) and during ischemia (0.1-1 mg/kg) on the ischemia/reperfusion-induced myocardial infarction. These differences between TY-12533 and the other drugs in vitro and in vivo may be ascribed to the pK(a) values of the guanidinium moiety of TY-12533 (6.93), TY-50893 (6.35) and cariporide (6.28).

Identification of novel polymorphisms in the AXIN1++ and CDX-2 genes

Axin and Cdx-2 play important roles in the tumorigenesis of human liver and colon. We have identified seven novel single-nucleotide polymorphisms (SNPs) in the AXIN1 gene and three in the CDX-2 gene. The identification of SNPs in these cancer-associated genes establishes a basis for future investigations to detect losses of heterozygosity in tumors; these SNPs may also provide genetic background information associated with cancer risk.

Hemorheological abnormalities in experimental cerebral ischemia and effects of protein kinase inhibitor on blood fluidity

The aim of this study was to investigate the mechanisms of the pathogenesis of hyperviscosity following cerebral ischemia. Focal ischemia was produced by embolic occlusion of the right middle cerebral artery (MCA) in rats for 1 hour, followed by recirculation. Twenty-four hours after MCA occlusion, fasudil, a protein kinase inhibitor, was administered intraperitoneally. Blood samples were taken from the abdominal aorta, and viscosity was measured using a cone-plate viscometer. The viscosity of whole blood in the ischemic attack group was significantly increased compared with the sham operated group 24 hours after MCA occlusion. Fasudil dose-dependently and significantly decreased the blood viscosity, and reduced to the normal range after administration of 10 mg/kg of fasudil (sham-operated rats, 5.17+/-0.05 cP; pre dose/ischemic rats, 6.05+/-0.08 cP; post dose/ischemic rats, 5.23+/-0.14 cP; 37.5 sec(-1)). Our findings suggest that cerebral ischemia induces a potent, systemic and long-lasting hyperviscosity, and that the inhibition of protein kinases, especially rho kinase, is efficacious in preventing this hyperviscosity.

Expression of genes responsible for ethylene production and wilting are differently regulated in carnation (Dianthus caryophyllus L.) petals

Carnation petals exhibit autocatalytic ethylene production and wilting during senescence. The autocatalytic ethylene production is caused by the expression of 1-aminocyclopropane-1-carboxylate (ACC) synthase and ACC oxidase genes, whereas the wilting of petals is related to the expression of the cysteine proteinase (CPase) gene. So far, it has been believed that the ethylene production and wilting are regulated in concert in senescing carnation petals, since the two events occurred closely in parallel with time. In the present study, we investigated the expression of these genes in petals of a transgenic carnation harboring a sense ACC oxidase transgene and in petals of carnation flowers treated with 1,1-dimethyl-4-(phenylsulfonyl)semicarbazide (DPSS). In petals of the transgenic carnation flowers, treatment with exogenous ethylene caused accumulation of the transcript for CPase and in-rolling (wilting), whereas it caused no or little accumulation of the transcripts for ACC oxidase and ACC synthase and negligible ethylene production. In petals of the flowers treated with DPSS, the transcripts for ACC synthase and ACC oxidase were accumulated, but no significant change in the level of the transcript for CPase was observed. These results suggest that the expression of ACC synthase and ACC oxidase genes, which leads to ethylene production, is differentially regulated from the expression of CPase, which leads to wilting, in carnation petals.

[Thoracoscopic major lung resection using a newly developed instrument retraction system and a voice-controlled robot]

We report a case of thoracoscopic major lung resection using a newly-developed instrument retraction system and a voice-controlled robot for lung cancer in a 72-year-old woman. The patient was referred to our department for further examination of an abnormal shadow on chest x-ray. A chest computed tomographic scan indicated a suspicion of malignancy. Bronchoscopic brush cytology revealed a lung cancer. Thoracoscopic middle lobectomy of the right lung with dissection of the mediastinal lymphnodes was successfully performed without a human assistance with no complications. The postoperative course was uneventful. Thoracoscopic major lung resection using an instrument retraction system and a voice-controlled robot may be feasible in selected cases.

Treatment with dimethylthiourea prevents left ventricular remodeling and failure after experimental myocardial infarction in mice: role of oxidative stress

Oxidative stress might play an important role in the progression of left ventricular (LV) remodeling and failure that occur after myocardial infarction (MI). We determined whether reactive oxygen species (ROS) are increased in the LV remodeling and failure in experimental MI with the use of electron spin resonance spectroscopy and whether the long-term administration of dimethylthiourea (DMTU), hydroxyl radical (.OH) scavenger, could attenuate these changes. We studied 3 groups of mice: sham-operated (sham), MI, and MI animals that received DMTU (MI+DMTU). Drugs were administered to the animals daily via intraperitoneal injection for 4 weeks.OH was increased in the noninfarcted myocardium from MI animals, which was abolished in MI+DMTU. Fractional shortening was depressed by 65%, LV chamber diameter was increased by 53%, and the thickness of noninfarcted myocardium was increased by 37% in MI. MI+DMTU animals had significantly better LV contractile function and smaller increases in LV chamber size and hypertrophy than MI animals. Changes in myocyte cross-sectional area determined with LV mid-free wall specimens were concordant with the wall thickness data. Collagen volume fraction of the noninfarcted myocardium showed significant increases in the MI, which were also attenuated with DMTU. Myocardial matrix metalloproteinase-2 activity, measured with gelatin zymography, was increased with MI after 7 and 28 days, which was attenuated in MI+DMTU. Thus, the attenuation of increased myocardial ROS and metalloproteinase activity with DMTU may contribute, at least in part, to its beneficial effects on LV remodeling and failure. Therapies designed to interfere with oxidative stress might be beneficial to prevent myocardial failure.

A new model of cerebral microthrombosis in rats and the neuroprotective effect of a Rho-kinase inhibitor

BACKGROUND AND PURPOSE

The aim of this study was to develop a new model of stroke based on endothelial damage and thrombotic occlusion in a perforating artery, leading to small cerebral infarcts and neurological deficits in rats. Moreover, the neuroprotective efficacy of fasudil, a rho-kinase inhibitor, was investigated in this model.

METHODS

Fifty-six male Sprague-Dawley rats were used in the present study. Rats were anesthetized with sodium pentobarbital, and 100 microg of sodium laurate was injected into the left internal carotid artery on days 1 and 3. The thrombus induction and consequent of ischemic brain damage were examined by histopathological analyses and neurological deficit scoring in a posture reflex test. To investigate the neuroprotective effects of fasudil, 1 or 10 mg/kg was administered intraperitoneally 5 minutes after the first injection of sodium laurate and once daily thereafter on the following 2 days.

RESULTS

One hour after the injection of sodium laurate, microscopic examination of phosphotungstic acid hematoxylin-stained sections (n=5) revealed that microthrombi containing fibrin strands obstructed the perforating arteries in the ipsilateral hemisphere. Under a transmission electron microscope (n=6), endothelial cells appeared exfoliated and the vascular lumen was obstructed by a thrombus composed of degranulated platelets, fibrin, leukocytes, and erythrocytes. No evidence of endothelial cell damage or thrombus could be found in the ipsilateral side of the pial artery (middle cerebral artery). Twenty-four hours after the second injection of sodium laurate (day 4), 13 of 15 rats (86.6%) showed mild to severe neurological deficits. Multiple small cerebral infarcts were observed in the hippocampus, cortex, and thalamus. Treatment with fasudil (1 and 10 mg/kg, n=15 each) resulted in a significant improvement in neurological deficits. Fasudil also significantly reduced the area of cerebral infarction.

CONCLUSIONS

We present a new model of stroke in rats, in which the perforating arteries are selectively occluded by microthrombi. This model is useful to investigate the pathophysiology and treatment of small cerebral infarction, which is caused by perforating arterial occlusive diseases such as lacunar infarcts. Fasudil may be beneficial in the treatment of acute ischemic stroke.

An autopsy case of Alzheimer's disease with a progressive supranuclear palsy overlap

A 74-year-old man developed abnormal forgetfulness, soon followed by unstable speech content and marked disorientation. At 77 years of age, the patient started to occasionally fall, an aspect of progressive supranuclear palsy. He then became bedridden. The patient eventually died of pneumonia at 79 years of age. Neuropathological examination revealed profiles of both progressive supranuclear palsy and Alzheimer's disease. Although the two conditions both belong to tauopathy, their pathologically proven combination was rare. Furthermore, the case had the possibility of being a subgroup of tauopathy.

Role of potassium channels in catecholamine secretion in the rat adrenal gland

We elucidated the functional contribution of K(+) channels to cholinergic control of catecholamine secretion in the perfused rat adrenal gland. The small-conductance Ca(2+)-activated K(+) (SK(Ca))-channel blocker apamin (10-100 nM) enhanced the transmural electrical stimulation (ES; 1-10 Hz)- and 1, 1-dimethyl-4-phenyl-piperazinium (DMPP; 5-40 microM)-induced increases in norepinephrine (NE) output, whereas it did not affect the epinephrine (Epi) responses. Apamin enhanced the catecholamine responses induced by acetylcholine (6-200 microM) and methacholine (10-300 microM). The putative large-conductance Ca(2+)-activated K(+) channel blocker charybdotoxin (10-100 nM) enhanced the catecholamine responses induced by ES, but not the responses induced by cholinergic agonists. Neither the K(A) channel blocker mast cell degranulating peptide (100-1000 nM) nor the K(V) channel blocker margatoxin (10-100 nM) affected the catecholamine responses. These results suggest that SK(Ca) channels play an inhibitory role in adrenal catecholamine secretion mediated by muscarinic receptors and also in the nicotinic receptor-mediated secretion of NE, but not of Epi. Charybdotoxin-sensitive Ca(2+)-activated K(+) channels may control the secretion at the presynaptic site.

Isolation and characterization of a novel human gene, DRCTNNB1A, the expression of which is down-regulated by beta-catenin

Beta-catenin plays significant roles in cell-to-cell adhesion and the Wnt/Wg signal transduction pathway. Accumulation of this protein in the cytoplasm and nucleus as a result of mutations of the adenomatous polyposis coli tumor suppressor gene or of the beta-catenin gene itself is often seen in a wide variety of tumors including carcinomas of the colon, liver, uterus, and brain. Interaction of accumulated beta-catenin with Tcf/Lef transcription factors is known to deregulate expression of some downstream genes, but the precise mechanisms whereby beta-catenin contributes to carcinogenesis remain to be disclosed. Here we report isolation of a novel murine gene, Drctnnb1a (down-regulated by Ctnnb1, a), the expression of which was experimentally down-regulated in response to the activated form of beta-catenin. To investigate a possible role of DRCTNNB1A in cancers, we also isolated the human homologue, DRCTNNB1A, the deduced product of which was 91% identical to the murine protein. The transcript was expressed in all human tissues examined, and we assigned the genomic location of DRCTNNB1A to chromosomal band 7p15.3 by in situ hybridization. Expression of DRCTNNB1A in SW480 colon cancer cells was significantly increased in response to reduction of intracellular beta-catenin by adenovirus-mediated transfer of the beta-catenin-binding domain of the adenomatous polyposis coli gene into the cells. Furthermore, we documented reduced expression of DRCTNNB1A in 12 of 15 primary colorectal cancers examined, compared with corresponding adjacent noncancerous mucosae. Our results implied that DRCTNNB1A is one of the genes involved in the beta-catenin-Tcf/Lef signaling pathway, and that reduced expression of DRCTNNB1A may have some role in colorectal carcinogenesis.

Effects of NKH477 on endothelin-1-induced renal responses in anaesthetized dogs

1. Intrarenal arterial infusion of a direct adenylate cyclase activator (NKH477; 300 ng/kg per min) increased renal blood flow, urine flow rate and urinary sodium excretion in anaesthetized dogs. 2. Intrarenal arterial infusion of endothelin (ET)-1 (2 ng/kg per min) reduced basal values of these parameters and glomerular filtration rate, which were recovered by the addition of NKH477 during ET-1 infusion. 3. These results demonstrate that NKH477 can counteract ET-1-induced antinatriuresis, mainly by restoring glomerular filtration.

Effect of angiotensin II on aldosterone secretion in canine adrenal gland in situ

To investigate the effect of angiotensin (ANG) II on aldosterone (ALDO) secretion, we measured arterial and adrenal venous plasma aldosterone concentrations in anesthetized dogs. The intraadrenal arterial infusion of ANG II (0.3 ng/kg/min) or potassium chloride (KCl) (0.6 mg/min) increased ALDO secretion. The changes in ALDO secretion in response to ANG II were tested during the concomitant arterial infusion of two graded doses of losartan (10 and 100 ng/kg/min), PD 123319 (50 and 500 ng/kg/min), nifedipine (25 and 250 ng/kg/min), or TMB-8 (2 and 20 microg/kg/min). All of these test drugs except PD123319 inhibited the ANG II-induced increase in ALDO secretion. Losartan did not affect the KCl-induced increase in ALDO secretion. These results indicate that ANG II acts on ANG II type 1 receptors in the adrenal gland and enhances ALDO secretion. They also suggest the involvement of both intracellular and extracellular calcium in the aldosterone response to stimulation by ANG II. Under these in vivo experimental conditions, the KCl-stimulated ALDO secretion does not appear to involve ANG II formation in the adrenal gland.

Suppression of facilitative glucose transporter 1 mRNA can suppress tumor growth

We attempted to suppress glucose transporter 1 (GLUT1) expression by transfecting MKN45 cells with cDNA for antisense GLUT1. Glucose transport was significantly decreased in cells with antisense GLUT1 compared with wild-type cells or cells with vector alone. Suppression of GLUT1 mRNA resulted in a decreased number of cells in the S phase. This was accompanied by overexpression of p21 protein. Tumorigenicity in the nude mice injected with antisense GLUT1 expressing cells was significantly slower than in those with wild-type MKN45 cells. These results suggest that antisense GLUT1 mRNA inhibits tumor growth through a G(1) arrest and that expression of antisense GLUT1 mRNA via gene therapy can be used as a tool in the treatment of cancer.

Expression of facilitative glucose transporter 1 mRNA in colon cancer was not regulated by k-ras

The expression of facilitative glucose transporter isoforms in colon adenocarcinoma and the possible role of k-ras in inducing GLUT (glucose transporter) mRNA were studied. RT-PCR demonstrated GLUT2 and GLUT3 expression in 100% of the ten normal colon mucosa samples but detected no GLUT1 mRNA. By contrast, GLUT1 mRNA was detected in all 20 (100%) colon cancer samples examined. GLUT4 mRNA was not detected in either normal mucosa or colon cancer tissues. Semiquantitative PCR demonstrated equal amounts of GLUT2 and GLUT3 mRNA in both normal mucosa and colon cancer samples. A point mutation in codon 12 of k-ras was detected in only six of the 20 (30%) colon cancer samples. Thus, a major difference between normal colon epithelia and colon cancer was the acquisition of GLUT1 expression, which was unlikely to have been induced by a point mutation in codon 12 of k-ras.

Observation of a spin-flip M1 transition in 7(lambda)Li

Using a large-acceptance germanium detector array (Hyperball), we have observed a spin-flip M1 gamma transition between the ground-state spin doublet of (7)(Lambda)Li (3/2(+)-->1/2(+)). The observed energy of 691.7+/-0.6(stat)+/-1.0(syst) keV provides crucial information on the strength of the spin-spin interaction between a Lambda and a nucleon. This is the first observation of well-identified hypernuclear gamma transitions using germanium detectors.

Three patients with adrenal tumors having been treated simply for diabetes mellitus

Three patients with functional adrenal tumors, Cushing's syndrome, primary aldosteronism and pheochromocytoma, who underwent adrenalectomy and were subsequently cured, were studied. All these patients had been treated for diabetes for several years before the diagnosis of adrenal tumors. In each case the state of diabetes before and after surgery, including parameters of insulin secretion and insulin resistance, was compared to demonstrate how the adrenal disorder influenced the nature of diabetes. In the case of Cushing's syndrome the hypercortisolemia caused insulin resistance in the peripheral tissues. In the case of primary aldosteronism, excessive production of aldosterone diminished insulin secretion possibly through hypokalemia. Pheochromocytoma affected both insulin secretion and insulin sensitivity through hypersecretion of catecholamines. In all these patients the adrenal tumors were found in clinical contexts other than management of diabetes itself. By careful retrospective review of these three patients' history, several important points that might have drawn the physician's attention to the underlying adrenal disorders were pointed out. These included past history of acute myocardial infarction with onset at unexpectedly young age in the case of Cushing's syndrome and unexpectedly high insulin resistance for the patient's body mass index in the case of pheochromocytoma.

Interaction between norepinephrine release and intrarenal angiotensin II formation during renal nerve stimulation in dogs

We examined possible interactions between intrarenal angiotensin II (ANG II) formation and norepinephrine (NE) release during renal sympathetic nerve stimulation (RNS) in anesthetized dogs. During 10 min of continuous RNS (1.5-2 Hz), the ANG II formation rates (ANG II-FR) and NE secretion rates (NE-SR) were determined at 1 and 10 min. Under control conditions, almost the same extent of increase in the NE-SR was observed at 1 and 10 min of RNS, whereas a significant increase in ANG II-FR was observed at 10 min but not at 1 min. During intrarenal arterial infusion of enalaprilat or losartan, the increase in NE-SR and reduction in renal blood flow at 10 min of RNS were suppressed, whereas the NE release and vasoconstriction responses at 1 min remained unaffected. The RNS-induced increases in ANG II-FR were completely abolished during infusion of enalaprilat. These results suggest that NE release on continuous RNS is enhanced by concomitantly formed ANG II, and this interaction depends on the time-related changes in intrarenal ANG II formation during RNS in the canine kidney.

Complicating risk factors for pyelonephritis after extracorporeal shock wave lithotripsy

PURPOSE

The score to predict the risk of post-extracorporeal shock wave lithotripsy (ESWL) pyelonephritis was evaluated. The score was based on the multivariate analysis of risk factors available pre-operatively. Stone size, pyuria, bacteriuria, previous pyelonephritis and other adjunctive procedures had been selected and scored.

METHODS

Three-hundred and forty-eight adult patients without active urinary infection undergoing ESWL therapy were studied. One of three regimens were selected by either doctor or patient: (i) no antimicrobial treatment; (ii) one dose of levofloxacin; or (iii) 1 week course of levofloxacin. Who and why selected it were described. Post-ESWL fever over 38 degrees C was defined as the unfavorable event.

RESULTS/CONCLUSION

With increasing score, doctors recommend taking an antimicrobial. There were 11 bacteriuric patients and post-ESWL pyelonephritis developed in one of them. Bacteria within the stone and post-ESWL ureteral obstruction caused by the stone fragments were considered to be important in developing pyelonephritis. However, multiple factors were related with it. Although their decision was not based simply on the score, the score was confirmed to be useful in identifying the high-risk patients and, therefore, to implement cost-effective antimicrobial use.

Isolation and characterization of human NBL4, a gene involved in the beta-catenin/tcf signaling pathway

beta-Catenin, a key regulator of cellular proliferation, is often mutated in various types of human cancer. To investigate cellular responses related to the beta-catenin signaling pathway, we applied a differential display method using mouse cells transfected with an activated form of mutant beta-catenin. This analysis and subsequent northern-blot hybridization confirmed that expression of a murine gene encoding NBL4 (novel band 4.1-like protein 4) was up-regulated by activation of beta-catenin. To examine a possible role of NBL4 in cancer, we isolated the human homologue of the murine NBL4 gene by matching mNBL4 against the human EST (expressed sequence tag) database followed by 5' rapid amplification of cDNA ends (5'RACE). The cDNA of hNBL4 encoded a protein of 598 amino acids that shared 87% identity in amino acid sequence with murine NBL4 and 71% with zebrafish NBL4. A 2.2-kb hNBL4 transcript was expressed in all human tissues examined with high levels of expression in brain, liver, thymus and peripheral blood leukocytes and low levels of expression in heart, kidney, testis and colon. We determined its chromosomal localization at 5q22 by fluorescence in situ hybridization. Expression of hNBL4 was significantly reduced when beta-catenin was depleted in SW480 cells, a human cancer cell line that constitutionally accumulates beta-catenin. The results support the view that NBL4 is an important component of the beta-catenin / Tcf pathway and is probably related to determination of cell polarity or proliferation.

Facilitation and inhibition by endothelin-1 of adrenal catecholamine secretion in anesthetized dogs

We examined the participation of endothelin ET(A) and ET(B) receptors in modulation by endothelin-1 of adrenal catecholamine secretion during cholinergic activation in pentobarbital-anesthetized dogs. Drugs were infused intra-arterially into the adrenal gland. Splanchnic nerve stimulation (1 and 3 Hz) increased adrenal catecholamine output in a frequency-dependent manner. Endothelin-1 (0.2, 0.6, and 2 ng/kg/min) enhanced the catecholamine response induced by the 3-Hz nerve stimulation. Under pretreatment with an endothelin ET(A) receptor antagonist (R)-2-[(R)-2-[(S)-2-[[1-(hexahydro-1H-azepinyl)]carbonyl]amino-4-m eth ylpentanoyl]amino-3-(2-pyridyl) propionic acid (FR139317) (1 microg/kg/min), endothelin-1 suppressed the 1- and 3- Hz nerve stimulation-induced catecholamine response in a dose-dependent manner. No inhibitory or facilitatory effect of endothelin-1 was observed under simultaneous pretreatment with FR139317 and an endothelin ET(B) receptor antagonist N-cis 2, 6-dimethylpiperidinocarbonyl-L-gamma-methylleucyl-D-1-met hox ycarbonyl tryptophanyl-D-norleucine (BQ-788) (1 microg/kg/min) or under pretreatment with BQ-788 alone. These results suggest that in the dog adrenal gland, endothelin-1 facilitates and inhibits adrenal catecholamine secretion during cholinergic activation by stimulating endothelin ET(A) and ET(B) receptors, respectively.

Causes of maternal mortality in Japan

CONTEXT

Japan's maternal mortality rate is higher than that of other developed countries.

OBJECTIVES

To identify causes of maternal mortality in Japan, examine attributes of treating facilities associated with maternal mortality, and assess the preventability of such deaths.

DESIGN AND SETTING

Cross-sectional study of maternal deaths occurring in Japan between January 1, 1991, and December 31, 1992.

SUBJECTS

Of 230 women who died while pregnant or within 42 days of being pregnant, 197 died in a hospital and had medical records available, 22 died outside of a medical facility, and 11 did not have records available.

MAIN OUTCOME MEASURES

Maternal mortality rates per 100,000 live births by cause (identified by death certificate review and information from treating physicians or coroners); resources and staffing patterns of facilities where deaths occurred; and preventability of death, as determined by a 42-member panel of medical specialists.

RESULTS

Overall maternal mortality was 9.5 per 100,000 births. Hemorrhage was the most common cause of death, occurring in 86 (39%) of 219 women. Seventy-two (37%) of 197 deaths occurring in facilities were deemed preventable and another 32 (16%) possibly preventable. Among deaths that occurred in a medical facility with an obstetrician on duty, the highest rate of preventable deaths (4.09/100,000 live births) occurred in facilities with 1 obstetrician. Among the 72 preventable deaths, 49 were attributed to 1 physician functioning as the obstetrician and anesthetist. While the unpreventable maternal death rate was highest in referral facilities, the preventable maternal death rate was 14 times lower in referral facilities than in transferring facilities.

CONCLUSIONS

Inadequate obstetric services are associated with maternal mortality in Japan. Reducing single-obstetrician only delivery patterns and establishing regional 24-hour inpatient obstetrics facilities for high-risk cases may reduce maternal mortality in Japan. JAMA. 2000;283:2661-2667.

Factors regulating amylase secretion from chicken pancreatic acini in vitro

In mammals, cholecystokinin regulates pancreatic exocrine secretion under physiological conditions. We have shown, however, that cholecystokinin at physiological concentrations does not induce pancreatic amylase secretion in birds. Therefore, we investigated the effects of various neurotransmitters and gut hormones on the pancreatic amylase secretory response in isolated chicken pancreatic acini. Acetylcholine (half-maximal stimulation at 800 nM) and vasoactive intestinal polypeptide (half-maximal stimulation at 40 pM) produced a concentration-dependent increase in amylase secretion at physiological concentrations. The combination of acetylcholine and vasoactive intestinal polypeptide produced an additive response in amylase secretion. Sodium nitroprusside, a spontaneous nitric oxide releaser, and bombesin, induced amylase secretion at concentrations greater than 10 nM and 100 nM, respectively. Gastrin and secretin increased amylase secretion at pharmacological concentrations (10 to 100 nM). Our findings suggest that neural regulation is important for pancreatic enzyme secretion in birds and the contribution of gut hormones seems to be physiologically unimportant.

Cleavage of hepatitis C virus nonstructural protein 5A by a caspase-like protease(s) in mammalian cells

Nonstructural 5A protein (NS5A) of hepatitis C virus (HCV) is localized in the cytoplasm although it has a functional nuclear localization signal. To clarify the determinant of NS5A cytoplasmic localization, various N- or C-terminal deleted NS5A mutants were generated and their subcellular localization was analyzed in cell lines after transient expression. N-terminal deleted forms of NS5A were localized in the nucleus, and the sequence of the N-terminal 27 amino acids of NS5A had sufficient function to cause retention of a normally nuclear protein in the cytoplasm. These observations indicated that cytoplasmic localization of NS5A is determined primarily by the N-terminal region of the molecule. In addition, we found proteolytic processing of NS5A in transiently expressing cells. In these cells, cleavage occurred at a few sites located in the N- and C-terminal regions of NS5A. This cleavage in cells was enhanced by apoptotic stimuli and was inhibited by the caspase inhibitor Z-VAD-FMK, suggesting that a caspase-like protease(s) contributes to the cleavages of NS5A. Based on the results of mutational analysis of NS5A, we predicted one cleaved form, which had lost both the N- and the C-terminal portions of NS5A, to be composed of amino acid residues 155 to 389. Peptide containing the same amino acid sequence as this cleaved product was localized in the nucleus. Furthermore, we found that a fusion protein consisting of Gal4 DNA-binding domain fused with this cleaved form showed transcriptional activity only when the alpha-catalytic subunit of protein kinase A (PKA) was coproduced, suggesting that the transcriptional activity of this product was regulated by PKA. These results suggested that the cleavage product of NS5A by a caspase-like protease(s) plays a role in transcriptional regulation of the host cell gene(s) in HCV-infected cells.

[Therapeutic bronchoscopy for stenotic lesions of central airway]

We retrospectively studied 26 patients with stenotic lesions of the central airway who had undergone bronchoscopic treatment. Thirteen of the patients had malignant tumors, and 13 had benign lesions (1 with post-tracheostomy difficulty in tube retrieval, 2 with bronchial obstruction due to granulation after bronchoplasty, 1 with bronchial stenosis due to granulation after pulmonary lobectomy, 7 with endobronchial foreign bodies, and 2 with hemoptysis). The patients ranged from 5 to 88 years of age with an average of 59.7 years. As a rule, bronchoscopic treatment was performed with endotracheal intubation up to 1993, and with laryngeal mask placement in 1994 and thereafter. Of the 26 eligible patients, 24 (92%) experienced good or excellent outcomes. Emergency bronchoscopy may be useful in treating a variety of emergency airway conditions. Use of a laryngeal mask may benefit emergency patients, including infants and children requiring a secure airway without complications.