Molecular and morphological analyses revealed a cryptic species of dojo loach Misgurnus anguillicaudatus (Cypriniformes: Cobitidae) in Japan.

Although it has been reported that populations of the Japanese dojo loach Misgurnus anguillicaudatus (Cypriniformes: Cobitidae) belong to two distinct mitochondrial (mt)DNA (Type I and Type II), the taxonomic status of the species remains unresolved. To address this question, nuclear DNA and morphological analyses were performed on M. anguillicaudatus population in the Nakaikemi Wetland, where Type I and Type II lineages are sympatric. Results suggest the existence of a cryptic species (Type I) within the Japanese dojo loach.

Multimode dynamics and emergence of a characteristic length scale in a one-dimensional quantum system.

We study the nonequilibrium dynamics of a coherently split one-dimensional Bose gas by measuring the full probability distribution functions of matter-wave interference. Observing the system on different length scales allows us to probe the dynamics of excitations on different energy scales, revealing two distinct length-scale-dependent regimes of relaxation. We measure the crossover length scale separating these two regimes and identify it with the prethermalized phase-correlation length of the system. Our approach enables a direct observation of the multimode dynamics characterizing one-dimensional quantum systems.

A prospective randomized study on the benefits of a new small-caliber colonoscope.

BACKGROUND AND STUDY AIMS: We compared the performance efficiency of a newly developed small-caliber colonoscope (PCF-PQ260 L) with passive bending, high force transmission, and an outer diameter of 9.2 mm with that of a standard colonoscope, in female and male patients, particularly with regard to passage through acute angulations or into the proximal colon. PATIENTS AND METHODS: A total of 330 patients were randomly allocated to undergo small-caliber (n = 164) or standard (n = 166) colonoscopy. The patients were assessed for pain using a visual analogue scale (0 = none, 100 = extremely painful), and for cecal intubation, withdrawal time, difficulty of colonoscopy, dosage and level of sedation used, and any complications. RESULTS: Median maximum pain and overall pain during colonoscopy were significantly lower in the small-caliber group than in the standard group in women (25 vs. 45, P < 0.001 and 15 vs. 26, P = 0.001, respectively), whereas no significant differences were seen in men (8 vs. 10, P = 0.103 and 16 vs. 20, P = 0.166, respectively). Furthermore, no significant differences were seen between groups in cecal intubation rate or time to cecum in all patients or by sex. CONCLUSIONS: Use of the small-caliber colonoscope reduced pain in female patients, but offered no advantage over standard colonoscopy in male patients. The performance of the small-caliber colonoscope was equivalent to that of the standard colonoscope in terms of cecal intubation rate and time to cecum, regardless of the sex of the patient.

Direct observation of cooling of heme upon photodissociation of carbonmonoxy myoglobin.

The formation of vibrationally excited heme upon photodissociation of carbonmonoxy myoglobin and its subsequent vibrational energy relaxation was monitored by picosecond anti-Stokes resonance Raman spectroscopy. The anti-Stokes intensity of the nu4 band showed immediate generation of vibrationally excited hemes and biphasic decay of the excited populations. The best fit to double exponentials gave time constants of 1.9 +/- 0.6 and 16 +/- 9 picoseconds for vibrational population decay and 3.0 +/- 1.0 and 25 +/- 14 picoseconds for temperature relaxation of the photolyzed heme when a Boltzmann distribution was assumed. The decay of the nu4 anti-Stokes intensity was accompanied by narrowing and frequency upshift of the Stokes counterpart. This direct monitoring of the cooling dynamics of the heme cofactor within the globin matrix allows the characterization of the vibrational energy flow through the protein moiety and to the water bath.

The effects of seasonal and interannual variability of oceanic structure in the western Pacific North Equatorial Current on larval transport of the Japanese eel Anguilla japonica.

As the North Equatorial Current (NEC)-bifurcation is known to be related to El Niño-Southern Oscillation (ENSO) events, the influence of the position of the NEC bifurcation on transport success of the larval Japanese eel Anguilla japonica was investigated. Using a Lagrangian modelling approach, larval transport was simulated and the relative influence of El Niño and La Niña events and the NEC-bifurcation position on the success of particle transport analysed. The number of particles transported from the NEC to the Kuroshio tended to be lowest during El Niño years, and differences between La Niña and regular years were small. The transport success observed in simulations showed some relationships to annual A. japonica glass eel recruitment to Tanegashima Island over 1993 to 2001, but not in 2002. The study shows that particle tracking simulations can be used to improve knowledge of the oceanic migration of A. japonica but further studies are required, including comparisons with the effects on larval survival of fluctuations in temperature and food availability.

[Surgical repair of type A aortic dissection with severe atherosclerosis; report of a case].

We report a case of type A aortic dissection with severe atherosclerosis. An 81-year-old man with acute type A aortic dissection was referred to our hospital. Computed tomography revealed DeBakey type II dissection with severe atherosclerosis. Ascending aortic replacement was performed urgently, and an autologous pericardium strip was placed in the lumen to prevent atheroembolization and to reinforce the friable atherosclerotic intima This technique was useful for avoiding cerebral vascular accidents. The patient was discharged on the 24th operative day with no complications.

Impact of long-term enteral nutrition on clinical and endoscopic recurrence after resection for Crohn's disease: A prospective, non-randomized, parallel, controlled study.

BACKGROUND: The impact of enteral nutrition on post-operative recurrence has not been properly examined. AIM: To investigate the impact of enteral nutrition using an elemental diet on clinical and endoscopic recurrence after resection for Crohn's disease. METHODS: Forty consecutive patients who underwent resection for ileal or ileocolonic Crohn's disease were studied. After operation, 20 patients continuously received enteral nutritional therapy (EN group), and 20 had neither nutritional therapy nor food restriction (non-EN group). In the EN group, enteral formula (Elental) was infused through a nasogastric tube in the night-time, and low fat foods were taken in the daytime. All patients were followed up regularly for 1 year after operation. Ileocolonoscopy was performed at 6 and 12 months after operation. RESULTS: One patient (5%) in the EN group and seven (35%) in the non-EN group developed clinical recurrence during 1-year follow-up (P = 0.048). Six months after operation, five patients (25%) in the EN group and eight (40%) in the non-EN group developed endoscopic recurrence (P = 0.50). Twelve months after operation, endoscopic recurrence was observed in six patients (30%) in the EN group and 14 (70%) in the non-EN group (P = 0.027). CONCLUSIONS: Our long-term enteral nutritional therapy significantly reduced clinical and endoscopic recurrence after resection for Crohn's disease.

Long-term follow-up study of patients with phenylketonuria detected by the newborn screening programme in Japan.

The objective of this report is to determine the need for and value of the long-term follow-up study of phenylketonuria (PKU) patients detected by newborn screening (NBS) in Japan. NBS was started in 1977 and the nationwide follow-up study of the identified patients was introduced into the NBS system. Outcome data from the continuous follow-up study showed in 1993 that IQ of PKU patients was inversely correlated with blood phenylalanine levels. Accordingly, in 1995, new treatment guidelines were issued that involved more stringent restriction of phenylalanine levels. Follow-up data confirmed that mean blood phenylalanine levels decreased after the introduction of the new guidelines, which included the recommendation to start dietary treatment within 20 days postpartum. Follow-up data also confirmed that dietary treatment did in fact commence earlier after the guidelines were issued. The need for lifelong dietary treatment is a difficult issue and the number of patients who stop dietary treatment was found to increase gradually with age. At present 60% of PKU patients born between 1977 and 1981 have stopped their dietary restriction of phenylalanine. The data gained from NBS and the long-term follow-up study were found to be valuable for the improvement of blood phenylalanine levels for patients with PKU, indicating the need for parties responsible for NBS and the follow-up study of the identified patients to work cooperatively. Further, the evaluations of the effectiveness of the two initiatives as well as the treatment guidelines issued should be based on outcome data, which depend on the continuation of the follow-up study of patients with PKU.

[Colopleural fistula caused by recurrence of gastric cancer; report of a case].

Perforation of colon into the pleural space without diaphragmatic hernia is extremely rare. This report illustrates a case of pneumo-pyothorax caused by perforation of metastatic tumor of the transverse colon of a 67-year-old woman with a history of total gastrectomy and splenectomy for advanced gastric carcinoma 4 years before. The patient was admitted to our hospital presenting with fever and dyspnea, which subsided after a thoracic drainage. Cultures of drained effusion revealed Escherichia coli, Klebsiella and Bacteroides. An emergent laparotomy for treatment of mechanical ileus 2 weeks after her admission disclosed a tumor obstructing the splenic flexure of the transverse colon, and a double-barreled colostomy was made. Pathologic examination of the tumors obtained from colon, mesocolon and the parietal peritoneum revealed poorly differentiated adenocarcinoma that was the same as her primary gastric cancer.

DNA repair synthesis in rat retinal ganglion cells treated with chemical carcinogens or ultraviolet light in vitro, with special reference to aging and repair level.

A system in which the retinal tissues of noninbred Wistar rats were used in combination with autoradiography was developed for measurement of DNA repair synthesis in ganglion cells of the central nervous system. Retinal tissues in short-term organ culture were treated with various carcinogens plus tritiated thymidine ([methyl-3H]dThd) or were irradiated with UV light and then treated with [methyl-3H]dThd. Preliminary study with retinal tissues from rats at various ages revealed no age-associated changes in the levels of unscheduled DNA synthesis in ganglion cells.

Sequential phenotypic changes in hyperplastic areas during hepatocarcinogenesis in the rat.

Sequential phenotypic changes in hyperplastic areas of rat liver during N-2-fluorenylacetamide feeding were studied by enzyme and immunohistochemical methods combined with radioautography. Hyperplastic area showed a marked deficiency of beta-glucuronidase and serine dehydratase during their developing phase, the 6th through the 9th experimental weeks, and were fairly specifically labeled by injections of tritiated thymidine after partial hepatectomy performed at the 9th week. A sequential observation on these labeled hyperplastic areas revealed a considerable elevation of the levels of these marker enzymes in the majority of the labeled areas in 3 to 18 weeks after labeling. On the other hand, there was a small group of hyperplastic areas in which the enzyme deficiency persisted during the observation period. This type of lesion was generally larger than those showing enzymic maturation. Labeled cells were not detectable either in distinct hyperplastic nodules at late phase or in carcinomas. The metabolic regulation in the cells comprising hyperplastic areas was studied by checking the induction and repression of serine dehydratase after dietary stimuli. Serine dehydratase was not inducible in hyperplastic areas during the developing phase or in areas with persistent enzyme deficiency, but it was clearly induced and repressed in areas where there was an elevation of the endogenous enzyme level. The areas of hyperplasia with persistent enzyme deficiency and growth appeared to be more important than the ones of phenotypic maturation in relation to the later development of carcinoma. The phenotypic maturation in hyperplastic areas might represent reversion of altered cells towards normalcy from the condition related with neoplastic transformation.

Correlation between time of partial hepatectomy after a single treatment with diethylnitrosamine and induction of adenosinetriphosphatase-deficient islands in rat liver.

Full-grown Sprague-Dawley rats were given a single i.p. injection of diethylnitrosamine (80 mg/kg) and subjected to partial hepatectomy at various times from 4 hr to 7 days later to induce semisynchronized liver cell proliferation. Then, they were maintained on basal diet containing 0.05% phenobarbital, which is known to promote hepatocarcinogenesis, for 16 weeks. By this method, significant numbers of adenosinetriphosphatase-deficient islands were induced in the liver. These islands are considered to be formed by immediate progeny of "initiated cells" or cell precursors in hepatocarcinogenesis, and they can be used as a marker of carcinogenic activity. Results showed that the number of enzyme-altered islands induced was inversely proportional to the time between carcinogen treatment and subsequent partial hepatectomy. The incidence of enzyme-altered islands was greatest when the two treatments were separated by 4 hr and decreased when they were separated by 7 days. These data suggest that carcinogen-induced DNA damage, if not repaired before cell proliferation, is intimately related to the initiation-fixation process of carcinogenesis.

The regulation of serine dehydratase and glucose-6-phosphatase in hyperplastic nodules of rat liver during diethylnitrosamine and N-2-fluorenylacetamide feeding.

Changes in the levels of serine dehydratase and glucose-6-phosphatase induced by dietary stimuli or starvation in hyperplastic nodules of rat liver during diethylnitrosamine or N-2-fluorenylacetamide feeding were studied by immuno- and enzyme histochemical methods. The study was performed during carcinogenesis through a combined method of enzyme histochemistry and radioautography. Serine dehydratase was observed diffusely in the cytoplasm of the original hepatocytes in the periportal zone and was induced markedly during diethynitrosamine feeding but only slightly during N-2-fluorenylacetamide feeding. The enzyme was deficient and not inducible in hyperplastic nodules during their developing phase. Later during the feeding period, however, there was an elevation of the level of serine dehydratase and its inducibility with time in the majority of the nodules. A good correlation was observed between serine dehydratase and glucose-6-phosphatase in their elevated levels and response to enviornmental stimuli. There was a minor group of hyperplastic nodules in which the deficiencies of these enzymes persisted and enzyme induction was not observed. A greater number of hyperplastic nodules with persistent enzyme deficiency was seen during diethylnitrosamine carcinogenesis. These results provide further information about the changing biological nature of hyperplastic nodules with respect to their metabolic adaptability and enzyme levels during hepatocarcinogenesis.

Enzyme immunoassay for pepleomycin, a new bleomycin analog.

An antibody directed toward pepleomycin, a new antitumor antibiotic related structurally to bleomycin, has been produced in rabbits by immunization with a pepleomycin-protein conjugate which was prepared by a novel procedure of coupling pepleomycin to mercaptosuccinylated bovine serum albumin using N-(gamma-maleimidobutyryloxy)succinimide as a coupling agent. The antiserum was monospecific to pepleomycin and showed almost no cross-reactivity with a variety of other bleomycin analogs. An enzyme immunoassay for pepleomycin has been developed utilizing this antiserum and beta-D-galactosidase-labeled pepleomycin. The lower limit of detection by this assay, which involves a double antibody technique for the separation of antibody-bound and free antigen, was 50 pg of pepleomycin per tube. Using this assay, drug levels were easily determined in blood and urine of rabbits following administration of pepleomycin in a single dose of 1.2 mg/kg i.v. This assay is also suitable for measuring pepleomycin in the presence of other drugs since the assay is not significantly affected by any other antineoplastic agents tested. Since pepleomycin is now undergoing clinical trial, the enzyme immunoassay of the drug will be a valuable tool in clinical pharmacological studies.

Development of enzyme immunoassay for chromomycin A3 and olivomycin using beta-D-galactosidase as a label.

An antibody specific for chromomycin A3 (CHM; byname, toyomycin) was produced in sufficiently high titer in rabbits by immunization with a CHM-bovine serum albumin conjugate, prepared using diazotized p-aminobenzoic acid as a coupling agent. CHM was also coupled with beta-D-galactosidase (EC 3.2.1.23) using diazotized m-aminobenzoic acid and was used as a tracer. With these reagents, a double-antibody enzyme immunoassay for CHM and for the CHM homologue olivomycin was developed which was highly sensitive and accurate enough to measure as little as 10 and 50 pg of each drug per assay tube, respectively. The enzyme immunoassay did not cross-react with mithramycin and drugs commonly used with CHM in combination chemotherapy for cancer treatment. Using this assay, drug levels were easily determined in blood and urine of rats following administration of CHM in a single dose of 2.0 mg/kg i.v. The sensitivity and specificity of the enzyme immunoassay for CHM and olivomycin should provide a valuable new tool for use in pharmacokinetic and toxicity studies of these drugs.

Induction by X-irradiation of adenosine triphosphatase-deficient islands in the rat liver and their characterization.

The potential of X-rays to induce preneoplastic lesions in the rat liver was studied in order to clarify the reason why X-rays are ineffective in inducing hepatocellular carcinoma in this animal. Male newborn rats at 8 or 22 days of age received whole body X-ray irradiation of 100 to 400 rads. After weaning they were fed either basal diet or a diet containing 0.05% phenobarbital as a promoter. X-rays induced numerous adenosine triphosphatase-deficient islands appearing in the liver by wk 22 of age. However, they were generally small, gamma-glutamyl transpeptidase-negative, and did not clearly respond to the promoting stimulus of phenobarbital. No hepatic tumors were observed by 22 mo after radiation, even in phenobarbital-treated animals. Thus the X-ray-induced enzyme-altered islands differ somewhat qualitatively from those induced by potent hepatic carcinogens and their preneoplastic potential if at all present may be very low. Similarities between these X-ray-induced lesions and some types of spontaneous enzyme-altered islands are pointed out.

Establishment and characterization of a chicken hepatocellular carcinoma cell line, LMH.

A hepatocellular carcinoma cell line, LMH, has been established from a hepatocellular carcinoma induced in a male leghorn chicken by diethylnitrosamine. The cell line is characterized by well-differentiated morphological and biochemical features including the expression of glucose-6-phosphatase and canalicular ATPase activities and triploid karyotype with six marker chromosomes. The cells have been continuously propagated in culture for 5 yr and are now at about the 120th passage. Morphological change occurred in culture associated with gradual increase in growth rate at about the 40th passage. However, the biochemical and chromosomal features remained constant. This is the first established domestic fowl epithelial cell line and will allow comparative investigation of a number of parameters relevant to chicken hepatocarcinogenesis.

Enzyme immunoassay for the quantification of mithramycin using beta-D-galactosidase as a label.

A sensitive enzyme immunoassay for mithramycin (MTM) has been developed by using antibody induced in rabbits, beta-D-galactosidase-labeled MTM, and a double-antibody separation technique, which allowed us to measure accurately as little as 100 pg of MTM per assay tube. MTM-antibody was produced against MTM-bovine serum albumin conjugate prepared by the use of diazotized p-aminobenzoic acid as a cross-linker. The beta-D-galactosidase-labeled MTM conjugate was similarly prepared by a geometric m-isomer of diazotized aminobenzoic acid. This enzyme immunoassay was specific to MTM and showed a very slight cross-reactivity with MTM analogues, chromomycin A3 (5.6%) and olivomycin (2.4%), but no cross-reactivity with drugs commonly used with MTM in combination chemotherapy for cancer treatment. The values of MTM concentrations detected by this assay were comparable to those detected by the high-pressure liquid chromatography method. However, the enzyme immunoassay method was 100 times more sensitive in detecting MTM in lower concentrations. Using this assay, drug levels were easily determined in the blood and urine of rats during 6 h after i.v. administration of MTM in a single dose of 2.0 mg/kg. Since MTM has long been used against a variety of human cancers, the enzyme immunoassay of the drug will be a valuable new tool in clinical pharmacological studies.

Unscheduled DNA synthesis in cells from N-2-fluorenylacetamide-induced hyperplastic nodules of rat liver maintained in a primary culture system.

The level of unscheduled DNA synthesis in the parenchymal cells from hyperplastic nodules and from the entire liver of rats fed N-2-fluorenylacetamide was studied and compared with that of normal liver cells. Measurements of unscheduled DNA synthesis were carried out by the use of a primary liver cell culture system. Livers were perfused with collagenase, the cells from individual hyperplastic nodules, and/or from the whole liver aspirated and plated onto plastic Petri dishes. Simultaneous histochemical measurements of beta-glucuronidase were carried out in the cultured cells as an aid in distinguishing functional cell types. The cells from hyperplastic nodules obtained from the liver during carcinogen feeding survived much longer than normal liver cells in culture. The level of unscheduled DNA synthesis was determined radioautographically after exposing cells to ultraviolet light and incubating with [3H]thymidine. [3H]Thymidine labeling was variable among individual nodules or animals and fluctuated as a function of the number of days in culture. In general, however, the level of unscheduled DNA synthesis in the cells from hyperplastic nodules was always higher than or similar to that of normal liver cells. Thus, the cells of hyperplastic nodules are not more readily transformed into the malignant state than normal cells as a result of their lowered DNA repair mechanisms.