Dosage time affects alkylating agents induced micronuclei in mouse peripheral blood reticulocytes through the function of erythropoietin.

Previously, we reported that the frequency of micronucleated reticulocytes (MNRETs) in the peripheral blood of male C3H/He mice intraperitoneally administered ethylnitrosourea (ENU) (25 mg/kg body weight) in the dark period (zeitgeber time, ZT15) was higher than in the light period (ZT3). In this study, to clarify the mechanism underlying this phenomenon, we investigated the differences in micronucleus (MN) induction observed between ZT3 and ZT15 using five chemicals, methylnitrosourea (MNU), ethylmethane sulfonate (EMS), mitomycin C, cyclophosphamide and vincristin. MNU and EMS, monofunctional alkylating agents, showed higher frequencies of MNRETs in the ZT15 than the ZT3 treatment similar to ENU. However, no differences were observed for the other chemicals. In the comet assay, more DNA damage was induced by ENU in the ZT15 than the ZT3 treatment. Furthermore, the plasma erythropoietin (EPO) level, a known effector of MN induction with anti-apoptotic activity mediated by Bcl-xL expression, was higher in the dark than in the light period. EPO did not increase the frequency of MNRETs. However, in the ENU treatment group at ZT3 following EPO injection a significant increase of MNRETs was observed similar to the ZT15 treatment. Higher expression of apoptosis-related genes such as Bcl-xL was induced in bone marrow cells from mice treated with ENU at ZT15 compared with ZT3. From these results, it was speculated that the differences in MN induction in the peripheral blood of mice exposed to monofunctional alkylating agents such as ENU depend on apoptotic or anti-apoptotic conditions related to the circadian rhythms of EPO in bone marrow.

Changing clinical and molecular characteristics of hepatitis E virus infection in Mie Prefecture, Japan: Disappearance of indigenous subtype 3e strains.

AIM: To evaluate the clinical and molecular characteristics of hepatitis E virus (HEV) infection in Mie Prefecture, Japan, from 2004 through 2018. METHODS: The clinical information of hepatitis E cases was collected from 21 medical institutions in Mie Prefecture. The nucleotide sequences of infecting HEV strains were determined for cases with available serum samples. The origins or transmission routes were inferred from phylogenetic analyses of the nucleotide sequences. RESULTS: Fifty-three patients were diagnosed with HEV infection. The number of cases increased each year through 2012 and then decreased. Analyses of the clinical characteristics of the cases indicated that even mild cases were detected in the latter 10 years of the study. Nucleotide sequence analyses were undertaken on 38 of the 53 cases. The HEV subtype 3e (HEV-3e) strains identified for 13 cases were closely related to a swine HEV-3e strain that was isolated from the liver of a pig bred in Mie Prefecture. The number of cases infected with the indigenous Mie HEV-3e strains increased until 2012 but have not been reported since 2014. In the latter half of the study, cases involving various HEV strains of different genotypes and subtypes emerged. CONCLUSIONS: The disappearance of indigenous Mie HEV-3e strains appeared to be the primary cause for the decrease in hepatitis E cases in Mie Prefecture. The disappearance might have been associated with improved hygienic conditions on pig farms or the closure of contaminated farms. The results suggest that indigenous HEV strains can be eradicated by appropriate management.

Historical control data on developmental toxicity studies in rodents.

Historical control data on rodent developmental toxicity studies, performed between 1994 and 2010, were obtained from 19 laboratories in Japan, including 10 pharmaceutical and chemical companies and nine contract research organizations. Rats, mice, and hamsters were used for developmental toxicity studies. Data included maternal reproductive findings at terminal cesarean sections and fetal findings including the spontaneous incidences of external, visceral, and skeletal anomalies. No noticeable differences were observed in maternal reproductive data between laboratories. Inter-laboratory variations in the incidences of fetuses with anomalies appeared to be due to differences in the selection of observation parameters, observation criteria, classification of the findings, and terminology of fetal alterations. Historical control data are useful for the appropriate interpretation of experimental results and evaluation of the effects of chemical on reproductive and developmental toxicities.

Phase control and its mechanism of CuInS2 nanoparticles.

CuInS(2) nanoparticles (NPs) usually take chalcopyrite-(CP) structure. Recently, CuInS(2) NPs with pseudo-wurtzite (WZ) structure, which is thermodynamically less favored, have been synthesized. However, the formation mechanism of this metastable-phase has not been understood yet. In this report, the key issue of phase selectivity of CuInS(2) (CIS) NPs has been investigated using various metal sources and ligands. Experimental results suggested that the crystalline structure and morphology of CIS NPs were decided by the stability of indium ligand complex; the active ligand reduces the precipitation rate of In(2)S(3), resulting in pre-generation of Cu(2)S seed NPs. Crystallographic analogy and superionic conductivity of Cu(2)S remind us that the formation of WZ CIS NPs is attributed to the pre-generation of Cu(2)S seed NPs and the following cation exchange reaction. In order to confirm this hypothesis, Cu(2-)(x)S seed NPs with various structures have been annealed in indium-ligand solution. This experiment revealed that the crystalline structure of CIS NP was determined by that of pre-generation Cu(2-)(x)S NPs. Our results provide the important information for the phase control and synthesis of ternary chalcogenide NPs with a novel crystalline structure.

Historical control data on prenatal developmental toxicity studies in rabbits.

Historical control data on rabbit prenatal developmental toxicity studies, performed between 1994-2010, were obtained from 20 laboratories, including 11 pharmaceutical and chemical companies and nine contract laboratories, in Japan. In this paper, data were incorporated from a laboratory if the information was based on 10 studies or more. Japanese White rabbits and New Zealand White rabbits were used for prenatal developmental toxicity studies. The data included maternal reproductive findings at terminal cesarean sections and fetal findings including spontaneous incidences of morphological alterations. No noticeable differences between strains or laboratories were observed in the maternal reproductive and fetal developmental data. The inter-laboratory variations in the incidences of fetal external, visceral, and skeletal alterations seem to be due to differences in the selection of observation parameters, observation criteria, and classification of the findings, and terminology of fetal alterations.

Differences in micronucleus induction in peripheral blood reticulocytes of mice exposed to N-ethyl-N-nitrosourea at light and dark dosing times.

Mammals, including human beings, have a circadian clock system to regulate behavioral and physiological processes. In this study, we investigated the effect of dosing time on micronucleus induction in the bone marrow by evaluating the frequencies of micronucleated peripheral reticulocytes (MNRETs) in mice exposed to N-ethyl-N-nitrosourea (ENU) to assess any difference in genotoxic sensitivity to chemicals between light and dark periods (inactive phase for rodents and active phase for rodents). Male C3H/He mice were treated intraperitoneally with ENU (12.5 or 25 mg/kg body weight) at zeitgeber time (ZT) 3 in the light period or ZT15 in the dark period, and then the time courses of the frequencies of the MNRETs were determined. The frequencies of the MNRETs induced by ENU increased time-dependently and peaked at 48 hr after treatment for ZT3 and ZT15, and were obviously higher in the ZT15 treatment group than the ZT3 treatment group. The MNRETs were measured at 48 hr after treatment with ENU (25 mg/kg body weight) at various dosing times (ZT0, 3, 6, 12, 15 and 18). The frequencies of the MNRETs in mice treated at ZT0, 15 and 18 were significantly higher than those in mice treated at ZT3, 6 and 12. These results suggest that genotoxic sensitivity to chemicals in mouse bone marrow is different between light and dark periods maybe due to different biological responses (detoxification, cell cycle, DNA repair, etc.) related to circadian rhythms.

Low polydispersed copper-sulfide nanocrystals derived from various Cu-alkyl amine complexes.

Copper-sulfides, Cu2-xS nanocrystals (NCs) have been synthesized using the reaction between a Cu-alkyl amine complex and a sulfur/1-dodecanethiol. Here, 1-dodecanthiol plays an important role to reduce the reaction temperature of sulfuration. The Cu/S composition (the Cu-defect density) of Cu2-xS NCs depends on the stability of Cu-alkyl amine complex. XPS analyses reveal that the substance of Cu-defect is attributed to an introducing of Cu+2S2-2 species. There is a good correlation between an intensity of a near IR absorption peak and a Cu-defect density estimated by XPS analyses. These results demonstrate that optical properties of Cu2-xS NCs in a near IR region are tunable.

Posterior retroperitoneoscopic partial adrenalectomy: clinical experience in 47 procedures.

OBJECTIVES: We evaluated posterior retroperitoneoscopic partial adrenalectomy with regard to operative complications, operation time, intraoperative blood loss. PATIENTS AND METHODS: Between January 1997 and April 2002, we performed 47 posterior retroperitoneoscopic partial adrenalectomies. There were 18 males and 29 females with a mean age of 48 years (range 28-82 years). The average adrenal tumor size was 26 mm (range 10-50mm). All procedures required three trocars. RESULTS: There was no mortality and conversion rate to open surgery was 2.1%. Average operative time and average blood loss was 198.0 ml (range 71-420 ml) and 40.8 ml (range 0-1100 ml), respectively. There was a significant correlation of operative time with the number of procedures performed. However, no significant correlation was observed between intraoperative blood loss and the number of procedures. Tumor size did not correlate with intraoperative blood loss and operative time. No significant correlation was found between body mass index and operative time. The operative time in the initial 20 cases was significantly longer than that in the subsequent 26 cases. CONCLUSION: Posterior retroperitoneoscopic partial adrenalectomy is a safe and less invasive method for treatment of adrenal tumors. With improved operative technique, the time required for this procedure has been decreased.

Posterior retroperitoneoscopic partial nephrectomy using microwave tissue coagulator for small renal tumors.

BACKGROUND AND PURPOSE: Laparoscopic partial nephrectomy remains surgically challenging because of the potential for excessive blood loss, infection, and the development of urinary fistulas. In addition, posterior retroperitoneoscopic partial nephrectomy is not popular because of the limited space for surgical manipulation. We evaluated the usefulness of a microwave tissue coagulator in posterior retroperitoneoscopic partial nephrectomy for small posterior renal tumor. PATIENTS AND METHODS: Posterior retroperitoneoscopic partial nephrectomy was performed without renal pedicle clamping using a microwave tissue coagulator in six patients with small posterior renal tumors. RESULTS: The mean operative time was 136 minutes (range 78-180 minutes), and the blood loss was <20 mL. No serious operative complications occurred, and there was no significant deterioration of renal function. CONCLUSION: Posterior retroperitoneoscopic partial nephrectomy using a microwave tissue coagulator can be a safe and less invasive method for the treatment of small posterior renal tumors.

Polyphyletic strains of hepatitis E virus are responsible for sporadic cases of acute hepatitis in Japan.

Among 87 patients who were previously treated for acute hepatitis of unknown etiology between 1992 and 2001 at five hospitals in Japan, 11 (13%) patients were positive for immunoglobulin M-class antibodies to hepatitis E virus (HEV) by enzyme immunoassay and had detectable HEV RNA by reverse transcription-PCR with two independent sets of primers derived from well-conserved genomic areas in open reading frames 1 and 2. Clinical HEV infection was significantly associated with male sex (9 of 11 versus 29 of 76 patients [P < 0.01]) and older age (52 +/- 11 [mean +/- standard deviation] versus 41 +/- 17 years [P < 0.05]), and its prevalence differed by geographic region (6 to 25%), with a higher rate in the northern part of Japan. At admission, the 11 patients with HEV-associated hepatitis had elevated alanine aminotransferase levels of 914 to 4,850 IU/liter, and all but 1 had elevated bilirubin levels of 1.5 to 24.0 mg/dl. The 11 HEV isolates were of genotype III or IV and were segregated into three groups with intergroup nucleotide differences of 9.5 to 22.0%. Phylogenetic analysis revealed that four isolates of genotype III were closely related to a Japanese isolate, while the other four isolates of the same genotype were nearest those from the United States. The remaining three isolates were close to known isolates of genotype IV in China and Taiwan but shared less than 88% identity with them. These results indicate that multiple genotypes of HEV cocirculate in Japan and contribute to the development of sporadic acute hepatitis, with the prevalence differing by age, sex, and geographic region.

5Alpha-reductase type 2 genes in Japanese males do not appear to be associated with cryptorchidism.

OBJECTIVE: To evaluate the occurrence of mutations of 5alpha-reductase type 2 gene in patients with cryptorchidism or idiopathic azoospermia. DESIGN: Controlled clinical study. SETTING: Yamagata University Hospital, Yamagata and Tokyo Electric Power Company Hospital, Tokyo, Japan. PATIENT(S): Patients with isolated cryptorchidism (n = 48) or idiopathic azoospermia (n = 33) and a control group of males with proven fertility (n = 51). INTERVENTION(S): Collection and analysis of blood, leukocytic DNA, semen, and testicular biopsy. MAIN OUTCOME MEASURE(S): Semen analysis, screening of the 5alpha-reductase type 2 gene within exon 1 using direct sequencing and exons 2-5 using single strand conformational polymorphism analysis. RESULT(S): No mutations were detected in isolated cryptorchid men, idiopathic azoospermic men, or controls within the 5 exons of the 5alpha-reductase type 2 gene. CONCLUSION(S): 5Alpha-reductase type 2 gene abnormalities do not constitute a major factor in the development of cryptorchidism or idiopathic azoospermia.