Novel biallelic mutations in the PNPT1 gene encoding a mitochondrial-RNA-import protein PNPase cause delayed myelination.

Recent studies suggest that impaired transcription or mitochondrial translation of small RNAs can cause abnormal myelination. A polynucleotide phosphorylase (PNPase) encoded by PNPT1 facilitates the import of small RNAs into mitochondria. PNPT1 mutations have been reported in patients with neurodevelopmental diseases with mitochondrial dysfunction. We report here 2 siblings with PNPT1 mutations who presented delayed myelination as well as mitochondrial dysfunction. We identified compound heterozygous mutations (c.227G>A; p.Gly76Asp and c.574C>T; p.Arg192*) in PNPT1 by quartet whole-exome sequencing. Analyses of skin fibroblasts from the patient showed that PNPase expression was markedly decreased and that import of the small RNA RNaseP into mitochondria was impaired. Exogenous expression of wild-type PNPT1, but not mutants, rescued ATP production in patient skin fibroblasts, suggesting the pathogenicity of the identified mutations. Our cases expand the phenotypic spectrum of PNPT1 mutations that can cause delayed myelination.

Identification of bovine leukocyte antigen class II haplotypes associated with variations in bovine leukemia virus proviral load in Japanese Black cattle.

Bovine leukemia virus (BLV) is the etiological agent of enzootic bovine leukosis, which is the most common neoplastic disease of cattle. Bovine leukocyte antigen (BoLA) is strongly involved in the subclinical progression of BLV infections. Recent studies show that the BoLA-DRB3 gene might play a direct role in controlling the number of BLV-infected peripheral B lymphocytes in vivo in Holstein cattle. However, the specific BoLA class II allele and DRB3-DQA1 haplotypes determining the BLV proviral load in Japanese Black cattle are yet to be identified. In this study, we focused on the association of BLV proviral load and polymorphism of BoLA class II in Japanese Black cattle. We genotyped 186 BLV-infected, clinically normal cattle for BoLA-DRB3 and BoLA-DQA1 using a polymerase chain reaction-sequence-based typing method. BoLA-DRB3*0902 and BoLA-DRB3*1101 were associated with a low proviral load (LPVL), and BoLA-DRB3*1601 was associated with a high proviral load (HPVL). Furthermore, BoLA-DQA1*0204 and BoLA-DQA1*10012 were related to LPVL and HPVL, respectively. Furthermore, we confirmed the correlation between the DRB3-DQA1 haplotype and BLV proviral load. Two haplotypes, namely 0902B or C (DRB3*0902-DQA1*0204) and 1101A (DRB3*1101-DQA1*10011), were associated with a low BLV proviral load, whereas one haplotype 1601B (DRB3*1601-DQA1*10012) was associated with a high BLV proviral load. We conclude that resistance is a dominant trait and susceptibility is a recessive trait. Additionally, resistant alleles were common between Japanese Black and Holstein cattle, and susceptible alleles differed. This is the first report to identify an association between the DRB3-DQA1 haplotype and variations in BLV proviral load.

Identification of an FBN1 mutation in bovine Marfan syndrome-like disease.

Mutations in the gene encoding fibrillin-1 (FBN1), a component of the extracellular microfibril, cause Marfan syndrome (MFS). Frequent observation of cattle with a normal withers height, but lower body weight than age-matched normal cattle, was recently reported among cattle sired by phenotypically normal Bull A, in Japanese Black cattle. These cattle also showed other characteristic features similar to the clinical phenotype of human MFS, such as a long phalanx proximalis, oval face and crystalline lens cloudiness. We first screened a paternal half-sib family comprising 36 affected and 10 normal offspring of Bull A using the BovineSNP50 BeadChip (illumina). Twenty-two microsatellite markers mapped to a significant region on BTA10 were subsequently genotyped on the family. The bovine Marfan syndrome-like disease (MFSL) was mapped onto BTA10. As FBN1 is located in the significant region, FBN1 was sequenced in Bull A, and three affected and one normal cattle. A G>A mutation at the intron64 splicing accepter site (c.8227-1G>A) was detected in 31 of 36 affected animals (84.7%). The c.8227-1G>A polymorphism was not found in 20 normal offspring of Bull A or in 93 normal cattle unrelated to Bull A. The mutation caused a 1-base shift of the intron64 splicing accepter site to the 3' direction, and a 1-base deletion in processed mRNA. This 1-base deletion creates a premature termination codon, and a 125-amino acid shorter Fibrillin-1 protein is produced from the mutant mRNA. We therefore conclude that the c.8227-1G>A mutation is causative for MFSL. Furthermore, it was suggested that Bull A exhibited germline mosaicism for the mutation, and that the frequency of the mutant sperm was 14.9%.

Outcomes of endoscopic and surgical resection for a second primary cancer in the residual cervical esophagus after thoracic esophagectomy.

Patients who have received subtotal esophagectomy for thoracic esophageal cancer must be closely monitored for second primary malignancies. The purpose of this study is to review and assess patients who developed a second primary esophageal cancer in the residual cervical esophagus. Between 1996 and 2010, 10 patients were diagnosed in our hospital with esophageal squamous cell cancer in the residual cervical esophagus after undergoing thoracic esophagectomy and were treated with endoscopic or surgical resection. Data from these patients were reviewed retrospectively. Seven of the 10 patients (70%) had multiple primary carcinoma lesions at the time of their esophagectomy. A second primary cancer in the residual cervical esophagus was detected in eight patients during follow-up endoscopic examinations while the patients were still asymptomatic. Seven of the patients underwent endoscopic resection for a superficial cancer. None of those patients experienced any complications, and all are currently alive and cancer-free. The remaining three patients underwent resection of the cervical esophagus with regional lymph node dissection. Two of those patients experienced severe complications; one subsequently died (hospital death) from pneumonia, 12 months after surgery, while the other died from recurrence of his cancer. The third patient is alive and cancer-free. Early detection of a second primary malignancy in the residual cervical esophagus followed by endoscopic resection is the best treatment strategy for patients who previously received subtotal esophagectomy for thoracic esophageal cancer. Surgical resection puts patients at high risk of mortality or morbidity.

Phrixotrix luciferase and 6'-aminoluciferins reveal a larger luciferin phenolate binding site and provide novel far-red combinations for bioimaging purposes.

How the unique luciferase of Phrixothrix hirtus (PxRE) railroad worm catalyzes the emission of red bioluminescence using the same luciferin of fireflies, remains a mystery. Although PxRE luciferase is a very attractive tool for bioanalysis and bioimaging in hemoglobin rich tissues, it displays lower quantum yield (15%) when compared to green emitting luciferases (>40%). To identify which parts of PxRE luciferin binding site (LBS) determine bioluminescence color, and to develop brighter and more red-shifted emitting luciferases, we compared the effects of site-directed mutagenesis and of larger 6'-substituted aminoluciferin analogues (6'-morpholino- and 6'-pyrrolidinyl-LH) on the bioluminescence properties of PxRE and green-yellow emitting beetle luciferases. The effects of mutations in the benzothiazolyl and thiazolyl parts of PxRE LBS on the KM and catalytic efficiencies, indicated their importance for luciferin binding and catalysis. However, the absence of effects on the bioluminescence spectrum indicated a less interactive LBS in PxRE during light emission. Mutations at the bottom of LBS of PxRE blue-shifted the spectra and increased catalytic efficiency, suggesting that lack of interactions of this part of LBS with excited oxyluciferin phenolate underlie red light emission. The much higher bioluminescence activity and red-shifted spectra of PxRE luciferase with 6'-morpholino- (634 nm) and 6'-pyrrolidinyl-luciferins (644 nm), when compared to other beetle luciferases, revealed a larger luciferin phenolate binding pocket. The size and orientation of the side-chains of L/I/H348 are critical for amino-analogues accommodation and modulate bioluminescence color, affecting the interactions and mobility of excited oxyluciferin phenolate. The PxRE luciferase and 6'-aminoluciferins provide potential far-red combinations for bioimaging applications.

New strategy of therapy for functional dyspepsia using famotidine, mosapride and amitriptyline.

BACKGROUND: In functional gastrointestinal (GI) disorders including functional dyspepsia (FD) and irritable bowel syndrome (IBS), there might be no small extent of contributions of psychosomatic factors. As a therapy for IBS patients, the effectiveness of antidepressants has been reported. AIM: In this study, we evaluated the efficacy of H2-receptor antagonist (famotidine) and 5-HT4 receptor agonist (mosapride citrate). In addition, the effect of antidepressants was assessed as the second-step therapy. METHODS: Patients complaining upper GI symptoms were diagnosed as FD excluding organic diseases. Randomized patients received 20 mg/day of famotidine or 15 mg/day of mosapride citrate for 4 weeks and the efficacy was compared between the two groups based on a 10-point visual analogue scale. When symptoms were not relieved (score improvement 0-2 points), patients received amitriptyline (30 mg/day) or no medication for 4 weeks randomly. Patients who had depression in psychological test (SDS) were omitted. RESULTS: As the first-step therapy, both famotidine and mosapride showed beneficial effects regardless of FD subtypes, age and gender. The efficacy of these two drugs in relieving FD symptoms was not significantly different. In patients who failed in the first-step therapy, amitriptyline showed beneficial effects. CONCLUSIONS: These findings might be clinically important in view of the efficient relief of symptoms in FD patients.

Suppression of the formation of megamitochondria by scavengers for free radicals.

In the present study we have attempted to suppress the formation of megamitochondria by scavengers for free radicals since conditions for the formation of megamitochondria are often intimately related to the generation of free radicals. We employed three different experimental conditions to induce megamitochondria in the liver: ethanol, hydrazine and chloramphenicol (CP). Scavengers for free radicals tested were: alpha-tocopherol, coenzyme Q10(CoQ10) and 4-hydroxy-2,2,6,6-tetramethyl-piperidine-1-oxyl(4-OH-TEMPO). Allopurinol (AP), a xanthine oxidase inhibitor, was also tested. Results obtained were as follows. (1) Changes observed in the liver of animals treated with ethanol, hydrazine or CP were: formation of megamitochondria; decreases in the body weight and the weight of the liver; remarkable increases in the level of lipid peroxidation; increases in the activity of xanthine oxidase. (2) 4-OH-TEMPO was most effective in improving these changes. A mechanism of the formation of megamitochondria is proposed stressing the role of free radicals in the mechanism.

Role of free radicals in the mechanism of the hydrazine-induced formation of megamitochondria.

The effect of 4-hydroxy-2,2,6,6-tetramethyl-piperidine-1-oxyl(4-OH-TEMPO), a scavenger for free radicals, and 4-hydroxypyrazolo [3,4-d(pyrimidine)allopurinol], a xanthine oxidase inhibitor, on the hydrazine-induced changes of mitochondrial ultrastructure and those in the antioxidant system of the liver were investigated using rats as experimental animals. Animals were placed on a powdered diet containing 0.5% hydrazine for 7 d in the presence and absence of a combined treatment with 4-OH-TEMPO or allopurinol. Results obtained were as follows. 4-OH-TEMPO completely prevented the hydrazine-induced formation of megamitochondria in the liver, while it was partly prevented by allopurinol. The following changes observed in hydrazine-treated animals were improved almost completely by 4-OH-TEMPO:decreases in the body weight and liver weight; lowered rates of ADP-stimulated respiration and coupling efficiency of hepatic mitochondria; remarkable elevation of the level of lipid peroxidation. Improving effects of allopurinol were incomplete. The present results suggest that free radicals may play a key role in the mechanism of the hydrazine-induced formation of megamitochondria and that a part of free radicals generated during the hydrazine intoxication is ascribed to the degradation of purine nucleotides via xanthine oxidase. A general mechanism of the megamitochondria formation induced in various pathological conditions besides the case of hydrazine are discussed.

Complete suppresion of ethanol-induced formation of megamitochondria by 4-hydroxy-2,2,6,6-tetramethyl-piperidine-1-oxyl (4-OH-TEMPO).

An attempt has been made to suppress the ethanol-induced formation of megamitochondria (MG) in the rat liver by 4-hydroxy-2,2,6,6-tetramethyl-piperidine-1-oxyl (4-OH-TEMPO), a free radical scavenger, and by allopurinol (AP), a xanthine oxidase inhibitor. Changes observed in the liver of animals given ethanol (EtOH) for 1 month were remarkable decreases both in the body weight gains during the course of the experiment and in the liver weight at the time of sacrifice compared to those of the control; remarkable increases in the level of thiobarbituric acid reactive substances and lipid soluble fluorophores both in microsomes and mitochondria; decreases in the content of cytochrome a+a3 and b and lowered phosphorylating ability of mitochondria; and formation of MG in the liver. A combined treatment of animals with EtOH plus 4-OH-TEMPO completely suppressed the formation of MG in the liver induced by EtOH and distinctly improved the changes caused by EtOH, as specified above, while AP partly suppressed the MG formation. Results described herein provide additional insight into chronic hepatotoxicity of EtOH besides that previously reported. A novelty of the present work is that we were able for the first time to demonstrate reversibility of EtOH-mediated ultrastructural changes of the liver by a simple administration of aminoxyl-type free radical scavenger, 4-OH-TEMPO. Our results suggest that free radicals may be involved in the mechanism of the formation of MG induced by EtOH.

Studies on urea synthesis in the liver of rats treated chronically with ethanol using perfused livers, isolated hepatocytes, and mitochondria.

Changes in urea synthesis in the liver of rats treated with 32% ethanol in the drinking water for up to 6 months were studied using perfused livers, isolated hepatocytes, and mitochondria. Results obtained from ethanol-treated rats are summarized as follows: (1) the mitochondria of the hepatocytes of rats treated with ethanol for 2 months or longer became enlarged to various degrees, (2) the levels of ammonia in the serum remained within a normal range, while those in liver tissue were elevated compared with the control, (3) urea synthesis from ammonia in perfused livers was decreased markedly, while that from citrulline remained in the normal range, (4) the activities of carbamyl phosphate synthetase (CPS; EC 2.7.2.5) and ornithine transcarbamylase (OTC; EC 2.1.3.3) in mitochondria were unchanged compared with those of the control, and (5) the levels of ATP in liver tissue and the ability of mitochondria to synthesize ATP were decreased markedly compared with the control. Both the level of ATP in the hepatocytes and the synthesis of urea from ammonia by perfused livers of rats treated with ethanol were resistant to externally added ethanol, while those of control animals were severely affected. These results suggest that the intracellular level of ATP is intimately related to urea synthesis in both control and ethanol-treated animals, and lowered levels of ATP may be a key factor in the suppression of urea synthesis in ethanol-treated animals.

Mechanism of the formation of megamitochondria in the mouse liver induced by chloramphenicol.

Correlation between chloramphenicol-induced formation of megamitochondria in the mouse liver and oxidative stress was studied by lipid peroxidation analysis and electron microscopic technique. Chloramphenicol suppressed increases in the body weight and liver weight of experimental animals and at the same time induced a remarkable increase in lipid peroxidation in the liver during the formation of megamitochondria. A spin trapping agent, 4-hydroxy-2,2,6,6-tetramethyl-piperidine-1-oxyl, abolished all these changes induced by chloramphenicol. Namely, both the body weight and liver weight of chloramphenicol-treated animals stayed at the same levels as those of the control, and the formation of megamitochondria was completely suppressed. Allopurinol, a xanthine oxidase (EC 1.2.3.2) inhibitor, partly inhibited the changes induced by chloramphenicol, as described above. These results suggest that chloramphenicol-induced formation of megamitochondria is not simply ascribed to the suppression of the dividing process of mitochondria due to lowered protein synthesis in mitochondria but is intimately related to oxidative stress. Furthermore, the results obtained with allopurinol may indicate that enhanced levels of lipid peroxidation observed in chloramphenicol-treated animals are partly due to enhanced rate of the degradation of purine nucleotides catalyzed by xanthine oxidase.

Potentiating effects of organomercuries on clastogen-induced chromosome aberrations in cultured Chinese hamster cells.

Mercury compounds are among the most serious environmental pollutants. In this communication, the potentiating effects of organic and inorganic mercuries on clastogen-induced chromosome aberrations were studied in Chinese hamster CHO K1 cells. Post-treatment with monoalkylated mercuries--methyl mercuric chloride (MeHgCl) and ethyl mercuric chloride (EtHgCl)--increased the number of breakage- and exchange-type aberrations induced by 4-nitroquinoline 1-oxide (4NQO) and methyl methanesulfonate. With the DNA crosslinking agents mitomycin C (MMC) and cisplatin, MeHgCl enhanced both types of aberrations while EtHgCl enhanced breakage-type aberrations only. Since these monoalkylated mercuries did not show clastogenic effects by themselves under the present experimental conditions, the increases in chromosome aberrations were not additive. Dialkylated mercuries (dimethyl mercury and diethyl mercury) and inorganic mercuries (HgCl and HgCl2) did not show any potentiating effects. When MMC- or 4NQO-treated cells were post-treated with MeHgCl during the G1 phase, both breakage- and exchange-type aberrations were enhanced. Treatment with EtHgCl during the G1 phase also enhanced both types of aberrations induced by 4NQO. With MMC, however, G1 treatment with EtHgCl did not show any potentiating effect. MeHgCl and EtHgCl treatments during the G2 phase enhanced breakage-type aberrations only. Based on these results, the following possible mechanisms for potentiation of clastogenicity by monoalkylated mercuries were suggested; (1) they interfere with repair of base lesions induced by 4NQO and MMS during the pre-replicational stage, thereby increasing unrepaired DNA lesions which convert into DNA double-strand breaks in S phase, (2) MeHgCl (but not EtHgCl) also inhibits repair of crosslinking lesions during the pre-replicational stage, and (3) their G2 effects enhance breakage-type aberrations only.

In vivo evaluation of a fluorine-acryl-stylene-urethane-silicone antithrombogenic coating material copolymer for intravascular stents.

RATIONALE AND OBJECTIVES: We evaluated the effectiveness of a fluorine-acryl-styrene-urethane-silicone (FASUS) copolymer as an antithrombogenic coating material for intravascular stents in dogs. METHODS: FASUS copolymer-coated stents were placed in the right iliac veins, and uncoated 304 stainless steel stents were placed in the left iliac veins. We examined platelet deposition, microthrombus formation, and neointimal hyperplasia 4 weeks after stent placement by measuring the activity of 111In-labeled platelets, by using scanning electron microscopy, and by measuring neointimal thickness. RESULTS: Platelet deposition was significantly decreased on coated than on uncoated stents (p < .05). A less pronounced increase in red blood cell deposition was observed at the sites of the coated than uncoated stents (p < .05). Neointimal thickness 4 weeks after stent placement also was significantly less at the sites of the coated stents (0.27 +/- 0.08 mm versus 0.48 +/- 0.23 mm, p < .05). CONCLUSION: FASUS copolymer coating over the vascular stent is effective for preventing thrombus formation and neointimal hyperplasia.

Effect of alcohol on tumor growth of hepatocellular carcinoma with type C cirrhosis.

To investigate the influence of alcohol intake on tumor growth of hepatocellular carcinoma (HCC) in patients with type C cirrhosis, we examined the tumor volume doubling time (TVDT) of 35 nodules from 35 cases of HCC, calculated through ultrasonographic imaging. The patients were divided into two groups according to their drinking habit; 21 habitual drinkers (alcohol group; 80g ethanol/day for 5 years), and 14 patients without alcohol abuse (non alcoholic group). The average value of TVDT in the alcoholic group was 78 +/- 47 days, although that of the non alcoholic group was 142 +/- 60 days. A statistically significant difference (p < 0.01) was found between the two groups. Of the 21 habitual alcohol drinkers, 8 refrained from drinking after detection of HCC; their TVDT was about 30 days shorter than those who continued alcohol intake. In conclusion we found that alcohol intake was closely related to the tumor growth of HCC in patients with type C cirrhosis.

Inhibition of N-butyl-N-(4-hydroxybutyl) nitrosamine-induced urinary bladder tumor in rats by alpha-difluoromethylornithine.

The therapeutic effects of alpha-difluoromethylornithine (DFMO) on rats with bladder tumors induced by N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN) were examined. Eight-week-old male Wistar rats were given 0.05% BBN in their drinking water for a period of 4 weeks. Therapy (0.1% DFMO in their drinking water) was started at week 4 and all rats were killed at week 60. DFMO was seen to significantly reduce the incidence, the mean number and the total size of tumors. No side-effects of DFMO were noted, except alopecia, which started at month 7 of the therapy.

Effects of bovine fatty acid synthase, stearoyl-coenzyme A desaturase, sterol regulatory element-binding protein 1, and growth hormone gene polymorphisms on fatty acid composition and carcass traits in Japanese Black cattle.

The quality of fat is an important factor in defining the quality of meat. Fat quality is determined by the composition of fatty acids. Among lipid metabolism-related genes, including fatty acid synthesis genes, several genetic variations have been reported in the bovine fatty acid synthase (FASN), stearoyl-CoA desaturase (SCD), sterol regulatory element-binding protein 1 (SREBP1), and GH genes. In the present study, we evaluated the single and epistatic effects of 5 genetic variations (4 SNP and 1 insertion/deletion) in 4 genes (FASN, SCD, SREBP1, and GH) on the fatty acid composition of the longissimus thoracis muscle and carcass and meat quality traits in 480 commercial Japanese Black cattle. Significant single effects of FASN, SCD, and GH(L127V) polymorphisms on the fatty acid composition of the longissimus thoracis muscle were detected. The A293V polymorphism of SCD had the largest effect on myristic acid (C14:0, P < 0.001), myristoleic acid (C14:1, P < 0.001), stearic acid (C18:0, P < 0.001), oleic acid (C18:1, P < 0.001), and MUFA (P < 0.001). Polymorphisms in the FASN, SCD, and SREBP1 genes showed no effect on any meat yield trait. There were no significant epistatic effects on fatty acid composition among pairs of the 3 genes (FASN, SCD, and SREBP1) involved in fatty acid synthesis. No epistatic interactions (P > 0.1) were detected between FASN and SCD for any carcass trait. When the genotypes of 3 markers (FASN, SCD, and GH(L127V)) were substituted from the lesser effect allele to the greater effect allele, the proportion of C18:1 increased by 4.46%. More than 20% of the genetic variance in the C18:1 level could be accounted for by these 3 genetic markers. The present results revealed that polymorphisms in 2 fatty acid synthesis genes (FASN and SCD) independently influenced fatty acid composition in the longissimus thoracis muscle. These results suggest that SNP in the FASN and SCD genes are useful markers for the improvement of fatty acid composition in commercial Japanese Black cattle.