Reversal of ischemia-induced mitochondrial dysfunction after coronary reperfusion

This study was designed to clarify the mechanism of the reversal of ischemia-induced mitochondrial dysfunction after a reperfusion of the myocardium in dogs. The occlusion of the left anterior descending coronary artery for 30 min led to the significant increase of acyl-CoA level in ischemic mitochondria and the ischemic mitochondrial function was disturbed. Pre-infusion of 1 ml/kg of lipid before occlusion further increased the acyl-CoA accumulation in ischemic mitochondria, and concomitantly, the mitochondrial dysfunction was extended much more. On the other hand, 40 min of reperfusion following 30 min of occlusion diminished the accumulation of acyl-CoA in the reperfused mitochondria and restored the mitochondrial function. However, when lipid was pre-infused, acyl-CoA level in the reperfused mitochondria was still high and mitochondrial dysfunction was observed. Administration of carnitine prior to reperfusion not only suppressed the accumulation of acyl-CoA in the reperfused mitochondria but also preserved the mitochondrial function, despite the pre-infusion of lipid. There was a clear reciprocal correlation (r = ?0.97) between acyl-CoA level and mitochondrial function. These results suggest that acyl-CoA accumulation is one of the important factors in ischemia-induced mitochondrial dysfunction, and that reversal of the dysfunction after reperfusion is closely dependent upon the lowering of the acyl-CoA accumulation.     

A heterozygous mutation of GALNTL5 affects male infertility with impairment of sperm motility

For normal fertilization in mammals, it is important that functionally mature sperm are motile and have a fully formed acrosome. The glycosyltransferase-like gene, human polypeptide N-acetylgalactosaminyltransferase-like protein 5 (GALNTL5), belongs to the polypeptide N-acetylgalactosamine-transferase (pp-GalNAc-T) gene family because of its conserved glycosyltransferase domains, but it uniquely truncates the C-terminal domain and is expressed exclusively in human testis. However, glycosyltransferase activity of the human GALNTL5 protein has not been identified by in vitro assay thus far. Using mouse Galntl5 ortholog, we have examined whether GALNTL5 is a functional molecule in spermatogenesis. It was observed that mouse GALNTL5 localizes in the cytoplasm of round spermatids in the region around the acrosome of elongating spermatids, and finally in the neck region of spermatozoa. We attempted to establish Galntl5-deficient mutant mice to investigate the role of Galntl5 in spermiogenesis and found that the heterozygous mutation affected male fertility due to immotile sperm, which is diagnosed as asthenozoospermia, an infertility syndrome in humans. Furthermore, the heterozygous mutation of Galntl5 attenuated glycolytic enzymes required for motility, disrupted protein loading into acrosomes, and caused aberrant localization of the ubiquitin–proteasome system. By comparing the protein compositions of sperm from infertile males, we found a deletion mutation of the exon of human GALNTL5 gene in a patient with asthenozoospermia. This strongly suggests that the genetic mutation of human GALNTL5 results in male infertility with the reduction of sperm motility and that GALNTL5 is a functional molecule essential for mammalian sperm formation.O-glycosylation begins by the addition of N-acetylgalactosamine to the serine or threonine residues in the target protein. This first step occurs in the Golgi apparatus, and is mediated by UDP-GalNAc: polypeptide N-acetylgalactosaminyltransferases (pp-GalNAc-T; EC 2.4.1.41), which transfer GalNAc from the nucleotide sugar to the acceptor residues (1). Polypeptide N-acetylgalactosaminyltransferase-like protein 5 [GALNTL5, also described as pp-GalNac-T19 (2) or GalNac-T20 (3); Refseq accession no.: {"type":"entrez-protein","attrs":{"text":"NP_660335.2","term_id":"281485547","term_text":"NP_660335.2"}}NP_660335.2] is classified as a member of the pp-GalNAc-T family because GALNTL5 possesses highly conserved catalytic domains of pp-GalNAc-T, whereas it uniquely lacks the conserved lectin domain at the C terminus. Thus far, 20 distinct pp-GalNAc-T genes have been identified in the human genome (2, 4–6). The in vitro enzymatic activities as a glycosyltransferase have been confirmed for 14 members of this family using acceptor peptide substrates (2, 7), but not identified for the other 6 members, including GALNTL5. During the preparation of this paper, it was reported that the transferase activity of GALNTL5 (GalNAc-T20) could not be detected using in vitro assays (3). The in vivo functions of these isoforms are poorly understood because of the absence of specific enzymatic activity. Meanwhile, O-fucosyltransferase 1, a member of a fucosyltransferase family, exhibits chaperon activity specific to Notch folding in Drosophila (8). One possibility is that the isoforms lacking enzymatic activities may have functions other than characteristics of glycosyltransferases, despite having typical glycosyltransferase motifs.Spermatogenesis is a complex process in which spermatogonial stem cells form spermatozoa through the proliferative phase (spermatogonia), the meiotic phase (spermatocytes), and the differentiation or spermiogenic phase (spermatids). Spermatids are connected by intercellular bridges, through which cytoplasmic constituents are shared among haploid spermatids (9). In the last spermiogenic phase, the round haploid spermatids differentiate into spermatozoa where acrosomes and tails unique and necessary for fertilization are developed. Spermatozoa are released through the seminiferous lumen into the epididymis, where they undergo further maturation and acquire motility. Sperm motility is an important factor in normal fertilization, whereas over 80% of sperm samples from infertile men demonstrate asthenozoospermia, poor sperm motility (10). Although defects of many potential genes are reported in mouse models exhibiting asthenozoospermia (11), it is rare that mutations in these genes are identified in human patients with asthenozoospermia.To investigate the biochemical machineries and biological functions of glycosylation, we performed comprehensive identification of the mammalian glycosyltransferase genes using various approaches and confirmed their enzymatic activity in vitro using biochemical methods (12). During these studies, we identified a unique isoform of the human GALNTL5 gene restricted to the human testis. However, we could not confirm the glycosyltransferase activity of GALNTL5, including whether it is a functional molecule in spermatogenesis. Therefore, using the mouse Galntl5 gene, we attempted to elucidate the biological role of GALNTL5 in spermatogenesis and found that the heterozygous mutation of Galntl5 causes male infertility by reducing sperm motility, which highly resembles human asthenozoospermia. In reference to the aberrant protein compositions of sperm from the Galntl5 heterozygous mutant mice (Ht mice), we found a patient with asthenozoospermia carrying one heterozygous nucleotide deletion at the sixth exon of the human GALNTL5 gene. Together with these data, we speculate that the function of GALNTL5 is indispensable for mature sperm formation and that GALNTL5 might have a unique role in mammalian spermiogenesis.     

Comparison of Expression and Proliferative Effect of Pituitary Adenylate Cyclase-Activating Polypeptide (PACAP) and its Receptors on Human Astrocytoma Cell Lines

Pituitary adenylate cyclase-activating polypeptide (PACAP) is a pleiotropic neuropeptide considered to be a potent regulator of astrocytes. It has been reported that PACAP also affects astrocytoma cell properties, but the proliferative effects of this peptide in previous reports were inconsistent. The purpose of this study was to search for correlations between malignant potential, PACAP/PACAP receptor expression, and the proliferative potential of four astrocytoma cell lines (KNS-81, KINGS-1, SF-126, and YH-13). Immunohistochemical observations were performed using astrocyte lineage markers with a view to establishing malignant potential, which is inversely correlated to differentiation status in astrocytoma cells. YH-13 showed the most undifferentiated astrocyte-like status, and was immunopositive to a cancer stem cell marker, CD44. These observations suggest that YH-13 is the most malignant of the astrocytoma cell lines tested. Moreover, the strongest PAC1-R immunoreactivity was observed in YH-13 cells. Using real-time PCR analysis, no significant differences among cell lines were detected with respect to PACAP mRNA, but PAC1-R and VPAC1-R mRNA levels were significantly increased in YH-13 cells compared with the other cell lines. Furthermore, when cell lines were treated with PACAP (10^?11 M) for 3 days, the YH-13 cell line, but not of the other cell lines, exhibited a significantly increased cell number. These results suggest that PACAP receptor expression is correlated with the malignant and proliferative potential of astrocytoma cell lines.     

A case of intrahepatic splenosis: usefulness of splenic scintigraphy

Abdominal Radiology - We report a 39-year-old male with intrahepatic and peritoneal splenosis, focusing on scintigraphic findings. Dynamic computed tomography (CT) showed a 3 cm lesion in...     

A Simultaneous Analytical Method for Catecholamines, Indoleamines, and Related Compounds in 11 Rat Brain Regions

Abstract: A simple high-performance liquid chromatographic method that allowsthe determination of 10 biogenic amines and related compounds for crude brain extracts has been developed. The compounds that can be quantified comprise norepinephrine, epinephrine, 3,4-dihydroxyphenylacetic acid, 3-methoxy-4-hydroxyphenylglycol, dopamine, 5-hydroxyindole-3-acetic acid, homovanillic acid, 3-methoxytyramine, 5-hydroxytryptamine and tryptophan. The detection system involves a three electrode-coulometric determination followed by fluorometric determination. This method is highly selective and sensitive, and in the present study, the usefulness of this methodology was confirmed by applying it to the determination of the levels of these various substances in 11 rat brain regions.     

Serum Levels of Maprotiline and Its Adverse Effects on Depressed Patients

Abstract: The relationships between the side effects of maprotiline (MPT) andthe serum concentration of MPT and desmethylmaprotiline (DMPT) were investigated with 27 blood samplings in 15 depressed inpatients. There were significant correlations between the side effects and serum levels of MPT and DMPT. Mild side effects frequently occurred at levels of more than 130 ng/ml of MPT and 70 ng/ml of DMPT. At more than 220 ng/ml of the MPT levels and 110 ng/ml of DMPT levels, severe side effects occurred. Nearly sigmoidalserum level/side effect response curves occurred with both compounds.     

Sentinel lymph node biopsy and low axillary node sampling for breast cancer

Since sentinel lymph node(SLN) biopsy has a higher negative predictive value than that of four-node sampling, SLN biopsy might become the new acknowledged standard of clinical care for patients with early breast cancer. SLN biopsy is widely used in Western countries despite the lack of data from randomized trials. Clinical practice guidelines document that SLN biopsy should be performed with prudent informed consent and thorough surgical technique. Before surgeons replace axillary dissection with SLN biopsy as the staging procedure at their institution, they should perform backup axillary dissection until a detection rate of more than 90% and a false-negative rate of less than 5% are achieved. Recently, SLN biopsy has more often been indicated for multicentric breast cancer, larger tumors, prior excisions, and noninvasive carcinoma. While SLN biopsy is widely used in Western countries, there is little experience in Japan. If randomized studies, clinical practice guidelines, and the coverage of lymphoscintigraphy under health insurance were introduced, SLN biopsy would be used more widely in Japan.