Mitochondrial DNA deletion-dependent podocyte injuries in Mito-miceΔ, a murine model of mitochondrial disease

Focal segmental glomerulosclerosis (FSGS) is a major renal complication of human mitochondrial disease. However, its pathogenesis has not been fully explained. In this study, we focused on the glomerular injury of mito-miceΔ and investigated the pathogenesis of their renal involvement. We analyzed biochemical data and histology in mito-miceΔ. The proteinuria began to show in some mito-miceΔ with around 80% of mitochondrial DNA deletion, then proteinuria developed dependent with higher mitochondrial DNA deletion, more than 90% deletion. Mito-miceΔ with proteinuria histologically revealed FSGS. Immunohistochemistry demonstrated extensive distal tubular casts due to abundant glomerular proteinuria. Additionally, the loss of podocyte-related protein and podocyte’s number were found. Therefore, the podocyte injuries and its depletion had a temporal relationship with the development of proteinuria. This study suggested mitochondrial DNA deletion-dependent podocyte injuries as the pathogenesis of renal involvement in mito-miceΔ. The podocytes are the main target of mitochondrial dysfunction originated from the accumulation of mitochondrial DNA abnormality in the kidney.     

Identification of the major antioxidative metabolites in biological fluids of the rat with ingested (+)-catechin and (-)-epicatechin.

(+)-Catechin and (-)-epicatechin are known to be biologically effective antioxidants present in the human diet, particularly in wine and tea. We studied the metabolism of these compounds to elucidate the truly active structures in biological fluids by their oral administration to rats. Without any treatment with beta-glucuronidase and sulfatase, a pair of metabolites were detected at much higher concentrations in the plasma, bile, and urine than the originally ingested compounds. Each major metabolite found in the plasma at the highest concentration was excreted in both the bile and urine, and was purified from urine. Their chemical structures were established to be (+)-catechin 5-O-beta-glucuronide and (-)-epicatechin 5-O-beta-glucuronide by MS and NMR analyses. These glucuronide conjugates exhibited high antioxidative activities as superoxide anion radical scavengers like their parent compounds. It is concluded that (+)-catechin 5-O-beta-glucuronide and (-)-epicatechin 5-O-beta-glucuronide are the biologically active in vivo structures of the ingested polyphenolic antioxidants.     

Opposite sex-specific effects of Wolbachia and interference with the sex determination of its host Ostrinia scapulalis

In the adzuki bean borer, Ostrinia scapulalis, the sex ratio in most progenies is 1 : 1. Females from Wolbachia-infected matrilines, however, give rise to all-female broods when infected and to all-male broods when cured of the infection. These observations had been interpreted as Wolbachia-induced feminization of genetic males into functional females. Here, we show that the interpretation is incorrect. Females from both lines have a female karyotype with a WZ sex-chromosome constitution while males are ZZ. At the time of hatching from eggs, WZ and ZZ individuals are present at a 1 : 1 ratio in broods from uninfected, infected and cured females. In broods from Wolbachia-infected females, ZZ individuals die during larval development, whereas in those from cured females, WZ individuals die. Hence, development of ZZ individuals is impaired by Wolbachia but development of WZ females may require the presence of Wolbachia in infected matrilines. Sexual mosaics generated (i) by transfection of uninfected eggs and (ii) by tetracycline treatment of Wolbachia-infected mothers prior to oviposition were ZZ in all tissues, including typically female organs. We conclude that: (i) Wolbachia acts by manipulating the sex determination of its host; and (ii) although sexual mosaics can survive, development of a normal female is incompatible with a ZZ genotype.     

Ultrastructure of orexin-1 receptor immunoreactivities in the spinal cord dorsal horn

The ultrastructural properties of orexin 1-receptor-like immunoreactive (OX1R-LI) neurons in the dorsal horn of the rat spinal cord were examined using light and electron microscopy techniques. At the light microscopy level, the most heavily immunostained OX1R-LI neurons were found in the ventral horn of the spinal cord, while some immunostained profiles, including nerve fibers and small neurons, were also found in the dorsal horn. At the electron microscopy level, OX1R-LI perikarya were identified containing numerous dense-cored vesicles which were more heavily immunostained than any other organelles. Similar vesicles were also found within the axon terminals of the OX1R-LI neurons. The perikarya and dendrites of some of the OX1R-LI neurons could be seen receiving synapses from immunonegative axon terminals. These synapses were found mostly asymmetric in shape. Occasionally, some OX1R-LI axon terminals were found making synapses on dendrites that were OX1R-LI in some cases and immunonegative in others. The synapses made by OX1R-LI axon terminals were found both asymmetric and symmetric in appearance. The results provide solid morphological evidence that OX1R is transported in the dense-cored vesicles from the perikarya to axon terminals and that OX1R-LI neurons in the dorsal horn of the spinal cord have complex synaptic relationships both with other OX1R-LI neurons as well as other neuron types.     

Clinical isolates of <Emphasis Type="Italic">Nocardia brasiliensis</Emphasis> from Japan exhibit variable susceptibility to the antibiotic imipenem

Clinical isolates of Nocardia brasiliensis from Japan were classified into two groups based on their susceptibility to the carbapenem antibiotic, imipenem (IPM). Of 33 strains tested, 10 belonged to an IPM susceptible group, with MIC of from 0.25 to 2 εg/ml and a MIC₈₀ value of 1.5 εg/ml for this antibiotic. The remaining 23 strains belonged to an IPMresistant group with MIC and MIC₈₀ values of 8–16 εg/ml and >16 εg/ml, respectively. The type strain of N. brasiliensis belonged to this resistant group. Analysis of 16S rDNA genes sequences showed that the IPM susceptible group had characteristic single nucleotide substitutions at positions 103 (T), 381 (A), and 456 (A), in contrast to the IPM resistant group. This grouping, however, was not associated with their clinical manifestation.     

Rapid identification and quantification of Collinsella aerofaciens using PCR

The number and incidence of Collinsella aerofaciens in the human intestine are the highest among Gram-positive non-spore-forming bacilli. Identification of this species is very difficult and requires considerable time. A PCR-based identification system using C. aerofaciens-specific primers is described. Using this PCR method, we identified 181 C. aerofaciens-like species isolated from human feces. These 181 strains were identified using the traditional method in past studies. Results of both methods matched. The direct detection method was performed using human feces samples from seven adults. Nested PCR was applied directly to the samples and all seven samples were positive. Quantification studies were performed using LightCycler?trade mark omitted?. The assay uses a double-stranded DNA dye to continuously monitor product formation and in a short time is able to quantify samples to 5 log units in concentration.     

Electron microscopy examination of galanin-like peptide (GALP)-containing neurons in the rat hypothalamus

Galanin-like peptide (GALP) is a novel peptide which is isolated from the porcine hypothalamus. GALP-containing neurons are present in the arcuate nucleus (ARC), being particularly densely concentrated in medial posterior regions. To observe the ultrastructure and synaptic relationships of GALP-containing neurons in the ARC, light and immunoelectron microscopy techniques were used. At the light microscope level, GALP-containing neurons were observed distributed rostrocaudally throughout the ARC, with the majority present in the posterior, periventricular zones. At the electron microscope level, many immunopositive dense-cored vesicles were evident in the perikarya, dendrites and axon terminals of the GALP-containing neurons. Furthermore, these neurons received synapses from immunonegative axon terminals that were symmetric in the case of synapses made on perikarya, and both asymmetric and symmetric for synapses made on dendrites. Axon terminals of GALP-containing neurons often made synapses on immunonegative dendrites. Such synapses were all symmetric. Synapses were also found between axon terminals and perikarya as well as dendrites of GALP-containing neurons. These findings suggest that the physiological role of the GALP-containing neurons in the ARC is based on complex synaptic relationships between GALP-containing neurons and either GALP-immunopositive or -immunonegative neurons.