Three-dimensional visualization of green fluorescence protein-labelled Edwardsiella tarda in whole Medaka larvae.

The invasive fish pathogen Edwardsiella tarda is common in aquatic environments and causes the environmentally and economically destructive emphysematous putrefactive disease called edwardsiellosis. In order to understand the organism's infection pathway, medaka larvae (Oryzias latipes) were immersion-infected with E. tarda labelled with green fluorescence protein (GFP) and then visualized in three dimensions under confocal laser microscopy and light-sheet fluorescence microscopy. Confocal microscopy revealed GFP-labelled E. tarda in the mouth, head, gill bridges, gill cover, skin, membrane fin, gastrointestinal tract and air bladder, and in the caudal vein, somite veins, caudal artery and caudal capillaries. Light-sheet microscopy additionally showed GFP-labelled E. tarda in the pharyngeal cavity, muscle of the pectoral fin and cardiac atrium and ventricle. These findings suggest that during its infection of fish, E. tarda initially adheres to, and invades, the epithelial cells of the skin, gills and gastrointestinal tract (through the pharyngeal cavity); E. tarda then enters the blood vessels to access organs, including the air bladder and heart.

Phenotypic spectrum of patients with PLA2G6 mutation and PARK14-linked parkinsonism.

BACKGROUND: PLA2G6 is the causative gene for infantile neuroaxonal dystrophy, neurodegeneration associated with brain iron accumulation, and Karak syndrome. Based on previous reports, patients with PLA2G6 mutations could show axonal dystrophy, dystonia, dementia, and cerebellar signs. Recently, PLA2G6 was also reported as the causative gene for early-onset PARK14-linked dystonia-parkinsonism. METHODS: To clarify the role of PLA2G6 mutation in parkinsonism, we conducted mutation analysis in 29 selected patients with very early-onset (≤ 30, mean 21.2 ± 8.4 years, ± SD) parkinsonism. These patients had other clinical features (e.g., mental retardation/dementia [14/29], psychosis [15/29], dystonia [11/29], and hyperreflexia [11/29]). RESULTS: Two novel compound heterozygous PLA2G6 mutations were detected (patient A: p.F72L/p.R635Q; patients B1 and B2: p.Q452X/p.R635Q). All 3 patients had early-onset l-dopa-responsive parkinsonism with dementia and frontotemporal lobar atrophy. Disease progression was relatively rapid. SPECT in patient B1 showed frontotemporal lobar hypoperfusion. MRI in patient A showed iron accumulation in the substantia nigra and striatum. CONCLUSIONS: Although the clinical presentation of PLA2G6-associated neurodegeneration was reported to be homogeneous, our findings suggest patients with PLA2G6 mutation could show heterogeneous phenotype such as dystonia-parkinsonism, dementia, frontotemporal atrophy/hypoperfusion, with or without brain iron accumulation. Based on the clinical heterogeneity, the functional roles of PLA2G6 and the roles of PLA2G6 variants including single heterozygous mutations should be further elucidated in patients with atypical parkinsonism, dementia, or Parkinson disease. PLA2G6 mutations should be considered in patients with early-onset l-dopa-responsive parkinsonism and dementia with frontotemporal lobar atrophy.

A LRRK2 G2019S mutation carrier from Turkey shares the Japanese haplotype.

The leucine-rich repeat kinase 2 (LRRK2) G2019S mutation is recognized as the most common cause of familial autosomal dominant and also sporadic forms of Parkinson disease (PD). A common founder has been described for most Europeans and all North Africans and Jews; besides, two distinct G2019S LRRK2 haplotypes were found in a small proportion of European families and in Japanese PD patients. This study revealed a Turkish patient heterozygous for the G2019S mutation sharing the Japanese haplotype. To the best of our knowledge, it is the first time that the G2019S-associated Japanese haplotype has been reported in a different population.

Link between obstructive sleep apnea and increased bone resorption in men.

UNLABELLED: The bone metabolic abnormalities in patients with obstructive sleep apnea (OSA) were examined. Severity-dependent increases in the serum/urinary levels of bone resorption markers and their attenuation following continuous positive airway pressure therapy in subjects with OSA provide the first evidence of a link between OSA and abnormal bone metabolism. INTRODUCTION: Hypoxia, microinflammation and oxidative stress, well-known pathophysiological features of obstructive sleep apnea (OSA), are also known to affect bone metabolism. We examined the bone metabolic abnormalities in patients with OSA and also the effects of continuous positive airway pressure (CPAP) therapy on these abnormalities. METHODS: A cross-sectional and prospective study was conducted in 50 consecutive male subjects visiting a sleep clinic and 15 age-matched control subjects without OSA. Plasma concentrations of IL-1beta, IL-6, TNF-alfa, 3-nitrotyrosine, osteocalcin, bone-specific alkaline phosphatase (BAP), and urinary concentrations of cross-linked C-terminal telopeptide of type I collagen (CTX) were examined before and after 3 months' CPAP in subjects with OSA. RESULTS: The plasma levels of the cytokines as well as the urinary CTX levels were higher in subjects with severe OSA than in those with mild OSA or control subjects. Significant decrease of the urinary excretion of CTX (before: 211+/-107 vs. after: 128+/-59 microg/mmol/creatinine; p<0.01) as well as of the plasma levels of the cytokines was observed following 3 months' CPAP. CONCLUSIONS: Severity-dependent increases in the serum/urinary levels of bone resorption markers and their reversal following CPAP in subjects with OSA provide the first evidence of a link between OSA and abnormal bone metabolism.

Progress in familial Parkinson's disease.

To date 11 forms of familial Parkinson's disease (PD) have been mapped to different chromosome loci, of which 6 genes have been identified as the causative genes, i.e., alpha-synuclein (SNCA), parkin, UCH-L1, PINK1, DJ-1, and LRRK2. For UCH-L1, additional families with this mutation are necessary before concluding that UCH-L1 is the definite causative gene for PARK5, as only one family so far has been reported. SNCA, UCH-L1, and LRRK2 mutations cause autosomal dominant PD and the remaining gene mutations autosomal recessive PD. Age of onset tends to be younger in familial PD compared with sporadic PD, particularly so in autosomal recessive PD. Generally familial cases respond to levodopa quite nicely and progression of the disease tends to be slower. It is an interesting question how familial PD-causing proteins are mutually related each other. In this article, we review recent progress in genetics and molecular biology of familial PD.

Morphology of the enteric nervous system in the hindgut of an infant with cloacal exstrophy.

The authors describe the morphology of the enteric nervous system in the hindgut of an infant with cloacal exstrophy. Cloacal exstrophy was diagnosed at 32 weeks' gestation using prenatal ultrasonography. The baby was delivered at 34 weeks' gestation and underwent a separation of the cecum from bladder halves, reapproximation of hemibladders, closure of the omphalocele and pubic symphysis, and a distal colostomy. Intestinal wall specimens were obtained at colostomy from the distal end of the rudimentary hindgut. Serial frozen sections were prepared for histochemical acetylcholinesterase staining. Histological investigations demonstrated a strikingly crowded, immature enteric ganglia and prominent bundles of wandering cholinergic nerves. These findings suggest the unique pathology of the enteric nervous system development in cloacal exstrophy, in which the rudimentary hindgut behaves as a blind alley of the migratory pathway for neural crest-derived cells during embryogenesis. Histological examinations of the hindgut enteric nervous system in cloacal exstrophy may be beneficial for evaluating the postnatal development of the distal colon which might be utilized for a pull-through procedure.

Clinicogenetic study of PINK1 mutations in autosomal recessive early-onset parkinsonism.

The authors performed PINK1 mutation analysis of 51 families with autosomal recessive Parkinson disease (ARPD). They found two novel PINK1 mutations: one was a homozygous deletion (13516-18118del) and the other a homozygous missense mutation (C388R). Clinically, the patients with the deletion had dementia. Thus, early-onset PD with dementia may be considered PINK1-linked parkinsonism. Furthermore, patients with PINK1 mutations form 8.9% of parkin- and DJ-1-negative ARPD families.

Characterization of the rat INSL3 receptor.

Human LGR8, initially discovered as a low-affinity relaxin receptor, has now been characterized as the INSL3 receptor. To investigate LGR8 function in the rat, an LGR8 ortholog was identified in the rat genome, and the full-length sequence was cloned and expressed. Rat LGR8 bound INSL3 with high affinity, clearly demonstrating that it is the rat INSL3 receptor. Interestingly, native rat relaxin did not activate rat LGR8, indicating that relaxin is not an endogenous ligand for rat LGR8. LGR8 mRNA expression was demonstrated in the gubernaculum at the time of testis descent and in the testis associated with germ cells.

Synthesis, conformation, receptor binding and biological activities of monobiotinylated human insulin-like peptide 3.

Biotin-avidin immobilization has been routinely used as a tool to study peptide-receptor and peptide-antibody interactions. Biotinylated peptides can also be employed to localize cells that express the peptides' receptor, and to analyse ligand-receptor binding. Insulin-like peptide 3 (INSL3) is a peptide hormone which contains A- and B-chains connected by two disulphide bonds and plays a role in testicular descent during sexual development. In order to study the interaction of INSL3 with its receptor LGR8, a G protein-coupled receptor, we chemically synthesized Nalpha-mono-biotinylated human INSL3 (B-hINSL3) and compared it structurally and biologically with hINSL3. Both peptides exhibited similar, but high, receptor binding affinities on human foetal kidney fibroblast 293T cells transfected human LGR8 based on a competition radioreceptor assay with 33P-labelled relaxin H2 (B33). The modified B-hINSL3 showed full biological activity as determined by the stimulation of gubernacular cell proliferation. The labelled B-hINSL3 contains a higher alpha-helix content, and this increased helical structure is accompanied by an increase in ability to stimulate cAMP accumulation in 293T cells expressing LGR8. Our results suggest that the N-terminal region of the A-chain is not involved in the interaction of INSL3 with its receptor. However, the introduction of biotin onto the N-terminus of the A-chain promoted conformational stability which, in turn, permitted better receptor activation.

Relationship between the type of RET/GDNF/NTN or SOX10 gene mutations and long-term results after surgery for total colonic aganglionosis with small bowel involvement.

BACKGROUND/PURPOSE: Germline mutations of the RET-mediated or SOX10-mediated signaling pathway genes have been reported in total colonic aganglionosis (TCA). The authors investigated the possible relationship between the type of such genomic abnormalities and surgical outcomes. METHODS: Sixteen patients with TCA with extensive small bowel involvement were studied. DNA sequences of all the RET/GDNF/NTN and SOX10 coding regions were determined by the direct DyeDeoxy Terminator Cycle method. Data on the patients' clinical courses were obtained retrospectively from their medical charts and surgical records. RESULTS: RET or SOX10 germline mutations were identified in 11 of the 16 patients (68.8%). In children with aganglionosis up to the jejunum or ileum, most grew up within normal ranges, and the frequency of bowel movements decreased to 2 to 4 times per day within 5 years. However, in 5 infants with total intestinal aganglionosis, only 2 survived beyond 2 years of age, both of whom underwent Ziegler's myectomy-myotomy. A SOX10 mutation was identified in an infant with Shah-Waardenburg's syndrome, and he showed persistent bowel malfunction. CONCLUSION: The existence or type of RET mutation usually did not affect surgical results in this series of TCA patients, whereas the mutational analysis suggested 2 disease categories of TCA showing different postoperative courses, which may reflect the disparate pathogenesis in the enteric nervous system development induced by impaired RET or SOX10 signaling pathway.

Angiotensin-converting enzyme inhibition improves defective angiogenesis in the ischemic limb of spontaneously hypertensive rats.

OBJECTIVES: Natural angiogenesis has been shown to be impaired in spontaneously hypertensive rats (SHR). The purpose of this study was to determine whether pathological angiogenesis in the setting of tissue ischemia is also impaired in SHR, and to what extent it is modified by angiotensin-converting enzyme (ACE) inhibition. METHODS: Ischemia was induced in the hindlimb of SHR by excision of the femoral artery, after which the animals were randomly assigned to receive low-dose perindopril (sub-antihypertensive, 0.2 mg/kg/day), high-dose perindopril (antihypertensive, 2.0 mg/kg/day), or vehicle for 3 weeks. Wistar-Kyoto rats (WKY) with femoral artery excision served as a control group. RESULTS: Tissue ACE activity in SHR was significantly increased compared to WKY (49.4+/-6.2 vs. 34.0+/-14.2 IU/mg, P<0.01). Administration of perindopril significantly reduced ACE activity in SHR (low dose: 12.4+/-2.3; high dose: 11.0+/-2.1 IU/mg, P<0.005). Angiogenesis of the ischemic limb muscles was significantly impaired at 4 weeks in SHR versus WKY as indicated by the lower capillary density in the former (364.5+/-43.0 vs. 463.8+/-63.0/mm(2), P<0.05) as well as the reduced hindlimb perfusion assessed by laser Doppler imaging (0.86+/-0.08 vs. 1.03+/-0.09, P<0.05). Administration of perindopril significantly augmented both the capillary density (low dose: 494.3+/-69.8; high dose: 543.9+/-76.9/mm(2), P<0.005) and the limb perfusion (low dose: 1.06+/-0.15; high dose: 1.05+/-0.12, P<0.05) of the ischemic limb in SHR. CONCLUSIONS: These findings indicate that pathological angiogenesis in the setting of tissue ischemia is impaired in SHR compared with WKY, and that this impairment can be reversed by ACE inhibition. The angiogenic properties of an ACE inhibitor may benefit patients with essential hypertension presenting with lower limb vascular insufficiency.

Identification of hepatitis B virus-specific CTL epitopes presented by HLA-A*2402, the most common HLA class I allele in East Asia.

BACKGROUND/AIMS: The aim of this study was to identify and characterize hepatitis B virus (HBV)-specific cytotoxic T lymphocytes (CTL) epitopes presented by human leukocyte antigen (HLA)-A*2402, most common HLA class I allele in East Asia. METHODS: HLA-A*2402-restricted CTL epitopes were identified by reverse immunogenetics. Immunogenecity of these epitopes was investigated using peripheral blood mononuclear cell (PBMC) from HLA-A24+ patients with acute hepatitis B. RESULTS: An HLA-A*2402 stabilization assay demonstrated that 36 of 63 HBV peptides carrying HLA-A*2402 anchor residues have high- and medium-HLA-A*2402 binding affinity. Two (C117-125 and P756-764) of the 36 peptides induced peptide-specific CTLs. CTL clones and lines specific for these peptides killed HBV recombinant vaccinia virus-infected target cells expressing HLA-A*2402, indicating that these two peptides are CTL epitopes presented by HLA-A*2402. These two peptides were able to induce specific CTLs in 7 and 11 of 12 HLA-A24+ patients with acute hepatitis B, respectively. CONCLUSIONS: We identified two immunodominant CTL epitopes restricted by HLA-A*2402. Because HLA-A*2402 is the most common allele in East Asia, a region in which there are approximately 200 million HBV carriers, these epitopes will be useful for analysis of CTL responses in patients from East Asia.

Introduction of tapasin gene restores surface expression of HLA class I molecules, but not antigen presentation of an HIV envelope peptide in a hepatoma cell line.

A hepatoma cell line, Hep G2, reveals the diminished HLA class I surface expression and the reduced expression of LMP2, LMP7, and tapasin transcripts, suggesting that the reduced expression of these transcripts may be associated with the low expression of HLA class I molecules. Introduction of tapasin gene dramatically up-regulates the surface expression of HLA class I molecules on Hep G2 cells, and unexpectedly, enhances the expression of LMP2 and LMP7 transcripts as well. Unlike Hep G2, these tapasin-transfected Hep G2 cells are recognized by allo-specific CTL. However, the transfectant is unable to endogenously present an HIV envelope peptide to an HIV-specific CTL clone, suggesting that a proteasome-independent antigen processing pathway exists and still remains defective in the transfectant. These data may provide significant evidence that the nonproteasomal antigen processing pathway as well as the proteasomal pathway may be impaired in tumor cells to escape immune surveillance performed by CTL.

Mutational analysis of the RET and GDNF gene in children with hypoganglionosis.

Germline mutations of the RET (10q11.2) have been reported in Hirschsprung's disease (HSCR) at a rate of 15-45%. Recently, the glial cell line-derived neurotrophic factor (GDNF) was identified as one of the ligands of the RET, and GDNF (5p12-p13.1) mutations were also found in association with RET mutations in HSCR patients. We analysed the DNA sequence of RET and the GDNF of patients with hypoganglionosis. We investigated the germline mutation in 5 patients histologically diagnosed with hypoganglionosis. DNAs were extracted from peripheral blood lymphocytes of these patients. The PCR primers were designed for RET tyrosine kinase domain (exon 13-17) and GDNF (exon 1-2). The DNA sequence was determined using a direct DyeDeoxy Terminator Cycle method. The analysis of RET showed silent mutation at the codon 769 (CTT-->CTG) by DNA polymorphism in all patients. No other mutation of the RET or GDNF was evident. These results suggest that the RET or GDNF may not contribute to the pathogenesis of hypoganglionosis, which is suspected to be genetically different from HSCR.

A homozygous missense mutation in the tyrosine E kinase domain of the RET proto-oncogene in an infant with total intestinal aganglionosis.

Germline mutations of the RET proto-oncogene (RET), its ligand glial cell-derived neurotrophic factor (GDNF), and neurturin (NTN) gene have been reported in patients with Hirschsprung's disease. A targeted mutation in the tyrosine kinase domain of RET produced total intestinal aganglionosis and renal agenesis in homozygous transgenic mice. Here we describe a homozygous mutation of the human gene for the RET tyrosine kinase domain that was present in a male neonate with total intestinal aganglionosis. Gut wall biopsy specimens from the stomach to the anorectum showed no ganglion cells. No urinary tract abnormalities were detected. Genomic DNAs were isolated from peripheral blood lymphocytes of the infant and his parents. DNA sequences of all the RET/GDNF/NTN coding regions were determined using a direct DyeDeoxy Terminator Cycle method. A homozygous missense mutation (CGG-to-TGG) at RET codon 969 was identified in this patient, which resulted in an amino acid change from arginine to tryptophan. No germline RET/GDNF/NTN mutations were found in his parents. In this case, the homozygous RET mutation seemed to cause a critical alteration of the Ret tyrosine kinase activity, which resulted in total intestinal aganglionosis but not renal agenesis. Discrepancies in phenotypic expression between humans and mice suggest differing threshold values for RET signal transduction in species or organs.

Systemic and renal effects of atrial natriuretic peptide in patients with heart failure treated with angiotensin-converting enzyme inhibitor or in acute saline solution loading.

BACKGROUND: Our purpose was to study the effects of atrial natriuretic peptide (ANP) on cardiorenal functions when it is used to manage patients with heart failure who are receiving an angiotensin-converting enzyme inhibitor (ACEi) or in acute saline solution loading. METHODS: Seventeen patients with mild to moderate heart failure were entered into protocol 1 or 2. Protocol 1 was ANP (30 ng/kg/min) infused before and after treatment with ACEi (n = 9). Protocol 2 was acute saline loading with or without coadministration of ANP (n = 8). In both protocols cardiorenal hemodynamics and urinary sodium excretion were assessed before and after each intervention. RESULTS: Protocol 1: Although ANP infusion significantly increased urinary sodium excretion to a similar extent before and after ACEi treatment, the infusion increased the glomerular filtration rate (75 +/- 16 --> 82 +/- 15 mL/min, P <.05) and renal blood flow (390 +/- 123 --> 438 +/- 140 mL/min, P <.05) only before ACEi treatment. Protocol 2: Acute saline solution loading decreased plasma renin activity (P <.05) but did not affect ANP level. Coadministration of ANP with saline solution load enhanced the increase of urinary sodium excretion (75% +/- 34% increase) compared with the acute saline solution load alone (49% +/- 33% increase) (P <.05) but had no affect on renal hemodynamics. CONCLUSIONS: When ANP is used in patients with mild to moderate heart failure who are on combined ACEi treatment or in acute saline solution loading, the vasodilatory effect of ANP is blunted while the natriuretic effect of ANP is preserved. The renin-angiotensin system seems to modulate the vasodilatory effect of ANP.

Visual demonstration of hepatitis C virus-specific memory CD8(+) T-cell expansion in patients with acute hepatitis C.

Hepatitis C virus (HCV)-specific CD8(+) T cells in peripheral blood mononuclear cells (PBMCs) from patients infected with HCV were quantitatively analyzed by flow cytometry using an HLA-B*3501-HCV epitope tetrameric complex. In chronic hepatitis C, tetramer(+)CD8(+) T cells were detected at frequencies ranging from 0.05% to 0.12% of total CD8(+) T cells. The number of tetramer(+)CD8(+) T cells in acute phase PBMCs from patients with acute hepatitis C was about 3 to 5 times higher than in recovery phase PBMCs from the same patients and in PBMCs from patients with chronic hepatitis C. Expanding tetramer(+)CD8(+) T cells in PBMCs from patients with acute hepatitis C express a CD28(+)CD45RA(-) memory T-cell phenotype. In contrast, tetramer(+)CD8(+) T cells in PBMCs from patients with chronic hepatitis C did not predominantly express this phenotype. These tetramer(+)CD8(+) T cells did not have perforin in their cytoplasma. The present study visually showed that a high number of circulating HCV-specific CD8(+) T cells in acute phase PBMCs from patients with acute hepatitis C are mostly memory T cells.