Decreased thymic output predicts progression of chronic kidney disease

BACKGROUND

Chronic kidney disease (CKD) is age-related disease, and decreased renal function is associated with the premature aging of T cells and increased incidence of other age-related diseases. However, the relationship between T cell senescence and CKD progression remains unclear. Here, we investigated the relationship between T cell senescence, as indicated by decreased thymic output and increased proportion of highly differentiated CD28^- T cells, and CKD progression.

RESULTS

A total of 175 patients with non-dialysis-dependent CKD were enrolled in this study. Thymic output was assessed based on the CD45RA⁺CD31⁺CD4⁺ cell (recent thymic emigrant [RTE]) counts (RTEs) (/mm³) and the proportion of RTE among CD4⁺ T cells (RTE%). Highly differentiated T cells were assessed based on the proportion of CD28^- cells among CD4⁺ T cells (CD28^-/CD4⁺) and CD28^- cells among CD8⁺ T cells (CD28^-/CD8⁺). The primary outcome was estimated glomerular filtration rate (eGFR) decline of ≥40% or initiation of renal replacement therapy. The association between T cell senescence and renal outcomes was examined using Cox proportional hazards models and restricted cubic splines. The median age was 73 years, 33% were women, and the median eGFR was 26 mL/min/1.73 m². The median RTEs, RTE%, CD28^-/CD4⁺, and CD28^-/CD8⁺ were 97.5/mm³, 16.2, 5.3, and 49.7%, respectively. After a median follow-up of 1.78 years, renal outcomes were observed in 71 patients. After adjusting for age, sex, eGFR, proteinuria, diabetes, and cytomegalovirus seropositivity, decreased RTEs, which corresponded to decreased thymic output, significantly and monotonically increased the risk of poor renal outcome (p = 0.04), and decreased RTE% and increased highly differentiated CD28^-/CD4⁺ T cells also tended to monotonically increase the risk (p = 0.074 and p = 0.056, respectively), but not CD28^-/CD8⁺ T cells.

CONCLUSIONS

Decreased thymic output in CKD patients, as well as increased highly differentiated CD4⁺ T cells, predicted renal outcomes. Thus, the identification of patients prone to CKD progression using T cell senescence, particularly decreased RTE as a biomarker, may help to prevent progression to end-stage kidney disease.

Gitelman syndrome with a novel frameshift variant in SLC12A3 gene accompanied by chronic kidney disease and type 2 diabetes mellitus

Gitelman syndrome is an autosomal recessive genetic disease caused by pathogenic variants in SLC12A3 resulting in the loss of function of the Na-Cl co-transporter (NCC) in the distal tubules. Hypokalemia and diuretic effects can cause secondary type 2 diabetes and renal function decline. Here, we present the case of a 49-year-old male patient with chronic persistent treatment-resistant hypokalemia for the past 13 years who had been receiving treatment for type 2 diabetes mellitus for 6 years. He was referred to our department due to the presence of urinary protein, impaired renal function, high renin activity, and hyperaldosteronism. Laboratory test results showed hypokalemia, hypomagnesemia, hypocalciuria, and metabolic alkalosis. Using next-generation and Sanger sequencing, we identified a novel stop-gain variant (NM_000339.3:c.137del [p.His47fs]) and a missense variant (NM_000339.3:c.2927C > T [p.Ser976Phe]) in the SLC12A3 gene. This novel pathogenic variant was located at the intracellular N-terminus of the NCC. Based on these findings, the patient was diagnosed with Gitelman syndrome. The use of next-generation sequencing facilitated the exclusion of diseases with similar clinical symptoms.

Catalytic Chemoselective O-Phosphorylation of Alcohols

Phosphorylation of alcohols is a fundamentally important reaction in both life science and physical science. Product phosphate monoesters play key roles in living organisms, natural products, pharmaceuticals, and organic materials. Most of the chemical methods to date for synthesizing phosphate monoesters, however, require multistep sequences or are limited to specific types of substrates possibly due to harsh conditions. An alternative way to enable the simple production of phosphate monoesters from highly functionalized precursor alcohols is, thus, highly desired. We report herein a catalytic phosphorylation of alcohols with high functional group tolerance using tetrabutylammonium hydrogen sulfate (TBAHS) and phosphoenolpyruvic acid monopotassium salt (PEP-K) as the catalyst and phosphoryl donor, respectively. This method enables the direct introduction of a nonprotected phosphate group to the hydroxy group of a diverse menu of alcohol substrates, including functionalized small molecules, carbohydrates, and unprotected peptides. Nuclear magnetic resonance, mass spectrometric, and density functional theory analyses suggest that an unprecedented mixed anhydride species, generated from PEP-K and TBAHS, acts as an active phosphoryl donor in this reaction. This operationally simple and chemoselective catalytic phosphorylation allows for the efficient production of densely functionalized O-phosphorylated compounds, which are useful in diverse fields including biology and medicine.

Parathyroid hormone and premature thymus ageing in patients with chronic kidney disease

Premature immune ageing, including thymic atrophy, is observed in patients with chronic kidney disease (CKD). Parathyroid hormone (PTH) and fibroblast growth factor 23 (FGF23), which are mineral and bone disorder (MBD)-related factors, affect immune cells and possibly cause thymic atrophy. We examined the cross-sectional association between thymic atrophy, evaluated as the number of CD3⁺CD4⁺CD45RA⁺CD31⁺ cells [recent thymic emigrants (RTE)/μL], and MBD-related factors [(serum PTH, FGF23, and alkaline phosphatase (ALP) level] in 125 patients with non-dialysis dependent CKD. Median estimated glomerular filtration rate (eGFR) was 17 mL/min/1.73 m². Older age (r = −0.46), male sex (r = −0.34), lower eGFR (r = 0.27), lower serum-corrected calcium (r = 0.27), higher PTH (r = −0.36), and higher ALP level (r = −0.20) were identified as determinants of lower number of RTE. In contrast, serum concentrations of FGF23 and phosphorus were not correlated with RTE. Multivariate non-linear regression analysis indicated a negative association between serum PTH and log-transformed RTE (P = 0.030, P for non-linearity = 0.124). However, the serum levels of FGF23 and ALP were not associated with RTE. In patients with CKD, serum PTH concentrations were related to thymic atrophy which contributes to immune abnormality.

Effect of Bacillus subtilis C-3102 on loose stools in healthy volunteers

Ingestion of Bacillus subtilis C-3102 spores (C-3102) has relieved the symptoms of diarrhoea in piglets and changed the composition of gut microbiota in humans. Recently, it was suggested that the composition of the human gut microbiota affects stool consistency. In this study, a double-blind, randomised, placebo-controlled trial was conducted to assess the preventive effects of chronic diarrhoea in healthy volunteers with loose stools by ingestion of C-3102. The results showed that oral doses of C-3102 tablets significantly decreased the Bristol Stool Scale score and stool frequency, and also significantly improved abdominal sounds. With regard to gut microbiota, the relative abundance of Lachnospira, Actinomyces and SMB53 were significantly changed. This study shows that C-3102 could be effective for treating loose stools (Trial registration: UMIN000022583, http://tinyurl.com/ya4refqn ).

Visualization of kidney fibrosis in diabetic nephropathy by long diffusion tensor imaging MRI with spin-echo sequence

Renal fibrosis (RF) is an indicator for progression of chronic kidney disease (CKD). Although diabetic nephropathy (DN) is the leading cause of CKD and end-stage renal disease in Western populations, the ability of MRI to evaluate RF in DN patients has not been determined. As a first step to identify possible MRI methods for RF evaluation, we examined the use of diffusion tensor imaging (DTI) MRI to evaluate RF in a rat model of DN (SHR/NDmcr-cp(cp/cp): SHR/ND). The signal-to-noise ratio in DTI MRI was enhanced using a spin-echo sequence, and a special kidney attachment was developed for long-term stabilization. The changes in renal temperature and blood flow during measurement were minimal, suggesting the feasibility of this method. At 38 weeks of age, RF had aggressively accumulated in the outer stripe (OS) of the outer medulla. FA maps showed that this method was successful in visualizing and evaluating fibrosis in the OS of the SHR/ND rat kidney (r = 0.7697, P = 0.0126). Interestingly, in the FA color maps, the directions of water molecule diffusion in RF were random, but distinct from conventional water diffusion in brain neuron fibers. These findings indicate that DTI MRI may be able to evaluate RF in CKD by DN.

Studies of Pig Complement: Measurement of Pig CH50, ACH50, and Components

BACKGROUND

On the basis of a comparison of the hemolytic complement titer in pigs with that in humans, the complement system of pigs was investigated. The response of innate immunity, such as the natural antibodies, against humans was also examined.

METHODS

Hemolytic complement activity of pig serum was measured with the use of a microtitration technique. CH50 was determined according to the method of Mayer. ACH50 was assayed according to the methods of Platts-Milles and Ishizaka. Hemolytic activities of C1, C4, C2, C3, C5, C8, and C9 were estimated through the use of intermediate cells and reagents, as described previously. In addition, the pig natural anti-human antibody was studied with the use of human peripheral blood mononuclear cells (PBMCs). Human PBMCs were stained with 5% pig serum, followed by staining with fluorescein isothiocyanate-labeled goat anti-pig IgG and IgM. The resulting stained cells were quantified by use of a FACScalibur system. The alternative pathway of pig complement was also measured with the use of human erythrocytes and normal pooled pig serum with or without Mg(++)EGTA.

RESULTS

Both the CH50 and ACH50 titers were lower than those of humans. Concerning the components, except for C3, each component, that is, C1, C4, C2, C5, C8, and C9, was also lower than that of humans, based on measured values for human complement components. Pig serum clearly contains natural antibodies, IgG and IgM, to human PBMCs. The alternative pathway of pig complement reacted with human erythrocytes.

CONCLUSIONS

As a whole, pig innate immunity, the complement system and natural antibody, recognizes the surfaces of human cells.

Azilsartan Improves Salt Sensitivity by Modulating the Proximal Tubular Na+-H+ Exchanger-3 in Mice

A potent angiotensin II type-1 receptor blocker, azilsartan, has been reported to reduce blood pressure more effectively than candesartan. Interestingly, azilsartan can also restore the circadian rhythm of blood pressure. We hypothesized that azilsartan could also improve salt sensitivity; thus, we examined the effect of azilsartan on sodium handling in renal tubules. Subtotal nephrectomized C57BL/6 mice received azilsartan (1.0 mg/kg/day), candesartan (0.3 mg/kg/day), or vehicle via the oral route in conjunction with a normal- (0.3%) or high-salt (8.0%) diet. Two weeks later, the azilsartan group showed significantly lower blood pressure during the light period than the candesartan and vehicle groups (azilsartan: 103.1 ± 1.0; candesartan: 111.7 ± 2.7; vehicle: 125.5 ± 2.5 mmHg; P < 0.05; azilsartan or candesartan vs. vehicle). The azilsartan group also showed higher urinary fractional excretion of sodium during the dark period than the candesartan and vehicle groups (azilsartan: 21.37 ± 3.69%; candesartan: 14.17 ± 1.42%; vehicle: 13.85 ± 5.30%; P < 0.05 azilsartan vs. candesartan or vehicle). A pressure—natriuresis curve demonstrated that azilsartan treatment restored salt sensitivity. Immunofluorescence and western blotting showed lower levels of Na⁺-H⁺ exchanger-3 (NHE3) protein (the major sodium transporter in renal proximal tubules) in the azilsartan group, but not in the candesartan or vehicle groups. However, azilsartan did not affect NHE3 transcription levels. Interestingly, we did not observe increased expression of downstream sodium transporters, which would have compensated for the increased flow of sodium and water due to non-absorption by NHE3. We also confirmed the mechanism stated above using cultured opossum kidney proximal tubular cells. Results revealed that a proteasomal inhibitor (but not a lysosomal inhibitor) blocked the azilsartan-induced decrease in NHE3 protein expression, suggesting that azilsartan increases NHE3 ubiquitination. In conclusion, azilsartan (but not candesartan) improved salt sensitivity possibly by decreasing NHE3 expression via ubiquitin—proteasomal degradation.

Non-invasive magnetic resonance imaging in rats for prediction of the fate of grafted kidneys from cardiac death donors

The main objective of this study was to assess cardiac death (CD) kidney grafts before transplantation to determine whether blood oxygen level-dependent (BOLD) and diffusion MRI techniques can predict damage to these grafts after transplantation. We assessed CD kidney tissue by BOLD and diffusion MRI. We also examined pathological and gene expression changes in CD kidney grafts before and after transplantation. Although there was significantly more red cell congestion (RCC) in the inner stripe of the outer medulla (IS) in both 1 h after cardiac death (CD1h) and CD2h kidneys destined for grafts before transplantation compared with CD0h (p<0.05), CD2h, but not CD1h, kidney grafts had significantly different RCC in the IS 2 days after transplantation (p<0.05). Consistent with these pathological findings, tissue plasminogen activator (tPA) gene expression was increased only in the cortex and medulla of CD2h kidney grafts after transplantation. BOLD MRI successfully and non-invasively imaged and quantified RCC in the IS in both CD1h and CD2h kidney grafts (p<0.05). Diffusion MRI also non-invasively assessed increased the apparent diffusion coefficient in the IS and decreased it in the outer stripe (OS) of CD2h grafts, in concordance with interstitial edema in the IS and tubule cellular edema in the OS. These two types of edema in the outer medulla could explain the prolonged RCC in the IS only of CD2h kidney grafts, creating part of a vicious cycle inhibiting red cells coming out of capillary vessels in the IS. Perfusion with University of Wisconsin solution before MRI measurements did not diminish the difference in tissue damage between CD1h and CD2h kidney grafts. BOLD and diffusion MRI, which are readily available non-invasive tools for evaluating CD kidney grafts tissue damage, can predict prolonged organ damage, and therefore the outcome, of transplanted CD kidney grafts.

Influence of Bacillus subtilis C-3102 on microbiota in a dynamic in vitro model of the gastrointestinal tract simulating human conditions

Survival and germination rate of Bacillus subtilis C-3102 spores were investigated in a stomach and small intestine model (TIM-1), while the impact of C-3102 cells that had passed through TIM-1 on human colon microbiota was evaluated in a model of the large intestine (TIM-2). The survival of C-3102 spores in TIM-1 was 99%; 8% of the spores had germinated. Effluent of TIM-1 was subsequently introduced into TIM-2 and a micro-array platform was employed to assess changes in the microbiota composition. The effluent, which contained germinated C-3102 cells, increased some Bifidobacterium species and decreased some Clostridium groups. These changes were greater compared to those obtained by adding C-3102 spores directly to TIM-2. The present study suggests that oral doses of B. subtilis C-3102 spores have the potential to modulate the human colon microbiota. This effect may be caused by germination of the spores in the gastrointestinal tract.

Hyper IgM syndrome and complement Clq deficiency in an individual with systemic lupus erythematosus-like disease

Many immunedeficiency syndromes are associated with autoimmune disorders. We here report on a girl with a systemic lupus erythematosus-like disease who suffered from both hyperimmunoglobulin M syndrome (HIGMS) and C1q deficiency. Despite severe central nervous system-lupus like disease, probably due to C1q deficiency, kidney function was relatively spared. IgM autoantibody might play a protective role against lupus-glomerulonephritis.

[Plasma B-type natriuretic peptide level predicts the renal outcome in patients with chronic kidney disease]

PURPOSE

Elevation of the plasma level of B-type natriuretic peptide (BNP) is commonly seen in patients with chronic kidney disease (CKD), but its significance remains unclarified. We conducted a prospective study to evaluate the role of plasma BNP level as a predictive marker of renal outcome.

METHODS

237 patients with CKD stage 3, 4 not on dialysis were prospectively enrolled as a hospital cohort from August 2004 to December 2008. Combined renal endpoint was doubling of baseline serum creatinine or end-stage renal disease requiring dialysis. Endpoint free renal survival was calculated by Kaplan Meier analysis and compared by the log-rank test. We used Cox proportional hazards analysis to determine the independent predictor for renal outcome among the clinical data at the time of referral to a nephrologist. ROC analysis was used to determine the best cut-off value of plasma BNP level to predict the renal outcome.

RESULTS

The mean follow-up period was 2.5 +/- 1.1 years. Median age was 65 years. Of the subjects, 65.8% were men and 37.9% had diabetes mellitus. Median serum creatinine level was 2.7 mg/dL. Plasma BNP level was significantly higher among 147 patients who reached the combined renal endpoint compared with 90 patients who did not (116.0 pg/mL vs 54.5 pg/mL, p<0.001). After adjustment with other established predictive factors of renal outcome, plasma BNP level was selected to be the strongest predictive marker for renal endpoint (Hazard ratio 1.173, 95%CI 1.000-1.376). The optimal cut-off value of plasma BNP level suggested by ROC analysis was 69.5 pg/mL. Patients with a plasma BNP level above the cut-off point revealed a significantly poor renal outcome compared with those with a plasma BNP level below the cut-off point.

CONCLUSIONS

The present study suggests that the plasma BNP level might be a predictive marker for renal outcome and a guide for management of cardio-renal interaction.

[Clinical characteristics of five elderly patients with severe hypokalemia induced by glycyrrhizin derivatives]

Although hypokalemia is a common clinical problem, symptoms generally do not become manifest unless the serum potassium (K) falls rapidly. We encountered five cases with symptomatic severe hypokalemia (K<2.0 mEq/L) hospitalized for the past 15 months at our hospital. We examined the clinical characteristics and treatment of these patients. All five patients were women, and their mean age was 77.8 (73-82)years. They suffered from hypertension. Mean K level at admission was 1.66 (1.4-1.9) mEq/L and HCO3(-) was 48.3 (33.6-56.1) mmol/L. Plasma aldosterone level was low and plasma rennin activity was suppressed. All patients developed progressive muscle weakness with elevated creatinine phosphokinase. Three of the patients had received Chinese medicine which contained licorice, one received glycyrrhizin and the other one had received both. We diagnosed these cases as pseudoaldosteronism induced by glycyrrhizin. With discontinuation of the drugs and intravenous as well as oral K supplementation, serum K were normalized and clinical symptoms improved within 12 days. For one patient who developed cardiac dysfunction, concentrated K solution (230 mEq/L) was infused into the central vein. These findings show that glycyrrhizin ingestion should be kept in mind as a cause of an extreme degree of an hypokalemia, especially in elderly patients.

Increased insulin demand promotes while pioglitazone prevents pancreatic beta cell apoptosis in Wfs1 knockout mice

AIMS/HYPOTHESIS

The WFS1 gene encodes an endoplasmic reticulum (ER) membrane-embedded protein called Wolfram syndrome 1 protein, homozygous mutations of which cause selective beta cell loss in humans. The function(s) of this protein and the mechanism by which the mutations of this gene cause beta cell death are still not fully understood. We hypothesised that increased insulin demand as a result of obesity/insulin resistance causes ER stress in pancreatic beta cells, thereby promoting beta cell death.

METHODS

We studied the effect of breeding Wfs1 ( -/- ) mice on a C57BL/6J background with mild obesity and insulin resistance, by introducing the agouti lethal yellow mutation (A ( y ) /a). We also treated the mice with pioglitazone.

RESULTS

Wfs1 ( -/- ) mice bred on a C57BL/6J background rarely develop overt diabetes by 24 weeks of age, showing only mild beta cell loss. However, Wfs1 ( -/- ) A ( y ) /a mice developed selective beta cell loss and severe insulin-deficient diabetes as early as 8 weeks. This beta cell loss was due to apoptosis. In Wfs1 ( +/+ ) A ( y ) /a islets, levels of ER chaperone immunoglobulin-binding protein (BiP)/78 kDa glucose-regulated protein (GRP78) and phosphorylation of eukaryotic translation initiation factor 2, subunit alpha (eIF2alpha) apparently increased. Levels of both were further increased in Wfs1 ( -/- ) A ( y ) /a murine islets. Electron micrography revealed markedly dilated ERs in Wfs1 (-/-) A ( y ) /a murine beta cells. Interestingly, pioglitazone treatment protected beta cells from apoptosis and almost completely prevented diabetes development.

CONCLUSIONS/INTERPRETATION

Wfs1-deficient beta cells are susceptible to ER stress. Increased insulin demand prompts apoptosis in such cells in vivo. Pioglitazone, remarkably, suppresses this process and prevents diabetes. As common WFS1 gene variants have recently been shown to confer a risk of type 2 diabetes, our findings may be relevant to the gradual but progressive loss of beta cells in type 2 diabetes.

[Case of scleroderma with rapid progressive glomerulonephritis associated with both MPO-ANCA and anti-GBM antibodies]

A 66-year-old male with scleroderma developed rapidly progressive glomerulonephritis (RPGN). Renal pathology revealed crescentic glomerulonephritis with interstitial inflammation and fibrosis. Immunofluorescent micrography showed linear deposition of IgG along the glomerular capillary wall. Both anti-glomerular basement membrane antibody (anti-GBM Ab), and myeloperoxidase-antineutrophil cytoplasmic antibody (MPO-ANCA) were detected by an enzyme-linked immunosorbent assay (ELISA). These findings were compatible with ANCA-related vasculitis and anti-GBM Ab nephritis. Laboratory findings showed rapid elevation of the serum creatinine level (5.9 mg/dL), and a high titer of MPO-ANCA (530 EU) and anti-GBM Ab (21 EU). He was started on methylprednisolone pulse therapy and temporary hemodialysis. Since the immunosuppressive therapy lowered both antibody titers steadily and improved renal function, hemodialysis was discontinued 4 weeks after the therapy. It has been reported that some scleroderma patients developed rapid progressive glomerulonephritis due to ANCA-associated vasculitis in addition to the typical scleroderma renal crisis. There have been few reports of a scleroderma patient associated with RPGN, in whom both MPO-ANCA and anti GBM antibodies were detected.

Changes in the Burgers vector of perfect dislocation loops without contact with the external dislocations

We report the observations of a new type of changing process in the Burgers vector of dislocations by in situ transmission electron microscopy. Small interstitial-type perfect dislocation loops in bcc iron with diameters less than approximately 50 nm are transformed from a 1/2<111> loop to another 1/2<111> one or an energetically unfavorable <100> one; furthermore, a <100> loop is transformed to a 1/2<111> one. These transformations occurred on high-energy electron irradiation or simple heating without contact with external dislocations. The origin of these phenomena is discussed.

cDNA cloning and functional characterization of Xenopus laevis DNase γ

We report here the cDNA cloning and functional analysis of Xenopus DNase gamma (xDNase gamma). Two forms of cDNAs are isolated from adult spleen: one composing a 933 bp open reading frame for the enzymatically active xDNase gamma protein, and the other encoding an inactive short alternative form. Northern blot analysis revealed that the xDNase gamma mRNA is expressed in spleen, liver, testis, and ovary. xDNase gamma expression is scarcely detected in the tail muscle of tadpoles; however, it increases during metamorphosis and reaches a maximum during the late metamorphic climax. The ectopic expression of xDNase gamma results in the appearance of extensive DNA fragmentation in C2C12 myoblasts after the induction of apoptosis. In contrast, Xenopus DNase I fails to induce apoptotic DNA ladder formation under the same conditions. Our results suggest a possible involvement of xDNase gamma in apoptosis during amphibian metamorphosis.

The relation between intraocular pressure peak in the water drinking test and visual field progression in glaucoma

AIM

To compare the results of the water drinking test between glaucomatous eyes with and without visual field progression.

METHODS

Retrospective analysis of 76 eyes of 76 open angle glaucoma patients followed for a mean period of 26.0 (SD 13.8) months. Patients were submitted to the water drinking test at the beginning of the follow up period. Reliable achromatic automated perimetry tests performed during the studied period were used to characterise visual field progression. All subjects were under clinical therapy and had an intraocular pressure (IOP) lower than 17 mm Hg monitored by isolated measurements during the follow up period. The results of the water drinking test were compared between glaucomatous eyes with and without visual field progression.

RESULTS

Twenty eight eyes reached definite visual field progression. There were no significant differences in the mean age, sex, race, basal IOP, number of antiglaucomatous drugs, initial mean deviation (MD), and corrected pattern standard deviation (CPSD) between eyes that showed visual field progression and the ones who did not progress. A significant difference of 1.9 (SD 0.6) mm Hg (p = 0.001, analysis of covariance; 95% CI 0.8 to 3.0) was observed between glaucomatous eyes that showed visual field deterioration and glaucomatous eyes that did not progress. A significant difference of 16.8% (SD 4.6%) in the mean percentage of IOP variation was also observed between the two groups (p<0.001, analysis of covariance; 95% CI 7.7 to 26.0).

CONCLUSIONS

Mean IOP peak and percentage of IOP variation during water drinking test were significantly higher in patients with visual field progression compared with patients who did not progress.

Intraocular pressure variability in patients who reached target intraocular pressure

AIM

To assess the intraocular pressure (IOP) variability in patients with primary open angle glaucoma (POAG) under clinical treatment who reached an established target pressure based on isolated office readings.

METHODS

Retrospective analysis of 65 eyes from 65 POAG patients under clinical therapy who submitted to modified diurnal tension curve (mDTC) (measurements at every 3 hours between 8 am and 5 pm) followed by a water drinking test (WDT). All subjects had established target IOP < or =15 mm Hg at 11 am or 2 pm. IOP variability during mDTC or WDT was evaluated.

RESULTS

mDTC revealed IOP measurements > or =17 mm Hg in 16 of 65 eyes (24.6%). Nine eyes (13.8%) presented values > or =18 mm Hg. The highest IOP detected by mDTC was 20 mm Hg in one patient (1.5%). WDT demonstrated IOP values > or =17 mm Hg in 32 of 65 eyes (49.2%). 22 eyes (33.8%) presented values > or =18 mm Hg after water ingestion. Moreover, IOP levels > or =20 mm Hg were observed in 14 eyes (21.5%).

CONCLUSION

A great percentage of POAG patients undergoing clinical treatment and with IOP control based on single office measurement present significantly higher IOP measurements when performing mDTC and, especially, the WDT.

Listeria monocytogenes isolated from cold-smoked fish products in Osaka City, Japan

Listeria monocytogenes contamination of ready-to-eat seafood products commercially available in Osaka was examined between 1999 and 2000. L. monocytogenes was isolated from 12 (13%) of the 95 products tested. All positive samples were from cold-smoked fish with 9 being obtained during the summer. Thirteen isolates of L. monocytogenes were typed by pulsed-field gel electrophoresis (PFGE) and polymerase chain reaction (PCR)-based typing methods. Isolates of the same serotype originating from the same manufacturer gave similar DNA profiles, irrespective of the type of sample or date of isolation. The finding suggest that persistent strains in each manufacturing facility proliferate during the summer and contaminate products during manufacturing processes.

Functional cross-talk of HIV-1 Tat with p53 through its C-terminal domain

Human immunodeficiency virus type 1 (HIV-1) Tat repressed the p53-dependent gene expression through its C-terminal domain of Tat (amino acid residues 73-86) independent of the involvement of NF-kappaB and coactivator CBP/p300. Although Tat did not directly bind to p53, this repression required the N-terminal domain of p53. In contrast, Tat and p53 cooperated in the activation of HIV-1 gene expression. Thus, the cross-talk between Tat and p53 may be linked with cellular transformation by HIV-1 infection or activation of HIV-1 replication.

Calcium phosphate crystal-associated proteins: alpha-2-HS-glycoprotein, prothrombin fragment 1 and osteopontin

To study the inhibitory effects of calcium phosphate-associated proteins on calcium oxalate crystallization and urinary concentrations of proteins in people who form stones and healthy controls. From 60 L of urine from healthy men, calcium phosphate-associated proteins (alpha-2-HS-glycoprotein, prothrombin fragment 1 and osteopontin) were obtained. The effects of the proteins on calcium oxalate (CaOx) crystallization were studied with a mixed suspension mixed product removal system. To examine urinary concentrations of the proteins, urine samples were collected from 17 healthy subjects and 15 stone formers and analyzed using anion-exchange chromatography and an enzyme immunoassay. Prothrombin fragment 1 (PTF1) and osteopontin (OPN) had strong inhibitory effects on CaOx crystallization, while alpha-2-HS-glycoprotein had a mild inhibitory effect. Urinary concentrations of PTF1 and OPN were lower in stone formers than in healthy controls. Low urinary concentrations of PTF1 and OPN might be one of the reasons for stone formation.

Two types of replication protein A 70 kDa subunit in rice, Oryza sativa: molecular cloning, characterization, and cellular & tissue distribution

Replication protein A (RPA), which is comprised of three subunits, is an important factor involved in DNA replication, repair, and transcription. We isolated and characterized 70 and 32 kDa subunits of RPA from rice (Oryza sativa cv. Nipponbare) termed OsRPA70a and OsRPA32. OsRPA70a shows a low level of homology with OsRPA1 which was isolated from deepwater rice (Oryza sativa cv. Pin Gaew 56), previously. We also succeeded to isolate OsRPA70b which is homologue to OsRPA1 from Oryza sativa cv. Nipponbare. OsRPA70a shows only 33.8% sequence identity with OsRPA70b, indicating that two different types of 70 kDa RPA subunits are present in Oryza sativa cv. Nipponbare. These subunits showed differences in their expression patterns among tissues. The transcripts of OsRPA70a and OsRPA32 were expressed strongly in proliferating tissues such as root tips and young leaves that contain root apical meristem and marginal meristem, respectively, and weakly in the mature leaves which have no proliferating tissues. On the other hand, OsRPA70b was expressed mostly in the proliferating tissues. The roles of these molecules in plant DNA replication and DNA repair are discussed.

Thickness of the retinal nerve fiber layer in amblyopic and normal eyes: a scanning laser polarimetry study

PURPOSE

To compare scanning laser polarimeter (GDx, Laser Diagnostic Technologies, San Diego, Calif) measurements of the peripapillar retinal nerve fiber layer in amblyopic and normal eyes.

METHODS

Scanning laser polarimetry was performed on 21 patients with unilateral strabismic amblyopia who had an absence of neurologic diseases or glaucoma and a minimum age of 7 years. A mean retardation map was calculated from separate scans or was considered to be the best scan obtained for each eye. Polarimetric indices were analyzed comparing amblyopic and contralateral normal eyes.

RESULTS

The mean age was 15 +/- 9 years (7-35 years) and the male:female ratio was 13:8. There were 6 right and 15 left amblyopic eyes, with the amblyopic group having a mean visual acuity of 0.3 +/- 0.1. The mean (+/- SD) indices did not differ significantly between normal and amblyopic eyes, except the number that summates information from the individual parameters, which was higher in normal (20.71 +/- 11.98) than in amblyopic (15.14 +/- 6.81) eyes, P =.02.

CONCLUSION

There was no statistical difference in thickness of the nerve fiber layer between amblyopic and normal eyes. A previous study found similar results in adults with strabismic amblyopia.

The cyclic AMP/PKA signal pathway is required for initiation of spore germination in Schizosaccharomyces pombe

Spore germination, a transition from the quiescent G0 phase to the proliferation cycle, is triggered by glucose in Schizosaccharomyces pombe. The role of cAMP/protein kinase A (PKA) signalling in germination is investigated. Gene disruption of cyr1+, pka1+ and gpa2+ encoding adenylate cyclase, PKA and the alpha-subunit of a trimeric GTP-binding protein, respectively, reduced the colony-forming efficiency of spores in minimal medium. Isolated spores of these null mutants did not germinate in minimal medium for up to 12 h, at which time wild-type spores had completed germination and formed germ projections. In wild-type spores, cortical actin patches randomly distributed in the early stage of outgrowth and then localized to one side of spores before the formation of projections. In contrast, the mutant spores exhibited no actin patches, but the cell surface was predominantly stained, like ungerminated spores of wild-type. Flow fluorocytometric analysis of propidium iodide-stained spores revealed a distinct 1C DNA peak after germination was completed. The fluorescent profile of the mutant spores, however, did not change during 12 h incubation in the minimal medium. These observations indicate that spores harbouring either cyr1Delta, pka1Delta or gpa2Delta are hardly triggered to germination. When wild-type spores were exposed to glucose, the intracellular cAMP level transiently increased in a few minutes, but gpa2Delta spores did not respond to glucose. We conclude that S. pombe spores initiate germination in response to glucose through the cyclic AMP-PKA pathway.

Molecular cloning and characterization of a plant homologue of the origin recognition complex 1 (ORC1)

By using the rice EST database, we have isolated a 2.8 kb cDNA, termed Oryza sativa ORC1 (OsORC1), from rice (O. sativa) encoding a protein that shows homology with the eukaryotic ORC1 proteins. Alignment of the OsORC1 protein sequence with the sequence of ORC1 from human and yeasts S. cerevisiae and S. pombe showed a high degree of sequence homology (38.7, 32.9 and 35.0% identity, respectively), particularly around the C-terminal region containing the CDC-NTP domain. Interestingly, the OsORC1 protein had an A+T hook-like motif, which was not present in the human or yeast genes. Genomic analysis indicated that OsORC1 existed as a single copy per genome. OsORC1 transcripts were expressed strongly in root tips and weakly in young leaves containing root apical meristem and marginal meristem, respectively. No expression was detected in the mature leaves. The level of OsORC1 expression was significantly reduced when cell proliferation was temporarily halted by the removal of sucrose from the growth medium. When the growth-halted cells began to re-grow following addition of sucrose to the medium, OsORC1 was again expressed at high levels. These results suggested that OsORC1 is required for cell proliferation. The role of OsORC1 in plant DNA replication will be discussed.

My4+/LeuM3- molecule and CD19 antigen are down-modulate by low affinity Fc gamma receptor II (CD32) stimulation on CD56-positive B-lymphoma cells

My4+/LeuM3- molecule is recognized by My4, but not by LeuM3, both well known mAbs to CD14. In a previous study we showed that the My4+/LeuM3- molecule on a human monoblastic cell line, U937, is not CD14, but another cell surface antigen. The roles and functions of the My4+/LeuM3- molecule remained unknown. We now report that specific stimulation of Fc gammaR with aggregated IgG or anti-Fc gammaRII antibody down-modulated the My4+/LeuM3- molecules, as well as CD19, in a case of CD56-positive B cell lymphoma. Stimulation of Fc gammaR with anti-mu antibody, which induced concomitant stimulation of sIg, did not induce down-modulation of either molecule. Stimulation of CR2 (CD21), a protein which is functionally or physically associated with CD19, with anti-CR2 (CD21) mAbs also had no effect. The modulation occurred specifically on CD56-positive B-lymphoma cells, since My4+/LeuM3(-)-positive, CD56-negative B-lymphoma cells did not respond to the stimulation. These results suggest that CD19 and My4+/LeuM3- molecules are functionally or physically associated with Fc gammaR II on CD56 positive B-lymphoma cells defined as being at a terminal B cell differentiation stage.

Urine levels of CD46 (membrane cofactor protein) are increased in patients with glomerular diseases

Soluble membrane cofactor protein (MCP, CD46) has not been detected by conventional ELISA in human urine. Here, we established a highly sensitive assay method for determination of urinary MCP (uMCP) using monoclonal antibody-coated paramagnetic beads. This method enabled us to detect less than 0.05 ng/ml of purified membrane and recombinant soluble MCP, a sensitivity 10-fold higher than that of conventional ELISA. In normal subjects, the levels of uMCP were <0. 05 ng/ml. The levels of uMCP were elevated in patients with IgA nephropathy and more prominently in patients with rapidly progressive glomerulonephritis. The levels of uMCP were correlated significantly with those of serum MCP (sMCP) and N-acetyl-beta-glucosaminidase and nonsignificantly with those of beta(2)-microglobulin, total urine protein, or serum creatinine. The properties of uMCP were inconsistent with those of the reported sMCP, since uMCP showed three bands on SDS-PAGE/immunoblotting with molecular mass profiles different from those of sMCP. uMCP exhibited factor I cofactor activity for cleavage of C3b comparable to that of sMCP. The origin of uMCP, however, remains to be determined. These results, taken together with the parameter correlation profiles, suggested that uMCP is secreted or produced secondary to tubular or glomerular damage. The physiological role and clinical significance of uMCP are now within the scope of our investigation by establishment of this assay.

Molecular remodelling of human CD46 for xenotransplantation: designing a potent complement regulator without measles virus receptor activity

In pig-to-human discordant xenotransplantation, human complement (C) is a major barrier to long survival of xenografts. The current idea on how to cope with this barrier is that human complement regulatory proteins are forcibly expressed on xenografts to serve as safeguards against host C-induced hyperacute rejection of xenografts. Co-expression of decay-accelerating factor (DAF) (CD55) and membrane cofactor protein (MCP) (CD46) would be the first choice for this trial, because most of the human cells are protected from C-mediated damage by two different modes with these two kinds of C-regulators. Many problems have arisen, however, for MCP expression on grafts. (i) MCP acts as a measles virus receptor, which may function to render donor pigs measles virus (MV) sensitive. (ii) MCP signals immune suppression which causes devastation of the recipient's immune responses. (iii) MCP exerts relatively low self-protective activity against C compared with other cofactors; development of more efficient forms is desirable. (iv) Grafts with a high expression level of MCP are difficult to produce. In this study, we made a number of cDNA constructs of MCP, expressed them on swine endothelial cell lines, and tested cell-protective potency and MV susceptibility. The short consensus repeat 1 (SCR1)-deleted MCP with glycosyl phosphatidylinositol (GPI)-anchored form (Delta1MCP-PI) of MCP was found to be most suitable for the purpose of overcoming these problems. However, it was also found that MV induces two modes of cytopathic effect (CPE) on swine endothelial cells, either MCP-dependent or -independent. Here, we discuss these two points which will be raised through study of MCP-transgenic animals.

Distribution of sarcophytol A in soft coral of the Sarcophyton genus

The distribution of sarcophytol-A in the Sarcophyton genus was investigated in seven samples belonging to S. glaucum (3 samples), S. infundibulifurme (2 samples), S. crassocaule (1 sample) and S. trocheliophorum (1 sample) that were collected on Ishigaki Island in Okinawa Prefecture. Sarcophytol-A was present in one sample each of S. glaucum and S. infundibulifurme. This study indicates that the composition of cembranoids in the Sarcophyton genus is not related with the respective species, but with the individual samples collected.

A new nonamyloid transthyretin variant, G101S, detected by electrospray ionization/mass spectrometry. Mutations in brief no. 201. Online

Familial amyloidotic polyneuropathy is caused by transthyretin (TTR) variants. The identification of new variants with and without amyloidosis may help to clarify the mechanism of amyloid fibril formation. We detected several variant TTRs from patients with and without symptoms of amyloidosis using mass spectrometry (MS). TTR was isolated by mixing test serum with anti-transthyretin antiserum, and the generated immunoprecipitate was analyzed by high performanced liquid chromatography/electrospray ionization (HPLC/ESI) MS. Variant TTRs showed extra peaks in addition to normal TTR peaks. A variant found in nonamyloid group was sequenced by HPLC/ESI tandem MS using peptides obtained by protelytic digestion of TTR and by DNA analysis. The structure was new, [G101S], and was found in a 74 years old Japanese male. This mutation results from substitution in a CpG hot spot. The substitution in the surface loop, 98-102, between F and G b-strands may not cause amyloid formation.

Plant homologue of flap endonuclease-1: molecular cloning, characterization, and evidence of expression in meristematic tissues

Flap endonuclease-1 (FEN-1) is an important enzyme involved in DNA replication and repair. We isolated a 1.4 kb cDNA from rice (Oryza sativa), termed OsFEN-1, encoding a protein which shows homology with the eukaryotic FEN-1 proteins. OsFEN-1 protein was overexpressed in Escherichia coli and purified to near homogeneity. DNA cleavage analysis using different branched DNA structures indicated that OsFEN-1 protein possesses both 5'-flap endonuclease and 5' to 3' double-stranded DNA exonuclease activities. OsFEN-1 protein incises a 5'-flap and 5'-pseudo Y structure one base 3' of the branched point in the duplex region. The enzymatic properties indicated that we succeeded in obtaining the gene and the protein of a plant counterpart of FEN-1. OsFEN-1 transcripts were expressed strongly in proliferating tissues such as root tips and young leaves that contain root apical meristem and marginal meristem, respectively. No expression was detected in mature leaves although the leaves were exposed to UV. We analyzed the spatial distribution pattern of OsFEN-1 transcripts by in situ hybridization. In the shoot apex, OsFEN-1 mRNA was abundant in the shoot apical meristem, tiller bud, leaf primordia, ligule primordia and marginal meristem of young leaves. In the roots, the transcript accumulated to high levels in the root apical meristem. Our results indicate that OsFEN-1 is expressed in tissues rich in proliferating cells, and its expression may be required for cell growth and organ formation.

Calcium phosphate crystal-associated proteins: alpha2-HS-glycoprotein, prothrombin F1, and osteopontin

PURPOSE

To elucidate the process of urinary stone formation, many urinary constituents have been examined as inhibitors or promoters.

MATERIALS AND METHODS

We analyzed specific binding proteins of calcium phosphate (CaP) crystals generated in human urine and found that the separated proteins were alpha2-HS-glycoprotein, prothrombin fragment 1 (PTF1), and osteopontin (OPN). We also studied their inhibitory effects on calcium oxalate crystallization and the quantitative differences in urinary excretion of the proteins in healthy individuals and stone formers.

RESULTS

Both PTF1 and OPN had strong inhibitory effects on growth of calcium oxalate crystals. No differences in alpha2-HS-glycoprotein were found between healthy subjects and stone formers. Urinary concentrations of PTF1 and OPN were lower in stone formers than in healthy controls. No differences in these proteins were seen between single and recurrent stone formers.

CONCLUSION

Low urinary concentrations of PTF1 and OPN might be one reason for stone formation.

Analysis of urinary concentrations of calcium phosphate crystal-associated proteins: alpha2-HS-glycoprotein, prothrombin F1, and osteopontin

It has been reported that prothrombin F1 and osteopontin (OPN) have strong inhibitory effects on calcium oxalate crystallization and are produced in stone-forming kidneys in animal models. It is important to evaluate urinary concentrations of these proteins for patients with renal stones and healthy control subjects. Urinary macromolecules were collected from nine healthy individuals, nine stone-formers, and five patients with primary hyperparathyroidism (HPT). Each 50-mg aliquot of urinary macromolecules was mixed with calcium phosphate solution, and calcium phosphate crystal-precipitated proteins (alpha2-HS-glycoprotein, prothrombin F1, and OPN) were obtained. The proteins were analyzed by anion-exchange chromatography. Furthermore, OPN levels in whole urine from 18 healthy individuals, 31 stone-formers, and two patients with HPT were measured using a new enzyme immunoassay system. The elution peaks for prothrombin and OPN were significantly smaller for the stone-formers and patients with HPT, compared with the healthy control subjects. Urinary concentrations of OPN assessed using the enzyme-linked immunosorbant assay were significantly lower for stone-formers. Lower urinary excretion of prothrombin F1 and OPN by stone-formers might be one of the reasons for stone formation.