A particle tracking model approach to determine the dispersal of riverine plastic debris released into the Indian Ocean.

Although the Indian Ocean receives a large amount of land-based plastic waste, the studies on pathways of riverine plastic debris are limited to date. Therefore, a particle tracking model that included ocean surface currents, horizontal diffusion, Stokes drift, windage, and beaching/re-drifting processes was developed to reproduce the behavior of riverine plastic debris in the Indian Ocean. The modeled particles were released in the model domain based on riverine plastic debris database. The maximum abundance of beached particles occurred during the southwesterly monsoon season, particularly in the Bay of Bengal. The particles released from the rivers were trapped in the northern Indian Ocean unless both Stokes drift and windage were excluded from transportation velocity. These results suggest that the riverine plastic debris was trapped in the northern Indian Ocean until it fragmented into less buoyant small microplastics drifting in the subsurface layer, free from windage and Stokes drift at increasing depths.

Successful therapy with tonsillectomy for severe ISKDC grade VI Henoch-Schönlein purpura nephritis and persistent nephrotic syndrome.

Henoch-Schönlein purpura (HSP) is a systemic disorder characterized by leukocytoclastic vasculitis involving the capillaries and the deposition of IgA immune complexes. Renal involvement is the principal cause of morbidity and mortality in children with HSP. We report here a 13-year-old girl with Henoch-Schönlein purpura nephritis (HSPN) of International Study of Kidney Disease in Children (ISKDC) grade VI and persistent nephrotic syndrome despite receiving conventional therapy, such as prednisolone, methylprednisolone and urokinase pulse therapy and plasmapheresis (PP). The patient was treated with tonsillectomy, which subsequently decreased proteinuria, induced the disappearance of microscopic hematuria, and improved renal pathological findings. A regimen of methylprednisolone and urokinase pulse therapy plus PP with tonsillectomy may be an effective and useful therapy for some children with severe HSPN children of ISKDC grade VI and persistent nephrotic syndrome.

IgA nephropathy in a patient with dominant dystrophic epidermolysis bullosa.

Dystrophic epidermolysis bullosa (DEB) is a rare and severe hereditary dermatosis. On the other hand, IgA nephropathy is the most common form of glomerulonephritis in childhood and adults, and clinically characterized by microhematuria and proteinuria and histologically by deposition of immunoglobulin A in mesangial lesions. Several renal complications of recessive DEB including IgA nephropathy and amyloidosis have been reported. However, there have been no reports on dominant DEB associated with IgA nephropathy. We report here for the first time a 17-year-old girl with dominant DEB associated with IgA nephropathy. The patient has suffered from episodes of urinary, upper airway, and skin infections. At 17 years of age, proteinuria and hematuria were detected, with a high value of serum IgA. Renal biopsy was performed, and immunofluorescence microscopic examination revealed segmental deposits of IgA in mesangial lesions, with many glomeruli exhibiting diffuse segmental mesangial-proliferative glomerulonephritis. We diagnosed dominant DEB associated with IgA nephropathy on the basis of proteinuria, hematuria, and deposits of IgA in mesangial lesions on immunofluorescence microscopic examination, and diffuse segmental mesangial-proliferative glomerulonephritis. These findings suggest that repeated skin infections might have contributed to the pathogenesis of IgA nephropathy in this patient.

Renal expression of alpha-smooth muscle actin and c-Met in children with Henoch-Schönlein purpura nephritis.

Alpha-smooth muscle actin (alpha-SMA) is the actin isoform that predominates within vascular smooth-muscle cells and plays an important role in fibrogenesis. On the other hand, c-Met is the receptor for hepatocyte growth factor (HGF), which plays a role in protection from injury and has anti-fibrogenetic effects. To clarify whether alpha-SMA and HGF are associated with the progression of renal injury in Henoch-Schönlein purpura nephritis (HSPN), we evaluated the renal expression of alpha-SMA and c-Met in HSPN patients. Patients were divided into three groups. Group 1 consisted of eight patients (male:female 4:4) with stage II or less in the classification of the International Study of Kidney Disease in Children (ISKDC), Group 2 consisted of 20 patients (male:female 11:9) with ISKDC stage III or greater and a good prognosis, and group 3 consisted of seven patients (male:female 3:4) with ISKDC stage III or greater and poor prognosis. Renal biopsy findings, including c-Met and alpha-SMA staining, were investigated for each group. At first biopsy, the mean scores for renal alpha-SMA and glomerular c-Met in groups 2 and 3 were higher than those in group 1, while mean scores for neither renal alpha-SMA nor glomerular c-Met differed between groups 2 and 3. At second biopsy, the mean scores for renal alpha-SMA staining in group 3 were higher than those in group 2, and mean score for glomerular c-Met staining in group 3 was lower than that in group 2. In groups 2 and 3, the mean scores for glomerular and interstitial alpha-SMA staining at first biopsy were correlated with the chronicity index (CI) at second biopsy, but the mean score for glomerular c-Met staining at first biopsy correlated with neither the activity index (AI) nor CI in the first or second biopsies in all groups. Our findings suggest that the expression of renal alpha-SMA may be associated with progression of renal injury in HSPN.

Development of glomerular endothelial cells, podocytes and mesangial cells in the human fetus and infant.

The process of glomerular development consists of four developmental stages: vesicle (V) stage, S-shaped body (S) stage, capillary loop (C) stage and maturation (M) stage. However, the development of glomerular endothelial, mesangial and epithelial cells in fetal and infant kidneys remains unclear. In order to determine the characteristics of human glomerular development, we investigated the process of glomerular development by staining fetal and infant kidneys for CD31, CD34 and FB21, markers for endothelial cells, alpha-smooth muscle actin (alpha-SMA), a marker for mesangial cells, and nephrin, a marker for podocytes. These series of studies were carried out on kidneys obtained at autopsy from 27 fetuses and 5 infants. The fetuses were divided into the following 5 groups according to gestational age; 13-19, 20-24, 25-29, 30-34 and 35-39 weeks. In each group, glomerular development was classified according to the developmental stage and the staining patterns for CD31, CD34, FB21, alpha-SMA and nephrin. The proportion of V-stage development in 100 glomeruli examined was highest at 13-19 weeks. After 20 weeks, the V-stage proportion decreased gradually, and the proportion of S stage became highest at 20-24 weeks. The C-stage proportion was highest at 25-29 weeks, while the M-stage proportion was highest in infants aged 1-6 months. The staining patterns for CD31, CD34 and FB21 were similar in endothelial cells after 25 weeks of gestation. Staining of alpha-SMA and nephrin was first observed in the S stage. In conclusion, maturation of endothelial cells starts at 25 weeks and is completed by 35 weeks of gestation. Epithelial cells and mesangial cells first appear during the S stage.

Efficacy of steroid pulse, plasmapheresis, and mizoribine in a patient with focal segmental glomerulosclerosis.

There have been few reports on successful treatment for focal segmental glomerulosclerosis (FSGS) complicated by leukoencephalopathy. We report the efficacy of the steroid pulse and mizoribine (MZB) combined with plasmapheresis (PP) for a case of FSGS with leukoencephalopathy induced by cyclosporine (CyA). The patient was a 4-year-old boy with FSGS who presented with steroid-resistant nephrotic syndrome (NS) and was treated with CyA. On the 7th day after starting CyA, he complained of one visual disorder, and hypertension and tonic convulsions were observed. Electroencephalography (EEG) revealed generalized slow waves, and magnetic resonance imaging (MRI) disclosed high signal intensity in the white matter. A diagnosis of leukoencephalopathy induced by CyA was made on the basis of these findings with the improvement in clinical manifestations upon discontinuation of CyA. We treated the patient with steroid pulse therapy and MZB combined with PP, and the proteinuria gradually decreased and only microscopic hematuria remained. We report that steroid pulse and MZB combined with PP may be an effective treatment in a patient with FSGS complicated by CyA-induced leukoencephalopathy.

Profound reduction in T-helper (Th) 1 lymphocytes in peripheral blood from patients with concurrent type 1 diabetes and Graves' disease.

Type 1 diabetes likely is mediated by T-helper (Th) 1 lymphocytes, while Graves' disease may involve Th2 predominance. We investigated the balance between Th1 and Th2 cells and between Th1- and Th2-associated chemokine receptor expression on peripheral lymphocytes in subjects including patients with coexisting type 1 diabetes and Graves' disease. Peripheral blood mononuclear cells of all subjects were examined by flow cytometry for intracellular cytokines (IFN-gamma for Th1; IL-4 for Th2) and expression of the chemokine receptors CXCR3 (Th1-associated) and CCR4 (Th2-associated). Plasma concentrations of interferon-inducible protein (IP)-10, a CXCR3 ligand, and thymus and activation-regulated chemokine (TARC), a CCR4 ligand, were measured by enzyme-linked immunosorbent assays. IFN-gamma producing-T lymphocytes were significantly fewer in patients with coexisting type 1 diabetes and Graves' disease (12.4 +/- 6.8%, n = 6) than in healthy control subjects (19.9 +/- 4.1%, n = 6; P < 0.01) or patients with type 2 diabetes (19.1 +/- 4.5%, n = 5; P < 0.05). We found no significant difference in IFN-gamma-producing T lymphocytes between healthy controls and patients with only type 1 diabetes (n = 8) or Graves' disease (n = 5). Plasma IP-10 concentrations were significantly higher in patients with coexisting type 1 diabetes and Graves' disease than in control subjects (106.3 +/- 30.48 vs. 66.7 +/- 25.3 pg/ml, P = 0.0343). Considering only patients with type 1 diabetes alone, duration of diabetes correlated positively with IFN-gamma-producing T lymphocytes (r = 0.773, P = 0.0242) and the ratio of CXCR3 to CCR4 receptor expression (r = 0.947, P = 0.0004). In conclusion, Th1-associated T lymphocytes were fewer in peripheral blood from patients having both type 1 diabetes and Graves' disease than in those with either disease alone. Numbers of peripheral Th1 lymphocytes increased with increasing time from onset of type 1 diabetes in patients with type 1 diabetes alone.

Correlation between increased platelet-associated IgG and thrombocytopenia in secondary dengue virus infections.

Although the public health impact of dengue is increasing rapidly, the mechanism of thrombocytopenia in this disease remains unknown. To elucidate this mechanism, the relationship between platelet-associated IgG (PAIgG) and platelet count in 53 patients in the acute phase of secondary dengue virus infection was investigated in a prospective-hospital-based study. A significant inverse correlation between the two parameters was found in these patients, while no correlation was observed in healthy volunteers. The low baseline platelet counts during the acute phase in 12 patients with secondary dengue virus infection significantly increased during the convalescent phase, while the increased PAIgG levels during the acute phase in these patients significantly decreased during the convalescent phase. Anti-platelet IgG autoantibody was detected rarely in the plasma of 53 patients with secondary dengue infection. The involvement of anti-dengue virus IgG was also shown in platelets from all of 8 patients in the acute phase of secondary dengue virus infection. These findings suggest that PAIgG formation involving anti-dengue virus IgG plays a pivotal role in the induction of transient thrombocytopenia during the acute phase of secondary dengue virus infection.