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AbstractBackground: The reduction in nephrons in IgA nephropathy is critical to the prognosis of this disease. However, the immunopathological mechanism of the modifications seen in glomerular lesions is not clear. We thus investigated the influence of nephron reduction by heminephrectomy on renal lesions in a high immunoglobulin A inbred strain of ddY mouse (HIGA mouse), which shows progressive mesangial sclerosis with elevated renal expression of transforming growth factor (TGF)-β. Methods: Five-week-old HIGA mice were heminephrectomized (Nx), and were evaluated in comparison with a sham-operated group (S) at 40 weeks old. Histological findings, immunoglobulin depositions (IgG, IgA, and IgM), and expressions of cytokine and extracellular matrix proteins (TGF-β, fibronectin, collagen type I and IV) were analysed. PCNA and TUNEL stainings were performed with electron microscopic detection of apoptosis. Tissue renin-angiotensin systems (RAS) were also investigated by real-time quantitative RT-PCR. Results: In the Nx group, the glomerular tuft area and ratio of mesangial matrix area per tuft were significantly increased, and the glomerular cell count per tuft area was significantly decreased. Glomerular immunoglobulin deposits of IgG, IgA, and IgM in Nx were all significantly expanded in the paramesangium. The glomerular expressions of TGF-β and the extracellular matrix proteins were significantly increased in Nx mice. In contrast to the significant decrease of PCNA-positive cells, TUNEL-positive cells were significantly increased in Nx. Angiotensin-converting enzyme (ACE) was significantly increased in the renal cortex of Nx. Conclusion: Simple heminephrectomy, other than 5/6 renal ablation, of HIGA mice may be a potential model for research into the progressive glomerulosclerosis of human IgA nephropathy. The pathological role of apoptosis is apparently involved in these disease processes, possibly through upregulated RAS.Copyright © 2002 S. Karger AG, Basel

α-Helical polypeptides containing a pair of L-1-pyrenylalanine and L-p-nitrophenylalanine that are separated by 0−8 amino acid units were synthesized. The rates of photoinduced electron transfer (ET) from the pyrenyl group to the nitrophenyl group were evaluated from the decay curves of pyrenyl fluorescence recorded at different temperatures from −58 to +30 °C. The rate constants showed a complex dependence on the number of spacer amino acids. In particular, recoveries of the ET rates with increasing the number of spacer amino acids from 1 to 2 and from 5 to 6 were found. The ET rate constants, however, exhibited a simple exponential dependence on the edge-to-edge distance between the two chromophores, with a distance decay factor β = 0.66 ± 0.1 (Å^-1). The ET data on the α-helical polypeptides were analyzed on the basis of the tunneling pathway model. The optimum ET pathways from the pyrenyl group to the nitrophenyl group were searched, and the relative values of the ET matrix elements were evaluated for each polypeptide with different number of the spacer units. The calculated distance dependence was in reasonable agreement with the experimental one when jumps through hydrogen bonds were taken into account.

Our recently established high immunoglobulin (Ig)A inbred strain (HIGA) of ddY mice showed constantly high serum IgA levels, progressive mesangial sclerosis accompanied by IgA deposits, and elevated renal expression of transforming growth factor (TGF)-beta, mimicking IgA nephropathy. In the present study, we assessed the role of the immune system, especially of T cells, in this strain.

Summary: Sepabeads FP series with a variety of anion-exhanger type functional groups have been examined as largescale chromatographic separation media for proteins. The adsorption-desorption behavior of proteins has been found to be dependent mainly on the type and partly on the content of the attached amino ligands. The effect of the attached groups are discussed using batch measurement data. It has been found that the existence of ethanol residue on the nitrogen atom incrases the hydrophilic nature of quaternary ammonium type packings and thus gives a higher protein adsorption capacity. Among weakly basic type anionexchangers, polyethyleneimine-modified packings showed very large protein capacities.

TheBcl2-related genes, Bax and Bcl2l (formerly called Bclx), are involved in the regulation of apoptotic cell death, and the chromosome location of these two genes was determined in the mouse and rat by fluorescence in situ hybridization. Bcl2l was localized to mouse chromosome 2H1 and rat chromosome 3q41.2, and BΑx was localized to mouse chromosome 7B5 and rat chromosome 1q31.2. Both genes mapped in a region of conserved linkage homology between the two species. Molecular linkage analysis using interspecific backcross mice revealed the murine Bcl21locus at 0.7 cM terminal to D2MU22, and the murine BΑx locus at 0.8 cM terminal to D7Nds5.

Temporal dynamics of a lentic microphagotroph community were studied during leaf litter decomposition from December to May. Small plastic vessels containing leaf litter were placed on a pond bottom. They were sampled periodically to collect microphagotrophs. Three abiotic factors and abundance of two food items were also measured to analyze the autogenic and allogenic phenomena during a microphagotroph succession. Three behavior types were recognized in dominant taxa: a free-swimming type, a vagile (creeps on substratum, sometimes swims) type, and a voluntarily fixed type. Dominant taxa changed from the free-swimming to the vagile type up to mid-March, and the reverse change occurred from mid-April. Principal component analysis (PCA) indicated four factors affecting the dynamics of the community: water temperature as a seasonal factor, detritus volume on the litter surface as a habitat factor, and densities of bacteria and small flagellates as food factors. Taxa replacement appeared to occur through two mechanisms. (1) Dominance of small holotrichs, a free-swimming type, was brought about by a high bacterial density caused by seasonal events, i.e., leaf fall in December and detritus formation by litter feeders in mid-April. This is an allogenic aspect of community dynamics. (2) The free-swimming type was replaced by the vagile one during the period with high taxa diversity. This replacement occurred through intertaxa competition for scarce food and/or selective predation by larger microphagotrophs. It is an autogenic process within the community.

A case is presented of anterior mediastinal bronchogenic cyst associated with adenocarcinoma arising from the cyst wall. The presence of a solid component in the lower portion of the mass was suspected from CT and confirmed by MRI.