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Biomedical subjects

H J Duan

Publications and source records attributed to H J Duan.

17 recordsLinked to original sources
PubMed1994

Light and electron microscopic radioautographic study on the incorporation of 3H-thymidine into the lung by means of a new nebulizer.

The aim of this study was to investigate whether the water particles produced by a nebulizer can reach the alveoli of the lung when they are inhaled with the air. For the purpose of demonstrating water particle incorporation into the lung, light and electron microscopic radioautography with tritiated thymidine was employed. Tritiated thymidine was dissolved in distilled water and nebulized to fine water particles with a new type nebulizer named Shinki, then inhaled by mice. The lungs were taken out and processed by either rapid-freezing and freeze-substitution for dry-mounting radioautography or conventional chemical fixation for wet-mounting radioautography. By wet-mounting radioautography, silver grains were observed in the nuclei of a few alveolar type 2 cells and interstitial cells, demonstrating DNA synthesis. By dry-mounting radioautography numerous silver grains were located diffusely in all the epithelial and interstitial cells, demonstrating diffuse localization of soluble radioisotope-labeled compounds. These results show that water particles produced by the Shinki nebulizer can directly reach the alveoli and thus, better therapeutic effect can be acquired with the Shinki nebulizer than with the usual nebulizer. Further, the nebulizer can be used for the radioautographic studies of the lung in demonstrating incorporation of some drugs into alveolar tissues.

Animals↗
PubMed1993

Anionic sites in glomerular basement membrane of rats with serum sickness nephritis: quick-freezing and deep-etching study.

Serum sickness nephritis was induced in male Fisher 344/JCL rats by injecting egg albumin into the foot pads and peritoneal cavity. The alteration of anionic sites in the glomerular basement membrane (GBM) of the rats with significant proteinuria was studied with a quick-freezing and deep-etching method using polyethyleneimine as a cationic probe. In control rats, anionic sites were located around the fibrils of the lamina rara externa, which radiated perpendicularly from the lamina densa to podocyte cell membranes. In the glomeruli of proteinuric rats, many electron-dense deposits were observed in the subepithelial side of the GBM, where the fibrils of the lamina rara externa were usually obscured and anionic sites around them could not be recognized. However, in some areas, a clear boundary could be observed between deposits and the lamina densa. Electron micrographs of freeze-fractured deposits showed that the fibrils radiated perpendicularly from the lamina densa and that anionic sites around them had been preserved. These results suggest that some of the deposits simply passed through the GBM and masked transiently the fibril structures of the GBM, but others probably destroyed these fibril structures, including anionic sites.

Animals↗
PubMed1993

Glomerular extracellular matrices and anionic sites in aging ddY mice: a morphometric study.

A morphometric study was undertaken to examine age-related changes in glomerular ultrastructure and anionic sites in ddY male mice at various ages. A progressive increase in glomerular extracellular matrices, including thickening of the glomerular basement membrane (GBM), formation of GBM nodules, and mesangial matrix increase, was found to be the primary age-related ultrastructural change in aging mice; there were also electron-dense deposits in mesangial and subepithelial regions. The extent of GBM thickening in mice was less than was reported in rats. Rather, the GBM nodules, which had the same electron density as the lamina densa (LD) and protruded on the subepithelial side of the GBM, were more striking. Quantitative evaluation showed that GBM thickness, number and size of GBM nodules, and the area of the mesangial matrix were significantly correlated with the age of the mice. The distribution of anionic sites in the glomeruli of aging animals was described for the first time. No statistically significant differences were noted between the number of glomerular anionic sites in the different age groups. These results indicate that the increase in glomerular extracellular matrices reported in aged rats was also present in aged mice, although the extent of various changes was different. The results also indicate that this increase in glomerular extracellular matrices with age was not accompanied by significant alteration in glomerular anionic sites.

Aging↗
PubMed1992

Polyarteritis nodosa with atrophy of the left hepatic lobe.

A 73-year-old Japanese man with a history of partial gastrectomy due to gastric cancer 4 years previously was admitted because of intermittent fever. The patient developed abdominal pain, erythema, and myalgia in addition to the fever during the final clinical course, and died of acute heart failure. Autopsy disclosed atrophy of the left lobe of the liver and acute myocardial infarction. Neither metastasis nor recurrence of the cancer was observed. Small- and medium-sized arteries of the visceral organs showed various stages of necrotizing vasculitis with narrowing of the lumina. The vasculitis was most prominent in the left lobe of the liver and in the heart. Narrowing of the portal vein due to portal tract inflammation in addition to vasculitis of the hepatic arteries may have induced ischemia and infarction, which had resulted in atrophy of the left hepatic lobe.

Aged↗
PubMed1992

Immune deposits in the glomerular extracellular matrix detected by the quick-freezing and deep-etching method.

Chronic serum sickness nephritis was induced in rats by sensitization with egg albumin. The glomeruli were then examined by the quick-freezing and deep-etching method with immunohistochemical identification of immune complex deposits on replica membranes. In control rats, the glomerular basement membrane showed a three-layered structure. The middle layer was composed of a compact meshwork of fine fibrils that was connected to adjacent endothelial and epithelial cells by perpendicular fibrils in the inner and outer layers. The mesangial matrix contained a similar but looser meshwork structure. In the nephritic rats, small granular deposits were observed within the meshwork, distorting its fine structure. Larger nodular aggregates extended continuously from the middle layer to the epithelial side. Disruption of the connecting fibrils overlying these larger aggregates was noted. The deposits were stained by antiegg albumin or antirat IgG antibodies. Gold particles immunostaining for the sensitizing antigen were also localized within the deposits. These findings suggest that the deposition of immune complexes occurs in the fibrillary meshworks of the mesangium and lamina densa in this experimental model, with the resultant distortion of their meshwork structures and the formation of nodular aggregates.

Animals↗
PubMed1992

Age-related character of glomerular lesions in IgA nephritis. (2). Histopathological peculiarity in childhood onset.

Histopathological analysis was performed in the first renal biopsy specimens of patients over and under 10 yrs of IgA nephritis. They were divided clinically into two groups, the one with remission and the other with prolonged disease state respectively. Increased mesangial sclerosis, frequent occurrence of segmental glomerular lesions and tubulointerstitial change were significantly evident in the group with prolonged disease state. It is suggested that similar glomerular events are progressing in IgA nephritis which is carried over to adult age.

Adolescent↗
PubMed1991

Ultrastructure of matriceal changes in chronic phase of Masugi nephritis by quick-freezing and deep-etching method.

The three-dimensional ultrastructure of glomerular sclerosis in the chronic phase of Masugi nephritis was investigated using a quick-freezing and deep-etching method. Newly formed mesangial matrix, which was increased in the axial portions, was composed of fine fibrillar networks similar to those in the lamina densa of the basement membrane. These fibrils were 10-20 nm in diameter and directly attached to the cell membranes of mesangial cells, endothelial cells and podocytes by connecting fibrils. Moreover, thicker fibrils with diameters of 20-30 nm were present in the networks and were connected with cross-bridges. A newly formed matrix of fine fibrillar networks was also seen in the areas of mesangial interposition in the glomerular capillary wall. The border between the matrix and lamina densa was unclear. The fibrils organizing the networks of lamina densa of the glomerular loop were thickened, with some decoration. Connecting fibrils were disrupted in the areas of endothelial detachment. It is suggested that prolonged tissue injury with endothelial detachment might induce mesangial sclerosis composed of fine fibrillar networks. The increase in density of the networks seemingly interfere with the contractile function of mesangial cells, which is followed by alteration of mesangial flow.

Animals↗
PubMed1991

Masking of anionic sites by deposits in lamina rara externa in immune complex nephritis in rats.

Alterations in glomerular basement membrane (GBM) anionic sites associated with immune deposits (ID) were observed using polyethyleneimine (PEI) as a cationic probe in serum sickness nephritis induced by egg albumin (EA). The anionic sites were fewer in number than in other GBM segments and were irregular in distribution in most, but not all, of the segments of the GBM with ID on the epithelial side of the lamina densa (LD). The disappearance of anionic sites was obvious in areas where the internal aspects of the lamina rara externa (LRE) of the GBM were occupied by ID, even if the ID were very small. In contrast, the disappearance of anionic sites was not evident, even though no change in anionic sites was found in some areas, where the ID had departed from the internal aspects of the LRE and a pale band was seen between the ID and the LD. Further, PEI aggregates, showing localization of anionic sites, were seen within the low density ID, but no PEI aggregates were seen within the high density ID. The results suggest that: 1) whether or not ID induce the disappearance of anionic sites is independent of the size of the ID, but is dependent on the density of and the place occupied by the ID, and 2) the ID seem to induce the disappearance of anionic sites by masking rather than destroying them.

Animals↗
PubMed1991

Small cell carcinoma of the gallbladder combined with adenocarcinoma.

A rare case of small cell carcinoma (SCC) of the gallbladder combined with adenocarcinoma is reported. The patient was a 70-year-old Japanese man, who died of the disease shortly after the onset of symptoms. Autopsy disclosed a small tumor (1.0 cm in longest diameter) in the fundus of the gallbladder, with widespread metastasis. Histochemically, the tumor cells showed negative reactions for argyrophilic and argentaffin stainings, a weak immunohistochemical reaction only for neuron-specific enolase, and negative reactions for all of the other neurosecretory markers used, including neurofilament, chromogranin, somatostatin, gastrin and leu-7. However, electron microscopic examination revealed a few typical neurosecretory granules (NSG) in the cytoplasm of some tumor cells. We suggest that: 1. The presence of NSG in the cytoplasm of tumor cells is the most reliable diagnostic criterion for SCC. 2. SCC, at least the combined type, arises from a multipotential stem cell.

Adenocarcinoma↗
PubMed1991

Diffuse malignant peritoneal mesothelioma in a young woman with a high serum level of CA125.

An autopsy case of diffuse malignant peritoneal mesothelioma in a young woman who showed a high serum level of CA125 is reported. Autopsy revealed extensive tumor involvement of the visceral and parietal peritoneum. The liver, spleen and other abdominal viscera were encased by tumor nodules. Histologically, the polygonal tumor cells were arranged mostly in a sheet-like fashion with a few tubular or papillary forms. No PAS reaction-positive mucin was recognized, but there was a strongly positive colloidal iron reaction. The colloidal iron positivity was effaced after combined treatment with hyaluronidase and sialidase. Immunohistochemically the tumor cells showed strongly positive reactions for CA125, epithelial membrane antigen (EMA) and cytokeratin, weak positivity for carcinoembryonic antigen (CEA) and focal positivity for vimentin. Ultrastructurally, the most characteristic feature was the expression of numerous long microvilli projecting from the tumor cell surfaces and abundant long desmosomes between the tumor cells. We consider that pretreatment using a combination of hyaluronidase and sialidase might be useful for the diagnosis of malignant mesothelioma. CA125 staining should be performed routinely in cases where this tumor is suspected.

Adolescent↗
PubMed1991

[Studies on the analysis of beta-blocking agents].

A method for the separation and identification of 13 beta-blockers using GC/MS and GC/NPD are described. The TFA and TMS derivatives were prepared by adding TFAA, MSTFA and MBTFA to the standard drugs. The mixture was heated at 65 degrees C for 20 min and chromatographed on FS capillary columns (HP-5). Preliminary results show that the derivatization with MSTFA is better than that with TFAA or MBTFA. There is not much difference between TFAA and MBTFA derivatization. The method is reliable, rapid and simple and may be used to screen these drugs and further applied to the analysis of biological fluids such as plasma and urine.

Adrenergic beta-Antagonists↗
PubMed1991

Study on the doping control method for the detection of narcotic analgesics and beta-blockers.

The analytical method for doping control analysis has been studied. Twenty-nine drugs including eighteen narcotic analgesics, nine beta-blockers, one stimulant and one internal standard were analysed simultaneously by gas chromatograph equipped with a nitrogen-phosphorous detector and gas chromatograph combined with a mass selective detector after derivatization of the drugs.

Adrenergic beta-Antagonists↗
PubMed1991

[Studies on the analysis of anileridine, levorphanol, nalbuphine and ethamivan in urine].

The method for the analysis of anileridine, levorphanol, nalbuphine and ethamivan in urine by means of GC/NPD and GC/MSD is described. TFAA and MSTFA-MBTFA have been used in this procedure for TFA and TMS derivatization. The parent forms and the metabolites of the four drugs can be found by GC/NPD screening and GC/MSD confirmation. The method is reliable, fast and sensitive.

Benzamides↗
PubMed1991

Influence of subepithelial deposits on permeability of the glomerular capillary wall in serum sickness nephritis in the rat.

Serum sickness nephritis was induced in male Fisher rats by immunization with egg albumin (EA). Correlations of subepithelial deposits (SD) with size and charge barriers of the glomerular filter were investigated using native (NF) and cationized (CF) ferritin as tracer probes. In proteinuric animals large numbers of NF molecules perfused from the abdominal aorta were observed to cross the glomerular basement membrane (GBM) and enter SD. The concentration of NF molecules was higher in GBM segments with SD than in GBM segments without SD, and the concentration of these molecules was higher within SD than in the intervening GBM. In contrast, CF clusters were fewer in number in the lamina rara externa (LRE) of GBM segments with SD than in the GBM segments without SD. CF particles could not be observed within SD, even in the areas of podocyte detachment. It is suggested that permeability in GBM segments with SD increases and that the development of proteinuria in this model can be attributed to alterations in both charge- and size-selective barriers to glomerular filtration.

Animals↗
PubMed1990

Sequential ultrastructural podocytic lesions and development of proteinuria in serum sickness nephritis in the rat.

Serum sickness nephritis was induced in Fisher rats by immunization with egg albumin (EA) and correlations between immune complex deposition, alterations of podocytes and development of proteinuria were analysed. Immunoelectron microscopy showed that EA, rat IgG and C3 were confined to the electron-dense deposits (Ds). From 3 weeks, when significant proteinuria had developed, the subepithelial region was filled with large numbers of Ds on the peripheral capillary wall as well as in the paramesangium. The loss of slit diaphragms and detachment of foot processes overlying Ds were observed and the escape of Ds into urinary space was frequently detected. Morphometric evaluation showed that the volume of subepithelial Ds and the number of the sites of podocytic detachment correlate significantly with the amount of proteinuria. In addition, the native ferritin injected via the abdominal aorta was seen in large amounts in the urinary space near the areas devoid of epithelial covering. The development of podocytic detachment was clearly coincident with the appearance of proteins with a larger molecular weight in urine. From these results, it is suggested that the loss of slit diaphragms and the detachment of podocytes resulting from the progressive accumulation of Ds will allow the leakage of proteins of larger molecular weight across the capillary wall. These podocytic lesions may be one of the main aetiologies for the development of heavy proteinuria in this model.

Animals↗
PubMed1989

[Studies on the analysis of some narcotic analgesics and CNS-stimulants].

Procedures for the separation and identification of 12 narcotic analgesics and 2 CNS-stimulants are described using GC/FID, GC/NPD and GC/MSD. The TFA and TMS derivatives were prepared by adding TFAA, MB TFA and MSTFA to the standard drugs. The mixture was heated at 70 degrees C for 30 min and chromatographed on FS capillary columns (SE-54, HP-5). Preliminary results show that all the derivatization with TFAA is better than that with MBTFA, but not much different from MSTFA derivatization. The method is reliable, fast and simple and may be used to screen these drugs and further applied to the analysis of biological fluids such as plasma and urine.

Analgesics, Opioid↗