Search PubMed⌕ Search

Biomedical subjects

H Chiang

Publications and source records attributed to H Chiang.

117 records · Page 7Linked to original sources
PubMed1982

Cystine accumulation and clearance by normal and cystinotic leukocytes exposed to cystine dimethyl ester.

Upon exposure to 0.25 mM cystine dimethyl ester, normal and cystinotic leukocytes accumulate substantially more intracellular cystine than is present endogenously in cystinotic cells. Leukocytes loaded by exposure to cystine dimethyl ester may have abnormally lucent and distended lysosomes, and the cystine is compartmentalized within the granular fraction of the cells. After the cells are exposed to cystine dimethyl ester, cystine clearance from normal leukocytes is much faster than from cystinotic cells. The ratios of labeled cysteine-N-ethylmaleimide to cystine are also greater in normals than in cystinotics 60 min after termination of loading. No overlap in ranges of cystine clearance half-times or cystine-N-ethylmaleimide to cystine ratios was observed in normal compared to cystinotic leukocytes. Limited experiments with fibroblasts exposed to cystine dimethyl ester suggest a correspondingly prolonged cystine clearance for cystinotic cells. These experiments provide evidence for defective clearance of cystine from cystinotic lysosomes in situ.

Cystine↗
PubMedDate not supplied

Influence of carbon disulphide on hydroxyl radicals in the phenanthroline chemiluminescence system.

We investigated the effects of carbon disulphide (CS2) on hydroxyl radical generation using the phenanthroline chemiluminescence system. The influence of CS2 on the phenanthroline chemiluminescence system without CuSO4 and vitamin C were tested. The results showed that CS2 enhanced the emission intensity of chemiluminescence and advanced the peak time of the chemiluminescence. There was a dose-effect relationship between CS2 concentrations (0-160 mg/ml) and chemiluminescence peak intensity (r = 0.955, R2 = 0.913, p = 0.003), as well as CS2 concentrations and peak time (r = -0.927, R2 = 0.860, p = 0.008). The enhanced chemiluminescence induced by CS2 could be inhibited by thiourea, and the inhibition rate gradually deceased along with increasing CS2 concentration (r = -0.816, R2 = 0.666, p = 0.048). When the system was free of CuSO4 and vitamin C, CS2 also induced the emission of chemiluminescence intensity. We conclude from these results that CS2 can induce the phenanthroline chemiluminescence system to generate hydroxyl radicals and advance the peak time, and that thiourea can inhibit the effect. The mechanism may be explained by a catalytic effect of CS2 directly on H2O2.

Ascorbic Acid↗
PubMedDate not supplied

Transurethral resection of the prostate-related changes in the prostate gland: correlation of MRI and histopathology.

PURPOSE: The purpose of this work was to demonstrate signal changes of the prostatic urethra after transurethral resection of the prostate (TURP) on MR images and histopathologic correlation. METHOD: Sixty-three patients with prostate cancer confirmed by either TURP (Group A, 19 patients) or transrectal biopsy (Group B, 44 patients) were evaluated by endorectal MRI before radical prostatectomies. The MR images of postcurettaged prostatic urethras were correlated with the histopathologic features. RESULTS: On the T2-weighted images, a thin zone of hypointense signal surrounding the curettaged prostatic urethra was identified in 52.6% (10/19) of Group A patients, imaged soon after (mean 21.1 days) TURP, but was indiscernible in Group B patients and the other Group A patients, imaged later after TURP (mean 49.2 days). This hypointense signal zone histopathologically correlates with a zone of inflammatory tissue reaction surrounding the widened urethra. CONCLUSION: Inflammatory tissue reaction surrounding curettaged prostatic urethra after TURP accounts for the presence of a low signal zone on T2-weighted images.

Aged↗
PubMedDate not supplied

A prospective evaluation of biopsy site in the diagnosis of gastric malignancy: the margin or the base?

The diagnostic value of endoscopic biopsy from the ulcer margin (six specimens) and the base (six specimens) in 46 cases of gastric malignancy was evaluated. The biopsy positive rates for malignancy from the ulcer margin and the base were 42 of 46 (91.3%) and 37 of 46 (80.4%), respectively (P = 0.2312). The diagnostic positive rate was increased to 95.6% (44 of 46) when the results of 12 biopsy specimens obtained from the ulcer margin and the base were combined. The diagnostic positive rate was not statistically different when the morphology or the location of the gastric malignancy was considered. No complication of massive bleeding or perforation was found after both sites had been biopsied. It is concluded that the margin and the base of a gastric malignant ulcer are both suitable and diagnostically effective for endoscopic biopsy. If the ulcer margin of the gastric malignancy is difficult to approach, the ulcer base appears to be a satisfactory alternative site for endoscopic biopsy.

Adenocarcinoma↗
PubMedDate not supplied

Evaluation of an automatic hematology analyzer in patients with nonhematologic conditions.

The Coulter STKS is a new automated hematology analyzer that provides complete blood counts (CBCs) and a five-part white blood cell (WBC) differential count. This study evaluated its performance and determined its value in reducing the extensive manual work required to obtain WBC differential counts from patients with nonhematologic conditions. The evaluations included precision, carryover, effects of storage duration and temperature, comparison of primary (automated) and secondary (manual) methods of aspiration, comparison with the Technicon H*1 machine, and WBC differential capability. Both primary and secondary methods provided CBC values that were precise, repeatable, and satisfactory. The WBC differential results also were accurate and comparable to those obtained manually. The Coulter STKS not only precisely analyzes CBCs but also screens blood samples without WBC abnormalities, as it has a 98% predictive value of negative test results. This instrument is suitable for use in nonhematology patients in large medical centers, teaching hospitals, and general hospitals.

Automation↗
PubMedDate not supplied

Childhood nephrotic syndrome and heavy proteinuria in Taiwan. A retrospective clinicopathologic study.

From April 1981 to November 1987, 347 children with either nephrotic syndrome (NS; 262 cases, 75.5%) or heavy proteinuria (85 cases, 24.5%) were studied to determine the clinicopathologic manifestation of these diseases among Taiwanese children. All of the children were less than 18 years of age and all had undergone renal biopsy. IgM mesangial nephropathy (IgMN; 93 cases, 26.9%) and minimal change nephrotic syndrome (MCNS; 62 cases, 17.8%) are the most frequently found pathologic lesions. The clinical course of MCNS is always responsive to steroids and less relapsive. However, IgMN is characterized by its good initial response to steroids and frequent relapses. As for secondary glomerulonephritis, lupus nephritis has the first position and comprises 18.4% (64 cases) of all cases. Membranous nephropathy associated with hepatitis B antigenemia (HBVMN; 34 cases, 9.8%) has the second position. Most cases of membranous nephropathy in children in Taiwan are HBVMN. The age of peak incidence is around 2-7 years old. Most of them had frequent relapses of NS or persistent heavy proteinuria. Membranoproliferative glomerulonephritis (MPGN) accounts for only 1.2% (4 cases) of all cases, relatively lower than reported elsewhere. The high incidence of IgMN, HBVMN and low incidence of MPGN are probably due to geographic or racial differences in Taiwan with respect to those in other countries.

Adolescent↗
PubMedDate not supplied

Persistent histological and immunological abnormalities in congenital syphilitic glomerulonephritis after disappearance of proteinuria.

A 40-day-old male infant suffered from generalized anasarca, proteinuria and hematuria. Serologic study revealed marked elevation of antibody titer against Treponema pallidum, the same serologic finding was also noted in both his parents. Two weeks of treatment with penicillin was given. The edema subsided 7 days later, and proteinuria and hematuria disappeared 20 days after the initiation of penicillin treatment. At the age of 60 days, all the clinical symptoms and signs vanished; urinalysis and renal function were all within normal limits and renal biopsy was performed. Pathologic study revealed membranous glomerulonephritis with deposition of IgG, IgM and complement C3, C1q, C4 and treponema antigen in the subepithelial area of the glomerular basement membrane. These phenomena suggest that treponemal antigen-antibody complexes were deposited in the glomeruli and activated the classic pathway of complements, leading to an immune complex nephritis. Immunologic study revealed that the patient had high circulating helper T cells (CD4 cells), low level of suppressor T cells (Leu2+15+ cells) with high CD4/CD8 ratio. It was accompanied by detectable circulating immune complex and high titer of T. pallidum hemagglutinin antibody titer. This change suggests that abnormal immune regulation may play an important role in the development of syphilitic glomerulonephritis.

Glomerulonephritis↗