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Biomedical subjects

H Chiang

Publications and source records attributed to H Chiang.

At least 91 records · Page 5Linked to original sources
PubMed1992

The establishment of radioimmunoassay of cyclic AMP.

Succinyl cyclic AMP, coupled with human albumin, was injected into rabbit to elicit antibodies to the cyclic nucleotide hapten. The succinyl cyclic nucleotides were conjugated to human albumin through a carbodiimide coupling procedure. The radioligand was prepared essentially by the modified method of Hunter and Greenwood. The resulting radiolabeled 125-ScAMP-TME was subsequently purified by reverse phase chromatography on Seppak C18 cartridge and used as tracers. Free and bound form of labeled antigens in the assay system were separated according to their differences in adsorption to solid material, i.e., charcoal. The antisera in routine use had 8% cross-reactivity with cyclic GMP, but had no cross-reactivity with ADP, 5'-AMP or ATP. The sensitivity of the assay in standard was around 0.05 pmol/ml. The sequential saturation analysis system was superior to the equilibrium study in terms of its sensitivity in standard curve determination. The media dilution and recovery studies showed good parallelism with the standard curve. The intra-assay and inter-assay coefficient variations were 5% and 7%, respectively. It showed that a significant increase in tracer binding to the antibodies in equilibrium incubating system was obtained when they were incubated at 4 degrees C for up to 72 hours. When the standard curve was derived for Scatchard plot analysis, Kd of the curve decreased inversely with the increase of the antibodies diluted, the total binding capacity of the antibody would not alter. A thyroid-stimulating hormone produced a normal response of cyclic AMP concentrations in FRTL-5 tissue cultures.

Animals↗
PubMed1992

Parathyroid carcinoma in a patient with non-secretory pituitary tumor: a variant of multiple endocrine neoplasia type-I?

We report a case of pituitary adenoma in association with parathyroid carcinoma as an unusual combination of multiple endocrine neoplasia (MEN). A 48-year-old man had a trans-sphenoidal hypophysectomy and transcranial partial removal of a recurrent pituitary chromophobe adenoma followed by a course of radiotherapy in 1980. Four years later, he developed hypercalcemic crisis from a parathyroid carcinoma with invasion to the adjacent thyroid gland and skeletal muscle. A hemithyroidectomy and resection of the left lower parathyroid gland was performed. Three years later, he had local recurrence and anterior chest wall metastasis accompanied by hypercalcemia. After resection of the remnant and metastatic lesion, eucalcemia was achieved. There was no family history of endocrine tumors. This case illustrates the rare association of a malignant parathyroid tumor and a chromophobe adenoma of the pituitary as a variant of MEN syndrome.

Adenoma, Chromophobe↗
PubMed1991

Inhibition of microtubule assembly is a possible mechanism of action of mitoxantrone.

We have found that mitoxantrone can inhibit the polymerization of brain tubulin in a dose dependent manner. MXT had relatively high affinity for tubulin but had no appreciable effect on tubulin associated guanosine-triphosphatase (GTPase) activity nor could it compete with vinblastine (VB) and colchicine (Col) for tubulin binding sites. Furthermore, MXT (0.1-10 microM) is antiproliferative to cold-treated (0 degree C) epithelial cells after only brief exposure (30 min). These results indicated that MXT is a microtubule inhibitory agent and can exert its anticellular effect through modulation of microtubule assembly.

Animals↗
PubMed1991

Hamartoma of spleen: a case report.

Hamartoma of the spleen is a rare benign tumor. Only about 105 cases in English-writing literature were reported after first description by Rokitansky in 1861. We reported one case of asymptomatic splenic hamartoma in Taiwan which was found incidentally by ultrasonographic examination. Ultrasonography of abdomen revealed a slightly hypoechoic and nearly isoechoic tumor mass in the spleen. Computed tomography of the abdomen revealed a well-defined, low-attenuation mass in the spleen, which became isodense after contrast injection. Celiac arteriography and superselective splenic arteriography revealed a hypervascular mass with fine tumor vessels and tumor stains in the spleen. Splenectomy was performed and the microscopic examinations revealed typical red-pulp type hamartoma of the spleen.

Adult↗
PubMed1991

Comparison between histopathology and DNA histogram of testis.

From January to July 1989, the DNA histogram of testicular open biopsies was done for 11 patients of primary infertility and 7 patients of a control group. There were 2 failures in these 36 specimens. The flow cytometric analysis revealed characteristic patterns in the relative numbers of haploid (1C), diploid (2C), and tetraploid (4C) cells. In the presence of normal spermatogenesis, the haploid compartment contained the majority of cells, followed by the diploid, and then the tetraploid (1C greater than 2C greater than 4C). The other diagnostic criteria of flow cytometry were as follows: hypospermatogenesis (2C greater than 1C greater than 4C), the maturation arrest (2C greater than 4C greater than 1C), and Sertoli-cell-only syndrome (2C, near 100%). According to the aforementioned diagnostic criteria, the results of DNA histograms were compared with the histopathology diagnosed by junior or senior pathologists. These patterns of DNA histograms correlated with the diagnoses by senior pathologists in 28 of 34 specimens (82.6%), while there were only 20 of 36 pathologic diagnoses (55.6%) which matched between junior and senior pathologists. It is shown that abundant experience is needed for testis pathologists to diagnose accurately. The DNA histograms correlate well with pathological findings, with the advantages of quantification and fewer specimens needed. In conclusion, testicular tubular cell DNA histograms appear to be a reliable modality in the evaluation of spermatogenesis. They provide the quantitative information of sperm maturation and help in making appropriate decisions in the management of male infertility.

DNA↗
PubMed1990

Invasiveness of renal cell carcinoma--an in vitro model.

The invasive properties of human renal cell carcinoma were tested on a gel-like reconstituted basement membrane matrix extracted from Engelbreth-Holm-Swarm transplantable mouse tumor (Matrigel). Both high-grade (Fuhrmans's nuclear grade III) and low-grade (Fuhrman's nuclear grade I) renal carcinoma cells as well as normal human renal tubular cells were seeded onto a thin-layered, full-strength gel (1-2 mm). The normal tubular cells migrated to form small irregular colonies interconnected by polygonal networks of cell cords and grew along the surface contour of the gel. No evidence of distortion, dissolution, or invasion of underlying gel was observed but a thin layer of electron dense lamina was found to form underneath the cells. The noninvasive morphology was observed to have lasted for more than 3 weeks. On the contrary, both low-grade and high-grade carcinoma cells formed individual colonies and invaded the underlying matrix by developing invasion buds and subsequently cords or tubule-like structures of variable length. No basement-membrane-like electron dense deposit was observed at the cell-matrix interface. The observation that the mean invasion depth was higher in high nuclear grade carcinoma has significant implications on the association between invasiveness and nuclear grade. The findings that cancer cells closely contacted the surrounding matrix and reorganized the matrix in the immediate vicinity provided additional evidence of cell-matrix interaction.

Basement Membrane↗
PubMed1990

Papillary cystadenocarcinoma of the epididymis--report of a case.

A papillary cystadenocarcinoma of epididymis with right paraureteral metastases in a 27-year-old man is presented. It was a 14x13x8 cm cystic mass in the right testicular adnexa which had been noted for more than 10 years. From its prolonged clinical course and the morphological findings, this tumor was thought to be a malignant transformation from previously benign lesion--papillary cystadenoma. Review of the literature disclosed that it is a very rare malignancy arising from the testicular adnexa.

Adult↗
PubMed1990

Mumps associated with nephritis.

During an endemic of mumps in 1987, urinalysis was performed in 124 children with the symptoms of mumps during the acute phase of the disease, 36 children (29.0%) with microscopic hematuria and 8 children (6.4%) with proteinuria were studied. In the children with abnormal urinalysis, whose creatinine clearance was within the normal range, an urine culture for mumps virus was also performed. Nine specimens (20.4%) were positive, 8 (88.8%) of them during the first 5 days of illness. Renal biopsy, performed in a girl with persistent hematuria, revealed a mild mesangial proliferative glomerulonephritis with deposition of immunoglobulins A and M, C3, and mumps virus antigen in the glomerulus, suggesting an immune complex deposition. Electron microscopy demonstrated a moderate number of granular electron-dense deposits in the paramesangial regions. The relationship between the development of mumps and the onset of nephritis and the immunofluorescent demonstration of mumps antigen in the glomeruli suggested that the mesangial nephropathy may have developed after the mumps infection. Therefore, in our cases, the clinical course was benign.

Child, Preschool↗
PubMed1989

Improvement of histological and immunological change in steroid and immunosuppressive drug-resistant lupus nephritis by high-dose intravenous gamma globulin.

From July 1984 to December 1987, 9 patients with lupus nephritis did not respond to the administration of two courses of methylprednisolone pulse therapy and cyclophosphamide treatment for 56 days. Therefore, high-dose intravenous human gamma-globulin (IVIG) was administrated. Before IVIG therapy, renal biopsy showed class IV lupus nephritis in 5 cases, class V in 2 cases, and class IV with V in 2 cases. Immunofluorescence of the renal biopsy showed heavy IgG deposits along the glomerular capillary walls. These heavy glomerular IgG deposits were dissociated after in vitro incubation of the cryostat kidney sections with plasmin-treated, PEG-treated, sulfonated human gamma-globulin and a human Fc fragment, as evidenced by a dramatic decrease or even absence of fluorescent intensity. After high-dose IVIG treatment, 3 out of 5 cases of class IV lupus nephritis had a good response with decreased proteinuria and creatinine; serum C3, C4 levels and CH50 hemolytic activity also increased. The glomerular IgG deposits decreased in the follow-up biopsy. Pathologically, 2 of them transformed into class IIb. The capacity to synthesize immunoglobulin after pokeweed mitogen stimulation was reduced and the circulating immune complexes (CIC) lowered after high-dose IVIG treatment. In the others there was partial response. These clinical and immunological improvements after high-dose IVIG therapy are probably related to the modulation of macrophage-T cell function and enhancement of suppressor T cell function. The toxicity of high dose IVIG was minimal, but the cost is high, search for an optimal dosage is warranted.

Antigen-Antibody Complex↗
PubMed1989

Hemodynamic effects of verapamil during fentanyl-nitrous oxide anesthesia.

The hemodynamic effects of a verapamil infusion were investigated in six dogs given fentanyl-nitrous oxide anesthesia. Verapamil, 0.2 mg/kg, was given followed by an infusion of 3, 6, and 9 micrograms/kg per minute, which produced plasma verapamil concentrations ranging from 98 to 204 ng/ml. Verapamil significantly reduced the systemic vascular resistance index and mean arterial pressure. The decrease in afterload led to an increase in cardiac index, since there was little change in myocardial contractility (LV dP/dt). Administration of calcium chloride, 20 mg/kg, did not reverse the hemodynamic effects of verapamil. The data indicate that in dogs verapamil can be given, even in high concentrations, during fentanyl-nitrous oxide anesthesia without serious adverse electrophysiologic or hemodynamic consequences.

Anesthesia, Inhalation↗
PubMed1989

[Hypereosinophilic syndrome with Löffler's endomyocarditis: report of an autopsy case].

Hypereosinophilic syndrome (HES) with Löffler's endomyocarditis is a rare disease with poor prognosis. Clinically, it mainly affects young adults, characterized by prolonged idiopathic blood eosinophilia, cardiopulmonary symptoms and hepatosplenomegaly. Pathological features consist of ventricular mural thrombi, marked fibrotic thickening of endocardium with scarring of myocardium, and multiorgan eosinophilic infiltration. We report a 2-year-old girl with idiopathic HES associated with Löffler's endomyocarditis. The girl was noted to have constitutional symptoms, cardiomegaly, and hepatosplenomegaly. Her total eosinophil count reached 150,000/microliters. She had no history of allergic diseases. The microbiological studies were negative. Echocardiography suggested thickened endocardium, mitral stenosis and regurgitation. In spite of intensive medical management, the girl died of refractory congestive heart failure. Autopsy revealed thick fresh mural thrombi involving the biventricular inflow tracts, inflammation and fibrosis of the endomyocardium, systemic thromboembolism and multiorgan eosinophilic infiltration. The pathology and pathogenesis of the disease are discussed and the literature is reviewed.

Child, Preschool↗
PubMed1988

Reversal of the adverse cardiovascular effects of intravenous diltiazem in anesthetized dogs.

Intravenous diltiazem can be used to treat myocardial ischemia, hypertension, and supraventricular dysrhythmias, but significant adverse effects including atrioventricular block and hypotension have been reported. At the present time, there is controversy as to which drug is most effective in reversing these sequelae. This study was designed to assess the effectiveness of calcium chloride v epinephrine in reversing these side effects. The hemodynamic and electrophysiologic effects of diltiazem infusion were investigated in eight dogs anesthetized with fentanyl and nitrous oxide/oxygen. This study confirmed that diltiazem infusions in high concentrations produced predominantly atrioventricular conduction depression followed by profound hypotension. Epinephrine infusion proved to be most effective in attenuating and eliminating each of these deleterious side effects. In contrast, calcium chloride did not significantly increase heart rate or blood pressure or reverse atrioventricular block. In two instances calcium chloride produced further depression of atrioventricular conduction, leading to severe bradycardia and sinus arrest. Although calcium chloride increased left ventricular contractile force (LV dP/ dt) and cardiac index (CI), mean arterial pressure was not affected and SVR was further decreased. This study indicates that calcium chloride should not be given to reverse the side effects of diltiazem in the presence of atrioventricular conduction block or profound hypotension. Calcium chloride is indicated only when isolated myocardial depression is present and after the calcium channels have been reopened by epinephrine.

Anesthesia↗
PubMed1988

Sodium-valproate-induced interstitial nephritis.

A 5-year-old Chinese girl had had absence seizures and received sodium valproate (VPA) treatment which provided good control. Six months later, she developed interstitial nephritis with proteinuria and microhematuria. Renal biopsy revealed interstitial nephritis with granular deposition of immunoglobulin G (IgG) and C3 in the renal tubular basement membrane (TBM). Ultrastructurally, dilated smooth endoreticular cisternae with mitochondrial degeneration in the tubular cells and scattered electron-dense deposits within the TBM were also noted. Serum circulating immune complexes were detectable, ACH50 and properdin factor B increased. Mononuclear cells (MNC) from the patient after in vitro incubation with VPA (100 micrograms/ml) induced interleukin-2 (IL-2) production and lymphoproliferative response. However, there was no response in controls. The serum VPA level ranged from 84 to 92 micrograms/ml. After VPA was stopped, the microhematuria and proteinuria disappeared. These observations indicate that VPA-induced interstitial nephritis represents a sequence of interrelationships among multiple immunologic factors.

Child, Preschool↗
PubMed1988

Differential diagnosis of chronic lymphocytic leukemia and diffuse well-differentiated lymphoma using monoclonal antibodies.

Diffuse well-differentiated lymphocytic lymphoma (DWDL) with leukemic change and chronic lymphocytic leukemia (CLL) are not significantly different in morphology, immunophenotype and clinical course. Two monoclonal antibodies (MoAbs), designated L20 and A01, were established with respective reactivity against DWDL and CLL cells. The L20 MoAb reacted with both DWDL and CLL cells, and 20-50% of normal B cells. The second MoAb, A01, reacted not only with CLL cells but also with 33% of non-T, non-B cells. Immunoprecipitation patterns of L20 and A01 MoAbs against 125I-surface-labeled BALL and Daudi cell extracts revealed respective bands with molecular weights of 86 and 66 kilodaltons. These results showed that DWDL and CLL cells are different in nature, and that these two MoAbs can be used to distinguish DWDL from CLL cells.

Adult↗
PubMed1988

Conjunctival involvement of lymphomatoid granulomatosis.

Lymphomatoid granulomatosis is an angiocentric and angiodestructive lympho-proliferative disorder involving multisystems but rarely conjunctiva. We present a 62-year-old Chinese female with lymphomatoid granulomatosis who had an ulcerative conjunctival nodule. Conjunctival biopsy revealed pathological findings important for diagnosis and indicating progression of disease severity. To our knowledge, this is the first report to demonstrate pathological findings characteristic of lymphomatoid granulomatosis with conjunctival involvement.

Biopsy↗
PubMed1988

Pseudomelanosis duodeni. Case report and review of literature.

Pseudomelanosis duodeni is an extremely rare disease that has been only recently recognized. We present what we take to be the first Oriental case with typical endoscopic and histological manifestations. With detailed studies of histochemistry and electron microscopy, we have confirmed that the pigment is composed of iron and lipofuscin. A detailed review of the literature may be found here.

China↗