Search PubMed⌕ Search

Biomedical subjects

J W Huang

Publications and source records attributed to J W Huang.

At least 37 records · Page 2Linked to original sources
PubMed1996

Immunohistochemical evaluation of the Ca(2+)-binding S-100 proteins S-100A1, S-100A2, S-100A4, S-100A6 and S-100B in salivary gland tumors.

The Ca(2+)-binding S-100 proteins are involved in the regulation of a number of cellular processes and an altered expression has been reported in several neoplastic tissues. Tissue specimens of normal salivary glands (n = 23), pleomorphic adenomas (n = 60), basal cell adenomas (n = 6), canalicular ademomas (n = 2), myoepitheliomas (n = 2), adenoid cystic carcinomas (n = 26) and adenocarcinomas NOS (n = 11) were evaluated for the expression of S-100A1, S-100A2, A-100A4, S-100A6 and S-100B by using highly specific polyclonal and monoclonal antibodies generated against the recombinant human protein. In normal salivary glands, the ductal cells showed mild to intense immunoreactivity for S-100A1, S-100A2, S-100A4 and S-100A6, while S-100B was observed in nerve fibers in the connective tissue. The normal myoepithelial cells were unreactive. In pleomorphic adenoma, the luminal tumor cells of the duct-like structures showed moderate to intense immunoreactivity for S-100A2, while reactivity for S-100A1, S-100A4 and S-100A6 was relatively weak. The non-luminal cells, also termed neoplastic myoepithelial cells, showed immunoreactivity for S-100B, while tumor cells in the solid, myxoid and chondroid areas were immunoreactive for S-100A1, S-100A4, S-100A6 and S-100B. The non-luminally located tumor cells in basal cell adenomas and canalicular adenomas, and numerous tumor cells in clusters in myoepitheliomas were intensely reactive for S-100A2. In adenoid cystic carcinomas and in adenocarcinomas not otherwise specified, the luminal cells forming the tubular or cribriform structures were markedly positive for S-100A2 and/or S-100A6. Squamous metaplastic cells in salivary tumors showed intense immunoreactivity for S-100A2. The results of the present study suggest that the majority of the tumor cells in salivary neoplasms, despite the most heterogeneous tumor cell differentiation, express S-100 proteins more heterogeneously than the normal glandular ducts. The salivary ducts in normal glands, the luminal tumor cells and squamous metaplastic cells in the neoplastic lesions were intensely immunoreactive for S-100A2 as compared to S-100A1, S-100A4 or S-100A6. In contrast, the non-luminal tumor cells showed a rather heterogeneous expression of the S-100 proteins.

Adenocarcinoma↗
PubMed1996

Complete structures of three rice sucrose synthase isogenes and differential regulation of their expressions.

By cloning and sequencing cDNA and genomic DNA and transcription initiation site mapping, the total structures including at least 1 kb of putative regulatory sequences upstream of the transcription initiation sites of three genes encoding rice sucrose synthase isoprotomers were either newly established or amended. The third type of SS gene, RSus3, has not been found in other plants. The structures of the three genes and the gene products were compared and their evolutionary sequence was proposed. Specific probes for the three SS mRNA's were developed and used for analyzing their steady state levels at different organs and under some physiological stress conditions. It appears that RSus2 is a house-keeping gene, RSus3 is highly specific to the grain, and the expression of RSus1 shows a tendency to complement that of RSus3. A possible cause of the presence of the third rice SS gene was discussed. We also reported a novel method to synthesize single-stranded DNA for S1 mapping of a transcription initiation site associated with extended secondary structures.

Base Sequence↗
PubMed1995

Production of fumonisins by Fusarium species of Taiwan.

Twenty-nine Fusarium species isolated from various sources in different districts of Taiwan were tested for their ability to produce fumonisins in corn cultures. Only Fusarium moniliforme produced fumonisin B1 (FB1) and fumonisin B2 (FB2). The finding that the other 28 Fusarium species produced neither FB1 nor FB2 is preliminary because only one strain per species was studied. The detection of FB1 and FB2 in cultures of F. moniliforme was demonstrated by TLC and HPLC, and FB1 was further confirmed by mass spectrometry. In a separate experiment, in which 38 strains of F. moniliforme were tested for fumonisins, approximately 66% (25/38) produced FB1 and/or FB2. Of the 25 strains, 14 produced only FB1 and 11 produced both FB1 and FB2, and the amounts of FB1 and FB2 produced by different strains varied greatly. This is the first report that fumonisins are found in corn cultures experimentally infected with F. moniliforme strains from Taiwan. It is safe to assume that fumonisin producing strains of F. moniliforme are widely distributed among the economic crops such as corn, rice, sugarcane, and sorghum throughout the Island.

Food Microbiology↗
PubMed1994

Voltage-dependent Ca2+ influx into right-side-out plasma membrane vesicles isolated from wheat roots: characterization of a putative Ca2+ channel.

We report on the identification of a voltage-dependent Ca2+ transport system that mediates Ca2+ influx across the plasma membrane (PM) of wheat (Triticum aestivum) root cells. The experimental approach involved the imposition of transmembrane electrical potentials (via K+ diffusion potentials) in populations of purified, right-side-out PM vesicles isolated from wheat roots. Using 45Ca2+ to quantify Ca2+ influx into the PM vesicles, the voltage-dependent characteristics of Ca2+ transport were found to be similar to those exhibited by L-type voltage-gated Ca2+ channels in animal cells. The putative PM Ca2+ channel opened upon depolarization of the membrane potential, and Ca2+ flux increased to a maximum upon further depolarization and then decreased back to zero upon further successive depolarizations. This channel was found to be selective for Ca2+ over Mg2+, Sr2+, K+, and Na+; was blocked by very low concentrations of La3+; was unaffected by high concentrations of the K+ channel blocker tetraethylammonium; and exhibited Michaelis-Menten-type transport kinetics. Based on these transport properties, we argue that this transport system is a PM Ca2+ channel. We suggest that the use of radiotracer flux analysis of voltage-clamped PM vesicles derived from plant roots is a straightforward approach for the characterization of certain voltage-gated ion channels functioning in cellular membranes of higher plant cells.

Calcium↗
PubMed1992

Presence of three rice sucrose synthase genes as revealed by cloning and sequencing of cDNA.

By sequencing cDNA clones, we have concluded that three distinct sucrose genes are expressed in rice (Oryza sativa cv. Tainong 67). When the amino acid sequences deduced from these cDNAs as well as those of known sucrose synthase are compared, the highest divergence is found in the C-termini. The most suitable DNA sequences for use as specific for the mRNA derived from these genes have been suggested.

Amino Acid Sequence↗
PubMed1992

Vimentin expression in sweat gland tumours.

Immunohistochemical localization of vimentin was studied in 93 cases of sweat gland tumours using a monoclonal anti-vimentin antibody. A strong immunoreactivity of vimentin was observed in modified myoepithelial or neoplastic myoepithelial cells of mixed tumour of the skin, syringoma, and sweat gland adenoma. Tumour cells in outer layers of tubular, ductal, and duct-like structures usually showed positive staining for vimentin, which coincided with modified myoepithelial cells. All tumour cells of clear cell hydroadenoma showed positive vimentin staining. Tumour cells of the luminal border of tubulo-ductal structures of mixed tumours were rarely immunoreactive for vimentin. Positive vimentin staining of tumour cells in the outer zone of tubulo-ductal structures in sweat gland tumours may be related to reactive proliferation of modified myoepithelial cells and simultaneous growth of luminal tumour cells.

Adenoma↗
PubMed1992

Aluminum effects on calcium fluxes at the root apex of aluminum-tolerant and aluminum-sensitive wheat cultivars.

The role of Ca(2+) transport in the mechanism of Al toxicity was investigated, using a Ca(2+)-selective microelectrode system to study Al effects on root apical Ca(2+) fluxes in two wheat (Triticum aestivum L.) cultivars: Al-tolerant Atlas 66 and Al-sensitive Scout 66. Intact 3-day-old low-salt-grown (100 micromolar CaCl(2), pH 4.5) wheat seedlings were used, and it was found that both cultivars maintained similar rates of net Ca(2+) uptake in the absence of Al. Addition of Al concentrations that were toxic to Scout (5-20 micromolar AlCl(3)) immediately and dramatically inhibited Ca(2+) uptake in Scout, whereas Ca(2+) transport in Atlas was relatively unaffected. The Al-induced inhibition of Ca(2+) uptake in Scout 66 was rapidly reversed following removal of Al from the solution bathing the roots. Similar studies with morphologically intact root cell wall preparations indicated that the Al effects did not involve Al-Ca interactions in the cell wall. These results suggest that Al inhibits Ca(2+) influx across the root plasmalemma, possibly via blockage of calcium channels. The differential effect of Al on Ca(2+) transport in Al-sensitive Scout and Al-tolerant Atlas suggests that Al blockage of Ca(2+) channels could play a role in the cellular mechanism of Al toxicity in higher plants.

Journal Article↗
PubMed1992

Rare expression of the c-erbB-2 oncoprotein in salivary gland tumors: an immunohistochemical study.

An immunohistochemical study of c-erbB-2 oncoprotein expression was carried out on 201 cases of primary salivary gland tumors, using a polyclonal antibody, raised to the intracytoplasmic domain of the c-erbB-2 oncogene product. An intense membrane reactivity was observed in one case of sialocarcinoma transformed from pleomorphic adenoma (n = 8) and one case of mucoepidermoid carcinoma (n = 22). A comparative histopathologic evaluation of c-erbB-2 positive tumors showed marked variation in cell size, nuclear pleomorphism, multinucleation, a high mitotic rate and increased lymphoid cell infiltration and an aggressive clinical course with poor survival. The results indicate that c-erbB-2 oncoprotein is rarely expressed in malignant salivary gland tumors. However, the overexpression appears to have a distinct histopathologic feature, but a larger study incorporating histopathology and clinical data would be necessary to correlate the significance of c-erbB-2 oncogene product in salivary malignant tumors.

Adenolymphoma↗
PubMed1990

[A quantitative study on invasive process of mouse uterine cervix carcinoma (U14) cells implanted subcapsularly in testis].

Computer-image processing system was used for the quantitative study on tumor invasion in vivo in this experiment. Fragments of U14 tumor were subcapsularly transplanted in testis of the inbred 615-line mouse. One of serial sections (5-8 microns) through the thickest site of the inoculated tumor was selected and stained by PAP for quantitative study of the tumor invasion on day 1, 3, 5, 7, 9, 11 after transplantation. Both the volume of the lesion region and that of the total region were calculated. The invasion of U14 tumor cells in testis was shown to be progressive. The computer-image processing system is a good method for quantitative study of tumor invasion.

Animals↗
PubMed1989

Observation of growth and invasiveness of human uterine cervix carcinoma cell line (CC801) in the testes of nude mice.

A human uterine cervix carcinoma cell line (CC801) was implanted subcapsularly in the testes of nude mice and its growth and invasiveness was observed. The results showed that the taking rate of CC801 tumor cells was 70%. Two weeks after implantation, the tumor cells were surrounded by pseudocapsule and showed no invasiveness, but 4 weeks after transplantation, they began to proliferate and to penetrate the pseudocapsule. Thereafter, the tumor cells continued to invade the neighboring tissues, causing degeneration and atrophy of seminiferous tubules at later stages. After 12 weeks, the tumor tissues occupied the whole testis. The process of invasion could be divided into 5 stages: latency, proliferation, early invasion, intermediate invasion and late invasion. The rate of lymphatic metastasis was 6.6%, but no lung metastasis was found.

Animals↗
PubMed1989

[Study on the invasiveness of mouse uterine cervix carcinoma cell (U14) implanted in mouse testis].

A good invasion and metastasis pattern was observed after implanting of U14 tumor cells subcapsular in testis, which provided a new model in vivo for studying tumor invasion and metastasis. The transplantability of U14 tumor-inoculation was 90%, retaining high metastasis in lymph-node (88.8%) and lung (77.7%). On the first day after implantation, U14 tumor cells were in a state of relative rest. On the 3rd day, tumor cells began to proliferate and invade the neighboring tissue along the natural space between seminiferous tubules. Degenerative and atrophic changes of seminiferous tubules appeared in the invasion areas. The process of invasion can be divided into 4 stages, namely latency, proliferation, early invasion and late invasion.

Animals↗
PubMed1987

The study of byssinosis in China: a comprehensive report.

Cross-sectional studies were conducted during 1981-1983 among 861 textile workers in 3 cotton mills and 822 controls in 2 silk factories. Questionnaire and lung function tests were taken and inhalable dust concentrations were measured. Prevalence of byssinosis was 5.6%. Average dust concentrations were highest in carding rooms, 1.47-1.99 mg/m3. The correlations (r) between prevalence of byssinosis and dust concentrations was 0.64 (p less than 0.05). The prevalence of chronic bronchitis was 14.4% in cotton workers and 5.1% in controls (p less than 0.05). Acute FEV1 percent decrement (greater than 5%) was higher among cotton workers (32.1%) compared to controls (14.5%) (p less than 0.001). In one cotton blanket factory, the prevalence of byssinosis and chronic bronchitis was higher among workers in the high-dust work areas. Long-term effect studies included pulmonary function test among 173 cotton workers and 373 controls, retired 1-10 years, using the flow volume curve (FVC); chest X-rays of 140 pairs of cotton workers and controls with working tenures over 20 years; and examination of lobectomy specimens of 8 textile workers matched with 16 controls. In male cotton workers, only smokers had a prominent decrement of lung function indices, except FVC. For non-smoking females, there was no difference between the two groups. Additive effects were seen between smoking and dust exposure. According to the International Labor Organization (ILO) Pneumoconiosis Classification, the prevalence of abnormality (profusion greater than 1/0) was 4.3% and 8.7% in non-smoking controls and cotton workers. The interstitial changes on X-ray due to smoking would be much heavier. Additive effects also existed between smoking and dust exposures. No significant changes attributable to dust exposure were seen on pathological section of lobectomy specimens.

Aged↗
PubMed1986

Radiographic findings in cotton textile workers and the relationship to cigarette smoking.

A group of 140 cotton textile workers from Shanghai, Shandong, Guangxi, and Beijing have had their chest radiographs taken using similar requirements. Most had come from the preparatory departments of cotton mills and had a history of exposure to cotton dust for at least 20 years. As controls, 140 healthy individuals with no dust exposure were matched with respect to sex, age, and smoking history. All the radiographs were read according to the ILO International Pneumoconiosis Classification, and the manifestations belonging to categories 0/0 and 0/1 were grouped as "normal," whereas categories 1/0, 1/1, and 1/2 and above as "abnormal." There was no significant difference in X-ray abnormalities between cotton textile workers and controls (P greater than 0.05). But when the data on the cotton textile workers and controls were combined, an appreciable difference in the incidence of radiographic abnormalities was found between smokers and non-smokers (P less than 0.001). Cotton dust exposure may induce nonspecific interstitial pulmonary changes, but these changes were exaggerated by cigarette smoking. These two factors appeared to have an additive effect on the pulmonary X-ray findings.

Female↗
PubMed1982

Correlation of specific keratins with different types of epithelial differentiation: monoclonal antibody studies.

We have prepared three monoclonal antibodies against human epidermal keratins. These antibodies were highly specific for keratins and, in combination, recognized all major epidermal keratins of several mammalian species. We have used these antibodies to study the tissue distribution of epidermis-related keratins. In various mammalian epithelia, the antibodies recognized seven classes of keratins defined by their immunological reactivity and size. The 40, 46 and 52 kilodalton (kd) keratin classes were present in almost all epithelia; the 50 kd and 58 kd keratin classes were detected in all stratified squamous epithelia, but not in any simple epithelia; and the 56 kd and 65-67 kd keratin classes were unique to keratinized epidermis. Thus the expression of specific keratin classes appeared to correlate with different types of epithelial differentiation (simple versus stratified; keratinized versus nonkeratinized).

Animals↗
PubMed1975

Hydrophobic binding sites on human interferon.

Human interferon binds to a omega-carboxpentyl-agarose column at low ionic strength (0.15 M NaCl) and is still retained when the ionic strength is raised (to 1.0 M NaCl). The binding can be reversed, however, by ethylene glycol, indicating a hydrophobic interaction. The binding of human interferon to omega-aminohexyl-agarose is weak, even at a low ionic strength, and is probably exclusively electrostatic. This disparate binding behavior may be caused by the presence of a positive charge, adjacent to the hydrophobic binding site, on human interferon. The interaction of human interferon with omega-carboxypentyl-agarose is quite selective, inasmuch as the majority of proteins present in interferon preparations pass through the column unretained. Hydrophobic chromatography of human interferon may thus be useful in its purification.

Binding Sites↗