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Biomedical subjects

H Tai

Publications and source records attributed to H Tai.

At least 37 records · Page 2Linked to original sources
PubMed1997

[Lung cancer with a sarcoid-like reaction in the primary tumor].

An 80-year-old woman was admitted to the hospital because of a nodular lesion in the right upper lobe of the lung. Transbronchial biopsy was performed and adenocarcinoma of the lung was confirmed by pathological examination. The tumor was resected by right upper lobectomy and was found to be a moderately differentiated tubular adenocarcinoma. Numerous non-caseating epithelioid cell granulomas were also found intermingled with the cancer cells. Metastasis was apparent in several regional lymph nodes but no granulomatous lesions were found in any lymph node, regardless of metastasis. These findings were compatible with a "sarcoid-like reaction" because there was no clinical evidence of generalized sarcoidosis or pulmonary mycobacterial infection. Although sarcoid-like reactions are occasionally associated with cancer, formation of an epithelioid cell granuloma inside the primary tumor is very rare. All the reported cases of a sarcoid-like reaction within the primary lung tumor so far were with adenocarcinoma. The sarcoid-like reaction may be a local immune response to the cancer cells.

Adenocarcinoma↗
PubMed1995

[Histological evaluation of bronchial tissue from elderly individuals with bronchial asthma].

We studied morphologic and morphometric characteristics of the bronchial walls in lungs obtained at autopsy form elderly patients who had had bronchial asthma. Thirteen patients (age at time of death 57 to 98 years; average, 81 years) were divided into three groups: AS, died of severe asthma attack (n = 4); AC, admitted with asthma symptoms but died of other diseases (n = 6); and NA, died of other diseases and had had no asthma symptoms in the year before death (n = 3). Lungs from ten non-smokers with no history of bronchial asthma or other lung disorders were used as control. Transverse sections of segmental and subsegmental bronchi were prepared, and four quantities were analyzed: 1) the ratio of total bronchial gland area to total area of the bronchial wall (Yamanaka index), 2) the thickness of the basement membrane, 3) the thickness of the smooth muscle bundle, and 4) the ratio of luminal area to total area of the bronchial wall (bronchial dilation ratio). In the AS group, the Yamanaka index and the thickness of the smooth muscle bundles and of the basement membrane were significantly greater than those in the control group at both the segmental and subsegmental levels, with massive eosinophil infiltration into the bronchial walls. Furthermore the bronchial dilation ratio at the subsegmental level correlated closely with the Yamanaka index. Thickness of the smooth muscle bundle seemed to be most representative of the severity of asthma symptoms. In conclusion, morphometric findings of bronchial walls in elderly patients with asthma symptoms seem to be similar to those in their younger counterparts.

Age Factors↗
PubMed1994

[A case of Castleman's disease that recurred nine years after initial surgical removal].

Castleman's disease (CD) is a lymphoproliferative disorder with resemblance in histopathology of thymoma. Here we describe a 48-year-old man with bloody sputum and a mass lesion of the right hilum on chest roentgenogram. He had undergone an incomplete surgical removal of a mediastinal tumor nine years earlier, which proved to be CD with characteristics of hyaline-vascular type pathology. The regrown mass lesion as well as the right upper and middle lobes were removed surgically. Histological examination of the tumor specimen revealed characteristics of hyaline-vascular type CD which were nearly identical to those of the tumor removed nine years earlier. Recurrence of CD as observed in the present report is very uncommon, since only 5 cases, including this one, have been reported. We suggest that in CD the primary tumor as well as regional lymph nodes should be completely removed, and the patients should be kept under long-term postoperative observation to check for recurrence.

Castleman Disease↗
PubMed1993

3-Ketoacyl-acyl carrier protein synthase III from spinach (Spinacia oleracea) is not similar to other condensing enzymes of fatty acid synthase.

A cDNA clone encoding spinach (Spinacia oleracea) 3-ketoacyl-acyl carrier protein synthase III (KAS III), which catalyzes the initial condensing reaction in fatty acid biosynthesis, was isolated. Based on the amino acid sequence of tryptic digests of purified spinach KAS III, degenerate polymerase chain reaction (PCR) primers were designed and used to amplify a 612-bp fragment from first-strand cDNA of spinach leaf RNA. A root cDNA library was probed with the PCR fragment, and a 1920-bp clone was isolated. Its deduced amino acid sequence matched the sequences of the tryptic digests obtained from the purified KAS III. Northern analysis confirmed that it was expressed in both leaf and root. The clone contained a 1218-bp open reading frame coding for 405 amino acids. The identity of the clone was confirmed by expression in Escherichia coli BL 21 as a glutathione S-transferase fusion protein. The deduced amino acid sequence was 48 and 45% identical with the putative KAS III of Porphyra umbilicalis and KAS III of E. coli, respectively. It also had a strong local homology to the plant chalcone synthases but had little homology with other KAS isoforms from plants, bacteria, or animals.

3-Oxoacyl-(Acyl-Carrier-Protein) Synthase↗
PubMed1993

Changes in complement and immunoglobulin G receptor expression on neutrophils associated with Porphyromonas gingivalis-induced inhibition of phagocytosis.

We examined the phagocytic capacity and receptor expression on neutrophils stimulated with Porphyromonas gingivalis soluble products. Stimulated neutrophils had decreased phagocytic capacities and altered expression of CR1, CR3, Fc gamma RII, and Fc gamma RIII. For cases in which TLCK (N-alpha-p-tosyl-L-lysine chloromethyl ketone) neutralized the effects of the stimuli, the P. gingivalis-derived factors causing the phenomena seem to be trypsin-like proteases.

Humans↗
PubMed1993

Extracellular ATP-induced regulation of epidermal growth factor signaling in cultured renal LLC-PK1 cells.

We investigated the effect of extracellular ATP on the interaction of epidermal growth factor (EGF) with its receptor in cultured renal epithelial cells, LLC-PK1. Pretreatment with ATP, but not adenosine, inhibited the binding of 125I-labeled EGF. The inhibition demonstrated by ATP resulted from a decrease in the affinity of EGF receptors for its ligand, with no change in the number of EGF receptors. Incubation of phorbol 12-myristate 13-acetate (PMA) for 30 min mimicked the ATP-mediated inhibition. On the other hand, prolonged pretreatment with PMA, which leads to disappearance of protein kinase C activity, reversed the inhibition. In addition, pretreatment with the protein kinase C inhibitor 1-(5-isoquinoline sulfonyl)-2-methylpiperazine prevented the ATP-mediated inhibition. ATP triggered an increase in inositol 1,4,5-trisphosphate levels and translocation of protein kinase C from cytosol to membranes, consist with the stimulation of phospholipase C and the activation of protein kinase C. These results demonstrate that extracellular ATP attenuates the ligand binding affinity of EGF receptor via the stimulation of phospholipase C, leading to the activation of protein kinase C in the LLC-PK1 cells.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1993

[A case of bronchogenic squamous cell carcinoma associated with Swyer-James syndrome].

Swyer-James syndrome is considered to be a relatively uncommon disease entity presenting with unilateral hyperlucent lung due to hypoplasia of a pulmonary artery and bronchiectasis of the affected lung. Association of bronchogenic carcinoma with Swyer-James syndrome has not apparently been reported in any previous literature, except for one Japanese case. In the present paper, we describe a 48-year-old male individual, who developed poorly differentiated squamous cell carcinoma of the right upper lobe bronchus after he had been diagnosed to have Swyer-James syndrome with unilateral hyperradiancy of the left lung. It is suggested that the bronchial epithelium of the unaffected lung in Swyer-James syndrome is likely to be more exposed to extrinsic carcinogens than that of the affected, underventilated lung, hence resulting in a higher risk of developing bronchogenic carcinoma.

Carcinoma, Squamous Cell↗
PubMed1992

Calcium-binding protein regucalcin increases calcium-independent proteolytic activity in rat liver cytosol.

The effect of regucalcin, isolated from rat liver cytosol, on neutral proteolytic activity in the hepatic cytosol was investigated. The Ca(2+)-requiring proteinase required 5-10 microM Ca2+ for maximal activity in the presence of a protein substrate (globin). The proteinase activity was markedly elevated by the addition of regucalcin (0.25-2.0 microM) in the absence or presence of Ca2+ (5.0 microM) added. The effect of regucalcin, however, was the greater in the absence of Ca2+ than that in the presence. The pronounced effect of regucalcin on the proteinase activity was also seen in the presence of 1.0 mM EGTA with or without Ca2+ (5.0 microM). In the absence of Ca2+, the regucalcin-increased proteinase activity was clearly inhibited by the presence of anti-regucalcin antiserum (diluted to 240-fold), leupeptin (20 and 200 micrograms/ml), and heavy metals (25 microM cadmium or 25 microM zinc), although the inhibition was not complete at the concentration used. The present findings suggest that regucalcin increases proteolytic activity in rat liver cytosol, and that regucalcin may activate Ca(2+)-independent neutral cysteinyl-proteinase.

Animals↗
PubMed1991

Inhibitory effect of calcium-binding protein regucalcin on Ca2+/calmodulin-dependent cyclic nucleotide phosphodiesterase activity in rat liver cytosol.

The effect of regucalcin, a calcium-binding protein isolated from rat liver cytosol, on Ca2+/calmodulin-dependent cyclic nucleotide (AMP) phosphodiesterase activity in rat liver cytosol was investigated. The addition of Ca2+ (50 microM) and calmodulin 160 U/ml in the enzyme reaction mixture caused a significant increase in cyclic AMP phosphodiesterase activity. This increase was inhibited by the presence of regucalcin (0.5-3.0 microM); the inhibitory effect was complete at 1.0 microM. Regucalcin (1.0 microM) did not have an appreciable effect on basal activity without Ca2+ and calmodulin. The inhibitory effect of regucalcin was still evident even at several fold higher concentrations of calmodulin (160-480 U/ml). However, regucalcin (1.0 microM) did not inhibit Ca2+/calmodulin-dependent cyclic AMP phosphodiesterase activity in the presence of 100 and 200 microM Ca2+ added. Meanwhile, Cd2+ (25-100 microM)-induced decrease in Ca2+/calmodulin-dependent cyclic AMP phosphodiesterase activity was not reversed by the presence of regucalcin (1.0 microM). The present results suggest that regucalcin can regulate Ca2+/calmodulin-dependent cyclic AMP phosphodiesterase activity due to binding Ca2+ in liver cells.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1991

Serodiagnosis of cancer by using Candida cytochrome c recognized by human monoclonal antibody HB4C5.

Cytochrome c from various sources, such as Candida krusei, yeast, horse, and cattle, was found to be recognized by human monoclonal antibody HB4C5 specific to lung cancer. Therefore, the cytochrome c was applied to the measurement of antibody amount in patient sera with a similar reactivity to the antibody HB4C5 for serodiagnosis of cancer. The cytochrome c from Candida krusei was most valuable for the serodiagnosis of various cancers, and the yeast cytochrome c was also useful. However, horse and bovine cytochrome c did not react with antibody of the cancer patients. By using Candida cytochrome c lung, bile duct, esophagus, and liver cancers were detected at high rates of more than 50%. In the case of lung cancer, the detection rates of small-cell, squamous, large-cell and adenocarcinoma were 78%, 63%, 100%, and 34%, respectively. The rate for small-cell carcinoma was higher than that with the currently used NSE assay system, and the rate for squamous carcinoma was comparable to that with the SCC assay system, although the system using cytochrome c did not show similar reactivity to that with the SCC system. Furthermore, lung cancer was detected at early stages by using cytochrome c, and even in the case of adenocarcinoma, the rate at early stages with the cytochrome c system was higher than that with the CEA assay system. On the other hand, false positive rates of benign diseases and normal were low--8% and 2%, respectively.

Antibodies, Monoclonal↗
PubMed1991

Detection of lung cancer in clinical specimens using a human monoclonal antibody HB4C5-clone 3.

Biopsies of 18 patients with lung cancer and cellular specimens of 21 lung cancer patients were analyzed with human monoclonal antibody HB4C5-clone 3 using avidin-biotin-peroxidase techniques. Analyses with the biopsies showed that HB4C5-clone 3 reacted with 16 of 18 biopsy specimens at a high rate of about 90% and reacted with all specimens of five adenocarcinoma tissues, five of six squamous cell carcinomas, two of three large cell carcinomas, both specimens of small cell carcinomas, and both of the other types of carcinomas. In all the reactive cases, the monoclonal antibody was reactive with greater than 50% of cancer cells. With cellular specimens of lung cancer patients, HB4C5-clone 3 reacted with 7 of 13 adenocarcinoma specimens, two of six squamous cell carcinomas, and one of two small cell carcinomas. The immunoreaction with HB4C5-clone 3 was observed in sites of the cytoplasm of cancer cells. From these data, HB4C5-clone 3 is considered to be of potential use in diagnoses of tissues and cellular specimens of lung cancer.

Adenocarcinoma↗