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C T Lin

Publications and source records attributed to C T Lin.

At least 127 records · Page 7Linked to original sources
PubMed1994

Association of heterotrimeric GTP binding regulatory protein (Go) with mitosis.

BACKGROUND: The heterotrimeric GTP-binding regulatory proteins (or G proteins) play an important role in regulation of membrane signal transduction. Previously, we have identified the beta-subunit of G proteins (G beta) to be closely associated with mitotic spindles. In the present study, we have conducted experiments to examine whether the G alpha subunit is also associated with mitotic spindles. EXPERIMENTAL DESIGN: We prepared polyclonal antibodies against synthetic oligopeptides from different G alpha subunits and used them to localize G alpha in a nasopharyngeal carcinoma cell line by both immunohistochemistry and immunoelectron microscopy, and to see whether any specific G alpha subunit was present in the mitotic spindle region. Subsequently, we used a colocalization method to identify the overlapping distributions of specific G alpha subunits and beta-tubulin. To be sure that the findings represented a general phenomenon, several other cell types were also examined. To identify whether the G alpha subunit in the mitotic spindle was present in a heterotrimeric form, we performed ADP ribosylation experiments. RESULTS: (a) Only Go alpha subunit but not Gi alpha or Gs alpha was localized in the mitotic spindle. (b) Go alpha was colocalized with beta-tubulin in the mitotic spindle. (c) The precise site of localization of Go alpha on spindle microtubules was confirmed by immunoultrastructural study. (d) The association of Go alpha with the mitotic spindle could be found in both human and animal cell types. (e) The mitotic spindle preparation could be ADP ribosylated in the presence of pertussis toxin. CONCLUSIONS: The heterotrimeric Go protein is shown to be closely associated with the mitotic spindle. This finding suggests that Go protein may play some role in the regulation of mitotic spindles in addition to its regulation of signal transduction in neuronal cell membranes.

Adenosine Diphosphate Ribose↗
PubMed1994

Pulmonary sequestration.

BACKGROUND: Pulmonary sequestration is a relatively rare congenital abnormality. It is a cystic mass of nonfunctioning lung tissue which lacks an obvious communication with the tracheobronchial tree and which receives all or most of its arterial blood from anomalous systemic vessels. METHODS: Six patients with intralobar pulmonary sequestration were treated at this Hospital from 1982 to 1993. The two males and four females had ages ranging from 15 years to 56 years. Five of the six patients were symptomatic, with histories of chronic cough, intermittent fever, hemoptysis, and/or pleuric chest pain. The other patient was asymptomatic. Locations of the lesion included the left lower lobe in three, the right lower lobe in two and the right middle lobe in one. RESULTS: All patients received surgical intervention. Lobectomies were performed in five, and segmentectomy in one. There was no postoperative complication or mortality and all have remained asymptomatic during the follow-up period. CONCLUSIONS: A high index of suspicion is the most important element in the diagnosis of pulmonary sequestration. Angiography is mandatory to demonstrate the aberrant arterial supply and the venous drainage of pulmonary sequestration. Surgery should be performed early in order to reduce potentially life threatening obstruction and infection, and hasten the return of normal pulmonary function.

Adolescent↗
PubMed1994

Thymic carcinoma. Ten years' experience in twenty patients.

Thymic carcinoma is a rare neoplasm with extremely poor prognosis. To evaluate the outcome of treatment in thymic carcinoma, we reviewed a 10-year (1982 to 1992) experience with 20 consecutive patients in Taichung Veterans General Hospital. There were 9 men and 11 women: ages ranged from 34 to 70 years old (mean 51.4 years). None of these patients had concomitant myasthenia gravis. All of the patients received surgical intervention, and the diagnosis was made by pathologic study. Postoperative staging was made according to the modified Masaoka staging system. None of our patients were in stage I. One patient (5%) had stage II disease, 12 (60%) stage III, and 7 (35%) stage IV. The pathologic subtypes of thymic carcinoma included eight squamous cell carcinomas, seven undifferentiated carcinomas, one lymphoepithelioma-like carcinoma, one clear-cell carcinoma, 1 mucoepidermoid carcinoma, and two carcinoid tumors. Curative resection could be done in seven patients (35%). The overall cumulative survival was 45.9% at 3 years and 34.4% at 5 years. The median survival times for patients with complete and incomplete resection were 39.0 months and 14.3 months, respectively (p = 0.1752). The median survival times of patients with postoperative radiotherapy and without postoperative radiotherapy were 39.3 months and 15.0 months, respectively (p = 0.0738). The median survival times of patients with squamous cell carcinoma and undifferentiated carcinoma were 25.4 months and 11.3 months, respectively (p = 0.1464). Our data show that complete resection, postoperative radiotherapy, and squamous cell carcinoma do not indicate a significantly favorable result, even though they result in longer median survival times. Yet a positive trend of favorable outcome in patients who received postoperative radiotherapy is ambiguously shown.

Adult↗
PubMed1993

Detection of low level of human papilloma virus type 16 DNA sequences in cancer cell lines derived from two well-differentiated nasopharyngeal cancers.

Human papilloma virus type 16 (HPV16) related sequences were detected in two EBV-negative nasopharyngeal carcinoma (NPC) cell lines derived from two well-differentiated NPC by polymerase chain reaction. E2 and E6 related sequences of HPV16 were demonstrated using two pairs of primers derived from these two regions. DNA sequence analysis of amplified products excluded the possibility of laboratory viral DNA contamination.

Antigens, Viral↗
PubMed1993

Cloning and characterization of a cDNA encoding the cytosolic copper/zinc-superoxide dismutase from sweet potato tuberous root.

A full-length cDNA clone encoding a putative copper/zinc-superoxide dismutase (SOD) of sweet potato, Ipomoea batatas (L.) Lam. cv Tainong 57, was isolated from a cDNA library constructed in lambda gt10 from tuber root mRNA. Nucleotide sequence analysis of this cDNA clone revealed that it comprises a complete open reading frame coding for 152 amino acid residues. The deduced amino acid sequence showed higher homology (78-86%) with the sequence of the cytosolic SOD than that of the chloroplast SOD from other plant species. The residues required for coordinating copper and zinc are conserved as they are among all reported Cu/Zn-SOD sequences. In addition, it lacks recognizable plastic or mitochondrial targeting sequences. These data suggest that the isolated sweet potato clone encodes a cytosolic Cu/Zn-SOD.

Amino Acid Sequence↗
PubMed1993

Characterization of seven newly established nasopharyngeal carcinoma cell lines.

BACKGROUND: Nasopharyngeal carcinoma (NPC) has a relatively high incidence in Chinese living in Taiwan, Hong Kong, Singapore, and South China. To better understand this cancer, we have established several new NPC cell lines. EXPERIMENTAL DESIGN: We collected biopsy specimens from suspected NPC patients and divided each specimen into two parts: the first part was fixed for routine histopathologic examination, and the other part was put into culture medium for primary culture. Once the cell lines were established, they were extensively characterized. RESULTS: Seven NPC cell lines were established, and all have been passaged more than 100 times. Two lines were derived from keratinizing carcinomas and five from undifferentiated carcinomas. Electron microscopic examination revealed that both dark and light tumor cells contained intermediate filaments with clear desmosome formation. The average doubling time ranged from 10.7 to 16.3 hours. Karyotypic analysis showed multiple chromosome abnormalities with the average chromosome number between 84 and 95. Colony forming efficiency in soft agar was 18-42%. All cell lines could induce solid tumor mass formation when transplanted into nude mice, and the histopathological findings showed two keratinizing and five nonkeratinizing carcinomas. All cell lines contained less acidic keratin polypeptides than basic keratin polypeptides. Strong expression of vimentin in each single cell of all cell lines was also observed. The oncosuppressor retinoblastoma gene in each cell line showed no remarkable abnormality, but retinoblastoma protein was abnormally expressed in some interphase cells. The oncogenes, erbB and c-fgr, were both normally expressed. While the c-myc oncogene in all cell lines was overexpressed when compared with the Burkitt's lymphoma Raji Cell line, the c-myc DNA sequence in each cell line showed neither amplification nor rearrangement. CONCLUSIONS: The newly established seven NPC cell lines have been well characterized, and all showed overexpression of c-myc oncogene. The oncosuppressor retinoblastoma gene revealed no remarkable rearrangement, but its protein product was abnormal in certain interphase cells of each cell line.

Adult↗
PubMed1993

Sclerosing hemangioma of the lung: a clinicopathologic study.

The clinical and pathological features of 11 cases with sclerosing hemangiomas of the lung seen between 1982, and 1992 were reviewed. There were 1 male and 10 female patients aged 15 to 74 years (mean age, 53 years) at operation. Among the 11, 4 were asymptomatic, with the tumor discovered only on routine chest roentgenograms. All 11 patients had a solitary tumor showing as a well-defined homogeneous round or oval shadow on chest x-rays. Microscopically, 8 of the 11 tumors consisted of a mixture of the four major patterns: hemorrhagic, sclerotic, papillary and solid. Five patients received enucleation; four, wedge resection; one, segmentectomy and one, lobectomy. Since this tumor is usually clinically benign and surgically curative, thoracotomy and complete removal of the tumor by limited resection is recommended.

Adolescent↗
PubMed1993

[Carcinosarcoma of the esophagus].

Carcinosarcoma of the esophagus is a rare neoplasm of the esophagus, composes both of carcinomatous and sarcomatous elements. From Oct. 1982 to Sept. 1991, there were 516 neoplasms of the esophagus, 2 (0.39%) carcinosarcoma, treated at our hospital. The first patient was a 62-year-old man, pathological stage III (T3N2M0). The second patient was a 68-year-old man, pathological stage I (T1N0M0). The tumors were polypoid and located at the middle portion of the esophagus. They had received subtotal esophagectomy, mediastinal lymph node dissection and cervical esophagogastrostomy, retrosternally. The first patient has still lived disease free for seven years. The second patient died one year after the operation due to intra-abdominal lymphadenopathy, liver metastasis and massive ascites. As epidermoid carcinoma, radical esophagectomy with lymph node dissection is the standard procedure for carcinosarcoma of the esophagus.

Aged↗
PubMed1993

Surgical management of intrathoracic goiter.

Thirty-three consecutive patients of intrathoracic goiters underwent resection at the TCVGH during a nine-year period 1982-1991. The mean age of 21 men and 12 women was 65 years. Six (18 per cent) had undergone prior thyroid surgery. Thirty-one of the 33 patients were euthyroid. Thirty patients underwent transcervical approach for resection; three had cervical incision plus median sternotomy. Pathological examination revealed multinodular goiter in 31 (94 per cent) and follicular carcinoma in two (6 per cent). The mean mass of goiter was 201.25 g and the mean greatest dimension was 10 cm. Thyroidectomy is advisable in all cases of intrathoracic goiter and resection can almost invariably be performed through a transcervical approach.

Adult↗
PubMed1992

Expression of neurofibromin, the neurofibromatosis 1 gene product: studies in human neuroblastoma cells and rat brain.

Neurofibromatosis type 1 (NF1) is one of the most frequent Mendelian disorders in man and one of the most common autosomal dominant disorders affecting the nervous system. The NF1 gene has recently been cloned, and shows homology to the GTPase activating protein. In order to characterize the NF1 gene product, now called neurofibromin, we raised polyclonal antibodies against C- and N-terminal regions of neurofibromin and analyzed the protein by Western blot analysis and immunohistochemical studies of rat brain.

Amino Acid Sequence↗
PubMed1992

Fluorescence anisotropy studies of dibucaine.HCl in micelles and bacteriorhodopsin.

Emission and excitation spectra for the local anesthetic drug, dibucaine.HCl in neutral and charged surfactant solutions and in bacteriorhodopsin (bR) have been investigated for lambda(ex) = 266 nm at room temperature. The total fluorescence and fluorescence anisotropy decays of the anesthetic in the same environments were also measured using a picosecond laser/streak camera system (lambda (ex = 266 nm)). The total fluorescence decay gave two components for dibucaine micellar and dibucaine bR solutions, one component in the range of 200-500 ps and the other in the range of 1200-3400 ps. Only the nanosecond timescale component was found for the dibucaine monomer surfactant solutions (1200-3000 ps), indicating that the anesthetic resides in the bulk solution. The fluorescence anisotropy decays of dibucaine in Triton X-100 and in lithium dodecyl sulfate (LDS) micelles are approximately 200 ps, which is attributed to dibucaine solubilized in the micellar environment. Dibucaine.HCl in anionic monomer solution exhibits an unusually large fluorescence anisotropy, r(t)max = 0.22 and a depolarization decay of less than 100 ps. This presumably results from a head-to-tail exciplex aggregation between the positively charged dibucaine and negatively charged dodecyl sulfate surfactant molecules. The anisotropy decay of dibucaine in bR is 300 ps. This solution was the only one which exhibited a residual fluorescence anisotropy, r(infinity) - 0.08. This implies that dibucaine is restricted in its rotational motion and suggests protein binding rather than lipid solubility.

Anesthetics, Local↗
PubMed1992

Localization of HPV-16 DNA sequence in CaSki cells by electron microscopic hybridocytochemistry.

We investigated the HPV-16 DNA sequence in the CaSki cervical carcinoma cell line by electron microscopic hybridocytochemistry using biotinylated HPV-16/18 probes. At the light microscopic level, reaction product of hybridized HPV-16 DNA sequence was not seen in the cytoplasm but appeared as spots or rods randomly distributed in the nuclei. By electron microscopy, reaction product was seen aggregated in several regions in the nuclei. Most of the stained areas did not reveal particular architecture but showed part of the chromatin structure. In other nuclei, reaction product was observed to be associated with strings of loop-like structure, and some stained loops were seen to be connected directly to the nuclear filamentous chromatin structure. The skeletonized images of hybridized HPV-16 DNA in the nuclei were illustrated by computerized image analysis. In conclusion, we have demonstrated the HPV-16 DNA sequence in the nuclei of CaSki cells by electron microscopy. The identification of stained areas localized only in the chromatin suggests an integrated form of HPV-16 DNA sequence in the cells. This method could be used to identify an integrated or episomal form of viral DNA in the virus-containing cells.

Biotin↗
PubMed1992

Surgical treatment of metastatic lung tumor.

Since the first pulmonary resection for metastatic cancer of the lung in 1939, the following procedure can now be offered to any patient who meets these criteria: 1. a controlled primary tumor, 2. resectable lung lesion, 3. unavailability of a better treatment and 4. a good surgical candidate. From 1982 to 1992, there were 42 patients who underwent an operation for pulmonary metastasis at the Taichung Veterans General Hospital. Their cumulative 3-year and 5-year survival rates were 35% and 25% respectively. The overall estimated median survival time was 23.1 months. The overall operative mortality was 2.4% (1/42). We analyzed the effect of different types of primary tumors, the disease-free interval, and the number of lesions on patient survival. In our series, we concluded that none of the above had an effect on the therapeutic results.

Adolescent↗
PubMed1992

[Multiple primary malignant neoplasms: a case report].

One individual with two or three malignant neoplasms is not uncommon. However, a patient with more than 5 primary malignancies is unusual. We present a 51-year-old female who developed 6 metachronous primary malignant neoplasms in a period of 10 years. The anatomic sites of neoplasms in this patient included the cervix, larynx, skin, left breast, bladder and right lung (middle lobe). All of the tumors were proven by pathologic examination, and each of these tumors was recognized as a distinct primary tumor. Aggressive surgical resection, post-operative irradiation and chemotherapy showed good response in this patient. This patient had no familial or hereditary tendencies but, definite impairment of the cellular immunity had been identified.

Breast Neoplasms↗
PubMed1992

Identification of beta-subunit of GTP-binding regulatory protein in mitotic spindle.

BACKGROUND: The heterotrimeric GTP-binding regulatory protein (G protein) is important in membrane signal transduction. Since the function of the beta-subunit of G protein (G beta) in tumor cells is not well-documented, identification of G beta in tumor cells was performed. EXPERIMENTAL DESIGN: Immunolocalization, Western blotting, and immunoprecipitation of G beta in mammalian tumor and normal cells were investigated using rabbit antisera against amino and carboxyl terminal peptide fragments of G beta. A human nasopharyngeal carcinoma cell line (NPC-TW039) was used as the cell model because of its short doubling time. RESULTS: Anti-G beta immunoreactivity was found to be associated with the plasma membrane and the mitotic spindle throughout the mitotic phase of cell replication. Colcemid pretreatment resulted in random distribution of the anti-G beta reaction product in the mitotic cells. The same phenomenon was also seen in various other tumor and normal cell lines. When solubilized membranous, cytosolic, and mitotic spindle fractions were analyzed by Western blotting, G beta (35 +/- 1 kDa) was found to be associated with the plasma membrane and mitotic spindle fractions. Immunoprecipitation of isolated mitotic spindles with anti-G beta further confirmed these results. CONCLUSIONS: These findings indicate that G beta is closely associated with the mitotic spindle as well as the plasma membrane and may be important in regulation of cell mitosis in addition to transmembrane signal transduction.

Amino Acid Sequence↗
PubMed1992

Nasopharyngeal carcinoma and retinoblastoma gene expression.

BACKGROUND: The pathogenesis of nasopharyngeal carcinoma (NPC) is not well defined yet. To evaluate oncosuppressor genes in NPC, two NPC cell lines were investigated for expression of the retinoblastoma (RB) gene. EXPERIMENTAL DESIGN: We used Western blotting to identify RB protein species, and checked the RB gene conformation by Southern blotting. We also used immunohistochemistry, in situ nucleic acid hybridization, and in situ extraction of RB protein to observe RB protein in NPC culture cells. RESULTS: Both cell lines as well as sublines could synthesize normal RB proteins of 110, 113 and 114 kilodaltons. These cells showed no RB DNA rearrangement. Most interphase cells showed variable amounts of anti-RB reaction product in their nuclei when immunostained by 13 monoclonal antibodies. However, all mitotic cells contained RB protein either in the cytosol or the chromosomes, depending upon the mitotic phase. The level of RB mRNA increased slightly in mitotic cells as compared with interphase cells. Double localization of bromodeoxyuridine and RB protein in NPC cells and localization of RB protein in synchronized NPC cells in different phases of the cell cycle revealed random RB protein expression in each individual tumor cell. Co-localization of RB mRNA and RB protein in interphase cells showed a different degree of RB message expression in each cell. Low-salt hypotonic buffer could remove a fraction of RB protein from stained interphase nuclei. A similar finding with slight variations was observed in 16 other cancer cell lines. CONCLUSIONS: These data indicate that our NPC cell lines contain no obvious RB gene rearrangement, but each cancer cell may have an abnormal expression of RB mRNA and protein. This phenomenon may also be true in other cancer cell lines with a normal RB gene.

Antibodies, Monoclonal↗
PubMed1991

Primary structure of sweet potato starch phosphorylase deduced from its cDNA sequence.

Sweet potato (Ipomoea batatas) starch phosphorylase cDNA clones were isolated by screening an expression library prepared from the young root poly(A)(+) RNA successively with an antiserum, a monoclonal antibody, and a specific oligonucleotide probe. One cDNA clone had 3292 nucleotide residues in which was contained an open reading frame coding for 955 amino acids. This sequence was compared with those of potato (916 residues plus 50-residue putative transit peptide) and rabbit muscle (841 residues) phosphorylases. The sweet potato phosphorylase has an overall structural feature highly homologous to that reported for potato phosphorylase, in conformity with the finding that they belong to the same class of plant phosphorylase. High divergencies of the two enzymes are found in the about 70 residue N-termini each including a putative transit peptide, and the midchain 78 residue insert typical of type I plant phosphorylase. We consider that the very high dissimilarity found in the midchain inserts is related to the difference in proteolytic lability of the two plant phosphorylases. Some structural features of the cDNA clone were also discussed.

Journal Article↗