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Biomedical subjects

T T Kuo

Publications and source records attributed to T T Kuo.

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

One-step transformation of yeast in stationary phase.

A fast yeast-transformation technique has been developed by adding thio compounds to alkali-ion based protocols and incubating at 45 degrees C. This procedure is especially recommended for cells from stationary phase at a density up to 2.5 x 10(8) cells/ml. It involves only one step for the preparation and transformation of competent cells within 30 min. The yield was more than 10(4) transformants/microgram plasmid DNA. This protocol is easy to scale up for many DNA samples and is also applicable for yeast cells from different types of storages.

DNA, Fungal↗
PubMed1992

Kinetic study of alterations in the host RNA polymerase and protein synthesis during phage Xp 10 infection.

We monitored the compositional change of host RNA polymerase in Xp 10 infected cells by one-step immunoprecipitation with core enzyme-specific antiserum. Results showed a rapid loss of sigma subunit from the RNA polymerase complex by 3 min after infection. In addition, some putative binding proteins were reduced to various extents. In contrast, increasing levels of several other polypeptides were detected. The de novo host protein synthesis was inhibited within 1 min after Xp 10 infection. On the other hand, a sequential expression of phage specific proteins was found and can be categorized as early, middle, and late stage. The alteration of host RNA polymerase and the shutdown of early class proteins took place in parallel.

Bacterial Proteins↗
PubMed1992

Role of anisotropy in determining the selective action of antiarrhythmics in atrial flutter in the dog.

OBJECTIVE: The aim was to clarify the electrophysiological and anatomical features of the preferential site of action of antiarrhythmic drugs in the re-entrant circuit of canine atrial flutter. METHODS: Electrophysiological and anatomical findings were correlated in 17 anaesthetised adult mongrel dogs with atrial flutter associated with an intercaval anatomical obstacle, before and after intravenous administration of disopyramide (2 mg.kg-1) and flecainide (2 mg.kg-1). RESULTS: Before drug injection, a rate dependent prolongation of conduction time occurred in the low right atrium where the conduction was slow during atrial flutter. Disopyramide (n = 8 dogs) and flecainide (n = 9 dogs) terminated atrial flutter, with conduction block occurring in this slow conduction area in the low right atrium. Although the degree of drug induced prolongation of refractoriness in this particular area was similar to those in other areas of the right atrium, conduction was depressed to a greater extent in this region. Anatomical study revealed that a thick pectinate muscle that branched from the crista or crista terminalis itself ran perpendicular to the wavefront of the pacing impulse and atrial flutter in this slow conduction area. CONCLUSIONS: These data indicated that slow conduction might be attributed, at least in part, to anisotropic conduction over the thick muscle bundle in the low right atrium, and that antiarrhythmic drugs preferentially produced conduction block in this area. Anisotropic conduction in the low right arium is an anatomical substrate for slow conduction in the re-entrant circuit and for the site preference of antiarrhythmic drugs in the present canine model.

Animals↗
PubMed1992

New observations in a child with angiofollicular lymph node hyperplasia (Castleman's disease) originated from the mesenteric root.

Localized plasma cell type Castleman's disease (CD) is an unusual pathologic entity. It is frequently associated with clinical and laboratory characteristics and rarely occurs in children. Total surgical excision results in cure in all aspects. To make early diagnosis of mesenteric CD is not easy, especially for children. An 11-year-old Taiwanese boy was recently evaluated for anemia and delayed growth. His clinical findings included a syndrome of severe hypochromic microcytic anemia, neutropenia, thrombocytosis, hypoferremia, hypergammaglobulinemia, and growth failure. Radiological examinations (abdominal ultrasound, small intestinal series, and computerized tomography) identified hepatosplenomegaly, nephromegaly, and huge masses in the middle abdomen with precaval, celiac, and paraaortic lymph nodal enlargement. However, detailed physical examination failed to detect a mass. At laparotomy a double-fist-sized confluent mass was found arising from the mesenteric root. Most masses were discrete and were excised individually. The pathologic diagnosis was plasma-cell type angiofollicular lymph node hyperplasia (Castleman's disease). Seven weeks after surgery, he had an episode of acute hepatitis B. Postoperatively, he exhibited a dramatic growth spurt; the hemoglobin, red blood cell indices, serum iron, and immunoglobulins returned to normal in 2 months. Neutropenia, which has not been previously related to mesenteric CD, was an unexpected finding in our case; however, it resolved spontaneously 3 months after the surgery, suggesting its causal relationship with the tumor.

Castleman Disease↗
PubMed1992

Primary osteosarcoma of the skin.

Primary cutaneous osteosarcoma is extremely rare. An extraskeletal osteosarcoma of the skin occurring in the popliteal region of a 51-year-old woman is described. There were no associated predisposing conditions.

Female↗
PubMed1992

Acinar cell carcinoma of the pancreas. Report of two cases with complex histomorphologic features causing diagnostic problems.

Two pancreatic acinar cell carcinomas with distinctive morphologic features are described. Both tumors showed a variable combination of different histomorphologic patterns formed by tumor cells in different degrees of acinar differentiation. They caused diagnostic problems involving differential diagnosis from normal pancreas and from mixed acinar-endocrine tumor. The presence of mitosis, nuclear atypia, and tumor necrosis are helpful for recognizing its neoplastic nature, and the ultrastructural finding of zymogen-like but not neurosecretory granules prevented the misdiagnosis of a mixed acinar-endocrine tumor. Immunohistochemical studies revealed variable immunostaining patterns corresponding to different types of tumor cell present. Both tumors were found to be aneuploid by flow cytometric DNA study. Our study confirmed previous observations that pancreatic acinar cell carcinomas are highly malignant tumors in spite of the fact that they can differentiate into highly differentiated acinar cells.

Adult↗
PubMed1992

Prognosis of thymic carcinoma: analysis of 16 cases.

Primary thymic carcinoma is a rare malignant neoplasm which arises from the thymic epithelium. Between May 1982 and September 1990, 16 patients with thymic carcinomas, diagnosed at Chang Gung Memorial Hospital, were reviewed. Their ages ranged from 19 to 75 years, with a median of 40 years. Males predominated (male to female ratio was 11:5). The most common presenting symptoms were chest pain, cough, body weight loss and dyspnea. No paraneoplastic syndromes were seen. Chest roentgenograms of 15 patients revealed a mediastinal mass, but a definitive diagnosis could not be made until surgery. Adjacent mediastinal tissues were invaded, or adhered to, by all the tumors. Six distinct histologic types were found, squamous cell carcinoma being the most common (seven cases). The primary treatment of surgical resection was attempted in 14 patients, but only in five cases could the tumors be completely resected; two had a biopsy only. Radiotherapy, with or without chemotherapy, given postoperatively, achieved additional local control in seven of the nine partially resected patients (77%). Distant metastasis occurred in nine of 16 patients (56%). Lymph nodes, bone and lung were the most common metastatic sites. Chemotherapy with cisplatin and/or adriamycin-based regimens was given to patients who had distant metastasis, but the responses were unsatisfactory. The overall survival at one, three and five years was 88%, 51% and 31%, respectively. The median survival was 30 months. The median survival of patients with pure squamous cell carcinoma (> 49 months) was superior to that of patients with other histologic types (18 months; p < 0.01).

Adult↗
PubMed1991

A new method for estimating preexcitation index without extrastimulus technique and its usefulness in determining the mechanism of supraventricular tachycardia.

The preexcitation index has been shown to be useful in determining the mechanism of paroxysmal supraventricular tachycardia (SVT) and the site of the accessory pathway in atrioventricular (AV) reentrant tachycardia. To test whether a preexcitation index could be computed analytically instead of by scanning the whole SVT cycle with extrastimuli, 19 patients with SVT were studied. The new index was computed using the following formula: (AV conduction time during SVT) + (ventriculoatrial conduction time during ventricular pacing at the SVT cycle length) - (SVT cycle length). There was a strong correlation between the preexcitation index determined by the extrastimulus technique and the new index in 15 patients in whom the preexcitation index could be determined (r = 0.99, p less than 0.01). The value on the new index was greater than 90 ms only in patients with dual AV nodal pathways. In the 4 patients in whom the preexcitation index could not be determined by the extrastimulus technique, the new index could differentiate AV reentrant tachycardia (index for 2 patients, 60 and 60 ms, respectively) from AV nodal reentrant tachycardia (index for 2 patients, 100 and 105 ms, respectively). In conclusion, the new index provided help in determining the mechanism of SVT, even when retrograde atrial preexcitation by a ventricular extrastimulus did not occur.

Adolescent↗
PubMed1991

Characterization of the pp70 protein phosphorylation in the extract of rice young panicle.

The endogenous phosphorylation pattern of the extract prepared from rice young panicle has been examined. The extract was phosphorylated in vitro by incubating with [gamma-32p] ATP, and then analyzed by SDS-PAGE and autoradiography. At least eight major phosphoproteins with apparent molecular weights of 70, 60, 52, 40, 33, 30, 20, 16 and 15 kd were detected in the crude extract of rice young panicle. The pp70 which represents the major phosphoprotein in the crude extract of young panicle of rice is a cytosolic protein. Photoaffinity labeling with 8-azido-ATP revealed that a major protein with molecular weight 42,000 dalton but not pp70 can be specifically bound ATP. This suggests that pp70 is not a protein kinase itself, but a substrate of protein kinase. The in vitro phosphorylation of the pp70 occurs at a serine or threonine residue and is time and temperature dependent. The phosphorylation of pp70 does not depend by exogenous Ca++ or cAMP, suggesting that pp70 is a major substrate of an Ca++ or cAMP independent protein kinase in rice young panicle.

Calcium↗
PubMed1991

Intrapericardial pheochromocytoma.

In a 34-year-old man with hypertension and increased urinary catecholamine excretion for 12 years, an m-[131I]iodobenzylguanidine scan and chest computed tomography located an intrapericardial pheochromocytoma in the left atrium. The tumor was excised through a left thoracotomy with cardiopulmonary bypass and circulatory arrest. At 34-month follow-up, blood pressure and urine catecholamine levels were normal. In the 15 cases of intrapericardial pheochromocytoma treated by resection reported in the literature, all 11 survivors were symptom-free except 1 who had residual left atrial tumor and multiple skeletal metastatic lesions. Computed tomography directed by the m-[131I]iodobenzylguanidine scan can be used for detailed location of the tumor. Appropriate surgical approach and use of cardiopulmonary bypass are critical in the resection of these highly vascular tumors.

Adult↗
PubMed1991

Identification and nucleotide sequence analysis of an open reading frame involved in high-frequency conversion of turbid to clear plaque mutants of filamentous phage Cf1t.

Clear plaque mutants (Cf1c) isolated from the temperate filamentous phage Cf1t occurred at a frequency of approximately 10(-3). The pahge yield from Cf1c-infected cells was higher than that from Cf1t-infected cells. Results of spot complementation tests implied that the turbid plaque phenotype is dominant. DNA fragment substitution studies indicated that a NcoI/KpnI fragment of 591 bp was responsible for the determination of plaque turbidity. Sequence data from four Cf1c isolates revealed base pair alterations and a deletion located in the upstream region of an open reading frame (ORFII) which might encode a 18.2-kDa protein. When the ORFII in Cf1t was disrupted by a frameshift mutation, this recombinant phage formed clear plaques. These observations suggest that ORFII may participate in the formation of turbid plaques. ORFII does not show significant homology with the sequence of f1 gpII, gpV, or other known phage proteins.

Amino Acid Sequence↗
PubMed1991

Expression of perforin by natural killer cells within first trimester endometrium in humans.

The lymphocyte pore-forming protein (PFP)--perforin, also named cytolysin--is a potent mediator of cytotoxicity found in the granules of cytotoxic T lymphocytes and natural killer (NK) cells. Granulated metrial gland (GMG) cells found in the pregnant mouse uterus express perforin and are thought to be highly activated cytolytic lymphocytes related to NK cells. Their role in pregnancy is unknown. Human endometrial granulocytes (EGs) are phenotypically similar to murine GMG cells and, like them, express NK cell markers. However, up to now it was not known whether EGs also express perforin. By means of immunohistochemical analysis, using antisera specific for perforin and monoclonal antibodies to CD56 (NKH-1), CD2 (T11), CD3 (Leu-4), CD4 (Leu-3a), and CD8 (OKT-8), we demonstrated that perforin is present in EGs in the decidualized endometrial stroma and decidual tissue of first-trimester gestational endometrium. In fact, double immunohistochemical labeling demonstrated the co-expression of perforin and NKH-1. This population also expressed some T-cell surface antigens (Leu-4 and T11), but not Leu-3a or OKT-8. Chorionic villi, in contrast, lack perforin+ cells. The presence of a potent cytolytic mediator in NK-like cells in both murine and human pregnant uterus raises the issue of the function of such cells in pregnancy.

Adult↗
PubMed1991

Human T-cell lymphotropic virus type I associated adult T-cell leukaemia/lymphoma in Taiwan Chinese.

Twenty-five Chinese patients with human T-cell lymphotropic virus type I (HTLV-I) associated adult T-cell leukaemia/lymphoma (ATLL) were identified in Taiwan. No patients had been outside Taiwan and none were descendants of Japanese heritage. Their ages ranged from 28 to 71 years. There were 17 men and eight women. Main clinical and laboratory features at presentation were lymphadenopathy (16), skin lesions (11), hepatosplenomegaly (11), pulmonary lesions (11), hypercalcaemia (10) and bone marrow infiltration (14). Peripheral blood was characterized by leucocytosis with presence of pleomorphic abnormal lymphocytes but rare anaemia or thrombocytopenia. The clinical subtypes were acute in 15, chronic in three, smouldering in one, and lymphoma type in six. The immunophenotypes of the ATLL cells were characterized by the expression of CD2+, CD4+, CD7-, CD8- and CD25+. The overall prognosis was poor with a median survival of 5 months. The acute form had a significantly shorter survival (2 months) than lymphoma type (13 months). Susceptibility to various infections was common. Pulmonary complications accounted for 73% of the causes of death. The clinicopathologic features of ATLL in Taiwan are indistinguishable from those in HTLV-I endemic areas. The present series adds to the knowledge of the worldwide pattern of the disease.

Adult↗
PubMed1991

Atrophie blanche. A clinicopathological study of 27 patients.

Twenty seven patients (8 males and 19 females) with atrophie blanche were observed in the past 7-years. The mean age at onset was 32 years (ranging from 23 years to 57 years) and 19 years (ranging from 11 years to 36 years) for male and female patient, respectively. The mean disease duration was 2.5 years (ranging from 2 months to 16 years) prior to their consultation. Sixty-three percent of them had summer exacerbation. Four patients had essential cryoglobulinemia, one of whom also developed bilateral iliofemoral artery stenosis one year later. Twelve patients also manifested concurrent purpura pigmentosa chronica (PPC)-like lesions. The observation of the natural course and clinical morphology, being divided into white atrophy-predominant and ulcer-predominant type, led to the impression that atrophie blanche and livedo vasculitis are synonyms with the same disease spectrum. Furthermore, white atrophy is not ulcer scars but lesions de novo suggesting dermal vasculopathy. An attempt was made to explain the uniqueness of clinical morphology. First line treatment included local wound care, bed rest and low-dose aspirin plus dipyridamole. Thirteen patients responded to these treatment either at the first attack or the recurrent episodes. Heparin (5000 units subcutaneous injection once daily) was effective for control of intractable painful ulceration in active stage in 70% of the remaining patients.

Adolescent↗
PubMed1990

Intraepidermal neutrophilic IgA dermatosis.

We report a patient with a vesiculopustular eruption with features distinct from typical subcorneal pustular dermatosis. Clinically, well-formed pustular lesions, which were flowerlike in appearance, were present. Histopathologically, early vesicular lesions showed intraepidermal bullae containing numerous neutrophils, a few eosinophils, and acantholytic cells. Direct immunofluorescence study revealed IgA deposits in the intercellular space of the epidermis. The patient's serum, however, did not contain circulating antibodies reactive with the epidermis. We consider this eruption an immunologically mediated, intraepidermal blistering disease, similar to intraepidermal neutrophilic IgA dermatosis.

Adult↗
PubMed1990

Cutaneous manifestation of Kikuchi's histiocytic necrotizing lymphadenitis.

A young man who presented with cervical Kikuchi's histiocytic necrotizing lymphadenitis later developed a cutaneous plaque lesion. Histologic study of the cutaneous lesion revealed dermal patchy infiltrates composed of large lymphoreticular cells and scattered cells resembling Hodgkin or Reed-Sternberg cells. This condition was initially mistaken for a large-cell lymphoma. But it was later discovered that the dermal cellular infiltrates were similar to that of the involved lymph node. Many of the large cells in the infiltrates were found to be histiocytes. Immunohistochemical study revealed that the cells resembling Hodgkin or Reed-Sternberg cells were activated fibroblasts. The presence of foamy histiocytes and the absence of neutrophils in the skin lesions were also similar to the involved lymph node. Cutaneous Kikuchi's disease may be mistaken for cutaneous lymphoma. Cutaneous involvement by Kikuchi's disease may also denote a worse clinical course.

Adult↗
PubMed1990

Thymic carcinomas: histopathological varieties and immunohistochemical study.

Thirteen cases of primary thymic carcinomas are described. The patients' ages ranged from 19 to 64 years, with a median of 40 years. Nine of them were male. Chest pain with or without cough was the main presenting symptom. No patient had myasthenia gravis. Five histological types were identified; two were undifferentiated (lymphoepithelioma-like) carcinoma, one was a clear-cell carcinoma, two were mixed squamous and small-cell carcinoma, and six were squamous cell carcinoma. All the tumors were variably positive for anti-keratin antibody AE1 and AE3, but negative for AE2. Anti-neuron specific enolase antibody was useful in identifying and confirming the small-cell carcinoma component of the mixed carcinomas. Anti-epithelial membrane antigen antibody aided in revealing the glandular structures in mixed adenosquamous and small-cell carcinomas. Thymic carcinomas were histopathologically differentiated from thymomas by their malignant cytological appearance, increased mitotic activity, and central tumor necrosis. All six patients with pure squamous-cell carcinoma were still alive, with a median survival time of 27 months. All but one of the other patients of different histological types died, the exception being a recent case of mixed adenosquamous and small-cell carcinoma; their median survival was 19.5 months, or 18 months when the latter surviving case is included. The prognosis of patients with pure squamous-cell carcinoma was better.

Adult↗