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Biomedical subjects

T T Kuo

Publications and source records attributed to T T Kuo.

154 records · Page 9Linked to original sources
PubMed1969

Suppression of proline requirement of proA and proAB deletion mutants in Salmonella typhimurium by mutation to arginine requirement.

Eleven variants able to grow without proline (provided arginine was absent) were obtained by spontaneous mutation from Salmonella typhimurium LT7 proA and proAB deletion mutants. Suppression resulted from mutation at argG, which specifies N(alpha)-acetylornithine delta-transaminase. In the absence of exogenous arginine, deficiency of this enzyme would cause derepression of the arginine pathway and accumulation of N-acetylglutamic gamma-semialdehyde. N-acetylglutamic gamma-semialdehyde, if deacetylated, would produce glutamic gamma-semialdehyde, the proline precursor whose synthesis from glutamate is blocked in proA and proAB mutants. All of the mutants grew only slowly (some very slowly) if not supplied with arginine. Sonic-treated preparations of eight mutants had no measurable acetylornithine delta-transaminase activity, but those of the three mutants least dependent on arginine had 0.11, 0.28, and 1.48 of wild-type activity; presumably, their enzymes have low specific activity, at least in vivo. Phage P22 cotransduced argG and strA. Genetic analysis showed that the minor degree of arginine dependence of the mutant with greater than wild-type in vitro enzyme activity was a characteristic of its argG allele, not the result of modification of the argG phenotype by mutation elsewhere.

Arginine↗
PubMedDate not supplied

Pancreatic tuberculosis mimicking pancreatic head carcinoma: a case report and review of the literature.

A 24-year-old man presented with vague abdominal fullness and a mild epigastric dull pain for about 3 months was found to have a pancreatic head tumor at a medical center 2 months ago. He came to our hospital for further treatment. Ultrasonography, endoscopic retrograde cholangiopancreatography (ERCP) and abdominal computed tomography (CT) all revealede a pancreatic head tumor. Laparotomy was performed because pancreatic head carcinoma was highly suspected. Indurated mass in the pancreatic head, enlarged lymph nodes and white tubercles on the intestine proved to be tuberculosis on histological examination of a frozen section. Acid fast bacilli were also found. The patient was given antituberculous therapy and is now doing well. To avoid unnecessary laparotomy, CT, echo-guided percutaneous aspiration cytology or biopsy and culture of the tissue for mycobacteria should be done in a patient with pancreatic mass, especially in a region where pulmonary and abdominal tuberculosis are common.

Adult↗
PubMedDate not supplied

Classification of thymic epithelial neoplasms: a controversial issue coming to an end?

The classification of thymic epithelial neoplasms has been one of the most controversial issues in tumor pathology. There are two opposing schools of pathologists holding different views regarding the classification of thymic epithelial neoplasms. One school of pathologists believe that histological classification of thymomas is not possible or useful. Another school of pathologists believe that thymomas can be histologically subclassified despite their complex histomorphology and that these histological subtypes correlate with their aggressiveness and clinical behavior. A compromised histological classification has been established by World Health Organization (WHO) to designate thymic epithelial neoplasms with letters and numbers. This classification should be adopted internationally to facilitate the communication among concerned pathologists and oncologists. A simple histological classification of thymomas based on cytomorphology and supported by cytokeratin expressions is proposed and compared to the WHO and Müller-Hermelink's histogenetic classifications.

Humans↗
PubMedDate not supplied

Pathologic studies of fatal cases in outbreak of hand, foot, and mouth disease, Taiwan.

In 1998, an outbreak of enterovirus 71-associated hand, foot, and mouth disease occurred in Taiwan. Pathologic studies of two fatal cases with similar clinical features revealed two different causative agents, emphasizing the need for postmortem examinations and modern pathologic techniques in an outbreak investigation.

Disease Outbreaks↗
PubMedDate not supplied

Subcutaneous panniculitic T-cell lymphoma developing in a child with idiopathic myelofibrosis.

PURPOSE: Subcutaneous panniculitic T-cell lymphoma is reported in a child with idiopathic myelofibrosis. Both disease entities are rarely seen in children. PATIENT AND METHODS: A girl aged 5 years and 9 months had pancytopenia and severe constitutional symptoms. Idiopathic myelofibrosis was subsequently diagnosed. RESULTS: A transient response was achieved after treatment with a course of high-dose methylprednisolone therapy. However, proptosis and skin nodules developed during tapering of steroid therapy. A computed tomography scan of the orbit also revealed a mass lesion in the right lacrimal gland region. A skin biopsy specimen showed a subcutaneous panniculitic T-cell lymphoma. The clinical course was marked by high fever, profound pancytopenia, massive gastrointestinal bleeding, and severe, recurrent infections. Her condition rapidly deteriorated, and she died from polymicrobial sepsis 4 months after her initial examination. CONCLUSIONS: Subcutaneous panniculitic T-cell lymphoma is a distinctive clinicopathologic entity that is rarely seen in children. The association of myelofibrosis and peripheral T-cell lymphoma as seen in this has been rarely reported.

Child↗
PubMedDate not supplied

p16INK4 gene mutation and allelic loss of chromosome 9p21-22 in Taiwanese hepatocellular carcinoma.

BACKGROUND: The p16INK4 (MTS1/CDNK2A) gene, located on chromosome 9p21, is an inhibitor of cyclin-dependent kinase 4. Various data have shown that it is frequently inactivated in several types of cell lines and primary human cancers. MATERIALS AND METHODS: Thirty cases with hepatocellular carcinoma were studied for possible p16INK4 gene mutation in Taiwan. Homozygous deletion was determined using polymerase chain reaction (PCR). The p16INK4 gene mutation was first screened by single strand conformation polymorphism, then direct DNA sequencing was performed on the cases with mobility shifts. Deletion mapping of chromosome 9p21-22 was also carried out with two polymorphic microsatellite markers (D9S925 and D9S168) using PCR. RESULTS: One of the 30 cases had homozygous deletion at exon 3 of the p16INK4 gene. Another tumor had altered electrophoresed mobility in exon 2 with G to T transversion in the first nucleotide of codon 61 by direct sequencing causing a stop codon (GAG-->TAG). At the D9S925 and D9S168 loci, six out of 24 (25%) and three out of 19 (16%) informative cases showed loss of heterozygosity, respectively. CONCLUSION: Point mutation and homozygous deletion of the p16INK4 gene are present in a subset of hepatocellular carcinomas in Taiwan. The patterns of the p16INK4 gene alteration are, however, different from those from other regions. In addition, allelic loss on chromosome 9p21-22 is not an uncommon event in hepatocellular carcinomas. Therefore, the significance of chromosome 9p loss deserves to be extensively investigated.

Adult↗