Functional analysis of a gene encoding homoserine kinase from rice

Homoserine kinase (HSK) is an enzyme that catalyzes the common pathway in threonine and methionine biosynthesis in plants. The genes encoding HSK have been reported in many bacteria and some plants including Arabidopsis. Our group recently reported a gene for threonine synthase (TS) from rice. In this study, we functionally characterized a gene encoding HSK from rice (OsHSK). Analysis of a cDNA sequence and genome of rice revealed that a full-length open leading frame of OsHSK consisted of 378 amino acids, which corresponded to a protein with the molecular weight of approximately 37.8 kDa and with the predicted isoelectric point of 6.86. The predicted amino acid sequence of OsHSK harbored a distinct signature motif for ATP binding and was highly homologous to that of enzymes of plant and bacterial HSKs. Expression of OsHSK in the thrB mutant of Escherichia coli showed that the gene was able to functionally complement the mutant. These results suggest that OsHSK encodes a protein for HSK in rice.Keywords: Homoserine, homoserine kinase, rice (Oryza sativa), thr

Heterogeneity of Adenosine Triphosphate-Based Chemotherapy Response Assay in Colorectal Cancer - Secondary Publication

PURPOSE: Adenosine triphosphate-based chemotherapy response assay (ATP-CRA) is a well-documented and validated technology that can individualize chemotherapy for patients with lung, stomach, or breast cancer. This study explored the feasibility of ATP-CRA as a chemosensitivity test in patients with colorectal cancer. MATERIALS AND METHODS: A total of 118 patients who underwent surgical resection for colorectal adenocarcinoma were analyzed for chemosensitivity to 6 anticancer drugs using ATP-CRA. We calculated the cell death rate (CDR) by measuring intracellular ATP levels of drug-exposed cells and untreated controls. RESULTS: Interpretable results were available for 85.5% (118/138) of patients. The mean coefficient of variation for triplicate ATP measurements was 9.2%. The highest CDR was observed in irinotecan (34.0%) and the lowest CDR in etoposide (21.0%). Paclitaxel had the broadest range of CDR (0-86.7%) and 5-FU had the narrowest range of CDR (0-56.8%). The overall highest responsiveness was seen most prevalently in irinotecan (24.7%, 23/93 patients). Irinotecan had the greatest responsiveness in patients with well differentiated and moderately differentiated carcinoma. CONCLUSION: Our study suggests that ATP-CRA could be used to identify patients with colorectal cancer who might benefit from treatment with a specific chemotherapeutic agent.ope

How Respiratory Muscle Strength Correlates with Cough Capacity in Patients with Respiratory Muscle Weakness

PURPOSE: The purpose of this study is to investigate how respiratory muscle strength correlates to cough capacity in patients with respiratory muscle weakness. MATERIALS AND METHODS: Forty-five patients with amyotrophic lateral sclerosis (ALS), 43 with cervical spinal cord injury (SCI), and 42 with Duchenne muscular dystrophy (DMD) were recruited. Pulmonary function tests including forced vital capacity (FVC) and respiratory muscle strength (maximal expiratory pressure, MEP; maximal inspiratory pressure, MIP) were performed. The correlation between respiratory muscle strength and cough capacity was analyzed. RESULTS: In the SCI group, FVC in a supine position (2,597 +/- 648 mL) was significantly higher than FVC in a sitting position (2,304 +/- 564 mL, p < 0.01). Conversely, in the ALS group, FVC sitting (1,370 +/- 604 mL) was significantly higher than in supine (1,168 +/- 599 mL, p < 0.01). In the DMD group, there was no statistically significant difference between FVC while sitting (1,342 +/- 506 mL) and FVC while supine (1,304 +/- 500 mL). In addition, the MEP and MIP of all three groups showed a significant correlation with peak cough flow (PCF) (p < 0.01, Pearson's correlation analysis). In the SCI group, MIP was more closely correlated with PCF, while in the ALS and DMD groups, MEP was more closely correlated with PCF (p < 0.01, multiple regression analysis). CONCLUSION: To generate cough flow, inspiratory muscle strength is significantly more important for SCI patients, while expiratory muscle function is significantly more important for ALS and DMD patients.ope

Primary Acinic Cell Carcinoma of the Breast: A Case Report with an Immunohistochemical and Ultrastructural Studies

Acinic cell carcinoma (ACC) of the breast is extremely rare and is characterized by widespread acinar cell-like differentiation. We report of a 39-year-old woman presented with a palpable breast mass with significant morphological, immunohistochemical and ultrastructural findings. Histologically, ACC showed a diffuse glandular infiltrative pattern, with small acinar or glandular structures mixed with solid nests. Neoplastic cells were monotonous proliferation of cells with a granular or clear cytoplasm, resembling acinar cells of the salivary glands or Paneth cells. Both glandular and solid tumor cell populations were strongly positive for lysozyme and α-1-antitrypsin

Giant Cell Tumor of Soft Tissue: a Case with Atypical US and MRI Findings

We report the case of a giant cell tumor with diffuse interstitial hemorrhaging and unusually prominent cystic components in the soft tissue of the thigh which has not been reported previously. Magnetic resonance image (MRI), showed signal intensity typical of a giant cell tumor. However, because of its conspicuous large well-circumscribed cystic components, the differential diagnoses, based on the image findings from an ultrasonography (US) and MRI, were complicated epidermoid cyst, cystic change of a neurogenic tumor, and a parasitic cyst

A Case of Hyperglycemic Hyperosmolar State Associated with Graves' Hyperthyroidism: A Case Report

Hyperglycemic hyperosmolar state (HHS) is an acute complication mostly occurring in elderly type 2 diabetes mellitus (DM). Thyrotoxicosis causes dramatic increase of glycogen degradation and/or gluconeogenesis and enhances breakdown of triglycerides. Thus, in general, it augments glucose intolerance in diabetic patients. A 23-yr-old female patient with Graves' disease and type 2 DM, complying with methimazole and insulin injection, had symptoms of nausea, polyuria and generalized weakness. Her serum glucose and osmolarity were 32.7 mM/L, and 321 mosm/kg, respectively. Thyroid function tests revealed that she had more aggravated hyperthyroid status; 0.01 mU/L TSH and 2.78 pM/L free T3 (reference range, 0.17-4.05, 0.31-0.62, respectively) than when she was discharged two weeks before (0.12 mU/L TSH and 1.41 pM/L free T3). Being diagnosed as HHS and refractory Graves' hyperthyroidism, she was treated successfully with intravenous fluids, insulin and high doses of methimazole (90 mg daily). Here, we described the case of a woman with Graves' disease and type 2 DM developing to HHS