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Biomedical subjects

C T Wu

Publications and source records attributed to C T Wu.

At least 37 records · Page 2Linked to original sources
PubMed1999

Stabilization of chromatin structure by PRC1, a Polycomb complex.

The Polycomb group (PcG) genes are required for maintenance of homeotic gene repression during development. Mutations in these genes can be suppressed by mutations in genes of the SWI/SNF family. We have purified a complex, termed PRC1 (Polycomb repressive complex 1), that contains the products of the PcG genes Polycomb, Posterior sex combs, polyhomeotic, Sex combs on midleg, and several other proteins. Preincubation of PRC1 with nucleosomal arrays blocked the ability of these arrays to be remodeled by SWI/SNF. Addition of PRC1 to arrays at the same time as SWI/SNF did not block remodeling. Thus, PRC1 and SWI/SNF might compete with each other for the nucleosomal template. Several different types of repressive complexes, including deacetylases, interact with histone tails. In contrast, PRC1 was active on nucleosomal arrays formed with tailless histones.

Animals↗
PubMed1999

Core promoter elements can regulate transcription on a separate chromosome in trans.

Transvection can cause the expression of a gene to be sensitive to the proximity of a homolog. It can account for many cases of intragenic complementation at the Drosophila yellow gene, where one mode of transvection involves the action of enhancers in trans on a promoter present on a separate chromosome. Our goal was to identify cis-acting elements that regulate the trans action of enhancers. Using gene replacement, we altered two core promoter elements at yellow and tested the resulting alleles for their ability to support transvection. We found that the TATA box and initiator element can regulate transvection.

Drosophila Proteins↗
PubMed1999

Preincisional dextromethorphan decreases postoperative pain and opioid requirement after modified radical mastectomy.

PURPOSE: To examine whether preincisional dextromethorphan (DM) improved analgesia after modified radical mastectomy (MRM). METHODS: Sixty patients (ASA I-II) scheduled for MRM were included and randomly allocated into two groups. Patients in the treatment group (DM) received 40 mg DM and 20 mg chlorpheniramine maleate (CPM) i.m., and those in the control group received 20 mg CPM i.m. alone 30 min before skin incision. Meperidine, 1 mg x kg(-1) i.m., was given for postoperative pain relief as required. The time to first meperidine injection, total meperidine consumption, worst pain score, bed-rest time, and side effects were recorded every 24 hr for 48 hr after surgery by a resident anesthesiologist on a double-blind basis. RESULTS: A longer time to first meperidine injection (19.2 +/- 1.6 vs 1.5 +/- 0.23 hr, P < 0.001) and lower meperidine consumption (0[10] vs 75[50] mg, median [interquartile range], P < 0.001) were observed in the DM group than in the control group. The bed-rest time was shorter in the DM than in the control group (18.0[4] vs 23.0[19] hr, P < 0.001). No difference was noted in worst VAS pain score. Meperidine-related side effects (nausea, vomiting, pruritus, dizziness, headache) were more frequent in the control (10/30) than in the DM group (3/30, P < 0.05). The number of patients who required meperidine injection for pain relief was lower in the DM (7/30) than in the control group (25/30, P < 0.005). No DM- or CPM-associated side effects were observed. CONCLUSION: Preincisional IM. DM treatment decreased postoperative pain and opioid requirement after MRM surgery.

Analgesics, Opioid↗
PubMed1999

Thoracic epidural anesthesia for pain relief and postoperation recovery with modified radical mastectomy.

The purpose of this study was to investigate whether thoracic epidural anesthesia (TEA) provides better postoperative pain relief and recovery than general anesthesia (GA) for modified radical mastectomy (MRM) surgery. Sixty-four patients rated as American Society of Anesthesiologists (ASA) 1 to 3 who underwent MRM surgery were included in the study. In TEA group patients, 2% lidocaine (15-20 ml) was administered via the epidural route as primary anesthesia, in conjunction with midazolam (5-10 mg) and fentanyl (<250 microg) for amnesia. The GA patients were maintained with isoflurane and 50% nitrous oxide in oxygen. After operation the patients were given pethidine (1 mg/kg IM) as required for pain relief. The time to first pethidine requirement, total pethidine consumption, worst pain score, bed rest time, satisfaction score, and anesthesia-related side effects were recorded for 2 days after surgery. The results show that TEA provided a more prolonged analgesic effect than GA after operation. A longer time to first pethidine requirement (19.2 +/- 1.5 vs. 7.6 +/- 2.5 hours) (p < 0. 001) and decreased pethidine consumption (17.2 +/- 7.0 vs. 76.3 +/- 17.4 mg) (p < 0.001) were observed in the TEA group than in the GA group, respectively. A worse visual analog scale (VAS) pain score was observed in the GA group (5.7 +/- 0.6) than in TEA patients (4.3 +/- 0.4) (p < 0.01). The average bed rest time was significantly shorter in the TEA group (16.9 +/- 0.9 hours) (p < 0.01) than in the GA group (27.1 +/- 4.1 hours). Overall satisfaction scores were significantly higher in the TEA group (4.4 +/- 0.1) (p < 0.01) than in the GA group (3.5 +/- 0.2). Side effects were observed at a higher frequency in the GA group (16/32) (p < 0.0001) than in the TEA group (3/32). The frequency of pethidine injection for pain relief was significantly lower in the TEA group (8/32) (p < 0.0001) than in the GA group (24/32). The total hospital cost (NT 64,392 +/- 3,523 vs. NT 53,806 +/- 2,817) (p = 0.0342) and anesthesia cost (NT 7,968 +/- 246 vs. NT 5,268 +/- 262) (p < 0.0001) are also significantly lower in the TEA group than the GA group. In conclusion, TEA provided better postoperative pain relief and recovery and lower cost than GA for MRM surgery.

Analgesics, Opioid↗
PubMed1999

Thoracic solitary fibrous tumor: clinical and pathological diversity.

Fourteen cases (13 pleural and one intrapulmonary) of solitary fibrous tumors (SFTs) (the so-called fibrous mesothelioma) were studied. The lesions occurred more in females (nine cases) than males (five cases). The age of patients ranged from 44 to 73 years old (median 60 years). The tumors presented as cough with or without blood-tinged sputum, exertional dyspnea, chest pain, nausea, body weight loss, fever, or as asymptomatic masses detected by routine chest radiograph. Two patients with huge (tumor larger than 20 cm) malignant tumors had accompanying pleural effusion and one associated with hypoglycemia. Ten benign tumors measured 2-11 cm (median size 7 cm) while the remaining four histologically malignant ones measured 20-30 cm in size. All of them were well circumscribed and thinly encapsulated. Hemorrhage and necrosis were more frequently seen in the malignant tumors. Histologically, these lesions were characterized by 'patternless pattern' with occasional hemangiopericytic features (three cases). The tumor cells were all immunoreactive for vimentin, CD 34, and focally actin-positive in one case, but not for keratin, desmin, S-100 protein, carcinoembryonic antigen, alpha 1-ACT and F VIII-related antigen, supported a primitive mesenchymal origin. p53 protein was expressed in two of the malignant cases. Proliferating cell nuclear antigen stain was positive with 50 and 80% of the labeling index in the benign and malignant tumors, respectively, but retinoblastoma gene protein was negative in all tumors. This analysis confirmed the relationship between histological malignant SFTs and tumor size, cellularity, mitotic activity, necrosis and tumor suppressor gene expression. However, the clinical behavior was unpredictable. Complete respectability seemed to be the most important indicator of clinical outcome in the less aggressive tumors.

Actins↗
PubMed1999

Transvection and other homology effects.

The presence of homologous nucleic acid sequences can exert profound effects on chromosomal and gene function in a wide range of organisms. These homology effects reveal remarkable forms of regulation as well as suggest possible avenues for the development of new technologies.

DNA Methylation↗
PubMed1999

Preincisional dextromethorphan treatment decreases postoperative pain and opioid requirement after laparoscopic cholecystectomy.

UNLABELLED: In the present study, we examined whether preincisional treatment with dextromethorphan (DM) provides preemptive analgesia. Ninety patients scheduled for laparoscopic cholecystectomy were included. Patients receiving chlorpheniramine maleate (CPM) 20 mg via an IM injection 30 min before skin incision were designated as the control group. Patients in Group A received DM 40 mg (containing CPM 20 mg) IM after removal of the gallbladder, whereas in Group B, DM 40 mg (containing CPM 20 mg) was administered IM 30 min before skin incision. Meperidine (1 mg/kg IM) was given for postoperative pain relief as required. Times to first meperidine injection, total meperidine consumption, worst pain score, bed rest time, and side effects were recorded for 48 h after surgery. Times to first meperidine injection were 9.3+/-15.9, 17.4+/-3.4, and 28.6+/-3.9 h for the control group and Groups A and B, respectively. The total meperidine consumption was 90.7+/-11.9, 77.5+/-12.7, and 20.0+/-4.4 mg for the control group and Groups A and B, respectively. The worst visual analog pain scores were 6.0+/-0.2, 6.0+/-0.2, and 4.0+/-0.4 for the control group and Groups A and B, respectively. The bed rest times were 21.0+/-0.5, 20.0+/-0.5, and 19.0+/-0.4 h for the control group and Groups A and B, respectively. The number of patients who required meperidine injection was 26, 22, and 12 for the control group and Groups A and B, respectively. We conclude that DM is more effective in producing postoperative analgesia when it is administered preincision rather than after the gallbladder removal treatment, which suggests a preemptive analgesic effect. IMPLICATIONS: Preincisional dextromethorphan (40 mg IM) treatment offers a preemptive analgesic effect, thus improving the postoperative pain management.

Analgesics, Opioid↗
PubMed1999

Ephedrine-induced complete atrioventricular block with ventricular asystole during rapid concomitant phenytoin infusion: a case report.

Ephedrine is widely used to elevate blood pressure, however, one should be cautious to use it concomitantly with phenytoin infusion in neurosurgical procedures. A 59-year-old female was admitted for craniotomy with removal of metastatic brain tumor. During operation phenytoin infusion was given to forestall postoperative seizure. Hypotension, bradycardia and complete atrioventricular block followed by ventricular asystole suddenly occurred when the patient was given ephedrine to elevate the blood pressure to see the hemostatic effect close to the end of operation. We discontinued the phenytoin infusion and immediately injected 1.5 mg epinephrine. She was successfully resuscitated. We conclude that when phenytoin is used intraoperatively it should be administered by an infusion pump at a rate of less than 25 mg/min and under continuous monitoring of cardiac rhythm, heart rate, and blood pressure. When pressure support is required, the use of a pure alpha-agonist may minimize the risk of adverse reactions in the presence of phenytoin infusion.

Anticonvulsants↗
PubMed1999

Paget's disease of the tibia.

Paget's disease of the bone is perceived to be rare in Asia. We report the first documented case of Paget's disease of the bones in Taiwan. A 66-year-old native Taiwanese woman was admitted to hospital with a 10-year history of pain and a bowing deformity of her left leg. Laboratory data disclosed elevated serum calcium and alkaline phosphatase levels, but no leukocytosis. A plain X-ray film of the left leg showed a curved tibia with thickening of the tibial cortex, while a technetium 99m bone scan revealed abnormal uptake in the left tibia. Elevated serum levels of bone-specific alkaline phosphatase and urinary collagen N-telopeptide were also noted. Histologic examination of a biopsy specimen of the left tibia lesion confirmed the diagnosis of Paget's disease in the bone. The patient received treatment with sodium chlodronate, and the symptoms improved rapidly. Laboratory data then revealed decreased levels of serum calcium, bone-specific alkaline phosphatase, and urinary collagen N-telopeptide after treatment.

Aged↗
PubMed1999

Postoperative intramuscular dextromethorphan injection provides postoperative pain relief and decreases opioid requirement after hemorrhoidectomy.

BACKGROUND: Previous studies have shown that dextromethorphan (DM) produces an analgesic/antihyperalgesic effect. This study was designed to examine whether postoperative DM intramuscular (i.m.) injection could reduce post-hemorrhoidectomy pain. METHODS: At the end of the surgery, patients in the study group (n = 30) were given an intramuscular injection of 40 mg DM and 20 mg chlorpheniramine (CPM) while in the study group (n = 30), the patients were given intramuscular 20 mg CPM only. Pethidine (1 mg/kg, i.m.) was prescribed for postoperative pain relief if required. The time to first pethidine injection, total pethidine consumption, worst pain score, and pethidine-related side effects were recorded for 48 h postoperatively. RESULTS: The time from the end of operation to the first pethidine injection was 5.4 +/- 1.6 h and 17.8 +/- 3.7 h (P = 0.006) in the control group and the study group, respectively. Total pethidine consumption was 139.5 +/- 11.5 mg and 77.5 +/- 12.2 mg (P < 0.001) in the control group and the study group, respectively. The worst VAS score was 7.5 +/- 0.2 and 7.1 +/- 0.2 (P = 0.09) in the control and the study groups, respectively. The number of patients who required pethidine injection was 29 and 21 (P < 0.005) in the control and the study groups, respectively. The number of patients who suffered pethidine-related side effects was 7 and 1 (P < 0.025) in the control and the study groups, respectively. CONCLUSIONS: We found that intramuscular DM given at the end of operation could provide good postoperative pain relief and decrease the pethidine requirement after hemorrhoidectomy.

Adult↗
PubMed1999

[Effects of basic fibroblast growth factor on repairing injury of intestinal mucosa in acute necrotic pancreatitis].

OBJECTIVE: To observe the effects of basic fibroblast growth factor (bFGF) on repairing injury of intestinal mucosa in acute necrotic pancreatitis (ANP). METHODS: Sixteen dogs of ANP animal model were made by injection of 5% sodium taurocholate (0.5 ml/kg) with 3,000 U/kg trypsin into the pancreatic duct. The mucosa structure, content of protein, DNA and malondiethylaldehyde (MDA) were observed after ANP and treatment with bFGF, and the plasma lipopolysaccharide and endothelin-1 were detected. The organs of dogs were made to bacterial culture. Ileal mucosa was collected for histological and ultrastructural studies. RESULTS: The results showed that after treatment with bFGF, the injury of intestinal mucosa in ANP was abated. The length, height and area of mucosa microvillus, the content of DNA and protein of ileal mucosa were significantly increased, while the plasma endothelin-1 and lipopolysaccharide were reduced. The organ bacterial translocation rate was also decreased in 50%. CONCLUSION: bFGF has good effects on abating injury of intestinal mucosa, protecting gut barrier function, reducing the incidence of lipopolysaccharide and bacterial translocation after ANP.

Animals↗
PubMed1998

Two modes of transvection: enhancer action in trans and bypass of a chromatin insulator in cis.

Ed Lewis introduced the term "transvection" in 1954 to describe mechanisms that can cause the expression of a gene to be sensitive to the proximity of its homologue. Transvection since has been reported at an increasing number of loci in Drosophila, where homologous chromosomes are paired in somatic tissues, as well as at loci in other organisms. At the Drosophila yellow gene, transvection can explain intragenic complementation involving the yellow2 allele (y2). Here, transvection was proposed to occur by enhancers of one allele acting in trans on the promoter of a paired homologue. In this report, we describe two yellow alleles that strengthen this model and reveal an unexpected, second mechanism for transvection. Data suggest that, in addition to enhancer action in trans, transvection can occur by enhancer bypass of a chromatin insulator in cis. We propose that bypass results from the topology of paired genes. Finally, transvection at yellow can occur in genotypes not involving y2, implying that it is a feature of yellow itself and not an attribute of one particular allele.

Animals↗
PubMed1998

Chondromyxoid fibroma of bone: a clinicopathologic review of 278 cases.

In a study of the clinical, radiographic, and pathological features of chondromyxoid fibroma, the tumor was slightly more common in men, usually in the second decade of life. Almost half of the tumors involved the long bones, although the ilium and the small bones were also common sites. Roentgenograms showed a sharply marginated, lobulated, lucent defect in the metaphysis. The tumor involved the medullary bone in an eccentric fashion, and the cortex was thinned and expanded. Periosteal reaction and soft tissue extension were uncommon. Mineralization was identified in 13% of the lesions. Histologically, the tumors were almost always arranged in lobules, which were prominent (macrolobular) or somewhat indistinct (microlobular). The tumor cells were spindle-shaped or stellate and arranged in a myxoid matrix. Calcification was seen in more than one third of the cases but was rarely prominent. Hyaline cartilage and chondroblastoma-like areas were not uncommon. Approximately 18% of tumors showed bizarre nuclei. Permeation of bony trabeculae was uncommon. Treatment was conservative surgical removal; approximately one fourth of the patients had recurrence.

Adolescent↗
PubMed1998

Oncocytic adenomatous hyperplasia of the lacrimal sac: a case report and review of the literature.

Oncocytic tumors of the lacrimal sac are very rare, with only 21 cases documented in the world literature. The authors report a 75-year-old woman who sought treatment for recurrent dacryocystitis and a palpable mass in the left medial canthal area. The patient underwent surgery for removal of a suspected lacrimal sac cancer, but pathologic findings indicated benign oncocytic adenomatous hyperplasia. Complete removal of the tumor and long-term follow-up are necessary in patients with lacrimal sac oncocytic lesions. The authors discuss the characteristic features of ocular adnexal oncocytic lesions and review the literature.

Adenocarcinoma↗
PubMed1998

Relation between histological intensity of transforming growth factor-beta isoforms in human osteosarcoma and the rate of lung metastasis.

Even though adjuvant chemotherapy has improved the 5-year survival rate of osteosarcoma patients, a significant percentage of patients eventually die from lung metastasis. Since transforming growth faCtor-beta (TGF-beta) has been demonstrated to be related to the tumor progression, we investigated the clinical implications of the presence of TGF-beta isoforms in 16 human osteosarcoma tissue. There were 10 males and 6 females with a mean age of 20.8 years of age (range, 8 to 57 years). Biopsied specimen before chemotherapy was fixed in 10% formalin, demineralized and followed by paraffin embedding. The locations of tumor included femur (10), tibia (3), humerus (1), fibula (1), and ilium (1). Histologic subtypes included osteoblastic (11), chondroblastic (2), and fibroblastic (3). All patients were followed for a minimum of 1 year (range 12 to 44 months) or to the development of lung metastasis. Five patients (31.3%) developed subsequent lung metastasis during the follow up. We used immunohistochemistry technique to investigate the presence of the TGF-beta isoforms in osteosarcoma tissue and its relationship to the subsequent pulmonary metastasis. The results showed the presence of one or more TGF-beta isoforms in tumor cells in osteosarcoma tissues (13 of 16, 81.3%) in all of the subtypes. However, minimal presence of TGF-beta isoforms was shown in the tumor bone matrix. The expression of TGF-beta1 or TGF-beta3 isoforms was associated with a higher rate of subsequent lung metastasis (p < 0.05, chi-square test). Further research is warranted to determine the utility of routine TGF-beta analysis in the clinical practice.

Adolescent↗