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Biomedical subjects

C T Liew

Publications and source records attributed to C T Liew.

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

The efficacy of collagen dermis membrane and fibrin on cultured epidermal graft using an athymic mouse model.

A human skin substitute consisting of human cultured keratinocytes, collagen dermis, and fibrin was evaluated in athymic mice. Eighty athymic mice were divided randomly into four groups. A 1.5x1.5-cm full-thickness wound defect was created on the back of each athymic mouse under anesthesia. These wounds were covered by sheets of cultured epidermal graft (group A), cultured epidermal graft with collagen dermis and fibrin (group B), cultured epidermal graft with collagen dermis (group C), or cultured epidermal graft with fibrin (group D). The grafts were secured and kept moist by specially designed saline gauze chambers. The take rates of the cultured graft with more than 50% of the wound covered were 65%, 15%, 50%, and 45% respectively. Group B had a significantly lower graft take rate, however the difference was not significant among groups A, C, and D. Light microscopy of biopsies of the grafted sites at 12 days showed complete epithelialization. The incidence of discharge from wound beds in groups A, B, C, and D was 0%, 15%, 15%, and 10% respectively. The results suggest that cultured cells are best grafted directly onto the wound bed or in combination with either a thin layer of collagen or fibrin but not both because the collagen dermal membrane and the fibrin together may impose too great a diffusion barrier for the cultured cell graft to become vascularized.

Animals↗
PubMed1999

Complete pathological remission is possible with systemic combination chemotherapy for inoperable hepatocellular carcinoma.

The purpose of this Phase II study was to determine the response rate, the toxicity, and the effect on survival of the combination of cisplatin, doxorubicin, 5-fluorouracil, and alpha-IFN (PIAF) in advanced unresectable hepatocellular carcinoma. Fifty patients with either unresectable or metastatic disease were treated with PIAF: cisplatin (20 mg/m2 i.v., days 1-4), doxorubicin (40 mg/m2 i.v., day 1), 5-fluorouracil (400 mg/m2 i.v., days 1-4), and alpha-IFN (5 MU/m2 s.c., days 1-4). Treatment was repeated every 3 weeks to a maximum of six cycles. All patients were evaluable for response, toxicity, and survival. As assessed by conventional imaging criteria, there were no complete responses, but 13 patients (26%) had a partial response. Among the 36 patients who had an initially high alpha-fetoprotein level (>500 ng/ml), 15 (42%) had a >50% fall after therapy. Nine patients underwent surgical resection after achieving partial response and, in 4 of these patients, histological examination of the resected specimens revealed no viable tumor cells. All these nine patients are alive, and eight patients remain in complete remission at between 7.6 and 25.8 months at the time of analysis. The overall median survival was 8.9 months. Toxicity was mainly myelosuppression and mucositis. There were two treatment-related deaths due to neutropenic sepsis. PIAF is active in hepatocellular carcinoma despite considerable hematological toxicity. Complete pathological remission is possible with this systemic combination. Apparently, persistent radiological lesions may still represent complete pathological resolution of active disease.

Adolescent↗
PubMed1999

[A preliminary study of loss of heterozygosity on chromosome 1p in primary hepatocellular carcinoma].

OBJECTIVE: Ten (10) loci on chromosome 1p were analyzed to detect LOH in 38 cases of hepatocellular carcinomas (HCC) in order to locate the deletion area and the possible deleted tumor suppressor gene (TSG) in HCC. METHODS: PCR based microsatellite instability analysis were used to detect LOH on chromosome 1p31 and 1p35-p36 in HCC. RESULTS: LOH were detected on chromosome 1p in 84.2% of HCC. High frequency of LOH (> 40%) were occurred at locus D1S186 on 1p31, locus D1S482 on 1p35 and loci D1S243, D1S160, D1S165 and D1S170 on 1p36. CONCLUSION: LOH occurred mostly on chromosome 1p31 and 1p35-p36 in HCC. There may be more than two TSGs which associated with development of HCC on chromosome 1p31 and 1p35-p36.

Adult↗
PubMed1998

Helicobacter pylori and the null genotype of glutathione-S-transferase-mu in patients with gastric adenocarcinoma.

BACKGROUND: Chronic Helicobacter pylori infection now is recognized as an important causative agent for gastric carcinoma. However, only a small minority of infected individuals develop the malignancy, even in areas with a high prevalence of gastric carcinoma. It has been postulated that the absence of glutathione-S-transferase-mu (GST-mu), which impairs detoxification of exogenous carcinogens, might predispose some infected individuals to the development of gastric carcinoma. METHODS: Patients with histologically confirmed adenocarcinoma of the stomach were tested for H. pylori infection and the GST-mu genotype. Prevalence of GST-mu gene deletion was compared with the H. pylori status of the patients. A group of gender- and age-matched control subjects with known H. pylori-related nonulcer dyspepsia also were tested for the GST-mu genotype and compared with patients with H. pylori positive carcinoma. RESULTS: Fifty-one patients with gastric adenocarcinoma were enrolled into the study. Thirty-five were found to have H. pylori in the resected specimens. The null genotype of GST-mu was significantly more common among those patients with H. pylori positive carcinoma compared with the H. pylori negative group (65.7% vs. 31.3%; P < 0.05). Homozygous deletion of GST-mu was significantly higher in the H. pylori positive carcinoma patients than in the H. pylori-infected, nonmalignant control group (65.7% vs. 37.1%; P < 0.05). CONCLUSIONS: The null genotype for GST-mu is found more commonly in gastric carcinoma associated with H. pylori infection. The absence of the GST-mu enzyme may increase the risk of the development of gastric carcinoma in these patients.

Adenocarcinoma↗
PubMed1998

Altered expression of the growth and transformation suppressor PML gene in human hepatocellular carcinomas and in hepatitis tissues.

The promyelocytic leukaemia (PML) gene, which encodes a transformation and growth suppressor, was first identified at a chromosomal translocation break point in acute promyelocytic leukaemia. To elucidate if PML may be involved in hepatocellular carcinoma (HCC), the expression of PML was analysed using immunohistochemistry in human HCC and hepatitis tissues. Our studies demonstrated overexpression of PML protein in the PML-oncogenic domain (POD) structure in 50% of HCC (11/22). Enhanced expression and cytoplasmic localisation of PML was associated with cirrhosis. Increased expression of PML was also found in liver abscesses. However, in colon metastasis to the liver, the expression of PML was moderate to low, although strong expression was seen in the surrounding interstitial cells, macrophages and lymphocytes, an indication of the inflammation process associated with tumour growth. Most interestingly, strong expression of PML was found in neoplastic cells at the periphery of the tumours, but progressively decreased in cells at the centre of the tumours, which may be associated with an altered transform phenotype or apoptosis. The altered expression of PML indicates that this nuclear protein may play an important role in cellular response to stress and inflammation, as well as in compensatory cell growth.

Carcinoma, Hepatocellular↗
PubMed1998

Hep Par 1 and selected antibodies in the immunohistological distinction of hepatocellular carcinoma from cholangiocarcinoma, combined tumours and metastatic carcinoma.

AIMS: To examine the usefulness of Hep Par 1 together with selected antibodies in the separation of hepatocellular carcinoma (HCC) from cholangiocarcinoma (CC), combined tumours (HCC-CC) and metastatic carcinoma. METHODS AND RESULTS: Antibodies to Hep Par 1, CK19, CK20 and factor XIIIa were applied to 32 HCCs, 27 CCs, five HCC-CCs and 19 metastatic carcinomas from a variety of sites. Hep Par 1 produced distinctive granular staining of all benign hepatocytes and stained 30 HCCs in a heterogeneous manner, irrespective of the degree of differentiation. While labelling all cases of combined HCC-CC, the antibody also stained the mucus-secreting cells of four cases of pure CC. Anti-CK19 produced distinctive staining of bile ducts and CC but also decorated four HCCs and 10 metastatic tumours. Factor XIIIa was not found in normal, reactive or neoplastic hepatocytes. CK20 was found in some cases of HCC and CC and in all cases of metastatic carcinomas from the colon. CONCLUSIONS: Hep Par 1 was a sensitive marker of hepatocytes but its variable staining in HCC may produce false negative results in small biopsies and it was occasionally found in CC. The highest diagnostic yield was obtained when anti-Hep Par 1, CK19 and CK20 were used in a panel. Factor XIIIa staining has no role in the diagnosis of liver cancers.

Antibodies↗
PubMed1998

Bilateral arteritic central retinal artery occlusion in a Chinese patient.

PURPOSE: To report the first case of bilateral central retinal artery occlusion caused by giant cell arteritis in a Chinese patient. METHODS: We studied a Chinese patient who had a history of weight loss, calf claudication and sequential right and left central retinal artery occlusion. RESULTS: The erythrocyte sedimentation rate was greater than 150 mm/h. Temporal artery biopsy confirmed the diagnosis of giant cell arteritis. Systemic steroid prevented further visual loss in the second eye. CONCLUSIONS: We believe that this is the first report in literature on the ophthalmological presentation of giant cell arteritis in a Chinese patient. Giant cell arteritis as a cause of central retinal artery occlusion should always be on the list of differential diagnosis, as early diagnosis and treatment may help to salvage the first eye and prevent blindness from developing in the second eye.

Aged↗
PubMed1998

Histochemical, clinical, and in vitro beta cell responses in a neonate with persistent hyperinsulinaemic hypoglycaemia of infancy.

When treatment with diazoxide and somatostatin for persistent hyperinsulinaemic hypoglycaemia of infancy failed, subtotal pancreatectomy was performed on a neonate on day 41. The pancreatic tissue was saved and used for immunohistochemical and cell culture studies. The initial immunohistochemistry of beta cells for insulin was negative, using a 1 in 200 dilution of insulin antiserum, but positive results were obtained with an increased concentration of the antiserum. The insulin to somatostatin cell ratio in islets of Langerhans was about 1:1, with no somatostatin cells outside the islets. Glucose stimulated insulin secretion in a concentration dependent manner in vitro. Isobutyl methyl xanthine doubled insulin secretion, but lithium had no effect. The glucose stimulated insulin secretion was inhibited by somatostatin, epinephrine, and in the absence of Ca2+. In view of the normal in vitro responses of beta cells to various secretory analogues, the lack of responsiveness to somatostatin analogue before pancreatectomy may not have been due to deficiency or resistance to somatostatin, but to beta cell hyperplasia overwhelming the paracrine regulatory mechanism(s).

1-Methyl-3-isobutylxanthine↗
PubMed1998

Percutaneous biopsy of small hepatic lesions using an 18 gauge automated needle.

This study evaluates the efficacy of ultrasound guided percutaneous biopsy using an 18 gauge automated side-cutting needle in the diagnosis of small (< or = 3 cm) focal hepatic lesions. 137 consecutive percutaneous biopsies of 131 different small (< or = 3 cm) focal hepatic lesions were included. 11 biopsies were performed on lesions of < or = 1 cm in diameter, 56 were on lesions 1.1-2 cm in size and 70 on lesions 2.1-3 cm in size (average 2.3 +/- 0.7 cm; median 2.3 cm; range 0.7-3 cm). The biopsy specimen was sufficient for diagnosis in 135 cases (98.5%). The sensitivity for diagnosing malignancy was 96.4%; specificity was 100%, positive and negative predictive values were 100% and 94.6%, respectively; accuracy was 97.8%. There was no statistically significant difference in the diagnostic efficacy for lesions of different pathology and size. No significant post-biopsy complication occurred. It is concluded that the 18 gauge Temno needle is safe and effective in diagnosing small hepatic lesions.

Adolescent↗
PubMed1998

Incidence and predictive value of congenital hypertrophy of retinal pigment epithelium in Chinese familial adenomatous polyposis patients.

OBJECTIVE: To investigate the incidence and predictive value of congenital hypertrophy of retinal pigment epithelium (CHRPE) in the Chinese familial adenomatous polyposis (FAP) patients. METHODS: Eleven FAP patients and 28 at risk relatives from 7 families were examined for CHRPE lesions. RESULTS: CHRPE was present in all 11 FAP patients. Nine CHRPE lesions were found in 9 of the 28 at risk relatives. There were great intra and inter-familial variations of the CHRPE lesions. Two at risk relatives were diagnosed to have FAP only after our screening and subsequent proctosigmoidoscopy. Nine at risk relatives were put under high surveillance because of the presence of CHRPE. CONCLUSION: The incidence of CHRPE in the FAP patients in our study is 100%. Eye examination for CHRPE for FAP patients and their at risk relatives is of very high value. A central FAP registry is thus recommended.

Adenomatous Polyposis Coli↗
PubMed1998

[Study on telomerase activity in hepatocellular carcinoma and chronic hepatitic disease].

OBJECTIVE: To compare telomerase activity of hepatocellular carcinoma (HCC) with that of chronic liver disease to analyze the significance of telomerase activity in diagnosis of malignancy. METHODS: Telomerase activity was detected in 38 cases of HCC and corresponding non-tumor liver tissue with different chronic disease. That is 21 cases of hepatic cirrhosis, 2 cases of mild fibrosis, 2 cases of chronic viral hepatitis and 7 cases of non-tumor liver with no significant histopathological changes using TRAP assay. 4 cases of biliary atresia were also detected and 4 cases of normal liver tissue were the control. RESULTS: Telomerase activity was detected in 32 of 38 (86.8%) cases of HCC. Telomerase activity in HCC was not related with tumor cell differentiation types, tumor size and HBV infection, but expression of telomerase was highly correlated with serum alpha-fetal protein (AFP) level of patients. Telomerase negative HCC group has statistically significant lower level of AFP (P < 0.01) when compared with telomerase positive HCC groups. Telomerase activity was not present in normal liver tissue (0/4), biliary atresia (0/4), mild fibrosis (0/2), chronic viral hepatitis (0/4) and no significant changes of non-tumor liver tissue (0/7). Weak telomerase activity was detected in 4 of 21 hepatic cirrhosis. CONCLUSION: Telomerase activity was only detected in most of HCC and few cases of hepatic cirrhosis, which may play a crucial role in hepatocarcinogenesis and may be useful for the diagnosis of malignancy.

Carcinoma, Hepatocellular↗
PubMed1997

Safety of percutaneous biopsy of hepatocellular carcinoma with an 18 gauge automated needle.

OBJECTIVE: Accurate histological diagnosis and subtyping of hepatocellular carcinoma (hepatoma) is likely to be enhanced if a large biopsy tissue specimen is made available to the pathologist. However biopsy of this tumour can be dangerous, especially if the liver is cirrhotic and the lesion is superficial. This study evaluates the safety of an 18 gauge spring loaded side-cutting needle in the percutaneous biopsy of hepatoma in cirrhotic patients under ultrasonographic (US) guidance. Particular attention was paid to establishing the necessary length of needle track through interposing liver parenchyma to be certain of maximum safety. MATERIALS AND METHODS: One hundred and thirty-nine consecutive biopsy procedures were performed on 129 hepatomas which belonged to 113 men and 12 women of average age 57 +/- 15 years old (median 60, range 8 months-88 years). Ninety-six (69.1%) of these biopsies were performed in cirrhotic livers. The length of biopsy needle track traversing interposing liver parenchyma was less than 1 cm in two cases, 1 cm in 41 cases, between 1 and 2 cm in 46 cases and > 2 cm in 50 cases. The mean tumour size was 7.2 +/- 4.5 cm (median 6.8 cm, range 0.7-25 cm). The average number of needle pass in each biopsy was 2.1 +/- 0.8 times (median 2, range 1-5). RESULTS: One hundred and twenty-six (90.6%) of the biopsy procedures were diagnostic of hepatoma. There were two cases of post-biopsy bleeding, both occurred in procedures with an interposing liver parenchymal track less than 1 cm in length. CONCLUSION: The biopsy technique described was found to be safe for diagnosing hepatoma in patients with or without liver cirrhosis provided that the length of interposing liver parenchymal track is not < 1 cm.

Adolescent↗
PubMed1997

Evaluation of artificial skin (Integra) in a rodent model.

The biocompatibility of artificial skin (Integra) has been investigated in clean surgical wounds of 20 guinea-pigs. A rectangular 3 x 3 cm full-thickness skin defect with excision carried down to the panniculus carnosus was prepared on the dorsal area of the guinea-pig. A thin layer of silver sulfadiazine cream was applied and artificial skin was placed to cover the wound. At day 14, the uppermost silicone layer was removed. Good take of the artificial skin was observed in 18 of 20 animals. Microscopy showed good vascular ingrowth in 14 of the 18 animals. The remaining four animals showed necrotic tissue, absence of vascularization and haemorrhage in the wound bed. Two of the 20 wounds showed purulent discharge. In this animal model, clinical 'take' of the neodermis was achieved in 18/20 animals (90 per cent), while vascular ingrowth was observed in only 14/20 animals (70 per cent). These results suggested that artificial skin in clean surgical wound is readily biologically incorporated into surrounding viable tissue.

Animals↗
PubMed1997

Cystic schwannoma of the orbit.

Cystic schwannoma of the orbit is unreported in the world literature. A 54-year-old Caucasian man presented to our clinic with a 5 year history of progressive right-sided proptosis and diplopia. A large paramedian cystic mass displacing the right globe downwards and laterally was demonstrated. From the clinical and radiological features, the presumptive diagnosis of right frontal sinus mucocoele was made. However, the excisional biopsy of the lesion revealed the rare diagnosis of cystic schwannoma, arising from a branch of the first division of the trigeminal nerve. Post-operatively, the patient had a smooth recovery with visual acuity of 20/20 in each eye; full binocular single vision was also re-established. The differential diagnoses of cystic orbital mass, and the radiological and histological findings of the lesion, are described and discussed.

Cysts↗
PubMed1997

A logical approach to hepatocellular carcinoma presenting with jaundice.

OBJECTIVE: This prospective cohort study on patients with hepatocellular carcinoma (HCC) presenting with jaundice emphasized the importance of differentiating patients with hepatic insufficiency from patients with obstructive jaundice caused by tumor. SUMMARY BACKGROUND DATA: There are little data in the medical literature on the management of patients with HCC presenting with jaundice. Experience has accumulated mainly from case reports and retrospective studies. METHODS: Data were collected prospectively on 2095 patients with HCC seen over a 12-year period. All patients were investigated with blood tests, abdominal ultrasound, and chest radiography. Endoscopic retrograde cholangiopancreatography-percutaneous transhepatic cholangiography, computed tomography and hepatic angiography were carried out in selected patients. RESULTS: Of the 530 patients who had clinically detectable jaundice, 481 had jaundice due to hepatic insufficiency and 49 patients had obstructive jaundice. Patients with hepatic insufficiency had extremely poor prognosis, and 90% of them died within 10 weeks of first presentation. "Curative" resection, however, was possible in 9 of 49 patients with obstructive jaundice, and histologic analysis showed resectional margin involvement by tumor in 1 patient. In addition, 35 patients were treated with biliary stents to relieve the obstructive jaundice. Supportive treatment only was given to five patients who were considered too terminally ill. The overall survival of patients with HCC with obstructive jaundice was similar to those patients who presented with no clinical detectable jaundice and was much better than those with jaundice due to hepatic insufficiency (log-rank test, p < 0.001). CONCLUSIONS: The prognosis of patients with HCC who presented with jaundice due to hepatic insufficiency was dismal. It is important to identify the patients who had obstructive jaundice because with proper treatment, good palliation and occasional cure are possible.

Adult↗
PubMed1996

Prospective analysis of the distal margin of clearance in anterior resection for rectal carcinoma.

The distal resection margin measured in situ at operation, on the fresh specimen and on the fixed specimen was analysed prospectively in 55 consecutive patients undergoing anterior resection for carcinoma of the rectum. There was obvious contraction in length from the operative margin to the specimen margin and to the fixed margin. As measured by contraction coefficients, contraction was greater in more proximal tumours than in distal ones. Eight of 55 patients had microscopic intramural spread in the fixed distal margin and the maximum spread was 12 mm. Taking contraction of the fixed margin into account, the extrapolated microscopic spread in the operative margin ranged from 0 to 47 mm.

Adult↗