PubMed Health⌕ Search

Biomedical subjects

P Y Chong

Publications and source records attributed to P Y Chong.

At least 19 recordsLinked to original sources
PubMed2006

RUNX3 protein is overexpressed in human basal cell carcinomas.

Basal cell carcinomas (BCC), which are the most common form of skin malignancy, are invariably associated with the deregulation of the Sonic Hedgehog (Shh) signalling pathway. As such, BCC represent a unique model for the study of interactions of the Shh pathway with other genes and pathways. We constructed a tissue microarray (TMA) of 75 paired BCC and normal skin and analysed the expression of beta-catenin and RUNX3, nuclear effectors of the wingless-Int (Wnt) and bone morphogenetic protein/transforming growth factor-beta pathways, respectively. In line with previous reports, we observed varying subcellular expression pattern of beta-catenin in BCC, with 31 cases (41%) showing nuclear accumulation. In contrast, all the BCC cases tested by the TMA showed RUNX3 protein uniformly overexpressed in the nuclei of the cancer cells. Analysis by Western blotting and DNA sequencing indicates that the overexpressed protein is normal and full-length, containing no mutation in the coding region, implicating RUNX3 as an oncogene in certain human cancers. Our results indicate that although the deregulation of Wnt signalling could contribute to the pathogenesis of a subset of BCC, RUNX3 appears to be a universal downstream mediator of a constitutively active Shh pathway in BCC.

Blotting, Western↗
PubMed2005

Clinical usefulness of endoscopic ultrasonography with or without fine needle aspiration in the diagnosis and staging of pancreatic carcinoma.

INTRODUCTION: The aims of this study was to show the accuracy and clinical usefulness of endoscopic ultrasonography (EUS) with EUS-guided fine needle aspiration (FNA) in the diagnosis and staging of pancreatic cancer not obvious in computed tomographic (CT) scan abdomen imaging. MATERIALS AND METHODS: Five male patients were evaluated; 4 presented with obstructive jaundice and 1 had unexplained loss of weight. The mean age was 66 years (range, 40 to 77). All had CT scan abdomen imaging which did not show any obvious pancreatic tumour. EUS with FNA was done for all cases when indicated. Surgical findings, if any, were obtained and compared to EUS findings. RESULTS: EUS easily detected the pancreatic tumour in all 5 cases. The tumour sizes detected ranged from 27 to 40 mm in diameter. These corresponded fairly accurately with that of surgical findings for all 3 who had surgery. EUS reported 3 cases with pathological lymph node involvement. All 5 cases were confirmed by FNA or surgery. EUS was also accurate in 4 cases, which reported the absence of portal vein or superior mesenteric vein invasion. Surgical documentation could not verify the fifth case. There were no complications at all from the EUS with/without FNA. CONCLUSION: This case series showed that EUS with/without FNA appears to be useful and safe in diagnosing and staging pancreatic head tumours not detectable by CT scanning.

Adult↗
PubMed2000

Synthesis of carbamate-containing cyclodextrin analogues.

[formula: see text] The one-pot cyclooligomerization of a saccharide-derived p-nitrophenyl carbamate monomer was developed to generate a series of novel carbamate-containing cyclodextrin analogues. The "transcarbamoylation" occurs by initial base-induced activation to the isocyanate, followed by polycondensation/cyclization of the isocyanato alcohol. In the presence of NaH, only cyclized oligomers were observed, suggesting the importance of Na+ in promoting the efficiency of the cyclization process. The facile deprotection of the oligomers was achieved.

Carbamates↗
PubMed1999

A case report on aggressive fibromatosis with bone involvement.

Aggressive fibromatosis is a locally infiltrative fibroblastic tumour that arises from fascial planes of soft tissue but does not metastasize. It is known to invade muscle, subcutaneous tissue and neurovascular structures. However, bone involvement is very rare and there has been few reports of bone involvement. We present a case of a young man with aggressive fibromatosis of the right lower leg with fibula involvement.

Adult↗
PubMed1998

Delayed diagnosis of tuberculosis presenting as small joint arthritis--a case report.

Small joint arthritis is an uncommon manifestation of tuberculosis. We report a case of tuberculosis presenting as arthritis of the midtarsal joints with concomitant spinal involvement. This case illustrates the difficulties in diagnosing tuberculous arthritis as it has an insidious onset, paucity of constitutional symptoms, unremarkable early physical findings and frequent absence of associated pulmonary involvement. A high index of suspicion in high-risk individuals with chronic monoarthritis, is required to avoid delayed diagnosis.

Adult↗
PubMed1998

A case of metastatic nasopharyngeal carcinoma in benign nasal polyps.

An unusual case of recurrent nasopharyngeal carcinoma occurring within the stroma of benign nasal polyps is described. The patient was primarily treated with radiotherapy at first diagnosis. Two years later, he was diagnosed to have benign nasal polyps and had endoscopic sinus surgery. The recurrence was only diagnosed from histological examination of the polyps. The necessity for preoperative histological examination of any nasal polyp in patients with a past history of nasopharyngeal carcinoma and the importance of histological examination of all nasal polyps removed at surgery are emphasized.

Adult↗
PubMed1995

Clustered intramammary microcalcifications not associated with a mass.

Over a period of two and a half years, 36 biopsies performed for clustered microcalcifications not associated with a mass revealed 30 benign and 6 malignant lesions. Of the 30 benign cases, 4 showed histological features which are thought to be associated with an increased risk of developing carcinoma. As similarities can exist in the mammographic appearances between benign and malignant microcalcifications, clusters of microcalcifications showing overlapping features or increasing in number over time require histopathologic study as there is no radiologic means at present of predicting which cluster will be malignant. We observe that our Chinese female population has a tendency towards dense breast parenchyma often associated with microcalcifications, both scattered and clustered. The presence of these clustered microcalcifications prompts biopsy even though the yield for malignancy is anticipated to be low.

Adult↗
PubMed1995

Extramammary Paget's disease: a report of three cases and review of the literature.

Extramammary Paget's disease (FMPD) is a rare skin disease with a tendency to recur even in the face of adequate excision. It was first suggested by Weiner in 1937 to be a carcinoma of the apocrine sweat gland with intraepithelial excision. Thus, most cases of EMPD occur in the perianal, perigenital and axilla regions where sweat glands abound, with scrotal EMPD being the commonest. EMPD can occur in both benign or malignant form and is often confused with chronic dermatitis. Diagnosis can only be confirmed by an excision biopsy. The long-term survival in patients without an underlying carcinoma is good. However, EMPD associated with an underlying adnexal carcinoma tends to be more aggressive and the prognosis is poor in such cases. EMPD is also associated with other malignancies such as prostatic, rectal, cervical, breast, bladder and skin carcinomas. Incidences of up to 40% have been reported. Thus, patients with EMPD should be thoroughly screened for associated primary growths. The treatment of EMPD is essentially by surgical excision with clear margins. The options available for a clear margin include intraoperative frozen section,Moh's surgery and paraffin section with delayed re-excision. In this report, we present three cases of EMPD with markedly different outcomes and a review of the literature.

Aged↗
PubMed1994

Temporal bone chondroblastoma: big and small.

Chondroblastoma represents approximately one per cent of all primary bone tumours. It is even rarer in the temporal bone and so far only 34 cases have been reported. We report here two cases with chondroblastoma of the temporal bone. The first case was discovered as a small lesion of the attic and root of zygoma. It was removed via mastoidectomy and reconstruction of the bony defect achieved normal external ear canal anatomy and hearing post-operatively. The second case presented as an advanced tumour involving the infratemporal fossa and parapharyngeal space. It was treated surgically via the infratemporal fossa approach. As clear surgical margins were not obtained, post-operative radiotherapy was also given to minimize the chance of recurrence.

Adult↗
PubMed1994

Thyroid carcinomas in Singapore autopsies.

Four hundred and forty four thyroid glands were obtained from coronial autopsies from 1983 to 1984. These were fixed and serially sectioned. Forty five glands (10%) were found to contain carcinomas. Forty one of these were papillary carcinomas, 2 were follicular carcinomas and 2 were undifferentiated carcinomas. No medullary carcinomas were found.

Adult↗
PubMed1993

Severe abdominal pain in low dosage clofazimine.

We describe a 41 yr old leprosy patient treated for 10 yrs with clofazimine who underwent laparotomy for severe abdominal pain. At surgery, the only significant findings were that the coeliac lymph nodes were enlarged and stained purplish black as were the omentum and the intraperitoneal fat. No other cause of abdominal pain was identified. On histological examination, reddish-purple crystals were identified at frozen section but not in the paraffin sections.

Abdominal Pain↗
PubMed1990

Treatment of adrenal cortical carcinoma with mitotane: outcome and complications.

Adrenal cortical carcinoma is a rare tumour with a poor prognosis. We report a patient with metastatic adrenal cortical carcinoma who responded dramatically to Mitotane (o,p'-DDD). Unlike previous reports of metastatic adrenal cortical carcinoma in which complete remission was obtained with high dose Mitotane treatment, the dose of Mitotane used in this patient was low. However, she developed unusual side-effects such as hyperpigmentation, low plasma cortisol and high adrenocorticotropic (ACTH) levels. The side effects closely resemble those in Nelson's syndrome and were reversed by cortisone replacement. The mechanism of actions of Mitotane is discussed with emphasis on its effect on corticosteroid metabolism.

Adrenal Cortex Neoplasms↗
PubMed1988

Tumour infiltrating lymphocytes in nasopharyngeal carcinoma.

Tumour infiltrating lymphocytes were studied in 28 cases of undifferentiated carcinoma using a panel of monoclonal antibodies. For the T subsets we used OKT4 (helper/inducer), 8 (suppressor/cytotoxic), 11 (pan T), 9 (transferrin receptor) and Dako T6. For the B cells we used polyclonals IgM, D, G and A. Others were HNK-1 (natural-killer cells), THB-5 and W6/32 (HLA-ABC) and HLA-DR. Most of the lymphocytes were T cells and in 26 of 28 biopsies there were more T8 than T4 cells which could be seen around and within the tumour masses. There was also an increase in HNK and T6 cells. Tumour cells were positive for both W6/32 and HLA-DR. Occasional THB-5 positive cell could be seen within tumour masses. All tumour cells stained strongly with keratin and cytokeratin.

Antibodies, Monoclonal↗
PubMed1986

A rare case of carpal tunnel syndrome due to tenosynovial osteochondroma.

A rare case of carpal tunnel syndrome due to an extra-articular synovial osteochondroma arising from the synovial sheath of the flexor pollicis longus tendon, is described. This has not been described in the literature previously. The cyst with the contained osteochondroma was excised with good relief of symptoms. The histological examination of the osteochondroma revealed another interesting and unusual feature. We would like to document a case of tenosynovial chondrometaplasia of the synovial lining of a tendon sheath. Only a few such cases have been reported in the literature.

Carpal Tunnel Syndrome↗
PubMed1986

Omental cryptococcoma. An unusual presentation of cryptococcosis.

A case of an omental cryptococcal granuloma, believed to be the first reported, presented as an abdominal mass in a 29-year-old man. An exploratory laparotomy revealed a soft, 8-cm lesion in the omentum. Pathologic examination showed this to be a cryptococcal granuloma containing masses of budding, encapsulated yeasts. Aggregates of eosinophils were also noted. This case is unusual in both site (as cryptococcosis tends to localize in the central nervous system) and size.

Adult↗