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C Y Lo

Publications and source records attributed to C Y Lo.

At least 37 records · Page 2Linked to original sources
PubMed2001

Adrenal lipomatous tumours: a 30 year clinicopathological experience at a single institution.

AIMS: Fatty tumours of the adrenal gland are uncommon and their features have received little attention in the literature. The aim of this study is to analyse the features of adrenal lipomatous tumours. METHODS: The histological features of primary adrenal tumours reported over a 30 year period (1970 to 1999) in Queen Mary Hospital, Hong Kong were reviewed and the clinicopathological features of adrenal lipomatous tumours were analysed. RESULTS: Adrenal lipomatous tumours were noted in 20 patients (12 men, eight women), and they accounted for 4.8% of the primary adrenal tumours reported. The adrenal fatty tumours comprised 11 myelolipomas, three lipomas, three teratomas, two angiomyolipomas, and one liposarcoma. Calcification or bone was noted in one third (seven of 20) of the adrenal tumours. In some fatty tumours (myelolipoma and angiomyolipoma), the fatty component may be inconspicuous. This is the first report in the English literature of angiomyolipoma and liposarcoma of the adrenal gland. CONCLUSIONS: Different types of fatty tumours were noted in the adrenal gland. A high index of suspicion should be maintained with an aim of surgical treatment for selected patients with large and symptomatic adrenal lipomatous lesions. Histological confirmation is needed for diagnosis.

Adolescent↗
PubMed2001

Morphological analysis of adrenal glands: a prospective analysis.

There is a lack of studies to document the weight range of normal adrenal glands. The aims of the current study are to find out the weight range of normal adrenal glands in Chinese patients and to analyze any potential factors affecting it. Adrenal glands not affected by disease were prospectively collected from autopsies on 333 Chinese patients (208 men, 125 women). The weight and longest dimension of each adrenal gland were noted. The impact of various clinicopathological factors on the adrenal weight was studied. In addition, the morphometric features of these adrenal glands were compared with that of 28 surgically resected adrenal glands with cortical adenomas. The mean combined weight of adrenal glands was 11.8 g (range = 5.8 g to 19.9 g). The left adrenal gland was often heavier than the right (mean weight = 6.1 g and 5.7 g respectively) and with a greater longitudinal length than the right (mean length = 5.2 cm and 4.8 cm respectively). Adrenal glands were often heavier in male, younger age group (less than 60-yr-old) and patients with history of hypertension or lung cancers. In comparison, the mean weight of right adrenal gland with cortical adenoma was 11.7 g (range = 6 g to 26 g) and that of left adrenal gland with cortical adenoma was 9.4 g (range = 4.6 g to 25 g). This is the first study in the English literature that provides data on the weight of normal adrenal glands in a solely Chinese population. Adrenal weight may be affected by patients' gender, age, laterality of adrenal gland and presence of systemic disease.

Adenoma↗
PubMed2001

A retrospective survey of attitudes toward acceptance of peritoneal dialysis in Chinese end-stage renal failure patients in Hong Kong--from a cultural point of view.

OBJECTIVE: We undertook to study the attitudes toward dialysis of patients approaching end-stage renal failure and to analyze those attitudes from a cultural perspective. SETTING: The study was performed in the pre-dialysis clinic of a tertiary referral renal center. PATIENTS: All patients of Chinese ethnic origin seen in the pre-dialysis clinic from 1995 to 2000 for assessment of dialysis therapy were included. METHOD: We performed a retrospective analysis of patient records with regard to attitudes of the patients toward dialysis, reasons for those attitudes, and factors that could lead to a subsequent change in attitude. RESULTS: We assessed 462 patients over the 6-year period. Their mean age was 65.5 +/- 13.3 years, and 43.9% of the patients had diabetes. Peritoneal dialysis (PD) was offered to 74% of the patients, and hemodialysis (HD) to 3.9%. Among the patients offered PD, only 44% accepted dialysis. After counselling, 54% of the patients who originally declined PD ultimately accepted it. The major reasons for refusing PD were the ideas of "having lived long enough" and "lack of family support." Most other reasons could be overcome by counselling. Only a minority of patients demanded hemodialysis. CONCLUSIONS: Declining an offer of dialysis was common. Counselling helped patients to accept PD. Certain cultural elements that hindered acceptance of dialysis were involved in the ideas of "having lived long enough" and "lack of family support." Those cultural elements should be tackled more specifically during counselling.

Adult↗
PubMed2000

Total synthesis of (+)-blastmycinone, (-)-litsenolide C1, and related natural trisubstituted lactones via alkynyltungsten compounds.

A general method for total synthesis of natural trisubstituted gamma-lactones is developed on the basis of the chemistry of alkynyltungsten compounds. The key step in this approach involves the cycloalkenation of tungsten-eta1-(3R,4S)-pent-1-yne-3,4-diol with aldehydes to give tungsten-oxacarbenium salts, further leading to 3-alkylidene-4-hydroxy-5-methyl-gamma-lactones upon demetalation. This synthetic sequence proceeds well for alkynylaldehydes and the MOM derivative of tungsten-eta1-(3R,4S)-pent-1-yne-3,4-diol. The resulting butyrolactone products are transformed into natural trisubstituted butyrolactones including (+)-blastmycinone, (+)-blastmycinolactol, (+)-antimycinone, NFX-2, and (+)-isodihydromahubanolide A. By using the same approach based on (R)-ethyl lactate, the natural (-)-litsenolide C1 can be prepared in a few steps.

4-Butyrolactone↗
PubMed2000

A prospective evaluation of recurrent laryngeal nerve paralysis during thyroidectomy.

HYPOTHESIS: Recurrent laryngeal nerve paralysis after thyroidectomy can be unrecognized without routine laryngoscopy, and patients have a good potential for recovery during follow-up. DESIGN: A prospective evaluation of vocal cord function before and after thyroidectomy. Periodic vocal cord assessment was performed until recovery of cord function. Persistent cord palsy for longer than 12 months after the operation was regarded as permanent. SETTING: A university hospital with about 150 thyroid operations performed by 1 surgical team per year. PATIENTS: From January 1, 1995, to April 30, 1998, 500 consecutive patients (84 males and 416 females) with documented normal cord function at the ipsilateral side of the thyroidectomy were studied. MAIN OUTCOME MEASURES: Vocal cord paralysis after thyroidectomy. RESULTS: There were 213 unilateral and 287 bilateral procedures, with 787 nerves at risk of injury. Thirty-three patients (6.6%) developed postoperative unilateral cord paralysis, and 5 (1.0%) had recognizable nerve damage during the operations. Complete recovery of vocal cord function was documented in 26 (93%) of 28 patients. The incidence of temporary and permanent cord palsy was 5.2% and 1.4% (3.3% and 0.9% of nerves at risk), respectively. Among factors analyzed, surgery for malignant neoplasm and recurrent substernal goiter was associated with an increased risk of permanent nerve palsy. Primary operations for benign goiter were associated with a 5.3% and 0.3% incidence (3.4% and 0.2% of nerves at risk) of transient and permanent nerve palsy, respectively. CONCLUSIONS: Unrecognized recurrent laryngeal nerve palsy occurred after thyroidectomy. Thyroid surgery for malignant neoplasms and recurrent substernal goiter was associated with an increased risk of permanent recurrent nerve damage. Postoperative vocal cord dysfunction recovered in most patients without documented nerve damage.

Adult↗
PubMed2000

Role of laparoscopic ultrasonography in intraoperative localization of pancreatic insulinoma.

BACKGROUND: A combination of digital palpation and ultrasonography plays an important role in locating insulinomas intraoperatively. Laparoscopic resection of insulinomas has been described recently, but experience in locating insulinomas during laparoscopy is lacking. METHODS: From January 1998 to January 1999, three patients with pancreatic insulinomas underwent laparoscopy and laparoscopic ultrasonography aimed at intraoperative localization and potential resection. The role of laparoscopy and laparoscopic ultrasonography in locating insulinomas is evaluated. RESULTS: Preoperative localization studies were routinely performed, and two patients had an occult tumor before laparoscopy. None of the tumors was detected by laparoscopic examination, but laparoscopic ultrasonography identified solitary tumors located at the body and tail of the pancreas. Conversion to laparotomy was performed in one patient as a planned procedure. One patient underwent laparoscopic enucleation, whereas the other had a laparoscopic distal pancreatectomy. CONCLUSIONS: Laparoscopic ultrasonography seems to be sensitive in locating insulinomas at the body and tail of the pancreas. It optimizes and facilitates resection of insulinomas through a minimally invasive approach.

Adult↗
PubMed2000

Adrenal pheochromocytoma remains a frequently overlooked diagnosis.

BACKGROUND: Adrenal pheochromocytoma is potentially lethal if undetected and is associated with long-term morbidity. METHODS: Records of patients (11 men, 18 women) with confirmed pheochromocytoma were studied with respect to clinicopathological features and outcome. RESULTS: Pheochromocytoma was diagnosed in 4 of 8,486 (0.05%) autopsies and accounted for 3 of the 4 immediate causes of death. Operative mortality occurred in 1 patient with undiagnosed tumor. Hypertensive-related complications occurred in 6 patients before diagnosis. Malignancy was documented in 7 patients with distant metastases (n = 4) or locally invasive tumors (n = 3). During a median follow-up of 4 years, 23 patients are alive and free of disease (79%). Four of the 6 patients (67%) who died had distant metastases compared with 2 of 23 patients (9%) without distant metastases (P = 0.04). Persistent hypertension and diabetes requiring treatment were present in 8 (35%) and 4 (17%) of 23 patients respectively. CONCLUSIONS: Fatal complications preceded diagnosis in a significant proportion of patients with pheochromocytoma. The presence of distant metastases was associated with poor survival.

Adolescent↗
PubMed2000

Value of intra-arterial calcium stimulated venous sampling for regionalization of pancreatic insulinomas.

BACKGROUND: Intra-arterial calcium stimulation with hepatic venous sampling (ASVS) for insulin gradients has been reported to be the most sensitive preoperative localizing technique for insulinomas. We reviewed our experience with ASVS to localize and guide the treatment of insulinomas over the past decade. METHODS: Eighteen patients who underwent ASVS before surgical exploration for insulinoma were studied. The accuracy of ASVS was compared with intraoperative findings and other localizing studies. RESULTS: There were no complications arising from the procedures. A more than 2-fold step-up in insulin level 30 to 60 seconds after injection to at least 1 feeding artery was observed in 16 patients. Fourteen of the 16 solitary tumors (87.5%) were correctly located; 100% (6/6 tumors) at the head and 80% (8/10 tumors) at the body/tail. The overall accuracy of this test was 89%, compared with 11%, 33%, 38%, and 63% of ultrasonography, computed tomography, magnetic resonance imaging, and endoscopic ultrasonography, respectively. Six enucleations and 10 distal resections were performed, which included 2 laparoscopic procedures. The combination of intraoperative ultrasonography with preoperative ASVS identified all tumors. CONCLUSIONS: ASVS is the most accurate preoperative localization tool for the localization of insulinomas and, in combination with intraoperative ultrasonography, can enhance surgical success.

Adult↗
PubMed2000

Vaccination with DNA encoding internal proteins of influenza virus does not require CD8(+) cytotoxic T lymphocytes: either CD4(+) or CD8(+) T cells can promote survival and recovery after challenge.

DNA vaccination offers the advantages of viral gene expression within host cells without the risks of infectious virus. Like viral vaccines, DNA vaccines encoding internal influenza virus proteins can induce immunity to conserved epitopes and so may defend the host against a broad range of viral variants. CD8(+) cytotoxic T lymphocytes (CTL) have been described as essential effectors in protection by influenza nucleoprotein (NP), although a lesser role of CD4(+) cells has been reported. We immunized mice with plasmids encoding influenza virus NP and matrix (M). NP + M DNA allowed B6 mice to survive otherwise lethal challenge infection, but did not protect B6-beta(2)m(-/-) mice defective in CD8(+) CTL. However, this does not prove CTL are required, because beta(2)m(-/-) mice have multiple immune abnormalities. We used acute T cell depletion in vivo to identify effectors critical for defense against challenge infection. Since lung lymphocytes are relevant to virus clearance, surface phenotypes and cytolytic activity of lung lymphocytes were analyzed in depleted animals, along with lethal challenge studies. Depletion of either CD4(+) or CD8(+) T cells in NP + M DNA-immunized BALB/c mice during the challenge period did not significantly decrease survival, while simultaneous depletion of CD4(+) and CD8(+) cells or depletion of all CD90(+) cells completely abrogated survival. We conclude that T cell immunity induced by NP + M DNA vaccination is responsible for immune defense, but CD8(+) T cells are not essential in the active response to this vaccination. Either CD4(+) or CD8(+) T cells can promote survival and recovery in the absence of the other subset.

Amino Acid Sequence↗
PubMed2000

Insular and anaplastic carcinoma of the thyroid: a 45-year comparative study at a single institution and a review of the significance of p53 and p21.

OBJECTIVE: To analyze the clinicopathologic features of a large cohort of patients with insular or anaplastic carcinomas treated at a single institution. SUMMARY BACKGROUND DATA: Insular and anaplastic carcinomas of the thyroid, although uncommon, have more aggressive clinical behavior than well-differentiated carcinomas of the thyroid. In the literature, the incidence and features of these carcinomas have not been fully characterized. METHODS: The authors reclassified 740 primary thyroid carcinomas diagnosed and treated between January 1, 1954, and December 30, 1998, to select those with features that met the histologic criteria of insular or anaplastic carcinoma. The clinicopathologic features of these carcinomas were studied and compared. The expression of p53 and p21 in these tumors was analyzed by immunohistochemistry. RESULTS: Twenty-two patients (5 men, 17 women) with insular carcinoma and 38 patients (7 men, 31 women) with anaplastic carcinoma were found. Patients with insular carcinomas were younger (mean age 45 vs. 70 years) and had smaller tumors than those with anaplastic carcinomas (mean diameter 5 vs. 8 cm). Insular carcinomas were commonly mislabeled as other histologic subtypes, whereas anaplastic carcinomas might be overdiagnosed on pathologic examination. A history of longstanding goiter (>10 years) was noted in 27% of patients with insular carcinoma and 24% of patients with anaplastic carcinomas. Concomitant well-differentiated carcinomas of the thyroid were noted in 59% of patients with insular carcinoma and 39% of patients with anaplastic carcinoma. In anaplastic carcinomas, 13% of patients had concomitant insular carcinoma. Calcification or bone was noted in the stroma of 23% of patients with insular carcinomas and 47% of those with anaplastic carcinomas. The 10-year survival rates for patients with insular carcinoma and anaplastic carcinoma were 42% and 3%, respectively. Distant metastases were seen in 32% of patients with insular carcinoma and in 47% of patients with anaplastic carcinomas. In both types of carcinomas, metastatic tumors were often seen in bone and lung. Distant metastases were noted in a variety of organs in anaplastic carcinomas. In insular carcinoma, neither p53 nor p21 expression was present. In anaplastic carcinoma, p53 and p21 expression was identified in 69% and 3%, respectively. Concomitant expression of p53 and p21 was noted in one tumor. CONCLUSIONS: Insular carcinoma and anaplastic carcinoma had distinctive clinicopathologic features, and recognition of these histologic variants is important for better management of these tumors in the future. p53 overexpression might have a role in dedifferentiation from insular carcinoma to anaplastic carcinoma.

Adolescent↗
PubMed2000

Telomerase activity in pancreatic endocrine tumours: a potential marker for malignancy.

AIMS: Telomerase activation is known to be a common event in human cancer and may be a useful marker for malignancy. In general, the histological features of pancreatic endocrine tumours cannot be used to determine their malignant potential. The aim of this study was to investigate the role of testing telomerase activity in pancreatic endocrine tumours. METHODS: Prospectively collected fresh frozen tissue specimens from 10 patients with pancreatic endocrine tumours (nine insulinomas, one adrenocorticotrophin producing pancreatic endocrine tumour) were examined by a highly sensitive polymerase chain reaction (PCR) based telomerase repeat protocol (TRAP). RESULTS: Of the 10 pancreatic endocrine tumours, three had telomerase activity. The positive cases included two frankly malignant tumours with liver metastases and one pancreatic endocrine tumour occurring in the setting of multiple endocrine neoplasia type 1. The latter had an infiltrative border. Vascular and perineural tumour infiltration was noted. In the two malignant pancreatic endocrine tumours with liver metastases, telomerase activity was noted in the tumour and the adjacent morphologically non-neoplastic pancreas. CONCLUSION: To our knowledge, this is the first report of the role of telomerase activity in pancreatic endocrine tumours. Telomerase activity might be useful for distinguishing between benign and malignant pancreatic endocrine tumours.

Adult↗
PubMed2000

Parathyroid adenomas with pronounced lymphocytic infiltration: no evidence of autoimmune pathogenesis.

Pronounced lymphocytic infiltration in parathyroid adenoma is rare, with only six previously reported cases in the literature. The aims of this study are to review the features and investigate the pathogenesis of this rare entity. Two solitary parathyroid adenomas having this feature were reported, and the clinicopathologic features of all the documented cases were reviewed. The nature of the lymphoid infiltrate and the presence of Epstein-Barr virus (EBV) were analyzed to unveil the pathogenesis of this infiltrate. One adenoma was found in a 70-yr-old woman with primary hyperparathyroidism and valvular heart disease. The other was an autopsy finding in a 48-yr-old man who had presented with hypercalcemic crisis. The lymphoid cell population within the tumors was composed of B cells and different subsets of T cells. EBV was not detected in the infiltrates. The lymphocytic infiltrate in parathyroid adenoma is an unusual histologic entity. Its presence is unlikely to imply an autoimmune disorder. We hypothesize that the lesion may be a result of local tissue response to parathyroid adenoma.

Journal Article↗
PubMed2000

Simultaneous removal and reinsertion of Tenckhoff catheters for the treatment of refractory exit-site infection.

Exit-site infection (ESI) refractory to medical therapy is an important complication of continuous ambulatory peritoneal dialysis (CAPD). Between July 1994 and June 1998, 28 patients in our hospital underwent simultaneous removal and reinsertion of Tenckhoff catheters for the treatment of refractory ESI. The ESI was caused by Pseudomonas aeruginosa in 22 patients (78%), methicillin-resistant Staphylococcus aureus in 5 patients (18%), and diphtheroid bacilli in 1 patient (4%). The patients had received antibiotic treatment for a mean duration of 11.6 +/- 5.8 weeks (range: 3-28 weeks) before their operations. During each operation, the old Tenckhoff catheter was removed and a new catheter was inserted in the opposite side of the abdomen. CAPD was resumed after two weeks of intermittent peritoneal dialysis. All patients received intravenous antibiotic cover for seven days after the operation. Early post-operative complications were uncommon. At one year after the operation, 22 patients (78%) were free of ESI. Six patients (22%) had a recurrence of ESI 21.3 +/- 6 weeks (range: 16-32 weeks) after their operation. All new infections were treated successfully with antibiotics. Seven patients (25%) had one episode of peritonitis each, all of which resolved with intraperitoneal antibiotic treatment. We conclude that simultaneous removal and reinsertion of Tenckhoff catheters is a safe and effective method for the treatment of refractory ESI. The procedure alleviates the need for temporary hemodialysis and allows an early return to CAPD.

Adult↗
PubMed1999

Parathyroid autotransplantation during thyroidectomy: is frozen section necessary?

OBJECTIVE: To evaluate the accuracy of parathyroid gland identification and the need for routine frozen section examination before parathyroid autotransplantation during thyroidectomy. DESIGN: A prospective case series. SETTING: An endocrine surgical unit. PATIENTS: From January 1, 1995, to December 31, 1997, parathyroid autotransplantation was attempted for devascularized or inadvertently removed glands in 152 (33.7%) of 450 patients during thyroidectomy. Before autotransplantation, a biopsy specimen of the transplanted tissue was sent for histological examination without frozen section confirmation. MAIN OUTCOME MEASURES: Positive identification of parathyroid tissue in microscopic examination. RESULTS: Of 179 attempted autotransplantations of parathyroid glands, parathyroid tissue was confirmed in 167 biopsy specimens (93.3%). Incorrect identification of parathyroid gland occurred in 12 instances. The tissue mistaken as parathyroid gland included fat in 6 cases, thyroid tissue in 4 cases, lymph node in 1 case, and thymus in 1 case. Transplantation of at least 1 parathyroid gland (range, 1-3) was confirmed in 144 patients. For patients with confirmed parathyroid autotransplantation at risk of hypoparathyroidism (n = 112), postoperative transient hypocalcemia occurred in 22 (19.6%), while no patient developed any permanent hypocalcemia during a median follow-up of 6 months. CONCLUSIONS: Devascularized or inadvertently removed parathyroid glands can be identified expeditiously without routine frozen section during thyroid surgery. Immediate autotransplantation should be performed and permanent hypoparathyroidism can be avoided with this measure.

Adolescent↗
PubMed1999

Pancreatic solid-cystic-papillary tumor: clinicopathologic features in eight patients from Hong Kong and review of the literature.

Solid-cystic-papillary tumors (SCPTs) of the pancreas are rare. The clinicopathologic features and pathogenesis of these tumors have attracted a number of investigations, but the results remain unclear. We investigated the clinicopathologic data, immunohistochemical expression of the pan-endocrine markers, hormones, steroid receptors, and p53 overexpression in pancreatic SCPTs from eight Chinese patients (seven women, one man) collected over a 24-year period. They accounted for 2.5% of the primary pancreatic tumors. The tumors were seen in young women (mean age 27 years). They were large (mean size of resected tumor was 8.4 cm), benign, had solid and cystic areas, and were evenly distributed in the pancreas. The main differential diagnosis was pancreatic endocrine tumor. The tumors were negative for pan-endocrine markers, hormones, estrogen receptor, progesterone receptor, and p53. To date, 452 pancreatic SCPTs have been documented in the English literature. They occurred in patients of different ethnic groups, particularly in non-Caucasians. The tumors were frequently noted in young females. Uncommon cases of malignant pancreatic SCPTs were often found in older men and had indolent behavior. It was concluded that pancreatic SCPTs have distinct clinicopathologic characteristics. The present observations, together with a review of the literature suggests that overexpression of p53 or estrogen receptor is not important in the pathogenesis of pancreatic SCPTs.

Adolescent↗
PubMed1999

Anaplastic carcinoma of the thyroid.

BACKGROUND: Anaplastic thyroid carcinoma, albeit rare, is one of the most aggressive human tumors, with a dismal prognosis. METHODS: Twenty-eight patients with anaplastic thyroid carcinoma were identified during the past 30 years to evaluate its clinicopathologic features and to document our experience in management. Potential risk factors for survival time were analyzed. RESULTS: The usual presentation was that of a rapidly enlarging neck mass. Distant metastases were present in 50% of patients on presentation. Palliative resection was performed in 16 patients. The median survival was 38 days, and the 2-year survival rate was 4%. Among factors analyzed, patients selected for surgical resection, absence of distant metastases at presentation, young age, and tumor size <6 cm were associated with an increased survival time. Concomitant well-differentiated thyroid carcinoma and p53 overexpression were present in 12 of the 22 and 13 of the 19 specimens, respectively. CONCLUSIONS: Patients with anaplastic carcinoma of thyroid have a dismal prognosis heralding imminent death. Surgical ablation followed by adjuvant therapy can provide palliation for selected patients only.

Aged↗