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C Y Lo

Publications and source records attributed to C Y Lo.

At least 73 records · Page 4Linked to original sources
PubMed1998

Percutaneous transluminal angioplasty for stenosis of arteriovenous fistulae: a review of local experience.

The stenosis and subsequent thrombosis of the arteriovenous fistulae may lead to a loss of vascular access sites; this a major problem in chronic haemodialysis patients. Percutaneous transluminal angioplasty has been a popular way of correcting such lesions in recent years. We have reviewed patients who underwent this operation from 1993 to 1996 at the Queen Mary Hospital. Among 11 patients who were documented as having arteriovenous fistula stenosis, 60% of lesions were in the anastomotic area while 40% were in the venous limb. All patients had abnormal dialysis blood line pressures corresponding to the actual site of stenosis. The initial success rate of percutaneous transluminal angioplasty in treating the stenotic lesions was 73%. This method is thus a promising form of semi-invasive treatment for symptomatic arteriovenous fistula stenosis.

Journal Article↗
PubMed1998

Metastatic tumors of the thyroid gland: a study of 79 cases in Chinese patients.

OBJECTIVE: To evaluate the clinical and pathologic impact of metastases to the thyroid gland. CASE MATERIAL: We studied the clinical/autopsy records and pathologic features of 79 Chinese patients (38 men, 41 women) with secondary tumors of the thyroid over a 26-year period. RESULTS: The incidence of thyroid secondaries at autopsy was 0.5% and at thyroidectomies for malignancy was 1.2%. Eighteen (23%) of the 79 patients presented with an enlarged mass in the thyroid. The diagnosis of metastasis in the thyroid gland was suspected clinically in six cases. Fine-needle aspiration cytology detected an 80% malignancy rate, but in only half of such cases was the diagnosis specific for secondary malignancy. Many of the metastatic lesions in the thyroid gland occurred shortly after the detection of primaries (mean latency period, 9 months). The time from diagnosis of the primary tumor to metastasis to the thyroid gland was greater than or equal to 3 years in only eight patients. The majority (81%) of the secondary tumors were carcinomas. Of these, the lung was the most common primary tumor site (43%), followed by the breast (9%) and stomach (8%). Rare sources of primary tumors, such as nasopharyngeal carcinoma, choriocarcinoma, malignant phylloides, and osteosarcoma, were also found. The metastatic lesions in the thyroid gland could be identified macroscopically in 43 patients (54%). Lesions were often solitary (n = 24) rather than diffuse (n = 8) or multiple (n = 11). Microscopic examination revealed that secondary thyroid tumors were often moderate or poorly differentiated adenocarcinomas (n = 42). All the patients died shortly after the appearance of metastatic lesions in the thyroid gland. CONCLUSIONS: Metastasis in the thyroid gland is uncommon and may be a diagnostic problem. Its presence often indicates a poor prognosis.

Adenocarcinoma↗
PubMed1997

Mechanisms of heterosubtypic immunity to lethal influenza A virus infection in fully immunocompetent, T cell-depleted, beta2-microglobulin-deficient, and J chain-deficient mice.

Immunity that is cross-protective between different influenza A virus subtypes (termed heterosubtypic immunity) can be demonstrated readily in some animals but only rarely in humans. Induction of heterosubtypic immunity in humans by vaccines would provide public health benefit, perhaps offering some protection against pandemics or other new influenza A strains. Therefore, we studied mechanisms mediating heterosubtypic immunity in mice. Immunization with either A/H1N1 or A/H3N2 virus protected mice against mortality following heterosubtypic challenge while providing modest reductions in lung virus titers. No cross-protection was seen with distantly related type B influenza virus. Depletion of CD4+ or CD8+ T cells or both around the time of challenge had no significant effect on survival, indicating that these cells are not required at the effector stage. beta2-microglobulin knockout mice could be protected readily against heterosubtypic challenge, confirming that class I-restricted T cells are not required. In beta2-microglobulin -/- mice, depletion of CD4+ T cells partially abrogated heterosubtypic immunity, showing that they play a role in these mice. Passive transfer of Abs to naive recipients protected against subsequent challenge with homologous but not heterosubtypic virus. Because a role for secretory Abs has been suggested, we studied dependence on the J chain, which is required for polymeric Ig receptor-mediated IgA transport. J chain knockout mice were readily protected by heterosubtypic immunity, indicating that polymeric Ig receptor-mediated transport is not required. Better understanding of heterosubtypic immunity should be valuable in analyzing new vaccines, including peptide and DNA vaccines, intended to induce broadly cross-reactive immunity.

Animals↗
PubMed1997

Pancreatic insulinomas. A 15-year experience.

OBJECTIVE: To describe our experience in the management of patients with pancreatic insulinomas, emphasizing the need for preoperative localization and the outcome of surgical treatment. DESIGN: A case series. SETTING: A university hospital in Hong Kong. PATIENTS: From 1981 to 1995, 27 patients with pancreatic insulinomas were surgically treated; the mean follow-up was 25.4 months. MAIN OUTCOME MEASURES: Postoperative morbidity and euglycemia during the follow-up period. RESULTS: The accuracy of tumor localization by ultrasonography, computed tomography, and angiography was 33%, 44%, and 52%, respectively. Venous sampling for an insulin assay regionalized 90% of the tumors. In 24 patients with solitary tumors, most lesions detected or missed by preoperative localization could be either seen (n = 14) or palpated (n = 22). Intraoperative ultrasonography (n = 17) has been routinely performed since 1987; nonpalpable tumors were imaged in 2 of 15 patients with solitary tumors. Eight solitary occult tumors were detected by palpation alone or a combination of palpation and intraoperative ultrasonography. Operative mortality occurred in 1 (3.7%) of the 27 patients, while major morbidity developed in 9 (33%) of the patients. Euglycemia was achieved in 25 patients. Surgery cured all patients with benign insulinomas, whereas the cure rate for patients with malignant neoplasms was only 33%. The type of surgical treatment or correct preoperative localization did not affect the outcome of surgery. CONCLUSIONS: Pancreatic insulinomas can be readily localized intraoperatively despite failed preoperative localization studies. Surgical treatment cured benign adenomas but was associated with notable morbidity.

Adolescent↗
PubMed1997

Endoscopic sphincterotomy: 7-year experience.

The present study documents the indications and results of endoscopic sphincterotomy (ES) performed over 7 years in a surgical endoscopy unit. Potential improvement of results over this time period was analyzed. ES was associated with rare but undesirable morbidity and mortality. Specific improvement of results over time has not been reported. ES was attempted in 706 patients (336 men, 370 women) from 1987 to 1994 and was accomplished in 689 patients (97.6%). Complications occurred in 50 patients (7.1%), 13 of whom required emergency operative intervention. The overall 30-day mortality was 4.7% (n = 33), and procedure-related mortality was 0. 7% (n = 5). There was a significant decrease in hospital mortality (p < 0.01) and operative intervention for procedure-related complications (p < 0.001) after 1990. Procedure-related mortality has been reduced from 1.3% to 0.3% since 1990 (p = 0.1). ES in emergency situations or for malignant biliary obstruction did not adversely affect the outcome. It was concluded that ES can be performed safely in most patients. With increasing experience, procedure-related morbidity and mortality can possibly be reduced.

Adult↗
PubMed1997

Resolution of eosinophilic peritonitis with ketotifen.

Eosinophilic peritonitis is frequently observed in patients of all ages started on peritoneal dialysis. Peritoneal effluent may or may not become noticeably turbid, and if an aliquot for white cell count is sampled at all, eosinophils will be seen to predominate. It does not usually cause concern and settles spontaneously, many times even without the clinician noticing. Occasionally, this condition lingers on for months, and a short course of intraperitoneal hydrocortisone has been shown to be effective in clearing up the eosinophilia. We report a patient with steroid-resistant eosinophilic peritonitis and its successful resolution with ketotifen.

Aged↗
PubMed1997

Pancreatic endocrine tumour: a 22-year clinico-pathological experience with morphological, immunohistochemical observation and a review of the literature.

The clinico-pathological features of 53 Chinese patients (27 males; 26 females) with pancreatic endocrine tumours were studied. The age range was from 14 to 78 years old (mean: 48 years) with the modal peak in the sixth decade for both sexes. Pancreatic endocrine tumours accounted for 14% of the primary pancreatic tumours operated on in Queen Mary Hospital. The autopsy incidence was 0.11%. Seventy-two per cent (38 cases) of the tumours were clinically functioning, comprising 33 insulinomas, three gastrinomas and two glucagonomas. A rare case of malignant gastrinoma associated with Cushing's syndrome was also documented. The functional tumours were seen in the younger patients. The calculated annual incidence of clinically significant tumours was approximately 0.2 per 100,000 population. There was no correlation between the site, functional status and histological patterns of the tumours. Seventy-two per cent of the tumours showed a trabecular pattern. Calcification was present in 5.7% (three cases); two such cases being gastrinomas. Amyloid was found in 25% of tumours, chiefly (92%) in the insulinomas. The main difficulty encountered in diagnosis was distinguishing between solid and cystic tumours of the pancreas. The incidence of malignancy was 15% and the histological features were poor predicative indicators of malignant potential. The metastatic pancreatic endocrine tumours were often detected in the liver and lymph nodes. Immunohistochemical stains showed evidence of multi-hormone production in 18% of cases and all tumours showed a positive reaction to at least one of the six markers, namely, neuron-specific enolase (NSE), chromogrannin (CG), synaptophysin (SYN), insulin (INS), glucagon (GLU) or somatostatin (SOM). The three panendocrine markers (NSE, SYN, CG) were satisfactory for initial screening of the endocrine nature of the tumours if used in combination, as 92% of tumours were positive for at least one of these three markers.

Adenoma, Islet Cell↗
PubMed1997

Evidence for specific proteolytic cleavage of the N-terminal domain of human profilaggrin during epidermal differentiation.

Profilaggrin is a large phosphoprotein that is expressed in the granular cells of epidermis where it is localized in keratohyalin. It consists of multiple copies of single filaggrin units plus N- and C-terminal sequences that differ from filaggrin. Profilaggrin is dephosphorylated and proteolytically processed during terminal differentiation to yield filaggrin, which associates with keratin intermediate filaments to form macrofibrils in the lower layers of the stratum corneum. The N-terminal sequence of human profilaggrin comprises two distinct domains; an acidic A domain of 81 amino acids that binds Ca2+, and a cationic B domain of 212 residues. In this report, we further characterize the N-terminal domain by immunohistochemistry and immunoblot analysis using anti-peptide antibodies raised to the A and B regions. All of these antibodies (n = 4) immunostained keratohyalin in the granular layer of human epidermis and also showed some reaction with the lower stratum corneum. In immunoblot studies, the high molecular weight human profilaggrin reacted with both B domain antibodies whereas it showed a weak and variable reaction with A domain antibodies. In addition to profilaggrin, a cationic 32-kDa protein was detected with all N-terminal antibodies. A similar-sized N-terminal peptide was also produced by in vitro proteolysis of human profilaggrin with endoproteinase 1 (PEP1), a protease involved in processing of mouse profilaggrin, and in cultured rat epidermal keratinocytes transfected with a human profilaggrin cDNA construct. Evidence for at least one additional cleavage within the N-terminal domain is shown by immunoreactivity of smaller (16-20 kDa) acidic and basic proteins with A and B domain antibodies, respectively. These results demonstrate that the N-terminal domain is an integral part of profilaggrin in keratohyalin but is proteolytically cleaved from profilaggrin during the terminal differentiation of keratinocytes to yield a 32-kDa peptide.

Amino Acid Sequence↗
PubMed1997

Distinct genotypic distributions of cytomegalovirus (CMV) envelope glycoprotein in bone marrow and renal transplant recipients with CMV disease.

A prospective study of the spectrum of glycoprotein B (gB) and glycoprotein H (gH) genotypes of cytomegalovirus (CMV) was conducted with five categories of patients: viremic bone marrow-transplant (BMT) recipients who developed CMV disease after BMT (n = 22), viremic BMT recipients without CMV disease (n = 11), viremic renal-transplant recipients who developed CMV disease after transplantation (n = 14), viremic renal-transplant recipients without CMV disease (n = 13), and premature babies with asymptomatic congenital CMV infections (n = 13). Genotypic stability was observed because the gB and gH genotypes of multiple isolates obtained from a single patient were identical. The distribution of gH genotypes in patients of all groups studied were similar. However, there was a unique distribution of the gB genotype in the first category of patients, i.e., BMT recipients with CMV disease, which was distinct from those of all other categories (P < 0.05). CMV isolates from 54% of BMT recipients with CMV disease exhibited gB type 2, while isolates from 46, 50, 69, and 77% of the BMT recipients without CMV disease, renal-transplant recipients with and those without CMV disease, and premature babies with congenital CMV infection, respectively, were of gB type 1. An analysis of the clinical characteristics of BMT recipients with CMV disease indicated that all underwent either an allogeneic or matched, unrelated donor transplant, and half had severe acute graft-versus-host disease (grades 2 to 4). The statistically significant genotypic difference between CMV isolates from BMT recipients with and without CMV disease was not observed between isolates from renal-transplant recipients with and without CMV disease. We speculate that differences in pathogenesis in different patient groups might account for these observations. These findings would also facilitate decision making about the choice of recombinant CMV glycoprotein vaccine required to immunize transplant donors and the subsequent adoptive transfer of immunity to BMT recipients. When the source of CMV DNA required for genotyping was investigated among renal-transplant recipients, direct use of peripheral blood leukocytes was 95% effective compared to the effectiveness of cells obtained from conventional culture of peripheral blood specimens.

Adult↗
PubMed1997

Diagnosing cytomegalovirus disease in CMV seropositive renal allograft recipients: a comparison between the detection of CMV DNAemia by polymerase chain reaction and antigenemia by CMV pp65 assay.

The optimal diagnostic test for CMV disease in renal allograft recipients in a locality with a high CMV seropositive rate has not been fully determined. We compared the usefulness of the CMV pp65 antigenemia (CMV-Ag) assay with the detection of DNAemia by a nested polymerase chain reaction (PCR) method in diagnosing CMV disease in 56 renal allograft recipients, of whom 50 (89.2%) were CMV seropositive prior to transplant (tx). Positive CMV-Ag assays were found in 126/281 samples (44.8%) of 27 patients (48.2%) of whom five had seven episodes of CMV disease. The remaining 22 patients were asymptomatic. The symptomatic patients had significantly higher median peak CMV-Ag levels than the asymptomatic patients [800 (160-1380) vs. 5 (1-604) per 2 x 10(5) peripheral blood leukocyte (PBL), p < 0.0001]. One hundred and eight samples were tested by both CMV-Ag and PCR methods. Out of the 108 samples, 89 showed concordant results (37 positive and 52 negative for both tests). Seventeen samples of 11 patients were CMV-Ag negative/PCR positive. Out of these 11 patients, two had CMV disease and the discrepancy in the results was due to blood samples taken after the start of ganciclovir therapy. Falsely negative PCR tests were found in two samples of two patients with positive CMV-Ag assays. With a outoff antigenemia level of 100 per 2 x 10(5) PBL, the sensitivity, specificity, positive and negative predictive values for diagnosing CMV disease were 100, 96, 71.4 and 100%, respectively. On the other hand, CMV DNAemia was detected in many asymptomatic patients, and the PCR test results correlated poorly with the clinical manifestations of the disease. In symptomatic patients undergoing ganciclovir therapy, the quantification of antigenemia level allowed the assessment of treatment efficacy. In addition, positive CMV-Ag assays at the end of therapy were associated with the subsequent relapse of CMV disease in two patients. The high specificity, together with the short processing time of 4 h, make the CMV-Ag assay the test-of-choice for diagnosing CMV disease in a renal transplant population with a predominance of CMV seropositive patients.

Adolescent↗
PubMed1997

Surgical treatment for primary hyperparathyroidism.

OBJECTIVE: To document the recent surgical results in the treatment of primary hyperparathyroidism (HPT) at Queen Mary Hospital. METHODS: From 1995 to 1996, 30 patients underwent 31 operations for primary HPT. The data of 11 men and 19 women with ages ranging from 19 to 86 years (median: 57 years) were prospectively recorded with emphasis on the need of preoperative localization. RESULTS: Symptoms of hypercalcemia were present in 20 (67%) and complications in 17 (57%) patients, respectively. Seventy-seven localization studies were performed in 28 patients (average: 2.6 tests/patient). Localization was accurate in 12 of 23 (52%) ultrasonographies, 11 of 26 (42%) CT scans and 16 of 27 (59%) scintigraphies. Twenty-six patients had a single adenoma excised while 3 patients with multiple endocrine neoplasia type I (MEN I) had subtotal parathyroidectomy for multiglandular hyperplasia during cervical exploration. Immediate normocalcemia was achieved in 29 patients. One patient had persistent hypercalcemia due to a supernumerary fifth gland in the superior mediastinum that was successfully excised in a second operation. One patient had a unilateral vocal cord paralysis and 4 patients needed calcium supplement on discharge. During a median follow-up of 5 months, all patients were normocalcemic with one requiring calcium supplements. CONCLUSION: Surgical treatment for primary HPT is a safe procedure and is associated with a high success rate. In our experience routine preoperative localization study is not cost-effective.

Adenoma↗
PubMed1996

Adrenalectomy for metastatic disease to the adrenal glands.

A policy of supportive treatment is frequently adopted for patients with metastatic disease to the adrenal glands. This study reports an experience with adrenalectomy for adrenal metastasis. Between 1983 and 1993, adrenalectomy was performed in 52 patients for metastasis to the adrenal glands. Survival was calculated by the Kaplan-Meier method and compared with the log rank test. Primary tumour sites included kidney (n = 15), lung (n = 11), colon (n = 7), unknown (n = 5), stomach (n = 3), melanoma (n = 3) and other (n = 8). Adenocarcinoma (69 per cent) was the most common histological cell type. Thirty-two patients were asymptomatic on initial evaluation. Symptomatic adrenal pain relief was achieved in 11 of 13 patients. Overall survival rates were 73 per cent at 1 year and 40 per cent at 2 years. Patients with potentially curative resection had better survival than those who had a palliative procedure. Patients with adrenal metastases due to adenocarcinoma had improved survival compared with that in those with other histological cell types. Although long-term survival is generally poor, highly selected patients with adrenal metastasis (symptomatic disease or adenocarcinoma) may benefit from surgical resection.

Adrenal Gland Neoplasms↗
PubMed1996

Surgical treatment of Graves' disease in patients younger than 18 years.

Eighty-two children and adolescents (18 males, 64 females; median age 14 years) surgically treated for Graves' disease at a single institution between 1979 and 1993 were retrospectively reviewed. Most of the patients (74%) coming to thyroidectomy had been treated medically for a period ranging from 2 to 80 (median 15) months. Bilateral subtotal thyroid resection was the most frequently performed procedure (86%). Postoperatively, no permanent recurrent laryngeal nerve palsy or permanent hypocalcemia occurred. Operative mortality was zero. With a median follow-up of 8.3 years, recurrent hyperthyroidism occurred in five patients (6%), one of whom required reoperation. Most children and adolescents with Graves' disease can be rendered euthyroid by nonsurgical treatment options. However, prolonged and ineffective medical treatment should be avoided in these patients who are in the formative years of their lives. Surgical treatment, when indicated and employed, offers young patients with Graves' disease a safe, rapid, definitive, cost-effective treatment with a high success rate.

Adolescent↗
PubMed1996

Islet cell carcinoma of the pancreas.

Islet cell carcinoma (ICC) of the pancreas is a rare, indolent malignancy associated with higher resectability rate and better survival than ductal carcinoma. This retrospective study presents results of surgical treatment from a single institution. From 1985 through 1993 a total of 64 patients (36 men, 28 women) were surgically treated for ICC. Ages ranged from 22 to 80 years (median 55 years) with a median postoperative follow-up of 39 months (range 10-97 months). Of the 64 patients, 30 (47%) had functioning and 34 (53%) nonfunctioning tumors. Gastrinoma (n = 11) followed by glucagonoma (n = 6) and insulinoma (n = 4) were the most common functioning tumors. In the patients undergoing a laboratory study, 67% of the nonfunctioning tumors had elevated peptide hormone levels. Potentially curative resections were performed in 17 patients (26%), palliative procedures in 35 (55%), and exploratory laparotomy alone in 12 (19%). One patient (2%) died within 30 days after operation. Symptomatic improvement was achieved in 96% of patients with a mean duration of 22 months. Three- and five-year survivals were 66% and 49%, respectively. In patients with curative resection, the disease-free survival at 3 years was 53% (95% CI: 32-86%). The presence of diffuse hepatic metastases was a predictor of poor survival at 3 years (74% versus 58%;p = 0.05); there was no statistically significant difference in survival between functioning and nonfunctioning groups (p > 0.1). Although curative resection for ICC is rare, meaningful palliation can be achieved in most patients with rare mortality and acceptable morbidity.

Adult↗
PubMed1996

Acute diverticulitis of the right colon.

BACKGROUND: Acute diverticulitis of the right colon is a rare condition with a higher incidence in Oriental populations than in Occidental populations. PATIENTS AND METHODS: A retrospective review was conducted between 1982 and 1993 on 22 surgically treated Chinese patients (14 men, 8 women; mean age 47 years) with documented right colon diverticulitis. RESULTS: Most patients presented with right lower quadrant pain and local peritoneal signs. Acute appendicitis was the preoperative diagnosis in 82% (18/22) of the patients. Only one diagnosis subsequently proved correct. The pathology was easily recognized in 4 patients during surgery, while examination of the resected specimen confirmed the intraoperative suspicion in 13 patients. The right colon was resected and an ileocolonic anastomosis performed in 21 patients; the remaining patient underwent diverticulectomy and drainage of a pericolic abscess. There was no postoperative mortality, and 4 patients developed wound infection. CONCLUSIONS: Our results showed that acute diverticulitis of the right colon was encountered once in 180 cases of acute appendicitis. Local resection or colectomy with primary anastomosis without bowel preparation is the procedure of choice.

Acute Disease↗
PubMed1996

Characteristics of patients surgically treated for primary hyperparathyroidism with and without renal stones.

BACKGROUND: Between 1980 and 1984, 312 (30%) of 1038 patients undergoing initial cervical exploration for primary hyperparathyroidism (pHPT) at our institution had proven renal stones. METHODS: In this retrospective study we focused on clinical characteristics, biochemical tests, perioperative and pathologic findings, and immediate outcomes of operation, comparing findings in patients with and without renal stones. RESULTS: Patients with renal stones were more often younger male patients, had serum phosphorus levels significantly lower (p < 0.02) and 24-hour urinary calcium excretion significantly higher (p < 0.0001) than patients without renal stones, and had a significantly higher (p < 0.05) proportion of abnormal glands weighing less than 250 mg. Relevant diagnostic preoperative variables were evaluated by means of multivariate analysis to determine whether they independently had predictive power with regard to renal stones. Male gender and younger age were significantly associated with the presence of renal stones, providing odds ratios of 2.5 and 1.4, respectively. In addition, the risk of having renal stones was significantly related to minimally elevated serum calcium levels (p < 0.05), serum phosphorus levels (p = 0.02), and 24-hour urine calcium excretion (p < 0.05). CONCLUSIONS: In patients with renal stones the diagnosis of pHPT should be considered. If the diagnosis is confirmed, a liberal approach to cervical exploration should be taken.

Adenoma↗