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An-Hang Yang

Publications and source records attributed to An-Hang Yang.

At least 19 recordsLinked to original sources

Leptin augments myofibroblastic conversion and fibrogenic activity of human peritoneal mesothelial cells: a functional implication for peritoneal fibrosis.

BACKGROUND: Myofibroblastic conversion of mesothelial cells is proposed to play an important role in pathological changes following serosal membrane injury. METHODS: Human peritoneal mesothelial cells (HPMCs) were isolated and maintained in culture. The gene expression was assessed by RT-PCR. Activation of signal transduction was determined by western blot and densitometry. Morphological changes were observed by phase-contrast and electron microscopy. RESULTS: In vitro study showed that TGF-beta1-induced myofibroblastic growth of HPMCs was significantly enhanced in the presence of leptin. Augmented expression of alpha-smooth muscle actin, fibronectin and type I collagen mRNA in HPMCs induced by leptin were TGF-beta1-dependent, suggesting that leptin promoted peritoneal fibrogenesis through synergistic activation of the TGF-beta1 signaling system. Leptin and TGF-beta1 synergistically augmented activation of signalling components of mitogen-activated protein kinase (MAPK), STAT3 and Smad but did not modulate the expression of LEPR-B. CONCLUSION: Leptin may act as a profibrogenic TGF-beta1 activated cytokine in peritoneal bioenvironment associated with TGF-beta1 activated pathogenic processes.

Actins↗

Insular thyroid carcinoma: collective analysis of clinicohistologic prognostic factors and treatment effect with radioiodine or radiation therapy.

BACKGROUND: Insular thyroid carcinoma is a distinctive clinicopathologic entity with aggressive behavior and frequent lethal disease. But because it is rare, no single institute has sufficient experience with the clinicopathologic features and treatment effect of radioiodine. A literature review and collective analysis might facilitate patient management. METHODS: From January 1991 to December 2005, 9 patients with insular thyroid carcinoma were diagnosed in Taipei Veterans General Hospital. Clinicopathologic data were collected for analysis. The English literature about insular carcinoma was searched in Medline. Patients with detailed descriptions of treatment and followup were enrolled. Clinicopathologic features, rate of lymph node and distant metastasis, and prognostic factors were analyzed. RESULTS: Seventy-three of 486 patients collected from 23 articles with detailed description of treatment and followup were combined with our 9 patients for analysis, making a total of 82 patients in this article. The mean period of patient followup was 84.5 months. There were 26 (31.7%) men and 56 (68.3%) women. The rate of lymph node metastasis was 49%, and distant metastasis was 57.5%. Disease-specific death rate was 37.8%. The 5- and 10-year survival rates of insular carcinoma were 72.2% and 52%, respectively. Patient age older than 45 years (p=0.0004) and distant metastasis (p<0.0001) were poor prognostic factors. Use of radioiodine therapy (p=0.9789) and radiation therapy (p=0.2172) were not associated with prolonged survival. CONCLUSIONS: Patients with insular thyroid carcinoma have unfavorable outcomes. Postoperative radioiodine therapy or radiotherapy seemed not to be strongly associated with prolonged survival.

Adult↗

Normocalcemic primary hyperparathyroidism in patients with recurrent kidney stones: pathological analysis of parathyroid glands.

The lack of overt elevation of serum calcium concentration in some patients suffering from primary hyperparathyroidism is an intriguing clinical phenomenon. Previous studies have substantiated abnormal parathyroid tissue in these patients, but the extent and mode of derangements remained largely undefined. The parathyroid tissues from patients of normocalcemic primary hyperparathyroidism (NCPHPT) and those having normal parathyroid glands, hypercalcemic primary hyperplasia, secondary hyperplasia, and adenoma were compared by undertaking quantitative immunohistochemistry analysis on tissue microarray. The statistic results suggested that the parathyroid tissue of NCPHPT approximates more to normal gland than to its counterpart in other groups of parathyroid proliferative diseases in terms of the lack of significant alterations of calcium-sensing receptor (CaSR), chromogranin A (CGA), parathyroid hormone (PTH), and proliferation index (Ki67). On the other hand, the depressed vitamin D receptor (VitDR) and elevated cyclin D1 (CyD1) of NCPHPT indicated the inherent functional abnormalities in parathyroid cells. Our results imply that inherent functional disengagement may exist between CaSR and CyD1 or between CaSR and VitDR or both in parathyroid cells of symptomatic NCPHPT. Lack of enhanced release of CGA and PTH and discordance between proliferative activity and CyD1 expression in parathyroid cells may further hinder the development of hypercalcemia.

Calcium↗

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy: two novel mutations in the NOTCH3 gene in Chinese.

BACKGROUND: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a hereditary disorder caused by NOTCH3 mutations, usually localized to exons 3 and 4, and characterized by recurrent subcortical infarctions, dementia and leukoencephalopathy. So far, there has been only limited information about CADASIL in Chinese population. OBJECTIVES: To analyze the NOTCH3 mutations in ethnic Chinese in Taiwan with clinically suspected CADASIL and to characterize their clinical and molecular features. METHODS: Mutation analysis of NOTCH3 by direct nucleotide sequencing was performed in eight unrelated Chinese patients with clinically suspected CADASIL. Skin biopsy with ultrastructural studies by electronic microscopy was performed in four patients. RESULTS: Five NOTCH3 mutations, S118C, R141C, R332C, R544C and C977S, respectively, were identified from five patients, of which S118C and C977S are novel. None of these nucleotide sequence variations could be found among 50 healthy controls. Among the five mutations, two were in exon 4, and the other three were in exons 6, 11 and 18, respectively. Skin biopsy showed the presence of characteristic granular osmiophilic material only in the patient with the NOTCH3 mutation of R332C. CONCLUSION: Our study demonstrated the clinical and molecular features of CADASIL in Chinese patients and broadened the spectrum of NOTCH3 mutations. Lack of evidence of a strong clustering of mutations in a particular exon tentatively suggests that a comprehensive screening of NOTCH3 mutation is still necessary for molecular diagnosis of CADASIL in Chinese population.

Adult↗

Primary hyperparathyroidism in multiple endocrine neoplasia type 1: individualized management with low recurrence rates.

BACKGROUND: To evaluate the outcomes in different surgical modalities for primary hyperparathyroidism in multiple endocrine neoplasia type 1 (MEN1) patients, intraoperative findings from a single surgeon were studied to investigate a potentially improved modality of parathyroidectomy (PTx). METHODS: All 22 patients had PTx by a single surgeon in the past 21 years. Three modalities of PTx were used, depending on the operative findings, after all parathyroids and the thymus were identified. If fewer than three glands were enlarged, selective removal of the enlarged glands with or without biopsy of a normal-appearing gland was performed (selective PTx); if all glands were enlarged, either a subtotal PTx leaving a 50-mg remnant in situ or a total PTx with autotransplantation (TPTx + AT) was performed. RESULTS: There were 7 men and 15 women, aged 22 to 67 years (average, 43 years). Sixteen had familial and six had sporadic MEN1. They underwent 23 operations, including 11 selective PTx, 6 subtotal PTx, and 6 TPTx + AT. On follow-up for 1 to 19 years, only one patient (4.6%) had recurrent hyperparathyroidism 5.5 years after subtotal PTx. Others had either normocalcemia (n = 14; 63.6%) or hypocalcemia (n = 7; 31.8%). Those who had either a subtotal PTx or TPTx + AT had a significantly higher rate of postoperative hypocalcemia than those who had a selective PTx (9.9% vs. 54.5%; P = .032; Fisher's exact test). CONCLUSIONS: Primary hyperparathyroidism in our MEN1 patients was less aggressive than that reported in the literature. Selective PTx according to the intraoperative findings achieved optimal outcomes.

Adult↗

Expression of c-kit, Flk-1, and Flk-2 receptors in benign and malignant tumors of follicular epithelial origin.

BACKGROUND: Vascular endothelial growth factor (VEGF) is a key regulator of physiologic as well as pathologic angiogenesis. The response of VEGF to endothelial cell mitogenesis and survival, as well as angiogenesis and microvascular permeability, is mainly mediated through its receptor-2, VEGFR2 (kinase domain receptor or fetal liver kinase-1, KDR or Flk-1). This study aimed to detect the expression of VEGFR2 in various forms of thyroid tumors. In addition, the expression of Flk-2 (receptor for Flt-3) and c-Kit (receptor for steel locus factor), which shows strong similarity to Flk-1, was also examined in thyroid tumors. METHODS: RT-PCR analyses of c-Kit and immunohistochemical staining of c-Kit, Flk-1, and Flk-2 were performed in archived samples of 18 papillary thyroid carcinoma (PTC), 9 follicular thyroid carcinoma (FTC), 12 follicular adenoma (FA), and 7 nodular goiter (NG) samples. The data were correlated to clinicopathologic features. RESULTS: By RT-PCR analyses, c-Kit expression was detected in 22% (4/18) of PTC, 22% (2/9) of FTC, 25% (3/12) of FA, and 57% (4/7) of NG samples. However, positive immunostaining signals of c-Kit were only observed in 17% (3/18) of PTC samples, and not in the others. Similarly, Flk-1 expression was only detected by immunohistochemistry in 67% (12/18) of PTC and 43% (3/7) of NG samples, and not in the others. Interestingly, the expression of Flk-2 was found in 89% (16/18) of PTC, 89% (8/9) of FTC, 75% (9/12) of FA, and 29% (2/7) of NG samples. An inverse relationship of thyroid cancer size with Flk-2 expression was found. CONCLUSION: Flk-2 expression was detected in various forms of thyroid tumors and increased Flk-2 expression was correlated with thyroid tumors with increased transforming activity, suggesting that Flk-2 is involved in pathogenic development of thyroid malignancy. Similarly, Flk-1 expression was also found in some thyroid tumors, while the expression of c-Kit-mediated pathways may not play a major role in thyroid tumorigenesis.

Adenocarcinoma, Follicular↗

Anaplastic thyroid cancer with uncommon long-term survival.

In general, most thyroid cancers are indolent and have a slowly progressive course. The exception is anaplastic thyroid cancer. It is one of the most fatal neoplasms in humans, with median survival of 4-12 months. Here, we present a patient with anaplastic thyroid cancer who survived for more than 10 years after diagnosis. A 68-year-old man was incidentally found to have anaplastic thyroid cancer during operation for follicular neoplasm. Total thyroidectomy was performed and hyperfractionated radiotherapy was carried out. After operation, annual follow-up examinations were negative for residual tumor or metastatic lesions. The patient also had chronic obstructive pulmonary disease and unfortunately died of pneumonia in a local hospital 10 years after thyroid operation.

Aged↗

Junctional epidermolysis bullosa.

Epidermolysis bullosa (EB) encompasses a heterogeneous group of genodermatoses, characterized by fragility and blistering of the skin, often associated with extracutaneous manifestations. The level of vesiculation within the skin defines 3 major subtypes of EB: EB simplex, junctional EB, and dystrophic EB. We present the case of a male neonate of 36 weeks of gestation, who was born with a few blisters with erosions and who rapidly developed extensive blistering of the skin. Histopathology revealed subepidermal blistering. Electron microscopy confirmed the cleavage of epidermis from dermis within the lamina lucida. Junctional EB was the diagnosis. The patient was discharged after hospitalization for 28 days. The development of new blisters with erosions were gradually improved after AQUACEL Ag dressing, and the general condition was much better than at admission. The patient likely has a subtype of junctional EB termed generalized atrophic benign EB that clinically improves with age. He has the potential to father children and has a normal life expectancy.

Epidermolysis Bullosa, Junctional↗

Clinical features and morphological characterization of 10 patients with noninsulinoma pancreatogenous hypoglycaemia syndrome (NIPHS).

OBJECTIVE: Noninsulinoma pancreatogenous hypoglycaemia syndrome (NIPHS), characterized by postprandial neuroglycopaenia, negative prolonged fasts and negative perioperative localization studies for insulinoma, but positive selective arterial calcium stimulation tests and nesidioblastosis in the gradient-guided resected pancreas, is a rare hypoglycaemic disorder of undetermined aetiology. We analysed the clinical, morphological and immunohistological features to further clarify the aetiology and pathogenesis of this rare disease. PATIENTS: Ten consecutive patients with NIPHS (nine men and one woman, aged 29-78 years) were included in the study. Six of the 10 received a gradient-guided subtotal (70%) or distal (50%) pancreatectomy. In the remaining four patients, diazoxide treatment was initiated and the precise mechanism of its action was assessed by meal tests. RESULTS: All of the patients showed a combination of postprandial neuroglycopaenia, negative prolonged fasts (except one patient) and negative localization studies for insulinoma, but positive calcium stimulation tests and nesidioblastosis in the gradient-guided resected pancreas. Immunohistological studies of the resected pancreatic tissues revealed neither an increased rate of proliferation of beta-cells nor an abnormal synthesis and/or processing of either proinsulin or amylin. Evidence of overexpression of the two pancreatic differentiation factors, PDX-1 and Nkx-6.1, as well as the calcium sensing receptor (CaSR) was absent. Nevertheless, abnormal expression of islet neogenesis-associated protein (INGAP), a human cytokine expressed only in the presence of islet neogenesis, in ducts and/or islets, was identified in three of the five patients studied. All of the six patients who received a surgical operation were relieved of further neuroglycopaenic attacks, but one patient who received a subtotal pancreatectomy developed diabetes. In the remaining four patients who received diazoxide treatment, hypoglycaemic episodes were satisfactorily controlled with an attenuated response of beta-cell peptides to meal stimulation. CONCLUSIONS: Our results strengthen the existence of this unique clinical hypoglycaemic syndrome from beta-cell hyperfunction as well as the value of the selective arterial calcium stimulation test in its correct diagnosis and localization. The mechanisms underlying beta-cell hyperfunction and release of insulin to calcium, however, remain poorly characterized. Nevertheless, in a subset of patients with NIPHS, there exists some, as yet undefined, pancreatic humoral/paracrine factor(s) other than proinsulin, amylin, PDX-1, Nkx-6.1 and possibly glucagon-like peptide-1 (GLP-1) that are capable of inducing the INGAP gene and, if activated, will initiate ductal proliferation and islet neogenesis. As for the treatment, we recommend that diazoxide be tried first in each patient and, should it fail, a gradient-guided subtotal or distal pancreatectomy be attempted.

Adult↗

A unique pancreatic tumor with exclusive hepatocytic differentiation.

Only 7 cases of pancreatic tumor with hepatocytic differentiation have been reported in the literature, including 6 cases of hepatoid carcinoma and one case of hepatoid adenoma. Diagnosis of hepatoid carcinoma depends on recognition of characteristic histological features, supported by other evidence linked to hepatic lineage including alpha-fetoprotein production, positive immunoreactivity to liver synthesized proteins, and in situ hybridization detection of albumin mRNA. In addition, a synchronous focus of carcinoma arising in pancreatic ducts, islet cells, or acinar cells is essential. We report a unique case of pancreatic tumor with exclusive hepatocytic differentiation. In this tumor, we were unable to find a synchronous focus of carcinoma arising in pancreatic ducts, islet cells, or acinar cells, ruling out the possibility of its being hepatoid carcinoma. Long term follow-up can help to determine whether this tumor is benign or malignant. The patterns of reticulin staining and immunohistochemical staining are suggestive of malignancy, but mitotic activity is low and nuclear pleomorphism is minimal.

Adult↗

Septic arthritis caused by vancomycin-intermediate Staphylococcus aureus.

Four methicillin-resistant Staphylococcus aureus isolates were consecutively isolated from synovial fluid and a knee wound of a patient with septic arthritis. Determination of the MIC of vancomycin and population analysis confirmed these isolates as vancomycin-intermediate S. aureus (VISA). Results of this study also revealed that cell wall thickness and reduced susceptibility to Triton X-100 were characteristic features of VISA.

Adult↗

Clinicopathological relevance of HER2/neu and a related gene-protein cubic regression correlation in colorectal adenocarcinomas in Taiwan.

While HER2/neu receptor tyrosine kinase is involved in various malignancies, studies on colorectal adenocarcinoma (CRC) remain controversial. To try to clarify the role played by HER2/neu in CRC, sixty-seven CRC patients in Taiwan were analyzed. For this analysis, we used normalized dual-color fluorescence in situ hybridization (FISH) and Photoshop-aided immunohistochemistry (IHC) between cancers and their autologous non-neoplastic epithelia. The results revealed that HER2/neu status was unrelated to age, sex, location and positive-nodal percentage. Intramucosal carcinomas had earlier HER2/neu protein upregulation than regional stromal invasion within Dukes' A, and had a gene level that had not risen yet. Both gene gains and protein increases were significant in later stages in regards to volumetric progression and nodal-metastatic Dukes' stage. Overall, there were 1.53-fold (gene) and 1.81-fold (protein) increases from non-neoplastic enterocytes to CRCs. The upregulating directions of gene (88%) and protein (88%) presented symmetric agreement. Most CRCs exhibited low to intermediate levels of HER2/neu overexpression with double-minute gene amplicons and cytosolic HER2/neu proteins. Normalized FISH and IHC showed high cubic-regression correlation, especially in Dukes' C. According to the correlation curve, the points with IHC index >2.41 and FISH ratio >1.22 defined the area where gene-amplification-dependent HER2/neu overexpression was present. Eleven (16%) patients had values above the cut-off point (IHC = 2.41 and FISH = 1.22), including 7 (10%) cases in cytosolic and 4 (6%) cases in membranous HER2/neu overexpressions. The results suggest that HER2/neu plays a crucial role in CRC tumorigenicity with gene-amplification-independent transcriptional activations early in the carcinogenesis, and gene-amplification-dependent overexpression later in the advanced stages. This indicates that HER2/neu can be a good biological marker for selecting patients that may improve under therapies that employ adequate HER2/neu-targeting strategies.

Adenocarcinoma↗

Telomerase and c-myc expression in hepatocellular carcinomas.

BACKGROUND: Telomerase is activated in the majority of cancer tissues and immortalized cell lines. The hTERT (human telomerase reverse transcriptase-major component of telomerase) gene promoter has been cloned and contains many c-myc binding sites that mediate hTERT transcriptional activation. Thus far, the role of hTERT in tumorigenesis in hepatocellular carcinoma (HCC) has been little studied using RNA in situ hybridization. The relationship between c-myc and telomerase in human HCC tissue is undetermined. MATERIALS AND METHODS: The telomerase activity was assayed using TRAP in specimens from 23 HCC patients, hTERTmRNA was detected using in situ hybridization from 57 HCC patients. The immunohistochemistry for c-myc and DNA sequence for hTERT promoter, and tumour differentiation in relation to hTERT and c-myc expression were determined in 57 specimens. RESULT: hTERTmRNA was found in 47/57 (82.5%) HCC specimens using in situ hybridization. The hTERT expression paralleled telomerase activity, but hTERTmRNA regulation was not significantly associated with c-myc level ( P<0.954) The DNA sequence analysis of the hTERT promoter in specimens from 17 HCC revealed 15 cases of nucleotide transition (T-->C) over 5'-end of distal E-box and one case of nucleotide transversion (G-->C) over 5'-end of proximal E-box. Neither the hTERT expression (P< 0.890) nor c-myc level (P < 0.348) were related to HCC differentiation. CONCLUSIONS: The hTERT expression paralleled telomerase activity. The telomerase activity in HCC was not only regulated by c-myc. Another pathways might contribute to hTERT and telomerase activity regulation. The lack of telomerase activity in specimens from 17.4% of HCC cases might indicate an alternative pathway for maintaining telomere length. Furthermore, both the telomerase activity and c-myc had no significant role in HCC differentiation.

Carcinoma, Hepatocellular↗

Acute interstitial nephritis and pigmented tubulopathy in a patient after wasp stings.

Acute renal failure (ARF) is an unusual complication of wasp stings and mostly results from toxic-ischemic acute tubular necrosis. This patient, who was stung by a swarm of wasps, experienced an allergic reaction, rhabdomyolysis, intravascular hemolysis, and subsequent ARF. The originality of this case report is related to the finding of combined lesions of acute tubulointerstitial nephritis and acute tubular nephropathy. From our extensive literature review, it is the first case of a patient developing this type of injury after wasp stings, and the complications have been documented previously only in one form or another. Renal biopsy should be encouraged, especially for a patient with delayed recovery of renal function after wasp stings, to facilitate early steroid treatment for the patient with the histological change of acute interstitial nephritis. Early use of steroid therapy may hasten renal recovery by preventing the development of interstitial fibrosis.

Acute Kidney Injury↗

Intra-arterial calcium stimulation test for detection of insulinomas: detection rate, responses of pancreatic peptides, and its relationship to differentiation of tumor cells.

The selective intra-arterial calcium stimulation test has greatly facilitated the precise regionalization of insulinomas smaller than 2 cm, which noninvasive techniques (ultrasound [US], computed tomography [CT], magnetic resonance imaging [MRI]) often fail to localize. This study examined not only the role of the test in the localization of insulinomas, but also the responsiveness of 3 beta-cell peptides (insulin, C peptide, and proinsulin) and their relationship to the degree of differentiation of the tumor cells, using percentage decrease of both proinsulin/insulin (P/I) and proinsulin/C peptide (P/C) ratios after stimulation as indices. Ten consecutive surgically proven insulinoma patients each received an injection of calcium into the arteries supplying the pancreas after standard selective angiography and beta-cell peptide levels were measured in samples taken from the right hepatic vein before and 30, 60, 90, 120, and 180 seconds after each injection prior to operation. After surgery, the expressions of the calcium sensing receptor (CaSR) on the resected tumors were assessed by immunohistochemistry. Intra-arterial calcium stimulation with sampling either for insulin or for C peptide correctly predicted the site of insulinoma in 8 of 9 patients or in 7 of 8 patients if the 2 big malignant insulinomas were excluded; thus, the detection rate of this test was 89% and 88%, respectively. Calcium administration stimulated a marked and prompt release of insulin and C peptide simultaneously. Both peaked within 30 to 60 seconds, then declined gradually thereafter, remaining above the baseline at 180 seconds. The magnitude of increase correlated well with the corresponding percentage decrease of P/I and P/C ratios. The response of proinsulin was much less. Immunohistochemistry demonstrated variable membraneous staining for CaSR in normal pancreatic islets and in about 9% of the total normal beta cells, whereas staining in tumor cells was only minimally detectable. We conclude that selective intra-arterial calcium stimulation with hepatic venous sampling either for insulin or for C peptide is a highly sensitive method for the preoperative localization of small insulinomas. Calcium injection stimulates a brisk response of insulin, C peptide, and proinsulin simultaneously and the magnitude of increase of both insulin and C peptide appears to be correlated well with the degree of differentiation of the tumor cells. The exact mechanism by which calcium provokes the release of beta-cell peptides is less clear and whether the CaSR is involved in the mechanism of its action requires further study.

Adult↗

Lipoprotein glomerulopathy associated with psoriasis vulgaris: report of 2 cases with apolipoprotein E3/3.

Lipoprotein glomerulopathy (LPG) is a rare disease, characterized by a special histology, including dilated glomerular capillaries filled with pale-stained and meshlike lipoprotein thrombi. It always presents with proteinuria or nephrotic syndrome. Although hyperlipidemia is not always seen, most patients have type III hyperlipoproteinemia with apolipoprotein (apo) E2/3 phenotyping. Although the clinical feature of LPG is rarely described, LPG associated with other glomerulopathy, including IgA nephropathy, membranous nephropathy, and lupus nephritis, has been documented. Until now, there have been no reports of psoriasis vulgaris associated with LPG. The authors present 2 cases of LPG with apo E3/3 genotyping associated with psoriasis vulgaris. The first patient was a 65-year-old woman who presented with nephrotic syndrome with daily urinary protein loss of 9.05 g and itchy erythematous scaly plaques on her trunk and lower limbs for 1 year. The renal biopsy results showed LPG, and the skin biopsy results showed psoriasis. The second patient was a 50-year-old man with history of psoriasis over his trunk and 4 limbs for 30 years. He also presented with nephrotic syndrome with daily urinary protein loss of 7.55 g. The renal biopsy results also showed LPG. The genotype of apo E showed E3/3, and lipoprotein electrophoresis showed a type III hyperlipoproteinemia-like pattern in both cases. The authors suggest that presence of apo E3/3 genotype cannot rule out the diagnosis of type III hyperlipoproteinemia and LPG. Besides, LPG should be included in the differential diagnosis of psoriatic patients with nephrotic syndrome, especially in Asian patients who show poor response to traditional therapy. Renal biopsy should be performed to make the definitive diagnosis.

Aged↗