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S S Chang

Publications and source records attributed to S S Chang.

At least 19 recordsLinked to original sources
PubMed2001

Metastatic renal cell carcinoma neovasculature expresses prostate-specific membrane antigen.

OBJECTIVES: To determine whether the tumor-associated neovasculature of metastatic prostate and metastatic conventional (clear cell) renal carcinoma express prostate-specific membrane antigen (PSMA). PSMA is a type II integral membrane glycoprotein highly expressed in prostate cancer cells and also recently discovered to be expressed in the neovasculature of non-prostatic primary malignancies. METHODS: We examined metastatic prostate carcinoma (22 patients) and metastatic conventional (clear cell) renal carcinoma (20 patients) in various anatomic sites, including bone, lymph nodes, liver, lung, and soft tissue. Using the biotin-streptavidin method, we performed immunohistochemical reactions with the anti-PSMA monoclonal antibodies (mAbs) 7E11 and PM2J004.5 and with the anti-endothelial cell mAb CD34. RESULTS: Metastatic conventional (clear cell) renal carcinoma consistently expressed PSMA. The PM2J004.5 mAb was positive in 20 of 20 specimens, and the 7E11 mAb was positive in 15 of 20. The anti-PSMA immunoreactions with the neovasculature were confirmed by similar staining by the anti-CD34 mAb (20 of 20). Although the metastatic prostatic cancer cells expressed PSMA in all the specimens, only 2 of 22 had neovasculature PSMA expression. CONCLUSIONS: As in primary prostatic adenocarcinomas, the neovasculature of metastatic prostate cancer, regardless of site, rarely express PSMA. The neovascular endothelial cells of metastatic clear cell renal carcinoma, however, express PSMA. This expression may make PSMA an effective target for mAb-based antineovasculature therapy in metastatic renal carcinoma.

Adenocarcinoma, Clear Cell↗
PubMed2001

Amyloidosis-induced gastrointestinal bleeding in a patient with multiple myeloma.

We present a case of multiple myeloma (MM) complicated by recurrent amyloidosis-induced gastrointestinal bleeding. The patient presented with episodes of coffee-ground vomitus or massive hematochezia. No bleeding focus could be identified using endoscopy, a red blood cell scan, or angiography. Finally, a tissue biopsy taken at the irregular mucosa beside protruding vessels in the duodenum confirmed the diagnosis of gastrointestinal amyloidosis. As this case illustrates, the absence of systemic symptoms of amyloidosis and nonspecific endoscopic findings in gastrointestinal amyloidosis may make diagnosis difficult. Therefore, we recommend that a diagnosis of amyloidosis-induced gastrointestinal bleeding should be considered in patients with MM with an obscure hemorrhage.

Aged↗
PubMed2000

Short term neoadjuvant androgen deprivation therapy does not affect prostate specific membrane antigen expression in prostate tissues.

BACKGROUND: Prostate specific membrane antigen (PSMA) is a transmembrane glycoprotein highly expressed in benign prostate secretory-acinar epithelium and prostate carcinoma. The results of several studies suggest that PSMA expression is increased in prostate carcinoma cell lines subjected to androgen deprivation and in androgen-independent tumors. The authors studied the effects of short term (3-month) androgen deprivation on PSMA expression in prostate carcinoma specimens using two anti-PSMA monoclonal antibodies (mAbs), 7E11 and PM2J004.5. METHODS: The study included patients with clinically localized prostate carcinoma who were prospectively randomized into 1 of 2 treatment groups: 3 months of neoadjuvant androgen deprivation therapy followed by radical prostatectomy (ADT/RP), or radical prostatectomy (RP) alone. Representative formalin fixed, paraffin embedded prostate sections were immunostained with the anti-PSMA mAbs 7E11 and PM2J004.5 by the streptavidin-biotin method. The authors recorded the staining intensity and the percentage of positive cells stained in benign epithelium, high grade prostatic intraepithelial neoplasia (PIN), and prostate carcinoma. They compared the results of 7E11 with those of PM2J004.5 in benign epithelium, high grade prostate, and carcinoma and also compared the results between the two treatment groups (ADT/RP vs. RP alone). RESULTS: Both anti-PSMA mAbs stained benign secretory-acinar epithelium, high grade PIN, and prostate carcinoma. In both treatment groups, PM2J004.5 reacted with a significantly greater percentage of cells (P < 0.001) and with significantly greater intensity (P < 0.001) compared with 7E11 in benign epithelium and prostate carcinoma. With both anti-PSMA mAbs, the percentage of cells stained and the intensity of staining in high grade PIN was similar to that in prostate carcinoma. In the group that received RP alone, the percentage of cells stained and the intensity of staining with 7E11 were significantly greater in high grade PIN and prostate carcinoma compared with benign epithelium (P < 0.001), and the intensity of staining with the PM2J004.5 was significantly greater in high grade PIN and prostate carcinoma compared with benign epithelium (P < 0.001). In the ADT/RP group, the percentage of cells stained and the intensity of staining with 7E11 and PM2J004.5 were significantly greater in prostate carcinoma compared with benign epithelium (P < 0.006). PSMA staining did not correlate with either Gleason score (in the group that received RP alone) or pathologic stage (in both the RP-alone and ADT/RP groups) and did not differ between the two treatment groups. CONCLUSIONS: Short term neoadjuvant ADT does not affect PSMA expression in benign prostate secretory-acinar epithelium, high grade PIN, or prostate carcinoma. Prostate carcinoma and high grade PIN express significantly higher levels of PSMA than benign prostate secretory-acinar epithelium. Compared with 7E11, the PM2J004.5 anti-PSMA mAb is a more sensitive immunohistochemical marker of prostate carcinoma in formalin fixed, paraffin embedded tissue.

Aged↗
PubMed2000

Effect of a calcium channel blocker and antispasmodic in diarrhoea-predominant irritable bowel syndrome.

BACKGROUND: Irritable bowel syndrome (IBS) is a colonic function disorder. Both pinaverlum bromide (a selective calcium channel blocker) and mebeverine (an antispasmodic) are reported to be effective in the long-term (12-16 weeks) treatment of IBS patients. Their efficacy in the short-term treatment of IBS patients and colonic transit time is unclear. Furthermore, substance P and neuropeptide Y have either excitatory or inhibitory effects on colonic motility. Whether the efficacy of both drugs is mediated through these neuropeptides remains unknown. METHODS AND RESULTS: A clinical trial was conducted with 91 patients with diarrhoea-predominant IBS. After basal measurement of the total colonic transit time, IBS patients were randomized to receive either pinaverlum bromide (50 mg, t.i.d.) or mebeverine (100 mg, t.i.d.) for 2 weeks. The symptomatic scores regarding defaecation, total colonic transit time and serum levels of substance P and neuropeptide Y were measured before and after treatments. The daily defaecation frequency was markedly decreased after treatment (pinaverlum bromide, 2.9+/-1.2 vs 2.0+/-1.0, P< 0.05; mebeverine, 2.7+/-1.1 vs 2.1+/-1.0, P< 0.05). The stool consistency became well formed after both treatments (P< 0.05). Both drugs similarly improved the global well-being in these IBS patients (pinaverlum bromide vs mebeverine 73.4 vs 71.8%, P> 0.05). The total colonic transit time was significantly prolonged only after pinaverlum bromide treatment (21.4+/-15.5 vs 30.8+/-14.8 h, P< 0.01). Neither substance P nor neuropeptide Y serum level was significantly changed after either treatments. CONCLUSION: Pinaverlum bromide and mebeverine have similar therapeutic efficacies on diarrhoea-predominant IBS patients. Prolonged colonic transit time may be one of the factors responsible for the efficacy of pinaverlum bromide on the IBS patients. Substance P and neuropeptideY appear less important in the pathogenesis of diarrhoea-predominant IBS.

Calcium Channel Blockers↗
PubMed2000

Pseudogastroparesis as a presentation of small-bowel malignancy.

Establishing the diagnosis of small-bowel malignancy is sometimes an extremely difficult challenge owing to its non-specific symptoms. The mainstay of treatment is early recognition, diagnosis and surgical resection. The prognosis depends primarily on the degree of spread and stage at presentation. We present two cases with initially obscure presentations of a small-bowel tumour. One was a jejunal adenocarcinoma, but an initial upper gastrointestinal and small-bowel series did not disclose the lesion; the other was a primary ileal lymphoma, first thought to be diabetes mellitus gastroparesis. Therefore, a negative small-bowel series or presentation of a systemic disease-associated intestinal pseudo-obstruction or gastroparesis does not exclude the possibility of a small-bowel malignancy, if the clinical symptoms are not alleviated after prokinetic medications. The clinicians should further pursue the possibility of an obstructing lesion.

Adenocarcinoma↗
PubMed2000

Repeated episodes of spontaneous intracystic hemorrhage of hepatic cysts mimicking malignancy.

Repeated episodes of spontaneous intracystic hemorrhage in the liver are very rare. We present the case of a patient with spontaneous intracystic hemorrhage mimicking hepatic malignancy, following an episode of spontaneous hemorrhage of a cyst in the left lobe of the liver. Sonography revealed a heterogenous mass with amorphous material in one episode and a cystic mass with internal papillary projections and septations in the other. The patient experienced acute abdominal pain in the first episode and remained asymptomatic during the two-year follow-up period. With an accurate diagnosis, spontaneous hemorrhage of a hepatic cyst may follow a benign course and be treated conservatively.

Aged↗
PubMed2000

Overview of evolving strategies incorporating prostate-specific membrane antigen as target for therapy.

Prostate-specific membrane antigen (PSMA) is a potential target in prostate cancer patients because it is very highly expressed and because it has been reported to be upregulated by androgen deprivation. This overview addresses the expression of the PSMA gene in terms of the promoter and enhancer and how that may play a role in gene therapy. We also review PSMA as a target for antibodies for imaging and treatment and the development of a novel hybrid T-cell receptor that combines the specificity of anti-PSMA antibodies with that of T-cell receptor activation when introduced into primary lymphocytes by retroviral-mediated gene transfer. We also discuss our recent findings on the expression of a PSMA-like gene and how that understanding allows specific targeting of PSMA.

Animals↗
PubMed1999

Five different anti-prostate-specific membrane antigen (PSMA) antibodies confirm PSMA expression in tumor-associated neovasculature.

Prostate-specific membrane antigen (PSMA) is a type II integral membrane glycoprotein that was initially characterized by the monoclonal antibody (mAb) 7E11. PSMA is highly expressed in prostate secretory-acinar epithelium and prostate cancer as well as in several extraprostatic tissues. Recent evidence suggests that PSMA is also expressed in tumor-associated neovasculature. We examined the immunohistochemical characteristics of 7E11 and those of four recently developed anti-PSMA mAbs (J591, J415, and Hybritech PEQ226.5 and PM2J004.5), each of which binds a distinct epitope of PSMA. Using the streptavidin-biotin method, we evaluated these mAbs in viable prostate cancer cell lines and various fresh-frozen benign and malignant tissue specimens. In the latter, we compared the localization of the anti-PSMA mAbs to that of the anti-endothelial cell mAb CD34. With rare exceptions, all five anti-PSMA mAbs reacted strongly with the neovasculature of a wide spectrum of malignant neoplasms: conventional (clear cell) renal carcinoma (11 of 11 cases), transitional cell carcinoma of the urinary bladder (6 of 6 cases), testicular embryonal carcinoma (1 of 1 case), colonic adenocarcinoma (5 of 5 cases), neuroendocrine carcinoma (5 of 5 cases), glioblastoma multiforme (1 of 1 cases), malignant melanoma (5 of 5 cases), pancreatic duct carcinoma (4 of 4 cases), non-small cell lung carcinoma (5 of 5 cases), soft tissue sarcoma (5 of 6 cases), breast carcinoma (5 of 6 cases), and prostatic adenocarcinoma (2 of 12 cases). Localization of the anti-PSMA mAbs to tumor-associated neovasculature was confirmed by CD34 immunohistochemistry in sequential tissue sections. Normal vascular endothelium in non-cancer-bearing tissue was consistently PSMA negative. The anti-PSMA mAbs reacted with the neoplastic cells of prostatic adenocarcinoma (12 of 12 cases) but not with the neoplastic cells of any other tumor type, including those of benign and malignant vascular tumors (0 of 3 hemangiomas, 0 of 1 hemangioendothelioma, and 0 of 1 angiosarcoma). The mAbs to the extracellular PSMA domain (J591, J415, and Hybritech PEQ226.5) bound viable prostate cancer cells (LNCaP and PC3-PIP), whereas the mAbs to the intracellular domain (7E11 and Hybritech PM2J004.5) did not. All five anti-PSMA mAbs reacted with fresh-frozen benign prostate secretory-acinar epithelium (28 of 28 cases), duodenal columnar (brush border) epithelium (11 of 11 cases), proximal renal tubular epithelium (5 of 5 cases), colonic ganglion cells (1 of 12 cases), and benign breast epithelium (8 of 8 cases). A subset of skeletal muscle cells was positive with 7E11 (7 of 7 cases) and negative with the other four anti-PSMA mAbs. PSMA was consistently expressed in the neovasculature of a wide variety of malignant neoplasms and may be an effective target for mAb-based antineovasculature therapy.

Antibodies, Monoclonal↗
PubMed1999

Prostate-specific membrane antigen (PSMA)-specific monoclonal antibodies in the treatment of prostate and other cancers.

Prostate-specific membrane antigen (PSMA) is a cell surface glycoprotein that is expressed by prostate epithelial cells. PSMA-specific monoclonal antibodies have been utilized to characterize the biologic function and in vivo biodistribution of PSMA. PSMA is an attractive target protein for monoclonal antibody directed imaging or therapeutics for prostate cancer since its expression is relatively restricted to prostate epithelial cells and is over-expressed in prostate cancer, including in advanced stages. Currently, clinical usage of PSMA specific monoclonal antibodies has been limited to diagnostic immunohistochemistry and imaging of patients with prostate cancer. Novel applications for these antibodies will be discussed.

Antibodies, Monoclonal↗
PubMed1999

Soluble cellular adhesion molecules in proliferative vitreoretinopathy and proliferative diabetic retinopathy.

PURPOSE: To measure vitreous levels of soluble intercellular adhesion molecule-1 (sICAM-1) and soluble vascular cellular adhesion molecule-1 (sVCAM-1) in the eyes of patients with retinal detachment (RD) due to proliferative diabetic retinopathy (PDR) or proliferative vitreoretinopathy (PVR) and to determine whether the levels of these mediators correlated with clinical parameters of disease. METHODS: Undiluted vitreous specimens were collected from 50 eyes of 48 patients undergoing vitrectomy for traction RD due to PDR (21 specimens) and recurrent RD due to PVR (19 specimens). Control vitreous specimens were obtained from patients undergoing macular hole repair (10 specimens). The levels of sICAM-1 and sVCAM-1 were measured in each sample by specific enzyme-linked immunoadsorbent assays. RESULTS: Vitreous levels of sICAM-1 were significantly increased in vitreous specimens from both PVR (median +/- SD; 12.0 +/- 76.3 ng/ml; P < 0.01) and PDR (8.4 +/- 24.0 ng/ml; P < 0.01) when compared to vitreous from eyes with macular holes (0. 3 +/- 4.2 ng/ml). Vitreous levels of sVCAM-1 were significantly increased in both PVR (36.5 +/- 255.2 ng/ml; P < 0.001) and PDR (26. 2 +/- 93.5 ng/ml; P < 0.01) when compared to control vitreous (17.7 +/- 7.8 ng/ml). The vitreous levels of sICAM-1 were higher in cases of PDR which developed recurrent proliferative disease (P < 0.01) and recurrent RD (P = 0.01), whereas the levels of sICAM-1 in PVR and sVCAM-1 in PDR and PVR did not significantly correlate with these clinical parameters. CONCLUSIONS: Soluble forms of ICAM-1 and VCAM-1 are increased in the vitreous cavity of patients with RD due to PDR or PVR, reflecting the inflammatory nature of these conditions and suggesting a possible role for these mediators in the pathogenesis of proliferative retinal disease. The vitreous levels of these sCAMs at the time of surgery may serve as a marker of inflammation, but their specific levels do not predict the likelihood of recurrent proliferation or surgical anatomic success in most cases of PVR and PDR.

Adult↗
PubMed1999

Monoclonal antibodies: will they become an integral part of the evaluation and treatment of prostate cancer--focus on prostate-specific membrane antigen?

Over the past two decades, monoclonal antibody technology has had an increasing impact on clinical diagnostic and therapeutic options, and this is true in the realm of managing prostate cancer. Several targets such as prostate-specific antigen and prostatic acid phosphatase as well as, more recently, angiogenic antigens such as vascular endothelial growth factor have been examined for therapy. Prostate-specific membrane antigen, a type II integral membrane glycoprotein initially characterized by the monoclonal antibody 7E11, has shown promise. Recent evidence suggests that prostate-specific membrane antigen is also expressed in tumor-associated neovasculature of a wide variety of malignant neoplasms. With its expression in prostate secretory-acinar epithelium and the prostate and in the neovasculature associated with tumors, prostate-specific membrane antigen represents an excellent antigenic target for monoclonal antibody diagnostic and therapeutic options. As research continues, the role of monoclonal antibody imaging and therapy will become increasingly important in the management of prostate cancer.

Antibodies, Monoclonal↗
PubMed1999

Acute febrile neutrophilic dermatosis (Sweet's syndrome) in hairy cell leukemia: a case report.

Sweet's syndrome is a cutaneous reactive process that is usually associated with fever, but rarely occurs in patients with hairy cell leukemia (HCL). We report the case of a patient with HCL who developed typical Sweet's syndrome five months after the diagnosis of HCL. Skin eruptions and constitutional symptoms subsided rapidly after short-term systemic adrenocorticosteroid treatment without recurrence, until the patient died from disease exacerbation and uncontrolled infection. According to his manifestations, chemical allergens, microorganisms or HCL progression were unlikely to have been the precipitating factors for development of Sweet's syndrome. Because immunologic disorders and opportunistic infection are not uncommon in patients with HCL, a skin biopsy should be taken as early as possible when cutaneous lesions and fever develop in order to establish a correct diagnosis. Hence, unnecessary and prolonged use of antibiotics is avoided and prompt relief of the symptoms by appropriate management can be achieved.

Diagnosis, Differential↗
PubMed1999

Poisoning by Datura leaves used as edible wild vegetables.

The causes of Datura intoxication include medication overdose, misuse of edible vegetables, deliberate abuse as a hallucinogen, homicidal or robbery and accidental intoxication from contaminated food. We report an incident of 14 people with Datura intoxication caused by ingesting wild Datura suaveolans for food. The incubation period was 15 to 30 min. The symptoms/signs were dizziness, dry mouth, flushed skin, palpitation, nausea, drowsiness, tachycardia, blurred vision, mydriasis, hyperthermia, disorientation, vomiting, agitation, delirium, urine retention, hypertension and coma. Three patients were hospitalized for 2-3 days. Thirteen persons received supportive fluid therapy. One patient did not receive medical therapy, he induced vomiting and drank a lot of water. Four patients presented with delirium/coma and 3 received physostigmine therapy with good response. One patient was intubated because of coma and respiratory depression. Three persons needed Foley catheterization for urine retention or coma status. One patient had a complication of urinary tract infection and antibiotic management. All patients recovered with no sequelae.

Adult↗
PubMed1999

Prostate-specific membrane antigen is produced in tumor-associated neovasculature.

Prostate-specific membrane antigen (PSMA), a type II transmembrane protein, was originally thought to be strictly expressed in prostatic tissue, but recent studies have demonstrated PSMA protein expression in nonprostatic tumor neovasculature as well. Using immunohistochemistry, reverse transcription-PCR assays, and in situ hybridization, we have demonstrated PSMA mRNA transcripts and protein expression in the endothelium of tumor-associated neovasculature of multiple nonprostatic solid malignancies. In addition, we found no PSMA mRNA or protein expression in the vascular endothelial cells of corresponding benign tissue examples. Our findings expand the possible therapeutic role of PSMA and establish it as a unique biomarker specifically produced and expressed by tumor-associated neovasculature but not produced or expressed by normal vessels.

Antigens, Neoplasm↗
PubMed1998

Mechanism of capillary electrophoresis enantioseparations using a combination of an achiral crown ether plus cyclodextrins.

The addition of an achiral crown ether (18-crown-6) to a cyclodextrin-based separation can significantly affect the capillary electrophoresis (CE) enantioresolution of organic racemates that contain a primary amine functional group. In most cases an enhancement of the enantioseparation was observed. However, there are also cases where the addition of 18-crown-6 was detrimental to a cyclodextrin-based CE enantioseparation. The effect of concentration of the two complexing additives as well as the effect of pH and added potassium ion were examined. A specific three-body complex involving simultaneous, dual inclusion complex formation can be used to explain both the enhanced and diminished enantioselectivities observed when 18-crown-6 is added to the run buffer.

Amines↗
PubMed1998

The suitability and efficiency of human follicular fluid as a protein supplement in human in vitro fertilization programs.

OBJECTIVE: To evaluate the suitability and efficiency of human follicular fluid (HFF) as a protein supplement in human IVF programs. DESIGN: Comparative study of the effects of HFF and other protein supplements on the in vitro development of mouse oocytes and on the pregnancy rate in human IVF programs. SETTING: In Vitro Fertilization Center, Hanna Women's Clinic, Seoul, Korea. PATIENT(S): Three hundred twenty-seven patients (388 cycles) who were down-regulated with GnRH agonist and stimulated with hMG. INTERVENTION(S): The suitability was evaluated with the results of animal studies and the efficiency of HFF was investigated with the results of human IVF programs. MAIN OUTCOME MEASURE(S): Meiotic maturation of mouse oocytes, development of mouse embryos, morphological grades of human embryos, pregnancy rate in human IVF programs, and electrophoresis. RESULT(S): Human follicular fluid significantly stimulated meiotic resumption in mouse oocytes, even in the presence of meiotic inhibitors, and enhanced the developmental potential of mouse embryos in vitro. Compared with human fetal cord serum, human follicular fluid also improved the morphological grade of human embryos by reducing cytoplasmic fragmentation. In conventional IVF cycles of human IVF programs, use of HFF significantly increased the clinical PR (109/234 cycles, 46.5%; P < .05), compared with use of human fetal cord serum (14/52 cycles, 26.9%). However, in intracytoplasmic sperm injection cycles, there was no difference in PRs between use of HFF (38/85 cycles, 44.7%) and use of human fetal cord serum (7/17 cycles, 41.1%). When the protein compositions of human fetal cord serum and HFF were investigated by electrophoresis, a protein of 21 kD was detected specifically in HFF. CONCLUSION(S): Human follicular fluid is suitable for use as a protein supplement and is effective in increasing the pregnancy rate in human IVF programs.

Animals↗
PubMed1998

Mutations in the mineralocorticoid receptor gene cause autosomal dominant pseudohypoaldosteronism type I.

Pseudohypoaldosteronism type I (PHA1) is characterized by neonatal renal salt wasting with dehydration, hypotension, hyperkalaemia and metabolic acidosis, despite elevated aldosterone levels. Two forms of PHA1 exist. An autosomal recessive form features severe disease with manifestations persisting into adulthood. This form is caused by loss-of-function mutations in genes encoding subunits of the amiloride-sensitive epithelial sodium channel (ENaC; refs 2,3). Autosomal dominant or sporadic PHA1 is a milder disease that remits with age. Among six dominant and seven sporadic PHA1 kindreds, we have found no ENaC gene mutations, implicating mutations in other genes. As ENaC activity in the kidney is regulated by the steroid hormone aldosterone acting through the mineralocorticoid receptor, we have screened the mineralocorticoid receptor gene (MLR) for variants and have identified heterozygous mutations in one sporadic and four dominant kindreds. These include two frameshift mutations (one a de novo mutation), two premature termination codons and one splice donor mutation. These mutations segregate with PHA1 and are not found in unaffected subjects. These findings demonstrate that heterozygous MLR mutations cause PHA1, underscore the important role of mineralocorticoid receptor function in regulation of salt and blood pressure homeostasis in humans and motivate further study of this gene for a potential role in blood pressure variation.

Base Sequence↗