Biomedical subjects

C Y Cheng

Publications and source records attributed to C Y Cheng.

At least 109 records · Page 6Linked to original sources

PubMed1995

Cerebrin-50, a human cerebrospinal fluid protein whose mRNA is present in multiple tissues but predominantly expressed in the lymphoblastoid cells and the brain.

A full-length cDNA of 2295 bp coding for a human cerebrospinal fluid protein, designated cerebrin-50, has been isolated from a human brain cDNA expression library. Nucleotide sequence analysis of this cDNA revealed that it codes for a 435 amino acid polypeptide which starts with an ATG initiation codon from the 5'-end and ends with a TGA termination codon with a calculated molecular weight of 51,484 daltons. A 10-amino acid peptide of NH2-SGDLETRYWG based on the deduced amino acid sequence of the cerebrin-50 cDNA was synthesized, conjugated to bovine serum albumin and was used to raise a monospecific polyclonal antibody in a rabbit. Immunoblot analysis using this antibody indicated the presence of a 52 kD protein in the human cerebrospinal fluid, brain cytosol, T lymphoblastoid cell-conditioned medium, and human serum; it is also noted that the concentration of this 52 kD protein is several order of magnitude higher in the cerebrospinal fluid than in other biological fluids. The presence of its mRNA in the brain, T lymphoblastoid cells, spleen, liver, and testis was confirmed by sequential use of reverse-transcription and polymerase chain reaction (RT-PCR). Preliminary analysis by quantitative RT-PCR has noted that the expression of the cerebrin-50 mRNA is higher in the lymphoblastoid cells and brain than the spleen, liver, and testis.

Amino Acid Sequence↗

PubMed1994

Synthesis and opioid activity of 7-oxygenated 2,3,4,4a,5,6,7,7a-octahydro-1H-benzofuro[3,2-e]isoquinolin-9-ols.

3-(Cyclopropylmethyl)-9-hydroxy-7-oxo-2,3,4,4a alpha,5,6,7,7a alpha- octahydro-1H-benzofuro[3,2-e]isoquinoline (4b) containing the ACNO ring system of morphine and a 7-keto function on ring C has been synthesized and found to possess potent PQW (ED50 = 0.15 mg/kg sc) and anti-Straub tail (ED50 = 0.02 mg/kg sc) activity. As compared to its 7-deoxy analog 1b, introduction of the 7-keto group did not significantly affect binding to any of the three opioid receptors (mu, kappa, and delta), but caused a 34-fold reduction in sigma-binding, suggesting reduced propensity to induce psychotomimetic effects. The C/D cis isomer of 4b (4c) was much less potent at the three opioid receptors, while displaying a slight increase in sigma affinity. Both 7-hydroxy derivatives 4e and 4f were active in anti-Straub tail assay (ED50 < or = 0.8 mg/kg sc), but only the alpha-isomer 4e demonstrated analgesic activity (PQW ED50 = 0.37 mg/kg sc) in the dose range tested. In guinea pig ileum preparations, 4e was characterized as a selective full agonist at the kappa opioid receptor (IC50 = 2.8 nM); while its beta-isomer 4f was a partial agonist (78% at 1 microM), with antagonist activity observed at both mu- and kappa-opioid receptors.

Analgesics↗

PubMed1994

Purification of gonadotropin surge-inhibiting factor from Sertoli cell-enriched culture medium.

Gonadotropin surge-inhibiting factor (GnSIF) is a novel biological factor in follicular fluid that inhibits the pre-ovulatory LH and FSH surges. Recent studies suggest that the biological activity of GnSIF can be attributed to inhibin. Preliminary studies showed that the Sertoli cell-conditioned medium contains GnSIF-like biological activity. Using 32 liters of primary Sertoli cell-enriched culture medium and an in vitro pituitary bioassay, GnSIF was isolated. GnSIF is a single monomeric polypeptide (Mr of 37,000) with a partial N-terminal amino acid sequence of NH2-SDXXPQL which is distinct from any existing protein sequences. The identity of the inhibin that was separated from GnSIF was confirmed by direct protein sequencing. The purified GnSIF inhibited GnRH-stimulated LH- and basal FSH-release from pituitary cells cultured in vitro dose-dependently with a half maximal effective dose of about 1.4 ng/ml and 3.5 ng/ml, respectively. The half maximal effective dose of inhibin to suppress the pituitary GnRH-stimulated LH- and basal FSH-release was 2.5 ng/ml and 0.8 ng/ml, respectively. This study demonstrates that GnSIF is a unique protein that shares some biological activities with inhibin.

Amino Acid Sequence↗

PubMed1994

Regulation of clusterin secretion and mRNA expression in astrocytes by cytokines.

Clusterin is an authentic Sertoli cell secretory product initially identified in the ram and rat testis. Subsequent studies have shown that this protein is present in almost all organs and in multiple species. Its mRNA increases in the brain undergoing degeneration as a result of infection, brain injury, and other pathological conditions such as Alzheimer's disease. However, its site(s) of synthesis and modulator(s) in the brain are not known. The objectives of this study were to determine if astrocytes could synthesize and secrete clusterin in vitro and to investigate the effects of various cytokines on the secretion and the mRNA expression of clusterin in the primary cultures of astrocytes. Astrocytes were isolated from cerebral cortices of neonatal rats and enriched to a purity of greater than 95% as judged by immunocytochemical staining using antibody against glial fibrillary acidic protein (GFAP), a specific marker of astrocytes. Using immunoprecipitation techniques, we have demonstrated that astrocytes actively synthesize and secrete clusterin in vitro. Immunocytochemical staining using a monospecific antibody against clusterin showed that this protein is localized in the entire cytoplasm and the processes of astrocytes. Treatment of astrocytes with either interleukin-1 beta, or interleukin-2, induced a significant increase in the production and the mRNA levels of clusterin, whereas other cytokines including interleukin-3, interleukin-6, and interferon-gamma had no apparent effect. The results of this study suggest that clusterin may be a marker to study the immune response in the brain.

Animals↗

PubMed1994

Facilins, a novel class of biological factors that facilitate the aortic response to dopamine and other biogenic amines.

Biological fluids and tissues extracts were shown to contain biological factors, termed facilins, that facilitate the dopamine-, adrenaline-, and serotonin-mediated aortic contraction at concentrations devoid of any direct effect. Cyproheptadine and phentolamine antagonized the direct contracting effect of biogenic amines, but not the facilitated component of the aortic response thus indicating that the mechanism of action of facilins was unlike that of biogenic amines. Fresh schizophrenics' CSF displayed a stronger facilitating effect than normal CSF on the dopamine-mediated aortic response. This finding, however, was not confirmed with samples kept frozen for prolonged periods of time. Multiple molecular forms of facilins were detected in rabbit serum. Those with a high apparent molecular weight were proteinous and were neither insulin nor other factors known for their contracting effects on the aorta such as epidermal growth factor, transforming growth factor-beta, and platelet-derived growth factor.

Adrenal Glands↗

PubMed1994

Sclerotherapy for esophageal variceal bleeding in advanced hepatocellular carcinoma: an 8-year experience in Taiwan.

Between August 1983 and December 1991 at the Taichung Veterans General Hospital, Taiwan, 65 advanced hepatocellular carcinoma (HCC) patients with esophageal variceal bleeding received endoscopic injection sclerotherapy (EIS) and 60 such patients received conservative medical treatment without EIS. The rate of successful control of acute bleeding was 72.5% (27/40 patients) in the EIS group and 56.7% (34/60 patients) in the non-EIS group. The rebleeding rate was lower in the EIS group than in the non-EIS group (26.9% vs 73.5%). Thirty-one of the EIS and 44 of the non-EIS treatment patients, mainly Child's B and C patients, died within 2 months after the first bleeding. In the short term, EIS decreased the mortality due to esophageal variceal bleeding, but the survivors still had to face hepatic failure and tumor growth. Thus, benefits of EIS were noted on short- but not on long-term survival. The mean survival times were 2.38 months for the EIS group and 1.79 months for the non-EIS group. Since EIS had no beneficial effects on long-term survival it is doubtful whether sclerotherapy applied to esophageal variceal bleeding in patients with advanced HCC would be worthwhile, as the endoscopic procedure would only add to their suffering.

Acute Disease↗

PubMed1994

Identification of protein A-binding components in Spisula oocytes.

Components involved in sustaining meiosis arrest of oocytes were determined. Proteins that bind to protein A from meiosis-arrested and 5-HT-matured Spisula oocytes were analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis. Meiosis-arrested oocytes contained three doublets of proteins with estimated Mrs of 43 and 45, 38 and 40, and 21 and 23 kDa. In 5 HT-matured oocytes the 21 and 23 and 38 and 40 kDa proteins were retained; whereas the 43 and 45 kDa proteins were absent. The protein A-bound proteins did not interact with antibodies against the various subclasses of human, mouse, rat and rabbit IgG or human Fc fragment. The amino acid sequence of the N-terminus of the 43 kDa protein was determined to be NH2-VLRIGSGMXDT. Comparison of this sequence with existing database at Protein Identification Resource (R 32.0), GenBank (R 72.0), SWISS-PROT (R 22.0), and EMBL (R 31.0) showed no homology with any reported protein. The protein A-bound components from meiosis-arrested oocytes were incubated in vitro with [gamma-32P]ATP. Only the 68 kDa protein was radiophosphorylated. This protein was not detected in 5-HT-matured oocytes. The disappearance of the 43, 45, and 68 kDa proteins in 5-HT-matured oocytes suggests that these components may be involved in sustaining meiosis meiosis. A unique property of these proteins is that they interact with protein A and are distinctly different from immunoglobulin.

Adenosine Triphosphate↗

PubMed1994

Rat seminiferous tubular culture medium contains a biological factor that inhibits Leydig cell steroidogenesis: its purification and mechanism of action.

Seminiferous tubules prepared from adult rats cultured for 48 h in serum-free conditions produce multiple biological factors that modulate Leydig cell steroidogenic function in vitro. Using gel filtration chromatography, it was shown that seminiferous tubular culture medium (STCM) contained at least three inhibitory activities designated AI, AII, and AIII that inhibited testosterone production by purified Leydig cells. The factor that induced AIII activity, designated Leydig cell inhibitor (LCI), was further purified to apparent homogeneity by sequential HPLC using gel permeation, C8-, C18-, C2/C18-reversed-phase, and microbore anion exchange columns. When this batch of purified factor was resolved by SDS-PAGE under reducing conditions, only a single silver stained band with an apparent M(r) of 21,000 was detected. Protein sequence analysis using about 100 pmol of purified LCI revealed that its N-terminus was blocked. Incubation of this highly purified factor with Percoll gradient purified Leydig cells induced a dose-dependent inhibition of hCG-stimulated testosterone production. LCI inhibited the basal testosterone production and hCG-stimulated cAMP production by Leydig cell dose-dependently. It also inhibited the forskolin- and cholera toxin-stimulated testosterone and cAMP production but had no apparent effect on the binding of 125I-labeled hCG to LH receptors. These data suggest that this LCI exerts its inhibitory action at steps beyond the LH receptors but prior to the cAMP formation by affecting the adenylate cyclase activity directly or indirectly through inhibition of the stimulatory G-protein (Gs-protein); however, it is also possible that it decreases the coupling of the receptors to the Gs-protein. LCI also inhibited the conversion of exogenously added 22R-hydroxycholesterol, pregnenolone, progesterone, and 17 alpha-hydroxyprogesterone to testosterone. However, it had no effect on the conversion of dehydroepiandrostenedione and androstenedione to testosterone. These data strongly suggest that LCI affects the steroidogenic enzymes metabolizing cholesterol to testosterone, the cytochrome P-450 side-chain cleavage (P-450SCC), and cytochrome P-450 17 alpha-hydroxylase/17,20-lyase (P-450C17). However, it has no effect on the 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD) and 17 beta-hydroxysteroid dehydrogenase (17 beta-HSD) enzyme activities. Based on the results of the present study, it is apparent that this LCI is distinct from other known potent Leydig cells inhibitors such as interleukin-1 (IL-1) and transforming growth factor-beta (TGF-beta). The LCI appears to involve in the paracrine regulation of Leydig cell function.

Adenylate Cyclase Toxin↗

PubMed1994

Response of alpha 2-macroglobulin messenger ribonucleic acid expression to acute inflammation in the testis is different from the response in the liver and brain.

Recent studies from this laboratory have shown that Sertoli cells derived from 20-day-old rats and cultured in vitro synthesize and secrete a nonspecific protease inhibitor that is structurally and immunologically similar to serum alpha 2-macroglobulin (alpha 2-MG). In contrast to its serum homologue, the testicular alpha 2-MG is not an acute-phase protein in the rat since its protein concentration in the rete-testis fluid does not increase in response to inflammation. In the present study we examined the expression of alpha 2-MG mRNA in the rat testis in comparison to that in the brain and liver following induced inflammation. alpha 2-MG mRNA in the testis did not respond to induced inflammation, whereas its protein concentration in serum and its mRNA level in the brain and liver increased significantly in 20-day-old inflamed rats. In 8-day-old rat testis, where the blood-testis barrier is not yet formed, alpha 2-MG mRNA expression also did not respond to induced inflammation. The mRNA expression of clusterin, another authentic Sertoli cell protein whose secretion appears to be closely related to cell-cell interactions in the seminiferous epithelium, was shown to be unaffected by induced inflammation in the testis, brain, and liver. In view of the unexpected differential expression of alpha 2-MG mRNA to induced inflammation in the testis and liver, we sought to examine whether Sertoli cell alpha 2-MG would respond to FSH and testosterone (T), the major regulators of testicular function. Interestingly, expression of alpha 2-MG and clusterin mRNA in the Sertoli cell was not regulated by FSH, T, or a combination of FSH and T. Since there is an intimate morphological relationship between Sertoli cells and germ cells, we next examined the effect of germ cell-conditioned medium (GCCM) on Sertoli cell alpha 2-MG and clusterin mRNA expression. It was noted that GCCM caused a dose-dependent stimulation of alpha 2-MG and inhibition of clusterin mRNA expression in Sertoli cells, respectively. Therefore, our studies have shown that the regulatory mechanism that modulates the expression of alpha 2-MG mRNA in the rat testis is different from its counterpart in the brain and liver.

Aging↗

PubMed1994

Cyclic and postnatal developmental changes of testin in the rat seminiferous epithelium--an immunohistochemical study.

Testin is an authentic Sertoli cell secretory protein consisting of two molecular variants designated testin I (M(r) 35 000) and testin II (M(r) 37 000). N-Terminal amino acid sequence analysis revealed that testin I is identical to testin II except that testin II has three extra N-terminal amino acids of threonine-alanine-proline (TAP). Earlier studies by immunoflorescence microscopy have shown that testin is detected in the seminiferous epithelium consistent with localization in the junctions between Sertoli cells as well as Sertoli-germ cells, and that it appears to be a component of junctional complexes in the testis. In the present study, we have examined the localization of testin in different stages of the spermatogenic cycle of the adult rat testis when germ cells migrate from the basal portion of the seminiferous epithelium to the tubular lumen. In stages I-IV, testin was localized mainly in the basement laminae in the junctional complexes between adjacent Sertoli cells as well as between Sertoli cells, spermatogonia, and pachytene spermatocytes. When elongated spermatids were embedded into the seminiferous epithelium in stage VII of the cycle, testin was detected predominantly on the concave side of the elongated spermatids, but relatively few testin reaction products were seen in the round spermatids. In the beginning of stage VIII of the spermatogenic cycle, intense testin immunoreactive substances were detected around the heads of the elongated spermatids; these substances were virtually undetectable in late stage VIII after the release of the mature sperm into the tubular lumen, suggesting that testin may be a novel marker to divide stage VIII into stages VIIIa and VIIIb.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1994

Rat testicular testibumin is identical to sulfated glycoprotein-1 (SGP-1) whose mRNA expression in the testis is age- but not germ cell-dependent.

Using sequential HPLC and capillary electrophoresis (CE), testibumin (CMB-1) has been purified to apparent homogeneity from Sertoli cell-enriched culture medium prepared from 20-day-old rat testes. N-Terminal amino acid sequence analysis of the purified testibumin revealed a partial sequence of NH2-XPVQDPKI. When this partial sequence was compared to existing protein database, it was shown that it is identical to a previously isolated Sertoli cell secretory protein, sulfated glycoprotein I (SGP-1). The fact that testibumin is equivalent to SGP-1 was further confirmed when its full-length cDNA was isolated and sequenced. Studies using quantitative PCR to examine the changes of steady-state mRNA level of testibumin (SGP-1) in the rat testes between 3 and 60 days of age indicated that its mRNA increased rapidly after birth, peaked at 10-20 days, and declined rapidly where the adult testibumin mRNA level was similar to the neonatal rat at 3 days of age. Depletion of germ cells by a single dose of lonidamine, an antispermatogenic drug, did not induce an increase in testibumin (SGP-1) mRNA level indicating its mRNA expression is not dependent on germ cells.

Aging↗

PubMed1994

Sclerotherapy on liver cirrhosis with esophageal variceal bleeding: eight years of experience.

BACKGROUND: Patients with liver cirrhosis usually die of hepatic failure and variceal bleeding. Successful treatment of the latter can reduce mortality. Sclerotherapy is one method often used. This study compared (a) the successful rate of acute bleeding control; (b) short- and long-term survival rate between those with and without treatment with sclerotherapy to evaluate the clinical benefit of sclerotherapy for liver cirrhosis patients with esophageal variceal bleeding. METHODS: Between August 1983 and December 1991, 183 cirrhotic patients with esophageal variceal bleeding receiving endoscopic injection sclerotherapy (EIS) was compared with 123 patients without sclerotherapy treatment retrospectively. The severity of underlying liver disease was classified using a modified Child's classification. Sclerotherapy was done within 48 hours after active bleeding in the sclerotherapy-treated group, while the medical treatment group received Sengstaken-Blakemore (SB) tube or pitressin infusion only. RESULTS: Successful rate of acute bleeding control was 81.63% (120/147) in the EIS group and 59.35% (73/123) in the medical treatment group. The worse the hepatic function of the patients, the lower the success of acute bleeding control in both groups. Fifty subjects (74.63%) had varices eradicated in 67 sclerotherapy treatment patients with regular follow-up. Patients receiving EIS had a better long-term survival than those without treatment. Benefit of EIS on long-term survival was more significant in Child B patients and less in Child C and Child A patients. Death from variceal bleeding was lower in the EIS group than in the medical treatment group (32% vs 62.6%). Complications of EIS were rare. Eight patients died of aspiration pneumonia, spontaneous bacterial peritonitis or acute renal failure after sclerotherapy, and most were Child B and C patients. Sixteen patients had esophageal stricture. Four needed dilatation treatment. CONCLUSIONS: The sclerotherapy-treated group had a higher control rate of acute bleeding and lower mortality rate from esophageal variceal bleeding compared with the medical-treated group. The procedure prolonged long-term survival in Child B patients but did so less frequently in Child A and Child C patients. The incidence of complications was low. As a whole, EIS is a safe and efficient method for control of esophageal variceal bleeding.

Adult↗

PubMed1994

Krukenberg tumor in pregnancy with delivery of a normal baby: a case report.

Successful termination of a pregnancy and delivery of a normal infant in a young woman with Krukenberg tumor is reported. This association has rarely been described previously. The persistent gastrointestinal symptoms mimicking the early nausea and vomiting of pregnancy mask the presentation of a tumor in the stomach. Growth of the fetus leading to abdominal distension masks the presence of the metastatic ovarian tumor in the pelvic cavity. Thus, early diagnosis of the tumor may be delayed. We emphasize the importance of differentiation between physiological morning sickness and unusual persistent gastrointestinal symptoms in pregnant women. Persistent unusual gastrointestinal symptoms need careful evaluation by panendoscopic examination.

Adult↗

PubMed1994

Carcinosarcoma of the lung: an analysis of 6 operated cases.

BACKGROUND: Carcinosarcoma of the lung is a rare malignant pulmonary neoplasm, and constitutes 0.1% to 0.3% of all lung tumors. Typically, these tumor have both carcinomatous and sarcomatous components with a poor prognosis due to late diagnosis and early metastases. METHODS: From July 1980 to December 1993, six patients with pulmonary carcinosarcoma who underwent surgical treatment were studied. None of them had accurate tissue diagnosis before operation except one case with peripheral variant carcinosarcoma who was diagnosed by percutaneous transthoracic fine needle biopsy under sonographic guidance. All of our patients had a huge peripheral lung tumor 3.8 to 10 cm in diameter. Pneumonectomy was done in two patients, and lobectomy in three. The other patient had unresectable tumor. RESULTS: The histopathological components in carcinoma were epidermoid carcinoma in and adenocarcinoma in 3. Differentiation of sarcomatous lesions included spindle cell sarcoma in 3, fibrosarcoma in 2 and undifferentiated mesenchymal sarcoma in one patient. In the resectable group, 1 was at stage II and 4 were at stage IIIa. None of the patients survived more than 2 years due to distant metastasis and cachexia. The mean survival was 140 days. CONCLUSIONS: The carcinomatous portion tends to metastasize to regional lymph nodes whereas the sarcomatous part gives rise to systemic dissemination. Due to early systemic dissemination and poor prognosis, combination of extensive surgical intervention resection with aggressive postoperative chemotherapy and radiotherapy might be a reasonable consideration to improve survival in primary pulmonary carcinosarcoma.

Adult↗

PubMed1993

The use of high-performance electrophoresis chromatography for the micropurification of cerebrospinal fluid proteins in the rat.

Using reversed-phase high-performance liquid chromatography (HPLC) on a Vydac C8 column in conjunction with sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis (PAGE) and silver staining, we have identified more than 30 proteins in cerebrospinal fluid collected from adult rats by cannulation of cisterna magna. When these partially purified cerebrospinal fluid proteins were further fractionated by high-performance electrophoresis chromatography (HPEC) on an Applied Biosystems 230A HPEC system using a 10% T SDS-polyacrylamide gel with a phosphate base running buffer system under nonreducing conditions, we have purified more than 10 proteins to apparent homogeneity from a pool of 10 ml of rat cerebrospinal fluid as verified by silver staining and direct N-terminal amino acid sequencing. Two additional series of experiments using rat cerebrospinal fluid over a 12-month period yielded virtually identical results. A major advantage of HPEC over conventional HPLC is that the recovery of protein is almost quantitative and is in the range of 90-95% using as little as 1 microgram of protein. The purified proteins from HPEC are ready for direct protein sequencing following a buffer exchange to remove residual Tris and phosphate without additional manipulation. The potential use of HPEC for micropurification of proteins was discussed.

Amino Acid Sequence↗

PubMed1993

Testins are structurally related to the mouse cysteine proteinase precursor but devoid of any protease/anti-protease activity.

Testin I (M(r) 35,000) and testin II (M(r) 37,000) (testins) are two structurally and immunologically related testicular proteins that are actively synthesized and secreted by Sertoli cells. Treatment of adult rats with busulfan to destroy germ cells selectively in the testis could lead to a significant increase in the testicular testins level; as the germ cells reappeared in the testis, the testicular testins level declined and returned to the normal level. These observations indicated that the testicular content of testins in the rat is inversely correlated to the number of germ cells. When the partial N-terminal amino acid sequences for testin I and testin II were compared with the existing protein data base at Protein Identification Resource, it was noted that they displayed remarkable identity with CTLA-2 alpha and CTLA-2 beta, two novel molecules expressed in mouse activated T lymphocytes and mast cells, and the mouse cysteine proteinase proregion. When purified testins were assayed for the proteolytic and anti-protease activity using [14C]-casein, it was noted that it possessed neither proteolytic nor anti-protease activity, suggesting that it is not functioning as a protease and/or protease inhibitor in the testis.

Amino Acid Sequence↗

PubMed1993

Abnormal glycosylation of alpha 2-macroglobulin, a non-acute-phase protein in patients with autoimmune diseases.

Previous studies from this and other laboratories have shown that abnormal glycosylation of several acute-phase proteins can be detected in various pathological conditions including autoimmune diseases. In the present study, we have investigated if abnormal glycosylation is limited to acute-phase proteins. We used the concanavalin A (Con A) blots in conjunction with the peptide mapping techniques to analyze serum samples and cerebrospinal fluids (CSF) obtained from patients with autoimmune diseases: systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), mixed connective tissue disease (MCTD), scleroderma (SCL), Sjögren's syndrome (SS), and polymyositis (PM); diseases of probable autoimmune origin: hepatopathies (HP); diseases of suspected autoimmune origin: schizophrenia and Alzheimer's disease (AZ); and conditions not related to autoimmunity: pregnancy (PG) and elevation of the carcinoembryonic antigen (CEA), in comparison to normal donors (NHS). We have micropurified two human proteins; alpha 2-macroglobulin, a non-acute-phase protein and beta-chain of haptoglobin, a known acute-phase protein, from serum samples of individual patients with SLE, RA, MCTD, SCL and SS, and from PG and NHS for analysis. The identity of the purified proteins was confirmed by immunoblots using either monospecific polyclonal or monoclonal antibodies, and by direct N-terminal amino acid sequencing. Peptide maps for each of these proteins were generated using Staphylococcus aureus protease V8, a Glu-C endopeptidase. When the peptide fragments of alpha 2-macroglobulin were resolved by SDS-PAGE and visualized using silver staining, no differences were noted between patient samples and controls. However, when they were examined by lectin blots using Con A, the Con A-reactive fragments increased specifically and significantly in samples derived from patients of SLE, SCL, MCTD, and RA. Similarly when the peptide fragments of the beta-chain of haptoglobin were visualized by silver staining, no differences were noted; however, the Con A reactivity of specific fragments increased in SLE, RA, SCL, and SS patients. Analysis of these results indicated that there has been a selective increase in Con A-reactive fragments in both acute-phase and non-acute-phase proteins in autoimmune conditions. Thus, the study of changes in glycosylation patterns in selected serum proteins may be a valuable diagnostic approach to define the pathophysiology of inflammatory and autoimmune disorders.

Acute-Phase Proteins↗

PubMed1993

Changes of immunoreactivity in alpha 1-antitrypsin in patients with autoimmune diseases.

Recent studies from this laboratory have shown that a monoclonal antibody prepared against a specific epitope on alpha 1-antitrypsin is a valuable diagnostic marker for autoimmune conditions. In the present study we have further characterized this monoclonal antibody and reassessed its diagnostic value in screening samples from patients with various autoimmune conditions. alpha 1-Antitrypsin was micropurified from patients with selected autoimmune conditions and from normal donors. The purified alpha 1-antitrypsin isolated from patients with autoimmune conditions and normal donors was deglycosylated using both a mixture of exoglycosidases and endoglycosidase F. The immunoreactivity of the native and deglycosylated alpha 1-antitrypsin was examined using both a monoclonal antibody and a polyclonal antibody in enzyme linked immunosorbent assay (ELISA) and radioimmunoassay (RIA), respectively. It was noted that alpha 1-antitrypsin isolated from patients with autoimmune diseases generated a displacement curve dissimilar to alpha 1-antitrypsin purified from normal donors or alpha 1-antitrypsin from patients with autoimmune diseases subjected to deglycosylation when these samples were examined by ELISA using the monoclonal antibody. However, when the polyclonal antibody was used for these studies, no difference was found between the native and deglycosylated alpha 1-antitrypsin suggesting that the monoclonal antibody recognized an epitope not detectable by the polyclonal antibody.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗