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K M Das

Publications and source records attributed to K M Das.

At least 91 records · Page 5Linked to original sources
PubMed1986

Isolation and characterization of Crohn's disease tissue-specific glycoproteins.

Two Crohn's disease tissue-specific proteins are identified and purified several thousand-fold from crude tissue extracts by different chromatographic procedures. The two proteins migrate in sodium dodecyl sulfate-polyacrylamide gel electrophoresis as 200-210-kilodalton and 150-160-kilodalton species. They are glycoproteins, as evidenced by their binding to concanavalin A-Sepharose 4B and positive staining with Schiff's reagent. Specific immunoreactivity of the two glycoproteins against Crohn's disease sera was demonstrated by immunotransblot analysis. All but one of the operative specimens of colon or small intestine (or both) from 13 patients with Crohn's disease contained either or both of the proteins; they were not detected in specimens of colon from 5 patients with ulcerative colitis, 1 patient with diverticulitis, 1 patient with ischemic colitis, from the normal bowel segments resected from 3 patients with colon cancer, and from two normal ileal tissue specimens. The two glycoproteins did not react with antihuman IgG, IgM, and IgA, suggesting that they are not immunoglobulins. The purified glycoproteins may provide important leads toward the understanding of the pathogenesis of Crohn's disease.

Adult↗
PubMed1986

Seropositivity in Dutch Crohn's disease patients against primed nude mouse lymph nodes, and the difference with lymphocytotoxic antibodies.

Sera from patients with Crohn's disease have been reported to show positive immunofluorescence with lymph nodes of nude mice primed with a filtrate of intestinal tissue affected with Crohn's disease. An indirect immunofluorescence assay was used to test sera of 63 unrelated patients with Crohn's disease, 21 with ulcerative colitis and 36 control subjects against lymph nodes of athymic nude (nu/nu) mice which had been injected with Crohn's disease and ulcerative colitis intestinal tissue filtrates. Forty nine per cent of Crohn's disease patients, 10% of ulcerative colitis patients and 3% of control sera reacted against lymph nodes of mice injected injected with ulcerative colitis intestinal tissue filtrates, 18% of Crohn's disease sera were with intestinal tissue homogenate from Dutch Crohn's patients. With the lymph nodes of mice injected with ulcerative colitis intestinal tissue filtrates, 18% of Crohn's disease sera were positive, whereas all ulcerative colitis and control sera were negative. Lymph nodes from 18 of the 19 mice injected with Crohn's disease tissue filtrates reacted with Crohn's disease sera, whereas only three of these 19 mice reacted with ulcerative colitis sera. A comparative study, carried out in parallel with Crohn's disease filtrate induced hyperplastic lymph nodes from the Bilthoven colony (W2) and from the New York colony (E671) using sera from 54 Crohn's disease patients from Leiden, showed immunoreactivity with 44 and 57% of the Crohn's disease sera against the two hyperplastic lymph nodes. Thirty six of the 54 Crohn's disease sera (67%) reacted with either or both lymph nodes. Only 11% of the Crohn's disease sera which were examined for immunofluorescence and lymphocytotoxic antibodies had lymphocytotoxic antibodies, whereas 40% and 46% of the same sera showed positive immunofluorescence against E671 and W2, respectively. Absorption studies indicated that lymphocytotoxic antibodies activity and the immunofluorescence against the primed nude mouse lymph node are mediated by different serum antibodies in Crohn's disease. The reproducibility of the nude mouse immunofluorescence test system for a preferential immunoreactivity of Crohn's disease sera against Crohn's disease tissue primed murine lymph nodes has been confirmed by the present study. Further studies are necessary to find out whether crossreactive antigen(s) as recognised by some of the Crohn's disease sera in mice injected with ulcerative colitis tissue filtrate is similar to the antigen(s) detected by Crohn's disease sera in mice injected with Crohn's disease tissue filtrates.

Absorption↗
PubMed1986

Chromium 51-ethylenediaminetetraacetate test: a useful test in the assessment of inflammatory bowel disease.

We evaluated the usefulness of urinary excretion values in assessing mucosal damage in inflammatory bowel disease after administration of chromium 51-labeled EDTA either orally or rectally. In the oral study, 19 controls, 18 patients with Crohn's disease, and 13 patients with ulcerative colitis were given 100 microCi 51Cr-EDTA by mouth. The amount of 51Cr-EDTA in a 24-hour urine collection was expressed as a percentage of the ingested dose. The patients with Crohn's disease of the small bowel excreted 6.3% +/- 4.3%, which was significantly (P less than 0.001) higher than the percentage in patients with ulcerative colitis (1.7% +/- 1.1%) and controls (1.4% +/- 0.6%). In the enema study, 19 patients with ulcerative colitis, two with Crohn's disease, two with radiation colitis, and four controls (spastic colitis, lactose intolerance) were given 100 microCi 51Cr-EDTA by retention enema. The patients with active colonic inflammation excreted 8.4% +/- 3.9% of the dose given by enema, which was significantly (P less than 0.01) higher than in other controls (1.9% +/- 0.91%) or patients with inactive colitis (2.2% +/- 1.9%). The 51Cr-EDTA excretion test is a safe, inexpensive test useful in evaluating patients with inflammatory bowel disease. It can be given orally to screen patients with abdominal complaints who are suspected of having Crohn's disease involving the small intestine, and when given by enema it provides additional objective assessment of idiopathic ulcerative colitis or proctitis.

Administration, Oral↗
PubMed1986

Serum antibodies from patients with Crohn's disease and from their household members react with murine lymphomas induced by Crohn's disease tissue filtrates.

Injection into athymic nude mice (nu/nu) of filtrates of Crohn's disease tissue produces lymphoid hyperplasia and lymphomas, which react with serum antibody from other patients with Crohn's disease. We examined for such antibodies in sera of 14 patients with Crohn's disease and 25 of their household members and compared results with sera from 36 healthy unselected controls and from 14 patients with ulcerative colitis and 19 of their household members. Sera from all patients with Crohn's disease and ulcerative colitis and household members were collected in Michigan, coded, and examined by an indirect immunofluorescence assay against two primary nu/nu lymphomas and one transmitted lymphoma produced by three Crohn's disease tissue filtrates. Seven patients with Crohn's disease had antibodies against antigen(s) in the Crohn's disease lymphomas. Seven household members of patients with Crohn's disease and no household members of patients with ulcerative colitis (P less than 0.05) reacted with Crohn's disease lymphomas. However, none of the patients with ulcerative colitis (P less than 0.01) and no control healthy subjects (P less than 0.005) demonstrated immunoreactivity against nu/nu lymphomas. None of the sera reacted with a control nu/nu lymphoma. Five household members who had positive assay results were first-degree blood relatives, and the other two were spouses of patients with Crohn's disease. These results suggest that a common environmental factor may be associated with Crohn's disease, that there is a familial association in Crohn's disease, and that nu/nu mice are an important model to study the pathogenesis of Crohn's disease.

Adult↗
PubMed1985

Sulfasalazine and renal tubular function: lack of an effect.

Sulfasalazine (SASP) is frequently used in the treatment of chronic inflammatory bowel disease (IBD), particularly colitis. Because the drug poses a theoretical risk for renal tubular damage, 26 patients, 8-18 years of age, with Crohn's ileocolitis were studied. Thirteen children were receiving SASP while 13 served as disease controls. Renal tubular function was assessed by measurement of urinary beta 2-microglobulin and n-acetylglucosaminidase activity. No abnormalities were found on routine measurement of renal function. Similarly, urinary beta 2-microglobulin and n-acetylglucosaminidase activities were within normal limits for patients receiving SASP, as well as for disease controls. Although there is a theoretical risk for renal tubular damage from the prolonged use of SASP, this study would suggest that IBD patients receiving the drug are at no greater risk for renal injury than their counterparts not receiving the medication.

Adolescent↗
PubMed1985

Isolation and characterization of a colonic autoantigen specifically recognized by colon tissue-bound immunoglobulin G from idiopathic ulcerative colitis.

Patients with idiopathic ulcerative colitis (UC) have a colonbound antibody (CCA-IgG) that reacts with colon tissue extracts. We have partially characterized a colonic protein that is specifically recognized by CCA-IgG. CCA-IgG was eluted from operative colon specimens from 10 patients with UC. A colon tissue-bound IgG was similarly eluted from six patients with Crohn's colitis, two with ischemic colitis, and one with diverticulitis. Purified serum IgG from patients with Crohn's disease, from normal subjects and a patient with myeloma were also used as additional controls. For detection of antigen(s), tissue extracts were prepared from 26 specimens of colon (UC, 12; Crohn's disease, 6; normal, 4; other controls, 4), 8 specimens of human normal stomach, duodenum, ileum, and liver (2 each). Tissue extracts were also prepared from rats and mice, including germ-free rat colons and rat's fetal colons. Immunorecognition of CCA-IgG to the tissue extracts was examined by affinity-column chromatography and by transblot analysis. Tissue-extracted proteins were electrophoresed in SDS-polyacrylamide gel, transferred to nitrocellulose sheet, and probed with iodinated CCA-IgG, colonic IgG from other inflammatory bowel disease patients, UC serum IgG, and control serum IgG. Although many proteins were present in colon tissue extracts, 9 of 10 CCA-IgG consistently recognized a protein of 40 kD. None of the nine IgG preparations from colon specimens of patients with Crohn's colitis and other colonic inflammatory diseases reacted with the 40-kD protein. Five of six symptomatic UC serum IgG and none of eight control serum IgG reacted with the 40-kD protein. The 40-kD protein was present in all colon specimens and it appeared to be organ specific. It was absent in mouse and rat tissues, including colon. The 40-kD protein is not actin and nor a part of the Ig molecule. These results suggest that the 40-kD protein is a colonic "autoantigen" that may initiate a specific IgG antibody response in UC.

Autoantigens↗
PubMed1984

Antibody-dependent cell-mediated cytotoxicity in serum samples from patients with ulcerative colitis. Relationship to disease activity and response to total colectomy.

A group of six medically treated patients with ulcerative colitis were followed for up to 30 months along with eight additional patients who underwent proctocolectomy. Patients were examined frequently, and serum samples were collected for antibody-dependent cell-mediated cytotoxicity studies. Clinically active disease was substantiated by history, physical examination, laboratory investigations, proctoscopy and, when feasible, by rectal and/or colonic biopsy specimens. During active clinical disease, serum samples from patients with ulcerative colitis showed antibody-dependent cell-mediated cytotoxicity of 16.5 +/- 1.6 percent (range 8.2 to 25.8 percent). During remission of the disease, serum samples from the same patients demonstrated a mean antibody-dependent cell-mediated cytotoxicity value of 5.9 +/- 1.3 percent (range 0.4 to 11.1 percent) (p less than 0.01). In the eight patients who underwent proctocolectomy, mean preoperative antibody-dependent cell-mediated cytotoxicity value was 19.5 +/- 2.3 percent (range 4.1 to 38.6 percent). One month after proctocolectomy, antibody-dependent cell-mediated cytotoxic activity decreased by 72 +/- 11 percent of the preoperative value (p less than 0.001). These findings reveal a positive correlation between the antibody-dependent cell-mediated cytotoxicity with RPMI-4788 and clinical activity of ulcerative colitis, and support the hypothesis that the antibody being studied has direct relation to the presence of the ulcerative colitis colon in situ.

Adult↗
PubMed1984

Cell-wall defective bacteria and Crohn's disease: studies using athymic nude mice.

Indirect immunofluorescence studies were performed to determine whether the antigenic recognition by Crohn's disease (CD) sera of lymphoid tissue from nude (nu/nu) mice injected with CD filtrate is related to cell wall defective pseudomonas-like bacterial revertant forms (CWD-RF). Antisera raised in rabbits against two CWD-RF isolates from CD tissues did not stain lymphomas or hyperplastic lymph nodes produced by CD filtrates, although these tissues demonstrated positive immunofluorescence with CD sera. Pre-absorption of reactive CD sera with CWD-RF did not block this immunofluorescence. Formalinized suspensions of CWD-RF were injected into 36 nu/nu, 12 nu/+, and 31 conventional mice. Thirty other mice were fed suspensions of bacteria. Several nu/nu injected with CWD-RF developed lymphoma (n = 2) and plasma cell hyperplasia (n = 5), none of which reacted with CD sera. Mice fed bacteria did not show intestinal pathology. These studies demonstrate that CWD-RF are not directly related to lymphomagenesis in nu/nu induced by CD filtrates and that different CD serum antibodies are involved in recognition of CWD-RF and lymphoid tissues from nu/nu previously injected with CD filtrates.

Animals↗
PubMed1984

Persistence of an antigen recognized by Crohn's disease sera during in vivo passage of a Crohn's disease-induced lymphoma in athymic nude mice.

Previous studies from this laboratory have shown that lymphoma and lymph node hyperplasia develop in athymic nude mice injected with Crohn's disease tissue filtrates. In addition, use of an indirect immunofluorescence assay has demonstrated that an antigen(s) in these lymphoid tissues is recognized by sera from patients with Crohn's disease. In our study, one such lymphoma was passed through 10 generations of athymic nude mice and used for immunofluorescence studies. Suspended cells (1 to 5 X 10(8)/mouse) from the primary lymphoma and from the lymphomas that developed in mice of each subsequent generation were injected subcutaneously into groups of three to eight mice. As a control, lymphoma induced in a nude mouse by the injection of sarcoid lymph node filtrate was passed through successive generations in the same manner as the Crohn's disease-induced lymphoma. Lymphoma developed locally in 81% of recipient mice 3 to 6 weeks after injection of suspended cells. In 47 mice, representing 10 generations, Crohn's disease-related lymphoma developed at the sites of injection and at axillary or inguinal lymph nodes. These tumors were examined by immunofluorescence assay using a panel of 20 sera coded for Crohn's disease or control. Immunofluorescence assay yielded positive results in 61% of the lymphomas and 59% of the lymph node with sera from patients with Crohn's disease, but not with control sera. Control lymphomas did not stain with any serum. Our studies demonstrate the transmissibility or inducibility of an antigen(s) in lymphoid tissue of athymic nude mice that is recognized by sera from patients with Crohn's disease, but not by control sera.

Adult↗
PubMed1984

Detection and partial characterization of Crohn's disease tissue specific proteins recognized by Crohn's disease sera.

To identify immunoreactive proteins in Crohn's disease (CD) tissue, we examined intestinal tissues from eight patients with CD, seven patients with ulcerative colitis (UC) and four normal colon specimens from patients with colon carcinoma. Tissues were homogenized in 0.05 M Tris-buffered saline containing 2 mM phenyl-methyl-sulphonyl fluoride, and the cell free supernatants were incubated with sera from eight patients with CD, five with UC and five normal volunteers. Immune complexes formed in vitro were precipitated with pansorbin, washed with several detergents and analysed by SDS-polyacrylamide gel electrophoresis. When CD tissue was immunoprecipitated with CD sera, three major proteins of 160,000, 120,000 and 110,000 daltons were detected. Partial enrichment of these proteins were achieved when immune complexes formed in vitro were precipitated with polyethylene glycol followed by protein A-Sepharose 4B chromatography. Affinity gel chromatography and autoradiographic studies with purified serum IgG from CD patients further confirmed the presence of these immunoreactive proteins in CD tissue extracts. When similarly examined, these proteins were absent from UC and control tissue extracts after incubation with CD, UC or control sera. These studies suggest that CD tissue contains several proteins which are specifically recognized by CD patients' sera. Characterization of these immunoreactive proteins may provide an important lead in understanding the pathogenesis of CD.

Antibody Specificity↗
PubMed1983

Pharmacotherapy of inflammatory bowel disease. Part 1. Sulfasalazine.

Published studies suggest that sulfasalazine is effective in treating mild to moderate attacks of ulcerative colitis. Its usefulness in severe attacks has not been adequately tested. Published reports also justify the use of sulfasalazine to prevent recurrence of ulcerative colitis. It is not clear how long maintenance therapy should be continued, but evidence to date favors prolonged treatment in the absence of side effects. In treatment of Crohn's disease, sulfasalazine has been shown to be effective when disease involves the colon or the colon and small intestine. Maintenance therapy does not prevent relapse. Recent studies have indicated that 5-aminosalicylic acid (5-ASA) may be the therapeutic moiety of sulfasalazine, and sulfapyridine (SP) may be related to most of the side effects. Therefore, research is under way to develop a product that contains 5-ASA without the sulfonamide component and that is capable of reaching the colon without being absorbed in the upper small intestine.

Aminosalicylic Acids↗
PubMed1983

Studies of the etiology of Crohn's disease using athymic nude mice.

Following injection of Crohn's disease tissue filtrates, lymphomas and hyperplastic lymph nodes developed in 16% of athymic nude (nu/nu) mice; whereas only 4% of control nude mice developed lymphadenopathy (p less than 0.025). One hundred forty coded sera from 111 patients (Crohn's disease = 36, ulcerative colitis = 28, diarrheal and other controls = 47) were assayed by indirect immunofluorescence for immunoreactivity with the lymphomas and hyperplastic lymph nodes. Coded sections were examined by two observers and scored on a 0 to 3 + scale. Fifty-four percent of the sera from patients with Crohn's disease were reactive with the Crohn's disease induced lymphoma by this assay. Eighty percent of sera from patients with symptomatic Crohn's disease were positive, whereas 22% of sera from patients in remission were positive. Sixty-six percent of sera from patients with symptomatic Crohn's disease reacted against hyperplastic lymph nodes induced by Crohn's disease filtrates. In contrast, only one control serum (from a patient with ulcerative colitis) reacted with the lymphomas or hyperplastic lymph nodes. Lymphomas induced by other means or arising spontaneously did not show immunofluorescence with Crohn's disease or control sera. Electron microscopy revealed C-type viral particles in five lymphomas induced by Crohn's disease filtrates and in one control lymphoma, but not in five hyperplastic lymph nodes and five control lymph nodes. Absorption of Crohn's disease sera with control lymphoma or with murine leukemia virus infected fibroblasts did not diminish immunoreactivity, whereas similar absorption with lymphomas induced by Crohn's disease filtrates abolished the immunofluorescence. These studies indicate that Crohn's disease tissue, when injected into athymic nude mice, induces lymphoid hyperplasia and lymphomas that contain an antigen(s) recognized by Crohn's disease sera.

Animals↗
PubMed1982

Desensitization of patients with inflammatory bowel disease to sulfasalazine.

Seventeen patients with ulcerative colitis and three patients with Crohn's disease exhibited different side effects during sulfasalazine therapy. Eighty percent of these patients belonged to slow acetylator phenotypes. All side effects except skin rash were associated with a mean serum total sulfapyridine concentration of 62.9 +/- 17.4 micrograms/ml and free sulfapyridine concentration of 42 +/- 9.5 micrograms/ml. All patients were successfully desensitized, which allowed them the benefit of continued sulfasalazine therapy for prevention of relapses.

Colitis, Ulcerative↗
PubMed1982

Absorption, enterohepatic circulation, and excretion of 5-aminosalicylic acid in rats.

After oral administration of sulfasalazine, the majority of the administered dose reaches the colon, where it is split into 5-aminosalicylic acid (5-ASA) and sulfapyridine. 5-ASA is believed to be the effective component in the treatment of inflammatory bowel disease. After intraduodenal administration of 5-ASA (20 mg) in rats, 91% of the drug was absorbed in the proximal small intestine. Peak serum 5-ASA concentration (55 micrograms/ml) was reached in 1 h. Approximately 61 and 6% of the administered dose were excreted in the urine and bile, respectively, in 24 h, almost exclusively in the acetylated form. When sulfapyridine (20 mg) was administered in addition to 5-ASA, 70% of the sulfapyridine was absorbed in the small intestine, peak serum concentration (50 micrograms/ml) was reached in 1 h, and 30% of the administered dose was excreted in the urine in 24 h. The results indicate that after oral administration of 5-ASA, a therapeutically significant concentration of the drug is not expected in the terminal ileum which is a common site of involvement in Crohn's disease. The therapeutic implications of these findings are discussed herein.

Aminosalicylic Acids↗
PubMed1982

Glomerular immune complex formation and induction of lymphoma in athymic nude mice by tissue filtrates of Crohn's disease patients.

Lymph nodes and intestinal filtrates from Crohn's disease patients produced lymphoma in five and plasma cell hyperplasia in two of 63 athymic (nu/nu) mice. None of 27 mice injected with intestinal filtrates from ulcerative colitis patients but one of 13 mice injected with normal-appearing colon developed lymphoma. With an indirect immunofluorescence technique, sera from all nine patients with symptomatic Crohn's disease and one of 15 patients with asymptomatic Crohn's disease demonstrated cytoplasmic immunofluorescence in a lymphoma produced by Crohn's disease filtrates, but not in a control filtrate-induced lymphoma. None of 46 sera from ulcerative colitis patients or control subjects demonstrated immunofluorescence. In addition, immunofluorescent staining with symptomatic Crohn's disease sera recognized an antigen(s) within glomeruli that were also stained with anti-mouse IgG and IgM. Kidneys from the control mice did not show any staining. These studies suggest that an agent present in lymph nodes and intestine of patients with Crohn's disease can induce lymphoma and glomerular immune complexes in nu/nu mice.

Animals↗