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Biomedical subjects

K Kett

Publications and source records attributed to K Kett.

At least 37 records · Page 2Linked to original sources
PubMed1989

Raised number of jejunal IgG2-producing cells in untreated adult coeliac disease compared with food allergy.

The subclass distribution of IgG-producing immunocytes was studied by two colour immunohistochemistry with monoclonal antibodies in jejunal biopsy specimens from 10 adults with untreated coeliac disease, 11 coeliac disease patients on a gluten free diet, and seven patients with established food allergy. Paired immunofluorescence staining was performed with subclass specific murine monoclonal antibodies in combination with polyclonal rabbit antibody reagent to total IgG; the proportion of cells belonging to each subclass could thereby be determined. The ratio of IgG2 immunocytes was significantly higher (p less than 0.05) in untreated coeliac disease patients (median, 35.2%; range, 26.7-65.2%) than in those on a gluten free diet (median, 7.3%; range, 0-31.9%) or those having food allergy (median, 12.5%; range, 0-36.5%). The disparity in the local IgG2 response between patients with untreated coeliac disease and those with food allergy might be due to differences in the nature of the antigenic stimuli, dissimilar genetic 'make-up' of the subjects, or both.

Adolescent↗
PubMed1988

J-chain expression is more prominent in immunoglobulin A2 than in immunoglobulin A1 colonic immunocytes and is decreased in both subclasses associated with inflammatory bowel disease.

Paired immunofluorescence staining demonstrated reduced J-chain positivity of both immunoglobulin A1 (IgA1)- and IgA2-producing cells in colonic mucosa from patients with ulcerative colitis and Crohn's colitis compared with controls (p less than 0.002). J-chain expression was generally higher in IgA2 than in IgA1 immunocytes. The median proportion in normal mucosa was 100% for IgA2 vs. 88% for IgA1 (p less than 0.005); in ulcerative colitis, 69% vs. 46% (p less than 0.004); and in Crohn's colitis, 74% vs. 46% (p less than 0.004). Taken together with the overall IgA-subclass distribution, however, these results showed that the proportion of J-chain-positive IgA2 cells in the total IgA-cell population was lower for ulcerative colitis (20%) and Crohn's colitis (32%) than for normal mucosa (63%) (p less than 0.002). In relation to the total J-chain-positive IgA-cell population, which contributes to the secretory IgA system, an increased proportion (p less than 0.002) belonged to IgA1 in ulcerative colitis (61% vs. normal, 27%), whereas IgA2 was reduced (39% vs. normal, 73%). Similar but smaller trends were noted in Crohn's colitis. The disease-associated reduction of J chain might be compensated by the previously reported twofold numeric increase of IgA cells in colitis. Our study, therefore, did not suggest that the secretory IgA-cell system was quantitatively impaired in inflammatory bowel disease.

Adolescent↗
PubMed1987

Mucosal subclass distribution of immunoglobulin G-producing cells is different in ulcerative colitis and Crohn's disease of the colon.

As a marked local immunoglobulin G (IgG) response has previously been found to be the most prominent immunopathological feature of both ulcerative colitis and Crohn's disease, the subclass distribution of colonic IgG-producing immunocytes was examined. This study included tissue specimens from 10 patients with ulcerative colitis and 8 with Crohn's colitis. Paired immunofluorescence staining was performed with subclass-specific murine monoclonal antibodies combined with a rabbit antibody reagent of IgG; the proportion of cells belonging to each subclass could thereby be determined in relation to the total number of mucosal IgG immunocytes. A significantly higher median proportion of IgG1 immunocytes was found in ulcerative colitis (81.3%) than in Crohn's colitis (66.5%). Conversely, the median proportion of IgG2 immunocytes was significantly higher in Crohn's colitis (24.9%) than in ulcerative colitis (9.4%). This disparity in the local IgG subclass response might reflect dissimilar mucosal exposure to mitogenetic or antigenic stimuli or genetically determined immunoregulatory differences in the two categories of patients.

Adult↗
PubMed1987

Local IgA subclass alterations in ulcerative colitis and Crohn's disease of the colon.

The subclass distribution of IgA producing cells was determined by paired immunofluorescence staining in colonic specimens from 10 patients with ulcerative colitis and eight with Crohn's disease. Compared with normal colonic mucosa, the percentage of IgA1 immunocytes showed a striking increase in both disorders. The proportion of mucosal IgA1 cells was significantly higher (p less than 0.05) in ulcerative colitis (median, 71.2%) than in Crohn colitis (median, 56.9%). Within each category of specimens no significant differences were noted between luminal and basal mucosal zones. The submucosal proportion of IgA1 cells was, however, significantly higher than the mucosal one in both ulcerative colitis (median, 89.1%; p less than 0.002) and Crohn colitis (median, 91.8%; p less than 0.005). The mucosal shift towards IgA1 production paralleled the magnitude of the submucosal IgA1 cell proportion in individual tissue samples. Taken together with the previously reported dramatic increase of local IgG production (particularly observed in the submucosa and basal parts of the mucosa), our findings indicated that there is an influx and/or proliferation of B cells representing systemic secondary immunity in the lesions of both diseases.

Adult↗
PubMed1987

Production and secretion of immunoglobulins in the gastrointestinal tract.

Two decades ago it was shown that the major immunoglobulin (Ig) present in human secretions is a dimeric IgA covalently bound to an epithelial glycoprotein of about 80 kD, now called the secretory component (SC). Pentameric IgM is likewise actively enriched in most exocrine fluids and is associated with SC, although not in a covalently stabilized complex. Three findings explain the selective translocation of polymeric Ig (pIg) into exocrine fluids: (1) preferential local production; (2) J-chain-expressing capacity of pIg-producing immunocytes; and (3) SC-mediated epithelial transport. Human hepatocytes lack SC and the human liver, therefore, cannot act as an efficient "IgA pump". This is in contrast to the rat liver which shows a remarkable capacity for transport of dimeric IgA from blood into the bile. The J chain of pIg and the epithelial SC represent the "lock and key" in the glandular transport of secretory IgA (SIgA) and SIgM. It has recently been shown that SC is synthesized as a transmembrane protein of about 95 kD and constitutes the actual pIg surface receptor. Complexing between ligand and receptor in the plasma membrane is followed by endocytosis. The completed SIgA and SIgM molecules are then translocated in cytoplasmic vesicles through the epithelial cell to the gland lumen along with an excess of free SC. The main function of SIgA is to exert immune exclusion; that is, by intimate cooperation with innate nonspecific defense factors it decreases penetration of soluble antigens and inhibits epithelial colonization of bacteria and viruses. Especially in selective IgA deficiency, SIgM may exert a similar protective function since its synthesis is markedly increased in the intestinal mucosa. Leakage of IgG into exocrine fluids is enhanced by mucosal irritation. Although IgG should not be considered as a SIg, it may contribute to immune exclusion. This is seen especially in the respiratory tract where IgG is less easily subjected to proteolytic degradation than in the intestinal juice. In contrast, by activating complement, IgG antibodies may at the same time be phlogistic and accelerate mucosal penetration of antigens. IgG may thus contribute to persistent immunopathology in mucosal disease. The same is true for IgE antibodies which may be carried into mucous membranes and secretions by mast cells and cause their degranulation with local histamine release. Traces of IgD may likewise be found in the secretions but without obvious biologic significance. Regulation of secretory immunity takes place both in organized lymphoepithelial structures, such as the Peyer's patches, and adjacent to the glands in the lamina propria.(ABSTRACT TRUNCATED AT 400 WORDS)

Celiac Disease↗
PubMed1986

Different subclass distribution of IgA-producing cells in human lymphoid organs and various secretory tissues.

A highly reproducible paired immunofluorescence staining method was used to map the relative distribution of IgA1- and IgA2-producing cells in peripheral lymphoid organs and various secretory tissues. Spleen, peripheral lymph nodes, and tonsils all contained a marked predominance (91 to 95%) of IgA1 immunocytes. However, striking variations were demonstrated among the secretory tissues with regard to the median proportion of IgA1-producing cells: nasal mucosa, 96%; lacrimal glands, 81%; major salivary glands, 66%; mammary glands, 63%; gastric and proximal small intestinal mucosa, 84 to 77%; ileum, 55%; and large bowel, 41%. Thus, IgA2 production is relatively enhanced mainly in the distal gut and in mammary and salivary glands, in that order.

Animals↗
PubMed1984

[Elephantiasis of the genitalia and its treatment].

Under analysis were results of the surgical treatment of 24 patients with lymphostasis of genitalia (27 operations). The method of choice for the 1st stage of edema (lymphedema) is considered to be lympho-venous shunting. In cases with fibredema (elephantiasis) the authors prefered radical excisions of edematous tissues of genitalia.

Adolescent↗
PubMed1983

Intoxication with sodium valproate. A case report.

Sodium valproate is a relatively new compound in the treatment of epilepsy. A female patient was admitted to the hospital after voluntary intake of 30 g sodium valproate. Her serum concentration was 4925 mumol/l, but the course of the intoxication was mild and the patient was soporous for only 12 hours after intake of the compound. Biochemical data may suggest a slight transitory liver affection.

Adolescent↗
PubMed1982

Passage through the lymph node. II. Functional dependence on the site of application of antigens.

Following a previous comment on the compartmentalization of lymph nodes by lymphography performed through separate bundles of afferent lymphatics, the authors attempted to prove that sectoral arrangement has its functional equivalent, too. They found an elective uptake of tritiated thymidine and a rather circumscript response in cellular activity, if antigenic stimuli--such as VX-2 carcinoma cells and living BCG colonies--were transferred through the same bundle of afferent lymphatics which supply the lymph node part investigated.

Animals↗
PubMed1982

Weight loss after jejuno-ileal bypass surgery.

The changes in body weight after jejuno-ileal bypass surgery in 23 cases of massive obesity are reported. After an initial rapid weight reduction, body weight fell at a constant rate over six months. The weight reduction curves correspond to a zero order kinetics. After the first six months the rate of weight loss declined, but the weight continued to fall. By 12 to 24 months after the operation stabilization of body weight at an average level corresponding to 38% of the preoperative weight was attained.

Body Weight↗