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Biomedical subjects

M Kieffer

Publications and source records attributed to M Kieffer.

At least 19 recordsLinked to original sources
PubMed2001

Developmental programmes in floral organ formation.

In contrast to animals, organogenesis in plants is continuous, allowing development in response to intrinsic and extrinsic signals. Organs arise from primordia formed on the flanks of meristems. The apical meristem produces primordia that acquire leaf identity, while floral meristems form primordia which develop into four organ types: sepals, petals, stamens and carpels. The production of mature organs involves two distinct processes, the initiation of organ primordia and the establishment of meristem, primordia and cell identities. Here we concentrate on floral organogenesis in Arabidopsis and examine the extent to which these processes utilize similar control mechanisms and regulatory molecules.

Arabidopsis↗
PubMed2001

A cost effective protocol for in vitro mass propagation of cauliflower.

An improved and cost effective protocol for in vitro mass propagation of cauliflower from fractionated and graded curd is presented. The protocol is optimised for the production of clones of 2000 plants from one mother curd. Microshoots are produced en masse in 12 days, selected by flotation on a sucrose pad and transferred to rooting medium after suspension in a viscous medium. Fully rooted propagules are transferred to the glasshouse in 4-5 weeks and ready for transfer to the field 3-5 weeks later. The propagule unit cost was drastically reduced and is now close to that of a seed derived module grown plantlet. The strengths and limitations of this protocol are discussed. Clones produced highly homogeneous curds in the field with a short cutting period. Their overall quality depended essentially on the quality of the selected mother curd. The screening of populations to select elite genotypes combining high quality curd and good response in vitro is central to the use of this protocol on an industrial scale.

Journal Article↗
PubMed1992

Atopic dermatitis of the face, scalp, and neck: type I reaction to the yeast Pityrosporum ovale?

We have previously reported that a lipophilic yeast, Pityrosporum ovale (P. ovale) produced a high frequency of positive skin prick tests and in vitro histamine-release (HR) tests in patients suffering from atopic dermatitis (AD) of the face, scalp, and neck. In the present study, our aim was to confirm the involvement of P. ovale-specific IgE and to produce a standardized extract for diagnostic tests; 7/20 sera from patients with a positive HR test were positive in RAST. Several IgE-binding proteins could be detected with sodium dodecyl sulfate-polyacrylamide gel electrophoresis, followed by immunoblotting. Comparison of different extraction methods demonstrated that allergens were not released from P. ovale until after mechanical destruction of the yeast cells. Extraction of cultured P. ovale, obtained from the skin of various individuals suffering from AD of the face, scalp, and neck, resulted in very heterogenous patterns of constituents in sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting analysis. Nevertheless, all extracts were recognized by patients' IgE. P. ovale may express varying protein patterns, depending on either source or stage of differentiation. Thus, at present, skin and HR tests may be superior to other available assays for diagnosing type I reactions to P. ovale in AD of the face, neck, and scalp.

Cross Reactions↗
PubMed1990

Immune reactions to Pityrosporum ovale in adult patients with atopic and seborrheic dermatitis.

Pityrosporum ovale is a lipophilic yeast commonly present in the seborrheic areas of the skin of adults. Fifty-five young adult patients with atopic dermatitis, 19 patients with seborrheic dermatitis, and 19 healthy control subjects were examined for immune reactions to P. ovale, including tests for specific IgE antibodies (prick test, histamine release), IgG antibodies and epicutaneous testing. IgE antibodies against P. ovale were found in two thirds of the patients with atopic dermatitis and were more frequent in patients with lesions predominantly in the seborrheic areas. In addition, some atopic patients had positive reactions to epicutaneous tests, which suggest that delayed allergic reactions to P. ovale may also be important. In patients with seborrheic dermatitis, no evidence of immediate or delayed hypersensitivity to P. ovale was found. IgG antibody levels were low in all groups.

Adolescent↗
PubMed1989

Recent investigations on the relationship between fungal skin diseases and atopic dermatitis.

Atopic dermatitis may be associated with chronic dermatophyte infections and Pityrosporum related disorders. Recent epidemiologic studies in school children and young recruits have confirmed that atopic individuals have an increased susceptibility to Trichophyton rubrum infections of the feet and an increased risk for persistent infections. In contrast, an investigation on skin reactivity in dermatophyte infected atopic patients indicated that a group of these patients is fully able to eliminate the fungi concomitant with the development of a delayed type skin reactivity. Facial erythema and scaling, often including neck and shoulders, is present in many young adults with atopic dermatitis. Preliminary data from a Danish-Swedish investigation have shown that atopic dermatitis patients with head-neck-shoulder dermatitis compared to a group without this disorder and normal individuals more often demonstrate positive prick test, RAST and specific histamine release using extract of Pityrosporum ovale. These findings indicate that the presence of Pityrosporum ovale in the skin may cause an allergic reaction leading to dermatitis.

Arthrodermataceae↗
PubMed1988

Esophageal candidosis in progressive systemic sclerosis: occurrence, significance, and treatment with fluconazole.

Esophageal mucosal brushings from 51 consecutive patients with progressive systemic sclerosis (PSS) (group I), 18 PSS patients continuously treated with high-dose ranitidine or omeprazole (group II), 34 controls referred to the outpatient clinic for endoscopy (group III), and 10 patients receiving long-term potent antireflux therapy for idiopathic gastroesophageal reflux (group IV) were cultured for Candida albicans. There were 44%, 89%, 9%, and 0% Candida albicans culture-positive patients in groups I through IV, respectively. Fifteen patients with candida esophagitis from group II were treated with fluconazole systemically. Eleven and 14 patients became culture-negative after 2 and 4 weeks' treatment, respectively. Three months after fluconazole withdrawal the recurrence rate was 100%. It is concluded that esophageal dysmotility predisposes for candidosis. Adding gastric acid inhibitory treatment to dysmotility enhances the risk significantly (p less than 0.01). The efficiency of fluconazole treatment was close to 100%, but so was the recurrence rate within a short period.

Adult↗
PubMed1987

Pseudouridine excretion in patients with psoriasis.

The excretion of pseudouridine in the urine of 17 patients with psoriasis was significantly increased. The largest increase was found in patients with psoriatic arthritis. No correlation between the extent of psoriasis and pseudouridine excretion was found. The excretion of pseudouridine was followed in 10 of the 17 patients during treatment with anthralin or PUVA. Pseudouridine excretion decreased significantly during therapy. The possible application of pseudouridine excretion in monitoring the disease activity in psoriasis is discussed.

Adult↗
PubMed1984

Sequential studies of gliadin antibodies in patients with dermatitis herpetiformis.

Sequential studies of circulating gliadin antibodies (IgG, IgA, IgM, IgD) were performed in 24 patients with dermatitis herpetiformis (DH) by an ELISA. Three groups of patients were studied: (a) 14 patients who responded to a gluten-free diet and were able to stop their drug therapy, (b) 5 patients who did not respond to a gluten-free diet, (c) 5 patients with normal jejunal biopsies, who did not receive a gluten-free diet. Most of the serum gliadin antibodies detected were of IgG class, but in several patients IgA gliadin antibodies were found in addition. When the patients were on a normal diet, 63% had elevated IgG gliadin antibody titres (titres which exceeded the maximum titre of the controls by one dilution) and there were no significant differences between the three groups. When the patients were followed up, there was a significant fall in the gliadin antibody titres in those who responded to a gluten-free diet compared to the two other groups of patients. Thus assays of IgG gliadin antibodies might be helpful in some patients in judging the compliance of patients on a gluten-free diet.

Adolescent↗
PubMed1984

Bilateral diffuse malignant melanoma of the uvea associated with large cell carcinoma, giant cell type, of the lung. Case report of a newly described syndrome.

A new syndrome consisting of bilateral diffuse malignant uveal melanoma and simultaneous occurrence of another systemic malignant neoplasm was described in 6 patients in 1982. The present study reports a seventh case. Our patient was younger than the patients previously reported. He had large cell carcinoma of the right lung. The bilateral intraocular neoplasm was characterized as a diffuse malignant uveal melanoma of the mixed cell type by light microscopy and by transmission electron microscopy. All parts of the tumor contained S-100 protein. In addition to the two primary neoplasms, the patient had a combination of Ota's and Ito's naevi on the left side.

Carcinoma, Small Cell↗
PubMed1983

Increased gliadin antibodies in dermatitis herpetiformis and pemphigoid.

The mean titres of serum IgG and IgA gliadin antibodies were significantly increased in thirty-four patients with bullous pemphigoid, and in twenty-three patients with dermatitis herpetiformis, compared with twenty-four healthy controls. The patients with pemphigoid also had increased IgG and IgA gliadin antibodies compared with nine patients with pemphigus. The reason for the high titres of gliadin antibodies in pemphigoid is obscure. These patients may have increased intestinal permeability (suggested by the presence of beta-lactoglobulin antibodies in some patients). Alternatively gliadin may somehow precipitate the autoimmune process.

Aged↗
PubMed1983

Naturally developing antibodies to wheat gliadin fractions and to other cereal antigens in rabbits, rats and guinea pigs on normal laboratory diets.

Rabbits, rats and guinea pigs on normal laboratory diets were examined for gliadin and other cereal antibodies comparable to those found in the sera of human coeliac patients. Many of the rabbits had very high levels of gliadin antibodies. Rats showed much lower titres more comparable to the findings in normal human sera. In both these species the reactivity was directed principally against the alpha-gliadins. The spectrum of reactivity against the prolamines of other cereals was again comparable to that of human coeliac sera. A difference, however, was the high reactivity with maize prolamine; this was decidedly lower in sera of coeliac patients. Guinea pigs were distinctive in having relatively no serum antibodies to wheat gliadin and also minimal reactivity to the albumins, globulins and glutenins of wheat. Normal guinea pigs did, however, have antibodies to oat and maize prolamines. Following parenteral injection with total ethanol-soluble wheat gliadin, guinea pigs developed high-titred antibodies, not only to wheat gliadin fractions 1-8 (alpha-, beta-, gamma- and omega-gliadins), but also to all the cereal prolamines except those of rice. These investigations are steps in the evaluation of the role of circulating gliadin antibodies in gluten-sensitive enteropathy.

Animals↗
PubMed1982

Influence of autologous monocytes on the pokeweed mitogen-induced generation of immunoglobulin-secreting cells in man.

The regulatory influence of autologous blood monocytes on the PWM-induced generation of Ig-secreting cells was assessed using a reverse haemolytic plaque forming cell (PFC) assay. The PWM-induced PFC responses of monocyte-depleted cells were low or absent in most cases. Addition of 12-42% freshly isolated monocytes fully reconstituted the IgM-, IgG- and IgA-PFC responses. With more monocytes added, the PFC responses declined. Monocytes precultured for 48 h supported the PFC responses of monocyte-depleted cells less well and addition of monocytes stimulated with phorbol myristate acetate (PMA) did not increase the response. The low responses of monocyte-depleted cells co-cultured with precultured monocytes were not increased by addition of supernatant from monocyte cultures. The PFC responses of mononuclear cells induced by PWM were significantly inhibited by unstimulated precultured monocytes, and to a larger degree by PMA-treated monocytes, indicating the presence of suppressor cells among the precultured monocytes. The PWM-induced thymidine incorporation by monocyte-depleted cells with precultured monocytes added was only slightly lower than that obtained with freshly isolated monocytes added, suggesting that the suppressive role of precultured monocytes was not due to cytotoxicity.

Antibody-Producing Cells↗
PubMed1982

Wheat gliadin fractions and other cereal antigens reactive with antibodies in the sera of coeliac patients.

The mixed reverse solid phase passive antiglobulin haemadsorption test (MRSPAH) and the enzyme linked immunosorbant assay (ELISA) were found equally sensitive and fitted for the measurement of serum IgG antibodies against alcohol soluble gliadins. Using the ELISA method, three coeliac sera with elevated antibody titres against gliadins and two control sera with low titres were tested for IgG antibodies against the main groups of wheat proteins (acetic acid soluble glutenins, salt soluble albumins and globulins and alcohol soluble gliadins), eight fractions of gliadin and the alcohol soluble proteins of barley, rye, oat, maize and rice. As rice contained little alcohol soluble protein, a test against acid soluble rice proteins was included. In all three patient sera, titres higher than or equal to that for crude gliadin were found for wheat glutenin and for gliadin fractions seven and eight, both containing alpha gliadins. Similar high titres were found when these coeliac sera were tested against rye, barley and oat prolamines. Maize prolamines gave only low titres and no antibodies could be detected against rice proteins, in line with the tolerance of these latter two cereals by patients with coeliac disease. It would appear that sera from coeliac patients react with more than one antigenic fraction of protein in wheat and other cereals. Also sera from two normal persons appeared to have the same spectrum of reactivity against these cereal proteins as did the three sera from coeliac patients. The titres in normal sera were however much lower.

Antigens↗