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Biomedical subjects

A M Roucayrol

Publications and source records attributed to A M Roucayrol.

At least 19 recordsLinked to original sources
PubMed2001

Goats' milk of defective alpha(s1)-casein genotype decreases intestinal and systemic sensitization to beta-lactoglobulin in guinea pigs.

Contradictory results have been reported on the use of goats' milk in cows' milk allergy. In this study the hypothesis was tested, using a guinea pig model of cows' milk allergy, that these discrepancies could be due to the high genetic polymorphism of goats' milk proteins. Forty guinea pigs were fed over a 20 d period with pelleted diets containing one of the following: soyabean proteins (group S), cows' milk proteins (group CM), goats' milk proteins with high (group GM1) or low (group GM2) alpha(s1)-casein content. Parenteral sensitization to GM1 and GM2 proteins as also assessed. The sensitization was measured (1) by systemic IgG1 antibodies directed against bovine or caprine beta-lactoglobulin (beta-lg), alpha-lactalbumin (alpha-la) and whole caseins, and (2) by intestinal anaphylaxis measured in vitro in Ussing chambers, by the rise in short-circuit current (delta Isc) in response to milk proteins. Guinea pigs fed on CM and GM1 developed high titres (> 1500) of anti-beta-lg IgG1, with an important cross reactivity between goat and cow beta-lg. However, in guinea pigs fed on GM2, anti-goat beta-lg IgG1 antibodies were significantly decreased compared with GM1 guinea pigs (mean IgG1 titres were 546 and 2046 respectively), and the intestinal anaphylaxis was significantly decreased (3.5+/-4.5 microA/cm2) compared with that observed in GM1 guinea pigs (8.3+/-7.6 microA/cm2). Animals receiving GM1 or GM2 proteins via the parenteral route developed a marked sensitization. These results suggest that the discrepancies observed in the use of goats milk in cows' milk allergy could be due, at least in part, to the high genetic polymorphism of goats' milk proteins.

Anaphylaxis↗
PubMed2000

Histomorphological characteristics of gastric mucosa in patients with Zollinger-Ellison syndrome or autoimmune gastric atrophy: role of gastrin and atrophying gastritis.

The role of gastrin in the pathophysiology of two diseases affecting the human stomach, the Zollinger Ellison syndrome (ZES) and the pernicious anemia (PA), is reviewed. Both diseases present chronic hypergastrinemia but from different origins. The ZES is characterized by the occurrence of ectopic endocrine gastrin-secreting tumors and PA by a fundic atrophic gastritis leading to complete atrophy of fundus and resulting in achlorhydria. In PA, the lack of acid induces continuous gastrin cell activation and is responsible for the subsequent gastrin hypersynthesis and secretion. In ZES, hypergastrinemia causes hypertrophy of the oxyntic mucosa, which, in addition, displays hyperplasia of parietal and mucus cells. In both diseases, hypergastrinemia also induces the hyperproliferation of enterochromaffin-like endocrine cells in the fundic mucosa, which can offer all aspects from hyperplasia, then dysplasia, until true carcinoid tumor. The influence of antisecretory treatments and MEN 1 in the ZES as well as that of several other factors and antrectomy in PA on the behavior of the different gastric cells is evoked. Finally, the role that gastrin and its receptor play in the maintenance of the normal development of gastric mucosa and gastric acid secretion is emphasized by results observed in gene knockout models.

Anemia, Pernicious↗
PubMed1998

Sensitization to cow's milk proteins during refeeding of guinea pigs recovering from polydeficient malnutrition.

We have previously shown that milk sensitization aggravates intestinal dysfunction in the malnourished guinea pigs, suggesting that it may also impair the recovery from malnutrition. To test this hypothesis, the growing guinea pigs were malnourished by feeding only maize for 7 d and then were refed for 21 d with a balanced diet containing either intact or hydrolyzed cow's milk proteins. The control animals received the hydrolyzed milk protein diet for 28 d. After an initial period of total inhibition of growth owing to maize, guinea pigs gained weight regularly, with both balanced diets, and there was no evidence of mucosal damage at the end of the refeeding period. However, refeeding with intact milk proteins induced milk sensitization, which was demonstrated on the systemic level by the presence of anti-beta-lactoglobulin IgG1 antibodies, and on the local level by the intestinal anaphylaxis measured by the increase in short circuit current induced by beta-lactoglobulin (16.4 +/- 2.6 microA/cm2) in jejunal segments mounted in Ussing chambers. Such an immune sensitization was associated with impaired intestinal permeability, as both the ionic conductance (21.0 +/- 1.6 versus 14.6 +/- 0.7 mS/cm2) and the transepithelial fluxes of horseradish peroxidase (537 +/- 203 versus 152 +/- 28 ng/h x cm2) were significantly increased in guinea pigs refed with the intact milk proteins compared with controls. In contrast, there was no difference in intestinal permeability between controls and guinea pigs refed with the hydrolyzed milk protein diet. These data show that sensitization to cow's milk proteins can develop in guinea pigs recovering from severe malnutrition and may impair full intestinal repair.

Anaphylaxis↗
PubMed1998

[Epithelioma cuniculatum. Apropos of a case in the anterior gingiva with involvement of the mandibular symphyseal bone and reconstruction using a fibular osteocutaneous flap and integrated implants].

We present a case report of an anterior gingival epithelioma cuniculatum in place of teeth 41 and 42, with osseous mandibular extension for which a one time reconstruction with an osteocutaneous free fibula flap was performed with three dental osseointegrated implants. We reviewed the literature on this type of carcinoma and discuss the diagnosis difficulty. Radical surgical treatment is required.

Bone Transplantation↗
PubMed1996

[Venous hemangioma of the temporal muscle. Review of the literature: apropos of a case].

A 41-year-old woman progressively developed a painful tumefaction in the left temporal fossa. The scan showed a isodense intramuscular structure weakly enhanced by contrast medium. Surgical exeresis was performed via the coronal access. Histology of the surgical specimen reported the diagnosis of venous muscular haemangioma. The diagnosis and management of these rare tumours is discussed.

Adult↗
PubMed1995

Helicobacter pylori infection: physiopathologic implication of N alpha-methyl histamine.

BACKGROUND/AIMS: In the gastric mucosa of Helicobacter pylori-infected subjects, we previously detected N alpha-methyl histamine (N alpha-MeHA), a minor catabolite of histamine and a potent agonist of histamine H3 receptors. The origin of N alpha-MeHA and its effects on gastric histamine and somatostatin in infected subjects were investigated. METHODS: Ten noninfected patients and 13 patients with intense colonization were compared. N alpha-MeHA content and its synthetic enzyme activity, N alpha-histamine methyltransferase, binding of [3H]N alpha-MeHA, histamine and somatostatin contents, and histidine decarboxylase activity were assayed in antral and fundic biopsy specimens and in cultured H. pylori strains. RESULTS: Gastric histamine and somatostatin contents as well as histidine decarboxylase activity were decreased in infected patients and were restored to normal after antimicrobial treatment. Both N alpha-MeHA and N alpha-histamine methyltransferase activity were present in the mucosa of infected patients and in cultured strains and were very low in noninfected patients or after eradication of H. pylori. [3H]N alpha-MeHA bound to gastric mucosa but not to cultured strains. The [3H]N alpha-MeHA specific binding sites were characterized as H3 receptors. The amount of bound [3H]N alpha-MeHA seemed correlated positively with somatostatin content and histidine decarboxylase activity and negatively with N alpha-MeHA content and N alpha-histamine methyltransferase activity. CONCLUSIONS: H. pylori is the main source of gastric N alpha-MeHA that may lower histidine decarboxylase activity and somatostatin content through H3 receptors.

Gastric Mucosa↗
PubMed1992

Seven years of recurrent severe strongyloidiasis in an HTLV-I-infected man who developed adult T-cell leukaemia.

OBJECTIVE: Human T-cell leukaemia/lymphoma virus type I (HTLV-I) is endemic in Japan, the Caribbean basin and Africa, where it has been aetiologically linked to certain chronic myelopathies and adult T-cell leukamia (ATL). We sought to investigate whether strongyloidiasis, a parasitic disease common in these areas, might be a cofactor in the pathogenesis of ATL, as some reports have suggested. PATIENTS, PARTICIPANTS: One 35-year-old HTLV-I-seropositive French West Indian man with a 7-year history of recurrent strongyloidiasis associated with episodic hyperinfestation presenting at the Centre Hospitalier Intercommunal, Villeneuve St Georges, France. INTERVENTIONS: Treatment with various chemotherapeutic agents and symptomatic therapy for hypercalcaemia and antiviral therapy (zidovudine and interferon). RESULTS: The patient developed ATL and died shortly after, despite chemotherapy. Immunological and virological studies performed during the last 15 months of his life showed an increase of the percentage of peripheral ATL cells, and progression from a polyclonal to a monoclonal integration of HTLV-I proviral DNA in the peripheral blood mononuclear and lymph-node cells. CONCLUSIONS: Recurrent strongyloidiasis appears to have been a possible cofactor associated with progression from healthy carrier state to ATL in our patient.

Adult↗
PubMed1992

Argyrophil cells, mast cells, and histamine in the fundic mucosa of antrectomized patients.

Fasting gastrinemia, fundic argyrophil cell density, mast cell number, basal fundic histamine content and histidine decarboxylase activity were determined in 20 antrectomized patients and 20 control subjects. Fasting gastrinemia and fundic argyrophil cell density were significantly lower in antrectomized patients than in controls, whereas fundic mast cell number, basal histamine content, and histidine decarboxylase activity did not differ significantly between the two groups. In antrectomized patients the basal fundic histamine content appears related to the fundic mast cell number, as a consequence of the reduced effect of gastrin on argyrophil cells.

Aged↗
PubMed1992

[Muscular insertions on the temporo-mandibular disk. Physiologic implications].

The aim of this work was to identify the elements of an anatomical consensus about the description of the direct and indirect muscular insertions on the temporomandibular meniscus. A classical dissection was performed on two joints and completed with a histological study. Fourteen joints were studied, after deep-freezing of fresh whole heads, with 3-millimeter thick macroscopic sections in the coronal, sagittal and axial planes and in a plane perpendicular to the axis of the condyle. The study of the specimens with a binocular magnifying glass was completed by oriented histological sections after fixation in 10% formaldehyde. The comparison of our findings with the studies published in the literature shows that the ideas are evolving towards an anatomical consensus about the reality of the direct and indirect insertion of the sole mandibular elevator muscles on the temporomandibular articular disk. The classical description of the dynamics of the meniscus must therefore be changed.

Humans↗
PubMed1991

First heterotransplantation of a human carcinoid tumor into nude mice.

The first successful heterotransplantation of a human carcinoid tumor into nude mice is reported. CSH, a voluminous hepatic metastasis of a primary bronchial carcinoid tumor (CSB) was resected and transplanted into three irradiated nude (Swiss-nu/nu) mice both by subcutaneous (SC) and intramuscular (IM) routes; the success rate was five of six. Heterotransplanted tumors took 4 to 5 months to appear in the mice and 1 month to attain a width of 0.5 cm. Both human and mouse tumors (named CSH-SC and CSH-IM) were studied by light and electron microscopy. They were Grimelius-positive, neuron-specific enolase-positive, and bombesin-negative by immunocytochemistry. Furthermore, CSH-SC cells presented characteristic (pear-shaped, rod-shaped, or tadpole-shaped) neurosecretory granules. Although CSB and CSH were slightly serotonin positive by immunocytochemistry, only a few serotonin-positive cells were found in CSH-SC and none in CSH-IM, suggesting partial loss of differentiation or an increase in serotonin catabolism during transplantation.

Aged↗
PubMed1990

Evolution of fundic argyrophil cell hyperplasia in nonantral atrophic gastritis.

Fundic argyrophil cells were studied for a mean period of 68.7 months (range, 11-170) in 18 patients with fundic atrophic gastritis and achlorhydria. Initially, 12 patients had hyperplasia of the argyrophil cells, the severity of which was assessed using a semiquantitative classification based on the number of argyrophil clusters per square millimeter. At the end of the study, the degree of hyperplasia was unchanged in 9 patients, had decreased in 2, and had increased in 1; no significant increase in the number of argyrophil clusters, precarcinoid changes, or carcinoid tumors were observed and the high level of gastrinemia [mean, 4.8 (range, 1.9-8.1) times the upper limit for normal) did not change significantly. Of the 6 patients with no hyperplasia at the outset of the study, 4 continued without hyperplasia and 2 presented a low-grade hyperplasia at the 20th and 130th month. Gastrinemia increased significantly in the last patient and stayed normal in the other 5. This study argues in favor of the stable appearance of fundic argyrophil cells in patients with atrophic gastritis and stable gastrinemia.

Achlorhydria↗