Biomedical subjects

Nicole Maurin

Publications and source records attributed to Nicole Maurin.

4 recordsLinked to original sources

PubMed2007

Progression of tumors arising from large ACF is associated with the MUC5AC expression during rat colon MNNG carcinogenis.

Aberrant crypt foci (ACF) are microscopic lesions which have been postulated to precede the development of adenomas, precursors of colon cancer. The gastric M1/MUC5AC mucin has also been described as an early marker of colon carcinogenesis in the human and in the rat. To study changes in mucin expression associated with the genesis of tumors, Wistar rats were treated by intrarectal instillations of MNNG, twice a week for 2 weeks, and were sacrificed 10 (n = 20), 14 (n = 20), 22 (n = 20), 30 (n = 10) and 66 (n = 16) weeks after the beginning of the treatment. In the treated rats, the MUC5AC mucin was mainly expressed in ACF compared with the histologically normal mucosae, which showed few isolated MUC5AC-positive normal crypts. During carcinogenesis, the percentage of large ACF [> or =10 aberrant crypts] increased and the number of MUC5AC-positive (NCs) decreased. At Week 30, small tumors were observed arising from large ACF, both types of lesions expressing MUC5AC. At Week 66, large tumors showed remnants of MUC5AC-positive ACF in their adjacent mucosae. This observation suggests that the expression of MUC5AC is associated with the ACF/adenoma sequence and supports the notion of large ACF as precursors of adenomas/adenocarcinomas. Moreover, the expression of MUC5AC in the transitional mucosa adjacent to both rat and human colon tumors suggests that some human tumors could arise from large ACF, and reinforces the concept of the premalignant potential of these lesions.

Adenocarcinoma↗

PubMed2005

Cystathionine beta synthase deficiency affects mouse endochondral ossification.

Cystathionine beta synthase (CBS) is a crucial regulator of plasma concentrations of homocysteine. Severe hyperhomocysteinemia due to CBS deficiency confers diverse clinical manifestations, notably characteristic skeletal abnormalities. To investigate this aspect of hyperhomocysteinemia, we analyzed the skeleton of CBS-deficient mice, a murine model of severe hyperhomocysteinemia. Radiography, Alcian Blue/Alizarin Red S-stained whole skeletal preparations, and histological comparisons were used to determine the extent, pattern, and distribution of skeletal abnormalities in CBS-deficient mice. Disruption of the murine CBS gene leads to skeletal abnormalities, notably kyphoscoliosis, with temporal shortening of long bones due to impaired cartilage differentiation, albeit to differing degrees.

Animals↗

PubMed2004

Maternal phenylketonuria: the French survey.

UNLABELLED: We report the French experience regarding pregnancies in maternal phenylketonuria (PKU). In 2001, a questionnaire was sent to each referring PKU specialist in the 20 centres of each region of France, collecting reports on 135 pregnancies in 79 women born between 1958 and 1980. The majority of the 135 pregnancies occurred after 1990. A total of 42 women were informed of the risks of untreated pregnancy, while 26 were not informed (no data for 11). A strict diet was achieved in 83% of informed and in 16% of uninformed mothers prior to conception. Healthy offspring were observed in 43% of the 135 pregnancies, spontaneous abortions in 10.4%, elective abortions in 4.4%, therapeutic abortions in 12.6%, and embryopathies (EP) in 21.5%. In 8.1% of cases, the outcomes (in earliest pregnancies) are unknown. The proportion of healthy children increased over time and reached 80% of the pregnancies of informed females. There were seven heart defects, all in cases of EP, but although microcephaly and intrauterine growth retardation (IUGR) were almost constant in EP, we also found nine healthy children with IUGR. A continuum between EP and healthy children is suggested. The anthropometric data of the mothers showed that their body mass index (BMI) distribution was shifted to the left compared to women of the general population. This lower BMI and poor weight gain during pregnancy could contribute to the IUGR observed in normal babies whose mothers received a phenylalanine-restricted diet during pregnancy. CONCLUSION: the information and the preconception diet are effective for avoiding embryopathies in maternal phenylketonuria. Nutritional parameters can influence fetal growth and the nutritional state must be closely monitored throughout pregnancies of women with phenylketonuria.

Adolescent↗

PubMed2004

Hyperkeratosis in cystathionine beta synthase-deficient mice: an animal model of hyperhomocysteinemia.

Cystathionine beta synthase (CBS) is a crucial regulator of plasma concentrations of homocysteine. Severe hyperhomocysteinemia due to CBS deficiency confers diverse clinical manifestations. Patients with severe hyperhomocysteinemia have fine hair and thin skin, but it is unclear whether these changes are related to CBS deficiency or are coincidental. To investigate these aspects of hyperhomocysteinemia, we characterized skin abnormalities of CBS-deficient mice, a murine model of severe hyperhomocysteinemia. Histological and histomorphometric analyses revealed that CBS-deficient mice have wrinkled skin with hyperkeratinosis of the epidermis and thinning of the dermis.

Animals↗