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Biomedical subjects

D Hénin

Publications and source records attributed to D Hénin.

At least 19 recordsLinked to original sources
PubMed2001

H ferritin knockout mice: a model of hyperferritinemia in the absence of iron overload.

Ferritin, the iron-storing molecule, is made by the assembly of various proportions of 2 different H and L subunits into a 24-mer protein shell. These heteropolymers have distinct physicochemical properties, owing to the ferroxidase activity of the H subunit, which is necessary for iron uptake by the ferritin molecule, and the ability of the L subunit to facilitate iron core formation inside the protein shell. It has previously been shown that H ferritin is indispensable for normal development, since inactivation of the H ferritin gene by homologous recombination in mice is lethal at an early stage during embryonic development. Here the phenotypic analysis of the mice heterozygous for the H ferritin gene (Fth(+/-) mice) is reported, and differences in gene regulation between the 2 subunits are shown. The heterozygous Fth(+/-) mice were healthy and fertile and did not present any apparent abnormalities. Although they had iron-overloaded spleens at the adult stage, this is identical to what is observed in normal Fth(+/+) mice. However, these heterozygous mice had slightly elevated tissue L ferritin content and 7- to 10-fold more L ferritin in the serum than normal mice, but their serum iron remained unchanged. H ferritin synthesis from the remaining allele was not up-regulated. This probably results from subtle changes in the intracellular labile iron pool, which would stimulate L ferritin but not H ferritin synthesis. These results raise the possibility that reduced H ferritin expression might be responsible for unexplained human cases of hyperferritinemia in the absence of iron overload where the hereditary hyperferritinemia-cataract syndrome has been excluded. (Blood. 2001;98:525-532)

Alleles↗
PubMed2001

Hypertrophic neuropathy of the facial nerve.

Hypertrophic neuropathy is a peripheral nerve lesion that is histologically characterized by onion bulb formations around axons. This histologic picture, which is usually seen in generalized hypertrophic neuropathies, can occasionally be observed in single nerves as localized hypertrophic neuropathy. Cranial involvement of such localized hypertrophic neuropathy represents a very rare entity; only a few cases have been reported in the literature. We report the history of a progressive facial paralysis with a tumorous enlargement of the seventh cranial nerve that was clinically suspected of being a schwannoma. Pathological examination permitted the diagnosis of hypertrophic neuropathy.

Adult↗
PubMed2001

[Familial orthochromatic leukodystrophy: clinicopathological study of two cases].

This paper reports the clinico-pathological data in a French family with orthochromatic leukodystrophy. The parents were first cousins and had seven children. Among those, two sisters and one brother presented with neurological signs, with onset around the 5(th) decade, including a dementing syndrome of frontal type, a tetrapyramidal syndrome, seizures, and, in one sibling, a cerebellar syndrome. CT scan or MRI showed diffuse involvement of the white matter. The neurological signs worsened progressively leading to death within 11 and 22 months. Neuropathological examination was performed in two cases. It revealed characteristic orthochromatic leukodystrophy. In one case, the presence of pigmented macrophages and astrocytes was suggestive of Van Bogaert and Nyssen disease. However there were some atypical features including the absence of pigmented cells in the second case whose clinical course was shorter, and the cavitary appearance of the white matter changes with a relative increase in the number of oligodendrocytes raising the issue of a possible link between this condition and cavitary orthochromatic leukodystrophies.

Aged↗
PubMed2001

[Atypical CADASIL phenotypes and pathological findings in two new French families].

Atypical phenotypes of CADASIL and corresponding anatomical data in two cases are described in 6 members of 2 new French families. In the first family, 4 cases in the same kindred were probably affected, two of them with a predominant psychiatric presentation, two others with dementia and a pseudo-bulbar syndrome of progressive evolution. No history of migraine or ischemic event were documented in any. In the propositus, the diagnosis was documented by skin biopsy, Notch 3 gene mutation and autopsy after the patient had died when 67 years old, 8 years after onset. Brain examination showed a widespread leukoencephalopathy with subcortical infarcts. Characteristic granular lesions of the small arteries of the brain and other organs were observed. In the second family, two cases are reported. One patient died when 63 years old after a subacute evolution mimicking intracranial hypertension. The anatomical diagnosis was retrospectively proven typical of CADASIL with Notch 3 immunostaining of arterial smooth muscle cells. The other case had a progressive evolution over 20 years of limb paresthesia with a mild spasticity diagnosed as a progressive form of multiple sclerosis. It was followed by a pseudo-bulbar syndrome and a mild subcortical dementia without acute ischemic attack. The diagnosis was confirmed by skin biopsy and mutation of the Notch 3 gene. This report illustrates

Aged↗
PubMed2000

Angiogenesis in the neoplastic sequence of Barrett's oesophagus. Correlation with VEGF expression.

The purpose of this study was to determine the angiogenic profile of human oesophageal adenocarcinoma. This study was carried out on a large series of surgically resected Barrett's adenocarcinomas and associated preneoplastic lesions. Vascularization was quantified by microvessel counting and measurement of the percentage microvessel surface area after immunohistochemistry using the CD34 antibody. The expression of vascular endothelial cell growth factor (VEGF) was also examined by immunohistochemistry. Results were correlated with clinico-pathological data and prognosis. Vascularization, assessed by both microvessel counting and measurement of the microvessel surface, was statistically higher in superficial cancers than in others. Higher vascularization was correlated with a lower rate of lymph node and distant metastasis, as well as with better survival. However, when superficial carcinomas were excluded from the study, microvessel count failed to provide any significant prognostic information. Irrespective of the inclusion or exclusion of superficial tumours, the expression of VEGF was correlated with a higher vascularisation but did not provide prognostic significance. It is concluded that high angiogenic properties are acquired in precancerous lesions and early cancers in Barrett's oesophagus. Vascularization as assessed by both microvessel counting and measurement of the microvessel surface is not informative for prognosis in infiltrative Barrett's adenocarcinomas. The expression of VEGF is correlated with vascularization, but has no independent prognostic relevance.

Adenocarcinoma↗
PubMed2000

E-Cadherin and CD44 expression in cervical intraepithelial neoplasia: comparison between HIV-positive and HIV-negative women and correlation with HPV status.

AIMS: We aimed to compare the expression patterns of E-cadherin and CD44 isoforms in cervical intraepithelial neoplasia (CIN) between patients with or without infection by the human immunodeficiency virus (HIV). METHODS: An immunohistochemical analysis using the monoclonal antibody HECD-1 against E-cadherin and the monoclonal antibodies 2C5, binding to CD44s and all the variants encoded by exons 3 to 10, 3G5, specific for CD44v3 and 2F10, and specific for CD44v6, was performed in formalin-fixed, paraffin-embedded samples of 138 CIN (74 from HIV-negative and 64 from HIV-positive patients). RESULTS: In HIV-negative patients, the mean percentages (+/-SD) of E-cadherin-positive cells in CIN of grades I, II, and III were, respectively, 33% +/- 4, 63% +/- 5, and 91% +/- 9. The difference was statistically significant between the three groups of tumors (P < 0.0001). In HIV-negative patients, the mean percentages (+/-SD) of CD44-positive cells in CIN of grades I, II, and III were, respectively, 37% +/- 7, 57% +/- 8, and 90% +/- 11. The difference was statistically significant between the three groups of tumors (P < 0.0001). No difference in E-cadherin and CD44 expressions was noted between HIV+ and HIV- women. Further analysis showed no relation between E-cadherin or CD44 expression and the HPV status and CD4 T cell serum levels. CONCLUSION: Our study confirms that alterations in E-cadherin and CD44 expression in CIN depend on the histological grade but suggest nondirect involvement and are not related to HIV and immune status.

Adult↗
PubMed2000

Absence of microsatellite instability in transitional cell carcinoma of the bladder.

OBJECTIVES: To investigate the prevalence of the microsatellite instability related to mismatch repair (MMR) gene defects using a panel of six microsatellite markers, as recommended by a recent workshop on microsatellite instability in colon cancer, because it is still unclear whether abnormalities in DNA MMR genes are involved in transitional cell carcinoma (TCC) of the bladder. METHODS: Three mononucleotide repeats (BAT26, TGFbetaRII, and BAX) were studied in 33 TCC samples and in four bladder cancer cell lines. Three dinucleotide repeats (D2S123, D5S346, and D17S250) were studied in 21 of these 33 TCC samples. RESULTS: No alteration was detected either in the 33 TCC samples analyzed or in the four bladder cancer cell lines (T24, J82, 647V, and 1207) studied. A difference between normal and tumor DNA was observed in only 1 of 21 tumor samples for D17S250. CONCLUSIONS: These data indicate that microsatellite instability is very uncommon in TCC of the bladder.

Aged↗
PubMed2000

[Genotyping of Toxoplasma gondii strains from immunocompromised patients].

The genotypes of Toxoplasma gondii strains isolated from HIV and non-HIV immunocompromised patients with cerebral and extracerebral toxoplasmosis were determined and compared to those of strains isolated from non-immunocompromised patients in order to identify the possible relationships between parasite genotype and morbidity of toxoplasmosis. One hundred and ten strains of T. gondii were obtained, either by cell culture (n = 73), brain biopsy (n = 17) or mouse inoculation (n = 20). Ninety strains isolated from immunocompromised patients (74 HIV+ and 16 non-HIV patients) were compared to 20 strains isolated from immunocompetent patients (17 cases of congenital toxoplasmosis, and three cases of primary acquired infection). Genotyping was performed by PCR/RFLP on locus SAG2, and T. gondii strains were classified as Type I, II or III. Ninety out of 110 strains were successfully genotyped, including 20 strains that had been maintained in mice, 69/73 strains maintained in cell cultures, but only 1/17 strains from formalin-fixed paraffin-embedded brain biopsies. 76.7% of the strains in the study population were of type II, 15.6% were type I and 7.7% were type III. The distribution of strain genotypes in immunocompromised and non-immunocompromised patients was comparable: 14.1% and 21% for type I, 76.1% and 79% for type II and 9.8% and 0% for type III, respectively; no correlation could be established between genotype and clinical presentation, i.e., cerebral or extracerebral toxoplasmosis. These results suggest that the type of infecting parasitic strain does not predominantly influence the pathogenesis of toxoplasmosis in immunocompromised patients and fully supports the need for specific prophylaxis in patients infected by T. gondii, regardless of the strain genotype.

AIDS-Related Opportunistic Infections↗
PubMed2000

[Disseminated mucormycosis in AIDS].

Mucormycosis is a rare often fatal opportunistic condition. It mainly occurs in immunocompromised subjects but rarely in AIDS patients. An eighteen-year-old HIV+ man from Zaire died rapidly from disseminated mucormycosis with pulmonary, cardiac, renal, hepatic, splenic and gastric involvement. Fungi were observed in all these organs with a particular vascular trophism. Rhizopus orizae was identified on cultures. Rapid microscopic diagnosis, in the localized stage, could improve the poor prognosis of this infection.

AIDS-Related Opportunistic Infections↗
PubMed2000

[Cerebral amyloid angiopathy presenting as a pseudotumor: 2 cases with spontaneously favorable outcomes].

A rare clinical and radiographical presentation of cerebral amyloid angiopathy mimicking a brain neoplasm was observed in 2 patients. The signs and symptoms included seizures and focal parieto-occipital dysfunction in 1 case, massive left hemisphere dysfunction and akinetic mutism in the other. Brain CT and MRI showed nonspecific focal white matter abnormalities suggestive of the diagnosis of low-grade glioma. Gradient echo T1 and T2-weighted images showing multiple areas of signal void suggesting multiple disseminated petechial hemorrhages led to the diagnosis of cerebral amyloid angiopathy. An eventless brain biopsy confirmed the diagnosis. The neuropathology examination disclosed amyloid angiopathy of the pial and cortical vessels selectively stained by anti A-beta protein antibodies. The clinical course was remarkable in the two cases with almost complete clinical recovery without any particular treatment.

Aged↗
PubMed2000

[Contribution of immunohistochemistry and electron microscopy for the diagnosis of meningeal hemangiopericytomas. 15 case reports].

Meningeal hemangiopericytomas (HPC) are rare CNS tumors with a pour prognosis compared to meningiomas. In order to define diagnosis criteria, we performed an immunohistochemical and ultrastructural study in respectively 15 and 5 meningeal HPC. The following antibodies anti-KL1, EMA, vimentin, CD34, factor VIII, alpha-smooth actin, estrogen and progesteron receptors (RE, RP) were used in paraffin embedded sections whereas anti-NCAM and E-cadherin antibodies were used on frozen sections when available. We can differentiate meningeal HPC from meningioma because of a complete lack of immunostaining with epithelial markers as well as with NCAM antibody or RE and RP receptors. Besides a positivity with CD34 and alpha-smooth actin antibodies was always observed even focally in HPC. On the other hand, solitary fibrous tumor showed a strong and diffuse positivity with anti CD34 and anti-vimentin antibodies. Electron microscopy can be helpful in some instances showing membrane basal-like substance and absence of desmosomes.

Adult↗
PubMed2000

[Practical recommendations for management of the biopsy in an expansive intra-cerebral process].

Diagnosis of an intracerebral mass requires a good collaboration between clinicians and pathologists. Different techniques may be necessary. The interest of cytological preparations and immunohistochemistry is reported. The main characteristic features of cerebral tumors are described and the differential diagnosis with reactive and inflammatory masses simulating neoplasia is discussed.

Biopsy↗
PubMed2000

[The anatomo-pathologic examination of the brain].

Guidelines for the neuropathological examination of the central nervous system (in adults) are proposed. They include the techniques used for the removal of the brain and spinal cord, the dissection of the skull, the removal of the brain, the fixation of the specimens, the sectioning of the brain, the choice of the blocks for histology, the usual staining methods and the main antibodies to be recommended for immunohistochemistry. Diagrams are given on which the lesions may be drawn and the samples, identified.

Adult↗