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Biomedical subjects

Dominique Hénin

Publications and source records attributed to Dominique Hénin.

At least 19 recordsLinked to original sources

Cortical consequences of in vivo blockade of monocarboxylate transport during brain development in mice.

In addition to glucose, monocarboxylates including lactate represent a major source of energy for the developing brain and appears to be crucial in the pathogenesis and recovery after brain damage. We hypothesized a role of monocarboxylates transport in the energy supply of neurons of the immature cerebral cortex. The effects of the blockade of monocarboxylates transport in vivo on the cortical development was investigated in neonatal mice using alpha-cyano-4-hydroxycinnamate (CIN) diluted either in DMSO (CD) or in ethanol (CE) administered intraperitoneally over postnatal day (P) P1 to P3. Injection of CIN induced a cytoarchitectonic disorganization in the parietal cortex likely due to a combination of slight disturbance of cortical neuronal migration and an increased neuronal cell death observed in CE (p < 0.05) but not in CD group. An increased number of activated GFAP-positive astroglia was observed in the neocortex in groups treated with CIN (CD and CE) on P10. These data: 1) Provide first evidence of deleterious effects observed in vivo after blockade of monocarboxylates transport in the developing brain; 2) emphasize the role of lactate during neuronal migration as a major source of energy; and 3) suggest the synergistic effect of ethanol-induced hypoglycemia in cortical brain damage induced by CIN.

Animals↗

Percutaneous transplantation of genetically-modified autologous fibroblasts in the rabbit femoral artery: A novel approach for cardiovascular gene therapy.

OBJECTIVE: Arterial cell and gene therapies are promising strategies for the treatment of cardiovascular diseases; however, the optimal cell type and delivery technique for such treatment remain to be determined. The aim of the present study was to design a new approach for arterial cell and gene therapy in which genetically modified autologous skin fibroblasts are percutaneously delivered in stented rabbit femoral arteries in vivo. METHODS: Autologous skin fibroblasts underwent in vitro transfection with the cationic lipid FuGene and plasmids expressing the human form of the tissue inhibitor of metalloproteinase (hTIMP-1) or nls-LacZ reporter genes. RESULT: Transfection efficiency was about 50% and there were high levels of hTIMP-1 secretion up to 14 days after gene transfer. We demonstrated the feasibility of in vivo percutaneous transplantation of fluorescent fibroblasts in the rabbit femoral artery. Results were confirmed by scanning electron microscopy. In vivo local delivery of hTIMP-1-expressing fibroblasts in stented femoral arteries also resulted in high-levels of hTIMP-1 secretion ex vivo for 7 days. Fibroblast transplantation resulted in a modest increase in intimal hyperplasia at the target site, which was reversed with hTIMP-1-transfected fibroblasts. CONCLUSION: Percutaneous transplantation of genetically modified autologous fibroblasts could be used as a cellular platform for locoregional secretion of therapeutic proteins to treat either specific arterial diseases or the diseased organ (eg, the heart) supplied by the target artery. CLINICAL RELEVANCE: Cell and gene therapies are potential new treatments for cardiovascular diseases. We demonstrated that autologous fibroblasts could be easily harvested from a skin biopsy specimen, genetically modified in vitro with nonviral vectors, and percutaneously seeded in vivo in rabbit femoral arteries, leading to locoregional secretion of abundant amounts of recombinant proteins. This new approach has important advantages over alternative approaches that use endothelial cells, viral vectors, and intraoperative cell delivery. Clinical applications may include local treatment of atherosclerotic plaques or aneurysms and also treatment of the diseased organs supplied by the target artery (eg, ischemic or failing heart).

Animals↗

Increased apoptosis in cervical intraepithelial neoplasia associated with HIV infection: implication of oncogenic human papillomavirus, caspases, and Langerhans cells.

PURPOSE: Increasing risk of squamous cervical intraepithelial neoplasia (CIN) exits in HIV-infected women. However, the relatively low incidence of invasive carcinoma in the untreated HIV-infected population suggests an imbalance between cell proliferation and apoptosis. We investigated apoptosis and caspases in cervical samples from this population comparatively to non-HIV-infected and control subjects. EXPERIMENTAL DESIGN: Apoptotic terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling method, immunohistochemistry for caspase-2, caspase-3, caspase-8, caspase-9, and other apoptosis markers were done on 12 normal cervical samples and 103 low- and high-grade cervical lesions, containing human papillomavirus(es) from 35 HIV-negative and 33 HIV-positive women before tritherapy advent. RESULTS: (a) The apoptotic index (AI) in epithelial cells did not vary between normal mucosa and condyloma acuminata infected or not with HIV. (b) AI augmented with the CIN severity in HIV-positive and HIV-negative women. (c) AI dramatically increased in oncogenic human papillomavirus-infected CIN of HIV-positive population compared with the CIN of similar grade in HIV-negative one. This was associated with a greater expression of caspase-8, active caspase-9, and active caspase-3 in those samples. Moreover, densities of Langerhans' cells, involved in apoptotic bodies engulfment, were greatly reduced in CIN of HIV-positive women. In samples, these densities were highly inversely correlated with AI (r = -0.88, P < 0.002). CONCLUSIONS: This study provides the first evidence for the strongly enhanced apoptosis levels and caspase expression in CIN of untreated HIV-infected women. We suggest that the reduction in Langerhans' cell number could contribute at least partly to apoptotic cell accumulation.

Antigens, CD1↗

Identification of FcalphaRI as an inhibitory receptor that controls inflammation: dual role of FcRgamma ITAM.

Serum IgA is considered a discrete housekeeper of the immune system with multiple anti-inflammatory functions, whereas IgA-immune complexes mediate inflammatory responses. Here, we identify FcalphaRI as a molecular device that determines the nature of IgA responses. In the absence of sustained aggregation, receptor targeting by serum IgA or anti-FcalphaRI Fab inhibits activating responses of heterologous FcgammaR or FcepsilonRI. The inhibitory mechanism involves recruitment of tyrosine phosphatase SHP-1 to FcalphaRI and impairment of Syk, LAT, and ERK phosphorylation induced by FcepsilonRI engagement. SHP-1 recruitment is dependent on ERK. Conversely, sustained aggregation of FcalphaRI by multimeric ligands stimulates cell activation by recruiting high amounts of Syk and aborting SHP-1 binding. Both types of signals require the FcRgamma-ITAM motif. Anti-FcalphaRI Fab treatment suppresses manifestations of allergic asthma in FcalphaRI transgenic mice. These findings redefine FcalphaRI as a bifunctional inhibitory/activating receptor of the immune system that mediates both anti- and proinflammatory functions of IgA.

Animals↗

Anal carcinoma: incidence and effect of cumulative infections.

INTRODUCTION: Human papilloma virus (HPV) causes anal condyloma that is a risk factor for anal carcinoma. The incidence and mechanism of invasive anal carcinoma in patients with anal condyloma are prospectively determined. PATIENTS AND METHODS: From 1993 to 2002, 228 consecutive patients (164 HIV positive) with anal canal condylomas were included in the study, after curing of their lesions. They were asked to attend follow-up visits at 3- or 6-month intervals. We checked for anal co-infection with syphilis, gonococci, viruses (Epstein-Barr virus, cytomegalovirus, herpes simplex, HPV types), and quantified Langerhans' cells (LC) in anal mucosa at baseline and during follow up. We cured and analysed relapsed condylomas during follow up (3-112 months; median 26). Serum HIV loads and CD4 T-lymphocyte counts were determined at each visit and the densities of LC in consecutive specimens from patients with cancers were compared with that for a matched control group (n = 23). RESULTS: Analysis of 199 patients showed high-grade dysplasia (HGD) in 13.6% of patients, more in HIV-positive (16%) than in HIV-negative (6%) patients at baseline. During follow up, 3.5% (7/199; six HIV positive) patients developed invasive carcinoma after 13-108 months and 112 (56%) patients relapsed condylomas. HIV and anal co-infection were identified as independent risk factors (P < 0.01) for HGD and cancer: odd ratio (95% confidence interval) of 9.4 (2.4-37.4) and 3.67 (0.95-14.2), respectively. LC densities in anal mucosa were lower in patients with invasive carcinoma than in controls. CONCLUSION: The risk of invasive carcinoma in HPV-infected patients is increased by HIV and anal co-infection. Decreases in LC numbers in anal mucosa may favour this outcome.

Adult↗

IL-10 inhibits vascular smooth muscle cell activation in vitro and in vivo.

The anti-inflammatory cytokine IL-10 inhibits intimal hyperplasia after stent implantation via a powerful inactivation of monocytes. We tested the hypothesis that IL-10 may also inhibit vascular smooth muscle cell (SMC) activation via the inhibition of the NF-kappaB/I-kappaB system. The IL-10 receptor was detected in rat SMCs in vitro and in vivo. In LPS-stimulated rat SMCs, 1 ng/ml recombinant murine IL-10 (mIL-10) reduced I-kappaBalpha and I-kappaBbeta degradation, NF-kappaB activation, as well as the expression of the NF-kappaB-dependent gene IL-6 by 32%, 31%, 75%, and 19%, respectively (P < 0.05 for all). Similar results were obtained in vivo 6 h and 4 days after balloon abrasion of the rat aorta, a model in which intimal hyperplasia results essentially from SMC activation. Moreover, mIL-10 reduced SMC proliferation and migration in vitro (by 60% for both, P < 0.0001), resulting in reduced SMC proliferation and intimal growth 14 days after balloon abrasion of the rat aorta (by 76% and 75%, respectively; P < 0.005). In conclusion, mIL-10 has a direct inhibitory effect on SMCs in vitro and in vivo. This effect is mediated in part by NF-kappaB inactivation and may participate in the overall protective effect of IL-10 on postangioplasty restenosis.

Animals↗

Clinical and autopsy diagnoses in the intensive care unit: a prospective study.

BACKGROUND: Autopsy rates have declined worldwide, but recent retrospective intensive care unit (ICU) data indicate major discrepancies between more than 25% of clinical and autopsy diagnoses. METHODS: We conducted a 3-year prospective study of all consecutive autopsies performed on patients who died in a university hospital medical-surgical ICU to determine how many might have benefited from a different level of care, had the autopsy diagnosis been made before death. All clinical diagnoses were compared with autopsy findings at monthly clinical-pathological meetings. Major and minor diagnostic discrepancies were categorized according to the criteria of Goldman et al. RESULTS: Of 1492 patients admitted to the ICU, 315 died, of whom 167 (53.0%) were autopsied. The most common reason (79.7%) for not obtaining an autopsy was family refusal. The mean +/- SD clinical characteristics were similar for autopsied vs nonautopsied patients, except for shorter length of ICU stay (13 +/- 17 vs 20 +/- 27 days, P =.006), shorter duration of mechanical ventilation (13 +/- 16 vs 19 +/- 25 days, P =.01), and lower percentage of postcardiac surgery patients (38.9% vs 50.0%, P =.05). Among the intensivists' 694 clinical diagnoses, 33 (4.8%) were refuted and 13 (1.9%) were judged incomplete by autopsy findings. Autopsies revealed 171 missed diagnoses, including 21 cancers, 12 strokes, 11 myocardial infarctions, 10 pulmonary emboli, and 9 endocarditis, among others. Major diagnostic errors (class I and class II discrepancies) were made in 53 (31.7%) of 167 patients, with a high percentage of immunocompromised patients also observed among these. Similar percentages of patients with class I and class II errors vs other patients had undergone modern diagnostic techniques during their ICU stay. CONCLUSION: Even in the era of modern diagnostic technology, regular comparisons of clinical and autopsy diagnoses provide pertinent information that might improve future management of ICU patients.

Aged↗

[Solitary cutaneous infantile myofibromatosis].

Infantile myofibromatosis is the most frequent fibromatosis in childhood. It is a benign proliferation of fibroblasts and myofibroblasts. This case report concerns a newborn who presented at birth with a purple cutaneous nodule on the scalp. Surgical excision was performed at the age of 16 months. Infantile myofibromatosis was diagnosed on histology. Infantile Myofibromatosis (IMF) was first described by Enzinger in 1981. Three types can exist. Solitary MFI, the most frequent, is a solitary lesion, cutaneous/subcutaneous, osseous or involving soft tissues. Multicentric disease is characterized by multiple locations and generalized form by visceral involvement. Morphological features are identical in all types. The histological diagnosis relies on the identification of two separate components, a fascicular myofibroblastic pattern at the periphery with a hemangiopericytoma like pattern in the centre. Both components are positive for alpha-smooth muscle actin. Atypia, or mitotic activity, are not observed usually but features of intravascular growth can be seen in the centre of the lesion. Infantile MF carries a good prognosis when solitary but death frequently occurs in generalized MF with visceral involvement.

Humans↗

JC virus leukoencephalopathy complicating Wegener's granulomatosis.

Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease of the brain caused by the JC virus. It occurs in association with immunodepression due, for instance, to a hematological malignancy, HIV infection, or immunosuppressive therapy for an organ transplant or systemic disease. We describe the fourth reported case of PML in a patient receiving immunosuppressants for Wegener's granulomatosis. A 71-year-old woman receiving azathioprine and glucocorticoid therapy experienced onset of right-sided hemiplegia within a few days, became comatose, and died within a few days. MRI of the brain showed a subcortical lesion in the left parietal lobe generating low signal on T1 images and high signal on T2 images. The initial diagnosis was cerebral vasculitis. However, the postmortem examination showed PML. The diagnosis of PML rests on JC virus detection in the cerebrospinal fluid by PCR assay and on demonstration in a brain biopsy of the typical histological pattern with presence of the JC virus within the demyelinated lesions. No specific or effective treatments are available. Immunosuppressant drugs should be discontinued if possible.

Aged↗

Clinical and Histologic Parameters Correlated with Facial Nerve Function After Vestibular Schwannoma Surgery.

This study was conducted to identify clinical and histologic factors that would influence, independently of tumor staging, postoperative facial function after removal of a vestibular schwannoma. A prospective study was performed on 35 consecutive patients with vestibular schwannomas who underwent the translabyrinthine approach. Facial function was assessed before and 1 year after surgery. The factors that influenced the postoperative outcome of the facial function independently of tumor staging were the absence or the desynchronization of homolateral auditory brainstem responses and tumor edema. Other factors (audiovestibular signs of brainstem compression, tumor inflammation, positive p53 protein immunostaining) were predictive of postoperative facial function but also correlated with tumor staging. Besides the well-known prognostic value of tumor staging for postoperative facial outcome, clinical (auditory brainstem responses) and histologic (tumor edema) factors correlated with postoperative facial function.

Journal Article↗

Hepatocyte growth factor and c-Met in cervical intraepithelial neoplasia: overexpression of proteins associated with oncogenic human papillomavirus and human immunodeficiency virus.

PURPOSE: High prevalence of squamous cervical intraepithelial neoplasia (CIN) linked to oncogenic human papillomavirus (HPV) exits in HIV-infected women. Hepatocyte growth factor (HGF) and its receptor, c-Met, promote cell proliferation and are involved in tumor progression. Nothing is yet known about their expression in low- and high-grade CIN. Therefore, the expression, localization, and behavior of HGF and c-Met in normal and dysplastic cervical epithelium were investigated. EXPERIMENTAL DESIGN: We studied normal cervical mucosa from 10 healthy women, and low- and high-grade cervical lesions, uninfected (condyloma acuminata) or infected with oncogenic HPVs, from 40 HIV-negative and 48 HIV-positive women, using in situ molecular techniques, immunocytochemistry and morphoquantitative methods. RESULTS: In 154 oncogenic HPV-infected CIN encountered in biopsy samples, the total number of epithelial cell layers increased significantly during lesion progression. This number was significantly higher in HIV-positive than in HIV-negative women for CIN1 and CIN2 (P < 0.025 to P < 0.01). In HIV-negative women, the number and percentage of HGF and c-Met immunostained cell layers, and the intensity of immunostaining were enhanced in oncogenic HPV-infected lesions as compared with normal mucosa and condyloma acuminata. The latter parameters were significantly higher in tissues of HIV-positive women (oncogenic HPV-infected CIN1 and CIN2, normal-appearing mucosa contiguous to CIN, condyloma acuminata) than in the corresponding tissues of HIV-negative women (P < 0.025 to P < 0.0001). CONCLUSIONS: Overexpression of HGF/c-Met complex strongly correlates with oncogenic HPV and HIV infection. This overexpressed complex may stimulate cell proliferation in condyloma acuminata and participate in tumor progression in oncogenic HPV-infected lesions.

Adolescent↗

[Pilomatrix carcinoma: histologic and immunohistochemical features. Two studies].

Malignant pilomatricoma is a rare malignant hair follicle tumor, that was initially described in 1980. Histologically, it shares common features with the more frequent, which benign pilomatricoma, makes its diagnosis difficult. It is a deep dermis-hypodermis epithelial tumor, well circumscribed, with no relation with the epidermis. It is composed of nodular structures with rows of basaloid cells in their periphery, as well as focal necrosis and mummified "ghost" cells in their central parts. Immunohistochemistry is of little value and can not confirm malignancy. The diagnosis remains essentially morphological. Histological examination must stress on the evaluation of the degree and extent of infiltration of the surrounding tissues, the degree of necrosis, the presence of atypical mitotic figures, and the presence or not of peri-neural or vascular invasion. Surgical wide resection is the recommended treatment. It reduces the risk of local recurrence by 50%. Malignant pilomatricoma carries a high risk of metastases to the bones, lungs, and lymph nodes. No feature is specific to confirm wether a malignant pilomatricoma arises de novo, or whether it is a malignant transformation of a pre-existing benign pilomatricoma.

Adult↗

[Non tuberculous mycobacterial diseases].

Mycobacteria species other than members of Mycobacterium tuberculosis complex are called non tuberculous mycobacteria (NTM) or "atypical" mycobacteria. To date, about 80 mycobacterial species have been described. They are usually opportunistic pathogens with variable degrees of virulence. Tuberculosis is the commonest mycobacterial disease in the world, followed by leprosy and Buruli ulcer. Before the AIDS epidemic, NTM diseases were confined to the lungs (M. kansasii, M. intracellulare and M. avium), the skin (M. marinum) or cervical lymph nodes (M. scrofulaceum). The outbreak of AIDS epidemic has dramatically changed the epidemiology of NTM diseases. Between 25 to 50% of AIDS patients in Europe and USA are infected with NTM. NTM infections are usually disseminated in patients with profound immunodeficiency. The inflammatory response and the prognosis of NTM diseases depend on the immunological status and the NTM species. Diagnosis may be difficult, especially in AIDS patients in whom numerous diseases are often associated. Diagnostic criteria involve clinical, radiological, microbiological and pathological findings. Identification of Mycobacterium species in cultures is the gold standard. Pathological examination has several interests: it may reveal an NTM disease, it provides a more rapid assessment of the infection than cultures, and helps to evaluate the virulence of NTM species identified by cultures.

HIV Infections↗

[Unusual parosteal osteochondromatous proliferation or Nora's tumor. A clinicopathological analysis of 4 cases].

Nora's lesion, also known as bizarre parosteal osteochondromatous proliferation (B.P.O.P.), involves mostly the small tubular bones of the hands and feet. Histologically, it is characterized by a proliferation of chondroid, bony and fibrous tissues, sometimes with high cellular density, bizarre chondrocytes but is devoid of cellular atypia and necrosis. Distinct blue color is noted at the interface of bone and cartilage. The most important lesions that present differential diagnostic problems are chondrosarcoma, parosteal osteosarcoma and florid reactive periostitis. The lesion is benign but may recur locally in as many as 55%. The clinical and pathological findings of four cases of Nora's lesion are presented.

Adolescent↗

Relationship between vascular development and vascular differentiation during liver organogenesis in humans.

BACKGROUNDS/AIMS: The complex vascular architecture characteristic of the normal adult liver is progressively acquired during the fetal life. In this study, we aimed to evaluate the relationship between angiogenesis and vascular differentiation during liver organogenesis. METHODS: We studied, in 51 fetuses of different gestational ages, the expression of markers of endothelial cell differentiation, integrins, pro- and anti-angiogenic extracellular matrix components, vascular endothelial growth factor (VEGF) and its receptors. RESULTS: Three main stages in the development of the vascular architecture of the liver were identified: (a) from 5 to 10 gestation weeks (GW), no evidence of de novo angiogenesis was detected; the vessels present in the liver primordium were the precursors of portal veins and sinusoids, deriving from preexisting vessels; (b) from 10 to 25 GW, angiogenesis and vasculogenesis resulted in the development of, respectively, arteries and intra-portal capillaries, while portal veins and hepatic sinusoids followed a differentiation process; (c) after 25 GW, little changes were detected in the various vascular compartments. The maximal expression of VEGF and its receptors was from 5 to 25 GW. CONCLUSIONS: The development of the hepatic vascular architecture is a multistep process combining angiogenesis, vasculogenesis and vascular differentiation, regulated by specific growth and differentiation factors including VEGF.

Biomarkers↗