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J C Fournet

Publications and source records attributed to J C Fournet.

At least 37 records · Page 2Linked to original sources
PubMed1998

Invasive pulmonary infection due to Scedosporium apiospermum in two children with chronic granulomatous disease.

Scedosporium apiospermum is an opportunistic fungus in humans. The incidence of S. apiospermum infection in patients with acquired neutropenia (e.g., patients receiving chemotherapy and bone marrow transplant recipients) is steadily increasing. S. apiospermum has poor in vitro susceptibility to "conventional" antifungal agents, rendering the management of infections complex. Patients with chronic granulomatous disease (CGD) are highly susceptible to fungal infections, which are mostly due to Aspergillus species. We describe two children with CGD and invasive pulmonary infection due to S. apiospermum. Both patients were treated with antifungal therapy including azole derivatives (itraconazole or voriconazole) and surgical resection of infected tissues. These cases highlight that scedosporium infection can closely mimic aspergillus infection and should be considered in any case in which there is a failure to respond to appropriate "conventional" antifungal therapy. We also suggest that the emergence of this pathogen may have been favored by long-term use of amphotericin B in both patients.

Adolescent↗
PubMed1998

Loss of imprinted genes and paternal SUR1 mutations lead to hyperinsulinism in focal adenomatous hyperplasia.

Two types of histopathological lesions, a focal adenomatous hyperplasia of islet cells of the pancreas in about 30% of operated sporadic cases, and a diffuse form can be observed in congenital hyperinsulinism, or Persistent Hyperinsulinemic Hypoglycemia of Infancy (PHHI). In sporadic focal forms, specific losses of maternal alleles (LOH) of the imprinted chromosomal region 11p15, restricted to the hyperplastic area of the pancreas, were observed. Similar mechanisms are observed in embryonal tumors and in the Beckwith-Wiedemann syndrome which is also associated with neonatal but transient hyperinsulinism. However this region also contains the sulfonylurea receptor (SUR1) gene and the inward rectifying potassium channel subunit (KIR6.2) gene, involved in recessive familial forms of PHHI, but not known to be imprinted. We now report somatic reduction to hemizygosity or homozygosity of a paternal SUR1 constitutional heterozygous mutation, in five patients with a focal form of PHHI. Thus this somatic event (LOH) which leads both to b cell proliferation and to hyperinsulinism can be considered as the somatic equivalent, restricted to a microscopic focal lesion, of constitutional uniparental disomy associated with unmasking of a heterozygous parental mutation leading to a somatic recessive disorder.

ATP-Binding Cassette Transporters↗
PubMed1997

Somatic deletion of the imprinted 11p15 region in sporadic persistent hyperinsulinemic hypoglycemia of infancy is specific of focal adenomatous hyperplasia and endorses partial pancreatectomy.

Sporadic persistent hyperinsulinemic hypoglycemia of infancy (PHHI) or nesidioblastosis is a heterogeneous disorder characterized by profound hypoglycemia due to inappropriate hypersecretion of insulin. An important diagnostic goal is to distinguish patients with a focal hyperplasia of islet cells of the pancreas (FoPHHI) from those with a diffuse abnormality of islets (DiPHHI) because management strategies differ significantly. 16 infants with sporadic PHHI resistant to diazoxide and who underwent pancreatectomy were investigated. Selective pancreatic venous sampling coupled with peroperative surgical examination and analysis of extemporaneous frozen sections allowed us to identify 10 cases with FoPHHI and 6 cases with DiPHHI. We show here that in cases of FoPHHI, but not those of DiPHHI, there was specific loss of maternal alleles of the imprinted chromosome region 11p15 in cells of the hyperplastic area of the pancreas but not in normal pancreatic cells. This somatic event is consistent with a proliferative monoclonal lesion. It involves disruption of the balance between monoallelic expression of several maternally and paternally expressed genes. Thus, we provide the first molecular explanation of the heterogeneity of sporadic forms of PHHI such that it is possible to perform only partial pancreatectomy, limited to the focal somatic lesion, so as to avoid iatrogenic diabetes in patients with focal adenomatous hyperplasia.

Chromosome Deletion↗
PubMed1997

Comparison between vasoactive intestinal polypeptide and pituitary adenylate cyclase activating polypeptide levels in neuroblastoma tumour tissues.

Vasoactive intestinal polypeptide (VIP) is reported to exert an autocrine control on neuroblastoma cell tumours: VIP is produced by the tumour and stimulates cell differentiation. This study tested the hypothesis that the parent peptide; the pituitary adenylate cyclase activating polypeptide (PACAP) may have a similar role. It was found that PACAP mRNA and PACAP were expressed in 12/12 tumours; it was also observed that PACAP receptor mRNA and functional PACAP receptors were expressed in 12/12 and 5/9 tumours, respectively. VIP mRNA and VIP were detected in 9/12 tumours. VIP receptor mRNA was expressed in 5/12 tumours and functional VIP receptors were never demonstrated. The tumours having the highest VIP levels also had the highest PACAP contents and were associated with a watery diarrhoea syndrome due to activation of intestinal VIP receptors. As PACAP recognizes the PACAP receptors and the VIP receptors with the same high affinity it may contribute to the syndrome and is a likely candidate for an autocrine control of neuroblastoma cell growth and differentiation.

Autocrine Communication↗
PubMed1997

Interaction of Neisseria maningitidis with the components of the blood-brain barrier correlates with an increased expression of PilC.

A fatal untreated case of fulminant meningococcemia was examined to investigate the crossing of the blood-brain barrier (BBB) by Neisseria meningitidis. Microscopic examination showed bacteria in vivo adhering to the endothelium of both the choroid plexus and the meninges. Comparison of the isolates cultivated from the blood and the cerebrospinal fluid (CSF) revealed no antigenic variation of the pilin or the class 5 protein, whereas the expression of the PilC protein was greater in the CSF and the choroid plexus than in the blood. This was due to an increased activity of one of the pilC promotors. This higher expression of PilC correlated in vitro with greater adhesiveness to endothelial cells. A mutation in the single pilC locus of this strain abolished in vitro pilus-mediated adhesion to endothelial cells. These data suggest that PilC plays an important role in the crossing of the BBB, likely through pilus-mediated adhesion.

Bacterial Adhesion↗
PubMed1997

Renal chromophobe cell carcinoma and oncocytoma. A comparative morphologic, histochemical, and immunohistochemical study of 124 cases.

BACKGROUND: Renal oncocytoma has several features that overlap with other renal neoplasms, including the eosinophilic subtype of chromophobe cell carcinoma. In fact, strict criteria for renal oncocytoma have not been well defined and remain a matter of controversy. Ultrastructural studies or sophisticated methods such as flow cytometry and cytogenetic techniques can be of great use in distinguishing the two tumors, but are difficult to propose as routine methods because of their limited availability. OBJECTIVE: To further characterize the histologic criteria of these tumors, we undertook a retrospective study to define the utility of routinely available histochemical and immunohistochemical techniques. DESIGN AND SETTING: Twenty-one cases of chromophobe cell carcinoma, eosinophilic subtype, and 103 cases of oncocytoma were tested with histochemical (Perls, periodic acid-Schiff, and Hale's colloidal iron) and immunohistochemical (peanut agglutinin antigen and UEA-1 for lectins; cytokeratin KL1, epithelial membrane antigen, vimentin, S100 protein, and lysozyme) staining. RESULTS: The antibodies tested and the histochemical staining using Hale's colloidal iron allowed eosinophilic chromophobe cell carcinoma to be distinguished by its characteristic reaction pattern. Seventy-six percent of the chromophobe cell carcinomas showed a microvacuolated pattern, and 89% of the renal oncocytomas showed an apical positivity with Hale's colloidal iron staining (P < .01). Peripheral cell accentuation reactivity for cytokeratin KL1 was observed in 66% of the chromophobe cell carcinoma cases, and apical cytoplasmic positivity was observed in 37% of the renal oncocytoma cases (P = .01). Significant patterns were observed with anti-epithelial membrane antigen and anti-peanut agglutinin antigen antibodies (P = .05 and P = .01, respectively). Positive reactions for vimentin, S100 protein, lysozyme, and UEA-1 were not significant characteristics. CONCLUSION: Our study demonstrated that a precise morphologic description associated with simple histochemical and immunohistochemical techniques provides sufficient criteria for a high level of discrimination between the eosinophilic subtype of chromophobe cell carcinoma and renal oncocytoma.

Adenocarcinoma↗
PubMed1997

[Severe colitis in mucoviscidosis].

We report the association of severe indeterminate colitis with cystic fibrosis in a 21 year old woman, with mild pulmonary involvement, and without digestive or pancreatic symptoms or pancreatic enzyme preparation. Ten cases of inflammatory bowel disease associated with a cystic fibrosis have been reported. Most fit with the diagnostic criteria of Crohn's disease. Although this case was compatible with this diagnosis, we have retained the diagnosis of "severe indeterminate colitis" because of the lack of specific histological features of Crohn's disease. The association between inflammatory bowel disease and cystic fibrosis is probably not fortuitous, although the pathophysiological link between the two diseases is unknown.

Adolescent↗
PubMed1996

Correlations of allelic imbalance of chromosome 14 with adverse prognostic parameters in 148 renal cell carcinomas.

To investigate cumulative genetic alterations during development and progression of renal cell carcinoma (RCC), we examined DNAs that were isolated from 148 RCCs for allelic imbalance (AI) at four loci on chromosome arm 3p and at 26 loci on chromosome arm 14q by using polymorphic microsatellite markers and densitometric scanning. Because the analysis of solid tumor unbalanced rearrangements remains difficult due to the large proportion of cells that infiltrate from the stroma, we developed a method for the detection and quantification of AI between control and tumor samples by using polymerase chain reaction (PCR) amplification of microsatellite markers. This technique allows detection down to 20% of contaminating cells with good accuracy. We detected AI on 3p and 14q in 57 and 28% of RCC, respectively. A comparison of genetic changes with clinicopathological data showed that, in marked contrast to AI on 3p, AI on 14q was correlated significantly with the stage and grade of the tumors, with 56 and 58% of RCC in Stage IV and Grade 4, respectively, showing AI. Our results suggest that tumor suppressor genes on 3p, including the von Hippel-Lindau gene, may be involved in early steps of carcinogenesis in clear cell carcinoma and that AI on 14q may play an important role in the progression of clear cell and papillary chromophilic cell carcinomas. Loss of heterozygosity (LOH) on 14q may be a new prognostic factor in RCC. Despite the size of the series of tumors and the number of markers used, only rearrangements that involved the whole length of the long arm of chromosome 14 were observed in the present study. The localization of the putative tumor suppressor gene on 14q will require further investigation of RCC with structural rearrangements of 14q.

Adult↗
PubMed1996

Pulmonary alveolar proteinosis: experience with eight pediatric cases and a review.

We report eight pediatric cases of pulmonary alveolar proteinosis (PAP) that illustrate the polymorphic nature of this disease: two cases with severe neonatal onset, three cases with progressive respiratory distress in patients under 1 year old, and three cases in older children with mild symptoms. Consanguineous parents or affected siblings were identified or suspected in four families. Three patients suffered from associated immune or blood disorders (severe combined immune deficiency, myelodysplasia). The respective roles of a macrophagic dysfunction and of an anomaly of the surfactant are discussed according to the various clinical presentations of pediatric PAP. We performed eight unilateral pulmonary lavages under endoscopy and selective ventilation for two patients under 7 kg in weight. These interventions led to progressive discontinuation of oxygen therapy in one case, and temporarily stabilized the disease for the second. Subsequent recurrence in this second patient was treated by massive lavage under extracorporeal oxygenation. A third infant was successfully transplanted with no recurrence within 3 years. Ambroxol was administered in one case. The three oldest children of our series remained asymptomatic, whereas three of the younger patients died. In the light of this experience, we propose that the treatment administered should be determined according to the age of the patient, the degree of respiratory deficiency, and the nature of any associated pathology.

Ambroxol↗
PubMed1996

[Internet, a new resource for anatomopathology?].

The Internet network is the largest computer network in the world. It can be accessed by a telephone line and a modem. Its different functions are the electronic mail (e-mail), the discussion forums ("newsgroups"), the transfer of files and the navigation between "hypertext" pages ("World Wide Web"). This network offers multiple services for pathology: access to databases, consultation of image banks or electronic journals, teleteaching, informations about congresses and societies, participation to thematic forums. We have connected to this network on October 1995 a french-english web site called "Anapath Web" (http://www.anapath.necker.fr) devoted to pathology. Its purpose is to collect information useful to pathologists and to develop specific applications. We are conceiving several projects for teleteaching.

Computer Communication Networks↗
PubMed1992

Multicentric Kaposi's sarcoma in a 5-year-old human immunodeficiency virus-negative renal allograft recipient.

We describe the clinical and pathologic features of a case of pediatric multicentric Kaposi's sarcoma (KS) associated with allograft transplantation in a human immunodeficiency virus (HIV)-negative child. A lethal polyadenopathic and visceral KS occurred in a 5-year-old Caribbean boy who had undergone an allogenic renal transplantation for diffuse mesangial sclerosis with end-stage renal failure 4 months previously. The HIV-1 and HIV-2 serologies were negative. Despite its rarity, KS must be considered as a differential diagnosis in posttransplantation polyadenopathic or multisystemic syndromes in children.

Autopsy↗
PubMed1992

[Genetic aspects of renal tumors in adults].

The aetiopathogenesis of adult renal tumors is poorly understood. The specific chromosomal changes detected by the study of tumor karyotypes suggest a cascade of oncogene activation and tumor suppressor gene inactivation in the course of renal carcinogenesis. These cytogenetic studies have isolated two entities: non-papillary carcinomas (clear cell and/or eosinophil carcinomas) and tubulopapillary tumors (cortical adenoma, basophil papillary carcinoma). Specific changes of the short arm of chromosome 3 are observed in 70 to 85% of cases of clear cell carcinomas, while trisomy 17 is detected in 70% of cases of tubulopapillary tumors. Cytogenetics is also able to distinguish low and high grade malignant tubulopapillary carcinomas. Limited data are available at the present time concerning oncocytomas.

Adenoma↗
PubMed1991

Parvovirus B19 infection can induce histiocytic necrotizing lymphadenitis (Kikuchi's disease) associated with systemic lupus erythematosus.

We report three cases of systemic lupus erythematosus (SLE) associated with necrotizing histiocytic lymphadenitis (Kikuchi's disease) and immunologically proven human parvovirus B19 infection. Simultaneous occurrence of SLE and Kikuchi's disease was a characteristic of the three cases. Kikuchi's disease is an uncommon disease that usually affects young women and is characterized by painless unilateral cervical lymph-node enlargement. T-cell regions of affected lymph nodes are exclusively involved with patchy paracortical necrosis surrounded by a polymorphous cell population of histiocytes and macrophages. However, lymphadenopathy in patients with SLE may be histologically indistinguishable from Kikuchi's necrotizing lymphadenitis. The cause of Kikuchi's disease remains uncertain, although infectious agents have been proposed. A positive IgM-specific anti-human parvovirus B19 antibody test in our three cases suggests that B19 can induce a necrotizing histiocytic lymphadenitis and possibly a clinical SLE flare. High-dose (1 mg/kg/day) and medium-dose (0.5 mg/kg/day) oral prednisone was an effective treatment for constitutional and visceral symptoms of Kikuchi's and SLE diseases.

Adolescent↗
PubMed1991

[3 cases of Kituchi's lymphadenitis in systemic lupus erythematosus. Role of the parvovirus B19].

Florid necrotizing lymphadenitis, characterized by segmental infarction and lymphoid hyperplasia, is an uncommon feature of systemic lupus erythematosus (SLE). Kikuchi's disease is a well-defined clinicopathological entity, with a strong preference for the cervical lymph nodes of young women. The etiology of histiocytic necrotizing lymphadenitis (HNL) remains unknown, although viral agents have been proposed. HNL may reflect a self-limited SLE-like autoimmune disease but full-blown SLE associated with this condition has not, to the best of our knowledge, been reported. Thus, ours is the first description of the coexistence of SLE and HNL in 3 patients with immunologically proven parvovirus B19 infections. SLE and HNL were diagnosed simultaneously in 2 patients, but was retrospective in the third, in whom anti-tuberculous therapy was ineffective. Patients 1 and 2 were treated with prednisone (1 mg/kg/d) and responded rapidly. These data suggest that both HNL and SLE flares can be caused by parvovirus B19 infection.

Adult↗