Failure to obtain hybridomas between human macrophages and human tumoral U-937 cells is probably due to parental macrophages

Despite more than 50 attempts and the use of various methods, it has been impossible to establish homologous hybridomas between human mature macrophages and 8-azaguanine-resistant U-937 clones prepared in the laboratory. To rule out the possibility that these clones were unsuitable for the selection of hybrids, a study of their properties was done. It was shown that U-937 wild type cells were able to produce HPRT, whereas 8-azaguanine (8-aza)-resistant clones did not. Curiously, exonic and intronic HPRT sequences were undetectable both in wild type and in 8-aza-resistant cell genomes, under conditions where they were detected in control cells. Chromosome analysis of the clone UM9, one of the most frequently used in fusion experiments, revealed many qualitative and quantitative differences with the U-937 wild type cells. 8-aza-resistant U-937 cells were capable of fusion with human macrophages and gave rise to heterokaryons and probably to synkaryons, which survived for weeks without dividing in hypoxanthine-aminopterin-thymidine medium. The results could be interpreted in terms of the existence of a transacting negative regulatory mechanism of the macrophage genome on the proliferative capacity of homospecific hybridomas.

HBV infection in pediatric liver transplantation

When hepatitis B virus (HBV) infection precedes orthotopic liver transplantation (OLT), an important issue is to avoid post-OLT HBV infection of the transplanted liver. When HBV infection is found after OLT, the main objective is to prevent the complication of cirrhosis. A study of HBV infection in 162 liver-transplanted children followed at Hôpital de Bicêtre is presented here. One hundred forty-one of these children were completely vaccinated against HBV; 89% of them still disposed of protective titers of serum antibodies to hepatitis B surface antigen (anti-HBs) (> 10 IU/L) 6-60 months after OLT. Four children had a HBV-associated liver disease that required OLT. In these children a passive immunoprophylaxis maintaining serum anti-HBs levels > 100 IU/L allowed three of them to remain free of serum hepatitis B surface antigen (HBsAg) and HBV-DNA during follow-up at 10, 20, and 36 months. Four other children have been found to be HBsAg+ after OLT, but it was not clear whether the source of HBV was a reactivation or a de novo infection. Low doses of cyclosporin and prednisone were administered, in order to avoid the complications of HBV infection. Liver needle biopsies in three of these patients 37, 42, and 46 months after OLT showed a moderate chronic active hepatitis and mild fibrosis. Immunostaining for HBs and hepatitis B core (HBc) antigens indicated active viral replication.(ABSTRACT TRUNCATED AT 250 WORDS)

[Evaluation of an reference anatomo-clinical classification of varices of the lower limbs]

In order to set up a common and objective language for everyone, the authors have laid the foundation of anatomoclinical classification which can be used as a reference in the study of varicose veins in lower limbs. They are comparing a group of patients with varicose veins to a control group of healthy patients. The groups are classified in four stages according to the importance of the varicose pathology and the histological characteristics. The conclusion is the following: there is no parallelism between these four clinical stages and the histological characteristics. According to the authors, it is necessary to make a distinction between fibrous reaction veins and muscular wall veins. This phenomenon is reported to have particular therapeutic implications in the prescription of substances of exciting venous tonicity.

[Production of oxygenated free radicals and the role of exogenous antioxidants in liver transplantation in rats]

It has been suggested that, in transplantation organs, the lesions observed after conservation then reperfusion could be related to the formation of oxygenated free radicals. The aim of our work was first to verify the hypothesis that oxygenated free radical are formed after ischaemia-reperfusion of the liver, then to evaluate the effects of the allopurinol and glutathion, known antagonists of oxygenated free radicals, contained in the University of Wisconsin conservation fluid. The University of Wisconsin solution was compared with a Collins solution which does not contain oxygenated free radical antagonists. An orthotopic liver transplantation model was used in Wistar rats. Three groups were studied. In the control group, 5 rats underwent laparotomy then were closed with no surgery being performed. In the Wisconsin group (n = 6) and the Collins group (n = 6) the livers were washed and conserved in the corresponding solution at 4 degrees C before transplanting. Plasma levels of malonyldialdehyde, measured by high performance liquid chromatography, were used as a marker for the formation of oxygenated free radicals. Impaired liver function was assessed on the basis of mortality and serum transaminases, alkaline phosphatase and total bilirubin levels. Liver biopsy was performed at sacrifice. The level of malonyldialdehyde was significantly higher in the transplanted groups compared with the control group (p < 0.01). There was no difference between the Wisconsin and the Collins groups. Hepatic function was significantly reduced in the transplanted groups compared with the control group (p < 0.05). There was no significant difference between the Wisconsin and the Collins groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Overexpression of p53: a rare event in a large series of white patients with hepatocellular carcinoma

Mutant p53 has been found in a wide variety of human malignancies including carcinomas of the lung, breast and colon. Because of the controversial mutational rate of the p53 gene in hepatocellular carcinoma, a large series of liver tumors from white patients with different risk factors was examined immunohistochemically for expression of the p53 mutant to assess its prevalence and the relationships between p53 overexpression and clinicopathological data. Nine of 58 specimens were found to have detectable evidence of p53 gene mutation by virtue of the immunohistochemical detection of mutant p53 protein. The p53 mutation was more frequent in patients with serological hepatitis B and C markers than in patients without these markers (p = 0.046). The prevalence of p53-positive tumors was also significantly higher in the group of tumors with invaded portal branches than in the group without (p = 0.02). Our results showed that p53-positive hepatocellular carcinoma is a rare finding in patients exposed to a low dietary aflatoxin intake and that p53 mutation seems to occur at a late stage of the tumoral process and could contribute to an aggressive tumoral phenotype.

Intrahepatic bile duct damage in children with Kawasaki disease

Three children with Kawasaki disease had liver biopsies because of evidence of hepatic disease. Cholangitis or bile duct injury and proliferation were found. Similar damage to the hepatic ductular system may explain the hydrops of the gallbladder sometimes seen in this disease.

Unilateral benign medulloepithelioma associated with bilateral retinal detachment

A two-month-old girl presented with a unilateral benign cystic medulloepithelioma from the ciliary body associated with bilateral retinal non-attachment. The authors discuss the histopathologic findings and the pathogenesis of the congenital retinal non-attachment: are these incidental occurrences or do they arise from a common pathogenetic mechanism?

Effects of ascorbate-deficiency on collagen secretion and resorption in cultured mouse incisor germs

The effects of ascorbic acid deficiency on mouse incisors, grown in vitro, has been investigated at the histological and cytological levels. In this model, continuously growing mouse incisors are characterized by the existence of different type of predentin-dentin matrix on its lingual (root-analogue) and labial (crown-analogue) surface and the absence of enamel on the lingual surface. Our observations indicated that ascorbate-deficiency affected the behavior of mouse tooth germs in vitro: odontoblast differentiation was disturbed and morphological evidence for odontoblast-mediated collagen resorption were observed. An abnormal amorphous predentin-dentin matrix existed and the basement membrane was prematurely disrupted. The dentin mineralization, as well as functional differentiation of ameloblasts were strongly hampered. Chronic deficiency led to disorganization of the dental tissues.

Ultrastructural similarities between epidermal Langerhans cell Birbeck granules and the surface-connected canalicular system of EDTA-treated human blood platelets

Birbeck granules characterize under the electron microscope epidermal Langerhans cells. These distinctive pentalaminar organelles are indeed not detectable in the possible precursors of human Langerhans cells and tend to disappear in cultured human Langerhans cells. The mechanisms that lead to the appearance of Birbeck granules in epidermal Langerhans cells and to their later disappearance still remain unknown. In the present study we show that the more or less dilated elements of the surface-connected canalicular system of human blood platelets collapse after EDTA treatment. Made up of two parallel limiting membrane and central irregular striated density, these elements show great ultrastructural similarities with the Birbeck granules of human epidermal Langerhans cells. These platelet morphologic changes i) are directly dependent on the EDTA-induced dissociation of the glycoprotein GP IIb-IIIa, the platelet-specific calcium-dependent heterodimer complex, member of the beta 3 integrin subfamily (alpha IIb beta 3) and ii) apparently result from a cross-linking of the dissociated glycoproteins. These findings lead us to propose that in the same manner cells of the Langerhans lineage, on reaching the epidermis, will find themselves in contact with an epidermal specific ligand. Interactions between this epidermal ligand and Langerhans cell receptors could then induce, all along the circuit taken by the ligand-receptor complexes, morphologic modifications, i.e., appearance of structures of Birbeck granule type.

Deficiency of long-chain 3-hydroxyacyl-CoA dehydrogenase: a cause of lethal myopathy and cardiomyopathy in early childhood

A child presented in early childhood with episodes of coma and hypoglycemia and a rapidly evolutive myopathy and cardiomyopathy leading to death at 9 mo of age. Ketosis was decreased (blood beta-hydroxybutyrate: 0.07 mmol/L) despite normal plasma levels of fatty acids (0.81 mmol/L). The patient's urine contained excessive amounts of the C6 to C10 dicarboxylic acids present in almost all defects of fatty acid mitochondrial oxidation. More specifically, gas chromatography-mass spectrometry identified an accumulation of medium- and long-chain (C8 to C14) 3-hydroxy-dicarboxylic acids, suggesting a defect of the mitochondrial enzyme that normally dehydrogenates these 3-hydroxyacyl-CoA esters. Biochemical studies in the patient's cultured fibroblasts confirmed the impairment of medium- and long-chain fatty acid oxidation, and allowed the recognition of the deficiency of long-chain 3-hydroxyacyl-CoA dehydrogenase. The activities of long-, medium-, and short-chain acyl-CoA dehydrogenases and 3-ketoacyl-CoA thiolase were normal. These results describe a disorder of fatty acid metabolism that affects the liver, skeletal muscles, and myocardium. It is important to point out that long-chain 3-hydroxyacyl-CoA deficiency shares many clinical similarities with systemic carnitine deficiency, as well as with carnitine-palmityl-CoA transferase and long-chain acyl-CoA dehydrogenase deficiencies. The differential diagnosis of this disease relies on the demonstration of long-chain urinary dicarboxylic acids with a hydroxyl group in 3-position and the study of the enzyme activity in cultured fibroblasts.

Cloning and characterization of cDNAs for murine macrophage inflammatory protein 2 and its human homologues

A cDNA clone of murine macrophage inflammatory protein 2 (MIP-2) has been isolated from a library prepared from lipopolysaccharide (LPS)-stimulated RAW 264.7 cells and the nucleotide sequence determined. This cDNA was used to clone cDNAs for human homologues of MIP-2 from a library prepared from phorbol myristate acetate-treated and LPS-stimulated U937 cells. Two homologues were isolated and sequenced. Human MIP-2 alpha and MIP-2 beta are highly homologous to each other and to a previously isolated gene, human gro/melanoma growth-stimulating activity (MGSA). These three human genes, MIP-2 alpha, MIP-2 beta, and gro/MGSA, constitute a sub-family within the cytokine family represented by platelet factor 4 and interleukin 8.

Nodular regenerative hyperplasia of the liver, peliosis hepatis, and perisinusoidal fibrosis. Association with angioimmunoblastic lymphadenopathy and severe hypoxemia

Three different liver lesions were found in a 20-year-old woman with angioimmunoblastic lymphadenopathy. The lesions included nodular regenerative hyperplasia of the liver, perisinusoidal fibrosis, and peliosis hepatis. It is suggested that the association of angioimmunoblastic lymphadenopathy with this broad spectrum of liver lesions was not fortuitous.

Human epidermal Langerhans cells express only the 40-kilodalton Fc gamma receptor (FcRII)

In man, three distinct classes of receptors for the Fc fragments of IgG (FcRI, II, III) have been defined. The FcRI has a Mr of about 72 kDa, binds human IgG-coated E, and is recognized by mAb such as 32. The FcRII has a Mr of 40 kDa, binds murine IgG1-coated E, and reacts with the mAb IV.3 and CIKM5, which recognize CDw32 moieties. Lastly, the FcRIII has a Mr of 50 to 70 kDa and is recognized by anti-CD16 mAb. In the present study we have shown that i) only murine IgG1-coated E form rosettes with 49 +/- 1.5% (mean +/- SEM, n = 9) of CD1a+ epidermal cells (EC) (which represent Langerhans and indeterminate cells) and that ii) the mAb anti-FcRII CIKM5 prevents this rosette formation. Among the mAb reacting with the three different types of FcR, only those recognizing FcRII i) stain about 55 +/- 1.5% (mean +/- SEM, n = 9) of the CD1a+ EC and ii) reveal the presence of dendritic cells in epidermal sheets obtained by suction blister. Under the electron microscope i) apparently all the cells forming rosettes or reacting with the gold-labeled anti-FcRII mAb (CIKM5 or the F(ab) fragment of IV.3) contained Birbeck granules and ii) the gold-labeled mAb were internalized in unfixed Langerhans cells by receptor-mediated endocytosis and accumulated in lysosomes. Labeling by the anti-FcRII mAb of the CD1a+ cells in suspension disappears after 48 h of culture. All these observations strongly suggest that CD1a+ EC express only the FcRII. This conclusion was confirmed by immunoprecipitation experiments, whereas no specific immunoprecipitate was noted with the anti-FcRI or anti-FcRIII mAb, the anti-FcRII mAb immunoprecipitated a protein of Mr 40 kDa.

Human epidermal Langerhans cells express only the 40-kilodalton Fc gamma receptor (FcRII)

In man, three distinct classes of receptors for the Fc fragments of IgG (FcRI, II, III) have been defined. The FcRI has a Mr of about 72 kDa, binds human IgG-coated E, and is recognized by mAb such as 32. The FcRII has a Mr of 40 kDa, binds murine IgG1-coated E, and reacts with the mAb IV.3 and CIKM5, which recognize CDw32 moieties. Lastly, the FcRIII has a Mr of 50 to 70 kDa and is recognized by anti-CD16 mAb. In the present study we have shown that i) only murine IgG1-coated E form rosettes with 49 +/- 1.5% (mean +/- SEM, n = 9) of CD1a+ epidermal cells (EC) (which represent Langerhans and indeterminate cells) and that ii) the mAb anti-FcRII CIKM5 prevents this rosette formation. Among the mAb reacting with the three different types of FcR, only those recognizing FcRII i) stain about 55 +/- 1.5% (mean +/- SEM, n = 9) of the CD1a+ EC and ii) reveal the presence of dendritic cells in epidermal sheets obtained by suction blister. Under the electron microscope i) apparently all the cells forming rosettes or reacting with the gold-labeled anti-FcRII mAb (CIKM5 or the F(ab) fragment of IV.3) contained Birbeck granules and ii) the gold-labeled mAb were internalized in unfixed Langerhans cells by receptor-mediated endocytosis and accumulated in lysosomes. Labeling by the anti-FcRII mAb of the CD1a+ cells in suspension disappears after 48 h of culture. All these observations strongly suggest that CD1a+ EC express only the FcRII. This conclusion was confirmed by immunoprecipitation experiments, whereas no specific immunoprecipitate was noted with the anti-FcRI or anti-FcRIII mAb, the anti-FcRII mAb immunoprecipitated a protein of Mr 40 kDa.

Familial hyperinsulinism with nesidioblastosis of the pancreas: further evidence for autosomal recessive inheritance

We report on a brother and sister with hyperinsulinism and nesidioblastosis of the pancreas. In addition, one brother and one sister who died in the neonatal period were probably affected. The parents of these children were healthy and consanguineous. We think that this is strongly suggestive of autosomal recessive inheritance. Seven other reports of presumed autosomal recessive hyperinsulinism are reviewed. To our knowledge, we report the first case in sibs whose parents were consanguineous. We think that early recognition of the condition is of obvious importance not only for therapy, but also for purposes of genetic counseling.

[Does nimodipine improve the outcome of perioperative complications of aneurysm rupture? Results of systematic treatment]

Morbidity after aneurysmal subarachnoid hemorrhages is proceeding from many factors; ischemic etiology is underestimated and frequently thought to be vasospasm related only. Other undoubted mechanisms are in the setting of ischemic disorders after ruptured aneurysms. The management of these disorders is relevant of new calcium blockers. Early administration of prophylactically oral nimodipine, with temporary intravenous administration of the therapy after surgery or in the setting of delayed ischemic deterioration, were assigned to 36 patients with aneurysm surgery. Efficacy was judged on prevention and outcome of ischemic disorders at discharge and three months later using the Glasgow Outcome Scale. On all, twenty-nine patients were disabled from any etiology; twenty made full or improved recoveries at discharge; twenty-eight get independent conditions of life at 3 months. Fourteen patients have return to their pre-rupture activity. Twenty-two surgical patients (61%) set an undoubtly ischemic disability during any time of their hospitalization, but many etiologies were identified in majority of cases. Spasm is the main factor of stroke in only 6 patients, and one of the ischemic factors in 15 cases. Among these ischemic deteriorations, twenty improved or made full recovery at discharge and get independent life at 3 months. No death with spasm. These data support the assumption that vasodilatating is not the only mode of nimodipine action. Hypervolemia must be adjunct with nimodipine to prevent regional hypoperfusion.

ATPase and morphologic changes in Langerhans cells induced by epicutaneous application of a sensitizing dose of DNFB

We have previously described an ATPase Langerhans cell (LC) staining technique allowing progression from light to electron microscope observation. Using this technique we have studied, following epicutaneous application of a sensitizing dose of a hapten, 2,4-dinitro-1-fluorobenzene (DNFB), the fate of the epidermal LC located in the sensitization zone. We wanted to know, under the light microscope, if the density and/or morphology of the LC are modified by such a treatment and, under the electron microscope, what are the ultrastructural changes accompanying the possible light microscope modifications. Under the light microscope, the observation of LC during the 5 d necessary for the development of contact sensitivity to DNFB shows that their number drops in the course of the first 24 h to normalize again 3 d later. Under the electron microscope, observations over the first 24 h revealed that LC remained in the epidermis, but were ATPase-negative. The disappearance of the membrane ATPase activity took place while the LC presented an increased number of coated pits, coated vesicles, endosomes, and lysosome organelles which characterize, at the ultrastructural level, the process of receptor-mediated endocytosis (RME). Following RME, many Birbeck granules (BG) appeared in the cytoplasm. Thus, epicutaneous application of DNFB leads to an endocytic activation of LC. However, the ligand(s) and/or the cell-surface components, which probably internalize during the RME process, remain unknown.

[Idiopathic granulomatous hepatitis and lymphoma of serous membranes]

We described the case of a woman with idiopathic granulomatous hepatitis who developed a type B lymphoma with serous effusion six years later. This association raised the hypothesis that sarcoidosis or lymphoma could present as idiopathic liver granuloma. We suggest that lymphoma developed in our patient as a consequence of the granulomatous hepatitis. This lymphoma was particular because only sera were involved.

Quantitative study of centrolobular hepatic fibrosis in alcoholic disease before cirrhosis

In an attempt to determine the importance of perivenular fibrosis (PVF) in alcoholic liver disease, we studied 71 liver biopsies using histological grading and a morphometric method. The histological grading used 7 variables which allowed us to classify the patients into 7 groups: controls, patients without alcoholic hepatitis but with steatosis, steato-fibrosis, portal fibrosis and patients with mild, moderate, or severe alcoholic hepatitis. The quantitative analysis examined 3 parameters: (1) The inner diameter of the terminal hepatic veins (THV). (2) The thickness of the THV rims, related to perivenular fibrosis (PVF). (3) Centrolobular fibrosis (CLF) which represented the association of perivenular and perisinusoidal centrolobular fibrosis. No changes in the inner diameter of the terminal hepatic veins was observed for the different groups except in the case of severe alcoholic hepatitis. This fact indicated the absence of veno-occlusive lesions in early stages of mild and moderate alcoholic disease. In severe alcoholic hepatitis, THV were destroyed by centrolobular scars and most of them were indistinguishable and unmeasurable. Of the 26 cases with steatosis (with or without portal fibrosis) only two cases with steatofibrosis showed perivenular fibrosis. In contrast, a significant increase in PVF and in CLF appeared in patients with alcoholic hepatitis. CLF is easier to quantify and more significative than PVF. Thus, it seems to us that CLF is a better indicator of the intensity of sclerosis and of the risk of developing cirrhosis than PVF alone.