Early evolution of cytochrome bc complexes.

Primary structures, functional characteristics and phylogenetic relationships of subunits of cytochrome bc complexes from phylogenetically diverse bacterial and archaeal species were analysed. A single case of lateral gene transfer, i.e. the import of an epsilon-proteobacterial cytochrome bc(1) complex into Aquificales, was identified. For the enzyme in the remainder of the species studied, the obtained phylogenies were globally in line with small subunit rRNA trees. The distribution of a few key phylogenetic markers, such as contiguousness of cytochrome b, nature of the c-type subunit or spacing between b-heme ligands, are discussed. A localised modification of previous tree topologies is proposed on the basis of the obtained data. The comparison of extant enzymes furthermore allowed us to define the minimal functional and evolutionary core of the enzyme. The data furthermore suggest that the ancestral enzyme was put together from subunits that previously had played a role in other electron transfer chains.

Thyroid hormone and dietary carbohydrate induce different hepatic zonation of both "spot 14" and acetyl-coenzyme-A carboxylase: a novel mechanism of coregulation.

The S14 gene encodes a protein found in the nuclei of lipogenic tissues that is induced synergistically by thyroid hormone (T3) and dietary carbohydrate, as are several lipogenic enzymes. In hyperthyroid rats, hepatic expression of S14 protein is zonated. The established association of S14 gene expression with lipogenesis, therefore, prompted a comparison of the zonal distribution of induction of S14 and acetyl-coenzyme-A-carboxylase (ACC), a rate-determining enzyme of fatty acid synthesis, by T3, dietary carbohydrate, and both stimuli together. As determined by immunohistochemistry, liver from chow-fed hypothyroid or euthyroid fasted rats showed essentially no reactivity for either S14 or ACC. Sections from hyperthyroid rats exhibited nuclear staining with anti-S14 antibodies and cytoplasmic reactivity for ACC that was primarily perivenous in both cases. In contrast, sections from euthyroid-fasted animals refed a high carbohydrate, fat-free diet for 3 days exhibited panlobular expression of both antigens. Animals receiving both T3 and high carbohydrate diet refeeding showed increased intensity of staining, compared to the refed group, for both S14 and ACC across the entire lobule. Therefore, in rats consuming normal chow, T3 induced S14 and ACC only in the perivenous zone of the acinus, whereas it further induced these proteins across the entire lobule in the presence of increased carbohydrate intake. Modulation, by the carbohydrate content of the diet, of the fraction of the liver that may express S14 and ACC in response to T3 provides a mechanism for coregulation of the genes involved in hepatic lipid formation. Moreover, the observed cozonation of S14 and ACC as well as the quantitatively similar effects of T3 and dietary carbohydrate on S14, ACC, fatty acid synthetase, and ATP-citrate lyase protein abundance prompt the speculation that S14 acts in the nucleus to promote expression of the genes involved in the lipogenic pathway.

Nuclear localization and hepatic zonation of rat "spot 14" protein: immunohistochemical investigation employing anti-fusion protein antibodies.

S14 protein and mRNA levels are rapidly regulated by hormones and diet. We have purified a 45-Kd fusion protein from lysates of transformed E. coli that includes the entire S14 polypeptide. Affinity-purified rabbit anti-fusion protein antibodies were used in immunohistochemistry to determine the distribution of S14 protein across the hepatic lobule, and to reassess its intracellular location. In hyperthyroid liver, S14 protein clustered near the central venous zone, and was not detectable in the periportal area of the acinus. The signal in perivenous hepatocytes was primarily nuclear in location, in stark contrast to previous subcellular fractionation studies. Visualization of identical hepatic distribution and subcellular localization employing anti-synthetic peptide antiserum provided evidence for the specificity of the immunostaining, as did attenuation of the signal by preincubation of the antibody with its antigen. No staining was observed in sections of heart or hypothyroid liver, as expected from the low levels of S14 protein in those tissues. The data indicate that induction of S14 protein expression by T3 occurs through enhanced expression by perivenous hepatocytes, rather than by recruitment of cells in more peripheral zones of the lobule. Nuclear localization of the S14 protein by immunohistochemistry suggests that it is lost from nuclei during standard fractionation procedures, and prompts consideration of a role for S14 in regulation of nuclear structure and/or function.

Metastatic medulloblastoma: the experience of the French Cooperative M7 Group.

A retrospective analysis was performed to determine the outcome of children with metastatic medulloblastoma given a standardised treatment programme. Of 68 consecutive patients treated in the French M7 protocol for medulloblastoma, 23 presented with metastatic disease. They were uniformly treated with surgery, and the same protocol of chemotherapy and craniospinal radiotherapy. The 7-year relapse-free survival rate is 43% for metastatic patients compared to 68% for patients with localised disease. Survival did not correlate with age, sex, location of metastases, extent of initial surgery and the dose of radiation therapy on the posterior fossa. Survival did correlate with the dose to the cranial field with a threshold dose of 30 Gy. Patients with metastatic disease have a worse prognosis and require more aggressive therapies at initial presentation. The prognostic impact of the different sites of metastatic disease requires further evaluation in cooperative studies.

M4 protocol for cerebellar medulloblastoma: supratentorial radiotherapy may not be avoided.

The main goal of the M4 protocol was to evaluate the efficacy of treatment excluding supratentorial radiation in patients with newly diagnosed medulloblastoma. All patients underwent surgical resection and received postoperative chemotherapy. Chemotherapy was adapted to the initial staging and prognostic factors (Group A: good-risk; Group B: poor-risk). Chemotherapy was started early after surgery, and consisted of two courses of the "eight drug in one day" regimen and two courses of high dose methotrexate. Radiotherapy was delayed until 5 (Group B) to 7 (Group A) weeks after the first course of chemotherapy. Radiotherapy was administered only to the posterior fossa and the spinal axis. Only 3/16 patients (18%) are alive and disease-free with a mean follow up of 6 years. The site of progression was supratentorial in 9 out of 13 patients and three patients had spinal and/or cerebrospinal fluid relapses. Only one patient had isolated posterior fossa relapse. The mean time to relapse was 484 days. We conclude that the chemotherapy regimens used in the M4 protocol do not allow the reduction of irradiation fields in patients with cerebellar medulloblastoma. In spite of long-term side effects on neurocognitive functions, supratentorial radiotherapy should remain a major component of medulloblastoma treatment.

Simultaneous occurrence of a T-cell lymphoma and a chronic myelogenous leukemia with an unusual karyotype.

The simultaneous occurrence of malignant T-cell lymphoma and chronic myelogenous leukemia is reported. The lymph nodes contained E rosette forming cells. Blood and bone marrow cell morphology were consistent with the diagnosis of chronic myelogenous leukemia. Lymph nodes, bone marrow and blood mitosis showed a t(6;8) (6pter----6q27 ::8p12----8pter;6qter----6q27 ::8p12----8qter) translocation. So far a number of recent reports have shown simultaneous B lymphoid and myeloid proliferations in some malignancies, this is apparently the first reported case of simultaneous T lymphoid and myeloid proliferations.

Myelofibrosis and acute megakaryoblastic leukemia in a child: topographic relationship between fibroblasts and megakaryocytes with an alpha-granule defect.

In a child with acute megakaryoblastic leukemia--severe thrombocytopenia and myelofibrosis, EM studies on bone marrow showed a strict topographic relationship between the presence of clusters of abnormal megakaryocytes and the increased number of fibroblasts and extracellular fibers. Megakaryocytes and platelets lacked alpha-granules while the plasma thromboglobulin level was three times the normal level. This suggested that the alpha-granular proteins were synthesized but not retained in alpha-granules. If this occurs, the increased marrow levels of platelet-derived growth factor and factor 4 would favor the proliferation of fibroblasts and the synthesis of collagen, and thereby promote myelofibrosis. After therapy-induced remission, the number of marrow megakaryocytes decreased, the alpha-granules were normally produced, the plasma beta-thromboglobulin level was normal and the myelofibrosis disappeared. These observations suggest that during acute megakaryoblastic leukemia, an acquired gray-platelet syndrome occurs and that the local excretion of alpha-granule proteins triggers the myelofibrosis.

Treatment of an acyclovir and foscarnet-resistant herpes simplex virus infection with cidofovir in a child after an unrelated bone marrow transplant.

Herpes simplex virus (HSV) causes serious problems in immuno-compromised patients such as those receiving a bone marrow transplant (BMT) for a hematological malignancy. Resistance to acyclovir (ACV) is a growing major concern. Foscarnet is a non-thymidine kinase-dependent agent, but the emergence of ACV and foscarnet-resistant HSV requires a new therapeutic approach. We describe a girl treated with cidofovir for a life-threatening ACV-resistant HSV infection after an unrelated BMT for a relapse of an acute myeloblastic leukemia (AML).

Preirradiation chemotherapy including "eight drugs in 1 day" regimen and high-dose methotrexate in childhood medulloblastoma: results of the M7 French Cooperative Study.

The aim of this study was to evaluate the feasibility and efficacy of a protocol that includes "sandwich" chemotherapy, that is, chemotherapy alternated with radiotherapy, and reduced doses of supratentorial irradiation in children with medulloblastoma. Between March 1985 and September 1988, 70 successive children with newly diagnosed medulloblastoma from eight centers were treated in this prospective nonrandomized study. Patients were assigned to two risk groups. Group A included patients with macroscopically complete or subtotal excision, no brainstem involvement, no atypical cells in the cerebrospinal fluid, normal myelography, and who were more than 2 years of age. Group B patients encompassed those who did not fit the criteria for Group A. Two children were excluded from analysis after histological review confirmed ependymoma. Thus, a population of 68 children was selected, with 31 in Group A and 37 in Group B. Treatment consisted of two courses of the "eight drugs in 1 day" ("8/1") regimen followed by two courses of high-dose methotrexate (12 g/m2). Radiotherapy was begun during the 7th week after surgery in Group A and during the 5th week in Group B. In patients older than 2 years, the median radiation dose to the posterior fossa, the spinal axis, and the brain was 54 Gy, 36 Gy, and 27 Gy, respectively. Group B patients received postirradiation chemotherapy with four 8/1 courses monthly. The median time from surgery to radiation therapy was 50 days (range 21 to 141 days). One fatality due to chicken pox on Day 102 and one World Health Organization Grade IV infection occurred. The estimated 5- and 7-year disease-free survival (DFS) rates were 62% and 59%, respectively. These were 74% and 62% in Group A and 57% and 57% in Group B. Patient age, extent of resection, and radiation dose to the whole brain had no prognostic value. Patients with metastasis had a nonsignificant trend for a worse prognosis than patients with nonmetastatic disease (7-year DFS 45% vs. 68%, p = 0.11). In Group B, the 7-year DFS rates for children who received more or less than 30 Gy to the brain were 69% and 52% respectively (p = 0.15). There were recurrences in the posterior fossa (37%), spine (20%), and brain (20%). After a review of radiotherapeutic treatments, only one supratentorial failure could be blamed on reduction of the supratentorial radiation dose. This "sandwich" chemotherapy appeared to be feasible and did not show adverse survival data when compared to other series.

New evaluations of circulating granulocyte and macrophage stem cells in healthy adults using conditioned media and recombinant human growth factors.

Peripheral human blood contains granulo-monocyte (CFU-GM) and eosinophil (CFU-Eo) progenitors. In vitro, the number of colony forming units is thought to range from 0.1-14 per 2 x 10(5) plated cells. We show that the number of CFU-GM, Eo depends on culture methods. By modifying the usual assay method (using human umbilical cord plasma and the association of 2 stimulating conditioned media: activated lymphocyte conditioned medium and bone marrow fibroblast conditioned medium), we found different circulating CFU-GM, Eo numbers. The mean number of circulating CFU-GM, Eo in 107 healthy adults was 22.4 per 2 x 10(5) plated cells (range: 1-84). There was a slight difference between males (mean number: 23.6) and females (mean number: 20.4). The mean number of CFU-GM, Eo harvested on Percoll gradient was 123/ml of peripheral blood (range: 7-513). These results are far over those commonly reported in literature. This suggests that these latter results were probably underestimated. The use of recombinant human interleukin 3 and recombinant human GM (granulocyte-monocyte) colony-stimulating factors shows that CFU-GM, Eo numbers are found to be comparatively increased compared to that obtained with our modified method (using rhIL-3 alone), or that the size of those colonies is notably increased (using rhIL-3 + rhGM-CSF).

[Congenital aortic valve stenosis treated by dilatation. Apropos of a case with hemodynamic control 12 months later]. / Rétrécissement valvulaire aortique congénital traité par dilatation.

Intraluminal dilatation of congenital aortic valve stenosis was attempted in a 14-year old boy. Significant improvement was obtained, with a fall in transaortic gradient from 80 to 30 mmHg. A control haemodynamic examination performed 12 months later confirmed that the result was stable; there was no aortic leakage, and myocardial hypertrophy had begun to regress at echocardiography. This case is of interest in that dilatation is less costly than surgical commissurotomy. However, this technique cannot be widely used until satisfactory long-term results have been demonstrated in a large population of children.

[Paraplegia due to medullary ischemia after repair of coarctation of the aorta in an infant]. / Paraplégie par ischémie médullaire après cure chirurgicale d'une coarctation de l'aorte.

UNLABELLED: Paraplegia after repair of coarctation of the aorta is uncommon. CASE REPORT: A 2-month-old boy underwent excision of the coarctation area and primary anastomosis because of persistent heart failure. Spastic paraplegia was noted some hours after surgery. Motor deficit partially improved, but bladder dysfunction appeared some months after. Medullary magnetic resonance imaging (MRI) revealed an ischemia-related narrowing of the medullary diameter. CONCLUSION: Paraplegia after repair of coarctation of the aorta, described in adults and infants, is also seen in neonates. Prevention by preoperative monitoring of somatosensory evoked potentials is effective in adults, but difficult to perform in very young children.

[Hypoplasia of abdominal aorta, rare cause of hypertension in childhood]. / Hypoplasie de l'aorte abdominale, cause rare d'hypertension artérielle du grand enfant.

BACKGROUND: The majority of children with secondary hypertension have a renal abnormality or renovascular lesions. Coarctation of the aorta is also a classical cause, rarely located to the abdominal aorta. CASE REPORTS: Two girls, 11 and 12 years-old, were suspected of having recent sustained hypertension. Pulsed-wave doppler ultrasonography and angiography showed abdominal aortic hypoplasia associated with renal artery stenosis, unilateral in one patient and bilateral in the other. Both patients became normotensive 10 and 18 months, respectively, after corrective vascular surgery. CONCLUSION: Examination of the abdominal part of the aorta is mandatory in all patients with hypertension.

[Langerhans-cell histiocytosis in twin sisters]. / Histiocytose langerhansienne chez deux soeurs jumelles.

BACKGROUND--Histiocytosis of Langerhans cells includes a range of clinical manifestations that have been described as bone eosinophilic granuloma, Hand-Schüller-Christian syndrome, Letterer-Siwe syndrome and Hashimoto-Pritzker histiocytosis. These syndromes represent a spectrum of severity and prognosis of the same underlying disorder which is usually sporadic. It has occurred in monozygotic twins and in a familial pattern. This report describes monozygotic twins who developed the disease a few months after their father was found to be suffering from Hodgkin's disease. Case n. 1.--A 4 month-old girl was admitted because of fever, disseminated lymphadenopathy and hepatomegaly. She also had interstitial pneumonia. Infiltrating abnormal histiocytes were demonstrated in lymph node and bone marrow biopsies. X-rays showed lytic areas in the skull. Serology for EBV infection was negative. Special studies with immune markers of lymph node histiocytes confirmed the diagnosis of Langerhans cell histiocytosis, and more precisely, Letterer-Siwe syndrome. The patient was given prednisolone followed by vinblastine without success. She was given etoposide 11 weeks later, which induced remission. This treatment was replaced by vinblastine when the patient was aged 2 years 9 months. Case n. 2.--The monozygotic twin of the case n. 1 was also admitted at 4 months of age because of the same manifestations. Laboratory findings were identical to those of her sister, as was her response to the same drugs. The father was diagnosed as having Hodgkin's disease 3 months before the first manifestation of Langerhans cell histiocytosis in his daughters. His maternal uncle had also been treated for Hodgkin's disease. Immunologic studies of the twin were negative. CONCLUSION--These cases of Langerhans cell histiocytosis in monozygotic twins have no apparent relationship with the Hodgkin's disease of their father. Etoposide seems to be useful for treating such severe forms of the disease.

[Cefepime-amikacin combination in febrile neutropenic children with malignant hemopathy or tumor]. / Association céfépime-amikacine chez les enfants neutropéniques fébriles atteints d'hémopathies ou de tumeurs malignes.

UNLABELLED: Our aim was to evaluate retrospectively the efficacy of a therapeutic strategy with a first line combination based on cefepime-amikacin in febrile neutropenic children treated with chemotherapy. PATIENTS AND METHODS: Sixty-five neutropenic febrile episodes in 43 children treated by the association cefepime-amikacin, were evaluated according to the clinical status, the depth and duration of neutropenia, the underlying disease and the initial treatment. RESULTS: Thirty-nine (60%) episodes were successfully treated by the association cefepime-amikacin. Among the 26 persisting febrile episodes, adjunction of vancomycin and amphotericin B was effective in 11 (76% of total rate success) and 5 (84% of total rate success) cases respectively. The efficacy of the first line antibiotherapy was not different as regards to the duration and the depth of neutropenia. Otherwise, febrile episodes after chemotherapy against solid tumours were rapidly controlled by the first and second line of the anti-microbial strategy. Children treated for haematological malignancies presented a lower response rate (P = 0.03). CONCLUSION: In febrile and neutropenic children treated with chemotherapy, the association cefepime-amikacin appeared to be a safe empirical treatment. In a neutropenic child, the immunodeficiency and possibly the clinical status should be the major factors of the infectious prognosis more than the duration of aplasia.

[Antineoplastic chemotherapy and Wernicke's encephalopathy]. / Chimiothérapie anticancéreuse et encéphalopathie de Gayet-Wernicke.

BACKGROUND: Wernicke's encephalopathy is usually seen in alcoholic adults. It is rare in childhood and usually discovered in a context of several pathological events. We report here a typical case of a teenager. CASE REPORT: A 15-year-old girl with acute leukemia was given chemotherapy that resulted in profound aplasia and serious infection. She exhibited abnormal eye movements, ataxia, lethargy, enuresis and amnesia. MR examination showed T2-weighted images with increased signal in the thalami (pulvinar) and periaqueducal region. The symptoms improved dramatically with thiamine therapy. Omission of the usual vitamin supplementation between the courses of chemotherapy was responsible for this encephalopathy. CONCLUSION: Thiamine deficiency can lead to death or amnesia. Rapid efficacy of vitamin supplementation helps diagnosis and prevents sequelae.

[Imerslund's disease. Clinical and biological aspects. Apropos of 6 cases]. / Maladie d'Imerslund. Aspects cliniques et biologiques. A propos de six cas.

BACKGROUND: Imerslund syndrome, a recessive autosomal disease, initially described by Imerslund and Grasbeck in 1960, associates megaloblastic anemia and proteinuria. CASE REPORT: We report on six cases, studied in five different families. All patients (mean age: 3.5 years) had clinical symptoms of anemia, three had malabsorption, proteinuria was present in five, at the time of diagnosis. Hemogram and decreased serum vitamin B12 levels were consistent with the diagnosis in all cases. Intra-muscular injections of cyanocobalamine was instituted on a life-time basis and the long term prognosis is good. CONCLUSION: The diagnosis should be evoked when the three typical features are present: macrocytic anemia, decreased serum B12 level and proteinuria. It will be confirmed by the bone marrow megaloblastic aspects and the Schilling test findings.

[Aniridia and Wilms tumor: 2 cases of fetal rhabdomyomatous nephroblastoma]. / Aniridie et tumeur de Wilms: deux cas de néphroblastome foetal rhabdomyomateux.

BACKGROUND: Wilms tumor is associated in 7 to 10% of patients with congenital abnormalities. Among those, aniridia is the most constant feature of the WAGR syndrome that includes, in one third of cases. Wilms tumor. We report two cases of aniridia associated with fetal rhabdomyomatous nephroblastoma. CASE REPORTS: Case 1. A one-year old girl with congenital aniridia was admitted for macroscopic hematuria. Abnormal ultrasonography and tomodensitometry revealed a large, bilateral, kidney tumor. The patient was given actinomycin and vincristine, without efficacy. Bilateral tumorectomy was performed 6 months later and the histological study showed a fetal rhabdomyomatous nephroblastoma. This patient is in remission at the age of 5. Case 2. A boy, also with congenital aniridia, presented with macroscopic hematuria at the age of 2 years revealing a nephroblastoma located on his right kidney. Preoperative chemotherapy remained uneffective and the nephrectomy performed 1 month later permitted the diagnosis of fetal rhabdomyomatous nephroblastoma. The patient is well 4 years later. CONCLUSION: Both cases of fetal rhabdomyomatous nephroblastoma, a histological variant of Wilms tumor, seem to be the first reported in the WAGR syndrome.

[Eczema-like cutaneous graft versus host disease treated by UV-B therapy in a 2-year-old child]. / GVH cutanée eczématiforme traitée par UV-B thérapie chez un enfant de deux ans.

INTRODUCTION: Chronic graft versus host disease (GVHD) has rarely been reported in children. Optimal treatment should minimize infectious complications and preserve the child's growth. We report a case of cutaneous GVHD in a two year-old boy, who presented an eczema-like eruption and responded well to broad band UV-B therapy. CASE REPORT: A two year-old boy with acute myeloblastic leukemia had a heterologous bone marrow transplantation with a graft issued from an unrelated female donor. Three month later, he developed eczema-like lesions of the trunk, arms and legs associated with diffuse alopecia, despite oral corticosteroids and cyclosporine treatment. Histologic findings were consistent with GVHD. Topical corticosteroids and broad band UV-B therapy were initiated, while oral corticosteroids and cyclosporine doses were tappered off. GVHD lesions cleared, allowing withdrawal of oral corticosteroids and cyclosporine 3 and 12 months respectively after initiation of UV-B therapy. No relapse occurred 24 months after systemic treatment discontinuation and 12 months after broad band UV-B therapy was stopped. CONCLUSION: This observation suggests that broad band UV-B therapy is an effective treatment for eczema-like, cutaneous GVHD.