Variability of sweat chloride concentration in subjects with cystic fibrosis and G551D mutations.

INTRODUCTION: Sweat chloride concentration, a biomarker of CFTR function, is an appropriate outcome parameter in clinical trials aimed at correcting the basic CF defect. Although there is consensus on a cut-off value to diagnose CF, we have only limited information on the within subject variability of sweat chloride over time. Such information would be useful for sample size calculations in clinical trials. Therefore, we retrospectively analyzed repeated sweat chloride values obtained in patients with G551D mutation(s) assigned to placebo in an ivacaftor interventional trial. METHODS: In subjects with G551D at least 12years of age, a pilocarpine sweat test using Macroduct collector was taken on both arms at 8 time points over 48weeks. We explored 1062 pilocarpine sweat test values obtained in 78 placebo patients of the VX08-770-102 trial. RESULTS: Mean overall sweat chloride value (all patients, all tests, n=1062) was 100.8mmol/L (SD 12.7mmol/L). Using a multilevel mixed model, the between-subject standard deviation (SD) for sweat chloride was 8.9mmol/L (95% CI 7.4-10.6) and within-subject SD was 8.1mmol/L (95% CI 7.5-8.7). Limits of repeatability for repeat measurements were -19.7 to +21.6mmol/L using values from one arm, and -13.3 to 11.8mmol/L using mean of values obtained at 4 test occasions. Sample size calculations showed that the minimal treatment effect on sweat chloride concentration that can be demonstrated for a group of 5 patients is around 15mmol/L, using a cross-over design and combinations of 4 tests for each phase of the trial. CONCLUSION: Although the sweat test is considered a robust measure, sweat chloride measurements in patients with CF and a G551D mutation had an inherent biological variability that is higher than commonly considered. Further analyses of placebo group data are crucial to learn more about the natural variability of this outcome parameter.

Evaluation of the impact of urban pollution on the quality of skin: a multicentre study in Mexico.

OBJECTIVE: After pilot and preliminary studies aimed at identifying pertinent biochemical parameters, a multicenter clinical study was performed to evaluate the effect of pollution on human skin. METHODS: The clinical study was performed in collaboration with the 'Centre Régional de lutte contre le cancer de Montpellier' and the 'National Institute of Public Health of Mexico' on 96 subjects in Mexico City (exposed to pollution) and 93 subjects in Cuernavaca (less exposed to pollution). Both biochemical and clinical skin parameters were studied. RESULTS: The study demonstrated significant quantitative and qualitative modifications of parameters related to sebum excretion in Mexico City compared to Cuernavaca one: An increased level of sebum excretion rate, a lower level of vitamin E and squalene in sebum, an increase of lactic acid and a higher erythematous index on the face of the subjects. In the stratum corneum, a significant higher level of carbonylated proteins and a lower level of IL 1α were noticed, as well as a decrease of ATP concentration with a decrease of chymotrysin like activity, without modifications of corneodesmosin content and trypsin like activity. From a clinical point of view, a higher frequency of atopic and urticarial skins, a higher frequency of red dermographism, an important seborrheic status at the forehead level and a lower level of dandruffs were noted in Mexico City population. The analysis taking into account the sex does not modify the observed results. CONCLUSION: The study demonstrated an important impact of polluted environmental conditions on skin quality, evidencing important modifications of superficial biochemical parameters. The cause/effects relationships of these modifications remain, however, to be further assessed by a complementary in vitro/in vivo approaches.

High prevalence of chitotriosidase deficiency in Peruvian Amerindians exposed to chitin-bearing food and enteroparasites.

The human genome encodes a gene for an enzymatically active chitinase (CHIT1) located in a single copy on Chromosome 1, which is highly expressed by activated macrophages and in other cells of the innate immune response. Several dysfunctional mutations are known in CHIT1, including a 24-bp duplication in Exon 10 causing catalytic deficiency. This duplication is a common variant conserved in many human populations, except in West and South Africans. Thus it has been proposed that human migration out of Africa and the consequent reduction of exposure to chitin from environmental factors may have enabled the conservation of dysfunctional mutations in human chitinases. Our data obtained from 85 indigenous Amerindians from Peru, representative of populations characterized by high prevalence of chitin-bearing enteroparasites and intense entomophagy, reveal a very high frequency of the 24-bp duplication (47.06%), and of other single nucleotide polymorphisms which are known to partially affect enzymatic activity (G102S: 42.7% and A442G/V: 25.5%). Our finding is in line with a founder effect, but appears to confute our previous hypothesis of a protective role against parasite infection and sustains the discussion on the redundancy of chitinolytic function.

[Seriousness of AL amyloidosis of the digestive system]. / Gravité de l'amylose AL de localisation digestive.

Systemic amyloidosis usually does not spare the digestive tract but its involvement is rarely symptomatic. The clinical manifestations are not specific. We report a 64-year-old patient, presenting with a weight loss related to an AL amyloidosis. The amyloidosis was apparently limited to the digestive tract. We discuss the various presentations of the digestive amyloidosis and we insist on the seriousness of this localization.

[The outcome of children presenting with a prenatally diagnosed arachnoid cyst]. / Devenir des enfants présentant un kyste arachnoïdien de diagnostic anténatal.

AIM: Evaluate the outcome of children with prenatally diagnosed arachnoid cysts. MATERIAL AND METHODS: Retrospective study of seventeen cases of children who were diagnosed with an arachnoid cyst during prenatal MRI between July 1994 and January 2007 and followed up for a mean 6 years and 6 months. Follow-up was based on evaluation of clinical files and contacts with the physicians who were following the children. The children were divided into three groups: group 1 normal development, group 2: minor clinical signs, normal schooling, group 3: major clinical symptoms, schooling disturbed. RESULTS: Eight of the 17 patients included in this study underwent derivation surgery for the cyst. Eight of the 17 children were in group 1, and 3 in group 2. Four of the 6 children in group 3 had associated symptoms. Two of the children in group 3 present with a supratentorial cyst, and 4 with a cyst of the posterior fossa. CONCLUSION: The prenatal diagnosis of a arachnoid cyst should be accompanied by a search for associated lesions. The risk of hydroencephalitis should be explained to the parents.

Epidemiology of invasive aspergillosis and risk factors in non neutropaenic patients.

INTRODUCTION: Invasive aspergillosis is a major cause of mortality in allogeneic bone marrow transplant recipients and patients treated for blood malignancies. The diagnostic tools, treatments and preventive strategies, essentially developed for neutropaenic patients, have not been assessed in populations whose immune systems are considered to be competent. STATE OF THE ART: Beside the standard picture of chronic Aspergillus infection, the incidence of invasive aspergillosis is increasing in non neutropaenic patients, such as those with chronic lung diseases or systemic disease treated with long-term immunosuppressive drugs and solid organ transplant recipients. This study reviews the specific features of invasive aspergillosis in non neutropaenic subjects (NNS) and discusses the value of the diagnostic tools and treatment in this population. PROSPECTS: A better understanding of the pathophysiology and the epidemiological characteristics of invasive aspergillosis would provide a means of adapting the staging and classification of the disease for NNS. CONCLUSIONS: Invasive aspergillosis is under diagnosed in NNS who may already be colonised when they receive immunosuppressive treatment; this can lead to an adverse outcome in patients who are considered to be a moderate risk population.

[Epidemiology of and risk factors for invasive aspergillosis in nonneutropenic patients]. / Epidémiologie et facteurs de risque de l'aspergillose invasive du sujet non neutropénique.

INTRODUCTION: Invasive aspergillosis is a major cause of mortality among patients with hematological malignancies and undergoing bone marrow transplantation. Whereas diagnosis and therapeutic strategies are evaluated for neutropenic patients, only limited data among nonneutropenic patients are available. STATE OF THE ART: Beside classical chronic pulmonary aspergillosis, an increased incidence of acute invasive aspergillosis is reported for nonneutropenic patients, such as patients suffering from chronic respiratory diseases or systemic diseases treated with corticosteroid therapy, and solid organ transplant recipients. PERSPECTIVES: A better knowledge of pathophysiology and epidemiology of invasive aspergillosis is needed to adapt the disease classification for nonneutropenic patients. Beside, the performance of diagnostic tools must be evaluated specifically in this population. CONCLUSIONS: Invasive aspergillosis is underdiagnosed in nonneutropenic patients which may simultaneously be colonized by Aspergillus and receive immunosuppressive therapy. It remains a life-threatening disease as severe as in neutropenic patients, at least partially related to a delayed diagnostic.

[Difficult weaning due to tracheal compression by an esophageal bezoar]. / Difficulté de sevrage par compression trachéale due à un bézoard.

INTRODUCTION: Bezoars result from the aggregation of ingested materials (food, drugs, hair) that accumulate at a certain anatomic level in the gastrointestinal tract. It is a rare condition, which is favoured by a reduction in intestinal motility, or by a primary abnormality reducing the patency of gastrointestinal tract. CASE REPORT: We present a case when acute respiratory symptoms revealed an oesophageal bezoar. The patient presented with compression of the posterior tracheal wall by an oesophageal bezoar. The diagnosis was confirmed by oesophageal endoscopy. Treatment consisted in endoscopy-guided fragmentation and removal of the bezoar followed by topical lavage. CONCLUSION: Oesophageal bezoars may account for compression of the posterior tracheal wall causing acute respiratory failure or difficult weaning from the ventilator. The close anatomic proximity between the gastrointestinal and respiratory tract may explain the impact of oesophageal bezoars on the respiratory tract.

C4d: a marker for hepatic transplant rejection.

BACKGROUND: Acute rejection is still a common complication of hepatic transplantation. The diagnosis, based on the histological examination of the graft, may be difficult to confirm in the setting of combined hepatitis C virus infection. The presence of C4d in the portal capillaries could facilitate differentiation between acute rejection and relapsed hepatitis C. The deposit of C4d provides evidence of activation of humoral immunity. To attempt to confirm this hypothesis, we searched for the presence of C4d in posttransplant hepatic biopsies. METHODS: Thirty-six biopsies from 34 patients were analyzed retrospectively. The samples had been requested for one of the following reasons: suspected rejection, relapsed hepatitis C infection, or systematic check-up 1 year after the transplant. RESULTS: C4d expression was common in biopsies classified as acute rejection (33%) and chronic rejection (100%). C4d was never detected in the event of recurrent hepatitis C infection without rejection. CONCLUSION: These results, which are comparable to recently published data, give credence to the theory that C4d could be used as a marker for rejection following hepatic transplantation.

Comparison of epidemiological, clinical, and biological features of invasive aspergillosis in neutropenic and nonneutropenic patients: a 6-year survey.

BACKGROUND: Invasive aspergillosis is an opportunistic infection that occurs mainly among patients with prolonged neutropenia. Few data are available on invasive aspergillosis in nonneutropenic patients. METHODS: The aim of this survey was to compare neutropenic and nonneutropenic patients who had received a diagnosis of invasive aspergillosis at our institution during a 6-year period. RESULTS: Among the 88 cases of invasive aspergillosis analyzed here, 12 were histologically proven, 52 were probable, and 24 were possible. Forty-seven percent of cases were diagnosed in the intensive care unit, and 40% were diagnosed in hematology units. Neutropenia was a risk factor for 52 patients (59%), most of whom had hematological or solid malignancies. Among the 36 nonneutropenic patients (41%), the main underlying conditions were steroid-treated chronic obstructive pulmonary disease, asthma, rheumatoid arthritis, giant-cell arteritis, and microvascular disorders; 10 patients were recipients of solid-organ transplants, and 1 patient was seropositive for human immunodeficiency virus. The distribution of proven and probable invasive aspergillosis was similar for neutropenic and nonneutropenic patients. The mortality rate was 71.5% overall and was significantly higher among nonneutropenic patients than among neutropenic patients (89% vs. 60%; P<.05). Compared with neutropenic patients, nonneutropenic patients were significantly less likely to have symptoms of invasive aspergillosis and more likely to have frequent intercurrent pneumonia due to another microorganism. The sensitivity of mycological examination of bronchoalveolar lavage fluid specimens was higher for nonneutropenic patients than for neutropenic patients (85% vs. 58%; P<.05), whereas the sensitivity of antigenemia was the same for the 2 populations (65% vs. 64%). Findings on thoracic computed tomographs were similar, except that segmental areas of consolidation occurred more frequently among neutropenic patients. CONCLUSION: This survey at a whole institution underlines the high number of cases of invasive aspergillosis among nonneutropenic patients, with an overall mortality rate that was significantly higher than that for neutropenic patients.

[Cryptococcal meningitis associated with chronic lymphocytic leukemia: a case report. Review of the literature]. / Cryptococcose neuroméningée et leucémie lymphoïde chronique: à propos d'une observation. Revue de la littérature.

INTRODUCTION: The authors report the occurrence of a cryptococcal meningitis in a patient treated by corticosteroids and polychemotherapy for a chronic lymphocytic leukemia. EXEGESIS: A 63-year-old man with chronic lymphocytic leukemia was sent to hospital because of impaired condition with fever. Neurological disorders appeared. Cryptococcal meningitis was diagnosed. Under treatment, the outcome was favorable. CONCLUSION: This paper highlights the feature of this infection most likely underestimated in HIV-seronegative patients and the need to a priori consider this diagnosis.

Acute respiratory failure caused by secondary alveolar proteinosis in a patient with acute myeloid leukemia: a case report.

Pulmonary alvelolar proteinosis (PAP) is a rare cause of chronic respiratory failure due to progressive alveolar accumulation of a periodic acid-schiff (PAS) positive proteinaceous material. In some cases, the rapid accumulation of intra-alveolar material leads to acute respiratory failure (ARF). We report the causative role of secondary PAP in the case of a 26-year-old man with acute myeloid leukemia who developed fever, increased serum lactate dehydrogenase level and ARF, and required mechanical ventilation. The diagnosis of PAP was established by the examination of material obtained by bronchoalveolar lavage (BAL). Respiratory improvement occurred several days after the patient had recovered from neutropenia. This report underlines the importance of the early diagnosis of PAP as a potential cause of ARF in leukemic patients. Adequate stain on BAL fluid provides the diagnosis and avoids repeated invasive procedures and inappropriate treatments.

Dimerization of Cdc25p, the guanine-nucleotide exchange factor for Ras from Saccharomyces cerevisiae, and its interaction with Sdc25p.

The oligomerization state of Cdc25p, the guanine nucleotide exchange factor for ras from yeast, was analyzed using different complementary approaches. The two-hybrid system showed that the C-terminal part of Cdc25p (Cdc25-Ct) can interact with itself but also with Sdc25p-Ct, the corresponding part of Sdc25p, the other guanine exchange factor from yeast. The homotropic interaction of Cdc25p-Ct has been confirmed in yeast using immunoprecipitation experiments with epitope-tagged and beta-galactosidase-fused polypeptides. No other component was required for this interaction, since dimerization was shown to occur with material synthesized in vitro. The size of Cdc25-Ct produced in Escherichia coli has been directly measured on gel filtration columns and corresponds to a dimer. The dimerization domain is localized in the same part of the molecule as the catalytic domain and the portion responsible for membrane localization. The biological relevance of dimerization is still an open question, however by allowing heterodimerization with Sdc25p it could permit a more complex combinatorial regulation of ras in yeast.

["De novo" cancer after organ transplantation]. / Les cancers "de Novo" après transplantation d'organe.

From March 1972 to 1st of January 1996, 804 kidney, liver and pancreas transplants were performed in 690 patients. 39 post transplant cancers occurred in 27 patients. 21 skin tumors (15 squamous cell carcinoma, 4 basocellular carcinomas, 1 squamous carcinoma, 1 melanoma), 4 squamous cancers (anus, esophagus, tongue, and parotid), 4 post-transplant lymphoproliferative disorders, 1 non-Hodgkin's lymphoma T, 4 gynecological tumors (breast, ovarian peritoneal carcinomatosis, 2 uterine cervix cancers), 4 miscellaneous tumors (larynx, right colon, brain, prostate, own kidney). 14 patients died (14/27: 52%). Post transplant de novo cancers are a major risk in transplant patients These cancers are mainly represented by skin tumors and lymphomas. Skin cancers are mainly spinocellular and occur in the areas which are exposed to the sun. Post transplant lymphoproliferative disorders are very close to Burkitt's lymphoma, they produced B lymphocyte proliferation due to the reduction of the control of T lymphocytes and induced by Epstein-Barr virus. They can disappear with the diminution of immunosuppression.

[200 first hepatic transplantation at the Rennes University Hospital]. / Les 200 premières transplantations hépatiques du C.H.U. de Rennes.

UNLABELLED: From 21st of april 1978 to 1st september 1994, 200 liver transplantations in 172 patients were performed in the Medical Center of University of Rennes. Three patients had a liver and kidney transplant. 26 patients received a second transplant (13%) and 2 patients a third transplant (1%). There were 110 males and 62 females with a mean age of 43.7 years (range 17 months-66 years). The indications of transplantations were the following: 22 fulminant hepatitis (12%), 104 cirrhosis (60.5%), including 41 alcoholic cirrhosis (24%), 21 post-hepatitis B cirrhosis (12.2%), 24 post-hepatitis C cirrhosis (14%), 6 autoimmune cirrhosis, 7 primary biliary cirrhosis (4%), 21 non A non B cirrhosis (12.9%), 3 undetermined cirrhosis. Thirty one patients had a liver transplantation for cancer. The other indications were 5 sclerosing cholangitis and 2 atresia of the biliary tract. 45% of the patients had an uneventful postoperative course. In hospital mortality rate is related to the indication and Child Pugh classification in cirrhotic patients. The vascular surgical complications were 8.5%, biliary complications 6.1%, intra-abdominal infection 9.2%, intra-abdominal bleeding 5.5%. The rate of reoperation was 18.5%. 23 re-transplantations were performed in emergency and 6 electively (one from outside). The overall survival of patients from 1978 to 1994, including the patients before cyclosporine era, the use of extracorporeal circulation, the preservation with Wisconsin solutions and with main indications for cancer was 69% at 1 year and 59% at 5 years. After 1988, the overall patient survival was 75% at 1 year and 70% at 5 years. The graft and patient survival is mainly related to the indications. In fulminant and subfulminant hepatitis, the quality of the graft was preferred as often as possible. The actuarial graft survival at 1 year, 3 years and 5 years was respectively 75%, 70.45% and 70.45%. The actuarial patient survival was 77.3%, 72.5% and 72.5%. In liver transplantation for cancer, the actuarial patient survival at 1 year, 3 years and 5 years is respectively 55%, 32% and 23.5%. 5 patients are alive and well at 5 years, including a patient who underwent a Cluster operation for Klatskin tumor. In post-hepatitis cirrhosis, the patient actuarial survival at 1 year, 3 years and 5 years was 79%, 76.5% and 76.5% and in alcoholic cirrhosis 75%, 72% and 72%. The actuarial survival is closely related to Child Pugh Classification (at one year Child A 87%, Child B 72.4%, Child C 58%). CONCLUSION: in this series of the first 200 liver transplants at the University of Rennes Medical Center, graft and patient survival depends on the evolution of the surgical technic but it is also closely related to the indication. In fulminant hepatitis, the quality of the graft (without incompatible graft, if possible) should permit to avoid retransplantation and to obtain results closely to the elective transplantation. Liver transplantation for cancer should be restricted. In cirrhosis, results are depending upon Child Pugh classification. The conclusions of Paris consensus conference should be followed. The limited number of donor livers call for the "priorization" (T.E. Starzl) favoring those patients who will benefit most, i.e., patients with the most serious conditions and the poorest short term vital prognosis.

[Infections on permanent endocavitary pacemaker leads: value of transesophageal echocardiography]. / Infections sur sonde de stimulation endocavitaire permanente: intérêt de l'échocardiographie transoesophagienne.

The prevalence of infection of permanent pacing material ranges from 0.13 to 19.9% of patients according to published series. The seriousness of this condition requires early diagnosis and treatment. Transesophageal echocardiography visualised vegetations on the intracardiac pacing lead in all of 11 patients studied, whereas transthoracic echocardiography and polynuclear leucocyte scintigraphy only provided positive diagnoses in 4 cases for each investigation. Three types of vegetation were visualised; no cases of tricuspid valve endocarditis were observed. Treatment was based on explantation of all implanted material by endovascular traction in 7 cases and by surgery in the other 4 cases according to the results of transesophageal echocardiography. There were no deaths or recurrence of infection. Transesophageal echocardiography is the investigation of choice for imaging a vegetation on an endocavitary pacing lead. Complete explanation is essential for a complete recovery of this infection.

Identification of guanine exchange factor key residues involved in exchange activity and Ras interaction.

We have carried out a functional analysis of the human HGRF55 exchange factor in the yeast Saccharomyces cerevisiae. Twelve residues conserved among most of all known guanine exchange factors (GEFs) have been independently changed to alanine. Taking advantage of the ability of Hgrf55p to replace the yeast Cdc25p exchange factor, and using the two-hybrid system with RAS2ala22 allele, we have identified key residues for the interaction with Ras and/or its activation. Substitution of arginine 392 to alanine leads to a complete loss of interaction with Ras, though the protein remains stable. Substitution of Asp266 or Arg359 to alanine results in inactive proteins at 39 degrees C, still able however to interact with Ras. The other charged-to-alanine substitutions led to no detectable phenotype when present alone but most of them dramatically increased the temperature sensitive phenotype observed with [Asp266Ala] substitution. Surprisingly, the cysteine to alanine substitution in the highly conserved PCVPF/Y motif proved to be without effect, suggesting that the sulfhydryl group is not essential for stability or interaction with Ras.

Successful treatment of a brain abscess due to Trichoderma longibrachiatum after surgical resection.

A case of brain abscess due to Trichoderma longibrachiatum in a leukemic patient with prolonged neutropenia is reported. Definitive cure was achieved after neurosurgical resection of the abscess and prolonged antifungal therapy. Trichoderma is a filamentous fungus species, which is only exceptionally pathogenic in humans. This genus and particularly the species Trichoderma longibrachiatum should be added to the growing list of fungi causing infection in immunocompromised patients.