Expanding the clinical spectrum of hereditary fibrosing poikiloderma with tendon contractures, myopathy and pulmonary fibrosis due to FAM111B mutations

Background

Hereditary Fibrosing Poikiloderma (HFP) with tendon contractures, myopathy and pulmonary fibrosis (POIKTMP [MIM 615704]) is a very recently described entity of syndromic inherited poikiloderma. Previously by using whole exome sequencing in five families, we identified the causative gene, FAM111B (NM_198947.3), the function of which is still unknown. Our objective in this study was to better define the specific features of POIKTMP through a larger series of patients.

Methods

Clinical and molecular data of two families and eight independent sporadic cases, including six new cases, were collected.

Results

Key features consist of: (i) early-onset poikiloderma, hypotrichosis and hypohidrosis; (ii) multiple contractures, in particular triceps surae muscle contractures; (iii) diffuse progressive muscular weakness; (iv) pulmonary fibrosis in adulthood and (v) other features including exocrine pancreatic insufficiency, liver impairment and growth retardation. Muscle magnetic resonance imaging was informative and showed muscle atrophy and fatty infiltration. Histological examination of skeletal muscle revealed extensive fibroadipose tissue infiltration. Microscopy of the skin showed a scleroderma-like aspect with fibrosis and alterations of the elastic network. FAM111B gene analysis identified five different missense variants (two recurrent mutations were found respectively in three and four independent families). All the mutations were predicted to localize in the trypsin-like cysteine/serine peptidase domain of the protein. We suggest gain-of-function or dominant-negative mutations resulting in FAM111B enzymatic activity changes.

Conclusions

HFP with tendon contractures, myopathy and pulmonary fibrosis, is a multisystemic disorder due to autosomal dominant FAM111B mutations. Future functional studies will help in understanding the specific pathological process of this fibrosing disorder.

A fixed point algorithm for extracting the atrial activity in the frequency domain

In this work we present a fixed point algorithm to extract the atrial rhythm in atrial tachyarrhythmias from the surface electrocardiogram (ECG). In the frequency domain the atrial signal is characterized by a concentration of power around a main peak in the bandwidth 3-10Hz. The proposed algorithm exploits this discriminative property of the atrial component in combination with the decoupling of the atrial and other components superposed in the ECG. It recovers only the interesting atrial rhythm in a simple, fast and reliable way using the information contained in all the leads and reducing the average computational time from 0.902s (FastICA) to 0.023s (the proposed method). The algorithm is applied successfully to synthetic and real data. In simulated ECGs, the correlation index obtained was 0.792. In real ECGs, the accuracy of the results was validated using spectral and temporal parameters. The average peak frequency and spectral concentration obtained were 5.354Hz and 59.4%, respectively, and the kurtosis was 0.065.

Constrained temporal extraction of the atrial rhythm in Atrial Fibrillation episodes

The extraction of the Atrial Activity from the Ventricular Activity in Atrial Fibrillation episodes is a must for clinical analysis. We follow the semi Blind Source Extraction S-BSE approach to solve the problem. The proposed algorithm modifies the BSE contrast function to satisfy the prior knowledge about the spectral content of the atrial signal. The introduction of this prior allows obtaining a new algorithm with the following advantages: it allows the extraction of only the atrial component and it improves the quality of the recovered atrial signal in terms of spectral concentration as we show in the results.

Clarithromycin with minocycline and clofazimine for Mycobacterium avium intracellulare complex lung disease in patients without the acquired immune deficiency syndrome. GETIM. Groupe d'Etude et de Traitement des Infections à Mycobactéries

SETTING

An open clinical trial for the treatment of Mycobacterium avium intracellulare complex (MAIC) lung disease in human immunodeficiency virus (HIV)-seronegative patients.

OBJECTIVE

To assess the efficacy and tolerance of clarithromycin (0.75-2 g/day) combined with minocycline (200 mg/day) and clofazimine (100 mg/day) for 15 months.

DESIGN

The study was carried out from August 1992 to June 1994 by pulmonologists of various French medical centres. The patients to be enrolled were of either sex, over 18 years of age, HIV-seronegative and suffering from MAIC lung disease, with a confirmed bacteriological and radiological diagnosis. Examinations were to be performed after 1, 2, 3, 6, 9, 12 and 15 months of treatment.

RESULTS

Thirty patients were included, 16 males and 14 females. Eight did not complete the study due to deviations from protocol or adverse effects. The remainder completed the study with a post-treatment follow-up of 27 +/- 7 months. Among the 22 evaluable patients, 18 had a history of lung disease. Tolerance to the drugs was generally good, apart from three cases of hepatic disturbances and three cases of ototoxicity, which required a decrease in clarithromycin dosage after a short interruption of treatment. There were 14 treatment successes, seven treatment failures, defined by absence of bacteriologic conversion, and in one patient the disease evolution remains uncertain.

CONCLUSION

The combination of clarithromycin with minocycline and clofazimine proved effective with persistently negative cultures in 64% of the patients, and an overall good drug tolerance.

First case of mother-to-infant HIV type 1 group O transmission and evolution of C2V3 sequences in the infected child. French HIV Pediatric Cohort Study Group

We report the first case of mother-to-infant transmission and follow-up for an HIV-1 group O virus from Cameroon. Isolates were obtained from the mother at delivery and from the child at birth and when 16 and 30 months old. We analyzed the viral evolution within mother and child by examining 51 sequences spanning C2V3 regions of the viral envelope gene. The mother carried two genotypes, v1 and v2. The genotype v1 was dominant in the child at birth, and persisted as a minor genotype at age 30 months. The genotype v2 was absent in the child sequences. The variability of the nucleotide sequences of the isolates from the child increased with age from 0.8 to 6%, and a novel genotype (v3) appeared at age 30 months. The nonsynonymous-to-synonymous mutation ratio increased with the age of the child, from 0.75 at birth to 1.86 at 30 months, indicating a high rate of fixation of amino acid changes in the child. The overall pattern was similar to that reported by Ganeshan et al. (J Virol 1997;71:663-677) for group M viruses infecting child with a slow-developing form of the disease.

Mucosal T-lymphocytes in central airways of lung transplant recipients

The immunohistochemical profile of mucosal lymphocytes was investigated in the central airways of lung transplant recipients. Bronchial and transbronchial biopsies (BB and TBB, respectively) and bronchoalveolar lavage for culture of bacteria and viruses were performed during a fibroscopic procedure in patients without evidence of chronic rejection, 3 to 10 mo after surgery. Analysis was restricted to samples without concurrent airway infection: 23 pairs of BB and TBB from 18 transplant recipients were analyzed. An immunohistochemical technique was used to identify and score mucosal cells that reacted with monoclonal antibodies against CD4, CD8, CD45-Ro (memory T-cells), and HLA-DR molecules. The same procedure was applied in nine nonsmoking control subjects (NS group). Data from transplant recipients were allocated to R+ (n = 11) or R- groups (n = 12), depending on the presence or absence of histologic evidence of acute rejection on TBB. A statistically significant depletion of every immunoreactive cell subset was observed in the R+ and the R- groups, but not in the NS group. Conversely, no significant difference for either score of immunoreactive cells were found between R+ and R- groups. The immunosuppressive regimen is suspected to play to play a major role in this depletion of bronchial mucosal T-cells. The acute lung rejection process does not appear to affect concurrently the immunohistochemical profile of immunoreactive cells in the bronchial mucosa.

Effectiveness and safety of bolus administration of alteplase in massive pulmonary embolism

Animal studies have demonstrated that thrombolysis with recombinant tissue-type plasminogen activator (rt-PA) is accelerated and that bleeding is reduced when rt-PA is infused over a short period. Previous clinical studies in patients with venous thromboembolism have shown that rt-PA is an effective thrombolytic agent when administered by continuous infusion over 2 to 24 hours. Clinical experience of bolus rt-PA administration in patients with massive acute pulmonary embolism (PE) is, however, limited. A prospective open study was conducted in which 54 patients with massive PE (Miller index > or = 20 of 34) received a 10-minute infusion of rt-PA at a dose of 1 mg/kg. Perfusion lung scanning was used to assess the change in pulmonary perfusion after drug administration. At 48 hours and 10 days, the mean absolute improvements in the perfusion defect were 11 and 31%, respectively. In addition, a significant clinical improvement occurred within 2 hours in 11 of the 15 shocked patients. Five patients died (9%) as a result of persistent shock (3 patients), neurologic damage (1 patient) or intracranial bleeding (1 patient). Major bleeding occurred in 8 patients (15%). Long-term follow-up information was available for 44 of the 49 discharged patients: 2 had died and 12 (27%) complained of persistent exertional dyspnea, 7 of whom had an associated heart or lung disease or chronic thromboembolism at admission. These results suggest that a bolus regimen of rt-PA could provide a convenient approach to thrombolytic therapy in patients with massive PE.(ABSTRACT TRUNCATED AT 250 WORDS)