Comparison between SLC3A1 and SLC7A9 cystinuria patients and carriers: a need for a new classification

Recent developments in the genetics and physiology of cystinuria do not support the traditional classification, which is based on the excretion of cystine and dibasic amino acids in obligate heterozygotes. Mutations of only two genes (SLC3A1 and SLC7A9), identified by the International Cystinuria Consortium (ICC), have been found to be responsible for all three types of the disease. The ICC set up a multinational database and collected genetic and clinical data from 224 patients affected by cystinuria, 125 with full genotype definition. Amino acid urinary excretion patterns of 189 heterozygotes with genetic definition and of 83 healthy controls were also included. All SLC3A1 carriers and 14% of SLC7A9 carriers showed a normal amino acid urinary pattern (i.e., type I phenotype). The rest of the SLC7A9 carriers showed phenotype non-I (type III, 80.5%; type II, 5.5%). This makes the traditional classification imprecise. A new classification is needed: type A, due to two mutations of SLC3A1 (rBAT) on chromosome 2 (45.2% in our database); type B, due to two mutations of SLC7A9 on chromosome 19 (53.2% in this series); and a possible third type, AB (1.6%), with one mutation on each of the above-mentioned genes. Clinical data show that cystinuria is more severe in males than in females. The two types of cystinuria (A and B) had a similar outcome in this retrospective study, but the effect of the treatment could not be analyzed. Stone events do not correlate with amino acid urinary excretion. Renal function was clearly impaired in 17% of the patients.     

The use of sleep measures to compare a new 5HT1A agonist with buspirone in humans

The partial agonist buspirone has a REM (rapid eye movement) suppressing effect on human sleep probably via a 5HT(1A) receptor in the pontine area. Eptapirone is a new 5HT(1A) agonist with a greater intrinsic effect than buspirone. The objective of this study was to examine the effects of eptapirone on sleep architecture, particularly REM sleep, in normal volunteers and compare it with buspirone and placebo. This was a randomized, double-blind placebo-controlled four-way crossover study in 12 healthy volunteers. Volunteers were screened to ensure that they had normal overnight sleep EEG (electroencephalogram) and were extensive CYP 2D6 metabolizers. Sleep was recorded on pairs of nights on four occasions, with medication being taken before the second night. Treatments were eptapirone 1.5mg at 10 AM, eptapirone 1.5mg at 11 PM, buspirone 20mg at 11 PM and placebo. Standard measures of sleep were derived and compared among the four treatments using ANOVA. REM sleep was significantly suppressed supporting the proposition that activation of post-synaptic 5HT(1A) receptors reduces REM sleep. Sleep fragmentation increased by both drugs. REM sleep suppression was significantly greater with morning eptapirone than with buspirone. Wakefulness in sleep was significantly greatest after morning eptapirone. REM sleep effects were greatest after evening eptapirone, suggesting a greater effect on central serotonin receptors than that of buspirone.     

Gene structure,chromosomal localization,and mutation screening of the human gene for the inner ear protein otospiralin

Otospiralin is a novel protein of unknown function that is produced by non-sensory cells (fibrocytes) of the inner ear (cochlea and vestibule). We showed that downregulation of otospiralin in guinea pigs leads to deafness and we therefore hypothesized that genetic defects in the otospiralin gene could also cause deafness in humans. In this study, we cloned and localized OTOSP, the human gene for otospiralin. OTOSP spans 1,630 nucleotides, contains four exons and codes for a 567-nucleotide cDNA. By fluorescence in situ hybridization and hybrid panel mapping we localized OTOSP on chromosome 2 at position q37.3. There is currently no deafness family linked to this region. We screened OTOSP for mutations in 410 unrelated patients exhibiting various levels of hearing loss. Beside intronic polymorphisms, a rare variant (Pro7Leu) was found in 4 deafness patients and 3 control individuals, indicating that this change is not involved in this condition and excluding OTOSP as a major gene for genetic deafness. Electronic Publication     

Rapid molecular syndromic testing for aetiological diagnosis of gastrointestinal infections and targeted antimicrobial prescription: experience from a reference paediatric hospital in Spain

European Journal of Clinical Microbiology & Infectious Diseases - Aetiological diagnosis of gastrointestinal infections is challenging since a wide range of bacteria, parasites and viruses can...     

Endobronchial ultrasound-guided transbronchial needle aspiration in the diagnosis of intrathoracic lymph node metastases from extrathoracic malignancies

Intrathoracic lymph node enlargement is a common finding in patients with extrathoracic malignancies. Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is a technique that is commonly used for lung cancer diagnosis and staging but that has not been widely investigated for the diagnosis of enlarged mediastinal and lobar lymph nodes in patients with extrathoracic malignancies. We conducted a retrospective study of 117 patients with extrathoracic malignancies who underwent EBUS-TBNA for diagnosis of intrathoracic lymph node enlargement from October 2005 to December 2009 and compared the EBUS-TBNA findings with the final diagnoses. EBUS-TBNA diagnosed mediastinal metastases in 51 of the 117 (43.6 %) cases and gave an alternate diagnosis or ruled out the presence of malignancy in 35 (56.4 %). Fourteen of these 35 patients underwent further surgical investigation, while the remaining 21 had clinical and radiological follow-up for 18 months. No false negatives were found in the surgery group. In the follow-up group, 13 patients had stable or regressive lymphadenopathy, and eight developed clinicoradiological progression and were assumed to have been false negatives by EBUS-TBNA. The sensitivity and negative predictive value of EBUS-TBNA were 86.4 and 75 %, respectively. Immunohistochemical staining (IHC) was performed in 80.4 % of the samples obtained by EBUS-TBNA. In samples obtained from ten patients with metastatic breast cancer, estrogen receptor expression was successfully assessed in eight patients and progesterone receptor and human epidermal growth factor receptor 2 in four. EBUS-TBNA is an accurate procedure for the diagnosis of thoracic lymph node metastases in patients with extrathoracic malignancies and should be an initial diagnostic tool in these patients. Furthermore, EBUS-TBNA can obtain high-quality specimens from metastatic lymph nodes for use in molecular analyses.     

Similarities and differences between the immunopathogenesis of COVID-19–related pediatric multisystem inflammatory syndrome and Kawasaki disease

Multisystem inflammatory syndrome associated with the SARS-CoV-2 pandemic has recently been described in children (MIS-C), partially overlapping with Kawasaki disease (KD). We hypothesized that (a) MIS-C and prepandemic KD cytokine profiles may be unique and justify the clinical differences observed, and (b) SARS-CoV-2–specific immune complexes (ICs) may explain the immunopathology of MIS-C. Seventy-four children were included: 14 with MIS-C, 9 patients positive for SARS-CoV-2 by PCR without MIS-C (COVID), 14 with prepandemic KD, and 37 healthy controls (HCs). Thirty-four circulating cytokines were quantified in pretreatment serum or plasma samples and the presence of circulating SARS-CoV-2 ICs was evaluated in MIS-C patients. Compared with HCs, the MIS-C and KD groups showed most cytokines to be significantly elevated, with IFN-γ–induced response markers (including IFN-γ, IL-18, and IP-10) and inflammatory monocyte activation markers (including MCP-1, IL-1α, and IL-1RA) being the main triggers of inflammation. In linear discriminant analysis, MIS-C and KD profiles overlapped; however, a subgroup of MIS-C patients (MIS-C^plus) differentiated from the remaining MIS-C patients in IFN-γ, IL-18, GM-CSF, RANTES, IP-10, IL-1α, and SDF-1 and incipient signs of macrophage activation syndrome. Circulating SARS-CoV-2 ICs were not detected in MIS-C patients. Our findings suggest a major role for IFN-γ in the pathogenesis of MIS-C, which may be relevant for therapeutic management.