Incidence and risk factors of peripheral nerve injuries 3 months after ICU discharge: a retrospective study comparing COVID-19 and non-COVID-19 critically ill survivors.

BACKGROUND: Peripheral nerve injuries (PNI) have been associated with prone positioning (PP) in mechanically ventilated (MV) patients with COVID-19 pneumonia. The aims of this retrospective study were to describe PNI prevalence 3 months (M3) after intensive care unit (ICU) discharge, whether patients survived COVID-19 or another critical illness, and to search for risk factors of PNI. RESULTS: A total of 55 COVID (62 [54-69] years) and 22 non-COVID (61.5 [48-71.5] years) patients were followed at M3, after an ICU stay of respectively 15 [9-26.5] and 13.5 [10-19.8] days. PNI symptoms were reported by 23/55 (42.6%) COVID-19 and 8/22 (36%) non-COVID-19 patients (p = 0.798). As the incidence of PNI was similar in both groups, the entire population was used to determine risk factors. The MV duration predicted PNI occurrence (OR (CI95%) = 1.05 (1.01-1.10), p = 0.028), but not the ICU length of stay, glucocorticoids, or inflammation biomarkers. CONCLUSION: In the present cohort, PNI symptoms were reported in at least one-third of the ICU survivors, in similar proportion whether patients suffered from severe COVID-19 or not.

Wiedemann-Steiner syndrome as a major cause of syndromic intellectual disability: A study of 33 French cases.

Wiedemann-Steiner syndrome (WSS) is a rare syndromic condition in which intellectual disability (ID) is associated with hypertrichosis cubiti, short stature, and characteristic facies. Following the identification of the causative gene (KMT2A) in 2012, only 31 cases of WSS have been described precisely in the literature. We report on 33 French individuals with a KMT2A mutation confirmed by targeted gene sequencing, high-throughput sequencing or exome sequencing. Patients' molecular and clinical features were recorded and compared with the literature data. On the molecular level, we found 29 novel mutations. We observed autosomal dominant transmission of WSS in 3 families and mosaicism in one family. Clinically, we observed a broad phenotypic spectrum with regard to ID (mild to severe), the facies (typical or not of WSS) and associated malformations (bone, cerebral, renal, cardiac and ophthalmological anomalies). Hypertrichosis cubiti that was supposed to be pathognomonic in the literature was found only in 61% of our cases. This is the largest series of WSS cases yet described to date. A majority of patients exhibited suggestive features, but others were less characteristic, only identified by molecular diagnosis. The prevalence of WSS was higher than expected in patients with ID, suggesting than KMT2A is a major gene in ID.

MED13L-related intellectual disability: involvement of missense variants and delineation of the phenotype.

Molecular anomalies in MED13L, leading to haploinsufficiency, have been reported in patients with moderate to severe intellectual disability (ID) and distinct facial features, with or without congenital heart defects. Phenotype of the patients was referred to "MED13L haploinsufficiency syndrome." Missense variants in MED13L were already previously described to cause the MED13L-related syndrome, but only in a limited number of patients. Here we report 36 patients with MED13L molecular anomaly, recruited through an international collaboration between centers of expertise for developmental anomalies. All patients presented with intellectual disability and severe language impairment. Hypotonia, ataxia, and recognizable facial gestalt were frequent findings, but not congenital heart defects. We identified seven de novo missense variations, in addition to protein-truncating variants and intragenic deletions. Missense variants clustered in two mutation hot-spots, i.e., exons 15-17 and 25-31. We found that patients carrying missense mutations had more frequently epilepsy and showed a more severe phenotype. This study ascertains missense variations in MED13L as a cause for MED13L-related intellectual disability and improves the clinical delineation of the condition.

SF1 and spleen development: new heterozygous mutation, literature review and consequences for NR5A1-mutated patient's management.

Steroidogenic factor 1 (encoded by SF1/NR5A1) is a transcription factor with multiple target genes involved in the development and function of multiple steroidogenic and non-steroidogenic tissues. NR5A1 mutations lead to several phenotypes, including sex reversal, spermatogenesis failure, premature ovarian failure and adrenocortical insufficiency. The implication of NR5A1 mutations in spleen development anomalies was recently highlighted. We provide new evidence of this involvement, describing a novel heterozygous non-sense NR5A1 mutation in a 46,XY-DSD with polysplenia female proband and her father, who had hypospadias and asplenia.

Multiple congenital anomalies in two boys with mutation in HCFC1 and cobalamin disorder.

The cobalamin type C deficiency is a rare condition that results from impaired biosynthesis of both methylcobalamin (MeCbl) and adenosylcobalamin (AdoCbl). Hemizygous mutations of the HCFC1 gene explain the majority of clinically and biologically compatible cblC patients without MMACHC mutations (OMIM 309541). We report a family with two maternal half-brothers with multiple congenital anomalies and HCFC1 gene mutation in the second Kelch domain. Both presented with dysmorphic features (flat profile, cleft lip for one), increased nuchal translucency, prenatal onset microcephaly and hypospadias. Additionally to early onset intractable epilepsy and profound neurocognitive impairment, this familial observation suggests that HCFC1 gene should be considered in boys with midline malformations, even without proven cobalamin C deficiency.

A 38-year-old hairdresser with irritant-associated vocal cord dysfunction.

The present case study reports the first case of a 38-year-old hairdresser with irritant-associated vocal cord dysfunction (VCD) due to alkaline persulfate, who was referred on suspicion of occupational asthma. Several tests were performed, including specific inhalation challenge and upper airway endoscopy. During the specific inhalation challenge to alkaline persulfate, the patient experienced dysphonia and a non-significant decrease in forced expiratory volume in 1 second on spirometry. Upper airway endoscopy was then performed and revealed VCD. A specific inhalation challenge test is therefore essential in cases of VCD to exclude possible concomitant occupational asthma.

Respiratory impedance response to a deep inhalation in asthmatic children with spontaneous airway obstruction.

The aim of the study was to determine whether the bronchomotor effect of a deep inhalation (DI) may be detected during tidal breathing in asthmatic children with spontaneous airway obstruction (AO). Two groups of children aged 5-15 yrs were studied. AO was mild in group 1 (n=12, forced expiratory volume in one second (FEV1) > or = 75% predicted) and moderate-to-severe in group 2 (n=9, FEV1 > or = 70% pred). The forced oscillation technique at 12 Hz using a head generator allowed the determination of respiratory resistance in inspiration (Rrsi) and expiration (Rrse) before and after DI, at baseline and after salbutamol. At baseline, Rrsi but not Rrse was found to decrease significantly after DI in group 1 but not in group 2. The change induced by DI was significantly different in group 1 (-1.5+/-0.5 hPa x s x L(-1)) compared to group 2 (0.5+/-0.5 hPa x s x L(-1)) and exhibited significant negative correlation to FEV1 % pred. After salbutamol, DI had no effect. In conclusion, asthmatic children show a bronchomotor response to deep inhalation that depends on the degree of airway obstruction. The effect is more readily demonstrated in inspiration than in expiration.

Subcortical neglect as a consequence of a remote parieto-temporal dysfunction. A quantitative EEG study.

In patients with a right-sided deep-seated lesion, a causal relationship between a cortical dysfunction in the right temporo-parietal region and the occurrence of neglect has been suggested. In the present study we tried to correlate clinical and quantitative EEG data from a sample of 33 right stroke patients divided into two subgroups according to the presence or absence of neglect. A 20-channel EEG cartography system was used for EEG mapping. Delta and theta activities were calculated in sixteen regions of interest. The analysis of raw values stressed the importance of the right parieto-temporal cortex to discriminate between the two subgroups of patients. These results suggest that in patients with right subcortical damage, a remote cortical parieto-temporal dysfunction within an intra-hemispheric network is necessary to provoke neglect.

Pathogenesis of subcortical visuo-spatial neglect. A HMPAO SPECT study.

The pathophysiology of neuropsychological disorders due to right deep-seated hemispheric lesions remains a debated point. We undertook this study to check the hypothesis according to which remote cortical dysfunction could be responsible for the occurrence of neglect. Twenty-eight patients presenting with a right-sided subcortical stroke were studied. A neuropsychological battery of tests suitable for assessment of possible visuo-spatial neglect was performed as well as HMPAO SPECT. Neglect was observed in 15 cases out of 28. The lesion's site (at CT and/or MRI) did not allow discrimination between patients without neglect and patients with neglect. The latter however could be distinguished from the former by the presence of a remote decrease in cortical blood flow in the right temporo-parietal region. By suggesting that cortical involvement is necessary for the occurrence of neglect, the results were interpreted according to a network approach in which subcortical neglect is attributed to a cortical deprivation from afferent input in the posterior part of the brain.

Remote cortical dysfunction as a possible cause of subcortical neglect? A regional cerebral blood flow study.

Cortical remote effects of right deep-seated lesions were studied with two cerebral blood flow measurement methods (two-dimensional xenon-133 inhalation and 99mTc HMPAO SPECT) in a population of 13 right-handed stroke patients. A neuropsychological battery of tests suitable for assessment of possible visual neglect was performed. Neglect was present in 7 cases. A regional cortical hypoperfusion was observed in all patients. However, in neglect patients it was more extended and involved the right inferior parietal region suggesting a causal relationship between cortical dysfunction and neuropsychological deficit. This finding supports the model attributing neglect to a unilateral attention-arousal defect in a cortico-limbic-reticular loop.

The H-NS protein is involved in the biogenesis of flagella in Escherichia coli.

The function of the flagellum-chemotaxis regulon requires the expression of many genes and is positively regulated by the cyclic AMP-catabolite activator protein (cAMP-CAP) complex. In this paper, we show that motile behavior was affected in Escherichia coli hns mutants. The loss of motility resulted from a complete lack of flagella. A decrease in the level of transcription of the flhD and fliA genes, which are both required for the synthesis of flagella, was observed in the presence of an hns mutation. Furthermore, the Fla- phenotype was not reversed to the wild type in the presence of a cfs mutation which renders the flagellum synthesis independent of the cAMP-CAP complex. These results suggest that the H-NS protein acts as a positive regulator of genes involved in the biogenesis of flagella by a mechanism independent of the cAMP-CAP pathway.

Bacterial lipases.

Many different bacterial species produce lipases which hydrolyze esters of glycerol with preferably long-chain fatty acids. They act at the interface generated by a hydrophobic lipid substrate in a hydrophilic aqueous medium. A characteristic property of lipases is called interfacial activation, meaning a sharp increase in lipase activity observed when the substrate starts to form an emulsion, thereby presenting to the enzyme an interfacial area. As a consequence, the kinetics of a lipase reaction do not follow the classical Michaelis-Menten model. With only a few exceptions, bacterial lipases are able to completely hydrolyze a triacylglycerol substrate although a certain preference for primary ester bonds has been observed. Numerous lipase assay methods are available using coloured or fluorescent substrates which allow spectroscopic and fluorimetric detection of lipase activity. Another important assay is based on titration of fatty acids released from the substrate. Newly developed methods allow to exactly determine lipase activity via controlled surface pressure or by means of a computer-controlled oil drop tensiometer. The synthesis and secretion of lipases by bacteria is influenced by a variety of environmental factors like ions, carbon sources, or presence of non-metabolizable polysaccharides. The secretion pathway is known for Pseudomonas lipases with P. aeruginosa lipase using a two-step mechanism and P. fluorescens lipase using a one-step mechanism. Additionally, some Pseudomonas lipases need specific chaperone-like proteins assisting their correct folding in the periplasm. These lipase-specific foldases (Lif-proteins) which show a high degree of amino acid sequence homology among different Pseudomonas species are coded for by genes located immediately downstream the lipase structural genes. A comparison of different bacterial lipases on the basis of primary structure revealed only very limited sequence homology. However, determination of the three-dimensional structure of the P. glumae lipase indicated that at least some of the bacterial lipases will presumably reveal a conserved folding pattern called the alpha/beta-hydrolase fold, which has been described for other microbial and human lipases. The catalytic site of lipases is buried inside the protein and contains a serine-protease-like catalytic triad consisting of the amino acids serine, histidine, and aspartate (or glutamate). The Ser-residue is located in a strictly conserved beta-epsilon Ser-alpha motif. The active site is covered by a lid-like alpha-helical structure which moves away upon contact of the lipase with its substrate, thereby exposing hydrophobic residues at the protein's surface mediating the contact between protein and substrate.(ABSTRACT TRUNCATED AT 400 WORDS)

Crystallization and preliminary X-ray analysis of a lipase from Bacillus subtilis.

Single crystals of the lipase from Bacillus subtilis have been obtained using a mixture of polyethylene glycol 4000 and sodium sulphate solution as the precipitant. The crystals grow at room temperature in two to three weeks in the presence of n-octyl-beta-D-glucoside. They belong to the monoclinic space group C2 with a = 121.20 A, b = 93.19 A, c = 80.96 A, and beta = 110.67 degrees, with four protein molecules per asymmetric unit. The crystals diffract to at least 2.5 A resolution and are suitable for an X-ray structure analysis.

Genetic analysis and overexpression of lipolytic activity in Bacillus subtilis.

The previously cloned Bacillus subtilis lipase gene (lip) was mapped on the chromosome and used in the construction of a B. subtilis derivative totally devoid of any lip sequence. Homologous overexpression was performed in this strain by subcloning the lip open reading frame on a multicopy plasmid under the control of a strong gram-positive promoter. A 100-fold overproducing strain was obtained, which should facilitate purification of the secreted protein. Furthermore, the delta lip strain BCL1050 constitutes an ideal host for the cloning of heterologous lipase genes.

The structure-function relationship of the lipases from Pseudomonas aeruginosa and Bacillus subtilis.

Within the BRIDGE T-project on lipases we investigate the structure-function relationships of the lipases from Bacillus subtilis and Pseudomonas aeruginosa. Construction of an overproducing Bacillus strain allowed the purification of > 100 mg lipase from 30 l culture supernatant. After testing a large variety of crystallization conditions, the Bacillus lipase gave crystals of reasonable quality in PEG-4000 (38-45%), Na2SO4 and octyl-beta-glucoside at 22 degrees C, pH 9.0. A 2.5 A dataset has been obtained which is complete from 15 to 2.5 A resolution. P.aeruginosa wild-type strain PAC1R was fermented using conditions of maximum lipase production. More than 90% of the lipase was cell bound and could be solubilized by treatment of the cells with Triton X-100. This permitted the purification of approximately 50 mg lipase. So far, no crystals of sufficient quality were obtained. Comparison of the model we built for the Pseudomonas lipase, on the basis of sequences and structures of various hydrolases which were found to possess a common folding pattern (alpha/beta hydrolase fold), with the X-ray structure of the P.glumae lipase revealed that it is possible to correctly build the structure of the core of a protein even in the absence of obvious sequence homology with a protein of known 3-D structure.

Purification and preliminary characterization of the extracellular lipase of Bacillus subtilis 168, an extremely basic pH-tolerant enzyme.

The extracellular lipase of Bacillus subtilis 168 was purified from the growth medium of an overproducing strain by ammonium sulfate precipitation followed by phenyl-Sepharose and hydroxyapatite column chromatography. The purified lipase had a strong tendency to aggregate. It exhibited a molecular mass of 19,000 Da by SDS-PAGE and a pI of 9.9 by chromatofocusing. The enzyme showed maximum stability at pH 12 and maximum activity at pH 10. The lipase was active toward p-nitrophenyl esters and triacylglycerides with a marked preference for esters with C8 acyl groups. Using trioleyl glycerol as substrate, the enzyme preferentially cleaved the 1(3)-position ester bond. No interfacial activation effect was observed with triacetyl glycerol as substrate.

Sequential elution of denatured proteins, hydrolyzed RNA, and plasmid DNA of bacterial lysates adsorbed onto stacked DEAE-cellulose membranes.

Modified membrane chromatography is emerging as a widely applicable technique for the separation of macromolecules. The use of DEAE-cellulose membranes (MemSep) for the purification of bacterial plasmid DNA has been assessed. Cleared bacterial lysates were injected directly onto the membranes without any prior sample cleanup. A single phenol extraction of adsorbed DNA was carried out and about 60 times less phenol was required to achieve the same extent of deproteination for DNA adsorbed onto the membranes as compared to DNA in solution. After chloroform and ethanol wash, (oligo)ribonucleotides resulting from RNase treatment were desorbed with 0.3 M LiCl, 5 mM LiOH. Finally, DNA was eluted with 0.5 M NaCl, 5 mM NaOH. The complete elution of DNA required NaOH in addition to NaCl and the latter salt was a better eluent than LiCl. Without RNase treatment, plasmid DNA-RNA complex required 2 M NaCl, 5 mM NaOH to be completely desorbed. The whole procedure took less than 40 min. The DEAE-cellulose membranes can withstand more than 100 cycles of regenerations and uses without any noticeable decrease of their binding capacity. No cross-contamination of successive DNA preparations was observed. Plasmid DNA was a good substrate for DNA endonucleases. Restriction fragments repurified by this procedure were amenable to ligation. Transformation of Escherichia coli and Saccharomyces cerevisiae with plasmid DNA was observed.

Sequence of the Salmonella typhimurium StyLT1 restriction-modification genes: homologies with EcoP1 and EcoP15 type-III R-M systems and presence of helicase domains.

The StyLT1 restriction-modification (R-M) system of Salmonella typhimurium has recently been suggested to belong to the type-III R-M systems [De Backer and Colson, Gene 97 (1991) 103-107]. The nucleotide sequences of StyLT1 mod and res have been determined. Two closely adjacent open reading frames were found 12 bp apart with coding capacities of 651 (Mod) and 982 (Res) amino acids (aa), respectively. The genes, lying in the same direction of transcription in the mod-res order, are transcribed as distinct units. The deduced aa sequences reveal homologies with known type-III enzymes from the Escherichia coli P1 prophage, E. coli P15 plasmid and Bacillus cereus chromosome. In addition, the StyLT1 restriction endonuclease (ENase), like other type-I and type-III ENases, contains sequence motifs characteristic of superfamily-II helicases, which may be involved in DNA unwinding at the cleavage site.