Clinical re-biopsy of segmental gains-the primary source of preimplantation genetic testing false positives.

Purpose: Does re-biopsy of blastocysts classified as abnormal (ABN) due to segmental aneuploidy (SA) have clinical utility?

Methods: The live birth (LB) outcomes of mosaic SAs, compared to other categories, were determined after transfer of 3084 PGT-A tested blastocysts. An initial 12-month trial thawed 111 blastocysts classified as ABN due to a SA for clinical re-biopsy, with an additional 58 from a subsequent 16-month revised protocol. Where re-biopsy failed to corroborate the original classification, blastocysts were reported as mosaic and suitable for clinical use.

Molecular and phenotypic characteristics of seven novel mutations causing branched-chain organic acidurias.

Specific mitochondrial enzymatic deficiencies in the catabolism of branched-chain amino acids cause methylmalonic aciduria (MMA), propionic acidemia (PA) and maple syrup urine disease (MSUD). Disease-causing mutations were identified in nine unrelated branched-chain organic acidurias (BCOA) patients. We detected eight previously described mutations: p.

Vitamin D deficiency in Serbian patients with Rett syndrome.

Introduction: Rett syndrome (RTT) is a severe neurodevelopmental disorder. Bone manifestations of RTT include osteopenia and fractures. Studies addressing serum vitamin D levels in patients with RTT are scarce.

Newborn screening for cystic fibrosis in Serbia: a pilot study.

Background: We performed a pilot study of neonatal screening for cystic fibrosis (CF) in order to introduce it to the national screening program in Serbia.

Methods: Immunoreactive trypsinogen (IRT) concentrations were analyzed in dried blood spot samples. Patients were recalled for repeated measurements in case of high IRT levels.

IGFBP-3 binds GRP78, stimulates autophagy and promotes the survival of breast cancer cells exposed to adverse microenvironments.

Despite the established role of insulin-like growth factor binding protein-3 (IGFBP-3) as a growth inhibitor in vitro, a high level of IGFBP-3 in breast tumor tissue is associated with the stimulation of xenograft growth in mice and poor prognosis in patients. To understand the contribution of IGFBP-3 to breast cancer progression, tandem affinity purification was used to identify novel interacting proteins. The endoplasmic reticulum protein, glucose-regulated protein 78 (GRP78), was shown to bind to IGFBP-3, confirmed by colocalization, coimmunoprecipitations, glutathione S-transferase (GST) pulldowns and a nanomolar binding affinity.

Novel cftr gene sequence variation in Serbian patient with idiopathic disseminated bronchiectasis.

This paper reports a novel Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene variant, 1811+1G-->T, detected in a 5-year-old girl diagnosed with idiopathic disseminated bronchiectasis and negative sweat chloride test (17 mmol/L). The performed CFTR gene mutation analysis included detection of the F508del mutation, analysis of Tn polymorphism and screening of CFTR exons 3, 10 and 11. The CFTR gene screening has shown the altered band pattern in exon 11.

[Very long chain fatty acids in the pathogenesis, prenatal and postnatal diagnosis of X-linked adrenoleukodystrophy].

Introduction: X-linked adrenoleukodystrophy (X-ALD) is a hereditary disorder of peroxisomal metabolism, biochemically characterized by accumulation of saturated very long chain fatty acids. DIAGNOSIS OF X-ADRENOLEUKODYSTROPHY: The biochemical diagnosis of X-linked adrenoleukodystrophy is done by gas-chromatographic analysis of plasma very long chain fatty acids. Accumulation of these fatty acids is associated with cerebral demyelination, peripheral nerve abnormalities, adrenocortical insufficiency and it may play a role in the pathogenesis of the brain inflammatory response.

X-linked adreno leukodistrophy: Profiles of very long chain fatty acids in plasma and fibroblasts in eigth Serbian patients.

X-linked adrenoleukodistrophy is a severe neurodegenerative disorder with impaired very long chain fatty acid metabolism. The disease associated ABCD1 gene encodes a peroxisomal membrane protein which belongs to the superfamily of ATP-binding cassette transporters. We investigated eight male X-ALD patients diagnosed among 142 suspected patients referred for investigation.

[Camptomelic dysplasia--a case report].

Campomelic/camptomelic dysplasia is a very rare, severe osteochondrodysplasia characterised by severe skeletal and nonskeletal malformations and lethal outcome mainly in neonatal period. Characteristic abnormality by which the syndrome got its name is short, bowed long bones of lower extremities, most often of femur, manifested by short and bowed legs. Skin dimpling on tibial anterior side is another prominent characteristic of this syndrome.

Molecular and phenotypic characteristics of patients with phenylketonuria in Serbia and Montenegro.

Phenylketonuria (PKU) is the most common inborn error of amino acid metabolism in Caucasians. PKU is caused by mutations in the gene encoding phenylalanine hydroxylase (PAH) enzyme. Here, we report the spectrum and the frequency of mutations in the PAH gene and discuss genotype-phenotype correlation in 34 unrelated patients with PKU from Serbia and Montenegro.

New insights into BS69 functions.

The BS69 protein has been commonly described as a co-repressor associated with various transcription factors. However, this hypothesis relied predominantly on overexpression of tagged proteins due to the lack of a reliable BS69 antibody. We present for the first time a complete sequence of BS69 and valuable tools to characterize the endogenous protein.

Urinary catecholamine metabolites: Capillary gas chromatography method and experience with 12 cases of neuroblastoma.

We propose a rapid, simple metodology for routine analysis of human urine to detect vanillylmandelic and homovanillic acid related to neuroblastoma. The assay were specific capillary gas chromatography with flame ionization detection. In this methodology an internal standard is used and the procedure involves ethyl ester formation without isolation of the compounds of interest.

[Rubinstein-Taybi syndrome].

Rubinstein-Taybi syndrome is a malformation occurring with approximate incidence of 1 per 10,000 live-born children. The diagnosis is usually based on specific facial dysmorphism in neonatal period, as well as on characteristic deformities of the hands and feet. Our study presents a male child who was diagnosed to have Rubinstein-Taybi syndrome when he was one month old.

[Initial antibiotic therapy of neonatal sepsis].

It is certain that in the past the types of bacterial agents responsible for neonatal sepsis and their sensitivity to antibiotics were not the same in all historical periods. However, the reports confirming the conclusion have been published only in the last three years. According to these facts, the bacterial causes of neonatal sepsis were analyzed in patients treated at the University children's hospital in Belgrade (S&M) as well as their sensitivity to antibiotics to determine the most effective initial therapy.

Interactions of the QacR multidrug-binding protein with structurally diverse ligands: implications for the evolution of the binding pocket.

The QacR multidrug-binding repressor protein regulates the expression of the Staphylococcus aureus qacA gene, a multidrug resistance (MDR) locus that is prevalent in clinical isolates of this important human pathogen. In this paper we demonstrate that the range of structurally diverse compounds capable of inducing qacA transcription is significantly more varied than previously appreciated, particularly in relation to bivalent cations. For all of the newly identified inducing compounds, induction of qacAexpression was correlated with a matching ability to dissociate QacR from operator DNA.

Stable low-copy-number Staphylococcus aureus shuttle vectors.

A series of Staphylococcus aureus-Escherichia coli shuttle vectors were constructed which contained the replication and maintenance functions of the S. aureus theta-mode multiresistance plasmid pSK1. The utility of the newly constructed vectors was demonstrated by the successful cloning and expression of several genes that had previously proven difficult to express in S.

Regulation of bacterial drug export systems.

The active transport of toxic compounds by membrane-bound efflux proteins is becoming an increasingly frequent mechanism by which cells exhibit resistance to therapeutic drugs. This review examines the regulation of bacterial drug efflux systems, which occurs primarily at the level of transcription. Investigations into these regulatory networks have yielded a substantial volume of information that has either not been forthcoming from or complements that obtained by analysis of the transport proteins themselves.

Structural basis for cooperative DNA binding by two dimers of the multidrug-binding protein QacR.

The Staphylococcus aureus multidrug-binding protein QacR represses transcription of the qacA multidrug transporter gene and is induced by multiple structurally dissimilar drugs. QacR is a member of the TetR/CamR family of transcriptional regulators, which share highly homologous N-terminal DNA-binding domains connected to seemingly non-homologous ligand-binding domains. Unlike other TetR members, which bind approximately 15 bp operators, QacR recognizes an unusually long 28 bp operator, IR1, which it appears to bind cooperatively.

Structural mechanisms of QacR induction and multidrug recognition.

The Staphylococcus aureus multidrug binding protein QacR represses transcription of the qacA multidrug transporter gene and is induced by structurally diverse cationic lipophilic drugs. Here, we report the crystal structures of six QacR-drug complexes. Compared to the DNA bound structure, drug binding elicits a coil-to-helix transition that causes induction and creates an expansive multidrug-binding pocket, containing four glutamates and multiple aromatic and polar residues.

The staphylococcal QacR multidrug regulator binds a correctly spaced operator as a pair of dimers.

Expression of the Staphylococcus aureus plasmid-encoded QacA multidrug transporter is regulated by the divergently encoded QacR repressor protein. To circumvent the formation of disulfide-bonded degradation products, site-directed mutagenesis to replace the two cysteine residues in wild-type QacR was undertaken. Analysis of a resultant cysteineless QacR derivative indicated that it retained full DNA-binding activities in vivo and in vitro and continued to be fully proficient for the mediation of induction of qacA expression in response to a range of structurally dissimilar multidrug transporter substrates.

Transcriptional regulation of multidrug efflux pumps in bacteria.

As integral membrane proteins demonstrating an extraordinarily wide substrate range, some degree of regulatory control over the expression of bacterial multidrug-resistance (MDR) transporters is to be expected. Excessive expression could be deleterious, due to direct, physical disruption of membrane integrity, or the unwanted export of essential metabolites, a potential side-effect of their broad substrate specificity. There are limited clues as to the physiological functions of most MDR transporters, but their expression is likely to be up-regulated in response to the presence of natural substrates of these pumps.

QacR is a repressor protein that regulates expression of the Staphylococcus aureus multidrug efflux pump QacA.

The Staphylococcus aureus QacA protein is a multidrug transporter that confers resistance to a broad range of antimicrobial agents via proton motive force-dependent efflux of the compounds. Primer extension analysis was performed to map the transcription start points of the qacA and divergently transcribed qacR mRNAs. Each gene utilized a single promoter element, the locations of which were confirmed by site-directed mutagenesis.

Investigation of a phage resistant Serratia entomophila strain (BC4B), establishment of generalised transduction and construction of S. entomophila RecA mutants.

A recA clone was isolated from a cosmid library of Serratia entomophila constructed in the Escherichia coli strain HB101. Subcloning and transposon mutagenesis were used to identify a 1.36 kb fragment containing the recA gene.