PREVALENCE OF AMPC Î’-LACTAMASES IN CLINICAL ISOLATES OF E. COLI FROM A TERTIARY CARE RURAL HOSPITAL

Objective: Organisms over expressing AmpC (Ambler Class C) β-lactamases are of clinical concern because they restrict therapeutic options causing treatment failures and are increasing in occurrence worldwide. So the present study was to undertaken with the aim to know the prevalence of plasmid mediated AmpC and inducible AmpC β-lactamases in clinical isolates of E. coli in our tertiary care rural hospital.Methods: 74 cefoxitin resistant E. coli isolates were tested for AmpC production by combined disc diffusion test and disk approximation test.Results: Out of 74 cefoxitin resistance E. coli isolated from various clinical specimen 25(33.78%) showed AmpC β-lactamases production. PMABL was seen in 22(29.73%) and inducible AmpC in 3(4.05%). Among 25 AmpC producing E. coli, 8(32%) were from urine, 5(20%) from miscellaneous, 4(16%) from sputum and 12% respectively from stool and Pus and in Blood 2(8%). Age-wise higher distribution of AmpC β-lactamase was in an age group below 1yr (44.44%) and in age group of 20-39yrs (40%). The higher distribution of AmpC b lactamases producer from Medicine, Obgy, ICU(20% respectively) paediatric 16%,surgery 8%, TB 12% and lower from OPD(4%). In our study, multidrug resistance has been observed among the PMABL producing strains. Higher resistance was seen in gentamicin 22(88%), ciprofloxacin 23(92%), ceptazidime 25(100%), cefaclor 25(100%). Whereas PMABL isolates was susceptible to tigecycline (100%), meropenem (92%), amikacin(60%).Conclusion: The overall prevalence of 10.50% AmpC β-lactamase in E. coli and Multidrug resistance is a matter of concern. So identification of AmpC may help in formulating the hospital infection control committee decreasing the selective antibiotic pressure.Â

Borderline mucinous ovarian tumour – a rare bilateral presentation

Surface epithelial tumours are the most common ovarian tumours. According to the cell type, surface epithelial tumours can be serous, mucinous, endometrioid etc. Mucinous tumours of ovary are the neoplasms characterized by glandular, cystic architecture and are lined to variable extents by mucin-containing epithelium. Further these tumours are sub-classified into benign, borderline and malignant category. Typically, borderline tumours are non-invasive neoplasms that have nuclear abnormalities and mitotic activity intermediate between benign and malignant tumours of similar cell type. Borderline ovarian tumours are clinical entities less frequently encountered by pathologists and gynaecologists. Mucinous borderline ovarian tumours are among the most difficult ovarian neoplasms for surgical pathologists to interpret. They occur in younger women and present at an early stage. However, borderline tumours are difficult to diagnose correctly preoperatively using imaging methods because their macroscopic features overlap with invasive and benign ovarian tumours. Most importantly, these tumours have a superior prognosis when compared with ovarian carcinomas stage for stage. The borderline tumours may be of intestinal type or mullerian (endocervical like) type. The intestinal type tumours are by far the most common. Approximately 5% of the borderline mucinous tumours are bilateral. We here report a rare case of bilateral borderline mucinous tumours diagnosed on histopathology

Clinical Phenotype in Individuals With Birk-Landau-Perez Syndrome Associated With Biallelic SLC30A9 Pathogenic Variants

BACKGROUND AND OBJECTIVES: Birk-Landau-Perez syndrome is a genetic disorder caused by biallelic pathogenic variants in SLC30A9 presenting with a complex movement disorder, developmental regression, oculomotor abnormalities, and renal impairment. It has previously been reported in 2 families. We describe the clinical phenotype of 8 further individuals from 4 unrelated families with SLC30A9-related disease. METHOD: Following detailed clinical phenotyping, 1 family underwent research whole-genome sequencing (WGS), 1 research whole-exome sequencing, and 2 diagnostic WGS. Variants of interest were assessed for pathogenicity using in silico prediction tools, homology modeling, and, where relevant, sequencing of complementary DNA (cDNA) for splicing effect. RESULTS: In 2 unrelated families of Pakistani origin (1 consanguineous and 1 not), the same homozygous missense variant in SLC30A9 (c.1253G>T, p.Gly418Val) was identified. Family 1 included 2 affected brothers, and family 2 one affected boy. In family 3, also consanguineous, there were 4 affected siblings homozygous for the variant c.1049delCAG, pAla350del. The fourth family was nonconsanguineous: the 1 affected individual was compound heterozygous for c.1083dup, p.Val362Cysfs*5, and c.1413A>G, p.Ser471=. Despite phenotypic variability between the 4 families, all affected patients manifested with a progressive hyperkinetic movement disorder, associated with oculomotor apraxia and ptosis. None had evidence of severe renal impairment. For the novel missense variant, the conformation of the loop domain and packing of transmembrane helices are likely to be disrupted based on structure modeling. Its presence in 2 unrelated Pakistani families suggests a possible founder variant. For the synonymous variant p.Ser471=, an effect on splicing was confirmed through cDNA analysis. DISCUSSION: Pathogenic variants in SLC30A9 cause a progressive autosomal recessive neurologic syndrome associated with a complex hyperkinetic movement disorder. Our report highlights the expanding disease phenotype, which can present with a wider spectrum of severity than has previously been recognized

Multicystic encephalomalacia as an end-stage finding in abusive head trauma

Abusive head trauma (AHT) is one of the most severe forms of physical child abuse. If a child initially survives severe AHT the neurological outcome can be poor. In recent years several children were seen who developed multicystic encephalomalacia (MCE) after documented severe AHT. A search of the Netherlands Forensic Institute database in The Hague was performed. Inclusion criteria were cases of AHT between 1999 and 2010 where the child was under the age of 1 year old at the time of trauma. Trauma mechanism and radiological information were collected. Five children, three boys and two girls (mean age 57 days, range 8–142 days) who developed cystic encephalomalacia after inflicted traumatic brain injury were included. Survival ranged from 27 to 993 days. In all cases judicial autopsy was performed. All cases came before court and in each case child abuse was considered to be proven. In two cases the perpetrator confessed, during police interrogation, to shaking of the child only. Although a known serious outcome, this is one of the few reports on MCE as a result of AHT. In all cases the diagnosis was confirmed at autopsy

Macrocyclisation of small peptides enabled by oxetane incorporation

Cyclic peptides are an important source of new drugs but are challenging to produce synthetically. We show that head-to-tail peptide macrocyclisations are greatly improved, as measured by isolated yields, reaction rates and product distribution, by substitution of one of the backbone amide C═O bonds with an oxetane ring. The cyclisation precursors are easily made by standard solution- or solid-phase peptide synthesis techniques. Macrocyclisations across a range of challenging ring sizes (tetra-, penta- and hexapeptides) are enabled by incorporation of this turn-inducing element. Oxetane incorporation is shown to be superior to other established amino acid modifications such as N-methylation. The positional dependence of the modification on cyclisation efficiency is mapped using a cyclic peptide of sequence LAGAY. We provide the first direct experimental evidence that oxetane modification induces a turn in linear peptide backbones, through the observation of dNN (i, i + 2) and dαN (i, i + 2) NOEs, which offers an explanation for these improvements. For cyclic peptide, cLAGAY, a combination of NMR derived distance restraints and molecular dynamics simulations are used to show that this modification alters the backbone conformation in proximity to the oxetane, with the flexibility of the ring reduced and a new intramolecular H-bond established. Finally, we incorporated an oxetane into a cyclic pentapeptide inhibitor of Aminopeptidase N, a transmembrane metalloprotease overexpressed on the surface of cancer cells. The inhibitor, cCNGRC, displayed similar IC50 values in the presence or absence of an oxetane at the glycine residue, indicating that bioactivity is fully retained upon amide C═O bond replacement

Synthesis and Functionalization of Azetidine-Containing Small Macrocyclic Peptides

Cyclic peptides are increasingly important structures in drugs but their development can be impeded by difficulties associated with their synthesis. Here, we introduce the 3-aminoazetidine (3-AAz) subunit as a new turn-inducing element for the efficient synthesis of small head-to-tail cyclic peptides. Greatly improved cyclizations of tetra-, penta- and hexapeptides (28 examples) under standard reaction conditions are achieved by introduction of this element within the linear peptide precursor. Post-cyclization deprotection of the amino acid side chains with strong acid is realized without degradation of the strained four-membered azetidine. A special feature of this chemistry is that further late-stage modification of the resultant macrocyclic peptides can be achieved via the 3-AAz unit. This is done by: (i) chemoselective deprotection and substitution at the azetidine nitrogen, or by (ii) a click-based approach employing a 2-propynyl carbamate on the azetidine nitrogen. In this way, a range of dye and biotin tagged macrocycles are readily produced. Structural insights gained by XRD analysis of a cyclic tetrapeptide indicate that the azetidine ring encourages access to the less stable, all-trans conformation. Moreover, introduction of a 3-AAz into a representative cyclohexapeptide improves stability towards proteases compared to the homodetic macrocycle

Recessive mutations in SPTBN2 implicate β-III spectrin in both cognitive and motor development

β-III spectrin is present in the brain and is known to be important in the function of the cerebellum. Heterozygous mutations in SPTBN2, the gene encoding β-III spectrin, cause Spinocerebellar Ataxia Type 5 (SCA5), an adult-onset, slowly progressive, autosomal-dominant pure cerebellar ataxia. SCA5 is sometimes known as "Lincoln ataxia," because the largest known family is descended from relatives of the United States President Abraham Lincoln. Using targeted capture and next-generation sequencing, we identified a homozygous stop codon in SPTBN2 in a consanguineous family in which childhood developmental ataxia co-segregates with cognitive impairment. The cognitive impairment could result from mutations in a second gene, but further analysis using whole-genome sequencing combined with SNP array analysis did not reveal any evidence of other mutations. We also examined a mouse knockout of β-III spectrin in which ataxia and progressive degeneration of cerebellar Purkinje cells has been previously reported and found morphological abnormalities in neurons from prefrontal cortex and deficits in object recognition tasks, consistent with the human cognitive phenotype. These data provide the first evidence that β-III spectrin plays an important role in cortical brain development and cognition, in addition to its function in the cerebellum; and we conclude that cognitive impairment is an integral part of this novel recessive ataxic syndrome, Spectrin-associated Autosomal Recessive Cerebellar Ataxia type 1 (SPARCA1). In addition, the identification of SPARCA1 and normal heterozygous carriers of the stop codon in SPTBN2 provides insights into the mechanism of molecular dominance in SCA5 and demonstrates that the cell-specific repertoire of spectrin subunits underlies a novel group of disorders, the neuronal spectrinopathies, which includes SCA5, SPARCA1, and a form of West syndrome

De novo point mutations in patients diagnosed with ataxic cerebral palsy

Cerebral palsy is a sporadic disorder with multiple likely aetiologies, but frequently considered to be caused by birth asphyxia. Genetic investigations are rarely performed in patients with cerebral palsy and there is little proven evidence of genetic causes. As part of a large project investigating children with ataxia, we identified four patients in our cohort with a diagnosis of ataxic cerebral palsy. They were investigated using either targeted next generation sequencing or trio-based exome sequencing and were found to have mutations in three different genes, KCNC3, ITPR1 and SPTBN2. All the mutations were de novo and associated with increased paternal age. The mutations were shown to be pathogenic using a combination of bioinformatics analysis and in vitro model systems. This work is the first to report that the ataxic subtype of cerebral palsy can be caused by de novo dominant point mutations, which explains the sporadic nature of these cases. We conclude that at least some subtypes of cerebral palsy may be caused by de novo genetic mutations and patients with a clinical diagnosis of cerebral palsy should be genetically investigated before causation is ascribed to perinatal asphyxia or other aetiologies.peer-reviewe