Alpha-thalassemia/mental retardation syndrome in a 45,X male

An unbalanced Y;autosome translocation leading to a male with a 45,X karyotype is rare with about 30 published cases. A male with a 45,X karyotype as a result of a unique, submicroscopic, unbalanced Y;16 translocation is presented with alpha-thalassemia/mental retardation syndrome.     

Unwanted hydrolysis or α/β-peptide bond formation: how long should the rate-limiting coupling step take?

Nowadays, in Solid Phase Peptide Synthesis (SPPS), being either manual, automated, continuous flow or microwave-assisted, the reaction with various coupling reagents takes place via in situ active ester formation. In this study, the formation and stability of these key active esters were investigated with time-resolved ¹H NMR by using the common PyBOP/DIEA and HOBt/DIC coupling reagents for both α- and β-amino acids. Parallel to the amide bond formation, the hydrolysis of the α/β-active esters, a side reaction that is a considerable efficacy limiting factor, was studied. Based on the chemical nature/constitution of the active esters, three amino acid categories were determined: (i) the rapidly hydrolyzing ones (t < 6 h) with smaller (Ala) or even longer side chains (Arg) holding a large protecting group; (ii) branched amino acids (Ile, Thr) with slowly hydrolyzing (6 < t < 24 h) propensities, and (iii) non-hydrolyzing ones, such as the hard-to-couple β-amino acids or β-sugar amino acid derivatives, stable for longer times (t > 24 h) in solution. The current insight into the kinetics of this key hydrolysis side reaction serves as a guide to optimize the coupling conditions of α- and β-amino acids, thereby saving time and minimizing the amounts of reagents and amino acids to be used – all key factors of more environmentally friendly chemistry.

Parallel to the amide bond formation, the hydrolysis of the active esters of α/β-amino acids, as an unwanted side reaction limiting coupling efficacy, is studied.     

Meta-analysis of randomized trials on access site selection for percutaneous coronary intervention in ST-segment elevation myocardial infarction

Introduction

Superior outcomes with transradial (TRPCI) versus transfemoral coronary intervention (TFPCI) in the setting of acute ST-segment elevation myocardial infarction (STEMI) have been suggested by earlier studies. However, this effect was not evident in randomized controlled trials (RCTs), suggesting a possible allocation bias in observational studies. Since important studies with heterogeneous results regarding mortality have been published recently, we aimed to perform an updated review and meta-analysis on the safety and efficacy of TRPCI compared to TFPCI in the setting of STEMI.

Material and methods

Electronic databases were searched for relevant studies from January 1993 to November 2012. Outcome parameters of RCTs were pooled with the DerSimonian-Laird random-effects model.

Results

Twelve RCTs involving 5,124 patients were identified. According to the pooled analysis, TRPCI was associated with a significant reduction in major bleeding (odds ratio (OR): 0.52 (95% confidence interval (CI) 0.38–0.71, p < 0.0001)). The risk of mortality and major adverse events was significantly lower after TRPCI (OR = 0.58 (95% CI: 0.43–0.79), p = 0.0005 and OR = 0.67 (95% CI: 0.52–0.86), p = 0.002 respectively).

Conclusions

Robust data from randomized clinical studies indicate that TRPCI reduces both ischemic and bleeding complications in STEMI. These findings support the preferential use of radial access for primary PCI.     

Phase II study of oral methyl-CCNU and prednisone in previously treated alkylating agent-resistant multiple myeloma.

Thirteen patients with multiple myeloma (MM) who either failed to respond to or who were relapsing from standard agents and who received four or more courses of methyl-CCNU + prednisone (adequate drug trial) are reported in this paper. Methyl-CCNU was given orally before breakfast at 6-week intervals at a starting dose of 50 mg/m2 with the intention of increasing the dose to 100, 150, and 200 mg/m2 with each subsequent course. The dose of prednisone was 75 mg/day x 7 with each course. The response rate was 46% (six of 13 patients). No patient had better than a fair response. Drug toxicity, severe enough to prevent further dose escalation, was observed in every case. Prior BCNU therapy or the lack of response to previous alkylating agents did not prevent a response to methyl-CCNU + prednisone. The response rate of methyl-CCNU + prednisone in MM is comparable to the results achieved with other agents in similar groups of patients.     

The role of ventromedial prefrontal cortex in addiction disorders

Recently a significant conceptual change emerged in the interpretation of addictological disorders. Despite this significant progress, the exact neuronal mechanisms of these disorders are still unknown. By the development of cognitive neuroscience novel clinical tests became available which are devoted to the evaluation of more properly defined neuronal structures. These novel approaches are designed to separately investigate memory/attention-related and affective processes in decision-making. These investigations along with animal models and functional neuroimaging approaches suggest the crucial role of a complex neuronal network in the pathomechanism of addictological disorders, including the ventromedial prefrontal cortex and the amygdala-accumbens system. The aim of this paper is to review these novel findings in order to gain insight into the neurocognitive mechanisms of addictological disorders.     

The pathogenesis of nasal polyposis by immunoglobulin E and interleukin-5 is completed by transforming growth factor-beta1

OBJECTIVES/HYPOTHESIS: Nasal polyps are benign mucosal protrusions into the nasal cavity of multifactorial origin and are characterized by chronic mucosal inflammation. The suggested multifactorial pathological mechanisms comprise several factors including cytokines and immunoglobulin E (IgE). The study was designed to examine the suggested roles of IgE, interleukin-5 (IL-5), and transforming growth factor-beta1 (TGF-beta1) in the pathogenesis of nasal polyposis. METHODS: Nasal polyps (n = 34) and healthy nasal mucosa samples (n = 9) were taken during routine endonasal surgeries. Immunoglobulin E (n = 13), IL-5 (n = 22), and TGF-beta1 (n = 27) concentrations were measured with enzyme-linked immunosorbent assay technique in homogenized polyp tissue and in control mucosa. Atopic and nonatopic groups were selected and compared. Histomorphological examination and immunohistochemical analysis to detect IL-5 and TGF-beta1 were performed in five specimens. RESULTS: The level of tissue-bound IgE was significantly higher in polyps compared with control specimens and in atopic compared with nonatopic polyps, but between nonatopic polyps and control specimens the difference was not significant. However, significant correlation was found between tissue and serum IgE in the complete polyp (P =.001) and atopic polyps group (P =.05). Tissue IL-5 concentration was significantly higher in polyps compared with control specimens, in which it was below the limit (15 pg/mL), and there was no difference between atopic and nonatopic polyps. In atopic polyps there was significant correlation between tissue IgE and IL-5. Transforming growth factor-beta1 concentration proved to be significantly higher in control mucosa than in polyps, with no difference between atopic and nonatopic polyps. Immunohistochemical analysis revealed numerous IL-5-positive eosinophil cells and TGF-beta1 positivity in the lamina propria of polyp samples, but none in control specimens. CONCLUSIONS: High tissue TGF-beta1 quantity in healthy nasal mucosa without its active form on the cell surface and its low quantity in polyps may reflect its essential role in the inhibitory mechanisms of nasal polyposis. Interleukin-5 plays a key role in the eosinophil recruitment and activation, and both atopic and nonatopic pathways might activate this process. The main sources of IL-5 and TGF-beta1 are the eosinophils and macrophages. Immediate hypersensitivity, besides other mechanisms, might be related to atopic polyps, but the involvement of other, local allergic mechanisms in IgE production of nonatopic polyp tissue cannot be excluded.     

Vaccine-driven serotype-rearrangement is seen with latency in clinical isolates: Comparison of carried and clinical pneumococcal isolates from the same time period in Hungary

Young children – the main asymptomatic carriers of pneumococcus – are often the source of pneumococcal infections. PCV13 replaced PCV7 in 2010 in Hungary and it became a mandatory vaccine in 2014. In this work we surveyed the effect of vaccination in three groups: in healthy children under 7?years; in children of the same age but infected with pneumococcus (P1); in older patients (P2) who were very likely not vaccinated.Nasal swabs were taken from 522 healthy children to screen pneumococcal carriage between March 2015 and May 2016. In the same time period, 146 clinical isolates were collected, mainly from mucosal infections. Serotypes, antibiotic susceptibility and clonality of the isolates was determined and compared.The carriage rate was 39.1%. Regarding carriage, the serotype distribution showed the total disappearance of serotypes 3 and 6A compared to former Hungarian studies. The prevalence of PCV13 serotypes was only 5.8% represented by three serotypes (19F, 19A, 9V). Of note, serotype 19A (a very resistant and invasive type) also decreased significantly. In the patient groups, PCV13 prevalence was higher: 17.5% (P1) and 32.6% (P2). Although serotype 3 was present in P1 (7.9%), the leading serotype was 23B (22.2%), a non-vaccine type (NVT). P2 showed the most diverse serotype distribution, but serotype 3 was predominant here (15.7%). Pneumococcal isolates from the patients were more resistant towards the tested antibiotics compared to those from carriers.PCV13 seems to be highly successful in reducing the prevalence of vaccine serotypes. The serotype-rearrangement can be seen also among clinical isolates, albeit somewhat later in time. Fortunately, the replacing serotypes are less invasive and less resistant, but, most worrisome, serotype 19F can be found again with increased frequency among carriage isolates and mucosal infections. Further surveillance is needed to carefully monitor such successful, antibiotic resistant “refugees”.     

Peroxidasin Is Secreted and Incorporated into the Extracellular Matrix of Myofibroblasts and Fibrotic Kidney

Mammalian peroxidases are heme-containing enzymes that serve diverse biological roles, such as host defense and hormone biosynthesis. A mammalian homolog of Drosophila peroxidasin belongs to the peroxidase family; however, its function is currently unknown. In this study, we show that peroxidasin is present in the endoplasmic reticulum of human primary pulmonary and dermal fibroblasts, and the expression of this protein is increased during transforming growth factor-β1-induced myofibroblast differentiation. Myofibroblasts secrete peroxidasin into the extracellular space where it becomes organized into a fibril-like network and colocalizes with fibronectin, thus helping to form the extracellular matrix. We also demonstrate that peroxidasin expression is increased in a murine model of kidney fibrosis and that peroxidasin localizes to the peritubular space in fibrotic kidneys. In addition, we show that this novel pathway of extracellular matrix formation is unlikely mediated by the peroxidase activity of the protein. Our data indicate that peroxidasin secretion represents a previously unknown pathway in extracellular matrix formation with a potentially important role in the physiological and pathological fibrogenic response.Peroxidases are heme-containing enzymes with highly conserved structure, serving diverse functions in the plant and animal kingdom.¹ Peroxidases catalyze the oxidation of various substrates in the presence of H₂O₂. Mammalian peroxidases have an important role in several physiological processes including host defense and hormone biosynthesis. The family of mammalian peroxidases consists of myeloperoxidase, eosinophil peroxidase, lactoperoxidase, thyroid peroxidase, and the mammalian peroxidasin. Myeloperoxidase, eosinophil peroxidase, and lactoperoxidase have antimicrobial activity and serve in the first line of host defense, while thyroid peroxidase has an essential role in the biosynthesis of thyroid hormones.^2,3,4 The function of the mammalian peroxidasin is currently unknown. Peroxidases in plants and in lower animal species frequently participate in extracellular matrix (ECM) formation. In the presence of H₂O₂, peroxidases enzymatically cross-link extracellular proteins through tyrosine residues.⁵ ECM stabilization by dityrosine bridges is well-documented during sea urchin fertilization, where secreted ovoperoxidase is responsible for the formation of cross-links.⁶ Dityrosine formation is also involved in the stabilization of C. elegans cuticle, where dual oxidases, carrying both NADPH oxidase and peroxidase-like domains, provide hydrogen peroxide for the crosslinking reaction.⁷Peroxidasin (PXDN), a unique form of peroxidase was first identified in Drosophila melanogaster.⁸ Beside containing a peroxidase domain, which is highly homologous to other animal peroxidases, peroxidasin also contains protein domains characteristic for proteins of the ECM. Drosophila PXDN was found to be expressed in several stages of development, but the exact function remained unknown.⁸ Little is still known about the mammalian PXDN protein. A human homolog of Drosophila PXDN was originally identified as a p53-responsive gene product from a colon cancer cell line, but it was not characterized in detail.⁹ An independent cloning effort, using subtractive hybridization also led to the identification of the mammalian PXDN gene, which was originally named melanoma gene 50, based on the expression in melanoma samples.¹⁰ This latter study has characterized PXDN as a possible potent melanoma-associated antigen, but it did not examine the possible physiological role of the protein.Here we demonstrate that peroxidasin is expressed by human primary cells, including fibroblasts of different origin, where the protein is localized to the endoplasmic reticulum. On stimulation by transforming growth factor (TGF)-β1, differentiating myofibroblasts show increased expression of peroxidasin. The protein becomes secreted to the extracellular space where it is organized into a fibril-like network. We also show that this pathway of ECM formation is probably not mediated by the peroxidase activity of the protein. Our results suggest that beside the secretion of well-known constituents of the ECM, PXDN secretion by myofibroblasts is a novel way of ECM modification in wound repair and tissue fibrosis.     

Post traumatic lesion absence of beta-dystroglycan-immunopositivity in brain vessels coincides with the glial reaction and the immunoreactivity of vascular laminin

Following brain lesions, the gliovascular basal lamina undergoes destruction and the gliovascular connections 'decouple'. Laminin receptors, as dystroglycan, are essential in these processes. The present study compares the immunoreactivities of beta-dystroglycan, glial fibrillary acidic protein (GFAP), and laminin following stab wounds in adult rats. In intact brain the vessels were immunopositive to beta-dystroglycan, whereas the laminin of their basal lamina proved to be unavailable to immunoreactions. Following stab wound, however, the adjacent vessels lost their immunopositvity to beta-dystroglycan, whereas immunopositivity to laminin became detectable in them. In an advanced stage of glial reaction the territory of GFAP immunopositive reactive astrocytes coincided with the area where vessels lost their immunopositivity to beta-dystroglycan. When glial reaction regressed, the beta-dystroglycan immunopositivity re-appeared, and laminin immunopositivity became undetectable again. Post-lesional disappearance of vascular beta-dystroglycan immunostaining was described earlier, and was attributed to the cleavage of beta-dystroglycan by matrix metalloproteinases as a mechanism of the decoupling of the gliovascular connections. Our results, which were obtained in a different type of lesion support that the loss of vascular beta-dystroglycan immunopositivity is a general phenomenon following cerebral lesions, and an indirect marker of gliovascular decoupling. For the first time coincidences were presented between vascular immunonegativity to beta-dystroglycan, glial reaction and detectability of laminin. Manifestation of laminin immunoreactivity also indicates gliovascular decoupling. Coincidence between glial reaction and lack of vascular beta-dystroglycan suggests mutual enhancement between them. The observations may have clinico-pathologic importance since similar investigations may help to follow the progression and regression of post-lesion processes.