Origin of the 31P MR signal at 5.3 ppm in patients with critical limb ischemia

An unknown intense signal (P_un) with a mean chemical shift of 5.3 ppm was observed in ³¹P MR spectra from the calf muscles of patients with the diabetic foot syndrome. The aim of the study was to identify the origin of this signal and its potential as a biomarker of muscle injury. Calf muscles of 68 diabetic patients (66.3 ± 8.6 years; body mass index = 28.2 ± 4.3 kg/m²) and 12 age‐matched healthy controls were examined by (dynamic) ³¹P MRS (3 T system, ³¹P/¹H coil). Phantoms (glucose‐1‐phosphate, P_i and PCr) were measured at pH values of 7.05 and 7.51. At rest, P_un signals with intensities higher than 50% of the P_i intensity were observed in 10 of the 68 examined diabetic subjects. We tested two hypothetical origins of the P_un signal: (1) phosphorus from phosphoesters and (2) phosphorus from extra‐ and intracellular alkaline phosphate pools. 2,3‐diphosphoglycerate and glucose‐1‐phosphate are the only phosphoesters with signals in the chemical shift region close to 5.3 ppm. Both compounds can be excluded: 2,3‐diphosphoglycerate due to the missing second signal component at 6.31 ppm; glucose‐1‐phosphate because its chemical shifts are about 0.2 ppm downfield from the P_i signal (4.9 ppm). If the P_un signal is from phosphate, it represents a pH value of 7.54 ± 0.05. Therefore, it could correspond to signals of P_i in mitochondria. However, patients with critical limb ischemia have rather few mitochondria and so the P_un signal probably originates from interstitia. Our data suggest that the increased P_un signal observed in patients with the diabetic foot syndrome is a biomarker of severe muscular damage.     

Increased in vitro uptake of the complement C3b in the serum of patients with Guillain-Barré syndrome, myasthenia gravis and dermatomyositis

To examine the role of complement in certain autoimmune neuromuscular diseases, we used an in-vitro quantitative complement uptake assay that allows measurement of the capacity of patients' sera to deposit fragments of the third complement component onto sensitized targets. C3 uptake was significantly higher in patients with active dermatomyositis, Guillain-Barré syndrome and myasthenia gravis, compared to inclusion body myositis and controls. The in-vitro C3 uptake assay supports the role of C3b neoantigen and Membranolytic Attack Complex deposition in the target tissues and may be a useful tool to monitor disease activity in patients with complement-mediated neurological disorders.     

Botulinum toxin efficacy in the treatment of patients with spasmodic dysphonia

BACKGROUND/AIM: Spasmodic dysphonia (DS) is a disabling speech disturbance appearing as the consequence of dystonic vocal folds contraction. Its intermittent appearance in the laryngeal muscles causes vocal function discontinuation. The quality of life of these patients is significantly disturbed. Surgical and a medical therapy appear to be inadequate and unsuccessful ones of no steady improvement. It is the botulinum toxin therapy that proved to be highly efficacious one, with the established improvement in 80-100% of patients. The aim of our study was to evaluate the efficacy of botulinum toxin therapy in patients with SD and to show our preliminary results. METHODS: The study included 10 patients with adductor spasmodic dysphonia. After diagnostic procedures, botulinum toxin was applied either in one or both vocal folds, in doses of 12-16 units each. In our study we applied indirect technique originally developed by Hocevar and Pirtosek. Perceptive voice and speech analysis was performed prior to and after the instillation of botuline toxin as per structured Scale of pathological characteristics of voice and speech appearing in the spasmodic dysphonia. RESULTS: The majority of our patients experienced both subjective improvement and the improvement in the terms of the quality of life, Voice Henolicap Index--(VHI) that was rated as rather significant one (t = 3.562; p = 0.006). CONCLUSION: Regardless unquestionable improvement of definite phonation, further function restitution requires individual vocal therapy and psychotherapy. Vocal therapy includes structural vocal techniques which reduce degree of vocal tension and rapid changes in the power and the height of voice. Further investigations are necessary for the scope of the definition of a standardized therapeutically procedure for spasmodic dysphonia treatment which comprises multidisciplinary approach in diagnosis, therapy and treatment efficacy evaluation.     

Impact of vaginal and cervical colonisation/infection on preterm delivery

BACKGROUND/AIM: Preterm delivery together with insufficient body weight and death cases in newborns is the main issue in obstetrics. About 40% of preterm delivery is caused by infections. The aim of this study was to investigate whether and which bacterial infections of genital tract can be associated with preterm delivery, and depending on when diagnosis was made. METHOD: The study involved 216 pregnant women. According to pregnancy outcome, two groups were formed. The study group involved 29 pregnant women who had preterm delivery out of which nine were examined in I trimester, eight in II trimester and 12 in III trimester. The control group involved 187 pregnant women out of which 47 were examined in I trimester, 73 in II trimester and 67 in III trimester. Bacteriological examination of vaginal and cervical swabs was done in all pregnant women. Infection was diagnosed by finding bacterial antigen in cervical swabs or positive cultures of vaginal and/or cervical swabs followed by the presence of the increased number of polymorphonuclears in direct microscopic preparation. RESULTS: The results showed that in III trimester of pregnancy vaginal bacterial infection was statistically more common (p = 0.021) in women who had preterm delivery (66.7%) in relation to women who delivered in term (29.9%). In this period of gestation the increased number of polymorphonuclears in DMP of vaginal swabs is more common in the women of the study group (75%) than in the women of the control group (43.3%). Preterm delivery was registered in 16.1% women whose microbiological analyses were done in I trimester, 9.9% women in whom microbiological analyses were done in II trimester and in 15.2% pregnant women microbiologically tested in III trimester. CONCLUSION: Based on the obtained results it could be concluded that bacterial infections of genital tract and period of gestation when infection is diagnosed have influence on reducing perinatal morbidity and mortality caused by preterm delivery.     

Measurement of functional residual capacity by helium dilution during partial support ventilation: in vitro accuracy and in vivo precision of the method

Objective Measurement of functional residual capacity (FRC) during controlled and especially during assisted ventilation remains a challenge in the physiological evaluation of ventilated patients. To validate a bag-in-box closed helium dilution technique allowing measurements both during pressure-controlled (PCV) and pressure-support ventilation (PSV). Design and setting Experimental study on lung models containing different volumes, and measurements in patients in the intensive care unit of a university hospital. In patients measurements were performed in duplicate during controlled and assisted ventilation. Patients Thirty-three patients (aged 57 ± 17 years) mechanically ventilated with PCV and PSV. Measurements and results In the lung model assessment of accuracy showed an overall mean difference between FRC measurements and lung model volume of 0.5% (2 SD 5.7%). In patients assessment of repeatability showed a bias between duplicate FRC measurements of −1 ± 70 ml (95% CI −141 to +139 ml). The coefficient of variation was of 3.2% for all measurements with a comparable repeatability in PSV and PCV mode (coefficient of variation of 3.4 and 3.2%, respectively). During the rebreathing period a small reduction in tidal volume (−8.5 ± 5.4%) and mean airway pressure (−2.3 ± 4.7%) was observed with only a 0.3 cmH₂O mean increase in PEEP and no change in respiratory rate and I/E ratio. Conclusions This specifically designed closed helium dilution bag-in-box technique allows accurate FRC measurement with good repeatability during both partial PSV and PVC without exposing patients to disconnection and changes in PEEP. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Induction of MHC class I molecule cell surface expression and epigenetic activation of antigen-processing machinery components in a murine model for human papilloma virus 16-associated tumours

Epigenetic events play an important role in tumour progression and also contribute to escape of the tumour from immune surveillance. In this study, we investigated the up-regulation of major histocompatibility complex (MHC) class I surface expression on tumour cells by epigenetic mechanisms using a murine tumour cell line expressing human E6 and E7 human papilloma virus 16 (HPV16) oncogenes and deficient in MHC class I expression, as a result of impaired antigen-presenting machinery (APM). Treatment of the cells with the histone deacetylase inhibitor Trichostatin A, either alone or in combination with the DNA demethylating agent 5-azacytidine, induced surface re-expression of MHC class I molecules. Consequently, the treated cells became susceptible to lysis by specific cytotoxic T lymphocytes. Further analysis revealed that epigenetic induction of MHC class I surface expression was associated with the up-regulation of APM genes [transporter associated with antigen processing 1 (TAP-1), TAP-2, low-molecular-mass protein 2 (LMP-2) and LMP-7]. The results demonstrate that expression of the genes involved in APM are modulated by epigenetic mechanisms and suggest that agents modifying DNA methylation and/or histone acetylation have the potential to change the effectiveness of antitumour immune responses and therapeutically may have an impact on immunological output.     

Neurobehavioral continuity from fetus to neonate

Neurobehavior represents development of the central nervous system (CNS). Fetuses and newborns exhibit a large number of endogenously generated motor patterns, among which general movements are often investigated pre- and post-natally. Spontaneous activity is probably a more sensitive indicator of brain dysfunction than reactivity to sensory stimuli while testing reflexes. Nutritional stress at critical times during fetal development can have persistent and potentially irreversible effects particularly on brain growth and function. Unfavorable intrauterine environment can affect adversely brain growth. All endogenously generated movement patterns from un-stimulated CNS might be observed as early as from the seven to eight weeks' gestation, with a rich repertoire of movements within the next two or three weeks, continuing for five to six months postnatally. It is still uncertain whether a new scoring system for prenatal neurological assessment will be adequate for the distinction between normal and abnormal fetuses in low-risk pregnancies. The continuity of behavioral patterns from prenatal to postnatal life might answer these intriguing questions.     

Mutation Screening of the HGD Gene Identifies a Novel Alkaptonuria Mutation with Significant Founder Effect and High Prevalence

Alkaptonuria (AKU) is an autosomal recessive disorder; caused by the mutations in the homogentisate 1, 2‐dioxygenase (HGD) gene located on Chromosome 3q13.33. AKU is a rare disorder with an incidence of 1: 250,000 to 1: 1,000,000, but Slovakia and the Dominican Republic have a relatively higher incidence of 1: 19,000. Our study focused on studying the frequency of AKU and identification of HGD gene mutations in nomads. HGD gene sequencing was used to identify the mutations in alkaptonurics. For the past four years, from subjects suspected to be clinically affected, we found 16 positive cases among a randomly selected cohort of 41 Indian nomads (Narikuravar) settled in the specific area of Tamil Nadu, India. HGD gene mutation analysis showed that 11 of these patients carry the same homozygous splicing mutation c.87 + 1G > A; in five cases, this mutation was found to be heterozygous, while the second AKU‐causing mutation was not identified in these patients. This result indicates that the founder effect and high degree of consanguineous marriages have contributed to AKU among nomads. Eleven positive samples were homozygous for a novel mutation c.87 + 1G > A, that abolishes an intron 2 donor splice site and most likely causes skipping of exon 2. The prevalence of AKU observed earlier seems to be highly increased in people of nomadic origin.     

Geometric cues for directing the differentiation of mesenchymal stem cells

Significant efforts have been directed to understanding the factors that influence the lineage commitment of stem cells. This paper demonstrates that cell shape, independent of soluble factors, has a strong influence on the differentiation of human mesenchymal stem cells (MSCs) from bone marrow. When exposed to competing soluble differentiation signals, cells cultured in rectangles with increasing aspect ratio and in shapes with pentagonal symmetry but with different subcellular curvature—and with each occupying the same area—display different adipogenesis and osteogenesis profiles. The results reveal that geometric features that increase actomyosin contractility promote osteogenesis and are consistent with in vivo characteristics of the microenvironment of the differentiated cells. Cytoskeletal-disrupting pharmacological agents modulate shape-based trends in lineage commitment verifying the critical role of focal adhesion and myosin-generated contractility during differentiation. Microarray analysis and pathway inhibition studies suggest that contractile cells promote osteogenesis by enhancing c-Jun N-terminal kinase (JNK) and extracellular related kinase (ERK1/2) activation in conjunction with elevated wingless-type (Wnt) signaling. Taken together, this work points to the role that geometric shape cues can play in orchestrating the mechanochemical signals and paracrine/autocrine factors that can direct MSCs to appropriate fates.