Variability issues in determining the concentration of isoprene in human breath by PTR-MS

This paper deals with variability issues connected with the proton transfer reaction-mass spectrometry (PTR-MS) measurements of isoprene concentration. We focus on isoprene as an abundant and widely studied compound in human breath. The variability caused by the measurement process is described by the within-sample distribution. Thus, based on the formula for computing isoprene concentration that reflects the principle of the PTR-MS, a theoretical model for the within-sample distribution of isoprene concentration is suggested. This model, which assumes that the distribution is proportional to a quotient of two independent Poisson-distributed random variables, is then confronted with empirical distributions obtained from 17 breath samples collected from a healthy individual within a month. (In each sample, isoprene concentration was determined 97 times.) The empirical within-sample distributions are also compared to normal and log-normal distributions. While those seem to be satisfactory approximations, the theoretical model is found suitable only in 10 out of 17 breath samples. We also comment on the stability of samples during the measurement process in the PTR-MS instrument and, for the sake of comparison, determine the within-sample and the within-subject variability of isoprene concentrations in our data. The respective geometric standard deviations are 1.01 and 1.29.     

Users' Perspective on the Evaluation of Mental Health Services

Introduction: The inclusion of mental health service users' perspective in the evaluation of the services contributes both to its validity and to the protection of rights of individuals with mental illness. While the development of evaluations that take into account users' views is increasing, the practice still lacks diffusion in real-life settings, that is, incorporation in everyday service management practices, especially in developing countries. Objective: Describe and analyze users' perspective on a discharge program for women in Argentina, with emphasis on the strategies that facilitate the inclusion of their perspective on service evaluation in real life settings in a developing country. Methods: A qualitative study was carried out with fifty-six users of a discharge program associated with a psychiatric hospital in the southern zone of Greater Buenos Aires, from 2011 to 2012. The qualitative methodologies used were participant observation, records analysis, questionnaires, and focus groups. Results: The participative feature of the program, mental health workers' use of narrative language, and the focus on users' "everyday life" concerns emerged as variables that promote the inclusion of users' perspective. Conclusions: Results raise a discussion about the concept of "care" in contrast to "health care." Consequently, further development of the care component in community mental health services evaluations is proposed.     

Lenalidomide induced therapeutic response in a patient with aggressive multi-system Langerhans cell histiocytosis resistant to 2-chloro-deoxyadenosine and early relapsing after high-dose BEAM chemotherapy with autologous peripheral blood stem cell transplantation

Adult Langerhans cell histiocytosis (LCH) usually follows a favorable course. Very rarely, however, multi-system (multi-organ) LCH difficult to manage either with traditional first line treatment (vinblastine, mercaptopurine, prednisone or etoposide) or 2-chlorodeoxyadenosine occurs. In these patients, other treatment modalities have to be used. We describe a patient with LCH manifesting with generalized lymphadenopathy and infiltrating the pulmonary parenchyma and skin. The disease activity was always associated with B-symptoms (weight loss, subfebrile states, night sweats). Histological investigations repeatedly showed higher proliferation activity than that usual in adult patients with LCH. Expression of Ki-67 proliferation marker was up to 30% and there were 8-10 cells in mitosis in the microscope viewing field. Therefore, therapy started with the application of stimulation regimen (cyclophosphamide 2 g/m2 on day 1 and etoposide 200 mg/m2 on days 1-3) followed by collection of peripheral blood stem cells. Then, treatment with 2-chlorodeoxyadenosine, the first 3 cycles as monotherapy of 5 mg/m2 SC on days 1-5 in 28-day cycles, the next 3 cycles in combination with cyclophosphamide 150 mg/m2 on days 1-5 and methylprednisolone 250 mg on days 1-5, was used. However, the disease relapsed 2 months after completion of the therapy. This early relapse was treated with 4 cycles of CHOEP chemotherapy (cyclophosphamide, doxorubicin, vincristine, etoposide, prednisone). Following the 4th cycle of CHOEP, high-dose BEAM chemotherapy (carmustine, etoposide, cytarabine, melphalan) with autologous stem cell transplantation were administered. According to the follow-up PET-CT examination, this treatment resulted in complete disease remission. However, the disease relapsed again in the lymph nodes, lungs, skin and bones 5 months after the high-dose chemotherapy. The progression was documented on PET-CT scanning. Lenalidomide 25 mg daily for 21 days in 28-day cycles with dexamethasone 20 mg once a week were administered as the 4th line treatment. After the 4th cycle of lenalidomide, PET-CT was performed, where the CT component suggested a significant reduction (more than 50%) in the size of the lymph nodes and the PET component showed substantial reduction in fluorodeoxyglucose accumulation in the affected lymph nodes as well as in the bone lesions. HRCT showed disappearance of pulmonary nodules. During the treatment, CRP levels declined and hemoglobin rose from 110 to 141 g/l, i.e. partial remission was achieved after 4 cycles. Etoposide (100 mg IV) was added to lenalidomide and dexamethasone on days 22, 23 and 24 of the above mentioned 28-day cycle. The added etoposide further intensified treatment response. In all, 11 cycles of this chemotherapy were given, resulting in complete remission confirmed by follow-up PET-CT. The achieved remission was consolidated using allogeneic bone marrow transplantation after FLAMSA reduced intensity conditioning without amsacrine. Four months after allogeneic transplantation, the patient has been relapse free. Herein we presented treatment response of highly aggressive LCH to lenalidomide. The used four cycles led to partial remission only and with the combination of lenalidomide, dexamethasone and etoposide the treatment response was further intensified to complete remission.     

Arthroscopic lysis and lavage in patients with temporomandibular anterior disc displacement without reduction

The authors prospectively analysed 50 patients with chronic anterior disc displacement without reduction, who underwent arthroscopic lysis and lavage of the temporomandibular joint (TMJ). Patients with symptoms lasting less than 1 year were assigned to Group A (n=28) and patients with symptoms lasting more than 1 year to Group B (n=22). The most common problems were inflammatory changes of synovial and retrodiscal tissue (Group A, 71%; Group B, 82%). Fibrous adhesions were present in 14% of Group A patients and 45% of Group B patients. Degenerative changes of the disc and articular surface were present in 4% of Group A patients and 32% of Group B patients. Mouth opening increased 123% from baseline in Group A, and 112% in Group B (P<0.05). Pain decreased significantly in both groups (Group A, 2.5 points; Group B, 1.68 points; P<0.05). In conclusion, almost all patients with chronic anterior disc displacement without reduction benefited from arthroscopic lysis and lavage of the TMJ. Patients with a shorter duration of symptoms problems benefited more than those with a longer duration. Arthroscopic lysis and lavage of the TMJ is safe and beneficial in chronic anterior disc displacement without reduction.     

Morphology and physiology of lamina I neurons of the caudal part of the trigeminal nucleus

It has been suggested that in mammals, trigeminal lamina I neurons play a role in the processing and transmission of sensory information from the orofacial region. We investigated the physiological and morphological properties of trigeminal subnucleus caudalis (Sp5C) lamina I neurons in slices prepared from the medulla oblongata of 13- to 15-day-old postnatal rats using patch-clamp recordings and subsequent biocytin-streptavidin-Alexa labeling. Twenty-five neurons were recorded and immunohistochemically stained. The Sp5C lamina I consisted of several types of neurons which, on the basis of their responses to somatic current injection, can be classified into four groups: tonic neurons, which fired throughout the depolarizing pulse; phasic neurons, which expressed an initial burst of action potentials; delayed onset neurons, which showed a significant delay of the first action potential; and single spike neurons, characterized by only one to five action potentials at the very beginning of the depolarizing pulse even at high levels of stimulation intensity. Electrical stimulation of the spinal trigeminal tract evoked AMPA receptor-mediated excitatory postsynaptic currents (EPSC) exhibiting a strong polysynaptic component. AMPA receptor-mediated miniature excitatory postsynaptic currents (mEPSC) were characterized by a 10-90% rise time of 0.50+/-0.06 ms and a decay time constant of 2.5+/-0.5 ms. The kinetic properties of NMDA receptor-mediated EPSCs were measured at +40 mV. The 10-90% rise time was 8+/-2 ms and the deactivation time constants were 94+/-31 and 339+/-72 ms, respectively. Intracellular staining and morphological analysis revealed three groups of neurons: fusiform, pyramidal, and multipolar. Statistical analysis indicated that the electrophysiological properties and morphological characteristics are correlated. Tonic and phasic neurons were fusiform or pyramidal and delayed onset and single spike neurons were multipolar. Our results show that both the physiological and morphological properties of Sp5C lamina I neurons exhibit significant differences, indicating their specific integration in the processing and transmission of sensory information from the orofacial region.     

Pulmonary delivery of polyplexes for combined PAI-1 gene silencing and CXCR4 inhibition to treat lung fibrosis

This report describes the development of polyplexes based on CXCR4-inhibiting poly(ethylenimine) derivative (PEI-C) for pulmonary delivery of siRNA to silence plasminogen activator inhibitor-1 (siPAI-1) as a new combination treatment of pulmonary fibrosis (PF). Safety and delivery efficacy of the PEI-C/siPAI-1 polyplexes was investigated in vitro in primary lung fibroblasts isolated from mice with bleomycin-induced PF. Biodistribution analysis following intratracheal administration of fluorescently labeled polyplexes showed prolonged retention in the lungs. Treatment of mice with bleomycin-induced PF using the PEI-C/siPAI-1 polyplexes resulted in a significant down-regulation of the PAI-1 expression and decreased collagen deposition in the lung. The results of this study provide first evidence of the potential benefits of combined inhibition of CXCR4 and PAI-1 in the pulmonary treatment of PF.     

Reproducibility of sonographic measurement of the substantia nigra

The aim of this study was to evaluate inter-reader, intra-investigator and inter-investigator reproducibility and correlations in the assessment of substantia nigra (SN) echogenicity and area measurement by a physician-sonographer (PS), a sonographic laboratory assistant (SLA) and a physician without sonographic experience (PN). A total of 22 patients with extrapyramidal symptoms were examined using transcranial sonography (TCS). SN images were encoded and evaluated by the three readers. A second TCS examination was performed after 7+/-2 d. A second investigator performed TCS examination 1 mo later. Spearman rank correlation and Pearson's correlation coefficient were used when assessing the agreement between readers. All three readers identified the same 15 patients with SN echogenicity III or more. Inter-reader SN echogenicity and area measurement correlations were r=0.55 to 0.82 and r=0.31 to 0.74 between PS and SLA and r=0.55 to 0.77 and 0.49 to 0.62 between PS and PN, respectively (p<0.05 in all cases). Intra-reader echogenicity and area measurement correlations (r=0.85 to 0.96 and r=0.51 to 0.69) were statistically significant only for PS (p<0.001). All intra- and inter-investigator correlations of SN area measurement (r=0.69 to 0.88 and r=0.5 to 0.61) and SN echogenicity (r=0.64 to 0.92 and r=0.51 to 0.69) were statistically significant (p<0.05). Semiquantitative evaluation of SN echogenicity and area using TCS is highly dependent on the experience of the sonographer. Only an experienced sonographer was able to produce very reproducible results with statistically significant correlations; SLA and PN intra-reader correlations were poor.     

Vascular access monitoring: methods and procedures--something to standardize?

The article discusses the issue of suitable parameters (pressures, recirculation and access flow) to assess hemodialysis vascular access quality (VAQ), available methods to measure those parameters and the setup of the entire VAQ surveillance system (VAQS) in a dialysis facility. Special attention is paid to factors which need some standardization to enable evaluation of VAQ trends in an individual as well as comparison of data from different patients and different dialysis facilities. The discussed procedures are documented with the authors' own measurement results and the results of the VAQS implemented in their unit. Both dynamic and static pressures exhibit insufficient sensitivity in detecting stenoses in native arteriovenous fistulas. Access recirculation is a late finding because with its non-zero value dialysis quality is already compromised. Timely and reliable detection of a deteriorating access condition is enabled by access flow (QVA) only. No standardization is needed in extracorporeal blood flow used in QVA evaluation by ultrasonic dilution. Multiple measurements may increase the reliability of thermodilutional measurements and are a must in optodilutional ones. Timing of the measurement during dialysis should be standardized. Measurement frequency should take into account access type, QVA value and access history. Shortened intervals are needed in the immediate post-intervention period with regard to risk of re-stenosis incidence and strongly nonlinear QVA decreases in such cases. A significant shift-over from surgical interventions to balloon angioplasties is to be expected with the introduction of a VAQS, and appropriate measures must be taken to ensure their quick availability.