Atomic force microscopy investigation of vocal fold collagen

OBJECTIVES: Collagen is an important constituent of the vocal fold extracellular matrix and is necessary for providing tensile strength and maintaining tissue geometry. Traditional investigations of vocal fold collagen using light and electron microscopy do not provide information on the organization and mechanical properties of collagen in native topographic state. The primary objective of this study was to use Atomic Force Microscopy (AFM) to examine the surface characteristics and organization of collagen in the deep layer of the lamina propria at nanoscale resolution. STUDY DESIGN: Experimental in vitro design. METHODS: Freshly dissected porcine vocal folds were mounted on AFM discs and imaged under contact and tapping mode to obtain information on topographic distribution of collagen. RESULTS: AFM imaging of the deep layer of the lamina propria revealed dense, abundant collagen fibers with a characteristic banding pattern. The distribution of collagen was heterogeneous, with both hydrophilic and hydrophobic regions within a sample. CONCLUSIONS: AFM offers a useful tool to obtain topographic information about biologic samples at nanoscale resolution with minimal sample preparation. Mapping the topography and mechanical properties of vocal fold collagen is necessary for designing rheologically compatible bioimplants for the treatment of dysphonia resulting from vocal fold scarring and bowing.     

Size of lower jaw as an early indicator of skeletal class III development

BACKGROUND/AIM: Malocclusion of skeletal class III is a complex abnormality, with a characteristic sagital position of the lower jaw in front of the upper one. A higher level of prognatism of the lower jaw in relation to the upper one can be the consequence of its excessive length. The aim of this study was to find the differences in the length of the lower jaw in the children with skeletal class III and the children with normal sagital interjaw relation (skeletal class I) in the period of mixed dentition. METHODS: After clinical and x-ray diagnostics, profile tele-x-rays of the head were analyzed in 60 examinees with mixed dentition, aged from 6 to 12 years. The examinees were divided into two groups: group 1--the children with skeletal class III and group 2--the children with skeletal class I. The length of the lower jaw, upper jaw and cranial base were measured. The proportional relations between the lengths measured within each group were established and the level of difference in the lengths measured and their proportions between the groups were estimated. RESULTS: No significant difference between the groups was found in the body length, ramus and the total length of the lower jaw. Proportional relation between the body length and the length of the lower jaw ramus and proportional relation between the forward cranial base and the lower jaw body were not significantly different. A significant difference was found in proportional relations of the total length of the lower jaw with the total lengths of cranial base and the upper jaw and proportional relation of the length of the lower and upper jaw body. CONCLUSION: Of all the analyzed parameters, the following were selected as the early indicators of the development of skeletal class III on the lower jaw: greater total length of the lower jaw, proportional to the total lengths of cranial base and theupper jaw, as well as greater length of the lower jaw body, proportional to the length of the upper jaw body.     

Effect of potassium channel opener pinacidil on the contractions elicited electrically or by noradrenaline in the human radial artery

In order to discover an agent that can prevent spasm of the human radial artery, the aim of our study was to evaluate the effect of the K⁺ channel opener, pinacidil, on contractions in the radial artery. Contractions of the radial artery were evoked by exogenously applied noradrenaline or by electrical field stimulation (EFS, 20 Hz, neurogenic). Pinacidil induced concentration-dependent inhibition of both EFS- and noradrenaline-evoked contractions of the radial artery. Glibenclamide, a selective blocker of ATP-sensitive K⁺ channels (Kir6.x containing subunit) antagonized in the same manner the pinacidil-induced inhibition of neurogenic contractions and contractions evoked by exogenous noradrenaline. The inhibition of pinacidil relaxation by tetraethylammonium (TEA), a blocker of Ca-sensitive K⁺ (K_Ca) channels, was more pronounced in EFS-contracted preparations. A blocker of voltage-sensitive K⁺ (K_V) channels, 4-aminopyridine (4-AP), inhibited pinacidil relaxation only in EFS-contracted preparations. In order to test the presence of different K⁺ channels, immunohistochemistry of K⁺ channels expression in the radial artery was performed. The vascular wall of the human radial artery showed variable positivity with the following applied antibodies: Kv1.2, Kv1.3, Kir6.1, and K_Ca1.1. The antibodies against Kv1.6, Kv2.1, and Kir6.2 channel subunits were completely negative. These results suggest that the inhibitory effect of pinacidil on contractions of the human radial artery might be postsynaptic and associated with opening of smooth muscle Kir6.1-containing K_ATP channels. TEA- and 4-AP-sensitive K⁺ channels may also contribute to pinacidil effect in the human radial artery.     

Molecular pathogenesis of H5 highly pathogenic avian influenza: the role of the haemagglutinin cleavage site motif

The emergence of H5N1 highly pathogenic avian influenza has caused a heavy socio‐economic burden through culling of poultry to minimise human and livestock infection. Although human infections with H5N1 have to date been limited, concerns for the pandemic potential of this zoonotic virus have been greatly intensified following experimental evidence of aerosol transmission of H5N1 viruses in a mammalian infection model. In this review, we discuss the dominance of the haemagglutinin cleavage site motif as a pathogenicity determinant, the host‐pathogen molecular interactions driving cleavage activation, reverse genetics manipulations and identification of residues key to haemagglutinin cleavage site functionality and the mechanisms of cell and tissue damage during H5N1 infection. We specifically focus on the disease in chickens, as it is in this species that high pathogenicity frequently evolves and from which transmission to the human population occurs. With >75% of emerging infectious diseases being of zoonotic origin, it is necessary to understand pathogenesis in the primary host to explain spillover events into the human population. © 2015 The Authors. Reviews in Medical Virology published by John Wiley & Sons Ltd.     

Leptomeningeal form of Immunoglobulin G4-related hypertrophic meningitis with perivascular spread: a case report and review of the literature

Purpose

Immunoglobulin G4 (IgG4)-related disease represents a spectrum of fibro-inflammatory disorders that affects various organ systems, including the central nervous system.

Methods

Here we present the case of lgG4-related hypertrophic meningitis with exclusively leptomeningeal involvement and spread via perivascular spaces.

Results

A 58-year-old male patient presented with complex partial seizures. Initial computed tomography examination showed left frontal sulcal hyperdensity. Subsequent magnetic resonance examination revealed FLAIR hyperintensity in the central sulcus, with post-contrast enhancement in the form of “dotted line.” Physical examination, routine laboratory, and cerebrospinal fluid analyses were unremarkable. Meningeal biopsy confirmed IgG4-related meningitis. After corticosteroid treatment, a complete resolution of imaging findings was observed. Two months later, the patient presented with relapsing neurological symptoms and radiological findings in postcentral, precentral, and temporal sulci, resembling the form of “dotted line” contrast enhancement. In addition, linear intraparenchymal enhancement that followed perivascular spaces was seen in the left parietal lobe. After repeated steroid therapy, all lesions resolved completely.

Conclusion

We reported the first case of isolated IgG4-related leptomeningeal involvement with a “dotted line” enhancement and perivascular intraparenchymal spread. Although IgG4-related meningitis represents a rare disease, both clinicians and radiologists should include this condition in the differential diagnosis of unclear leptomeningeal disease.

     

Combination of anthracyclines and anti-CD47 therapy inhibit invasive breast cancer growth while preventing cardiac toxicity by regulation of autophagy

Background

The 21-gene recurrence score (RS) predicts outcome and benefit from adjuvant chemotherapy benefit in breast cancer patients treated with adjuvant endocrine therapy. In the NSABP B-28 study, we evaluated the 21-gene RS for its prognostic impact and its ability to predict benefit from paclitaxel (P) in node-positive, estrogen receptor-positive (ER+) breast cancer patients treated with adjuvant chemotherapy plus tamoxifen.

Methods

The B-28 trial compared doxorubicin/cyclophosphamide (AC) with AC followed by P in 3060 patients. Tamoxifen for 5 years was also given to patients > 50 years and those < 50 years with ER+ and/or progesterone receptor-positive (PR+) tumors. The present study includes 1065 ER-positive, tamoxifen-treated patients with RS assessment. Median follow-up time was 11.2 years.

Results

In univariate analyses, RS was a significant predictor of outcome. In multivariate analyses, RS remained a significant independent predictor of outcome beyond clinico-pathologic factors, age, and type of surgery (p < 0.001). In the study population (n = 1065), the disease-free survival (DFS) hazard ratio (HR) with adding P to AC was 0.87 (95% CI 0.72–1.05; p = 0.14). RS was not a significant predictor of P benefit: for DFS, HRs for adding P to AC in RS low, intermediate, and high subgroups were 1.01 (95% CI 0.69–1.47; p = 0.99), 0.84 (95% CI 0.62–1.14; p = 0.26), and 0.81 (95% CI 0.60–1.10; p = 0.21), respectively (interaction p = 0.64). Similar findings were observed for the other study endpoints.

Conclusions

RS maintains significant prognostic impact in ER-positive, node-positive patients treated with adjuvant chemotherapy plus tamoxifen. However, RS did not significantly predict benefit from adding paclitaxel to AC chemotherapy. (Trial Registration: PDQ: NSABP-B-28).

     

Correlates of basal insulin persistence among insulin-naïve people with type 2 diabetes: results from a multinational survey

Background and objective: People with T2DM who initiate basal insulin therapy often stop therapy temporarily or permanently soon after initiation. This study analyzes the reasons for and correlates of stopping and restarting basal insulin therapy among people with T2DM.

Methods: An online survey was completed by 942 insulin-naïve adults with self-reported T2DM from Brazil, France, Germany, Japan, Spain, UK, and US. Respondents had initiated basal insulin therapy within the 3–24 months before survey participation and met criteria for one of three persistence groups: continuers had no gaps of ≥7 days in basal insulin treatment; interrupters had at least one gap in insulin therapy of ≥7 days within the first 6 months after initiation and had since restarted basal insulin; and discontinuers stopped using basal insulin within the first 6 months after initiation and had not restarted.

Results: Physician recommendations and cost were strongly implicated in patients stopping and not resuming insulin therapy. Continuous persistence was lower for patients with more worries about insulin initiation, greater difficulties and weight gain while using insulin, and higher for those using pens and perceiving their diabetes as severe. Repeated interruption of insulin therapy was associated with hyperglycemia and treatment burden while using insulin. Resumption and perceived likelihood of resumption were associated with hyperglycemia upon insulin cessation. Perceived likelihood of resumption among discontinuers was associated with perceived benefits of insulin.

Conclusion: Better understanding of the risk factors for patient cessation and resumption of basal insulin therapy may help healthcare providers improve persistence with therapy.     

Early indicators of prognosis in fulminant hepatic failure: an assessment of the Model for End-Stage Liver Disease (MELD) and King's College Hospital criteria.

While King's Hospital Criteria (KCH) criteria are used worldwide, the Model for End-Stage Liver Disease (MELD) is a more recently developed scoring system that has been validated as an independent predictor of patient survival in conditions for liver transplantation (LT). The aim of the present study was to compare MELD and KCH criteria with other early clinical prognostic indicators (CPI) in a cohort of patients with fulminant hepatic failure (FHF). A total of 144 patients (mean age 31.7 +/- 14.7 yr; range 12-82 yr; 62 males) with FHF due to acute viral hepatitis were included into the study. Variables found significant on univariate analysis were entered into a multivariate logistic regression analysis. A total of 52 (36.1%) patients survived, the remaining 92 (63.9%) died. Univariate analysis showed that age, duration of jaundice, jaundice-encephalopathy interval (JEI), grade of encephalopathy, presence of cerebral edema, bilirubin, prothrombin time, creatinine, and MELD score were significantly different between survivors and nonsurvivors. Multivariate logistic regression identified 6 independent CPI of adverse outcome on admission: age >or=50 yr, JEI >7 days, grade 3 or 4 encephalopathy, presence of cerebral edema, prothrombin time >or=35 seconds, and creatinine >or=1.5 mg/dL. Presence of any 3 of 6 CPI was optimum in identifying survivors and nonsurvivors. A MELD score of >or=33 was found to be best discriminant between survivors and nonsurvivors by the construction of receiver operating characteristic (ROC) curves. Any 3 CPI were superior to MELD and KCH criteria in predicting the outcome (c-statistic [95% confidence interval]: CPI 0.802 [0.726-0.878], MELD 0.717 [0.636-0.789], and KCH criteria 0.676 (0.588-0.764); P values: CPI vs. MELD 0.045, CPI vs. KCH criteria 0.019, and MELD vs. KCH criteria 0.472). In conclusion, MELD and KCH criteria are not as useful as a combination of other early CPI in predicting adverse outcome in patients with FHF due to acute viral hepatitis.