The correlation between zeta potential and mucoadhesion strength on pig vesical mucosa

The detachment forces of various polymers are frequently measured to determine their mucoadhesion strength. As the process of mucoadhesion is a consequence of interactions between the mucus layer on mucosa and mucoadhesive polymers, it is greatly dependent on mucus and polymer structure including their charge. It is also known that the glycosaminoglycan layer, which covers the urinary bladder mucosa surface, is highly negatively charged. Therefore, by measuring the zeta potential of polymer dispersions and mucosal homogenates an insight into electrostatic interactions during mucoadhesion can be obtained. In our experiments we chose three polymers, two anionic (polycarbophil, PC; sodium carboxymethyl cellulose, CMCNa) and one cationic (chitosan hydrochloride, CH), for which we expected different zeta potential values and different mucoadhesion strengths. The correlation between the zeta potential and the detachment force was determined. In addition to that, the zeta potential of the scraped surface layer of pig urinary bladders was measured to confirm its negative value. The mucoadhesion strength decreased in the following order: CH>CMCNa=PC. The zeta potentials for all three polymers and for porcine vesical mucosal homogenates were measured in Tyrode solution and two NaCl solutions with different ionic strengths. The lower values of the detachment force correlated well with the more negative zeta potential of the polymer, which might be a consequence of the greater repulsion between negative charges of polymers and glycosaminoglycans.     

Possible mechanism of acute effect of ethanol on intestinal IgA expression in rat

The purpose of this study was to investigate the possible mechanism of acute effect of ethanol on IgA expression in rat intestine. To this end, adult female Wistar rats showing diestrus day 1 were treated with (a) ethanol (2 or 4 g/kg, i.p.); (b) N omega-nitro-L-arginine-methyl ester (L-NAME), which inhibits the activity of all isoforms of nitric oxide synthase, (30 mg/kg, s.c.) followed by ethanol 3 h later; and (c) L-NAME (30 mg/kg, s.c.) followed by saline 3 h later. Saline-injected and untreated rats were used as controls. The animals were sacrificed 0.5 h after ethanol administration. Intestinal expression of IgA was evaluated by both immunohistochemistry and Western immunoblotting. Morphometric analysis showed that acute ethanol treatment increased the number of IgA-immunoreactive cells in a dose-dependent manner. Pretreatment with L-NAME abolished this action of alcohol. Injection of L-NAME followed by saline had no influence on the number of IgA+cells. The results, obtained by Western immunoblotting, paralleled our immunohistochemical findings. Taken together, these data suggest that acute effect of ethanol on intestinal IgA might be mediated by endogenous nitric oxide.     

Oxidative burst of neutrophils against melanoma B16-F10

Intensive oxidative burst was determined by chemiluminescence of peripheral blood neutrophils of mice that were intramuscularly injected with melanoma B16-F10 and/or subcutaneously with Sephadex G-200. The neutrophils from papula developed at the site of Sephadex injection were cytotoxic for the B16-F10 cells in vitro. However, survival of Sephadex injected tumour-bearing mice was lower than of control animals bearing B16-F10, while their tumours grew faster and were less necrotic. Thus, it is likely that injection of Sephadex distracted the neutrophils from the tumour allowing faster progression of the tumour, indicating that neutrophils may have an important role in the host defence against malignant cells in the early stage of tumour development.     

Asialoglycoprotein receptor promotes cancer metastasis by activating the EGFR-ERK pathway

Although the importance of glycans in malignant cell behavior is well documented, the potential involvement of endogenous lectins as modifiers of progression and metastasis in the tumor microenvironment has not been explored. In this study, we show that loss of the hepatic asialoglycoprotein receptor (ASGPR) in mice severely reduces the frequency of spontaneous lung metastasis after intrahepatic implantation of murine Lewis lung carcinoma (3LL) cells. Conversely, in vitro treatment with recombinant ASGPR increased the invasive and metastatic capacity of 3LL cells before intrahepatic implantation. ASGPR treatment in vitro increased the expression and production of matrix metalloproteinase-9 through activation of the epidermal growth factor receptor-extracellular signal-regulated kinase (EGFR-ERK) pathway. Our findings identify ASGPR as a novel important factor that responds to endogenous lectins in the tumor microenvironment to promote cancer metastasis by activating the EGFR-ERK pathway through interactions with counter-receptors on cancer cells.     

Longitudinal tumor fraction trajectories predict risk of progression in metastatic HR+ breast cancer patients undergoing CDK4/6 treatment

Despite improved clinical outcomes, intrinsic or acquired resistance to CDK4/6 inhibitor treatment has limited the success of this treatment in HR⁺HER2⁻ metastatic breast cancer patients. Biomarkers are urgently needed, and longitudinal biomarker measurements may harbor more dynamic predictive and prognostic information compared to single time point measurements. The aim of this study was to explore the longitudinal evolution of circulating tumor fractions within cell‐free DNA assessed by an untargeted sequencing approach during CDK4/6 therapy and to quantify the potential association between longitudinal z‐score measurements and clinical outcome by using joint models. Forty‐nine HR⁺HER2⁻ metastatic breast cancer patients were enrolled, and z‐score levels were measured at baseline and during 132 follow‐up visits (median number of measurements per patient = 3, 25^th–75^th percentile: 3–5, range: 1–8). We observed higher baseline z‐score levels (estimated difference 0.57, 95% CI: 0.147–0.983, P‐value = 0.008) and a constant increase of z‐score levels over follow‐up time (overall P‐value for difference in log z‐score over time = 0.024) in patients who developed progressive disease. Importantly, the joint model revealed that elevated z‐score trajectories were significantly associated with higher progression risk (HR of log z‐score at any time of follow‐up = 3.3, 95% CI, 1.44–7.55, P = 0.005). In contrast, single z‐score measurement at CDK4/6 inhibitor treatment start did not predict risk of progression. In this prospective study, we demonstrate proof‐of‐concept that longitudinal z‐score trajectories rather than single time point measurements may harbor important dynamic information on the development of disease progression in HR⁺HER2⁻ breast cancer patients undergoing CDK4/6 inhibitor treatment.

Abbreviations

CDK4/6

cyclin‐dependent kinase 4/6

CI

confidence interval

ctDNA

circulating tumor DNA

HER2

human epidermal growth factor 2

HR

hazard ratio

HR

hormone receptor

mFAST‐SeqS

modified Fast Aneuploidy Screening Test‐Sequencing System

OS

overall survival

PFS

progression‐free survival

     

Optimal scan time for evaluation of parathyroid adenoma with [18F]-fluorocholine PET/CT

Background

Parathyroid adenomas, the most common cause of primary hyperparathyroidism, are benign tumours which autonomously produce and secrete parathyroid hormone. [¹⁸F]-fluorocholine (FCH), PET marker of cellular proliferation, was recently demonstrated to accumulate in lesions representing enlarged parathyroid tissue; however, the optimal time to perform FCH PET/CT after FCH administration is not known. The aim of this study was to determine the optimal scan time of FCH PET/CT in patients with primary hyperparathyroidism.

Patients and methods.

43 patients with primary hyperparathyroidism were enrolled in this study. A triple-phase PET/CT imaging was performed five minutes, one and two hours after the administration of FCH. Regions of interest (ROI) were placed in lesions representing enlarged parathyroid tissue and thyroid tissue. Standardized uptake value (SUV_mean), retention index and lesion contrast for parathyroid and thyroid tissue were calculated.

Results

Accumulation of FCH was higher in lesions representing enlarged parathyroid tissue in comparison to the thyroid tissue with significantly higher SUV_mean in the second and in the third phase (p < 0.0001). Average retention index decreased significantly between the first and the second phase and increased significantly between the second and the third phase in lesions representing enlarged parathyroid tissue and decreased significantly over all three phases in thyroid tissue (p< 0.0001). The lesion contrast of lesions representing enlarged parathyroid tissue and thyroid tissue was significantly better in the second and the third phase compared to the first phase (p < 0.05).

Conclusions

According to the results the optimal scan time of FCH PET/CT for localization of lesions representing enlarged parathyroid tissue is one hour after administration of the FCH.     

Sodium and calcium intakes and bone mass in rats revisited

OBJECTIVE: High sodium intake accompanied by insufficient dietary calcium may have detrimental effects on bone mass. Our study evaluated the effects of increased sodium and decreased calcium intakes on bone mineral density (BMD) and bone mineral content (BMC) in rats. METHODS: Four-month-old female Wistar rats were given deionized water or 1.8% solution of sodium chloride in deionized water and fed normal (1.2%) or marginal (0.33%) calcium in the diet for 2 mo. At the end of the experiment, BMD and BMC of the whole body and urinary sodium and calcium excretion were evaluated. All rats were killed and right femurs were removed to assess dry and ash weights. Two-way analysis of variance was used to evaluate effect of salt intake and effect of dietary calcium on these parameters. RESULTS: Salt-loaded animals had greater water consumption during the entire 2-mo period and significantly lower body weight from week 5 of the experiment. High salt intake increased urine volume and urinary excretion of sodium and calcium. Urinary calcium was about five times higher in salt-loaded animals than in rats on deionized water irrespective of dietary calcium content. Calcium in diet itself had no significant effect on these parameters. High salt intake slightly, but not significantly, decreased BMD, BMC, and femur weights. Lower calcium in diet significantly decreased BMD, and its effect on femur ash weight almost reached a level of significance. CONCLUSION: We confirmed the benefit of adequate calcium intake to BMD. Under our experimental condition, high salt intake in rats for 2 mo had no statistically significant effect on femur weights, BMD, or BMC even with marginal calcium in the diet.     

Molecular characterization of specific H<Subscript>1</Subscript>-receptor agonists histaprodifen and its N<Superscript>α</Superscript>-substituted analogues on bovine aortic H<Subscript>1</Subscript>-receptors

We determined the molecular properties of the selective and potent H(1)-receptor agonist histaprodifen and its N(alpha) substituted analogues: methyl-, dimethyl-, and imidazolylethyl-histaprodifen (suprahistaprodifen). All derivatives show high affinity for (3)H-mepyramine labeled bovine aortic H(1)-receptor binding sites with the following order of potency: suprahistaprodifen > dimethylhistaprodifen > methylhistaprodifen > histaprodifen > histamine. Suprahistaprodifen and dimethylhistaprodifen were the most potent displacers of (3)H-mepyramine binding (K(i)=4.3 and 4.9 nM, respectively). Histaprodifen, methylhistaprodifen and suprahistaprodifen binding was differentially influenced by GTP, whereas dimethylhistaprodifen was not affected. All drugs, except dimethylhistaprodifen, were activators of G-proteins. Their order of potency was suprahistaprodifen > histamine > histaprodifen > methylhistaprodifen. Their effect on G-protein activation was abolished by the addition of the H(1)-receptor antagonist triprolidine (10 microM), which given alone did not activate G-proteins. Our data suggest that histaprodifens are potent but heterogeneous H(1)-receptor ligands with diverse effects on the molecular level in our model system. While the histaprodifen, methylhistaprodifen and suprahistaprodifen data are in agreement with their agonistic nature, as shown in the functional studies performed on different species (rat and guinea pig H(1)-receptor), dimethylhistaprodifen behaved as an antagonist in our study.     

Effect of soman intoxication on the organization of rat brain ribosomes and the translational activity of mRNA in a cell-free system

The effect of soman on rat brain ribosomes organization and translational activity of mRNA in cellfree system was studied in rats exposed to 1.3 LD₅₀ soman (120 g/kg body weight) and in rats repeatedly injected with 0.4 LD₅₀ soman (35 g/kg). Fifteen minutes after the injection of 1.3 LD₅₀ soman the heavy polyribosomal fraction from rat brain was found to be enriched and translational activity of mRNA was enhanced. In rats administered five injections of 0.4 LD₅₀ soman at 24-h intervals, the low density ribosomes appeared as the predominant fraction whereas the activity of mRNA in all cell-free system was significantly impaired. It is concluded that soman intoxication expresses a stimulatory or inhibitory effect on the processes of protein synthesis in the rat brain, depending on the dose schedule of soman administration.     

Comparison of Wavelight Allegretto Eye-Q and Schwind Amaris 750S excimer laser in treatment of high astigmatism

Purpose

To compare functional outcomes of Wavelight Allegretto Eye-Q 400Hz and Schwind Amaris 750S excimer laser for astigmatism between 2 and 7 diopters(D).

Methods

Prospective comparative non-randomized case series of 480 eyes assigned in two laser groups and further divided into myopic and mixed astigmatism subgroups. All treatments were centered on corneal vertex. One-year results were compared between the groups. Statistical analysis was performed using z-test.

Results

Both Allegretto and Amaris postoperative uncorrected distance visual acuity (UDVA) improved in comparison to preoperative corrected distance visual acuity (CDVA). The difference was significant in the Allegretto group for myopic astigmatism (p?=?0.017). There was no difference in postoperative UDVA between lasers. Average sphere decreased in all groups for both lasers (p?p?p?p?p?p?= 0.023, mixed astigmatism p?Conclusion Both lasers are effective in terms of UDVA, CDVA, spherical correction, and preservation of high-order aberrations. However, Amaris was more effective in cylinder correction.