Active motion of tangentially driven polymers in periodic array of obstacles.

One key question about transport of active polymers within crowded environments is how spatial order of obstacles influences their conformation and dynamics when compared to disordered media. To this end, we computationally investigate the active transport of tangentially driven polymers with varying degrees of flexibility and activity in two-dimensional square lattices of obstacles. Tight periodic confinement induces notable conformational changes and distinct modes of transport for flexible and stiff active filaments. It leads to caging of low activity flexible polymers inside the inter-obstacle pores while promoting more elongated conformations and enhanced diffusion for stiff polymers at low to moderate activity levels. The migration of flexible active polymers occurs via hopping events, where they unfold to move from one cage to another, similar to their transport in disordered media. However, in ordered media, polymers are more compact and their long-time dynamics is significantly slower. In contrast, stiff chains travel mainly in straight paths within periodic inter-obstacle channels while occasionally changing their direction of motion. This mode of transport is unique to periodic environment and leads to more extended conformation and substantially enhanced long-time dynamics of stiff filaments with low to moderate activity levels compared to disordered media. At high active forces, polymers overcome confinement effects and move through inter-obstacle pores just as swiftly as in open spaces, regardless of the spatial arrangement of obstacles. We explain the center of mass dynamics of semiflexible polymers in terms of active force and obstacle packing fraction by developing an approximate analytical theory.

Effects of inertia on conformation and dynamics of tangentially driven active filaments.

Active filamentlike systems propelling along their backbone exist across scales ranging from motor-driven biofilaments to worms and robotic chains. In macroscopic active filaments such as a chain of robots, in contrast to their microscopic counterparts, inertial effects on their motion cannot be ignored. Nonetheless, the consequences of the interplay between inertia and flexibility on the shape and dynamics of active filaments remain unexplored. Here we examine inertial effects on a flexible tangentially driven active polymer model pertinent to the above examples and we determine the conditions under which inertia becomes important. Performing Langevin dynamics simulations of active polymers with underdamped and overdamped dynamics for a wide range of contour lengths and activities, we uncover striking inertial effects on conformation and dynamics for high levels of activities. Inertial collisions increase the persistence length of active polymers and remarkably alter their scaling behavior. In stark contrast to passive polymers, inertia leaves its fingerprint at long times by an enhanced diffusion of the center of mass. We rationalize inertia-induced enhanced dynamics by analytical calculations of center-of-mass velocity correlations, applicable to any active polymer model, which reveal significant contributions from active force fluctuations convoluted by inertial relaxation.

Tim3 and PD-1 as a therapeutic and prognostic targets in colorectal cancer: Relationship with sidedness, clinicopathological parameters, and survival.

Background: Colorectal cancer (CRC) is a heterogeneous disease that complicates predicting patients' prognosis and their response to treatment. CRC prognosis is influenced by the tumor microenvironment (TME). The immune system is a critical component of the TME. Programmed cell death receptor 1 (PD-1) and T-cell immunoglobulin and mucin-domain containing-3 (Tim3) are inhibitory immune checkpoints that regulate immune response and may provide prognostic power. However, the effect of their expressions and co-expressions on the CRC prognosis remains unclear. Accordingly, this study aimed to investigate the prognostic value of the CD8, CD3, PD-1, Tim3 expression, and PD-1/Tim3 co-expression in patients with CRC. Materials and Methods: One hundred and thirty six patients with CRC who underwent curative surgery were enrolled in the study. Immunohistochemical staining was performed for PD-1, Tim3, CD8, and CD3, and the expression of each marker was evaluated in the center of the tumor (CT), invasive margin (IM), and adjacent normal-like tissue. Result: Our results indicated that high expression of PD-1 in IM was significantly associated with lower TNM stage, T-stage, M-stage, lack of metastasis, the presence of tertiary lymphoid structure (TLS), lack of recurrence (in the left-sided tumors), and larger tumor size (in right-sided tumors) (P<0.05). High expression of PD-1 in IM was also associated with improved overall survival (OS) in a subgroup of patients with high CD8 expression. High Tim3 expression in CT was associated with higher M-stage (M1) (in left-sided CRCs) (P<0.05). It was also associated with decreased OS in total cohort and left-sided CRCs and represented an independent prognostic factor for CRC patients in multivariate analysis. PD-1 and Tim3 co-expression had no synergistic effects on predicting OS. Conclusion: Our findings suggest that the clinicopathological and prognostic significance of immune system-related markers such as CD8, PD-1, and Tim3 depends on the primary tumor sides. We also showed that Tim3 could act as a prognostic factor and therapeutic target in CRC. This marker is probably a more preferred target for immunotherapy than PD-1, especially in left-sided CRCs.

Comparative Effect of the Active Substance of Thyme with N-Acetyl Cysteine on Hematological Parameters and Histopathological Changes of Bone Marrow and Liver in Rat Models of Acetaminophen Toxicity.

Acetaminophen has always been at the center of attention as a non-steroidal anti-inflammatory drug, which is generally associated with the serious side effects on liver and the hematological parameters. This study aimed to compare the effect of N-acetyl cysteine (NAC) and thyme extract on rat models of acetaminophen-induced toxicity. The present experimental study was conducted on 48 Wistar rats randomized into six groups, including the control group (no treatment); the Ac group (470 mg/kg of acetaminophen); the Ac + 100Ex, Ac + 200Ex, and Ac + 400Ex groups (acetaminophen + thyme extract at doses of 100, 200, 400 mg/kg); and Ac + NA group (acetaminophen + NAC). After weighing, a blood sample was taken from heart at the end of the period. The measured parameters were hematological, liver biochemical, and oxidative stress profiles. A part of the liver tissue was also fixed for the pathological examinations. The bone marrow was aspirated to check for cellular changes as well. The lowest mean of the final weight and liver weight to body weight ratio was observed in the Ac group. Weight loss was compensated in Ac + NA and Ac + 200Ex groups (P = 0.035). White blood cell (WBC), red blood cell (RBC), Hemoglobin (Hgb), and Hematocrit (HCT) in Ac and Ac + 400Ex groups showed significant differences from those of the other test groups (P < 0.001). Aspartate transaminase (AST), alanine transaminase (ALT), and alkaline phosphatase (ALP) enzymes in Ac + 200Ex and Ac + NA groups showed a significant decrease compared to those of the other treatment groups (P = 0.043). Total antioxidant capacity (TAC) and glutathione peroxidase (GPx) had the lowest levels in Ac and Ac + 400Ex groups, while malondialdehyde (MDA) had the highest content. In this regard, the liver histopathological indices (necrosis, hyperemia, and hemorrhage) in the Ac + 200Ex and Ac + NA groups reached their lowest grades in the treatment groups. The mean number of erythroid and myeloid cells in the Ac group reached the lowest (17.40 ± 3.48). The microscopic appearance of the bone marrow cells was different from normocytosis in the control group to hypocytosis in the Ac and Ac + 400Ex groups. Thymol, as an effective ingredient in thyme extract at a dose of 200 mg/kg compared to NAC, had a unique effect on reducing bone marrow and liver cell-tissue changes due to the acetaminophen toxicity.

Clinicopathological significance and prognostic role of LAG3 + tumor-infiltrating lymphocytes in colorectal cancer; relationship with sidedness.

BACKGROUND: It is well-documented that the interplay between tumor-infiltrating lymphocytes (TILs) and tumor cells is a major determining factor in cancer progression. CD45RO seems to be a reliable indicator for predicting prognosis and disease outcome, along with CD3 and CD8 markers. LAG-3 is another important marker that overexpresses on TILs in a variety of cancers and is associated with disease prognosis; however, its prognostic impact is controversial. Hence, in the present study, we aimed to investigate the presence of CD45RO + , LAG3 + , CD3 + , and CD8 + lymphocytes in CRC tumor tissues and their association with clinicopathological parameters of the disease as well as patients' survival, according to primary tumor locations. METHODS: Expression of CD45RO, LAG3, CD3, and CD8 was immunohistochemically assessed in tissue sections of 136 patients with CRC. The percentages of TILs expressing these markers were then separately determined in both invasive margin (IM) and center of tumor (CT). Their associations with clinicopathological factors and patients' survival were analyzed in the entire cohort and the subgroups of patients with right- and left- rectum tumors. RESULTS: Based on our observation, CD45RO + and CD3 + cells were the most frequent infiltrated lymphocytes in both CT and IM regions of colon tumor tissue. Whilst, LAG3 + lymphocytes were the least frequent subset in both areas. Statistical analysis indicated that the frequency of CD45RO + TILs was positively associated with advanced TNM stages (III/IV), in the entire cohort and right-sided tumors (P < 0.05). LAG3 + TILs in IM were also increased in tumor tissues with higher T-stages in the entire cohort (P = 0.027). In univariate analysis, high score of CD45RO + TILs in IM was associated with better overall survival in the entire cohort. High score of CD8 + and CD45RO + lymphocytes in IM were also associated with improved survival in patients with right-sided tumors. CONCLUSIONS: Our findings generally suggest that the clinicopathological and prognostic significance of immune system-related markers such as CD45RO and LAG3 depends on the primary tumor sides. Our results collectively demonstrated that infiltration of CD45RO + lymphocytes in IM could be an independent prognostic factor in a site-dependent manner.

Dynamics of Bacteria Scanning a Porous Environment.

It has recently been reported that bacteria, such as Escherichia coli Bhattacharjee and Datta, Nat. Commun. 10, 2075 (2019).NCAOBW2041-172310.1038/s41467-019-10115-1 and Pseudomonas putida Alirezaeizanjani et al., Sci. Adv. 6, eaaz6153 (2020).SACDAF2375-254810.1126/sciadv.aaz6153, perform distinct modes of motion when placed in porous media as compared to dilute regions or free space. This has led us to suggest an efficient strategy for active particles in a disordered environment: reorientations are suppressed in locally dilute regions and intensified in locally dense ones. Thereby the local geometry determines the optimal path of the active agent and substantially accelerates the dynamics for up to 2 orders of magnitude. We observe a nonmonotonic behavior of the diffusion coefficient in dependence on the tumbling rate and identify a localization transition, either by increasing the density of obstacles or by decreasing the reorientation rate.

Bottled water quality ranking via the multiple-criteria decision-making process: a case study of two-stage fuzzy AHP and TOPSIS.

Access to healthy drinking water is vital to human health and development. Bottled water consumption has been on the rise in recent years. As several chemical and bacteriological parameters affect bottled water quality, it is difficult to choose the highest-quality bottled water. Numerous studies have proposed the use of multiple-criteria decision-making (MCDM) methods to overcome this problem. Herein, the two-stage fuzzy analytic hierarchy process (FAHP) and technique for order preference by similarity to ideal solution (TOPSIS) method were adopted to rank different brands of bottled water. The FAHP approach allows working at the intervals of judgment rather than absolute values. TOPSIS is a technique for ordering performance based on its similarity to the ideal solution. An expert panel selected and classified the criteria and sub-criteria. A pairwise comparison questionnaire was then developed, and the weights of the criteria and sub-criteria were assigned by water quality experts. The data on the quality of different brands of water were collected from the Iranian bottled water database. The final data analysis and weight determination of each parameter were performed in Excel and R software Programs. Finally, the CCi (value of closeness coefficient) and rank of 71 bottled water brands were calculated, and the best brand was introduced. Among the selected criteria, carcinogenic chemical compounds with the weight of 0.368 were the most important compound in ranking bottled water brands, followed by bacteriologic, pathogenic chemical compounds, chemical compounds important in terms of toxicity, nutritious chemical compounds with a low toxicity level, chemical compounds related to esthetic effects, and chemical compounds without health effects, respectively.

Decontamination potential of five native plants in Maharlu Wetland, Iran.

This study investigates the level of toxic trace elements (TTE) in the rhizosphere soil and tissues of five native plants and their phytoextraction/phytostabilization potential growing in Maharlu Lake wetland, in Southern Iran. The study anticipated by determination of 11 potentially TTE concentrations (As, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, and Zn) in the soil, soil extract, and the plants' dry matter (root and shoot). Pollution index (PI), pollution load index (PLI), bioconcentration factor (BCF), bioaccumulation coefficient (BAC), and translocation factor (TF) were applied in the study. Two main results were pointed out in this study. Firstly, the result of pollution indexing and total and phyto-availability concentrations of TTE showed that some of them in the rhizosphere soil are problematic in the Maharlu wetland, in particular for Mo, Pb, Zn, and As. Secondly, the result of the correlation coefficients and phytoremediation indexing revealed that TTE accumulation in the plant tissues, not only depends on the concentration in the soil extract but is also plant-specific. Moreover, the results suggested that Halopeplis sp. has the potential for phytoextraction of Cd and Mo in the contaminated wetlands. Novelty statement: This manuscript addresses the toxic trace elements concentration in rhizosphere soil and tissues of five native plants and their phytoextraction/phytostabilization potential: Maharlu wetland in southern Iran.

The coronavirus disease 2019: the prevalence, prognosis, and recovery from olfactory dysfunction (OD).

BACKGROUND: Many patients with coronavirus disease 2019 (COVID-19) complain from olfactory dysfunction (OD). Aims/objectives: To evaluate the prevalence, prognosis, and recovery from OD in COVID-19 patients. MATERIAL AND METHODS: In this study, patients with COVID-19 symptoms who were referred to six different tertiary referral centres were recruited after positive results for COVID-19. All patients were assessed for a one-month follow-up after the initial diagnosis of COVID-19. RESULTS: Three hundred and eleven patients with COVID-19 were recruited in the present study. Two hundred and seven patients (66.6%) had a recent history of OD. One hundred and seventy-eight patients had experienced OD as a primary symptom intercurrent to other COVID-19 symptoms or solely. Sixty-nine patients had OD at the time of presentation to referral centres. Headache and nasal obstruction had significant relationships with recovery from OD in this subgroup, and the platelet count was the most important predictor for the recovery from OD. One hundred seventy-nine (86.4%) patients were nearly or fully recovered from OD approximately a month after the onset of OD. CONCLUSION: Headache, nasal obstruction, and platelet count may have specific roles as prognostic factors in the recovery from OD.

Integrating artificial neural network and scoring systems to increase the prediction accuracy of patient mortality and organ dysfunction.

The aim of this study was to develop and compare techniques to increase the prediction accuracy of patient mortality and organ dysfunction in the Intensive Care Units (hereinafter ICU) of hospitals. Patient mortality was estimated with two models of artificial neural network (ANN)-backpropagation (BP) and simplified acute physiology score (SAPS). Organ dysfunction was predicted by coupled ANN self-organizing map (SOM) and logistic organ dysfunction score (LODS) method on the basis of patient conditions. Input dataset consisted of 36 features recorded for 4,000 patients in the ICU. An integrated response surface methodology (RSM) and genetic algorithm (GA) was developed to achieve the best topology of the ANN-BP model. Although mortality prediction of the best ANN-BP (MSE = 0.0036, AUC = 0.83, R2 = 0.81) was more accurate than that of the SAPS score model (MSE = 0.0056, AUC = 0.82, R2 = 0.78), the execution time of the former (=45 min) was longer than that of the latter (=20 min). Therefore, the principal component analysis (PCA) was used to reduce the input feature dimensions, which, in turn, reduced the execution time up to 50%. Data reduction also helped to increase the network accuracy up to 90%. The likelihood of organ dysfunction determined by coupled ANN and scoring method technique can be much more efficient than the LODS model alone because the SOM could successfully classify the patients in 64 classes. The primary patient classification plays a major role in increasing the efficiency of an estimator.

The prevalence of comorbid depression in patients with diabetes: A meta-analysis of observational studies.

Depression is one of the most common psychiatric disorders in patients with diabetes, which can exacerbate and accelerate adverse diabetes complaints by reducing self-care behaviors and medication adherence. The purpose of this study is to estimate the prevalence of depression in Iranian patients with diabetes. The search was conducted in the databases of Scientific Information Database (SID), MagIran, PubMed, Scopus, Web of Science, and Google Scholar. The following keywords and their possible combinations were used: depressive disorder, major depressive disorder, dysthymic disorder, diabetes mellitus and Iran. Heterogeneity between studies was examined with I2. The data were analyzed using the meta-analysis method and random-effects model with Stata version 11.0. The analysis of 37 selected articles with a total sample size of 7849 indicated that the overall prevalence of depression in Iranian patients with diabetes was 54% (95% CI: 47.32-60.70). In addition, the prevalence of depression in women (56.25%; 95% CI: 48.83-63.68) was higher than that of men (41.05%; 95% CI: 32.74-49.36). The results showed that there was no relationship between the prevalence of depression and publication year (0.249), sample size (p = 0.529), and mean age of the subjects (p = 0.330). More than half of the patients with diabetes suffer from depression. Identification and treatment of these patients can be an important step in controlling and delaying the diabetes complication.

Psychometric Properties Of The Persian Version Of The Uncivil Behavior In Clinical Nursing Education Among Nursing Students.

BACKGROUND: Some clinical staff nurses show unprofessional behavior toward nursing students in clinical nursing education that can negatively affect their self-esteem and professionally. Examination of uncivil behavior toward nursing students requires a valid and reliable instrument. Therefore, the goal of the present study was to examine the psychometric properties of the Persian version of the Uncivil Behavior in Clinical Nursing Education (UBCNE) among nursing students. METHODS: In this methodological study, a total of 558 nursing students participated who were selected using a convenience sampling method, and were asked to complete the Persian version of the UBCNE. The UBCNE was translated based on the WHO guidelines. The face, content, and construct (using explanatory and confirmatory factor analysis) validities were assessed. In addition, internal consistency was assessed using the McDonald's omega and the Cronbach's alpha coefficient, and stability was assessed using the test-retest method. RESULTS: Explanatory factor analysis led to two factors, including Dismissive Behavior and Exclusionary Behavior that together explained 62.1% of the total variance of uncivil behavior. In the confirmatory factor analysis, the comparative and parsimonious fit indices were very good, but the absolute fit indices were poor (RMSEA=0.116, GFI=0.98, NFI=0.97, AFGI=0.83, PNFI=0.78). Reliability of the UBCNE was found to be 0.93 and 0.97, using the Cronbach's alpha coefficient and the test-retest method, respectively. CONCLUSION: The two-factor structure of the UBCNE has good validity and reliability among nursing students. Therefore, it can be used to assess civil behavior in clinical nursing education.

Dynamics of Active Filaments in Porous Media.

The motion of active polymers in a two-dimensional porous medium is shown to depend critically on flexibility, activity, and degree of polymerization. For a given Péclet number, we observe a transition from localization to diffusion as the stiffness of the chains is increased. Whereas stiff chains move almost unhindered through the porous medium, flexible ones spiral and get stuck. Their motion can be accounted for by the model of a continuous time random walk with a renewal process corresponding to unspiraling. The waiting time distribution is shown to develop heavy tails for decreasing stiffness, resulting in subdiffusive and ultimately caged behavior.

Nurses' families' experiences of involvement in nursing errors: A qualitative study.

BACKGROUND: The most important and irreversible consequence of medical errors is the human impact caused by unintended actions. In a few studies, the significant impact of this error on the private life of healthcare staff have been mentioned, but the problems of the involved nurses' families had been ignored, as of now. AIMS: This study aimed to explain the nurses' families' experiences of involvement in nursing errors. METHODS: This is a qualitative study using conventional content analysis with 20 semi-structured interviews conducted with nurses and family members of nurses involved in medical errors, done through purposeful sampling and willingness to participate in the study. RESULTS: The results of the data analysis consisted of five main categories including disruption in family functioning, the crisis of fear, oppression, damage, and neglect, along with 15 subcategories. CONCLUSION: Considering the effects of nursing errors on the families of nurses involved in the error, such as disruption of family functioning, the family of nurses involved in the error should also be considered and paid attention to. These families are abandoned and the need to promote the culture of supporting the family is tangible.

A Survey on Massive MIMO Systems in Presence of Channel and Hardware Impairments.

Massive multiple input multiple output (MIMO) technology is one of the promising technologies for fifth generation (5G) cellular communications. In this technology, each cell has a base station (BS) with a large number of antennas, allowing the simultaneous use of the same resources (e.g., frequency and/or time slots) by multiple users of a cell. Therefore, massive MIMO systems can bring very high spectral and power efficiencies. However, this technology faces some important issues that need to be addressed. One of these issues is the performance degradation due to hardware impairments, since low-cost RF chains need to be employed. Another issue is the channel estimation and channel aging effects, especially in fast mobility environments. In this paper we will perform a comprehensive study on these two issues considering two of the most promising candidate waveforms for massive MIMO systems: Orthogonal frequency division multiplexing (OFDM) and single-carrier frequency domain processing (SC-FDP). The studies and the results show that hardware impairments and inaccurate channel knowledge can degrade the performance of massive MIMO systems extensively. However, using suitable low complex estimation and compensation techniques and also selecting a suitable waveform can reduce these effects.

Health-related quality of life in Iranian patients with type 2 diabetes: An updated meta-analysis.

Diabetes is the most common metabolic causes of increased mortality rate due to its multiple complications. Diabetes, thus, influences patients' quality of life because of its resultant physical disabilities and mental health problems. This study aimed to investigate health-related quality of life among Iranian patients with type 2 diabetes. In this meta-analysis study, a search was conducted using the keywords: Quality of Life, Health-Related Quality of Life, QoL, HRQoL, Shortform questionnaire 36, SF-36, Diabetes and Iran in the national and international databases such as SID, MagIran, ISI/Web of Science, PubMed [including Medline], and Scopus between 2011 and 2018. Based on the heterogeneity of data, the random effects model was used. Data was analyzed using the Stata software version 14. Overall, 17 studies were eligible, with a total sample size of 5472 patients, and they showed that the mean score of the physical dimension in patients with type 2 diabetes (53.5, 95% CI: 43.1-63.9) was less than the mean of mental dimension score (54.5, 95% CI: 47-61.9). By increasing age of the samples, the mean of the HRQoL score of the Iranian patients with type 2 diabetes was significantly decreased (p = 0.015). The highest and lowest scores for the quality of life subscales were social function and general health, respectively. In conclusion, patients with type 2 diabetes have been shown to have moderate quality of life. Providing solutions to improve the quality of life in this group of patients, especially in the physical aspect, is required.

Sesamin imparts neuroprotection against intrastriatal 6-hydroxydopamine toxicity by inhibition of astroglial activation, apoptosis, and oxidative stress.

Parkinson's disease (PD) is one of the most prevalent neurodegenerative disorders in elders. Sesamin is a lignan compound and the active constituent of sesame oil with antioxidant and anti-inflammatory properties. This study was carried out to explore the mechanisms underlying sesamin effect against unilateral striatal 6-hydroxydopamine (6-OHDA) model of PD. Intrastriatal 6-OHDA-lesioned rats were pretreated with sesamin at doses of 10 or 20mg/kg/day for one week. Sesamin at a dose of 20mg/kg attenuated motor imbalance in narrow beam test, lowered striatal level of malondialdehyde (MDA) and reactive oxygen species (ROS), improved superoxide dismutase (SOD) activity, lowered striatal caspase 3 activity and α-synuclein expression, attenuated glial fibrillary acidic protein (GFAP) immunoreactivity, depressed nigral neuronal apoptosis, and prevented damage of dopaminergic neurons using tyrosine hydroxylase (TH) immunohistochemistry. These findings reveal the reversal effect of sesamin in 6-OHDA model of PD via attenuation of apoptosis, astrogliosis, oxidative stress, and down-regulation of α-synuclein.

Riluzole ameliorates learning and memory deficits in Aß25-35-induced rat model of Alzheimer's disease and is independent of cholinoceptor activation.

Alzheimer's disease (AD) is a major global public health concern and social care problem that is associated with learning, memory, and cognitive deficits. Riluzole is a glutamate modulator which has shown to improve memory performance in aged rats and may be of benefit in Alzheimer's disease. In the present study, its beneficial effect on attenuation of learning and memory deficits in Aß25-35-induced rat model of AD was assessed. Riluzole administration at a dose of 10mg/kg/day p.o. improved spatial memory in Morris water maze and retention and recall in passive avoidance task and its protective effect was not neutralized following intracerebroventricular microinjection of muscarinic or nicotinic receptor antagonists. Further biochemical analysis showed that riluzole pretreatment of intrahippocampal Aß-microinjected rats is able to attenuate hippocampal AChE activity and lower some oxidative stress markers, i.e. MDA and nitrite, with no significant change of the defensive enzyme catalase. Furthermore, riluzole prevented hippocampal CA1 neuronal loss and reduced 3-nitrotyrosine immunoreactivity. It is concluded that riluzole could exert a protective effect against memory decline induced by intrahippocampal Aß25-35 through anti-oxidative, anti-cholinesterase, and neuroprotective potential and its beneficial effect is possibly independent of cholinoceptor activation.

Evaluation of the olfactory bulb volume and olfactory threshold in patients with nasal polyps and impact of functional endoscopic sinus surgery: a longitudinal study.

BACKGROUND: Debate still persists on the relation between olfactory bulb volume (OBV) and olfactory function. Many studies suggest that olfactory deprivation decreases the OBV. The aim of this study was to compare the olfactory threshold and OBV of patients with nasal polyps to healthy individuals and to evaluate the impact of functional endoscopic sinus surgery (FESS) on OBV and olfactory threshold. METHODS: A longitudinal study was carried out in Tehran between 2011 and 2012. Twenty-two patients with nasal polyps were compared with 37 healthy individuals. Olfactory threshold test and magnetic resonance imaging (MRI) were performed on all participants. Twenty-two patients in case group were followed for 6 months after FESS. OBV and olfactory threshold were measured after 6 months. RESULTS: There was no significant difference between the age, gender, and OBV of the 2 groups. However, the difference between olfactory threshold was significant (p = 0.005). The olfactory threshold showed no significant relation with OBV (p > 0.05). The correlation between Lund-Mackay score and the mean total OBV and left OBV was significant (r = -0.15, p = 0.045; r = -0.22, p = 0.047; respectively). The decrease in olfactory threshold measured after FESS was statistically significant. Right, left, and total OBV significantly increased after FESS. CONCLUSION: The results of our study show that FESS has a significant impact on OBV increment and olfactory threshold decrement. The olfactory bulb is a plastic structure and improvement in peripheral olfactory function results in increase in OBV. However, further studies are mandated, in order to establish this result.

The efficacy of clarithromycin in patients with severe nasal polyposis.

Although several treatments have been suggested for nasal polyposis, from medical to surgical, there is no standard guideline for the management of this disease. During recent years increasing attention has been directed toward the effects of macrolide antibiotics on chronic sinusitis and nasal polyposis. In this study,  the efficacy of clarithromycin on severe nasal polyposis were examined. In a Prospective, before - after study, forty patients with severe nasal polyposis received clarithromycin 500 mg twice a day for 8 weeks. At the beginning and end of treatment, the severity of patients' symptoms (using subjective analogue scale), computed tomography (CT) scan and endoscopic findings were recorded. After treatment, the severity of nasal obstruction, smelling problems, Post Nasal Discharge and rhinorrhea decreased significantly (P<0.05). Furthermore, the degree of sinus opacification in CT scan and endoscopic findings showed significant improvement. Most patients completed their treatment course without significant side effects. Although a course of clarithromycin improved nasal symptoms, polyp size and CT findings, further studies with more patients are required to recommend this drug as a general treatment in nasal polyposis.