Retrospective study evaluating dental side effects of radiotherapy in patients treated for head and neck cancer

INTRODUCTION

Head and neck cancer squamous cell carcinoma (HNSCC) is the seventh most common cancer worldwide with around 600,000 new diagnosis each year. Nowadays, in locally advanced disease, radiotherapy (RT) play an important role, this with or without chemotherapy in organ preservation strategies. More specific for early stage localized disease, RT (or surgery) seems to give similar results on locoregional control (LRC) and choice is made according to the organ preservation issue. Despite the fact that technical improvements have been made to optimize the radiation dose delivery and minimize the normal tissue toxicity, RT is associated with potential early and late toxicities. Osteoradionecrosis of the jaw (ORNJ), especially seen after teeth extraction, is one of the associated toxicities and can significantly impair the patient's quality of life. Because of the fear of developing ORNJ, one is very reluctant to extract or place a dental implant post-radiotherapy, especially in high irradiation dose zones (>40 Gy). Hence, it is important to define teeth at risk of future extraction before initiating RT and to handle those in high-risk irradiation zones. In order to optimise extractions, we created a predictive model of the expected irradiation dose, and thus the need for extraction, to the teeth bearing bones. The aim of this study is to validate our model and to define the potential relationship between the radiation dose received by each tooth and the dental complications observed.

MATERIAL AND METHODS

Between March 2012 and March 2018, patients with HNSCC treated by intensity modulated RT were retrospectively analysed. The mean irradiation dose for each tooth was generated on the administered treatment plan by contouring each tooth separately on each dosimetric scan section using dedicated software (Eclipse, Varian). In order to validate our predictive model, we compared the actual generated/administered teeth irradiation doses with the irradiation doses predicted by our model.

RESULTS

Our predictive model was accurate in 69.6% of the cases. In 12.5% of cases the predicted dose was higher than the calculated dose and lower in 17,8% of the cases. A correct- or over-estimation (is the latter being clinically less worrying than an underestimated dose) was achieved in 82% of cases. For the 18% of cases underfitting, the mean margin of error was 5.7 Gy. No statistically significant association was found between the development of caries and doses to the teeth, doses to the parotid glands or dental hygiene. However, a significant association between dental irradiation at more than 40 Gy and the occurrence of dental fractures (p = 0.0002) were demonstrated.

CONCLUSIONS

Our predictive model seems to be 82% accurate for dose prediction, hence might be helpful for optimizing/minimizing prophylactic extractions. Indeed, following our model, professionals could decide not to extract damaged teeth in areas not at risk of ORNJ, lowering morbidity during and after RT. Contrary to the literature, no relationship was found between the occurrence of dental caries and parotid irradiation and the patient's oral hygiene. However, for the first time, a highly significant correlation between the occurrence of dental fracture and dental irradiation at more than 40 Gy was observed.

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.

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.

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.

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 CC_i (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.

An integrated experiment for identification of best decision styles and teamworks with respect to HSE and ergonomics program: The case of a large oil refinery

Decision making failure is a predominant human error in emergency situations. To demonstrate the subject model, operators of an oil refinery were asked to answer a health, safety and environment HSE-decision styles (DS) questionnaire. In order to achieve this purpose, qualitative indicators in HSE and ergonomics domain have been collected. Decision styles, related to the questions, have been selected based on Driver taxonomy of human decision making approach. Teamwork efficiency has been assessed based on different decision style combinations. The efficiency has been ranked based on HSE performance. Results revealed that efficient decision styles resulted from data envelopment analysis (DEA) optimization model is consistent with the plant's dominant styles. Therefore, improvement in system performance could be achieved using the best operator for critical posts or in team arrangements. This is the first study that identifies the best decision styles with respect to HSE and ergonomics factors.

Effect of covalent attachment of neomycin on conformational and aggregation properties of catalase

The carboxylic groups of glutamic acid and aspartic acid residues of catalase (CAT) were chemically modified using the treatment of the enzyme with 1-ethyl-3-(3'-dimethylamino) carbodiimide hydrochloride (EDC) and neomycin. The effect of covalent attachment of neomycin on the enzymatic activity, conformational and aggregation properties of CAT was investigated. The modification of CAT with different concentrations of neomycin showed two different types of behavior, depending up on the concentration range of neomycin. In the concentration range from 0.0 to 5.2 mM, neomycin-modified CAT, compared to the native enzyme exhibited higher a-helix content, reduced surface hydrophobicity, little enhancement in CAT activity and a better protection against thermal aggregation, whereas at concentrations greater than 5.2 mM, the modified enzyme exhibited a significant decrease in CAT activity and an increase in random coil content which may result in disorder in the protein structure and increase in thermal aggregation. This modification is a rapid and simple approach to investigate the role of aspartate and glutamate residues in the structure, function and folding of CAT.

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.

A misdiagnosis led to an extensive skull base surgery: infratemporal tuberculosis mimicking giant cell tumor

Tuberculosis is a major health problem in developing countries. Tuberculosis of the infratemporal region is not common and the diagnosis could be complicated because of the similarity of the presentation to neoplasm. In our paper, we report a 49 year old male presented with a preauricular mass with extension to parotid in right side of the face. The primary histologic diagnosis was giant cell tumor with bony involvement and radical surgery was taken. After 16 months the patient was developed recurrence of the primary lesion in association with post auricular fistula. Ultimately, infratemporal tuberculosis was diagnosed according to result of the drained discharge by AFB microscopy. Therefore, tuberculosis should be considered as an important differential diagnosis of mass lesions in head and neck area, even when there is no history of significant exposure and no systemic signs or symptoms of tuberculosis.

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&lt;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.

Knowledge, attitude and practice of pharmacists and health-care workers regarding oral contraceptives correct usage, side-effects and contraindications

Despite the success of the Iranian family planning programme, the number of unwanted pregnancies remains high. To investigate whether health workers in Tabriz are providing correct information and counselling about OCP use, the current study was planned to examine the level of knowledge, attitude and practice of OCP providers. A sample of 150 health-care workers in health houses and 150 community/hospital pharmacists answered a questionnaire about knowledge of correct use of OCP, side-effects, contraindications, danger signs/symptoms and non-contraceptive benefits, and whether they counselled patients about these subjects. Knowledge of pharmacists and health workers was not as high as expected and in many topics they were counselling patients even when they had incorrect knowledge and in other areas they were not providing information to patients despite having the correct knowledge. Better continuing education for OCP providers and especially for pharmacists seems necessary.

Hepatic steatosis in HIV-HCV coinfected patients receiving antiretroviral therapy is associated with HCV-related factors but not antiretrovirals

In this paper we evaluate the economic gains of a joint deployment of femtocells and macrocells for the provision of Long Term Evolution (LTE) mobile broadband services in urban environments. Frequency bands of 2.6 GHz and 900 MHz are analyzed and different parameters related to the business model are considered for a 30% market share operator. Results show important benefits for the base case where the service is offered to fixed-broadband clients, up to 75%, for small bandwidths. It results feasible to attribute subscriber loop costs to the radio access network (RAN) costs, so that the service could be offered to non fixed-broadband clients, in both cases of closed access and open access femtocells. However, initial savings result notably reduced, up to 50% less than in the base case if closed access is adopted and up to 13% less for open access. Site reuse reduces the initial savings only in 3%.

Validation of pediatric index of mortality-2 scoring system in a single pediatric intensive care unit in iran

OBJECTIVE

A study to validate and calibrate Pediatric Index of Mortality-2 (PIM2) in children admitted to our pediatric intensive care unit (PICU).

METHODS

This is a prospective cohort study performed in Bahrami Children's Hospital affiliated to Tehran University of Medical Sciences. We studied the patients admitted to PICU from May 2007 to November 2008. Clinical measures were identified upon arrival in PICU. We used PIM2 score and logistic regression analysis to compare expected mortality risk with observed mortality rate. Receiver operating characteristics (ROC) curve analysis was done and standardized mortality ratio was calculated. PIM2 Index assessment was performed by use of Hosmer and Lemeshow goodness-of-fit test.

FINDINGS

240 patients were included in this study. The model fit was achieved adequately (P value=0.741). The area under the ROC curve was 0.795 (0.715-0.875 for 95% confidence interval) and standardized mortality ratio was 1.8 (1.28-2.465 for 95% confidence interval) High-risk group diagnosis with adjusted odds ratio (AOR)=14.75, pupil reaction to light (AOR=0.13) and duration of stay in PICU (AOR=1.03) had significant statistical association to pediatric mortality.

CONCLUSION

PIM2 is a good index for prediction of mortality in our pediatric intensive care unit. This study revealed that there is significant statistical association between the children mortality and the length of hspita;ization, pupillary light reflex and the risk level category on admission.

Hepatic steatosis in HIV-HCV coinfected patients receiving antiretroviral therapy is associated with HCV-related factors but not antiretrovirals

Background

In HIV and hepatitis C virus (HCV) coinfected patients, the role of antiretroviral therapy (ART) on hepatic steatosis (HS) remains controversial.

Methods

HIV/HCV coinfected patients receiving ART and previously untreated for HCV who underwent a liver biopsy were included. Cumulative duration of exposure to each antiretroviral was recorded up to liver biopsy date. Logistic regression analyses evaluated factors associated with steatosis and its severity.

Results

184 patients were included: median age 41years, 84% male, 89% Caucasian, 61% with a past history of intravenous drug use. HCV genotypes were 1 (55%), 2 (6%), 3 (26%), and 4 (13%). Median HCV-RNA was 6.18 log₁₀ IU/ml. HIV-RNA was undetectable (<400 copies/ml) in 67% of patients. Median CD4 count was 321/mm³. All patients had been exposed to nucleoside reverse transcriptase inhibitors (median cumulative exposure 56months); 126 received protease inhibitors (23months), and 79 non-nucleoside reverse transcriptase inhibitors (16months). HS was observed in 102 patients (55%): 41% grade 1; 5% grade 2, and 9% grade 3. In multivariate analysis, HCV genotype 3 and HCV viral load were moderately associated with mild steatosis but strongly with grade 2-3 steatosis. After adjustment for the period of biopsy, no association was detected between HS and exposure to any antiretroviral class or drug, or duration of ART globally or comparing genotype 3 to others.

Conclusions

Among our ART-treated HIV-HCV cohort predominantly infected with genotype 1, 55% of patients had HS which was associated with HCV-related factors, but not ART class or duration of exposure.

Frozen section as a diagnostic test for major salivary gland tumors

Major salivary gland tumors are uncommon and the exact nature of these tumors is not obvious. This study was carried out to compare the histological results of intraoperative frozen sections against those of permanent reports for major salivary glands masses. One hundred thirty-nine patients with major salivary gland masses who were candidates for surgery underwent an intraoperative frozen section biopsy. A permanent histological examination was then performed for definite diagnosis and its result was compared with that of the frozen section. Sensitivity, specificity, accuracy and the positive and negative predictive values were analyzed. The frozen section had 98.4% sensitivity, 87% specificity, 97.1% accuracy, 98.4% positive predictive value and 87% negative predictive value in differentiating between non-neoplastic and neoplastic lesions. In addition, the frozen section's identification of a mass as either benign or malignant showed 98% sensitivity, 100% specificity, 99.2% accuracy, 100% positive predictive value and 99% negative predictive value. Based on the current study's findings, it can be suggested that the frozen section is considerably accurate in the diagnosis of malignant versus benign lesions of major salivary glands, regardless of the exact histopathological type of the malignant tumors.

Association between the functional polymorphism C-159T in the CD14 promoter gene and nasal polyposis: potential role in asthma

BACKGROUND

Nasal polyposis (NP) is a chronic inflammatory disease that is frequently associated with allergy and asthma. Corticosteroid therapy and surgical removal of polyps are the 2 most common treatment strategies for NP. Various allergic and inflammatory mediators are thought to play a major role in the pathophysiology of this disorder. The CD14 gene is located on chromosome 5q31-32, which is considered a critical region for several allergic and atopic diseases, including asthma. Consequently, variations in CD14 could have functional effects on the etiology and severity of allergy and asthma. The aim of this study was to investigate the association between the polymorphism C-159T in the CD14 gene of patients with NP and controls.

METHODS

The study population comprised 106 patients with NP diagnosed based on computed tomography scan of the paranasal sinus, endoscopy, and histological examination. Findings were compared with those from 87 controls. The frequency of C-159T was determined using polymerase chain reaction-restriction fragment length polymorphism analysis. DNA was extracted using the salting out technique.

RESULTS

A significant association was observed between C-159T and NP (P = .04). Patients with the CC genotype at position -159 of the CD14 promoter region had an increased risk of asthma (OR, 3.83, 95% CI, 0.99-13.91; P < .02). However, we did not find an association between the distribution of C-159T and serum immunoglobulin E level.

CONCLUSIONS

A genetic variation in the CD14 promoter might play a role in the pathogenesis of NP and in the incidence of asthma.

Huge myxoid liposarcoma of the esophagus: a case report

Although esophageal liposarcoma is an extremely rare tumor, liposarcoma is the most common soft tissue sarcoma in adults. Liposarcoma is currently classified into the types of well-differentiated, myxoid, round cell, pleomorphic and dedifferentiated liposarcoma. Up to now only a few cases of esophagus liposarcoma have been described in the world literature. We describe a myxoid type liposarcoma of the esophagus in a 68 year old man presented with hoarseness and intermittent dysphagea to solid food. He had a huge mass in his mouth which was mobile with gag reflex. A barium swallow, esophageal manometery and CT scan of the esophagus have not clearly revealed the mass. After endoscopic surgical resection of the tumor the histological examination revealed a myxoid liposarcoma. Both the presenting signs and symptoms and the histology type are rare for such tumor. This case demonstrate a rare differential diagnosis of intermittent dysphagia as early diagnosis is so important in those tumors and should kept in mind them, although they are quite rare.

Optical analog of Matthiessen's rule in a one-dimensional model for diffusive light transport in foams

We study photon diffusion in a one-dimensional model foam composed of thin films and Plateau borders. Each thin film or Plateau border is characterized by its own intensity transmittance. We relate l(Foam)*, the transport-mean-free path of photons diffusing in the foam, to the foam microstructure. Denoting by l(Film)* (l(PB)*) the transport-mean-free path of photons in a medium composed only of thin films (Plateau borders), we find 1/l(Foam)*=φ(F)/l(Film)*+φ(P)/l(PB)*. Here φ(F) and φ(P)=1-φ(F) are the fraction of films and Plateau borders, respectively.