Does Gadolinium Deposition Lead to Metabolite Alteration in the Dentate Nucleus? An MRS Study in Patients with MS.

BACKGROUND AND PURPOSE: Repeat contrast-enhanced MR imaging exposes patients with relapsing-remitting MS to frequent administration of gadolinium-based contrast agents. We aimed to investigate the potential metabolite and neurochemical alterations of visible gadolinium deposition on unenhanced T1WI in the dentate nucleus using MRS. MATERIALS AND METHODS: This prospective study was conducted in a referral university hospital from January 2020 to July 2021. The inclusion criteria for case and control groups were as follows: 1) case: patients with relapsing-remitting MS, visible gadolinium deposition in the dentate nucleus (ribbon sign), >5 contrast-enhanced MR images obtained; 2) control 1: patients with relapsing-remitting MS without visible gadolinium deposition in the dentate nucleus, >5 contrast-enhanced MR images obtained; 3) control 2: patients with relapsing-remitting MS without visible gadolinium deposition in the dentate nucleus, <5 contrast-enhanced-MR images obtained; and 4) control 3: adult healthy individuals, with no contrast-enhanced MR imaging. Dentate nucleus and pontine single-voxel 12 × 12 × 12 MRS were analyzed using short TEs. RESULTS: Forty participants (10 per group; 27 [67.5%] female; mean age, 35.6 [SD, 9.6] years) were enrolled. We did not detect any significant alteration in the levels of NAA and choline between the studied groups. The mean concentrations of mIns were 2.7 (SD, 0.73) (case), 1.5 (SD, 0.8) (control 1), 2.4 (SD, 1.2) (control 2), and 1.7 (SD, 1.2) (control 3) (P = .04). The mean concentration of Cr and mIns (P = .04) and the relative metabolic concentration (dentate nucleus/pons) of lipid 1.3/Cr (P = .04) were significantly higher in the case-group than in healthy individuals (controls 1-3). Further analyses compared the case group with cumulative control 1 and 2 groups and showed a significant increase in lactate (P = .02), lactate/Cr (P = .04), and Cr (dentate nucleus/pons) (P = .03) in the case group. CONCLUSIONS: Although elevated concentrations of Cr, lactate, mIns, and lipid in the dentate nucleus of the case group indicate a metabolic disturbance, NAA and choline levels were normal, implying no definite neuronal damage.

Radiomics Can Distinguish Pediatric Supratentorial Embryonal Tumors, High-Grade Gliomas, and Ependymomas.

BACKGROUND AND PURPOSE: Pediatric supratentorial tumors such as embryonal tumors, high-grade gliomas, and ependymomas are difficult to distinguish by histopathology and imaging because of overlapping features. We applied machine learning to uncover MR imaging-based radiomics phenotypes that can differentiate these tumor types. MATERIALS AND METHODS: Our retrospective cohort of 231 patients from 7 participating institutions had 50 embryonal tumors, 127 high-grade gliomas, and 54 ependymomas. For each tumor volume, we extracted 900 Image Biomarker Standardization Initiative-based PyRadiomics features from T2-weighted and gadolinium-enhanced T1-weighted images. A reduced feature set was obtained by sparse regression analysis and was used as input for 6 candidate classifier models. Training and test sets were randomly allocated from the total cohort in a 75:25 ratio. RESULTS: The final classifier model for embryonal tumor-versus-high-grade gliomas identified 23 features with an area under the curve of 0.98; the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 0.85, 0.91, 0.79, 0.94, and 0.89, respectively. The classifier for embryonal tumor-versus-ependymomas identified 4 features with an area under the curve of 0.82; the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 0.93, 0.69, 0.76, 0.90, and 0.81, respectively. The classifier for high-grade gliomas-versus-ependymomas identified 35 features with an area under the curve of 0.96; the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 0.82, 0.94, 0.82, 0.94, and 0.91, respectively. CONCLUSIONS: In this multi-institutional study, we identified distinct radiomic phenotypes that distinguish pediatric supratentorial tumors, high-grade gliomas, and ependymomas with high accuracy. Incorporation of this technique in diagnostic algorithms can improve diagnosis, risk stratification, and treatment planning.

Design and fabrication of a new multi-loop saddle coil for 1.5 T MRI.

Radiofrequency coils provide high-resolution magnetic resonance (MR) imaging of human tissues. A small RF coil produces MR images with a higher resolution compared to the commercial volume MR coils from mass limited samples. Signal to noise ratio (SNR) plays a key role in the optimal design of receiver radiofrequency coils. In this work, we present a three-loop saddle coil suitable for MR imaging of digits of the human body. The geometry of the introduced coil is optimized to achieve the highest SNR. The coil performance is evaluated through comparing the measured SNR maps of the optimal coil derived from MR images of a saline phantom with the corresponding measured SNR maps of a commercial head coil in axial and sagittal slices. Results verify that the image SNR of the introduced coil is 3.4 times higher than that of the head coil and 2 times higher than that of the similar saddle coils represented in the literature recently. To validate the measured results, SNR maps of the introduced saddle and head coils were simulated and their SNR difference was compared with the corresponding measured data of the two coils. Results show that the simulated and measured data are in agreement with less than 11.8% error.

Clonal relatedness and resistance characteristics of OXA-24 and -58 producing carbapenem-resistant Acinetobacter baumannii isolates in Tehran, Iran.

AIMS: The present study was conducted to investigate the mechanism of carbapenem resistance and the molecular epidemiology of carbapenem-resistant Acinetobacter baumannii (CRAB) isolates collected from two nearby hospitals in Tehran, Iran. METHODS AND RESULTS: A total of 180 CRAB isolates were studied. Antimicrobial susceptibility testing was performed using disk diffusion and Epsilometer tests. The detection of OXA-23, -24 and -58 was implemented for all isolates using polymerase chain reaction. Subsequently, isolates harbouring OXA-24 and -58 were investigated for the presence of resistance determinants of Ambler class A, metallo-ß-lactamases (MBLs), and carbapenem-hydrolysing class D ß-lactamases, ISAba1, and the genetic relatedness between them was analysed using pulsed-field gel electrophoresis (PFGE). All isolates were found to be resistant to imipenem with a MIC of ≥8 µg ml-1 and were susceptible to colistin with a MIC of ≤1·5 µg ml-1 . Sixty percent of the isolates had OXA-23. OXA-24 and -58 were detected in 31 of 180 CRAB isolates. These chosen isolates were devoid of MBLs and blaSHV , blaC TX-M , blaVEB ESBL genes. The PER determinant was detected in 38% of isolates as the most common extended spectrum ß-lactamases (ESBLs). Of these isolates, 51·6% had OXA-23, and ISAba1 was found to be upstream of OXA-23 and OXA-51 in 16 and 8 isolates, respectively. The band patterns produced by PFGE showed nine clonal pulsotypes distributed between the two hospitals. CONCLUSION: The findings showed that the refractory CRAB isolates were transmitted intra- and inter-hospital, particularly in the ICU due to shortcomings in infection control surveillance. SIGNIFICANCE AND IMPACT OF THE STUDY: Carbapenem resistance is a substantial threat in the treatment of infections caused by A. baumannii due to limitations in the therapeutic options.

Cold Tolerance of the Tribolium castaneum (Coleoptera: Tenebrionidae), Under Different Thermal Regimes: Impact of Cold Acclimation.

The red flour beetle, Tribolium castaneum (Herbst), is a serious pest of stored product worldwide. Cold tolerance or cold hardiness is an important ecophysiological trait related directly to survival, fitness, and distribution of insects. In this study, the effects of four thermal regimes, i.e., control (C), cold acclimation (CA), rapid cold hardening (RCH), and fluctuating-acclimation (FA), were examined for their effects on cold tolerance, supercooling point (SCP), lower lethal temperature (LLT), and chill-coma recovery time (CCRT) of the red flour beetle. In addition, changes in cryoprotectant (trehalose, sorbitol, and myo-inositol) levels were investigated under each thermal treatment. The results documented a substantial enhancement in the SCP, cold hardiness, and cryoprotectant levels of the adults of T. castaneum under CA regimes. The lowest SCP, highest trehalose and myo-inositol contents, and, subsequently, the greatest survival rate were observed in cold-acclimated beetles. In addition, coordination between cryoprotectant level, SCP, and cold tolerance of the pest was observed. The highest and lowest CCRT were observed at control and CA, respectively. In RCH regime with the highest impact, LLT reached the lowest level of -22°C. As most of the mortality of T. castaneum occurred at a temperature above the SCP, so this pest could be considered as a chill-susceptible insect.

Changes in biochemical contents and survival rates of two stored product moths under different thermal regimes.

Plodia interpunctella (Hübner) and Ectomyelois ceratoniae (Zeller) (Lepidoptera: Pyralidae) are two destructive pests of stored products. Survival and physiological changes of last instar larvae were investigated under different thermal regimes [i.e. control (optimal temperature), cold-acclimation (CA), fluctuating-acclimation (FA) and rapid cold-hardiness (RCH)]. Our results indicate a relationship between supercooling points, carbohydrate contents, enzyme activities and survival rates of the larvae under different thermal regimes. Glycogen content was greatest for control and RCH regimes whereas the greatest trehalose level was recorded for the CA regime. The supercooling points of control larvae of P. interpunctella and E. ceratoniae were - 14 and - 10 °C, respectively, and decreased to - 16 and - 18 °C under the CA regime. Thermal regimes had no significant effect on the survival of the larvae after 24 h exposure at 0 °C, but when larvae exposed to - 5 °C for 24 h, the highest and lowest survival rates were recorded in the CA and RCH regimes, respectively. Protein phosphatases 1 and cAMP-dependent protein kinase (AMPK) were found to have the highest enzyme activity. The activity of AMPK varied between different thermal regimes and was greatest under the CA regime. CA considerably increased lower lethal times of the larvae compared with the control regime. RCH showed the highest impact on lower lethal temperature limits of the larvae. Our results indicated a characteristic enhancement of the survival rates of the larvae of P. interpunctella and E. ceratoniae under the CA regime. This enhancement is likely related to elevated contents of low molecular weight carbohydrates under the CA regime.

Construction and evaluation of a whole-cell pneumococcal vaccine candidate.

AIMS: Pneumococcal infections are a major public health problem, especially in developing countries, and the current pneumococcal vaccines do not cover all pathogenic strains. New, more economical serotype-independent vaccines based on species-common protein antigens are being pursued. The pneumococcal whole-cell vaccine which is based on noncapsular antigens common to all strains induces serotype-independent immunity. In the present study, we developed a new candidate for a whole-cell pneumococcal vaccine in which two important virulence factors, the capsule and pneumolysin, were deleted. METHODS AND RESULTS: Protection was elicited by immunization against colonization in mice with a killed mutant strain and the antibody response in the mice serum was evaluated. This candidate vaccine was effective in preventing nasopharyngeal colonization. The mice immunized with this candidate vaccine had significantly higher serum antibody titres than mice that received the adjuvant alone. CONCLUSIONS: Based on obtained results in this study, the engineered whole-cell pneumococci can be considered as a vaccine candidate in future studies. SIGNIFICANCE AND IMPACT OF THE STUDY: This candidate vaccine can overcome the limitations of available polysaccharide vaccines.

Cooling rate and starvation affect supercooling point and cold tolerance of the Khapra beetle, Trogoderma granarium Everts fourth instar larvae (Coleoptera: Dermestidae).

Trogoderma granarium Everts (Coleoptera: Dermestidae) is an important insect pest of stored products. In this study, the survival strategies of T. granarium fourth instar larvae were investigated at different sub-zero temperatures following different cooling rates, acclimation to different relative humidity (RH) and different starvation times. Our results show that larvae of T. granarium are freeze-intolerant. There was a strong link between cooling rates and supercooling point, which means the slower the decrease in temperature, the lower the supercooling point. Trehalose content was greater in insects cooled at a rate of 0.5°C/min. According to results, the RH did not affect supercooling point. However, acclimation to an RH of 25% increased mortality following exposure to - 10°C/24h. The time necessary to reach 95% mortality was 1737h and 428h at - 5°C and - 10°C. The lowest lipid and trehalose content was detected in insects acclimated to 25% RH, although, the different RH treatments did not significantly affect glycogen content of T. granarium larvae. The supercooling point of larvae was gradually increased following starvation. By contrast, fed larvae had the greatest lipid, glycogen, and trehalose content, and insects starved for eight days had the lowest energy contents. There was a sharp decline in the survival of larvae between - 11 and - 18°C after 1h exposure. Our results indicate the effects of cooling rate and starvation on energy reserves and survival of T. granarium. We conclude that T. granarium may not survive under similar stress conditions of the stored products.

Trend of extensively drug-resistant Acinetobacter baumannii and the remaining therapeutic options: a multicenter study in Tehran, Iran over a 3-year period.

Comprehensive data on drug-resistant patterns of Acinetobacter baumannii isolates in developing countries is limited. We conducted a multihospital study to assess the rate and trend of drug-resistant phenotypes in Ac. baumannii using standardized definitions and to determine the remaining therapeutic options against resistant phenotypes. The 401 nonduplicate isolates were collected from six hospitals which are geographically distributed across Tehran, Iran over a 3-year period. Following PCR of blaOXA-51-like gene, susceptibility testing was performed against nine antimicrobial agent categories. Three hundred and ninety (97%) isolates were resistant to least two carbapenems; carbapenem-resistant Ac. baumannii. The majority of isolates (366, 91·3%) were extensively drug resistant (XDR) and the rest of the isolates were classified as multidrug resistant (26, 6·8%) and susceptible (9, 2·2%). The rate of XDR-AB slightly decreased from 93·8% in 2011 to 89·8% in 2013. A considerable decrease in resistance to doxycycline, minocycline and tigecycline was demonstrated. The XDR-AB isolates showed susceptibility to gentamicin (10·4%), tobramycin (23%), ampicilin-sulbactam (30·1%), minocycline (32·8%), tigecycline (10·7%), doxycycline (21·6%), colistin (100%) and polymixin B (100%). We demonstrated the rising trend of resistance to all antibiotic categories except tetracyclines and folate pathway inhibitors. We found that the treatment options against XDR-AB are extremely limited and each treatment alternative including even old, but safe, antibiotics might be considered. SIGNIFICANCE AND IMPACT OF THE STUDY: The high frequency of drug-resistant phenotypes including carbapenem-resistant Acinetobacter baumannii, multidrug-resistant, and extensively resistant has been demonstrated in Ac. baumannii isolates tested here. As the antibiotic resistance pattern of isolates varies in different geographical regions, this study can provide comprehensive information about the antibiotic resistance profile of Ac. baumannii isolates in Tehran. In addition, the resistance profiles could be effectively considered by clinicians to manage antibiotic therapy. This work also emphasizes on the prudent use of antibiotics and the monitoring of antibiotic susceptibility trend and rate.

Study and full simulation of ten different gases on sealed Multi-Wire Proportional Counter (MWPC) by using Garfield and Maxwell codes.

In this research gas sealed Multi-Wire Proportional Counter (MWPC) including blades between anode wires and beta particles of (90)Sr with 196keV mean energy were considered. Ten different gases such as Noble gases mixtures with methane and several other pure gases were studied. In this type of detector, by using Garfield and Maxwell codes and for each of the gases, variation of different parameters such as first Townsend, electron attachment coefficients with variable electric field and their effects on pulse height or collected charge and in turn on Signal to Noise Ratio (SNR) were studied. Also the effect of anode voltage and its diameter and the pressure of gas on the pulse height were studied. Results show that Garfield and Maxwell codes can be used to study and improve the design of other gaseous detectors.

Comparative in vitro activity of carbapenems against clinical isolates of Acinetobacter baumannii.

AIMS: The aim of this multi-hospital study was to assess the in vitro activity of doripenem and its comparators, imipenem and meropenem, using the new CLSI breakpoints against a large population of a frequently isolated nosocomial pathogen, Acinetobacter baumannii. METHODS AND RESULTS: During a 2-year period, four referral or tertiary hospitals submitted 400 isolates of Ac. baumannii for susceptibility testing using imipenem, meropenem and doripenem via disc diffusion and E-test methods. A subset of 390 isolates was resistant to all three tested carbapenems. Doripenem and meropenem (MIC50 , 32 µg ml(-1) ) had comparable activity, albeit doripenem's activity was greater than imipenem (MIC50 , >32 µg ml(-1) ). A significantly higher proportion of the isolates were inhibited by doripenem than by imipenem at MIC values of 12, 16, 24 and 32 µg ml(-1) (P < 0·05). The cumulative percentage of imipenem MICs was lower compared to its comparators. The comparison of resistance rate to imipenem and meropenem based on old and new breakpoints showed <1% difference. The overall agreement between the two susceptibility testing methods was ≥95%. CONCLUSION: Doripenem has a slightly greater in vitro activity than imipenem in terms of zone breakpoints and MIC values, but its activity is comparable to meropenem. SIGNIFICANCE AND IMPACT OF THE STUDY: Doripenem should be considered as a therapeutic option for monotherapy or combination therapy, particularly when the therapeutic options are limited.

Candida infection in the intensive care unit: A study of antifungal susceptibility pattern of Candida species in Milad hospital, Tehran, Iran.

OBJECTIVE: The occurrence of Candida infections has improved during the past two decades as a result of increase in the number of immunocompromised patients. In this study the antifungal susceptibility patterns of Candida species isolated from sterile body sites of patients admitted in Milad Intensive Care Unit (ICU) during 6 months were determined. METHODS: Candidal isolates were obtained from 50 patients admitted in Milad ICUs from April to September 2013. Identification of the isolates was performed by using morphological and polymerase chain reaction assay. Resistance to the antifungal agents containing caspofungin, posoconazole, voriconazole and amphotericin B was determined using E-test method. RESULTS: Out of 67 Candida isolates 47.8% were Candida glabrata, 28.3% were C. albicans, 7.5% were C. tropicalis, 7% were C. guilliermondii, 3% were C. krusei and 2% were C. dubliniensis. C. glabrata was the least susceptible species, with 9.4% of the isolates resistant to amphotericin B and 6.3% resistant to posoconazole and voriconazole. No resistance to caspofungin was observed among C. glabrata isolates. One of the C. krusei isolates was resistant to amphotericin B while no resistance to voriconazole, caspofungin and posoconazole was detected among C. krusei strains. Increase in the prevalence of antifungal-resistant non-C. albicans species in recent years has become a problematic event amongst clinicians caring for ICU patients. C. glabrata as the most common species isolated from ICU patients in this study indicated higher levels of antifungal resistance in comparison with other species. This observation accentuates the importance of managing preventive treatments to avoid development of resistance to the current antifungal drugs.

Association study of interleukin-1 family and interleukin-6 gene single nucleotide polymorphisms in recurrent aphthous stomatitis.

Recurrent aphthous stomatitis (RAS) is a common painful, ulcerative oral inflammatory disorder with unknown aetiology. Immune system and aberrant cytokine cascade deemed to be critical in outbreaks of RAS ulcers. Interleukin-1 (IL-1) and IL-6 are the most potent pro-inflammatory cytokines. Single nucleotide polymorphisms (SNPs) of IL-1 and IL-6 genes can affect the secretion of these cytokines. The aim of this study was to investigate the association between RAS and IL-6 and IL-1 in Iranian subjects with minor RAS. Genomic DNA was obtained from 64 Iranian patients with RAS. IL-1α C -889 T, IL-1ß C -511 T, IL-1ß C +3962 T, IL-1R C pst-I 1970 T, IL-1Ra C Mspa-I11100 T, IL-6 C -174 G and IL-6 A nt +565 G polymorphisms were determined using polymerase chain reaction with sequence-specific primers (PCR-SSP). The frequency of C -174 C genotype in the patients group was significantly different from the healthy control. No other significant differences were found in genotype and alleles frequencies between the two groups. These results indicate that certain SNPs of IL-6 gene at position -174 which located in promoter have association with predisposition of individuals to RAS.

Green synthesis of gold nanoparticles using Stevia rebaudiana leaf extracts: Characterization and their stability.

Various methods invented and developed for the synthesis of gold nanoparticles that increases daily consumed. According to this method, including potential environmental pollution problems and the complexity of the synthesis, in this study, the feasibility of using the leaves extract of Stevia rebaudiana (SR) for the reduction of gold ions to nanoparticles form have been studied. Stevia leaves were used to prepare the aqueous extract for this study. Gold nanoparticles were characterized with different techniques such as UV-vis spectroscopy, FT-IR spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Transmission electron microscopy experiments showed that these nanoparticles are spherical and uniformly distributed and its size is from 5 to 20 nm. FT-IR spectroscopy revealed that gold nanoparticles were functionalized with biomolecules that have primary amine group (NH2), carbonyl group, OH groups and other stabilizing functional groups. X-ray diffraction pattern showed high purity and face centered cubic structure of gold nanoparticles with size of 17 nm. The scanning electron microscopy (SEM) implies the right of forming gold nanoparticles. The results, confirm that gold nanoparticles have synthesized by the leaves extract of S. rebaudiana (SR).

Household transmission of 2009 H1N1 influenza virus in Yazd, Iran.

OBJECTIVES: The 2009 pandemic influenza A (H1N1) virus is a public health challenge. Notably, laboratory-confirmed cases do not represent the age group most susceptible to infection. To characterize the age distribution of all cases of H1N1 influenza, we studied the personal contacts of confirmed cases to identify the age group at the highest risk. METHODS: We investigated the family members of 162 laboratory-confirmed cases of 2009 H1N1 in Yazd, Iran. Family members were retrospectively asked whether they had ≥2 respiratory symptoms within 7days of the last contact with the associated index cases. The ages and symptoms of the patients as well as the interval between diagnosis and the onset of symptoms among household contacts were determined using a questionnaire. RESULTS: We identified 596 family members of index cases, 83 (13.9%) of whom developed acute respiratory illness. No acute respiratory illness was found in 104 families (64%); however, there were 2 cases in 15 families (9.3%) and ≥3 cases in 4 families (24%). Household contacts from 5 to 18years old were more susceptible to acute respiratory illness than those who were ≥51years old (RR=3.174, 95% CI 1.313-7.675 P-value=0.01). CONCLUSION: Individuals ≤18years old were most susceptible to infection by the H1N1 virus. Therefore, in low-income populations, prevention of the spread of H1N1 to this age group should be emphasized.

Prevalence of Chlamydia trachomatis and Mycoplasma genitalium in pregnant women of Sabzevar-Iran.

BACKGROUND: As prenatal screening for sexually transmitted infections and treatment of infected pregnant women is not routinely performed in Iran and prevalence of two sexually transmitted pathogens, Chlamydia trachomatis and Mycoplasma genitalium, in Sabzevar (east of Iran) is unknown, we decided to perform this prospective study. METHODS: One hundred ninety-six urine specimens of pregnant women attending the specialized maternity hospital of the city were collected and tested by duplex PCR. RESULTS: A total of 31 specimens were positive (15.81%) (27 Chlamydia trachomatis isolates, 13.77%; and 2 Mycoplasma genitalium isolates, 1.02%). Co-infection with both species was detected in 2 specimens (1.02%). A significant correlation was found between preterm labor and infection (P-value ≤ 0.05). CONCLUSION: The present study shows high prevalence of Chlamydial infections in comparison with Mycoplasma genitalium in this region. Further studies with larger sample size and more focused on different groups at risk are needed for a movement towards prevention and control of sexually transmitted infections (STIs).

Comparison of bone scan with carbohydrate antigen 15-3 for evaluation of bone metastasis of brest cancer.

This study aimed at comparing the bone scan and CA15-3 titer in patients with breast cancer for evaluation of bone metastasis. Thirty five patients with definite diagnosis of breast cancer were evaluated in Tabriz Imam Khomeini Hospital from 2007 to 2008. Bone scan (99 mTc-MDP) performed in all patients. The serum CA15-3 was measured by ECLIA method. The increased level was considered as >30 U mL(-1). The serum level of CA15-3 was compared between the patients with and without bone metastasis, as well as its correlation with the extent of bone involvement. Thirty five patients with the mean age of 51.69 +/- 10.77 (34-81) years were enrolled in the study. According to bone scan results, 24 (68.8%) patients revealed bone metastasis. The mean level of serum CA15-3 was significantly higher in patents with bone metastasis than patients without metastasis (26.37 +/- 4.74 U mL(-1) vs. 19.09 +/- 1.99 U mL(-1); p<0.001). There was not significant relation between the serum level of CA15-3 and the extent of bone metastasis (rho = -0.063, p = 0.769). Coordinates of the curve study yielded a cut-off point > 21.8 U mL(-1) for the serum level of CA15-3 in our patients, with a sensitivity and specificity of 91.7 and 91%, respectively. Serum level of CA15-3 is higher in the patients with bone metastatic breast cancer; however, the recommended cut-off point might not be suitable for Iranian patients. Further studies with large sample sizes are recommended.

Electromagnetic field (EMF) effects on channel activity of nanopore OmpF protein.

In this study, the effects of nonionizing electromagnetic fields (EMF; 925 MHz) on the OmpF porin channel have been characterized at the single-channel level. Channel activity was recorded in real time by the voltage clamp method. Our results showed an increase in the frequency of channel gating and voltage sensitivity. The effects of EMF lasted for several milliseconds after the field source was terminated. However, the conductance levels of channels did not change significantly. Thermal effects of EMF on single-channel properties are a possible cause, based on theoretical evaluation of results that were comparable to those seen in conventional experiments at different temperatures. We conclude that EMF affects both the dynamics and conformation of the channel, either directly by affecting critical amino acid side-chain arrangement, or indirectly, via the electrolyte or the lipid membrane.

A Novel open-ended intravascular MRI loop probe.

Recently, intravascular catheter probes have been developed to increase SNR for MR imaging of coronary arteries. Miniaturization of these catheter probes without degrading their performances is very essential in imaging small arteries. Since both signal and noise received by intravascular loop probes are of low level, the noise generated by the cable connecting the probe to the matching circuit may reduce SNR significantly. Therefore, the tuning and matching circuit must be placed very close to the loop probe, which restricts its miniaturization and flexibility. We propose a novel open-ended loop probe for 64 MHz with an input impedance of 20 Ohm and a length of only 4 cm in the bare case. This has two advantages. Firstly, the matching and tuning circuits of the proposed probe can be located outside the vessel. Secondly, its signal level and uniformity is superior to that of the conventional loop antennas.