Estimation of phase signal change in neuronal current MRI for evoke response of tactile detection with realistic somatosensory laminar network model

Magnetic field generated by neuronal activity could alter magnetic resonance imaging (MRI) signals but detection of such signal is under debate. Previous researches proposed that magnitude signal change is below current detectable level, but phase signal change (PSC) may be measurable with current MRI systems. Optimal imaging parameters like echo time, voxel size and external field direction, could increase the probability of detection of this small signal change. We simulate a voxel of cortical column to determine effect of such parameters on PSC signal. We extended a laminar network model for somatosensory cortex to find neuronal current in each segment of pyramidal neurons (PN). 60,000 PNs of simulated network were positioned randomly in a voxel. Biot–savart law applied to calculate neuronal magnetic field and additional phase. The procedure repeated for eleven neuronal arrangements in the voxel. PSC signal variation with the echo time and voxel size was assessed. The simulated results show that PSC signal increases with echo time, especially 100/80 ms after stimulus for gradient echo/spin echo sequence. It can be up to 0.1 mrad for echo time = 175 ms and voxel size = 1.48 × 1.48 × 2.18 mm³. With echo time less than 25 ms after stimulus, it was just acquired effects of physiological noise on PSC signal. The absolute value of the signal increased with decrease of voxel size, but its components had complex variation. External field orthogonal to local surface of cortex maximizes the signal. Expected PSC signal for tactile detection in the somatosensory cortex increase with echo time and have no oscillation.     

Resistance status of main malaria vector,Liston (Diptera:Culicidae) to insecticides in a malaria Endemic Area,Southern Iran

Objective: To evaluate the susceptibility of Anopheles stephensi(An. stephensi) Liston, the main malaria vector in southern Iran, to WHO recommended insecticides. Methods: Larvae of An. stephensi were collected from three different larval habitats in both urban and rural area of Bandar Abbas city and one rural area in Rudan county southern Iran. WHO standard method was used for evaluation of adult and larval mosquito susceptibility. Bendiocarb, permethrin, lambda-cyhalothrin, deltamethrin as insecticide and temephos and chlorpyriphos as larvicide were used at the diagnostic dosages recommended by WHO. Results: Findings of this study showed all larval populations of An. stephensi were completely susceptible to temephos and candidate for resistance to chlorpyriphos. Adult mosquitoes in rural areas of Bandar Abbas city were resistant to pyrethroid and carbamate insecticides. Conclusion: Comparison of the results of this survey with previous studies indicates that the resistance to pyrethroids and carbamates in this malaria endemic region is increasing. Wide use of pesticides in agriculture is certainly effective in increasing resistance. The inter-sectoral coordination and collaboration in health and agriculture seem to be necessary to manage insecticide resistance in malaria vectors.     

COVID-19 and hematology findings based on the current evidences: A puzzle with many missing pieces

In December 2019, a new type of coronavirus was detected for the first time in Wuhan, Hubei Province, China. According to the reported data, the emerging coronavirus has spread worldwide, infecting more than fifty-seven million individuals, leading to more than one million deaths. The current study aimed to review and discuss the hematological findings of COVID-19. Laboratory changes and hematologic abnormalities have been reported repeatedly in COVID-19 patients. WBC count and peripheral blood lymphocytes are normal or slightly reduced while these indicators may change with the progression of the disease. In addition, several studies demonstrated that decreased hemoglobin levels in COVID-19 patients were associated with the severity of the disease. Moreover, thrombocytopenia, which is reported in 5%-40% of patients, is known to be associated with poor prognosis of the disease. COVID-19 can present with various hematologic manifestations. In this regard, accurate evaluation of laboratory indicators at the beginning and during COVID-19 can help physicians to adjust appropriate treatment and provide special and prompt care for those in need.     

Population structures of Leishmania infantum and Leishmania tropica the causative agents of kala-azar in Southwest Iran

Parasitology Research - Visceral leishmaniasis (VL) is endemic in Iran and is caused predominantly by Leishmania infantum, but L. tropica is emerging as an important cause. We studied the...     

Granulocyte‐macrophage colony‐stimulating factor,a potent adjuvant for polarization to Th‐17 pattern: an experience on HIV‐1 vaccine model

Cytokines are mediators for polarization of immune response in vaccines. Studies show that co‐immunization of DNA vaccines with granulocyte‐macrophage colony‐stimulating factor (GM‐CSF) can increase immune responses. Here, experimental mice were immunized with HIV‐1_{tat/pol/gag/env} DNA vaccine with GM‐CSF and boosted with recombinant vaccine. Lymphocyte proliferation with Brdu and CTL activity, IL‐4, IFN‐γ, IL‐17 cytokines, total antibody, and IgG1 and IgG2a isotypes were assessed with ELISA. Results show that GM‐CSF as adjuvant in DNA immunization significantly increased lymphocyte proliferation and IFN‐γ cytokines, but CTL response was tiny increased. Also GM‐CSF as adjuvant decreased IL‐4 cytokine vs mere vaccine group. IL‐17 in the group that immunized with mixture of DNA vaccine/GM‐CSF was significantly increased vs DNA vaccine group. Result of total antibody shows that GM‐CSF increased antibody response in which both IgG1 and IgG2a increased. Overall, results confirmed the beneficial effect of GM‐CSF as adjuvant to increase vaccine immunogenicity. The hallmark result of this study was to increase IL‐17 cytokine with DNA vaccine/GM‐CSF immunized group. This study for the first time provides the evidence of the potency of GM‐CSF in the induction of IL‐17 in response to a vaccine, which is important for control of infection such as HIV‐1.     

<Emphasis Type="Italic">Leishmania major</Emphasis> infection in a patient with visceral leishmaniasis: treatment with Amphotericin B

We have reported an acute form of visceral leishmaniasis, which was caused by Leishmania major, in Southern Iran. The parasite was isolated from a 30-year-old man living in Bushehr Province, Southern Iran, and an endemic region of kala-azar in south of Iran. The patient had typical clinical signs of Mediterranean kala-azar, and besides parasitological, biochemical, and immunological findings confirming diagnosis of visceral leishmaniasis, the agent was identified as L. major using Nested polymerase chain reaction. The patient was treated successfully with Amphotericin B during a 1-month period.     

Expression of claudin‐11 by tumor cells in cutaneous squamous cell carcinoma is dependent on the activity of p38δ

The incidence of cutaneous squamous cell carcinoma (cSCC) is rapidly increasing, and the prognosis of patients with metastatic disease is poor. There is an emerging need to identify molecular markers for predicting aggressive behaviour of cSCC. Here, we have examined the role of tight junction (TJ) components in the progression of cSCC. The expression pattern of mRNAs for TJ components was determined with RNA sequencing and oligonucleotide array‐based expression analysis from cSCC cell lines (n=8) and normal human epidermal keratinocytes (NHEK, n=5). The expression of CLDN11 was specifically elevated in primary cSCC cell lines (n=5), but low or absent in metastatic cSCC cell lines (n=3) and NHEKs. Claudin‐11 was detected in cell‐cell contacts of primary cSCC cells in culture by indirect immunofluorescence analysis. Analysis of a large panel of tissue samples from sporadic UV‐induced cSCC (n=65), cSCC in situ (n=56), actinic keratoses (n=31), seborrhoeic keratoses (n=7) and normal skin (n=16) by immunohistochemistry showed specific staining for claudin‐11 in intercellular junctions of keratinizing tumor cells in well and moderately differentiated cSCCs, whereas no staining for claudin‐11 was detected in poorly differentiated tumors. The expression of claudin‐11 in cSCC cells was dependent on the activity of p38δ MAPK and knock‐down of claudin‐11 enhanced cSCC cell invasion. These findings provide evidence for the role of claudin‐11 in regulation of cSCC invasion and suggest loss of claudin‐11 expression in tumor cells as a biomarker for advanced stage of cSCC.     

A new tool to test active ingredient using lactic acid in vitro,a help to understand cellular mechanism involved in stinging test: An example using a bacterial polysaccharide (Fucogel®)

The stinging test is an in vivo protocol that evaluates sensitive skin using lactic acid (LA). A soothing sensation of cosmetics or ingredients can be also appreciated through a decrease in stinging score. To predict the soothing sensation of a product before in vivo testing, we developed a model based on an LA test and substance P (SP) release using a co‐culture of human keratinocytes and NGF‐differentiated PC12 cells. A bacterial fucose‐rich polysaccharide present in Fucogel^® was evaluated as the soothing molecule in the in vivo stinging test and our in vitro model. Excluding toxic concentrations, the release of SP was significant from 0.2% of lactic acid for the PC12 cells and from 0.1% of lactic acid for the keratinocytes. When the pH was adjusted to approximately 7.4, LA did not provoke SP release. At these concentrations of LA, 0.1% of polysaccharide showed a significant decrease in SP release from the two cellular types and in co‐cultures without modifying the pH of the medium. In vivo, a stinging test using the polysaccharide showed a 30% decrease in prickling intensity vs the placebo in 19 women between the ages of 21 and 69. Our in vitro model is ethically interesting and is adapted for cosmetic ingredients screening because it does not use animal experimentation and limits human volunteers. Moreover, Fucogel^® reduced prickling sensation as revealed by the in vivo stinging test and inhibits the neurogenic inflammation as showed by our new in vitro stinging test based on SP release.