Application and comparison of thermistors and fiber optic temperature sensor reference for ILP measurement of magnetic fluids in double cell magnetic hyperthermia.

One of the simplest way to characterize the heating efficiency of magnetic fluids used in hyperthermia treatment is the calorimetric measurement of the specific loss power with direct temperature detection. However, the performance of metallic sensors in an alternating magnetic field is degraded by the self-heating of the probes, and electromagnetic interference can be also significant. In our double cell differential thermometric system these disturbing effects can be compensated. Specific loss power measurements of EMG700 magnetic fluid with negative temperature coefficient thermistors in differential configuration are presented, and control measurements were performed with an optical fiber thermometer in f = 470 kHz - 1020 kHz frequency and H = 0.13 kA m - 1 - 1.19 kA m - 1 magnetic field strength range. We found that the specific loss power is proportional to the frequency and shows a quadratic dependence on the field strength in the low field strength region, therefore we calculated the intrinsic loss power of the fluid from the measured specific loss power. At this field conditions intrinsic loss power up to 0.53 nH m 2 kg - 1 was determined.

Breast adenocarcinoma-derived exosomes lower first-contact de-adhesion strength of adenocarcinoma cells to brain endothelial layer.

Despite of advances in modern therapeutics, one of the most feared complications of cancer are brain metastases, which often cause life impairing profound neurological symptoms and premature death. Breast adenocarcinoma is among the leading "sources" of brain metastases. Since the central nervous system lacks a classical lymphatic circulation, invading metastatic cells can reach the brain parenchyma only through haematogenous routes and must breach the blood-brain barrier (BBB). The key step before the transmigration of metastatic cells through the highly regulated interface of the BBB is the establishment of firm adhesion between the tumor cell and the cerebral endothelial layer. Using atomic force microscopy, as a high resolution force spectrograph, direct measurements of intercellular interactions was performed between living adenocarcinoma cells and a confluent endothelial layer pre-treated with carcinoma cell-derived exosomes. By immobilization of a living adenocarcinoma cell to an atomic force microscope's cantilever, intercellular de-adhesions were directly measured by single cell force spectroscopy (SCFS) at quasi-physiological conditions. De-adhesion dynamics and strength was characterized by several different calculated parameters, involving aspects of both membrane and cell surface related factors. Our results indicate that de-adhesion strength was lower in case of exosome pre-treated endothelial cells as compared to non-treated controls. Breast adenocarcinoma-derived exosomes have direct effect on de-adhesion pattern of brain endothelium.

Risk stratification in endoscopic type I. tympanoplasty.

PURPOSE: Several risk factors were studied in endoscopic type I. tympanoplasty, however, an easy-to-use risk stratification model is still missing. METHODS: Retrospective chart review, focusing on individual risk factors and middle ear risk index (MERI). Patients who underwent endoscopic type I. tympanoplasty were included. RESULTS: Closed tympanic cavity was succesfully created in 88.1% of the 42 cases, the overall 21,5 dB air-bone gap (ABG) was reduced by 9,8 dB. The average MERI score of the patients was 2.1 ± 1.5. 78.6% of the patients were categorised into the mild, while 21.4% into the moderate risk group. The perforation was considered small in 81.0% of the cases, while large in 19.0%. The size of the perforation and the preoperative ABG, but not the MERI status were the only single predictors of success. Using a risk stratification model that is based on the size of the perforation, the preoperative ABG and MERI status, patients could be referred into two distinct groups of risk: the majority expecting excellent outcomes with maximum one risk factor present, and patients with deteriorated rate of success when having two or three risk factors. CONCLUSIONS: Endoscopic type I. tympanoplasty with underlay perichondrium graft can be performed with good chance of success. However, if more than one risk factors are present, the chance of residual perforation becomes great. In addition to the established risk factors, our results point out that despite its strong correlation with perforation size, ABG may have a predictive role.

Mal de débarquement syndrome ­ "sickness of disembarkment" / [Mal de débarquement szindróma - "partraszállási betegség"]

Mal de débarquement syndrome is an uncommon vestibular disorder characterized by a constant sensation of swaying or motion after one disembarks from a vehicle such as a ship or plane, however, spontaneous onset also appears. These symptoms temporarily subside when the patient is subjected again to passive motion like driving a car. Chronic fatigue, anxiety, and depression are frequently associated with primary symptoms. The diagnosis is challenging, and often made by the patients themselves. The underlying pathophysiology and definitive therapy are unknown. Exposure to optokinetic stimulations and transcranial magnetic stimulations open therapeutic perspectives. We report a case series of 5 patients who presented with constant rocking, bobbing sensation that had been ongoing for several months. We found normal inner-ear function, non-related abnormalities and normal brain imaging. By presenting our patients' histories, we discuss the different diagnostic issues that help to diagnose this condition. We aimed to report the most recent findings on aetiology and treatment methods and to share our experiences with different therapeutic attempts. Mal de débarquement syndrome is a diagnosis of exclusion and often unrecognized. A thorough clinical history, negative or non-specific clinical findings with a high degree of suspicion are needed for recognizing this disorder. Increasing awareness can lead to early diagnosis and prevent multiple physician visits and unnecessary diagnostic testing. Frequent diagnostic failure has a negative impact on the quality of life, associated with anxiety and depression. Orv Hetil. 2020; 161(20): 846-851.

Magnetic field response of aqueous hydroxyapatite based magnetic suspensions.

During the biomedical and biotechnological applications of hydroxyapatite based magnetic biomaterials the response to various magnetic fields (i.e. change in flow behavior) plays a pivotal role in manipulating these materials. Numerous studies discuss the synthesis, characterization and possible applications of magnetic hydroxyapatite, however the number of reports related to the magnetic response is limited. In this study we investigated the response of aqueous suspensions of magnetite/hydroxyapatite composites with gelatin as an additive to homogeneous and inhomogeneous magnetic fields. Under homogeneous field the change in rheological properties was determined, and correlated with the composition of the composites. The effect of magnetite and gelatin content on the zero field viscosity and magnetic susceptibility were also evaluated. The response to inhomogeneous field was characterized by measuring the magnetic body force acting on droplets of the aqueous suspensions. We found that the formulation of the composites and the presence of additive largely affect the magnetic response.

Does The Type of Ossicular Chain Lesion Affect Outcomes in Chronic Suppurative Otitis Media Without Cholesteatoma?

OBJECTIVES: We evaluated the pattern of ossicular chain (OC) lesion in chronic suppurative otitis media (CSOM) without cholesteatoma and its impact on outcomes in primary and revision surgeries. MATERIALS AND METHODS: This was a retrospective chart review. Patients who underwent tympanoplasty due to CSOM with OC defect between 2010 and 2015 were included in the study. RESULTS: OC lesions were found during 40 of 147 tympanoplasties performed due to CSOM. The preoperative air-bone gap (ABG) was greater in both discontinuity and fixation cases than in cases with CSOM with an intact OC (p<0.001). Twenty-nine patients were followed up postoperatively, after excluding four patients with stapes footplate fixation, in whom stapedotomy was not performed simultaneously. Among the 29 patients, the audiological results were similar in cases of discontinuity and fixation regarding gap change, residual ABG, and the rate of successful ossiculoplasty. Primary tympanoplasties provided better results according to postoperative ABG and the rate of successful ossiculoplasty than revision surgeries (p<0.05); however, similar patterns of OC lesions were found during primary and revision surgeries. CONCLUSION: Both OC discontinuity and fixation occur in CSOM in a similar distribution in primary tympanoplasties and revision surgeries. The type of OC lesion does not affect outcomes. Primary surgeries provide better results, but that is not due to a difference in the character of the OC lesion.

Biotemplated synthesis of magnetic filaments.

With the aim of creating one-dimensional magnetic nanostructures, we genetically engineered flagellar filaments produced by Salmonella bacteria to display iron- or magnetite-binding sites, and used the mutant filaments as templates for both nucleation and attachment of the magnetic iron oxide magnetite. Although nucleation from solution and attachment of nanoparticles to a pre-existing surface are two different processes, non-classical crystal nucleation pathways have been increasingly recognized in biological systems, and in many cases nucleation and particle attachment cannot be clearly distinguished. In this study we tested the magnetite-nucleating ability of four types of mutant flagella previously shown to be efficient binders of magnetite nanoparticles, and we used two other mutant flagella that were engineered to periodically display known iron-binding oligopeptides on their surfaces. All mutant filaments were demonstrated to be efficient as templates for the synthesis of one-dimensional magnetic nanostructures under ambient conditions. Both approaches resulted in similar final products, with randomly oriented magnetite nanoparticles partially covering the filamentous biological templates. In an external magnetic field, the viscosity of a suspension of the produced magnetic filaments showed a twofold increase relative to the control sample. The results of magnetic susceptibility measurements were also consistent with the magnetic nanoparticles occurring in linear structures. Our study demonstrates that biological templating can be used to produce one-dimensional magnetic nanostructures under benign conditions, and that modified flagellar filaments can be used for creating model systems in which crystal nucleation from solution can be experimentally studied.

Severe neck infections that require wide external drainage: clinical analysis of 17 consecutive cases.

Infections in the neck layers and spaces are potentially life-threatening diseases causing further complications, like mediastinitis, airway obstruction, or sepsis. Despite of the need for a conservative approach, they still regularly require surgical intervention. Records of 17 patients with severe neck infections that were treated by wide external incision and open wound management were retrospectively analyzed. The aim of the study was to clinically characterize these most serious neck infections. The most common presenting symptoms were neck pain and tense neck mass (94-94%) regularly with fever (65%), always accompanied by a marked elevation of C reactive protein level (average 192 uG/l). These findings were constant and very similar among both the deep neck infection and necrotizing fasciitis cases. More than half of the patients (53%) had at least one systemic co-morbidity. The parapharyngeal space was most commonly affected (83%), but extended disease involving more than two major neck regions was found in 13 cases (76%). Dental (29%) was the most common primary infection, followed by peritonsillar abscess (23%), Microbiological results showed a wide variety of corresponding bacteria. Mediastinitis was developed in three cases (18%), and airway obstruction requiring tracheostomy in two cases (12%). All the patients survived. Severe neck infections are a heterogenous group of diseases regarding to the primary site of infection, microbiology, localisation and host reaction. However, rapidly developed, painful, tense neck mass with a highly elevated CRP level should always alert for an extended or phlegmonous process in the layers or spaces of the neck.

Primary tuberculosis of the middle ear cleft: diagnostic and therapeutic considerations.

Tuberculosis remains one of the most challenging infectious diseases, which rarely manifests in the middle ear cleft exclusively. Typical symptoms of tuberculosis have become more and more confusing due to the genetic evolution of different Mycobacterium species. In the diagnosis of tuberculous otitis media (TOM), clinical suspicion plays a fundamental role, when topical and/or systemic antibiotic treatment cannot lead to improvement in ear discharge and inflammation. If there is no other reason of persisting otorrhea, microbiological sampling and culturing are the subsequent steps of diagnosis. These investigations, however, have low sensitivity; therefore a canal wall-up mastoidectomy is recommended, which includes the removal of necrotic bone and multiple histological sampling from various locations. Currently, histopathological analysis is the most robust and reliable method in the diagnosis of TOM. Tuberculin skin test, Mycobacterium-specific PCR and interferon-gamma release assay cannot distinguish between active, inactive or post-infective conditions. According to these considerations, these methods may serve as supplementary assays for the final diagnosis. Having the appropriate diagnosis after surgical intervention and laboratory analysis, medical management should be continued by anti-tuberculosis chemotherapy. Hereby, we demonstrate two cases with primary TOM and provide an overview of the literature in the light of diagnostic and therapeutic guidelines in the management of TOM.

Expression of ets-1 transcription factor in human head and neck squamous cell carcinoma and effect of histamine on metastatic potential of invasive tumor through the regulation of expression of ets-1 and matrix metalloproteinase-3.

BACKGROUND: Ets-1 controls the expression of critical genes involved in matrix remodeling. The matrix metalloproteinase-3 (MMP-3) and urokinase type plasminogen activator (uPA) are typical ets-1 responsive genes. Recent studies have shown an increase in histamine synthesis and content in various human neoplasias. We hypothesized that the increased local histamine overproduction contributed to activation of matrix remodeling through the activation of MMP-3 expression of peritumoral fibroblasts by means of ets-1 regulation in head and neck squamous cell carcinomas (HNSCCs). METHODS: Paraffin-embedded sections of 30 HNSCCs were immunostained for ets-1. The presence of ets-1 and MMP-3 mRNA in tumor samples was confirmed by reverse transcriptase-polymerase chain reaction (RT-PCR). To simulate stromal reaction in vitro, cultured human mucosal fibroblast was used. The level of ets-1 and MMP-3 mRNA was compared by use of RT-PCR, as was their protein with flow-cytometry, in the presence or absence of basic fibroblast growth factor (bFGF) (10 ng/mL) and histamine (1 microM). RESULTS: Correlation between ets-1 expression and clinicopathologic background was not significant. In all cases, expression of ets-1 was seen in the stroma. In in vitro study, histamine upregulates production of ets-1 and MMP-3 in cultured fibroblast, and bFGF can stimulate histamine expression in fibroblast. Immunofluorescence staining supported the results of RT-PCR and flow cytometry. CONCLUSIONS: Ets-1 expression in HNSCCs has no prognostic value; however, ets-1 plays an important role in tumor-host interaction. Histamine may accelerate the spread of HNSCC through an ets-1-related mechanism.

Histamine elevates the expression of Ets-1, a protooncogen in human melanoma cell lines through H2 receptor.

Histamine is known to act, at least in part, as a growth factor for several cell types, and as production of this biogen amine has been found to accelerate the rate of tissue proliferation in wound repair, embryogenesis and malignant growth. Abundant experimental and clinical data suggest that histamine augments in vivo tumour cell proliferation via histamine H2 receptors (H2R). Here, we report that exogenously added histamine stimulates Ets-1 (v-ets erythroblastosis virus E26 oncogene homolog 1) synthesis in human melanoma cells. Involvement of histamine receptors in the histamine induced ets-1 expression has been also studied. Our data show that these newly recognized actions of histamine are mediated by the H2R. Modification of local protooncogen Ets-1 level is likely being involved in the regulation of melanoma growth.