Zinc Inhibits the GABAAR/ATPase during Postnatal Rat Development: The Role of Cysteine Residue.

Zinc ions (Zn2+) are concentrated in various brain regions and can act as a neuromodulator, targeting a wide spectrum of postsynaptic receptors and enzymes. Zn2+ inhibits the GABAARs, and its potency is profoundly affected by the subunit composition and neuronal developmental stage. Although the extracellular amino acid residues of the receptor's hetero-oligomeric structure are preferred for Zn2+ binding, there are intracellular sites that, in principle, could coordinate its potency. However, their role in modulating the receptor function during postembryonic development remains unclear. The GABAAR possesses an intracellular ATPase that enables the energy-dependent anion transport via a pore. Here, we propose a mechanistic and molecular basis for the inhibition of intracellular GABAAR/ATPase function by Zn2+ in neonatal and adult rats. The enzymes within the scope of GABAAR performance as Cl-ATPase and then as Cl-, HCO3-ATPase form during the first week of postnatal rat development. In addition, we have shown that the Cl-ATPase form belongs to the ß1 subunit, whereas the ß3 subunit preferably possesses the Cl-, HCO3-ATPase activity. We demonstrated that a Zn2+ with variable efficacy inhibits the GABAAR as well as the ATPase activities of immature or mature neurons. Using fluorescence recording in the cortical synaptoneurosomes (SNs), we showed a competitive association between Zn2+ and NEM in parallel changes both in the ATPase activity and the GABAAR-mediated Cl- and HCO3- fluxes. Finally, by site-directed mutagenesis, we identified in the M3 domain of ß subunits the cysteine residue (C313) that is essential for the manifestation of Zn2+ potency.

Effects of elimination diets and clinical findings on mothers' anxiety in infants with food allergy with non-life-threatening reactions.

Summary: Background. In food allergies (FA), the current treatment is eliminating the responsible food from the diet until tolerance develops. We aimed to determine the effects of the mother's elimination diets and clinical findings on the mothers' anxiety in infants with food allergy (FA) with non-life-threatening reactions. Methods. Our study included 100 infants with FA and 35 healthy infants as control. A data form was prepared to collect information about the infants' and their mothers' socio-demographic characteristics, clinical findings, features of the mother's elimination diet, and FA-related internet search. State-Trait Anxiety Inventory (STAI) was applied to all mothers. Results. The STAI (state anxiety and trait anxiety) scores of the mothers of the infants with FA were higher than the control group (p less than 0.001, p = 0.001, respectively). Of the infants with FA, 51% had food protein-induced allergic proctocolitis (FPIAP), 29% had atopic dermatitis (AD), 20% had urticaria-angioedema (U/AE). It was found that state anxiety scores were higher in mothers whose child had FPIAP, who had multiple food eliminations, who followed the allergy groups on social media, and who made the elimination diet herself (p = 0.008, p = 0.048, p less than 0.001, p = 0.001, respectively). Conclusions. The state anxiety and trait anxiety of the mothers of the infants with FA were higher than the control group, and the state anxiety scores were higher especially in the mothers of infants with FPIAP and multiple food elimination.

Physiological Role of ATPase for GABAA Receptor Resensitization.

γ-Aminobutyric acid type A receptors (GABAARs) mediate primarily inhibitory synaptic transmission in the central nervous system. Following fast-paced activation, which provides the selective flow of mainly chloride (Cl-) and less bicarbonate (HCO3-) ions via the pore, these receptors undergo desensitization that is paradoxically prevented by the process of their recovery, referred to as resensitization. To clarify the mechanism of resensitization, we used the cortical synaptoneurosomes from the rat brain and HEK 293FT cells. Here, we describe the effect of γ-phosphate analogues (γPAs) that mimic various states of ATP hydrolysis on GABAAR-mediated Cl- and HCO3- fluxes in response to the first and repeated application of the agonist. We found that depending on the presence of bicarbonate, opened and desensitized states of the wild or chimeric GABAARs had different sensitivities to γPAs. This study presents the evidence that recovery of neuronal Cl- and HCO3- concentrations after desensitization is accompanied by a change in the intracellular ATP concentration via ATPase performance. The transition between the desensitization and resensitization states was linked to changes in both conformation and phosphorylation. In addition, the chimeric ß3 isoform did not exhibit the desensitization of the GABAAR-mediated Cl- influx but only the resensitization. These observations lend a new physiological significance to the ß3 subunit in the manifestation of GABAAR resensitization.

Effects of total knee arthroplasty on balance and fall risk in elderly patients with severe gonarthrosis: An age- and sex-matched comparative study.

Background: Falls are a severe cause of morbidity and mortality in elderly patients, and gonarthrosis causes a tendency to fall. Total knee arthroplasty (TKA) is a widely used successful surgical procedure for end-stage gonarthrosis. Aims: To investigate whether there is a difference in the frequency of falls, balance and fall risk, and clinical and radiological results in patients with end-stage gonarthrosis with and without TKA. Patients and Methods: This was a single-center, retrospective, case-control study with age- and gender-matched groups. A total of 100 patients over 60 years of age, with end-stage gonarthrosis and who met the inclusion criteria were included in the study. Fall risk was analyzed using the Berg Balance Scale (BBS), TUG tests, and the ITAKI Fall Risk Test. Knee varus angles were measured using standing long-leg radiographs, and radiological gonarthrosis grading was performed. Pain levels and quality of life were assessed using the VAS and WOMAC. Each patient's knee extensor muscle strength and range of motion were measured. Results: WOMAC, ITAKI, TUG test, and VAS scores were significantly higher in the control group than in the TKA group. BBS scores were significantly lower in the control group. Although the number of falls was high in the control group, there was no statistically significant difference between the two groups. Conclusion: The results of this study showed that total knee arthroplasty provided statistically significant improvement in the clinical, radiological, and fall risk results of the patients. Although there was a decrease in the frequency of falls compared to the control group, it was statistically insignificant. In addition, in our study, it was evaluated that the most important risk factor for falling was advanced age.

Occurrence of a human-associated microbial source tracking marker and its relationship with faecal indicator bacteria in an urban estuary.

One of the main impacts of urban sprawl in rapidly growing countries has been contamination of coastal environments by waterborne pathogens, posing a critical risk to ecosystem and human health. Microbial source tracking (MST) has been a robust tool to identify the origin of these pathogens globally. This study compared the occurrence of a human-associated Bacteroides marker (BT-α) with faecal indicator bacteria (FIB) in an urban estuary (Golden Horn, Istanbul, Turkey). Faecal coliform (culture method), enterococci (both culture and qPCR method) concentrations and physicochemical variables were compared with the BT-α concentrations in monthly collected samples for a year (n = 108). Enterococci concentrations detected by culture and qPCR were positively correlated (r = 0·86, P < 0·01) suggesting that qPCR can be an alternative method for monitoring. BT-α marker was positive for 30% of the samples and positively correlated with enterococci (r = 0·61 and r = 0·64 for culture and qPCR methods respectively, P < 0·01). Rainfall had a moderate positive correlation with all faecal/MST indicators suggesting combined sewer overflows also severely impacted estuarine water quality. The high FIB and BT-α concentrations at upper estuary suggested that faecal pollution mainly originated from the peri-urban settlements around two creeks entering the estuary.

Intricacies of GABAA Receptor Function: The Critical Role of the ß3 Subunit in Norm and Pathology.

Neuronal intracellular chloride ([Cl-]i) is a key determinant in γ-aminobutyric acid type A (GABA)ergic signaling. γ-Aminobutyric acid type A receptors (GABAARs) mediate both inhibitory and excitatory neurotransmission, as the passive fluxes of Cl- and HCO3- via pores can be reversed by changes in the transmembrane concentration gradient of Cl-. The cation-chloride co-transporters (CCCs) are the primary systems for maintaining [Cl-]i homeostasis. However, despite extensive electrophysiological data obtained in vitro that are supported by a wide range of molecular biological studies on the expression patterns and properties of CCCs, the presence of ontogenetic changes in [Cl-]i-along with the consequent shift in GABA reversal potential-remain a subject of debate. Recent studies showed that the ß3 subunit possesses properties of the P-type ATPase that participates in the ATP-consuming movement of Cl- via the receptor. Moreover, row studies have demonstrated that the ß3 subunit is a key player in GABAAR performance and in the appearance of serious neurological disorders. In this review, we discuss the properties and driving forces of CCCs and Cl-, HCO3-ATPase in the maintenance of [Cl-]i homeostasis after changes in upcoming GABAAR function. Moreover, we discuss the contribution of the ß3 subunit in the manifestation of epilepsy, autism, and other syndromes.

Enzooty of non-Hodgkin's malignant lymphoma of Papio hamadryas in Sukhumi monkey colony. Clinical and morphological signs of pre-lymphoma.

Inoculation of hamadryas baboons with blood of leukemia ill people-induced malignant non-Hodgkin's lymphoma in experimental animals for a very considerable latency period. At close contact of inoculated baboons with healthy non-inoculated animals, the lymphoma spread between them. The epidemiological analysis, postmortem examination, histological analysis, tissue culturing, and PCR were used for the diagnostics of lymphoma and pre-lymphoma, purification, identification of STLV-1, and HVP viruses. Characteristic clinical and morphological signs designated by us as pre-lymphoma often precede the lymphoma development. In some cases, pre-lymphoma does not develop in lymphoma because animals die from various diseases and do not reach the point of the lymphoma development. The horizontal transmission of lymphoma arising with the participation of T-lymphotropic retrovirus STLV-1 is shown.

Application of wavelet analysis to detect dysfunction in cerebral blood flow autoregulation during experimental hyperhomocysteinaemia.

The purpose of the present study was to investigate the use of laser Doppler flowmetry (LDF) signals coupled with spectral wavelet analysis to detect endothelial link dysfunction in the autoregulation of cerebral blood flow in the setting of hyperhomocysteinaemia (HHcy). Fifty-one rats were assigned to three groups (intact, control, and HHcy) according to the results of biochemical assays of homocysteine level in blood plasma. LDF signals on the rat brain were recorded by LAKK-02 device to measure the microcirculatory blood flow. The laser operating wavelength and output power density were1064 nm and 0.051 W/mm2, respectively. A Morlet mother wavelet transform was applied to the measured 8-min LDF signals, and periodic oscillations with five frequency intervals were identified (0.01-0.04 Hz, 0.04-0.15 Hz, 0.15-0.4 Hz, 0.4-2 Hz, and 2-5 Hz) corresponding to endothelial, neurogenic, myogenic, respiratory, and cardiac origins, respectively. In initial state, the amplitude of the oscillations decreased by 38% (P < 0.05) in the endothelial range in HHcy rats than in control rats. Cerebral autoregulation was challenged by hemorrhagic hypotension. The lower limit of autoregulation raised in a rat model of chronic HHcy (71.5 ± 0.7 mmHg in HHcy vs. 62.3 ± 0.5 mmHg in control). The data obtained indicate that the laser Doppler method and wavelet analysis may be successfully applied to detect the dysfunction of the endothelial link in cerebral vessel tone and to reveal the pathological shift of lower limit of autoregulation.

DIAGNOSTIC VALUE OF DUPLEX DOPPLER ULTRASOUND PARAMETERS IN PAPILLARY THYROID CARCINOMA.

CONTEXT: Papillary thyroid carcinoma (PTC) is the most common type of thyroid cancer due to its high fibrotic content; it can affect the blood flow resistance. OBJECTIVE: To introduce duplex Doppler ultrasonography (DDUS) parameters of papillary thyroid carcinoma (PTC) and their correlation with size. DESIGN: The study was designed as a prospective study. SUBJECTS AND METHODS: Thyroid nodules of the patients who were already scheduled for thyroid surgery either for malignant thyroid nodules or multinodular goiter were evaluated for DDUS parameters. Size, systolic to diastolic flow velocity (S/D) ratio, pulsatility index (PI), and resistive index (RI) of each nodule were recorded. Nodules were diagnosed as PTC or benign nodules based on histopathology. DDUS parameters were compared between PTCs versus benign nodules and micro PTCs (≤ 10 mm) versus large PTCs (> 10 mm). A correlation analysis was performed between the size and DDUS parameters. RESULTS: 140 thyroid nodules (30 PTCs, 110 benign nodules) were obtained. The mean S/D ratio, PI, and RI values were significantly higher in PTC than in benign nodules (p values were 0.0001, 0.0003, and 0.0001 respectively). The optimal cut-off values of S/D (0.732), PI (0.732), and RI (0.738) had accuracy rates of 71%, 69%, and 69%, respectively. There was no statistically significant difference between micro PTC and large PTC with regards to DDUS parameters. The size and DDUS parameters of PTC showed no significant correlation. CONCLUSIONS: PTC has a high resistive flow pattern regardless of its size; however the clinical utility of DDUS to differentiate a PTC from benign nodule is limited.

Sequential binding of calcium ions to the B-repeat domain of SdrD from Staphylococcus aureus.

Biofilms of live bacteria forming on medical devices and implants contribute significantly to bacterial blood dissemination and to the spread of nosocomial infections. Cell surface SdrD protein plays a key role in the attachment of Staphylococcus aureus to the extracellular matrix (ECM) and in the formation of biofilm. SdrD binds calcium ions using its B1-B5 region bearing EF-hand Ca-binding sites, leading to conformational changes in the structure of SdrD. This alters the distance between the bacterial surface and the ECM-interacting domain of SdrD in a spring-like fashion, participating in bacterial attachment. In this study we investigated calcium binding to EF-hand sites of SdrD using isothermal titration calorimetry and determined the impact of this process on SdrD's thermodynamic stability. This allowed us to propose a model of B1-B5 reorganization upon binding of calcium and to get new insight into the molecular mechanism of SdrD's action.

Lack of association between the methylenetetrahydropholate reductase gene A1298C polymorphism and neural tube defects in a Turkish study group.

The etiology underlying neural tube defects (NTDs) is not fully understood and is believed to involve a complex milieu of genetic and environmental factors. The A1298C polymorphism in the methylenetetrahydropholate reductase gene (MTHFR) has been associated with mild risk for NTDs. In this study, the genotype distribution of the MTHFR gene A1298C polymorphism and the levels of serum homocysteine, vitamin B12, and folate were evaluated in 33 children with NTDs, their mothers, and 46 healthy controls. Genotyping of the A1298C polymorphism was performed by real-time polymerase chain reaction. The A and C allele frequencies in children with NTDs and their mothers were similar to controls (P = 0.160). The 1298AA and 1298CC genotype frequencies (P = 0.551 and 0.062, respectively) in children with NTDs and their mothers did not differ from controls. On the other hand, the 1298AC genotype frequencies in children with NTDs and their mothers were significantly different from controls (P = 0.025). The genotype frequency of 1298AC was lower in children with NTDs than in controls. There was no significant association between clinical distribution of NTDs and 1298AA/AC/CC genotypes (P > 0.05). Serum vitamin B12 levels were higher in children with NTDs than their mothers and controls (P = 0.001). There were no differences among serum homocysteine and folate levels in all groups (P = 0.494 and 0.141, respectively). Both genetic and nutritional factors are important in the etiology of NTDs. Thus, the A1298C polymorphism cannot be regarded as a major risk factor for NTDs.

High-temperature high-performance liquid chromatography on a porous graphitized carbon column coupled to an Orbitrap mass spectrometer with atmospheric pressure photoionization for screening exogenous anabolic steroids in human urine.

RATIONALE: The presence in a urinary matrix of a large number of endogenous steroids and corticosteroids with similar structures can hamper the detection of specific exogenous steroids using liquid chromatography/mass spectrometry (LC/MS) with reversed-phase columns. Therefore, the development of LC/MS methods using alternative columns is of great interest. Porous graphitized carbon is a unique stationary phase for high-performance liquid chromatography (HPLC), with properties differing from traditional silica-based and polymeric stationary phases. METHODS: The new method involves enzymatic hydrolysis, liquid-liquid extraction, and determination by high-temperature HPLC/Orbitrap mass spectrometry (HTLC/Orbitrap MS) with atmospheric pressure photoionization (APPI). To achieve APPI of doping substances, the mobile phase consisted of 0.1% CF3COOH (A) and a mixture of acetonitrile/2-propanol (25:75 v/v), containing 0.1% CF3COOH (B), which was used as an effective proton source. RESULTS: A screening method for the detection of 57 exogenous steroids has been developed. The method was validated by spiking 10 different blank urine samples at different concentration levels. Validation parameters included limit of detection (LOD), selectivity, ion suppression, extraction recovery, and repeatability. All studied compounds had an LOD lower than the minimum required performance level. Of the 57 steroids studied, 55 showed recovery better than 70%. For all of the analytes, the relative retention times proved to be stable between days, with relative standard deviations (RSDs) smaller than 0.3%. In addition, the interday RSDs of the peak area ratios ranged between 0.7% and 14.5%. CONCLUSIONS: The proposed method matches the basic requirements of all methods used to analyze drugs or metabolites in an antidoping laboratory, i.e., sensitivity, selectivity, and specificity. The acquisition of full-scan mass spectra with accurate masses can be a valuable tool in the retrospective evaluation of analyzed samples for anabolic steroids recently added to the prohibited list.

An enzootic outbreak of acute disease associated with pathogenic E. coli in Adler monkey colony.

BACKGROUND: In spring 2009 in Adler colony of the Institute of Medical Primatology, a large enzootic outbreak of acute intestine infection associated with pathogenic E. coli occurred and caused 5% mortality of population (209 animals). METHODS: The epidemiological analysis, bacteriological investigation, postmortem examination, histological analysis, and PCR were used to identify the infectious agent. RESULTS: Marked hemorrhagic diathesis, lethargy, dehydration, diarrhea with blood, wasting, and sometimes dystrophic changes in articular cartilages were noted. Morphologically, hemorrhagic enterocolitis and massive hemorrhages were found. PCR investigation of bacteriologically isolated E. coli characterized it as enteropathogenic and enteroinvasive E. coli. CONCLUSIONS: The outbreak in Adler colony slightly differed from similar outbreak in Florida in 2014 by more marked hemorrhagic diathesis and articular changes in some monkeys caused by polyavitaminosis developed in the course of infection. Sensitive to infection were M. mulatta, M. fascicularis, Cercopithecus aethiops, P. hamadryas and anubis, and Cebus capucinus.

Application of molecular markers to detect DNA damage caused by environmental pollutants in lichen species.

Pseudevernia furfuracea L. (Zopf), Peltigera praetextata (Flörke ex Sommerf.) Zopf, Lobaria pulmonaria (L.) Hoffm., and Usnea longissima Ach. lichen species were used as bioindicators to assess the genotoxicity of air pollutants. In the present study, we examined significant environmetal pollutants and investigate how changes may lead to damage in DNA structure using RAPD markers. In the study area (Erzurum, Turkey), poor-quality lignite, which generates a large amount of sulfur dioxide, nitrogen oxides, and particle matter, is used for domestic heating, and vehicles also contribute to air pollution. Control lichen samples were collected far from large urban and industrial settlements and transplanted to four polluted sites for 4, 8, or 12 months. The total soluble protein content of the examined four lichen species did not significantly change with exposure time (P < 0.05). The four lichen samples exposed to the pollutants for 8 months had the highest ratio of DNA changes. The ratio of band differences in P. praetextata was higher than that in the other three lichen species, possibly because it has broad leaves that accumulated more pollutants. The average incidences of polymorphism were 64.14, 54.58, 65.76, and 43.06% for P. furfuracea, P. praetextata, L. pulmonaria, and U. longissima, respectively. The genomic template stability (GTS) significantly decreased following exposure to pollutants. GTS ratios revealed that the highest value (98.36%) belonged to U. longissima samples from Site 1 (10 m) after 4 months of exposure, and the lowest values belonged to P. praetextata (73.58%) from Site 3 (100 m) after 8 months of exposure. Based on our findings, we recommend the use of P. praetextata as an indicator of genotoxicity.

Predictors and incidence of access site complications in transcatheter aortic valve implantation with the use of new delivery systems.

OBJECTIVES: The aim of this single-center study was to assess the incidence and predictors of in-hospital access site complications related to transcatheter aortic valve implantation (TAVI) performed with new delivery systems in our hospital which has the largest case series in Turkey. MATERIALS AND METHOD: We performed successful TAVI with the Edwards Sapien XT valve to 127 (46 male) patients via a transfemoral (121), trans-subclavian (5) and transapical (1) approach. Access site complications were defined according to the Valve Academic Research Consortium (VARC) end-point definitions. RESULTS: Vascular complications occurred in 10.1% of patients. There was negative correlation between vascular complications and diameter of the common femoral artery (r = - 0.301, p=0.004), external iliac artery (r = - 0.327, p=0.004) and common iliac artery (r = - 0.324, p=0.004), but positive correlation between diabetes (r =0.240, p=0.008), sheath to femoral artery ratio (SFAR), sheath to external iliac artery ratio (SEIAR), procedure time, discharge time and the Society of Thoracic Surgeons (STS) score (respectively; r=0.339, 0.001, 0.527, 0.361, 0.289, p=0.003, 0.001, 0.001, 0.001, 0.002). The incidence of vascular complications was significantly higher in patients with diabetes and a high STS score. VARC bleeding complications occurred in 11.7 % of patients. The learning curve pointing out the importance of experience was significantly important in decreasing both bleeding and vascular complications. CONCLUSIONS: In this study, we demonstrated that major vascular complications related to TAVI decrease with the use of smaller delivery systems and experience and increase with high-risk scores (STS) and the presence of diabetes. In addition, VARC major vascular complications, observed mostly in patients with diabete mellitus (DM) and high STS scores, were associated with vascular diameters. These results further underline the importance of experience and a multidisciplinary team in patient selection and management for TAVI.

Detection of S-adenosylhomocysteine and methylation index in blood by capillary electrophoresis.

This work proposes an approach to the direct analysis of S-adenosylhomocysteine (SAH) and the methylation index in blood using CE with UV detection (CE-UV). After application of meglumine postinjection, we achieved SAH in-capillary preconcentration in the HClO4 extracts of erythrocytes, which improved the detection limit (S/N = 3) of SAH up to 3 fmol or 180 nmol/L at the injection volume of 50 nL, taking into account the sample dilution rate. CE-UV was carried out in 30 mM glycine and 45 mmol/L HCl (pH ~1.8) at 17 kV in a capillary 48 cm in length and 50 µm id. Accuracy of the technique was 101% and reproducibility was about 12%.

Phenols and GABAA receptors: from structure and molecular mechanisms action to neuropsychiatric sequelae.

γ-Aminobutyric acid type A receptors (GABAARs) are members of the pentameric ligand-gated ion channel (pLGIC) family, which are widespread throughout the invertebrate and vertebrate central nervous system. GABAARs are engaged in short-term changes of the neuronal concentrations of chloride (Cl-) and bicarbonate (HCO3 -) ions by their passive permeability through the ion channel pore. GABAARs are regulated by various structurally diverse phenolic substances ranging from simple phenols to complex polyphenols. The wide chemical and structural variability of phenols suggest similar and different binding sites on GABAARs, allowing them to manifest themselves as activators, inhibitors, or allosteric ligands of GABAAR function. Interest in phenols is associated with their great potential for GABAAR modulation, but also with their subsequent negative or positive role in neurological and psychiatric disorders. This review focuses on the GABAergic deficit hypotheses during neurological and psychiatric disorders induced by various phenols. We summarize the structure-activity relationship of general phenol groups concerning their differential roles in the manifestation of neuropsychiatric symptoms. We describe and analyze the role of GABAAR subunits in manifesting various neuropathologies and the molecular mechanisms underlying their modulation by phenols. Finally, we discuss how phenol drugs can modulate GABAAR activity via desensitization and resensitization. We also demonstrate a novel pharmacological approach to treat neuropsychiatric disorders via regulation of receptor phosphorylation/dephosphorylation.

Evaluation of the host specificity of Bacteroides thetaiotaomicron alpha-1-6, mannanase gene as a sewage marker.

UNLABELLED: The specificity of a short fragment functional gene marker (alpha-1-6, mannanase) in Bacteroides thetaiotaomicron was compared with two other Bacteroidales markers used for identifying sewage as the source of pollution in water. A total of 11 different animal species and 230 faecal samples were tested using quantitative polymerase chain reaction. The results showed that the alpha-1-6, mannanase marker had high specificity (0·97). Limited cross-reactivity was found in swine, gull and cat faeces with copy numbers close to detection limit. Positives were detected in all bovine and sheep faeces tested for the Human-Bac1 marker. The human-specific alpha-1-6, mannanase marker showed greater specificity (0·97) than the HF 183 Bacteroides PCR marker (0·71) and the Human-Bac1 (qPCR) marker. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first study that compares Bacteroides thetaiotaomicron alpha-1-6, mannanase marker with other markers. Our study showed that this marker has strong potential to be used as an indicator for sewage pollution in water.

Comparison of tympanometric volume measurement with temporal bone CT findings in the assessment of mastoid bone pneumatization in chronic otitis media patients.

OBJECTIVE: Since mastoid bone aeration is a pressure buffer for the middle ear, it can be accepted as a prognostic factor for tympanoplasty. Temporal bone computed tomography (TBCT) is a primary method for estimating mastoid aeration. However, due to the risk of radiation and its high cost, there is a need for a more straightforward, faster, and more reliable method in non-complicated chronic otitis media cases (COM). Tympanometric volume measurement might be used for this purpose. This study investigated tympanometric volume measurement's reliability in showing mastoid bone aeration by comparing tympanometric volume measurement with TBCT aeration grading. PATIENTS AND METHODS: Preoperative tympanometric volume measurements were performed in patients who underwent audiological examination and temporal computerized tomography (CT) with the diagnosis of COM and sequela of COM without discharge for the last three months and were indicated for surgery. CT was classified into six grades: grade 0: there is no aeration, sclerotic mastoid; grade 1: pneumatization only in the mastoid antrum; grade 2: <25% pneumatization; grade 3: 25-50% pneumatization; grade 4: >50 pneumatization, grade 5: full pneumatization. Averages of tympanometric volume values were determined according to CT degrees. RESULTS: 48 left and 52 right ears (n: 100) of 81 patients, 24 females and 57 males, were included in the study. The mean age was 37.69±13.38. Mastoid pneumatization grades of patients were 32 grade 0, 23 grade 1, 16 grade 2, 14 grade 3, 11 grade 4, and 4 grade 5, respectively. Each grade's mean tympanometric volume (mL) was grade 0: 1.1594, grade 1: 1.6991, grade 2: 2.2250, grade 3: 3.0471, grade 4: 4.0327, and grade 5: 2.9775. CONCLUSIONS: There is a statistically significant relationship between tympanometrically measured ear volume and mastoid degrees of pneumatization on temporal bone tomography. As the degree of mastoid aeration increases, the tympanometric volume also increases. According to the results of this study, tympanometric air volume can be used reliably in the preoperative evaluation of mastoid bone aeration in cases of simple COM without ear drainage.