The effect of post-auricular canal wall down mastoidectomy on the position of the auricle.

OBJECTIVE: This study aimed to investigate the effect of surgical incision on the auricle position in patients undergoing canal wall down mastoidectomy to treat chronic otitis media. METHODS: Thirty-four patients who had undergone canal wall down mastoidectomy with a post-auricular incision approach were included in the study. Patients who had a previous auricle deformity, who underwent limited mastoidectomy surgery or mastoid obliteration, or who were younger than 18 years of age were excluded. The distances of the upper and middle parts of the auricle to the mastoid were measured. RESULTS: Measurements in the first post-operative year were found to be 13.15 ± 3.59 mm in the upper region and 16.29 ± 5.00 mm in the middle region. It was observed that the auricle was approaching the mastoid area in both regions. CONCLUSION: In patients undergoing radical mastoidectomy, the distance between the auricle and the mastoid may decrease, leading to narrowing of the auriculo-cephalic angle.

Osteoclastic activity in chronic otitis media with cholesteatoma-related bone destruction.

BACKGROUND: Cholesteatoma-related bone destruction is the cause of many complications due to chronic otitis media. This study aimed to evaluate osteoclastic activity in cholesteatoma-related bone destruction using tartrate-resistant acid phosphatase 5b, an enzyme specific to osteoclastic activity. METHOD: Seventy-two patients diagnosed with chronic otitis media were included in this study and were divided into two groups: with and without bone destruction. The blood serum and tissue tartrate-resistant acid phosphatase 5b levels from both groups were compared. RESULTS: There were no significant differences in the level of serum enzymes between both groups. However, in tissue samples, tartrate-resistant acid phosphatase 5b levels were significantly lower in the bone destruction group than the group without bone destruction. CONCLUSION: This study determined that the level of tartrate-resistant acid phosphatase 5b, a specific enzyme for osteoclastic activity in cholesteatoma-related bone destruction, is locally decreased. This data suggests that osteoclastic activity may decrease in cholesteatoma-related bone destruction. However, further experimental and clinical studies are required to clarify this highly complex mechanism.

Reconstruction of ear canal wall with superior pedicled composite multi-fractured osteoperiosteal flap: a new technique and preliminary outcomes.

OBJECTIVE: This study evaluated the functional results of the superior pedicled composite multi-fractured osteoperiosteal flap technique. This method is a novel technique for the reconstruction of the external auditory canal. The study also examined the effect of the superior pedicled composite multi-fractured osteoperiosteal flap technique on patients' disease-related quality of life. METHOD: A total of 37 patients who underwent the superior pedicled composite multi-fractured osteoperiosteal flap technique were enrolled in the study. Their functional hearing results and disease-related quality of life scores were evaluated. RESULTS: A significant improvement was observed in the patients' hearing scores at the post-operative sixth month relative to the pre-operative period, and the patients' disease-related quality of life increased significantly. CONCLUSION: The superior pedicled composite multi-fractured osteoperiosteal flap method can be safely used, especially in patients undergoing retrograde mastoidectomy because of limited cholesteatoma. This method contributes to improving patients' hearing levels and disease-related quality of life.

The Role of AMPARs in the Maturation and Integration of Caudal Ganglionic Eminence-Derived Interneurons into Developing Hippocampal Microcircuits.

In the hippocampal CA1, caudal ganglionic eminence (CGE)-derived interneurons are recruited by activation of glutamatergic synapses comprising GluA2-containing calcium-impermeable AMPARs and exert inhibitory regulation of the local microcircuit. However, the role played by AMPARs in maturation of the developing circuit is unknown. We demonstrate that elimination of the GluA2 subunit (GluA2 KO) of AMPARs in CGE-derived interneurons, reduces spontaneous EPSC frequency coupled to a reduction in dendritic glutamatergic synapse density. Removal of GluA1&2&3 subunits (GluA1-3 KO) in CGE-derived interneurons, almost completely eliminated sEPSCs without further reducing synapse density, but increased dendritic branching. Moreover, in GluA1-3 KOs, the number of interneurons invading the hippocampus increased in the early postnatal period but converged with WT numbers later due to increased apoptosis. However, the CCK-containing subgroup increased in number, whereas the VIP-containing subgroup decreased. Both feedforward and feedback inhibitory input onto pyramidal neurons was decreased in GluA1-3 KO. These combined anatomical, synaptic and circuit alterations, were accompanied with a wide range of behavioural abnormalities in GluA1-3 KO mice compared to GluA2 KO and WT. Thus, AMPAR subunits differentially contribute to numerous aspects of the development and maturation of CGE-derived interneurons and hippocampal circuitry that are essential for normal behaviour.

Afferent specific role of NMDA receptors for the circuit integration of hippocampal neurogliaform cells.

Appropriate integration of GABAergic interneurons into nascent cortical circuits is critical for ensuring normal information processing within the brain. Network and cognitive deficits associated with neurological disorders, such as schizophrenia, that result from NMDA receptor-hypofunction have been mainly attributed to dysfunction of parvalbumin-expressing interneurons that paradoxically express low levels of synaptic NMDA receptors. Here, we reveal that throughout postnatal development, thalamic, and entorhinal cortical inputs onto hippocampal neurogliaform cells are characterized by a large NMDA receptor-mediated component. This NMDA receptor-signaling is prerequisite for developmental programs ultimately responsible for the appropriate long-range AMPAR-mediated recruitment of neurogliaform cells. In contrast, AMPAR-mediated input at local Schaffer-collateral synapses on neurogliaform cells remains normal following NMDA receptor-ablation. These afferent specific deficits potentially impact neurogliaform cell mediated inhibition within the hippocampus and our findings reveal circuit loci implicating this relatively understudied interneuron subtype in the etiology of neurodevelopmental disorders characterized by NMDA receptor-hypofunction.Proper brain function depends on the correct assembly of excitatory and inhibitory neurons into neural circuits. Here the authors show that during early postnatal development in mice, NMDAR signaling via activity of long-range synaptic inputs onto neurogliaform cells is required for their appropriate integration into the hippocampal circuitry.

Conservative Management of Large Rectosigmoid Perforation under Peritoneal Reflection: Case Report and Review of the Literature.

Colonoscopy is accepted as the best method in diagnosis, treatment, and follow-up of colorectal diseases. As the amount of the usage of diagnostic and therapeutic colonoscopy rises, iatrogenic complications are more likely to be seen. The most important complications are perforations and bleeding. Whereas perforation is a complication that is seen rarely, because of the high ratio of morbidity and mortality, it should be analyzed more carefully. There is not a common view on the optimal treatment of colonoscopic perforation. Most cases require urgent surgery, and in some cases the iatrogenic perforation of colon can be managed by conservative methods. In this report, we present a rectosigmoid perforation under peritoneal reflection and conservative management of this case.