[Prospects for cochlear implantation in patients with auditory nerve dysplasia]

Auditory nerve dysplasia (AND) can encompass various conditions of the auditory nerve (AN), ranging from true aplasia to hypoplasia. The purpose of this review is to discuss the prospect of cochlear implantation (CI) and subsequent auditory speech rehabilitation for AN abnormality. Studies of different authors when working with this category of children, possible results and methods of diagnostics of the AN condition are presented.

[Micotic aneurysm of the internal carotid artery in a patient with sarcoidosis as a cause of ischemic stroke and profuse epitaxis]

The article describes the following case: a 63-year-old patient with sarcoidosis, who was on long-term therapy with metipred, developed profuse epistaxis, and upon admission to the hospital, clinical manifestation of stroke. Computer tomography (CT) of the brain at admission revealed destruction of the posterior wall of the sphenoid bone and an area of increased density in the projection of the left optic nerve regarded as a neoplasm of the sphenoid sinus or inflammatory changes. CT angiography revealed the occlusion of the left internal carotid artery (LICA) from the C1 segment throughout. At the time of thrombus extraction, the patient developed profuse bleeding from the nasal cavity. According to staged angiography, the antegrade blood flow through the LICA to the sphenoid segment was restored; against the background of profuse bleeding, the flow of contrast from the LICA into the sphenoid sinus and further into the nasopharynx is visualized; in the projection of the sphenoid sinus, a formation was revealed that required differentiation between a giant aneurysm, an arteriovenous fistula, and a neoplasm of the sphenoid sinus. Destructive embolization of the LICA at the level of the petrosal segment was performed for vital indications, the bleeding was stopped, but the patient died due to acute posthemorrhagic anemia. An autopsy revealed a mycotic aneurysm of the LICA, the rupture of the wall of which caused nasal bleeding, which was spontaneously stopped due to the formation of an extended thrombus, which, in turn, became the cause of stroke.

[Surgical tactic of cochlear implantation in patients with intraoperative CSF leakage]

Cochlear implantation (CI) is currently the recognized and most promising method of rehabilitation of patients suffering from profound hearing loss and deafness. During the surgical stage of CI, one of the most unpleasant intraoperative features is CSF leakage from the cochlea opening. Most often it occurs in patients with malformations of the inner ear, with temporal bone fractures and with cochlear otosclerosis. The difficulty of choosing the tactics of surgical intervention in these patients is caused by the large variability of the anatomical structures of the inner ear. In the period from 2017 to 2021, 1954 patients underwent CI, of which 83 were patients with cochlea malformations (65 intraoperative CSF leakages), 14 with the temporal bones fractures (2 intraoperative CSF leakage), 12 with cochlear otosclerosis (1 CSF leakage), while 3 spontaneous intraoperative CSF leakages were noted in patients with normal cochlea anatomy and hyperpnumotized temporal bone pyramid and enlarged vestibular aqueduct. The highest risk of intraoperative CSF leakage was observed in patients with inner ear malformations (common cavity - 10, incomplete partition type III - 15) and anomalies of the internal auditory canal - 5 (dilated IAC - more than 8.5 mm in diameter). Moderate risk of intraoperative CSF leakage was typical for patients with incomplete partition type I (15 patients) and type II (25 patients).

[Paradoxical air embolism of intracerebral arteries as a complication of tooth extraction]

The article describes the rare clinical case, demonstrating sudden onset of neurological manifestations (seizures and consequent formation of ischemic stroke foci) in a 29 year-old female patient during tooth extraction (right lower third molar) using the high-speed dental drill. Air injection through damaged tissues caused subcutaneous emphysema in the buccal area that caused air embolism. Presence of asymptomatic congenital heart defect in the patient (atrial septal defect) allowed the bubbles of air to move paradoxically from right to left with consequent embolization of small cerebral arteries. Treatment in specialized department was successful and had beneficial effect on patient's condition.

[Germline and Somatic Mutations in Archived Breast Cancer Specimens of Different Subtypes]

Molecular profiling of tumors may provide promising options for personalized treatment. We have examined the spectrum of germline and somatic mutations in 23 breast cancers (ВС) of various molecular subtypes, including tumors 1) with expression of estrogen, progesterone and/or epidermal growth factor receptor HER2/neu, and 2) with a triple negative phenotype. Genomic DNA specimens were isolated from archived tumor and normal tissue samples and subjected to targeted sequencing of the coding regions of 25 cancer-associated genes with a mean coverage of x 1000. In the triple negative subtype of ВС, the pathogenic germline mutations BRCA1 c.66_67delAG (185delAG) and BRCA1 c.3226_3227AG (3347delAG) were detected, while the germline mutation BRCA2 658_659del (886delGT) was found in patients with positive receptor staining. Mutations in BRCAl/2 were overrepresented by frequency (80%), pointing at common loss of heterozygosity affecting the normal allele. Somatic mutations in the TP53 gene were found in 7/10 (70%) patients with the triple negative subtype of ВС and in 3/13 (23%) in the group with positive receptor staining. Additionally, in both groups of patients, somatic mutations of the PTEN, MSH2, MSH6, and MUTYH genes were detected.

[Endometriosis of the ureter from the standpoint of implantation theory: some aspects of pathogenesis and clinical picture]

The article describes such fundamental and applied aspects of pathogenesis and clinical manifestations of such rare disease as endometriosis of ureters. Frequent involvement of left ureter in its pelvic part, close to distal colon, associated with its inflammatory diseases followed by leaky gut syndrome with bacterial spread to the fallopian tube causing its inflammation and dysfunction, provoking menstrual reflux and predisposing to affection of left ovary, peritoneum and contact spread of endometriosis to ureteral wall. This mechanism fits to the regurgitation theory of endometriosis. Surgery is the gold standard for endometriosis treatment and more beneficial, comparing with conservative treatment and essential for prevention of such dangerous complications as hydronephrosis and renal failure. But the early and in-time diagnostic of endometriosis depend on gynecologists, not urologist, that characterizes endometriosis as significant interdisciplinary problem. In the article symptoms, that must cause concern for this rare pathology are thoroughly described.

[The activities of the Soviet pathologist Vladimir Gerasimovich Molotkov during the Great Patriotic War (to the 75th anniversary of the Great Victory)]

This work is dedicated to the famous pathologist, scientist, teacher of the USSR Higher School of Medicine Vladimir Gerasimovich Molotkov. Being the main pathologist of the Western Front from 1941 to 1944, and the 3rd Belorussian Front from 1944 to 1945, Vladimir Gerasimovich successfully coped with the duties assigned to him. His activities during the Great Patriotic War made it possible to study in detail some aspects of the pathogenesis of various pathologies, in particular «field» or «digging» nephritis, and thereby significantly improve the quality of medical care for Soviet soldiers, which made an invaluable contribution to the victory. For his services to the fatherland, he was awarded the Order of the Red Star, Order of World War of II degree, the Red Banner of Labor Order, the Badge of Honor, as well as many other awards. From September 1945, he headed the department of the Smolensk Medical Institute and ruled it until his untimely death on February 14, 1976.

[Abnormal gut microbiota-induced hypoestrogenemia as a possible risk factor for malignancy in endometrioid heterotopia]

This paper reveals the pathogenetic impact of the abnormal gut microbiota on the development of female reproductive system diseases. A dynamic imbalance between the altered microbiota and the macroorganism has many manifestations as hormonal homeostatic disorders, one of which is dysbiosis-induced hypoestrogenemia. Using endometrioid heterotopia as an example, the authors trace the possibility of its progression and malignancy due to the occurrence of primary breakdown of the PTEN tumor-suppressor gene with subsequent genetic abnormalities in the ARID1A and TP53 genes. PTEN mutation in both endometriosis itself and its malignancy indicates that dysbiosis-induced hypoestrogenemia may be implicated in the pathogenesis of endometriosis. Thus, the relationship between female reproductive system diseases and gut microbiome disorders may be more significant; and the possibility of correcting the gut microbiota with prebiotics and probiotics opens new horizons not only in the prevention, but also in the treatment of many gynecological diseases associated with hormone disorders.

[Endometrial cell apoptosis impairment associated with hormonal imbalance as a key factor in the development of endometriosis]

The review describes the effect of certain hormones and their imbalance on apoptosis of retrogradely refluxed endometrial cells in the abdominal cavity and the effects of estrogen, progesterone, anti-Mullerian hormone, and gonadotropin-releasing hormone on the internal and external apoptotic pathways of various cell populations in endometriotic foci. The nuclear estrogen receptor β (ER-β) is shown to inhibit TNF receptors that trigger the external apoptotic pathway, but the effects of estrogens do not play a key role in the pathogenesis of endometriosis. The role of progesterone and changes in the receptor status towards prevalence of PR-A with a decreased response of endometrial tissue to progesterone and inhibition of apoptosis are described. We discuss the role of the anti-Müllerian hormone and gonadotropin-releasing hormone II (GnRH II) as activators of apoptosis in normal endometrial tissue and in endometriosis. Investigation of endocrine effects on apoptosis of parenchymal and stromal cells of endometriotic foci may provide a theoretical basis for searching for new therapeutic targets in this hormone-dependent pathology.

[Role of adipose tissue in the development and progression of colorectal cancer]

The paper gives the current data available in the literature on the relationship and pathogenetic mechanisms of influence of adipose tissue on colorectal carcinogenesis. It considers the aspects of changes in adipose tissue and microenvironment of the tumor itself, including those under the influence of biologically active substances secreted by adipocytes; differences in subcutaneous and visceral fat and their importance in the development and progression of colorectal cancer (CRC), as well as the role of adipose tissue-derived stem cells. Understanding these mechanisms for adipose tissue influence on CRC will assist not only in preventing this disease, but also in searching for new therapeutic targets.

Investigation of malignant transformation of sporadic adenomas of colon by fluorimetry

In this work, biochemical changes in sporadic adenoma during progression to colon cancer have been detected by spectral techniques. It is shown that spectra of all types of adenomas as well as adenocarcinoma have two maxima at 265 ÷ 270 nm and at 330 ÷ 340 nm. The first maximum is primarily defined by tryptophan containing peptides. The second maximum of the spectra is in the main defined by collagen presence in stroma of tumors and normal mucosa. Progression of precancer lesions to advanced cancer leads to increase of NADH concentration impacting on the second maximum of spectra. At the time, the spectra of both AC differ from each other by widths of the second maximum. For well-differentiated AC, the second maximum is wider. It gives reason to suggest that two fluorophores impact on its intensity. These fluorophores can be NADH and vitamin B₆. Correlation between microscopical and spectral results can allow to use fluorimetry for detail diagnostics and investigation of colon cancer development.