[A case of acute purulent otitis media complicated by atypical mastoiditis on the background of an unverified HIV infection]. / Sluchai ostrogo gnoinogo srednego otita, oslozhnennogo atipichnym mastoiditom, na fone neverifitsirovannoi VICh-infektsii.

According to the literature, acute otitis media is complicated by mastoiditis in 0.15-1% of cases. In turn, mastoiditis can be complicated by meningitis, encephalitis, abscess of temporal lobe of brain and cerebellum, epidural and subdural abscesses, facial nerve paresis, labyrinthitis, phlegmon of soft tissues of neck, as well as subperiosteal abscess, which makes 7% in the structure of mastoiditis complications. Nowadays, when doctors have a wide range of antibacterial preparations at their disposal, a complicated course of acute otitis media and further mastoiditis is caused both by an aggressive atypical infectious agent and immunocompromised status of a patient. The article deals with a clinical case of a prolonged course of acute otitis media complicated by mastoiditis and subperiosteal abscess against the background of outpatient courses of antibacterial therapy. The examination revealed an atypical pathogen of otitis media Pseudomonas aeruginosa and HIV-positive status of the patient, previously unknown. Timely surgical intervention and the right combination of antibacterial drugs, meropenem and ciprofloxacin, prevented the development of intracranial and septic complications, despite the presence of multiple foci of bone destruction of the mastoid process and temporal bone pyramid, bordering the middle fossa and sigmoid sinus, according to multispiral head computed tomography. As a part of additional examination in the Center for AIDS and Infectious Diseases Prevention and Control, the patient was diagnosed with HIV infection, clinical stage 4C, progressing phase on the background of absence of antiretroviral therapy, and the necessary amount of treatment was prescribed.

[Oncological results of repeat partial nephrectomy in patients with recurrence after nephron-sparing procedures].

AIM: To carried out a comparative analysis of the risk of complications and oncological results of repeat partial nephrectomy and radical nephrectomy in patients with local recurrence after previous organ-sparing procedures. MATERIALS AND METHODS: Retrospective and prospective data of 64 patients with local recurrence of kidney cancer after nephron-sparing procedures. who underwent surgical treatment in the department of oncourology of the National Medical Research Center of Oncology named after N.N. Blokhin in the period from 2000 to 2022. A total of 37 (57.8%) patients of the main group underwent repeat partial nephrectomy, while in 27 (42.2%) patients in the control group a radical nephrectomy was done. Median follow-up was 35 (3-131; Q1-Q3: 13-57) months. Both groups were comparable in terms of demographic and clinical characteristics (p>0.05). The median time to detect relapse after previous partial nephrectomy was 24 (2-172) months. RESULTS: Complications were noted in 8 (21.6%) patients after repeat partial nephrectomy, compared to 29.6% in the control group (n=8) (p=0.563). A comparative analysis revealed a significant advantage in overall survival in patients of the main group (p=0.042). There were no significant differences between groups in cancer-specific and disease-free survival (p=0.369 and p=0.537, respectively). CONCLUSION: Repeat partial nephrectomy for local recurrence of kidney cancer leads to an increase in overall survival compared to radical nephrectomy, in the absence of significant differences in cancer-specific and relapse-free survival.

[Clinical observation of a patient with bilateral tuberculous otitis media developing against the background of HIV infection]. / Klinicheskoe nablyudenie patsienta s dvustoronnim srednim tuberkuleznym otitom, razvivshimsya na fone VICh-infektsii.

The lesion of middle ear as a variant of clinical manifestation of secondary tuberculosis, according to international scientific literature, is a rare condition. However, in terms of real clinical practice, the proportion of this pathology should not be underestimated due to the wide spread of tuberculosis infection among the population of developing countries, including the Russian Federation. One of the risk factors for the systemic spread of mycobacterial flora is a concomitant HIV infection, which often acts as an opportunistic pathological agent for tuberculosis. The treatment of such a state is always challenging because of the high aggressiveness of bacteria and the low immunological resistance of the patient. This article presents a clinical case of bilateral tuberculosis otitis media, which was a manifestation of tuberculosis infection that developed on the background of HIV infection.

Simulating human sleep spindle MEG and EEG from ion channel and circuit level dynamics.

BACKGROUND: Although they form a unitary phenomenon, the relationship between extracranial M/EEG and transmembrane ion flows is understood only as a general principle rather than as a well-articulated and quantified causal chain. METHOD: We present an integrated multiscale model, consisting of a neural simulation of thalamus and cortex during stage N2 sleep and a biophysical model projecting cortical current densities to M/EEG fields. Sleep spindles were generated through the interactions of local and distant network connections and intrinsic currents within thalamocortical circuits. 32,652 cortical neurons were mapped onto the cortical surface reconstructed from subjects' MRI, interconnected based on geodesic distances, and scaled-up to current dipole densities based on laminar recordings in humans. MRIs were used to generate a quasi-static electromagnetic model enabling simulated cortical activity to be projected to the M/EEG sensors. RESULTS: The simulated M/EEG spindles were similar in amplitude and topography to empirical examples in the same subjects. Simulated spindles with more core-dominant activity were more MEG weighted. COMPARISON WITH EXISTING METHODS: Previous models lacked either spindle-generating thalamic neural dynamics or whole head biophysical modeling; the framework presented here is the first to simultaneously capture these disparate scales. CONCLUSIONS: This multiscale model provides a platform for the principled quantitative integration of existing information relevant to the generation of sleep spindles, and allows the implications of future findings to be explored. It provides a proof of principle for a methodological framework allowing large-scale integrative brain oscillations to be understood in terms of their underlying channels and synapses.

[The specific clinical features of otogenic intracranial complications: the current views].

The objective of the present study was to elucidate the specific clinical features of otogenic intracranial complications (ICC) encountered in the current otorhinolaryngological practice. The work is based on the results of the retrospective analysis of 106 adult patients presenting with otogenic intracranial complications admitted for the treatment to multidisciplinary clinics of Sankt-Peterburg and Krasnoyarsk. Forty six (42.5%) patients presented with acute otitis media. 90% of them had suppurative destructive mastoiditis. In sixty (56.6%) patients, chronic suppurative otitis media (epitympanophonia) was associated with the extensive destructive process spreading toward dura mater of the medial and posterior cranial fossae and onto the sigmoid sinus. The prevalence of intracranial complications among the adult patients suffering from suppurative otitis media and treated in the otorhinolaryngological clinics amounted to 3.17%. The overall structure of otogenic intracranial complications was as follows: meningitis 42.5%, brain and cerebellum abscess 24.5%, suppurative meningoencephalitis 19.8%, sinus thrombosis 5.7%, epidural and subdural empyemas 4.7%, the combined suppurative brain lesions 2.8%. Systemic inflammatory response syndrome (sepsis) was diagnosed in 33 (31%) patients with otogenic ICC. The high intrahospital mortality rate among the patients with this condition (20.8%) is emphasized. The main causes of the fatal outcome in the patients with otogenic intracranial complications are supposed to be brain oedema with the concomitant development of dyslocation syndrome and sepsis.

Heteroclinic contours in oscillatory ensembles.

In this work, we study the onset of sequential activity in ensembles of neuronlike oscillators with inhibitorylike coupling between them. The winnerless competition (WLC) principle is a dynamical concept underlying sequential activity generation. According to the WLC principle, stable heteroclinic sequences in the phase space of a network model represent sequential metastable dynamics. We show that stable heteroclinic sequences and stable heteroclinic channels, connecting saddle limit cycles, can appear in oscillatory models of neural activity. We find the key bifurcations which lead to the occurrence of sequential activity as well as heteroclinic sequences and channels.

Adaptive functional systems: learning with chaos.

We propose a new model of adaptive behavior that combines a winnerless competition principle and chaos to learn new functional systems. The model consists of a complex network of nonlinear dynamical elements producing sequences of goal-directed actions. Each element describes dynamics and activity of the functional system which is supposed to be a distributed set of interacting physiological elements such as nerve or muscle that cooperates to obtain certain goal at the level of the whole organism. During "normal" behavior, the dynamics of the system follows heteroclinic channels, but in the novel situation chaotic search is activated and a new channel leading to the target state is gradually created simulating the process of learning. The model was tested in single and multigoal environments and had demonstrated a good potential for generation of new adaptations.

Numerical studies of slow rhythms emergence in neural microcircuits: bifurcations and stability.

There is a growing body of evidence that slow brain rhythms are generated by simple inhibitory neural networks. Sequential switching of tonic spiking activity is a widespread phenomenon underlying such rhythms. A realistic generative model explaining such reproducible switching is a dynamical system that employs a closed stable heteroclinic channel (SHC) in its phase space. Despite strong evidence on the existence of SHC, the conditions on its emergence in a spiking network are unclear. In this paper, we analyze a minimal, reciprocally connected circuit of three spiking units and explore all possible dynamical regimes and transitions between them. We show that the SHC arises due to a Neimark-Sacker bifurcation of an unstable cycle.

Variety of synchronous regimes in neuronal ensembles.

We consider a Hodgkin-Huxley-type model of oscillatory activity in neurons of the snail Helix pomatia. This model has a distinctive feature: It demonstrates multistability in oscillatory and silent modes that is typical for the thalamocortical neurons. A single neuron cell can demonstrate a variety of oscillatory activity: Regular and chaotic spiking and bursting behavior. We study collective phenomena in small and large arrays of nonidentical cells coupled by models of electrical and chemical synapses. Two single elements coupled by electrical coupling show different types of synchronous behavior, in particular in-phase and antiphase synchronous regimes. In an ensemble of three inhibitory synaptically coupled elements, the phenomenon of sequential synchronous dynamics is observed. We study the synchronization phenomena in the chain of nonidentical neurons at different oscillatory behavior coupled with electrical and chemical synapses. Various regimes of phase synchronization are observed: (i) Synchronous regular and chaotic spiking; (ii) synchronous regular and chaotic bursting; and (iii) synchronous regular and chaotic bursting with different numbers of spikes inside the bursts. We detect and study the effect of collective synchronous burst generation due to the cluster formation and the oscillatory death.