Russian Medicine

BACKGROUND: Existing rodent models of polycystic ovary syndrome (PCOS) have several limitations: they do not match the hormonal profile of the human disease, do not fully reproduce metabolic disturbances, or are difficult to implement. This study describes a PCOS modeling methodology suitable for preclinical research.

AIM: To validate an experimental model of polycystic ovary syndrome in rats with the assessment of hormonal and histological parameters.

METHODS: The animals were divided into three groups: intact (n = 22, saline), PCOS model (n = 30), and PCOS + therapy model (n = 10, pathology induction + combined oral contraceptives [COCs]). PCOS modeling was carried out for 10 days via intramuscular injections of human chorionic gonadotropin (300 U/animal) and increasing doses of isophane insulin (from 1.5 to 3.5 U/animal). The PCOS + therapy group received COCs (drospirenone + ethinyl estradiol) orally for 14 days. Body weight dynamics and glucose levels were measured as indicators of metabolic disorders. Hormone levels, including anti-Müllerian hormone (AMH), follicle-stimulating hormone (FSH), estradiol, and sex hormone-binding globulin (SHBG) were measured by ELISA. Morphological analysis was also performed.

RESULTS: In modeling the pathology, PCOS model group showed a significant increase in body weight (295.2 ± 20.2 g) compared with the intact group (267.3 ± 22.4 g; p < 0.05) and the PCOS + therapy group (273.9 ± 18.5 g; p < 0.05). In the PCOS model group, levels of free testosterone, AMH, and estradiol increased, while SHBG decreased compared with the intact group (p < 0.05). The LH/FSH ratio on day 12 was significantly higher in the PCOS + therapy group (16.6 ± 7.6) than the intact group (6.9 ± 4.8; p < 0.05). Histological examination confirmed an increase in the number of cysts, atretic follicles, and corpora lutea in the ovaries of animals with induced PCOS. COCs therapy significantly reduced ovarian mass coefficients and glucose levels compared with the PCOS model group.

CONCLUSION: The presented PCOS model, based on the combined administration of hCG and insulin in Wistar rats, successfully reproduces the key features of the disease: an increased LH/FSH ratio, hyperandrogenemia, elevated AMH and estradiol, decreased SHBG, polycystic ovarian morphology with multiple functional and retention cysts, and metabolic disorders such as weight gain. Furthermore, the model demonstrates sensitivity to standard COCs therapy.

BACKGROUND: Rehabilitation of patients with severe maxillary atrophy can be performed using conventional implants (CI), zygomatic implants (ZI), and pterygomaxillary (pterygoid) implants (PI); these strategies differ in biomechanics and complication profiles.

AIM: To compare the frequency and nature of surgical, biological, and prosthetic complications associated with ZI, PI, and CI, and to summarize data on survival and success, and marginal bone loss.

METHODS: A PRISMA 2020–compliant systematic review was conducted. Searches were performed in MEDLINE and the Russian Science Citation Index up to November 1, 2025. Inclusion criteria were adults undergoing implant placement in the maxilla; outcomes included implant or prosthesis survival, complications, and bone loss. The study designs included randomized controlled trials, prospective and retrospective cohort studies, and case series. Risk of bias was assessed using RoB 2.0, Newcastle–Ottawa Scale, and the National Institutes of Health tool. Due to substantial heterogeneity, a narrative synthesis was performed.

RESULTS: Nineteen studies were included. For CI, 5-year survival in randomized controlled trials ranged from 99% to 100% (4 vs 6 supports; no differences in bone loss), whereas at 10–20 years, survival decreased to 93% and 87%, respectively; short and ultrashort implants were not inferior to sinus augmentation protocols regarding survival and were less invasive. Technical complications were more frequent with four supports, particularly in patients with bruxism. For ZI, mid- and long-term survival ranged from 94% to 98%; the complication profile was shifted toward sinus-related and soft-tissue events, and chronic sinusitis occurred less often with extra- and extramaxillary trajectories than with an intrasinus approach. For PI, 1-year survival and success ranged from 88% to 98% depending on the criteria used; key risks included nerve injury, rare implant fractures, and prosthetic failures; first-year marginal bone loss served as an indicator of an unfavorable course; better stability was observed in D2 bone and with bicortical fixation.

CONCLUSION: ZI, PI, and CI are complementary strategies with different complication profiles; method selection should consider anatomy, anticipated loading, and adherence to supportive care. Heterogeneity in outcome definitions and units of analysis limits meta-analysis; future studies require standardized criteria for success, peri-implantitis, mucositis, and reporting at the implant, patient, and prosthesis levels.

Due to advances in modern neonatology in the care of extremely premature infants in economically developed countries, including Russia, retinopathy of prematurity (ROP) and its consequences continue to represent a significant proportion of ophthalmic pathologies of early childhood. Thus, as the number of extremely immature premature infants increases, so does the number of severe, rapidly progressing forms of ROP localized to the central fundus (zone I ROP and aggressive posterior ROP) that are resistant to laser coagulation. In recent decades, intravitreal injection of anti-VEGF agents (VEGF, vascular endothelial growth factor) has been a primary treatment modality for ROP.

The purpose of this review is to systematically review studies on ROP reactivation. Risk factors for ROP reactivation, its frequency, and its dependence on the choice of treatment strategy are discussed. The effectiveness of all commonly used anti-VEGF agents worldwide is analyzed comparatively in relation to the development of signs of ROP reactivation, including dosage- and duration-dependent effects.

An important part of this review discusses the time course of ROP reactivation, since clear criteria for differentiating this timing have not yet been established. We also address long-term retinal changes in the cicatricial phase of the disease, which are clinically similar to those seen in active retinopathy and involve tractional-exudative changes at the borders of persistent avascular zones, as well as approaches to treatment, including preventive measures.

The review demonstrates an association between an increased frequency of ROP reactivation following anti-VEGF therapy, underscoring the need to develop new approaches to long-term follow-up of these patients. The prolongation of possible reactivation periods due to repeated anti-VEGF injections to achieve ROP regression should proportionally extend the duration of follow-up for these patients, especially when avascular zones persist in the retina.

INTRODUCTION: Over the last two decades, the number of recorded cases of drug-induced liver injury (DILI) has increased 30-fold, which is directly related to the expansion of the drug arsenal on the pharmaceutical market. According to statistics, DILI is diagnosed in 3% of patients in Russia, whereas abroad this rate is 10–20 cases per 100,000 population. Furthermore, about 40,000 deaths due to DILI are recorded annually worldwide.

The medical scientific community has described numerous common “culprits” of hepatotoxicity. We would like to highlight a clinical case of DILI in a 67-year-old man associated with etoricoxib use. Cyclooxygenase-2-selective non-steroidal anti-inflammatory drugs (NSAIDs) rarely affect the liver, making this case non-standard and, therefore, difficult to predict. However, the consequences of NSAID-induced liver damage are often serious: fulminant hepatic failure and hepatorenal syndrome. In this regard, only a physician’s vigilant attention to the drugs taken by the patient, as well as the ability to recognize drug-induced conditions using diagnostic tests as early as possible, can stop a prolonged, asymptomatic, life-threatening toxic process.

CASE DESCRIPTION: This article describes a clinical case of DILI in a 67-year-old man associated with etoricoxib use. On the morning of the second day of planned hospitalization for blood pressure adjustment, the patient began to complain of weakness and epigastric pain. A detailed physical examination revealed icteric sclera. The therapeutic approach included laboratory tests, differential diagnosis, and therapeutic measures. After the diagnosis of DILI was established, the causative drug was discontinued and adequate therapy was administered, leading to an improvement in laboratory parameters and the patient’s condition.

CONCLUSION: Drug-induced liver injury remains a pressing clinical and diagnostic problem in modern medicine. Even drugs that are considered safe and widely used in clinical practice can cause liver damage under certain conditions. Individual drug interaction profiles and treatment duration can increase the risk of hepatotoxicity. Therefore, no drug can be considered completely harmless to the liver, highlighting the need for rational prescribing, liver function monitoring, and careful attention to possible adverse effects of medications.

After publishing preprint of the the manuscript “Amirova EA, Danevich DI, Kukarkhoeva MB, et al. Hydrogel systems and organoid models in regenerative dentistry: A Review. Russian Medicine. 2026;32(3):e298–e314. DOI: 10.17816/medjrf701368 EDN: GCNZVJ”, the editors discovered that 83% of the text contained evidence of artificial intelligence generation. The editorial board conducted an editorial investigation, which concluded that the reported level of generation was unacceptable for a scientific journal and decided to retract the preprint.

A retraction notice for this article is published at https://doi.org/10.17816/medjrf714011

Regenerative dentistry is an actively developing field aimed at restoring the structure and function of dental and periodontal tissues through biologically based approaches. Among the most promising strategies, hydrogel-based systems and organoid models have attracted increasing attention due to their ability to recreate key features of the native extracellular microenvironment and support controlled cellular behavior. This review summarizes current advances in the design and application of hydrogel systems and organoid technologies in dental tissue engineering, with an emphasis on their biological rationale, functional properties, and translational potential. Hydrogels represent versatile biomaterials capable of mimicking the physical and biochemical characteristics of the extracellular matrix, thereby providing a supportive scaffold for cell survival, proliferation, and lineage-specific differentiation. Recent developments in functional, stimuli-responsive, and composite hydrogels have expanded their applicability in the regeneration of dental pulp, dentin, periodontal tissues, and alveolar bone. In parallel, organoid models derived from dental and oral stem cell populations offer three-dimensional systems that recapitulate key aspects of tissue morphogenesis, enabling advanced studies of development, disease modeling, and drug screening. The integration of hydrogel platforms with organoid technologies has opened new opportunities for creating physiologically relevant and customizable regenerative constructs. Despite significant progress, challenges related to mechanical stability, vascularization, standardization, and clinical translation remain. Addressing these limitations through interdisciplinary research and technological refinement is essential for advancing regenerative strategies toward predictable and long-term clinical outcomes. Overall, hydrogel-based systems and organoid models represent complementary and powerful tools that may significantly reshape future approaches in regenerative dentistry.