Preparation of a Single-Cell Suspension from Tumor Biopsy Samples for Single-Cell RNA Sequencing

An essential requirement for single-cell RNA sequencing in cancer is the preparation of high-quality single-cell suspensions from the tumor tissue. In this work, various methods of dissociation of tumor biopsy specimens were analyzed and developed to obtain a cell suspension with at least 80% viability. It was found that the optimal conditions for sample preparation are mechanical dissociation followed by incubation with a collagenase/hyaluronidase mixture with addition of DNAase I for 60 min. Thus, we optimize the approach for preparing single-cell suspensions from the tumor biopsy tissue for single-cell RNA sequencing.

[The effect of internal course intake of selenium-modified mineral water on bone mineral density after long-term diet-induced metabolic disorders in the experiment. (Randomized controlled trial)]

INTRODUCTION

The phenomenon of therapeutic and prophylactic effect of natural mineral waters (MW) used to restore tissue tolerance to glucose and normalize basal insulin secretion in metabolic syndrome is well known. At the same time, the use of selenium-enriched MW is promising due to its multitarget action including participation in the regulation of the protein-synthesizing function of cells.

AIM

To study the effect of internal course intake of selenium-modified mineral waters of different composition on bone mineral density after long-term diet-induced metabolic disorders in the experiment.

MATERIAL AND METHODS

The study was carried out on outbred male white rats that were distributed into 3 control groups (CG) and 4 main groups (MG). In CG1 14 animals received laboratory food and drinking water; in CG2 14 animals were modeled for diet-induced metabolic disorders, and they were withdrawn from the experiment the day after the cancellation of the hypercaloric diet (180 days); after the cancellation of the hypercaloric diet 180 days later 14 animals with diet-induced metabolic disorders in CG3 had a standard diet (laboratory food and drinking water) for 30 days. In the experimental groups (EG), the animals similarly to CG3 were modeled diet-induced metabolic disorders, after the cancellation of the diet they had a standard diet and watering with MW. In MG1 18 animals were given MW1 (Essentuki-4); in MG2 19 animals had a course of MW1Se (Essentuki-4 enriched with selenium); in MG3 14 animals had a course of MW2 (Slavyanovskaya); in MG4 18 animals had a course of MB2Se (Slavyanovskaya enriched with selenium). The weight (body weight) of the animals was monitored monthly. Biochemical studies, densitometry and computed microtomography were used to determine the effectiveness of MW.

RESULTS

The characteristics of spongy bone tissue of femoral metaphysis of the rats of the control groups revealed disorders of varying degrees, but, despite this, the bone tissue structure of the examined vertebral bodies in animals without a hyper caloric diet (CG1) was preserved. The analysis of the study results demonstrated a significant effectiveness of selenium-enriched MW in regulating metabolic processes (p<0.05-p<0.01), bone mineral density (p<0.05), reduced bone resorption (p<0.05), that is, the characteristics of spongy bone tissue of femoral metaphysis and vertebral bodies of animals showed a clear tendency to restore bone structure.

CONCLUSION

The results of this study make it possible to predict an increase in the effectiveness of medical rehabilitation of patients with somatic diseases when selenium-enriched MW is included in the programmes.

[Therapeutic physical factors in chronic inflammatory diseases of the pelvic organs. (A wounded home-controlled study)]

INTRODUCTION

In case of chronic inflammatory diseases of the pelvic organs (CID) in women, it is advisable to use therapeutic physical factors that have a sanogenetic effect in rehabilitation treatment programs.

AIM

To study the effectiveness of complex restorative treatment of patients with chronic salpingoophoritis with the consistent use of therapeutic physical factors.

MATERIAL AND METHODS

The study included 96 patients with chronic salpingoophoritis at the age of 18 to 49 years. Two groups were formed by a simple sampling method: in the main group (MG/n=44), against the background of standardized treatment in inpatient conditions, patients received intravaginal ultrasound therapy, in non-hospital settings - interference therapy; in the control group (CG/n=41) - women received only standardized therapy. The criteria for the effectiveness of treatment were: determination of markers of pain and inflammation; ultrasound examination of the ovarian arteries with their Doppler measurements; assessment of quality of life criteria.

RESULTS

Comprehensive restorative treatment of patients with chronic salpingoophoritis with sequential use of curative physical factors (CPF), according to direct and long-term observations, provides a significant reduction in pain intensity (p<0.01), inflammation (p<0.01), peripheral blood flow (p<0.01), physical and mental health (p<0.01).

CONCLUSION

The implementation of a new developed method of restorative treatment of patients with chronic salpingoophoritis with sequential use of CPF provided a significant increase of 10-12% in the effectiveness of therapeutic measures in comparison with standardized therapy (p<0.05-<0.01).

[High-tone therapy in complex rehabilitation of patients with post-sternotomy syndrome after coronary artery bypass surgery. (Open-label, prospective, randomized controlled trial)]

INTRODUCTION

At present it remains relevant to develop new rehabilitation technologies for patients with circulatory system diseases who have undergone a cardiac surgery to restore the functions of the cardiorespiratory system more quickly, improve physical and mental health, and prevent the development of the atherosclerotic process.

AIM

To study the effectiveness and safety of the new rehabilitation technology for the inpatient stage of medical rehabilitation of patients with post-sternotomy syndrome after coronary artery bypass surgery (CABS) using high-tone therapy.

MATERIAL AND METHODS

The study included 85 men (the average age was 56.8±2.46 years old) with post-sternotomy syndrome after CABS. They were divided into two groups by simple randomization: the first/main (42 patients) and the second/control (43 patients). The control group of the patients had a standard rehabilitation complex; the main group was additionally prescribed a high-tone therapy according to a local method. The immediate results of the treatment were assessed by the dynamics of the clinical picture, the six-minute walk test, respiratory function, echocardiography, the level of cytokines, C-reactive protein and natriuretic peptide (NT-proBNP); distant - by QOL endpoints (questionnaire MOS SF-36).

RESULTS

The groups of the patients were comparable in all baseline parameters. After the course of the procedures in the main group of patients there were positive reliable (p<0.05-0.001) shifts in clinical (pain, shortness of breath, general weakness), functional (forced expiratory vital capacity, forced expiratory volume1, effusion separation) and laboratory parameters (leukocytes, interleukin-2 and 10, NT-proBNP). The intergroup analysis of long-term results registered significant (p<0.05) differences in the QOL of patients in the main group by subscales: the role of somatic problems, vitality and mental health. Compliance to the III stage of medical rehabilitation (outpatient/home) was noted with 95.2% of the patients in the first group and 93.0% in the second.

CONCLUSION

The additional appointment of a high-tone therapy to the rehabilitation standard for the patients with post-sternotomy syndrome after CABS significantly improves the immediate and long-term results of the treatment (QOL) contributing to a more pronounced reverse development of inflammatory and edematous syndromes, an increase in physical activity and psychosomatic health. The absence of adverse reactions with all the patients indicates the safety of rehabilitation complexes.

Luminescent Carbon Dots from Wet Olive Pomace: Structural Insights, Photophysical Properties and Cytotoxicity

Carbon nanomaterials endowed with significant luminescence have been synthesized for the first time from an abundant, highly localized waste, the wet pomace (WP), a semi-solid by-product of industrial olive oil production. Synthetic efforts were undertaken to outshine the photoluminescence (PL) of carbon nanoparticles through a systematic search of the best reaction conditions to convert the waste biomass, mainly consisting in holocellulose, lignin and proteins, into carbon dots (CDs) by hydrothermal carbonization processes. Blue-emitting CDs with high fluorescence quantum yields were obtained. Using a comprehensive set of spectroscopic tools (FTIR, Raman, XPS, and ¹H/¹³C NMR) in combination with steady-state and time-resolved fluorescence spectroscopy, a rational depiction of WP-CDs structures and their PL properties was reached. WP-CDs show the up-conversion of PL capabilities and negligible cytotoxicity against two mammalian cell lines (L929 and HeLa). Both properties are excellent indicators for their prospective application in biological imaging, biosensing, and dynamic therapies driven by light.

[Nonspecific inflammatory reaction after implantation of palpebral implants]

PURPOSE

To identify the possible cause of an inflammatory reaction to a Russian-manufactured palpebral implant made of gold in the long term after surgery, and to determine the clinical and morphological changes in the tissues of the upper eyelid when the presence of the implant caused the inflammatory reaction.

MATERIAL AND METHODS

The results of 150 operations with placement of a palpebral implant were analyzed. In 12 cases, a nonspecific inflammatory reaction was revealed within 2 to 4 weeks after the operation, in 7 cases it necessitated explantation, in 5 cases the local long-term use of an ointment with a corticosteroid made it possible to avoid extrusion and explantation. Chemical microanalysis of the palpebral implant and fragments of the removed capsule was performed using scanning electron microscopy (SEM), as well as immunohistochemical (IHC), macro- and microscopic examination of the fragments of connective tissue capsule was carried out after removal of the palpebral implant.

RESULTS

The obtained data confirm the chemical purity of the implant, the absence of abnormal accumulation of metals in the tissues of the eyelid. IHC, macro- and microscopic examination of the presented fragments of the connective tissue capsule revealed signs characteristic of an inflammatory reaction to a foreign body.

CONCLUSION

Further research is needed to establish the factors and predictors for the development of inflammatory reactions to a foreign body and, in particular, to gold.

[Evaluation of resistance to transient occlusion of anterior mesenteric artery under the influence of the course of mineral water enriched with selenium (experimental research)]

OBJECTIVE

To evaluate the effect of the preventive course of drinking mineral water enriched with selenium on the processes of resistance to the damaging action of reversible occlusion of the anterior mesenteric artery based on the comparison of intestinal morphological changes in the experiment.

MATERIAL AND METHODS

There has been modeled ischemic reperfusion injury of the intestinal wall according to H. Ikeda and co-authors using reversible occlusion of the anterior mesenteric artery with 33 outbred male rats. The rats were divided into four groups by block randomization: the 1^st group - intact animals (n=7) - without an exposure; the control group - sham operated animals (n=6); the group of comparison (n=7) - with a model-operation; the experimental group (n=11) - animals with a model operation that had courses of intragastric watering of bottled sulfate-chloride-hydrocarbonate-sodium low-mineralized (2.2 g/l) drinking mineral water «Psyzh» enriched with selenium. Biopsies of the small intestine were taken for histological examination.

RESULTS

Histological examination of the small intestine of experimental animals determines various degrees of severity of damage: on average, the animals of the experimental group on the scale of C.J. Chiu (1970) had the lowest degree of severity of pathological changes, the animals of the group of comparison - 1.4 times higher (p=0.02). That is, the effect of a preventive course of mineral water «Psyzh» enriched with selenium was manifested in the formation of resistance to the damaging effect of reversible occlusion of the anterior mesenteric artery; in the presence of ischemic reperfusion damage to the intestinal wall, comparable in severity to changes with the animals without prevention, the most significant positive effect was realized in the containment of reactive changes.

CONCLUSION

The effect of the preventive course of drinking mineral water «Psyzh» enriched with selenium manifested itself in the formation of resistance to the damaging effect of reversible occlusion of the anterior mesenteric artery, which is the basis for introducing this technique into clinical practice in order to prevent the development of reperfusion injuries of the intestine.

[Questionnaire of the Ryzhikh National Medical Research Centre for Coloproctology is a new tool for assessing chronic pelvic pain and pelvic organ dysfunction]

The article presents the work of a multidisciplinary team of experts from various fields of medicine to optimize the «Questionnaire for assessing chronic pelvic pain and pelvic organ dysfunction (QCPPD) of the Ryzhikh National Medical Research Centre for Coloproctology» for use in clinical practice. The survey of respondents was conducted from June 28 to September 28, 2021. As a result of this survey, by repeatedly making edits and clarifications during communication with respondents, the final version was obtained, which allows assessing the patient's subjective sensations by the nature and localization of pelvic pain, sensitivity disorders and pelvic organ function. The main objective of this Questionnaire is to differentiate patients with neurogenic pain from a huge number of patients with chronic pelvic pain. This aspect will allow a more targeted approach to the diagnosis and pathogenetically justified treatment of patients, including after appropriate instrumental examinations. The work of a multidisciplinary team implies a higher degree of objectification and terminological accuracy of the Questionnaire under discussion. The presented version of the «Questionnaire for assessing chronic pelvic pain and pelvic organ dysfunction (QCPPD) of the Ryzhikh National Medical Research Centre for Coloproctology» will be primarily used in coloproctological patients with pelvic pain problems and anal incontinence and obstructive defecation. Further studies will be directed to the clinical evaluation of the results of the work carried out.

[Granulomatous inflammation of the orbit as a complication of stem cells injection (case study)]

The article present a case report of orbital granulomatous inflammation after a retrobulbar injection of allogenous stem cells. Experimental treatment resulted in an orbital tumor that required surgical excision. Lymphogranulomatous inflammation with a secondary abscess was verified by morphological and immunohistochemical analyses. This case demonstrates the possible dangerous complications of the "off-label" therapy amid the rising popularity of stem cells treatment.

[Experimental investigation of the efficacy of pirfenidone in prevention of ostium cicatricial closure after dacryocystorhinostomy]

One of the main reasons of failure of dacryocystorhinostomy (DCR) is cicatricial closure of the ostium. Finding a way to prevent this outcome remains one of the leading aims of research in dacryology. The effectiveness of the most widespread methods is often considered contradictory by various researchers. Pirfenidone is a small-molecule agent that demonstrated good antifibrotic effect and low toxicity in previous in vitro research. There haven't been any in vivo studies of its intraoperative use in DCR.

Purpose - to determine the in vivo efficacy of pirfenidone in prevention of ostium cicatricial closure following dacryocystorhinostomy in an animal experiment.

MATERIAL AND METHODS

The study was conducted on 18 Chinchilla rabbits. They were divided into 3 groups and each animal underwent modified dacryocystorhinostomy. On the final stage of surgery rabbits of group 1 were injected 1 ml of 0.15 mg/ml pirfenidone solution, rabbits of group 2 - 0.3 mg/ml pirfenidone solution. No injections were performed in group 3. Animals were terminated on days 7 (6 rabbits), 14 (6 rabbits) and 28 (6 rabbits) following surgery. Lacrimal stoma patency was evaluated in vivo by irrigation, and morphologically postmortem. Tissue samples obtained from the stoma area were examined histologically for signs of fibrosis.

RESULTS

Failure of dacryocystorhinostomy was observed in 4 out of 18 cases: all rabbits of group 3 terminated on days 14 and 28. The most pronounced morphological signs of fibrosis were also noted in group 3. No topical or systemic adverse effects of the medication were observed in groups 1 and 2.

CONCLUSION

Pirfenidone demonstrated high antifibrotic efficacy and low toxicity in experimental dacrycystorhinostomy in rabbits. These results provide grounds for further research into the use of pirfenidone in dacrycystorhinostomy.

[Scanning electron microscopy results of the vitreous body in asteroid hyalosis]

PURPOSE

To evaluate the structure of vitreous body in asteroid hyalosis by low vacuum scanning electron microscopy.

MATERIAL AND METHODS

The material of the study was samples of the vitreous body obtained from 7 patients aged from 62 to 72 years with vitreomacular traction syndrome during vitrectomy. In all cases, clinical manifestations of asteroid hyalosis (the presence of multiple point-like echo-positive inclusions) were identified during the preoperative examination. Samples for scanning electron microscopy and chemical microanalysis were prepared without using fixation elements, total dehydration, staining or centrifugation, and according to the so-called principle of bougienage, which consists in partial separation of fractions of the gel-like tissue with a stream of saline.

RESULTS

The conducted examinations made it possible to identify various types of local accumulations of mineral elements in the vitreous body in asteroid hyalosis - called asteroid bodies - that is, multiple complex rounded formations consisting of needle-shaped crystals of a radial fibrous structure.

CONCLUSION

The developed algorithm, which includes intraoperative sampling of the vitreous body in conditions of its minimal hydration and a special technique for preparing samples for scanning electron microscopy and chemical microanalysis, provides the capability for the in vivo assessment of morphological changes in hyaloid elements of the vitreous body. With that, asteroid bodies can be considered as markers of the vitreous structures that are difficult to visualize.

Monitoring the Cortical Activity of Children and Adults during Cognitive Task Completion

In this paper, we used an EEG system to monitor and analyze the cortical activity of children and adults at a sensor level during cognitive tasks in the form of a Schulte table. This complex cognitive task simultaneously involves several cognitive processes and systems: visual search, working memory, and mental arithmetic. We revealed that adults found numbers on average two times faster than children in the beginning. However, this difference diminished at the end of table completion to 1.8 times. In children, the EEG analysis revealed high parietal alpha-band power at the end of the task. This indicates the shift from procedural strategy to less demanding fact-retrieval. In adults, the frontal beta-band power increased at the end of the task. It reflects enhanced reliance on the top-down mechanisms, cognitive control, or attentional modulation rather than a change in arithmetic strategy. Finally, the alpha-band power of adults exceeded one of the children in the left hemisphere, providing potential evidence for the fact-retrieval strategy. Since the completion of the Schulte table involves a whole set of elementary cognitive functions, the obtained results were essential for developing passive brain-computer interfaces for monitoring and adjusting a human state in the process of learning and solving cognitive tasks of various types.

[Experimental investigation of the safety of terahertz radiation in corneal hydration assessment]

Application of terahertz (THz) radiation in novel non-invasive biomedical technologies has recently received considerable attention. However, experimental data about the safety of exposure to THz radiation for biological objects (including eye structures in vivo) are limited. To our knowledge, the safety of THz reflectometry (frequency range of 0.30-0.40 THz) has not been closely examined in an animal model with subsequent morphological assessment of corneal tissues.

PURPOSE

To assess the safety of pulsed THz radiation with various parameters (time, power, and frequency) for the cornea in a rabbit model.

MATERIAL AND METHODS

The sample for the current study consisted of 18 Chinchilla rabbits (18 eyes). Corneal imaging and epithelial cell density before and after the exposure were evaluated using confocal laser scanning microscopy (CLSM). The histological study for objective assessment of the cornea state (day 1 and day 14) was performed after experiment termination.

RESULTS

Single and multiple exposures of laser radiation at a frequency below 0.1 THz and power density below 30 nW/cm² do not cause visible structural changes in any layers of the rabbit cornea. The results obtained in the long-term period showed insignificant reversible morphological changes only within the epithelium.

CONCLUSION

The described parameters of terahertz and subterahertz radiation can be considered safe for assessing changes in corneal epithelium hydration level using non-invasive methods based on THz reflectometry.

[Uterine adenosarcoma. Report of 5 cases and review of literature]

Uterine adenosarcoma is an uncommon biphasic tumor with benign epithelial and malignant mesenchymal components, often presenting difficulties for morphological diagnosis. We describe 5 cases of adenosarcoma of the uterine corpus and cervix, and vaginal stump in patients aged 46-76 years. Clinical data, ultrasound results, morphological data, including immunohistochemical studies with antibodies to CD10, estrogen and progesterone receptors, desmin, smooth muscle actin, and Ki-67 are presented. Large polypoid mass of the epithelial-mesenchymal structure within the uterine cavity in women of peri - and postmenopausal age require the exclusion of malignancy of the mesenchymal component with searchig for diagnostic criteria - periglandular cuffing of the stromal cells and mitoses.

[Biointegration properties of eyelid weight implants made of various materials (experimental study)]

Palpebral eyelid weight implants are currently considered as the gold standard method for lagophthalmos correction. Manufactured from different precious metals, they have both benefits and drawbacks. The article presents the results of an experimental morphological study of biointegration of different eyelid weight implants used for correction of paralytic lagophthalmos.

PURPOSE

To investigate biointegration properties of implants made of gold, platinum and platinum-gold alloy.

MATERIAL AND METHODS

The study enrolled 4 Chinchilla rabbits (8 eyelids). Palpebral implants manufactured of gold, platinum and platinum-gold alloy were placed into the eyelids of the experimental animals. The morphological examination was performed 1 and 6 months after the implantation using paraffin sections.

RESULTS

Light microscopy revealed that the implant beds were surrounded by pronounced fibrovascular capsule of uneven thickness over the whole follow-up. The capsule formed after the placement of an implant made of gold and platinum alloy was more loose. However, the emerging connective tissue bridges of the capsule contributed to its immobilization in the tissues and lower risk of extrusion. No signs of an inflammatory and/or allergic reaction were observed in any of the cases.

CONCLUSION

The obtained results show that implants made of a 90/10% platinum-gold alloy and 999.9 fine platinum have similar biointegration in terms of morphological features during 6 months of the follow-up period.

[Histological verification of autofluorescence borders of periorbital skin tumors]

Tumor borders are one of the most significant characteristics of any tumor, including that of the skin.

PURPOSE

To compare histological borders of periorbital skin tumors with their autofluorescence borders built from the analysis of non-induced protoporphyrin IX autofluorescence.

MATERIAL AND METHODS

The study group included 8 patients with skin tumors of the eyelids, periorbital region, eyebrow and zygomatic regions aged 54-88 years. The tumors varied in size from 2 to 8 mm and all displayed signs of basal cell carcinoma (BCC). At admission, all the patients underwent non-induced autofluorescence diagnosis. The images were processed with the «CancerPlot» program. During radio excision, the autofluorescent border of each neoplasm was marked with a surgical incision of about 5 mm long and 2 mm deep.

RESULTS

Upon pathomorphological examination, solid BCC was identified in 7 cases. The remaining case was senile keratosis. All reference incisions were located in healthy tissues not farther than 1 mm from the tumor (or keratosis locus, correspondingly).

CONCLUSION

By the example of facial BCC, an evident correlation was established between histological borders of the tumor and its native (non-induced) protoporphyrin IX autofluorescence.

The Relationships Between Cortical Activity while Observing Images Featuring Different Degrees of Ambiguity and Ambiguity Tolerance

We performed a fMRI study during which 18 healthy subjects passively viewed abstract images and tried to name them. The images were geometric primitives, impossible images (Penrose images), and ambiguous images (Rorschach inkblots). Activation and deactivation areas were revealed for each task. The results of psychological assessment of ambiguity tolerance according to MSTAT-I inventory were used as regressors. Deactivation of the precuneus (Brodmann area 7) and neighboring structures (especially when observing geometric primitives and inventing names for them) and in the fronto-temporal areas was associated with high ambiguity tolerance. Similar links were observed for both activation and deactivation (depending on the certain contrast) of the occipito-cerebellar area.

[Clinical results of modified crosslinking in the treatment of purulent keratitis and corneal ulcers]

PURPOSE

To evaluate the efficiency of modified crosslinking (M-CXL) in the treatment of purulent keratitis (PK) and corneal ulcers, including ulcers of mixed etiology.

MATERIAL AND METHODS

M-CXL method involves simultaneous performance of CXL and frequent instillations of anti-infective agents (one drop every 5 minutes for 1 hour). The study included 39 patients (41 eyes) with purulent corneal ulcers (PCU) of various origin. The main group consisted of 26 patients (27 eyes) who were treated with M-CXL in combination with active conservative therapy. In the control group (13 patients, 14 eyes) only active conservative management was used.

RESULTS

Complete suppression of the purulent process in the main group was achieved in 21 (77.8%) eyes after 32.6±10.66 days, in the control group - in 9 (64.3%) eyes in 52.4±16.6 days. Complete suppression of purulent keratitis was achieved in 100% of cases with bacterial keratitis, 83% of cases with fungal keratitis and 70.5% of cases with mixed keratitis. When purulent infiltration occupied the entire depth of the stroma but was limited in area (less than 6 mm), the efficiency of M-CXL decreased to 66.6%. The clinical effect of M-CXL was absent or insufficient when PK extended to the Descemet's membrane with an area of more than 7 mm.

CONCLUSION

In 77.8% of cases, modified crosslinking has showed pronounced therapeutic effect - complete arrest of purulent corneal infiltration. Recovery time in the main group was 1.6 times shorter than in the control group (p<0.05). Resorption of the purulent infiltration occupying all layers of the stroma up to the Descemet's membrane with extensive areas was not achieved, however the corneal melting and keratitis progression were stopped, which allowed planned therapeutic penetrating keratoplasty with a graft of smaller diameter to be performed.

[The scientific rationale for the use of electroneurostimulation of the cervical sympathetic ganglia in patients with computer vision syndrome]

A frequent reason for visiting an ophthalmologist for patients of working age is computer vision syndrome (CVS): statistics show that up to 90% of users of personal electronic computers (PCs) suffer from this disease. Therefore, the actual task of modern rehabilitation medicine and ophthalmology is the search for an effective and safe way to prevent and treat the CVS among employees of enterprises.

THE PURPOSE OF THIS STUDY

Was a scientific justification, an assessment of the effectiveness and safety of the use of electroneurostimulation (ENS) of the cervical sympathetic ganglia in patients with CVS.

MATERIAL AND METHODS

120 patients with the syndrome observed on an outpatient basis were examined. Patients were divided into 3 groups using simple randomization method. The 1st group (the main group - MG) included 39 patients who, against the background of gymnastics of the oculomotor muscles and muscles of the shoulder girdle, used ENS on the area of the sympathetic ganglia; in the 2nd group (group of comparison - GoC) included 41 patients who strictly performed the same muscle gymnastics (after every 2 hours of work with the PC); Group 3 (control group - CG) consisted of 40 patients who took an ENS course of exposure in placebo mode. In the dynamics, the stock of relative accommodation, near heterophory, tear production, threshold electrical sensitivity of the retina, electrolability of the optic nerve, contrast sensitivity, reading speed, print speed and accuracy and the level of subjective asthenopia were evaluated.

RESULTS

Initially, groups of patients with CVS did not differ among themselves in any of the investigated parameters. After a course of procedures in the MG, in contrast to the other two (GoC and CG), statistically significant positive shifts were revealed in relation to the selected endpoints, reflecting the severity of asthenopia, sensorineural, accommodative and oculomotor functions of the visual analyzer, as well as ophthalmoergonomics. Of the side effects of the procedures were recorded: moderate drowsiness (in 4 patients), a feeling of heaviness of the head (in 1 patient) and an increase in blood pressure (BP) by more than 15% of the initial (in 1 patient). They disappeared on their own and did not require withdrawal of treatment. A patient who noted a single increase in blood pressure subsequently received therapy every other day. Redness of the skin of the neck in the area of application of the electrodes was found with the same frequency in MG and CG.

CONCLUSION

The inclusion of ENS in the rehabilitation treatment of workers professionally using a personal computer significantly increases the effectiveness of therapeutic measures, which proves the appropriateness of applying the proposed technology in CVS. The therapeutic action of complex therapy is realized through the effect of the ENS on an important reflexogenic zone - the cervical sympathetic ganglia, the activation of which ensures the normalization of the central, peripheral and autonomic functioning of the visual analyzer. Analysis of the frequency of registration of side effects in patients of the three groups allows us to conclude that the technique is safe.

[Experimental study of hyaluronic acid gel fillers biodegradation in orbit]

INTRODUCTION

Recently, hyaluronic acid gel (HAG) fillers were proposed as an effective alternative treatment option for surgical orbital volume augmentation. Several authors reported about long-standing effect of the filler.

PURPOSE

To assess the features of HAG biodegradation after intraorbital injection in experimental environment.

MATERIAL AND METHODS

In the course of the experiment, 7 chinchilla rabbits (14 eyes) received a single 1ml intraorbital HAG injection (Restylane SubQ, Galderma, Sweden) using a cannula. The animals' orbits were examined by ultrasound scan after the injection and at 1, 3, 6, 9, 12 and 18 months. The animals were subsequently sacrificed for morphological study of orbital tissue containing the HAG filler.

RESULTS

The HAG filler persisted in the orbit of experimental animals during the whole follow-up period. The volume of HAG depot and its density diminished gradually till the 18th month, after which the particles of HAG could still be detected with the morphological study and ultrasound.

CONCLUSION

The HAG filler persisted in the orbit of experimental animals up to 18 months. Incomplete biodegradation explains the longstanding duration of the injection effect.

[Inflammatory granuloma after intracanalicular punctal plug migration (a clinical case)]

At present, installation of punctal plugs (tear duct occluders) draws attention of ophthalmologists, but this method of treating dry eye syndrome (DES) is not without complications. Considering the rise of DES occurrence - the tendency anticipated to continue - as well as expansion of indications for installation of tear duct occluders, their usage can be expected to rise. The article describes a relatively rare clinical case that involved intracanalicular migration of silicone punctal plug. A female patient of 36 years old sought medical help in Research Institute of Eye Diseases (Moscow) to treat a lump in the area of lower lacrimal punctum in the left eye that was growing in size; the lump had appeared around 2 months prior to the visit. Patient's medical history read that around 2 years ago she had a silicone occluder installed in the lower lacrimal punctum of the left eye. On examination, in the area of lower lacrimal punctum, a body with a nutrient vascular pedicle deriving from lower lacrimal duct could be found. The occluder was absent in the opening of the lacrimal punctum. A revision of lower tear duct cavity was performed to remove its contents. The body filling tear duct opening was removed with forceps. Substance was then sent for histological examination. Tear duct was scraped out, the silicone occluder removed and sent to laboratory for scanning electron microscopy. The patient had no complaints 6 months after the procedure. CONCLUSION: The study showed that the forming body was granuloma resulting from aseptic inflammation. Surface of the silicone occluder in retention of lacrimal pathways remained unchanged. Described surgical tactic is suitable for treating patients with intracanalicular punctal plug migration.

[The nasal mucosa and outcomes of dacryocystorhinostomy]

OBJECTIVE

To investigate the impact of the nasal mucosa on the outcomes of dacryocystorhinostomy on the basis of morphologic findings.

MATERIAL AND METHODS

The investigation enrolled 73 patients who had undergone endonasal endoscopic dacryocystorhinostomy. Nasal mucosal biopsies were intraoperatively taken from all the patients. The obtained samples were subjected to standard histological examination, as well as to immunohistochemical study using an anti-alpha-smooth muscle actin antibody. To determine the intensity of inflammation in the tissue sample, a chronic inflammation score was calculated. The cell elements positively stained with α-smooth muscle actin were estimated using a semi-automatic method. The patients were divided into groups in accordance with the outcome of surgical treatment after 6 months.

RESULTS

An unfavorable outcome of dacryocystorhinostomy was observed in 10 (13.7%) patients. The samples obtained from the patients showed a higher chronic inflammation score (8.33%) and a larger number of the cell elements positively stained with α-smooth muscle actin (6026.38±1944.29). The correlation between the outcome of surgical intervention and the quantitative characteristics of myofibroblasts was statistically significant (p<0.05).

CONCLUSION

These studies suggest that there is a direct correlation of the efficiency of endonasal endoscopic dacryocystorhinostomy with the presence and degree of chronic nasal mucosal inflammation at baseline.

[Modified meibography in malignant eyelid tumors of epithelial origin]

INTRODUCTION

Eyelid tumors can be diagnosed using various diagnostic techniques. However, capability of existing methods for determining the type and margins of the tumor at the preoperative stage remains insufficiently studied.

PURPOSE

To improve the noncontact infrared meibography technique and determine its diagnostic capabilities for studying structural changes in meibomian glands in malignant eyelid tumors of epithelial origin.

MATERIAL AND METHODS

The study included 49 people (66 eyelids), among which 21 (21 eyelids) with malignant eyelid tumors, 11 - with benign eyelid tumors (11 eyelids), and 17 (34 eyelids) comprised the control group. The mean age of patients was 64.8±1.56 years. Meibomian glands of the lower eyelids were photographed in infrared light. Receiver-operating characteristic (ROC) curves were constructed to estimate the sensitivity and specificity of the method.

RESULTS

Modified meibography showed 100% sensitivity and 90% specificity in the differential diagnosis of malignant and benign eyelid tumors in 32 patients. Unlike other methods, the modified meibography technique can clarify the margins of tumor growth, which is considered when planning the resection volume.

CONCLUSION

Modified meibography can indicate the margins of tumor invasion; it can be successfully used in the differential diagnostics of malignant eyelid tumors of epithelial origin and benign eyelid tumors.

[Comparative electron microscopy study of the bone surfaces relief after ultrasonic and mechanical high-speed bone removal in orbital decompression]

PURPOSE

To compare the results of scanning electron microscopy studies of the surface of bone fragments of orbital lateral wall formed by mechanical and ultrasonic bone removal devices.

MATERIAL AND METHODS

The surfaces of 7 bone fragments have been investigated after bony orbital decompression in patients with thyroid eye disease (TED). Electron microscopy of the bone relief was performed after exposure to an ultrasonic surgical system or a high-speed drill.

RESULTS

Electron microscopy revealed that relief of the bony surface within a compact substance after application of an ultrasonic aspirator had parallel grooves of the same type up to 100 μm in depth and 80-100 μm wide, with relatively smooth edges. In the area of impact on spongy substance the bone surface became more amorphous, rougher due to the exposure of cellular structures at different depths. High-speed drill used in the area of compact substance left monotonous, almost flat relief with individual compact conglomerates of bone 'dust'. Removal of thinned fragments of the compact substance of the specimen led to appearance of the cellular structure typical for a spongy substance.

CONCLUSION

Data on features of the relief of the edges of bone 'window' obtained for the first time, as well as specifics of working in conditions of limited surgical access allowed the conclusion that modern ultrasonic bone aspiration is promising for deep lateral wall decompression and some other orbital interventions.

[Influence of frequent instillations of anti-infective solutions on eye tissues (an experimental study)]

PURPOSE

To investigate the toxic effects of frequent instillations of anti-infective solutions (antibiotic eye drops - 0.3 and 1.4% tobramycin, 0.5% levofloxacin and 0.5% moxifloxacin; antiseptic eye drops - 0.05% pyloxidine and 0.025% chlorhexidine; antifungal drug - 2 mg/ml fluconazole solution) on ocular tissues.

MATERIAL AND METHODS

The study was conducted on 21 Wistar rats (42 eyes) using method of semi-fine sections.

RESULTS

The majority of antibiotics and antifungal agents do not cause toxic reactions in rats` eyes when instilled with frequent regimen with the exception of 'fortified' 1.4% tobramycin and pyloxidine solutions, which caused a decrease in corneal endothelial cells density and formation of fibrovascular tissue in the anterior chamber.

CONCLUSION

Frequent instillations of antimicrobial drug solutions is a safe method for the treatment of purulent corneal ulcers and purulent keratitis. The exceptions were solutions of 'fortified' 1.4% tobramycin and piloxidine (vitabact).

[The substantiation of the application of the high-intensity pulsed magnetic field for the combined treatment of biliary sludge]

Despite the considerable achievements in the field of gastroenterology, there is still high incidence of diseases of the organs of the hepatobiliary system which necessitates the development of new therapeutic techniques for their management. Nowadays, high-intensity pulsed magnetic therapy is considered to be a highly efficacious method characterized by well-pronounced and many-sided action on the processes proceeding in the organism as a new preformed factor producing neurostimulatory, vasodilatory, trophic, and hypoalgesic effects. It appears to be effective with respect to biliary sludge (BS) since it can promote depletion of stagnant contents of the gall bladder and also intensify its contractile function.

AIM

The objective of the present study was to evaluate the effectiveness of the application of the high-intensity pulsed magnetic field in the combination with the intake of mineral water (MW) and rational pharmacotherapy as the components of the combined treatment of biliary sludge.

METHODS

The study included 117 patients presenting with biliary sludge (BS) who were randomly allocated to three groups. Group 1 was comprised of 38 patients and served as the control group. These patients received medicamentous therapy (hymecromone - 200 mg 3 times daily during two weeks and ursodeoxycholic acid at a dose of 10-15 mg/kg a day during a period from 3 to 6 months). The second group consisted of 40 patients and served as the group of comparison. The patients of this group received medicamentous therapy in the combination with the intake of 'Sernovodskaya' hydrocarbonate-chloride-sulphate sodium mineral water (from a spring in the Chechen republic). The third group was composed of 39 patients and constituted the main study group. These patients completed a course of therapy with the use of the high-intensity pulsed magnetic field applied to the gall bladder region. Each patient underwent 10 sessions of magnetic therapy after the completion of the treatment with hymecromone and 'Sernovodskaya' mineral water. The treatment was carried out with simultaneous monitoring dynamics of the clinical symptoms of biliary sludge, the ultrasound examination of the abdominal organs with the evaluation of the contractile function of the gall bladder, the level of bilirubin in the cystic bile, bile acids, cholesterol, and cholate-cholesteric coefficient.

RESULTS

The combined treatment of the patients suffering from BS including the application of the high-intensity pulsed magnetic field alleviated the clinical symptoms of the disease much faster than medicamentous therapy combined with the intake of 'Sernovodskaya' mineral water. Moreover, it promoted the restoration of the motor activity of the gall bladder and accelerated the evacuation of the hyperechoic particles.

CONCLUSION

The course of the combined treatment of the patients presenting with biliary sludge including the application of the high-intensity pulsed magnetic field in the combination with the intake of mineral water (MW) and rational pharmacotherapy significantly relieved abdominal pains, alleviated the symptoms of biliary dyspepsia, and improved the motor function of the biliary tract. These therapeutic effects persisted as long as 3 months. The results of the present study give evidence of the necessity of prescription of an optimum dose of ursodeoxycholic acid to the patients suffering from biliary sludge.

[The role of the combined balneotherapeutic treatment as the 'add-back therapy' against the background of the anti-hormonal effects of the agonists of gonadotropin-releasing hormone in the women suffering from endometriosis genitalis externa]

BACKGROUND

The use of agonists of gonadotropin-releasing hormone (GnRH) for the rehabilitation treatment of the patients presenting with endometriosis genitalis externa is known to significantly enhance the risk of development of hypoestrogenism. The so-called 'add-back-therapy' is carried out as a preventive measure to eliminate hypoestrogenism caused by the intake of GnRH agonists without detriment to the effectiveness of anti-hormonal therapy.

AIM

The objective of the present study was to estimate the effectiveness of the new method ('add-back hormone replacement therapy') in comparison with anti-hormonal therapy with the use of GRH agonists at the stage of the early postoperative medical rehabilitation based on the drinking of mineral waters (MW) and radon therapy (RT) in the patients who had undergone the laparoscopic interventions for the treatment of endometrioid heterotopies of the ovaries (1-3 months post-operatively).

MATERIAL AND METHODS

To evaluate the effectiveness of the spa and health resort-based rehabilitation measures, the long-term effects of GnRH agonists have been studied in 2 groups of the patients formed by the of simple randomization method. The main group (MG) was comprised of 45 women received medical rehabilitation under conditions of a spa and health resort setting with the application of medium-salt water from the Pyatigorsk spring and radon therapy in the combination with triptorelin. The group of comparison (CG) was composed of 44 women given the treatment with the use of triptorelin under the out-patient conditions. The assessment of the results of the study included: the estimation of the intensity of pelvic pain syndrome, indicators of the hormonal status and the quality of life (QL), ultrasonic examination of the pelvic organs, and the occurrence of adverse effects of triptorelin. The duration of the study was 3 years (2014-2016).

RESULTS

The analysis of the long-term results of the rehabilitative treatment has demonstrated that the rehabilitation activities under the spa and health resort conditions within 1-3 months after the surgical intervention including the application of MW and RT in the combination with an agonist of gonadotropin-releasing hormone (triptorelin) greatly contributed to the stability of the results of the treatment: specifically, only 2.5% of the patients suffered the recurrence of cystic ovarian endometriosis whereas 24.5% (p<0.001) reported the restoration of the reproductive function. The patients comprising the control group experienced the recurrence of the pathologic process in 7.5% of the cases and the restoration of the reproductive function in 15.8% of the cases (p<0.001). Simultaneously, the quality of life in the patients in the main group improved 3.4 times on the average in comparison with the initial level (p<0.001). The 2.2-fold improvement of the quality of life was documented in the control patients (p<0.001). At the same time, the frequency of adverse reactions to the treatment with triptorelin in the control patients was higher than in the main group including pain in the epigastric area, headache, irritability, hyperhidrosis, and instability of arterial blood pressure (ABP) that significantly deteriorated the life quality in these women.

CONCLUSION

The comparative analysis of the results of the follow-up observations has demonstrated that the application of drinking mineral water and radon therapy for the treatment of the women suffering from endometriosis genitalis externa can be recommended as 'add-back therapy' against the background of anti-hormonal effects of agonists of gonadotropin-releasing hormone.

Substrate Profile of the Phosphotriesterase Homology Protein from Escherichia coli

The phosphotriesterase homology protein (PHP) from Escherichia coli is a member of a family of proteins that is related to phosphotriestrase (PTE), a bacterial enzyme from cog1735 with unusual substrate specificity toward the hydrolysis of synthetic organic phosphates and phosphonates. PHP was cloned, purified to homogeneity, and functionally characterized. The three-dimensional structure of PHP was determined at a resolution of 1.84 Å with zinc and phosphate in the active site. The protein folds as a distorted (β/α)8-barrel and possesses a binuclear metal center in the active site. The catalytic function and substrate profile of PHP were investigated using a structure-guided approach that combined bioinformatics, computational docking, organic synthesis, and steady-state enzyme kinetics. PHP was found to catalyze the hydrolysis of phosphorylated glyceryl acetates. The best substrate was 1,2-diacetyl glycerol-3-phosphate with a kcat/ Km of 4.9 × 103 M-1 s-1. The presence of a phosphate group in the substrate was essential for enzymatic hydrolysis by the enzyme. It was surprising, however, to find that PHP was unable to hydrolyze any of the lactones tested as potential substrates, unlike most of the other enzymes from cog1735.

[Surgical treatment of purulent corneal ulcers in eyes with neurotrophic keratitis and paralytic lagophthalmos]

AIM

to develop a surgical approach to the treatment of purulent corneal ulcer in eyes with neurotrophic keratitis with lagophthalmos after auditory neuroma removal or stroke.

MATERIAL AND METHODS

A total of 12 patients (13 eyes) have been managed. All received combined surgery that included simultaneous keratoplasty, autoconjunctivoplasty, and permanent partial tarsorrhaphy.

RESULTS

Ocular integrity was preserved in all cases, and also vision - in half of them. In 29% of cases, visual acuity increased from 0.09±0.05 up tо 0.21±0.13. Lagophthalmos decreased from 5.86±1.35 mm down to 3.01±0.75 mm.

CONCLUSION

Patients with intracranial lesions complicated by neurotrophic keratitis and lagophthalmos often develop progressive purulent ulcers of the cornea. One-step keratoplasty, autoconjunctivoplasty, and permanent partial tarsorrhaphy is an effective treatment that can help preserve visual function in such eyes.

[New approaches to the treatment of keratoconjunctivitis sicca]

A new method has been developed for the treatment of severe forms of keratoconjunctivitis sicca (KCS) that involves the use of an original cyclosporine A (CyA) saturated soft contact lens (SCL) together with preservative-free artificial tears therapy.

AIM

to evaluate the effectiveness of the newly developed treatment for KCS based on the use of medical SCL saturated with 0.05% CyA.

MATERIAL AND METHODS

The patients (43 men, 60 eyes) with severe KCS were divided into 2 groups. Group 1 included 21 patients (30 eyes), who received artificial tears and wore 0.05% CyA-saturated silicone-hydrogel SCLs. Group 2 included 22 patients (30 eyes), who wore unsaturated original SCLs and received CyA instillations 2 times daily and, also, artificial tears. Apart from a standard ophthalmic examination, the assessment included Schirmer's test, Norn's test, vital eye stain tests, tear osmometry, laser confocal tomography of the cornea, optical coherence tomography of the anterior segment with meniscometry, impression cytology of the conjunctiva, tear pH measurement, plating of the content of the conjunctival cavity, measurement of the width of the palpebral fissure, and calculation of the ocular surface disease index. Treatment results were followed up at 1, 3, 6, and 12 months.

RESULTS

The use of 0.05% CyA-saturated SCLs allows to halve treatment time for patients with severe KSC (down to 1 week - 1 month) as compared to unsaturated original SCLs in combination with 0.05% CyA instillations and to reduce it 5 times as compared to 0.05% CyA instillations only.

CONCLUSION

The new method of KSC treatment that involves the use of medical SCL of original design (ensures even distribution of 0.05% CyA across the ocular surface) and preservative-free artificial tears has demonstrated high therapeutic effectiveness as compared to existing methods.

Mathematical model of polymerase chain reaction with temperature-dependent parameters

The course of the real-time polymerase chain reaction (PCR) is determined by the temperature dependence of the kinetics of the component reactions, particularly the DNA strand hybridization. To investigate the effect of thermal processes on the reaction behavior, a mathematical model in which the variable rate constant of dissociation of "primer-single strand" complexes depends on temperature was proposed. The reaction medium temperature, which depends on time, was also introduced into the model. The proposed model of real-time PCR makes it possible to analyze different aspects of the reaction, which are important for the development of instruments and reagents for PCR.

The hidden treasure in your data: phasing with unexpected weak anomalous scatterers from routine data sets

Single-wavelength anomalous dispersion (SAD) utilizing anomalous signal from native S atoms, or other atoms with Z ≤ 20, generally requires highly redundant data collected using relatively long-wavelength X-rays. Here, the results from two proteins are presented where the anomalous signal from serendipitously acquired surface-bound Ca atoms with an anomalous data multiplicity of around 10 was utilized to drive de novo structure determination. In both cases, the Ca atoms were acquired from the crystallization solution, and the data-collection strategy was not optimized to exploit the anomalous signal from these scatterers. The X-ray data were collected at 0.98 Å wavelength in one case and at 1.74 Å in the other (the wavelength was optimized for sulfur, but the anomalous signal from calcium was exploited for structure solution). Similarly, using a test case, it is shown that data collected at ∼1.0 Å wavelength, where the f'' value for sulfur is 0.28 e, are sufficient for structure determination using intrinsic S atoms from a strongly diffracting crystal. Interestingly, it was also observed that SHELXD was capable of generating a substructure solution from high-exposure data with a completeness of 70% for low-resolution reflections extending to 3.5 Å resolution with relatively low anomalous multiplicity. Considering the fact that many crystallization conditions contain anomalous scatterers such as Cl, Ca, Mn etc., checking for the presence of fortuitous anomalous signal in data from well diffracting crystals could prove useful in either determining the structure de novo or in accurately assigning surface-bound atoms.

Alternative solution of the simplest model of enzymatic synthesis of nucleic acids by homotopy perturbation method

Development of methods for obtaining approximate analytical solutions of nonlinear differential equations and their systems is a rapidly developing field of mathematical physics. Earlier, an approximate solution of the simplest system of kinetic enzymatic equations for calculating dynamics of complementary strands of nucleic acids was obtained. In this study, we consider an alternative approach to selecting the basic linear approximation of the used method, which makes it possible to obtain more accurate analytical solutions of the set problem.

[Combined YAG-laser capsulotomy in pseudophakic patients with anterior capsular contraction syndrome]

Progressive metaplastic fibrosis of the anterior capsulorhexis opening is a frequent complication of the postoperative period. There is a widely practiced method of anterior capsular contraction syndrome (ACCS) correction through radial anterior laser capsulotomy. Despite many advantages, it can be complicated by unpredictable anterior capsule tearing and intraocular lens (IOL) dislocation into the vitreous Body, which justifies the search for new technical solutions.

AIM

to develop a safe technique of combined laser anterior capsulotomy (LAC) in patients with ACCS.

MATERIAL AND METHODS

The study included 19 patients (20 eyes) with ACCS. The suggested LAC technique involved two differently directed YAG-laser cuts that could be regarded as a combination of radial anterior capsulotomy and anterior peripheral linear capsulotomy. With the cuts located perpendicularly to each other, the distal end of each radial cut was connected to the middle of each longitudinal cut.

RESULTS

The suggested technique allows an increase in the anterior capsulorhexis diameter up to more than twice the pre-laser size. The difference between the average pre- and post-laser capsulorhexis diameters was statistically significant (р<0.0001). Neither case developed an unpredictable anterior capsule tear.

CONCLUSION

The safety of the new technique is ensured by preliminary longitudinal cuts that create a barrier against unpredictable radial tears in the capsular bag during radial capsulotomy.

Fluorescence properties of p-tert-butyldihomooxacalix[4]arene derivatives and the effect of anion complexation

The intrinsic electronic absorption and fluorescence properties of several dihomooxacalix[4]arenes are studied.

[Effectiveness of soft contact lenses in severe keratoconjunctivitis sicca treated with local immunosuppressive therapy]

AIM

To study the effectiveness of soft contact lenses in severe keratoconjunctivitis sicca (KCS) treated with local immunosuppressive therapy.

MATERIAL AND METHODS

We have examined 41 patients (60 eyes) with severe KCS, including 3 men (4 eyes) and 38 women (56 eyes) aged from 27 to 76 years. Group 1 consisted of 22 persons (30 eyes) who were prescribed cyclosporine А 0.05% instillations 2 times daily, artificial tears, and soft contact lenses. Group 2 consisted of 19 patients (30 eyes) who received instillations of cyclosporine А 0.05% 2 times daily for no less than 6 months and artificial tears. Apart from the standard ophthalmic examination, the assessment included Schirmer's test, tear break-up time test, fluorescein eye stain test, tear osmometry, Heidelberg tomography of the cornea, optical coherence tomography of the anterior segment with meniscometry, impression cytology of the conjunctiva, tear pH measurement, plating of the content of the conjunctival cavity for its microflora, measurement of the width of the palpebral fissure, and calculation of the ocular surface disease index (OSDI). Treatment outcomes were evaluated at 1, 3, 6, and 12 months.

RESULTS

In group 1, complete re-epithelialization of the cornea (confirmed by all the methods used) was achieved rather shortly, in 1-3 months, while in group 2 - in 6 months.

CONCLUSION

The use of soft contact lenses in addition to cyclosporine A instillation therapy promotes restoration of corneal and conjunctival epithelium, reduces treatment time, and improves quality of life for patients, thus, proving itself a safe and effective treatment of autoimmune KCS.

Approximate analytic solution of a simple system of kinetic equations describing the enzymatic synthesis of nucleic acids

Macroscopic kinetic models describing the process of polymerase chain reaction (PCR) are currently solved only by numerical methods, which hampers the development of effective software algorithms for processing the results of the reaction. This paper considers the application of the homotopy perturbation method for obtaining approximate analytical solution of the simplest system of enzymatic kinetic equations describing the synthesis of nucleic acid molecules during PCR. The resulting approximate analytic solution with high accuracy reproduces the results of a numerical solution of the system in a wide range of ratios of enzyme and substrate concentrations both for the case of a large excess of the substrate over the enzyme and vice versa.

[The systemic approach to the health protection in the workers of industrial enterprises]

This paper presents the results of the systemic approach to the protection of health and prophylaxis of disability in the workers of industrial enterprises. The leading role in the technologies of rehabilitation (both short-term and long-term one) is played by the natural and physical therapeutic factors. The priority in the implementation of the therapeutic and health-promoting measures is given to the treatment based on the spa and health resort facilities as well as the factory health centers.

[Gold weight implants for lagophthalmos correction in chronic facial nerve paralysis (late results)]

Upper eyelid weigh gold implant is the widely accepted standard for the treatment of paralytic lagophthalmos (PL).

AIM

To evaluate late outcomes of PL correction with chain gold implants.

MATERIAL AND METHODS

Chain gold implants were inserted in the upper eyelids of 70 patients with lagophthalmos due to chronic facial paralysis. A comprehensive ophthalmic examination was performed prior to surgery and then at months 1, 3, 6, 12, 24, and 36.

RESULTS

The results obtained prove the method highly effective. None of the patients developed any severe complications. Cases of implant removal were few. Some of the studied biometric parameters decreased significantly after surgery, while the upper eyelid excursion increased. The implant had no effect on the inner surface of the cornea and its peripheral thickness.

CONCLUSION

Efficacy of the proposed eyelid implant has been convincingly demonstrated; late complications have been analyzed.

[Morphological assessment of lens capsule after different techniques of cataract extraction]

AIM

to evaluate morphological changes in the posterior lens capsule (LC) after different techniques of cataract extraction.

MATERIAL AND METHODS

Eight pseudophakic human autopsy eyes were divided into two groups by the technique used for cataract extraction. Group 1 included 4 eyes following extracapsular cataract extraction (ECCE) and rigid IOL implantation. Group 2 included 4 eyes after minimally invasive cataract surgery (MICS) that involves the use of ultrasound energy. Semithin LC sections were polychromatically stained, visually examined, and imaged for further analysis.

RESULTS

There were certain common features in clinical and morphological appearances of lens capsules from either group, including fibrous metaplasia of epithelial cells and/or pseudoregenerative Elschnig-Adamuk pearls on their inner surfaces, more significant in the ECCE group. MICS group, however, demonstrated many distinct and previously undescribed changes. In particular, post-MICS LCs looked swollen, flabby, and even amorphous, their architectonics were disturbed and fibers separated forming micro slit-like spaces, which could be a result of acoustic cavitation caused by ultrasound exposure. We have named this morphological type of secondary cataract «hyaloid-like».

CONCLUSION

Clinical and morphological type of postoperative LC opacification as well as its severity depends, to a certain extent, on the technique used for cataract extraction. Hyaloid-like opacifications are typical of minimally invasive surgery involving the use of ultrasound and often show no 'classic' changes (fibroproliferative and pseudoregenerative). The latter is explained by the fact that the posterior LC, which has lost its biomechanical properties, can no longer be a substrate for proliferating cells.

Mathematics analysis of polymerase chain reaction kinetic curves

The paper reviews different approaches to the mathematical analysis of polymerase chain reaction (PCR) kinetic curves. The basic principles of PCR mathematical analysis are presented. Approximation of PCR kinetic curves and PCR efficiency curves by various functions is described. Several PCR models based on chemical kinetics equations are suggested. Decision criteria for an optimal function to describe PCR efficiency are proposed.

Substrate Distortion and the Catalytic Reaction Mechanism of 5-Carboxyvanillate Decarboxylase

5-Carboxyvanillate decarboxylase (LigW) catalyzes the conversion of 5-carboxyvanillate to vanillate in the biochemical pathway for the degradation of lignin. This enzyme was shown to require Mn²⁺ for catalytic activity and the kinetic constants for the decarboxylation of 5-carboxyvanillate by the enzymes from Sphingomonas paucimobilis SYK-6 (k_cat = 2.2 s^–1 and k_cat/K_m = 4.0 × 10⁴ M^–1 s^–1) and Novosphingobium aromaticivorans (k_cat = 27 s^–1 and k_cat/K_m = 1.1 × 10⁵ M^–1 s^–1) were determined. The three-dimensional structures of both enzymes were determined in the presence and absence of ligands bound in the active site. The structure of LigW from N. aromaticivorans, bound with the substrate analogue, 5-nitrovanillate (K_d = 5.0 nM), was determined to a resolution of 1.07 Å. The structure of this complex shows a remarkable enzyme-induced distortion of the nitro-substituent out of the plane of the phenyl ring by approximately 23°. A chemical reaction mechanism for the decarboxylation of 5-carboxyvanillate by LigW was proposed on the basis of the high resolution X-ray structures determined in the presence ligands bound in the active site, mutation of active site residues, and the magnitude of the product isotope effect determined in a mixture of H₂O and D₂O. In the proposed reaction mechanism the enzyme facilitates the transfer of a proton to C5 of the substrate prior to the decarboxylation step.

[Embryological aspects of clinical presentations of congenital lens and vitreous anomalies]

This report gives a general overview of embryological features of the human eye. Key literature sources published during the last century on evaluation of congenital changes in the vitreous body and identification of signs of its 'underdevelopment' in certain types of congenital cataracts have been studied. The said changes were analyzed in terms of general pathology of the human body as well as local morphological manifestations. According to the authors, such an approach justifies the need for comparison of clinical manifestations of congenital lens and vitreous changes with possible embryonic defects.

[SEM visualization of corneal epithelium through lanthanoid staining based on Ca/Nd isomorphous substitution in Ca-dependent molecular systems]

Cumulative biomicroscopic evidence is usually sufficient for the diagnosis of recurrent corneal erosion or bullous keratopathy, however, exploration of the disease pathogenesis requires subcellular-level visualization of corneal structure. In the current study, lanthanoid staining and scanning electron microscopy were employed to visualize quite a number of structures responsible for epithelium organization. In particular, the study proves possible the use of Ca/Nd isomorphous substitution at Ca2+ sites of cytoadherence proteins for visualization of corresponding cellular structures.

AIM

To assess the value of information provided by scanning electron microscopy of corneal epithelium that involves lanthanoid staining based on the Ca/Nd isomorphous substitution in Ca-dependent molecular systems.

MATERIAL AND METHODS

Anterior corneal epithelial scrapes were obtained from patients with recurrent corneal erosion or bullous keratopathy and cadaver eyes with no signs of any ophthalmic disease. Samples were then studied under a scanning electron microscope (Zeiss EVO LS10, BSE, EP - 79 Pa, 20-28 kV, Ln-staining with the BioREE assay kit).

RESULTS

In all cases, lanthanoid staining of biopsy material provided high-contrast SEM images with well-recognizable structural and ultrastructural elements associated with Ca2+ sites of cytoadherence proteins.

CONCLUSION

Lanthanoid staining of biopsy material and subsequent SEM enabled detailed visualization of structural features of the corneal epithelium in various pathologies. Due to the Ca/Nd isomorphism we were able to evaluate structural position of the majority of protein molecules engaged in Ca-dependant processes and, consequently, in cytoadherence. Basing on the neodymium distribution within the basal membrane, we have described local effects of different substances on the lamina densa in the projection of basal layer cell borders that occur after unidirectional ultrafiltration. The results confirm the failure of the junctional adhesion complex in recurrent corneal erosion.

[Morphological analysis of reparative process at osteotomy site after endoscopic endonasal dacryocystorhinostomy]

Ostium closure due to local reparative processes is the most common cause of recurrence after endoscopic endonasal dacryocystorhinostomy (DCR), but as yet poorly studied.

AIM

To perform morphological study of reparative processes at osteotomy site after endoscopic endonasal DCR.

MATERIAL AND METHODS

The study included 18 patients (18 women) aged 62.59±10.07 years with nasolacrimal duct obstruction, who underwent endoscopic endonasal DCR (P.J. Wormald modification). Osteotomy site biopsies were taken on days 2, 5, 7, 10, 14, 21, 28, and 60 after the surgery. All the samples were stained with haematoxylin and eosin. For further details on cellular composition of inflammatory infiltrate, 54 samples were also processed into semi-thin sections. The slides were then viewed under Leica DM-2500 (Leica, Germany) photomicroscope. Leica DFC320 digital camera and ImageScope Color software were used for image acquisition and analysis.

RESULTS

Morphological examination revealed the predominance of inflammatory cells in biopsy material on day 1 after DCR. On day 14, the number of cells would usually be reduced indicating the completion of the exudative phase of inflammation. Since then, activated fibroblasts prevailed over the rest of cellular elements. Twenty eight days after DCR, proliferating fibroblasts and collagen fibers were present. Sixty days after the surgery, fibrillar component prevailed over cells and showed compaction.

CONCLUSION

Our results demonstrate that the reparation process nears completion before day 60 after the surgery. A series of morphological examinations of biopsy material from osteotomy sites has revealed individual features of reparation in nasal and lacrimal sac mucosa after endoscopic endonasal DCR.

[Chemical microanalysis of mineral deposits on explanted hydrophilic acrylic intraocular lenses]

AIM

to perform chemical microanalysis of mineral deposits on the surface of explanted hydrophilic acrylic intraocular lenses (IOL).

MATERIAL AND METHODS

Two soft IOLs made of hydrophilic acryl (one, however, hydrophobic surface coated) and explanted 3 and 6 years after implantation were examined by scanning electron microscopy (EVO LS10, "Karl Zeiss", Germany). Chemical composition of the lens surface was studied using an energy-dispersive spectrometer (EDS X-Max50, Oxford, Great Britain).

RESULTS

Chemical microanalysis allowed identification of the deposits, which turned out to be non-stoichiometric hydroxylapatite (also, hydroxyapatite (HA)) crystals with zinc impurity (up to 1.4%weight).

CONCLUSION

The two samples represent two stages of a single process. The early stage is associated with newly formed HA crystals that are unable to cause any significant changes to the lens surface. However, as spherocrystals grow, they exert a crystallization effort that moves their growth centers apart with subsequent lens rupture and deformation. Crystal morphology undergoes dynamic changes: while primary (newly formed) crystals are sheaf-like, mature are spheres. A growing HA is non-stoichiometric. Zinc abundance accounts for appearance of its separate mineral phase. Hydrophilic properties of acrylic polymer determine its high affinity for HA crystals. Hydrophobic coating (sample no.1) does not completely prevent lens opacification due to mineral deposits on its surface.

[Analyzing causes for opacification of acrylic IOLs]

AIM

to study the nature of intraocular lens (IOL) opacification depending on the patient's ocular status and general condition.

MATERIAL AND METHODS

A total of 9 patients (9 eyes) with 3-6 year history of progressive IOL opacification were enrolled. All the IOLs were acrylic (either hydrophilic--7 cases, or hydrophobic--2 cases). Two patients had their IOLs exchanged due to opacification. Six patients earlier underwent glaucoma surgery. Two patients were type 2 diabetic. Slit lamp biomicroscopy and optical microscopy were used for IOL examination.

RESULTS

The surface of hydrophilic acrylic lenses appeared bumpy because of multiple variously shaped translucent granules separated by a chaotic network of furrows and microfractures and located predominantly in the optic zone. In a more severe case, a bowl-shaped impression was observed in the area of opacification. Surface changes of hydrophobic acrylic lenses were in the form of isolated and confluent glistening formations (microcavities).

CONCLUSION

Signs of IOL degradation develop over a long period of time (3-6 years, in our experience) and mostly involve the anterior surface of the lens optic. Ocular comorbidity, glaucoma in particular, as well as other surgery and/or therapeutic treatment following IOL implantation may contribute to its opacification. Analysis of published data and own observations suggest that hydrophobic IOLs should be preferred in patients with concomitant diseases, especially diabetes mellitus. Granular deposits, if accumulate, may lead to deformation of the lens optic, as confirmed by the bowl-like impression in one of the explanted hydrophilic IOLs.

[Characteristic vitreous changes in congenital cataracts]

AIM

To analyze changes and identify specific signs of underdevelopment of the vitreous body in certain types of congenital cataracts.

MATERIAL AND METHODS

A total of 26 patients (52 eyes) with congenital changes in the lens and vitreous were examined by means of digital spatial ultrasound imaging.

RESULTS

On the basis of multiplanar ultrasound examination and three-dimensional virtual modelling of the eye, spatial ultrasonographic characteristics of combined congenital involvement of the lens and vitreous have been determined. The changes revealed are shown to be morphologically related.

CONCLUSION

The results suggest three-dimensional digital ultrasound virtual modelling useful for studying combined congenital changes in the lens and vitreous and, thereby, it enables 'decoding' of some elements of their normal morphology.

[Biointegration of eyelid gold weight implants (experimental study)]

The article presents the results of an experimental morphological study of biointegration of different eyelid weight implants used for paralytic lagophthalmos correction.

AIM

To investigate biointegration features of gold monolithic and chain implants.

MATERIAL AND METHODS

The study enrolled 11 Chinchilla rabbits (22 eyelids). Light and scanning electron microscopy was performed 2 weeks, 1, 2, 3 and 6 months after the implantation.

RESULTS

Over the whole follow-up period chain implants capsules remained more integrated with surrounding connective tissue than those of monolithic implants.

CONCLUSION

The obtained results prove better immobilization of a gold chain implant preventing it from dislocation in the late postoperative period.

[Topical cyclosporine for the treatment of ocular surface changes in contact lens wearers]

OBJECTIVE

To assess opportunities for the use of cyclosporine emulsion 0.05% for the treatment of dry eye syndrome in long-term contact lens wearers.

MATERIAL AND METHODS

A total of 25 long-term contact lens wearers (50 eyes) with signs of dry eye syndrome and corneal epitheliopathy of different degree, unresponsive to conventional artificial tears therapy, were observed. All of them were prescribed cyclosporine emulsion 0.05% twice daily at 12-hour intervals 10 min before inserting contact lenses or after removing. Biomicroscopy with fluorescein eye stain test, determination of the tear film break-up time (Norn's test), optical coherence tomography of tear meniscus (OCT-meniscometry), Jones test, impression cytology, and corneal confocal microscopy (Confoscan-4, "Nidek", Japan) were used to evaluate the treatment effect.

RESULTS

The treatment resulted in better contact lens tolerance, significantly increased mean values of tear film break-up time (by 13.2% at 1 month, 62% at 3 months, and 37.3% at 6 months as compared with the baseline) and basal tear secretion (by 29%, 32%, and 82.4% at 1, 3, and 6 months correspondingly). Confocal microscopy revealed restitution of corneal superficial epithelial structure and cell density. Goblet cells were present in impression cytology specimens.

CONCLUSION

Topical use of cyclosporine emulsion 0.05% has a positive effect on morphofunctional parameters of ocular surface and promotes basal tear secretion and precorneal tear film stability.