Connective Tissue Fibers Research Articles

The effectiveness of the use of various options for drainage of the abdominal cavity in creating a model of chronic peritonitis and the determination of indicators of total peritoneal fibrosis

For the early diagnosis and prognosis of chronic peritonitis, today there is an urgent need to create an optimal model of chronic peritonitis, to determine the indicators and rates of progression of peritoneal fibrosis.The aim is to evaluate the effectiveness of using different options for drainage of the abdominal cavity when creating a model of chronic peritonitis and determining the indicators of the formation of total peritoneal fibrosis in the dynamics of peritonitis.Materials and methods. In the experiment on 60 rats aged 90 days, weighing 220–250 g, chronic peritonitis was simulated by intraperitoneal injection of living cultures of E. coli bacteria and 10 % of fecal suspension (0.5 ml per 100 g of animal weight) through the drainage, as well different options for setting abdominal drainage for peritoneal lavage with an antiseptic were used. In group 1 in 20 rats, drainage was inserted under visual control through a laboratory wound and fixed to the parietal peritoneum on the right flank; in group 2 in 20 rats, the drainage was inserted under visual control through the laboratory wound and fixed to the parietal peritoneum on the right flank; in group 3 in 20 rats, blind insertion of abdominal drainage by trocar was performed. After 12 and 24 hours, the abdominal cavity was flushed three times with 0.9 % NaCl solution and 50 % betadine solution. All rats were injected with 5 ml of mesogel to prevent the formation of adhesions and ensure the functioning of drains, and on the 2nd day 10 % fecal suspension was administered (0.5 ml per 100 g of animal weight). After 12, 24 hours, 5 and 12 days of the experiment, the peritoneal inflammatory process was monitored taking into account blood leukocytosis. To evaluate the effectiveness of various abdominal drainage options, on the 5th, 7th, 14th, 30th, and 60th days, the cytological profile of the washes from the peritoneum of rats, the lethality of animals, the number of festering wounds and the drainage migration were determined.Results. It has been established that a model of chronic peritonitis with the support of chronic inflammation and the development of peritoneal fibrosis was created only by inserting abdominal drainage under visual control through counteraperture on the back of the surface with its fixation along the right flank to the parietal peritoneum. In these animals, stable long-term leukocytosis was achieved in the range of 10.2–13.3 × 109/l, the cytological profile of the peritoneum washes was characterized by a significant increase (P ˂ 0.05) in the number of mitoses in mesotheliocytes against the background of their relatively stable number. On the 60th day of the experiment, the histological examination determined the loss of the integumentary mesothelium, abundant overlap of connective tissue fibers was observed on the thickened basement membrane of the peritoneum; in the washes from the peritoneum, the number of mesotheliocytes inversely correlated with the degree of fibrosis following the increase in the number of fibrocytes in 1 mm3 (r = -0.98, P < 0.05).Conclusions. In late stages of experimental chronic peritonitis with the insertion of drainage of the abdominal cavity through conteraperture on the dorsal surface and fixation of its right flank to the parietal peritoneum in rats, persistent blood leukocytosis occurs within 10.2 × 109/l, in the washes from the peritoneum there is a decrease in the number of mitoses in mesotheliocytes and an increase in the number of fibrocytes, which allows us to consider these parameters as indicators of the development of diffuse peritoneal fibrosis.

Etiopathogenesis of Primary Acquired Nasolacrimal Duct Obstruction: What We Know and What We Need to Know.

To provide a systematic review of the literature on the etiopathogenesis of primary acquired nasolacrimal duct obstruction (PANDO). The authors performed a PubMed search of all articles published in English with specific reference to etiopathogenesis of PANDO or associations of PANDO. Data captured include demographics, study techniques, hypothesis, presumed or confirmed interpretations with regards to pathogenesis, mechanisms, or pathways. Specific emphasis was laid on addressing the lacunae and potential directions for future research. Numerous factors are believed to contribute to the etiopathogenesis of PANDO. The basic pathogenesis involves inflammation, vascular congestion, mucosal edema, fibrosis, obstruction, and stasis. Bony nasolacrimal duct diameter does not appear to play a significant role. There is no convincing data to substantiate nose as the site of disease origin and nasal factors appear to be comorbidities. Hormonal mechanisms are more evidence-based but can only partly explain the pathogenesis. Vascular theories are based on the behavior of perilacrimal cavernous bodies, their autonomic control, and additional structural changes in the helical patterns of connective tissue fiber arrangements. Repeated vascular malfunction leading to structural epithelial and subepithelial changes currently appears to be the most evidence-based and accepted theory. Tear proteomics holds a promise in decoding the etiopathogenesis of PANDO, at least in part. The etiopathogenesis of PANDO appears to be multifactorial. Hormonal microenvironments, vascular factors, and tear proteomics are promising candidates for further work. There is a need for focused work by Clinician-Scientists and the answers can have far reaching clinical implications.

290 Nonlinear microscopy for the visualization of calcification and assessment of connective tissue fibers in pseudoxanthoma elasticum

Pseudoxanthoma elasticum (PXE, OMIM 264800) is a rare disorder caused by mutations of the ABCC6 gene in which decreased plasma levels of inorganic pyrophosphate (PPi) lead to ectopic mineralization resulting in severe dermatological, ophthalmologic and cardiovascular complications. Components of the dermal connective tissue can be differentiated with nonlinear optical (NLO) techniques, as collagen emits a strong second harmonic generation (SHG) signal given its non-centrosymmetric structure, while elastin as an endogenous chromophore can be visualized by two-photon excitation fluorescence (TPF). We carried out deep phenotyping, molecular genetic testing and plasma PPi measurement of five patients with PXE. Ex vivo SHG and TPF imaging and conventional histopathological evaluation of their skin was performed and compared to five age- and gender-matched healthy controls. Pathological mutations were found in the ABCC6 gene in all patients and their plasma PPi levels were significantly lower compared to controls by unpaired t test (p=0,0005). We visualized and quantified the degradation and mineralization of elastin fibers and extensive mid-dermal calcium salt deposition as well as the alterations of the collagen structure in the mid-dermis of patients with PXE utilizing TPF and SHG, respectively. Based on our data, NLO enables high-detail imaging and quantification of the specific features of PXE-affected skin. In vivo NLO may be a promising method in the assessment of PXE in the future, facilitating early diagnosis and monitoring.

Influence of electrostimulation on the structural and functional characteristics of the muscles of the front abdomen

The purpose of the work is to study the effect of different-frequency electrical stimulation of the muscles of the anterior abdominal wall after hernioplasty.Research methods. Studies were performed on 40 rats with a simulated experimental ventral hernia after plasty with a polypropylene mesh. After hernioplasty, 20 animals received a physiotherapy course using pulsed electric current using the Neuro-pulse stimulator with various frequency characteristics (10, 100, 1000 Hz). Electrical stimulation was performed daily for 2 min for 10 days. The stimulation courses were repeated three times with 20‑day breaks. The material for the morphological study was prepared by the conventional method after 70 days.Results. The established degree of destructive changes in the muscles of the anterior abdominal wall in the area of the ventral hernia is directly dependent on the ratio of muscle and connective tissue fibers. The use of electrostimulation therapy enhances the repair processes and significantly reduces the recovery time of the structural and functional properties of skeletal muscles after modelling a ventral hernia with subsequent plastic surgery with a polypropylene mesh. The greatest therapeutic effect of electrical stimulation is observed at an electric field frequency of 10 Hz, and structural characteristics indicate a greater severity of signs of increased resistance to fatigue with a lower degree of functional tension of muscle fibers.Conclusion. Morphological changes in the rectus abdominis muscle, which are observed after electrostimulation, form the structural basis of the functional rehabilitation of the muscles of the anterior abdominal wall in ventral hernias.

Silver nanoparticle-induced nephrotoxicity in Clarias gariepinus: physio-histological biomarkers.

The present study investigates the nephrotoxic effects of two acute doses of silver nanoparticles (AgNPs) and silver nitrate (AgNO3) on the African catfish, Clarias gariepinus, using biochemical, histochemical, and histopathological changes as biomarkers. AgNP-induced impacts were recorded in some of these characteristics on the bases of their size (20 and 40nm) and concentration (10 and 100μg/L) but no significant interaction between size and concentration. AgNO3 had low significant adverse effects on some parameters in comparison with those impacts of AgNPs. The concentrations of creatinine and uric acid exhibited different significant variations under stress in all exposed groups compared with those in the control group. On the tissue and cell levels, histopathological changes were observed. These changes include hypertrophies of glomeruli, proliferation in the haemopoietic tissue, dissociation in renal tubules, shrinkage of glomerulus, hydropic degeneration, dilatation of renal tubules, aggregation of melanomacrophages, rupture of Bowman's capsule, and the glomerular tuft and dilatation of Bowman's space. In more severe cases, the degenerative process leads to tissue necrosis in the kidney of AgNP-exposed fish as well as carbohydrate depletion; a faint coloration was also observed in the brush borders and basement membrane with a large amount of connective tissue fibers around the blood vessels and the renal tubules. Recovery period for 15days led to improvement of most of the alterations in biochemical, histopathological, and histochemical parameters induced by AgNPs and AgNO3. In conclusion, one can postulate on the sensitivity of the kidney of C. gariepinus to AgNPs and recovery strategy is a must.

Combined staining of elastic and collagen fibers for histopathological and differential diagnosis in aorta pathologies

ABSTRACTHistochemical techniques are important for diagnosis of connective tissue fibers involved in different aorta pathologies. The aim of this study was to develop a histochemical staining method that identifies both elastic and collagen fibers simultaneously in the same section of aortic wall. Fragments of aorta from deceased dogs were processed according to standard histological technique for paraffin embedding. Sections were stained with orcein with counterstained with either light green or single step Gomori trichrome, and also orcein stain and picro-sirius red. Orcein stain combined with picro-sirius red allowed visualization of both elastic fibers (brown) and collagen fibers (red) with light microscopy using bright field illumination. Moreover, under polarized light microscopy only collagen fibers were detected, appearing as reddish birefringent fibers, confirming that picro-sirius red-stained fibers were collagen fibers. The combination staining by orcein and picro-sirius solutions provided visualization of both collagen and elastic fibers in the same section, facilitating identification of these connective tissue fibers in the aortic wall.

Powering the hagfish "bite": The functional morphology of the retractor complex of two hagfish feeding apparatuses.

Hagfish use forceful retractions of a dental plate to shear and ingest food. Retractile force is generated by the retractor muscle complex of the posterior hagfish feeding apparatus (HFA). While gross morphological descriptions exist, the organization of muscle and connective tissue fibers that form the soft tissue retractor complex do not. In this study, we used paraffin histology to prepare serial sections of Pacific (Eptatretus stoutii, Lockington, 1879) and Atlantic (Myxine glutinosa, Linnaeus, 1758) hagfishes in order to describe constituent soft tissue anatomy and fiber orientations. We generated 3D reconstructions in which digitized sections were segmented and fitted to volumetric scans of retractor complexes taken prior to microtomy. These models confirmed that the retractor complex is composed of a perpendicularis muscle that fits within the eye of a needle-shaped clavatus muscle, which anteriorly bears the dental plate tendon, and in turn fits within a sleeve-like tubulatus muscle. Analysis of fiber orientations within these muscles resulted in novel functional hypotheses: (a) The tubulatus muscle represents a novel tubular bipennate muscle with a considerable physiological cross-sectional area. Its activation may indirectly create tension in the dental plate tendon: as the tubulatus muscle forcefully extends, it displaces the terminal bulb and the clavatus muscle posteriorly. (b) Within the HFA terminal bulb, the muscle fibers of the clavatus and perpendicularis muscles are mutually perpendicular and may cocontract to form a swelling stopper knot-like muscular complex that resists being pulled through the tubulatus muscle. (c) While overall feeding apparatus muscle morphology is conserved, the physiological cross-sectional area of the tubulatus muscle in E. stoutii, is relatively larger than that of M. glutinosa, suggesting a more forceful retraction. The tubular bipennate construction of the tubulatus may represent a novel soft robotic actuator design.

Diode laser technology in the treatment of hemorrhoid disease. Laser HemorrhoidoPlasty (LHP) – description of the method

Hemorrhoids is one of the most common proctological diseases of the anal canal. In the guidelines presented in 2018 in „Diseases of the Colon & Rectum”, the American Society of Colon and Rectal Surgeons (ASCRS) hasn’t specified laser techniques as a method of treatment. The first attempts of laser trail in hemorrhoidal treatment were made at the end of the 70s by using laser CO2 instead of scalpel. Nowadays one of the newest devices is Leonardo laser which emits fan-shaped movement of 1470 nm length. It enabled the development of laser hemorrhoidoplasty technique (LHP). The advantage of this procedure is decrease of hemorrhoidal plexus by obliteration of hemorrhoidal vessels leading to their fibrosis. It reclaims almost anatomical architecture of anal canal without a necessity to excise the extended hemorrhoids. Development of the connective tissue fibers guarantees adequate adhesion of mucosa to the underlying tissue which prevents the recurrence of the disease, especially the ones connected with prolapsing of hemorrhoids. The article contains a description of the method recommended by the manufacturer of Leonardo laser with the autors’ modifications developed on the basis of their own experience.

Is a soft tissue graft harvested from the maxillary tuberosity the approach of choice in an isolated site?

Soft tissue augmentation procedures are becoming more popular these days. Different soft tissue graft harvesting approaches have been proposed. Nonetheless, the location of the donor site (whether anterior-, lateral-, superficial-, deep-palate or the maxillary tuberosity) can affect the graft shape and its composition. Soft tissue grafts from the maxillary tuberosity are rich in connective tissue fibers, with minimal presence of fatty or glandular components. Clinical, histological, and molecular evidence shows that a soft tissue graft obtained from the maxillary tuberosity has unique properties. In addition, harvesting from this area presents minimal risk for intra- or postoperative complications, leading to reduced patient morbidity. The aim of this commentary is to discuss the advantages and disadvantages of harvesting a soft tissue graft from the tuberosity and to compare it with the traditional palatal graft, while highlighting functional, esthetic, and patient-related outcomes.

Osteochondroma of the First Phalanx in Tbourida Horses.

This study aimed at describing anatomo-histopathological and imaging features, using computed tomography and magnetic resonance imaging on six ex vivo forelimbs of Tbourida horses, that presented a particular bone exostosis on the dorsal and proximal part of the first phalanx, diagnosed by X-ray. Gross anatomy of the bone exostosis revealed an irregular surface with poly-lobulated tissue masses showing a cauliflower shape. The diameter/depth varied from 0.5 to 5.1 cm with a mean of 3.9 ± 0.9 cm. The capsule of the metacarpophalangeal joint was hypertrophic and showed many invaginations in the inner part, in contact with the bone exostosis. Computed tomography revealed cortical and medullary continuity of the bone exostosis, with the underlying bone, and remodeling of the cortical surface of the dorsal and proximal part of the first phalanx. Magnetic resonance imaging showed an increased signal intensity of the bone exostosis on the T1- and T2*-weighted gradient fast echo. Histological examination of the bone exostosis revealed a cap of hyaline cartilage, including large foci of endochondral ossification with a base of cancellous bone surrounding marrow spaces, which confirmed the diagnosis of osteochondroma. The capsule of the metacarpophalangeal joint showed a large amount of recently formed connective tissue fibers in its inner part, interspersed with mature connective tissue. The hyperextension of the metacarpophalangeal joint during a Tbourida show, which occurs on a hard ground surface, and the use of hobbles in horse stabling are most likely responsible for the outgrowth of an osteochondroma of different shapes and sizes, and fracture complications in some cases.

Short-term use of resveratrol in alloplastic graft material applied with calvarial bone defects in rats

Purpose:The effects of resveratrol administration on calvarial bone defects with alloplastic graft material was investigated for osteoinductive reaction and bone development in rats.Methods:Healthy male rats were randomly divided into 3 groups consisting of 10 rats. Groups were as follows: control (defect) group, defect + graft group, and defect + graft + resveratrol group. A calvarial bone defect was created in all groups, alloplastic bone grafts were applied to the defect in the 2nd and 3rd group, resveratrol (5 mg/kg/day) was added to the drinking water of the animals following graft application for 28 days in the 3rd group.Results:Increase in osteoclasts and necrotic changes were observed histopathologically in the control group. In the 2nd group, reduction of inflammation, congestion of blood vessels, increased osteblastic activity, osteoinductive effect, progression of osteocyte development and increased collagen fibers in connective tissue were observed. In the 3rd group, osteoblasts seemed to secrete bone matrix and accelerate osteoinductive effect with increased osteopregenitor activity and positive osteopontin and osteonectin expressions.Conclusion:Resveratrol treatment was thought to be an alternative and supportive drug for implant application by inducing new bone formation in the calvaral defect region as a result of short-term treatment.

Морфологическая характеристика разных типов полипозного риносинусита

The publication presents the results of morphological study of patients with chronic polypous rhinosinusitis (ChPR). ChPR is characterized with a chronic productive type of inflammation of the nasal mucosa and paranasal sinuses, with the formation and growth of polyps. In this study, we examined 70 people (50 patients in the study group and 20 patients in the control group). In this work, the authors found the polypous changes in the tissue, three types of the nasal cavity polyps. 1. Edematous polyps – histological signs: an edematous polyp stroma containing a small number of fibroblasts and connective tissue fibers, due to which the intercellular space has a spongy, loose appearance. In the depth of the polypous tissue there are areas containing single glands, cysts. 2. Allergic (eosinophilic) polyps – histological signs: the presence of infiltrates with a significant number of eosinophils, alongside with monocytes and mast cells. 3. Fibrous (fibrous-vascular, fibrocystic, fibrous-glandular) polyps – histological signs: the stroma has dense compact structure, it is made of a great number of fibroblasts and surrounding connective tissue fibers. The stroma has a large number of various caliber vessel profiles.

The effect of graft application and allopurinol treatment on calvarial bone defect in rats1.

PurposeTo investigate the effects of allopurinol administration on osteoinductive reaction and bone development with graft material. MethodsThirty-six Wistar albino rats were divided into 3 groups. In the control group, calvarial bone defect was only created without any treatment. In the Defect + Graft group, allograft treatment was performed by forming 8 mm calvarial bone defect. In the Defect + Graft + Allopurinol group, alloplastic bone graft was placed in the calvarial bone defect and then, allopurinol (50 mg/kg/day) treatment was intraperitoneally applied for 28 days. ResultsHistopathological examination revealed inflammation, congestion in the vessels, and an increase in osteoclast cells in the defect area. We also observed that new osteocyte cells, increase in connective tissue fibers, and new bone trabeculae. Osteopontin expression was positive in osteoblast cells and lacunated osteocyte cells were located in the periphery of the new bone trabeculae. Osteopontin expression was also positive in osteoblasts and osteocytes cells of new bone trabeculae in the graft site. Conclusion It has been shown that allopurinol treatment in rat calvaria defects may induce osteoblastic activity, matrix development, mature bone cell formation and new bone formation when used with autogenous grafts.

Anatomical Explanations of the Pathogenesis of Proximal Hypospadias.

Aims:The aim of this study was to try to explain the pathogenesis of proximal hypospadias based on anatomical and histological findings.Methods:During 9 years, we performed systematic biopsies (in the lateral areas of the urethral plate, as well as under this plate) in 81 patients treated for proximal hypospadias. The histological study was performed by routine coloring, hematoxylin and eosin, and Masson's trichrome, which colors the collagen fibers in blue, and monoclonal antibody against alpha-smooth muscle actin.Results:There is a fibrosis tissue abnormally present on the ventral side of the penis. This tissue consists of a mixture of fibrous connective tissue, nerve nets, short vessels, and smooth muscle fibers. The penis' dartos does not contain smooth muscle fibers. These fibers can come from a blood vessel or spongy tissue which existed during the neonatal period in the distal part of the penis before disappearing.Conclusions:The proximal hypospadias is due presumably to avascular necrosis of the distal part poorly vascularized of the corpus spongiosum.

Elastosis perforans serpiginosa related to vascular Ehlers-Danlos syndrome

Elastosis perforans serpiginosa (EPS) is a rare skin disease with elimination of connective tissue fibers from dermis to epidermis. The typical presentation shows hyperkeratotic red or skin-colored papules arranged in a circinate pattern. We present a 26-year-old woman with EPS known to have vascular Ehlers-Danlos syndrome.

САРКОИДОЗ ПЕЧЕНИ

Background. Despite the fact that sarcoidosis is a rare liver pathology carrying out the differential diagnosis between it and other focal liver lesions causes difficulties. Objective – to present the morphological signs and features of liver damage in sarcoidosis. Materials and methods. The object of the study were liver fragments of a patient died due to generalized sarcoidosis. The pieces of the liver intended for light microscopy were fixed in 10% formalin solution and embedded in paraffin after posting. Histological sections were stained with hematoxylin and eosin, as well as pikrofuksin by van Gieson. Results. The morphological stages of granuloma formation are represented: the accumulation of monocytes and macrophages in the lesion; the formation of macrophage granulomas; eosinophilic masses resembling fibrinoid necrosis are detected in the central zones of granulomas; the formation of epithelioid cell granulomas (giant multinucleated cells); fibrosis with the appearance of argyrophil and collagen fibers, the development of hyalinosis; fibrinoid swelling of connective tissue fibers with necrobiosis without loss of fibrin and without the formation of caseous necrosis. Various localization of granulomas (inside the lobules, in portal tracts), fusion of granulomas with the formation of foci of various sizes visible to the naked eye are shown. Conclusion. Clinical and laboratory diagnostic methods, including instrumental imaging methods, do not accurately identify liver sarcoidosis. Morphological diagnosis of focal liver lesions is the most accurate method for early detection of liver sarcoidosis.

A Correlation between Histochemical Patterns of Connective Tissue Fibers and AgNORs in Breast Lesions

Background: The precise histopathologic diagnosis of a breast lesion is the first step towards the most appropriate inclusive patient’s management. The aim of this study was to evaluate the correlation between histochemical patterns of connective tissue fibers and NORs in breast lesions. Methodology: Patients with breast cancer (n = 25) were ascertained as the case group, and those with benign breast lesions were ascertained as a control group (n = 25). Histochemical evaluations of elastic fibers, reticular fibers and mean AgNORs count were performed for all study subjects. Results: Elastic fibers intensity was brought into being lessening in benign lesions and upturns in the direction of malignant lesions. The intensity of elastic fibers was found to intensify with rises of neoplastic changes in breast cancer and this was found to be statistically significant P < 0.001. Mean AgNORs counts displayed increased clusters among malignant cases equated to benign ones. Mean AgNORs count significantly increased with neoplastic proliferation P < 0.005. Conclusion: Demonstration of connective tissue fibers (particularly elastic fibers) can strength the diagnostic evidence for conventional histopathology diagnosis. Mean AgNORs count can merge as an important quantitative marker in breast cancer diagnosis.

Ultrastructural Changes of Collagen in Different Histopathological Grades of Oral Submucous Fibrosis.

Background and Objectives:Oral submucous fibrosis (OSMF) is a potentially malignant disorder and a crippling condition of oral mucosa. It is usually seen in adults with areca nut chewing habit, which is characterized by changes in the connective tissue fibers leading to stiffness of the mucosa and restricted mouth opening. Patients with severe cases have distinct difficulties in chewing, swallowing, and speaking. It predominantly occurs in Indians and other population of the Indian subcontinent with a prevalence of 0.2%–0.5%. The potentiality of malignant transformation associated with OSMF is much higher with a range of 4.5%–7.6%. This article is about the ultrastructural changes pertaining to collagen and with respect to the histopathological grades of OSMF.Materials and Methods:A total of 20 biopsy samples from clinically diagnosed OSMF subjects and 5 healthy controls were collected. After obtaining the biopsy, the specimens were divided into two halves, of which one was studied under light microscope and the other half was observed under transmission electron microscope.Results:Of the 20 subjects in the study group, most of the subjects were in the 20–29 years age group with an overall male predilection (19 subjects). Four subjects were in grade 1, nine were in grade 2, and seven were in grade 3. Collagen showed sparse to dense fibrosis and normal to thick collagen bundles, and some subjects showed encroachment of collagen into the blood vessels.Conclusion:This study showed definitive changes with respect to collagen in the OSMF samples compared to the controls. The changes were found to be increasing with the progression of the disease to the higher grades. The changes were pertaining to the collagen and were drawing toward an increased fibrosis of the connective tissue, which compresses the blood vessels. Hence, the state of hypoperfusion and subsequent epithelial atrophy can be considered in the progression of disease to the higher grades.

Features of distribution and dynamics of the connective tissue fibers in the ventricles of rat’s myocardium in normal conditions and after intranatal injection of dexamethasone.

Background. Any disturbance of the formation or organization of connective tissue such as undifferentiated connective tissue disease (UCTD) can lead to changes in extracellular matrix of the heart and deterioration of adaptive abilities in the future. The safety of using synthetic glucocorticoids in pregnant women is the subject of active discussions due to possible adverse effects of dexamethasone on the development of the fetus and, in particular, on connective tissue the heart. Objective. The purpose of this research is to study the features of distribution and dynamics of the connective tissue fibers in the ventricles of rat’s myocardium in normal conditions and after intranatal injection of dexamethasone. Methods. 144 hearts of laboratory rats were investigated. They were divided into 3 groups: the first group included intact rats, the second - control group, that get intrauterine injection of Sodium Chloride solution 0.9% 0.05 ml on the 18th day of antenatal development. The third group was formed by experimental animals, who were injected by 0.05 ml of dexametazone in a similar method. Serial sections were stained with orcein, van Gieson method and impregnation with silver carbonate by Lilly. Results. It was found that intrauterine administration of dexamethasone in rats causes a significant decrease of collagen fibers in the myocardium on 45-th day after birth comparison to control and intact groups by 30.8% and 29.1% respectively. In the structure of collagen fibers, the volume of type III fibers content at 14, 21 and 30 days were significantly higher in animals of intact and control groups than indexes of experimental group.Conclusion. Intranatal injection of dexamethasone may cause a violation in the development and lead to disorganisation of the connective tissue fibers in the ventricles of the heart. These changes may lead to development of UCTD and limitate the adaptive abilities of the heart in the future.

Histological and Some Immunofluorescence Studies on the Gills epithelium of the Gray Mullet (Mugil Cephalus) with reference to the age

Mugil cephalus fish is from euryhaline fish, so its gills have the ability for accommodation in both fresh and marine water. We studied the histological changes in gill epithelium at the age of three, six, eight months and one year as well as, expression of PPARα, PPARγ, BCL-2, BAX, KI67, and PCNA in gills epithelium. We used hematoxylin and eosin staining for general histological observations. As well as, we detected Immunofluorescence of PPARα, PPARγ, BCL-2, BAX, KI67, and PCNAantibodies. General histological observations detected that the gill filament was supported by hyaline cartilage and some connective tissue fibers, from the gill filament several secondary lamellae projects. There were several kinds of cells present in gill filament and secondary lamella e; mitochondria-rich cells (MRCS), pavement cells, mucous cells, red blood cells, pillar cells, melanincontaining macrophage and undifferentiated cells at the apex of gill filament. The mitochondria-rich cells gave a positive reaction with PPARγ which indicated a role of PPARγ in osmoregulation process performed by MRCS. However, PPARα was highly positive in red blood cells which suggested its role in respiration process. In all examined ages there was a high number of proliferative and apoptotic cells widely distributed all over the gills. An essential role of PPARγ in the process of osmoregulation was observed and an important role of PPARα in the respiratory function of gills. As well as, we distinguished the ability of gills epithelial cells to proliferate under the control of PCNA and KI67 for the maintenance of normal gill structure in hazard conditions. Also damaged cells undergo apoptosis process under the control of BAX and the anti-apoptotic process performed in gills under the control of BCL2 gene.