BACKGROUND AND PURPOSE Clinical research of drugs is a researching step subsequent to the preclinical studies in experimental animals. The aim of our research was to evaluate animal model of wound healing process after the burn inducement and effects of the ointment containing natural plants on the process of burn healing. MATERIAL AND METHODS Burn wounds were experimentally induced in two species of experimental animals which were treated with topically applied herbal preparation with concomitant monitoring of the healing process. Experimental groups (1) of 15 animals each (mice and rats), while control group (2) of 10 animals each (mice and rats) that were not being treated with herbal ointment. After the hair removal, burn was induced on the back of animals by heated brass seal. Different clinical symptoms including oedema of surrounding tissue, redness, exudation, size of the burn surface, histological and microbiological findings were monitored on the days 1, 3, 7, 14 and 21. A statistically significant difference was observed throughout descriptive statistics and paired Student's t-test. CONCLUSION Physiological healing processes of the acute burn wound following the topical application of herbal preparation can be monitored on the utilized animal model. A three-week treatment resulted in the 90% of completed epithelization in both animal species, indicating the effectiveness of topically applied herbal preparation.

Experimental studies of burns require the use of different animal models with the aim to imitate and reproduce pathophysiological conditions. The aim of this work was to establish experimental model of thermal injury. New Zealand rabbits, weighted from 1.8 kg to 2.3 kg, were utilised during our study. Another, also utilized, animal types were laboratory Rattus rats, species Wistar, albino type, females with body weight of about 232 g. All animals were from our own litter (Institute of Pharmacology, Clinical Pharmacology and Toxicology, Faculty of Medicine in Sarajevo). During the experiment, animal were properly situated in adequate cages and rooms, at the controlled temperature (22 +/- 2 degrees C), and in the air with normal humidity level. All animals took food and water ad libitum. Rabbits received anesthesia--intravenous pentobarbital sodium in a dose of 60 mg/kg, and then, hair from the upper side of the each rabbit ear was removed and burns were caused by a metal seal in the same manner as in rats. Rats were primarily anesthesied by intraperitoneal pentobarbital sodium in a dose of 35 mg/kg, and then, their hair was removed from the scapula zone (5 cm x 5 cm). Burns were caused by contact with a round metal seal, heated at 80 degrees C in a water bath, during the period of 14 seconds together with contact thermometer control. Round metal seal (radius: 2.5 cm; weight: 100 g; surface: 5 cm2) was just placed on the rat skin without any additional pressure. In order to maintain the microcirculation in the burn wound and to reduce the conversion of partial-thickness skin burns to the burns of the full-thickness skin, all burn wounds were immediately sunk in the 4 degrees C water. Subsequent to that procedure, all animals were individually situated in the proper cages, and left to rest for 4 hours with a constant cautious monitoring of the wound development and animal general state.

There some evidences that endocrine glands have marked influences on mast cells count The study was conducted to determine whether or not difference in mast cell count occurs in thymus gland of pincalectomized rats and to examine also sex difference in mast cell count under these condition adult Wistar rats were used. Pinealectomy was performed under light ether anesthesia. All animals were sacrificed by decapitation at 4 weeks after treatment. Samples were stained in Alcian-blue-PAS and, using Weibls multipurpose test system, the volume density (Vv), numerical density (Nv) and average volume of mastocytes were calculated. Analysis of morphometry has confirmed statistically significant increase in numerical density of mastocytes of pinealectomized female rats. The average volume of mastocytes has been also increased in both sex of animals after pinealectomy. The data from present studies show that there is marked sexual difference in reaction of mast cells after pinealectomy.

This article is done on the occasion of anniversary of 150th birth of Spanish histolog Santiago Ramón y Cajal (1852.-1934.) whom belongs position of founder neuroanatomy regarding that he gave wide descriptions cells organisation of central and peripheral nervous system for many animal species. Astonishing are his descriptions of different types of neurons, their links, and following glial cells, that are actual today. Special contribution of Cajal refers is to acts from domain of histological technique and micrography, and general pathology. He published more than 100 of scientific articles and a few books, that are classic works. In 1906 Santiago Ramón y Cajal and Camillo Golgi shared Nobel prize for medicine.

Stereological characteristics of ductular parenchyma epithelial cells are analysed ultrastructurally on 8 cases of normal breast tissue. Different physiological states have been compared and tahat pre- and postovulatory. Volume density (VV), surface density (SV) and specific surface density (SV/VV) of nuclei and epithelial cells cytoplasm have been stereologically examined and compared. Postovulatory, the volume density (VV) and surface density (SV) of nuclei as well as specific surface density (SV/VV) of epithelial cells cytoplasm are much less, while a volume density (VV) of epithelial cells cytoplasm is greater.

The mammary glands of primigravid Wistar rats were investigated by stereological analysis in conditions of lead acetate administration via drinking water. The experiment was made in early summer period when absorbing ability of rat intestinum for lead is highest. Morphological state of glands was observed on 7th, 14th and 21st day of pregnancy. Groups of control animals were drinking deionized water but groups of experimental animals were drinking deionized water with added lead acetate. On paraffin sections coloured by HE method, volume density (VV) of glands structural elements were determined by multipurpose test system M42. Stereological analysis shows that lead diminishes the proliferative capacity of the mammary parenchyma and changes the morphofunctional differentiation of the overall structure in mammary gland during pregnancy. At the same time lead modifies quantitative trait of the mammary gland, i.e. the composition of the volume units in organ, without changing intramammary syncornization between the epithelium and lipocytes.

The late effect of surgical ablation of pineal gland on the morphometric changes in epithelial cells of rat thymus were investigated. The aim of this study is to determine a possible existence of sex-different changes in composition of the epithelial cell component unit long after pinealecotmy what could be important for the subtle understanding of mutual correlation between pincal body and thymus. This article presents results of stereological ultrastructure parameters of thymuscortical and medullar epithelial cells of male and female rats two month after pinealectomy. The experimental animals were divide into two groups: an experimental one (pinealectomized) and the control group (shampinealectomized). Pinealectomized animals were submitted to surgical ablation of pineal gland while the control were undertaken the same surgical treatment but without removal of the pineal gland. Animals were sacrificed 60 th days following the surgery treatment. Parasagital pieces of thymus tissue were fixed by means of immersion in glutaraldehyde and prepared for transmission electron microscopy. Using Weibls multipurpose test system and multilevel sampling technique on electron micrographs the volume and surface density of nucleus (Vu, Sv) and cytoplasm of cortical and medullar thymus epithelial cells were calculated. At the different magnification level were established the volume and surface density of mitochondria (Vvm, Svm) endoplasmic reticulum (Vvr, Svr), vacoule(Vuv) as well as numerical density of mitochondria (Nvm). Our analysis has conformed statistically significant increase in Vv of reticulum and vacuole in both sex of pinealectomized rats. Sv of plasmalema, reticulum and mitochondrial membrane are markedly increased in thymus medullar epithelial cells of pienalectomized rats. Vv of mitochondria is significantly increased in cortical epithelial cells of pienalectomized animals. Results allow us to confirm that mutual correlation between pineal gland and thymus exists but present findings seem to support the concept of sex independent inhibitory action of pineal gland on thymus cortical and medullar epithelial cells.

The present study was undertaken to investigate the changes in composition of the mammary gland volume unit through all phases of lactation in rats subjected to lead acetate administration via drinking water during the first pregnancy and lactation. Stereological analysis was performed on serial slices of the organs. The point of support for our study was the fact that lead, apart from being a poison of wide range, is mostly poisonous for gonads and to their supervisory neuroendocrine structures and the mammary gland, in morpho-functional sense, should be admitted as their integral part. On the 7th day of lactation there was significant difference of the alveolar and ductal epithelium phase, which was significantly reduced in animals treated by lead. In the same animals there were larger lumens of the alveoli and ducti, more abundant connective tissue and greater number of the adipocytes but these differences in comparison to control group were not significant. On the 14th day of lactation there was significantly greater presence of the adipocytes phase and stromal tissue while the volume of the epithelium of alveoli and ducti was significantly reduced in study group. There was also an increase of the alveoloductal lumen phase but this was not significant. On the 21st day of lactation there were significant difference in epithelial and stromal tissue phases in two groups, having a significant decrease in the epithelium, and significant increase of stromal tissue in glands of lactating rats treated by lead acetate. There were non-significant differences as far as the presence of the adipocytes and alveoloductal lumen volume were concerned although the values for both phases in study group were above the control values. On the basis of given results we concluded that lead changes the quantitative characteristics of the mammary gland, i.e. the composition of the volume unit of the organ through all phases of lactation.

The aim of the study was to determine the effects of exogenous melatonin on Leydig cells in irradiation stress. Nuclear and cytoplasm surface of Leydig cells in sham pinealectomized and pinealectomized adult Wistar rats was determined after their total irradiation with 8 Gy of gama rays produced by 60 Co and with previously performed 14 days treatment by injecting of melatonin solution in a daily dose of 0.2 mg. Rats testes were histologically prepared 17 days after irradiation. Total melatonin administration significantly decreased surface of Leydig cells including both decrease of their nuclear and cytoplasm surface in irradiated sham pinealectomized and pinealectomized rats. The results suggested about direct effects of exogenous melatonin on Leydig cells in irradiation stress.

The effects of pinealectomy on the dynamics of morphometric changes in interdigitating cells(IDC) of rat thymus were investigated. The experimental animals were divided into two groups: an experimental one and the control group. Animals from the first group were subjected to pinealectomy while the second group were treated in the same manner, but without the removal of the pineal gland. All the animals were sacrificed 60. days following the surgery. The thymus tissue were fixed by means of immersion and prepared for transmission electron microscopy. Using Weibl's multipurpose test system and multilavel sampling technique on electron micrographs, the nuclear volume density(Vvn) and cytoplasmic volume density(Vvc) were calculated. At the different magnification level established the surface density(Sv) of nucleoid and cell membranes as wel as surface density of rough endoplasmic reticulum and mitochondrial membranes (Svm) and their volume density. Our analysis has confirmed statistically significant increase in Vv of the nucleus of pinealectomized rats. The average volumen of IDC has been also increased after pinealectomy as well as Vv, Nv and Sv of the mitochondria. The present findings seem to support the concept of inhibitory action of pineal gland on thymus IDC.

The mammary mast cells number, distribution, type and some other structural characteristics was studied at 7., 14. and 21. postpartum date in lactating Wistar rats receiving deionized water of lead acetate via drinking water during the first lactation. Toluidine blue or alcian blue and safranine staining of the material from left abdominal mammary glands were used for histological, histochemical and morphometry evaluation. Thirty random immersion fields of three distant tissue section in the stromal compartment of each gland's areas were counted. The fluctuation of mammary mast cells number with peak at 14th postpartum date and dominance of granulated and with epithelium unassociated mast cells was estimated in normal lactating animals. The parallel progress of safranine-positive granules and secretory activity of mammary mast cells with the length of lactation was observed in the same group of animals. The fluctuation of mammary mast cells number during the lactational period with significant increased at 14th postpartum date and dominance with epithelium associated cells at the same time was estimated in lead acetate treated lactating animals. Safranine-stained positive material was dominant in mammary mast cells under the influence of lead. In the same group of animals the progression of release the secretory granules from mast cells and partial to total degranulation of cells was observed. During the lactation and under the influence of lead the mammary mast cells are associated with the gland changes in morphology and function.

The mammary mast cells number, structure and distribution was studied at 7, 14 and 21 days post-plug data in Wistar rats receiving lead acetate via drinking water or deionized water during first pregnancy. Toluidine blue or alcian blue and safranine-staining of the material from left abdominal mammary glands were used for histological, histochemical and morphometry evaluation. Thirty random oil immersion fields of three distant tissue section in the stromal compartment of each gland's areas were counted. The parallel progress of mast cells number with gestational progression of mammary gland, dominance alcian blue-stained positive, granulated and with epithelial unassociated mammary mast cells was estimated in normal pregnant animals. Significant increased mammary cells number, dominance of safranine-stained positive, with epithelium unassociated and degranulating mast cells was estimated in lead acetate treated pregnant animals. We concluded that lead acetate exerts on qualitative and quantitative characteristics of mammary mast cells during pregnancy in Wistar rats. We propose some protective role of mammary mast cells in pregnant animals treated by lead acetate.

The authors were investigating the qualitative and quantitative characteristics of the cells of the thyroid gland of pinealectomized and melatonin treated rats whose body irradiated with 8 Gy gamma rays. It was established that melatonin decreased height of the thyreocytes in peripherical and central part of gland, and nuclear volume of thyreocytes only in the central part of gland. The results suggest the role of melatonin in determination of the behaviour of thyreocytes upon Pinealeotomy and Radiation.

The volume density of the seminiferous epithelium, lumen of tubules and the testis interstitium in the shampinealectomized adult Wistar rats was determined after melatonin treatment and whole-body irradiation with 8 Gy of gamma rays produced by 60 Co. The solvent was injected to the control group of animals. By the comparison of stereological results, it was shown that melatonin modifies the quantitative characteristics of seminiferous tubules reducing the effects of irradiation originally produced.