Neurologic and histologic outcome after intraneural injections of lidocaine in canine sciatic nerves.

BACKGROUND: Inadvertent intraneural injection of local anesthetics may result in neurologic injury. We hypothesized that an intraneural injection may be associated with higher injection pressures and an increase in the risk of neurologic injury. METHODS: The study was conducted in accordance with the principles of laboratory animal care, and was approved by the Laboratory Animal Care and Use Committee. Fifteen dogs of mixed breed (16-21 kg) were studied. After general endotracheal anesthesia, the sciatic nerves (n= 30) were exposed bilaterally. Under direct vision, a 25-gauge, long-beveled needle (30 degrees) was placed either epineurally (n= 10) or intraneurally (n= 20), and 4 ml of preservative-free lidocaine 20 mg/ml was injected using an automated infusion pump (4 ml/min). Injection pressure data were acquired using an in-line manometer coupled to a computer via an analog-to-digital conversion board. After injection, the animals were awakened and subjected to serial neurologic examinations. One week later, the dogs were killed, the sciatic nerves excised and histologic examination was performed by pathologists blind to the purpose of the study. RESULTS: All perineural injections resulted in low pressures (< or = 5 psi). In contrast, eight of 20 intraneural injections resulted in high pressures (20-38 psi) at the beginning of the injection. Twelve intraneural injections, however, resulted in pressures of less than 12 psi. Neurologic function returned to baseline within 3 h after perineural injections and within 24 h after intraneural injections, when the measured injection pressures were less than 12 psi. Neurologic deficits persisted throughout the study period after all eight intraneural injections that resulted in high injection pressures. Histologic examination of the affected nerves revealed fascicular axonolysis and cellular infiltration. CONCLUSIONS: The data in our canine model of intraneural injection suggest that intraneural injections do not always lead to nerve injury. High injection pressures during intraneural injection may be indicative of intrafascicular injection and may predict the development of neurologic injury.

Animal model of thermal injuries.

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.

[Ultrastructural stereologic parameters of epithelial cells of alveolar ducts in the pre-and postovulatory female breast]. / Ultrastrukturni stereoloski parametri epitelnih stanica alveolarnog duktulusa pre- i postovulatorne zenske dojke.

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.

[Stereologic analysis of mammary glands in primiparous rats with lead poisoning]. / Stereoloska analiza mlijecne zlijezde primigravidnih pacova tokom intoksikacije olovom.

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.

[Late effects of experimental ablation of the pineal gland on ultrastructural morphometric changes in thymic epithelial cells]. / Kasni efekti eksperimentalne ablacije pinealne zlijezde na ultrastrukturne morfometrijske promijene timusnih epitelialnih celula.

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.

[Reaction of thymic mononuclear phagocytes in rats 2 months after pinealectomy, ultrastructural-morphometric analysis of interdigitating cells]. / Reakcija timusnih mononuklearnih fagocita u pacova dva mjeseca nakon pinealektomije, ultrastrukturna-morfometrijska analiza interdigitantnih celula (IDC).

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.

[Morphometric characteristics of Leydig cells after total irradiation of rats treated with melatonin]. / Morfometrijske karakteristike Leydigovih stanica totalno ozracenih stakora tretiranih melatoninom.

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.

[Effect of lead acetate on qualitative and quantitative characteristics of mammary mast cells in lactating rats]. / Uticaj olovnog acetata na neke kvalitativne i kvantitativne karakteristike mamarnih mastocita kod pacova dojilja.

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 effect of lead acetate on qualitative and quantitative characteristics of mammary mastocytes in primigravid rats]. / Uticaj olovnog acetata na neke kvalitativne i kvantitativne karakteristike mamarnih mastocita kod primigravidnih pacova.

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.

[Morphometric characteristics of thyroid cells in irradiation-stressed rats treated with pinealectomy and melatonin]. / Morfometrijske odlike tireocita pinealektomisanih i melatoninom tretiranih pacova u iradijacionom stresu.

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.

Histochemical aspects and fine structural characteristics of thyreocytes in pinealectomized and melatonin treated rats prior to irradiation.

The authors were investigating the histochemical and electron microscopic characteristics of thyreocytes in pinealectomized rats treated with melatonin, prior to irradiation. They observed that the animals that did not receive melatonin show a higher degree of the destruction appearing at the level of all ultrastructural organelles and a very low expression of the DNA and RNA histochemical reaction. These results suggest the role of melatonin in the determination of the thyreocyte behaviour under given irradiation conditions.

[Morphometric aspects of seminiferous tubules in rats treated with melatonin and whole body irradiation (stereologic analysis)]. / Morfometrijski aspekt sjemenih kanalica totalno ozracenih pacova tretiranih melatoninom (stereoloska analiza).

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.

[Early histological changes in the thyroid gland in irradiated rats without a pineal body]. / Rane histoloske promjene stitnjace ozracenih pacova u uslovima anepifizije.

The authors investigated histological characteristics of the thyroid gland in irradiated rats under the conditions of anepiphysia. Pseudo-epiphysectomized rats and epiphysectomized rats were irradiated in toto with a single dose of 8 Gy gamma irradiation. The animals were decapitated on the 121st day of the postoperative period, in other words, on the 6th day following irradiation. The animals with an intact epiphysis showed significant changes in the histological structure of the thyroid, but they were of a considerably lesser intensity when compared to the changes observed in epiphysectomized rats. On the basis of the differences observed in behavioural characteristics as well as the degree of mortality, we propose that pineal gland absence has determined the behaviour of the glandular parenchyma, as well as of the whole organism in the given conditions.