New Oxazolo[5,4-d]pyrimidines as Potential Anticancer Agents: Their Design, Synthesis, and In Vitro Biological Activity Research.

Cancer is a large group of diseases in which the rapid proliferation of abnormal cells generally leads to metastasis to surrounding tissues or more distant ones through the lymphatic and blood vessels, making it the second leading cause of death worldwide. The main challenge in designing a modern anticancer therapy is to develop selective compounds that exploit specific molecular targets. In this work, novel oxazolo[5,4-d]pyrimidine derivatives were designed, synthesized, and evaluated in vitro for their cytotoxic activity against a panel of four human cancer cell lines (lung carcinoma: A549, breast adenocarcinoma: MCF7, metastatic colon adenocarcinoma: LoVo, primary colon adenocarcinoma: HT29), along with their P-glycoprotein-inhibitory ability and pro-apoptotic activity. These oxazolo[5,4-d]pyrimidine derivatives, which are structurally similar to nucleic purine bases in general, are characterized by the presence of a pharmacologically favorable isoxazole substituent at position 2 and aliphatic amino chains at position 7 of the condensed heterocyclic system. In silico analysis of the obtained compounds identified their potent inhibitory activity towards human vascular endothelial growth factor receptor-2 (VEGFR-2). Molecular docking was performed to assess the binding mode of new derivatives to the VEGFR-2 active site. Then, their physicochemical, pharmacokinetic, and pharmacological properties (i.e., ADME-administration, distribution, metabolism, and excretion) were also predicted to assess their druglikeness. In particular, compound 3g (with a 3-(N,N-dimethylamino)propyl substituent) was found to be the most potent against the HT29 cell line, with a 50% cytotoxic concentration (CC50) of 58.4 µM, exceeding the activity of fluorouracil (CC50 = 381.2 µM) and equaling the activity of cisplatin (CC50 = 47.2 µM), while being less toxic to healthy human cells (such as normal human dermal fibroblasts (NHDFs)) than these reference drugs. The results suggest that compound 3g is a potentially promising candidate for the treatment of primary colorectal cancer.

ß-adrenergic antagonists influence abdominal aorta contractility by mechanisms not involving ß-adrenergic receptors.

ß-adrenergic receptors (ß-AR) are widely distributed in the cardiovascular system, where they considerably contribute to the control of its functions. ß-blockers are commonly used in the treatment of disorders of the circulatory system. They act primarily by inhibiting cardiac ß-receptors. However, there are also reports of pleiotropic action of ß-blockers as well as of new compounds created to study ß3 adrenergic receptors. The study aimed to investigate additional mechanisms of action of ß-AR inhibitors in the rabbit abdominal aorta with emphasis on their action on α-adrenergic receptors and calcium influx. Responses to propranolol, betaxolol, metoprolol and SR59230A were evaluated in phenylephrine and PGF(2alpha) precontracted aortic rings. The effect of propranolol on the phenylephrine concentration-contraction curve was examined. Propranolol (≥ 10 µM) and SR59230A (≥ 0.1 µM) induced relaxations in phenylephrine-precontracted rings, while betaxolol and metoprolol had little effect. The ß-AR inhibitors produced further contraction of tissues preincubated with PGF(2alpha), excluding SR59230A, which after initial contraction, elicited marked relaxation at a concentration above 1 eM. 100 µM of propranolol caused a significant rightward shift of the concentration-contraction curve to phenylephrine with no reduction in the maximum response. Incubation of aortic rings in phentolamine reduced the maximal contraction to propranolol; verapamil pretreatment by contrast enhanced contractile response. In conclusion, SR59230A and propranolol most probably act as α1-AR competitive antagonists in the presence of phenylephrine in rabbit abdominal aortic rings. After α-ARs blockade, propranolol exerts a weak relaxing activity connected with Ca2+ channel inactivation. SR59230A at a high concentration acts on the rabbit aorta by an additional mechanism needing further investigation.

Comparison of the effect of alpha1- and alpha2-adrenoceptor agonists and antagonists on muscle contractility of the rabbit abdominal aorta in vitro.

The aim of the study was to demonstrate the effect of selected agonists and antagonists of alpha-adrenergic receptors on muscle contractility of the rabbit abdominal aorta in vitro with particular emphasis on alpha2-adrenergic receptor subtypes. The study was conducted on 30 New Zealand breed rabbits from which specimens of the abdominal aorta were collected. The sections were set up in an automatic water bath in a Krebs-Henseleit buffer at 37 degrees C. The experiments showed that alpha1-adrenergic receptors played the main role in the contractile response ofthe rabbit abdominal aorta. Stimulation of alpha1-adrenergic receptor by administration ofphenylephrine resulted in an increase in smooth muscle tonus ofthe rabbit abdominal aorta by an average of 4.75 mN. The reaction after stimulation of alpha2-adrenergic receptors by similar doses of their agonists was much weaker. Prolonged tissue response time and time needed to reach maximum tonus for alpha2-adrenergic receptor agonists were observed. The obtained results confirm the thesis that the alpha1-adrenergic receptor is the most important factor controlling the contractility of the rabbit abdominal aorta, but the alpha2-adrenergic receptor is also involved in maintaining muscle tissue tonus.

Nonspecific effects of ligands on the beta-adrenergic receptors in rabbit abdominal aorta in vitro.

The study was conducted on 30 New Zealand rabbits weighing 3-4 kg from which sample strips of the abdominal aorta were collected. The study investigated the in vitro reaction of rabbit aorta smooth muscle to ligands binding to beta-adrenergic receptors. The response of aortic strips to beta-adrenergic receptor agonists (dobutamine, isoproterenol, salbutamol) and the influence of beta-adrenergic receptor antagonists (propranolol, betaxolol) on contractile activity was determined. All tested agonists induced contraction of the rabbit abdominal aorta muscle in a concentration-dependent manner (dobutamine >> isoproterenol > salbutamol). Enhanced reaction to low concentrations of agonists (dobutamine, isoproterenol) after administration of propranolol and inhibition of contractility in the presence of high concentrations thereof (dobutamine, salbutamol) was observed. Maximal reaction to agonists decreased after betaxolol pretreatment. The results indicate that all the substances with beta-agonist activity also possess contracting properties (presumably by acting at alpha-adrenergic receptors), but are much weaker in the case of isoproterenol and salbutamol than for dobutamine. Propranolol and betaxolol reduce the contractile response of smooth muscle using probably other mechanisms than those associated with adrenergic receptors.

[Effect of atherosclerotic plaque on the contractility of human abdominal aorta sections]. / Wplyw blaszki miazdzycowej na kurczliwosc skrawków ludzkiej aorty brzusznej.

The study was performed on 18 sections of the aneurysm-like abdominal aorta sampled during elective procedures of aneurysm correction in humans, and 10 sections of pig abdominal aorta. We examined the extent to which the presence of atherosclerotic plaque impaired the aorta contractile function and measured the thickness and weight of atherosclerosis plaque and arterial wall. We observed reduced tissue response to adrenaline in human aneurysm-like aorta in comparison to the control group. In the sections of human aorta devoid of atherosclerotic plaque the response to adrenaline was about 30% higher than in those with atherosclerotic changes but 35% lower than in normal aorta sections from pigs. The wall of aneurysm-like human aorta sections was thinner when compared to normal aorta.

[Minimally invasive access to the abdominal aorta in pigs]. / Malo inwazyjne dojscie operacyjne do aorty brzusznej u swin.

Experiments were conducted on 10 sows weighing 50-60 kg. Animals were randomly divided into two experimental groups comprising 5 individuals each. Surgical procedure of reaching the abdominal aorta below the renal arteries was performed using two different methods. In animals from the first group the procedure involved cutting the linea alba in order to obtain access to the abdominal aorta through the abdominal cavity. In the second group the access to the abdominal aorta was obtained by retroperitoneal approach. The approach was made in lower lateral one-third of the abdomen cutting through the muscles and without opening the peritoneal cavity. The study showed superiority of the second surgical method over the median approach along the linea alba in the form of: better animal survival (100% of animals), shorter procedure time, lack of postoperative complications, shorter recovery period and better general postoperative condition

In vitro contractility of normal and aneurysmal abdominal aorta muscle coat sections in human and animal material.

The objective of the study was to demonstrate spontaneous contractile activity of the smooth muscle coat of the aorta in human and animal material. Spontaneous contractility of smooth muscle tissue, or tonus, is essential for the proper function of many internal organs as observed in the many types of muscle cells which make up the internal structures. The spontaneous contractile activity of the muscle tissue in blood vessels is particularly marked in resistance vessels, regulating circulation within organs or tissues. It can also be observed in large blood vessels such as arteries and veins. The contractile activity of muscular tissue isolated from arteries is the result of a number of factors, including endogenous paracrine substances, neurotransmitters released at postganglionic endings (mostly within the sympathetic system), cells capable of spontaneously generation of functional potentials (pacemaking cells) and the vascular endothelium. Pacemaking cells present in the aortic wall are an important factor in the development of the spontaneous contractility of the muscular coat of the aorta. They are capable of generating functional potentials, resulting in the constant tonus of the smooth muscular coat (comprising the aortic wall) due to tonic contraction. In vitro studies were carried out on abdominal aortic sections collected from 30 New Zealand rabbits with a body mass of 3-4 kilograms each and also on aneurysmal abdominal aortic sections collected during elective aneurysm repair procedures in humans (10 abdominal aortic sections). The 1.5 cm-long sections were mounted in chambers of an automated water bath. The sections were oriented in a transverse and longitudal fashion in order to compare contractility. The incubation medium consisted of Krebs-Henseleit buffer. Spontaneous contractile activity was observed during the study, characterized by rhythmic contractions of the muscular layer of the aorta. The contractile tension within the sections was 0.15 mN in the case of rabbit sections and 0.8 mN in the case of human sections. The average duration of a single contraction was 38.3 +/- 15.05 seconds. The average contraction frequency, i.e. the average number of contractions per minute, was 1.61 +/- 0.54 contractions per minute. The spontaneous contraction is modulated by many factors like endogenous paracrine substances, neurotransmitters or vascular endothelium.

Near-infrared photobiomodulation of blood reversibly inhibits platelet reactivity and reduces hemolysis.

Photobiomodulation (PBM) in the red/near-infrared (R/NIR) spectral range has become widely recognized due to its anti-inflammatory and cytoprotective potential. We aimed to assess the effects of blood PBM on platelets function and hemolysis in an in vitro setting. Porcine blood samples were separated into four aliquots for this study, one of which served as a control, while the other three were subjected to three different NIR PBM dosages. The platelet count and functions and the plasma free haemoglobin and osmotic fragility of red blood cells were measured during the experiment. The control group had a considerable drop in platelet number, but the NIR exposed samples had more minimal and strictly dose-dependent alterations. These modifications were consistent with ADP and collagen-induced platelet aggregation. Furthermore, red blood cells that had received PBM were more resistant to osmotic stress and less prone to hemolysis, as seen by a slightly lower quantity of plasma free hemoglobin. Here we showed under well-controlled in vitro conditions that PBM reversibly inhibits platelet activation in a dose-dependent manner and reduces hemolysis.

Local Effects of a 1940 nm Thulium-Doped Fiber Laser and a 1470 nm Diode Laser on the Pulmonary Parenchyma: An Experimental Study in a Pig Model.

The lungs are a common site of metastases from malignant tumors. Their removal with a minimal but safe tissue margin is essential for the long-term survival of patients. The aim of this study was to evaluate the usefulness of a 1940 nm thulium-doped fiber laser (TDFL) and a 1470 nm diode laser (DL) in a pig model of lung surgery that involved the incision and excision of lung tissue. Histopathological analysis was performed on days 0 and 7 after surgery. Neither TDFL nor DL caused significant perioperative or postoperative bleeding. Histological analysis revealed the presence of carbonized necrotic tissue, mixed fibrin-cellular exudate in the superficial zone of thermal damage and bands of deeper thermal changes. The mean total width of thermal damage on day 0 was 499.46 ± 61.44 and 937.39 ± 109.65 µm for TDFL and DL, respectively. On day 7, cell activation and repair processes were visible. The total width of thermal damage was 2615.74 ± 487.17 µm for TDFL vs. 6500.34 ±1118.02 µm for DL. The superficial zone of thermal damage was narrower for TDFL on both days 0 and 7. The results confirm the effectiveness of both types of laser in cutting and providing hemostasis in the lungs. TDFL caused less thermal damage to the lung parenchyma than DL.

Usefulness of Thulium-Doped Fiber Laser and Diode Laser in Zero Ischemia Kidney Surgery-Comparative Study in Pig Model.

BACKGROUND: The aim of this study was to evaluate the usefulness of a thulium-doped fiber laser and a diode laser in zero ischemia kidney surgery, by carrying out a comparative study in a pig model. MATERIAL AND METHODS: Research was carried out on 12 pigs weighing 30 kg each. A thulium-doped fiber laser (TDFL) and a diode laser (DL) operating at wavelengths of 1940 and 1470 nm, respectively, were used. The cut sites were assessed both macroscopically and microscopically. The zone of thermal damage visible in the histopathological preparations was divided into superficial and total areas. RESULTS: During partial nephrectomy, moderate to minimal bleeding was observed, which did not require additional hemostatic measures. All animals survived the procedure. On day 0, the total thermal damage depth was 837.8 µm for the TDFL and 1175.0 µm for the DL. On day 7, the depths were 1556.2 and 2301.7 µm, respectively. On day 14, the overall thermal damage depth for the DL was the greatest (6800 µm). The width of the superficial zone was significantly reduced on days 7 and 14 after TDFL application. CONCLUSION: Both lasers are suitable for partial wedge nephrectomy without ischemia in pigs. The TDFL produced similar or better hemostasis than the DL, with a smaller zone of thermal damage and, therefore, seems more suitable for application in human medicine.

Study of Flebogrif®-A New Tool for Mechanical Sclerotherapy-Effectiveness Assessment Based on Animal Model.

Sclerotherapy is the chemical occlusion of vessels using an intravenous injection of a liquid or foamed sclerosing agent that is used in the therapy of blood and lymphatic vessels malformations in the young, and for spider veins, smaller varicose veins, hemorrhoids and hydroceles in adults. This study aimed to assess the effectiveness of mechanosclerotherapy of venous veins with a new device-Flebogrif®-based on an animal model. The experiment was performed on nine Polish Merino sheep weighing 40-50 kilograms. The animals were anesthetized intravenously. The material was divided into three groups: two experimental (1 and 2) and control (3) group. The first experimental group was treated with the use of Flebogrif® and a sclerosant simultaneously, while only Flebogrif® was used in the second experimental group. Flebogrif® was applied into the lateral saphenous vein of both pelvic limbs. The vessel wall thickness was estimated at four points of the histological image in mm (V1, V2, V3, V4). For one month, the animals were euthanized, and the occlusion rate of the treated veins and changes in the vein wall were determined. Histological slides were analyzed under a light microscope and histometry of the vein wall was performed. The Shapiro-Wilk test and the quantity of the investigated parameter groups allowed for using a non-parametric method at four points to compare thickness measurements (the Mann-Whitney test), with p < 0.05. The Mann-Whitney test indicated statistically significant differences between both experimental groups. The results obtained from morphometrical and histological analysis showed better results in the first experimental group than those of the second experimental group. Finally, statistical analysis revealed significant differences between the both the experimental group and control group in morphological analysis. The achieved results allowed us to conclude that the simultaneous use of Flebogrif® and a sclerosant yielded better results of vein lumen reduction than the use of Flebogrif® alone.

Comparison of A 1940 nm Thulium-Doped Fiber Laser and A 1470 nm Diode Laser for Cutting Efficacy and Hemostasis in A Pig Model of Spleen Surgery.

Partial and total splenectomies are associated with a high risk of substantial blood loss. Lasers operating at wavelengths strongly absorbed by water have the potential to improve hemostasis and cut while providing a narrow zone of thermal damage. The aim of this study is to compare a thulium-doped fiber laser (TDFL) emitting a wavelength of 1940 nm and a diode laser (DL) operating at 1470 nm for spleen surgery in a pig model. A partial splenectomy and spleen incisions were made in 12 animals using the two laser devices. The hemostasis was evaluated visually during surgeries. Post-mortem and histopathological evaluations were done on days 0, 7, and 14 following surgery. Neither TDFL nor DL caused bleeding on day 0 or delayed bleeding. On day 14, pale streaks at the site of incision were slightly wider after cutting with DL than with TDFL. Histological analysis revealed a carbonized zone with exudation and a deeper zone of thermal tissue damage on day 0. The width of the thermal changes was 655.26 ± 107.70 µm for TDFL and 1413.37 ± 111.85 µm for DL. On day 7, a proliferation of fibroblasts and splenocytes was visible, as well as a formation of multinucleated giant cells adjacent to the residues of carbonization. The zone of thermal damage was broader for DL (1157.5 ± 262.77 µm) than for TDFL (682.22 ± 116.58 µm). On day 14, cutting sites were filled with connective and granulation tissues with the residues of carbonization. The zone of thermal damage was narrower for TDFL (761.65 ± 34.3 µm) than for DL (1609.82 ± 202.22 µm). Thus, both lasers are efficient in spleen surgery, providing good hemostasis. However, TDFL produces a narrower zone of thermal damage, which suggests its better efficiency for spleen surgery, especially when performing more precise procedures.

Anatomy and histology of the rabbit common calcanean tendon.

Despite the great progress in the field of tendon injuries and chronic tendinopathies in recent years, treatment of these conditions is still challenging. Research utilising animal models is crucial for further advancement in tendon research, with the rabbit being a commonly used species in this field. The objective of the present study was to comprehensively describe the macro- and microanatomy of the common calcanean tendon (tendo Achillei), together with associated structures. Eight female New Zealand rabbits were subjected to anatomical dissection and histologic analysis, revealing significant species-specific features. The soleus muscle presented a thin, spindle shape with no tendon of insertion and attached directly to the lateral gastrocnemius muscle. Therefore, it does not contribute to the formation of the common calcanean tendon. The calcaneal tendon of the semitendinosus muscle was identified as a strong tendinous band at the medial side of the medial gastrocnemius muscle and the superficial digital flexor muscle and tendon distally. The saphenous artery was accompanied by the medial saphenous vein and characteristic accessory medial saphenous vein. The complex structure of the paratendinous connective tissue is described, with the paratenon being contiguous with the epitenon of the individual tendons and epimysium of associated muscles. At the level of the calcaneal tuber, the retromalleolar fat pad was identified, adhering to the cranial surface of the conjoint gastrocnemius tendon. Histologic studies confirmed the presence of the subtendinous calcaneal bursa of superficial digital flexor tendon and the bursa of calcaneal tendon.

Publisher Correction: Low-level light therapy reduces platelet destruction during extracorporeal circulation.

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper.

Sheep model of haemodialysis treatment.

More than two million patients received haemodialysis (HD) in 2013. Many methods for improving dialysis therapy outcomes have been tested. Nevertheless, patients continue to experience high morbidity and mortality rates. We aimed to develop an animal model of HD treatment to study methods that would prevent the adverse effects of renal replacement therapy. The study was conducted using six male Merino sheep. The animals underwent a two-step bilateral nephrectomy, and a permanent dual-lumen catheter was inserted into the jugular vein. In each animal, 10 short, daily HD treatments were conducted. The dialysis prescription was adjusted individually to each animal. Measures of dialysis adequacy (spKt/V and urea reduction ratio [URR]) were calculated for each HD treatment. All animals remained in a good clinical state during the experiment. However, a sustained decrease in red blood cell count was detected. The average URR was 0.65 ± 0.01, whereas the calculated spKt/V was approximately 1.16 ± 0.03. Neither hyperphosphataemia nor a significant decline in serum albumin concentrations were detected during the study. A sustained increase in serum potassium concentrations was detected on consecutive days of the experiment. All sheep survived the treatment and were euthanized at the end of the experiment. In conclusion, we developed a reproducible sheep model of HD treatment. The gentle nature and specific anatomical features of sheep provided easy blood access and allowed us to perform HD without pharmacological intervention. However, some differences in sheep physiology relative to human physiology must be considered when interpreting the results of the study.

Low-Level Light Therapy Protects Red Blood Cells Against Oxidative Stress and Hemolysis During Extracorporeal Circulation.

Aim: An activation of non-specific inflammatory response, coagulation disorder, and blood morphotic elements damage are the main side effects of the extracorporeal circulation (ECC). Red-to-near-infrared radiation (R/NIR) is thought to be capable of stabilizing red blood cell (RBC) membrane through increasing its resistance to destructive factors. We focused on the development of a method using low-level light therapy (LLLT) in the spectral range of R/NIR which could reduce blood trauma caused by the heart-lung machine during surgery. Methods: R/NIR emitter was adjusted in terms of geometry and optics to ECC circuit. The method of extracorporeal blood photobiomodulation was tested during in vivo experiments in an animal, porcine model (1 h of ECC plus 23 h of animal observation). A total of 24 sows weighing 90-100 kg were divided into two equal groups: control one and LLLT. Blood samples were taken during the experiment to determine changes in blood morphology [RBC and white blood cell (WBC) counts, hemoglobin (Hgb)], indicators of hemolysis [plasma-free hemoglobin (PFHgb), serum bilirubin concentration, serum lactate dehydrogenase (LDH) activity], and oxidative stress markers [thiobarbituric acid reactive substances (TBARS) concentration, total antioxidant capacity (TAC)]. Results: In the control group, a rapid systemic decrease in WBC count during ECC was accompanied by a significant increase in RBC membrane lipids peroxidation, while in the LLLT group the number of WBC and TBARS concentration both remained relatively constant, indicating limitation of the inflammatory process. These results were consistent with the change in the hemolysis markers like PFHgb, LDH, and serum bilirubin concentration, which were significantly reduced in LLLT group. No differences in TAC, RBC count, and Hgb concentration were detected. Conclusion: We presented the applicability of the LLLT with R/NIR radiation to blood trauma reduction during ECC.

Low-level light therapy reduces platelet destruction during extracorporeal circulation.

Extracorporeal circulation causes many deleterious effects on blood cells. Low-level light therapy (LLLT) in the red/near-infrared spectral range is known for its cytoprotective properties but its use during cardiopulmonary bypass (CPB) has not yet been studied. We aimed to assess whether LLLT protects platelets during CPB. 24 pigs were connected to 1-hour-CPB and observed for the next 23 hours. In 12 animals, blood circulating through the oxygenator was treated with LLLT. Platelet count and function were monitored throughout the experiment. The decrease in platelet count was greater in the control group, especially during CPB and after 24 hours. In LLLT group CD62P expression remained quite stable up to the 12th hour of the experiment, whereas in the control group it continuously decreased till the end of observation. Platelets in the control group were more prone to aggregation in the postoperative period than at the beginning of the experiment, whereas platelets in the LLLT group aggregated similarly or less intense. Limitation of platelet loss, pattern of aggregation and CD62P expression suggest that LLLT may stabilize platelet function during CPB and diminish the negative effects associated with the interaction of cells with an artificial surface.

Preliminary Evaluation of Thulium Doped Fiber Laser in Pig Model of Liver Surgery.

Partial liver resection is a treatment of choice for liver tumors; the range of parenchyma excision varies from a small part of the tissue surrounding the neoplasm up to 70% of the organ. One of the major concerns during liver resection is blood loss. Thulium lasers which are characterized by the length of emission wave corresponding to a peak absorption of water create a new possibility of cutting tissues efficiently with minimal thermal damage and concurrently providing a good hemostasis control. The aim of our study was to evaluate an impact of liver transection with thulium doped fiber laser on an intraoperative bleeding and histopathological changes during postoperative period in swine model. Ten animals were subjected to open surgery partial liver resection and an incision of liver tissue with an all-fiber, diode-pumped, and continuous-wave Tm3+-doped fiber laser emitting 37.4 W of output power at ~1.94 µm wavelength. The macroscopic and histopathological evaluation was performed intraoperatively as well as 7 and 14 days after surgery. Macroscopically almost no bleeding was observed during surgery and no signs of bleeding were stated after 7 and 14 days. Histopathological analysis of the transection margin revealed a thermal damage area ranging in depth from 620.23 ± 23.82 µm on the day of surgery to 1817.70 ± 211.98 µm after 7 days. In the samples taken intraoperatively and after 7 days a superficial zone of carbonization was visibly separated from the deeper changes. After 14 days one 765.35 µm deep zone characterized by a granulation was present. In conclusion, thulium doped fiber laser is efficacious in cutting with a narrow zone of thermal injury and provides a good hemostasis during liver transection, thus being a potential tool for oncotic liver surgery.

Influence of ovariohysterectomy and deslorelin acetate on the spontaneous activity of the rabbit urinary bladder in vitro.

Lower urinary tract symptoms are not only a serious health problem but also a substantial sociologic issue affecting human beings and companion animals. Estrogen deficiency is considered an etiologic factor of urinary incontinence in postmenopausal women and spayed female dogs. However, insufficient effectiveness of hormonal therapy has caused an intensive search for new therapeutic options. GnRH analogs have positive clinical effects in neutered female dogs suffering from incontinence, but the mechanism of action is not known. The aim of our study was to determine the effect of long-acting deslorelin acetate on the spontaneous activity of urinary bladder sections from a rabbit model of long-term estrogen deprivation. The study was conducted on 21 female New Zealand White rabbits divided into the following groups: control group, ovariohysterectomized (OHX) group, and ovariohysterectomized group given a deslorelin acetate implant. Urinary bladders were excised immediately after sacrifice, and the spontaneous activity of dorsal and ventral strips of the bladder body was examined in organ bath chambers. The amplitude and frequency of the spontaneous contractions were evaluated. Most of the sections developed spontaneous activity. Ovariohysterectomy caused a decrease in the amplitude of spontaneous contractions of the tissues obtained only from the dorsal part of the bladder body. After OHX, the frequency was higher compared with the control group in both parts of the bladder. Deslorelin acetate did not significantly affect the spontaneous contraction amplitude but caused a decrease in the frequency in the dorsal and ventral parts of the bladder. In conclusion, long-term changes in the levels of hormones and other regulatory substances associated with the reproductive system are related to altered spontaneous activity of the urinary bladder, which may impact the symptoms of urgency and incontinence appearing in women after menopause and in female animals after gonadectomy. However, long-acting deslorelin acetate partially reverses the effect of OHX on the spontaneous activity of the bladder. This process might underlie the positive effects of GnRH analogs in incontinent spayed female dogs.

Vertebral disease in excavated canine in Lower Silesia, Poland.

A mostly complete canine skeleton was excavated during rescue archaeological explorations in Domaslaw (Lower Silesia, Poland). The archaeozoological analysis revealed loss of several left maxillary incisors. Discospondylitis was observed in two adjacent lumbar vertebrae. Potential causes of the vertebral pathology are discussed. The cause of death is unknown, but sepsis should be considered. No other pathological changes or evidence of human manipulation to the skeleton were identified.