Innovative prophylactic and therapeutic approaches in liver cirrhosis.

Liver cirrhosis is the consequence of chronicisation and of the evolution of untreated liver diseases. The complexity of the disease and the complications it can cause have been and are still intensively researched, aiming to discover new therapies or improve existing ones for the effective management of liver cirrhosis. Currently, the treatment used is directed against the cause that caused the disease, if it is known; in advanced cases, liver transplantation is the only valid therapeutic option. Hepatoprotectors that are currently on the market are numerous, having as common properties the antioxidant, anti-inflammatory, stabilizing properties of the hepatocytic membrane; A few examples: the ethanolic extract of Curcuma longa, the extract from the plant called Sophora flavescens, the extract of Glycyrrhiza glabra, silymarin (extracted from Sylibum marianum), the extract of Ganoderma lucidum, etc. Liver cirrhosis is accompanied by generalized hypovitaminosis, so supplementing the diet with hydro- and liposoluble vitamins is mandatory. Protein-caloric malnutrition can be prevented by a hyperprotein diet, especially beneficial being the supplementation with branched-chain amino acids, which are also applicable in the prophylaxis and treatment of hepatic encephalopathy. Nanoparticles are a state-of-the-art therapeutic option, proving increased bioavailability, for example polydopamine nanoparticles loaded with l-arginine have been tested as therapy in liver cirrhosis. Among the innovative treatment directions in liver cirrhosis are hybrid products (e.g. hybrid polymer nanoparticles loaded with caffeic acid), cell cultures and artificial or bioartificial liver support.

Neuronal apoptosis can be prevented by the combined therapy with melatonin and hypothermia in a neonatal rat model of hypoxic-ischemic encephalopathy.

INTRODUCTION: Birth hypoxia is a leading cause of perinatal mortality and neurological morbidity, resulting in central nervous system injury. Cerebral hypoxia and ischemia can produce a severe brain damage following a typical pattern, defined by selective vulnerability of the brain regions. The neonates are most prone to hypoxic-ischemic injuries due to the lack of efficient antioxidant defense. Neonatal hypoxia-ischemia (HI) in a 7-day-old rat HI model can produce cell death by apoptotic or necrotic mechanisms. The degree of apoptotic or necrotic mechanisms responsible for cell death in neonatal hypoxia-ischemia are not very clear as yet. The form of neuronal death may also depend on the severity of ischemic injury. Necrosis predominates in more severe cases, whereas apoptosis occurs in areas with milder ischemic injury. A human study demonstrated apoptotic and necrotic forms of cell death after hypoxic injury, whereas in some brains from stillbirths, only apoptotic figures were observed. The expression of activated caspase-3 reflects the role of apoptosis in neonatal hypoxic ischemic brain injury. OBJECTIVES: The aim of this study was to evaluate the possible neuroprotective effect of melatonin and hypothermia in hypoxic-ischemic encephalopathy in newborn rats. Local damages induced by hypoxia and ischemia were assessed by evaluating the changes in terms of histology and apoptosis. METHODS: The experiment was conducted on 20 newborn Wistar rats premedicated for seven days with melatonin in a dose of 20 mg/kg/day. On the 7th postnatal day (P7), the newborn rats were exposed to ischemia (by clamping the right carotid artery) and hypobaric hypoxia (8% O2 for 90 minutes) and some groups to hypothermia. RESULTS: In this experimental model of neonatal encephalopathy, melatonin, in a dose of 20 mg/kg/day has neuroprotective effect by reducing the number of cells expressing apoptosis in Cornu Ammonis (CA) (Ammon's Horn) CA1, CA2, CA3 and dentate gyrus of the hippocampus when combined with hypothermia. CONCLUSION: The results of this study prove that melatonin is protective in ischemic-hypoxic brain injuries, but the protection is conditioned in most of the brain regions (excepting cerebral cortex) by conjugation with post-injury hypothermia treatment.

Enhancement of bone consolidation using high-frequency pulsed electromagnetic short-waves and titanium implants coated with biomimetic composite embedded into PLA matrix: in vivo evaluation.

PURPOSE: Bone consolidation after severe trauma is the most challenging task in orthopedic surgery. This study aimed to develop biomimetic composite for coating Ti implants. Afterwards, these implants were tested in vivo to assess bone consolidation in the absence or the presence of high-frequency pulsed electromagnetic short-waves (HF-PESW). MATERIALS: Biomimetic coating was successfully developed using multi-substituted hydroxyapatite (ms-HAP) functionalized with collagen (ms-HAP/COL), embedded into poly-lactic acid (PLA) matrix (ms-HAP/COL@PLA), and subsequently covered with self-assembled COL layer (ms-HAP/COL@PLA/COL, named HAPc). METHODS: For in vivo evaluation, 32 Wistar albino rats were used in four groups: control group (CG) with Ti implant; PESW group with Ti implant+HF-PESW; HAPc group with Ti implant coated with HAPc; HAPc+PESW group with Ti implant coated with HAPc+HF-PESW. Left femoral diaphysis was fractured and fixed intramedullary. From the first post-operative day, PESW and HAPc+PESW groups underwent HF-PESW stimulation for 14 consecutive days. Biomimetic coating was characterized by XRD, HR-TEM, SEM, EDX and AFM. RESULTS: Osteogenic markers (ALP and osteocalcin) and micro-computed tomography (CT) analysis (especially bone volume/tissue volume ratio results) indicated at 2 weeks the following group order: HAPc+PESW>HAPc≈PESW (P>0.05) and HAPc+PESW>control (P<0.05), indicating the higher values in HAPc+PESW group compared to CG. The fracture-site bone strength showed, at 2 weeks, the highest average value in HAPc+PESW group. Moreover, histological analysis revealed the most abundant COL fibers assembled in dense bundles in HAPc-PESW group. At 8 weeks, micro-CT indicated higher values only in HAPc+PESW group vs CG (P<0.05), and histological results showed a complete-healed fracture in groups: HAPc+PESW, HAPc and PESW, but with more advanced bone remodeling in HAPc+PESW group. CONCLUSION: Using Ti implants coated by HAPc jointly with HF-PESW stimulation positively influenced the bone consolidation process, especially in its early phase, thus potentially providing a superior strategy for clinical applications.

Enhancement of bone consolidation using high-frequency pulsed electromagnetic fields (HF-PEMFs): An experimental study on rats.

In vitro studies showed that high-frequency pulsed electromagnetic fields (HF-PEMFs) increase the activity/expression of early and late osteogenic markers and enhance bone mineralization. The main aim of this study was to investigate the in vivo effects of HF-PEMFs on fracture healing using a rat model. A femur fracture was established by surgery in 20 male Wistar rats. Titanium nails were implanted to reduce and stabilize the fracture. After surgery, 20 rats were equally divided into untreated control and treated group (from the first postoperative day HF-PEMFs at 400 pulses/sec [pps] were applied for 10 minutes/day, for two weeks). Quantitative and qualitative assessment of bone formation was made at two and eight weeks following surgery and included morphological and histological analysis, serological analysis by ELISA, micro-computed tomography (micro-CT), and three-point bending test. At two weeks in HF-PEMF group, soft callus was at a more advanced fibrocartilaginous stage and the bone volume/total tissue volume (BV/TV) ratio in the callus area was significantly higher compared to control group (p = 0.047). Serum concentration of alkaline phosphatase (ALP) and osteocalcin (OC) was significantly higher in HF-PEMF group (ALP p = 0.026, OC p = 0.006) as well as the mechanical strength of femurs (p = 0.03). At eight weeks, femurs from HF-PEMF group had a completely formed woven bone with dense trabeculae, active bone marrow, and had a significantly higher BV/TV ratio compared to control (p = 0.01). HF-PEMFs applied from the first postoperative day, 10 minutes/day for two weeks, enhance bone consolidation in rats, especially in the early phase of fracture healing.

Neuroprotective strategy in an experimental newborn rat model of brain ischemia and hypoxia: effects of Resveratrol and hypothermia.

INTRODUCTION: Cerebral hypoxia and ischemia are the major causes of perinatal mortality resulting in central nervous system injury. Hypoxia and ischemia produce massive brain damage and one of the most important mechanisms in the lesion pattern is oxidative stress. AIMS: The objectives of this study are to assess the effects of resveratrol pretreatment in a cerebral hypoxic-ischemic (HI) newborn rat model as well as the influence that hypothermia has on redox parameters in this experimental model and the effects of the combined therapy from the oxidative stress perspective. MATERIAL AND METHOD: The experiment was performed on eighty newborn Wistar rats of both genders, weighing about 10 grams, placed into eight groups: control, treated with resveratrol (RES), RES+HI insult, RES+hypothermia, subjected to hypothermia only, HI insult+normothermia, HI insult+hypothermia. Resveratrol was administrated in a dose of 20 mg/kg/day for seven days as premedication. At the end of this period the animals were exposed to hypobaric hypoxia (9% O(2+) for 90 minutes) and ischemia (by clamping the right carotid artery). In order to test the effect of combined therapy of resveratrol with hypothermia, several animals were exposed after HI injury to whole body moderate hypothermia (with 4°C) for 3h. After recovery the malondialdehyde level and the activities of superoxide dismutase and glutathione peroxidase were determined in the brain tissue of the newborn rats. RESULTS: MDA levels were increased in the groups receiving resveratrol pretreatment. In the group subjected to simple hypothermia MDA levels were also increased. In the group subjected to HI insult and then to hypothermia, MDA levels were significantly lower. MDA levels were lower also in the group where RES was associated with hypothermia in HI insult context. GPx levels were decreased in groups pretreated with RES and subjected to HI, hypothermia, the same effect in case of hypothermia alone. Only in the group treated with RES was the GPx level higher than in controls. SOD levels were high in the RES pretreated group, but decreased in HI insult. In the group subjected to hypothermia after HI, SOD was significantly higher. CONCLUSION: The results of this study prove that hypothermia offers better neuroprotection in ischemic brain injuries than resveratrol. The combined therapy influenced the oxidative stress parameters. Hypothermia is a stress factor, but when applied in post-lesion condition, offers protection for the brain.