Impaired endothelium-derived hyperpolarizing factor-mediated dilations and increased blood pressure in mice deficient of the intermediate-conductance Ca2+-activated K+ channel

The endothelium plays a key role in the control of vascular tone and alteration in endothelial cell function contributes to several cardiovascular disease states. Endothelium-dependent dilation is mediated by NO, prostacyclin, and an endothelium-derived hyperpolarizing factor (EDHF). EDHF signaling is thought to be initiated by activation of endothelial Ca(2+)-activated K(+) channels (K(Ca)), leading to hyperpolarization of the endothelium and subsequently to hyperpolarization and relaxation of vascular smooth muscle. In the present study, we tested the functional role of the endothelial intermediate-conductance K(Ca) (IK(Ca)/K(Ca)3.1) in endothelial hyperpolarization, in EDHF-mediated dilation, and in the control of arterial pressure by targeted deletion of K(Ca)3.1. K(Ca)3.1-deficient mice (K(Ca)3.1(-/-)) were generated by conventional gene-targeting strategies. Endothelial K(Ca) currents and EDHF-mediated dilations were characterized by patch-clamp analysis, myography and intravital microscopy. Disruption of the K(Ca)3.1 gene abolished endothelial K(Ca)3.1 currents and significantly diminished overall current through K(Ca) channels. As a consequence, endothelial and smooth muscle hyperpolarization in response to acetylcholine was reduced in K(Ca)3.1(-/-) mice. Acetylcholine-induced dilations were impaired in the carotid artery and in resistance vessels because of a substantial reduction of EDHF-mediated dilation in K(Ca)3.1(-/-) mice. Moreover, the loss of K(Ca)3.1 led to a significant increase in arterial blood pressure and to mild left ventricular hypertrophy. These results indicate that the endothelial K(Ca)3.1 is a fundamental determinant of endothelial hyperpolarization and EDHF signaling and, thereby, a crucial determinant in the control of vascular tone and overall circulatory regulation.     

Infant death after nose-horned viper (Vipera ammodytes ammodytes) bite in Croatia: A case report

A case of a 45-day-old male infant, bitten on the neck by nose-horned viper (Vipera ammodytes ammodytes), is reported. This episode occurred while the baby was on a picnic with his parents in a hill near a town in southern Croatia. In spite of immediate arrival at hospital, where antivenom was administrated and all the necessary treatment measures were carried out, the infant died 6 h following the bite. The cause of death was severe and progressive hyperkalaemia, massive intravascular haemolysis, severe coagulopathy and myocardial dysfunction.     

Testicular pain after inguinal hernia repair: an approach to resection of the genital branch of genitofemoral nerve

BACKGROUND: The neuropathic groin pain after inguinal hernia repair is usually due to a neuroma of the ilioinguinal, iliohypogastric, or genitofemoral nerve. When the postherniorrhaphy pain symptoms include mostly testicular pain, then the genital branch of the genitofemoral nerve comes first in the differential diagnosis. Nerve blocks are helpful in determining which of the three nerves is implicated in the pain syndrome. Although the surgical approach to the ilioinguinal nerve is now well established, it has been difficult to identify the genitofemoral reliably enough to permit resection of this nerve. STUDY DESIGN: Anatomic cadaver dissections of nerves exiting the lumbosacral plexus were performed. Their course was followed to their final terminations. Based on these findings, an operative approach was designed to address the involved nerve at a specific site. The results and outcomes were prospectively followed. RESULTS: The present anatomic study identifies the site within the inguinal canal where the genital branch of the genitofemoral nerve may be identified. The designed operative approach points to the proximal site of the canal to be opened for an exposure. It also dictates that the nerve should be dissected and resected proximal to the surgical repair or mesh reconstruction, which allows its retroperitoneal placement. All four patients were relieved of their preoperative symptoms using this approach. CONCLUSIONS: Severe and chronic testicular pain after inguinal hernia repair can be treated by a designed approach that identifies the genital branch of the genitofemoral nerve in the proximal inguinal canal, its resection point proximal to the previous operative field, and placement behind the peritoneum.     

Acute rhabdomyolysis: a case report and literature review

Acute rhabdomyolysis is a syndrome characterized by the lesion of skeletal muscle resulting in subsequent release of intracellular contents into the circulatory system, which can cause potentially lethal complications. These contents include myoglobin, creatine phosphokinase, potassium, aldolase, lactate dehydrogenase and glutamic-oxaloacetic transaminase. There are numerous causes that can lead to acute rhabdomyolysis and many of patients present with multiple causes. The most common potentially lethal complication of rhabdomyoloysis is acute renal failure. In this article we present a case of a patient that developed clinical signs of acute rhabdomyolysis after consumption of heroin and alcohol. After approximately nine hours of alcohol and heroin induced coma he had acute compartment syndrome of the right arm, and clinical and laboratory signs of acute rhabdomyolysis with acute renal failure as a complication of rhabdomyolysis. Acute rhabdomyolysis developed in the patient as the result of acute compartment syndrome, with direct toxic activity of alcohol and diamorphine. During the period of coma, due to lying in particular position over a long period of time, pressure upon the certain part of the body caused muscle compression and capillary occlusion in fascial compartments, which led to ischemia. Upon pressure relief and beginning of tissue recovery, post ischemic compartment syndrome occurred with subsequent rhabdomyolysis. Getting out of coma the patient started to complain of severe pain in the right arm, which clinically worsened on passive stretching of the limb, with the loss of sensation and weakness. Laboratory findings showed high levels of creatine phosphokinase as the most sensitive marker of muscular damage. The peak of creatine phosphokinase level can be predictive for the development of acute renal failure because myoglobin level may return to normal within 6 hours after muscle injury. The peak of creatine phosphokinase (186.080 U/L; normal range 0-177) was recorded at 12 hours of admission. Other pertinent laboratory results such as urea, creatinine, prothrombin time, alanine aminotransferase and aspartate aminotransferase were also changed significantly. The peak of potassium level before dialysis was 6.8 mmol/L. Emergency fasciotomy of the anterior and posterior compartment syndrome was performed by a team of physicians after clinical examination. The second look debridement was performed at 48 and 72 hours. The plastic surgical procedure was performed 4 weeks later. On admission the patient also had oliguria with dark brown pigment in his urine. Arterial blood gases revealed metabolic and respiratory acidosis. The patient was hypovolemic and IV rehydratation with crystalloids, sodium bicarbonate and mannitol started immediately upon admission. Despite therapy his urine output decreased. Hemodialysis was initiated at serum potassium level of 6.8 mm/L and continued until his urine output returned to normal in three weeks. The patient was discharged from the hospital after six weeks, with normal urine output, without functional abnormality in his upper right limb. Acute rhabdomyolysis should be considered as a possibility in any patient with prolonged imobilization while in coma as well as in any intoxicated patient. Of course, creatine phosphokinase is the most sensitive indicator of muscle injury and the degree of creatine phosphokinase elevation correlates with the amount of muscle injury and disease severity. Other laboratory findings can help identify common complications of rhabdomyolysis such as acute renal failure, metabolic derangements and disseminated intravascular coagulopathy.     

Molecular characterization of <Emphasis Type="Italic">Atractolytocestus sagittatus</Emphasis> (Cestoda: Caryophyllidea), monozoic parasite of common carp,and its differentiation from the invasive species <Emphasis Type="Italic">Atractolytocestus huronensis</Emphasis>

Sequence structure of complete internal transcribed spacer 1 and 2 (ITS1 and ITS2) of the ribosomal DNA region and partial mitochondrial cytochrome c oxidase subunit I (cox1) gene sequences were studied in the monozoic tapeworm Atractolytocestus sagittatus (Kulakovskaya et Akhmerov, 1965) (Cestoda: Caryophyllidea), a parasite of common carp (Cyprinus carpio carpio L.). Intraindividual sequence diversity was observed in both ribosomal spacers. In ITS1, a total number of 19 recombinant clones yielded eight different sequence types (pairwise sequence identity, 99.7–100%) which, however, did not resemble the structure typical for divergent intragenomic ITS copies (paralogues). Polymorphism was displayed by several single nucleotide mutations present exclusively in single clones, but variation in the number of short repetitive motifs was not observed. In ITS2, a total of 21 recombinant clones yielded ten different sequence types (pairwise sequence identity, 97.5–100%). They were mostly characterized by a varying number of (TCGT)_n repeats resulting in assortment of ITS2 sequences into two sequence variants, which reflected the structure specific for ITS paralogues. The third DNA region analysed, mitochondrial cox1 gene (669 bp) was detected to be 100% identical in all studied A. sagittatus individuals. Comparison of molecular data on A. sagittatus with those on Atractolytocestus huronensis Anthony, 1958, an invasive parasite of common carp, has shown that interspecific differences significantly exceeded intraspecific variation in both ribosomal spacers (81.4–82.5% in ITS1, 74.4–75.2% in ITS2) as well as in mitochondrial cox1, which confirms validity of both congeneric tapeworms parasitic in the same fish host.     

Phenotypic and Genetic Properties of Susceptible and Multidrug-resistant Pseudomonas Aeruginosa Isolates in Southern Serbia

Drug resistance of Pseudomonas aeruginosa is a leading problem in hospital infections. The aim of this study was to determine the best molecular genetic discrimination method for Pseudomonas spp. isolates among 94 outpatients and inpatients and see their grouping by phenotype characteristics (biofilm formation, frequency of serotypes, pigmentation, production of different class of beta-lactamases, and susceptibility to different antibiotic classes) and genotype. The most common serotypes were P1, P6, and P11, while co-productions of pyoverdine and pyocyanin were observed in 70 % of isolates. A total of 77.66 % isolates were mostly weak and moderate biofilm producers. Isolates were susceptible to colistin (100 %), aztreonam (97.87 %), imipenem (91.49 %), doripenem (90.43 %), and meropenem (84.04 %). MICs values confirmed susceptibility to ceftazidime and cefepime and singled out meripenem as the most effective inhibitor. Most isolates were resistant to aminoglycosides and fluoroquinolones. Only two isolates produced ESBL, eight were carbapenemase producers, and five isolates produced MBLs. Twenty-nine isolates were multidrug-resistant; 82.8 % of which produced both pigments, 58.3 % were non-typeable, while the P6 and P11 serotypes were equally distributed (16.7 %). Thirteen MDR isolates were strong enzyme producers. RAPD PCR analysis using primer 272 proved the best at discriminatory fingerprinting for Pseudomonas isolates, as it allocated 12 clusters. A correlation between DNA patterns and antibiotic resistance, production of pigments, serotypes distribution, and biofilm formation was not observed, and only confirmed higher genetic heterogeneity among P. aeruginosa isolates, which suggests that other molecular methods are needed to reveal potential relations between genotypic patterns and phenotypic characteristics.     

Hepatitis B: who should be treated?

Patients with moderate to severe chronic hepatitis and active HBV replication should be managed according to HBeAg status and presence of coinfecting virus(es) (HDV, HCV, HIV). Treatment is also recommended for immunocompromised patients and those older than 60 years with acute HBV infection. Current treatment of chronic hepatitis B has limited long-term efficacy. The patient's age, severity of liver disease, likelihood of response and possibility of adverse effects and complications should be considered before deciding on treatment.     

The efficacy of photon-initiated photoacoustic streaming in the removal of calcium silicate-based filling remnants from the root canal after rotary retreatment

The aim of the study was to evaluate the efficacy of photon-initiated photoacoustic streaming (PIPS) in the removal of filling remnants from root canals after rotary phase of retreatment and to examine the difference in the amount of residual material considering the type of sealer. Thirty-six extracted single-rooted human teeth were instrumented and randomly divided into three groups according to the filling material used: group 1: EndoSequence BC Sealer (Brassler, USA), group 2: MTA Fillapex (Angelus Solucoes Odontologicas, Londrina, Brasil), and group 3: AH Plus sealer (Dentsply DeTrey, Konstanz, Germany). Cold lateral condensation technique was used. After 2 weeks, the root canals were retreated with a rotary phase retreatment system (ProTaper Universal Retreatment, Maillefer, Ballaigues, Switzerland), followed by Er:YAG laser-activated irrigation (photon-initiated photoacoustic streaming, PIPS). The specimens were scanned in a micro-computed tomographic (micro-CT) device after root canal filling, after the rotary retreatment, and after the PIPS. There was significant reduction in the amount of filling material after the rotary phase of retreatment in all groups (p < 0.05), the highest in the MTA Fillapex group (p < 0.001) and no difference between the EndoSequence BC and the AH Plus (p = 0.608). There was significant reduction of the filling remnants after the PIPS in all groups (p < 0.05). The MTA Fillapex was the most easily removed during rotary phase of the retreatment, and there were no differences in the amount of the remaining filling material between EndoSequence BC and the AH Plus groups after rotary phase of the retreatment. The PIPS improved the removal of filling remnants in all groups.     

Refinements of nerve repair with connector‐assisted coaptation

Peripheral nerve repair can be very rewarding for both surgeon and patient when expected outcomes are achieved. In many cases, however, the results are suboptimal due to number of possible objective and technical reasons. Although we cannot influence patent's comorbidities, the extent or mechanism of the nerve injury, we may help optimize technical details when aiming towards improved outcomes. While the suture coaptation for primary nerve repair or nerve reconstruction with grafting served as the reconstructive standard for many decades, technical imperfections remain threats to reconstructive goals. Tension, fascicular misalignment generated by over tightening suture coaptation, deeply placed sutures, reactive scarring to foreign material at anastomosis site, may all negatively affect axonal regeneration. As the goal of every nerve repair is to have ideally opposed tension free nerve fascicles, protected from the deleterious effects of the wound bed. The utilization of coaptation aids to overcome the challenges of nerve repair has been suggested as an alternative to the classical suture repair. A review of clinical literature was performed to assess the evidence for this technique and the critical success factors to consider when implementing this technique. Twelve clinical studies met criteria, majority suggesting improved outcomes by the utilization of a coaptation aid. Most commonly reported improvements were improved sensory outcomes, reduced tenderness or pain at the coaptation site and reduced operative time. The current clinical evidence data suggests that utilization of a coaptation aid is a technical innovation to help provide better nerve repair and reconstructive functional outcomes.     

TWIK-related two-pore domain potassium channel TREK-1 in carotid endothelium of normotensive and hypertensive mice

AIMS: Potassium channels are essential elements of endothelial function. Recently, evidence emerged that the TWIK (tandem of P domains in a weak inwardly rectifying K+ channel)-related K+ channel (TREK-1) of the two-pore domain potassium channel gene family (K2P) may be involved in the regulation of vascular tone. However, the functional and molecular characterization of vascular TREK-1 is incomplete. In this study, we therefore analysed the functional expression of TREK-1 in the endothelium. Moreover, we hypothesized that changes in channel expression may contribute to altered endothelial vasodilator response under conditions of elevated blood pressure. METHODS AND RESULTS: Gene expression and function of endothelial TREK-1 were analysed by single-cell RT-PCR, the patch-clamp technique and pressure myography in murine carotid arteries (CA). K+ outward currents displaying the characteristics of TREK-1 were observed following various TREK-1-activating stimuli such as membrane stretch, intracellular acidosis, polyunsaturated fatty acids, isoflurane (ISOFL), riluzole, and acetylcholine (ACh). In K(Ca)3.1(-/-) mice exhibiting elevated blood pressure, endothelial TREK-1 currents and TREK-1 mRNA expression were enhanced as compared with normotensive control mice. TREK-1-mediated vasodilator responses to alpha-linolenic acid, ISOFL, or ACh were increased. A similar up-regulation of endothelial TREK-1 was observed in spontaneously hypertensive rats. CONCLUSION: We have found that TREK-1 is an endothelial K+ channel capable of producing hyperpolarization and vasodilation. A correlation between hypertension and up-regulation of TREK-1 was observed in two different animal models of elevated blood pressure. Thus, TREK-1 may play a protective role in the cardiovascular system by providing a novel type of endothelial hyperpolarization-mediated vasodilator response.