Up-regulation of B-cell lymphoma factor-2 expression, inhibition of oxidative stress and down-regulation of pro-inflammatory cytokines are involved in the protective effect of cabbage (Brassica oleracea) juice in lead-induced endothelial dysfunction in rats

BACKGROUND

Oxido-inflammatory stress and dysregulation of nitric oxide (NO) system has been implicated in lead toxicity. Cabbage is an antioxidant-rich household vegetable with plethora of therapeutic potentials. The present study investigated the anti-oxido-inflammatory activity of cabbage in lead-induced endothelial dysfunction.

METHODS

Twenty (20) male Wistar rats were selected into four groups (n = 5) and treated with distilled water (1 mL/100 g b.wt), lead acetate (25 mg/kg b.wt), cabbage juice (1 mL/100 g b.wt) and lead acetate (25 mg/kg b.wt) plus cabbage juice (1 mL/100 g b.wt) respectively. Treatment was done orally for 28 days, thereafter, oxidative stress (SOD, CAT, GSH, and MDA), inflammatory (TNF-α and IL-6) and apoptotic (Bcl-2) markers were assayed using standard biochemical assays as well as histoarchitectural study of the endothelium.

RESULTS

The results showed that they were significant increase in MDA, ET-1, TNF-α and IL-6 while SOD, GSH, CAT, NO and Bcl-2 protein expression were decreased in Lead exposed animals. Endothelial histoarchitecture was also altered. Following Cabbage juice treatment, MDA, ET-I, TNF-α and IL-6 were down-regulated while SOD, GSH, CAT, NO and Bcl-2 protein expression were up-regulated. Histoarchitecture was significantly recovered.

CONCLUSION

The study suggests that cabbage juice could mitigates Lead-induced endothelial dysfunction by modulating oxido-inflammatory and anti-apoptotic mediators.

DATA AVAILABILITY

All data are available upon request.

Vasomotor effects of noradrenaline, 5-hydroxytryptamine, angiotensin II, bradykinin, histamine, and acetylcholine on the bat (Rhinolophus ferrumequinum) basilar artery

The responsiveness of the basilar artery to intrinsic vasoactive substances is species-specific and can be a unique characteristic. We investigated the responsiveness of the bat (Rhinolophus ferrumequinum) basilar artery to noradrenaline (NA), 5-hydroxytryptamine (5-HT), angiotensin (Ang) II, bradykinin (BK), histamine (His), and acetylcholine (ACh). NA, 5-HT, Ang II, and BK induced contraction, whereas His and ACh induced relaxation, in a concentration-dependent manner. The NA cumulative concentration-response curve was shifted to the right in parallel with phentolamine (an α-antagonist). However, propranolol, a β-antagonist, had no significant effect. The 5-HT curve was shifted to the right in parallel by ketanserin (a 5-HT₂ antagonist) and methiothepin (a 5-HT₁ and 5-HT₂ antagonist). Losartan (an AT₁ antagonist) shifted the Ang II curve to the right, whereas PD123319 (an AT₂ antagonist) had no significant effect. L-NA, indomethacin, and des-Arg⁹-[Leu⁸]-BK (a B₁ antagonist) did not significantly affect BK-induced contractions. HOE140 (a B₂ antagonist) shifted the BK concentration-response curve to the right. The His curve was shifted to the right weakly by diphenhydramine (an H₁ antagonist) and strongly by cimetidine (a H₂ antagonist). ACh-induced relaxation was significantly inhibited by L-NA, atropine, and pFHHSiD (a muscarinic M₃ antagonist), whereas pirenzepine and methoctramine (muscarinic M₁ and M₂ antagonists, respectively) showed no significant effects. At a resting vascular tone, L-NA-induced contraction and indomethacin induced relaxation. These results suggest that α-adrenergic, 5-HT₁, 5-HT₂, AT₁, and B₂ receptors might be important in arterial contraction, whereas M₃ and H₂ (>H₁) receptors might modify these contractions, inducing relaxation.

G protein-coupled receptor kinase 2 is essential to enable vasoconstrictor-mediated arterial smooth muscle proliferation

Hypertension is associated with increased production and circulation of vasoconstrictors, resulting in enhanced signalling through their cognate G protein-coupled receptors (GPCR). Prolonged vasoconstrictor GPCR signalling increases arterial contraction and stimulates signalling pathways that promote vascular smooth muscle cell (VSMC) proliferation, contributing to the development of atherosclerotic plaques, re-stenosis lesions and vascular remodelling. GPCR signalling through phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) promotes VSMC proliferation. In VSMC, G protein-coupled receptor kinase 2 (GRK2) is known to regulate numerous vasoconstrictor GPCRs and their downstream signalling pathways. As GRK2 is implicated in controlling various aspects of cellular growth, we examined whether GRK2 could affect VSMC proliferation. Using two indices of cell growth, we show that PI3K inhibition and depletion of GRK2 expression produced a similar ablation of pro-proliferative vasoconstrictor-stimulated VSMC growth. Furthermore, GRK2-knockdown ablated the sustained phase of endothelin-1 and angiotensin-II-stimulated Akt phosphorylation, whilst the peak (5 min) phase was unaffected. Conversely, the GRK2 inhibitor compound 101 did not affect vasoconstrictor-driven Akt phosphorylation. Vasoconstrictor-stimulated phosphorylation of the Akt substrates GSK3α and GSK3β was ablated following RNAi-mediated GRK2 depletion, or after PI3K inhibition. Moreover, GRK2 knockdown prevented endothelin-1 and angiotensin-II from increasing cyclin D1 expression. These data suggest GRK2 expression is essential to facilitate vasoconstrictor-driven VSMC proliferation through its ability to promote efficient prolonged PI3K-Akt signalling, and thus relieve the GSK3-mediated block on cell cycling. Considering VSMC GRK2 expression increases early in the development of hypertension, this highlights the potential for GRK2 to promote VSMC growth and exacerbate hypertensive pathophysiological vascular remodelling.

Adverse events associated with administration of vasopressor medications through a peripheral intravenous catheter: a systematic review and meta-analysis

BACKGROUND

It is unclear whether vasopressors can be safely administered through a peripheral intravenous (PIV). Systematic review and meta-analysis methodology was used to examine the incidence of local anatomic adverse events associated with PIV vasopressor administration in patients of any age cared for in any acute care environment.

METHODS

MEDLINE, EMBASE, CINAHL, the Cochrane Central Register of controlled trials, and the Database of Abstracts of Reviews of Effects were searched without restriction from inception to October 2019. References of included studies and related reviews, as well as relevant conference proceedings were also searched. Studies were included if they were: (1) cohort, quasi-experimental, or randomized controlled trial study design; (2) conducted in humans of any age or clinical setting; and (3) reported on local anatomic adverse events associated with PIV vasopressor administration. Risk of bias was assessed using the Revised Cochrane risk-of-bias tool for randomized trials or the Joanna Briggs Institute checklist for prevalence studies where appropriate. Incidence estimates were pooled using random effects meta-analysis. Subgroup analyses were used to explore sources of heterogeneity.

RESULTS

Twenty-three studies were included in the systematic review, of which 16 and 7 described adults and children, respectively. Meta-analysis from 11 adult studies including 16,055 patients demonstrated a pooled incidence proportion of adverse events associated with PIV vasopressor administration as 1.8% (95% CI 0.1-4.8%, I² = 93.7%). In children, meta-analysis from four studies and 388 patients demonstrated a pooled incidence proportion of adverse events as 3.3% (95% CI 0.0-10.1%, I² = 82.4%). Subgroup analyses did not detect any statistically significant effects associated with stratification based on differences in clinical location, risk of bias or design between studies, PIV location and size, or vasopressor type or duration. Most studies had high or some concern for risk of bias.

CONCLUSION

The incidence of adverse events associated with PIV vasopressor administration is low. Additional research is required to examine the effects of PIV location and size, vasopressor type and dose, and patient characteristics on the safety of PIV vasopressor administration.

[Implementation of the wide awake local anesthesia no tourniquet (WALANT) type of anesthesia in hand surgery]

Wide awake local anesthesia no tourniquet (WALANT) refers to an anesthesia technique with low bleeding and complication rates, which enables interventions on the hand in an awake patient without the use of a tourniquet. Bleeding control is achieved through addition of vasoconstrictors to the infiltration solution. Since the motor function of the extremity is not affected, it offers the additional possibility of intraoperative active function testing. The WALANT procedure constitutes an established, effective, easily learnt and resource-sparing technique. The spectrum of surgical possibilities with WALANT is wide and covers nearly all elective and many emergency procedures. Due to multiple advantages in contrast to other regional and general anesthesia procedures, WALANT features an increasing spectrum of surgical applications and practitioners. It is therefore of interest for hand surgeons working both in hospitals and private practices.

Vasoconstrictor and coagulation activator entrapped chitosan based composite hydrogel for rapid bleeding control

Chitosan (Cs) as a hemostatic agent has been in use to control hemorrage. Composite hydrogel formed by entrapment of vasoconstrictor-potassium aluminium sulfate (0.25 %PA) and coagulation activator-calcium chloride (0.25 %Ca) into Cs (2 %) hydrogel would enhance the hemostatic property of Cs. In this work, the prepared composite hydrogel was injectable, shear thinning, cyto and hemocompatible. The 2 %Cs-0.25 %PA-0.25 %Ca composite hydrogel caused rapid blood clotting by accelerating RBC/platelet aggregation and activation of the coagulation cascade. Further, in vivo studies on rat liver and femoral artery hemorrage model showed the efficiency of 2 %Cs-0.25 %PA-0.25 %Ca composite hydrogel to achieve hemostasis in a shorter time (20 ± 10 s, 105 ± 31 s) than commercial hemostatic agents-Fibrin sealant (77 ± 26 s, 204 ± 58 s) and Floseal (76 ± 15 s, 218 ± 46 s). In in vivo toxicological study, composite hydrogel showed material retention even after 8 weeks post-surgery, therefore excess hydrogel should be irrigated from site of application. This prepared composite hydrogel based hemostatic agent has potential application in low pressure bleeding sites.

Severe low cerebral oximetry in difficult cardiopulmonary bypass weaning of low body-weight infant: a case report and literature review

Background

For infants undergoing complex cardiac surgery, hemodynamic management after cardiopulmonary bypass (CPB) is challenging because of severe myocardial edema, vasomotor dysfunction and weak tolerance to a change in blood volume. More importantly, the lack of availability of equipment for advanced monitoring, such as transesophageal echocardiography or transthoracic echocardiography, restricts the accurate assessment of hemodynamics.

Case presentation

This is a case of severe hypotension and non-detectable pulse oxygen saturation (SpO₂) after CPB in a low-weight infant who had normal blood pressure and oxygen saturation before surgery. Epinephrine and milrinone were administered with cerebral oximetry monitoring rather than blood pressure measurements because cerebral oximetry was more responsive to treatment than blood pressure. Under the guidance of cerebral oximetry, the infant was successfully weaned from CPB and recovered after surgery without adverse neurological events.

Conclusions

For infants who develop refractory hypotension and failure in SpO₂ monitoring during the CPB weaning period, cerebral oximetry provides an index for assessing brain perfusion and valuable guidance for appropriate inotropic treatment.

Effects of lipopolysaccharide-induced septic shock on rat isolated kidney, possible role of nitric oxide and protein kinase C pathways

Objective(s):

Pathophysiology of sepsis-associated renal failure (one of the most common cause of death in intensive care units) had not been fully determined. The effect of nitric oxide and protein kinase C (PKC) pathways in isolated kidney of Lipopolysaccharide-treated (LPS) rats were investigated in this study.

Materials and Methods:

Vascular responsiveness to phenylephrine and acetylcholine in the presence and absence of a potent PKC inhibitor (chelerythrine) and nonspecific NO inhibitor (L-NAME) as well as responses to acetylcholine and sodium nitroprusside (SNP) were examined.

Results:

LPS (10 mg/kg, IP) treatment resulted in a lower systemic pressure and reduction of responses to vasoconstrictor and vasodilator agents (P<0.05 to P<0.01). The contractile response to phenylephrine and the relaxation response to acetylcholine were significantly blunted in isolated kidneys removed from LPS-treated rats. L-NAME (10 µM) preincubation modified the responses to acetylcholine in isolated kidneys of control animal (P<0.001) but not in LPS-treated rats. While, chelerythrine (10 µM) preincubation partially restored response to phenylephrine in LPS-treated tissues.

Conclusion:

Present study highlighted that five hours of intraperitoneal endotoxin injection is adequate to reduce renal basal perfusion pressure. These results also suggest that PKC inhibition may have a beneficial role in vascular hyporesponsiveness induced by LPS. Although our study partly elaborated on the effects of LPS on isolated renal vascular responses to vasoactive agents, further studies are required to explain how LPS exerts its renal vascular effects.

Renal Failure in Patients with Liver Cirrhosis: Novel Classifications, Biomarkers, Treatment

Renal failure is a severe complication in patients with liver cirrhosis. It is associated with increased mortality and morbidity. Diagnosis is a challenge because it is mainly based on serum creatinine, which does not seem to be an ideal measure of renal function in cirrhosis. The definition of renal failure in these patients has been changed for optimizing treatment and for improving outcome and prognosis. The new criteria are based on the adapted KDIGO (Kidney Disease: Improving Global Outcomes) staging system. The diagnosis of acute kidney injury (AKI) is based on an absolute increase of serum creatinine of >0.3 mg/dl from baseline within 48 h or an increase of >50% from baseline. This means smaller changes in serum creatinine in a shorter time frame which may lead to an early identification of renal failure in cirrhotic patients. The former cirrhotic-specific term hepatorenal syndrome (HRS) is now part of the new diagnostic criteria and is called HRS-AKI. The diagnostic criteria of HRS have changed due to the new criteria for AKI. Due to these criteria for HRS, the medical treatment will be started earlier. First-line treatment for renal AKI-HRS is the combination of a vasoconstrictor and albumin. Most data exist for terlipressin, a vasopressin analog, as vasoconstrictor. Besides this medical treatment, there are other options like the placement of a transjugular intrahepatic portosystemic shunt, renal replacement, and artificial extracorporeal liver support systems. However, these alternative treatment options have limitations. Liver transplantation is the treatment of choice for these patients and represents the definitive treatment. Using new biomarkers like urinary neutrophil gelatinase-associated lipocalin or interleukin-18 for renal failure in cirrhosis should help to differentiate the causes of renal failure and provide an indication regarding the prognosis.

The differential effects of systemic vasoconstrictors on human pulmonary artery tension

OBJECTIVES

Acute pulmonary hypertension following cardiac surgery can have a significant effect on postoperative morbidity and mortality. However, limited data are available on the efficacy and potency of clinically used systemic vasopressors on the pulmonary vasculature. The aim of this study was to use human pulmonary artery to characterize the pharmacological effects of clinically used vasopressors on the human pulmonary vasculature.

METHODS

Fifty-seven pulmonary artery rings of internal diameter 2-4 mm and 2 mm long, mounted in a multiwire myograph system, were used to measure changes in isometric tension. We constructed concentration response curves by cumulative addition to the myograph chambers of KCl, noradrenaline (NA), adrenaline (AD), vasopressin, endothelin-1 (ET-1) and prostaglandin F2a (PGF2a).

RESULTS

AD, NA, ET-1, PGF2a and KCl caused dose-dependent vasoconstriction in the pulmonary artery samples (EC50 246 nM [95% confidence interval, CI, 153-394 nM], 150 nM [95% CI 51-447 nM], 1.46 nM [95% CI 0.69-3.1 nM], 6.35 µM [95% CI 3.58-11.2 µM] and 17.24 mM [95% CI 12.43-24.07 mM], respectively), whereas vasopressin had no significant effect. The order of efficacy was KCl = PGF2a > AD > NA > ET-1 and the order of potency was ET-1 T-AD = NA > PGF2a > KCl.

CONCLUSIONS

This study demonstrated the efficacy and potency of clinically used vasopressors and endogenous vasopressors on human pulmonary vascular tone. PGF2a and KCl equally caused maximal amounts of constriction, whereas ET-1 had less effect and vasopressin had no effect. These effects may need to be taken into account in the clinical setting because they might result in the development of pulmonary hypertension.

The effect of angiotensin II on blood pressure in patients with circulatory shock: a structured review of the literature

BACKGROUND

Circulatory shock is a common syndrome with a high mortality and limited therapeutic options. Despite its discovery and use in clinical and experimental settings more than a half-century ago, angiotensin II (Ang II) has only been recently evaluated as a vasopressor in distributive shock. We examined existing literature for associations between Ang II and the resolution of circulatory shock.

METHODS

We searched PubMed, MEDLINE, Ovid, and Embase to identify all English literature accounts of intravenous Ang II in humans for the treatment of shock (systolic blood pressure [SBP] ≤ 90 mmHg or a mean arterial pressure [MAP] ≤ 65 mmHg), and hand-searched the references of extracted papers for further studies meeting inclusion criteria. Of 3743 articles identified, 24 studies including 353 patients met inclusion criteria. Complete data existed for 276 patients. Extracted data included study type, publication year, demographics, type of shock, dosing of Ang II or other vasoactive medications, and changes in BP, lactate, and urine output. BP effects were grouped according to type of shock, with additional analyses completed for patients with absent blood pressure. Shock was distributive (n = 225), cardiogenic (n = 38), or from other causes (n = 90). Blood pressure as absent in 18 patients.

RESULTS

For the 276 patients with complete data, MAP rose by 23.4% from 63.3 mmHg to 78.1 mmHg in response to Ang II (dose range: 15 ng/kg/min to 60 mcg/min). SBP rose by 125.2% from 56.9 mmHg to 128.2 mmHg (dose range: 0.2 mcg/min to a 1500 mcg bolus). A total of 271 patients with complete data were determined to exhibit a BP effect which was directly associated with Ang II. Subgroups (patients with cardiogenic, septic, and other types of shock) exhibited similar increases in BP. In patients with absent BP, deemed to be cardiac arrest, return of spontaneous circulation (ROSC) was achieved, and BP increased by an average of 107.3 mmHg in 11 of 18 patients. The remaining seven patients with cardiac arrest did not respond.

CONCLUSIONS

Intravenous Ang II is associated with increased BP in patients with cardiogenic, distributive, and unclassified shock. A role may exist for Ang II in restoring circulation in cardiac arrest.

Controversies in Microvascular Maxillofacial Reconstruction

The effectiveness and reliability of microvascular reconstruction for large defects in the head and neck is no longer disputed. However, many controversies still persist in the ideal perioperative management of patients undergoing free tissue transfer. The optimal method of postoperative monitoring, the use of vasoconstrictors in the perioperative period, and the use of anticoagulants in the postoperative period remain topics of debate. This article offers recommendations on each of these controversies based on a review of the current literature.

Increased pulmonary RhoA expression in the nitrofen-induced congenital diaphragmatic hernia rat model

PURPOSE

Persistent pulmonary hypertension remains a major cause of mortality and morbidity in cases of congenital diaphragmatic hernia (CDH). Recently, RhoA/Rho-kinase-mediated vasoconstriction has been reported to be important in the pathogenesis of pulmonary hypertension (PH). Several recent reports have described that fasudil, a potent Rho-kinase inhibitor and vasodilator, could represent a potential therapeutic option for PH. We designed this study to investigate the hypothesis that the expression level of RhoA is increased in the nitrofen-induced CDH rat model. The expression level of Wnt11, an activator of RhoA, was also evaluated.

METHODS

Pregnant rats were treated with or without nitrofen on gestational day 9 (D9). Fetuses were sacrificed on D17, D19 and D21 and were divided into control and CDH groups. Quantitative real-time polymerase chain reaction was performed to determine the pulmonary gene expression levels of both Wnt11 and RhoA. An immunofluorescence study was also performed to evaluate the expression and localization of RhoA.

RESULTS

The relative mRNA expression levels of pulmonary Wnt11 and RhoA on D21 were significantly increased in the CDH group compared with the control group (p=0.016 and p=0.008, respectively). The immunofluorescence study confirmed the overexpression of RhoA in the pulmonary vessels of CDH rats on D21.

CONCLUSIONS

Our results provide evidence that the RhoA/Rho-kinase-mediated pathway is involved in the pathogenesis of PH in the nitrofen-induced CDH rat model. Our data also suggest that the fasudil, a Rho-kinase inhibitor, could represent a therapeutic option for the treatment of PH in CDH.

Current position of vasoconstrictor and albumin infusion for type 1 hepatorenal syndrome

Spontaneous bacterial peritonitis (SBP), refractory ascites, hepatorenal syndrome (HRS), hyponatremia and hepatic encephalopathy are complications which frequently happen during a clinical course of decompensated cirrhosis. Splanchnic and peripheral vasodilatation, increased intrarenal vasoconstriction and impaired cardiac responsive function are pathological changes causing systemic and hemodynamic derangement. Extreme renal vasoconstriction leads to severe reduction of renal blood flow and glomerular filtration rate, which finally evolves into the clinical feature of HRS. Clinical manifestations of type 1 and type 2 HRS come to medical attention differently. Patients with type 1 HRS present as acute kidney injury whereas those with type 2 HRS will have refractory ascites as the leading problem. Prompt diagnosis of type 1 HRS can halt the progression of HRS to acute tubular necrosis if the combined treatment of albumin infusion and vasoconstrictors is started timely. HRS reversal was seen in 34%-60% of patients, followed with decreasing mortality. Baseline serum levels of creatinine less than 5 mg/dL, bilirubin less than 10 mg/dL, and increased mean arterial pressure of over 5 mmHg by day 3 of the combined treatment of vasoconstrictor and albumin are the predictors of good response. Type 1 HRS can be prevented in some conditions such as albumin infusion in SBP, prophylactic antibiotics for upper gastrointestinal hemorrhage, albumin replacement after large volume paracentesis in cirrhotic patients with massive ascites. The benefit of albumin infusion in infection with primary source other than SBP requires more studies.

Comparative Effects of Clonidine and Adrenaline with Lignocaine during Maxillary Infiltration Anaesthesia for Dental Extraction

INTRODUCTION

Lignocaine is a commonly used local anaesthetic in dental practice. Many practitioners use adrenaline (epinephrine) as additive with lignocaine, and some have used clonidine, instead of adrenaline. Both having benefits and limitations.

AIMS

Hence a study was undertaken in our department to evaluate the advantages and disadvantages of using (plain lidocaine local anaesthetic) versus (lidocaine with adrenaline as additive) versus (lidocaine with clonidine as additive).

STUDY DESIGN

Randomised, prospective, double blind study.

MATERIALS AND METHODS

Seventy five patients requiring extraction of maxillary molar teeth who fall under ASA I category were included and randomly divided into group - I (n=25) (Lignocaine), group - II (n=25) (Lignocaine ± Adrenaline) and group - III (n=25) (Lignocaine ± Clonidine). The observations recorded were, time of onset of anaesthesia, hemodynamic parameters, blood loss during procedure and duration of post operative analgesia.

STATISTICAL ANALYSIS

The statistical analysis was carried out using SPSS 16 software.

RESULTS

A statistically significant difference was seen in blood loss, being higher in group I and duration of anaesthesia, being shortest in group I. There was no statistical difference between the three groups amongst other parameters.

CONCLUSION

Adrenaline at 10 μg/ml and clonidine at 15 μg/ml can be safely used as additives with lignocaine, in maxillary infiltration anaesthesia for dental extraction; with addition of either of these two drugs, having an equal advantage over use of plain lignocaine; in terms of lower blood loss and longer duration of anaesthesia; but, with no difference in the onset of anaesthesia and with no significant hemodynamic changes.

Role of renal replacement therapy in patients with type 1 hepatorenal syndrome receiving combination treatment of vasoconstrictor plus albumin

PURPOSE

Utilization of renal replacement therapy (RRT) in cirrhotic patients has been controversial and is typically dependent on the status of transplantation. A better understanding of the central role for arterial vasodilatation in the pathogenesis of hepatorenal syndrome (HRS) has led to routine use of vasoconstrictors in combination with albumin as a medical therapy for HRS with prolonged patient survival. The role of RRT in HRS patients receiving such treatment, however, has not yet been examined.

METHODS

A total of 80 patients with type 1 HRS who received a combination therapy of vasoconstrictors and albumin were enrolled into a retrospective cohort study. The effects of RRT status on clinical outcome were analyzed.

RESULTS

Both short-term (30 days) and long-term (180 days) survival was similar between RRT and non-RRT groups of patients, but the length of hospital stay was significantly longer among patients in the RRT group, which remain unchanged despite adjustment of status for liver transplantation.

CONCLUSIONS

Based on our observation, routine use of RRT may not be beneficial in patients with type 1 HRS receiving combination treatment of vasoconstrictor plus albumin. Further prospective studies are needed to validate these findings and refine the specific indications for RRT in this patient population.

Ropivacaine: a new local anaesthetic agent in maxillofacial surgery

We have compared the anaesthetic efficacy, duration of action, pain, pulpal anaesthesia, and cardiovascular effects of 0.5% ropivacaine or 2% lignocaine hydrochloride in bilateral symmetrical impacted third molars. In a randomised single-blind trial we studied 78 healthy patients who required bilateral extraction of identical impacted lower third molars. A test dose was given to all patients with subdermal infiltration of 0.5% ropivacaine 0.5 ml. A classic inferior alveolar and long buccal nerve block was created using 0.5% ropivacaine 2 ml on one side and 2% lignocaine hydrochloride 2 ml with adrenaline on the other. The time to onset and duration of action were noted. Pain, numbness of the lip and tip of the tongue, and haemodynamic changes were monitored throughout the procedure. The teeth were extracted two weeks apart. The onset of anaesthesia ranged between 2 and 3 min after the injection and lasted for more than 5h. Ropivacaine alone did not cause appreciable changes in the cardiovascular variables, but lignocaine with adrenaline caused a transient increase in arterial pressure and heart rate 2 min after injection. We conclude the 0.5% ropivacaine alone does not affect the cardiovascular system and has more beneficial effects than 2% lignocaine hydrochloride with adrenaline. These findings may be useful for oral and maxillofacial surgeons who are looking for a local anaesthetic with minimal cardiovascular risk and without a vasoconstrictor to provide regional anaesthesia for long procedures.

Interception of the endotoxin-induced arterial hyporeactivity to vasoconstrictors

Septic shock is a severe pathophysiologic condition characterized by vasodilation, hypotension, hypoperfusion, tissue hypoxia, multiple organ failure and death. It is unclear what causes the septic vasodilation that may result from general dysfunction of vascular smooth muscles (VSMs) or selective disruption of vasomotor balances in VSMs. The latter could be due to enhanced vasorelaxation and/or depressed vasoconstriction. Understanding these may lead to pharmacological interventions to septic vasodilation. Therefore, we performed studies in isolated and perfused mesenteric arterial rings. A 20-h exposure of the rings to lipopolysaccharide (LPS, 1 μg/ml) led to hyporeactivity to phenylephrine (PE). However, the responses of the LPS-treated rings to high concentrations of KCl (60 mM) and ATP remained comparable to control rings, suggesting that contractility of VSMs is retained. The hyporeactivity was marginally affected by atropine, indomethacin and L-NAME, suggesting that endothelium-dependent vasorelaxation does not play a major role. In addition to PE, the LPS-treated rings were hyporeactive to dopamine, histamine and angiotensin II. They showed intermediate hyporeactivity to the thromboxane-A2 receptor agonist U46619. Little hyporeactivity to endothelin-1 (ET-1), serotonin (5-HT) and vasopressin was found. ET-1-induced vasoconstriction occurred without endothelium, whereas the effect of 5-HT was endothelium dependent. Although rings were hyporeactive to some of the vasopressors, their vasoconstriction effects were significantly potentiated by PE co-application. Taken together, these data suggest that the endotoxin-induced vasodilation may not result from general dysfunction of VSMs, neither from the endothelium-dependent vasorelaxation. The promising vascular response to various vasoconstrictors found in this study warrants further investigations of therapeutic potentials of these agents.