Methemoglobinemia Induced by Prilocaine in a Child With Noonan Syndrome.

Limited information is currently available on methemoglobinemia caused by the administration of prilocaine in children undergoing dental procedures in Japan. This case report presents the development of methemoglobinemia due to prilocaine overdose. The patient was a female aged 5 years 8 months with Noonan syndrome who also had pulmonary valve stenosis and hypertrophic cardiomyopathy. She presented with severe dental caries affecting 12 total teeth and required general anesthesia due to a lack of cooperation during dental treatment. General anesthesia was performed, during which 3% prilocaine with 0.03 IU/mL felypressin was administered intraoperatively via infiltration. Her SpO2 gradually decreased after 30 minutes, and cyanosis was observed postoperatively. Several assessments including a 12-lead electrocardiogram, an anteroposterior chest radiograph, and venous blood gas analysis were performed to identify potential causes. However, there were no indications of acute respiratory or cardiovascular abnormalities. It was noted that a total of 192 mg prilocaine was administered during the procedure, and methemoglobinemia was suspected to have developed because of overdose. Further testing revealed an elevated serum methemoglobin of 6.9%, supporting methemoglobinemia as the cause of her decreased SpO2. In dental procedures that require the use of prilocaine to treat multiple teeth, particularly for pediatric patients, it is important to carefully manage prilocaine dosing, as an overdose may lead to methemoglobinemia.

Patient Comfort with Various Local Infiltration Anesthetics for Minor Oculoplastic Surgery: A Systematic Review and Network Meta-Analysis.

BACKGROUND: Although local anesthetics have been extensively studied, limited evidence is available regarding the optimal solution for maximizing patient comfort in minor oculoplastic procedures. OBJECTIVES: To determine the optimal anesthetic solution for local infiltration in minor oculoplastic surgeries to maximize patient comfort. METHODS: This systematic review with network meta-analysis of prospective studies was conducted to understand the efficacy of different local anesthetics in combination to maximize patient comfort. The study was designed according to the Cochrane Handbook for Systematic Reviews of Interventions. The population comprised patients receiving local infiltration anesthesia in minor oculoplastic surgeries. Various anesthetics with adjuvants were compared with respect to injection pain, operative bleeding, and complications. Random-effects model was performed. The primary outcome of injection pain was measured using the visual analog scale (VAS) or a preference question (which intervention was the least painful). Other outcomes were operative bleeding and complications, which were evaluated with a similar preference question. RESULTS: Eleven randomized controlled trials (RCTs) of 521 patients (917 eyes) were included. The network meta-analysis revealed that "bicarbonate-buffered lidocaine with epinephrine" led to a significant decrease in injection pain (preference question) compared to "prilocaine with felypressin" and "lidocaine with epinephrine," whereas no significant differences were detected in the analysis of injection pain measured using the VAS. CONCLUSIONS: "Bicarbonate-buffered lidocaine with epinephrine" may be the optimal anesthetic solution for local infiltration in minor oculoplastic surgeries due to reduced injection pain, operative bleeding, and postoperative swelling. However, this should be interpreted cautiously as the confidence in the evidence was very low. THE CLINICAL TRIAL REGISTRATION NUMBER: CRD42021260332 (PROSPERO).

An Octopus-Derived Peptide with Antidiuretic Activity in Rats.

Discovering new drug candidates with high efficacy and few side effects is a major challenge in new drug development. The two evolutionarily related peptides oxytocin (OXT) and arginine vasopressin (AVP) are known to be associated with a variety of physiological and psychological processes via the association of OXT with three types of AVP receptors. Over decades, many synthetic analogs of these peptides have been designed and tested for therapeutic applications; however, only a few studies of their natural analogs have been performed. In this study, we investigated the bioactivity and usefulness of two natural OXT/AVP analogs that originate from the marine invertebrate Octopus vulgaris, named octopressin (OTP) and cephalotocin (CPT). By measuring the intracellular Ca2+ or cyclic AMP increase in each OXT/AVP receptor subtype-overexpressing cell, we found that CPT, but not OTP, acts as a selective agonist of human AVP type 1b and 2 receptors. This behavior is reminiscent of desmopressin, the most widely prescribed antidiuretic drug in the world. Similar to the case for desmopressin, a single intravenous tail injection of CPT into Sprague-Dawley rats reduced urine output and increased urinary osmolality. In conclusion, we suggest that CPT has a significant antidiuretic effect and that CPT might be beneficial for treating urological conditions such as nocturia, enuresis, and diabetes insipidus.

Anesthetic Management of a Patient With Citrullinemia Type I During Dental Treatment.

We report a case involving intravenous sedation for third molar extractions in a 32-year-old man with citrullinemia type I (CTLN1), a genetic disorder that affects the urea cycle. The patient was diagnosed with CTLN1 after he exhibited seizures soon after birth and was intellectually disabled because of persistent hyperammonemia, although his recent serum ammonia levels were fairly well controlled. We planned to minimize his preoperative fasting, continue his routine oral medications, and monitor his serum ammonia levels at least twice. Sedation with midazolam and a propofol infusion was planned to suppress his gag reflex and reduce protein hypercatabolism due to stress. Epinephrine-containing local anesthetics, which enhance protein catabolism, were avoided, replaced by plain lidocaine for blocks and prilocaine with felypressin for infiltration anesthesia. No significant elevation in ammonia levels was observed. In patients with CTLN1, sedation can be useful for preventing hyperammonemia. Patients who develop symptomatic hyperammonemia may require urgent/emergent treatment involving other medical specialists. Therefore, preoperative endocrinology consultation, perioperative monitoring of serum ammonia levels, and preemptively coordinating for appropriate care in the event hyperammonemia occurs should all be considered.

Comparison of two vasoconstrictors on glycemic levels in diabetic patients.

OBJECTIVES: The aim of this study was to evaluate glycemic levels in diabetic patients before, during, and after extractions using 2% lidocaine with 1:100,000 epinephrine (Lido/Epi) and 3% prilocaine with 0.03 IU/mL felypressin (Prilo/Fely). MATERIALS AND METHODS: A double-blind, randomized clinical trial was conducted to evaluate changes in body parameters and glycemic levels in diabetic patients undergoing two anesthetic protocols during dental extractions. During surgery, we evaluated blood pressure (BP), heart rate (HR), saturation (SpO2), and capillary glycemic levels (Gly). These parameters were measured at the following surgical moments: basal, 30 min after medication, incision, tooth removal, suture, and 30 and 60 min after anesthesia. RESULTS: Data analysis showed no differences between the groups considering age, weight, and time spent in surgery. Increased systolic BP and decreased diastolic BP were observed in the lido/epi group. No difference was observed in the prilo/fely group among the surgical moments or between the groups regarding BP. No difference was observed in HR and SpO2 between the groups at any surgical moment. However, differences were found when compared the differences in glycemic and basal levels in both groups with greater decreases in blood glucose values for the lido/epi group. In anxiety level evaluation, there was no difference between the different surgical moments. CONCLUSION: Thus, both lido/epi and prilo/fely (maximum 3.6 mL) can be safely used in controlled diabetic patients CLINICAL RELEVANCE: The use of lidocaine associated with epinephrine did not increase glycemic levels but leads to decrease over time when associated with an anxiety reduction protocol, offering some advantage over prilocaine plus felypressin for diabetic patients.

Passive Cigarette Smoking Impact on Blood Pressure Response to Epinephrine and Felypressin in 1K1C Hypertensive Rats Treated or not with Atenolol.

BACKGROUND: Cigarette smoking is usually associated with hypertension and may modify vasoconstrictor response. OBJECTIVE: The present study aimed to analyze and compare the interaction of passive cigarette smoking and hypertension on epinephrine and felypressin blood pressure effects after intravascular injection. METHOD: 45-day male Wistar rats had the main left renal artery partially constricted and the right kidney removed (1K1C model). Rats were placed in the chamber for exposition to passive cigarette smoking (10 cigarettes) during 10 min (6 days a week). Hypertensive rats received atenolol (90 mg/kg/day) by gavage for two weeks. Hypotensive and hypertensive response, response duration and heart rate were recorded from direct blood pressure values. The significance level was 5%. RESULTS: Passive cigarette smoking increased maximal hypertensive response to epinephrine in normotensive and 1K1C-atenolol treated rats and to felypressin only in 1K1C-atenolol treated rats; it also reduced epinephrine hypotensive response. Epinephrine increased heart rate in normotensive and hypertensive passive smokers or non-smoker rats. Comparing the two vasoconstrictors, epinephrine showed greater hypertensive response in normotensive smokers, 1K1C-atenolol treated smokers and non-smokers. However, in normotensive-nonsmoker rats, felypressin showed a greater and longer hypertensive effect. CONCLUSIONS: Our results suggest that passive cigarette smoking may reduce epinephrine vasodilation and increase hypertensive response when compared to felypressin. Therefore, felypressin may be safe for hypertensive patients to avoid tachycardia and atenolol interaction, but for normotensive and non-smoker patients, epinephrine may be safer than felypressin.

Increase in pulse pressure on administration of a dental local anesthetic solution, prilocaine hydrochloride with felypressin in male diabetic patients with coronary heart disease.

OBJECTIVES: This study aimed to evaluate pulse pressure fluctuation on dental local anesthetic administration in diabetic patients with and without coronary heart disease undergoing tooth extraction. MATERIALS AND METHODS: This retrospective study in diabetic patients undergoing tooth extraction included 33 patients with coronary heart disease (mean age 79.3 ± 7.4, 64% male) and 49 patients without coronary heart disease (mean age 78.6 ± 6.5, 29% male). The increase in pulse pressure before and after administration of local anesthetics was compared between diabetic patients with and without coronary heart disease. RESULTS: Pulse pressure was increased in male diabetic patients with coronary heart disease compared with those without coronary heart disease following administration of 3% prilocaine hydrochloride with felypressin 0.03 IU/mL (prilocaine) (15.6 ± 15.4 mmHg in those with coronary heart disease (n = 11) versus 4.3 ± 10.9 mmHg in those without coronary heart disease (n = 13), p = 0.03). CONCLUSIONS: Prilocaine administration increased pulse pressure in male diabetic patients with coronary heart disease compared with those without coronary heart disease. Further study is needed to reveal the mechanisms involved in the increase in pulse pressure. CLINICAL RELEVANCE: This is the first study of pulse pressure fluctuation in diabetic patients with and without coronary heart disease following administration of local anesthetics. Our findings can help guide the choice of local anesthetics and serve as a predictor of coronary vascular condition in diabetic patients during dental treatment.

Difference in the Effects of Lidocaine With Epinephrine and Prilocaine With Felypressin on the Autonomic Nervous System During Extraction of the Impacted Mandibular Third Molar: A Randomized Controlled Trial.

PURPOSE: Complications during local anesthesia include increased blood pressure and vasovagal reflex, which are caused by changes in the autonomic nervous system. The commonly used local anesthetic preparations are lidocaine to which the vasoconstrictor epinephrine is added (lidocaine-epinephrine) and prilocaine to which the vasoconstrictor felypressin is added (prilocaine-felypressin); however, their effects during dental treatment are unclear. We examined the effects of these 2 different local anesthetic preparations on the autonomic nervous system and circulation during extraction of the impacted mandibular third molar. MATERIALS AND METHODS: In this randomized controlled trial, 40 female patients scheduled for extraction of an impacted mandibular third molar were randomized to the lidocaine-epinephrine group or prilocaine-felypressin group. Heart rate variability, heart rate, and systolic blood pressure were recorded during the experiment. Descriptive and bivariate statistics were computed, and the P value was set at .05. RESULTS: The low frequency-high frequency ratio was significantly increased in the prilocaine-felypressin group during extraction compared with that in the lidocaine-epinephrine group (P < .05). In the lidocaine-epinephrine group, a significant decrease in the high-frequency component was observed during bone removal and extraction compared with that at rest (P < .05). In both groups, a significant increase in systolic blood pressure was observed during local anesthesia, incision and reflection of the flap, bone removal, separation of the tooth crown, extraction, and suturing compared with that at rest (P < .01). CONCLUSIONS: This study is the first to investigate the differences in the influence of 2 different local anesthetic preparations on the autonomic nervous system during extraction of the mandibular third molar. Changes in circulatory dynamics during tooth extraction with the 2 different local anesthetic preparations were the result of a decrease in parasympathetic nervous activity with lidocaine-epinephrine and an increase in sympathetic nervous activity with prilocaine-felypressin.

Cardiovascular Comparison of 2 Types of Local Anesthesia With Vasoconstrictor in Older Adults: A Crossover Study.

We assessed the effect of 2% lidocaine with 1:80,000 adrenaline (L + AD) and 3% prilocaine with 0.03 IU/mL felypressin (P + FP) on blood pressure and heart rate in older adults with systemic diseases undergoing dental extraction. This double-blind, randomized crossover study included 22 elderly participants, aged over 65 years. The participants were administered L + AD for one dental extraction and P + FP for the other. Blood pressure and heart rate were recorded immediately, 5, and 10 minutes after local anesthetic administration and the data were analyzed. The systolic and diastolic blood pressures in the P + FP group increased at all measurement points (p < .001). In the L + AD group, the diastolic blood pressure decreased at 5 and 10 minutes after local anesthetic administration (p < .05), whereas the heart rate increased at all measured time points (p < .001). There were statistically significant differences in systolic blood pressure at 5 and 10 minutes after local anesthetic administration and in diastolic blood pressure and heart rate at all time points between the 2 groups. In older adults, P + FP administration increased the systolic and diastolic blood pressures. L + AD administration increased the heart rate and decreased the diastolic blood pressure.

Comparison of epinephrine and felypressin pressure effects in 1K1C hypertensive rats treated or not with atenolol.

PURPOSE: Epinephrine is considered the gold standard vasoconstrictor for hypertensive patients, but few studies report felypressin's effects. The present study aimed to analyze and compare the effects of these two vasoconstrictors, injected by the intravenous route, on the arterial pressure of normotensive, hypertensive and atenolol-treated hypertensive rats. METHOD: The hypertension model was one-kidney-one-clip (1K1C): the main left renal artery was partially constricted and the right kidney was surgically removed in 45-day-old male Wistar rats. 1K1C hypertensive rats received atenolol (90 mg/kg/day) by gavage for 2 weeks. 28-35 days after hypertension induction, a catheter was inserted into the left carotid artery to record direct blood pressure values. The following parameters were recorded: minimal hypotensive response, maximal hypertensive response, response duration and heart rate. RESULTS: Epinephrine, but not felypressin, exerted an important hypotensive action; non-treated hypertensive rats showed more pronounced vasodilation. Treated and non-treated rats showed hypertensive responses of the same magnitudes in all groups; 1K1C atenolol rats showed reduced hypertensive responses to both vasoconstrictors. Felypressin's response duration was longer than that of epinephrine in all groups. Epinephrine increased heart rate while felypressin reduced this parameter only in the normotensive group. CONCLUSIONS: Our results suggest that felypressin has equipotent pressure responses when compared with epinephrine, showing a greater extent of action. Atenolol's reduction of hypertensive effects surprisingly suggests that atenolol ß-blockade may also be important for felypressin's cardiovascular effect, as is widely known for epinephrine. Our data suggest that felypressin is safe for hypertensive subjects, in particular those receiving atenolol.

Intraoperative local anaesthesia for reduction of postoperative pain following general anaesthesia for dental treatment in children and adolescents.

BACKGROUND: Whilst carrying out dental procedures under general anaesthesia (GA), practitioners routinely give local anaesthetics (LA) intraoperatively to children. Local anaesthetics are used to help manage postoperative pain and reduce bleeding and the physiological response to procedures. Studies of effectiveness of intraoperative LA to date have reported contradictory results. OBJECTIVES: To assess the effects of intraoperative local anaesthesia for reducing postoperative pain following general anaesthesia for dental treatment in children and young people aged 17 years or younger. SEARCH METHODS: We searched the following electronic databases: the Cochrane Oral Health Group Trials Register; the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, 2013, Issue 12), MEDLINE via OVID (1946 to 02 January 2014), EMBASE via OVID (1980 to 02 January 2014) and Web of Science Conference Proceedings (1990 to 02 January 2014). We searched for ongoing trials in the US National Institutes of Health Register, the metaRegister of Controlled Trials (mRCT) and the International Federation of Pharmaceutical Manufacturers & Associations (IFPMA) Clinical Trials Portal. We did not place any restrictions on the language or date of publication when searching the electronic databases. SELECTION CRITERIA: Randomised controlled trials in which local anaesthetic was given intraoperatively under general anaesthesia for dental treatment of children and young people aged 17 years or younger. DATA COLLECTION AND ANALYSIS: We used standard methodological procedures expected by The Cochrane Collaboration. We performed data extraction and assessment of risk of bias independently and in duplicate. We contacted authors to clarify omissions in trial reports. In the 'Summary of findings' tables, we elected to report the outcomes pain, distress, postoperative bleeding, and physiological parameters related to the general anaesthetic, as we considered these to be the outcomes of greatest importance to readers of the review. MAIN RESULTS: We included 14 trials in this review, with 1152 randomised participants. The studies were published between 1990 and 2009 and were conducted in the United Kingdom, Egypt, Saudi Arabia, and the United States. The age of participants ranged from 2 to 40 years. Three studies were at an overall high risk of bias, seven studies were at an unclear risk of bias, and we judged four studies to be at low risk of bias. The clinical heterogeneity of the included studies precluded pooling of studies in terms of method of administration of LA (e.g., intraligamental injection, infiltration injection, or topical delivery) and variation in the use of supplementary analgesics and follow-up time.Of the seven studies where administration of LA was by infiltration injection, six studies (very low-quality body of evidence, 542 participants analysed, 1 study had overall high risk of bias, 4 studies had overall unclear risk of bias, 1 study had overall low risk of bias) measured postoperative pain. The results were equivocal. There was a decrease in bleeding and increase in soft tissue damage in the LA groups, but we did not judge this to be clinically significant.In the 2 studies where administration of LA was by intraligamental injection, there was no difference in mean pain scores, and they did not report any soft tissue damage (very low-quality body of evidence, 115 participants analysed, 1 study had overall high risk of bias, 1 study had overall unclear risk of bias).One 3-armed study (very low-quality body of evidence, 54 participants analysed, overall high risk of bias) compared the effects of intraligamental and infiltration LA injection with no treatment. There was no evidence of a mean difference in pain, distress, or postoperative anxiety among the three groups.Four studies (very low-quality body of evidence, 343 participants analysed, 2 studies had overall low risk of bias, 2 studies had overall unclear risk of bias) evaluated the effects of topical LA compared with no treatment or placebo. One study (overall unclear risk of bias) with a no-treatment comparator reported lower mean pain in the LA group; all other studies reported no difference in mean pain scores. Two studies reported on bleeding (overall unclear risk of bias): One study reported a clinically insignificant increase in bleeding with no treatment; the other reported no difference.None of the studies reported on participant or child satisfaction. AUTHORS' CONCLUSIONS: In this review, it was difficult to reach firm conclusions as to the benefit of using local anaesthetic for dental treatment under general anaesthesia. The information reported in the included studies was comprehensive and applicable to the review question, but ultimately it was not sufficient to address the objective of the review. We were unable to pool the included studies in a meta-analysis because of substantial variation in outcome measures, interventions, and treatment types. The use of supplementary analgesia further obscured the effect of local anaesthetics.Based on the literature review and the results of this review, we recommend further randomised controlled trials that minimise bias through adequate allocation concealment and blinding of participants and assessors, and assess the effect of intraoperative local anaesthetic on the volume and type of anaesthetic used and on the cardiovascular system in participants receiving supplementary analgesics as well. Researchers should give consideration to the impact of any changes on the health and well-being of the participant and report baseline measures of pain or distress, or both, and preoperative anxiety.

Holter ECG assessment of the effects of three different local anesthetic solutions on cardiovascular system in the sedated dental patients with coronary artery disease.

OBJECTIVE: The purpose of the study is to compare the effects of lidocaine alone, epinephrine-combined lidocaine and prilocaine with octapressin on the cardiovascular system during minor oral surgery of sedated cardiac dental patients under local anesthesia. METHODS: Connected to a Holter electrocardiogram (ECG) monitor for a total of 5 hours starting 1 hour before the procedure, twenty patients with high risk of coronary artery disease were included in the prospective cohort study. All the patients had three operations at 3 different appointments with at least one-week intervals and each operation was performed under local anesthesia achieved by 3.6 mL of 3% prilocaine with octapressin, 3.6 mL of 2% lidocaine with 1:80.000 epinephrine and 3.6 mL of 2% lidocaine without a vasoconstrictor. Data of the Holter ECG device assessed at the end of every hour and evaluated statistically. Repeated measures ANOVA, Friedman test, and Wilcoxon signed ranks test were used to perform statistical analysis. RESULTS: Heart-rate showed significant differences between lidocaine with epinephrine and pure lidocaine in an hour following the injection (p<0.05 for all). Cardiac rhythm showed significant differences between prilocaine with octapressin and pure lidocaine at the second hour after its administration (p<0.05 for all). There were no significant differences between 3 local anesthetics in terms of ST segment deviation. CONCLUSION: In minor oral operation on the sedated patients with cardiac disease, the use of 3.6 mL or a less amount of local anesthetic injection containing epinephrine appears to be a predictable and safe method.

Felypressin increases blood pressure during dental procedures in hypertensive patients.

BACKGROUND: Felypressin has been added to local anesthetic to increase the length of the anesthetic effect and reduce toxicity during dental procedures. However, the effect on blood pressure remains uncertain, and this may be highly relevant in the dental treatment of hypertensive patients. OBJECTIVE: To investigate the effect of felypressin on blood pressure in hypertensive patients with controlled BP. METHODS: 71 subjects with these characteristics and in need of periodontal treatment were studied. After 10 minutes of rest, local anesthesia (prilocaine) was infiltrated with and without addition of felypressin. Then, a deep subgingival scaling was performed. Blood pressure was measured by an automated oscillometric device (DIXTAL DX2010). Ten minutes after the administration of the anesthetic, peak anesthetic action was recorded. The State-Trait Anxiety Inventory (STAI) was used to assess the patients' trait anxiety. RESULTS: Systolic blood pressure increased after anesthesia, regardless of association with felypressin, throughout the dental procedure (p<0.05) and this response can be explained, at least in part, by the trait anxiety levels of the subjects. However, a further increase in diastolic blood pressure was observed when prilocaine was associated with felypressin (p<0.05), but this response did not change with trait anxiety levels. CONCLUSION: Felypressin increased the diastolic blood pressure of hypertensive patients with controlled blood pressure. Patients with high trait anxiety presented increases in systolic blood pressure upon some procedures, suggesting that an increase in blood pressure might also be related to fear or anxiety.

Dopamine D1-like receptors play only a minor role in the increase of striatal dopamine induced by striatally applied SKF38393.

We studied the effects of the intra-striatal infusion of Ca(2+)-free medium on the intra-striatal injection of 0.5 µg SKF38393-induced striatal dopamine efflux. It is discussed that the amount of extracellular, striatal dopamine seen after striatally applied SKF38393, is the overall result of the (a) release of dopamine from the alpha-methyl-para-tyrosine-sensitive and Ca(2+)-insensitive pool of newly synthesised dopamine, (b) release of dopamine from the reserpine-sensitive and Ca(2+)-sensitive storage pool, (c) inhibition of uptake of dopamine into nerve terminals and glial cells, and (d) facilitation respectively of the inhibition of uptake into blood vessels: dopamine D1-like receptors play only a very limited role in these processes. The present study underlines our previous notion that the effects of SKF38393 cannot simply be ascribed to the dopamine D1-like receptor stimulation (Saigusa et al., 2009): in fact, the present study clearly reveals that SKF38393 is not at all selective in that respect.

Felypressin, but not epinephrine, reduces myocardial oxygen tension after an injection of dental local anesthetic solution at routine doses.

PURPOSE: The aim of this study was to evaluate the effect of epinephrine (Epi) or felypressin (Fely) contained in dental local anesthetics on myocardial oxygen balance. MATERIALS AND METHODS: Male Japanese White tracheotomized rabbits were anesthetized with isoflurane. Three doses of 0.18, 0.36, and 0.72 mL of 2% lidocaine hydrochloride containing 1:80,000 Epi or 3% prilocaine hydrochloride containing Fely 0.03 IU/mL were injected into the rabbit tongue muscle. These doses were equivalent to 2, 4, and 8 of dental local anesthetic cartridges in humans weighing 50 kg by body weight correction, respectively. Heart rate, blood pressure, aortic blood flow, myocardial tissue blood flow, and myocardial tissue oxygen tension were continuously monitored. Data were recorded immediately before and 10, 20, 30, and 60 minutes after the injection. RESULTS: Heart rate decreased in the Fely group. Systolic blood pressure increased in the Epi group, and diastolic blood pressure increased in both groups. Aortic blood flow and myocardial tissue blood flow increased, whereas myocardial tissue oxygen tension did not change in the Epi group. In contrast, aortic blood flow, myocardial tissue blood flow, and myocardial tissue oxygen tension decreased in the Fely group. CONCLUSION: It is suggested that Fely, but not Epi, decreases myocardial oxygen tension and aggravates myocardial oxygen demand/supply balance even after an injection of dental local anesthetic solution at routine doses.

Vasopressin/oxytocin-related peptides influence long-term memory of a passive avoidance task in the cuttlefish, Sepia officinalis.

The vasopressin (VP)/oxytocin (OT)-related peptides constitute a large superfamily found in a wide range of both vertebrate and invertebrate species. While intensive literature reports that these neuropeptides influence behavior, especially learning and memory, in numerous species from diverse vertebrate groups, their roles in behavioral regulation have never been studied in invertebrates. Here, we investigated the role of two VP/OT superfamily peptides, octopressin (OP) and cephalotocin (CT), on long-term memory (LTM) formation of a passive avoidance task in a cephalopod mollusc, the cuttlefish, Sepia officinalis. Subadult cuttlefish were intravenously injected, in a dose range of 3-60 microg/kg, 1h after the training phase (consolidation design); retention performance was tested 24h post-training. We found that administration of OP at low dose (3 microg/kg) enhanced LTM, whereas a dose of 60 microg/kg attenuated it. No effect of OP on LTM was observed for the 15 microg/kg dose. Conversely, an enhancement of retention performance was observed at all doses of CT tested. This study is the first to demonstrate the behavioral effects of VP/OT superfamily peptides in an invertebrate species. The valuable role of VP/OT-like peptides on memory processes offers new evolutionary perspectives on peptidergic transmission and neuromodulation.

The effect of different vasoconstrictors and local anesthetic solutions on substance P expression in human dental pulp.

The purpose of this study was to quantify the effect of the infiltration injection of different vasoconstrictor and anesthetic solutions on substance P (SP) expression in healthy human dental pulp. Thirty pulp samples were obtained from healthy upper premolars in which extraction was indicated for orthodontic reasons and were randomly assigned into three groups of 10 samples each: 2% lidocaine with 1:80,000 epinephrine (Lido group), 3% Prilocaine with 1:200000 felypressin (Prilo group); and 4% Prilocaine without vasoconstrictor (Prilo-no-VC group). All teeth were extracted 10 minutes after anesthetic application. Pulp samples were processed and SP was measured by radioimmunoassay. SP expression for the Lido, Prilo, and Prilo-no-VC groups were 616.49, 663.76, and 760.79 pmol/mg pulp tissue, respectively. Analysis of variance showed statistically significant differences between groups (p = 0.001). Tukey Honestly Significant Difference (HSD) post hoc tests showed significant statistical differences between the Prilo-no-VC group and the Lido group (p < 0.01) and between the Prilo-no-VC group and the Prilo group (p < 0.05). It can be concluded that infiltration injection of local anesthetics with vasoconstrictor attenuate SP expression in human dental pulp.

Effect of local anesthetics with and without vasoconstrictor agent in patients with ventricular arrhythmias.

BACKGROUND: The routine use of local anesthetics associated to vasoconstrictors for the dental treatment of patients with cardiopathies is still controversial, due to the risk of adverse cardiovascular effects. OBJECTIVE: To evaluate and compare the hemodynamic effects of the use of local anesthetics with a non-adrenergic vasoconstrictor in patients with ventricular arrhythmia, when compared to the use of anesthetics without vasoconstrictor. METHODS: A prospective randomized study evaluated 33 patients with positive serology for Chagas' disease and 32 patients with coronary artery disease that presented complex ventricular arrhythmia at Holter monitoring (>10 EV/h and NSVT), of which 21 were females, aged 54.73 + 7.94 years, submitted to routine dental treatment with pterygomandibular anesthesia. These patients were divided in two groups: group I received prilocaine 3% associated with felypressin 0.03 IU/ml and group II received lidocaine 2% without vasoconstrictor. The number and complexity of extrasystoles were analyzed, as well as the heart rate and systemic arterial pressure of the patients on the day before, one hour before, during the procedure and one hour after the dental procedure. RESULTS: No hemodynamic alterations or increase in the number and complexity of the ventricular arrhythmia related to the anesthetic used in the dental procedure were observed in either group. CONCLUSION: The results suggest that prilocaine 3% associated to a felypressin 0.03 IU/ml can be safely used in patients with Chagas' disease or coronariopathy with complex ventricular arrhythmia.