bluuebunny/crossref_metadata_2025 huggingface dataset:
Latent Structure of Depression in a Japanese Population Sample: Taxometric Procedures
Authors: Okumura Yasuyuki , Sakamoto Shinji , Ono Yutaka
Published: June 2009

Objective: Although the debate on whether mental disorders are categorical or dimensional is critical for researchers and practitioners, past findings of taxometric studies of depression have been somewhat contradictory and difficult to reconcile. One reason for the disagreement was that most researchers relied only on selected samples (students, clinical patients, or screened community samples). The present study investigated whether the latent structure of depression is categorical or dimensional using an unselected general community sample.

Method: To determine whether the latent structure of depression assessed by the Center for Epidemiologic Studies Depression Scale is categorical or dimensional, taxometric procedures were carried out on a Japanese general population-based sample of 20 987 individuals selected using a cluster sampling procedure.

Results: Both the means above and below a sliding cut (MAMBAC) and the maximum eigenvalue (MAXEIG) procedures, using indicators drawn from the Center for Epidemiologic Studies Depression scale yielded results that the latent structure of depression is dimensional.

Conclusions: The dimensional structure of depression should be considered when classifying individual differences and selecting suitable research designs.
Perceived Need for Mental Health Care: Findings from the 2007 Australian Survey of Mental Health and Wellbeing
Authors: Meadows Graham N. , Burgess Philip M.
Published: June 2009

Objectives: To provide an overview of perceived need for mental health care and response of services to those needs as assessed by the general Australian adult population.

Method: The Perceived Need for Care Questionnaire was administered to respondents of the Australian 2007 National Survey of Mental Health and Wellbeing. This instrument allows for self assessment of needs for five kinds of intervention from mental health services as needed in the last year. Specific needs assessed included: medication, information, counselling including psychotherapy, social interventions and skills training: Needs for care may be rated as unmet, partially met and met.

Results: Approximately 14% of the population perceived a need for mental health care and between 7% and 8% perceived a met need for either counselling or medication. Need for care was less likely to be perceived by people with substance use disorders than among those with anxiety or affective disorders. For just under half of the population with perceived need (45%), all perceived needs were rated as met, and for around one in five of those with perceived needs, none of their perceived needs were met. Proportionally, needs for medication are most likely to be rated as met at 84%, needs for counselling and information are met at a rate of between 50% and 60%, skills training approximately 40%, and social interventions needs are those least likely to be rated as fully met, at 25%.

Conclusions: Mental health care is delivered in large volume and often with high levels of acceptability to the Australian community, although major gaps still remain. It appears that the disparity between need and care may be proportionally larger in the areas described as skills training and social interventions than areas outside of conventional mental health service domains of provision and medication and psychotherapy or counselling.
Suicidal Thoughts and Behaviours Among Australian Adults: Findings from the 2007 National Survey of Mental Health and Wellbeing
Authors: Johnston Amy K. , Pirkis Jane E. , Burgess Philip M.
Published: June 2009

Objectives: To provide an overview of the lifetime and 12 month prevalence of suicidal ideation, suicide plans and suicide attempts for Australian adults as a whole and for particular sociodemographic and clinical population subgroups, and to explore the health service use of people with suicidality.

Method: Data came from the 2007 National Survey of Mental Health and Wellbeing (2007 NSMHWB), a nationally, representative household survey of 8841 individuals aged 16–85 years.

Results: A total of 13.3% of respondents had suicidal ideation during their lifetime, 4.0% had made a suicide plan and 3.2% had made a suicide attempt. The equivalent 12 month prevalence rates were 2.3%, 0.6% and 0.4%, for ideation, plans and attempts, respectively. In general, suicidality in the previous 12 months tended to be relatively more common in women, younger people, those outside the labour force, and those with mental disorders; and less common in those who were married or in de facto relationships, and those with moderate levels of education. A number of the differences in prevalence rates between sociodemographic and clinical subgroups did not reach statistical significance due to data availability constraints and the conservative tests of significance that were used by necessity. These patterns warrant further exploration. Service use for mental health problems was higher among people with suicidality than it was among the general population, but significant numbers of those experiencing suicidality did not receive treatment.

Conclusions: Suicidal thoughts and behaviours are not uncommon among the Australian adult population. These thoughts and behaviours are not only predictive of subsequent fatal suicidal acts, but are significant public health problems in their own right. They are associated with high levels of burden at an individual and societal level. Further analysis is required to assess the effectiveness of the national policy frameworks in reducing the spectrum of suicidal thoughts and behaviours.
Policy Implications of the 2007 Australian National Survey of Mental Health and Wellbeing
Authors: Whiteford Harvey , Groves Aaron
Published: June 2009

Objectives: To describe some of the policy implications of the Australian National Survey of Mental Health and Wellbeing.

Methods: A review of the initial findings from the Survey published by the Australian Bureau of Statistics and the five papers in this issue of the Journal, was done.

Results: Mental disorders are highly prevalent with the prevalence essentially unchanged since Australia's 1997 mental health survey. Mental disorders are often comorbid with each other and with physical disorders. Despite the disability they cause, most people with disorders do not seek treatment. This is largely because they do not perceive a need for treatment.

Conclusions: National epidemiological surveys are important for service planning. They are especially important in gaining an understanding of the population not accessing services. Innovative strategies, including action on mental health literacy, will be necessary to increase the treatment rates for common mental disorders.
Book Reviews
Authors: Zamfirov Dimitar
Published: June 2009

Teaching Atlas of Musculoskeletal Imaging. By P. L. Munk & A. G. Ryan. New York: Thieme Medical Publishers, Inc., 2008. ISBN: 978-3-13-141981-1. 780 pages. Price (hardcover): USD 150
Book Reviews
Authors: Rosendahl Karen
Published: June 2009

Pediatric Imaging: The Fundamentals. By L. F. Donnelly. Philadelphia, Pennesylvania: Saunders, Elsevier, 2009. ISBN: 978-1-4160-5907-3. 288 pages. Price (paperback): USD 79
Muscle atrophy through thick but not thin
Authors: Leslie Mitch
Published: June 2009

Ubiquitylating enzyme MuRF1 targets thick fibers in muscle.
Formation of cristae and crista junctions in mitochondria depends on antagonism between Fcj1 and Su e/g
Authors: Rabl Regina , Soubannier Vincent , Scholz Roland , Vogel Frank , Mendl Nadine , Vasiljev-Neumeyer Andreja , Körner Christian , Jagasia Ravi , Keil Thomas , Baumeister Wolfgang , Cyrklaff Marek , Neupert Walter , Reichert Andreas S.
Published: June 2009

Crista junctions (CJs) are important for mitochondrial organization and function, but the molecular basis of their formation and architecture is obscure. We have identified and characterized a mitochondrial membrane protein in yeast, Fcj1 (formation of CJ protein 1), which is specifically enriched in CJs. Cells lacking Fcj1 lack CJs, exhibit concentric stacks of inner membrane in the mitochondrial matrix, and show increased levels of F1FO–ATP synthase (F1FO) supercomplexes. Overexpression of Fcj1 leads to increased CJ formation, branching of cristae, enlargement of CJ diameter, and reduced levels of F1FO supercomplexes. Impairment of F1FO oligomer formation by deletion of its subunits e/g (Su e/g) causes CJ diameter enlargement and reduction of cristae tip numbers and promotes cristae branching. Fcj1 and Su e/g genetically interact. We propose a model in which the antagonism between Fcj1 and Su e/g locally modulates the F1FO oligomeric state, thereby controlling membrane curvature of cristae to generate CJs and cristae tips.
Role of Inn1 and its interactions with Hof1 and Cyk3 in promoting cleavage furrow and septum formation in S. cerevisiae
Authors: Nishihama Ryuichi , Schreiter Jennifer H. , Onishi Masayuki , Vallen Elizabeth A. , Hanna Julia , Moravcevic Katarina , Lippincott Margaret F. , Han Haesun , Lemmon Mark A. , Pringle John R. , Bi Erfei
Published: June 2009

Cytokinesis requires coordination of actomyosin ring (AMR) contraction with rearrangements of the plasma membrane and extracellular matrix. In Saccharomyces cerevisiae, new membrane, the chitin synthase Chs2 (which forms the primary septum [PS]), and the protein Inn1 are all delivered to the division site upon mitotic exit even when the AMR is absent. Inn1 is essential for PS formation but not for Chs2 localization. The Inn1 C-terminal region is necessary for localization, and distinct PXXP motifs in this region mediate functionally important interactions with SH3 domains in the cytokinesis proteins Hof1 (an F-BAR protein) and Cyk3 (whose overexpression can restore PS formation in inn1Δ cells). The Inn1 N terminus resembles C2 domains but does not appear to bind phospholipids; nonetheless, when overexpressed or fused to Hof1, it can provide Inn1 function even in the absence of the AMR. Thus, Inn1 and Cyk3 appear to cooperate in activating Chs2 for PS formation, which allows coordination of AMR contraction with ingression of the cleavage furrow.
Loss of spindle assembly checkpoint–mediated inhibition of Cdc20 promotes tumorigenesis in mice
Authors: Li Min , Fang Xiao , Wei Zhubo , York J. Philippe , Zhang Pumin
Published: June 2009

Genomic instability is a hallmark of human cancers. Spindle assembly checkpoint (SAC) is a critical cellular mechanism that prevents chromosome missegregation and therefore aneuploidy by blocking premature separation of sister chromatids. Thus, SAC, much like the DNA damage checkpoint, is essential for genome stability. In this study, we report the generation and analysis of mice carrying a Cdc20 allele in which three residues critical for the interaction with Mad2 were mutated to alanine. The mutant Cdc20 protein (AAA-Cdc20) is no longer inhibited by Mad2 in response to SAC activation, leading to the dysfunction of SAC and aneuploidy. The dysfunction could not be rescued by the additional expression of another Cdc20 inhibitor, BubR1. Furthermore, we found that Cdc20AAA/AAA mice died at late gestation, but Cdc20+/AAA mice were viable. Importantly, Cdc20+/AAA mice developed spontaneous tumors at highly accelerated rates, indicating that the SAC-mediated inhibition of Cdc20 is an important tumor-suppressing mechanism.
The role of aneuploidy in promoting and suppressing tumors
Authors: Weaver Beth A.A. , Cleveland Don W.
Published: June 2009

Impaired mitotic checkpoint signaling can both promote and suppress tumors. The mitotic checkpoint targets Cdc20, the specificity factor of the ubiquitin ligase that promotes anaphase by targeting cyclin B and securin for destruction. In this issue, Li et al. (2009. J. Cell Biol. doi:10.1083/jcb.200904020) use gene replacement to produce mice expressing a Cdc20 mutant that cannot be inhibited by the mitotic checkpoint. In addition to the expected aneuploidy, these animals have a high tumor incidence that is likely caused by persistent aneuploidy coupled with nonmitotic functions of mutant Cdc20.
Ecological studies of marine mammals using a seabed-mounted echosounder
Authors: Doksæter Lise , Godø Olav R. , Olsen Erik , Nøttestad Leif , Patel Ruben
Published: June 2009

Doksæter, L., Godø, O. R., Olsen, E., Nøttestad, L., and Patel, R. 2009. Ecological studies of marine mammals using a seabed-mounted echosounder. – ICES Journal of Marine Science, 66: 1029–1036. A seabed-mounted, upward-looking, 38 kHz echosounder (Simrad EK60) was used to monitor cetaceans for 128 d between July 2004 and June 2005. The echosounder was placed at 52°N 30°W at a depth of 910 m, in a frontal area with continuous upwelling creating a hotspot of marine life at all trophic levels. Echo tracks were observed, apparently resulting from one or more animals in close temporal and spatial proximity. The 69 “acoustic detections” were examined with a principal component analysis (PCA) considering mean target strength (TS), group size, and maximum dive depth and duration. The PCA conservatively classified 45 of the acoustic detections as “cetaceans”. Their mean TS values varied between −5 and −36 dB, in agreement with earlier TS measurements of whales and dolphins. Several of the supposed cetaceans were apparently feeding in the “deep-scattering layer” when this ascended at night. This study demonstrates that cetacean behaviour, including swimming, feeding, and vocalizing, can be observed and monitored with stationary active-acoustic instrumentation.
Venous Air Embolism during Total Laparoscopic Hysterectomy
Authors: Kim Chang Seok , Kim Ji Young , Kwon Ja-Young , Choi Seung Ho , Na Sungwon , An Jiwon , Kim Ki Jun
Published: June 2009

Background

Total laparoscopic hysterectomy (TLH) has become a widely accepted alternative to total abdominal hysterectomy (TAH). The aim of this study was to compare the incidence and grade of venous air embolism (VAE) in TLH to those in TAH using transesophageal echocardiography.

Methods

Eighty-two American Society of Anesthesiologists physical status I patients scheduled for either TLH or TAH were enrolled. After induction of general anesthesia, a multiplane transesophageal echocardiography probe was inserted. The midesophageal four-chamber or bicaval view was continuously monitored. An independent transesophageal echocardiography-certified anesthesiologist graded VAE.

Results

All patients undergoing TLH showed VAE, and 37.5% of patients had VAE grade higher than III. Fifteen percent of patients undergoing TAH showed VAE, and all of them were grade I. No patient in this study showed hemodynamic instability or electrocardiogram changes at the time of VAE occurrence. Most instances of VAE during TLH occurred during transection of the round ligament and dissection of the broad ligament.

Conclusion

The incidence of VAE in patients undergoing TLH was 100%. VAE grade in TLH was higher compared to that in TAH, especially during transection of the round ligament and dissection of the broad ligament. Although the hemodynamic instability associated with VAE during TLH was not observed in this study, anesthesiologists must be vigilant for detection of VAE during TLH.
LMA-ProSeal™ for Elective Postoperative Care on the Intensive Care Unit
Authors: Russo Sebastian G. , Goetze Benjamin , Troche Stefan , Barwing Jürgen , Quintel Michael , Timmermann Arnd
Published: June 2009

Background

Compared to an endotracheal tube, laryngeal mask airways are known to cause less hemodynamic alteration during the extubation phase of routine perioperative airway management. This study aims to examine the hypothesis that the LMA-ProSeal (PLMA, The Laryngeal Mask Company Limited, St. Helier, Jersey, Channel Islands) is an adequate tool for elective postoperative care in the intensive care unit (ICU) and potentially associated with less hemodynamic alteration during extubation in the ICU environment compared to an endotracheal tube.

Methods

Forty-eight patients were enrolled for this prospective randomized, controlled trial and were allocated to either control (ICU-T) or study group (ICU-P). In the ICU-P group, the endotracheal tube was replaced by a PLMA at the end of surgery.

Results

Forty-patients completed the study. Cardiovascular parameters increased significantly less in the ICU-P group: systolic blood pressure increased by 18.10 +/- 5.57 mmHg versus 34.65 +/- 5.63 mmHg (P < 0.05), mean arterial blood pressure increased by 11.23 +/- 3.25 mmHg versus 22.65 +/- 3.36 mmHg (P < 0.05), and heart rate increased by 9.3 +/- 2.9 versus 12.9 +/- 2.2 min (P < 0.05). Ventilation via the PLMA during transfer from the operation room to the ICU as well as during ICU stay was successful and without any adverse events.

Conclusions

Removal of the PLMA after recovery from anesthesia was associated with less cardiovascular change compared to the endotracheal tube. Ventilation was possible without reported adverse events during the entire trial. Elective endotracheal tube replacement by the PLMA may be a useful procedure in selected patients.
Chemosensitivity and Mechanosensitivity of Nociceptors from Incised Rat Hindpaw Skin
Authors: Kang Sinyoung , Brennan Timothy J.
Published: June 2009

Background

The authors have demonstrated a decrease in pH in the incisional wound environment, suggesting a possible contribution of low pH to postsurgical pain. In this study, the authors characterized the acid-responsiveness of nociceptors innervating the plantar aspect of the rat hind paw 1 day after plantar incision and compared this to plantar skin from unincised control rats.

Methods

Using the rat glabrous in vitro skin-tibial nerve preparation, afferent nerve activities from single mechanosensitive nociceptors were recorded. Differences in mechanosensitivity, spontaneous activity, and chemosensitivity of units were evaluated. For chemosensitivity, acid-responsiveness of nociceptors to lactic acid (pH 5.5 to 6.5) was studied.

Results

C-fibers showed dose-dependent, sustained responses to lactic acid. A greater proportion of C-fibers from 2 mm or less from the incision was activated by pH 6.0 lactic acid (52.9%) compared to control (14.3%). Total evoked potentials during acid exposure were greater in C-fibers innervating 2 mm or less from the incision compared to those in unincised skin. The prevalence of acid responses and total evoked potentials during acid exposure in C-fibers innervating more than 2 mm from the incision were not different from control. Few A-fibers responded to lactic acid, with a range of pH 5.5 to 6.5 in both incision and control groups. Increased spontaneous activity and mechanosensitivity were also evident.

Conclusions

C-fibers in the vicinity of the incision showed qualitatively and quantitatively greater chemosensitivity to pH 6.0 lactic acid compared to control. This change was localized to 2 mm or less from the incision, suggesting increased chemosensitivity of nociceptive C-fibers 1 day after plantar incision.
Propofol Activates and Allosterically Modulates Recombinant Protein Kinase Cϵ
Authors: Wickley Peter J. , Yuge Ryo , Martin Brad A. , Meyer Jacob S. , Damron Derek S.
Published: June 2009

Background

Myocardial protection by anesthetics is known to involve activation of protein kinase C epsilon (PKC epsilon). A key step in the activation process is autophosphorylation of the enzyme at serine 729. This study's objectives were to identify the extent to which propofol interacts with PKC epsilon and to identify the molecular mechanism(s) of interaction.

Methods

Immunoblot analysis of recombinant PKC epsilon was used to assess autophosphorylation of PKC epsilon at serine 729 before and after exposure to propofol. An enzyme-linked immunosorbant assay kit was used for measuring PKC epsilon activity. Spectral shifts in fluorescence emission maxima of the C1B subdomain of PKC epsilon in combination with the fluorescent phorbol ester, sapintoxin D, was used to identify molecular interactions between propofol and the phorbol ester/diacylglycerol binding site on the enzyme.

Results

Propofol (1 microM) caused a sixfold increase in immunodetectable serine 729 phosphorylated PKC epsilon and increased catalytic activity of the enzyme in a dose-dependent manner. Dioctanoylglycerol-induced or phorbol myristic acetate-induced activation of recombinant PKC epsilon activity was enhanced by preincubation with propofol. Both propofol and phorbol myristic acetate quenched the intrinsic fluorescence spectra of the PKC epsilon C1B subdomain in a dose-dependent manner, and propofol caused a further leftward-shift in the fluorescence emission maxima of sapintoxin D after addition of the C1B subdomain.

Conclusions

These results demonstrate that propofol interacts with recombinant PKC epsilon causing autophosphorylation and activation of the enzyme. Moreover, propofol enhances phorbol ester-induced catalytic activity, suggesting that propofol binds to a region near the phorbol ester binding site allowing for allosteric modulation of PKC epsilon catalytic activity.
Crossover Comparison of the Laryngeal Mask Supreme™ and the i-gel™ in Simulated Difficult Airway Scenario in Anesthetized Patients
Authors: Theiler Lorenz G. , Kleine-Brueggeney Maren , Kaiser Dagmar , Urwyler Natalie , Luyet Cedric , Vogt Andreas , Greif Robert , Unibe M M. E.
Published: June 2009

Background

The single-use supraglottic airway devices LMA-Supreme (LMA-S; Laryngeal Mask Company, Henley-on-Thames, United Kingdom) and i-gel (Intersurgical Ltd, Wokingham, Berkshire, United Kingdom) have a second tube for gastric tube insertion. Only the LMA-S has an inflatable cuff. They have the same clinical indications and might be useful for difficult airway management. This prospective, crossover, randomized controlled trial was performed in a simulated difficult airway scenario using an extrication collar limiting mouth opening and neck movement.

Methods

Sixty patients were included. Both devices were placed in random order in each patient. Primary outcome was overall success rate. Other measurements were time to successful ventilation, airway leak pressure, fiberoptic glottic view, and adverse events.

Results

Success rate for the LMA-S was 95% versus 93% for the i-gel (P = 1.000). LMA-S needed shorter insertion time (34 +/- 12 s vs. 42 +/- 23 s, P = 0.024). Tidal volumes and airway leak pressure were similar (LMA-S 26 +/- 8 cm H20; i-gel 27 +/- 9 cm H20; P = 0.441). Fiberoptic view through the i-gel showed less epiglottic downfolding. Overall agreement in insertion outcome was 54 (successes) and 1 (failure) or 55 (92%) of 60 patients. The difference in success rate was 1.7% (95% CI -11.3% to 7.6%).

Conclusions

Both airway devices had similar insertion success and clinical performance in the simulated difficult airway situation. The authors found less epiglottic downfolding and better fiberoptic view but longer insertion time with the i-gel. Our study shows that both devices are feasible for emergency airway management in patients with reduced neck movement and limited mouth opening.
Lipid Emulsion Combined with Epinephrine and Vasopressin Does Not Improve Survival in a Swine Model of Bupivacaine-induced Cardiac Arrest
Authors: Hicks Shawn D. , Salcido David D. , Logue Eric S. , Suffoletto Brian P. , Empey Philip E. , Poloyac Samuel M. , Miller Donald R. , Callaway Clifton W. , Menegazzi James J.
Published: June 2009

Background

This study sought to evaluate the efficacy of lipid emulsion in reversing bupivacaine-induced cardiovascular collapse when added to a resuscitation protocol that included the use of epinephrine and vasopressin.

Methods

After induction of general anesthesia and instrumentation, 19 mixed-breed domestic swine had cardiovascular collapse induced by an intravenous bolus of 10 mg/kg bupivacaine. After 5 min of resuscitation including chest compressions, epinephrine (100 microg/kg) and vasopressin (1.5 U/kg), animals were randomized to receive either a bolus of 20% lipid emulsion (4 ml/kg) followed by a continuous infusion (0.5 ml x kg(-1) x min(-1)) or an equal volume of saline. Investigators were blinded to the treatment assignment. The primary endpoint was return of spontaneous circulation (mean arterial pressure of at least 60 mmHg for at least 1 min).

Results

Treatment groups were similar with respect to baseline measurements of weight, sex, and hemodynamic and metabolic variables. The rates of return of spontaneous circulation were similar between groups: (3 of 10) in the lipid group and 4 of 9 in the saline group (P = 0.65). Total serum bupivacaine concentrations were higher in the lipid group at the 10-min timepoint (mean +/- SEM: 23.13 +/- 5.37 ng/ml vs. 15.33 +/- 4.04 ng/ml, P = 0.004). More norepinephrine was required in the lipid group compared to the saline group to maintain a mean arterial pressure above 60 mmHg during the 60-min survival period (mean +/- SEM: 738.6 +/- 94.4 vs.. 487.3 +/- 171.0 microg).

Conclusions

In this swine model, lipid emulsion did not improve rates of return of spontaneous circulation after bupivacaine-induced cardiovascular collapse.
Success of Spinal and Epidural Labor Analgesia
Authors: Grondin Lydia S. , Nelson Kenneth , Ross Vernon , Aponte Orlando , Lee Sherman , Pan Peter H.
Published: June 2009

Background

Comparison of air versus saline for loss of resistance technique (LORT) in combined spinal epidural labor analgesia (CSE) has not been evaluated, and neither has the relation between CSE characteristics (the presence/absence of initial spontaneous clear fluid return or upon aspiration) and spinal/epidural analgesia outcomes. The authors hypothesized that there is no difference in the spinal analgesia success or epidural catheter efficacy between using air versus saline LORT for CSE.

Methods

A total of 360 patients were randomized to air or saline LORT for CSE. Primary outcome was spinal analgesia success as defined by verbal pain score of no more than 3 at 15 min after spinal dose administration. Secondary outcomes were CSE characteristics, catheter replacement, and average hourly epidural drug consumption.

Results

Results from 345 patients were analyzed. Spinal analgesia success, epidural catheter replacement, and drug consumption were not different between using air or saline LORT and were also independent of the presence/absence of fluid return on aspiration if initial spontaneous fluid returned to the spinal needle. However, epidural catheters inserted in absence of initial fluid return had a significantly higher catheter replacement rate (28.6%) than the 4.1% among those with initial fluid return (P < 0.03).

Conclusions

Spinal analgesia success rate and epidural efficacy are independent of whether air or saline is used for LORT during CSE. Practice of aspiration for fluid after observing initial fluid return may be unnecessary because this practice does not alter spinal/epidural analgesia outcomes. However, epidural catheters inserted with the absence of initial fluid returned to spinal needle may pose a high failure risk.
Effects of Sevoflurane and Propofol on the Nociceptive Withdrawal Reflex and on the H Reflex
Authors: Baars Jan H. , Mager René , Dankert Katharina , Hackbarth Mark , von Dincklage Falk , Rehberg Benno
Published: June 2009

Background

The predominant target of anesthetics to suppress movement responses to noxious stimuli is located in the spinal cord. Although volatile anesthetics appear to produce immobility by actions on the ventral rather than the dorsal horn, the site of action of propofol remains unclear.

Methods

In a crossover design, the authors compared in 13 volunteers the effects of sevoflurane and propofol on the amplitudes of the H reflex, which is mediated exclusively in the ventral horn and a withdrawal reflex (RIII Reflex), which integrates dorsal and ventral horn function. The concentrations were adjusted according to a Dixon up-and-down approach, depending on movement responses to tetanic stimulation.

Results

Sevoflurane and propofol concentrations ranged from 1.2 to 1.6 Vol% and 3 to 6 mg/l, respectively. Sevoflurane reduced the H reflex amplitude significantly to 66 +/- 17% (mean +/- SD) of its control values. Propofol did not significantly reduce the H reflex. The reductions under the two drugs differed significantly. The RIII reflex amplitude was significantly reduced to 19 +/- 10% and 27 +/- 12% (mean +/- SD) of the control values by sevoflurane and propofol, respectively. The reductions did not differ between the drugs.

Conclusions

Probably because of the polysynaptic relay, the attenuation of the withdrawal reflex exceeds the attenuation of the H reflex. Sevoflurane produces a larger inhibitory effect on the H reflex than propofol, which confirms that the ventral horn is a more important target for volatile anesthetics, whereas effects of propofol on this site of action are rather limited. Our findings indirectly suggest for propofol a relatively stronger effect within the dorsal horn.
Reversal of Neuromuscular Blockade by Sugammadex after Continuous Infusion of Rocuronium in Patients Randomized to Sevoflurane or Propofol Maintenance Anesthesia
Authors: Rex Christopher , Wagner Stefanie , Spies Claudia , Scholz Jens , Rietbergen Henk , Heeringa Marten , Wulf Hinnerk
Published: June 2009

Background

Sugammadex rapidly reverses neuromuscular blockade induced by bolus rocuronium doses, but it has not been investigated after continuous rocuronium infusion in surgical patients. We therefore examined the clinical effect of sugammadex for neuromuscular blockade induced by continuous rocuronium infusion in adults undergoing surgery under maintenance anesthesia with sevoflurane or propofol.

Methods

This four-center, comparative, parallel-group study, randomly assigned 52 adult patients (American Society of Anesthesiologists Class I-III) to maintenance anesthesia with sevoflurane or propofol. Neuromuscular blockade was induced by bolus injection of 0.6 mg/kg rocuronium followed by continuous infusion of 7 microg x kg(-1) x min(-1) rocuronium adjusted to maintain a neuromuscular blockade depth of zero response to train-of-four and a posttetanic count of no more than 10 responses. A single dose of 4 mg/kg sugammadex was administered at first twitch (T1) 3-10%. The primary clinical effect variable was recovery time to a train-of-four ratio of 0.9.

Results

Median recovery time from start of sugammadex administration to a train-of-four ratio of 0.9 in the sevoflurane and propofol groups was 1.3 and 1.2 min, respectively. The estimated difference in recovery time between groups was 9 s (95% confidence interval -6 to 20 s), entirely within the predefined equivalence interval. Median plasma rocuronium concentration just before sugammadex administration was 33% lower during maintenance anesthesia with sevoflurane than with propofol. Sugammadex was well tolerated. One adverse event (procedural hypotension) was considered to be probably related to sugammadex.

Conclusions

Single-dose sugammadex (4 mg/kg) after continuous rocuronium infusion is equally effective and well tolerated during maintenance anesthesia with sevoflurane or propofol.
Reduction of Bone Cancer Pain by Activation of Spinal Cannabinoid Receptor 1 and Its Expression in the Superficial Dorsal Horn of the Spinal Cord in a Murine Model of Bone Cancer Pain
Authors: Furuse Shingo , Kawamata Tomoyuki , Yamamoto Jun , Niiyama Yukitoshi , Omote Keiichi , Watanabe Masahiko , Namiki Akiyoshi
Published: June 2009

Background

Bone cancer pain has a strong impact on the quality of life of patients, but it is difficult to treat. Therefore, development of a novel strategy for the treatment of bone cancer pain is needed for improvement of patient quality of life. This study examined whether selective spinal cannabinoid receptor 1 (CB1) activation alleviates bone cancer pain and also examined the spinal expression of CB1.

Methods

A bone cancer pain model was made by implantation of sarcoma cells into the intramedullary space of the mouse femur. In behavioral experiments, the authors examined the effects of activation of spinal CB1 and inhibition of metabolism of endocannabinoid on bone cancer-related pain behaviors. Immunohistochemical experiments examined the distribution and localization of CB1 in the superficial dorsal horn of the spinal cord using specific antibodies.

Results

Spinal CB1 activation by exogenous administration of a CB1 agonist arachidonyl-2-chloroethylamide reduced bone cancer-related pain behaviors, including behaviors related to spontaneous pain and movement-evoked pain. In immunohistochemical experiments, although mu-opioid receptor 1 expression was reduced in the superficial dorsal horn ipsilateral to the site of implantation of sarcoma cells, CB1 expression was preserved. In addition, CB1 was mainly expressed in the axon terminals, but not in the dendritic process in the superficial dorsal horn.

Conclusion

Spinal CB1 activation reduced bone cancer-related pain behavior. Presynaptic inhibition may contribute to the analgesic effects of spinal CB1 activation. These findings may lead to novel strategies for the treatment of bone cancer pain.
Hydroxyethyl Starches
Authors: Westphal Martin , James Michael F. M. , Kozek-Langenecker Sibylle , Stocker Reto , Guidet Bertrand , Van Aken Hugo , Warner Mark A.
Published: June 2009

With the development of a new generation of hydroxyethyl starches (HES), there has been renewed interest in their clinical potential. High doses of first- and second-generation HES were associated with adverse effects on renal function, coagulation, and tissue storage, thereby limiting their clinical applicability. Newer HES products have lower molar substitution and in vivo molecular weight, resulting in more rapid metabolism and clearance. In this review article, the differences between HES generations are highlighted, with particular emphasis on the improved safety profile of the third generation products. These improvements have been achieved with no loss of efficacy, and they contradict the assumption that efficacy of HES solutions is directly linked to plasma concentration. The impact of source material on structure and pharmacokinetics is highlighted, and the role of the carrier solution is critically assessed.
Cervical Spine Motion
Authors: Turkstra Timothy P. , Pelz David M. , Jones Philip M.
Published: June 2009

Background

The optimal technique to intubate the trachea in patients presenting with a potential or documented cervical spine (C-spine) injury remains unresolved. Using continuous fluoroscopic video assessment, C-spine motion during laryngoscopy with an AirTraq Laryngoscope (King Medical Systems, Newark, DE) was compared to that with intubation using a Macintosh blade.

Methods

Twenty-four healthy surgical patients gave written consent to participate in a crossover randomized controlled trial; all patients were subjected to both Macintosh and AirTraq laryngoscopy with manual inline stabilization after induction of anesthesia. The C-spine motion was examined at four areas: the occiput-C1 junction, C1-C2 junction, C2-C5 motion segment, and C5-thoracic motion segment. The time required for laryngoscopy was also measured.

Results

C-spine motion using the AirTraq was less than that during Macintosh laryngoscopy, averaging 66% less (P < 0.01) at three of the motion segments studied, occiput-C1, C2-C5, and C5-thoracic. There was no difference at the C1-C2 segment. There was no significant difference in the time to accomplish laryngoscopy between the two devices.

Conclusions

For patients in whom C-spine movement is undesirable, use of the AirTraq Laryngoscope may be useful to limit movement without an increase in the duration of intubation.
Noninvasive Temperature Monitoring in Postanesthesia Care Units
Authors: Langham Geoffrey E. , Maheshwari Ankit , Contrera Kevin , You Jing , Mascha Edward , Sessler Daniel I.
Published: June 2009

Background

Initial postoperative core temperature is a physician and hospital performance measure. However, the extent to which core temperature changes during emergence from anesthesia and transport from the operating room to the postanesthesia care unit (PACU) remains unknown. Similarly, the accuracy of many noninvasive temperature-monitoring methods used in the PACU has yet to be quantified. This study, therefore, quantified the change in core temperature occurring during emergence and transport and evaluated the accuracy and precision of eight noninvasive thermometers in the PACU.

Methods

In 50 patients having laparoscopic surgery, the authors measured temperatures upon PACU arrival and 30 and 60 min thereafter. Monitoring methods included oral, axillary, temporal artery, forehead skin-surface, forehead liquid-crystal display, infrared aural canal, deep forehead, and deep chest. Bladder temperature was used as the reference and was also measured at the end of surgery. The primary outcome was agreement between individual temperatures from each method and bladder temperature in the PACU. A priori, the authors chose 0.5 degrees C as a clinically important temperature deviation.

Results

Bladder temperature increased 0.2 +/- 0.3 degrees C (95% confidence interval 0.1 to 0.3 degrees C), P < 0.001, during transport. None of the tested noninvasive thermometers was consistently within 0.5 degrees C of bladder temperature. However, oral, deep forehead, and temporal artery temperatures were significantly better than other methods and agreed reasonably well with bladder temperature.

Conclusions

Invasive temperature monitoring available intraoperatively is more accurate than any generally available postoperative methods. Physician performance measures should therefore not be based exclusively on postoperative temperatures. Among the generally available postoperative monitoring methods, electronic oral thermometry appears to be the best.
An Estimation of the Minimum Effective Anesthetic Volume of 2% Lidocaine in Ultrasound-guided Axillary Brachial Plexus Block
Authors: O’Donnell Brian D. , Iohom Gabrielle
Published: June 2009

Background

Ultrasound guidance facilitates precise needle and injectate placement, increasing axillary block success rates, reducing onset times, and permitting local anesthetic dose reduction. The minimum effective volume of local anesthetic in ultrasound-guided axillary brachial plexus block is unknown. The authors performed a study to estimate the minimum effective anesthetic volume of 2% lidocaine with 1:200,000 epinephrine (2% LidoEpi) in ultrasound-guided axillary brachial plexus block.

Methods

After ethical approval and informed consent, patients undergoing hand surgery of less than 90 min duration were recruited. A step-up/step-down study model was used with nonprobability sequential dosing based on the outcome of the previous patient. The starting dose of 2% LidoEpi was 4 ml per nerve. Block failure resulted in a dose increase of 0.5 ml; block success in a reduction of 0.5 ml.A blinded assistant assessed sensory and motor blockade at 5-min intervals up to 30 min. Block performance time and duration were measured. Two predetermined stopping points were used; a minimum of five consecutive block success/failures and five consecutive successful blocks at 1 ml per nerve.

Results

The study was terminated when five consecutive patients had successful blocks using 1 ml of 2% LidoEpi per nerve (overall group n = 11). All five patients had surgical anesthesia within 10 min. The mean (SD) block performance time was 445 (100) s, and block duration was 190 min (range 120-310 min). All surgical procedures were performed under regional anesthesia with anxiolytic sedation provided in 3 of 11 cases.

Conclusion

Successful ultrasound-guided axillary brachial plexus block may be performed with 1 ml per nerve of 2% LidoEpi.
QX-314 Produces Long-lasting Local Anesthesia Modulated by Transient Receptor Potential Vanilloid Receptors in Mice
Authors: Ries Craig R. , Pillai Ray , Chung Cheryl C. W. , Wang Jimmy T. C. , MacLeod Bernard A. , Schwarz Stephan K. W.
Published: June 2009

Background

The quaternary lidocaine derivative QX-314 is now known to produce long-lasting local anesthesia despite its positive charge. However, recent research suggests that the transient receptor potential vanilloid receptor agonist, capsaicin, should reduce the onset and offset times, whereas the transient receptor potential vanilloid receptor antagonist, capsazepine, should delay the onset time of sensory blockade by QX-314.

Methods

Sensory blockade in the tail of the conscious mouse was investigated using QX-314 2.5% in combination with capsaicin 0.1% and/or capsazepine (50 microg/ml). After tail injection, onset and offset times of local anesthesia were measured using the hot water tail-flick latency test.

Results

Capsaicin reduced the onset time of local anesthesia by QX-314 by more than 75% (Mann-Whitney test, P = 0.007; n = 10 per group) with no effect on the offset time of QX-314. For QX-314 without capsaicin, the onset and offset times were 23 min (interquartile range 15-30 min) and 300 min (interquartile range 285-375 min), respectively. For QX-314 with capsaicin, the onset and offset times were 4 min (interquartile range 3-8 min) and 360 min (interquartile range 285-435 min), respectively. In the antagonist study, capsazepine without added capsaicin decreased QX-314's efficacy, as 6 out of 9 mice did not develop sensory blockade after 90 min (Fisher exact test, P = 0.009).

Conclusion

We have confirmed in a sensory blockade model that QX-314 is a local anesthetic with a slow onset and a long duration of reversible blockade. Capsaicin, a transient receptor potential vanilloid receptor agonist, accelerated QX-314's onset kinetics, whereas capsazepine, a transient receptor potential vanilloid receptor antagonist, decreased QX-314's efficacy. These observations raise the possibility that endovanilloids may modulate cell entry of QX-314.
Preoperative Melatonin and Its Effects on Induction and Emergence in Children Undergoing Anesthesia and Surgery
Authors: Kain Zeev N. , MacLaren Jill E. , Herrmann Leslie , Mayes Linda , Rosenbaum Abraham , Hata Justin , Lerman Jerrold
Published: June 2009

Background

Studies conducted in adults undergoing surgery reported a beneficial effect of oral melatonin administered before surgery. There is a paucity of such data in children undergoing anesthesia and surgery.

Methods

Children undergoing surgery were randomly assigned to receive preoperatively oral midazolam 0.5 mg/kg or oral melatonin 0.05 mg/kg, 0.2 mg/kg, or 0.4 mg/kg. The primary outcome of the study was preoperative anxiety (Yale Preoperative Anxiety Scale). The secondary outcomes were the children's compliance with induction (Induction Compliance Checklist), emergence behavior (Keegan scale), and parental anxiety (State-Trait Anxiety Inventory).

Results

Repeated measures ANOVA showed that children who received melatonin at any of the three doses were more anxious compared with children who received midazolam (P < 0.001). Parental anxiety did not differ on the basis of the experimental condition (P = ns). The melatonin groups showed a dose-response effect on emergence behavior. Children who received melatonin developed less emergence delirium compared with those who received midazolam (P < 0.05), and the effect was dose related; the incidence after 0.05 mg/kg melatonin was 25.0%, incidence after 0.2 mg/kg melatonin was 8.3%, and incidence after 0.4 mg/kg melatonin was 5.4%.

Conclusions

Midazolam is more effective than melatonin in reducing children's anxiety at induction of anesthesia. Melatonin showed a direct dose-dependent effect on emergence delirium.
Ultrasound Assessment of Gastric Content and Volume
Authors: Perlas Anahi , Chan Vincent W. S. , Lupu Catalin M. , Mitsakakis Nicholas , Hanbidge Anthony
Published: June 2009

Background

Aspiration of gastric contents can be a serious perioperative complication, attributing up to 9% of all anesthesia-related deaths. However, there is currently no practical, noninvasive bedside test to determine gastric content and volume in the perioperative period.

Methods

The current study evaluates the feasibility of using bedside ultrasonography for assessing gastric content and volume. In the pilot phase, 18 healthy volunteers were examined to assess the gastric antrum, body, and fundus in cross-section in five prandial states: fasting and after ingestion of 250 mL of water, 500 mL of water, 500 mL of effervescent water, and a solid meal. In the phase II study, the authors concentrated on ultrasound examination of the gastric antrum in 36 volunteers for whom regression analysis was used to determine the correlation between gastric volume and antral cross-sectional area.

Results

The gastric antrum provided the most reliable quantitative information for gastric volume. The antral cross-sectional area correlated with volumes of up to 300 mL in a close-to-linear fashion, particularly when subjects were in the right lateral decubitus position. Sonographic assessment of the gastric antrum and body provides qualitative information about gastric content (empty or not empty) and its nature (gas, fluid, or solid). The fundus was the gastric area least amenable to image and measure.

Conclusions

Our preliminary results suggest that bedside two-dimensional ultrasonography can be a useful noninvasive tool to determine gastric content and volume.
Suppression of Shivering during Hypothermia Using a Novel Drug Combination in Healthy Volunteers
Authors: Lenhardt Rainer , Orhan-Sungur Mukadder , Komatsu Ryu , Govinda Raghavendra , Kasuya Yusuke , Sessler Daniel I. , Wadhwa Anupama
Published: June 2009

Background

Hypothermia may be beneficial in stroke victims; however, it provokes vigorous shivering. Buspirone and dexmedetomidine each linearly reduce the shivering threshold with minimal sedation and no respiratory depression. This study tested the hypotheses that the combination of buspirone and dexmedetomidine would (1) synergistically reduce the shivering threshold, (2) synergistically reduce the gain and maximum intensity of shivering, and (3) produce sufficient inhibition to permit cooling to 34 degrees C without excessive hypotension or sedation.

Methods

Eight healthy men were randomly assigned on 4 days to (1) no drug, (2) buspirone (60 mg orally), (3) dexmedetomidine (intravenous infusion to target plasma concentration of 0.6 ng/ml), or (4) combination of buspirone and dexmedetomidine at same doses. Lactated Ringer's solution (approximately 3 degrees C) was infused intravenously to decrease tympanic membrane temperature by 1.5 degrees C/h. Shivering threshold was defined as an increase in oxygen consumption greater than 20%. Sedation was evaluated using the Observer's Assessment of Sedation/Alertness scale.

Results

Mean arterial pressure and heart rate were slightly lower on dexmedetomidine and combination days. Likewise, the level of sedation was statistically different on these 2 days but clinically unimportant. Buspirone reduced the shivering threshold from 36.6 degrees C +/- 0.4 degrees C to 35.9 degrees C +/- 0.4 degrees C, dexmedetomidine reduced it to 34.7 degrees C +/- 0.5 degrees C, and the combination to 34.1 +/- 0.4 degrees C. The interaction effect of 0.04 degrees C was not significant. The gain of shivering and maximum shivering intensity were similar on each day.

Conclusions

The combination of buspirone and dexmedetomidine additively reduced the shivering threshold. Thus, supplementing dexmedetomidine with buspirone blocks shivering and causes only minimal sedation.