Video Laryngoscopy vs Direct Laryngoscopy for Endotracheal Intubation in the Operating Room: A Cluster Randomized Clinical Trial

Importance

Endotracheal tubes are typically inserted in the operating room using direct laryngoscopy. Video laryngoscopy has been reported to improve airway visualization; however, whether improved visualization reduces intubation attempts in surgical patients is unclear.

Objective

To determine whether the number of intubation attempts per surgical procedure is lower when initial laryngoscopy is performed using video laryngoscopy or direct laryngoscopy.

Design, Setting, and Participants

Cluster randomized multiple crossover clinical trial conducted at a single US academic hospital. Patients were adults aged 18 years or older having elective or emergent cardiac, thoracic, or vascular surgical procedures who required single-lumen endotracheal intubation for general anesthesia. Patients were enrolled from March 30, 2021, to December 31, 2022. Data analysis was based on intention to treat.

Interventions

Two sets of 11 operating rooms were randomized on a 1-week basis to perform hyperangulated video laryngoscopy or direct laryngoscopy for the initial intubation attempt.

Main Outcomes and Measures

The primary outcome was the number of operating room intubation attempts per surgical procedure. Secondary outcomes were intubation failure, defined as the responsible clinician switching to an alternative laryngoscopy device for any reason at any time, or by more than 3 intubation attempts, and a composite of airway and dental injuries.

Results

Among 8429 surgical procedures in 7736 patients, the median patient age was 66 (IQR, 56-73) years, 35% (2950) were women, and 85% (7135) had elective surgical procedures. More than 1 intubation attempt was required in 77 of 4413 surgical procedures (1.7%) randomized to receive video laryngoscopy vs 306 of 4016 surgical procedures (7.6%) randomized to receive direct laryngoscopy, with an estimated proportional odds ratio for the number of intubation attempts of 0.20 (95% CI, 0.14-0.28; P < .001). Intubation failure occurred in 12 of 4413 surgical procedures (0.27%) using video laryngoscopy vs 161 of 4016 surgical procedures (4.0%) using direct laryngoscopy (relative risk, 0.06; 95% CI, 0.03-0.14; P < .001) with an unadjusted absolute risk difference of -3.7% (95% CI, -4.4% to -3.2%). Airway and dental injuries did not differ significantly between video laryngoscopy (41 injuries [0.93%]) vs direct laryngoscopy (42 injuries [1.1%]).

Conclusion and Relevance

In this study among adults having surgical procedures who required single-lumen endotracheal intubation for general anesthesia, hyperangulated video laryngoscopy decreased the number of attempts needed to achieve endotracheal intubation compared with direct laryngoscopy at a single academic medical center in the US. Results suggest that video laryngoscopy may be a preferable approach for intubating patients undergoing surgical procedures.

Trial Registration

ClinicalTrials.gov Identifier: NCT04701762.

Implementing an Interdisciplinary Procedure Curriculum

INTRODUCTION

This curriculum was designed to improve access to procedures for our internal medicine residents.

METHODS

We created an interdisciplinary procedure course (IDPC) composed of two simulation sessions and a one-week procedural rotation supervised by multiple specialties including nephrology, cardiology, cardiothoracic anesthesiology, general anesthesiology, and interventional radiology. After the course, residents completed two surveys documenting the number of procedures and their level of confidence on a Likert scale (1 = very unconfident to 5 = very confident) prior to and after completing the curriculum.

RESULTS

Sixteen residents participated in the course from September 2021 to June 2022. The collective number of procedures performed by these 16 residents increased from 176 to 343 after a one-week rotation. For arterial lines, the proportion of residents that reported an improvement in confidence scores was 0.44 (95% confidence interval 0.23 to 1, p-value of 0.60). The proportion of residents that had an increase in their confidence performing central lines was 0.63 (95% confidence interval 0.39 to 1, p-value of 0.23). For intubations, the proportion of residents that reported an improvement in confidence was 0.94 (95% confidence interval 0.72 to 1, p-value of 0.0006).

CONCLUSION

By collaborating with multiple specialties, residents almost doubled the number of procedures performed during training and reported an increased level of confidence in procedural performance for airway intubation. We learned residents want to improve their access to procedures and described a curriculum that was easily implemented.

Serratus anterior and pectoralis plane blocks for robotically assisted mitral valve repair: a randomised clinical trial

BACKGROUND

Minimally invasive cardiac surgery provokes substantial pain and therefore analgesic consumption. The effect of fascial plane blocks on analgesic efficacy and overall patient satisfaction remains unclear. We therefore tested the primary hypothesis that fascial plane blocks improve overall benefit analgesia score (OBAS) during the initial 3 days after robotically assisted mitral valve repair. Secondarily, we tested the hypotheses that blocks reduce opioid consumption and improve respiratory mechanics.

METHODS

Adults scheduled for robotically assisted mitral valve repairs were randomised to combined pectoralis II and serratus anterior plane blocks or to routine analgesia. The blocks were ultrasound-guided and used a mixture of plain and liposomal bupivacaine. OBAS was measured daily on postoperative Days 1-3 and were analysed with linear mixed effects modelling. Opioid consumption was assessed with a simple linear regression model and respiratory mechanics with a linear mixed model.

RESULTS

As planned, we enrolled 194 patients, with 98 assigned to blocks and 96 to routine analgesic management. There was neither time-by-treatment interaction (P=0.67) nor treatment effect on total OBAS over postoperative Days 1-3 with a median difference of 0.08 (95% confidence interval [CI]: -0.50 to 0.67; P=0.69) and an estimated ratio of geometric means of 0.98 (95% CI: 0.85-1.13; P=0.75). There was no evidence of a treatment effect on cumulative opioid consumption or respiratory mechanics. Average pain scores on each postoperative day were similarly low in both groups.

CONCLUSIONS

Serratus anterior and pectoralis plane blocks did not improve postoperative analgesia, cumulative opioid consumption, or respiratory mechanics during the initial 3 days after robotically assisted mitral valve repair.

CLINICAL TRIAL REGISTRATION

NCT03743194.

Effectiveness of Simulation- Versus Didactic Video-Based Learning to Teach Advanced Lung Isolation Techniques

OBJECTIVES

Mastery of lung isolation is crucial for optimal cardiothoracic anesthesia education. The authors tested the hypothesis that simulation- is more effective than didactic video-based learning (cognitive, affective, and psychomotor) to teach anesthesiology fellows advanced lung isolation techniques.

DESIGN

A prospective randomized study.

SETTING

At a single academic heart center, simulation laboratory.

PARTICIPANTS

Thirty anesthesiology fellows with equivalent prior experience in basic lung isolation techniques.

INTERVENTIONS

Randomized participants received 1 of 2 structured educational interventions of equivalent duration designed to teach advanced lung isolation skills, a simulation workshop, or a video-based didactic session.

MEASUREMENTS AND MAIN RESULTS

To assess Bloom's taxonomy domains, performance measurements included pre- and postintervention cognitive tests and affective surveys and a postintervention psychomotor task (time to complete lung isolation). Changes in test and survey scores and time to completion were compared using the Mann-Whitney U test; p values < 0.05 were considered significant. Improvements in lung isolation learning assessments were greater in the simulation group, but significant differences only existed in the affective domain. Specifically, affective survey score increases were greater in the simulation group (simulation- versus video-based didactic: +19.0 v +4.0; p ≤ 0.001), whereas there was no significant difference in cognitive pre- to posttest scores (simulation- versus video-based: +28.6 v +19.1, p = 0.23), and time to achieve lung isolation (simulation- versus video-based: 32 v 36 seconds, p = 0.46).

CONCLUSIONS

Although greater affective learning of advanced lung isolation skills occurred with simulation-based compared to didactic video-based education, the authors found no differences between the teaching approaches in cognitive and psychomotor learning among anesthesiology fellows.

New Opportunities in Heart Failure with Preserved Ejection Fraction: From Bench to Bedside… and Back

Heart failure with preserved ejection fraction (HFpEF) is a growing public health problem in nearly 50% of patients with heart failure. Therefore, research on new strategies for its diagnosis and management has become imperative in recent years. Few drugs have successfully improved clinical outcomes in this population. Therefore, numerous attempts are being made to find new pharmacological interventions that target the main mechanisms responsible for this disease. In recent years, pathological mechanisms such as cardiac fibrosis and inflammation, alterations in calcium handling, NO pathway disturbance, and neurohumoral or mechanic impairment have been evaluated as new pharmacological targets showing promising results in preliminary studies. This review aims to analyze the new strategies and mechanical devices, along with their initial results in pre-clinical and different phases of ongoing clinical trials for HFpEF patients. Understanding new mechanisms to generate interventions will allow us to create methods to prevent the adverse outcomes of this silent pandemic.

Acoustic Noise-Based Detection of Ferroresonance Events in Isolated Neutral Power Systems with Inductive Voltage Transformers

Power-quality events and operation transients in power systems (PS) with isolated neutral can saturate inductive voltage transformers (IVT), which, when interacting with the overhead and underground cable capacitances, can cause ferroresonance events in the local PS. This abnormal operating mode can partially or totally damage the transformers and switchgears within the affected PS. Distribution system operators (DSO) can minimize these effects by detecting ferroresonance events accurately and fast enough and changing the mode of operation accordingly. Direct detection methods, i.e., based on voltage measurements, are reliable, but the massive deployment of this solution is relatively expensive; i.e., power quality analyzers cost thousands of USD. Alternatively, indirect detection methods are also available, e.g., IVT vibration measurements with accelerometers costing hundreds of USD, but their reliability depends on the installation method used. This manuscript proposes using the acoustic noise caused by magnetostriction forces within the IVT core during ferroresonance events to detect their occurrence. Compared to other indirect methods, electret condenser microphones with preamplifying stage cost less than USD 10 and are less sensitive to the installation procedure. The proposed method is validated experimentally, and its performance compared to IVT vibration measurements one by using the same detection methodology.

Extracorporeal CO2 removal and renal replacement therapy in acute severe respiratory failure in COVID-19 pneumonia: Case report

The COVID‐19 pandemic significates an enormous number of patients with pneumonia that get complicated with severe acute respiratory distress syndrome (ARDS), some of them with refractory hypercapnia and hypoxemia that need mechanical ventilation (MV). Those patients who are not candidate to extracorporeal membrane oxygenation (ECMO), the extracorporeal removal of CO₂ (ECCO₂R) can allow ultra protective MV to limit the transpulmonary pressures and avoid ventilatory induced lung injury (VILI).

We report a first case of prolonged ECCO₂R support in 38 year male with severe COVID‐19 pneumonia refractory to conventional support. He was admitted tachypneic and oxygen saturation 71% without supplementary oxygen. The patient's clinical condition worsens with severe respiratory failure, increasing the oxygen requirement and initiating MV in the prone position. After 21 days of protective MV, PaCO₂ rise to 96.8 mmHg, making it necessary to connect to an ECCO₂R system coupled continuous veno‐venous hemodialysis (CVVHD). However, due to the lack of availability of equipment in the context of the pandemic, a pediatric gas exchange membrane adapted to CVVHD allowed to maintain the removal of CO₂ until completing 27 days, being finally disconnected from the system without complications and with a satisfactory evolution.

Point-of-Care Ultrasound to Identify Landmarks of the Proximal Humerus: Potential Use for Intraosseous Vascular Access

OBJECTIVES

The inability to identify landmarks is an absolute contraindication for intraosseous access. The feasibility of landmark identification using ultrasound (US) has been demonstrated on human cadavers. We aimed to study the feasibility of point-of-care US in identifying proximal humerus landmarks in living human patients.

METHODS

This was a prospective cohort study conducted from May 3 to June 7, 2017, after approval from the Institutional Review Board at the Cleveland Clinic. Sixty upper extremities of 30 consenting participants across 3 distinct body mass index (BMI) groups (normal, obese, and morbidly obese) were alternately examined with a 12 L-RS linear US transducer (GE Healthcare, Chicago, IL) by 2 investigators. Six anatomic landmarks were identified: the humeral shaft, the surgical neck of the humerus, the lesser tubercle, the greater tubercle, the inter tubercular sulcus, and the target site for needle insertion on the greater tubercle. Rates of successful identification of all 6 landmarks as defined by independent agreement between the investigators were reported as estimated incidence rates with 95% bootstrap confidence interval (CI) sampling at the participant level.

RESULTS

Ultrasound had an overall success rate of 0.87 (95% CI, 0.78-0.95) in identifying all 6 landmarks with slight variability among various BMI groups. After excluding the surgical neck, the overall success rate improved to 0.93 (95% CI, 0.87-0.98), with minimum variability across BMI groups and no change in the ability to identify the target site.

CONCLUSIONS

Ultrasound is reliable in identifying proximal humerus intraosseous landmarks, with reasonable accuracy across various BMI groups.

Dissolved Gas Analysis Equipment for Online Monitoring of Transformer Oil: A Review

Power transformers are the most important assets of electric power substations. The reliability in the operation of electric power transmission and distribution is due to the correct operation and maintenance of power transformers. The parameters that are most used to assess the health status of power transformers are dissolved gas analysis (DGA), oil quality analysis (OQA) and content of furfuraldehydes (FFA) in oil. The parameter that currently allows for simple online monitoring in an energized transformer is the DGA. Although most of the DGA continues to be done in the laboratory, the trend is online DGA monitoring, since it allows for detection or diagnosis of the faults throughout the life of the power transformers. This study presents a review of the main DGA monitors, single- or multi-gas, their most important specifications, accuracy, repeatability and measurement range, the types of installation, valve or closed loop, and number of analogue inputs and outputs. This review shows the differences between the main existing DGA monitors and aims to help in the selection of the most suitable DGA monitoring approach according to the needs of each case.

Experimental Observation of Proton Bunch Modulation in a Plasma at Varying Plasma Densities

We give direct experimental evidence for the observation of the full transverse self-modulation of a long, relativistic proton bunch propagating through a dense plasma. The bunch exits the plasma with a periodic density modulation resulting from radial wakefield effects. We show that the modulation is seeded by a relativistic ionization front created using an intense laser pulse copropagating with the proton bunch. The modulation extends over the length of the proton bunch following the seed point. By varying the plasma density over one order of magnitude, we show that the modulation frequency scales with the expected dependence on the plasma density, i.e., it is equal to the plasma frequency, as expected from theory.

Experimental Observation of Plasma Wakefield Growth Driven by the Seeded Self-Modulation of a Proton Bunch

We measure the effects of transverse wakefields driven by a relativistic proton bunch in plasma with densities of 2.1×10^{14} and 7.7×10^{14}  electrons/cm^{3}. We show that these wakefields periodically defocus the proton bunch itself, consistently with the development of the seeded self-modulation process. We show that the defocusing increases both along the bunch and along the plasma by using time resolved and time-integrated measurements of the proton bunch transverse distribution. We evaluate the transverse wakefield amplitudes and show that they exceed their seed value (<15  MV/m) and reach over 300  MV/m. All these results confirm the development of the seeded self-modulation process, a necessary condition for external injection of low energy and acceleration of electrons to multi-GeV energy levels.

Ability of a Generalist Seed Beetle to Colonize an Exotic Host: Effects of Host Plant Origin and Oviposition Host

The colonization of an exotic species by native herbivores is more likely to occur if that herbivore is a generalist. There is little information on the life-history mechanisms used by native generalist insects to colonize exotic hosts and how these mechanisms are affected by host properties. We examined the ability of the generalist seed beetle Stator limbatus Horn to colonize an exotic species. We compared its host preference, acceptability, performance, and egg size when ovipositing and developing on two native (Pithecellobium dulce (Roxb.) Benth and Senegalia riparia (Kunth)) and one exotic legume species (Leucaena leucocephala (Lam.)). We also analyzed the seed chemistry. We found that females recognize the exotic species as an unfavorable host for larval development and that they delayed oviposition and laid fewer and larger eggs on the exotic species than on the native species. Survivorship on the exotic host was 0%. Additionally, seeds of the native species contain five chemical compounds that are absent in the exotic species, and the exotic species contains three sterols, which are absent in the native legumes. Genetically based differences between beetles adapted to different hosts, plastic responses toward new hosts, and chemical differences among seeds are important in host colonization and recognition of the exotic host. In conclusion, the generalist nature of S. limbatus does not influence its ability to colonize L. leucocephala. Explanations for the colonization of exotic hosts by generalist native species and for the success of invasive species must be complemented with studies measuring local adaptation and plasticity.

Novel application of rapid prototyping for simulation of bronchoscopic anatomy

OBJECTIVE

The authors used rapid prototyping (RP) technology to create anatomically congruent models of tracheo-bronchial tree for teaching relevant bronchoscopic anatomy.

DESIGN

Pilot study.

SETTING

A single level tertiary academic medical center.

INTERVENTIONS

Two 3 dimensional (3D) models of tracheo-bronchial tree (one showing normal anatomy and another with an early take off of right apical bronchus) were recreated from Computed Tomographic images using RP technology. These images were then attached to mannequins and examined with a flexible fiberoptic bronchoscope (FFB). These images were then compared with the actual FFB images obtained during lung isolation.

MEASUREMENTS AND MAIN RESULTS

The images obtained through the 3D models were found to be congruent to actual patient anatomy.

CONCLUSIONS

RP can be successfully used to create anatomically accurate models from imaging studies. There is potential for RP to become a valuable educational tool in the future.

Catatonia and its clinical course: Descriptive analysis of 12 consecutive cases in a general hospital psychiatric inpatient unit

Introduction

Scientific research regarding Catatonia is limited to individual clinical cases. Few well-design studies investigating its clinical course or therapeutic options have been carried out. We aimed to describe a sample of consecutive Catatonic patients admitted to the Basurto's Hospital Adult Psychiatric Inpatient Unit to obtain more data about its clinical presentation.

Material and methods

Subjects diagnosed of Catatonia anytime during admission were included (n = 12). Subject's admission dates ranged between December 2008 to September 2010. Catatonia was diagnosed following DSM-IV-TR criteria. Data was retrospectively obtained reviewing subject's clinical notes.

Results

The sample was predominantly composed of women (66.7%). Media of age was 55.3 years. All subjects reported previous mental illness. More prevalent diagnosis were Schizophrenia (33.2%), Bipolar Disorder (33.2%), Non Specified Psychotic Disorder (16.6%), Schizoaffective Disorder (8.3%) and Recurrent Depressive Disorder (8.3%). Nine subjects (75%) reported previous admission to a psychiatric unit. No subjects had previously suffered from Catatonia and only 2 had previously received electroconvulsive therapy (ECT). More frequent catatonia subtype was retarded (66.7%) with no subjects presenting with malignant catatonia. CGI at admission showed a media of 6.64.

Regarding treatment, 83.3% did not recover with benzodiazepines and needed ECT anytime during admission. Media admission length was 36.17 days.

Conclusions

Catatonia was more frequently observed in female, middle-aged women with no previous history of catatonia or ECT treatment but a history of previous psychotic or affective illness and hospital admissions. Symptom severity was very high and thus required aggressive treatment and longer hospital stays in order to achieve recovery.

Role of neuronal voltage-gated K(+) channels in the modulation of the nitrergic neurotransmission of the pig urinary bladder neck

BACKGROUND AND PURPOSE

As nitric oxide (NO) plays an essential role in the inhibitory neurotransmission of the bladder neck of several species, the current study investigates the mechanisms underlying the NO-induced relaxations in the pig urinary bladder neck.

EXPERIMENTAL APPROACH

Urothelium-denuded bladder neck strips were dissected and mounted in isolated organ baths containing a physiological saline solution at 37 degrees C and continuously gassed with 5% CO(2) and 95% O(2), for isometric force recording. The relaxations to transmural nerve stimulation (EFS), or to exogenously applied acidified NaNO(2) solution were carried out on strips pre-contracted with phenylephrine, and treated with guanethidine and atropine, to block noradrenergic neurotransmission and muscarinic receptors, respectively.

KEY RESULTS

EFS (0.2-1 Hz) and addition of acidified NaNO(2) solution (1 microM-1 mM) evoked frequency- and concentration-dependent relaxations, respectively. These responses were potently reduced by the blockade of guanylate cyclase and were not modified by the K(+) channel blockers iberiotoxin, charybdotoxin, apamin or glibenclamide. The voltage-gated K(+) (Kv) channels inhibitor 4-aminopyridine, greatly enhanced the nitrergic relaxations evoked by EFS, but did not affect the NaNO(2) solution-induced relaxations.

CONCLUSIONS AND IMPLICATIONS

NO, whose release is modulated by pre-junctional Kv channels, relaxes the pig urinary bladder neck through a mechanism dependent on the activation of guanylate cyclase, in which post-junctional K(+) channels do not seem to be involved. Modulation of Kv channels could be useful in the therapy of the urinary incontinence produced by intrinsic sphincteric deficiency.

Swelling of the leg, deep venous thrombosis and the piriformis syndrome

BACKGROUND

The piriformis syndrome, which was first described 60 years ago, is a well recognized cause of sciatica, leg pain and low back pain, due to the entrapment of the sciatic nerve in the piriformis and other rotator muscles. Very few complications relating to this syndrome have been described.

AIMS

To discuss how the piriformis syndrome may cause venous engorgement in the lower limb, and how the piriformis syndrome should be included as a possible cause of acute deep venous thrombosis in a not initially swollen leg. Both complications can occur independently.

METHODS

Two cases of swelling of the leg and acute deep venous thrombosis independently associated with the piriformis syndrome are presented.

CONCLUSIONS

Swelling of the leg and deep venous thrombosis are possible complications of the piriformis syndrome that occur due to entrapment of nerves and vessels within the leg, secondary to a severe spasm and hypertrophy of the piriformis and other rotator muscles.

Sangre de grado Croton palanostigma induces apoptosis in human gastrointestinal cancer cells

Sangre de grado is an ethnomedicinal red tree sap obtained from Croton spp. that is used to treat gastrointestinal ulcers, cancer and to promote wound healing. To evaluate the potential role of sangre de grado (SdG) in cancer we examined its effects on human cancer cells, AGS (stomach), HT29 and T84 (colon). Viability of cells treated with SdG (10-200 microg/ml) decreased (P<0.01) in a dose dependent manner measured over a 24-h period. Cell proliferation at 48 h decreased (P<0.01) in all cells treated with SdG (>100 microg/ml). When cells in suspension were treated with SdG (100 microg/ml) cell adherence was severely compromised (>85%). Cells treated with SdG (100 microg/ml) underwent apoptosis as detected by nucleus condensation and DNA fragmentation determined by ELISA, and flow cytometry. Morphological changes as assessed by acridine orange. These effects were similar to that observed with Taxol (30 microM). A significant alteration of microtubular architecture was equally observed in both stomach and colon cancer cells exposed to SdG (100 microg/ml). The induction of apoptosis and microtubule damage in AGS, HT29 and T84 cells suggest that sangre de grado should be evaluated further as a potential source of anti-cancer agents.

NK2 tachykinin receptors mediate contraction of the pig intravesical ureter: tachykinin-induced enhancement of non-adrenergic non-cholinergic excitatory neurotransmission

The current study was designed to characterize the functionally active tachykinin receptors involved in tachykinin-elicited contractions in the pig intravesical ureter, and to investigate the possible modulation exerted by the natural tachykinins substance P (SP) and neurokinin A (NKA) on the non-adrenergic non-cholinergic (NANC) excitatory ureteral neurotransmission. In pig intravesical ureteral strips pretreated with phosphoramidon (10(-5) mol/L) to block the endopeptidase activities, isometric force recordings showed that SP, NKA, and the NK2 receptor selective agonist [beta-Ala(8)]-NKA (4-10), all three induced contractions, with the following potency order: NKA > [beta-Ala(8) ]-NKA (4-10) > SP. [Sar(9), Met(O(2))(11)]-SP and senktide, selective agonists of the NK1 and NK3 receptors, respectively, failed to modify the ureteral tone. Urothelium removal and incubation with tetrodotoxin (10(-6) mol/L), phentolamine (10(-7) mol/L), propranolol (3 x 10(-6) mol/L), atropine (10(-7) mol/L) and indomethacin (3 x 10(-6) mol/L), did not alter the contraction induced by a submaximal (10(-7) mol/L) dose of [beta-Ala(8)]-NKA (4-10). MEN 10,376 (10(-8)-10(-7) mol/L), a NK2 receptor antagonist, reduced the contraction to 3 x 10(-8) mol/L NKA. GR 82334 (10(-6) -10(-5) mol/L) and SR 142801 (10(-8)-10(-7) mol/L), selective antagonists of the NK1 and NK3 receptors, respectively, did not modify that contraction. In pig intravesical ureteral strips in NANC conditions, SP and NKA induced a potentiation of the contractions to electrical field stimulation (EFS) and to exogenous ATP. The results suggest that the tachykinins evoke a direct contraction of pig intravesical ureteral strips through NK2 receptors located in the smooth muscle. SP and NKA exert an enhancement of the NANC excitatory neurotransmission of the pig intravesical ureter.

[Imported myiasis: 7 cases of cutaneous parasitism caused by Dermatobia hominis flie larvas]

Myiasis is the parasitism of organs and tissues of warm-blooded vertebrates by flies larvae. D hominis is a flie geographically restricted to tropical America from Mexico to northern Argentina. The adult flie, which is not hematophagous, needs to put its eggs on the abdominal surface of hematophagous arthropods which serve as carriers of future larvae which are deposited on the skin of the hosts (mammals, birds and accidentally men) when biting. Seven patients (two females) aged 7 to 35 years old, of different nationalities, recalled receiving mosquito bites, after staying in tropical American areas in the previous forty days. They presented furuncle-like lesions in exposed surfaces of the body. These lesions, 2-3 cm long, pruritic and mildly tender, broke and released a serous or serohematic fluid. Through the resulting opening, it was possible to partially observe the larva. Larvae were extracted by manual pressure (4) or surgical incision (3) and identified as D hominis larvae. Diagnosis of dermatobiasis, an imported myiasis, must be based on the characteristics of lesions and the previous residence in endemic areas of America.

Tachykininergic excitatory neurotransmission in the pig intravesical ureter

PURPOSE

The present investigation was designed to study the role played by neurokinin A (NKA) in the non adrenergic non cholinergic (NANC) neurotransmission of the pig intravesical ureter.

MATERIALS AND METHODS

We used immunohistochemical techniques to evidence the distribution of NKA-immunoreactive (NKA-IR) fibers in the pig intravesical ureter. We have also performed isolated organ bath experiments to release endogenous tachykinins from ureteral nerves and to characterize the functionally active receptor through which endogenous ligands evoke contraction, and to show the effect of exogenous tachykinins on intravesical ureteral smooth muscle.

RESULTS

NKA-IR fibers were found penetrating through ureteral adventitia and distributed in the subepithelial and muscular layers. NKA-IR fibers were not found around small arteries supplying the ureter or in the associated intramural ganglia. Electrical field stimulation (EFS, 1 ms duration, 2 to 16 Hz, 20 s trains) performed in NANC conditions evoked frequency-dependent contractions which were reduced by capsaicin (10-5 M) and GR 94800 (3 x 10-8 M), sensory neurotoxin and NK2 receptor antagonist, respectively. Contractions to EFS were abolished by tetrodotoxin (10-6 M). Exogenous NKA and substance P (SP) induced dose-dependent contractions, characterized by an increase of the ureteral basal tone, NKA being more potent than SP.

CONCLUSIONS

These results suggest that tachykinins, especially NKA, released from capsaicin-sensitive primary afferents, are involved in the NANC excitatory neurotransmission, contracting the smooth muscle via NK2 receptors activation, in the pig intravesical ureter. NKA at this level does not seem to participate in the regulation of local blood flow, plasmatic extravasation or ganglionar transmission.

A2B adenosine receptors mediate relaxation of the pig intravesical ureter: adenosine modulation of non adrenergic non cholinergic excitatory neurotransmission

1. The present study was designed to characterize the adenosine receptors involved in the relaxation of the pig intravesical ureter, and to investigate the action of adenosine on the non adrenergic non cholinergic (NANC) excitatory ureteral neurotransmission. 2. In U46619 (10(-7) M)-contracted strips treated with the adenosine uptake inhibitor, nitrobenzylthioinosine (NBTI, 10(-6) M), adenosine and related analogues induced relaxations with the following potency order: 5'-N-ethylcarboxamidoadenosine (NECA) = 5'-(N-cyclopropyl)-carboxamidoadenosine (CPCA) = 2-chloroadenosine (2-CA) > adenosine > cyclopentyladenosine (CPA) = N6-(3-iodobenzyl)-adenosine-5'-N-methylcarboxamide (IB-MECA) = 2-[p-(carboxyethyl)-phenylethylamino]-5'-N-ethylcarboxamidoaden os ine (CGS21680). 3. Epithelium removal or incubation with indomethacin (3 x 10(-6) M) and L-N(G)-nitroarginine (L-NOARG, 3 x 10(-5) M), inhibitors of prostanoids and nitric oxide (NO) synthase, respectively, failed to modify the relaxations to adenosine. 4. 1,3-dipropyl-8-cyclopentylxanthine (DPCPX, 10(-8) M) and 4-(2-[7-amino-2-(2-furyl) [1,2,4]-triazolo[2,3-a][1,3,5]triazin-5-ylamino]ethyl)phenol (ZM 241385, 3 x 10(-8) M and 10(-7) M), A1 and A2A receptor selective antagonists, respectively, did not modify the relaxations to adenosine or NECA. 8-phenyltheophylline (8-PT, 10(-5) M) and DPCPX (10(-6) M), which block A1/A2-receptors, reduced such relaxations. 5. In strips treated with guanethidine (10(-5) M), atropine (10(-7) M), L-NOARG (3 x 10(-5) M) and indomethacin (3 x 10(-6) M), both electrical field stimulation (EFS, 5 Hz) and exogenous ATP (10(-4) M) induced contractions of preparations. 8-PT (10(-5) M) increased both contractions. DPCPX (10(-8) M), NECA (10(-4) M), CPCA, (10(-4) M) and 2-CA (10(-4) M) did not alter the contractions to EFS. 6. The present results suggest that adenosine relaxes the pig intravesical ureter, independently of prostanoids or NO, through activation of A2B-receptors located in the smooth muscle. This relaxation may modulate the ureteral NANC excitatory neurotransmission through a postsynaptic mechanism.

Vasorelaxant effect of the analgesic clonixin on rat aorta

1. A novel vasorelaxant effect of clonixinate of L-lysine (Clx), analgesic and anti-inflammatory, was studied in rat aortic rings. 2. Clx completely relaxed aortic rings contracted by KCl 70 mM and together with its analog flunixin exhibited lesser potency but equal efficacy than verapamil. In comparison, indomethacin, which is a more potent cyclo-oxygenase inhibitor relaxed only about 40% of the maximal contraction of aortic rings. 3. Furthermore, Clx antagonized Ca2+ dependent aortic contraction and BAY K-8644 induced aortic contraction suggesting its calcium antagonist character. 4. From these results it can be concluded that the hypotensive effect seen in rats in vivo after Clx i.v. injection arises because of vasodilatory effect of Clx and gives further support to the proposal that the pharmacological mechanism of action of Clx should be calcium antagonism.

[Depression in the early course of schizophrenia]

Depressive syndromes in schizophrenia are reported in the prodromal stage of the early course, during the first or later psychotic episodes, but also after the fading out of an acute episode and as a precursor of relapse. According to these multiple conditions several explanations also exist as to how to understand depression in schizophrenia. Some authors interpret it as an elementary part of the schizophrenic symptomatology, which is only masked by positive symptoms (revealed depression). However, it can also be understood as a reactive depression or as caused by neuroleptic treatment, as part of the negative syndrome or as co-morbidity. In the ABC-Schizophrenia-Study, depression in the early course was analysed for patients in their first psychotic episode at index admission and an ICD-9 diagnosis of schizophrenia (ICD 295). In 81% of this sample depression was observed, beginning on average 4.3 years prior to index admission. In 42% of the patients depression began in the prepsychotic phase. In 18% the positive and the depressive syndrome developed within one month, and in 21% depression started after the first positive symptom occurred. We could only observe a clear sequence of depressive, negative and positive symptoms in the subgroup characterised by prepsychotic depression. A clear order of negative and positive symptoms was not observed in the other groups. Patients without depression in the early course have lower symptom levels at index admission. They present less positive symptoms (CATEGO-subscore DAH), fewer behavioural disturbances (subscore BSO) and also lower scores of non-specific symptoms (subscores SNR and NSN). More than 80% of the patients with depression in the early course also had a simple depression (as defined by the CATEGO-syndrome SD). Contrary to this, only 20% of the patient group without depression in the early course have positive SD values. Comparable percentages of males and females have depression in the early course, but in females depression begins more frequently in the prepsychotic phase, whereas in the male subgroup it more often starts postpsychotically, i.e. after the onset of the first psychotic symptom.

Population study of horizontal cells in live carp retinas using microinjections of horseradish peroxidase

In order to randomly sample horizontal cells (HCs) of carp retina, horseradish peroxidase (HRP) was delivered into axon terminals by means of vitreally inserted micropipettes in live fish. Survival time was extended to several hours to permit label diffusion into HC somata. A function measuring the relative complexity of cell contours was defined in order to help classify HCs according to their morphological types. The histogram of measurement from 313 HCs showed three modes fitting normal distributions. The numbers of cells in each group were 267, 36 and 10, respectively, representing a relative population of 85.3% H1s, 11.5% H2s and 3.2% H3s. It is suggested that cone HC somata are extended in a monolayer constituted by predominant type-H1 with interspersed groups of both type-H2 and type-H3 cells.

[Clinical and urodynamic study of enuresis in a juvenile male population]

We carried out a clinical and urodynamic assay of 100 cases of enuresis of a male population of ages ranging from 17 to 25. 64% displayed urodynamic alterations and these were significantly greater (p less than 0.005) amongst those suffering from nocturnal enuresis with diurnal symptoms (90%) than amongst those suffering from nocturnal enuresis only (59%). 36% of the patients did not display any urodynamic alteration. The urodynamic dysfunction most commonly displayed was vesical instability (46%). The other urodynamic dysfunctions found were 18% of the total, and detrusor contraction alteration constituted 10% of these (2 of the cases corresponded to vesical-urethral neurogenic dysfunction). The presence of minimum latent rachichisis was accompanied by urodynamic alterations in a significantly larger proportion (p less than 0.005) than in individuals not displaying this. The three case of wide-scale rachischisis were accompanied by urodynamic alterations corresponding to vesico-urethral neurogenic dysfunction. The case of secondary enuresis displayed neither urodynamic nor radiological alterations. Juvenile age enuresis displayed similar characteristics to infantile enuresis, although the percentage of vesical instability was lower. However, detrusor contraction alterations increased and the presence of previously non diagnosed vesico-urethral neurogenic dysfunctions was displayed.

Fast activity and oscillatory potential of carp retina in the frequency domain

There are two kinds of fast activity in the ERG: fast retinal potentials (FRP), an irregular series of spiky wavelets and oscillatory potentials (OP), a rhythmic sequence of events. Corneal ERG from nine intact young carps, evoked by extended pulses of diffuse white light under mesopic adaptation, displayed two different groups of wavelets related to ON and OFF, respectively. Stimulation and recording conditions were established to permit separate Fourier analysis of both groups of wavelets. Power distributions of normalized ON spectra showed both a wide dispersion and a high inter-subject variability. All normalized OFF spectra showed, instead, components within a narrow band from 52 to 56 Hz, most of them maximum relative power peaks. It is concluded that FRP originating in highly labile sources dominate ON fast activity, while the predominant OFF fast activity are OP originating in a stable discrete source.

Chronic effects of an alpha-glucosidase inhibitor (Bay o 1248) on intestinal disaccharidase activity in normal and diabetic mice

Bay o 1248 is a potent alpha-glycosidase inhibitor that reduces postprandial hyperglycemia when administered p.o. with sucrose or maltose. The compound binds to and competitively inhibits the alpha-disaccharidases and is also readily absorbed across the intestinal mucosa. To evaluate its effect on the activity of disaccharidases and on metabolic control, groups of obese diabetic mice (C57BLKsJ db/db) were given the drug for periods of 3, 7 and 84 days as a drug food mixture (5 or 10 mg/100 g of food). Nondiabetic mice of the same strain were dosed for 3 and 7 days. The drug did not influence body growth, food intake or fasting blood glucose. However, urine glucose excretion was significantly decreased at the higher dose in the diabetic mice. The drug had no effect on the protein content of jejunum (proximal and middle thirds) or ileum (distal third) of the small intestine. The activity of sucrase and maltase was significantly decreased in practically all segments of the small intestine in both diabetic and nondiabetic mice. These changes were evident after 3 days of drug administration. Lactase was not affected by the drug. The mechanism underlying these changes, although unclear, is of significant interest and deserves further investigation.