Minimum anesthetic concentration of isoflurane and sevoflurane and cardiorespiratory effects of varying inspired oxygen fractions in Magellanic penguins (Spheniscus magellanicus).

The aim of this study was to determine the minimum anesthetic concentration of isoflurane (MACISO) and sevoflurane (MACSEVO) and evaluate the cardiorespiratory changes induced by varying fractions of inspired oxygen (FiO2) in Magellanic penguins (Spheniscus magellanicus). Twenty adult penguins (3.53 ± 0.44 kg) of undetermined sex were used. Both MACISO (n = 9) and MACSEVO (n = 13) were established using an up-and-down design. Next, twelve mechanically ventilated penguins were maintained at 1 MACISO or 1 MACSEVO (n = 6 per group) with the FiO2 initially set at 1.0. Three FiO2 values (0.6, 0.4 and 0.2) were then held constant during anesthesia for 20 minutes each. Arterial blood samples were collected for gas analysis after the 20-minute period for each FiO2. Mean ± SD MACISO was 1.93 ± 0.10% and MACSEVO was 3.53 ± 0.13%. Other than heart rate at 0.6 FiO2 (86 ± 11 beats/minute in MACISO and 132 ± 37 beats/minute in MACSEVO; p = 0.041), no significant cardiorespiratory differences were detected between groups. In both groups, decreasing the FiO2 produced increased pH values and reduced partial pressures of carbon dioxide and bicarbonate. Partial pressures of oxygen (PaO2) gradually lowered from 1.0 FiO2 through 0.2 FiO2, though hypoxemia (PaO2 < 80 mmHg) occurred only with the latter FiO2. The MACISO and the MACSEVO for the Magellanic penguin fell within the upper range of reported avian MAC estimates. To prevent hypoxemia in healthy, mechanically ventilated, either isoflurane- or sevoflurane-anesthetized Magellanic penguins, a minimum FiO2 of 0.4 should be used.

Genomic Features of an MDR Escherichia coli ST5506 Harboring an IncHI2/In229/blaCTX-M-2 Array Isolated from a Migratory Black Skimmer.

Migratory birds have contributed to the dissemination of multidrug-resistant (MDR) bacteria across the continents. A CTX-M-2-producing Escherichia coli was isolated from a black skimmer (Rynchops niger) in Southeast Brazil. The whole genome was sequenced using the Illumina NextSeq platform and de novo assembled by CLC. Bioinformatic analyses were carried out using tools from the Center for Genomic Epidemiology. The genome size was estimated at 4.9 Mb, with 4790 coding sequences. A wide resistome was detected, with genes encoding resistance to several clinically significant antimicrobials, heavy metals, and biocides. The blaCTX-M-2 gene was inserted in an In229 class 1 integron inside a ∆TnAs3 transposon located in an IncHI2/ST2 plasmid. The strain was assigned to ST5506, CH type fumC19/fimH32, serotype O8:K87, and phylogroup B1. Virulence genes associated with survival in acid conditions, increased serum survival, and adherence were also identified. These data highlight the role of migratory seabirds as reservoirs and carriers of antimicrobial resistance determinants and can help to elucidate the antimicrobial resistance dynamics under a One Health perspective.

Ultrasound-guided femoral access in patients with vascular closure devices: a prespecified analysis of the randomised UNIVERSAL trial.

BACKGROUND: Whether ultrasound (US)-guided femoral access compared to femoral access without US guidance decreases access site complications in patients receiving a vascular closure device (VCD) is unclear. AIMS: We aimed to compare the safety of VCD in patients undergoing US-guided versus non-US-guided femoral arterial access for coronary procedures. METHODS: We performed a prespecified subgroup analysis of the UNIVERSAL trial, a multicentre randomised controlled trial of 1:1 US-guided femoral access versus non-US-guided femoral access, stratified for planned VCD use, for coronary procedures on a background of fluoroscopic landmarking. The primary endpoint was a composite of major Bleeding Academic Research Consortium 2, 3 or 5 bleeding and vascular complications at 30 days. RESULTS: Of 621 patients, 328 (52.8%) received a VCD (86% ANGIO-SEAL, 14% ProGlide). In patients who received a VCD, those randomised to US-guided femoral access compared to non-US-guided femoral access experienced a reduction in major bleeding or vascular complications (20/170 [11.8%] vs 37/158 [23.4%], odds ratio [OR] 0.44, 95% confidence interval [CI]: 0.23-0.82). In patients who did not receive a VCD, there was no difference between the US- and non-US-guided femoral access groups, respectively (20/141 [14.2%] vs 13/152 [8.6%], OR 1.76, 95% CI: 0.80-4.03; interaction p=0.004). CONCLUSIONS: In patients receiving a VCD after coronary procedures, US-guided femoral access was associated with fewer bleeding and vascular complications compared to femoral access without US guidance. US guidance for femoral access may be particularly beneficial when VCD are used.

The fraction of inspired oxygen does not affect the time to extubation in mechanically ventilated, sevoflurane-anesthetized green sea turtles (Chelonia mydas).

OBJECTIVE: To evaluate the effects of providing 100% O2, compared with the provision of 21% O2 (equivalent to room air), in mechanically ventilated, sevoflurane-anesthetized green sea turtles (Chelonia mydas). ANIMALS: Eleven juvenile green sea turtles. PROCEDURES: In a randomized, blinded, cross-over study (1-week interval between treatments), turtles were anesthetized with propofol (5 mg/kg, IV), orotracheally intubated, mechanically ventilated with 3.5% sevoflurane diluted in 100% O2 or 21% O2 for 90 minutes. Sevoflurane delivery immediately ceased and animals remained under mechanical ventilation with the assigned fraction of inspired oxygen until extubation. Recovery times, cardiorespiratory variables, venous blood gases, and lactate values were evaluated. RESULTS: Cloacal temperature, heart rate, end-tidal partial pressure of carbon dioxide, and blood gases were unremarkable between treatments. The SpO2 was higher with the provision of 100% O2 than 21% O2 during both anesthesia and recovery (P < .01). Time to bite the bite block was longer in 100% O2 (51 [39-58] minutes) than in 21% O2 (44 [31-53] minutes; P = .03), while time to first muscle movement, attempt to extubate, and extubation were comparable between treatments. CLINICAL RELEVANCE: Blood oxygenation appears to be lower during sevoflurane anesthesia in room air than in 100% O2, though both fractions of inspired oxygen were able to supply the aerobic metabolism of turtles based on acid-base profiles. In relation to room air, the provision of 100% O2 did not produce meaningful effects on the time to recovery in mechanically ventilated green turtles submitted to sevoflurane anesthesia.

Treatment of Calcified Lesions Using a Dedicated Super-High Pressure Balloon: Multicenter Optical Coherence Tomography Registry.

BACKGROUND: Calcified lesions often lead to difficulty achieving optimal stent expansion. OPN non-compliant (NC) is a twin layer balloon with high rated burst pressure that may modify calcium effectively. METHODS: Retrospective, multicenter registry in patients undergoing optical coherence tomography (OCT) guided intervention with OPN NC. Superficial calcification with > 180o arc and > 0.5 mm thickness, and/or nodular calcification with > 90o arc were included. OCT was performed in all cases before and after OPN NC, and after intervention. Primary efficacy endpoints were frequency of expansion (EXP) ≥80 % of the mean reference lumen area and mean final EXP by OCT, and secondary endpoints were calcium fractures (CF), and EXP ≥90 %. RESULTS: 50 cases were included; 25 (50 %) superficial, and 25 (50 %) nodular. Calcium score of 4 in 42 (84 %) cases and 3 in 8 (16 %). OPN NC was used alone, or after other devices if further modification was needed, NC in 27 (54 %), cutting in 29 (58 %), scoring in 1 (2 %), IVL in 2 (4 %); or if non-crossable lesion, rotablation in 5 (10 %) cases. EXP ≥80 % was achieved in 40 (80 %) cases with mean final EXP post intervention of 85.7 % ± 8.9. CF were documented in 49 (98 %) cases; multiple in 37 (74 %). There were 1 flow limiting dissection requiring stent deployment and 3 non-cardiovascular related deaths in 6 months follow-up. No records of perforation, no-reflow or other major adverse events. CONCLUSION: Among patients with heavy calcified lesions undergoing OCT guided intervention with OPN NC, acceptable expansion was achieved in most cases without procedure related complications.

Pure Aortic Regurgitation Complicated by Membranous Interventricular Septum Aneurysm Treated With Transcatheter Aortic Valve Replacement.

An 89-year-old woman with severe aortic regurgitation and an aneurysmal interventricular membranous septum extending into the aortic annulus underwent successful transcatheter aortic valve replacement. A challenging case because of the risk of valve mispositioning complications attributed to the co-occurrence of pure aortic regurgitation (very low calcium burden) with an aneurysmal interventricular membranous septum. (Level of Difficulty: Intermediate.).

Design and Rationale of Routine UltrasouNd GuIdance for Vascular AccEss foR Cardiac Procedures: A Randomized TriaL (UNIVERSAL).

Background: A significant limitation of femoral artery access for cardiac interventions is the increased risk of vascular complications and bleeding compared to radial access. Ultrasound (US)-guided femoral access may reduce major vascular complications and bleeding. We aim to determine whether routinely using US guidance for femoral arterial access for coronary angiography or intervention will reduce Bleeding Academic Research Consortium (BARC) 2, 3, or 5 bleeding or major vascular complications. Methods: The Ultrasound Guidance for Vascular Access for Cardiac Procedures: A Randomized Trial (UNIVERSAL) is a multicentre, prospective, open-label, randomized trial with blinded outcomes assessment. Patients undergoing coronary angiography with or without intervention via a femoral approach with fluoroscopic guidance will be randomized 1:1 to US-guided femoral access, compared to no US. The primary outcome is the composite of major bleeding based on the BARC 2, 3, or 5 criteria or major vascular complications within 30 days. The trial is designed to have 80% power and a 2-sided alpha level of 5% to detect a 50% relative risk reduction for the primary outcome based on a control event rate of 14%. Results: We completed enrollment on April 29, 2022, with 621 randomized patients. The patients had a mean age of 71 years (25.4% female), with a high rate of comorbidities, as follows: 45% had a prior percutaneous coronary intervention; 57% had previous coronary artery bypass surgery; and 18% had peripheral vascular disease. Conclusions: The UNIVERSAL trial will be one of the largest randomized trials of US-guided femoral access and has the potential to change guidelines and increase US uptake for coronary procedures worldwide.

Introduction: Par rapport à l'abord radial, la limitation importante de l'abord artériel fémoral lors des interventions au cœur pose un risque accru de complications vasculaires et de saignements. L'abord fémoral guidé par ultrasons (US) peut contribuer à réduire les complications vasculaires majeures et les saignements. Nous avons pour objectif de déterminer si l'utilisation systématique du guidage par US pour l'abord artériel fémoral lors des angiographies ou des interventions coronariennes contribuera à réduire les saignements de type 2, 3 ou 5 selon le B leeding A cademic R esearch C onsortium (BARC) ou les complications vasculaires majeures. Méthodes: L' U ltrasou n d Gu i dance for V ascular Acc e ss fo r Cardiac Procedure s : A Randomized Tria l (UNIVERSAL) est un essai multicentrique, prospectif, ouvert, à répartition aléatoire, réalisé par une évaluation à l'insu des résultats. Les patients subissant une angiographie coronarienne avec ou sans intervention par voie fémorale sous guidage fluoroscopique seront répartis de façon aléatoire 1:1 à l'abord fémoral guidé par US ou sans US. Le principal critère d'évaluation est le critère composite de saignements majeurs de type 2, 3 ou 5 selon les critères du BARC ou de complications vasculaires majeures dans les 30 jours. L'essai est conçu de façon à avoir une puissance de 80 % et un seuil alpha bilatéral de 5 % pour déterminer la réduction du risque relatif de 50 % du critère d'évaluation principal selon un taux d'événements dans le groupe témoin de 14 %. Résultats: Le 29 avril 2022, nous avons terminé le recrutement de 621 patients choisis aléatoirement. Les patients avaient un âge moyen de 71 ans (25,4 % de femmes) et un taux élevé de comorbidités : 45 % avaient déjà subi une intervention coronarienne percutanée, 57 % avaient déjà subi un pontage aorto-coronarien et 18 % avaient une maladie vasculaire périphérique. Conclusions: L'essai UNIVERSAL qui sera l'un des plus vastes essais à répartition aléatoire sur l'abord fémoral guidé par US a le potentiel de faire changer les lignes directrices et de faire augmenter le recours aux US lors des interventions coronariennes dans le monde entier.

Routine Ultrasonography Guidance for Femoral Vascular Access for Cardiac Procedures: The UNIVERSAL Randomized Clinical Trial.

Importance: A significant limitation of femoral artery access for cardiac interventions is the increased risk of vascular complications and bleeding compared with radial access. Strategies to make femoral access safer are needed. Objective: To determine whether routinely using ultrasonography guidance for femoral arterial access for coronary angiography/intervention reduces bleeding or vascular complications. Design, Setting, and Participants: The Routine Ultrasound Guidance for Vascular Access for Cardiac Procedures (UNIVERSAL) randomized clinical trial is a multicenter, prospective, open-label trial of ultrasonography-guided femoral access vs no ultrasonography for coronary angiography or intervention with planned femoral access. Patients were randomized from June 26, 2018, to April 26, 2022. Patients with ST-elevation myocardial infarction were not eligible. Interventions: Ultrasonography guidance vs no ultrasonography guidance for femoral arterial access on a background of fluoroscopic landmarking. Main Outcomes and Measures: The primary composite outcome is the composite of major bleeding based on the Bleeding Academic Research Consortium 2, 3, or 5 criteria or major vascular complications within 30 days. Results: A total of 621 patients were randomized at 2 centers in Canada (mean [SD] age, 71 [10.24] years; 158 [25.4%] female). The primary outcome occurred in 40 of 311 patients (12.9%) in the ultrasonography group vs 50 of 310 patients (16.1%) without ultrasonography (odds ratio, 0.77 [95% CI, 0.49-1.20]; P = .25). The rates of Bleeding Academic Research Consortium 2, 3, or 5 bleeding were 10.0% (31 of 311) vs 10.7% (33 of 310) (odds ratio, 0.93 [95% CI, 0.55-1.56]; P = .78). The rates of major vascular complications were 6.4% (20 of 311) vs 9.4% (29 of 310) (odds ratio, 0.67 [95% CI, 0.37-1.20]; P = .18). Ultrasonography improved first-pass success (277 of 311 [86.6%] vs 222 of 310 [70.0%]; odds ratio, 2.76 [95% CI, 1.85-4.12]; P < .001) and reduced the number of arterial puncture attempts (mean [SD], 1.2 [0.5] vs 1.4 [0.8]; mean difference, -0.26 [95% CI, -0.37 to -0.16]; P < .001) and venipuncture (10 of 311 [3.1%] vs 37 of 310 [11.7%]; odds ratio, 0.24 [95% CI, 0.12-0.50]; P < .001) with similar times to access (mean [SD], 114 [185] vs 129 [206] seconds; mean difference, -15.1 [95% CI, -45.9 to 15.8]; P = .34). All prerandomization prespecified subgroups were consistent with the overall finding. Conclusions and Relevance: In this randomized clinical trial, use of ultrasonography for femoral access did not reduce bleeding or vascular complications. However, ultrasonography did reduce the risk of venipuncture and number of attempts. Larger trials may be required to demonstrate additional potential benefits of ultrasonography-guided access. Trial Registration: ClinicalTrials.gov Identifier: NCT03537118.

Bespoke valve sizing avoids annular rupture in patients treated with a balloon-expandable transcatheter heart valve.

BACKGROUND: Annular and left ventricular outflow tract (LVOT) calcification increase the risk of annular rupture following transcatheter aortic valve replacement (TAVR). The outcomes of a strategy of routine use of a balloon-expandable valve (BEV) for all patients irrespective of annular or LVOT calcium is unknown. OBJECTIVES: We evaluated the impact of bespoke sizing on annular rupture in patients treated with a BEV. METHODS: All consecutive patients undergoing TAVR at a single centre (February 2020-February 2022) were treated only with a BEV. No other valve design was used. Annular/LVOT calcification was assessed using a standardized grading system. For each annular area, we determined the percentage valve oversizing with nominal deployment. The balloon deployment volume was then adjusted when required (over-/underfilled) to achieve over-sizing of approximately 5% in the presence of annular/LVOT calcium and 5%-10% in the absence of annular/LVOT calcium. Adjusted valve areas were assumed to change proportionately to the change in balloon deployment volume. RESULTS: Among 533 TAVR treated patients, annular/LVOT calcification was present in 166 (31.1%) and moderate or severe in 90 (16.9%). In patients with annular/LVOT calcification, the adjusted oversizing was 3.5 ± 3.6% and in patients without annular/LVOT calcification, the adjusted oversizing was 6.8 ± 4.7% (p < 0.001). There were no cases of annular rupture and no cases with more than mild paravalvular leak (PVL). Mild PVL was more frequent in patients with annular/LVOT calcium (10.8% vs 4.6%, p = 0.01). CONCLUSION: Bespoke BEV sizing by adjustment of balloon deployment volume avoided annular rupture in patients undergoing TAVR.

SWALKIT: A generic augmented walker kit to provide haptic feedback navigation assistance to people with both visual and motor impairments.

Feedback solutions are a privileged form of assistance in order to increase mobility and independence of people with both motor and visual impairments. Indeed, it empowers the ability of the person to make decisions and take actions based on the provided information. Moreover, it maintains the use of the walker, and thus the residual locomotor skills. We here propose the SWALKIT, an open-source, cost-efficient, lightweight, easy to install and generic augmented walker kit. The SWALKIT can be equipped on any walker without requiring modifications of the structure or advanced technical knowledge. Vibrotactile feedback is provided through the handles to indicate the proximity of obstacles on the way of the user. The open source project is reproducible thanks to the online repository https://github.com/IH2A/Swalkit. In this paper, we present the design of the SWALKIT based on a user-centered approach following target users and therapists guidelines. Then, we present a technical validation study performed with 14 able-bodied blindfolded participants on a cardboard circuit. They were asked to use a standard walker with and without activation of the SWALKIT system. Results of this pilot study showed the efficiency and reliability of the proposed solution. Finally, we provide feedback after 2 months of daily life use by a target user.

Using Optical Coherence Tomography to Identify Lipid and Its Impact on Interventions and Clinical Events　- A Scoping Review.

BACKGROUND: Optical coherence tomographic (OCT) imaging has enabled identification of lipid, with increasing interest in how it may affect coronary interventions and clinical outcomes. This review summarizes the available evidence around OCT identification of lipid and its effect on interventions, clinical events, and the natural history of coronary disease.Methods and Results:We conducted a scoping review using the Medline, HealthStar, and Embase databases for articles published between 1996 and 2021. We screened 1,194 articles and identified 51 for inclusion in this study, summarizing the key findings. The literature supports a common OCT definition of lipid as low-signal regions with diffuse borders, validated against histology and other imaging modalities with acceptable intra- and inter-rater reliability. There is evidence that OCT-identified lipid at the site of stent implantation increases the risk of edge dissection, incomplete stent apposition, in-stent tissue protrusion, decreased coronary flow after stenting, side branch occlusion, and post-procedural cardiac biomarker increases. In mostly retrospective studies, lipid indices measured at non-stented sites are associated with plaque progression and the development of recurrent ischemic events. CONCLUSIONS: There is extensive literature supporting the ability of OCT to identify lipid and demonstrating a substantial impact of lipid on percutaneous coronary intervention outcomes. Future work to prospectively evaluate the effect of the characteristics of lipid-rich plaques on long-term clinical outcomes is needed.

VENOUS AND ARTERIAL ACID-BASE ANALYSIS OF MAGELLANIC PENGUINS (SPHENISCUS MAGELLANICUS), AWAKE AND ANESTHETIZED BY ISOFLURANE.

This study aimed to compare the venous acid-base status of healthy awake versus anesthetized Magellanic penguins (Spheniscus magellanicus). Ten nonanesthetized penguins were manually restrained, and a venous blood sample was collected. Six of these penguins were anesthetized by 2% isoflurane and, after an anesthetic stabilization period, both venous and arterial blood samples were simultaneously withdrawn. Using an i-STAT analyzer, partial pressure of carbon dioxide (PCO2), partial pressure of oxygen (PO2), pH, standard bicarbonate concentration (HCO3-), total carbon dioxide (ctCO2), oxygen saturation (SO2), base excess (BE), Na+, and K+ levels were measured in venous blood samples of awake (Gawake) penguins and in venous (Gven) and arterial blood (Gart) samples of anesthetized penguins. There were no significant differences between groups in pH, BE, or Na+. Venous carbon dioxide pressure, HCO3-, and venous ctCO2 were higher in Gven than Gawake penguins, whereas PCO2 was higher in Gven than Gart penguins. PO2 and SO2 were higher in the Gart group than in the other groups. Both venous and arterial blood samples may be used to evaluate the acid-base profile of Magellanic penguins.

Novel herpesviruses in riverine and marine cetaceans from South America.

Herpesvirus (HV) infections in cetaceans are frequently associated with skin and mucosal lesions. Although HV infections have been reported worldwide, their occurrence in southern Atlantic marine mammals is still poorly understood. We tested skin, oral and genital mucosal beta-actin PCR-positive samples from 109 free-ranging Brazilian cetaceans using a universal herpesvirus DNA polymerase PCR. Herpesvirus-positive skin samples from a Guiana dolphin (Sotalia guianensis), a dwarf sperm whale (Kogia sima), a Bolivian river dolphin (Inia boliviensis), and a lingual sample from an Atlantic spotted dolphin (Stenella frontalis) were histologically evaluated. Additional tissue samples from these animals were also PCR-positive for HV, including a novel sequence obtained from the dwarf sperm whale's stomach and mesenteric lymph node. Four novel HV species were detected in the Guiana dolphin (one), the dwarf sperm whale (two) and the Bolivian river dolphin (one). The cutaneous lesions (marked, focally extensive, chronic proliferative dermatitis) of the Guiana dolphin and the Bolivian river dolphin were similar to previous HV reports in cetaceans, despite the absence of intranuclear inclusion bodies. This is the largest HV survey in South American cetaceans and the first detection of HV infection in riverine dolphins worldwide.

Principais estudos clínicos sobre implante de válvula aórtica transcateter / Main clinical studies on transcatheter aortic valve implantation

A estenose aórtica (EA) é uma doença frequente na população idosa e, quando sintomática, tem prognóstico desfavorável, sendo recomendada nesta situação a substituição valvar cirúrgica. Embora o tratamento cirúrgico seja o padrão para a correção da EA muitos pacientes não são candidatos adequados, devido ao risco perioperatório muito elevado. O implante da valva aórtica transcateter (TAVI) surgiu como interessante alternativa, principalmente nos casos de pacientes inoperáveis, demonstrando melhora significativa na sobrevida com relação ao tratamento clínico. Nos pacientes com risco cirúrgico elevado apresentou resultados equivalentes à troca valvar aórtica cirúrgica, com taxas de sobrevivência equivalentes ou até superiores. Os resultados clínicos encorajadores somados aos rápidos avanços da tecnologia geraram interesse no uso desses dispositivos em pacientes de risco intermediário. Atualmente já existem evidências demonstrando a não inferioridade da TAVI com relação à cirurgia para a correção da EA em pacientes de médio risco e esses dispositivos já estão aprovados nos Estados Unidos e Europa para o tratamento desse grupo de pacientes. No presente artigo são sumarizados os principais estudos que foram fundamentais para a implementação da TAVI na prática clínica atual e para aprovação pelos principais órgãos reguladores mundiais

Aortic stenosis (AS) is a common disease in the elderly population; when symptomatic, it has an unfavorable prognosis and aortic valve replacement is recommended. Although surgical replacement is the standard treatment for AS, many patients are not suitable candidates because of high perioperative risk. Transcatheter aortic valve implantation (TAVI) has emerged as an interesting alternative, especially in inoperable cases, showing significant improvements in survival over clinical treatment. In patients with high surgical risk TAVI has demonstrated results equivalent to surgical aortic valve replacement with similar or even higher survival rates. These encouraging clinical results coupled with advances in technology have generated interest in using TAVI in lower-risk populations. There is currently evidence showing that TAVI is not inferior to surgical treatment of AS in intermediate-risk patients, and these devices have already been approved in the United States and Europe for treating this group of patients. This article summarizes the main studies that were fundamental in implementing TAVI into current clinical practice and approval by the main global regulatory agencies

Histological aspects of the mucosa of the spermaceti chamber of a dwarf sperm whale / Aspectos histológicos da mucosa da câmera do espermacete de cachalote-anão

The sound producing apparatus of the dwarf sperm whale (Kogia sima) presents a complex anatomic structure composed of melon, spermaceti, phonic lips, vocal cap, case, papillae, spermaceti chamber and other airspaces, as well as facial muscles involved in sound production. The spermaceti chamber rests on the caudal portion of the premaxilla, with part of its mucosa covered with spherical/oval-shaped structures (approximately 1 to 2 mm in diameter), compatible with vesicles (previously referred to as "papillae"). Macroscopical examination revealed whitish, firm, widely and irregularly distributed vesicular mucosa on the premaxillary portion of the spermaceti chamber of a K. sima specimen stranded on the coast of Santos (southeastern Brazilian coast). Upon microscopic examination, walls of connective tissue with abundant type I collagen forming vesicles with an internal space or cavity filled with a small amount of eosinophilic substance compatible with mucoproteic fluid were observed. The base of such vesicles presented glands within the connective tissue, probably responsible for fluid production. This study describes the histology of the mucosa of the spermaceti chamber of a K. sima specimen and characterizes the glands associated with fluid production.(AU)

O sistema de produção sonora do cachalote-anão (Kogia sima) apresenta uma complexa estrutura anatômica composta por melão, espermacete, lábios fônicos, "vocal cap", "case", papilas, câmara do espermacete e outros espaços aéreos, além de músculos faciais envolvidos na produção sonora. A câmara do espermacete localiza-se na porção caudal da pré-maxila, apresentando parte de sua mucosa recoberta por estruturas esférico-ovaladas de aproximadamente 1 a 2 mm de diâmetro, compatíveis com vesículas (previamente denominadas "papilas"). Ao exame macroscópico de um espécime de K. sima encalhado no litoral de Santos (sudeste da costa brasileira), foi identificada mucosa esbranquiçada e firme ao corte, ampla e irregularmente distribuída na porção pré-maxilar da câmara do espermacete. Ao exame microscópico foram observadas vesículas compostas por abundante tecido conectivo de colágeno tipo I, dando origem a um espaço interno ou cavidade, contendo pequena quantidade de substância eosinófila, compatível com fluido mucoprotêico. Estruturas glandulares foram observadas em tecido conjuntivo na base das vesículas, provavelmente responsáveis pela produção do fluido observado no interior das mesmas. Esse estudo caracteriza histologicamente a mucosa da câmara do espermacete de um espécime de K. sima e as glândulas relacionadas a sua produção secretória.(AU)