RESUMO
With increasing global life expectancy, the significance of geriatric assessment parameters has increased. Sarcopenia is a crucial assessment parameter and is defined as the age-related loss of muscle mass and strength. Sarcopenia is widely acknowledged as a risk factor for postoperative complications in diverse advanced malignancies and has a detrimental effect on the long-term prognosis. While most studies have primarily concentrated on the correlation between sarcopenia and advanced cancer, more recent investigations have focused on the relationship between sarcopenia and early-stage cancer. Endoscopic submucosal dissection (ESD), which is less invasive than surgical intervention, is extensively employed in the management of early-stage cancer, although it is associated with complications such as bleeding and perforation. In recent years, several reports have revealed the adverse consequences of sarcopenia in patients with early-stage cancer undergoing ESD. This literature review briefly summarizes the recent studies on the association between sarcopenia and ESD.
RESUMO
Background and study aims This study aimed to evaluate the relationship between sessile serrated lesion (SSL) size and the comorbidity rate of SSL with dysplasia (SSLD) and cancer in SSL (SSL-cancer). Patients and methods This retrospective, single-center analysis identified SSL cases that underwent endoscopic resection between January 2015 and December 2022. The prevalence of SSL, SSLD, and SSL-cancer and their annual trends were assessed. The tumor diameter was stratified as 0 to 5 mm, 6 to 9 mm, 10 to 19 mm, and ≥ 20 mm in size. Furthermore, the frequency of SSL-D/SSL-cancer was determined in each group. Results The prevalence of SSL was 2.9% (1328/45799). This prevalence was 1.8% (112/6192) in 2015 and 4.2% (230/5500) in 2022, indicating an increasing trend over time. A total of 1825 lesions were assessed: 1751 (96.0%), 55 (3.0%), 14 (0.8%), and 5 (0.3%) of lesions were SSL, SSL with low-grade dysplasia, SSL with high-grade dysplasia and SSL-cancer, respectively. Stratifying the SSLs by size: 0 to 5 mm, 5 to 9 mm, 10 to 19 mm, and ≥ 20 mm, SSLD and SSL-cancer rates were 2.3% (10/429), 2.4% (16/674), 5.3% (31/584), and 11.8% (16/136), respectively. SSLD and SSL-cancer were observed in 2.4% (26/1103) of small SSLs < 10 mm. Conclusions In cases of SSL, the rate of SSLD and SSL-cancer increased as the lesion diameter increased. A certain rate of SSLD and SSL-cancer was observed even in small SSLs less than 5mm.
RESUMO
BACKGROUND: The proliferative zone of colonic adenomas is confined to the upper third of the crypt or is scattered along its entire axis. In contrast, there are unusual adenomas with proliferative zones confined to the lower two-thirds of the crypt. We investigated the frequency and endoscopic features of adenomas with lower proliferative zones. METHODS: We retrospectively reviewed consecutive patients who underwent colonoscopies between September 2022 and March 2023 at the Toyoshima Endoscopy Clinic. Colorectal polyps were endoscopically assessed using the Japan Narrow-Band Imaging Expert Team (JNET) classification. All resected polyps were histologically examined, and the proliferative zone locations were assessed in the adenomas. RESULTS: The frequency of adenomas with a lower proliferative zone was 1.8% (44/2420) in adenomas. Among these adenomas, JNET type 1 incidence was 43.2% (19/44), which was significantly higher than that in adenomas with a normal proliferative zone. Adenomas with a lower proliferative zone were diminutive (mean size: 2.5 mm) and prone to develop in the proximal colon. CONCLUSION: Colonic adenomas with proliferative zones confined to the lower two-thirds of the crypt often appear as diminutive, hyperplastic polyps.
Assuntos
Adenoma , Neoplasias do Colo , Pólipos do Colo , Neoplasias Colorretais , Humanos , Pólipos do Colo/patologia , Estudos Retrospectivos , Neoplasias do Colo/patologia , Adenoma/patologia , Colonoscopia , Neoplasias Colorretais/patologia , HiperplasiaRESUMO
The ABC method is a classification method used for stratifying the risk of gastric cancer. However, whether the ABC method should be performed only once or multiple times throughout an individual's lifetime remains unclear. Therefore, this study aimed to analyze whether performing ABC screening twice in a lifetime is useful. We retrospectively analyzed the data of individuals who participated in health checkups in 2010 and 2015. We collected data on patient characteristics, pepsinogen levels, anti-Helicobacter pylori antibody titers, and the presence of gastric cancer. Overall, 7129 participants without a history of H. pylori eradication were included in this study. The participants' average age in 2010 was 48.4 ± 8.3 years, and 58.1% were male. In addition, 11 and 20 cases of new H. pylori infection (0.15%) and spontaneous eradication (0.28%), respectively, were recorded. No significant difference was found in the incidence of gastric cancer between participants who underwent the ABC method once and those who underwent it twice (Group A: 0.16% vs. 0.16%; Group B: 0.47% vs. 0.39%; and Group C + D: 1.97% vs. 1.82%). Therefore, performing the ABC method twice, 5 years apart, does not significantly improve gastric cancer risk stratification.
RESUMO
BACKGROUND: Accurate diagnosis and early resection of colorectal polyps are important to prevent the occurrence of colorectal cancer. However, technical factors and morphological factors of polyps itself can lead to missed diagnoses. Image-enhanced endoscopy and chromoendoscopy (CE) have been developed to facilitate an accurate diagnosis. There have been no reports on visibility using a combination of texture and color enhancement imaging (TXI) and CE for colorectal tumors. AIM: To investigate the visibility of margins and surfaces with the combination of TXI and CE for colorectal lesions. METHODS: This retrospective study included patients who underwent lower gastrointestinal endoscopy at the Toyoshima Endoscopy Clinic. We extracted polyps that were resected and diagnosed as adenomas or serrated polyps (hyperplastic polyps and sessile serrated lesions) from our endoscopic database. An expert endoscopist performed the lower gastrointestinal endoscopies and observed the lesion using white light imaging (WLI), TXI, CE, and TXI + CE modalities. Indigo carmine dye was used for CE. Three expert endoscopists rated the visibility of the margin and surface patterns in four ranks, from 1 to 4. The primary outcomes were the average visibility scores for the margin and surface patterns based on the WLI, TXI, CE, and TXI + CE observations. Visibility scores between the four modalities were compared by the Kruskal-Wallis and Dunn tests. RESULTS: A total of 48 patients with 81 polyps were assessed. The histological subtypes included 50 tubular adenomas, 16 hyperplastic polyps, and 15 sessile serrated lesions. The visibility scores for the margins based on WLI, TXI, CE, and TXI + CE were 2.44 ± 0.93, 2.90 ± 0.93, 3.37 ± 0.74, and 3.75 ± 0.49, respectively. The visibility scores for the surface based on WLI, TXI, CE, and TXI + CE were 2.25 ± 0.80, 2.84 ± 0.84, 3.12 ± 0.72, and 3.51 ± 0.60, respectively. The visibility scores for the detection and surface on TXI were significantly lower than that on CE but higher than that on WLI (P < 0.001). The visibility scores for the margin and surface on TXI + CE were significantly higher than those on CE (P < 0.001). In the sub-analysis of adenomas, the visibility for the margin and surface on TXI + CE was significantly better than that on WLI, TXI, and CE (P < 0.001). In the sub-analysis of serrated polyps, the visibility for the margin and surface on TXI + CE was also significantly better than that on WLI, TXI, and CE (P < 0.001). CONCLUSION: TXI + CE enhanced the visibility of the margin and surface compared to WLI, TXI, and CE for colorectal lesions.
RESUMO
INTRODUCTION: Helicobacter pylori eradication is expected to significantly change the prevalence of Barrett's esophagus (BE). However, few reports on this relationship exist. We analyzed the risk factors of BE using the current consensus on length of BE considering H. pylori infection status. METHODS: We analyzed 10,122 individuals (5,962 men; mean age = 52.9 ± 9.9 years) who had undergone esophagogastroduodenoscopy as part of a medical checkup. Correlations among factors including H. pylori infectious status, endoscopic findings, and BE ≥1 cm were analyzed. RESULTS: Prevalence of BE, long-segment BE, and esophageal adenocarcinoma was 22.5%, 0.014%, and 0%, respectively. Logistic regression analysis showed that the risk factors for BE were hiatal hernia (odds ratio [OR]: 2.89 [2.59-3.24]), female sex (OR: 0.52 [0.46-0.59]), social drinking (OR:0.77 [0.68-0.87]), H. pylori eradication therapy (OR: 1.34 [1.19-1.51]), proton pump inhibitor (PPI) use (OR: 1.52 [1.18-1.96]), bile reflux (OR: 1.18 [1.04-1.33]), age ≥50 years (OR: 1.13 [1.02-1.26]), and nonsteroidal anti-inflammatory drug (NSAID) use (OR: 1.29 [1.02-1.62]). Although reflux esophagitis (RE) was more common in H. pylori-negative patients (17.2%) than in those after H. pylori eradication therapy (11.8%, p < 0.00001), the latter was correlated with BE, disputing RE as a strong risk factor for BE. Therefore, we conducted a subgroup analysis; most of the risk factors except for PPI use (p = 0.75), H2-receptor antagonist use (p = 0.078), and atrophic gastritis absence (p = 0.72) were positively correlated with BE after H. pylori eradication therapy compared with H. pylori-negative status. CONCLUSIONS: H. pylori eradication, bile reflux, PPI use, and NSAID use were risk factors for BE along with hiatal hernia, male sex, and older age.
Assuntos
Esôfago de Barrett , Refluxo Biliar , Esofagite Péptica , Infecções por Helicobacter , Helicobacter pylori , Hérnia Hiatal , Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Esôfago de Barrett/diagnóstico , Esôfago de Barrett/epidemiologia , Estudos Transversais , Hérnia Hiatal/epidemiologia , Refluxo Biliar/complicações , Refluxo Biliar/tratamento farmacológico , Japão/epidemiologia , Infecções por Helicobacter/complicações , Infecções por Helicobacter/tratamento farmacológico , Infecções por Helicobacter/epidemiologia , Esofagite Péptica/tratamento farmacológico , Inibidores da Bomba de Prótons/uso terapêutico , Anti-Inflamatórios não Esteroides/uso terapêutico , Fatores de RiscoRESUMO
Although the mortality rates of gastric cancer (GC) are gradually declining, gastric cancer is still the fourth leading cause of cancer-related death worldwide. This may be due to the high rate of patients who are diagnosed with GC at advanced stages. However, in countries such as Japan with endoscopic screening systems, more than half of GCs are discovered at an early stage, enabling endoscopic resection (ER). Especially after the introduction of endoscopic submucosal dissection (ESD) in Japan around 2000, a high en bloc resection rate allowing pathological assessment of margin and depth has become possible. While ER is a diagnostic method of treatment and may not always be curative, it is widely accepted as standard treatment because it is less invasive than surgery and can provide an accurate diagnosis for deciding whether additional surgery is necessary. The curability of ER is currently assessed by the completeness of primary tumor removal and the possibility of lymph node metastasis. This review introduces methods, indications, and curability criteria for ER of EGC. Despite recent advances, several problems remain unsolved. This review will also outline the latest evidence concerning future issues.
Assuntos
Ressecção Endoscópica de Mucosa , Neoplasias Gástricas , Detecção Precoce de Câncer , Mucosa Gástrica/patologia , Mucosa Gástrica/cirurgia , Gastroscopia , Humanos , Neoplasias Gástricas/patologia , Neoplasias Gástricas/cirurgiaRESUMO
Tissue-hardening effect and health-hazard issue of formaldehyde (FA) have long been a great disadvantage of this conventional fixative in anatomical research. We recently developed a FA-free embalming method for cadavers which utilizes N-vinyl-2-pyrrolidone (NVP) and enables assessment of motion kinetics by maintaining the softness of embalmed tissue. By assessing the feasibility of NVP-embalmed tissue to mimic vocalization, this study aimed to prove the potential of embalmed cadavers, which have previously been used only for the understanding of anatomical morphology, for the assessment of precise motion physiology in the human body. Ten cadavers embalmed in NVP (n = 6) and FA (n = 4) were incorporated in this study. Excised larynges underwent experimental phonation to mimic vocalization with fast and pliable vibration of vocal folds. High-speed digital imaging was utilized for the assessment of vocal fold vibration. Furthermore, acoustic analysis of the voiced sound, and reproducibility examination were also performed. Regular vocal fold vibrations successfully produced voiced sounds during experimental phonation using NVP-embalmed larynges. The vibratory frequency, vibration amplitude, and stretch rate of the vocal folds were comparable to those of living humans. Six months after the first experiment, the vocal parameters were reproduced, to suggest the long-term preservation potential of our NVP-embalming technique. On the other hand, neither voiced sound nor vocal fold vibration were observed in FA-embalmed larynges. This novel embalming technique could pioneer the next era to utilize embalmed cadavers for the examination of motion physiology in the human body.
Assuntos
Laringe , Prega Vocal , Cadáver , Embalsamamento , Humanos , Pirrolidinonas , Reprodutibilidade dos Testes , Vibração , Prega Vocal/fisiologiaRESUMO
OBJECTIVES: Recent technology manufactured a nasopharyngeal videoscope with pistol-shaped grip (PG). This study aimed to assess the ergonomic feasibility of this novel device in daily ENT practice. METHODS: To assess the ergonomic impact of grip shape on ENT physicians, conventional grip videoscope (CG) and PG were utilized in this study. Surface electromyography (sEMG) was recorded to assess the muscle activity in the upper limb during endoscopy on a training model. Bilateral sEMG recordings were performed including thenar muscle, pronator teres muscle, brachioradialis muscle, and biceps brachii muscle. Mean value of the mean sEMG amplitude throughout the task in triplicated examinations (mMA) with each electrode, total values of four mMAs in both of the grip-side and the insertion tube-side limb muscles, and total value of all eight mMAs were calculated, and compared between CG and PG. Subgroup analyses were also performed in the experienced ENT physicians and the residents. RESULTS: PG provided significantly lower mMA values in thenar muscle and brachioradialis muscle of the grip-side limb compared with CG. Total value of four mMAs in PG was significantly lower compared with that in CG in the grip-side limb, and total value of all eight mMAs in PG was significantly lower compared with that in CG. Furthermore, total value of four mMAs in PG was significantly lower compared with that in CG in the grip-side limb, in both of the subgroups. CONCLUSION: This is the first study to support the idea that the newly designed pistol-grip endoscope may have an ergonomic advantage over conventional endoscope for otolaryngologists in daily practice. LEVEL OF EVIDENCE: 4.
RESUMO
PURPOSE: Ultra-high-resolution computed tomography (UHRCT) is an emerging imaging technology that is able to achieve simultaneous 160 slices with super-thin 0.25 mm thickness. The purpose of this study was to assess the feasibility of UHRCT to visualize laryngeal structure and kinetics. METHODS: Three normal volunteers and three patients with unilateral vocal fold paralysis (UVFP) were incorporated in this case series. First, images were taken under five conditions in normal volunteers. Five tasks consisted of (1) air inspiration through the nose (IN), (2) breath holding (BH), (3) sustained vowel /i:/ phonation (IP), (4) humming phonation (HP), and (5) forced glottic closure during exhalation (FC). Three-dimensional CT images of arytenoid and cricoid cartilages, as well as virtual laryngoscopic images, were reconstructed using UHRCT data. Reconstructed images were compared among five conditions to assess the best tasks to picture laryngeal kinetics. Second, pre- and post-phonosurgical images were examined in UVFP patients to evaluate potential role of UHRCT to assess laryngeal pathology in hoarse patients. RESULTS: Among the five conditions, IN and IP conditions were considered suitable to visualize laryngeal structure at rest and during phonation, respectively. Kinetic abnormalities including asymmetric motion of arytenoid cartilages were elucidated in UVFP patients, and virtual endoscopy visualized the clinically invisible posterior three-dimensional glottic chinks. Furthermore, UHRCT was useful to understand changes in laryngeal structure achieved by phonosurgery. CONCLUSIONS: UHRCT is an emerging imaging technology that can be used for minimally invasive visualization and assessment of laryngeal structure and kinetics. Future studies to assess more number of patients with laryngeal dysfunction are warranted.
Assuntos
Processamento de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Laringe , Tomografia Computadorizada Multidetectores/métodos , Paralisia das Pregas Vocais , Adulto , Cartilagem Aritenoide/diagnóstico por imagem , Feminino , Humanos , Cinética , Laringoplastia/métodos , Laringoscopia/métodos , Laringe/diagnóstico por imagem , Laringe/fisiopatologia , Masculino , Pessoa de Meia-Idade , Fonação/fisiologia , Reprodutibilidade dos Testes , Paralisia das Pregas Vocais/diagnóstico , Paralisia das Pregas Vocais/fisiopatologia , Paralisia das Pregas Vocais/cirurgiaRESUMO
Toads on the ground control landing behavior by a simple strategy in which they extend their elbows at roughly the same time after take-off and continue extending them at the same velocity until they land. However, this simple strategy does not work well in much more complicated arboreal habitat. We analyzed properties of jumping and timing of forelimb extension of the tree frog, Hyla japonica, to demonstrate how the arboreal species land safely. The results showed that distance, duration, and velocity of jump were not affected by explicit optic flow information, whereas the all three parameters decreased significantly in the blindfolded animals. This suggests that the frogs do not use optic flow information during flight but need visual information to plan a jump to reach the destination appropriately. Many animals generate prelanding behavior when time-to-contact reaches a threshold value. However, the results showed that a significant positive correlation was found between jump duration and time-to-contact both in normal and blindfolded animals. The slopes and the intercepts of the linear regression lines were about 0.8 and about 50 msec, respectively, in both cases. These suggest that, without any visual inputs, the animal can make the decision for prelanding forelimb extension at 20% of jump duration and start extending the forelimb after a motor delay of about 50 msec as in the normal condition. This strategy enables the tree frog to always maintain 80% of the jump duration to prepare for landing in their complex habitat.
Assuntos
Anuros/fisiologia , Membro Anterior/fisiologia , Locomoção , Animais , Fenômenos BiomecânicosRESUMO
Unanticipated difficult airway is a challenging problem for anesthesiologists. Oropharyngeal stenosis (OPS) is a rare complication of upper airway surgery which may cause difficult airway. We present a patient whose postsurgical OPS was revealed during the induction of general anesthesia, and necessitated reschedule of surgery and tracheotomy. We also discuss the etiology and risk factors of postsurgical OPS.
RESUMO
Dysphagia and hoarseness caused by laryngopharyngeal paralysis associated with internal carotid artery (ICA) dissection is rare. We reported a case which recovered spontaneously. A 57-year old man visited our hospital complaining of dysphagia and hoarseness lasting for two weeks. Paralysis of right vocal fold and rotational movement of the posterior pharyngeal wall toward the left side during swallowing were observed. Magnetic resonance imaging was performed under diagnosis of isolated right vagus nerve paralysis, and dissection of the right ICA was revealed. He was treated conservatively, and both of laryngopharyngeal movement and the ICA dissection were improved completely. There is a possibility that laryngeal paralysis caused by ICA dissection has been misdiagnosed as an idiopathic paralysis.
Assuntos
Dissecação da Artéria Carótida Interna/diagnóstico , Paralisia/diagnóstico , Doenças do Nervo Vago/diagnóstico , Dissecação da Artéria Carótida Interna/complicações , Transtornos de Deglutição/etiologia , Rouquidão/etiologia , Humanos , Angiografia por Ressonância Magnética , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Paralisia/etiologia , Doenças do Nervo Vago/etiologiaRESUMO
In this study, we examined the collision avoidance behavior of the frog, Rana catesbeiana to an approaching object in the upper visual field. The angular velocity of the frog's escape turn showed a significant positive correlation with the turn angle (r(2)â=â0.5741, P<0.05). A similar mechanism of velocity control has been known in head movements of the owl and in human saccades. By analogy, this suggests that the frog planned its escape velocity in advance of executing the turn, to make the duration of the escape behavior relatively constant. For escape turns less than 60°, the positive correlation was very strong (r(2)â=â0.7097, P<0.05). Thus, the frog controlled the angular velocity of small escape turns very accurately and completed the behavior within a constant time. On the other hand, for escape turns greater than 60°, the same correlation was not significant (r(2)â=â0.065, P>0.05). Thus, the frog was not able to control the velocity of the large escape turns accurately and did not complete the behavior within a constant time. In the latter case, there was a small but significant positive correlation between the threshold angular size and the angular velocity (r(2)â=â0.1459, P<0.05). This suggests that the threshold is controlled to compensate for the insufficient escape velocity achieved during large turn angles, and could explain a significant negative correlation between the turn angle and the threshold angular size (r(2)â=â0.1145, P<0.05). Thus, it is likely that the threshold angular size is also controlled by the turn angle and is modulated by motor planning.
RESUMO
OBJECTIVES: Vocal fold polyp is generally thought to require surgical removal. However, a certain proportion of polyps resolve with conservative treatment. This study was performed to clarify the frequency of spontaneous resolution of vocal fold polyp and identify features associated with polyps that are likely to resolve without surgery. STUDY DESIGN: Retrospective study. METHODS: A review of the medical records of patients diagnosed with vocal fold polyps in Tokyo Voice Center from January 2001 to December 2008. RESULTS: Of 644 patients with the diagnosis of vocal fold polyp, 132 received conservative treatment, 433 were treated surgically, and 79 dropped out without attending for further consultation after the initial visit. Of those treated conservatively, 55 experienced complete resolution after a mean of 5.1 months of follow-up from the outset, and 29 showed lesion shrinkage after a mean of 4.1 months of follow-up. Polyps that resolved with conservative therapy were more likely than those that remained unchanged or enlarged to occur in women, be smaller, and have a shorter duration of symptoms. We could not determine the superiority of voice therapy. CONCLUSIONS: At least 9.7% of vocal fold polyps might resolve without surgery. Conservative treatment should be considered as an option for selected patients with smaller and more recent-onset polyps.
Assuntos
Disfonia/terapia , Fonação/efeitos dos fármacos , Pólipos/terapia , Esteroides/administração & dosagem , Prega Vocal/efeitos dos fármacos , Qualidade da Voz/efeitos dos fármacos , Treinamento da Voz , Administração por Inalação , Adulto , Idoso , Idoso de 80 Anos ou mais , Disfonia/tratamento farmacológico , Disfonia/etiologia , Disfonia/fisiopatologia , Disfonia/cirurgia , Feminino , Humanos , Japão , Masculino , Pessoa de Meia-Idade , Pólipos/complicações , Pólipos/tratamento farmacológico , Pólipos/patologia , Pólipos/cirurgia , Estudos Retrospectivos , Estroboscopia , Fatores de Tempo , Resultado do Tratamento , Gravação em Vídeo , Prega Vocal/fisiopatologia , Prega Vocal/cirurgia , Adulto JovemRESUMO
The genus Cryptosporidium includes many common parasites infecting animals and humans, and is a major cause of diarrheal illness worldwide. The biology of gastric Cryptosporidium spp., including replication in the stomach, has not been well documented. This study evaluated the viability of Cryptosporidium andersoni sporozoites in gastric environments after excystation and examined the endogenous development and histopathological changes in the stomachs of infected mice, using a novel type of C. andersoni. Sporozoites were affected by low pH (61.6% viability after 3h at pH2.0). Electron microscopy revealed developmental parasites on the gastric foveolae but not on the surface of the gastric mucosa. Histopathological examinations at 1, 2, 4 and 12 weeks p.i. uncovered three different lesions. The gastric mucosa of foveolae filled with parasites was extended and the amount of neutral mucopolysaccharide at the mucosal surface was decreased with the first type of lesion. The gastric mucosa was atrophied, some gastric glands were disrupted and the amount of acid mucopolysaccharide at the mucosal surface was increased with the second type. Finally, the gastric mucosa was slightly extended and goblet cells were present in the gastric mucosa, indicating intestinal metaplasia, in the third type. No parasites were detected in these areas with increased acidic mucin and indications of metaplasia. The results suggest that C. andersoni parasites could not survive in acidic environments for a long period before invading host cells and preferentially develop in neutral sites of the gastric mucosa, resulting in histopathological changes and chronic shedding of oocysts.
Assuntos
Criptosporidiose/patologia , Cryptosporidium , Esporozoítos , Estômago/patologia , Animais , Bovinos , Doenças dos Bovinos/parasitologia , Criptosporidiose/parasitologia , Cryptosporidium/crescimento & desenvolvimento , Cryptosporidium/ultraestrutura , Fezes/parasitologia , Feminino , Mucosa Gástrica/parasitologia , Mucosa Gástrica/patologia , Concentração de Íons de Hidrogênio , Camundongos , Camundongos SCID , Microscopia Eletrônica , Oocistos/fisiologia , Esporozoítos/crescimento & desenvolvimento , Esporozoítos/ultraestrutura , Estômago/parasitologiaRESUMO
In this study, we examined the neuronal correlates of frog collision avoidance behavior. Single unit recordings in the optic tectum showed that 11 neurons gave selective responses to objects approaching on a direct collision course. The collision-sensitive neurons exhibited extremely tight tuning for collision bound trajectories with mean half-width at half height values of 0.8 and 0.9° (n = 4) for horizontal and vertical deviations, respectively. The response of frog collision-sensitive neurons can be fitted by a function that simply multiplies the size dependence of its response, e(-αθ(t)), by the image's instantaneous angular velocity θ'(t). Using fitting analysis, we showed that the peak firing rate always occurred after the approaching object had reached a constant visual angle of 24.2 ± 2.6° (mean ± SD; n = 8), regardless of the approaching velocity. Moreover, a linear relationship was demonstrated between parameters l/v (l: object's half-size, v: approach velocity) and time-to-collision (time difference between peak neuronal activity and the predicted collision) in the 11 collision-sensitive neurons. In addition, linear regression analysis was used to show that peak firing rate always occurred after the object had reached a constant angular size of 21.1° on the retina. The angular thresholds revealed by both theoretical analyses were comparable and showed a good agreement with that revealed by our previous behavioral experiments. This strongly suggests that the collision-sensitive neurons of the frog comprise a threshold detector, which triggers collision avoidance behavior.
Assuntos
Comportamento Animal/fisiologia , Neurônios/fisiologia , Colículos Superiores/fisiologia , Animais , Eletrofisiologia , Feminino , Modelos Lineares , Masculino , Percepção de Movimento/fisiologia , Rana catesbeiana , Vias Visuais/fisiologiaRESUMO
Laryngeal carcinoma presenting as a cervical abscess is rare, so that its diagnosis is not easy. We described a case of laryngeal squamous cell carcinoma presenting as a prelaryngeal large abscess. Markedly swollen false vocal fold inhibited fiberscopic examination of the vocal folds. CT scan indicated destruction of the thyroid cartilage. Although biopsies from the abscess did not reveal malignancy, laryngeal squamous cell carcinoma was confirmed by laryngomicrosurgery with laryngeal vestibulectomy. The patient was treated by total laryngectomy with neck dissection followed by radiotherapy. The abscess was thought to be formed not by direct extension and necrosis of the tumor, but by the leakage of air and mucus through the fistula on the destroyed thyroid cartilage. Precise observation and biopsy under directscopic vestibulectomy played an important role in diagnosis of malignancy inherent in severe inflammatory tissues.