Topology of ON and OFF inputs in visual cortex enables an invariant columnar architecture.

Circuits in the visual cortex integrate the information derived from separate ON (light-responsive) and OFF (dark-responsive) pathways to construct orderly columnar representations of stimulus orientation and visual space. How this transformation is achieved to meet the specific topographic constraints of each representation remains unclear. Here we report several novel features of ON-OFF convergence visualized by mapping the receptive fields of layer 2/3 neurons in the tree shrew (Tupaia belangeri) visual cortex using two-photon imaging of GCaMP6 calcium signals. We show that the spatially separate ON and OFF subfields of simple cells in layer 2/3 exhibit topologically distinct relationships with the maps of visual space and orientation preference. The centres of OFF subfields for neurons in a given region of cortex are confined to a compact region of visual space and display a smooth visuotopic progression. By contrast, the centres of the ON subfields are distributed over a wider region of visual space, display substantial visuotopic scatter, and have an orientation-specific displacement consistent with orientation preference map structure. As a result, cortical columns exhibit an invariant aggregate receptive field structure: an OFF-dominated central region flanked by ON-dominated subfields. This distinct arrangement of ON and OFF inputs enables continuity in the mapping of both orientation and visual space and the generation of a columnar map of absolute spatial phase.

Otorhinolaryngological Management in Taiwanese Patients with Mucopolysaccharidoses.

Background: Mucopolysaccharidoses (MPSs) are lysosomal storage disorders wherein glycosaminoglycans accumulate because the enzymes that degrade them are insufficient. The earliest symptoms, which are the main reasons for seeking consultation, are otorhinolaryngological and commonly occur in MPS I, II, IV, and VI. This retrospective study aimed to determine the occurrence of otorhinolaryngological manifestations in MPS patients in Taiwan and to analyze the prognosis of surgical intervention, including its effect on symptoms. Methods: We reviewed 42 patients (30 males and 12 females), with a median age of 20.5 years, who had MPS (16.7% type I, 35.7% type II, 19.0% type IIIB, 21.4% type IVA, and 7.2% type VI). The following otorhinolaryngological manifestations were collected: annual number of upper respiratory tract infections (URTIs) and otitis media with effusion (OME) episodes, adenoid size, tonsillar size, and apnea-hypopnea index (AHI). Results: Among 42 patients, we found recurrent otitis media in 42.9% of the patients, hearing loss in 83.3% (mixed: 52.4%, conductive: 21.4%, and sensorineural: 9.5%), frequent URTIs in 47.6%, and obstructive sleep apnea syndrome in 35.7%. Moreover, 76% of the patients underwent ear, nose, and throat (ENT) surgery, including adenoidectomy, tonsillectomy, tympanostomy with ventilation tube insertion, tracheotomy, and supraglottoplasty. Conclusions: MPS patients had a high incidence of ENT problems. ENT surgery reduced the severity of hearing loss, degree of symptoms related to upper airway obstruction, and severity of respiratory tract and otological infections of patients with MPS.

Intraductal injection as an effective drug delivery route in the management of salivary gland diseases.

While conservative approaches for chronic sialoadenitis are in current use, the utility of intraductal injection therapy remains unclear. The purpose of this study is to provide evidence that substances delivered through intraductal injection of the salivary gland are able to be effectively distributed throughout the gland. Methylene blue dye (0.1 %) was injected intraductally into a porcine parotid gland (5 ml) of one group and the porcine submandibular gland (1 or 2 ml, n = 6 for each preparation) of another group. After the injection, the ductal systems were evaluated, sectioned, and observed microscopically. Color area analysis was performed on submandibular gland sections, and the infiltration ratio of the dye was calculated. The papillae of both Stensen's and Wharton's duct openings were easily identified with intraductally delivered methylene blue dye. The dye infiltration began from the central ductal region of the gland and could be easily observed to gradually disperse to the peripheral regions in each acinar. There were no statistically significant differences in infiltration ratios between anterior, midline, and posterior section of the submandibular gland. Also, there were no statistically significant differences in the ratios between 1 and 2 ml injections at all the three section positions. This study demonstrated that desired substances can be evenly delivered throughout the salivary gland through intraductal injections. The use of intraductal injections might serve as a potential therapeutic procedure in the management of salivary gland diseases.

Post-sialendoscopy ductoplasty by salivary duct stent placements.

With damage to a duct or papilla after sialendoscopy, a stent may be necessary to prevent re-stenosis and for maintaining the salivary duct open after complete sialendoscopy. However factors affecting outcomes and complications after stent placement remain unclear. This study aimed to report preliminary experiences in salivary duct stent placement after sialendoscopy. Data from 35 procedures in 33 patients who received sialendoscopy with salivary duct stent placements at Mackay Memorial Hospital between October 2013 and June 2014 were recorded and compared for clinical data, as well as procedural techniques, findings, and outcomes. In the 35 stent placement procedures, the hypospadias silastic stent tubes were used in 27 and the Fr. 5 pediatric feeding tubes were used in the remaining eight. When the hypospadias silastic stent tubes were used for stenting, the stent obstruction and irritation rates were higher compared to those who used the Fr. 5 pediatric feeding tube (100 vs. 0 % and 67 vs. 33 %, respectively). None of the stents secured by a 5-0 nylon suture were complicated by dislocation but when the stents were secured by 6-0 nylon sutures, the dislocation rate went as high as 47.4 %. The duration needed for salivary duct stent placement might be potentially shortened to only 2 weeks. If a salivary duct stent is intended to be placed for a certain period before its scheduled removal, a suture strength equivalent or stronger than the 5-0 nylon suture should be considered for stent fixation.

Primary caregivers of in-home oxygen-dependent children: predictors of stress based on characteristics, needs and social support.

AIM: To identify the predictors of primary caregivers' stress in caring for in-home oxygen-dependent children by examining the association between their levels of stress, caregiver needs and social support. BACKGROUND: Increasing numbers of primary caregivers of oxygen-dependent children experience caregiving stress that warrants investigation. DESIGN: The study used a cross-sectional design with three psychometric scales - Modified-Parenting Stress Index, Caregiver Needs Scale and Social Support Index. METHODS: The data collected during 2010-2011 were from participants who were responsible for their child's care that included oxygen therapy for ≧6 hours/day; the children's ages ranged from 3 months-16 years. Descriptive statistics and multivariable linear regression were used. RESULTS: A total of 104 participants (M = 34, F = 70) were recruited, with an average age of 39·7 years. The average age of the oxygen-dependent children was 6·68 years and their daily use of oxygen averaged 11·39 hours. The caregivers' overall levels of stress were scored as high and information needs were scored as the highest. The most available support from family and friends was emotional support. Informational support was mostly received from health professionals, but both instrumental and emotional support were important. Levels of stress and caregiver needs were significantly correlated. Multivariable linear regression analyses identified three risk factors predicting stress, namely, the caregiver's poor health status, the child's male gender and the caregiver's greater financial need. CONCLUSION: To support these caregivers, health professionals can maintain their health status and provide instrumental, emotional, informational and financial support.

Effect of perioperative dexamethasone on subjective voice quality after thyroidectomy: a meta-analysis and systematic review.

BACKGROUND: Prophylactic dexamethasone has been shown to reduce postoperative pain, nausea, and vomiting in patients undergoing thyroidectomy. However, its effects on postoperative voice outcomes remain uncertain. METHODS: A systematic review and meta-analysis of the literature was conducted. Cochrane database, MEDLINE, EMBASE, and CINAHL were thoroughly searched. Studies that compared intravenous dexamethasone administration with no dexamethasone in patients undergoing thyroidectomy were included. Main outcome measure was the difference in postoperative voice assessment between groups. Standardized mean difference (SMD) and 95 % confidence intervals (CIs) were estimated using fixed and random effects models. RESULTS: Four studies with a total of 313 patients met inclusion criteria. Significant heterogeneity of study results was noted. Using random effects models, pooled data showed no difference in subjective voice quality between groups preoperatively (SMD, 0.29; 95 % CI -0.37 to 0.96; P = 0.39), 24 h after thyroidectomy (SMD, -1.02; 95 % CI -2.36 to 0.31; P = 0.13), or at 48 h (SMD, -0.05; 95 % CI -0.30 to 0.21; P = 0.72). A sensitivity analysis excluding one observational study yielded similar results. CONCLUSION: There are insufficient data for definite conclusions to be drawn regarding the effectiveness of a single perioperative administration of dexamethasone to reduce short-term voice disturbances after thyroidectomy. Further prospective trials using objective voice analysis are warranted to evaluate the efficacy of dexamethasone.

Assessment of hearing loss by pure-tone audiometry in patients with mucopolysaccharidoses.

BACKGROUND: Patients with mucopolysaccharidoses (MPS) often have hearing loss. However, the characterization of hearing loss by pure-tone audiometry (PTA) in this rare disease population and its relationship to age and treatment is limited. METHODS: PTA was performed in 39 patients with MPS (29 males and 10 females; 3 with MPS I, 21 with MPS II, 9 with MPS IVA, and 6 with MPS VI; median age, 11.9 years; age range, 4.4-34.2 years). The degree of hearing loss was classified by the age-independent World Health Organization (WHO) clinical guidelines. RESULTS: Hearing loss by PTA was present in 85% (33/39) of patients and was categorized as mild (26-40 dB) in 18%, moderate (41-60 dB) in 36%, severe (61-80 dB) in 23%, and profound (≥81dB) in 5%. Among the patients with hearing loss, 33% were classified as mixed type (conductive and sensorineural), 30% as pure conductive type, 27% as pure sensorineural type, and 9% were undefined. The means of the right and left ear hearing thresholds at 2000 and 4000 Hz by air conduction (AC) and at 500, 1000, 2000, and 4000 Hz by bone conduction (BC) were all positively correlated with age (p<0.05). In the 6 patients with MPS II or VI who underwent follow-up PTA after ventilation tube insertion and enzyme replacement therapy for 1.9 to 8.5 years, all showed improvements in AC and BC of the better ear, as well as in the air-bone gap. CONCLUSIONS: Hearing impairment is common in MPS. Early otolaryngological evaluation and intervention are recommended. These findings and the follow-up data can be used to develop quality of care strategies for patients with MPS.

Sialendoscopy with holmium:YAG laser treatment for multiple large sialolithiases of the Wharton duct: a case report and literature review.

Sialolithiasis is defined as calcified stone(s) in the salivary duct or glands. Submandibular gland sialolithiasis is the most common (80 to 90%), followed by parotid gland sialolithiasis (5 to 15%). The typical clinical presentation is salivary gland swelling after eating. As the swelling persists, symptoms owing to local inflammation, such as pain and trismus, emerge. In severe cases, cellulitis and even abscess formation occur and subsequently lead to salivary gland atrophy or fistula formation if the sialolithiasis remains untreated. The most common treatment is complete excision of the affected gland together with the stone(s). In some cases, intraoral sialolithotomy is performed when the stone is solitary and easily palpable through the oral cavity. Sialendoscopy is increasingly performed because of its minimal invasiveness. The major limitation of endoscopic laser lithotripsy of the salivary glands is the size of the stone. Often, for a stone larger than 4 mm, multiple fragmentations of the stone into small pieces is necessary before the pieces can be removed by wire basket or grasping forceps. Recently, the holmium:YAG laser has been reported as quite effective in removing larger salivary gland stones. However, sialoendoscopic laser lithotripsy is a very time-consuming procedure and in most cases, when there are multiple large stones in a single gland, entire gland excision is recommended. This report describes a male patient diagnosed with multiple large stones in his left submandibular gland who was successfully treated under sialendoscopy with holmium:YAG laser lithotripsy.

Effect of uvulopalatopharyngoplasty on leptin and endothelial function in sleep apnea.

OBJECTIVES: This study evaluated the effects of uvulopalatopharyngoplasty (UPPP) on serum leptin levels and endothelial function in patients with obstructive sleep apnea syndrome (OSAS). METHODS: Fifteen healthy subjects and 35 patients with moderate to severe OSAS who desired UPPP were prospectively enrolled. The serum levels of leptin and nitric oxide derivative (NOx) from their peripheral blood samples were measured by enzyme-linked immunosorbent assay. All subjects participated in sleep studies, which were repeated 3 months after UPPP in the patients with OSAS. RESULTS: Before UPPP, the patients with OSAS had a higher serum level of leptin and a lower NOx level than did the control subjects. The serum leptin levels in the 17 of the 35 patients with OSAS who were surgical responders decreased from 24.2 ± 6.1 ng/mL before operation to 15.9 ± 6.0 ng/mL after operation. The serum NOx levels in these 17 patients increased from 18.5 ± 7.5 µmol/L before operation to 27.3 ± 8.2 µmol/L after operation. In the 18 patients who were unresponsive to surgery, the serum leptin and NOx levels remained impaired after the UPPP. CONCLUSIONS: Successful treatment of OSAS with UPPP leads to the normalization of serum leptin and NOx levels.

Respiratory and sleep disorders in mucopolysaccharidosis.

MPS encompasses a group of rare lysosomal storage disorders that are associated with the accumulation of glycosaminoglycans (GAG) in organs and tissues. This accumulation can lead to the progressive development of a variety of clinical manifestations. Ear, nose, throat (ENT) and respiratory problems are very common in patients with MPS and are often among the first symptoms to appear. Typical features of MPS include upper and lower airway obstruction and restrictive pulmonary disease, which can lead to chronic rhinosinusitis or chronic ear infections, recurrent upper and lower respiratory tract infections, obstructive sleep apnoea, impaired exercise tolerance, and respiratory failure. This review provides a detailed overview of the ENT and respiratory manifestations that can occur in patients with MPS and discusses the issues related to their evaluation and management.

Neonatal orbital abscess.

Orbital abscess is life-threatening and rare in children. Reported herein is a term male neonate who had methicillin-resistant Staphylococcus aureus orbital abscess, and a literature review of this disease. A total of 16 neonates diagnosed with neonatal orbital abscess are reported in the literature. There is a mild male predilection and two neonates were delivered prematurely. Leukocytosis, fever, ethmoiditis and associated upper respiratory tract infection were found in approximately half of them. Eight neonates had sepsis and 14 patients underwent surgical intervention. One patient died. Staphylococcus aureus was identified in 14 out of 17 patients. Neonatal orbital abscess is rarely encountered but may be fatal. Although streptococci are prevalent in childhood orbital infection, S. aureus was predominant in neonatal orbital abscess in the present series. Appropriate antimicrobial therapy against S. aureus is essential in treating neonatal orbital abs ess. This case suggests that a higher initial dose of vancomycin may be an effective and safe strategy for severe S. aureus infection in neonates.

Endoscopic and Image Analysis of the Airway in Patients with Mucopolysaccharidosis Type IVA.

Mucopolysaccharidosis (MPS) is a hereditary disorder arising from lysosomal enzymes deficiency, with glycosaminoglycans (GAGs) storage in connective tissues and bones, which may compromise the airway. This retrospective study evaluated patients with MPS type IVA with airway obstruction detected via endoscopy and imaging modalities and the effects of surgical interventions based on symptoms. The data of 15 MPS type IVA patients (10 males, 5 females, mean age 17.8 years) were reviewed in detail. Fiberoptic bronchoscopy (FB) was used to distinguish adenotonsillar hypertrophy, prolapsed soft palate, secondary laryngomalacia, vocal cord granulation, cricoid thickness, tracheal stenosis, shape of tracheal lumen, nodular deposition, tracheal kinking, tracheomalacia with rigid tracheal wall, and bronchial collapse. Computed tomography (CT) helped to measure the deformed sternal angle, the cross-sectional area of the trachea, and its narrowest/widest ratio (NW ratio), while angiography with 3D reconstruction delineated tracheal torsion, kinking, or framework damage and external vascular compression of the trachea. The NW ratio correlated negatively with age (p < 0.01), showing that airway obstruction progressed gradually. Various types of airway surgery were performed to correct the respiratory dysfunction. MPS type IVA challenges the management of multifactorial airway obstruction. Preoperative airway evaluation with both FB and CT is strongly suggested to assess both intraluminal and extraluminal factors causing airway obstruction.

Preoperative ultrasonography assessment of vocal cord movement during thyroid and parathyroid surgery.

BACKGROUND: Preoperative detection of vocal cord palsy is important in thyroid and parathyroid surgery. However, routine fiberoptic laryngoscopy may bring patients unnecessary discomfort. The aim of this study was to determine the feasibility of using surgeon-performed ultrasonography (US) as a screening tool for preoperative assessment of vocal cord movement. METHODS: In the first phase, patients had both laryngoscopic and US examination before surgery. In the second phase, patients had US evaluation first. Those with abnormal vocal cord movement on US, with invisible cord movement, or presenting with significant vocal symptoms underwent laryngeal examination. RESULTS: In all, 93 (82 %) of 114 patients had successful US evaluation of vocal cord movement during the first phase. Two of them had vocal cord paralysis. In the second phase, vocal cord movement could be evaluated by US in 349 (84 %) of 415 patients. Four patients with abnormal movement were confirmed to have vocal cord palsy by laryngoscopy. None of 46 symptomatic patients with normal movement on US had vocal cord palsy. One other patient whose cord movement could not be seen by US had vocal cord palsy on laryngoscopic examination. CONCLUSIONS: Surgeon-performed US appears to be a relatively accurate method for assessing vocal cord movement in the preoperative setting. It can be used to select patients to undergo laryngoscopic examination before thyroidectomy and parathyroidectomy.

Epidemiological and microbiological characteristics of culture-proven acute otitis media in Taiwanese children.

BACKGROUND/PURPOSE: Acute otitis media (AOM) is one of the most common diseases in children. Here, we describe the epidemiological and microbiological characteristics of AOM in Taiwanese children over a 10-year period. METHODS: We retrospectively enrolled pediatric patients with culture-proven AOM who were treated at Mackay Memorial Hospital, Taipei between 1999-2008. The data include demographic characteristics, clinical history, and microbiological characteristics. RESULTS: Six hundred and fourteen patients were included. The male:female ratio was 1.4 (p<0.001). Greater than three-fourths of the patients (476 [77.5%]) were < 5 years of age, and most patients were 1-2 years of age. The most common isolated pathogen was Streptococcus pneumoniae (419 patients [68.2%]), followed by nontypeable Haemophilus influenzae (NTHi; 118 patients [19.2%]). The distributions of age, gender, use of tympanocentesis, history of previous AOM, and use of antibiotic between patients infected with the two pathogens were not significantly different. However, the number of patients with AOM caused by S. pneumoniae, but not NTHi, decreased during the study period (p=0.004). Three hundred and eighty-seven children (63.0%) with AOM developed spontaneous otorrhea. Compared with patients who underwent tympanocentesis, those with spontaneous otorrhea were younger (27.0±16.4 vs. 31.1±15.2 months of age, p=0.004), more likely to have a previous history of AOM (p=0.019), and more likely to receive more antibiotics (p=0.012). The third most common pathogen was S. pyogenes (25 patients [4.1%]). S. pyogenes occurred more often in children > 5 years of age and was associated with spontaneous otorrhea (p<0.001). CONCLUSION: S. pneumoniae and NTHi are common causes of culture-confirmed AOM in Taiwanese children. Although S. pyogenes is not as common, it usually causes AOM in children > 5 years of age and is associated with spontaneous otorrhea.

Montgomery T-Tube Airway Restoration and Swallowing Rehabilitation for a Near-Hanging Female.

Patients who fail to commit suicide by hanging often end up with laryngotracheal injuries, which may lead to a compromised airway, swallowing dysfunction, and dysphonia. Previous studies have mainly focused on airway management after near-hanging attempts. Few have shed light on the treatment of swallowing dysfunction after laryngotracheal injuries. Here, we present a near-hanging patient who developed complete dysphagia shortly afterward. We used a Montgomery T-tube as an endolaryngeal stent, combined with swallowing rehabilitation. The patient's swallowing ability was gradually restored one month after the surgery, and the stent was removed six months later. The present case report exemplifies the unique way of using the Montgomery T-tubes in clinical practice. Among the patients with airway stenosis affecting the larynx and extending to the vocal cords, Montgomery T-tube may be the only stent that can help manage strictures at the level of the vocal cords and in the supraglottic region, restoring swallowing function and maintaining the airway.

Airway Management of the Deformed Trachea Using T-Tube Stents in Patients with Mucopolysaccharidosis Type IVA.

INTRODUCTION: Mucopolysaccharidosis (MPS) type IVA usually results in airway obstruction due to thoracic cage deformity and crowding of intrathoracic structures, causing tracheal compression by the tortuous innominate artery. OBJECTIVES: To offer an alternative and effective method in dealing with the challenged deformity of the airway in patients with MPS type IVA. METHODS: We present 3 patients with MPS type IVA who underwent airway stenting using Montgomery® T-tube stents. Three-dimensional reconstructed computed tomography was essential to design the T-tube and evaluate the anatomical relationship between the innominate artery and the trachea. The Y-shaped Montgomery® Pediatric Safe-T-Tube™ is more suitable for MPS type IVA. Regular follow-ups using fiberoptic bronchoscopy are necessary to evaluate the complications. RESULTS: All 3 patients had good outcomes during the follow-ups until present, despite the complication of granulation formation, which was resolved by revising the limbs of the T-tube. CONCLUSIONS: T-tube stents placed below the vocal cord may restore airway patency and preserve laryngeal function, including respiration, phonation, and swallowing, in patients with MPS type IVA.

A common computational principle for vibrotactile pitch perception in mouse and human.

We live surrounded by vibrations generated by moving objects. These oscillatory stimuli propagate through solid substrates, are sensed by mechanoreceptors in our body and give rise to perceptual attributes such as vibrotactile pitch (i.e. the perception of how high or low a vibration's frequency is). Here, we establish a mechanistic relationship between vibrotactile pitch perception and the physical properties of vibrations using behavioral tasks, in which vibratory stimuli were delivered to the human fingertip or the mouse forelimb. The resulting perceptual reports were analyzed with a model demonstrating that physically different combinations of vibration frequencies and amplitudes can produce equal pitch perception. We found that the perceptually indistinguishable but physically different stimuli follow a common computational principle in mouse and human. It dictates that vibrotactile pitch perception is shifted with increases in amplitude toward the frequency of highest vibrotactile sensitivity. These findings suggest the existence of a fundamental relationship between the seemingly unrelated concepts of spectral sensitivity and pitch perception.

A sinusoidal transformation of the visual field is the basis for periodic maps in area V2.

Retinotopic maps of many visual areas are thought to follow the fundamental principles described for the primary visual cortex (V1), where nearby points on the retina map to nearby points on the surface of V1, and orthogonal axes of the retinal surface are represented along orthogonal axes of the cortical surface. Here we demonstrate a striking departure from this mapping in the secondary visual area (V2) of the tree shrew best described as a sinusoidal transformation of the visual field. This sinusoidal topography is ideal for achieving uniform coverage in an elongated area like V2, as predicted by mathematical models designed for wiring minimization, and provides a novel explanation for periodic banded patterns of intra-cortical connections and functional response properties in V2 of tree shrews as well as several other species. Our findings suggest that cortical circuits flexibly implement solutions to sensory surface representation, with dramatic consequences for large-scale cortical organization.

Aortotracheal fistula after slide tracheoplasty in a patient with dextrocardia, left pulmonary artery sling and tracheal stenosis: a case report.

BACKGROUND: Aortotracheal fistula (ATF) is an uncommon and fatal complication of tracheal or aortic surgery, especially among pediatric patients. CASE PRESENTATION: We reported a case in a 1-year-old boy with dextrocardia, left pulmonary artery sling and long segment tracheal stenosis. He received slide tracheoplasty at 9 months of age and had post-operative refractory granulation at distal trachea status post repeated balloon dilatation and laser vaporization. Episodes of hemoptysis occurred on post-operative day 81. Bronchoscopy revealed a pulsating pseudoaneurysm at lower trachea which ruptured during the procedure Urgent surgical repair under cardiopulmonary bypass with deep hypothermic circulatory arrest was done. No recurrent bleeding or significant neurologic deficits noticed at a 4-month follow-up. CONCLUSION: Congenital anomaly that changes the spatial relationship between trachea and aorta could have contributed to formation of ATF. This warrant future attention when managing tracheal granulation with this not uncommon anatomy.