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Seam carving is an algorithm that analyzes image content and can be used for size reduction in a manner that avoids direct compression or downscaling. Seam carving iteratively identifies horizontal and/or vertical paths of least visual importance and removes them from the image; each path removal reduces the length or width of the image by one row or column of pixels. This article adapts seam carving to reduce excess area of flow-based microfluidic chips that have been drawn by hand or by computer-aided heuristics without negatively impacting their functionality. The proposed approach leverages domain knowledge, wherein the image to be carved consists of I/O ports, components, and fluid channels, with known and understood fluidic behavior. Three different variants of seam carving are presented: 1) linear; 2) nonlinear; and 3) nonrectilinear; experimental results show that nonrectilinear, which is the most general of the three, yields the best results: it improves area utilization by 8.6\times and reduces fluid routing channel length by 73% across a set of benchmark microfluidic designs.

Objective: To report the clinical and MRI features, and histologic findings of thoracolumbar discal pseudocyst in dogs. Materials and Methods: The records of eight dogs with thoracolumbar discal cyst‐like structures were retrospectively collected to record their clinical signs, MRI features and surgical and histologic findings. Results: Eight dogs with surgically and histologically confirmed thoracolumbar discal pseudocysts were included in the case series. Six dogs presented with acute onset and two dogs presented with subacute onset of thoracolumbar myelopathy. MRI showed compressive thoracolumbar myelopathy due to a round to oval‐shaped epidural mass lesion communicating with the intervertebral disc, iso/hypointense on T1WI and mostly hyperintense on T2WI, associated with a variable contrast‐enhancing wall, compatible with a cyst‐like structure. These structures were surgically visualised and removed through a mini‐hemilaminectomy or hemilaminectomy and submitted for histologic investigation. One dog also underwent cytologic examination of the cystic content. Similar to that in humans, histology revealed a cyst‐like nature with a wall consisting of dense fibrous connective tissue containing clusters of chondroid cells accompanied by groups of notochordal cells and occasional erythrocytes; however, a real epithelial lining was missing and the term pseudocyst seemed more appropriate. Clinical Significance: This report describes clinical signs, and MRI and histologic findings of discal pseudocysts in dogs with thoracolumbar myelopathy. Despite being rare, discal pseudocysts should be considered as a differential diagnosis in dogs with acute onset thoracolumbar myelopathy. [ABSTRACT FROM AUTHOR]

Remyelination can be very effective in human. However, this process ultimately fails in multiple sclerosis (MS). In this paper, we discuss the possibility of stimulating endogenous oligodendrocyte precursors to participate in remyelination in experimental models (rat and primate Callithrix jacchus) of MS through thyroid hormone (TH) administration. TH is in fact known to be a key signal in brain development, oligodendrocyte development and myelin protein gene expression regulation. [ABSTRACT FROM AUTHOR]

Current evidence suggests that hearing-impaired (HI) children who receive hearing devices early in their life and are included in a high-quality training program can develop the necessary skills to access mainstream education. Nevertheless, HI children still appear to lag behind their normal- hearing peers in terms of linguistic, cognitive, and motor skills, while no consensus has been reached among scholars regarding the real advantage offered by habilitative programs available for CHL. Recent studies highlight that musical training can improve various cognitive ability in both typically developing and HI children, although neuro-cognitive and motor improvements in HI toddlers using hearing devices is still an under researched topic. In order to explore the benefits of a well-structured musical training program on various neuropsychological domains, we conducted a pilot study involving three children (age: 35-44 months) with isolated CHL of moderate to severe degree. The musical training program included two training sessions, for a total of 20 lessons each, administered over a period of six months, with a two-month break in between. Musical activities involved listening, linguistic production, and music-making exercises, specifically designed to combine cognitive, motor, and linguistic skills. Neuropsychological assessment was carried out before and after each session, and six months after the end of the program, to evaluate its effects over time. All three children showed neuropsychological improvements and consolidated acquisition, with highest scores achieved in motor sequence, memory for designs, and visual attention tests. Indirect evaluation of musical skills yielded similarly positive results. Outcomes are discussed in terms of clinical and educational perspectives in the developmental trajectory of HI children. [ABSTRACT FROM AUTHOR]

Children with congenital unilateral hearing loss (CUHL), although they can hear and learn through the normal hearing side, cannot benefit from binaural advantages and may encounter difficulties in accessing relevant acoustic information in adverse listening environments. Literature has shown that children with CUHL also experience greater difficulties than their normal hearing peers in a variety of domains. Nevertheless, individual performance is highly variable, with some children showing developmental delay and other seemingly demonstrating normal performance and development. Similarly, while recent neuroimaging research information shows effects of CUHL on auditory but also non-auditory brain regions, little is known about specific consequences on clinical neuropsychological domains. In order to highlight if CUHL affects cognitive disabilities that go beyond auditory system, particularly those connected with Executive Attention, we evaluated 15 children affected by CUHL (age 8-11yrs) with average scores on general cognitive abilities compared to control group (15 children). The assessment battery included tests examining several abilities (Executive attention, visuo-spatial short term memory, visual and motor search, complex visual constructive skills, word and non-word reading), following the rationale that Executive Attention is the basis of several complex abilities. The clinical sample shows significant differences with the control group. We found impairments that go beyond auditory problems and our results support the information derived from functional neuroimaging studies, showing effects of CUHL on auditory but also on non-auditory brain regions and suggesting that CUHL can represent the source of a functional connectivity alteration. Even though CUHL represents a modality specific deficit, it may well involve complex neuropsychological development and multi-modal processing. [ABSTRACT FROM AUTHOR]

A 4 years old boy developed a progressive hearing loss (HL) starting 3 weeks after Neisseria Meningitidis type B meningitis leading to a severe and profound degree on both ears. For the prospective risk of cochlear ossification, bilateral cochlear implantation (CI) was performed with optimal auditory-speech perception outcome achievement. Unaided hearing threshold began to show fluctuations and improvement up to a moderate HL on the left ear, starting 4 months after meningitis and continuing for years post CI surgery. In order to explore the residual cochlear function, an exclusively acoustic amplification was fitted on the improved left side 5 years post implantation. Audiological testing showed very satisfactory discrimination outcomes with acoustic amplification demonstrate that a good cochlear function has been preserved in this case. A certain degree of hearing recovery may be expected after meningitis related deafness. Moreover, this case example encourages surgeons and CI technology researchers to intensely explore techniques, therapies and technological solutions that can facilitate the preservation of inner ear structure and the still existing cochlear function during and after CI surgery in order to leave open the opportunities of new strategies adoption. [ABSTRACT FROM AUTHOR]

Objectives: This study aims to report on the clinical magnetic resonance imaging, histological features, treatment options and outcomes of spinal ependymomas in dogs., Materials and Methods: Retrospective evaluation of medical records from dogs histologically confirmed spinal ependymomas with clinical presentations, magnetic resonance imaging findings, histological aspects, treatment options and outcomes., Results: Eight dogs presented with acute to subacute onset of para- or tetraparesis. Magnetic resonance imaging findings included intramedullary oval-shaped space-occupying lesions that appeared hyperintense on T2-weighted images isointense on T1-weighted images and exhibited marked homogeneous or ring contrast enhancement. A peculiar feature, previously described only in human ependymomas, was observed in three patients - a T2-weighted hypointense rim, termed hemosiderin cap sign. Haematomyelia with necrotic foci was observed in one dog. Surgery, when performed, enabling a definitive intra-vitam diagnosis. Histological examination revealed that rosettes and pseudo-rosettes as disposition of neoplastic cells were the most common features reported. Furthermore, cerebrospinal fluid metastases were identified in one case., Clinical Significance: Clinical and histopathological findings in our case series were consistent with those previously reported in the literature. Magnetic resonance imaging features were fairly typical and highly suggestive of spinal ependymomas. The hemosiderin cap sign may aid in the presumptive intra-vitam diagnosis of these rare spinal tumours. Additionally, we described cerebrospinal fluid spread of neoplastic cells and subsequent multifocal or metastasis presentations. Surgery offered a dual benefit by facilitating intra-vitam diagnosis and, in some cases, extending survival time., (© 2024 British Small Animal Veterinary Association.)

Background: Early diagnosis of neosporosis in dogs is challenging., Objectives: To evaluate the feasibility of a compound multimodal testing approach for diagnosing in dogs neuromuscular and combined forms of neosporosis., Animals: A total of 16 dogs diagnosed with solely neuromuscular neosporosis or with a combination of neuromuscular and central nervous system neosporosis., Methods: Retrospective review of clinical signs, laboratory findings, treatment, and outcome with focus on the diagnostic utility of different tests. Development of a chromogenic in situ hybridization (ISH) assay for the identification of Neospora caninum in paraffin-embedded muscle samples., Results: 13/16 dogs had only neuromuscular signs of neosporosis, 3/16 had disease signs with concomitant central nervous system (CNS) involvement. Serology was performed in 15/16, with 10/15 showing titers >1 : 160 at admission. PCR on muscle samples detected N. caninum DNA in 11/16. Immunohistochemistry (IHC) detected N. caninum in 9/16 and ISH in 9/16. Histopathology revealed inflammatory myopathy in 10/16, necrotizing myopathy in 5/16, borderline changes in 1/16 and tachyzoites in 9/16. In 4 cases, N. caninum infection was confirmed with all 5 diagnostic methods, 3 cases with 4, 2 with 3, 6 with 2, and 1 animal with 1., Conclusions and Clinical Importance: Diagnosis of N. caninum infection should rely on a multimodal diagnostic approach and negativity of 1 single test should not allow for exclusion. Serology in combination with direct parasite identification via histopathology, DNA via PCR, or both modalities, appears a reliable diagnostic approach., (© 2024 The Author(s). Journal of Veterinary Internal Medicine published by Wiley Periodicals LLC on behalf of American College of Veterinary Internal Medicine.)

Background: Meningioma is the most common tumor of the central nervous system of dogs. For this tumor, surgery remains the treatment of choice, either alone or in combination with radiotherapy. Unfortunately, chemotherapeutic strategies are practically absent in dogs and palliative therapies are the only option to surgery. Somatostatin receptor subtype 2 (SSTR2) is expressed in canine meningioma. Since the potent cell-proliferation inhibiting effect of somatostatin (SST), the aim of this study was to investigate in vitro the effects of octreotide, as SST analog, in the viability of canine meningioma., Methods: Four surgical canine meningiomas were used in this study to establish cell cultures. Expression of SSTR2 was verified with immunolabelling in FFPE samples and cell cultures. The effects of octreotide on cell viability were assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT). After 24 hours they were exposed to different concentrations of octreotide (0.1 nM, 1 nM, 10 nM, 100 nM) for 24 and 48 hours., Results: All meningiomas consisted of grade I tumors. The cultured neoplastic cells expressed SSTR2 from 80% to 100%. Octreotide significantly increased cell death after 48 hours of continuous exposure, with 10 and 100 nM octreotide doses. The percentage of cell viability was 80.92 ± 4.9 and 80.49 ± 3.61, compared to the control, respectively, consistent with decreased cell viability of about 20% for both doses., Conclusions: Octreotide reduced the alive neoplastic cultured cells of low-grade canine meningioma in a dose-dependent pattern with continuous exposition for 48 hours. These results support an alternative systemic treatment of meningioma with octreotide in the dog., Competing Interests: The authors declare that they have no conflict of interest, (© The Author(s) 2024. Published by Oxford University Press, the Society for Neuro-Oncology and the European Association of Neuro-Oncology.)

Combustion processes are the primary source of fine particulate matter in indoor air. Since the 1970s, plants have been extensively studied for their potential to reduce indoor air pollution. Leaves can retain particles on their surfaces, influenced by factors such as wax content and the presence of hairs. This study introduces an innovative experimental approach using metal oxide particles in an office-like environment to evaluate the depolluting effect of plant walls. Two plant walls were installed in a controlled room, housing three plant species: Aglaonema commutatum 'Silver Bay', Dracaena fragrans , and Epipremnum aureum . Metal oxide particles were introduced via a compressed air blower positioned between the two walls. The concentration of these particles was monitored using PM 2.5 sensors, and the deposition of iron (Fe) on the leaves was quantified through Inductively Coupled Plasma Mass Spectrometry (ICP-MS). This novel methodology effectively demonstrated the utility of both real-time sensors and ICP-MS in quantifying airborne particle concentrations and leaf deposition, respectively. The results revealed that Dracaena fragrans had a 44% higher Fe particle retention rate compared to the control (wallpaper). However, further validation through methodological replication is necessary to confirm the reproducibility of these findings.

Objective: To compare prosthetic disc and vertebral distraction stabilization in dogs with disc-associated cervical spondylomyelopathy (DA-CSM)., Study Design: A retrospective clinical study., Animals: 25 dogs., Methods: Dogs presenting with clinical signs and MRI findings compatible with DA-CSM underwent surgery. Implantation of the Adamo's prosthetic disc (PD) or vertebral distraction-stabilization (DS) with intervertebral cage, ventral locking plates, and dorsal transarticular screws was performed. All dogs were followed-up and evaluated clinically for a minimum of 1 year and radiographically for at least 3 months. In particular, we focused on the evaluation of subsidence (the degree of vertebral collapse)., Results: Twenty-five dogs were enrolled: 12 with PD implantation and 13 with DS implantation. Of these, 24 dogs were followed-up at 1 year. Overall, 12 dogs improved (4 PD and 8 DS), eight were stable (4 PD and 4 DS), and four deteriorated (3 PD and 1 DS). Deterioration was more common in PD cases, especially soon after surgery. In a few PD cases, a second surgery was necessary. The most common complication in dogs with DS was discospondylitis. Subsidence was detected in 11 PD and 7 DS dogs. Subsidence was more severe and occurred sooner after surgery in PD cases compared to DS cases. DS cases were more prone to clinical improvement and less prone to subsidence than PD cases in this study. However, the statistical evidence was weak owing to the small sample size., Conclusion: The preliminary results suggest that prosthetic disc implantation is more prone to clinical and radiographic failures than distraction stabilization., Clinical Relevance: The DS technique is a valuable surgical option for treating dogs with DA-CSM, with favorable short- and long-term clinical and radiographic outcomes., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Falzone, Tranquillo and Gasparinetti.)

This study aimed to translate and adapt the English version of the Speech, Spatial, and Qualities of Hearing Scale (SSQ) for children and for parents into the Italian language; validate SSQ for hearing children and their parents; and evaluate the discriminant validity of the instrument. A group of 102 normal-hearing Italian children, aged between 9 and 16 years, and their parents were included in this study. A group of 31 parents of normal-hearing Italian children aged between 6 and 8 years was also included. A group of 57 hearing-impaired Italian children aged between 9 and 16 years, and their parents were also included, as well as a group of 30 parents of hearing-impaired Italian children aged between 6 and 8 years. Cronbach’s alpha in the SSQ for parents was 0.92; it was 0.95 in the SSQ for children. Guttmann’s split-half coefficient in SSQ for children for both λ4 and λ6 was 0.98; in SSQ for parents in λ4 was 0.96 and λ6 was 0.95. These data provide evidence for the discriminant validity of the SSQ scale (p-value < 0.001). Italian SSQ scales for children and for parents are now available.

Objective: To describe the use of a customized 3-D-printed titanium prosthesis as adjunctive treatment for foramen magnum decompression (FMD) in dogs with Chiari-like malformation (CM) and syringomyelia (SM)., Animals: 8 dogs with clinical signs and MRI findings of CM-SM., Procedures: 3-D reconstruction of CT images of the head was used to simulate an occipital craniectomy and design the prosthesis. FMD was performed, and the prosthesis was implanted. Follow-up was performed 1, 6, and 12 months later, and clinical status was scored. Repeated MRI images were compared to identify changes involving the neural structures, particularly the syrinx., Results: All prostheses were easily positioned based on the preoperative 3-D models, with no complications. At 12 months after surgery, 3 dogs were free of previous medications, 4 were still receiving steroid medications but at lower doses, and 1 was occasionally receiving acupuncture. MRI of 5 dogs 6 to 20 months after surgery revealed resolution of SM (n = 1), reduced size of SM (3), or worse SM (1). All dogs showed an increase in size of the caudal cranial fossa. Dogs with a longer presurgical duration of the clinical signs and wider syrinx generally had worse outcomes than other dogs., Clinical Relevance: Findings suggested that use of customized 3-D-printed titanium prosthesis and associated FMD can represent an adjunctive option to medically treated dogs with CM-SM. Although the small number of cases precludes definitive conclusions, early surgical treatment, particularly in dogs with a small syrinx, could ensure better long-term outcomes, as previously suggested.

Background: Muscle cramps (MCs) are prolonged, involuntary, painful muscle contractions characterized by an acute onset and short duration, caused by peripheral nerve hyperactivity., Objectives: To provide a detailed description of the clinical features and diagnostic findings in dogs affected by MCs., Animals: Fourteen dogs., Methods: Multicenter retrospective case series. Cases were recruited by a call to veterinary neurologists working in referral practices. Medical records and videotapes were searched for dogs showing MCs. The follow-up was obtained by telephone communication with the owner and the referring veterinarian., Results: Three patterns of presentation were identified depending on the number of affected limbs and presence/absence of migration of MCs to other limbs. In 9/14 (64%) of dogs, MCs were triggered by prompting the dogs to move. 8/14 (58%) dogs were overtly painful with 6/14 (42%) showing mild discomfort. The cause of MCs was hypocalcemia in 11/14 (79%) dogs: 9 dogs were affected by primary hypoparathyrodism, 1 dog by intestinal lymphoma and 1 dog by protein losing enteropathy. In 3/14 cases (21%) the cause was not identified, and all 3 dogs were German Shepherds., Conclusions and Clinical Importance: Muscle cramps can manifest in 1 of 3 clinical patterns. Muscle cramps are elicited when dogs are encouraged to move and do not always appear as painful events, showing in some cases only discomfort. The main cause of MCs in this study was hypocalcemia consequent to primary hypoparathyroidism. In dogs having MCs of unknown etiology, idiopathic disease or paroxysmal dyskinesia could not be ruled out., (© 2020 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals LLC on behalf of American College of Veterinary Internal Medicine.)

A fume hood is the most central piece of safety equipment available to researchers in a laboratory environment. While it is understood that the face velocity and sash height can drastically influence airflow patterns, few specific recommendations can be given to the researcher to guide them to maximize the safety of their particular hood. This stems from the issue that fundamentally little is known regarding how obstructions within the hood can push potentially harmful particles or chemicals out of the fume hood and into the breathing zone. In this work, we demonstrate how the position of a typical nanoparticle synthesis setup, including a Schlenk line and stir plate on an adjustable stand, influences airflow in a constant velocity fume hood. Using a combination of smoke evolution experiments and the aid of computational fluid dynamics simulations, we show how the location and height of the reaction components impact airflow. This work offers a highly visual display intended especially for new or inexperienced fume hood users. Based upon our studies and simulations, we provide detailed guidance to researchers and lab technicians on how to optimally modify reaction placement in order to protect the breathing zone while working., (Published by Oxford University Press on behalf of The British Occupational Hygiene Society 2019.)

Intravascular lymphoma (IVL) is a rare angiotropic large-cell lymphoma in which neoplastic lymphocytes proliferate within the lumina of small blood vessels in the absence of a primary extravascular mass or leukemia. This study included 10 cases of canine IVL restricted to the CNS. Dogs had an average age of 8 years and neurological signs mainly referred to brain involvement such as depression, seizures, and ambulatory deficits. Gross examination at necropsy showed focal extensive or multiple hemorrhagic areas mainly distributed in the telencephalon and diencephalon. Histopathologically, numerous veins and capillaries were filled with neoplastic lymphoid cells, accompanied by edema, hemorrhage, and thrombosis. Immunohistochemistry (IHC) for CD3, CD20, and PAX5 was performed to phenotype the neoplastic lymphocytes. IHC for CD44 and CD29 were used to investigate the pathogenetic mechanism leading to the intravascular aggregation of the neoplastic lymphocytes. The same IHC panel was applied to 8 cases of primary and metastatic canine CNS lymphoma in order to compare IVL immunoreactivity. Three IVLs were typified as T-cell, 3 as B-cell, and 4 as non-T non-B. Neoplastic lymphocytes showed marked expression of CD44 in all IVL cases, and CD29-immunolabeled cells were observed in 4 IVLs. CD44 immunoreactivity was consistent with the findings reported in human IVL, suggesting a predisposition to the formation of lymphocyte aggregates. CD29 was inconsistently immunonegative in canine IVL, confirming only partially the pathogenetic mechanism suggested for the human counterpart.

A novel form of neuroaxonal dystrophy is described in 3 Chihuahua pups, 2 of which were from the same litter. It was characterized not only by accumulation of numerous and widely distributed axonal swellings (spheroids) but also by a severe cavitating leukoencephalopathy. The dogs presented with progressive neurological signs, including gait abnormalities and postural reaction deficits. Magnetic resonance images and gross examination at necropsy revealed dilation of lateral ventricles and cerebral atrophy, accompanied by cavitation of the subcortical white matter. Histopathologically, severe axonal degeneration with formation of large spheroids was found in the cerebral and cerebellar white matter, thalamus, and brainstem nuclei. Small-caliber spheroids were observed in the cerebral and cerebellar gray matter. The telencephalic white matter had severe myelin loss and cavitation with relative sparing of the U-fibers. Different from previously reported cases of canine neuroaxonal dystrophy, in these Chihuahuas the spheroid distribution predominantly involved the white matter with secondary severe leukoencephalopathy.

Objective: To differentiate between hydrated nucleus pulposus extrusion and ventral intraspinal discal cysts in dogs., Study Design: Prospective case series., Animals: Twenty dogs with acute onset of cervical myelopathy due to hydrated nucleus pulposus extrusion or ventral intraspinal discal cysts., Methods: Clinical and magnetic resonance (MR) imaging findings, outcome after surgical treatment, cytologic and histologic findings of compressive material were taken into account. Comparisons and considerations were done between findings reported herein and what was previously described as suspected hydrated nucleus pulposus extrusion and intraspinal cysts., Results: All dogs were presented with acute onset of cervical myelopathy. MR imaging showed compressive cervical myelopathy at C2-C3 (n = 1), C3-C4 (n = 6), C4-C5 (n = 8), and C5-C6 (n = 5) intervertebral disc spaces, due to extradural material suggestive of either partially hydrated nucleus pulposus extrusion or intraspinal discal cyst, with T2 hyperintense and T1 iso-hypointense signal and variable contrast enhancement after gadolinium injection. All dogs were treated surgically by ventral slot (n = 15) or dorsolateral hemilaminectomy (n = 5). All dogs had a favorable outcome and regained a normal gait. The extradural material collected at surgery varied from liquid to more obvious gelatinous material. Cytologic or histologic examination of the material revealed similar findings for all dogs, compatible with partially degenerated nucleus pulposus., Conclusions: Dogs with acute onset of compressive cervical myelopathy due to extradural material resembling human intraspinal cysts on MR images are most likely to have extrusion of partially degenerated nucleus pulposus and should be treated accordingly., (© 2017 The American College of Veterinary Surgeons.)

A review of the literature published in 2015 on topics relating to public and environmental health risks associated with wastewater treatment, reuse, and disposal is presented. This review is divided into the following sections: wastewater management, microbial hazards, chemical hazards, wastewater treatment, wastewater reuse, agricultural reuse in different regions, greywater reuse, wastewater disposal, hospital wastewater, industrial wastewater, and sludge and biosolids.

The latest international guidelines highlight the importance of involving the family in the diagnostic and rehabilitation process of children affected by permanent hearing impairment. This emphasises how meaningful this approach is for the development of the deaf child. So far, there is very little evidence about this approach in Italy, and there are still some barriers to its practical management. The aim of this paper is to report the results of a strategic analysis, which identifies the strengths, weaknesses, opportunities and threats of the family empowerment process during early auditory diagnosis and rehabilitation. The audiology programme should have the goal to offer information and support to families in order to achieve a conscious decision about the use and type of auditory prosthesis and rehabilitation choice within three months after audiologic diagnosis. Within the framework of the Ministry of Health project CCM 2013 "Preventing Communication Disorders: a Regional Program for Early Identification, Intervention and Care of Hearing Impaired Children", a group of professionals identified three main recommendations that can be useful to foster the natural communicative development of the child by strengthening the therapeutic alliance and empowerment of the family. The recommendations obtained with this analysis can help to develop new Italian guidelines with the aim to foster natural communicative development of the child by strengthening the therapeutic alliance and empowerment of the family., (© Copyright by Società Italiana di Otorinolaringologia e Chirurgia Cervico-Facciale.)

Two young dogs were evaluated for an acute onset of abnormal head posture and eye movement. Neurological examination was characterized mostly by permanent neck extension, abnormalities of pupils, and eye movement. A mesencephalic mass lesion was detected on magnetic resonance imaging in both cases. Neurophysiological pathways likely responsible for this peculiar clinical presentation are discussed.

Practical Relevance: Blindness and behavioural changes occur relatively commonly in cats, either separately or in combination, causing devastating consequences for the cat and owner. Blindness can be caused by primary ophthalmic, metabolic or intracranial disease. Similarly behavioural changes may be the primary result of intracranial or systemic disease, but also occur secondarily to visual deficits or changes in interaction with the external environment (ie, non-medical problems). The anatomical pathways involved in vision are very close to those involved in behavioural regulation. It is, therefore, likely that a brain lesion (especially a forebrain lesion) that causes blindness will also cause behavioural abnormalities., Clinical Challenges: In cases of partial or unilateral blindness, obvious visual deficits may not be apparent to the owner or clinician. Rather, the visual impairment may manifest more subtly as changes in behaviour, reluctance to jump or unwillingness to go outside. Similarly, behavioural problems may be episodic and, hence, a cat presenting with behavioural disturbances may appear clinically normal on evaluation. Behavioural changes are unlikely to be noticed unless marked and associated with bilateral blindness or advanced systemic illness., Audience: This article discusses these two major disorders separately, with the aim of highlighting for the clinician some of the important aspects of the general clinical and neurological examination that can be performed to identify these challenging cases., (Copyright © 2011 ISFM and AAFP. Published by Elsevier Ltd. All rights reserved.)

The catalytic efficiency of the class D beta-lactamase OXA-10 depends critically on an unusual carboxylated lysine as the general base residue for both the enzyme acylation and deacylation steps of catalysis. Evidence is presented that the interaction between the indole group of Trp154 and the carboxylated lysine is essential for the stability of the posttranslationally modified Lys70. Substitution of Trp154 by Gly, Ala, or Phe yielded noncarboxylated enzymes which displayed poor catalytic efficiencies and reduced stability when compared to the wild-type OXA-10. The W154H mutant was partially carboxylated. In addition, the maximum values of k(cat) and k(cat)/K(M) were shifted toward pH 7, indicating that the carboxylation state of Lys70 is dependent on the protonation level of the histidine. A comparison of the three-dimensional structures of the different proteins also indicated that the Trp154 mutations did not modify the overall structures of OXA-10 but induced an increased flexibility of the Omega-loop in the active site. Finally, the deacylation-impaired W154A mutant was used to determine the structure of the acyl-enzyme complex with benzylpenicillin. These results indicate a role of the Lys70 carboxylation during the deacylation step and emphasize the importance of Trp154 for the ideal positioning of active site residues leading to an optimum activity.