Myasthenia Gravis Masquerading as Status Asthmaticus

Myasthenia gravis, an autoimmune disorder of neuromuscular transmission, can lead to varying degrees of weakness and fatigability of the skeletal musculature. Juvenile myasthenia gravis accounts for 10–15% of all cases of myasthenia gravis. The clinical presentation of juvenile myasthenia gravis varies tremendously, which presents itself as a diagnostic challenge for clinicians. We report a case of a 15-year-old female with mild intermittent asthma presenting with shortness of breath. Acute onset of dyspnea is a common chief complaint amongst the pediatric population with a broad differential diagnosis. Our patient was presumptively treated for status asthmaticus and required invasive mechanical ventilation. After extubating, the patient showed persistent ptosis, which led to the eventual work-up of myasthenia gravis. Upon further review, this patient had months of intermittent symptoms including ptosis and fatigue which went previously undiagnosed. This case demonstrates that dyspnea in an asthmatic can occur from nonairway processes and, if missed, may result in overtreatment of asthma or delayed diagnosis of an important neuromuscular process.

Developmental Evolution of Hypaxial Muscles: Insights From Cyclostomes and Chondrichthyans

Jawed vertebrates possess two distinct groups of muscles in the trunk (epaxial and hypaxial muscles) primarily defined by the pattern of motor innervation from the spinal cord. Of these, the hypaxial group includes muscles with highly differentiated morphology and function, such as the muscles associated with paired limbs, shoulder girdles and tongue/infrahyoid (hypobranchial) muscles. Here we summarize the latest findings on the evolutionary mechanisms underlying the morphological variety of hypaxial musculature, with special reference to the molecular insights obtained from several living species that diverged early in vertebrate evolution. Lampreys, extant jawless vertebrates, lack many of derived traits characteristic of the gnathostomes, such as jaws, paired fins and epaxial/hypaxial distinction of the trunk skeletal musculatures. However, these animals possess the primitive form of the hypobranchial muscle. Of the gnathostomes, the elasmobranchs exhibit developmental mode of hypaxial muscles that is not identical to that of other gnathostomes in that the muscle primordia relocate as coherent cell aggregates. Comparison of expression of developmental genes, including Lbx genes, has delineated the temporal order of differentiation of various skeletal muscles, such as the hypobranchial, posterior pharyngeal and cucullaris (trapezius) muscles. We have proposed that the sequential addition of distal muscles, associated with expression of duplicated Lbx genes, promoted the elaboration of skeletal musculature. These analyses have revealed the framework of an evolutionary pathway that gave rise to the morphological complexity and diversity of vertebrate body patterns.

Multiple contractures and their relationship with congenital amyoplasia

Context: Congenital amyoplasia is characterized by contractures (arthrogryposis) involving multiple large joints. Case report: The patient is a couple’s first daughter and no history of similar cases in the family. She was born at term, by cesarean delivery, weighing 3080 grams and with Apgar scores of 8 and 9. Gestational ultrasound revealed fetal akinesia, oligodramnia, and altered fetal skeletal musculature with shortening of the four limbs. During delivery, she suffered a fracture of the right femur. The patient evolved with a delay in neuropsychomotor development. On physical examination, hypotonia, nevus flammeus on the forehead, contractures involving several joints (including fingers, elbows, hips, knees and feet) were observed as well as pits in elbows and knees. Computed tomography scan of the skull showed cortical hypoplasia. Radiographic evaluation showed levoconvex thoracolumbar scoliosis and congenital changes in vertebral bodies of the thoracic spine, and thinning bone structures of the upper limbs. In addition, there were dysplastic acetabular, signs of constriction or tissue band in distal third of the right and middle thighs of the left, intense muscular hypotrophy, thinning of diaphysis of the femurs and echinovirus feet. Abdominal ultrasound and karyotype were normal. Conclusions: The clinical findings were compatible with those of congenital amyoplasia. Fetal akinesia or hypokinesia is a finding widely reported by mothers of children with this condition, as occurred in our case. Therefore, early interventions are very important, in order to avoid, in particular, greatest atrophy of the affected limbs, in addition to osteopenia.

Amyotrophic lateral sclerosis and the innate immune system: protocol for establishing a biobank and statistical analysis plan

IntroductionAmyotrophic lateral sclerosis (ALS) is a devastating, progressive disease that causes degeneration of the motor neurons leading to paresis of the bulbar and the skeletal musculature. The pathogenesis of ALS remains unknown. We will test the hypothesis that the complement system is involved in the pathophysiology of ALS. This protocol article describes our efforts to establish a national Danish ALS biobank. The primary aim is to obtain biological material from patients with ALS for the current study as well as for future studies.Methods and analysisWe intend to establish an observational ALS biobank; some of the material from this biobank will be used for a prospective, observational case–control study. The participants are patients with ALS, neurologically healthy controls and non-ALS neurological controls. Each participant consents to be interviewed and to donate blood and cerebrospinal fluid to the biobank. Analysis of the complement system will be carried out on the three groups of patients and compared.Ethics and disseminationThe project has been approved by the Committees on Health Research Ethics in the Capital Region of Denmark (Approval number H-16017145) and the Danish Data Protection Agency (file number 2012-58-0004). All results will be published in peer-reviewed, medical journals and presented at scientific conferences.Trial registration numberNCT02869048

A comparative description of the mesosomal musculature in Sphecidae and Ampulicidae (Hymenoptera, Apoidea) using 3D techniques

Conflicting hypotheses about the relationships among the major lineages of aculeate Hymenoptera clearly show the necessity of detailed comparative morphological studies. Using micro-computed tomography and 3D reconstructions, the skeletal musculature of the meso- and metathorax and the first and second abdominal segment in Apoidea are described. Females of Sceliphron destillatorium, Sphex (Fernaldina) lucae (both Sphecidae), and Ampulex compressa (Ampulicidae) were examined. The morphological terminology provided by the Hymenoptera Anatomy Ontology is used. Up to 42 muscles were found. The three species differ in certain numerical and structural aspects. Ampulicidae differs significantly from Sphecidae in the metathorax and the anterior abdomen. The metapleural apodeme and paracoxal ridge are weakly developed in Ampulicidae, which affect some muscular structures. Furthermore, the muscles that insert on the coxae and trochanters are broader and longer in Ampulicidae. A conspicuous characteristic of Sphecidae is the absence of the metaphragma. Overall, we identified four hitherto unrecognized muscles. Our work suggests additional investigations on structures discussed in this paper.

Kudoa ajurutellus n. sp. (Multivalvulida: Kudoidae), a parasite of the skeletal musculature of the Bressou sea catfish, Aspistor quadriscutis, in northeastern of the State of Pará

Kudoa ajurutellus n. sp. (Multivalvulida: Kudoidae) is described as a parasite of the Bressou catfish, Aspistor quadriscutis (Siluriformes) collected at Ajuruteua beach, northeastern Pará, Brazil. The new species is described based on the morphology of the spores and the sequence of the 18S rDNA. This parasite was found only in the skeletal muscular tissue of fish hosts. In the apical view, the spores were pseudo-quadrangular in shape, with rounded borders, and four symmetrical capsules. The spores are 6.63±0.53 μm in length and 8.16±0.75 μm in width. The polar capsules are piriform, 3.45±0.30 μm in length and 1.87±0.15 μm in width. The phylogenetic analysis based on the sequence of the 18S rDNA gene indicated that the new species is clearly distinct from all other Kudoa species, and that the degree of differentiation is constant with the existence of a new species of the genus Kudoa. This is the first marine Kudoa species recorded in northeastern of the State of Pará.

Pulmonary Carcinoma Metastasis in a Feline Digit

Background: Primary pulmonary neoplasia is rare in domestic cats, with fewer than 1% of all tumors diagnosed in this species. Primary lung tumors have a high percentage of metastases, observed in up to 75% of cases in cats. The lung-digit syndrome is characterized by primary pulmonary neoplasms with metastases to the extremities of the limbs, mainly distal phalanges, possibly involving several digits and more than one limb. This report describes a case of pulmonary carcinoma metastasis in a cat digit.Case: A 16-year-old neutered female cat was showing increased volume of the fourth digit was examined at the University of Caxias do Sul veterinary clinic. The animal also showed signs of progressive weight loss, apathy and limping on the right thoracic limb. After clinical evaluation, the animal was sent for radiographic examination of the right metacarpal/phalangeal region and the thorax. A radiopaque structure was observed with discreet central regions of radiolucency, measuring approximately 3 cm in height, 3.4 cm in length and 2.4 cm in depth in the left caudal lung, suggesting neoplasia or pulmonary abscess. Digit image revealed osteolysis of the right and middle distal phalanx measuring 2 cm in height, 3 cm in breadth and 1 cm in length. In view of these radiographic changes, we performed fine needle aspiration cytology of the digit and a nodule in the region of the skeletal musculature of the right thoracic limb. Cytological evaluation revealed cells had cilia on their surface (compatible with respiratory epithelium). The cytologic findings of the fine-needle biopsy were suggestive of carcinoma. After stabilization, the digit was amputated. The material was sent to the laboratory of the Federal University of Pelotas for histopathological examination. Histological evaluation of a digital pulmonary carcinoma metastasis was confirmed. In view of the prognosis and clinical evolution of the disease, the caretaker chose euthanasia. Necropsy and histopathological evaluation of the lung and other organs were not authorized.Discussion: According to the literature, primary lung tumors have a high percentage of metastases, observed in up to 75% of cases in felines.The size of the tumor mass is associated with its metastatic potential, and lung tumors smaller than 1 cm in diameter usually do not present metastases.In the present case, the mass in the lung was greater than 1 cm in size and the animal already presented metastasis in the digit and in the skeletal musculature. In addition to the thoracic cavity, sites where metastases from lung tumors may occur include regional lymph nodes, skin, eyes, skeletal muscle, multiple abdominal organs, and digits. Cats with pulmonary carcinoma and digital metastasis have a median survival 67 days after diagnosis, with intervals of 6 to 122 days reported. Most patients are euthanized due to persistent symptoms of lameness, lethargy and anorexia or evolution of respiratory signs, in addition to the short survival time associated with poor quality of life. In the case reported here, euthanasia was performed after 40 days of diagnosis due to the worsening of the animal's clinical condition.The combination of radiographic, cytological and histopathological findings suggested a primary lung tumor with digit metastasis, also known as lung-digit syndrome. For felines with claudication or digital inflammation, the lung-digit syndrome should be included in differential diagnosis, even if the animal does not present clinical signs associated with the respiratory system. Primary pulmonary carcinoma should be considered in any middle-aged to elderly cat with digital disease.

Chromoblastomycosis in two giant ditch frogs also known as mountain chicken frogs (Leptodactylus fallax)

Because of sudden death of several frogs following the renewal of a terrarium, two giant ditch frogs (Leptodactylus fallax) were submitted for post-mortem examination. The animals displayed extensive erythematous to ulcerative skin lesions as well as multiple granulomas in the liver, kidney and skeletal musculature. In skin lesions as well as in the brownish granulomas, pigmented fungal sclerotic bodies were found in addition to pigmented hyphal structures, though less common. The fungal pathogen, although not further classified in this study was identified as the etiological agent for chromoblastomycosis (synonym: chromomycosis), a leading cause of fatal systemic disease in poikilothermic animals. It is also a cause of chronic skin disease in human beings and therefore a potential zoonotic agent.