255 research outputs found
Interventional Atrial Septal Defect Closure Using a Totally Bioresorbable Occluder Matrix Development and Preclinical Evaluation of the BioSTAR Device
No full textObjectivesWe sought to test the hypothesis that interventional atrial septal defect (ASD) closure can be performed safely and effectively using a bioresorbable occluder matrix.BackgroundThe ideal septal occluder scaffold should promote the healthiest and most complete healing response while eventually facilitating the full resorption of the material and leaving “native” tissue behind, thus minimizing the potential for future complications from chronic foreign body and maintaining the possibility for later unobstructed transseptal access to the left atrium.MethodsThe STARFlex occluders (NMT Medical Inc., Boston, Massachusetts) were modified by substituting the conventional polyester fabric for a bioengineered, acellular type-I collagen matrix derived from porcine submucosa with a heparin-coated surface (BioSTAR occluder, NMT Medical Inc.). Comparative transcatheter closure of ASDs was performed in young sheep (n = 36). Gross pathology and histopathology were obtained after follow-up periods ranging from 7 days to 2 years.ResultsThe STARFlex (control) devices were encapsulated time-dependently by ingrown fibrous tissue. Histology showed a mild but chronically persisting foreign body reaction. By contrast, BioSTAR devices exhibited a mild-to-moderate transient cellular immune response. Heparin coating of the BioSTAR surface improved the biocompatibility of the device by reducing surface thrombogencity. A remodeling process of the collagen scaffold, starting after 30 days in vivo, resulted in the full replacement of the matrix by host tissue after 2 years of follow-up.ConclusionsThe BioSTAR device is the first septal occluder with a totally bioresorbable matrix that is fully replaced by host tissue during the healing process. The promising results of this study support testing of the BioSTAR device in clinical trials
Clinical, genetic, and pathological features of male pseudohermaphroditism in dog
No full textAbstract Male pseudohermaphroditism is a sex differentiation disorder in which the gonads are testes and the genital ducts are incompletely masculinized. An 8 years old dog with normal male karyotype was referred for examination of external genitalia abnormalities. Adjacent to the vulva subcutaneous undescended testes were observed. The histology of the gonads revealed a Leydig and Sertoli cell neoplasia. The contemporaneous presence of testicular tissue, vulva, male karyotype were compatible with a male pseudohermaphrodite (MPH) condition.</p
Transmission of lungworms of harbour porpoises and harbour seals: molecular tools determine potential vertebrate intermediate hosts
No full textHarbour porpoises (Phocoena phocoena) and harbour seals (Phoca vitulina) from German waters are infected by six species of lungworms (Metastrongyloidea). These nematodes parasitise the respiratory tract, are pathogenic and often cause secondary bacterial infections. In spite of their clinical and epidemiological significance, the life cycle and biology of lungworms in the marine environment is still largely unknown. Regions of ribosomal DNA (ITS-2) of all lungworms parasitising harbour porpoises and harbour seals in German waters were sequenced to characterise and compare the different species. The phylogenetic relationship among the lungworm species was analysed by means of their ITS-2 nucleotide sequences and the species-specific traits of the ITS-2 were used to screen wild fish as possible intermediate hosts for larval lungworms. Molecular markers were developed to identify larval nematodes via in-situ hybridisation of tissues of harbour porpoise and harbour seal prey fish. Potential wild intermediate fish hosts from the North Sea were dissected and found to harbour larval nematodes. Histological examination and in-situ hybridisation of tissue samples from these fish showed lungworm larvae within the intestinal wall. Based on larval ITS-2 nucleotide sequences, larval nematodes were identified as Pseudalius inflexus and Parafilaroides gymnurus. Turbot (Psetta maxima) bred and raised in captivity were experimentally infected with live L1s of Otostrongylus circumlitus and ensheathed larvae were recovered from the gastrointestinal tract of turbot and identified using molecular tools. Our results show that fish intermediate hosts play a role in the transmission of metastrongyloid nematodes of harbour porpoises and harbour seals
as a recessive functional variant for hepatic fibrinogen storage disease in Wagyu cattle
No full textHepatic fibrinogen storage disease (HFSD) was diagnosed in a 5-month-old Wagyu calf with a history of recurrent respiratory disease. It was characterized by lethargy, dehydration, acidemia, and increased liver enzyme activities. Histologically, disseminated hepatocytes were swollen and showed a single, sharply demarcated, faintly eosinophilic cytoplasmic inclusion with a ground-glass appearance, with the nucleus in an eccentric position. Cytoplasmic inclusions did not stain with the periodic acid-Schiff (PAS) reaction. Using a rabbit polyclonal antibody against fibrinogen, the cytoplasmic vacuoles in the hepatocytes stained intensely. Electron microscopy disclosed hepatocytes with membrane-bound cytoplasmic inclusions filled with fine granular material interspersed with a few coarse-grained electron-dense granules. A trio whole-genome sequencing approach identified a deleterious homozygous missense variant in DGKG (p.Thr721Ile). The allele frequency in 209 genotyped Wagyu was 7.2%. This is a report of a DGKG-related recessive inherited disorder in cattle and adds DGKG to the list of candidate genes for HFSD in other species
Concurrent infection with Mycobacterium avium subsp. hominissuis and Giardia duodenalis in a chinchilla (Chinchilla lanigera f. dom.)
No full textA 3-year-old, female chinchilla (Chinchilla lanigera f. dom.) suffered from prolonged vaginal discharge. Sonographically, multiple nodules were detected in the uterus, and the lung showed a diffuse radiodensity, Ovario-hysterectomy was performed and histology of the uterus revealed a severe multifocal pyo-granulomatous metritis with myriads of acid-fast rod-shaped bacilli. Microbiological culture of formalin-fixed uterine tissue and a native vaginal swab resulted in the growth of mycobacteria that were identified as Mycobacterium (M.) avium subsp. hominissuis. The animal was euthanized and pathomorphological examination revealed severe multifocal granulomatous inflammation of lung, mediastinal and mesenteric lymph nodes, intestine, pancreas and kidneys. In addition, an infection of the small intestine with Giardia duodenalis was confirmed immunohistochemically. This is the first report describing a concurrent infection with M. avium subsp. hominissuis and Giardia duodenalis in a chinchilla. Both pathogens represent a potential health risk especially for young or immunosuppressed persons, in particular if infected animals show unspecific clinical symptoms.Ein dreijähriges, weibliches Chinchilla (Chinchilla lanigera f. dom.) zeigte anhaltenden Vaginalausfluss. Sonografisch wurden multiple, noduläre Umfangsvermehrungen im Uterus und eine diffuse Röntgendichte in der Lunge festgestellt. Es wurde eine Ovariohysterektomie durchgeführt und die histologische Untersuchung ergab eine hochgradige, multifokale pyo-granulomatöse Metritis mit unzähligen säurefesten stäbchenförmigen Bakterien. Die mikrobiologische Kultur von formalinfixiertem Uterusgewebe und einem nativen Vaginaltupfer führte zu einem Wachstum von Mykobakterien, die als Mycobacterium (M.) avium subsp. hominissuis identifiziert wurden. Das Tier wurde euthanasiert und pathomorphologisch wurden hochgradige, multifokale, granulomatöse Entzündungen in Lunge, mediastinalen und mesenterialen Lymphknoten, Darm, Pankreas und Nieren festgestellt. Zusätzlich wurde im Dünndarm immunhistologisch eine Infektion mit Giardia duodenalis nachgewiesen. Dieses ist die erste Beschreibung einer Ko-Infektion mit M. avium subsp. hominissuis und Giardia duodenalis bei einem Chinchilla. Beide Erreger können ein mögliches Gesundheitsrisiko insbesondere für junge oder immunsupprimierte Personen darstellen, besonders wenn infizierte Tiere eine unspezifische klinische Symptomatik zeigen
Degradation of tungsten coils implanted into the subclavian artery of New Zealand white rabbits is not associated with local or systemic toxicity
No full textObjective: To assess whether corrosion of tungsten coils is related to residual shunting and to evaluate whether elevated tungsten serum levels are associated with local or systemic toxicity. Methods: Tungsten coils (SPI, Balt, France) were implanted into the subclavian artery of New Zealand white rabbits leading to a residual high-flow shunt in 5/10 rabbits. Serial serum tungsten levels, complete blood count and clinical chemistry were analysed prior to the implantation as well as 15 min, 2 and 4 months thereafter. After 4 months the rabbits underwent repeat angiography before they were sacrificed and the internal organs were evaluated histopathologically. Results: Mean tungsten levels rose from 0.48 mug/l prior to the implantation to 12.4 mug/l 4 months post-implantation. The rise in serum tungsten levels was neither associated with residual shunting present at the time of implantation nor with residual shunting at the time of explantation. One animal had to be sacrificed because of non-resolving palsy of the upper extremity. The remaining animals had an uneventful clinical course with no signs of toxicity of the elevated tungsten levels. Histological examination revealed no evidence of local or systemic toxicity of the tungsten coils. Conclusion: Tungsten coils corrode and lead to a steady increase in serum tungsten levels starting as early as 15 min after implantation. Residual shunting does not seem to influence the kinetics of corrosion of tungsten coils. Despite markedly elevated serum tungsten levels 4 months after implantation degradation of tungsten coils is not associated with local or systemic toxicity. (C) 2002 Published by Elsevier Science Ltd
A novel approach to temporary stenting: degradable cardiovascular stents produced from corrodible metal - results 6-18 months after implantation into New Zealand white rabbits
No full textObjective-To determine whether corrodible materials may be safely used as biodegradable cardiovascular implants. Design-Corrodible iron stents (> 99.8% iron) were produced from pure iron and laser cut with a stent design similar to a commercially available permanent stent (PUVA-AS16). A total of 16 NOR-I stents were implanted into the native descending aorta of 16 New Zealand white rabbits (mean luminal diameter at the implantation site 3.4 mm, balloon diameter to vessel diameter ratio 1.13). Results-No thromboembolic complications and no adverse events occurred during the follow up of 6-18 months. All stents were patent at repeat angiography after 6 (n = 9), 12 (n = 5), and 18 months (n = 2) with no significant neointimal proliferation, no pronounced inflammatory response, and no systemic toxicity. Conclusions-This initial in vivo experience suggests that degradable iron stents can be safely implanted without significant obstruction of the stented vessel caused by inflammation, neointimal proliferation, or thrombotic events
Pathomorphological and immunohistological findings in cattle experimentally infected with rinderpest virus isolates of different pathogenicity
No full textPeste des Petits Ruminants in Unusual Hosts: Epidemiology, Disease, and Impact on Eradication
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