Clinical, virological, imaging and pathological findings in a SARS CoV-2 antibody positive cat.

This paper reports a presumptive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in a cat. A cat with respiratory disease living with three individuals with coronavirus disease 2019 showed bilateral ground-glass opacities in the lung on X-ray and computed tomography. The clinical swabs were negative for SARS-CoV-2 RNA, but the serum was positive for SARS-CoV-2 antibodies. Interstitial pneumonia and prominent type 2 pneumocyte hyperplasia were noted on histopathology. Respiratory tissues were negative for SARS-CoV-2 RNA or antigen, but the cat was positive for feline parvovirus DNA. In conclusion, the respiratory disease and associated pathology in this cat could have been due to exposure to SARS-CoV-2.

Bare dorsal thoracic fascial flap for esophageal defects: an experimental study with dogs.

BACKGROUND: Reconstruction of esophageal defects has challenged reconstructive surgeons for a long time. Problems that affect the continuity of the orogastic tract influence the patient's quality of life and general health. Bare free fascial flaps are used to restore soft tissue defects of the oral cavity because they provide thin, pliable tissues with a high capacity for epithelialization to preserve the local anatomy. An experimental study was planned to investigate reconstruction of anterior cervical esophageal defects using a pedicled dorsal thoracic fascial flap. METHODS: Eight hybrid dogs were used in the study. All operations were planned in three steps and performed with the animals under general anesthesia. For the two-layered reconstruction, the bare dorsal thoracic fascial flap was harvested and adapted like a patch to the defect. RESULTS: No partial or total flap loss was observed. On postoperative day 20 surgery, a complete epithelial lining on the same plane as the esophageal mucosa was observed over the flap tissue. A 4- to 5-mm longitudinal scar that did not form even a minimal stricture in any dog also was observed. No significant changes from postoperative day 20 to postoperative days 40 and 60 were observed. CONCLUSION: Bare fascial flaps in the oral cavity heal with spontaneous epithelialization and with no need for skin and mucosal grafts. Fascial flaps are easy to harvest and do not cause any functional loss because they are nonfunctional units. Their thin constitution helps the surgeon to shape the tissue and even form tubed flaps.

Injectable calcium phosphate cement as a bone-graft material around peri-implant dehiscence defects: a dog study.

PURPOSE: Peri-implant dehiscence defects occur frequently after dental implant placement. Various graft materials and techniques are proposed for treatment. In this study, an injectable calcium phosphate cement (Augmentech, Wetzlar, Germany) applied to a peri-implant defect was investigated. MATERIALS AND METHODS: Standardized buccal dehiscence defects (5.8 x 3.8 mm) were surgically created after implant site preparation in the right proximal tibiae of 5 beagle dogs. Fifteen stepped cylindrical implants (13 x 3.8 mm diameter) were inserted (3 per dog), and Augmentech injectable calcium phosphate cement was injected into the dehiscences. The bone at the distal side of the implant was left intact to serve as a control. Postsurgically, each dog received double staining of 2 fluorescent labels for estimation of bone cell activity at baseline and after 11 weeks of healing. The animals were sacrificed after 12 weeks. Dissected blocks were processed for histologic, histomorphometric, and fluorescence microscopic analysis, ie, percentage of bone-to-implant contact (BIC) and percentage linear bone height (LBH) were measured. Student t and Mann Whitney U tests were used for statistical analysis (P < .05). RESULTS: Healing was uneventful in all dogs. Augmentech injectable calcium phosphate cement showed good space maintenance and osteoconductive properties with no foreign body reaction. BIC was 34.42 (- 19.88) and 37.00 (- 21.33) (P = .375), while LBH was 84.23 (- 19.73) and 96.10 (- 6.66) (P = .125) for test and control sites, respectively. CONCLUSION: Within the limits of the present study, it was concluded that Augmentech injectable calcium phosphate cement may be a suitable material for the treatment of buccal dehiscence defects around dental implants.

Reconstruction of the urethral defects with autologous fascial tube graft in a rabbit model.

AIM: To investigate the feasibility of the autologous fascia graft in urethra defect reconstruction. METHODS: In 24 adult male rabbits, a standardized defect (17 mm) was created within the midportion of each urethra. Two-cm long fascial tube grafts were interposed between the cut ends of the urethra. Twenty-four rabbits were divided into 12 groups. At 0, 3, 10, 15, 21, 30, 45, 60, 90, 120, 150, and 180 days postoperatively, one group was killed. In the first four groups, rabbits were killed and specimens were obtained for histological examination. After 21 postoperative days, in the subsequent eight groups, retrograde urethrograms were carried out to evaluate urethral patency and caliber, then rabbits were killed and specimens were obtained. RESULTS: In the histological study, advancement of the urethral transitional epithelium along scaffold provided by the fascial graft was determined. At the 30th day, the new urethra was completely covered with the transitional epithelium. Fistula formation was observed in two of 24 rabbits. In urethrograms, narrowing was determined in three of 16 rabbits. CONCLUSION: For segmental urethral reconstruction, fascial graft is a good urethral substitute because of its rapid epithelization capacity, low contraction degree and thinness. We therefore propose the use of fascial grafts for reconstruction of male-urethra defects in humans.

Safety of a thermal vessel sealer on main pulmonary vessels.

OBJECTIVE: LigaSure (Valleylab, Tyco Healthcare, Boulder, CO) is a novel instrument with widespread use in various surgical disciplines for vessel sealing. It uses heat energy to denature collagen and elastin and achieve vessel sealing. We investigated the safety of LigaSure in pulmonary arteries (PA) and veins (PV). METHODS: Twelve sheep were anesthetized and endotracheally intubated. Six underwent right lower lobectomy (Group 1) and six right upper lobectomy (Group 2). All of the vessels in both groups were divided with LigaSure. Diameters of vessels were measured. Intraoperatively, pulmonary artery pressures (PAP) were monitored in Group 1. Following vascular division, ephedrine was injected to increase PAP in Group 1. In Group 2, animals were followed and euthanized at 7 days. Both immediate and 7 day samples were obtained from divided vessel stumps. Conventional histology was done. Statistical analysis was performed using t-test and Fisher's exact test. RESULTS: Mean diameter of PAs (n=9) divided in Group 1 was 8.3mm (3-11) and of PVs (n=8) was 10.4mm (4-15). Mean PAP increased from 18 (27/9) to 27 (45/18)mmHg after ephedrine injection. Dehiscence rate was 2/6 in PAs and 3/6 in PVs larger than 9 mm in diameter. Mean diameter of PAs (n=8) divided in Group 2 was 5.7 mm (3-7) and of PVs (n=9) was 4.6mm (4-6). No early or late (7 days) vascular disruption was seen in Group 2. Bleeding incidence was significantly different between groups (Fisher's exact test p=0.015). Overall no dehiscence was observed in vessels less than 7 mm in diameter. Histology of intraoperative samples showed thermal injury and necrosis. Seven day samples showed short segment necrosis limited to the vessel wall, fibrosis, thrombus formation without inflammation, and minimal granulation tissue. CONCLUSIONS: LigaSure achieves perfect sealing in pulmonary vessels less than 7 mm in diameter in sheep intra- and postoperatively even following a pressure challenge. It can safely be used in segmental branches of PAs and PVs during open or thoracoscopic surgery.

Tissue responses to an experimental calcium phosphate cement and mineral trioxide aggregate as materials for furcation perforation repair: a histological study in dogs.

The aim was to evaluate histologically the inflammatory reactions and tissue responses to an experimental tricalcium phosphate cement (TCP) and mineral trioxide aggregate (MTA) when used as repair materials in furcation perforations in dogs. Perforations were performed in 24 mandibular premolars of six anaesthetised dogs and filled either with ProRoot MTA (grey) or TCP. The root canals were subsequently shaped and filled, and the access cavities were closed with a bonded composite resin. The animals were killed at 12 weeks. After radiological examination, the teeth and surrounding structures were processed for light microscopy. Concerning the grades of inflammation, MTA exhibited significantly better results than TCP (chi-square test according to Pearson). No furcation was free of inflammatory cells. Mild inflammation was observed in nine of twelve cases with MTA and only twice in those with TCP. No significant differences were revealed between MTA and TCP in terms of bone reorganization or deposition of fibrous connective tissue (Mantel-Haenszel chi-square test). The grade of radiological examination corresponded with the grade of inflammation or differed by only one grade plus or minus. Perforations located in the furcation of teeth remain an endodontic and a periodontal problem with an uncertain prognosis, in spite of the promising modern materials applied.

Epithelialization process of free fascial flaps used in reconstruction of oral cavity mucosa defects in dogs.

Bare free fascial flaps are increasingly used for restoration of soft-tissue defects of the oral cavity because they provide thin, foldable tissues with high epithelialization capacity to preserve local anatomy as well as chewing, phonation, and deglutition. However, there are unanswered questions regarding the epithelialization process and other histopathologic changes occurring after transfer of these flaps into the oral cavity. To investigate these changes thoroughly, an experimental study was conducted in the dog model. Bare dorsal thoracic fascia was used as the free flap model. Ten adult dogs were used in this experiment. Oral mucosa defects measuring 6 x 5 cm were created. Free dorsal thoracic fascia flaps were harvested. The vascular pedicle of the fascia flap was anastomosed with the superior thyroidal artery and external jugular vein. Then, the flaps were transferred into the mucosa defects. The dogs were divided into groups, each composed of two animals. At 7, 14, 21, 30, and 60 days postoperatively, general anesthesia was administered to the groups 1, 2, 3, 4, and 5, respectively. First, clinical assessment was performed; then specimens were obtained. Initially, the flaps were gradually infiltrated by acute inflammatory cells coming from the circulation and then replaced by granulation tissue. Epithelial cells deriving from wound margins migrated onto the granulating flaps with eventual coverage of highly organized epithelium after 4 weeks, and the fascia flap could not be differentiated from the native mucosa. The flaps were replaced by normally maturated fibrous tissue containing regular collagen fibers, instead of atypical scar tissue. Wound contraction was calculated as 18 percent at postoperative day 60. It was detected that bare free fascia flaps used in the repair of mucosa defects act as a scaffold and complete epithelialization from surrounding margins. They can be accepted as the main surgical option for the reconstruction of oral cavity mucosa defects.

Experimental fascial flap model in the dog: free flap of the dorsal thoracic fascia.

For years, various types of fascial flaps have been used in clinical practice; however, there are many unanswered questions regarding their basic physiology, anatomy and histopathologic changes occurring after transfer. Simple and reliable flap models are needed to investigate these questions, but very few of these flap models have been described in experimental animals to date. The purpose of this study was to describe a new reliable fascia flap model in the dog-the dorsal thoracic fascia flap. This fascia is defined as the anatomic layer that contains the blood supply to the scapular and parascapular fasciocutaneous flaps. Fourteen adult dogs were used in this experiment. The vascular anatomy of the dorsal thoracic fascia was studied by anatomic dissection and microangiography. Anatomic dissection revealed that the main axial vessel supplying the dorsal thoracic fascia was the superficial branch of the thoracodorsal vessel. Based on the vascular pedicle, fascia flaps generally measuring 15 x 24 cm were created. At gross observation, all of these large flaps based solely on the vascular pedicle were observed to be well-perfused. Microangiographic examination revealed the intense vascularity of the superficial branches of the thoracodorsal vessels in the whole area of all flaps. It was concluded that this is a simple and reliable fascial flap model which can be prepared as a free or pedicled flap. It has a consistent, long vascular pedicle with large vessel diameters supporting a large fascial flap.

Maxillary ameloblastoma case of a dog.

In this report, an ameloblastoma case, which has been occurred on the left maxilla of a 10 year-old, male, German shepherd, was described on the clinical and morphological features. The mass with the dimensions of 5 x 2.5 cm was removed totally by maxillectomy and examined by radiography, magnetic resonance (MR) and biopsy. The tumor was histopathologically classified ameloblastoma of follicular type and in some fields showed acanthotic form. The invasiveness of the tumor was also observed to be high. This report is the first case of maxillary ameloblastoma in dogs in Turkey.