Gluten-Free Diet Induces Rapid Changes in Phenotype and Survival Properties of Gluten-Specific T Cells in Celiac Disease.

BACKGROUND & AIMS: The treatment of celiac disease (CeD) with gluten-free diet (GFD) normalizes gut inflammation and disease-specific antibodies. CeD patients have HLA-restricted, gluten-specific T cells persisting in the blood and gut even after decades of GFD, which are reactivated and disease driving upon gluten exposure. Our aim was to examine the transition of activated gluten-specific T cells into a pool of persisting memory T cells concurrent with normalization of clinically relevant biomarkers during the first year of treatment. METHODS: We followed 17 CeD patients during their initial GFD year, leading to disease remission. We assessed activation and frequency of gluten-specific CD4+ blood and gut T cells with HLA-DQ2.5:gluten tetramers and flow cytometry, disease-specific serology, histology, and symptom scores. We assessed gluten-specific blood T cells within the first 3 weeks of GFD in 6 patients and serology in an additional 9 patients. RESULTS: Gluten-specific CD4+ T cells peaked in blood at day 14 while up-regulating Bcl-2 and down-regulating Ki-67 and then decreased in frequency within 10 weeks of GFD. CD38, ICOS, HLA-DR, and Ki-67 decreased in gluten-specific cells within 3 days. PD-1, CD39, and OX40 expression persisted even after 12 months. IgA-transglutaminase 2 decreased significantly within 4 weeks. CONCLUSIONS: GFD induces rapid changes in the phenotype and number of gluten-specific CD4+ blood T cells, including a peak of nonproliferating, nonapoptotic cells at day 14. Subsequent alterations in T-cell phenotype associate with the quiescent but chronic nature of treated CeD. The rapid changes affecting gluten-specific T cells and disease-specific antibodies offer opportunities for clinical trials aiming at developing nondietary treatments for patients with newly diagnosed CeD.

Cross-transmission Is Not the Source of New Mycobacterium abscessus Infections in a Multicenter Cohort of Cystic Fibrosis Patients.

BACKGROUND: Mycobacterium abscessus is an extensively drug-resistant pathogen that causes pulmonary disease, particularly in cystic fibrosis (CF) patients. Identifying direct patient-to-patient transmission of M. abscessus is critically important in directing an infection control policy for the management of risk in CF patients. A variety of clinical labs have used molecular epidemiology to investigate transmission. However, there is still conflicting evidence as to how M. abscessus is acquired and whether cross-transmission occurs. Recently, labs have applied whole-genome sequencing (WGS) to investigate this further and, in this study, we investigated whether WGS can reliably identify cross-transmission in M. abscessus. METHODS: We retrospectively sequenced the whole genomes of 145 M. abscessus isolates from 62 patients, seen at 4 hospitals in 2 countries over 16 years. RESULTS: We have shown that a comparison of a fixed number of core single nucleotide variants alone cannot be used to infer cross-transmission in M. abscessus but does provide enough information to replace multiple existing molecular assays. We detected 1 episode of possible direct patient-to-patient transmission in a sibling pair. We found that patients acquired unique M. abscessus strains even after spending considerable time on the same wards with other M. abscessus-positive patients. CONCLUSIONS: This novel analysis has demonstrated that the majority of patients in this study have not acquired M. abscessus through direct patient-to-patient transmission or a common reservoir. Tracking transmission using WGS will only realize its full potential with proper environmental screening, as well as patient sampling.

1,4-dihydroxy quininib attenuates growth of colorectal cancer cells and xenografts and regulates the TIE-2 signaling pathway in patient tumours.

Colorectal cancer (CRC) is the second leading cause of cancer associated deaths in developed countries. Cancer progression and metastatic spread is reliant on new blood vasculature, or angiogenesis. Tumour-related angiogenesis is regulated by pro- and anti-angiogenic factors secreted from malignant tissue in a stepwise process. Previously we structurally modified the small anti-angiogenic molecule quininib and discovered a more potent anti-angiogenic compound 1, 4 dihydroxy quininib (Q8), an antagonist of cysteinyl leukotriene receptor-1 with VEGF-independent bioactivity. Here, Q8, quininib (Q1) and five structural analogues were assayed for anti-tumorigenic effects in pre-clinical cancer models. Q8 reduced clone formation of the human colorectal cancer cell line HT29-Luc2. Gene silencing of CysLT1 in HT29-Luc2 cells significantly reduced expression of calpain-2. In human ex vivo colorectal cancer tumour explants, Q8 significantly decreased the secretion of both TIE-2 and VCAM-1 expression. In vivo Q8 was well tolerated up to 50 mg/kg by Balb/C mice and significantly more effective at reducing tumour volume in colorectal tumour xenografts compared to the parent drug quininib. In tumour xenografts, Q8 significantly reduced expression of the angiogenic marker calpain-2. In summary, we propose Q8 may act on the TIE-2-Angiopoietin signalling pathway to significantly inhibit the process of tumour angiogenesis in colorectal cancer.

Intraoperative and major postoperative complications and survival of dogs undergoing surgical management of epiglottic retroversion: 50 dogs (2003-2017).

OBJECTIVE: To report intraoperative and major postoperative complications in dogs treated surgically for epiglottic retroversion (ER), compare the incidence of major postoperative complications between procedures, and report survival of surgically treated dogs. STUDY DESIGN: Multi-institutional retrospective study. SAMPLE POPULATION: Fifty dogs treated with 78 procedures. METHODS: Medical records of dogs diagnosed and surgically treated for ER from 2003 to 2017 at 11 institutions were reviewed. Complications were divided into intraoperative and major postoperative complications. RESULTS: Intraoperative complications occurred during 2 of 78 (2.6%) procedures. Thirty-six major postoperative complications were documented in 22 dogs after 36 of 74 (48.7%) procedures. Postoperative complications occurred after 7 of 12 (58.3%) nonincisional epiglottopexy, 23 of 43 (53.5%) incisional epiglottopexy, 2 of 4 (50%) partial epiglottectomy, 2 of 12 (16.7%) subtotal epiglottectomy, and 2 of 3 (66.7%) other surgical procedures. Epiglottopexy failure was the most common major postoperative complication. The incidence of major postoperative complications did not differ between procedures (P = .1239), although, when combined, epiglottopexy procedures (30/55) had a higher incidence of complications than epiglottectomy procedures (4/16; P = .048). Thirty (60%) dogs were alive at a median of 928 days (range, 114-2805), 8 (16%) were lost to follow-up after 411 days (range, 43-1158), and 12 (24%) were dead/euthanized after 301.5 days (range, 3-1212). Median survival time was not reached after a median of 716 days. CONCLUSION: Although intraoperative complications were uncommon, major postoperative complications were common, especially after epiglottopexy procedures. CLINICAL SIGNIFICANCE: Although surgical treatment of ER is associated with a high rate of major postoperative complications, especially epiglottopexy procedures, long-term survival can be achieved.

Children With Cystic Fibrosis Are Infected With Multiple Subpopulations of Mycobacterium abscessus With Different Antimicrobial Resistance Profiles.

BACKGROUND: Children with cystic fibrosis (CF) can develop life-threatening infections of Mycobacterium abscessus. These present a significant clinical challenge, particularly when the strains involved are resistant to antibiotics. Recent evidence of within-patient subclones of M. abscessus in adults with CF suggests the possibility that within-patient diversity may be relevant for the treatment of pediatric CF patients. METHODS: We performed whole-genome sequencing (WGS) on 32 isolates of M. abscessus that were taken from multiple body sites of 2 patients with CF who were undergoing treatment at Great Ormond Street Hospital, United Kingdom, in 2015. RESULTS: We found evidence of extensive diversity within patients over time. A clustering analysis of single nucleotide variants revealed that each patient harbored multiple subpopulations, which were differentially abundant between sputum, lung samples, chest wounds, and pleural fluid. The sputum isolates did not reflect the overall within-patient diversity and did not allow for the detection of subclones with mutations previously associated with macrolide resistance (rrl 2058/2059). Some variants were present at intermediate frequencies before the lung transplants. The time of the transplants coincided with extensive variation, suggesting that this event is particularly disruptive for the microbial community, but the transplants did not clear the M. abscessus infections and both patients died as a result of these infections. CONCLUSIONS: Isolates of M. abscessus from sputum do not always reflect the entire diversity present within the patient, which can include subclones with differing antimicrobial resistance profiles. An awareness of this phenotypic variability, with the sampling of multiple body sites in conjunction with WGS, may be necessary to ensure the best treatment for this vulnerable patient group.

CD10-/ALDH- cells are the sole cisplatin-resistant component of a novel ovarian cancer stem cell hierarchy.

It is long established that tumour-initiating cancer stem cells (CSCs) possess chemoresistant properties. However, little is known of the mechanisms involved, particularly with respect to the organisation of CSCs as stem-progenitor-differentiated cell hierarchies. Here we aimed to elucidate the relationship between CSC hierarchies and chemoresistance in an ovarian cancer model. Using a single cell-based approach to CSC discovery and validation, we report a novel, four-component CSC hierarchy based around the markers cluster of differentiation 10 (CD10) and aldehyde dehydrogenase (ALDH). In a change to our understanding of CSC biology, resistance to chemotherapy drug cisplatin was found to be the sole property of CD10-/ALDH- CSCs, while all four CSC types were sensitive to chemotherapy drug paclitaxel. Cisplatin treatment quickly altered the hierarchy, resulting in a three-component hierarchy dominated by the cisplatin-resistant CD10-/ALDH- CSC. This organisation was found to be hard-wired in a long-term cisplatin-adapted model, where again CD10-/ALDH- CSCs were the sole cisplatin-resistant component, and all CSC types remained paclitaxel-sensitive. Molecular analysis indicated that cisplatin resistance is associated with inherent- and adaptive-specific drug efflux and DNA-damage repair mechanisms. Clinically, low CD10 expression was consistent with a specific set of ovarian cancer patient samples. Collectively, these data advance our understanding of the relationship between CSC hierarchies and chemoresistance, which was shown to be CSC- and drug-type specific, and facilitated by specific and synergistic inherent and adaptive mechanisms. Furthermore, our data indicate that primary stage targeting of CD10-/ALDH- CSCs in specific ovarian cancer patients in future may facilitate targeting of recurrent disease, before it ever develops.

Lateral caudal axial pattern flap in 13 dogs.

OBJECTIVE: To describe the frequency and extent of complications associated with lateral caudal axial pattern flaps used to cover large traumatic or excision skin defects on the dorsum, gluteal, and perineal region in 13 dogs. STUDY DESIGN: Case series. ANIMALS: Thirteen client-owned dogs. METHODS: Medical records from 8 institutions were reviewed for dogs treated with a lateral caudal axial pattern flap, including cases in which the procedure was combined with other reconstructive techniques. The flap length relative to the tail length, location of tail skin incision, size and cause of the defect, and short- and long-term complications were recorded. RESULTS: Thirteen dogs were included, 11 with tumors and 2 with traumatic skin loss. The mean estimated length of the flap relative to tail length was 51% (range 33-70%). Four dogs had wound complications. This included 2 dogs with minor postoperative wound complications (mild distal dehiscence) that did not require surgical revision and 2 dogs with major complications that required surgical revision. Two of these 4 dogs had distal flap necrosis, one was revised surgically and one was managed conservatively. In these 2 dogs, the flap length was estimated as 80% and 65% of the tail length, respectively. At 30 days, flaps in all dogs were completely healed. No long-term complications were recorded in any dog. For some dogs, the reconstruction was not obvious, with only the change in hair direction and color noticeable. CONCLUSION: Lateral caudal axial pattern flap is a reconstructive option for gluteal, dorsal, and perineal skin defects in dogs. Distal flap necrosis and dehiscence due to wound infection occurred in 4 dogs that required additional wound care but not always surgical revision.

Regulatory B cells are induced by gut microbiota-driven interleukin-1ß and interleukin-6 production.

Regulatory B cells (Breg cells) differentiate in response to inflammation and subsequently restrain excessive immune responses via the release of interleukin-10 (IL-10). However, the precise inflammatory signals governing their differentiation remain to be elucidated. Here we show that the gut microbiota promotes the differentiation of Breg cells in the spleen as well as in the mesenteric lymph nodes. Perturbation of the gut microbiome imposed either by antibiotic treatment or by changes in the sterility of housing conditions reduces the number and function of Breg cells. Following the induction of arthritis, IL-1ß and IL-6 are produced only in conventionally housed mice and both cytokines directly promote Breg cell differentiation and IL-10 production. Mice lacking IL-6 receptor (IL-6R) or IL-1 receptor 1 (IL-1R1) specifically on B cells have a reduced number of IL-10-producing B cells and develop exacerbated arthritis compared to control animals. Thus, in response to inflammatory signals induced by both the gut flora and arthritis, Breg cells increase in number and restrain excessive inflammation.

Closed suction drainage for treatment of septic peritonitis of confirmed gastrointestinal origin in 20 dogs.

OBJECTIVE: To determine survival rate in dogs with septic peritonitis of confirmed gastrointestinal origin treated with closed suction drainage. STUDY DESIGN: Retrospective case series. ANIMALS: Dogs (n = 20) with septic peritonitis. METHODS: Medical records (2007-2010) of dogs with septic peritonitis of confirmed gastrointestinal origin treated by closed suction drainage were reviewed. Information on signalment, clinicopathologic abnormalities, underlying cause, surgical procedure performed, postoperative management, complications, and outcome was obtained. RESULTS: Dehiscence of a previous anastomosis was the most common source of contamination (80%). Drains remained in place, collecting fluid produced within the abdomen, for a median of 6 days (range, 2-11 days). Eighteen dogs received nutritional support, and 14 received plasma transfusions. Seventeen dogs (85%) survived to discharge. CONCLUSIONS: Closed suction drainage together with resolution of the underlying cause of peritonitis and appropriate postoperative management is an effective technique for treatment of septic peritonitis of confirmed gastrointestinal origin in dogs.

Caudal mediastinal paraesophageal abscesses in 7 dogs.

OBJECTIVE: To report clinical, imaging, and surgical findings associated with caudal mediastinal paraesophageal abscesses (CMPA) in dogs and outcome after surgical treatment. STUDY DESIGN: Case series. ANIMALS: Dogs (n = 7) with CMPA. METHODS: Medical records (April 2005-January 2010) were reviewed for dogs with CMPA treated surgically. Retrieved data were signalment, history, clinical findings, diagnostic investigations, surgical findings, surgical procedures performed, and postoperative recovery. Long-term follow-up information was obtained by telephone questionnaire of owners and referring veterinarians. RESULTS: Median sternotomy (5 dogs) or lateral thoracotomy (2 dogs) was used for access to CMPA, which were drained and partially debrided surgically. In 5 dogs, omentalization of the abscess cavity was performed through a diaphragmatic incision. Foreign material was not identified within any abscess. All dogs were discharged from the hospital and had full recovery. CONCLUSIONS: CMPA should be suspected when there is regurgitation and pyrexia associated with a mass or enlargement in the caudal mediastinum. CMPA appears to have a good prognosis after aggressive surgical therapy.

Minimally invasive inguinal approach for tube cystostomy.

OBJECTIVE: To report a technique for tube cystostomy placement via a minimally invasive inguinal approach and outcome in 9 dogs and 6 cats with urinary tract obstruction or detrusor atony. STUDY DESIGN: Case series. ANIMALS: Dogs (n=9) and cats (6). METHODS: Medical records (January 2004-January 2008) of dogs and cats that had tube cystostomy via an inguinal approach were reviewed. Retrieved data included signalment, diagnosis, surgical technique, and complications. Access to the bladder was through a muscle splitting approach in the inguinal region with the cystostomy tube placed through a skin incision made several centimeters proximal to this incision and secured in the bladder by a purse string suture. Cystopexy during closure of the muscle layers ensured secure closure and minimized the likelihood of uroabdomen if tube dislodgment occurred. RESULTS: Cystostomy tubes were placed in 5 cats as an emergency procedure for treatment of acute urinary tract obstruction or urethral rupture, and as an elective procedure in 9 dogs and 1 cat. No complications occurred during cystostomy tube placement. Postprocedural complications were minor (peristomal irritation in 2 dogs with latex catheters, catheter laceration, premature removal) and only occurred when tubes were retained for >4 weeks. Urinary tract infection at catheter removal in 6 dogs resolved with antibiotic administration. CONCLUSIONS: An inguinal approach for cystostomy tube placement facilitated rapid catheter placement into the bladder with minimal soft tissue dissection. Cystopexy during abdominal wall closure provided peritoneal protection should premature dislodgement of the cystostomy tube occur. CLINICAL RELEVANCE: An inguinal approach should be considered for rapid tube cystostomy particularly in metabolically compromised animals.

Repeat laparotomy for the treatment of septic peritonitis in a Bornean orangutan (Pongo pygmaeus pygmaeus).

A 9-yr-old female Bornean orangutan (Pongo pygmaeus pygmaeus) presented with a 48-hr history of depression, lethargy, anorexia, and mucoid discharge from the rectum. Clinical, radiographic, and ultrasonographic examination demonstrated the presence of multiple distended loops of intestine, intestinal adhesions, and free gas within the abdomen. During exploratory laparotomy, fibrinopurulent diffuse peritonitis as a result of a ruptured intrapelvic abscess with associated large bowel adhesions was evident. The abdomen was thoroughly lavaged, necrotic debris and abscess wall removed, and fibrinous adhesions disrupted. The orangutan was kept sedated for 48 hr to allow for intensive care. Six months later, when the orangutan presented with similar clinical signs, ultrasonographic examination demonstrated the presence of a pelvic abscess. The previous procedure was repeated with the addition of a hysterectomy. This report is the first documentation of long-term management following surgical intervention for internal abdominal abscessation and septic peritonitis in a great ape.

Pyothorax in a cat managed by intrathoracic debridement and postoperative ventilatory support.

: A domestic-longhair cat presented due to lethargy, dyspnoea and hypersalivation. Radiographic examination revealed a bilateral pleural effusion, which was diagnosed as pyothorax based on cytological examination. Ultrasonographic examination revealed extensive loculations within the thoracic cavity. Exploratory sternotomy, under general anaesthesia, allowed the removal of approximately 100 ml of purulent fluid and debridement of a partially walled-off abscess and necrotic material from the pleural cavity. Postoperative positive-pressure ventilation was required due to severe respiratory depression. Intensive postoperative care, including intensive continuous monitoring, thoracostomy tube drainage and lavage of the pleural cavity and oesophagostomy tube feeding, was performed. Complete resolution of clinical signs had occurred by 15 days postoperatively. Clinical or radiographic abnormalities were not detected at a follow-up examination one year after surgery.

Surgical management of 43 cases of chronic otitis externa in the dog.

: Over a seven-year period, chronic otitis externa was surgically managed in 43 dogs at the University Veterinary Hospital of University College Dublin. Lateral ear canal resection (LECR) was undertaken in nine of the 43 dogs: results were unsatisfactory, with a failure of the surgery in five of eight dogs and one dog lost to follow-up. Once end-stage otitis externa, with or without otitis media, is diagnosed, total ear canal ablation and lateral bulla osteotomy (TECA/LBO) is the best treatment option. In this series, 37 of 43 dogs underwent TECA/LBO and of the 29 dogs for which follow-up results were obtained 27 (93%) had an excellent or improved outcome to surgery. Complications following all procedures were most common in cases with a concurrent dermatopathy; therefore, definitive diagnosis and medical treatment for skin and ear disease is essential.