COVID-19: public health management of the first two confirmed cases identified in the UK.

We report key learning from the public health management of the first two confirmed cases of COVID-19 identified in the UK. The first case imported, and the second associated with probable person-to-person transmission within the UK. Contact tracing was complex and fast-moving. Potential exposures for both cases were reviewed, and 52 contacts were identified. No further confirmed COVID-19 cases have been linked epidemiologically to these two cases. As steps are made to enhance contact tracing across the UK, the lessons learned from earlier contact tracing during the country's containment phase are particularly important and timely.

Correction: AMN107 (nilotinib): a novel and selective inhibitor of BCR-ABL.

A correction to this paper has been published and can be accessed via a link at the top of the paper.

Decreasing case fatality rate following invasive pneumococcal disease, North East England, 2006-2016.

Declining mortality following invasive pneumococcal disease (IPD) has been observed concurrent with a reduced incidence due to effective pneumococcal conjugate vaccines. However, with IPD now increasing due to serotype replacement, we undertook a statistical analysis to estimate the trend in all-cause 30-day case fatality rate (CFR) in the North East of England (NEE) following IPD. Clinical, microbiological and demographic data were obtained for all laboratory-confirmed IPD cases (April 2006-March 2016) and the adjusted association between CFR and epidemiological year estimated using logistic regression. Of the 2510 episodes of IPD included in the analysis, 486 died within 30 days of IPD (CFR 19%). Increasing age, male sex, a diagnosis of septicaemia, being in ⩾1 clinical risk groups, alcohol abuse and individual serotypes were independently associated with increased CFR. A significant decline in CFR over time was observed following adjustment for these significant predictors (adjusted odds ratio 0.93, 95% confidence interval 0.89-0.98; P = 0.003). A small but significant decline in 30-day all-cause CFR following IPD has been observed in the NEE. Nonetheless, certain population groups remain at increased risk of dying following IPD. Despite the introduction of effective vaccines, further strategies to reduce the ongoing burden of mortality from IPD are needed.

Distance to treatment as a factor for loss to follow up of hepatitis C patients in North East England.

BACKGROUND: A large proportion of the 200 000 HCV-infected individuals in the UK are undiagnosed or lost to follow-up. Engaging known infected individuals in treatment is essential for elimination. METHODS: Using PHE surveillance data and HCV treatment registers from North East of England (NE) treatment centres for 1997-2016, we estimated the number of HCV cases not linked to treatment and the proportion with active infection. We compared distances of treated and untreated cases to treatment services, and assessed the effect of expanding HCV treatment into existing drug and alcohol treatment centres in the NEE on treatment accessibility. RESULTS: The odds of being treated was associated with distance to treatment services. Confirmatory results for ~50% were not reported to PHE NE. Overall, 3385 patients reported to PHE NE had no record of treatment; we estimated 1621 of these may have been lost to follow-up after confirmation of active infection. CONCLUSIONS: Poor access to healthcare services may contribute to under-diagnosis or loss to follow-up. Expanding HCV treatment delivery into NEE drug and alcohol treatment centres would improve the accessibility of treatment services to people infected with/at risk of HCV. This may increase the proportion receiving treatment and support progress towards elimination.

Midostaurin: a magic bullet that blocks mast cell expansion and activation.

Clinically relevant features in patients with systemic mastocytosis (SM) include the cosmetic burden of lesional skin, mediator-related symptoms, and organ damage resulting from mast cell (MC) infiltration in advanced forms of SM. Regardless of the SM variant, expansion of neoplastic MC in the skin and other organs is triggered by mutant forms of KIT, the most prevalent being D816V. Activation of MC with subsequent release of chemical mediators is often caused by IgE-dependent mechanisms in these patients. Midostaurin, also known as PKC412, blocks the kinase activity of wild-type KIT and KIT D816V, counteracts KIT-dependent growth of neoplastic MC, and inhibits IgE-dependent mediator secretion. Based on this activity-profile, the drug has been used for treatment of patients with advanced SM. Indeed, encouraging results have been obtained with the drug in a recent multi-center phase II trial in patients with advanced SM, with an overall response rate of 60% and a substantial decrease in the burden of neoplastic MC in various organs. Moreover, midostaurin improved the overall survival and relapse-free survival in patients with advanced SM compared with historical controls. In addition, midostaurin was found to improve mediator-related symptoms and quality of life, suggesting that the drug may also be useful in patients with indolent SM suffering from mediator-related symptoms resistant to conventional therapies or those with MC activation syndromes. Ongoing and future studies will determine the actual value of midostaurin-induced MC depletion and MC deactivation in these additional indications.

Target interaction profiling of midostaurin and its metabolites in neoplastic mast cells predicts distinct effects on activation and growth.

Proteomic-based drug testing is an emerging approach to establish the clinical value and anti-neoplastic potential of multikinase inhibitors. The multikinase inhibitor midostaurin (PKC412) is a promising new agent used to treat patients with advanced systemic mastocytosis (SM). We examined the target interaction profiles and the mast cell (MC)-targeting effects of two pharmacologically relevant midostaurin metabolites, CGP52421 and CGP62221. All three compounds, midostaurin and the two metabolites, suppressed IgE-dependent histamine secretion in basophils and MC with reasonable IC(50) values. Midostaurin and CGP62221 also produced growth inhibition and dephosphorylation of KIT in the MC leukemia cell line HMC-1.2, whereas the second metabolite, CGP52421, which accumulates in vivo, showed no substantial effects. Chemical proteomic profiling and drug competition experiments revealed that midostaurin interacts with KIT and several additional kinase targets. The key downstream regulator FES was recognized by midostaurin and CGP62221, but not by CGP52421 in MC lysates, whereas the IgE receptor downstream target SYK was recognized by both metabolites. Together, our data show that the clinically relevant midostaurin metabolite CGP52421 inhibits IgE-dependent histamine release, but is a weak inhibitor of MC proliferation, which may have clinical implications and may explain why mediator-related symptoms improve in SM patients even when disease progression occurs.

Long-term effectiveness of a community-based model of care in Maori and Pacific patients with type 2 diabetes and chronic kidney disease: a 4-year follow up of the DElay Future End Stage Nephropathy due to Diabetes (DEFEND) study.

BACKGROUND/AIM: The Delay Future End Stage Nephropathy due to Diabetes study was a randomised controlled trial of Maori and Pacific patients with advanced diabetic nephropathy, comparing a community-based model of care with usual care. The intervention group achieved lower blood pressure (BP), proteinuria and less end-organ damage. After the intervention ended, all patients reverted to usual care, and were followed to review the sustainability of the intervention. METHODS: A retrospective observation of 65 patients (aged 47-75 years) with type 2 diabetes, hypertension, chronic kidney disease 3/4 and proteinuria (>0.5 g/day) previously randomised to intervention/community care or usual care for 11-21 months. Follow up thereafter was until death, end-stage renal disease (ESRD) (estimated glomerular filtration rate (eGFR) ≤ 10 mL/min/1.73 m(2) )/dialysis or 1 February 2014. Primary end-points were death and ESRD/dialysis. Secondary outcomes were annualised glomerular filtration rate decline, non-fatal vascular events and hospitalisations. RESULTS: Median (interquartile ranges (IQR)) post-trial follow up was 49 (21-81) months and similar in both groups. The median (IQR) eGFR decline was -3.1 (-5.5, -2.3) and -5.5 (-7.1, -3.0) mL/min/year in the intervention and usual care groups respectively (P = 0.11). Similar number of deaths, renal and vascular events were observed in both groups. At the end of follow up, the number of prescribed antihypertensive medications was similar (3.4 ± 1.0 vs 3.3 ± 1.4; P = 0.78). There were fewer median (IQR) hospital days (8 (3, 18) vs 15.5 (6, 49) days, P = 0.03) in the intervention group. CONCLUSIONS: Short-term intensive BP control followed by usual care did not translate into reduction in long-term mortality or ESRD rates, but was associated with reduced hospitalisations.

Inhibition of CXCR4 in CML cells disrupts their interaction with the bone marrow microenvironment and sensitizes them to nilotinib.

Drug resistance is a growing area of concern. It has been shown that a small, residual pool of leukemic CD34+ progenitor cells can survive in the marrow microenvironment of chronic myeloid leukemia (CML) patients after years of kinase inhibitor treatment. Bone marrow (BM) stroma has been implicated in the long-term survival of leukemic cells, and contributes to the expansion and proliferation of both transformed and normal hematopoietic cells. Mechanistically, we found that CML cells expressed CXCR4, and that plerixafor diminished BCR-ABL-positive cell migration and reduced adhesion of these cells to extra cellular-matrix components and to BM stromal cells in vitro. Moreover, plerixafor decreased the drug resistance of CML cells induced by co-culture with BM stromal cells in vitro. Using a functional mouse model of progressive and residual disease, we demonstrated the ability of the CXCR4 inhibitor, plerixafor, to mobilize leukemic cells in vivo, such that a plerixafor-nilotinib combination reduced the leukemia burden in mice significantly below the baseline level suppression exhibited by a moderate-to-high dose of nilotinib as single agent. These results support the idea of using CXCR4 inhibition in conjunction with targeted tyrosine kinase inhibition to override drug resistance in CML and suppress or eradicate residual disease.

Traumatic fragmented medial coronoid process in a Chihuahua.

Fragmented medial coronoid process (FMCP) is a disease process that has not previously been reported in toy-breed dogs. This report describes a presumptive case of FMCP in a 14-month-old Chihuahua that was presented for evaluation approximately four weeks following acute onset of moderate lameness in the left forelimb. Definitive diagnosis of a fragmented medial coronoid process was based upon computed tomography (CT) scan. A CT scan also demonstrated moderate joint incongruity in the affected elbow. Surgical removal of the fragment and subtotal coronoidectomy were performed via a medial arthrotomy. An ulnar ostectomy was also performed to address joint incongruity. Histology of specimens removed at surgery did not demonstrate evidence of microdamage as characteristic of FMCP in large breed dogs, and instead, suggested that the fracture was acute and traumatic in nature. Rapid return to function was observed following surgery.

Enhanced BCR-ABL kinase inhibition does not result in increased inhibition of downstream signaling pathways or increased growth suppression in CML progenitors.

The therapeutic success of imatinib in chronic myeloid leukemia (CML) is hampered by persistence of malignant stem cells. We investigated whether nilotinib, a more potent BCR-ABL kinase inhibitor could target CML primitive progenitors more effectively than imatinib. CML and normal progenitor cells were cultured with nilotinib or imatinib in growth factor supplemented medium. Nilotinib inhibited BCR-ABL kinase activity at lower concentrations than imatinib. Nilotinib inhibited mitogen-activated protein kinase (MAPK), AKT and STAT5 phosphorylation in CML CD34(+) cells in the absence of growth factors (GFs), but did not suppress AKT and STAT5 activity, and resulted in increased MAPK activity, in the presence of GFs. Nilotinib and imatinib resulted in similar suppression of CML primitive and committed progenitors in long-term culture-initiating cell and colony-forming cell assays. Inhibition of progenitor growth was related to marked reduction in proliferation, but only a modest increase in apoptosis. Nilotinib did not show increased efficacy in reducing nondividing CML progenitors compared with imatinib. These results indicate that more potent tyrosine kinase inhibitors by themselves will not be more effective in eliminating CML progenitors than imatinib and that additional mechanism required for maintenance of malignant stem cells need to be identified to improve targeting of leukemia stem cells.

Expression of immune response genes in the stifle joint of dogs with oligoarthritis and degenerative cranial cruciate ligament rupture.

Dysregulation of immune responses within joints plays an important role in development of inflammatory arthritis. We determined expression of a panel of immune response and matrix turnover genes in synovial fluid collected from a group of dogs with stifle oligoarthritis and associated degenerative cranial cruciate ligament (CCL) rupture (n=27). We also studied synovial fluid gene expression in dogs affected with other forms of degenerative arthritis (n=9) and in the stifle joint of healthy dogs with intact CCL (n=14). After collection, synovial cells were pelleted and RNA was isolated. Relative expression of cathepsin K, cathepsin S, tartrate-resistant acid phosphatase (TRAP), matrix metalloproteinase-9 (MMP-9), invariant chain (li), toll-like receptor-2 (TLR-2), and TLR-9 was determined using real-time quantitative RT-PCR. Data were normalized to peripheral blood mononuclear cells (PBMC) as an internal control. Relative expression of cathepsin K, MMP-9, TRAP, and li was increased in the stifle synovial fluid of dogs with oligoarthritis, when compared with the stifles of healthy dogs (P<0.05). In contrast, relative expression of all of the genes-of-interest in synovial fluid from joints affected with other forms of arthritis was not significantly different from the stifles of healthy dogs. TRAP expression was also significantly increased in the stifle joints of dogs with oligoarthritis, when compared to joint expression of TRAP in dogs with other forms of degenerative arthritis (P<0.05). In the dogs with stifle oligoarthritis, expression of both matrix turnover and immune response genes was increased in stifle synovial fluid, when compared with the internal PBMC control, whereas in healthy dogs and dogs with other forms of arthritis, only expression of matrix turnover genes was increased in synovial fluid, when compared with the internal PBMC control (P<0.05). Taken together, these findings suggest that antigen-specific immune responses within the stifle joint may be involved in the pathogenesis of persistent synovitis and associated joint degradation in dogs with oligoarthritis and degenerative CCL rupture.

AMN107 (nilotinib): a novel and selective inhibitor of BCR-ABL.

Chronic myelogenous leukaemia (CML) and Philadelphia chromosome positive (Ph+) acute lymphoblastic leukaemia (ALL) are caused by the BCR-ABL oncogene. Imatinib inhibits the tyrosine kinase activity of the BCR-ABL protein and is an effective, frontline therapy for chronic-phase CML. However, accelerated or blast-crisis phase CML patients and Ph+ ALL patients often relapse due to drug resistance resulting from the emergence of imatinib-resistant point mutations within the BCR-ABL tyrosine kinase domain. This has stimulated the development of new kinase inhibitors that are able to over-ride resistance to imatinib. The novel, selective BCR-ABL inhibitor, AMN107, was designed to fit into the ATP-binding site of the BCR-ABL protein with higher affinity than imatinib. In addition to being more potent than imatinib (IC50< 30 nM) against wild-type BCR-ABL, AMN107 is also significantly active against 32/33 imatinib-resistant BCR-ABL mutants. In preclinical studies, AMN107 demonstrated activity in vitro and in vivo against wild-type and imatinib-resistant BCR-ABL-expressing cells. In phase I/II clinical trials, AMN107 has produced haematological and cytogenetic responses in CML patients, who either did not initially respond to imatinib or developed imatinib resistance. Dasatinib (BMS-354825), which inhibits Abl and Src family kinases, is another promising new clinical candidate for CML that has shown good efficacy in CML patients. In this review, the early characterisation and development of AMN107 is discussed, as is the current status of AMN107 in clinical trials for imatinib-resistant CML and Ph+ ALL. Future trends investigating prediction of mechanisms of resistance to AMN107, and how and where AMN107 is expected to fit into the overall picture for treatment of early-phase CML and imatinib-refractory and late-stage disease are discussed.

Rapid recycling of cholesterol: the joint biologic role of C-reactive protein and serum amyloid A.

Proteins that are highly conserved throughout evolution are presumed to have critical roles in the survival of the species. The two major acute phase proteins, C-reactive protein (CRP) and serum amyloid A (SAA) increase up to 1000-fold during inflammation. Both proteins have been highly conserved phylogenetically for at least the last 500 million years. Thus far the physiologic role and the evolutionary significance of each remains uncertain and their potential interactions have been totally ignored despite a vast and accelerating scientific literature on the involvement of each in human disease. CRP is known to bind to phosphocholine in dead eukaryote and some live bacterial cell walls suggesting that CRP facilitates the phagocytosis of fragmented or intact dead cells and/or enhances host bacterial defenses. SAA has recently been shown to increase the rate of export of cholesterol of phagocytosed cell membranes from macrophages fourfold. We postulate that their combined physiological role is to facilitate the rapid endogenous recycling of cell membrane cholesterol and phospholipids during acute inflammation. CRP promotes efficient phagocytosis of dying cells by macrophages; SAA enhances the export of their free cholesterol/phospholipid for reuse in the membranes of the hundreds of billions of new cells required daily during acute inflammation and repair. The evolutionary conservation of these proteins in species from the horseshoe crab and echinoderms to humans suggests that the rapid endogenous recycling of cholesterol and phospholipids during the highly vulnerable period of acute inflammation is critical for their continual survival.

Unilateral limb enlargement in a dog with a malignant peripheral nerve sheath tumor.

A 3- to 4-month-old female Golden Retriever dog presented with right hind limb enlargement. Physical examination of the limb and radiographic findings initially included soft tissue swelling with elongation, bowing, and cortical irregularity of the femur and tibia. During a period of approximately 7 months, pathology in the limb progressed to include tarsal laxity, muscle atrophy, avulsion of the gastrocnemius muscle, and luxation of the patella. During surgical intervention to shorten the limb and repair the patellar luxation, a large soft tissue cyst was identified along the caudal aspect of the femur and stifle. The limb was later amputated, and a final diagnosis of malignant peripheral nerve sheath (PNS) tumor of the sciatic nerve and surrounding soft tissues was made. The unilateral limb enlargement in this dog appears to have been because of the development and progression of a malignant PNS tumor. The presentation and associated pathologic changes in the limb are unusual for canine PNS tumor but have similarities with neurofibromatosis in the limbs of humans.

Comparison of the effects of caudal pole hemi-meniscectomy and complete medial meniscectomy in the canine stifle joint.

OBJECTIVE: To compare the effects of caudal pole hemi-meniscectomy (CPHM) and complete medial meniscectomy (MM), specifically with respect to development of secondary osteoarthritis, in the stifle joints of clinically normal dogs. ANIMALS: 14 large-breed dogs. PROCEDURE: Unilateral CPHM (7 dogs) or MM (7) was performed, and the left stifle joints served as untreated control joints. Gait was assessed in all dogs before surgery and at 4, 8, 12, and 16 weeks postoperatively. After euthanasia, joints were evaluated grossly; Mankin cartilage scores, subchondral bone density assessment, and articular cartilage proteoglycan extraction and western blot analyses of 3B3(-) and 7D4 epitopes were performed. RESULTS: Weight distribution on control limbs exceeded that of treated limbs at 4 and 16 weeks after surgery in the CPHM group and at 4 and 8 weeks after surgery in the MM group; weight distribution was not significantly different between the 2 groups. After 16 weeks, incomplete meniscal regeneration and cartilage fibrillation on the medial aspect of the tibial plateau and medial femoral condyle were detected in treated joints in both groups. Mankin cartilage scores, subchondral bone density, and immunoexpression of 3B3(-) or 7D4 in articular cartilage in CPHM- or MM-treated joints were similar; 7D4 epitope concentration in synovial fluid was significantly greater in the MM-treated joints than in CPHM-treated joints. CONCLUSIONS AND CLINICAL RELEVANCE: Overall severity of secondary osteoarthritis induced by CPHM and MM was similar. Investigation of 7D4 epitope concentration in synovial fluid suggested that CPHM was associated with less disruption of chondrocyte metabolism.

Evaluation of 5 types of fishing material, 2 sterilization methods, and a crimp-clamp system for extra-articular stabilization of the canine stifle joint.

OBJECTIVE: To evaluate the mechanical properties of 5 types of fishing material, 2 sterilization methods, and a commercially designed crimp-clamp system for the extra-articular repair of the canine stifle joint. STUDY DESIGN: Experimental study. SAMPLE POPULATION: Animals were not used in this study. METHODS: Two brands of monofilament nylon fishing line and 3 brands of monofilament nylon leader line were used to determine the effect of steam and ethylene oxide sterilization on strength and elongation of the material. A strand of 36-kg test monofilament nylon fishing material was wrapped around 2 rods or knotted to form a loop around 2 rods on a materials-testing machine. Ten trials of each brand of unsterilized, steam-sterilized, and ethylene oxide-sterilized fishing material were tested. A strand of each material was elongated to failure at a constant displacement of 1,000 mm/min to determine strength. A strand of each material was cycled 10 times to a load of 50 N to determine percent elongation. The brand of fishing material with the greatest strength and least elongation was crimped to form a loop around 2 rods on a materials-testing machine and tested as described above. ANOVA was used to determine the effect of sterilization method, brand of material, knot, wrap, and crimp on strength and elongation of the material, and a post-hoc t test was used when significant differences were found. A Student t test was used to compare fixation techniques (wrap, knot, and crimp). RESULTS: Sterilization by steam or ethylene oxide had no significant effect on the strength of the nylon fishing material. Steam sterilization resulted in significant increases (2- to 4-fold) in elongation of most nylon fishing material when compared with unsterilized material. Ethylene oxide sterilization had minimal effect on elongation of the fishing material. Mason leader line showed no significant change in strength or elongation regardless of sterilization method. Significantly less strength and significantly less elongation were demonstrated in Mason leader line that was crimped as compared with Mason leader line that was knotted. CONCLUSION: Ethlylene oxide was the preferred method of sterilization to preserve strength and minimize elongation of the fishing material. Of the materials tested, Mason leader line had the least elongation and the greatest preservation of strength when ethylene oxide was used as the sterilization method. Mason leader line and Sufix fishing line were comparable choices when steam was used as the sterilization method. Significantly less elongation was demonstrated in crimped Mason leader line as compared with knotted Mason leader line. CLINICAL RELEVANCE: Of the materials tested, Mason leader line and Sufix fishing line had the best mechanical properties for extracapsular stabilization of the canine stifle joint. Crimping is an attractive alternative to knotting and results in a reduction in elongation of the nylon fishing material.

Imatinib: a selective tyrosine kinase inhibitor.

The understanding of the pathophysiology of a large number of cancer types provides a strategy to target cancer cells with minimal effect on normal cells. Protein phosphorylation and dephosphorylation play a pivotal role in intracellular signaling; to regulate signal transduction pathways, there are approximately 700 protein kinases and 100 protein phosphatases encoded within the human genome. In cancer, as well as in other proliferative diseases, unregulated cell proliferation, differentiation and survival frequently results from abnormal protein phosphorylation. Although it is often possible to identify a single kinase that plays a pivotal role in a given disease, the development of drugs based upon protein kinase inhibition has been hampered by unacceptable side effects resulting from a lack of target selectivity. With the growing understanding of the molecular biology of protein tyrosine kinases and the use of structural information, the design of potential drugs directed towards the bind adenosine triphosphate (ATP)-binding site of a single target has become possible. These advances have transferred emphasis away from the identification of potent kinase inhibitors and more towards issues of target selectivity, cellular efficacy, therapeutic effectiveness and tolerability. In this paper, the relationship between molecular biology and drug discovery methods, as utilized for the identification of anticancer drugs, will be illustrated.

Tyrosine kinase inhibitors: from rational design to clinical trials.

Protein kinases play a crucial role in signal transduction as well as in cellular proliferation, differentiation, and various regulatory mechanisms. The inhibition of growth related kinases, especially tyrosine kinases, might provide new therapies for diseases such as cancer. The progress made in the crystallization of protein kinases has confirmed that the ATP-binding domain of tyrosine kinases is an attractive target for drug design. Three successful examples of drug design at Novartis using a tyrosine kinase as a molecular target are described. PKI166, a pyrrolo[2,3,-d]pyrimidine derivative, is a dual inhibitor of both the EGFR and the ErbB2 kinases. The compound entered clinical trials in 1999, based on its favorable preclinical profile: potent inhibition of EGF-mediated signalling in cells, in vivo antitumor activity in several EGFR overexpressing xenograft tumor models in nude mice, long-lasting inhibition of EGF-stimulated EGFR autophosphorylation in tumor tissue, good oral bioavailability in animals, and no prohibitive in vitro and in vivo toxicity findings. The anilino-phthalazine derivative PTK787/ZK222584 (Phase I, co-developed by Schering AG, Berlin) is a potent and selective inhibitor of both the KDR and Flt-1 kinases with interesting anti-angiogenic and pharmacokinetic properties (orally bioavailable). STI571 (Glivec, Gleevec), a phenylamino-pyrimidine derivative, is a potent inhibitor of the Abl tyrosine kinase, which is present in 95% of patients with chronic myelogenous leukemia (CML). The compound specifically inhibits proliferation of v-Abl and Bcr-Abl expressing cells (including cells from CML patients) and shows anti-tumor activity as a single agent in animal models at well-tolerated doses. Pharmacologically relevant concentrations are achieved in the plasma of animals (oral administration). Promising data from phase I and II clinical trials in CML patients (98% haematological response rate in Phase I) support the fact that the STI571 represents a new treatment modality for CML. In addition, potent inhibition of the PDGFR and c-Kit tyrosine kinases also indicates its possible clinical use in solid tumors.