Dual MET and ERBB inhibition overcomes intratumor plasticity in osimertinib-resistant-advanced non-small-cell lung cancer (NSCLC).

BACKGROUND: Third-generation epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) such as osimertinib are the last line of targeted treatment of metastatic non-small-cell lung cancer (NSCLC) EGFR-mutant harboring T790M. Different mechanisms of acquired resistance to third-generation EGFR-TKIs have been proposed. It is therefore crucial to identify new and effective strategies to overcome successive acquired mechanisms of resistance. METHODS: For Amplicon-seq analysis, samples from the index patient (primary and metastasis lesions at different timepoints) as well as the patient-derived orthotopic xenograft tumors corresponding to the different treatment arms were used. All samples were formalin-fixed paraffin-embedded, selected and evaluated by a pathologist. For droplet digital PCR, 20 patients diagnosed with NSCLC at baseline or progression to different lines of TKI therapies were selected. Formalin-fixed paraffin-embedded blocks corresponding to either primary tumor or metastasis specimens were used for analysis. For single-cell analysis, orthotopically grown metastases were dissected from the brain of an athymic nu/nu mouse and cryopreserved at -80°C. RESULTS: In a brain metastasis lesion from a NSCLC patient presenting an EGFR T790M mutation, we detected MET gene amplification after prolonged treatment with osimertinib. Importantly, the combination of capmatinib (c-MET inhibitor) and afatinib (ErbB-1/2/4 inhibitor) completely suppressed tumor growth in mice orthotopically injected with cells derived from this brain metastasis. In those mice treated with capmatinib or afatinib as monotherapy, we observed the emergence of KRAS G12C clones. Single-cell gene expression analyses also revealed intratumor heterogeneity, indicating the presence of a KRAS-driven subclone. We also detected low-frequent KRAS G12C alleles in patients treated with various EGFR-TKIs. CONCLUSION: Acquired resistance to subsequent EGFR-TKI treatment lines in EGFR-mutant lung cancer patients may induce genetic plasticity. We assess the biological insights of tumor heterogeneity in an osimertinib-resistant tumor with acquired MET-amplification and propose new treatment strategies in this situation.

Fragmentation of the dorsal distal aspect of the talus on weanling survey and pre-sale radiographs of juvenile Thoroughbreds: prevalence and 2- and 3-year-olds racing performance.

BACKGROUND: Fragmentation of the dorsal aspect of the distal talus (FDDT), at the dorsolateral articular margin of the proximal intertarsal joint (PITJ) on pre-sale radiographs of yearling Thoroughbreds has not been previously described and data to support decisions made by veterinarians to predict future racing potential of horses with these lesions are lacking. METHODS: In this retrospective case-control study we aimed to determine the prevalence of FDDT in juvenile Thoroughbreds and to report their race records. From a database of survey and repository radiographic examinations of 5709 horses, 36 with FDDT were identified. RESULTS: The prevalence of FDDT was 0.63% (36/5709; 95%CI 0.44, 0.87), compared with 5.01% (286/5709; 95%CI 4.46, 5.61) for osteochondrosis of the distal intermediate ridge of the tibia in the same population. In most cases, a single oval-shaped fragment 1-12 mm in diameter was present. When comparing cases with matched controls, there were no significant differences in mean sale price, whether horses started in a trial or race and mean number of starts, wins, places and prize money when 2- and 3-years old. CONCLUSION: FDDT did not appear to affect racing performance, although a larger-scale study is warranted to confirm this finding.

Prevalence, radiographic resolution and outcomes of slab fractures of the third and central tarsal bones in juvenile Thoroughbred horses.

BACKGROUND: Veterinarians are required to interpret the significance of radiographic findings for sale, soundness and future racing performance of weanling and yearling Thoroughbreds. We investigated the prevalence and radiographic appearance of slab fractures of the third (T3) and central tarsal (Tc) bones. METHODS: Weanling and yearling horses with complete or incomplete T3 or Tc fracture were identified by searching a database of radiographs. The prevalence and radiographic appearance at initial diagnosis and after continued pasture turnout, as well as prognosis for racing, of fractures of T3 and Tc were determined. RESULTS: Fractures were identified in 186 tarsi (184 T3 fracture only, 1 Tc fracture only, 1 Tc and T3 fracture) of 157 horses (126 unilateral T3, 29 bilateral T3, 1 contralateral Tc and T3, 1 unilateral Tc and T3) from 7676 examinations. The prevalence of T3 and Tc fractures was 2.40 (95% CI 2.07, 2.76) and 0.04 (95% CI 0.01, 0.11) per 100 radiographic examinations respectively. Fractures were identified on the D556-65°MPlLO view and occurred by survey examination at 11.1 ± 1.3 months in 85.7% horses. At initial diagnosis, 84.3% of T3 fractures appeared incomplete and involved the distal articular surface. Fracture score improved (P < 0.001), and dorsal modelling (P < 0.001) and osteoarthritis score increased in the distal intertarsal joint (P < 0.001), but not the tarsometatarsal joint, between survey and repository examinations. Fractures healed by repository examination in 71.9% of tarsi if there was > 6 months between examinations. There was no difference in sale price, and horses with T3 fractures had fewer trials when 2 and 3 years old (P = 0.023), yet no difference in other parameters of racing success when 2 or 3 years old compared with controls. CONCLUSION: Tarsal slab fractures can occur in juvenile Thoroughbreds and most heal with continued pasture turnout of > 6 months. Further investigation is required to determine risk factors and before making firm conclusions regarding the optimal management, prognosis for racing and long-term soundness.

Erythrocytosis and pleural effusion associated with a hepatoblastoma in a Thoroughbred yearling.

A 10-month-old Thoroughbred filly was presented with a 2-month history of recurrent fever and pleural effusion. Major clinical findings were pyrexia and congested mucous membranes. Clinical pathology tests revealed an erythrocytosis, hyperfibrinogenaemia and hyperglobulinaemia. Pleural fluid was seen on ultrasonographic examination of the thorax and analysis of a thoracocentesis sample indicated a lymphocytic, modified transudate. A transtracheal aspirate was normal. The erythrocytosis persisted despite IV fluid therapy. Arterial blood gas analysis and bone marrow aspirate were normal. These findings were indicative of secondary inappropriate erythrocytosis. Ultrasonographic examination of the abdomen showed a large encapsulated heterogeneous mass in the left lobe of the liver. Histopathological evaluation of a biopsy of the mass was indicative of a hepatic carcinoma. The filly was euthanased and necropsy confirmed the presence of a hepatic tumour with no evidence of systemic metastasis. Further histopathological evaluation confirmed the tumour to be an embryonal macrotrabecular epithelial-type hepatoblastoma, a type of hepatoblastoma that has not previously been reported in a horse.

Laparoscopic transection of restrictive bands of the mesosalpinx as adjunct to the use of prostaglandin E2 for mares with suspected uterine tubal blockage.

OBJECTIVE: To describe the laparoscopic transection of restrictive bands of the mesosalpinx as a useful adjunct to the topical application of prostaglandin E2 to treat mares with suspected uterine tubal blockage. METHODS: A standard left flank laparoscopic approach was made to the abdomen using three laparoscopic portals. If restrictive bands of the mesosalpinx were observed traversing the uterine tube perpendicularly, they were carefully transected and 1 mg of prostaglandin E2 was then applied to the external surface of the uterine tube. Skin incisions were closed with surgical staples and the procedure was repeated on the right uterine tube. RESULTS: Nine Thoroughbred mares suspected of uterine tubal blockage were treated. The treated mares had been barren for 1.8 years on average (range: 1-5 years). The overall postoperative conception rate in treated mares was 89% (8/9 mares). The mean number of mated oestrus cycles before pregnancy in the eight mares that conceived was 1.9 ± 1.6. These mares had been bred on average 6.2 ± 1.9 cycles without becoming pregnant prior to surgery. CONCLUSION: Transection of restrictive bands of the mesosalpinx is easily performed as an adjunctive procedure to laparoscopic-guided application of prostaglandin E2 to the uterine tube. The procedure does not appear to have any detrimental effects on fertility and may improve fertility in a particular subset of mares with complicated uterine tubal disease.

A DNA methylation map of human cancer at single base-pair resolution.

Although single base-pair resolution DNA methylation landscapes for embryonic and different somatic cell types provided important insights into epigenetic dynamics and cell-type specificity, such comprehensive profiling is incomplete across human cancer types. This prompted us to perform genome-wide DNA methylation profiling of 22 samples derived from normal tissues and associated neoplasms, including primary tumors and cancer cell lines. Unlike their invariant normal counterparts, cancer samples exhibited highly variable CpG methylation levels in a large proportion of the genome, involving progressive changes during tumor evolution. The whole-genome sequencing results from selected samples were replicated in a large cohort of 1112 primary tumors of various cancer types using genome-scale DNA methylation analysis. Specifically, we determined DNA hypermethylation of promoters and enhancers regulating tumor-suppressor genes, with potential cancer-driving effects. DNA hypermethylation events showed evidence of positive selection, mutual exclusivity and tissue specificity, suggesting their active participation in neoplastic transformation. Our data highlight the extensive changes in DNA methylation that occur in cancer onset, progression and dissemination.

Surgical indications and outcomes of tympanostomy tube removal.

OBJECTIVE: To evaluate factors affecting perforation healing in children with surgical removal of retained tympanostomy tubes. METHODS: We conducted a retrospective chart review of 82 pediatric patients (111 ears) who underwent surgical tube removal at a tertiary care pediatric hospital from 1/1/1999 to 12/31/2001. Patients included 47 males and 35 females with an age range of 2-15 years (average age, 6.8 years and median, 6 years). The length of intubation ranged from 12 months to 108 months (average, 44.6 months). The indications for removal included: prolonged intubation (61.3%), otorrhea or recurrent infection (21.6%), obstruction (7.2%), tube in middle ear (6.3%), enlarging perforation (2.7%), and in preparation for future cochlear implant surgery (9.9%). Interventions included removal of tympanostomy tubes and techniques for encouraging perforation closure. Seventy-six percent of the ears had a technique used to encourage healing. These techniques included freshen edges (11.8%), Gelfoam or Gelfilm (14.1%), Gelfoam and/or Gelfilm with freshened edges (50.6%). The main outcome measure was perforation healing. Chi-square statistical analysis were used to determine the statistical significant of observations. RESULTS: Overall closure rate for all patients available for follow up was 87.0%, regardless of technique used to encourage healing. There was no statistically significant difference between the average intubation time in ears that healed (44 months), versus those with persistent perforation after removal (42 months). There was no statistical significant difference in closure rate based on patient age. When tubes were removed for prolonged intubation, 87.0% closed. If the indication was otorrhea or recurrent infections, 93.0% healed. CONCLUSIONS: The overwhelming majority of patients who undergo surgical removal of tubes will show complete tympanic membrane healing independent of technique at time of removal, duration of intubation, patient age, or indication for removal.

Molecular characterization of a monoclonal antibody produced in response to a group C meningococcal polysaccharide peptide mimic.

We have developed a monoclonal antibody, designated anti-anti-Id Ab3-2C4 which reacts with Neisseria meningitidis serogroup C polysaccharide (MCPS). Anti-anti-Id Ab3-2C4 was produced by immunizing Balb/C mice with a peptide mimic of MCPS. This monoclonal antibody reacts with native polysaccharide and its anti-idiotype antibody Ab2-6F9 by ELISA. The synthetic peptide mimic was constructed based on the sequence of the VHCDR3 region of the anti-idiotype Ab2-6F9. We compared the cDNA sequence of Ab3-2C4 to the sequence of idiotype antibody Ab1-1E4 produced in response to native MCPS. The predicted amino acid sequence of the unique VHCDR3 of anti-anti-Id Ab3-2C4 is similar to that of idiotype Ab1-1E4. Also the VHCDR3 of both antibodies is similar to some of the known or suggested carbohydrate binding motifs. A different VH gene family was utilized by Ab3-2C4 than by Ab1-1E4. These results suggest that immunization with the anti-idiotype-derived peptide mimic of the MCPS antigen stimulates the production of antibodies with a binding site structurally related to idiotype antibodies, even though the antibodies Ab1-1E4 and Ab3-2C4 are not related in gene families. Our results support the premise that the use of peptide antigens which are mimics of carbohydrates is an alternate vaccine strategy for polysaccharide antigens and results in an appropriate response.

Genome-wide association data suggest ABCB1 and immune-related gene sets may be involved in adult antisocial behavior.

Adult antisocial behavior (AAB) is moderately heritable, relatively common and has adverse consequences for individuals and society. We examined the molecular genetic basis of AAB in 1379 participants from a case-control study in which the cases met criteria for alcohol dependence. We also examined whether genes of interest were expressed in human brain. AAB was measured using a count of the number of Antisocial Personality Disorder criteria endorsed under criterion A from the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition (DSM-IV). Participants were genotyped on the Illumina Human 1M BeadChip. In total, all single-nucleotide polymorphisms (SNPs) accounted for 25% of the variance in AAB, although this estimate was not significant (P=0.09). Enrichment tests indicated that more significantly associated genes were over-represented in seven gene sets, and most were immune related. Our most highly associated SNP (rs4728702, P=5.77 × 10(-7)) was located in the protein-coding adenosine triphosphate-binding cassette, sub-family B (MDR/TAP), member 1 (ABCB1). In a gene-based test, ABCB1 was genome-wide significant (q=0.03). Expression analyses indicated that ABCB1 was robustly expressed in the brain. ABCB1 has been implicated in substance use, and in post hoc tests we found that variation in ABCB1 was associated with DSM-IV alcohol and cocaine dependence criterion counts. These results suggest that ABCB1 may confer risk across externalizing behaviors, and are consistent with previous suggestions that immune pathways are associated with externalizing behaviors. The results should be tempered by the fact that we did not replicate the associations for ABCB1 or the gene sets in a less-affected independent sample.

Cholesterol screening in pediatric practice.

Four pediatricians introduced a portable cholesterol analyzer into their group practice. Their experience is described on the basis of 12 months of screening in 1665 children and adolescents. The overall 50th and 90th percentile values for a subgroup of 1406 routinely screened children were 156 and 197 mg/dL, respectively, but there was marked variation in these values among specific age and sex groups. Cholesterol levels decreased by age group during the early teenage years and increased thereafter, these changes occurring at ages approximately 2 years younger for girls than for boys. Further analysis of screening results for 398 sibling pairs demonstrated significant concordance between paired cholesterol levels when classified by the respective age- and sex-specific 90th percentile values for each member of the pair. Sibling pairs in which both members' cholesterol values exceeded their 90th percentile value were identified 2.4 times as frequently as expected (confidence interval 1.1 to 4.5, P = .029). The observations reported here indicate that office-based cholesterol screening in a pediatric practice may be both practical and useful, although further consideration of screening criteria is needed. Age- and sex-specific reference values for cholesterol levels during childhood could improve screening results. Special emphasis should be directed toward screening siblings of children in whom high cholesterol levels have been detected.

Severe proliferative retinopathy as the only sign of sickle cell hemoglobin C disease.

A 48-year-old black woman developed severe bilateral hypoxic proliferative retinopathy without other clinical manifestations. The hemoglobin level was 10.6 to 11.5 g/100 ml, reticulocyte level was 2.2%, targeted and sickled red blood cells were seen on blood smears, and hemoglobins S and C were demonstrated by electrophoresis. Glucose tolerance test was normal. The development of neovascular proliferation, vitreous hemorrhage, and retinal detachment unassociated with other clinical symptoms is unusual in sickle cell hemoglobin C disease.

Degradation of the phenoxy acid herbicide diclofop-methyl by Sphingomonas paucimobilis isolated from a Canadian prairie soil.

Sphingomonas paucimobilis, isolated from a soil in Manitoba, Canada, was able to utilize diclofop-methyl, (R,S)-methyl-2-[4-(2,4-dichlorophenoxy)phenoxy]propionate, as the sole source of carbon and energy. An actively growing aerobic culture completely degraded 1.5 &mgr;g diclofop-methyl ml(-1) to diclofop acid within 54 h, at 25 degrees C. A biphasic growth pattern indicated that this organism was capable of degrading diclofop acid to 4-(2,4-dichlorophenoxy)phenol and 2,4-dichlorophenol and/or phenol. The accumulation of 2,4-dichlorophenol in the growth medium, however, suggested that Sphingomonas paucimobilis was unable to utilize this compound as a source of carbon and energy.

Development of a vital-sign/fluid-balance flow sheet.

An improved flow sheet for recording vital signs and fluid balance on a medical oncology unit was developed and tested using quality-assurance techniques. The new form, which replaced three separate forms, measurably improved documentation on all quality-assurance monitors tested. Additional benefits include cost-savings and decreased time expenditures by nursing staff.

Surgical arthrodesis of distal tarsal joints in 17 horses clinically affected with osteoarthritis.

OBJECTIVE: To evaluate the outcome of 17 horses that underwent surgical arthrodesis of the tarsometatarsal and distal intertarsal joints for treatment of lameness due to osteoarthritis. DESIGN: Retrospective clinical study using client-owned animals. PROCEDURE: Horses with hindlimb lameness were diagnosed with osteoarthritis of the distal tarsal joints following relief of lameness after intra-articular anaesthesia or intra-articular corticosteroid injection. Surgery to stimulate ankylosis was performed on 27 hocks by placing 3 diverging 3.2 mm drill holes approximately 3 cm through the tarsometatarsal and distal intertarsal joints from the medial aspect of the limb. The results of surgery were assessed by postoperative examinations, telephone communication with clients and analysis of race results. RESULTS: In 71% of horses, surgery was considered to be successful as determined by clinical examination or telephone communication with clients: six of these horses had unilateral surgery and six had bilateral surgery. This represented 85% (6/7) of horses undergoing unilateral surgery and 60% (6/10) of horses having bilateral surgery. All (8/8) racing Standardbreds and 67% (4/6) of racing Thoroughbreds were considered a success. The average time between surgery and a return to racing was 9.5 months. CONCLUSIONS: The surgical technique used here can provide resolution of lameness from osteoarthritis of distal tarsal joints with a success rate similar to other reported surgical arthrodesis techniques that are more invasive and have a greater morbidity.

Helping your patient cope with Tourette syndrome.

Tourette Syndrome is a neurological disorder of unknown origin. The individual suffering from Tourette Syndrome encounters tics and often additional behaviors such as speech, sleep, and learning difficulties, as well as social isolation.

Perceived depth from simultaneous changes in length and direction of a single line.

Using a configuration of three lines joined like hands on a clockface, Brigner, Deni, and Hildreth in 1994 reported empirical support for Wallach, Adams, and Weisz's 1956 hypothesis regarding the elicitation of perceived depth by simultaneous changes in length and orientation of a configuration's elements. The current investigation extended these findings by showing that perceived depth can be elicited by simultaneous changes in size and orientation of either two lines or a single line.

Retrospective study of outcome following desmotomy of the accessory ligament of the deep digital flexor tendon for type 1 flexural deformity in Thoroughbreds.

OBJECTIVE: Determine the long-term outcome for Thoroughbreds undergoing desmotomy of the accessory ligament of the deep digital flexor tendon (DAL-DDFT) for type 1 flexural deformity of the distal interphalangeal joint (DIPJ). DESIGN: Retrospective matched cohort study PROCEDURE: Medical records were retrieved over a 17-year period for Thoroughbreds that underwent DAL-DDFT for type 1 flexural deformity. Long-term outcome was determined by analysis of race records and comparison with maternal siblings. Comparisons between cases and controls included 2-year-old, 3-year-old and total career performance data. RESULTS: There were 46 cases of DAL-DDFT. The mean age at surgery was 151 days (median 118, range 2-562); 48% of case horses and 77% of 90 controls started in a race. For case horses that did race, the time to first race, total number of starts and prize money per race were not significantly different to maternal siblings. Age at the time of surgery did not alter the likelihood of starting a race. CONCLUSION: Thoroughbreds undergoing DAL-DDFT for type 1 flexural deformity of the DIPJ are less likely to race when compared with their maternal siblings. For those that do race, the time to first race, total races and earnings per race are not different from controls. There is no evidence to suggest that age at the time of surgery influences the likelihood of racing.

Retrospective study of 108 foals with septic osteomyelitis.

OBJECTIVE: To determine the clinical characteristics, short-term outcome and future athletic performance of foals with septic osteomyelitis. DESIGN: Retrospective clinical study of 108 Thoroughbred foals with radiographic evidence of bone infection that were presented at the Scone Veterinary Hospital between August 1995 and December 2001. Medical records were reviewed and information concerning signalment, the clinical, laboratory and radiographic findings, treatment and outcome was obtained. Racing records were obtained and evaluated for surviving foals that had reached racing age. RESULTS: Mean age of foals at initial evaluation was 39 days (range 1-180 days); 21 foals had multiple radiographic bone lesions (19.4%), and 76 had concurrent septic arthritis (70.4%). The most frequently affected bones were the femur, tibia and distal phalanx. In total, 87 foals were discharged from the hospital (80.6%), 79 survived long-term to reach racing age and 52 raced (65.8%). Overall, 48% (52/108) of the foals treated for osteomyelitis raced. Foals less than 30 days of age at the time of diagnosis, critically ill foals and those with multiple bones or joints affected were significantly less likely to be discharged from hospital. Multiple septic joints, but not multiple bone involvement, had an unfavourable prognosis for racing. CONCLUSIONS: The prognosis for survival of foals with septic osteomyelitis or osteitis is favourable. Multiple bone or joint involvement is an important short-term prognostic indicator; however, the involvement of multiple joints, but not multiple infected bones, is associated with an unfavourable prognosis for racing.