1
|
Management and use of healthcare resources in patients with chronic lymphocytic leukemia initiating venetoclax in routine clinical practice. Leuk Lymphoma 2024; 65:609-617. [PMID: 38235709 DOI: 10.1080/10428194.2024.2301738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Accepted: 12/30/2023] [Indexed: 01/19/2024]
Abstract
Venetoclax is a first-in-class B-cell lymphoma-2 (BCL-2) inhibitor approved as continuous monotherapy and in combination with rituximab as fixed-treatment duration for relapsed and refractory chronic lymphocytic leukemia (R/R CLL). DEVOTE was a 24-week, multicenter observational study (NCT03310190) evaluating the safety, healthcare resource utilization (HCRU) and health-related quality of life (HRQoL) of patients initiating venetoclax for R/R CLL in Canada. Overall, 89 patients received 1 dose of venetoclax; 80% had prior exposure (42% resistant) to ibrutinib. Biochemical tumor lysis syndrome (TLS) occurred in five patients. We observed differences in hospitalization across Canadian provinces including in patients at low risk for TLS with no clear impact on TLS incidence. Additionally, a rapid and sustained improvement in several domains of HRQoL was observed during venetoclax initiation. Early adoption of venetoclax was mainly for R/R CLL patients with few treatment options; nonetheless, acceptable toxicity and a positive impact on HRQoL were observed.
Collapse
|
2
|
Canadian evidence-based guideline for treatment of relapsed/refractory chronic lymphocytic leukemia. Leuk Res 2023; 133:107372. [PMID: 37633157 DOI: 10.1016/j.leukres.2023.107372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 08/16/2023] [Accepted: 08/18/2023] [Indexed: 08/28/2023]
Abstract
Following the recent publication of Canadian evidence-based guidelines for frontline treatment of chronic lymphocytic leukemia (CLL), the same group of clinicians developed guidelines for CLL in the relapsed/refractory (R/R) setting. The treatment of R/R CLL has changed significantly in the past few years, with many novel therapeutics available to hematologists across the country. These guidelines aim to standardize the management of CLL in the relapsed/refractory setting, using the best evidence currently available.
Collapse
|
3
|
Impact of Fixed-Duration Oral Targeted Therapies on the Economic Burden of Chronic Lymphocytic Leukemia in Canada. Curr Oncol 2023; 30:4483-4498. [PMID: 37232797 DOI: 10.3390/curroncol30050339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 04/17/2023] [Accepted: 04/19/2023] [Indexed: 05/27/2023] Open
Abstract
BACKGROUND Continuous oral targeted therapies (OTT) represent a major economic burden on the Canadian healthcare system, due to their high cost and administration until disease progression/toxicity. The recent introduction of venetoclax-based fixed-duration combination therapies has the potential to reduce such costs. This study aims to estimate the prevalence and the cost of CLL in Canada with the introduction of fixed OTT. METHODS A state transition Markov model was developed and included five health states: watchful waiting, first-line treatment, relapsed/refractory treatment, and death. The number of CLL patients and total cost associated with CLL management in Canada for both continuous- and fixed-treatment-duration OTT were projected from 2020 to 2025. Costs included drug acquisition, follow-up/monitoring, adverse event, and palliative care. RESULTS The CLL prevalence in Canada is projected to increase from 15,512 to 19,517 between 2020 and 2025. Annual costs were projected at C$880.7 and C$703.1 million in 2025, for continuous and fixed OTT scenarios, respectively. Correspondingly, fixed OTT would provide a total cost reduction of C$213.8 million (5.94%) from 2020 to 2025, compared to continuous OTT. CONCLUSIONS Fixed OTT is expected to result in major reductions in cost burden over the 5-year projection, compared to continuous OTT.
Collapse
|
4
|
Corrigendum to “Canadian evidence-based guideline for frontline treatment of chronic lymphocytic leukemia: 2022 update” [Leukemia Research 125 (2023) 107016]. Leuk Res 2023; 128:107073. [PMID: 37019803 DOI: 10.1016/j.leukres.2023.107073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/05/2023]
|
5
|
Canadian evidence-based guideline for frontline treatment of chronic lymphocytic leukemia: 2022 update. Leuk Res 2023; 125:107016. [PMID: 36634577 DOI: 10.1016/j.leukres.2023.107016] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 12/22/2022] [Accepted: 01/03/2023] [Indexed: 01/06/2023]
Abstract
Chronic lymphocytic leukemia (cll) is the most common adult leukemia in North America. In 2018, the first unified national guideline in Canada was developed for the front-line treatment of cll that helped guide treatment across the country. As an update in 2022, a group of clinical experts from across Canada came together to provide input and guidance that included new and innovative treatments and approaches that will continue to provide health care professionals with clear guidance on the first-line management of cll. Recommendations were provided in consensus based on available evidence for the first-line treatment of cll.
Collapse
|
6
|
Low-dose trimethoprim-sulfamethoxazole for the treatment of Pneumocystis jirovecii pneumonia (LOW-TMP): protocol for a phase III randomised, placebo-controlled, dose-comparison trial. BMJ Open 2022; 12:e053039. [PMID: 35863836 PMCID: PMC9310160 DOI: 10.1136/bmjopen-2021-053039] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
INTRODUCTION Pneumocystis jirovecii pneumonia (PJP) is an opportunistic infection of immunocompromised hosts with significant morbidity and mortality. The current standard of care, trimethoprim-sulfamethoxazole (TMP-SMX) at a dose of 15-20 mg/kg/day, is associated with serious adverse drug events (ADE) in 20%-60% of patients. ADEs include hypersensitivity reactions, drug-induced liver injury, cytopenias and renal failure, all of which can be treatment limiting. In a recent meta-analysis of observational studies, reduced dose TMP-SMX for the treatment of PJP was associated with fewer ADEs, without increased mortality. METHODS AND ANALYSIS A phase III randomised, placebo-controlled, trial to directly compare the efficacy and safety of low-dose TMP-SMX (10 mg/kg/day of TMP) with the standard of care (15 mg/kg/day of TMP) among patients with PJP, for a composite primary outcome of change of treatment, new mechanical ventilation, or death. The trial will be undertaken at 16 Canadian hospitals. Data will be analysed as intention to treat. Primary and secondary outcomes will be compared using logistic regression adjusting for stratification and presented with 95% CI. ETHICS AND DISSEMINATION This study has been conditionally approved by the McGill University Health Centre; Ethics approval will be obtained from all participating centres. Results will be submitted for publication in a peer-reviewed journal. TRIAL REGISTRATION NUMBER NCT04851015.
Collapse
|
7
|
To Treat or Not? Remission Induction of Acquired von Willebrand Syndrome Secondary to Chronic Lymphocytic Leukemia: A Case Report. CLINICAL LYMPHOMA, MYELOMA & LEUKEMIA 2021; 21:e493-e496. [PMID: 33558201 DOI: 10.1016/j.clml.2021.01.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Accepted: 01/09/2021] [Indexed: 11/15/2022]
|
8
|
Abstract
This study examines the prevalence and outcomes of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection among migrant workers in Singapore.
Collapse
|
9
|
First-line therapy, autologous stem-cell transplantation, and post-transplantation maintenance in the management of newly diagnosed mantle cell lymphoma. Curr Oncol 2020; 27:e632-e644. [PMID: 33380879 PMCID: PMC7755434 DOI: 10.3747/co.27.7053] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Background In Ontario, no clearly defined standard of care for the management of mantle cell lymphoma (mcl) has been developed, and substantial variability from centre to centre is evident. This guidance document was prompted by the need to harmonize practice in Ontario with respect to first-line, conditioning, and post-transplantation maintenance therapy for patients newly diagnosed with transplantation-eligible mcl. Methods The medline and embase databases were systematically searched from January 2013 to January 2020 for evidence, and the best available evidence was used to draft recommendations relevant to first-line therapy, autologous stem-cell transplantation, and post-transplantation maintenance in the management of transplantation-eligible newly diagnosed mcl. Final approval of this guidance document was obtained from the Stem Cell Transplant Advisory Committee. Recommendations These recommendations apply to all cases of transplantation-eligible newly diagnosed mcl:■ Alternating cycles of r-chop (rituximab plus cyclophosphamide-doxorubicin-vincristine-prednisolone) and r-dhap [rituximab plus dexamethasone-high-dose cytarabine-cisplatin] is the recommended first-line treatment for symptomatic patients newly diagnosed with mcl before autologous stem-cell transplantation (asct).■ Rituximab plus hyperfractionated cyclophosphamide-vincristine-doxorubicin-dexamethasone (r-hypercvad), alternating with methotrexate and cytarabine, is not recommended for the treatment of patients with newly diagnosed mcl.■ beam (carmustine-etoposide-cytarabine-melphalan), beac (carmustine-etoposide-cytarabine-cyclophosphamide), and total-body irradiation-based regimens are reasonable conditioning options for patients with mcl who have responded to first-line therapy and who are undergoing asct.■ Maintenance therapy with rituximab is recommended for patients with newly diagnosed mcl who have undergone asct.
Collapse
|
10
|
Bruton tyrosine kinase inhibitors for the frontline treatment of chronic lymphocytic leukemia. Curr Oncol 2020; 27:e645-e655. [PMID: 33380880 PMCID: PMC7755444 DOI: 10.3747/co.27.6795] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Chronic lymphocytic leukemia (cll) is the most commonly diagnosed adult leukemia in Canada. Biologic heterogeneity of cll between patients results in variable disease trajectories and responses to therapy. Notably, compared with patients lacking high-risk features, those with such features-such as deletions in chromosome 17p, aberrations in the TP53 gene, or unmutated immunoglobulin heavy chain variable region genes-experience inferior outcomes and responses to standard chemoimmunotherapy. Novel agents that target the B cell receptor signalling pathway, such as Bruton tyrosine kinase (btk) inhibitors, have demonstrated clinical efficacy and safety in patients with treatment-naïve cll, particularly those with high-risk features. However, given the current lack of head-to-head trials comparing btk inhibitors, selection of the optimal btk inhibitor for patients with cll is unclear and requires consideration of multiple factors. In the present review, we focus on the efficacy, safety, and pharmacologic features of the btk inhibitors that are approved or under clinical development, and we discuss the practical considerations for the use of those agents in the Canadian treatment landscape.
Collapse
|
11
|
[Rhegmatogenous retinal detachment: Topography of breaks and agreement with lincoff's rules]. J Fr Ophtalmol 2019; 43:31-34. [PMID: 31761318 DOI: 10.1016/j.jfo.2019.01.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2018] [Revised: 12/23/2018] [Accepted: 01/07/2019] [Indexed: 10/25/2022]
Abstract
PURPOSE To study the topography of retinal breaks and their agreement with Lincoff's rules. MATERIALS AND METHODS We performed a retrospective descriptive study of patients with recent rhegmatogenous retinal detachments followed on the ophthalmology service of Abass Ndao Hospital from January 2006 through December 2016. Patients with no prior retinal treatment were included. RESULTS Over 11 years, we reviewed 97 patients with 107 eyes with retinal detachments. The mean age of our patients was 51.7 years, range 23-79 years. There were 69 male patients, for a male:female ratio of 2.46. Refraction revealed that 38.1% of patients were myopes. Fourteen percent (14%) of patients had experienced trauma to the eye with the detachment. The right eye was involved in 54.6% of patients. The onset was insidious in 54.6% of cases and sudden in 23.7% of cases. All patients had decreased visual acuity, associated with a scotoma in 26.8% of cases. Visual acuity was decreased to light perception through 7/10. In 64.9% of cases, Lincoff's rules were observed. DISCUSSION Lincoff's rules are still relevant for localization of the breaks in retinal detachments. CONCLUSION Diagnosis of a retinal detachment is an essential step, since it determines the treatment. Lincoff's rules still have a role in finding the retinal break in retinal detachments.
Collapse
|
12
|
[Giant retinal tears: Senegalese experience]. J Fr Ophtalmol 2019; 42:133-137. [PMID: 30709563 DOI: 10.1016/j.jfo.2018.06.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Revised: 06/17/2018] [Accepted: 06/27/2018] [Indexed: 11/28/2022]
Abstract
PURPOSE To appreciate the epidemiological characteristics and to show the therapeutic aspects of the giant retinal tears. PATIENTS AND METHODS We conducted a retrospective study from January 2014 to June 2017 on subjects with giant retinal tears. Patients with media opacities limiting examination were excluded. RESULTS We identified 17 cases of giant retinal tears. The frequency of detachments related to a giant retinal tear was 17% compared to all retinal tears. The mean age was 50.75 years with a sex ratio (M/F) of 6.5. We found three cases of high myopia, one case of hyperopia and four trauma cases. All patients had a decrease in visual acuity. The average time to consultation was four weeks. The mean intraocular pressure was 8mmHg. The tear was found in the left eye in eight cases and in the right eye in five cases; two cases were bilateral. We performed intraocular surgery in five eyes and laser in four eyes. We achieved anatomical reattachment and functional improvement in all operated patients. COMMENTS AND CONCLUSION The prognosis of a giant retinal tear remains guarded, especially if patients are seen and treated late. Laser photocoagulation of giant tears remains effective, especially in cases of early diagnosis.
Collapse
|
13
|
Minimal residual disease detected by immunoglobulin sequencing predicts CLL relapse more effectively than flow cytometry. Leuk Lymphoma 2017; 59:1986-1989. [DOI: 10.1080/10428194.2017.1397664] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
14
|
Current Status of Bruton's Tyrosine Kinase Inhibitor Development and Use in B-Cell Malignancies. Drugs Aging 2017; 34:509-527. [PMID: 28536906 DOI: 10.1007/s40266-017-0468-4] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The B-cell receptor (BCR) pathway plays an important role in the survival, proliferation and trafficking of cancer cells in a variety of B-cell malignancies. Recently, a number of agents have been developed to target various components of the BCR pathway. One such target is Bruton's tyrosine kinase (BTK), a Tec family kinase member found near the cell membrane that is involved in upstream BCR signaling. The biological function of BTK in several B-cell lymphoid malignancies has led to the development of the oral BTK inhibitor ibrutinib. In chronic lymphocytic leukemia (CLL), ibrutinib has demonstrated durable clinical responses in relapsed/refractory (R/R) patients, including those with the high-risk del(17p) cytogenetic abnormality. These findings have paved the way for trials evaluating ibrutinib in previously untreated CLL patients, and also in combination with chemoimmunotherapy or other novel agents. Durable clinical responses have also been demonstrated in mantle cell lymphoma (MCL) and Waldenström's macroglobulinemia (WM) patients treated with ibrutinib. Ibrutinib is generally well tolerated, although current follow-up remains short and patients of advanced age are more likely to discontinue treatment for toxicity. Treatment-specific side effects such as bleeding and atrial fibrillation may, at least partly, be related to off-target inhibition of non-BTK kinases. Studies evaluating other potential indications for BTK inhibition are ongoing, including in post-allogeneic hematopoietic stem cell transplant patients for whom ibrutinib may be effective in modulating graft-versus-host disease. Combination trials of ibrutinib with venetoclax, a Bcl-2 inhibitor, are underway and are supported by sound preclinical rationale. Several next-generation BTK inhibitors are under development with the goal of decreasing treatment-related toxicity and resistance.
Collapse
|
15
|
|
16
|
The potential combination of BCL-2 inhibitors and ibrutinib as frontline therapy in chronic lymphocytic leukemia. Leuk Lymphoma 2017; 58:2287-2297. [PMID: 28482721 DOI: 10.1080/10428194.2017.1312387] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
The recent development of small molecule inhibitors targeted at the B-cell receptor (BCR) pathway and the anti-apoptotic protein BCL-2 has revolutionized the care of patients with chronic lymphocytic leukemia (CLL). While durable responses to the BCR inhibitor ibrutinib have been observed in both previously untreated and relapsed/refractory CLL patients, residual disease is common in patients treated with single-agent ibrutinib. Interest remains high in therapeutic combinations that may lead to better quality remissions. A potential partner to ibrutinib with a distinct mechanism of action that is likely to lead to deeper responses is the BCL-2 inhibitor venetoclax. Preclinical studies have suggested synergism between inhibitors of BCR and BCL-2 and have paved the way to the development of ongoing clinical trials aimed at evaluating the combination of ibrutinib with venetoclax in CLL patients.
Collapse
|
17
|
Updates from the 2016 American Society of Hematology Annual Meeting: Practice-Changing Studies in Untreated Follicular Lymphoma. Curr Oncol 2017. [DOI: 10.3747/co.24.3586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The 2016 annual meeting of the American Society of Hematology took place in San Diego, California, 3–6 December. At the meeting, results from key studies on the first-line treatment of follicular lymphoma were presented. Of those studies, key oral presentations included two analyzing data from the gallium study, which evaluated the efficacy and safety of obinutuzumab plus chemotherapy (G-chemo) compared with rituximab plus chemotherapy (R-chemo), followed, in responding patients with follicular lymphoma, by obinutuzumab or rituximab maintenance; results from the sabrina study, which evaluated the efficacy and safety of subcutaneous compared with intravenous rituximab; results of a cost-effectiveness analysis of first-line treatment with bendamustine and rituximab from a Canadian perspective; and results from the SAKK 35/10 study, which evaluated the safety and efficacy of rituximab plus lenalidomide compared with rituximab monotherapy. Our meeting report describes the foregoing studies and includes interviews with the Canadian investigators, plus commentaries by those investigators about the potential impact on Canadian practice.
Collapse
|
18
|
Survival of Del17p CLL Depends on Genomic Complexity and Somatic Mutation. Clin Cancer Res 2016; 23:735-745. [PMID: 27503198 DOI: 10.1158/1078-0432.ccr-16-0594] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Revised: 06/17/2016] [Accepted: 07/17/2016] [Indexed: 12/30/2022]
Abstract
PURPOSE Chronic lymphocytic leukemia (CLL) with 17p deletion typically progresses quickly and is refractory to most conventional therapies. However, some del(17p) patients do not progress for years, suggesting that del(17p) is not the only driving event in CLL progression. We hypothesize that other concomitant genetic abnormalities underlie the clinical heterogeneity of del(17p) CLL. EXPERIMENTAL DESIGN We profiled the somatic mutations and copy number alterations (CNA) in a large group of del(17p) CLLs as well as wild-type CLL and analyzed the genetic basis of their clinical heterogeneity. RESULTS We found that increased somatic mutation number associates with poor overall survival independent of 17p deletion (P = 0.003). TP53 mutation was present in 81% of del(17p) CLL, mostly clonal (82%), and clonal mutations with del(17p) exhibit shorter overall survival than subclonal mutations with del(17p) (P = 0.019). Del(17p) CLL has a unique driver mutation profile, including NOTCH1 (15%), RPS15 (12%), DDX3X (8%), and GPS2 (6%). We found that about half of del(17p) CLL cases have recurrent deletions at 3p, 4p, or 9p and that any of these deletions significantly predicts shorter overall survival. In addition, the number of CNAs, but not somatic mutations, predicts shorter time to treatment among patients untreated at sampling. Indolent del(17p) CLLs were characterized by absent or subclonal TP53 mutation and few CNAs, with no difference in somatic mutation number. CONCLUSIONS We conclude that del(17p) has a unique genomic profile and that clonal TP53 mutations, 3p, 4p, or 9p deletions, and genomic complexity are associated with shorter overall survival. Clin Cancer Res; 23(3); 735-45. ©2016 AACR.
Collapse
|
19
|
|
20
|
Incidence and predictive factors of symptomatic thrombosis related to peripherally inserted central catheters in chemotherapy patients. Thromb Res 2012; 130:323-6. [DOI: 10.1016/j.thromres.2012.02.048] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2012] [Revised: 02/22/2012] [Accepted: 02/28/2012] [Indexed: 12/11/2022]
|
21
|
Genetic interactions between Pax9 and Msx1 regulate lip development and several stages of tooth morphogenesis. Dev Biol 2010; 340:438-49. [PMID: 20123092 DOI: 10.1016/j.ydbio.2010.01.031] [Citation(s) in RCA: 104] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2009] [Revised: 01/26/2010] [Accepted: 01/26/2010] [Indexed: 01/28/2023]
Abstract
Developmental abnormalities of craniofacial structures and teeth often occur sporadically and the underlying genetic defects are not well understood, in part due to unknown gene-gene interactions. Pax9 and Msx1 are co-expressed during craniofacial development, and mice that are single homozygous mutant for either gene exhibit cleft palate and an early arrest of tooth formation. Whereas in vitro assays have demonstrated that protein-protein interactions between Pax9 and Msx1 can occur, it is unclear if Pax9 and Msx1 interact genetically in vivo during development. To address this question, we compounded the Pax9 and Msx1 mutations and observed that double homozygous mutants exhibit an incompletely penetrant cleft lip phenotype. Moreover, in double heterozygous mutants, the lower incisors were consistently missing and we find that transgenic BMP4 expression partly rescues this phenotype. Reduced expression of Shh and Bmp2 indicates that a smaller "incisor field" forms in Pax9(+/-);Msx1(+/-) mutants, and dental epithelial growth is substantially reduced after the bud to cap stage transition. This defect is preceded by drastically reduced mesenchymal expression of Fgf3 and Fgf10, two genes that encode known stimulators of epithelial growth during odontogenesis. Consistent with this result, cell proliferation is reduced in both the dental epithelium and mesenchyme of double heterozygous mutants. Furthermore, the developing incisors lack mesenchymal Notch1 expression at the bud stage and exhibit abnormal ameloblast differentiation on both labial and lingual surfaces. Thus, Msx1 and Pax9 interact synergistically throughout lower incisor development and affect multiple signaling pathways that influence incisor size and symmetry. The data also suggest that a combined reduction of PAX9 and MSX1 gene dosage in humans may increase the risk for orofacial clefting and oligodontia.
Collapse
|
22
|
Effects of expectancy and abstinence on the neural response to smoking cues in cigarette smokers: an fMRI study. Neuropsychopharmacology 2006; 31:2728-38. [PMID: 16598192 DOI: 10.1038/sj.npp.1301075] [Citation(s) in RCA: 239] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Cues associated with drug taking can trigger relapse, drug seeking, and craving in addicted individuals. Behavioral studies suggest that drug availability and withdrawal can affect the individual response to drug cues. Moreover, the importance of subjective craving in cue-induced relapse has been questioned and an alternative model put forward according to which drug cues trigger habitual drug-seeking behaviors independently of craving. We used functional magnetic resonance imaging to compare the brain response to smoking and control videotapes in 20 healthy smokers, while varying their expectancy to smoke and abstinence levels. The neural response to cigarette cues was strongly modulated by expectancy and, to a lesser extent, abstinence. In people expecting to smoke immediately after the scan, smoking cues activated brain areas implicated in arousal, attention, and cognitive control. However, when subjects knew they would not be allowed to smoke for 4 h, there was almost no brain activation in response to smoking cues, despite equivalent reported levels of craving. In the dorsolateral prefrontal cortex, the neural response was a function of both craving and expectancy. Thalamo-cingulate connectivity, thought to be an index of arousal, was greater during expectancy than nonexpectancy. Our findings confirm the importance of expectancy in the neural response to drug cues, and lend support to the theory that these cues act on brain areas involved in arousal and attention.
Collapse
|
23
|
Pax9 is required for filiform papilla development and suppresses skin-specific differentiation of the mammalian tongue epithelium. Mech Dev 2004; 121:1313-22. [PMID: 15454262 DOI: 10.1016/j.mod.2004.07.002] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2004] [Revised: 07/01/2004] [Accepted: 07/02/2004] [Indexed: 10/26/2022]
Abstract
The epidermis is a derivative of the surface ectoderm. It forms a protective barrier and specific appendages including hair, nails, and different eccrine glands. The surface ectoderm also forms the epithelium of the oral cavity and tongue, which develop a slightly different barrier and form different appendages such as teeth, filiform papillae, taste papillae, and salivary glands. How this region-specific differentiation is genetically controlled is largely unknown. We show here that Pax9, which is expressed in the epithelium of the tongue but not in skin, regulates several aspects of tongue-specific epithelial differentiation. In Pax9-deficient mice filiform papillae lack the anterior-posterior polarity, a defect that is associated with temporal-spatial changes in Hoxc13 expression. Barrier formation is disturbed in the mutant tongue and genome-wide expression profiling revealed that the expression of specific keratins (Krt), keratin-associated proteins, and members of the epidermal differentiation complex is significantly down-regulated. In situ hybridization demonstrated that several 'hard' keratins, Krt1-5, Krt1-24, and Krt2-16, are not expressed in the absence of Pax9. Notably, specific 'soft' keratins, Krt2-1 and Krt2-17, normally weakly expressed in the tongue but present at high levels in skin and in orthokeratinized oral dysplasia are up-regulated in the mutant tongue epithelium. This result indicates a partial trans-differentiation to an epithelium with skin-specific characteristics. Together, our findings show that Pax9 regulates appendage formation in the mammalian tongue and identify Pax9 as an important factor for the region-specific differentiation of the surface ectoderm.
Collapse
|
24
|
Abstract
OBJECTIVES To quantify and compare fitness levels of middle aged practitioners of soo bahk do (SBD; a Korean martial art similar to karate) with those of sedentary subjects. METHODS Eighteen volunteers, 14 men and four women (aged 40-60 years), participated. Nine sedentary subjects (mean age 46.7 years) and nine SBD practitioners (mean age 46.8 years) were matched for sex and age. All subjects participated in a one day battery of fitness tests. The following dependent variables were tested: body composition, balance, flexibility, quadriceps strength, grip strength, muscle endurance, and aerobic capacity. RESULTS All dependent variables were analysed using paired t tests. Body composition (% body fat) for the SBD group was 18.9% v 30.8% for the sedentary group (p = 0.004). The SBD group was able to balance for 61.8 seconds v 26.2 seconds for the sedentary group (p = 0.02). The result for the sit and reach flexibility test was 22.3 cm for the SBD group v 10.4 cm for the sedentary group (p = 0.01). The number of push ups performed in one minute was 47.0 for the SBD group v 18.6 for the sedentary group (p = 0.0003), and the number of sit ups performed was 66.1 for the SBD group and 37.3 for the sedentary group (p = 0.00006). Aerobic capacity was 41.0 ml/kg/min v 31.1 ml/kg/min for the sedentary group (p = 0.04). Quadriceps strength was 99.5% (peak torque/body weight) v 83.0% for the sedentary group (p = 0.02). Only grip strength was not significantly different. CONCLUSIONS There were significant differences between the groups for most of the physical fitness tests. The SBD practitioners displayed greater aerobic capacity, balance, flexibility, muscle endurance, and strength, and less body fat than the sedentary controls matched for age and sex. SBD can be considered an excellent form of exercise for the promotion of fitness in adults. Health professionals should be aware that there are alternative methods to traditional exercise that can increase the physical fitness and health of the middle aged population.
Collapse
|