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Rubens FD, Ngu J, Malvea A, Samuels SJ, Burwash IG. Early Midterm Results After Valve Replacement With Contemporary Pericardial Prostheses for Severe Aortic Stenosis. Ann Thorac Surg 2020; 112:99-107. [PMID: 33080239 DOI: 10.1016/j.athoracsur.2020.08.029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Revised: 07/07/2020] [Accepted: 08/13/2020] [Indexed: 10/23/2022]
Abstract
BACKGROUND Clinical studies have demonstrated improved gradients after aortic valve replacement with the Trifecta (TR) valve (Abbott Cardiovascular, St Paul, MN) as compared with the Carpentier-Edwards Magna Ease (ME) valve (Edwards Lifesciences, Irvine, CA). Clinical benefits of this strategy have not been demonstrated. METHODS Patients undergoing aortic valve replacement for severe aortic stenosis with either valve were included. Patients were excluded if they underwent concomitant procedures other than coronary artery bypass grafting. Inverse proportion treatment weighting was used in the analysis. The primary outcome was a composite of cardiac mortality, need for reintervention, and freedom from first congestive heart failure (CHF). Secondary outcomes were all-cause mortality, the composite components, and cumulative CHF admission. Follow-up echocardiograms were assessed in a cohort of patients to assess structural valve degeneration. RESULTS There were 331 patients in the TR group and 360 patients in the ME group. The TR group had more women (48% vs 32%, P < .001) with smaller roots (left ventricular outflow tract diameter: TR, 2.11 cm; ME, 2.17 cm; P < .001). After weighting there was no significant difference in the composite measure between groups (P > .05). There was no difference in all-cause mortality (hazard ratio, 0.82; 95% confidence interval, 0.42-1.59; P = .56), and 5-year survival was 91.9% in the ME group and 93.4% in the TR group. There was no difference in cardiac death, reintervention, or first onset of CHF or incidence of structural valve degeneration between groups. There was no difference in the rate of admissions for CHF per 100 patients between the 2 valve types (P = .19). CONCLUSIONS Early hemodynamic benefits have not translated into differences in medium-term clinical outcomes between these 2 valves. Long-term follow-up is necessary.
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Affiliation(s)
- Fraser D Rubens
- Division of Cardiac Surgery, University of Ottawa Heart Institute, Ottawa, Ontario, Canada.
| | - Janet Ngu
- Division of Cardiac Surgery, University of Ottawa Heart Institute, Ottawa, Ontario, Canada
| | - Anahita Malvea
- Division of Cardiac Surgery, University of Ottawa Heart Institute, Ottawa, Ontario, Canada
| | - Steven J Samuels
- Department of Epidemiology and Preventive Medicine, University of California, Davis, Davis, California
| | - Ian G Burwash
- Division of Cardiology, University of Ottawa Heart Institute, Ottawa, Ontario, Canada
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Vo TX, Juanda N, Ngu J, Gawad N, LaBelle K, Rubens FD. Development of a median sternotomy simulation model for cardiac surgery training. JTCVS Tech 2020; 2:109-116. [PMID: 34317771 PMCID: PMC8298924 DOI: 10.1016/j.xjtc.2020.03.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 02/04/2020] [Accepted: 03/08/2020] [Indexed: 11/15/2022] Open
Abstract
Objective We sought to develop a simulation model to train resident physicians in the performance of a median sternotomy. Methods A modified Delphi consensus process was used with cardiac surgery staff to develop a 20-point checklist for the safe performance of a median sternotomy. Thirteen junior cardiac surgery trainees from across Canada participated in this study to assess the simulation model. Trainees performed the sternotomy before and after reviewing an instructional video. Two senior cardiac surgery resident physicians assessed the participants with the checklist during each session. An entry and exit questionnaire was given to the participants to evaluate the simulation model. Results Participants scored higher after the training (14.3 ± 2.0) compared with before training (8.0 ± 3.1) (P < .001). The mean duration of time for participants to complete the sternotomy was shorter before training (188 ± 52 seconds vs 228 ± 58 seconds; P = .003). The checklist interrater reliability was κ = 0.47 (moderate) for before training and κ = 0.37 (fair) for after training. All study participants rated the simulation sessions as very useful or extremely useful. Conclusions Using the simulation model, training video, and checklist, trainees were able to improve their skill in performing a median sternotomy. This improvement was associated with longer times to complete all procedure steps. Rater training may further improve interrater reliability. Our median sternotomy checklist and simulation model can be adopted for the technical skills training of future cardiac surgery trainees.
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Affiliation(s)
- Thin Xuan Vo
- Division of Cardiac Surgery, Department of Surgery, University of Ottawa Heart Institute, Ottawa, Ontario, Canada
| | - Nadzir Juanda
- Division of Cardiac Surgery, Department of Surgery, University of Ottawa Heart Institute, Ottawa, Ontario, Canada
| | - Janet Ngu
- Division of Cardiac Surgery, Department of Surgery, University of Ottawa Heart Institute, Ottawa, Ontario, Canada
| | - Nada Gawad
- Division of General Surgery, Department of Surgery, University of Ottawa, Ottawa, Ontario, Canada
| | - Kathy LaBelle
- University of Ottawa Skills and Simulation Centre, Ottawa, Ontario, Canada
| | - Fraser D. Rubens
- Division of Cardiac Surgery, Department of Surgery, University of Ottawa Heart Institute, Ottawa, Ontario, Canada
- Address for reprints: Fraser D. Rubens, MD, MSc, FACS, FRCSC, University of Ottawa Heart Institute, 40 Ruskin St, Ottawa, Ontario K1Y 4W7, Canada.
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Gharibeh L, Komati H, Bossé Y, Boodhwani M, Heydarpour M, Fortier M, Hassanzadeh R, Ngu J, Mathieu P, Body S, Nemer M. GATA6 Regulates Aortic Valve Remodeling, and Its Haploinsufficiency Leads to Right-Left Type Bicuspid Aortic Valve. Circulation 2019; 138:1025-1038. [PMID: 29567669 DOI: 10.1161/circulationaha.117.029506] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
BACKGROUND Bicuspid aortic valve (BAV), the most common congenital heart defect affecting 1% to 2% of the population, is a major risk factor for premature aortic valve disease and accounts for the majority of valve replacement. The genetic basis and mechanisms of BAV etiology and pathogenesis remain largely undefined. METHODS Cardiac structure and function was assessed in mice lacking a Gata6 allele. Human GATA6 gene variants were analyzed in 452 BAV cases from the BAV consortium and 1849 controls from the Framingham GWAS (Genome Wide Association Study). GATA6 expression was determined in mice and human tissues using quantitative real-time polymerase chain reaction and immunohistochemistry. Mechanistic studies were carried out in cultured cells. RESULTS Gata6 heterozygous mice have highly penetrant right-left (RL)-type BAV, the most frequent type in humans. GATA6 transcript levels are lower in human BAV compared with normal tricuspid valves. Mechanistically, Gata6 haploinsufficiency disrupts valve remodeling and extracellular matrix composition through dysregulation of important signaling molecules, including matrix metalloproteinase 9. Cell-specific inactivation of Gata6 reveals an essential role for GATA6 in secondary heart field myocytes because loss of 1 Gata6 allele from Isl- 1-positive cells-but not from endothelial or neural crest cells-recapitulates the phenotype of Gata6 heterozygous mice. CONCLUSIONS The data identify a new cellular and molecular mechanism underlying BAV. The availability of an animal model for the most frequent human BAV opens the way for the elucidation of BAV pathogenesis and the development of much needed therapies.
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Affiliation(s)
- Lara Gharibeh
- Department of Biochemistry, Microbiology, and Immunology, Molecular Genetics and Cardiac Regeneration Laboratory, University of Ottawa, Ontario, Canada (L.G., H.K., R.H., M.T., M.N.)
| | - Hiba Komati
- Department of Biochemistry, Microbiology, and Immunology, Molecular Genetics and Cardiac Regeneration Laboratory, University of Ottawa, Ontario, Canada (L.G., H.K., R.H., M.T., M.N.)
| | - Yohan Bossé
- Department of Molecular Medicine, Institut Universitaire de Cardiologie et de Pneumologie de Québec, Laval University, Canada (Y.B., P.M.)
| | - Munir Boodhwani
- Division of Cardiac Surgery, University of Ottawa Heart Institute, Ontario, Canada (M.B., J.N.)
| | - Mahyar Heydarpour
- Department of Biochemistry, Microbiology, and Immunology, Molecular Genetics and Cardiac Regeneration Laboratory, University of Ottawa, Ontario, Canada (L.G., H.K., R.H., M.T., M.N.)
| | | | - Romina Hassanzadeh
- Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA (M.H., S.B.)
| | - Janet Ngu
- Division of Cardiac Surgery, University of Ottawa Heart Institute, Ontario, Canada (M.B., J.N.)
| | - Patrick Mathieu
- Department of Molecular Medicine, Institut Universitaire de Cardiologie et de Pneumologie de Québec, Laval University, Canada (Y.B., P.M.)
| | - Simon Body
- Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA (M.H., S.B.)
| | - Mona Nemer
- Department of Biochemistry, Microbiology, and Immunology, Molecular Genetics and Cardiac Regeneration Laboratory, University of Ottawa, Ontario, Canada (L.G., H.K., R.H., M.T., M.N.)
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Ngu J, Tran D, Rubens F. Effect of Sex on Incidence of Post-Operative Atrial Fibrillation in Cardiac Surgery Patients. Can J Cardiol 2018. [DOI: 10.1016/j.cjca.2018.01.042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022] Open
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Labrosse MR, Jafar R, Ngu J, Boodhwani M. Planar biaxial testing of heart valve cusp replacement biomaterials: Experiments, theory and material constants. Acta Biomater 2016; 45:303-320. [PMID: 27570204 DOI: 10.1016/j.actbio.2016.08.036] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Revised: 07/22/2016] [Accepted: 08/19/2016] [Indexed: 12/13/2022]
Abstract
OBJECTIVES Aortic valve (AV) repair has become an attractive option to correct aortic insufficiency. Yet, cusp reconstruction with various cusp replacement materials has been associated with greater long-term repair failures, and it is still unknown how such materials mechanically compare with native leaflets. We used planar biaxial testing to characterize six clinically relevant cusp replacement materials, along with native porcine AV leaflets, to ascertain which materials would be best suited for valve repair. METHODS We tested at least six samples of: 1) fresh autologous porcine pericardium (APP), 2) glutaraldehyde fixed porcine pericardium (GPP), 3) St Jude Medical pericardial patch (SJM), 4) CardioCel patch (CC), 5) PeriGuard (PG), 6) Supple PeriGuard (SPG) and 7) fresh porcine AV leaflets (PC). We introduced efficient displacement-controlled testing protocols and processing, as well as advanced convexity requirements on the strain energy functions used to describe the mechanical response of the materials under loading. RESULTS The proposed experimental and data processing pipeline allowed for a robust in-plane characterization of all the materials tested, with constants determined for two Fung-like hyperelastic, anisotropic strain energy models. CONCLUSIONS Overall, CC and SPG (respectively PG) patches ranked as the closest mechanical equivalents to young (respectively aged) AV leaflets. Because the native leaflets as well as CC, PG and SPG patches exhibit significant anisotropic behaviors, it is suggested that the fiber and cross-fiber directions of these replacement biomaterials be matched with those of the host AV leaflets. STATEMENT OF SIGNIFICANCE The long-term performance of cusp replacement materials would ideally be evaluated in large animal models for AV disease and cusp repair, and over several months or more. Given the unavailability and impracticality of such models, detailed information on stress-strain behavior, as studied herein, and investigations of durability and valve dynamics will be the best surrogates, as they have been for prosthetic valves. Overall, comparison with Fig. 3 suggests that CC and SPG (respectively PG) patches may be the closest mechanical equivalents to young (respectively aged) AV leaflets. Interestingly, the thicknesses of these materials are close to those reported for porcine and younger human AV leaflets, which may facilitate surgical implantation, by contrast to the thinner APP which has poor handling qualities. Because the native leaflets as well as CC, PG and SPG patches exhibit anisotropic behaviors, from a mechanistic perspective alone, it stands to reason that cardiac surgeons should seek to intraoperatively match the fiber and cross-fiber directions of these replacement biomaterials with those of the repaired AV leaflets.
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Affiliation(s)
- Michel R Labrosse
- Department of Mechanical Engineering, University of Ottawa, 161 Louis Pasteur, Ottawa, Ontario K1N 6N5, Canada; Division of Cardiac Surgery, University of Ottawa Heart Institute, 40 Ruskin Street, Ottawa, Ontario K1Y 4W7, Canada.
| | - Reza Jafar
- Department of Mechanical Engineering, University of Ottawa, 161 Louis Pasteur, Ottawa, Ontario K1N 6N5, Canada; Division of Cardiac Surgery, University of Ottawa Heart Institute, 40 Ruskin Street, Ottawa, Ontario K1Y 4W7, Canada
| | - Janet Ngu
- Division of Cardiac Surgery, University of Ottawa Heart Institute, 40 Ruskin Street, Ottawa, Ontario K1Y 4W7, Canada
| | - Munir Boodhwani
- Division of Cardiac Surgery, University of Ottawa Heart Institute, 40 Ruskin Street, Ottawa, Ontario K1Y 4W7, Canada
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Ribeiro I, Ngu J, Tardioli K, Folch S, Gill G, Rubens F. HIGH FIDELITY BEATING HEART PORCINE MODEL FOR CARDIAC SURGERY AND CARDIOPULMONARY BYPASS TRAINING. Can J Cardiol 2016. [DOI: 10.1016/j.cjca.2016.07.296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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Ngu J, Rubens FD. It is the presence to be attuned to the needs of your community and to be mentally one step ahead of any disaster that may befall the people you lead and care for. Perfusion 2013; 29:4-5. [PMID: 24363271 DOI: 10.1177/0267659113513118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Abstract
Background—
Experimental cell therapy attenuates maladaptive cardiac remodeling and improves heart function. Paracrine mechanisms have been proposed. The effect of cell therapy on post infarction cardiac fibroblast and extracellular matrix (ECM) regulation was examined.
Methods and Results—
Vascular smooth muscle cells (VSMC) were injected into the border zone of subacute infarcted syngeneic Fischer rat hearts and compared with medium-injected controls. Twelve weeks post injection, cell-treated hearts showed preserved ECM content and attenuated structural chamber remodeling. Myofibroblast activation (α-smooth muscle actin expression) was decreased significantly, while basic fibroblast growth factor (bFGF) expression, a known inhibitor of transforming growth factor β-1–induced fibroblast differentiation, was increased. Matrix metalloproteinase-2 expression and activation by gelatin zymography was unchanged between groups, while its endogenous inhibitor, tissue inhibitors of matrix metalloproteinase (TIMP)-2, showed both increased expression and enhanced inhibitory capacity in cell-treated hearts. To define paracrine mechanisms, in vitro effects of VSMC conditioned media on myofibroblast activation were assessed by 3-D collagen gel contraction assay. VSMC conditioned media significantly inhibited collagen contraction, while a specific bFGF inhibitor abolished this paracrine response. TIMP-2 induced collagen contraction, but the effect was suppressed in the presence of bFGF.
Conclusions—
Extracellular matrix dysregulation post myocardial infarction is improved by cell therapy. These data suggest that cell transplantation attenuates myofibroblast activation and subsequent maladaptive structural chamber remodeling through paracrine mechanisms involving bFGF and TIMP-2.
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Affiliation(s)
- Paul W.M. Fedak
- From the Department of Cardiac Sciences, University of Calgary, Libin Cardiovascular Institute of Alberta, Alberta, Canada. Liping Bai was affiliated with Libin Cardiovascular Institute of Alberta at the time that this work was completed
| | - Liping Bai
- From the Department of Cardiac Sciences, University of Calgary, Libin Cardiovascular Institute of Alberta, Alberta, Canada. Liping Bai was affiliated with Libin Cardiovascular Institute of Alberta at the time that this work was completed
| | - Jeannine Turnbull
- From the Department of Cardiac Sciences, University of Calgary, Libin Cardiovascular Institute of Alberta, Alberta, Canada. Liping Bai was affiliated with Libin Cardiovascular Institute of Alberta at the time that this work was completed
| | - Janet Ngu
- From the Department of Cardiac Sciences, University of Calgary, Libin Cardiovascular Institute of Alberta, Alberta, Canada. Liping Bai was affiliated with Libin Cardiovascular Institute of Alberta at the time that this work was completed
| | - Kishan Narine
- From the Department of Cardiac Sciences, University of Calgary, Libin Cardiovascular Institute of Alberta, Alberta, Canada. Liping Bai was affiliated with Libin Cardiovascular Institute of Alberta at the time that this work was completed
| | - Henry J. Duff
- From the Department of Cardiac Sciences, University of Calgary, Libin Cardiovascular Institute of Alberta, Alberta, Canada. Liping Bai was affiliated with Libin Cardiovascular Institute of Alberta at the time that this work was completed
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Quakyi IA, Ndoutse L, Ngu J, Lohoue J, Fogako J, Befidi-Mengue R, Harun LT, Eno A, Walker-Abbey A, Folefack A, Alake G, Taylor DW, Tchinda V, Megnekou R, Ndountse L, Tietche F, Wansi E, Leke RG, Titanji V, Leke R, Sama G, Manga L, Johnson AH, Mvondo JL, Nyonglema P, Djokam R, Bomba-Nkolo C, Tsafack M, Hickey MA, Bigoga J, Bomba-Nkolo D, Kouontchou S, Meli J, Njeungue E, Metenou S, Same-Ekobo A. The epidemiology of Plasmodium falciparum malaria in two Cameroonian villages: Simbok and Etoa. Am J Trop Med Hyg 2000. [DOI: 10.4269/ajtmh.2000.63.222] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Quakyi IA, Leke RG, Befidi-Mengue R, Tsafack M, Bomba-Nkolo D, Manga L, Tchinda V, Njeungue E, Kouontchou S, Fogako J, Nyonglema P, Harun LT, Djokam R, Sama G, Eno A, Megnekou R, Metenou S, Ndountse L, Same-Ekobo A, Alake G, Meli J, Ngu J, Tietche F, Lohoue J, Mvondo JL, Wansi E, Leke R, Folefack A, Bigoga J, Bomba-Nkolo C, Titanji V, Walker-Abbey A, Hickey MA, Johnson AH, Taylor DW, Ndoutse L. The epidemiology of Plasmodium falciparum malaria in two Cameroonian villages: Simbok and Etoa. Am J Trop Med Hyg 2000; 63:222-30. [PMID: 11421368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023] Open
Abstract
In support of ongoing immunologic studies on immunity to Plasmodium falciparum, demographic, entomologic, parasitologic, and clinical studies were conducted in two Cameroonian villages located 3 km apart. Simbok (population = 907) has pools of water present year round that provide breeding sites for Anopheles gambiae, whereas Etoa (population = 485) has swampy areas that dry up annually in which A. funestus breed. Results showed that individuals in Simbok receive an estimated 1.9 and 1.2 infectious bites per night in the wet and dry season, respectively, whereas individuals in Etoa receive 2.4 and 0.4 infectious bites per night, respectively. Although transmission patterns differ, the rate of acquisition of immunity to malaria appears to be similar in both villages. A prevalence of 50-75% was found in children < 10 years old, variable levels in children 11-15 years old, and 31% in adults. Thus, as reported in other parts of Africa, individuals exposed to continuous transmission of P. falciparum slowly acquired significant, but not complete, immunity.
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Affiliation(s)
- I A Quakyi
- Department of Biology, Reiss Science Center, Georgetown University, Washington, District of Columbia 20057, USA
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Nkuo-Akenji T, Deas J, Leke R, Ngu J. Patterns of antibody levels to the 96 tR recombinant protein of Plasmodium falciparum in children over a six-month period. J Parasitol 1995; 81:195-9. [PMID: 7707194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Several Plasmodium falciparum asexual stage antigens have been reported as possible candidate antigens for vaccines against malaria. One such is the 96-kDa antigen. We used the 96 tR recombinant protein to determine the levels of antibodies to this protein over a 6-mo period in children 4 mo to 15 yr old, who make up the population at risk in Cameroon. The mean enzyme-linked immunosorbent assay (ELISA) on 83 children at the start of the study in June was 0.270, with 13% of these children having ELISA values considered to be positive (> or = 0.36). In the follow-up study in early December, the mean ELISA was 0.320 with 20% of the children having positive values. In the period between June and December, 85% of the children who returned for follow-up had had 1 or more attacks of malaria. The mean ELISA values of this latter group had increased from 0.235 in June to 0.318 in December, with 6% of the children in June having positive values compared with 18% in December. These findings reinforce our evidence from a previous study that reactivity to the 96-kDa antigen is related to adequate exposure or repeated infection.
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Affiliation(s)
- T Nkuo-Akenji
- Department of Life Sciences, Faculty of Science, University of Buea, Cameroon
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Nkuo-Akenji T, Deas J, Leke R, Ngu J. Patterns of Antibody Levels to the 96 tR Recombinant Protein of Plasmodium falciparum in Children over a Six-Month Period. J Parasitol 1995. [DOI: 10.2307/3283919] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Seligmann M, Pinching AJ, Rosen FS, Fahey JL, Khaitov RM, Klatzmann D, Koenig S, Luo N, Ngu J, Riethmüller G. Immunology of human immunodeficiency virus infection and the acquired immunodeficiency syndrome. An update. Ann Intern Med 1987; 107:234-42. [PMID: 3300461 DOI: 10.7326/0003-4819-107-2-234] [Citation(s) in RCA: 88] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Recent advances in the understanding of the pathogenesis of infection with human immunodeficiency virus (HIV) stems from the demonstration that the membrane glycoprotein, CD4, is the cellular receptor for HIV. This glycoprotein is found mainly on the surface of a major subpopulation of T lymphocytes and also on macrophages, natural killer cells, some B lymphocytes, and neuronal cells. Cells infected with HIV may be destroyed or have their normal function impaired. Host immune responses to HIV are poor and are not sustained. Neutralizing antibody often is not produced, or HIV may escape from normal immunosuppressive mechanisms through the process of rapid antigenic variation. Factors and markers that may be important in the outcome or that may predict progression of HIV infection are genetic (Gc type), environmental (nutritional status or intercurrent sexually transmitted diseases sustained by the host), and immunologic (rate of decline in number and impairment of function of CD4 lymphocytes and of decline in antibody titers to HIV core protein, p24). A recombinant vaccine will probably be developed for testing in future clinical trials.
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Ngu J, Youmbissi T. A comparative study with ceftriaxone (Rocephin) versus ampicillin and chloramphenicol in children with bacterial meningitis. Chemioterapia 1987; 6:417-8. [PMID: 3334588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- J Ngu
- CUSS-Department of Medicine, University of Yaoundé, Cameroon
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Abstract
Soluble antigen preparations were made from Onchocerca volvulus adults recovered from subcutaneous nodules, and from Necator americanus third-stage larvae. Intradermal skin tests were carried out on a total of 100 individuals clinically classified as having either the generalized form of onchocerciasis (86 cases, or the localized sowda form (14 cases). 91 of the people studied produced immediate reactions to the onchocercal antigen, but only those with sowda showed delayed reactions, though one person with generalized disease showed a doubtful delayed reaction. Reactions to N. americanus antigen, both immediate and delayed, were seen in both forms of the disease. The lack of delayed skin reaction in the generalized form of onchocerciasis is discussed, and a comparison is made with other diseases. Preliminary evidence for the existence of a true spectrum of clinical and immunological forms of onchocerciasis is suggested by one case in this study.
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Abstract
Three children in a West African family had Gaucher's disease of juvenile onset (Type 3), and all showed an identical neurological disorder. The diagnosis was substantiated by histochemical demonstration of Gaucher cells in bone marrow, liver, and spleen, the finding of an excess of glucosyl ceramides in a liver extract, and a deficient activity of the enzyme beta-glucosidase in cultured skin fibroblasts. The neurological picture was characterised by myoclonic epilepsy, muscle wasting, hypotonia, pyramidal signs, some intellectual deterioration, and a striking disturbance of eye movements. The latter appears to result from specific involvement of the supranuclear pathways subserving lateral gaze. The distinctive features of this clinical syndrome are emphasised.
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