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1.
Int J Environ Health Res ; : 1-25, 2024 Jun 23.
Artículo en Inglés | MEDLINE | ID: mdl-38909292

RESUMEN

Due to ongoing developmental projects, there is a need for regular monitoring of the impact of pollutants on the environment. This review documented the challenges and opportunities in the field of environmental health sciences in some African countries. A systematic review was used to investigate opportunities and challenges in the field of environmental health science in Africa by examining published work with a specific focus on Africa. The reports showed that funding and infrastructure as the major problems. The study also highlighted recruiting study participants, retention, and compensation as a bane in the field in Africa. The absence of modern equipment also hinders research. The review, however, noted research collaboration from the region including studies on emerging pollutants such as pharmaceuticals, per and polyfluoroalkyl substances (PFAS), and microplastic (MPs) as great opportunities. The study concluded that collaboration with other continents, exchange programs and improved governmental interventions may help.

2.
Toxicol Rep ; 12: 361-368, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38549679

RESUMEN

Milk may be consumed daily for the supply of essential nutrients in the body, however, depending on the source, milk may contain different concentrations of trace metals. The present study investigated the presence of trace metals in fresh milk purchased from different dairy farms and stores to determine the possible health risks to humans. A total of 15 fresh milk samples were purchased from various dairy farms (7 fresh milk samples) and stores (8 milk samples). Trace metals in collected milk samples were determined using Inductively Coupled Plasma Mass Spectrometer (ICP-MS). The human health risk was determined through the Hazard Quotient (HQ), Carcinogenic and Non-carcinogenic Risk. The results showed the presence of trace metals in fresh milk stores in the following order Pb>As>Se>Cr>Ni. The highest concentration for all the elements was recorded in Mg from milk purchased from the stores and ranged from 3.37±0.16 mg/L to 4.70±0.43 mg/L. In all the milk samples analyzed, levels of As, Pb, Se, Cr, and other elements were within the acceptable range recommended by the World Health Organization (WHO). Differences obtained in the concentrations of trace metals from both the purchased milk samples and those from the dairy farms were not significant (p<0.05). The Estimated Daily Intake (EDI) and Hazard Quotient Index showed no potential health risk for each trace metal indicating no health risk for the milk consumers at this stage. The traces of trace metals in the milk samples suggest the need for regular monitoring of trace metals in milk samples because prolonged exposure to these trace metals may seriously endanger the health of consumers.

3.
Front Genet ; 14: 1041103, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36923796

RESUMEN

Grasscutter (Thryonomys swinderianus) is a large-body old world rodent found in sub-Saharan Africa. The body size and the unique taste of the meat of this major crop pest have made it a target of intense hunting and a potential consideration as a micro-livestock. However, there is insufficient knowledge on the genetic diversity of its populations across African Guinean forests. Herein, we investigated the genetic diversity, population structures and evolutionary history of seven Nigerian wild grasscutter populations together with individuals from Cameroon, Republic of Benin, and Ghana, using five mitochondrial fragments, including D-loop and cytochrome b (CYTB). D-loop haplotype diversity ranged from 0.571 (± 0.149) in Republic of Benin to 0.921 (± 0.013) in Ghana. Within Nigeria, the haplotype diversity ranged from 0.659 (± 0.059) in Cross River to 0.837 (± 0.075) in Ondo subpopulation. The fixation index (FST), haplotype frequency distribution and analysis of molecular variance revealed varying levels of population structures across populations. No significant signature of population contraction was detected in the grasscutter populations. Evolutionary analyses of CYTB suggests that South African population might have diverged from other populations about 6.1 (2.6-10.18, 95% CI) MYA. Taken together, this study reveals the population status and evolutionary history of grasscutter populations in the region.

4.
Ann Ib Postgrad Med ; 21(2): 44-52, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38298343

RESUMEN

Background: Patients, post elective brain tumour surgeries, are usually admitted into the Intensive Care Unit (ICU) for quick identification of life-threatening complications or for elective ventilation. The Covid-19 pandemic exerted additional strain on the limited ICU spaces. This study was to probe the need for ICU admission following elective surgery for brain tumour in our environment on the background of enormous constraints. Methods: Data was collected prospectively from patients who had elective brain tumour surgery over 12-months at the University College Hospital, Ibadan. Data included the indications for ICU admission and outcome. Chi-square test and Student t-test were used for analysis at α ≤ 0.05. Results: There were 56 patients with a mean age of 44.6 years and M:F ratio of 1:1. 61.8% of the patients were admitted into the ICU for observation. Patients who had open surgeries were 2 times more likely to be admitted (p<0.01; OR = 2.2, CI: 2.0 - 36.8) than those who had endoscopic surgeries. Awake craniotomy patients did not require ICU care compared with the 63% of the patients who had General Anaesthesia + Endo Tracheal Tube (GA+ETT). Patients with skull base and posterior fossa tumours were more likely to be admitted into the ICU (p=0.036). Of the 34 patients admitted into the ICU, 11(19.6%) had prolonged ICU stay and were 2 times more likely to die compared with those with short admissions (p<0.01; OR = 2.5, CI: 2.29 - 70.02). Conclusion: Observation is the main reason patients are admitted into the ICU. The endoscopic and awake surgery approaches appear to preclude the need for ICU admission, thus capable of cutting costs.

5.
Mol Biol Evol ; 39(12)2022 Dec 05.
Artículo en Inglés | MEDLINE | ID: mdl-36413509

RESUMEN

African wild suids consist of several endemic species that represent ancient members of the family Suidae and have colonized diverse habitats on the African continent. However, limited genomic resources for African wild suids hinder our understanding of their evolution and genetic diversity. In this study, we assembled high-quality genomes of a common warthog (Phacochoerus africanus), a red river hog (Potamochoerus porcus), as well as an East Asian Diannan small-ear pig (Sus scrofa). Phylogenetic analysis showed that common warthog and red river hog diverged from their common ancestor around the Miocene/Pliocene boundary, putatively predating their entry into Africa. We detected species-specific selective signals associated with sensory perception and interferon signaling pathways in common warthog and red river hog, respectively, which contributed to their local adaptation to savannah and tropical rainforest environments, respectively. The structural variation and evolving signals in genes involved in T-cell immunity, viral infection, and lymphoid development were identified in their ancestral lineage. Our results provide new insights into the evolutionary histories and divergent genetic adaptations of African suids.


Asunto(s)
Adaptación Fisiológica , Animales , Porcinos , Filogenia , Especificidad de la Especie , Adaptación Fisiológica/genética , África
6.
Heliyon ; 7(9): e08025, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34589634

RESUMEN

The paper focuses on collection of information on recent multifaceted usage of biomass materials with critical examination on its sustainability. The use of biomass is becoming popular, with wide global acceptance as it is considered as green technology. The use of biomass products across industrial parallels, the material combination and production processes were elucidated in this paper. Biomass materials are seen as affordable alternative to conventional materials for domestic and industrial applications. The multifaceted use of biomass, which includes, energy generation, metallurgical applications, construction purposes, reinforcement in metal matrix composite, microelectromechanical system, biochemical and traditional medicine were discussed. This underscores the need to develop a sustainable plan to meet with its diverse usage to be beyond laboratory efforts. This paper examined whether the availability of biomass can sustain its multifaceted usage or not. It also examined the modalities to ensure sustainable use of biomass. Different policies were highlighted and discussed in line with continuous multifaceted use of biomass.

8.
Genome Biol Evol ; 13(6)2021 06 08.
Artículo en Inglés | MEDLINE | ID: mdl-34009300

RESUMEN

Domestication of the helmeted guinea fowl (HGF; Numida meleagris) in Africa remains elusive. Here we report a high-quality de novo genome assembly for domestic HGF generated by long- and short-reads sequencing together with optical and chromatin interaction mapping. Using this assembly as the reference, we performed population genomic analyses for newly sequenced whole-genomes for 129 birds from Africa, Asia, and Europe, including domestic animals (n = 89), wild progenitors (n = 34), and their closely related wild species (n = 6). Our results reveal domestication of HGF in West Africa around 1,300-5,500 years ago. Scanning for selective signals characterized the functional genes in behavior and locomotion changes involved in domestication of HGF. The pleiotropy and linkage in genes affecting plumage color and fertility were revealed in the recent breeding of Italian domestic HGF. In addition to presenting a missing piece to the jigsaw puzzle of domestication in poultry, our study provides valuable genetic resources for researchers and breeders to improve production in this species.


Asunto(s)
Domesticación , Galliformes/genética , Genoma , Filogenia , Animales , Variación Genética , Masculino , Filogeografía , Selección Genética
9.
Mol Biol Evol ; 38(3): 876-890, 2021 03 09.
Artículo en Inglés | MEDLINE | ID: mdl-32986826

RESUMEN

Guenons (tribe Cercopithecini) are the most widely distributed nonhuman primate in the tropical forest belt of Africa and show considerable phenotypic, taxonomic, and ecological diversity. However, genomic information for most species within this group is still lacking. Here, we present a high-quality de novo genome (total 2.90 Gb, contig N50 equal to 22.7 Mb) of the mona monkey (Cercopithecus mona), together with genome resequencing data of 13 individuals sampled across Nigeria. Our results showed differentiation between populations from East and West of the Niger River ∼84 ka and potential ancient introgression in the East population from other mona group species. The PTPRK, FRAS1, BNC2, and EDN3 genes related to pigmentation displayed signals of introgression in the East population. Genomic scans suggest that immunity genes such as AKT3 and IL13 (possibly involved in simian immunodeficiency virus defense), and G6PD, a gene involved in malaria resistance, are under positive natural selection. Our study gives insights into differentiation, natural selection, and introgression in guenons.


Asunto(s)
Cercopithecus/genética , Introgresión Genética , Especiación Genética , Genoma , Selección Genética , Animales , Femenino , Inmunidad/genética
10.
Heliyon ; 6(7): e04444, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32695915

RESUMEN

Quenching is one of the major processes of heat treatment of medium carbon steel that aims at improving its mechanical properties. However, the effectiveness of this process is dependent on several control factors that must be maximized to obtain optimum results in terms of hardness, yield strength, ultimate tensile strength among others. This study aims at optimizing the process of improving the mechanical properties of medium carbon steel by varying some key factors like the quenchant used (A), heat treatment temperature (B), and soaking time (C). The measured responses in this study were the hardness, yield strength (YS), and ultimate tensile strength (UTS). Optimization was conducted in two stages. The first stage dealt with the mono-optimization of process parameters using Taguchi's Signal-to-Noise (S/N) ratio. A total of nine (9) experiments were performed based on standard L9 orthogonal array because each of the three control factors has three (3) levels. The second stage was multi-objective optimization using Taguchi-based grey relational analysis (GRA). The optimal conditions for hardness, YS, and UTS were obtained at A2B3C3, A3B2C3, and A3B3C3, respectively. Using ANOVA as statistical analysis, it was observed that the soaking time was the main control factor for all three measured responses (31.95% contribution ratio for hardness, 62.46%, and 66.76% for YS and UTS, respectively), while the quenchant had the least contribution. Analysis of the Taguchi-based GRA revealed that the results obtained are in total conformance to that of the Taguchi method, with soaking time having the highest contribution ratio of 69.41%.

11.
Sci Rep ; 10(1): 7097, 2020 04 27.
Artículo en Inglés | MEDLINE | ID: mdl-32341417

RESUMEN

The silver butter catfish (Schilbe intermedius) is widely distributed across African river systems. To date, information on its mitochondrial genetic diversity, population structure, and historical demography are not well-established. Herein, we combined newly generated mitochondrial cytochrome c oxidase (COI) subunit I gene sequences with previously published COI sequences in the global databases to reconstruct its phylogeography, population genetic structure, and historical demography. Results from the mtDNA phylogeography and species delimitation tests (Cluster algorithm - Species Identifier, Automatic Barcode Gap Discovery and Poison Tree Process model) revealed that S. intermedius comprises at least seven geographically defined matrilines. Although the overall haplotype diversity of S. intermedius was high (h = 0.90), results showed that East (Kenya) and West (Nigeria) African populations had low levels of haplotype diversity (h = ~0.40). In addition, population genetic polymorphism and historical demographics showed that S. intermedius populations in both East and West Africa underwent severe contractions as a result of biogeographic influences. The patterns of genetic diversity and population structure were consistent with adaptive responses to historical biogeographic factors and contemporary environmental variations across African river systems. This is suggestive of the influence of historical biogeographic factors and climatic conditions on population divergence of S. intermedius across African river systems. Given our discovery of previously underappreciated diversity within S. intermedius, we recommend that this species be considered for increased conservation and management.


Asunto(s)
Bagres/genética , Código de Barras del ADN Taxonómico , ADN Mitocondrial/genética , Variación Genética , Filogenia , Animales , Kenia , Nigeria , Filogeografía , Ríos
12.
Curr Zool ; 65(6): 713-724, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31857818

RESUMEN

Nigeria is an Afrotropical region with considerable ecological heterogeneity and levels of biotic endemism. Among its vertebrate fauna, reptiles have broad distributions, thus, they constitute a compelling system for assessing the impact of ecological variation and geographic isolation on species diversification. The red-headed rock agama, Agama agama, lives in a wide range of habitats and, thus, it may show genetic structuring and diversification. Herein, we tested the hypothesis that ecology affects its genetic structure and population divergence. Bayesian inference phylogenetic analysis of a mitochondrial DNA (mtDNA) gene recovered four well-supported matrilines with strong evidence of genetic structuring consistent with eco-geographic regions. Genetic differences among populations based on the mtDNA also correlated with geographic distance. The ecological niche model for the matrilines had a good fit and robust performance. Population divergence along the environmental axes was associated with climatic conditions, and temperature ranked highest among all environmental variables for forest specialists, while precipitation ranked highest for the forest/derived savanna, and savanna specialists. Our results cannot reject the hypothesis that niche conservatism promotes geographic isolation of the western populations of Nigerian A. agama. Thus, ecological gradients and geographic isolation impact the genetic structure and population divergence of the lizards. This species might be facing threats due to recent habitat fragmentation, especially in western Nigeria. Conservation actions appear necessary.

13.
Data Brief ; 21: 1496-1503, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-30510979

RESUMEN

The dataset represented in this article describe a diagnostic schedule for a defective LC-195V5 CNC milling machine using PERT. The efficiency of the technicians who repaired the CNC machine tools was measured based on fault location within the shortest possible time. A diagnostic schedule was developed which showed the sequential means of troubleshooting within a possible shortest time. Two approaches were employed. Forward Pass (FP), which involved the diagnosis from electrical parts through Computer (CNC) to mechanical components and Backward Pass (BP) which involved the diagnosis from computer component through electrical parts to mechanical parts. Three different levels of expertise (trials) were used for each of the mode of diagnosis and the time to diagnose each component part was recorded. Two separate PERT network diagrams were drawn based on the inter-relationship of the component parts of the machine and their Critical Paths were determined.

14.
Data Brief ; 21: 1552-1557, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-30480067

RESUMEN

The quality of steel rods used in structural applications has been subjected to continuous scrutiny by researchers in Nigeria. In this data article, the experimental data on the chemical and mechanical properties of steel rods from collapsed building sites and local steel plants have been reported. The chemical composition consisting of carbon, manganese, silicon, sulphur, phosphorus among other elements were recorded using an optical emission spectrometer. Some of the main elements were used to evaluate the carbon equivalent value and the results are reported in this article. The yield strength, ultimate tensile strength and percentage elongation were also presented as obtained from the universal testing machine. The hardness values of the steel rod samples were also presented.

15.
Data Brief ; 20: 1224-1228, 2018 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-30238031

RESUMEN

Several wastes can be instrumental in the improvement of the mechanical properties of medium carbon steel when quenched. The quenching media employed such as coconut water (CW), pap water (PW) and spent engine oil (SPE) have been largely considered as wastes. The data in this article are related to the research article titled "Mechanical Properties Improvement Evaluation of Medium Carbon Steels Quenched in Different Media" (Ikubanni et al., 2017) [1]. The article provides information on the mechanical properties evaluation of medium carbon steel quenched in different media. Twenty-seven (27) samples of medium carbon steel samples were heated to temperatures of 730 °C, 760 °C and 790 °C and soaked for 30, 45 and 60 min respectively. The test results recorded include hardness value, yield strength (YS) and the ultimate tensile strength (UTS) for each of the samples at different heating temperatures and soaking time for the different quenching media.

16.
Ecol Evol ; 8(14): 6932-6951, 2018 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-30073057

RESUMEN

This study examines the utility of morphology and DNA barcoding in species identification of freshwater fishes from north-central Nigeria. We compared molecular data (mitochondrial cytochrome c oxidase subunit I (COI) sequences) of 136 de novo samples from 53 morphologically identified species alongside others in GenBank and BOLD databases. Using DNA sequence similarity-based (≥97% cutoff) identification technique, 50 (94.30%) and 24 (45.30%) species were identified to species level using GenBank and BOLD databases, respectively. Furthermore, we identified cases of taxonomic problems in 26 (49.00%) morphologically identified species. There were also four (7.10%) cases of mismatch in DNA barcoding in which our query sequence in GenBank and BOLD showed a sequence match with different species names. Using DNA barcode reference data, we also identified four unknown fish samples collected from fishermen to species level. Our Neighbor-joining (NJ) tree analysis recovers several intraspecific species clusters with strong bootstrap support (≥95%). Analysis uncovers two well-supported lineages within Schilbe intermedius. The Bayesian phylogenetic analyses of Nigerian S. intermedius with others from GenBank recover four lineages. Evidence of genetic structuring is consistent with geographic regions of sub-Saharan Africa. Thus, cryptic lineage diversity may illustrate species' adaptive responses to local environmental conditions. Finally, our study underscores the importance of incorporating morphology and DNA barcoding in species identification. Although developing a complete DNA barcode reference library for Nigerian ichthyofauna will facilitate species identification and diversity studies, taxonomic revisions of DNA sequences submitted in databases alongside voucher specimens are necessary for a reliable taxonomic and diversity inventory.

17.
Pediatr Radiol ; 47(3): 361-365, 2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-27878339

RESUMEN

Noonan syndrome is a genetic disorder with variable expression of distinctive facial features, webbed neck, chest deformity, short stature, cryptorchidism and congenital heart disease. The association of Noonan syndrome and giant cell granulomas of the mandible is widely reported. However, Noonan syndrome may also be associated with single or multifocal tenosynovial giant cell tumors, also referred to as pigmented villonodular synovitis. We report a child with Noonan syndrome, giant cell granulomas of the mandible and synovial and tenosynovial giant cell tumors involving multiple joints and tendon sheaths who was initially misdiagnosed with juvenile idiopathic arthritis. It is important for radiologists to be aware of the association of Noonan syndrome and multifocal giant cell lesions, which can range from the more commonly described giant cell granulomas of the mandible to isolated or multifocal intra- or extra-articular tenosynovial giant cell tumors or a combination of all of these lesions.


Asunto(s)
Tumor de Células Gigantes de las Vainas Tendinosas/diagnóstico por imagen , Tumores de Células Gigantes/diagnóstico por imagen , Neoplasias Mandibulares/diagnóstico por imagen , Síndrome de Noonan/complicaciones , Sinovitis Pigmentada Vellonodular/diagnóstico por imagen , Biopsia , Preescolar , Diagnóstico Diferencial , Tumor de Células Gigantes de las Vainas Tendinosas/complicaciones , Tumor de Células Gigantes de las Vainas Tendinosas/cirugía , Tumores de Células Gigantes/complicaciones , Tumores de Células Gigantes/cirugía , Humanos , Imagen por Resonancia Magnética , Masculino , Neoplasias Mandibulares/complicaciones , Neoplasias Mandibulares/cirugía , Sinovitis Pigmentada Vellonodular/complicaciones , Sinovitis Pigmentada Vellonodular/cirugía , Tomografía Computarizada por Rayos X
18.
Dis Esophagus ; 29(8): 1152-1158, 2016 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26663741

RESUMEN

The prognosis for locally advanced esophageal cancer is poor despite the use of trimodality therapy. In this phase II study, we report the feasibility, tolerability and efficacy of adjuvant sunitinib. Included were patients with stage IIa, IIB or III cancer of the thoracic esophagus or gastroesophageal junction. Neoadjuvant therapy involved Irinotecan (65 mg/m2 ) + Cisplatin (30 mg/m2 ) on weeks 1 and 2, 4 and 5, 7 and 8 with concurrent radiation (50Gy/25 fractions) on weeks 4-8. Sunitinib was commenced 4-13 weeks after surgery and continued for one year. Sixty-one patients were included in the final analysis, 36 patients commenced adjuvant sunitinib. Fourteen patients discontinued sunitinib due to disease recurrence (39%) within the 12-month period, 12 (33%) discontinued due to toxicity, and 3 (8%) requested cessation of therapy. In the overall population, median survival was 26 months with a 2 and 3-year survival rate of 52% and 35%, respectively. The median survival for the 36 patients treated with sunitinib was 35 months and 2-year survival probability of 68%. In a historical control, a prior phase II study with the same trimodality therapy (n = 43), median survival was 36 months, with a 2-year survival of 67%. Initiation of adjuvant sunitinib is feasible, but poorly tolerated, with no signal of additional benefit over trimodality therapy for locally advanced esophageal cancer.


Asunto(s)
Antineoplásicos/administración & dosificación , Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Neoplasias Esofágicas/terapia , Indoles/administración & dosificación , Pirroles/administración & dosificación , Adulto , Anciano , Antineoplásicos/efectos adversos , Quimioradioterapia , Quimioterapia Adyuvante/mortalidad , Cisplatino/administración & dosificación , Neoplasias Esofágicas/mortalidad , Neoplasias Esofágicas/patología , Esofagectomía , Unión Esofagogástrica/patología , Estudios de Factibilidad , Femenino , Humanos , Indoles/efectos adversos , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Terapia Neoadyuvante , Recurrencia Local de Neoplasia/mortalidad , Estadificación de Neoplasias , Periodo Posoperatorio , Pirroles/efectos adversos , Sunitinib , Tasa de Supervivencia , Privación de Tratamiento/estadística & datos numéricos
19.
Afr J Med Med Sci ; 44(1): 71-7, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26548118

RESUMEN

BACKGROUND: Struchium sparganophora is a medicinal herb useful in the treatment of pain, fever, arthritis, rheumatism, neurological and mental disorders in traditional system of medicine in Nigeria and some other African countries. This study was carried out to evaluate the anti-inflammatory and analgesic properties of Struchium sparganophora in mice. METHODS: The anti-inflammatory effect of Struchium sparganophora was evaluated using; carrageenan-induced paw oedema and histamine-induced paw oedema in mice. The analgesic properties of Struchium sparganophora were investigated utilizing; formalin, tail immersion and acetic acid-induced abdominal constriction tests in mice, respectively. RESULTS: Struchium sparganophora (100 - 400 mg/ kg; p.o) did not produce a dose dependent anti-oedematogenic activity against carrageenan and histamine induced paw oedema. Similarly, the leaf extract also exhibited analgesic effects that can be said to be active both centrally and peripherally in


Asunto(s)
Analgésicos/farmacología , Antiinflamatorios/farmacología , Asteraceae , Medicinas Tradicionales Africanas , Extractos Vegetales/farmacología , Animales , Modelos Animales de Enfermedad , Femenino , Dosificación Letal Mediana , Masculino , Ratones , Nigeria , Fitoterapia , Hojas de la Planta/química , Plantas Medicinales
20.
Clin Oncol (R Coll Radiol) ; 22(4): 265-71, 2010 May.
Artículo en Inglés | MEDLINE | ID: mdl-20398849

RESUMEN

AIMS: Uncertainty remains regarding the optimal therapy for patients with stage II or III rectal cancer. Systematic reviews and practice guidelines on preoperative and postoperative therapy for rectal cancer were published by the Gastrointestinal Cancer Disease Site Group in 2003 and 2000, respectively. The systematic reviews were updated and revised and new recommendations for preoperative and postoperative therapy were developed based on the updated body of evidence. The following research questions were addressed: After appropriate preoperative staging tests, should patients with resectable clinical stage II or III rectal cancer be offered preoperative radiotherapy (with or without chemotherapy)? What is the role of postoperative radiotherapy and/or chemotherapy for patients with resected stage II or III rectal cancer who have not received preoperative radiotherapy, in terms of improving survival and delaying local recurrence? MATERIALS AND METHODS: The MEDLINE, EMBASE and Cochrane Library databases, as well as meeting proceedings from the American Society of Clinical Oncology, were searched for reports of randomised controlled trials and meta-analyses comparing preoperative or postoperative therapy with surgery alone or other preoperative or postoperative therapy for stage II or III rectal cancer. The draft practice guideline and systematic reviews were distributed through a mailed survey to 129 health care providers in Ontario for review. RESULTS: Systematic reviews on preoperative and postoperative therapy for rectal cancer were developed. On the basis of the evidence contained in these reviews, the Gastrointestinal Cancer Disease Site Group drafted recommendations. Of the 33 practitioners who responded to the mailed survey, 97% agreed with the draft recommendations as stated, 88% agreed that the report should be approved as a practice guideline and 94% indicated that they were likely to use the guideline in their own practice. CONCLUSIONS: Preoperative chemoradiotherapy is preferred, compared with standard fractionation preoperative radiotherapy alone, to decrease local recurrence. Preoperative chemoradiotherapy is also preferred, compared with a postoperative approach, to decrease local recurrence and adverse effects. For patients with relative contraindications to chemotherapy in the preoperative period, an acceptable alternative is preoperative radiotherapy alone followed by surgery. Patients with resected stage II or III rectal cancer who have not received preoperative radiotherapy should be offered postoperative therapy with concurrent chemoradiotherapy plus fluoropyrimidine-based chemotherapy.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Neoplasias del Recto/tratamiento farmacológico , Neoplasias del Recto/radioterapia , Ensayos Clínicos como Asunto , Terapia Combinada , Humanos , Estadificación de Neoplasias , Cuidados Posoperatorios , Cuidados Preoperatorios , Dosificación Radioterapéutica , Neoplasias del Recto/patología
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