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1.
Assist Technol ; 36(3): 241-247, 2024 May 03.
Artículo en Inglés | MEDLINE | ID: mdl-38289978

RESUMEN

Adolescents with CP classified as Gross Motor Functional Classification System Level V attend school up to 8 h daily with limited ability to self-reposition. Despite pain reported within this population, perceived pain and self-pressure relief during prolonged classroom sitting is unknown. A case series design was used with a convenience sample of six students (13-18 years) with CP. Pain assessments were taken every 30 min for 5 h. Self-relief assessments using the SensiMATTM were recorded while students were in their wheelchairs. One student self-reported pain and three students proxy reported pain movements. All students had unrelieved pressure or did not self-relieve pressure for at least 1.5 consecutive hours. Four students increased their self-pressure relief movements after 3.5 h. This study provided preliminary data regarding perceived pain and self-pressure relief during prolonged sitting and demonstrated that the SensiMATTM can capture pressure relief movements in sitting of students with severe CP. Although there was no trend of reported pain, students may either be moving enough, as demonstrated by recorded pressure relief movements, to independently relieve pressure and pain, or current pain assessments may not be sensitive enough for those with the most severe disabilities.


Asunto(s)
Parálisis Cerebral , Humanos , Adolescente , Parálisis Cerebral/fisiopatología , Parálisis Cerebral/rehabilitación , Masculino , Femenino , Dimensión del Dolor , Dolor , Presión , Silla de Ruedas , Manejo del Dolor/métodos
2.
Cancer Med ; 12(1): 472-487, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-35691022

RESUMEN

BACKGROUND: Reproductive history and genetics are well-known risk factors of breast cancer (BC). Little is known about how these factors interact to effect BC. This study investigated the association of ten polymorphisms in DNA repair genes with BC susceptibility in the Tanzanian samples and further analyzed the association between reproductive risk factors and disease risk METHODS: A hospital-based case-control study in 263 histopathological confirmed BC patients and 250 age-matched cancer-free controls was carried out. Allelic, genotypic, and haplotype association analyses were executed. Also, multifactor dimensionality reduction (MDR), and interaction dendrogram approaches were performed. RESULTS: The frequency of genotypic and allelic variants of XRCC1-Arg399Gln (rs25487), XRCC2-Arg188His (rs3218536), XRCC3-Thr241Met (rs861539), XPG-Asp1104His (rs17655), and MSH2-Gly322Asp (rs4987188) were significantly different between the groups (p < 0.05). Moreover, XRCC1-Arg399Gln (rs25487), XRCC3-Thr241Met (rs861539), and XPG-Asp1104His (rs17655) were associated with the increased risk of BC in co-dominant, dominant, recessive, and additive genetic-inheritance models (p < 0.05). XRCC1-Arg/Gln genotype indicated a 3.1-fold increased risk of BC in pre-menopausal patients (p = 0.001) while XPG-His/His genotype showed a 1.2-fold increased risk in younger BC patients (<40 years) (p = 0.028). Asp/His+His/His genotypes indicated a 1.3-fold increased risk of BC in PR+ patients and a 1.1-fold decreased risk of BC in luminal-A patients (p = 0.014, p = 0.020, respectively). MDR analysis revealed a positive interaction between BC and the XPG-Asp1104His (rs17655) together with family history of cancer in the first-degree relatives. Dendrogram analysis indicated that the XPG-Asp1104His (rs17655) and family history of cancer in first-degree relatives were significantly synergistic and might be associated with an elevated risk of BC in Tanzania. CONCLUSIONS: The XPG-Asp1104His (rs17655) might exert both independent and interactive effects on BC development in the Tanzanian women.


Asunto(s)
Neoplasias de la Mama , Humanos , Femenino , Tanzanía/epidemiología , Neoplasias de la Mama/epidemiología , Neoplasias de la Mama/genética , Historia Reproductiva , Estudios de Casos y Controles , Factores de Riesgo , Genotipo , Predisposición Genética a la Enfermedad , Polimorfismo de Nucleótido Simple , Reparación del ADN , Proteína 1 de Reparación por Escisión del Grupo de Complementación Cruzada de las Lesiones por Rayos X/genética , Proteínas de Unión al ADN/genética
3.
Cancer Med ; 12(3): 3395-3409, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-35908255

RESUMEN

BACKGROUND: Growing prevalence and aggressiveness of breast cancer (BC) among East African women strongly indicate that the genetic risk factor implicated in the etiology of the disease may have a key role. Germline pathogenic variants in BRCA1 and BRCA2 (BRCA1/2) are known to increase the lifetime risk of BC. This study investigated the prevalence and spectrum of germline single nucleotide variant/insertion and deletion (SNV/indel), and copy number variations (CNVs) in BRCA1/2 among Tanzanian BC patients, and evaluated the associations of identified variants with patient's socio-demographic and histopathological characteristics. METHODS: One hundred BC patients were examined for BRCA1/2 variants using next-generation sequencing (NGS). Sanger sequencing and multiplex ligation-dependent probe amplification (MLPA) assay were performed for the confirmation of SNV/indel and CNVs, respectively. RESULTS: Six germline SNV/indel pathogenic variants were detected from six unrelated patients. Five of these variants were identified in BRCA1, and one in BRCA2. We also identified, in one patient, one variant of uncertain clinical significance (VUS). CNV was not detected in any of the BC patients. Furthermore, we found that in our cohort, BRCA1/2 variant carriers were triple-negative BC patients (p = 0.019). CONCLUSIONS: Our study provides first insight into BC genetic landscape by the use of NGS in the under-represented East African Tanzanian populations. Our findings support the importance of genetic risk factors in BC etiology in Tanzania and showed a relatively high overall prevalence (6%) of germline BRCA1/2 pathogenic variants in BC patients. Therefore, our results indicate that BRCA1/2 pathogenic variants may well contribute to BC incidence in Tanzania. Thus, the identification of frequent variants in BRCA1/2 genes will enable implementation of rapid, inexpensive population-specific BRCA1/2 genetic testing, particularly for triple-negative BC patients known for their high prevalence in Tanzania. This will, in turn, greatly contributes to provide effective therapeutic strategies.


Asunto(s)
Neoplasias de la Mama , Neoplasias de la Mama Triple Negativas , Humanos , Femenino , Genes BRCA2 , Neoplasias de la Mama/patología , Variaciones en el Número de Copia de ADN , Tanzanía , Prevalencia , Predisposición Genética a la Enfermedad , Proteína BRCA1/genética , Mutación de Línea Germinal , Neoplasias de la Mama Triple Negativas/genética , Proteína BRCA2/genética
4.
BMC Womens Health ; 21(1): 423, 2021 12 20.
Artículo en Inglés | MEDLINE | ID: mdl-34930226

RESUMEN

BACKGROUND: Recent epidemiological studies suggest that reproductive factors are associated with breast cancer (BC) molecular subtypes. However, these associations have not been thoroughly studied in the African populations. The present study aimed to investigate the prevalence of BC molecular subtypes and assess their association with reproductive factors in Tanzanian BC patients. METHODS: This hospital-based case-only cross-sectional study consisted of 263 histologically confirmed BC patients in Tanzania. Clinico-pathological data, socio-demographic characteristics, anthropometric measurements, and reproductive risk factors were examined using the Chi-square test and one-way ANOVA. The association among reproductive factors and BC molecular subtypes was analyzed using multinomial logistic regression. The heterogeneity of the associations was assessed using the Wald test. RESULTS: We found evident subtype heterogeneity for reproductive factors. We observed that post-menopausal status was more prevalent in luminal-A subtype, while compared to luminal-A subtype, luminal-B and HER-2 enriched subtypes were less likely to be found in post-menopausal women (OR: 0.21, 95%CI 0.10-0.41, p = 0.001; OR: 0.39, 95%CI 0.17-0.89, p = 0.026, respectively). Also, the luminal-B subtype was more likely to be diagnosed in patients aged ≤ 40 years than the luminal-A subtype (OR: 2.80, 95%CI 1.46-5.32, p = 0.002). Women who had their first full-term pregnancy at < 30 years were more likely to be of luminal-B (OR: 2.71, 95%CI 1.18-4.17, p = 0.018), and triple-negative (OR: 2.28, 95%CI 1.02-4.07, p = 0.044) subtypes relative to luminal-A subtype. Furthermore, we observed that breastfeeding might have reduced odds of developing luminal-A, luminal-B and triple-negative subtypes. Women who never breastfed were more likely to be diagnosed with luminal-B and triple-negative subtypes when compared to luminal-A subtype (OR: 0.46, 95%CI 0.22-0.95, p = 0.035; OR: 0.41, 95%CI 0.20-0.85, p = 0.017, respectively). . CONCLUSION: Our results are the first data reporting reproductive factors heterogeneity among BC molecular subtypes in Tanzania. Our findings suggest that breast-feeding may reduce the likelihood of developing luminal-A, luminal-B, and triple-negative subtypes. Meanwhile, the first full-term pregnancy after 30 years of age could increase the chance of developing luminal-A subtype, a highly prevalent subtype in Tanzania. More interventions to promote modifiable risk factors across multiple levels may most successfully reduce BC incidence in Africa.


Asunto(s)
Neoplasias de la Mama , Adulto , Neoplasias de la Mama/diagnóstico , Estudios Transversales , Femenino , Humanos , Oportunidad Relativa , Embarazo , Receptor ErbB-2 , Receptores de Progesterona , Factores de Riesgo , Tanzanía/epidemiología
5.
Can Respir J ; 2021: 9621572, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34457096

RESUMEN

Asthmatics are at an increased risk of developing exacerbations after being infected by respiratory viruses such as influenza virus, parainfluenza virus, and human and severe acute respiratory syndrome coronaviruses (SARS-CoV). Asthma, especially when poorly controlled, is an independent risk factor for developing pneumonia. A subset of asthmatics can have significant defects in their innate, humoral, and cell-mediated immunity arms, which may explain the increased susceptibility to infections. Adequate asthma control is associated with a significant decrease in episodes of exacerbation. Because of their wide availability and potency to promote adequate asthma control, glucocorticoids, especially inhaled ones, are the cornerstone of asthma management. The current COVID-19 pandemic affects millions of people worldwide and possesses mortality several times that of seasonal influenza; therefore, it is necessary to revisit this subject. The pathogenesis of SARS-CoV-2, the virus that causes COVID-19, can potentiate the development of acute asthmatic exacerbation with the potential to worsen the state of chronic airway inflammation. The relationship is evident from several studies that show asthmatics experiencing a more adverse clinical course of SARS-CoV-2 infection than nonasthmatics. Recent studies show that dexamethasone, a potent glucocorticoid, and other inhaled corticosteroids significantly reduce morbidity and mortality among hospitalized COVID-19 patients. Hence, while we are waiting for more studies with higher level of evidence that further narrate the association between COVID-19 and asthma, we advise clinicians to try to achieve adequate disease control in asthmatics as it may reduce incidences and severity of exacerbations especially from SARS-CoV-2 infection.


Asunto(s)
Asma/complicaciones , Asma/prevención & control , COVID-19/complicaciones , Dexametasona/uso terapéutico , Glucocorticoides/uso terapéutico , COVID-19/mortalidad , COVID-19/terapia , Humanos
6.
Microbiol Resour Announc ; 10(16)2021 Apr 22.
Artículo en Inglés | MEDLINE | ID: mdl-33888498

RESUMEN

The genus Limnospira includes cyanobacterial species used for industrial production of dietary supplements and nutraceutical agents. The metagenome-assembled genome of Limnospira sp. strain BM01 from Big Momela Lake, Tanzania, was 6,228,312 bp long with a GC content of 44.8% and carried 4,921 proteins and 52 RNA genes, including 6 rRNA genes.

7.
Int J Gynaecol Obstet ; 154(2): 318-323, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-33277704

RESUMEN

OBJECTIVE: To determine factors associated with risk of preterm delivery among pregnant women delivering at Muhimbili National Hospital in Tanzania. METHODS: A 1:1 case-control study was conducted to assess maternal sociodemographic, lifestyle, and current and previous obstetric factors associated with risk of preterm delivery. Mothers of preterm infants were regarded as cases and those of term infants were controls. Chi-square test and logistic regression were used to assess association between the factors and risk of preterm delivery. RESULTS: A total of 222 case-control pairs were studied. Maternal type of employment (P = 0.039), previous preterm delivery (P = 0.002), previous spontaneous abortion (P = 0.004), uterine scar (P < 0.001), parity (P = 0.034), number of prenatal care visits (P = 0.032), premature rupture of membranes (PROM) (P < 0.001), placenta previa (P = 0.002), bleeding during second trimester (P = 0.004), pre-eclampsia (P < 0.001), and maternal anemia (P = 0.033) were associated with risk of preterm delivery. The main risk factors associated with preterm delivery included previous preterm delivery (odds ratio [OR] 13.23, 95% confidence interval [CI] 1.72-101.95), placenta previa (OR 12.63, 95% CI 1.63-97.98), and PROM (OR 8.77, 95% CI 1.33-4.60). CONCLUSION: Close monitoring of pregnant women who present any of the risk factors is important to prevent or reduce the risk of preterm delivery in Tanzania.


Asunto(s)
Rotura Prematura de Membranas Fetales/epidemiología , Placenta Previa/epidemiología , Nacimiento Prematuro/etiología , Aborto Inducido/efectos adversos , Aborto Espontáneo/epidemiología , Adulto , Estudios de Casos y Controles , Femenino , Hospitales , Humanos , Recién Nacido , Recien Nacido Prematuro , Paridad , Preeclampsia/epidemiología , Embarazo , Segundo Trimestre del Embarazo , Atención Prenatal , Factores de Riesgo , Tanzanía , Adulto Joven
8.
J Nematol ; 52: 1-8, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32180386

RESUMEN

Banana (Musa spp. L.) is an important staple food and cash crop for about 30% of the population in Tanzania; however, the burrowing plant-parasitic nematode Radopholus similis causes black head disease and toppling in banana plants, which results in yield losses. We collected and identified 80 specimens of R. similis from four agro-ecological zones in Tanzania using morphological characters. We then used universal and specific R. similis primers to amplify the small subunit, internal transcribed spacer and large subunit of ribosomal DNA regions of these specimens. The amplicons were subsequently sequenced and analyzed using Bayesian inference. We identified two major clades, one that comprised all R. similis sequences derived from this study and another that included R. similis and Radopholus spp. sequences obtained from GenBank, indicating the separation of this species from congeneric sequences. Our findings provide a useful, simple and rapid method for identifying burrowing nematodes. This outcome could contribute to the development of permanent, integrated pest management strategies for the control of R. similis in banana and other crops in order to reduce associated yield losses in Tanzania. To our knowledge, this is the first study of nematodes to use combined morphological and molecular methods for the identification of R. similis in Tanzania.Banana (Musa spp. L.) is an important staple food and cash crop for about 30% of the population in Tanzania; however, the burrowing plant-parasitic nematode Radopholus similis causes black head disease and toppling in banana plants, which results in yield losses. We collected and identified 80 specimens of R. similis from four agro-ecological zones in Tanzania using morphological characters. We then used universal and specific R. similis primers to amplify the small subunit, internal transcribed spacer and large subunit of ribosomal DNA regions of these specimens. The amplicons were subsequently sequenced and analyzed using Bayesian inference. We identified two major clades, one that comprised all R. similis sequences derived from this study and another that included R. similis and Radopholus spp. sequences obtained from GenBank, indicating the separation of this species from congeneric sequences. Our findings provide a useful, simple and rapid method for identifying burrowing nematodes. This outcome could contribute to the development of permanent, integrated pest management strategies for the control of R. similis in banana and other crops in order to reduce associated yield losses in Tanzania. To our knowledge, this is the first study of nematodes to use combined morphological and molecular methods for the identification of R. similis in Tanzania.

9.
Biomed Res Int ; 2019: 1486072, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31687378

RESUMEN

Newcastle disease is a devastating viral disease of chicken in low- and middle-income countries where the backyard production system is predominant. Marker-assisted selection of chickens that are resistant to Newcastle disease virus (NDV) is the promising strategy that needs to be explored. The aim of the present study was to investigate polymorphisms of the promoter region of the chicken Mx gene and association with Kuroiler, Sasso, and local Tanzanian chicken embryos' survival variability to virulent NDV infection. Chicken embryos were initially challenged with a minimum lethal dose of virulent NDV suspension and then were followed over time to gather information on their survival variability. Using the survival data, high and less susceptible cohorts were established, and a total of 88 DNA samples from high and less susceptible groups were genotypes by sequencing. Five single-nucleotide polymorphisms (SNPs), which were previously reported, were detected. Interestingly, for the first time, the findings demonstrated the association of the promoter region of chicken myxovirus-resistance (Mx) gene polymorphisms with chicken embryos' susceptibility to the virulent NDV challenge. At the genotypic level, the SNP4 G > A mutation that was located within the IFN-stimulating response element was associated (LR: 6.97, P=0.03) with chicken embryos' susceptibility to the virulent NDV challenge. An allele G frequency was higher in the less susceptible cohort, whereas an allele A frequency was higher in the high susceptible cohort. At the haplotype level, the haplotype group ACGC was associated (OR: 9.8, 95% CI: 1.06-79.43, P=0.042) with the same trait and had a resistant effect. In conclusion, the results have demonstrated the association of chicken Mx gene promoter polymorphisms and chicken embryos' survival variability to the virulent NDV challenge, and the information is useful for breeding programs designed to develop chicken genotypes that are resistant to Newcastle disease virus.


Asunto(s)
Embrión de Pollo/virología , Enfermedad de Newcastle/genética , Polimorfismo Genético/genética , Regiones Promotoras Genéticas/genética , Virulencia/genética , Alelos , Animales , Supervivencia Celular/genética , Pollos/virología , Frecuencia de los Genes/genética , Genotipo , Enfermedad de Newcastle/virología , Virus de la Enfermedad de Newcastle/genética , Polimorfismo de Nucleótido Simple/genética , Enfermedades de las Aves de Corral/etiología
10.
Gene ; 590(1): 18-28, 2016 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-27259668

RESUMEN

Despite successful use of Plant Growth Promoting Rhizobacteria (PGPR) in agriculture, little is known about specific mechanisms of gene regulation facilitating the effective communication between bacteria and plants during plant colonization. Active PGPR strain Bacillus atrophaeus UCMB-5137 was studied in this research. RNA sequencing profiles were generated in experiments where root exudate stimulations were used to mimic interactions between bacteria and plants. It was found that the gene regulation in B. atrophaeus UCMB-5137 in response to the root exudate stimuli differed from the reported gene regulation at similar conditions in B. amyloliquefaciens FZB42, which was considered as a paradigm PGPR. This difference was explained by hypersensitivity of UCMB-5137 to the root exudate stimuli impelling it to a sessile root colonization behavior through the CcpA-CodY-AbrB regulation. It was found that the transcriptional factor DegU also could play an important role in gene regulations during plant colonization. A significant stress caused by the root exudates on in vitro cultivated B. atrophaeus UCMB-5137 was noticed and discussed. Multiple cases of conflicted gene regulations showed scantiness of our knowledge on the regulatory network in Bacillus. Some of these conflicted regulations could be explained by interference of non-coding RNA (ncRNA). Search through differential expressed intergenic regions revealed 49 putative loci of ncRNA regulated by the root exudate stimuli. Possible target mRNA were predicted and a general regulatory network of B. atrophaeus UCMB-5137 genome was designed.


Asunto(s)
Bacillus/genética , Proteínas Bacterianas/genética , Regulación Bacteriana de la Expresión Génica , Redes Reguladoras de Genes , Raíces de Plantas/microbiología , ARN no Traducido/genética , Rhizobiaceae/genética , Bacillus/clasificación , Bacillus/metabolismo , Bacillus amyloliquefaciens/clasificación , Bacillus amyloliquefaciens/genética , Bacillus amyloliquefaciens/metabolismo , Proteínas Bacterianas/metabolismo , Biopelículas/crecimiento & desarrollo , Sitios Genéticos , Filogenia , ARN no Traducido/metabolismo , Rhizobiaceae/clasificación , Rhizobiaceae/metabolismo , Rizosfera , Análisis de Secuencia de ARN , Simbiosis , Zea mays/microbiología
11.
Hum Genet ; 131(5): 683-96, 2012 May.
Artículo en Inglés | MEDLINE | ID: mdl-22065085

RESUMEN

Mutations in the gene OCA2 are responsible for oculocutaneous albinism type 2, but polymorphisms in and around OCA2 have also been associated with normal pigment variation. In Europeans, three haplotypes in the region have been shown to be associated with eye pigmentation and a missense SNP (rs1800407) has been associated with green/hazel eyes (Branicki et al. in Ann Hum Genet 73:160-170, 2009). In addition, a missense mutation (rs1800414) is a candidate for light skin pigmentation in East Asia (Yuasa et al. in Biochem Genet 45:535-542, 2007; Anno et al. in Int J Biol Sci 4, 2008). We have genotyped 3,432 individuals from 72 populations for 21 SNPs in the OCA2-HERC2 region including those previously associated with eye or skin pigmentation. We report that the blue-eye associated alleles at all three haplotypes were found at high frequencies in Europe; however, one is restricted to Europe and surrounding regions, while the other two are found at moderate to high frequencies throughout the world. We also observed that the derived allele of rs1800414 is essentially limited to East Asia where it is found at high frequencies. Long-range haplotype tests provide evidence of selection for the blue-eye allele at the three haplotyped systems but not for the green/hazel eye SNP allele. We also saw evidence of selection at the derived allele of rs1800414 in East Asia. Our data suggest that the haplotype restricted to Europe is the strongest marker for blue eyes globally and add further inferential evidence that the derived allele of rs1800414 is an East Asian skin pigmentation allele.


Asunto(s)
Factores de Intercambio de Guanina Nucleótido/genética , Proteínas de Transporte de Membrana/genética , Europa (Continente) , Color del Ojo , Asia Oriental , Frecuencia de los Genes , Haplotipos , Humanos , Desequilibrio de Ligamiento , Polimorfismo de Nucleótido Simple , Selección Genética , Pigmentación de la Piel , Ubiquitina-Proteína Ligasas
12.
Am J Hum Genet ; 86(2): 161-71, 2010 Feb 12.
Artículo en Inglés | MEDLINE | ID: mdl-20116045

RESUMEN

The polymorphic inversion on 17q21, sometimes called the microtubular associated protein tau (MAPT) inversion, is an approximately 900 kb inversion found primarily in Europeans and Southwest Asians. We have identified 21 SNPs that act as markers of the inverted, i.e., H2, haplotype. The inversion is found at the highest frequencies in Southwest Asia and Southern Europe (frequencies of approximately 30%); elsewhere in Europe, frequencies vary from < 5%, in Finns, to 28%, in Orcadians. The H2 inversion haplotype also occurs at low frequencies in Africa, Central Asia, East Asia, and the Americas, though the East Asian and Amerindian alleles may be due to recent gene flow from Europe. Molecular evolution analyses indicate that the H2 haplotype originally arose in Africa or Southwest Asia. Though the H2 inversion has many fixed differences across the approximately 900 kb, short tandem repeat polymorphism data indicate a very recent date for the most recent common ancestor, with dates ranging from 13,600 to 108,400 years, depending on assumptions and estimation methods. This estimate range is much more recent than the 3 million year age estimated by Stefansson et al. in 2005.


Asunto(s)
Inversión Cromosómica/genética , Cromosomas Humanos Par 17/genética , Filogenia , Animales , Heterocigoto , Humanos , Hibridación Fluorescente in Situ , Irlanda , Repeticiones de Microsatélite/genética , Polimorfismo de Nucleótido Simple/genética , Primates/genética
13.
Bioorg Med Chem ; 17(15): 5520-5, 2009 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-19592260

RESUMEN

The blending of key structural features from the purine and pyrimidine nucleobase scaffolds gives rise to a new class of hybrid nucleosides. The purine-pyrimidine hybrid nucleosides can be viewed as either N-3 ribosylated purines or 5,6-disubstituted pyrimidines, thus recognition by both purine- and pyrimidine-metabolizing enzymes is possible. Given the increasing reports of the development of resistance in many enzymatic systems, a drug that could be recognized by more than one enzyme could prove highly advantageous in overcoming resistance mechanisms related to binding site mutations. In that regard, the design, synthesis and results of preliminary biological activity for a series of carbocyclic uracil derivatives with either a fused imidazole or thiazole ring are presented herein.


Asunto(s)
Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacología , Nucleósidos de Purina/química , Nucleósidos de Purina/farmacología , Nucleósidos de Pirimidina/química , Nucleósidos de Pirimidina/farmacología , Adenosilhomocisteinasa/antagonistas & inhibidores , Adenosilhomocisteinasa/metabolismo , Inhibidores Enzimáticos/síntesis química , Imidazoles/química , Estructura Molecular , Nucleósidos de Purina/síntesis química , Nucleósidos de Pirimidina/síntesis química , Tiazoles/química , Uracilo/síntesis química , Uracilo/química , Uracilo/farmacología
14.
Am J Hum Genet ; 81(4): 842-6, 2007 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-17847010

RESUMEN

The ADH1B Arg47His polymorphism has been convincingly associated with alcoholism in numerous studies of several populations in Asia and Europe. In a review of literature from the past 30 years, we have identified studies that report allele frequencies of this polymorphism for 131 population samples from many different parts of the world. The derived ADH1B*47His allele reaches high frequencies only in western and eastern Asia. To pursue this pattern, we report here new frequency data for 37 populations. Most of our data are from South and Southeast Asia and confirm that there is a low frequency of this allele in the region between eastern and western Asia. The distribution suggests that the derived allele increased in frequency independently in western and eastern Asia after humans had spread across Eurasia.


Asunto(s)
Alcohol Deshidrogenasa/genética , Alelos , Asia , Asia Occidental , Pueblo Asiatico/genética , Secuencia de Bases , Cartilla de ADN/genética , Flujo Génico , Frecuencia de los Genes , Flujo Genético , Humanos , Selección Genética
15.
Bioorg Med Chem ; 14(23): 7967-71, 2006 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-16904326

RESUMEN

The design, synthesis, and unexpected inhibitory activity against S-adenosyl-homocysteine (SAH) hydrolase (SAHase, EC 3.3.1.1) for a series of truncated carbocyclic pyrimidine nucleoside analogues is presented. Of the four nucleosides obtained, 10 was found to be active with a Ki value of 5.0 microM against SAHase.


Asunto(s)
Adenosilhomocisteinasa/antagonistas & inhibidores , Nucleósidos de Pirimidina/síntesis química , Nucleósidos de Pirimidina/farmacología , Diseño de Fármacos , Cinética , Relación Estructura-Actividad
16.
Forensic Sci Int ; 164(1): 20-32, 2006 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-16360294

RESUMEN

Single nucleotide polymorphisms (SNPs) are likely in the near future to have a fundamental role in forensics in both human identification and description. However, considerable research is necessary to establish adequate scientific foundations for these applications. In the case of identification, because allele frequencies can vary greatly among populations, the population genetics of match probabilities is a critical issue. Some SNPs, however, show little allele frequency variation among populations while remaining highly informative. We describe here both an efficient strategy for identifying and characterizing such SNPs, and test that strategy on a broad representation of world populations. Markers with high heterozygosity and little frequency variation among African American, European American, and East Asian populations are selected for additional screening on seven populations that provide a sampling of genetic variation from the world's major geographical regions. Those with little allele frequency variation on the seven populations are then screened on a total of 40 populations ( approximately 2100 individuals) and the most promising retained. The preliminary panel of 19 SNPs, from an initial selection of 195 SNPs, gives an average match probability of <10(-7) in most of 40 populations studied and no greater than 10(-6) in the most isolated, inbred populations. Expansion of this panel to approximately 50 comparable SNPs should give match probabilities of about 10(-15) with a small global range.


Asunto(s)
Dermatoglifia del ADN/métodos , Genética Forense/métodos , Genética de Población , Polimorfismo de Nucleótido Simple , Grupos Raciales/genética , Frecuencia de los Genes , Humanos , Reacción en Cadena de la Polimerasa
17.
Alcohol Clin Exp Res ; 29(12): 2091-100, 2005 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-16385178

RESUMEN

BACKGROUND: Of the seven known human alcohol dehydrogenase (ADH) genes, the non-liver expressed ADH7 gene codes for the enzyme with the highest maximal activity for ethanol. Previous study from our laboratory has suggested that ADH7 has an epistatic role for protection against alcoholism based on a single ADH7 SNP. METHODS: We have now studied seven SNPs, additional populations for the SNP previously examined, and six more new SNPs, across 23 kb of ADH7 in 38 population samples originating from different geographical regions of the world. RESULTS: The overall linkage disequilibrium is moderate to strong across this region even though considerable 7-SNP haplotype diversity is observed. This uncommonly high haplotype diversity is explained by high LD within each "half," the three upstream SNPs and the four downstream SNPs, but near randomization between the "halves." This division significantly simplified the haplotype pattern: only four major haplotypes account for almost all chromosomes in all populations in each "half." CONCLUSIONS: The low linkage disequilibrium between these two "halves" suggests multiple recombination(s) have occurred in this region, specifically, within intron 7. The absence of strong LD between the functional variation in ADH1B that is strongly associated with alcoholism and any of the variation in ADH7 supports the genetic independence of ADH7 in association studies. Thus, the previously observed epistatic effect of ADH7 cannot be explained by its linkage disequilibrium with a causative factor in ADH1B.


Asunto(s)
Alcohol Deshidrogenasa/genética , Alcoholismo/enzimología , Alcoholismo/genética , Alcoholismo/epidemiología , Alelos , ADN/genética , Etnicidad , Frecuencia de los Genes , Genotipo , Haplotipos/genética , Humanos , Desequilibrio de Ligamiento , Polimorfismo de Nucleótido Simple
18.
Ann Hum Genet ; 68(Pt 2): 93-109, 2004 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-15008789

RESUMEN

The catalytic deficiency of human aldehyde dehydrogenase 2 (ALDH2) is caused by a nucleotide substitution (G1510A; Glu487Lys) in exon 12 of the ALDH2 locus. This SNP, and four non-coding SNPs, including one in the promoter, span 40 kb of ALDH2; these and one downstream STRP have been tested in 37 worldwide populations. Only four major SNP-defined haplotypes account for almost all chromosomes in all populations. A fifth haplotype harbours the functional variant and is only found in East Asians. Though the SNPs showed virtually no historic recombination, LD values are quite variable because of varying haplotype frequencies, demonstrating that LD is a statistical abstraction and not a fundamental aspect of the genome, and is not a function solely of recombination. Among populations, different sets of tagging SNPs, sometimes not overlapping, can be required to identify the common haplotypes. Thus, solely because haplotype frequencies vary, there is no common minimum set of tagging SNPs globally applicable. The Fst values of the promoter region SNP and the functional SNP were about two S.D. above the mean for a reference distribution of 117 autosomal biallelic markers. These high Fst values may indicate selection has operated at these or very tightly linked sites.


Asunto(s)
Aldehído Deshidrogenasa/genética , Evolución Molecular , Flujo Genético , Recombinación Genética , Selección Genética , Aldehído Deshidrogenasa Mitocondrial , Alelos , Animales , Frecuencia de los Genes , Genotipo , Haplotipos , Hominidae/genética , Humanos , Desequilibrio de Ligamiento , Polimorfismo Genético , Polimorfismo de Nucleótido Simple , Secuencias Repetidas en Tándem
19.
Org Lett ; 5(23): 4401-3, 2003 Nov 13.
Artículo en Inglés | MEDLINE | ID: mdl-14602010

RESUMEN

[structure: see text] Isoadenosine (IsoA), a structural isomer of adenosine, was shown to possess interesting biological activity but was inherently unstable. In an effort to overcome this, we have designed a series of carbocyclic IsoA analogues, combining the unique connectivity of IsoA with the structural features of some biologically significant Neplanocin A analogues. Their design, synthesis, and structural elucidation is reported.


Asunto(s)
Adenosina/análogos & derivados , Adenosina/química
20.
Vet Rec ; 152(7): 199-201, 2003 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-12620034

RESUMEN

Freemartins are XX/XY chimaeras that develop as a result of the fusion of the placental circulation of at least one male and one female fetus. The pituitary glands of eight normal ewes at various stages of the oestrous cycle and three rams were compared with those of two male-type and three undifferentiated-type freemartins. The pituitaries were heaviest in the male-type freemartins, and their pattern of gonadotrophs, assessed by differential staining, was more intense than in the normal males. The pituitaries of the undifferentiated-type freemartins weighed less than those of the normal ewes but had more stained gonadotrophs than the normal ewes or rams. In both types of freemartins the pattern of cells resembled that of a castrated male.


Asunto(s)
Quimera , Hipófisis/patología , Enfermedades de las Ovejas/patología , Animales , Femenino , Masculino , Ovinos
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