Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
1.
Genome Res ; 32(3): 488-498, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35031571

RESUMO

Although it is known that the mutation rate varies across the genome, previous estimates were based on averaging across various numbers of positions. Here, we describe a method to measure the origination rates of target mutations at target base positions and apply it to a 6-bp region in the human hemoglobin subunit beta (HBB) gene and to the identical, paralogous hemoglobin subunit delta (HBD) region in sperm cells from both African and European donors. The HBB region of interest (ROI) includes the site of the hemoglobin S (HbS) mutation, which protects against malaria, is common in Africa, and has served as a classic example of adaptation by random mutation and natural selection. We found a significant correspondence between de novo mutation rates and past observations of alleles in carriers, showing that mutation rates vary substantially in a mutation-specific manner that contributes to the site frequency spectrum. We also found that the overall point mutation rate is significantly higher in Africans than in Europeans in the HBB region studied. Finally, the rate of the 20A→T mutation, called the "HbS mutation" when it appears in HBB, is significantly higher than expected from the genome-wide average for this mutation type. Nine instances were observed in the African HBB ROI, where it is of adaptive significance, representing at least three independent originations; no instances were observed elsewhere. Further studies will be needed to examine mutation rates at the single-mutation resolution across these and other loci and organisms and to uncover the molecular mechanisms responsible.


Assuntos
Globinas beta , Talassemia beta , Heterozigoto , Humanos , Mutação , Taxa de Mutação , Globinas beta/genética , Talassemia beta/genética
2.
Afr J Reprod Health ; 18(4): 123-5, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25854100

RESUMO

Retrograde ejaculation, sometimes called dry orgasm, refers to the medical condition when semen enters the urinary bladder (retrograde) instead of emerging through the penis after orgasm (antegrade). In some instances, a very minute quantity of antegrade semen appears in the ejaculate and may or may not be devoid of spermatozoa. Complete retrograde ejaculation causes male infertility. Intracytoplasmic sperm injection (ICSI) has been employed to achieve fertilization in some cases of male subfertility, e.g., severe oligoasthenoteratozoospermia. Assisted reproductive techniques to aid conception in cases of retrograde ejaculation have been described extensively elsewhere but there is paucity of knowledge on the occurrence and treatment in Africa. This case report describes the identification and successful treatment of a couple where the male partner suffered from retrograde ejaculation.


Assuntos
Ejaculação , Infertilidade Masculina , Injeções de Esperma Intracitoplásmicas/métodos , Coleta de Urina/métodos , Adulto , Feminino , Humanos , Infertilidade Masculina/diagnóstico , Infertilidade Masculina/etiologia , Infertilidade Masculina/fisiopatologia , Infertilidade Masculina/terapia , Infertilidade Masculina/urina , Masculino , Resultado do Tratamento
3.
J Med Case Rep ; 18(1): 28, 2024 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-38263261

RESUMO

BACKGROUND: Heterotopic pregnancies are increasing in incidence with the advent of rising prevalence of in vitro fertilization and embryo transfer (IVF-ET) globally. Although rare, this condition is a serious potentially life-threatening gynaecological complication. CASE PRESENTATION: We present the case of a 36-year-old Ghanaian woman who conceived following IVF and presented two weeks after confirmation of intrauterine gestation with sudden onset lower abdominal pain. A diagnosis of ruptured heterotopic pregnancy was made, laparotomy and salpingectomy was done followed with further management of the intrauterine gestation. CONCLUSION: To the best of our knowledge, this is the first reported case of heterotopic pregnancy in Ghana. A high index of suspicion for heterotopic pregnancy is required even in the presence of a confirmed intrauterine gestation following IVF-ET.


Assuntos
Gravidez Heterotópica , Feminino , Gravidez , Humanos , Adulto , Gana , Transferência Embrionária , Fertilização in vitro , Ultrassonografia de Intervenção
4.
J Reprod Infertil ; 23(4): 264-270, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36452196

RESUMO

Background: The objective of this study was to evaluate treatment outcomes and assess predictors of clinical pregnancy in obstructive azoospermia cases treated with testicular sperm extraction (TESE) and intracytoplasmic sperm injection (ICSI) in Ghana. Methods: This study was a retrospective study conducted on 67 men seeking treatment for obstructive azoospermia at two study sites in Ghana from January 2018 to December 2019. First, archived data were reviewed and treatment outcomes of cases of obstructive azoospermia from the hospital records were evaluated. Infertile men who met the inclusion criteria were recruited. Descriptive data were expressed in the form of frequencies and percentages. The dependent and independent variables were analyzed using multiple logistic regression and reported as odds ratios (ORs). The confidence interval (CI) was set at 95% and a p-value <0.05 was considered significant. Results: The mean age of male participants was 42.43±9.11 years (mean±SD) while the mean age of their partners was 32.89±5.73 years (mean±SD). The average duration of infertility before intervention was 5.01±3.60 years (mean±SD). Successful pregnancy was observed in 52.2% (35/67) of the participants. After adjusting for confounders, the rate of a successful clinical pregnancy was 0.07 lower for every additional year increase in the male's age [AOR=0.93 (95%CI=0.87-0.99), p=0.02]. Conclusion: Overall the rate of clinical pregnancy following TESE/ICSI from our study was 52.2%. A man's age was a strong predictor of successful clinical pregnancy among couples treated with TESE-ICSI for obstructive azoospermia in Ghana.

5.
JBRA Assist Reprod ; 20(3): 132-6, 2016 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-27584606

RESUMO

OBJECTIVE: The rate of infertility continues to be on the increase in the developing world. Similarly, the rates of blood-borne viral infections (BBVs) such as Human Immunodeficiency Virus (HIV), Hepatitis B virus (HBV) and Hepatitis C virus (HCV) are also on this rise. In 2014, the World Health Organization (WHO) quoted prevalences of 1.5% (HIV), 15% (HBV) 1.3 - 8.4% (HCV) in the Ghanaian general population. It has been reported that BBVs can adversely affect male fertility, specifically sperm count and progressive motility. The aim of this study was to evaluate the prevalence of BBVs in people with infertility attending an IVF clinic and whether or not BBVs impacted on sperm parameters. METHODS: A retrospective cohort study at a private fertility center in Accra, Ghana. We had 229 recruited couples assayed for HBV, HCV and HIV. Sperm parameters of the male partners were also assessed. The analysis performed included student t-test and Fisher's exact test. RESULTS: We found prevalence rates of 1.7% (HIV), 7.9% (HBV) and 0.4% (HCV), which is similar to what has already been reported in the Ghanaian community. There was no significant difference between BBV positive and negative subjects for sperm count (13.6 million/ml vs. 17.7 million/ml, P = 0.0599), percentage of progressive motility (26% vs. 30%, P = 0.2129), percentage of normal forms (3% vs. 3%, P = 0.0617) and clinical pregnancy rates per embryo transfer (36.1% vs 34.9%, P = 0.5) between BBV positive and BBV negative subjects, respectively. CONCLUSION: There is a similar prevalence of BBVs in sub-fertile couples and the general Ghanaian population. However, no detrimental effect has been reported for sperm parameters on grounds of BBV infectivity of the male partner.


Assuntos
Fertilização in vitro/estatística & dados numéricos , Infecções por HIV , Hepatite B , Hepatite C , Infertilidade , Adulto , Instituições de Assistência Ambulatorial , Feminino , Gana/epidemiologia , Infecções por HIV/complicações , Infecções por HIV/epidemiologia , Hepatite B/complicações , Hepatite B/epidemiologia , Hepatite C/complicações , Hepatite C/epidemiologia , Humanos , Infertilidade/complicações , Infertilidade/epidemiologia , Masculino , Auditoria Médica , Pessoa de Meia-Idade , Gravidez , Prevalência , Estudos Retrospectivos , Análise do Sêmen/estatística & dados numéricos , Adulto Jovem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA