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2.
J Endourol ; 36(10): 1382-1387, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-35620899

RESUMEN

Background and Purpose: More than 40% of patients undergoing percutaneous nephrolithotomy (PCNL) are left with residual stone fragments and often require secondary procedures. Portable CT (PCT) technology allows surgeons to obtain intraoperative cross-sectional imaging, identify and extract residual stones immediately, and thereby reduce the need for subsequent procedures. This prospective trial evaluates how incorporation of PCT during PCNL affects perioperative outcomes. Patients and Methods: We prospectively enrolled eligible patients undergoing initial PCNL for this trial (n = 60), which entailed a single intraoperative CT abdomen and ipsilateral antegrade ureteroscopy when the surgeon felt stone treatment was visually complete. If residual fragments were identified, the surgeon continued nephroscopy to find and remove them; if not, the procedure was concluded. These patients were compared with a retrospective cohort (n = 174) who underwent initial PCNL with postoperative imaging performed the following day. Results: The two cohorts had similar demographic properties and stone characteristics, and location of percutaneous access. In the prospective arm, 50% of intraoperative PCT scans identified residual fragments, prompting continuation of surgery to remove them. This cohort had significantly higher stone-free rate (82% vs 36%, p < 0.01), lower rate of planned reintervention (7% vs 32%, p < 0.01), lower rate of urgent presentation with ureteral obstruction (0% vs 7%, p = 0.04), lower total CT-based effective radiation dose (8.4 mSv vs 14.6 mSv, p < 0.01), and shorter length of stay (2.3 days vs 3.5 days, p < 0.01) when compared with the retrospective cohort that did not use intraoperative PCT. Conclusions: Obtaining an intraoperative PCT scan during PCNL can substantially improve perioperative outcomes. Further evaluation of this modality through a randomized controlled trial is warranted. Clinical Trial Registration Number: NCT04556396.


Asunto(s)
Cálculos Renales , Nefrolitotomía Percutánea , Nefrostomía Percutánea , Humanos , Cálculos Renales/diagnóstico por imagen , Cálculos Renales/cirugía , Nefrostomía Percutánea/métodos , Estudios Prospectivos , Estudios Retrospectivos , Tomografía Computarizada por Rayos X , Resultado del Tratamiento
3.
Sci Rep ; 12(1): 8080, 2022 05 16.
Artículo en Inglés | MEDLINE | ID: mdl-35577817

RESUMEN

The carbon net negative conversion of bio-char, the low value byproduct of pyrolysis bio-oil production from biomass, to high value, very high purity, highly crystalline flake graphite agglomerates with rationally designed shape and size tailored for lithium-ion battery energy storage material is reported. The process is highly efficient, 0.41 g/Wh; the energy content of its co-product of the process, bio-oil, exceeds that needed to power the process. It is shown that the shape of the starting material is retained during the transformation, allowing the ultimate morphology of the graphite agglomerates to be engineered from relatively malleable biomass. In contrast to commercial graphite production, the process can be performed at small scale with low equipment costs, enabling individual research laboratories to produce Li-ion grade graphite with customizable shape, size and porosity for Si/graphite composite and other graphite involved anodes. The mechanism of the graphitization of bio-char, a "non-graphitizable" carbon, is explored, suggesting the molten metal catalyst is absorbed into the pore structure, transported through and transforming the largely immobile biochar. Finally, the transformation of biomass to rationally designed graphite morphologies with Li-ion anode performance that closely mimic commercial shaped graphite is demonstrated.


Asunto(s)
Grafito , Litio , Biomasa , Carbono/química , Suministros de Energía Eléctrica , Grafito/química , Iones/química , Litio/química
4.
Environ Sci Technol ; 55(18): 12414-12423, 2021 09 21.
Artículo en Inglés | MEDLINE | ID: mdl-34468124

RESUMEN

Understanding the transformation of graphitic carbon nitride (g-C3N4) is essential to assess nanomaterial robustness and environmental risks. Using an integrated experimental and simulation approach, our work has demonstrated that the photoinduced hole (h+) on g-C3N4 nanosheets significantly enhances nanomaterial decomposition under •OH attack. Two g-C3N4 nanosheet samples D and M2 were synthesized, among which M2 had more pores, defects, and edges, and they were subjected to treatments with •OH alone and both •OH and h+. Both D and M2 were oxidized and released nitrate and soluble organic fragments, and M2 was more susceptible to oxidation. Particularly, h+ increased the nitrate release rate by 3.37-6.33 times even though the steady-state concentration of •OH was similar. Molecular simulations highlighted that •OH only attacked a limited number of edge-site heptazines on g-C3N4 nanosheets and resulted in peripheral etching and slow degradation, whereas h+ decreased the activation energy barrier of C-N bond breaking between heptazines, shifted the degradation pathway to bulk fragmentation, and thus led to much faster degradation. This discovery not only sheds light on the unique environmental transformation of emerging photoreactive nanomaterials but also provides guidelines for designing robust nanomaterials for engineering applications.


Asunto(s)
Grafito , Nanoestructuras , Compuestos de Nitrógeno
5.
CJC Open ; 3(9): 1125-1131, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-33997751

RESUMEN

BACKGROUND: As a result of the COVID-19 pandemic first wave, reductions in ST-elevation myocardial infarction (STEMI) invasive care, ranging from 23% to 76%, have been reported from various countries. Whether this change had any impact on coronary angiography (CA) volume or on mechanical support device use for STEMI and post-STEMI mechanical complications in Canada is unknown. METHODS: We administered a Canada-wide survey to all cardiac catheterization laboratory directors, seeking the volume of CA use for STEMI performed during the period from March 1 2020 to May 31, 2020 (pandemic period), and during 2 control periods (March 1, 2019 to May 31, 2019 and March 1, 2018 to May 31, 2018). The number of left ventricular support devices used, as well as the number of ventricular septal defects and papillary muscle rupture cases diagnosed, was also recorded. We also assessed whether the number of COVID-19 cases recorded in each province was associated with STEMI-related CA volume. RESULTS: A total of 41 of 42 Canadian catheterization laboratories (98%) provided data. There was a modest but statistically significant 16% reduction (incidence rate ratio [IRR] 0.84; 95% confidence interval 0.80-0.87) in CA for STEMI during the first wave of the pandemic, compared to control periods. IRR was not associated with provincial COVID-19 caseload. We observed a 26% reduction (IRR 0.74; 95% confidence interval 0.61-0.89) in the use of intra-aortic balloon pump use for STEMI. Use of an Impella pump and mechanical complications from STEMI were exceedingly rare. CONCLUSIONS: We observed a modest 16% decrease in use of CA for STEMI during the pandemic first wave in Canada, lower than the level reported in other countries. Provincial COVID-19 caseload did not influence this reduction.


INTRODUCTION: Après la première vague de la pandémie de COVID-19, de nombreux pays ont déclaré une réduction de 23 % à 76 % des soins invasifs de l'infarctus du myocarde avec élévation du segment ST (STEMI). On ignore si ce changement a entraîné des répercussions sur le volume d'angiographies coronariennes (AC) ou sur l'utilisation des dispositifs d'assistance mécanique lors de STEMI et des complications mécaniques post-STEMI au Canada. MÉTHODES: Nous avons réalisé un sondage pancanadien auprès de tous les directeurs de laboratoire de cathétérisme cardiaque pour obtenir le volume d'utilisation des AC lors des STEMI réalisées durant la période du 1er mars 2020 au 31 mai 2020 (période de pandémie) et durant 2 périodes témoins (1er mars 2019 au 31 mai 2019 et 1er mars 2018 au 31 mai 2018). Le nombre de dispositifs d'assistance ventriculaire gauche utilisés et le nombre de cas de communications interventriculaires et de ruptures du muscle papillaire diagnostiqués ont également été enregistrés. Nous avons aussi évalué si le nombre de cas de COVID-19 enregistrés dans chaque province était associé au volume d'AC liées aux STEMI. RÉSULTATS: Au total, 41 des 42 laboratoires canadiens de cathétérisme (98 %) ont fourni des données. Lors de la comparaison de la première vague de la pandémie aux périodes témoins, nous avons noté une réduction modeste, mais significative, sur le plan statistique de 16 % (ratio du taux d'incidence [RTI] 0,84; intervalle de confiance à 95 % 0,80-0,87) des AC lors de STEMI. Le RTI n'était pas associé au nombre provincial de cas de COVID-19. Nous avons observé une réduction de 26 % (RTI 0,74; intervalle de confiance à 95 % 0,61-0,89) de l'utilisation de pompes à ballonnet intra-aortique lors de STEMI. L'utilisation d'une pompe Impella et les complications mécaniques après les STEMI étaient extrêmement rares. CONCLUSIONS: Nous avons observé une diminution modeste de 16 % de l'utilisation des AC lors de STEMI durant la première vague de la pandémie au Canada, soit une diminution plus faible que ce que les autres pays ont signalé. Le nombre provincial de cas de COVID-19 n'a pas influencé cette réduction.

6.
Can J Cardiol ; 33(9): 1201-1205, 2017 09.
Artículo en Inglés | MEDLINE | ID: mdl-28843330

RESUMEN

Once considered a childhood disease, the number of adults living with congenital heart disease (CHD) has now exceeded the number of pediatric patients. The landscape of percutaneous intervention for adult congenital heart disease (ACHD) has evolved over the past decade and has yet to be characterized in Canada. The aim of this study was to begin to understand the current infrastructure underlying ACHD interventions in Canada and to characterize the type and number of interventions being carried out across the country. A cross-sectional national survey was distributed by e-mail to all cardiac catheterization laboratory directors in 2015. All Canadian laboratories involved in ACHD interventions responded, encompassing 19 institutions spanning 69 cardiac catheterization laboratories. A total of 1451 percutaneous interventions were recorded. Nationwide, the most common simple ACHD interventions were for atrial septal defect and patent foramen ovale closures. The most common ACHD interventions of increased complexity were for coarctation stenting and transcatheter pulmonary valve implantation. There was a marked clustering of procedures in Ontario, Québec, British Columbia, and Alberta in keeping with Canada's population-density distribution. A total of 23 ACHD operators were identified, half of whom had ACHD-specific fellowship training. These data can be used as a starting point to inform the present state of affairs in the area and lay the groundwork for further work to assess resource allocation and human resource planning for the care of patients with ACHD in Canada.


Asunto(s)
Cateterismo Cardíaco/estadística & datos numéricos , Procedimientos Quirúrgicos Cardíacos/estadística & datos numéricos , Cardiopatías Congénitas/cirugía , Encuestas y Cuestionarios , Adulto , Canadá/epidemiología , Cateterismo Cardíaco/métodos , Procedimientos Quirúrgicos Cardíacos/métodos , Estudios Transversales , Cardiopatías Congénitas/epidemiología , Humanos , Incidencia
7.
Can J Cardiol ; 33(9): 1197-1200, 2017 09.
Artículo en Inglés | MEDLINE | ID: mdl-28314700

RESUMEN

Cardiovascular disease encompasses coronary artery disease and valvular heart disease, and the prevalence of both increases with age. Over the past decade, the landscape of interventional cardiology has evolved to encompass a new set of percutaneous procedures outside the coronary tree, including transcatheter aortic valve implantation, transcatheter mitral valve repair, and left atrial appendage occlusion. These interventions have sparked a new discipline within interventional cardiology referred to as structural heart disease (SHD) intervention. The access to and numbers of such procedures performed in Canada is currently unknown. This "first of its kind" survey of structural interventions provides insight into the landscape of SHD intervention in Canada and the challenges faced by cardiologists to deliver this important care.


Asunto(s)
Implantación de Prótesis Vascular/estadística & datos numéricos , Cateterismo Cardíaco/estadística & datos numéricos , Enfermedades de las Válvulas Cardíacas/cirugía , Encuestas y Cuestionarios , Implantación de Prótesis Vascular/métodos , Canadá/epidemiología , Cateterismo Cardíaco/métodos , Estudios Transversales , Enfermedades de las Válvulas Cardíacas/epidemiología , Humanos , Prevalencia , Estudios Retrospectivos
8.
PLoS One ; 9(10): e111037, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25343563

RESUMEN

OBJECTIVE: To assess residual cervical intraepithelial neoplasia (CIN) 2/3 disease and clearance of high-risk (hr) human papillomavirus (HPV) infections at 6 months after cryotherapy among HIV-positive women. DESIGN: Follow-up study. METHODS: 79 HIV-positive women received cryotherapy for CIN2/3 in Nairobi, Kenya, and underwent conventional cytology 6 months later. Biopsies were performed on high grade cytological lesions and hrHPV was assessed before (cervical cells and biopsy) and after cryotherapy (cells). RESULTS: At 6 months after cryotherapy CIN2/3 had been eliminated in 61 women (77.2%; 95% Confidence Interval, (CI): 66.4-85.9). 18 women (22.8%) had residual CIN2/3, and all these women had hrHPV at baseline. CD4 count and duration of combination antiretroviral therapy (cART) were not associated with residual CIN2/3. CIN3 instead of CIN2 was the only significant risk factor for residual disease (odds ratio, OR vs CIN2 = 4.3; 95% CI: 1.2-15.0) among hrHPV-positive women after adjustment for age and HPV16 infection. Persistence of hrHPV types previously detected in biopsies was found in 77.5% of women and was associated with residual CIN2/3 (OR = 8.1, 95% CI: 0.9-70). The sensitivity, specificity, and negative predictive value of hrHPV test in detecting residual CIN2/3 were 0.94, 0.36, and 0.96 respectively. CONCLUSIONS: Nearly one quarter of HIV-positive women had residual CIN2/3 disease at 6 months after cryotherapy, and the majority had persistent hrHPV. CD4 count and cART use were not associated with residual disease or hrHPV persistence. The value of hrHPV testing in the detection of residual CIN2/3 was hampered by a low specificity.


Asunto(s)
Crioterapia , Seropositividad para VIH/complicaciones , Seropositividad para VIH/virología , Neoplasia Residual/patología , Papillomaviridae/fisiología , Displasia del Cuello del Útero/terapia , Displasia del Cuello del Útero/virología , Adulto , Intervalos de Confianza , Femenino , Seropositividad para VIH/patología , Humanos , Kenia , Persona de Mediana Edad , Clasificación del Tumor , Neoplasia Residual/virología , Oportunidad Relativa , Displasia del Cuello del Útero/complicaciones , Displasia del Cuello del Útero/patología
9.
AIDS ; 27(18): 2909-19, 2013 Nov 28.
Artículo en Inglés | MEDLINE | ID: mdl-23842133

RESUMEN

BACKGROUND: A rigorous comparison of cervical cancer screening methods utilizing data on immune status, antiretroviral therapy (ART) and colposcopy-directed biopsy has not been performed among HIV-positive women. METHODS: Between June and November 2009, 500 HIV-positive women were enrolled at an HIV treatment clinic in Nairobi, Kenya, and underwent Papanicolau (Pap) smear, visual inspection with acetic acid (VIA), human papillomavirus (HPV) and colposcopy-directed biopsy (gold standard). Positive Pap smear (ASCUS+, LSIL+, HSIL+), VIA, HPV and their combinations were compared with CIN2/3+. Sensitivity, specificity and AUC (sensitivity and 1-specificity) were compared using pairwise tests and multivariate logistic regression models that included age, CD4⁺ cell count and ART duration. RESULTS: Of 500 enrolled, 498 samples were collected. On histology, there were 172 (35%) normal, 186 (37%) CIN1, 66 (13%) CIN2, 47 (9%) CIN3 and 27 (5%) indeterminate. Pap (ASCUS+) was the most sensitive screening method (92.7%), combination of both Pap (HSIL+) and VIA positive was the most specific (99.1%) and Pap (HSIL+) had the highest AUC (0.85). In multivariate analyses, CD4⁺ cell count of 350 cells/µl or less was associated with decreased HPV specificity (P = 0.002); ART duration of less than 2 years was associated with decreased HPV (P = 0.01) and VIA (P = 0.03) specificity; and age less than 40 years was associated with increased VIA sensitivity (P < 0.001) and decreased HPV specificity (P = 0.005). CONCLUSION: Pap smear is a robust test among HIV-positive women regardless of immune status or ART duration. Results should be cautiously interpreted when using HPV among those younger, immunosuppressed or on ART less than 2 years, and when using VIA among those aged 40 years or more.


Asunto(s)
Antirretrovirales/uso terapéutico , Detección Precoz del Cáncer/métodos , Infecciones por VIH/complicaciones , Infecciones por VIH/inmunología , Infecciones por Papillomavirus/diagnóstico , Neoplasias del Cuello Uterino/diagnóstico , Adolescente , Adulto , Factores de Edad , Biopsia , Recuento de Linfocito CD4 , Colposcopía/métodos , Femenino , Infecciones por VIH/tratamiento farmacológico , Histocitoquímica/métodos , Humanos , Kenia , Persona de Mediana Edad , Prueba de Papanicolaou/métodos , Infecciones por Papillomavirus/complicaciones , Sensibilidad y Especificidad , Factores de Tiempo , Neoplasias del Cuello Uterino/patología , Virología/métodos , Adulto Joven
10.
J Palliat Med ; 16(7): 768-73, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23718872

RESUMEN

BACKGROUND: Delirium is one of the most distressing and difficult to manage problems in advanced illness. Family caregivers have a unique view of the progression of delirium. OBJECTIVE: This study examined precursors to delirium from the perspective of family caregivers. DESIGN: This study utilized a two-stage concept mapping design that began with semistructured interviews with caregivers of patients suffering with delirium. The interview data was sorted and rated by clinicians prior to quantitative data analysis via multidimensional scaling (MDS) and cluster analysis. SUBJECTS/SETTINGS: The subjects were 20 family caregivers of patients with a diagnosis of delirium in a hospice inpatient unit. RESULTS: The main outcome of the study was a multidimensional model of precursors of delirium that included 99 specific items. The model included ten clusters within three general domains: Cognition, Distress, and Rest/Sleep. An exploratory analysis suggested that Rest and Sleep issues were evident to caregivers much earlier than other kinds of problems (mean=17.56 weeks prior to hospice admission, 95% CI=9.2-25.0 weeks). CONCLUSIONS: This study provides detailed insights from family caregivers about the progression of delirium. The caregiver observations were clustered by multivariate analysis to provide a map of symptom domains. The principal finding of this study is that sleep disturbance was identified by almost all family caregivers much earlier than other more commonly recognized symptoms associated with delirium. The study highlights the importance of sleep fragmentation in the temporal progression of delirium and points toward opportunities for improved measurement, prevention, and treatment.


Asunto(s)
Cuidadores/psicología , Delirio/diagnóstico , Cuidados Paliativos al Final de la Vida , Evaluación de Síntomas , Enfermo Terminal/psicología , Anciano , Anciano de 80 o más Años , Actitud del Personal de Salud , Confusión , Delirio/etiología , Delirio/psicología , Progresión de la Enfermedad , Femenino , Humanos , Entrevistas como Asunto , Masculino , Persona de Mediana Edad , Análisis Multivariante , Observación , Cuidados Paliativos/psicología , Agitación Psicomotora , Investigación Cualitativa , Trastornos del Sueño-Vigilia , Recursos Humanos
11.
AIDS ; 25(15): 1915-9, 2011 Sep 24.
Artículo en Inglés | MEDLINE | ID: mdl-21716072

RESUMEN

OBJECTIVE: To determine the effect of cryotherapy on HIV-1 cervical shedding. DESIGN: Prospective cohort study. METHODS: Five hundred HIV-positive women enrolled at an HIV treatment clinic in Nairobi, Kenya were screened for cervical cancer. Women diagnosed with cervical intraepithelial neoplasia stage 2 or 3 (CIN 2/3) by histology were offered cryotherapy treatment. The first 50 women had cervical swabs taken at baseline and at 2 and 4 weeks following treatment. Swabs were analyzed for HIV-1 RNA and compared using General Estimating Equation (GEE) with binomial or Gaussian links. RESULTS: Of the 50 women enrolled, 40 were receiving antiretroviral therapy (ART) and 10 were not receiving ART at the time of cryotherapy and during study follow-up. Among all women, the odds of detectable cervical HIV-1 RNA did not increase at 2 weeks [odds ratio (OR) 1.18; 95% confidence interval (CI) 0.65-2.13] or 4 weeks (OR 1.29; 95% CI 0.71-2.33) following cryotherapy. Among 10 women not receiving ART, the OR of detectable shedding at 2 weeks was higher, but not statistically significant (OR 4.02; 95% CI 0.53-30.79; P = 0.2), and at 4 weeks remained unchanged (OR 1.00; 95% CI 0.27-3.74). CONCLUSION: There was no increase in detectable cervical HIV-1 RNA among HIV-positive women after cryotherapy. The risk of HIV-1 transmission after cryotherapy may not be significant, particularly among women already on ART at the time of cervical treatment. However, further investigation is needed among women not receiving ART.


Asunto(s)
Crioterapia , Infecciones por VIH/patología , VIH-1 , Displasia del Cuello del Útero/terapia , Neoplasias del Cuello Uterino/terapia , Esparcimiento de Virus , Adulto , Estudios de Cohortes , Crioterapia/efectos adversos , Femenino , Infecciones por VIH/epidemiología , VIH-1/genética , Humanos , Kenia/epidemiología , Persona de Mediana Edad , Estadificación de Neoplasias , Estudios Prospectivos , ARN Viral , Neoplasias del Cuello Uterino/epidemiología , Neoplasias del Cuello Uterino/patología , Neoplasias del Cuello Uterino/virología , Displasia del Cuello del Útero/epidemiología , Displasia del Cuello del Útero/patología , Displasia del Cuello del Útero/virología
12.
Curr HIV Res ; 9(3): 180-5, 2011 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21585334

RESUMEN

BACKGROUND: The prevalence of cervical squamous intraepithelial lesions (SIL) among HIV-infected women on antiretroviral therapy in sub-Saharan Africa has not been well described. METHODS: HIV-infected women enrolled in an HIV treatment clinic in Nairobi, Kenya were offered free cervical screening with Papanicolaou (Pap) smear testing if they were 30 to 39 years of age and on antiretroviral therapy. Women with SIL were compared to those without SIL with univariate analyses and logistic regression. RESULTS: Of 595 eligible women, 267 accepted Pap testing and had available cytology results, of whom 258 (97%) were on a non-nucleoside reverse transcriptase inhibitor (NNRTI) based regimen. Median duration of antiretroviral therapy was 13 months [interquartile range (IQR), 8-19]. Abnormal cytology was found in 123 women (46%) with 70 women (26%) having low grade squamous intraepithelial lesions (LSIL), 22 (8%) high grade squamous intraepithelial lesions (HSIL), 30(11%) atypical squamous cells of unknown significance (ASCUS) and 1 (0.4%) atypical glandular cells (AGC). Women with SIL had lower median CD4 cell count (239 vs 287 cells/mm3; P=0.02), lower income (<70 USD per month: 57% vs 38%; P=0.01), and less regular condom use (24% vs 40%; P=0.02) compared to those with no SIL. Duration and type of antiretroviral regimen were not significantly associated with SIL. CONCLUSION: SIL is prevalent among women on antiretroviral therapy and is associated with immunosuppression, low income, and less frequent condom use. Cervical cancer screening and counseling on condom use should be routinely offered to HIV-infected women in antiretroviral treatment clinics in Africa.


Asunto(s)
Fármacos Anti-VIH/administración & dosificación , Infecciones por VIH/complicaciones , Infecciones por VIH/tratamiento farmacológico , Neoplasias de Células Escamosas/epidemiología , Displasia del Cuello del Útero/epidemiología , Adulto , Terapia Antirretroviral Altamente Activa/métodos , Condones/estadística & datos numéricos , Femenino , Humanos , Tolerancia Inmunológica , Kenia/epidemiología , Factores de Riesgo , Factores Socioeconómicos
13.
J Pharmacol Exp Ther ; 338(2): 598-604, 2011 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-21558439

RESUMEN

Steroidogenic acute regulatory protein facilitates the translocation of cholesterol to the inner mitochondrial membrane, thereby initiating steroidogenesis. At the inner mitochondrial membrane, cytochrome P450 side-chain cleavage enzyme converts cholesterol to pregnenolone, an oxidative process requiring electrons from NADPH. Pregnenolone then serves as the substrate for the formation of progesterone or dehydroepiandrosterone by downstream enzymes. Studies have shown that cigarette smoke (CS) influences steroid hormone levels. To better understand the underlying mechanisms, we used a mouse model to study the effects of chronic CS exposure on steroidogenesis. Through radioimmunoassay and metabolic conversion assays, we found that CS reduced progesterone and dehydroepiandrosterone without affecting cytochrome P450 side-chain cleavage enzyme or 3ß-hydroxysteroid dehydrogenase 2 expression. However, CS did reduce expression of cytochrome c oxidase IV (COX IV), a component of the mitochondrial complex that serves as the last enzyme in the electron transport chain. Small interfering RNA-mediated COX IV knockdown indeed decreased progesterone synthesis in steroidogenic cells. In summary, COX IV likely plays a role in steroidogenesis, and passive smoking may negatively affect steroidogenesis by disrupting the electron transport chain.


Asunto(s)
Deshidroepiandrosterona/biosíntesis , Complejo IV de Transporte de Electrones/antagonistas & inhibidores , Regulación Enzimológica de la Expresión Génica , Pregnenolona/biosíntesis , Progesterona/antagonistas & inhibidores , Fumar/metabolismo , Animales , Células COS , Chlorocebus aethiops , Deshidroepiandrosterona/antagonistas & inhibidores , Regulación hacia Abajo/genética , Complejo IV de Transporte de Electrones/biosíntesis , Femenino , Técnicas de Silenciamiento del Gen/métodos , Ratones , Ratones Endogámicos C57BL , Pregnenolona/antagonistas & inhibidores , Progesterona/biosíntesis , Distribución Aleatoria , Fumar/efectos adversos , Esteroides
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