Miguel Diaz - Academia.edu (original) (raw)
Papers by Miguel Diaz
Journal of Biosciences and Medicines, 2021
Background: COVID-19 is an ongoing global pandemic with paucity of the understanding of the natur... more Background: COVID-19 is an ongoing global pandemic with paucity of the understanding of the natural history of the disease and how it affects smokers. We aim to study the outcomes of COVID-19 in smokers in this descriptive review. Coronavirus disease 2019 caused by severe acute respiratory syndrome Coronavirus 2, gains entry to bronchial epithelial cells by attachment of the viral spike protein to Angiotensin-Converting Enzyme-2 (ACE-2) receptors. Accordingly, this review aims to understand the associated risk and worsen disease in relation to smoking and explore conflicting information regarding nicotine as well as its potential protective role. Methods: We conducted a nonsystematic review of databases with search engines such as, PubMed, Google Scholar with keywords like "COVID-19," "SARS-CoV-2," "novel coronavirus," smoking," "smokers," "nicotine." It included English articles related to the epidemiology of COVID-19 in adult smokers, containing systematic reviews, meta-analysis, prospective and retrospective cohort studies, cross-sectional studies, case series, and case reports based on the relevance of titles and abstracts to the topic. Results: A total of 33 articles were reviewed. Smokers were 1.4 times more likely to have severe COVID-19 (RR = 1.4, 95% CI: 0.98-2.00), and 2.4 times more likely to require an ICU admission (RR = 2.4, CI: 1.43-4.04) when compared to non-smokers (n = 926). Current smokers were less likely to experience an adverse outcome (OR: 0.42, 95% CI: 0.24-0.74), compared to former smokers. 22% of current smokers and 46% of former smokers had more severe complications compared to non-smokers with COVID-19 infection. Current smokers had a case fatality rate of 38.5% (n = 1790). They had higher odds of mortality compared to non-smokers (OR = 1.25), especially males > 65 years age (OR = 2.51). Tobacco smoke upregulates inflammatory cytokines like TNF-α, IL-1β, and neutrophils by activating NF-k. Hence, it leads to increased epithelial cell permeability, mucus production, and im
International Journal of Oncology, 2004
The primary form of therapy for prostate cancer is androgen ablation resulting in apoptosis and e... more The primary form of therapy for prostate cancer is androgen ablation resulting in apoptosis and expression of apoptotic genes (i.e. par-A). Prostate cancer cells that survive androgen ablation therapy express pro-survival genes (i.e. bcl-2) permitting these androgen independent (AI) cells to over come apoptotic signals and proliferate in the absence of normal growth signals. To disrupt tumor growth and progression to AI, we expressed the tumor suppressor gene, WT1 in LNCaP prostate tumor cells. The WT1 transcription factor modulates expression and activity of several prostate growth control genes (i.e. par-A, bcl-2 and AR) in vitro. To provide insight into potential mechanisms of prostate cancer growth suppression both the transcriptionally active form of wild-type WT1 (D) and an inactive WT1 (D) R394W mutant form were stably transfected in LNCaP cells. Surprisingly both transfected lines underwent apoptosis and were growth suppressed in nude mice. A 3-fold reduction in overall tumor incidence and volume was associated with increased apoptosis, as evidenced by DNA fragmentation and par-A expression, and was reduced or absent in early forming LNCaP tumors. After several months the indolent WT1-LNCaP cells became proliferative forming small tumors lacking par-4 protein. Although bcl-2 protein was present in all LNCaP tumors at this late-stage, it was detected in only a minority of WT1-LNCaP tumors, suggesting that pro-survival signals continued to be reduced in WT1suppressed tumor cells. While the mechanisms of WT1mediated growth suppression and apoptosis in LNCaP tumor cells are unknown, our results argue against simple trans criptional regulation since the mutant WT1 (D) R394W suppressed tumor formation similarly to wild-type WT1. This suggests that the mechanism of WTl-mediated growth suppression does not rely upon DNA binding at known WT1 recognition sites.
International Journal of Oncology, 2004
Chromosomal aneuploidy is associated with invasive bladder cancer and one of the genes implicated... more Chromosomal aneuploidy is associated with invasive bladder cancer and one of the genes implicated in these changes is Aurora-A/STK15/BTAK, that is localized on chromosome 20ql3 and encodes a centrosome-associated serine/threonine kinase. To better understand the association between Aurora-A/STK15 expression, tumor aneuploidy and clinical prognosis, we sought to determine whether overexpression of Aurora-A/STK15 in cultured urothelial cells facilitated chromosomal instability. Using immuno fluorescence staining, Northern and Western blot analyses, we verified that overexpression of Aurora-A/STK 15 in bladder tumor cell lines enhanced chromosomal instability. Additionally, we observed that some bladder tumor cell lines expressed more Aurora-A/STK15 than cultured normal urothelial cells and that Aurora-A/STK15 expression was higher in an immortalized E7 urothelial cell line having 20q amplification than in an E6 line lacking 20q amplification. These results were consistent with our observations of higher mRNA levels in some T3 invasive bladder tumors than in Tl superficial tumors and adjacent normal bladder tissue. Overall our results suggest that overexpression of Aurora-A/ STK 15 in bladder tumor cells contributes to tumor progression by promoting chromosomal instability leading to aneuploidy.
Biomédica : revista del Instituto Nacional de Salud
Salmonella Enteritidis is recognized worldwide as one of the main agents of human gastrointestina... more Salmonella Enteritidis is recognized worldwide as one of the main agents of human gastrointestinal infection. Several reports indicate the presence of isolates with decreased sensitivity to ciprofloxacin that can lead to a delayed response or the development of resistance during treatment. To describe and characterize isolates of Salmonella Enteritidis associated to an outbreak of food-borne diseases in Popayán, Cauca. Ten Salmonella Enteritidis isolates from nine patients and one food sample (chicken sandwich) were analyzed by biochemical tests, serotyping and antimicrobial sensitivity. The minimum inhibitory concentration to ciprofloxacin was determined by E-test and the genetic profile of the isolates was tested by pulsed field gel electrophoresis (PFGE) with XbaI and Blnl enzymes. Salmonella Enteritidis was identified in all isolates. They were resistant to nalidixic acid and had a decreased sensitivity to ciprofloxaxin between 0.25 and 0.5 μg/ml; all isolates were sensitive to ...
Investigative Radiology, 2002
Andreopouos D, Kasi LP, Kim EE, et al. Detection of acute postoperative mediastinitis in mice usi... more Andreopouos D, Kasi LP, Kim EE, et al. Detection of acute postoperative mediastinitis in mice using 99m Tc-liposomes. Invest Radiol 2002;37:435-439. RATIONALE AND OBJECTIVES. To evaluate the usefulness of size-modified 99m Tc-labeled liposomes for the detection of acute postoperative mediastinitis in a mouse model. METHODS. Fourteen mice underwent low-neck collar incision and had sterile abscesses induced in mediastinum with turpentine. Ten of these animals were injected intravenously with anionic liposomes of 516 ؎ 20 nm containing poly(ethylene)glycol labeled with 99m Tc; the remaining four mice were injected with 67 Ga citrate and used as positive controls. In addition, eight mice either underwent the same surgical procedure but without turpentine (n ؍ 4) or were not operated (n ؍ 4). These were used as negative controls. Therefore, scintigraphy using 99m Tc-liposomes was performed in eighteen and 67 Ga citrate in four mice. Target area of interest was outlined, and target to background count density ratio and percentage-injected dose were measured. RESULTS. Significant accumulation of radiolabeled liposomes was observed at sites of inflammation within 1 hour in abscess-bearing animals. This correlated well with the findings of the lower quality (contrast) of 67 Ga images at 24 and 48 hours. The radiopharmaceutical did not significantly accumulate in the mediastinum of negative control animals. CONCLUSION. 99m Tc-liposomes (size modified) may prove useful nonspecific agent for the early diagnosis of postoperativemediastinitis.
Journal of Biosciences and Medicines, 2021
Background: COVID-19 is an ongoing global pandemic with paucity of the understanding of the natur... more Background: COVID-19 is an ongoing global pandemic with paucity of the understanding of the natural history of the disease and how it affects smokers. We aim to study the outcomes of COVID-19 in smokers in this descriptive review. Coronavirus disease 2019 caused by severe acute respiratory syndrome Coronavirus 2, gains entry to bronchial epithelial cells by attachment of the viral spike protein to Angiotensin-Converting Enzyme-2 (ACE-2) receptors. Accordingly, this review aims to understand the associated risk and worsen disease in relation to smoking and explore conflicting information regarding nicotine as well as its potential protective role. Methods: We conducted a nonsystematic review of databases with search engines such as, PubMed, Google Scholar with keywords like "COVID-19," "SARS-CoV-2," "novel coronavirus," smoking," "smokers," "nicotine." It included English articles related to the epidemiology of COVID-19 in adult smokers, containing systematic reviews, meta-analysis, prospective and retrospective cohort studies, cross-sectional studies, case series, and case reports based on the relevance of titles and abstracts to the topic. Results: A total of 33 articles were reviewed. Smokers were 1.4 times more likely to have severe COVID-19 (RR = 1.4, 95% CI: 0.98-2.00), and 2.4 times more likely to require an ICU admission (RR = 2.4, CI: 1.43-4.04) when compared to non-smokers (n = 926). Current smokers were less likely to experience an adverse outcome (OR: 0.42, 95% CI: 0.24-0.74), compared to former smokers. 22% of current smokers and 46% of former smokers had more severe complications compared to non-smokers with COVID-19 infection. Current smokers had a case fatality rate of 38.5% (n = 1790). They had higher odds of mortality compared to non-smokers (OR = 1.25), especially males > 65 years age (OR = 2.51). Tobacco smoke upregulates inflammatory cytokines like TNF-α, IL-1β, and neutrophils by activating NF-k. Hence, it leads to increased epithelial cell permeability, mucus production, and im
International Journal of Oncology, 2004
The primary form of therapy for prostate cancer is androgen ablation resulting in apoptosis and e... more The primary form of therapy for prostate cancer is androgen ablation resulting in apoptosis and expression of apoptotic genes (i.e. par-A). Prostate cancer cells that survive androgen ablation therapy express pro-survival genes (i.e. bcl-2) permitting these androgen independent (AI) cells to over come apoptotic signals and proliferate in the absence of normal growth signals. To disrupt tumor growth and progression to AI, we expressed the tumor suppressor gene, WT1 in LNCaP prostate tumor cells. The WT1 transcription factor modulates expression and activity of several prostate growth control genes (i.e. par-A, bcl-2 and AR) in vitro. To provide insight into potential mechanisms of prostate cancer growth suppression both the transcriptionally active form of wild-type WT1 (D) and an inactive WT1 (D) R394W mutant form were stably transfected in LNCaP cells. Surprisingly both transfected lines underwent apoptosis and were growth suppressed in nude mice. A 3-fold reduction in overall tumor incidence and volume was associated with increased apoptosis, as evidenced by DNA fragmentation and par-A expression, and was reduced or absent in early forming LNCaP tumors. After several months the indolent WT1-LNCaP cells became proliferative forming small tumors lacking par-4 protein. Although bcl-2 protein was present in all LNCaP tumors at this late-stage, it was detected in only a minority of WT1-LNCaP tumors, suggesting that pro-survival signals continued to be reduced in WT1suppressed tumor cells. While the mechanisms of WT1mediated growth suppression and apoptosis in LNCaP tumor cells are unknown, our results argue against simple trans criptional regulation since the mutant WT1 (D) R394W suppressed tumor formation similarly to wild-type WT1. This suggests that the mechanism of WTl-mediated growth suppression does not rely upon DNA binding at known WT1 recognition sites.
International Journal of Oncology, 2004
Chromosomal aneuploidy is associated with invasive bladder cancer and one of the genes implicated... more Chromosomal aneuploidy is associated with invasive bladder cancer and one of the genes implicated in these changes is Aurora-A/STK15/BTAK, that is localized on chromosome 20ql3 and encodes a centrosome-associated serine/threonine kinase. To better understand the association between Aurora-A/STK15 expression, tumor aneuploidy and clinical prognosis, we sought to determine whether overexpression of Aurora-A/STK15 in cultured urothelial cells facilitated chromosomal instability. Using immuno fluorescence staining, Northern and Western blot analyses, we verified that overexpression of Aurora-A/STK 15 in bladder tumor cell lines enhanced chromosomal instability. Additionally, we observed that some bladder tumor cell lines expressed more Aurora-A/STK15 than cultured normal urothelial cells and that Aurora-A/STK15 expression was higher in an immortalized E7 urothelial cell line having 20q amplification than in an E6 line lacking 20q amplification. These results were consistent with our observations of higher mRNA levels in some T3 invasive bladder tumors than in Tl superficial tumors and adjacent normal bladder tissue. Overall our results suggest that overexpression of Aurora-A/ STK 15 in bladder tumor cells contributes to tumor progression by promoting chromosomal instability leading to aneuploidy.
Biomédica : revista del Instituto Nacional de Salud
Salmonella Enteritidis is recognized worldwide as one of the main agents of human gastrointestina... more Salmonella Enteritidis is recognized worldwide as one of the main agents of human gastrointestinal infection. Several reports indicate the presence of isolates with decreased sensitivity to ciprofloxacin that can lead to a delayed response or the development of resistance during treatment. To describe and characterize isolates of Salmonella Enteritidis associated to an outbreak of food-borne diseases in Popayán, Cauca. Ten Salmonella Enteritidis isolates from nine patients and one food sample (chicken sandwich) were analyzed by biochemical tests, serotyping and antimicrobial sensitivity. The minimum inhibitory concentration to ciprofloxacin was determined by E-test and the genetic profile of the isolates was tested by pulsed field gel electrophoresis (PFGE) with XbaI and Blnl enzymes. Salmonella Enteritidis was identified in all isolates. They were resistant to nalidixic acid and had a decreased sensitivity to ciprofloxaxin between 0.25 and 0.5 μg/ml; all isolates were sensitive to ...
Investigative Radiology, 2002
Andreopouos D, Kasi LP, Kim EE, et al. Detection of acute postoperative mediastinitis in mice usi... more Andreopouos D, Kasi LP, Kim EE, et al. Detection of acute postoperative mediastinitis in mice using 99m Tc-liposomes. Invest Radiol 2002;37:435-439. RATIONALE AND OBJECTIVES. To evaluate the usefulness of size-modified 99m Tc-labeled liposomes for the detection of acute postoperative mediastinitis in a mouse model. METHODS. Fourteen mice underwent low-neck collar incision and had sterile abscesses induced in mediastinum with turpentine. Ten of these animals were injected intravenously with anionic liposomes of 516 ؎ 20 nm containing poly(ethylene)glycol labeled with 99m Tc; the remaining four mice were injected with 67 Ga citrate and used as positive controls. In addition, eight mice either underwent the same surgical procedure but without turpentine (n ؍ 4) or were not operated (n ؍ 4). These were used as negative controls. Therefore, scintigraphy using 99m Tc-liposomes was performed in eighteen and 67 Ga citrate in four mice. Target area of interest was outlined, and target to background count density ratio and percentage-injected dose were measured. RESULTS. Significant accumulation of radiolabeled liposomes was observed at sites of inflammation within 1 hour in abscess-bearing animals. This correlated well with the findings of the lower quality (contrast) of 67 Ga images at 24 and 48 hours. The radiopharmaceutical did not significantly accumulate in the mediastinum of negative control animals. CONCLUSION. 99m Tc-liposomes (size modified) may prove useful nonspecific agent for the early diagnosis of postoperativemediastinitis.