European journal of clinical microbiology & infectious diseases : official publication of the European Society of Clinical Microbiology, Jan 18, 2015
Multidrug-resistant (MDR) and extensively drug-resistant (XDR) Gram-negative nosocomial pathogens... more Multidrug-resistant (MDR) and extensively drug-resistant (XDR) Gram-negative nosocomial pathogens commonly carry one carbapenemase gene conferring resistance to carbapenems and other beta-lactam antibiotics. However, increasing reports show that double-carbapenemase-producing (DCP) and even multi-carbapenemase-producing (MCP) bacteria are emerging in some parts of the world, diminishing further, in some cases, the already limited treatment options. In the present review, the up-to-date reports of DCP and MCP isolates are summarized and concerns regarding their emergence are discussed.
Heme oxygenase-1 (HO-1) is the enzyme that catabolizes heme into carbon monoxide, biliverdin, and... more Heme oxygenase-1 (HO-1) is the enzyme that catabolizes heme into carbon monoxide, biliverdin, and free iron. The induction of this enzyme is an important cytoprotective mechanism, which occurs as an adaptive and beneficial response to a wide variety of oxidant stimuli. HO-1 has recently been suggested to protect transplants from ischemia/reperfusion and immunologic injury. HO-1 inducibility is mainly modulated by a (GT)(n) repeat polymorphism in the promoter region, and has been shown that short repeats (S) are associated with greater upregulation of HO-1, compared with long repeats (L). In the present study we investigated the influence of this HO-1 gene polymorphism on clinical outcome after transplantation and on renal transplant function. DNA from 175 donor/recipient pairs who underwent transplantation between October 2002 and June 2007 was genotyped. We divided the HO-1 alleles into 2 subclasses, the S ≤ 27 repeats and L > 27 repeats. There has been significant relevance between the genotype of the donor and the outcome of the graft, as far as recipients with normal graft function and recipients with deteriorated graft function are concerned (P = .021). In patients with normal graft function, grafts from L-homozygotes were found in 24%, whereas in patients with deteriorated function, grafts from L-homozygotes exhibited in higher rate (50%). Neither the donor's nor the recipient's polymorphism influenced the graft survival (log-rank test P = .228 for the donors and log-rank test P = 0.844 for the recipients). There was no evidence of a gene-dose effect on graft survival (P = .469). Recipients of allografts from S-carriers donors had significantly lower serum creatinine levels at 24 months compared with recipients of allografts from L-homozygotes donors (P = .016).
ABSTRACT Purpose of the study: Recent studies suggest an association between community viral load... more ABSTRACT Purpose of the study: Recent studies suggest an association between community viral load and new diagnoses of HIV infection. Aim of our study was to explore a potential association between the pattern of new cases of transmitted drug resistance (TDR) in Northern Greece and the community viral load in the subset of patients who harbored HIV drug-resistant strains during 2000-2007. Methods: Data on viral load measurements and genotypic HIV drug resistance were extracted from the respective databases of the Infectious Diseases Division of the AHEPA University Hospital and the National Reference Laboratory for AIDS of Northern Greece which provide healthcare services free of charge for the majority of HIV-positive individuals in Northern Greece. Patients who had undergone at least once genotypic resistance testing were included in the study. The 2009 SDRM list was used to categorize patients in subsets with regard to genotypic resistance results. Community viral load (CVL) was calculated as follows: The per-year weighed mean viral load was calculated for each individual patient and the median value of this set was defined as the community viral load. Poisson log-linear regression models with robust estimators were employed to examine the association between new cases of TDR and CVL of patients with genotypic drug resistance, patient number and year. Results: 512 patients out of 701 ever recorded had undergone genotypic HIV drug resistance testing at least once (73%). Overall, 202 out of 512 patients (39.4%) were identified with at least one resistance mutation (106/512 NNRTI, 175/512 NRTI, 104/512 PI). Poisson log-linear multivariate models correlated new cases of TDR with either log CVL (p = 0.068, RR: 7.59, 95% CI: 0.863-66.71) and year (p = 0.013, RR: 2.19, 95% CI: 1.18-4.08) or log CVL (p = 0.030, RR: 5.08, 95% CI: 1.17-22.06) and number of patients with drug resistance (p = 0.0001, RR: 1.03, 95% CI: 1.01-1.06). Conclusions: Our results indicate that the community viral load of patients with HIV drug resistance may affect the number of new patients with TDR, underline the need for successful viral suppression in patients with resistant HIV strains from a public health standpoint and, should they be supported by further studies, suggest that community viral load could be used as a biomarker for TDR surveillance.
We studied the effect of pyridoxine deficiency state on the responses of human lymphocytes to cer... more We studied the effect of pyridoxine deficiency state on the responses of human lymphocytes to certain mitogenic factors. Deoxypyridoxine (DB6), a potent pyridoxine antagonist, considerably inhibited Bromodeoxyuridine (BrdU) incorporation into the newly synthesized DNA of lymphocytes cultured with Phytohemagglutinin (PHA) and Concanavalin A (Con A) in separate sets of experiments. The addition of deoxypyridoxine simultaneously with or few hours prior to initiation of cell cultures did not significantly alter the inhibitory action of deoxypyridoxine. Titration studies of deoxypyridoxine showed the direct relation between the concentration of deoxypyridoxine and the degree of DNA synthesis' inhibition with subsequent lymphocyte proliferation. The results obtained with monoclonal antibody (anti-BrdU) studies were further confirmed with tritiated thymidine incorporation (3H Thymidine) studies. Addition of pyridoxine concurrently with the addition of DB- or 8 hours later than initiation of lymphocyte incubation period was capable of effectively reversing the inhibition caused by its antagonist, the level of DNA synthesis reaching that of the control cultures where only PHA or Con A were present. Our results confirm part of previously reported findings concerning the involvement of vitamin B- in immune processes.
European journal of clinical microbiology & infectious diseases : official publication of the European Society of Clinical Microbiology, Jan 18, 2015
Multidrug-resistant (MDR) and extensively drug-resistant (XDR) Gram-negative nosocomial pathogens... more Multidrug-resistant (MDR) and extensively drug-resistant (XDR) Gram-negative nosocomial pathogens commonly carry one carbapenemase gene conferring resistance to carbapenems and other beta-lactam antibiotics. However, increasing reports show that double-carbapenemase-producing (DCP) and even multi-carbapenemase-producing (MCP) bacteria are emerging in some parts of the world, diminishing further, in some cases, the already limited treatment options. In the present review, the up-to-date reports of DCP and MCP isolates are summarized and concerns regarding their emergence are discussed.
Heme oxygenase-1 (HO-1) is the enzyme that catabolizes heme into carbon monoxide, biliverdin, and... more Heme oxygenase-1 (HO-1) is the enzyme that catabolizes heme into carbon monoxide, biliverdin, and free iron. The induction of this enzyme is an important cytoprotective mechanism, which occurs as an adaptive and beneficial response to a wide variety of oxidant stimuli. HO-1 has recently been suggested to protect transplants from ischemia/reperfusion and immunologic injury. HO-1 inducibility is mainly modulated by a (GT)(n) repeat polymorphism in the promoter region, and has been shown that short repeats (S) are associated with greater upregulation of HO-1, compared with long repeats (L). In the present study we investigated the influence of this HO-1 gene polymorphism on clinical outcome after transplantation and on renal transplant function. DNA from 175 donor/recipient pairs who underwent transplantation between October 2002 and June 2007 was genotyped. We divided the HO-1 alleles into 2 subclasses, the S ≤ 27 repeats and L > 27 repeats. There has been significant relevance between the genotype of the donor and the outcome of the graft, as far as recipients with normal graft function and recipients with deteriorated graft function are concerned (P = .021). In patients with normal graft function, grafts from L-homozygotes were found in 24%, whereas in patients with deteriorated function, grafts from L-homozygotes exhibited in higher rate (50%). Neither the donor's nor the recipient's polymorphism influenced the graft survival (log-rank test P = .228 for the donors and log-rank test P = 0.844 for the recipients). There was no evidence of a gene-dose effect on graft survival (P = .469). Recipients of allografts from S-carriers donors had significantly lower serum creatinine levels at 24 months compared with recipients of allografts from L-homozygotes donors (P = .016).
ABSTRACT Purpose of the study: Recent studies suggest an association between community viral load... more ABSTRACT Purpose of the study: Recent studies suggest an association between community viral load and new diagnoses of HIV infection. Aim of our study was to explore a potential association between the pattern of new cases of transmitted drug resistance (TDR) in Northern Greece and the community viral load in the subset of patients who harbored HIV drug-resistant strains during 2000-2007. Methods: Data on viral load measurements and genotypic HIV drug resistance were extracted from the respective databases of the Infectious Diseases Division of the AHEPA University Hospital and the National Reference Laboratory for AIDS of Northern Greece which provide healthcare services free of charge for the majority of HIV-positive individuals in Northern Greece. Patients who had undergone at least once genotypic resistance testing were included in the study. The 2009 SDRM list was used to categorize patients in subsets with regard to genotypic resistance results. Community viral load (CVL) was calculated as follows: The per-year weighed mean viral load was calculated for each individual patient and the median value of this set was defined as the community viral load. Poisson log-linear regression models with robust estimators were employed to examine the association between new cases of TDR and CVL of patients with genotypic drug resistance, patient number and year. Results: 512 patients out of 701 ever recorded had undergone genotypic HIV drug resistance testing at least once (73%). Overall, 202 out of 512 patients (39.4%) were identified with at least one resistance mutation (106/512 NNRTI, 175/512 NRTI, 104/512 PI). Poisson log-linear multivariate models correlated new cases of TDR with either log CVL (p = 0.068, RR: 7.59, 95% CI: 0.863-66.71) and year (p = 0.013, RR: 2.19, 95% CI: 1.18-4.08) or log CVL (p = 0.030, RR: 5.08, 95% CI: 1.17-22.06) and number of patients with drug resistance (p = 0.0001, RR: 1.03, 95% CI: 1.01-1.06). Conclusions: Our results indicate that the community viral load of patients with HIV drug resistance may affect the number of new patients with TDR, underline the need for successful viral suppression in patients with resistant HIV strains from a public health standpoint and, should they be supported by further studies, suggest that community viral load could be used as a biomarker for TDR surveillance.
We studied the effect of pyridoxine deficiency state on the responses of human lymphocytes to cer... more We studied the effect of pyridoxine deficiency state on the responses of human lymphocytes to certain mitogenic factors. Deoxypyridoxine (DB6), a potent pyridoxine antagonist, considerably inhibited Bromodeoxyuridine (BrdU) incorporation into the newly synthesized DNA of lymphocytes cultured with Phytohemagglutinin (PHA) and Concanavalin A (Con A) in separate sets of experiments. The addition of deoxypyridoxine simultaneously with or few hours prior to initiation of cell cultures did not significantly alter the inhibitory action of deoxypyridoxine. Titration studies of deoxypyridoxine showed the direct relation between the concentration of deoxypyridoxine and the degree of DNA synthesis' inhibition with subsequent lymphocyte proliferation. The results obtained with monoclonal antibody (anti-BrdU) studies were further confirmed with tritiated thymidine incorporation (3H Thymidine) studies. Addition of pyridoxine concurrently with the addition of DB- or 8 hours later than initiation of lymphocyte incubation period was capable of effectively reversing the inhibition caused by its antagonist, the level of DNA synthesis reaching that of the control cultures where only PHA or Con A were present. Our results confirm part of previously reported findings concerning the involvement of vitamin B- in immune processes.
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