Molecular characterization of Mycobacterium tuberculosis isolates presenting various drug susceptibility from Greece using three DNA typing methods

OBJECTIVES: The purpose of the present study was the molecular characterization of Mycobacterium tuberculosis clinical isolates using three DNA typing methods. METHODS: One hundred nineteen independent (77 susceptible to all antituberculous drugs, 17 rifampin-resistant and 25 isoniazid-resistant), and nine related Mycobacterium tuberculosis isolates obtained over a 3-years period (1997-1999) from Greece were typed with restriction fragment length polymorphism (RFLP), using the non-radioactive IS6110 probe (IS6110-RFLP), and two PCR-based molecular methods: random amplification of polymorphic domains (RAPD) using four different primers and double repetitive element-PCR (DRE-PCR). RESULTS: IS6110-RFLP and RAPD-PCR using IRIS primer were proved to be the most discriminatory methods, while DRE-PCR gave satisfactory results and RAPD-PCR methods using the other three primers (A1245, B1245 and Leg2) were not so effective. The related strains, isolated from affected members of four families, gave similar PCR and RFLP patterns, while the independent strains presented a high degree of polymorphism. In terms of cost effectiveness and technical simplicity, the PCR-based methods were found to be superior. CONCLUSIONS: So, they may serve as screening methods to classify a large number of isolates into clusters for further subtyping and recognition of well-defined genotype families.     

Association of Fitness and Grip Strength With Heart Failure: Findings From the UK Biobank Population-Based Study

ObjectiveTo investigate the associations of objectively measured cardiorespiratory fitness (CRF) and grip strength (GS) with incident heart failure (HF), a clinical syndrome that results in substantial social and economic burden, using UK Biobank data.Patients and MethodsOf the 502,628 participants recruited into the UK Biobank between April 1, 2007, and December 31, 2010, a total of 374,493 were included in our GS analysis and 57,053 were included in CRF analysis. Associations between CRF and GS and incident HF were investigated using Cox proportional hazard models, with adjustment for known measured confounders.ResultsDuring a mean of 4.1 (range, 2.4-7.1) years, 631 HF events occurred in those with GS data, and 66 HF events occurred in those with CRF data. Higher CRF was associated with 18% lower risk for HF (hazard ratio [HR], 0.82; 95% CI, 0.76-0.88) per 1–metabolic equivalent increment increase and GS was associated with 19% lower incidence of HF risk (HR, 0.81; 95% CI, 0.77-0.86) per 5-kg increment increase. When CRF and GS were standardized, the HR for CRF was 0.50 per 1-SD increment (95% CI, 0.38-0.65), and for GS was 0.65 per 1-SD increment (95% CI, 0.58-0.72).ConclusionOur data indicate that objective measurements of physical function (GS and CRF) are strongly and independently associated with lower HF incidence. Future studies targeting improving CRF and muscle strength should include HF as an outcome to assess whether these results are causal.     

Expression levels of matrix metalloproteinase (MMP)-9 and its specific inhibitor TIMP-1, in septic and aseptic arthritis of the knee

Purpose

In cases of septic knee arthritis, there is excess of matrix metalloproteinases (MMPs) over tissue inhibitors of metalloproteinases (TIMPs), due to enhanced expression and activation that are induced by bacteria in comparison with rheumatic or degenerative arthritis. The aim of this study was to explore the expression levels of synovial gelatinase MMP-9 and its specific inhibitor TIMP-1 in septic and aseptic arthritis and their potential use as additional aids to clinical investigation.

Methods

Gelatin zymography and western blot analysis were applied in effusions from knees of the patients with septic (SA—10 patients), rheumatic (RA—10 patients) and osteoarthritis (OA—10 patients).

Results

Zymographic analysis revealed that all samples contained latent MMP-2 activity, albeit activated MMP-2 appeared in more of the septic than aseptic effusions. MMP-9 was not detected in osteoarthritic synovial fluid samples. Only trace amounts of MMP-9 activity were detected in 4 of 10 patients with RA, whereas higher MMP-9 levels were evident in all samples from SA (P = 0.0241). In immunoblotting assays, samples from SA showed significantly higher levels of MMP-9 compared with samples from RA (P = 0.0052), confirming zymographic results. Although no significant difference in TIMP-1 levels was observed, the estimated MMP-9/TIMP-1 ratio of septic effusions was significantly higher compared with aseptic ones (P = 0.0029).

Conclusions

The data presented suggest enhanced expression and activation of MMP-9 in septic native knee arthritis compared with aseptic. The presence of high levels of MMP-9 with concomitantly increased MMP-9/TIMP-1 ratio and activated gelatinases in effusions, independent of neutrophilic counts, may be indicative for infection.     

Reading with central scotomas: is there a binocular gain?

PURPOSE: The purpose of this study was to compare reading performance under binocular versus monocular viewing conditions in patients with bilateral age-related macular degeneration (AMD). METHODS: Twenty-two patients with AMD participated. Distance acuity, reading acuity, and contrast sensitivity were recorded binocularly and monocularly with the better eye. An infrared eye tracker recorded eye movements during reading. Reading speed and reading eye movement parameters, including number of fixations and regressions, fixation duration, and number of saccades to find the next line, were calculated for both viewing conditions. The difference between binocular and monocular performance (binocular gain) was computed. Regression analysis was used to determine whether intraocular differences in distance and reading acuity and contrast sensitivity were predictive of binocular gain. RESULTS: Reading speed when using both eyes was highly correlated with the reading speed for the better eye. There was a small, but not significant, advantage of binocular viewing (6.9 words/minute, p = 0.33). No significant difference was detected in any eye movement parameters when comparing both eyes with the better eye. Although some patients showed either positive or negative binocular gain, the amount of gain was not predicted by intraocular differences in acuity or contrast sensitivity. CONCLUSIONS: Overall, there was no significant difference between binocular and monocular reading performance in patients with AMD.