Genotypic versus phenotypic characterization, with respect to susceptibility and identification, of 17 clinical isolates of Staphylococcus lugdunensis

OBJECTIVES: To compare different methods for the identification and determination of susceptibility to penicillin and methicillin of Staphylococcus lugdunensis. METHODS: Seventeen clinical isolates of S. lugdunensis (identified by PCR amplification and sequencing of the rpoB gene) were studied using the ATB32-Staph, Crystal, Vitek 2 and Wider commercial systems. The clumping factor test and the tube coagulase test were also performed. Beta-lactamase production was studied by chromogenic methods. Methicillin resistance was phenotypically studied by the MRSA slide latex agglutination test, growth in MRSA agar, and the Vitek 2 and Wider systems (based on oxacillin MIC), and genotypically studied by detection of the mecA gene by PCR. RESULTS: The clumping factor test was negative in 35.3% of strains. All isolates were correctly identified to species level by the ATB32-Staph system. Species misidentification rates were 5.9%, 23.5% and 29.4% with the Crystal, the Vitek 2 and the Wider systems, respectively, mostly as Staphylococcus haemolyticus. Beta-lactamase was present in 11.8% of strains. Whereas 76.5% and 47.1% of strains exhibited oxacillin resistance (MIC range 0.5-2 mg/L) by the Vitek 2 system and the Wider system, respectively, none of the strains was positive in the MRSA slide latex agglutination test or grew in MRSA agar. All strains lacked the mecA gene. CONCLUSIONS: The clumping factor test and some commercial systems may misidentify S. lugdunensis. Oxacillin resistance detected by commercial systems is not indicative of the presence of the mecA gene. These facts, together with beta-lactamase production, may preclude adequate treatment of infections by this virulent coagulase-negative Staphylococcus.     

PCR-restriction fragment length polymorphism assay for detection of gyrA mutations associated with fluoroquinolone resistance in Campylobacter coli

A fragment of the gyrA gene was sequenced from 34 isolates of Campylobacter coli, including 23 isolates resistant to ciprofloxacin. All ciprofloxacin-resistant isolates examined by DNA sequencing carried a point mutation at position Thr-86 on the gyrA gene product, involving the replacement of Thr-86 by Ile. A combined PCR-restriction fragment length polymorphism technique using RsaI was developed to detect this mutation.     

Vitreous levels of IGF-I, IGF binding protein 1, and IGF binding protein 3 in proliferative diabetic retinopathy: a case-control study

OBJECTIVE: To evaluate vitreous levels of IGF-I and its binding proteins IGFBP-1 and IGFBP-3 in patients with proliferative diabetic retinopathy (PDR). Because intravitreal proteins are elevated in patients with PDR due to the disruption of the blood-retinal barrier, we have corrected vitreal IGF-I and IGFBPs by total vitreal proteins to avoid this confounding factor. RESEARCH DESIGN AND METHODS: We compared 21 diabetic patients with proliferative retinopathy (group A) and 13 nondiabetic patients (group B) in whom a vitrectomy was performed. Both groups were matched by age, serum IGF-I, IGFBP-1, and IGFBP-3 levels. Serum and vitreous levels of IGF-I, IGFBP-1, and IGFBP-3 were measured by immunological methods. Vitreal proteins were assessed by turbidimetric method. RESULTS: Vitreal levels of IGF-I were elevated in group A (median 1.35 ng/ml [range 0.3-8.7]) in comparison with group B (median 0.25 ng/ml [range 0-1.38]), P<0.001. After adjusting by vitreal proteins [ratio IGF-I (ng/ml)/protein (mg/ml)], the differences remain significant (P<0.005). Vitreal levels of IGFBP-1 and IGFBP-3 were also elevated in diabetic patients (IGFBP-1: group A, median 1.6 ng/ml [range 0.6-20.7]; group B, median 0.4 ng/ml [range 0.3-1.9], P<0.001. IGFBP-3: group A, median 102.6 ng/ml [range 53.9-350.8]; group B, median 29.0 ng/ml [range 3.2-87.8], P<0.001). However, when the ratio IGFBP/protein was considered, the differences were not significant. CONCLUSIONS: Intraocular synthesis contributes to elevated vitreous concentrations of IGF-I found in PDR. By contrast, unspecific increase of intravitreal proteins is the main factor explaining the elevated vitreous levels of IGFBP-1 and IGFBP-3 found in diabetic patients.     

Laparoscopic Treatment of Median Arcuate Ligament Syndrome: Analysis of Long-Term Outcomes and Predictive Factors

Background

Laparoscopic arcuate ligament release has been demonstrated a valid therapeutic option for arcuate ligament syndrome. Nevertheless, long-term follow-up and predictive factors have not been described for this treatment.

Methods

Clinical and surgical data and short- and long-term outcomes together with the impact of the degree of stenosis of the celiac trunk were analyzed in 13 consecutive patients who underwent laparoscopic arcuate ligament release between 2001 and 2013.

Results

Thirteen patients (12 F/1 M) underwent surgery. The median age was 32 years old, and their mean body mass index was 20.7 (range 14.7–25). The 13 patients presented with intense postprandial abdominal pain. Ten cases were associated with weight loss. The median duration of symptoms was 24 months (range 2–240). Three patients presented symptoms associated with superior mesenteric artery syndrome. Median operative time was 120 min (range 90–240), and there were no conversions to open surgery. Median hospital stay was 3 days (range 2–14). Over a median follow-up of 117 months (range 45–185), nine patients had excellent results although two required endovascular procedures at 70 and 24 months after surgery. Four patients (30.7%) experienced poor outcomes. When we analyzed the impact of the degree of occlusion of the celiac trunk, we observed that in patients with severe occlusion (>?70%), better results were obtained, with complete resolution of symptoms in 71% of cases.

Conclusion

Laparoscopic arcuate ligament release constitutes an excellent treatment for arcuate ligament syndrome. The degree of occlusion of the celiac trunk may be a factor predictive of long-term outcomes.

     

Glycolysis supports calcium uptake by the sarcoplasmic reticulum in skinned ventricular fibres of mice deficient in mitochondrial and cytosolic creatine kinase

Several works have shown the importance of the creatine kinase (CK) system for cardiac energetics and Ca2+ homeostasis. Nevertheless, CK-deficient mice have cardiac function close to normal, at least under conditions of low or moderate workload. To characterize possible adaptive changes of the sarcoplasmic reticulum (SR) and potential role of glycolytic support in cardiac contractility we used the skinned fibre technique to study properties of the SR and myofibrils, in control and muscle-type homodimer (MM-/mitochondrial-CK)-deficient mice. In control fibres, SR Ca2+ loading with ATP and phosphocreatine (solution PL) was significantly better than loading with ATP alone (solution AL), as determined by analysis of caffeine-induced tension transients. Loading in the presence of ATP and glycolytic intermediates (solution GL) was not significantly different from solution PL. These data indicate that Ca2+ uptake by the SR in situ depends on a local ATP:ADP ratio that is controlled by both CK and glycolytic enzymes. In CK-deficient mice, Ca2+ loading was impaired in solution PL due to the absence of CK. In solution GL, loading was significantly increased, such that calculated Ca2+ release parameters were normalized to those in control fibres in solution PL. In CK-deficient mice, fibre kinetic parameters of tension recovery were impaired after quick stretch in solution PL and were not improved in solution GL. These results show that in CK-deficient mice, at least under basal conditions, glycolysis can replace the CK system in fueling the SR Ca2+ ATPase, but not the myosin ATPase, and may in part explain the limited phenotypic alterations seen in the hearts of these mice.     

Bone mineral density and bone fracture in male patients receiving long-term suppressive levothyroxine treatment for differentiated thyroid carcinoma

Studies on the effect of exogenous subclinical thyrotoxicosis on bone mineral density (BMD) in male patients treated with suppressive doses of levothyroxine for differentiated thyroid carcinoma (DTC) are not conclusive. In order to evaluate BMD (in femoral neck, lumbar spine, and distal radius) and bone fractures in men under long-term suppressive treatment with levothyroxine for DTC, we conducted a cross-sectional, retrospective study in 33 Caucasian men (mean?±?SD age: 56?±?14?years) under treatment for DTC. The control group comprised 33 healthy age- and body mass index-matched male volunteers. BMD was assessed by dual-energy X-ray absorptiometry (DXA). Bone turnover biomarkers (calcium, phosphate, alkaline phosphatase, PTH, vitamin D, urinary calcium, and N-Telopeptide/creatinine index) and testosterone were determined. Previous bone fractures were evaluated with a questionnaire and X-ray images of thoracic and lumbar vertebrae. Patients were treated for a mean duration of 15?±?5?years. No differences were found between patients and controls in bone turnover biomarkers or areal BMD, T-scores or Z-scores in all sites evaluated. No earlier fractures or pain episodes were registered in either group and the incidence of asymptomatic vertebral fractures did not differ significantly between patient (18.8%) and control groups (16.7%), (P?=?0.9). In conclusion, long-term suppressive treatment with levothyroxine in men with DTC does not appear to exert deleterious effects on bone mineral density or increase the prevalence of fracture.