Prevalence of pneumococcal serotypes and resistance to antimicrobial agents in patients with meningitis: ten-year analysis

ObjectivesTo determine the prevalence of pneumococcal serotypes and antimicrobial susceptibility in patients with meningitis, and to evaluate the implications for vaccine coverage.MethodsPneumococcal strains obtained from normally sterile fluids from patients admitted with meningitis were isolated at the Hospital de Clínicas of the Universidade Federal de Uberlândia, Minas Gerais State, and sent to the Instituto Adolfo Lutz, city of São Paulo, São Paulo State, for further identification, serotyping, and antimicrobial susceptibility determination.ResultsFrom April 1999 to April 2009, 338 pneumococcal strains were isolated, and 72 obtained from patients with meningitis, were analyzed. Patients’ ages varied from one month to 82.2 years (mean of 18.4 ± 22.9 years; median of 5.2 years) and 46 (63.9%) patients were male. Strains were isolated from cerebrospinal fluid [66 occasions (91.7%)] and blood [6 occasions (8.3%)]. The most commonly identified serotypes were 14, 19F, 3, 7F, 6A, 6B, 10A, 18C, 23F, 5, and 34. Of the 20 [27.8%] oxacillin-resistant strains, 17 [23.6%] were resistant to penicillin and nine [12.5%] to ceftriaxone, both resistance patterns being more common in children aged two years or less and during the 2005–2009 period.ConclusionsResistance to penicillin and ceftriaxone was detected in 23.6% and 12.5% of the strains, respectively, and predominated in children aged two years or less and during the 2005–2009 period. There were 24 different serotypes of pneumococcus and 79.8% of the serotypes were represented in the 7-valent conjugated vaccine [PVC7].     

Cold tolerance in hypothyroid rabbits: role of skeletal muscle mitochondria and sarcoplasmic reticulum Ca2+ ATPase isoform 1 heat production

Brown adipose tissue (BAT) is involved in rat and mice thermoregulation, and heat produced by BAT depends on the concerted action of thyroid hormones and catecholamines. Little is known about cold-induced thermogenesis in mammals that have little or no BAT, such as rabbits. In these animals, thermogenesis primarily occurs in skeletal muscle. In this work, we have studied the effect of cold acclimation (4 C for 10 d) in normal and hypothyroid rabbits. It is known that hypothyroid rats die after a few hours of cold exposure. We now show that, different from rats, hypothyroid rabbits sustain their body temperature and survive after 10 d cold exposure. When compared with rabbits kept at room temperature, the muscles of cold-exposed rabbits showed a dark red color characteristic of oxidative muscle fibers. According to this pattern, we observed that in both normal and hypothyroid rabbits, cold exposure promotes an increase in oxygen consumption by skeletal muscle mitochondria. Moreover, in red muscle, cold acclimation induces an increase in the expression and activity of sarcoplasmic reticulum Ca(2+) ATPase isoform 1 (SERCA1), one of the muscle enzymes involved in heat production. We conclude that rabbit cold tolerance is probably related to increased muscle oxidative metabolism and heat production by SERCA1 and that these changes are not completely dependent on normal thyroid function.     

Contrast medium in power Doppler ultrasound for assessment of synovial vascularity: comparison with arthroscopy

OBJECTIVE: To evaluate the reliability of contrast-unenhanced power Doppler (CUPD) and contrast-enhanced power Doppler (CEPD) ultrasound (US) assessment of synovial vascularity of knee joint synovitis by prospective comparison with the "gold standard," arthroscopy. METHODS: A total of 18 knees of 17 patients with refractory rheumatoid and psoriatic knee joint synovitis were examined by US. Recognition of PD synovial vessel flow and its spatial arrangement in relation to the pannus/cartilage interface (P/CI) or fluid/synovium interface (F/SI) were studied by CUPD- and CEPD-US after a single intravenous bolus of galactosel palmitic acid (Levovist). Arthroscopy video recordings were reanalyzed by computer image analysis to assess synovial vascular marking. CUPD and CEPD flow signal scores were compared with each other and with corresponding vascular marking scores. Using villous vascular marking as reference, CUPD and CEPD sensitivity and specificity were measured. Interobserver variability was evaluated. RESULTS: Compared with the unenhanced PD method, contrast administration increased the PD flow signal score in 13/18 knees (72.2%), allowing increased detection of F/SI PD flow signal configuration (p < 0.018) and of the coexistence of P/CI and F/SI PD imaging (p < 0.0078). With arthroscopy as reference, contrast-enhanced PD was found to be more useful than the unenhanced method, showing more reproducible PD signal scores (p = 0.05 vs p = nonsignificant), as well as higher sensitivity (80% vs 30%), but lower specificity (62% vs 87%), in the recognition of increased vascularity of synovial villi. Interobserver agreement was 100%. CONCLUSION: The prospective comparison with arthroscopy showed the reliability of the CEPD method in synovial vessel recognition and its potential clinical usefulness in assessment of knee joint synovitis.     

In salt-sensitive hypertension,increased superoxide production is linked to functional upregulation of angiotensin II

The balance between endothelial nitric oxide (NO) and angiotensin II (Ang II) maintains the homeostasis of the cardiovascular and renal systems. We tested the hypothesis that increased oxidant stress linked to a functional imbalance between NO and Ang II might play a central pathogenetic role in salt-sensitive (SS) hypertension. We studied Dahl SS (DS) rats during the prehypertensive (5 days) and hypertensive (12 weeks) phases of a high-salt (4% NaCl) diet. Control rats received a normal-salt (0.5% NaCl, [NS]) diet. Prehypertensive DS rats (systolic blood pressure [SBP] 138+/-2 mm Hg) manifested a 35% increase (P<0.05) in aortic superoxide (O2-) production without evidence of end-organ damage. Hypertensive DS rats (SBP 214+/-11 mm Hg) had impaired endothelium-dependent relaxation (EDR) and increased aortic O2- production (320%), urinary isoprostane excretion (83%), aortic (20%) and left ventricular (LVH, 21%) hypertrophy, and proteinuria (124%). In prehypertensive DS rats, candesartan (10 mg x kg(-1) x d(-1)) an Ang II type 1 receptor blocker (ARB), normalized O2- production. In hypertensive DS rats, the ARB decreased aortic O2- production by 71% and normalized EDR without affecting SBP (212+/-8 mm Hg), aortic hypertrophy, LVH, or proteinuria. Switching hypertensive DS rats to an NS diet did not affect SBP (208+/-8 mm Hg), LVH, aortic hypertrophy, or proteinuria and had minimal effects on O2- and EDR. Concomitant ARB administration plus a switch to an NS diet normalized SBP (138+/-8 mm Hg) as well as end-organ damage. Dahl salt-resistant rats fed an HS diet for 12 weeks did not show hypertension or increased O2- production. Thus, SS hypertension might represent a specific vascular diathesis linked to functional upregulation of Ang II action (increased O2- synthesis) accompanied by insufficient NO bioavailability, which promotes severe endothelial dysfunction.