Presence of the RHD pseudogene and the hybrid RHD-CE-Ds gene in Brazilians with the D-negative phenotype

The molecular basis for RHD pseudogene or RHDpsi is a 37-bp insertion in exon 4 of RHD. This insertion, found in two-thirds of D-negative Africans, appears to introduce a stop codon at position 210. The hybrid RHD-CE-Ds, where the 3' end of exon 3 and exons 4 to 8 are derived from RHCE, is associated with the VS+V- phenotype, and leads to a D-negative phenotype in people of African origin. We determined whether Brazilian blood donors of heterogeneous ethnic origin had RHDpsi and RHD-CE-Ds. DNA from 206 blood donors were tested for RHDpsi by a multiplex PCR that detects RHD, RHDpsi and the C and c alleles of RHCE. The RHD genotype was determined by comparison of size of amplified products associated with the RHD gene in both intron 4 and exon 10/3'-UTR. VS was determined by amplification of exon 5 of RHCE, and sequencing of PCR products was used to analyze C733G (Leu245Val). Twenty-two (11%) of the 206 D-negative Brazilians studied had the RHDpsi, 5 (2%) had the RHD-CE-Ds hybrid gene associated with the VS+V- phenotype, and 179 (87%) entirely lacked RHD. As expected, RHD was deleted in all the 50 individuals of Caucasian descent. Among the 156 individuals of African descent, 22 (14%) had inactive RHD and 3% had the RHD-CE-Ds hybrid gene. These data confirm that the inclusion of two different multiplex PCR for RHD is essential to test the D-negative Brazilian population in order to avoid false-positive typing of polytransfused patients and fetuses.

In vitro antimicrobial activity of a new series of 1,4-naphthoquinones

The antibacterial activity of a series of 1,4-naphthoquinones was demonstrated. Disk diffusion tests were carried out against several Gram-positive and Gram-negative bacteria. The compound 5-amino-8-hydroxy-1,4-naphthoquinone was the most effective, presenting inhibition zones measuring 20 mm against staphylococci, streptococci and bacilli at 50 µg/ml. Methicillin-resistant Staphylococcus aureus and several clinical isolates of this bacterium were also inhibited. Naphthazarin, 5-acetamido-8-hydroxy-1,4-naphthoquinone, and 2,3-diamino-1,4-naphthoquinone were the next most active compounds. The minimal inhibitory concentration of the active compounds was determined against S. aureus, ranging from 30 to 125 µg/ml. All compounds presented a minimal bactericidal concentration higher than 500 µg/ml, indicating that their effect was bacteriostatic. The EC50, defined as the drug concentration that produces 50% of maximal effect, was 8 µg/ml for 5-amino-8-hydroxy-1,4-naphthoquinone against S. aureus, S. intermedius, and S. epidermidis. These results indicate an effective in vitro activity of 5-amino-8-hydroxy-1,4-naphthoquinone and encourage further studies for its application in antibiotic therapy.

Assessing negative priming by attended distractors in a paper-and-pencil task

The paper-and-pencil digit-comparison task for assessing negative priming (NP) was introduced, using a referent-size-selection procedure that was demonstrated to enhance the effect. NP is indicated by slower responses to recently ignored items, and proposed within the clinical-experimental framework as a major cognitive index of active suppression of distracting information, critical to executive functioning. The digit-comparison task requires circling digits of a list with digit-asterisk pairs (a baseline measure for digit-selection), and the larger of two digits in each pair of the unrelated (with different digits in successive digit-pairs) and related lists (in which the smaller digit subsequently became a target). A total of 56 students (18-38 years) participated in two experiments that explored practice effects across lists and demonstrated reliable NP, i.e., slowing to complete the related list relative to the unrelated list, (F(2, 44) = 52.42, P < 0.0001). A 3rd experiment examined age-related effects. In the paper-and-pencil digit-comparison task, NP was reliable for the younger (N = 8, 18-24 years) and middle-aged adults (N = 8, 31-54 years), but absent for the older group (N = 8, 68-77 years). NP was also reduced with aging in a computer-implemented digit-comparison task, and preserved in a task typically used to test location-specific NP, accounting for the dissociation between identity- and spatial-based suppression of distractors (Rao R(3, 12) = 16.02, P < 0.0002). Since the paper-and-pencil digit-comparison task can be administered easily, it can be useful for neuropsychologists seeking practical measures of NP that do not require cumbersome technical equipment.

Negative inotropic and chronotropic effects on the guinea pig atrium of extracts obtained from Averrhoa carambola L. leaves

It has been reported that star fruit can lead to a fatal outcome in uremic patients. The intoxication syndrome consists of hiccups, mental confusion, dizziness, and vomiting. On the other hand, folk medicine uses teas and infusions of carambola leaves to treat headache, vomiting, cough, insomnia, and diabetes. This motivated us to determine if Averrhoa carambola can act on the contractility and automaticity of the guinea pig heart. We measured the atrial isometric force in stimulated left atria and determined the chronotropic changes in spontaneously beating right atria. The carambola leaf extracts (1.5 mg/ml) abolished the contractile force in a concentration-dependent manner. Among the crude, methanolic, ethanolic, aqueous, and acetic extracts, the aqueous one was the most potent (EC50 = 520 ± 94 µg/ml; flavonoids and tannins are the main constituents; Na+ and K+ contents in 1.0 mg/ml of aqueous extract were 0.12 ± 0.016 and 1.19 ± 0.15 mM, respectively). The aqueous extract abolished the positive Bowditch staircase phenomenon and reduced the inotropic response to CaCl2 (0.17-8.22 mM), events that are dependent on the cellular Ca2+ inward current. The adrenergic, muscarinic or opioid membrane receptors do not seem to participate in the mechanism of action of the cardioactive substance(s). In spontaneously beating atria, the aqueous extract promoted a negative chronotropic effect that was antagonized by 0.1 µM isoproterenol bitartrate. With this agonist, the EC50 of the aqueous extract increased from 133 ± 58 to 650 ± 100 µg/ml. These data regarding the effect of A. carambola on guinea pig atrial contractility and automaticity indicate an L-type Ca2+ channel blockade.

Factors associated with bacteremia due to multidrug-resistant Gram-negative bacilli in hematopoietic stem cell transplant recipients

The epidemiology of bacteremia developing during neutropenia has changed in the past decade, with the re-emergence of Gram-negative (GN) bacteria and the development of multidrug resistance (MDR) among GN bacteria. We conducted a case-control study in order to identify factors associated with bacteremia due to multidrug-resistant Gram-negative (MDRGN) isolates in hematopoietic stem cell transplant recipients. Ten patients with MDRGN bacteremia were compared with 44 patients with GN bacteremia without MDR. Bacteremia due to Burkholderia or Stenotrophomonas sp was excluded from analysis (3 cases), because the possibility of intrinsical resistance. Infection due to MDRGN bacteria occurred in 2.9% of 342 hematopoietic stem cell transplant recipients. Klebsiella pneumoniae was the most frequent MDRGN (4 isolates), followed by Pseudomonas aeruginosa (3 isolates). Among non-MDRGN, P. aeruginosa was the most frequent agent (34%), followed by Escherichia coli (30%). The development of GN bacteremia during the empirical treatment of febrile neutropenia (breakthrough bacteremia) was associated with MDR (P < 0.001, odds ratio = 32, 95% confidence interval = 5_190) by multivariate analysis. Bacteremia due to MDRGN bacteria was associated with a higher death rate by univariate analysis (40 vs 9%; P = 0.03). We were unable to identify risk factors on admission or at the time of the first fever, but the occurrence of breakthrough bacteremia was strongly associated with MDRGN bacteria. An immediate change in the antibiotic regimen in such circumstances may improve the prognosis of these patients.

Negative correlation between phospholipase and esterase activity produced by Fusarium isolates

Fusarium species have emerged as one of the more outstanding groups of clinically important filamentous fungi, causing localized and life-threatening invasive infections with high morbidity and mortality. The ability to produce different types of hydrolytic enzymes is thought to be an important virulence mechanism of fungal pathogens and could be associated with the environment of the microorganism. Here, we have measured the production of two distinct lipolytic enzymes, phospholipase and esterase, by sixteen Fusarium isolates recovered from the hospital environment, immunocompromised patients’ blood cultures, foot interdigital space scrapings from immunocompromised patients, and foot interdigital space scrapings from immunocompetent patients (4 isolates each). Fourteen of these 16 isolates were identified asFusarium solani species complex (FSSC) and two were identified as F. oxysporum species complex (FOSC). Some relevant genus characteristics were visualized by light and electron microscopy such as curved and multicelled macroconidia with 3 or 4 septa, microconidia, phialides, and abundant chlamydospores. All Fusarium isolates were able to produce esterase and phospholipase under the experimental conditions. However, a negative correlation was observed between these two enzymes, indicating that a Fusarium isolate with high phospholipase activity has low esterase activity and vice versa. In addition, Fusarium isolated from clinical material produced more phospholipases, while environmental strains produced more esterases. These observations may be correlated with the different types of substrates that these fungi need to degrade during their nutrition processes.

Negative emotions affect postoperative scores for evaluating functional knee recovery and quality of life after total knee replacement

This study aimed to determine whether psychological factors affect health-related quality of life (HRQL) and recovery of knee function in total knee replacement (TKR) patients. A total of 119 TKR patients (male: 38; female: 81) completed the Beck Anxiety Inventory (BAI), Beck Depression Inventory (BDI), State Trait Anxiety Inventory (STAI), Eysenck Personality Questionnaire-revised (EPQR-S), Knee Society Score (KSS), and HRQL (SF-36). At 1 and 6 months after surgery, anxiety, depression, and KSS scores in TKR patients were significantly better compared with those preoperatively (P<0.05). SF-36 scores at the sixth month after surgery were significantly improved compared with preoperative scores (P<0.001). Preoperative Physical Component Summary Scale (PCS) and Mental Component Summary Scale (MCS) scores were negatively associated with extraversion (E score) (B=-0.986 and -0.967, respectively, both P<0.05). Postoperative PCS and State Anxiety Inventory (SAI) scores were negatively associated with neuroticism (N score; B=-0.137 and -0.991, respectively, both P<0.05). Postoperative MCS, SAI, Trait Anxiety Inventory (TAI), and BAI scores were also negatively associated with the N score (B=-0.367, -0.107, -0.281, and -0.851, respectively, all P<0.05). The KSS function score at the sixth month after surgery was negatively associated with TAI and N scores (B=-0.315 and -0.532, respectively, both P<0.05), but positively associated with the E score (B=0.215, P<0.05). The postoperative KSS joint score was positively associated with postoperative PCS (B=0.356, P<0.05). In conclusion, for TKR patients, the scores used for evaluating recovery of knee function and HRQL after 6 months are inversely associated with the presence of negative emotions.

Ocurrence of Vibrio spp., positive coagulase staphylococci and enteric bacteria in oysters (Crassostrea gigas) harvested in the south bay of Santa Catarina island, Brazil

The aim of this study was to assess the contamination of oysters (Crassostrea gigas), harvested in six different regions of the South Bay of Santa Catarina Island, with Coliforms at 45 ºC, Escherichia coli, Vibrio spp., positive coagulase staphylococci, and Salmonella sp. over a period of one year. One hundred eighty oyster samples were collected directly from their culture sites and analyzed. Each sample consisted of a pool of 12 oysters. All of the samples analyzed showed absence of Salmonella, 18 (10%) samples showed presence of Escherichia coli, 15 (8.3%) samples were positive for V. alginolyticus, and Vibriocholerae was detected in 4 samples (2.2%). The counts of positive-coagulase staphylococci varied from <10 to 1.9 x 102 CFU.g-1, whereas the counts of Coliforms at 45 ºC and E. coli ranged from <3 to 1.5 x 102 MPN.g-1 and <3 and 4.3 x 10 MPN.g-1, respectively. Counts of V. parahaemolyticus and V. vulnificus ranged between <3 and 7 MPN.g-1, for both microorganisms. This suggests the need for monitoring these Vibrios contamination in oysters. Based on the results of the microbiological assays, the samples analyzed showed acceptable bacteriological quality, i.e., they were within the parameters established by Brazilian Legislation.