The value of bacterial culture during clean orthopedic surgery: a prospective study of 1,036 patients.

OBJECTIVE: To determine whether bacterial cultures of the wounds of patients undergoing clean orthopedic surgery would help predict infection. METHODS: During 1 year, 1,256 cultures were performed for 1,102 patients who underwent clean orthopedic surgery. Results were analyzed to evaluate their ability to predict postoperative infection. RESULTS: The sensitivity, specificity, positive predictive value, and negative predictive value of the cultures were 38%, 92%, 7%, and 99%, respectively. CONCLUSIONS: Cultures performed during clean orthopedic surgery were not useful for predicting postoperative infection.     

Comparison Between Incremental and Single-Dose Allergen Administration in Bronchial Provocation Tests

To study the effect of different schedules of allergen administration on the early (EAR) and late allergic reaction (LAR), 15 asthmatic patients with dual response after allergen challenge were submitted to two consecutive bronchoprovocation tests (BPT). BPT₁ was carried out with semilogarithmic increase of allergen doses until a FEV₁ drop of 20% was recorded. BPT₂ was performed 2 weeks later using the highest allergen dose that had elicited the dual reaction in BPT₁. Both EAR and LAR were very similar for a given patient. As the allergen dose used in BPT₂ is smaller than the cumulative allergen dose administered in BPT₁, this protocol takes into account a possible influence on BPT₂ of bronchial hyperreactivity induced by BPT₁ performed 2 weeks before.     

Effectiveness of gentamicin-impregnated cement in the prevention of deep wound infection after primary total knee arthroplasty.

Effectiveness of gentamicin-impregnated cement in preventing deep wound infection after total knee arthroplasty (TKA) was estimated using data from prospective surveillance. In multivariate analysis, the protective effect of gentamicin-impregnated cement on the development of infection was close to the limit of significance. Gentamicin-impregnated cement may prevent TKA infections.     

Assessment of laboratory and field assays of sunlight-induced killing of mosquito larvae by photosensitizers

The effectiveness of light-induced killing of mosquito larvae in the presence of photosensitizers was studied with larvae of Aedes aegypti (L.), Anopheles stephensi (Liston), and Culex quinquefasciatus Say grown in the laboratory and of Cx. quinquefasciatus grown under field conditions. Tested photosensitizers included xanthene, chlorin, and porphyrin derivatives. All the larvae were treated at the fourth instar. Preliminary laboratory experiments showed a light-induced lethal effect of Rose Bengal (RB) on three species of mosquito larvae. Compared with other photosensitizers, RB seemed to be more efficient at even lower concentration than chlorin (e6) and chlorophyllin on Ae. aegypti larvae. Among the four porphyrin derivatives, i.e., chloroquinoline tetraphenyl propioamidoporphine, tetraphenyl porphine tetrasulfonate, hematoporphyrin (HP), and tetraphenylporphinepropionic acid porphine, HP was the only effective photosensitizer on Ae. aegypti larvae. The best conditions for field tests using RB were conducted on Cx. quinquefasciatus in Bobo-Dioulasso, Burkina Faso. The mortality induced by RB varied from 80 to 96% obtained with unfiltered cesspit water to 0.4 to 6.7% in cesspits with a heavy load of organic materials, thus providing the basis for further developments of this technique under field conditions.     

Modulation of paired-pulse responses in the dentate gyrus: effects of prenatal protein malnutrition

Since our major hypothesis is that prenatal protein malnutrition significantly affects hippocampal neuroplasticity, this study examined the effects of prenatal protein malnutrition on the modulation of dentate granule cell excitability in freely moving rats at 15, 30 and 90 days of age across the vigilance states of quiet waking (QW), slow-wave sleep (SWS) and rapid eye movement (REM) sleep. Using paired-pulse stimulation, the paired-pulse index (PPI), a measure of the type and degree of modulation of dentate granule cell excitability elicited by stimulation of the medial perforant path, was obtained for each vigilance state at each stage of development. Four specific measures of granule cell excitability were computed, namely, PPI using both population spike amplitude (PSA) and EPSP slope measures, absolute values of PSA(1) and EPSP(1) slope. PPI values obtained at 15, 30 and 90 days of age, however, were altered during normal ontogenetic development, but not by vigilance state. At 15 days of age, the malnourished group exhibits greater early inhibition of the PPI using the PSA measure at IPIs between 20 and 30 ms regardless of vigilance state, while at 30 days of age, the malnourished group exhibits greater facilitation at IPIs between 50 and 70 ms during QW and SWS, but not during REM sleep. In the control adult (PND90) and juvenile (PND30) animal, PSA(1) values are significantly higher during SWS than in QW or REM sleep. However, for the younger malnourished animals (PND15 and PND30), PSA(1) values were found to be significantly greater during REM sleep rather than SWS. Therefore, as the animal matures, there appears to be a shift in vigilance state dependent synaptic transmission through the hippocampal trisynaptic circuit from REM sleep to SWS in both control and malnourished animals, with the change occurring later in malnourished animals when compared to control ones. Furthermore, our findings suggests that prenatal protein malnutrition significantly alters modulation of dentate granule cell excitability (i.e., PPI values using the PSA measure) during the earlier stages of development but not in adulthood.     

Dentate granule cell modulation in freely moving rats: vigilance state effects

Dentate granule cell population responses to paired-pulse stimulation applied to the perforant pathway across a range of interpulse intervals (IPIs) were examined during different vigilance states-quiet waking (QW), slow-wave sleep (SWS), and rapid-eye movement (REM) sleep-in freely moving rats at 15, 30 and 90 days of age. Using these evoked field potentials, the paired-pulse index (PPI), a measure of the type and degree of modulation of dentate granule cell excitability, was computed and shown to be altered as a function of age. Animals, 15 days old, showed significantly lower levels of early inhibition (20-40 ms IPIs), i.e., greater PPI values, during all three vigilance states when compared to both the 30- and 90-day old animals. Adult, i.e, 90-day old animals, on the other hand, showed significantly greater levels of late inhibition (300-1000 ms IPIs), i.e., lower PPI values, than the younger animals (15- and 30-day old) during QW and SWS. These results indicate that as the dentate field of the hippocampal formation matures there are significant alterations in the modulation of dentate granule cell activity.     

Infectious complications following allogeneic HLA-identical sibling transplantation with antithymocyte globulin-based reduced intensity preparative regimen.

In the setting of reduced-intensity conditioning (RIC) regimens for allogeneic stem cell transplantation (allo-SCT), the epidemiology of transplant-related infections is still poorly defined. In 101 high-risk patients who received an HLA-identical sibling allo-SCT after RIC, including fludarabine, busulfan and antithymocyte globulin (ATG), we report during the first 6 months a cumulative incidence of positive CMV antigenemia of 42% (95% CI 32-52%), developing at a median of 37 (range 7-116) days without evidence of CMV disease (median follow-up, 434 days). The cumulative incidence of bacteremia was 25% (95% CI 17-33%), occurring at a median of 67 (range 7-172) days, while patients had recovered a full neutrophil count. In all, 65% of the bacteremia (95% CI 49-81%) were gram negative. The cumulative incidence of fungal infections was 8% (95% CI 3-13%), with a median onset of 89 (range 7-170) days. In multivariate analysis, stem cell source (bone marrow; P=0.0002) was significantly associated with the risk of positive CMV antigenemia, while higher doses of prednisone (>2 mg/kg) represented the major risk factor for bacteremia (P=0.0001). Infectious-related mortality was 5% (95% CI 1-9%), with aspergillosis being the principal cause. Collectively, these results suggest that prospective efforts are warranted to develop optimal antimicrobial preventive strategies after RIC allo-SCT.