[Antibiotic prophylaxis and (pre-)dental implant surgery]. / AB-profylaxe en (pre)implantologische chirurgie.

Recent literature indicates that in a healthy patient, who has sufficient bone volume to allow implant placement, it is justified to refrain from prophylactic administration of antibiotics. The patient should, however, rinse with chlorhexidine digluconate 1 day prior to treatment and at least 1 week postoperatively. In the case of an immune-compromised patient, a single antibiotic gift is indicated 1 hour before the procedure (2 grams of amoxicillin orally or 2 grams of cefazoline intravenously). In the case of a healthy patient, antibiotic (AB) prophylaxis is also indicated if autologous bone, a bone filler or membranes are applied. Although AB prophylaxis is not necessary when harvesting extraoral bone grafts, it is indicated because the harvested bone is applied intraorally in the same treatment session. The question whether postoperative administration of antibiotics is still needed remains open.

Reduction of ventilator-associated pneumonia in the Neuroscience Intensive Care Unit: a multimodality prevention and testing protocol.

AIM: Ventilator-associated pneumonia (VAP) is a serious concern for patients in the Neuroscience Intensive Care Unit (NSICU). The risks to patients are significant and the monetary costs are astronomical. We review a multimodality approach that substantially reduced VAP rate in our ICU METHODS: Data from all patients admitted to the NSICU between January 2005 and April 2010 were reviewed. All ventilated patients were treated according to a multimodality VAP assessment and prevention protocol, implementation of which began in August of 2008 and was completed by March 2009. Rates of VAP before, during, and after implementation of the protocol are compared. VAP rates are also compared to national rates as obtained from the National Healthcare Safety Network (NHSN). RESULTS: In the pre-implementation period, the VAP rate was 11.6 per 1000 ventilator days. This rate was twice the national average. In the post implementation period, the VAP rate was 5.5/1000 ventilator days. VAP rate dropped precipitously after full compliance with the protocol was achieved. CONCLUSION: Although intubated patients in the NSICU are at high risk for VAP, a significant reduction in VAP-related morbidity and monetary costs can be obtained with multimodality prevention and testing protocols.

Evolutionary fate of rhizome-specific genes in a non-rhizomatous Sorghum genotype.

What is the fate of organ-specific genes after the organ is lost? For Sorghum propinquum and Sorghum halepense genes that were previously shown to have rhizome-enriched expression, we have conducted comparative analysis of both coding regions and regulatory sequences in Sorghum bicolor (non-rhizomatousness) and S. propinquum (rhizomatousness). Most genes with rhizome-enriched expression appear to have similar numbers of paralogous copies in both genotypes, with only three of 24 genes studied showing significant differences in copy numbers. We detected no greater propensity for mutation in S. bicolor than in S. propinquum of genes with rhizome-enriched expression in the latter. Several cis-acting regulatory elements, particularly an Myb-binding core (AACGG) that is involved in the regulation of the mitotic cyclin, were more abundant in promoters of S. propinquum than in non-rhizomatous S. bicolor or Oryza sativa (rice). We suggest that many genes with rhizome-enriched expression in S. propinquum may serve multiple functions, with partial loss of some of these functions in S. bicolor but ongoing purifying selection acting to preserve the remaining functions. Expressed genes in polyploid S. halepense rhizomes appeared to be more frequently derived from the S. propinquum than the S. bicolor progenitor, but there was some evidence of formation of novel alleles and 'recruitment' of S. bicolor genes to rhizome-enriched expression in S. halepense, suggesting that polyploidy may have offered new evolutionary potential to S. halepense.

Gametophyte genetics in Zea mays L.: dominance of a restoration-of-fertility allele (Rf3) in diploid pollen.

In Zea mays L. plants carrying the S-type of sterility-inducing cytoplasm, male fertility is determined by a gametophytic, nuclear restoration-of-fertility gene. Haploid pollen carrying the fertility-restoring allele (historically designated Rf3) is starch-filled and functional, whereas pollen carrying the nonrestoring allele (historically designated rf3) is shrunken and nonfunctional. Because restoration of fertility occurs in haploid tissue, the dominance relationship of restoring and nonrestoring alleles is unknown. We have tested the dominance relationship of the restoring and nonrestoring alleles at the rf3 locus in diploid pollen. The meiotic mutant elongate was used to generate tetraploid plants carrying both Rf3 and rf3 alleles in the S cytoplasm. These plants shed predominantly starch-filled pollen, consistent with dominance of the restoring allele. Restriction fragment length polymorphisms linked to the rf3 locus demonstrated cotransmission of rf3 and Rf3 alleles through heterozygous diploid pollen, providing conclusive genetic evidence that the restoring allele is the dominant or functional form of this restoration-of-fertility gene. We suggest that other S-cytoplasm restorers result from loss-of-function mutations and propose analysis of unreduced gametes as a test of this model.

Bacteria: a major pathogenic factor for anastomotic insufficiency.

The aim of this study was to determine the influence of bacteria on the development of anastomotic insufficiency following gastrectomy in the rat. Fifty-seven male Wistar rats were randomly assigned to three groups and subjected to gastrectomy. Group I (n = 20) was orally inoculated with 10(9) Pseudomonas aeroginosa organisms on postoperative day 1. Group II (n = 20) served as the control group. Group III (n = 17) was decontaminated with 320 mg of tobramycin, 400 mg of polymyxin B, and 500 mg of vancomycin per liter of fluid administered from preoperative day 7 to postoperative day 10. Swabs from the oropharynx and rectum were cultured and analyzed daily for gram-positive and gram-negative bacteria. Surviving animals were sacrificed on postoperative day 10. All animals were autopsied immediately following death. Anastomotic insufficiency was defined as a histologically proven transmural defect at the suture line. Along with an effective reduction of pathogenic bacteria colonizing the oropharynx, the rate of anastomotic insufficiency could be reduced significantly, to 6% in decontaminated animals compared with 80% in controls (P < 0.001 by Fisher's exact test). Inoculation of group I animals with P. aeruginosa led to an increase of anastomotic insufficiency up to 95% and a significant increase in mortality (P < 0.05). We conclude that bacteria play a major role in the pathogenesis of anastomotic insufficiency following gastrectomy in the rat.

Generation of GW radiation pulses from a VUV free-electron laser operating in the femtosecond regime.

Experimental results are presented from vacuum-ultraviolet free-electron laser (FEL) operating in the self-amplified spontaneous emission (SASE) mode. The generation of ultrashort radiation pulses became possible due to specific tailoring of the bunch charge distribution. A complete characterization of the linear and nonlinear modes of the SASE FEL operation was performed. At saturation the FEL produces ultrashort pulses (30-100 fs FWHM) with a peak radiation power in the GW level and with full transverse coherence. The wavelength was tuned in the range of 95-105 nm.