Taking dental self-care to the extreme: 24-month incidence of dental self-extractions in the Florida Dental Care Study

Four hundred thirteen Staphylococcus sp. were identified by Staphaurex, Staphaurex Plus, and BACTiStaph kits using tube coagulase as reference. Among 222 coagulase-positive isolates, 56 were oxacillin-resistant Staphylococcus aureus. All tests were accurate in distinguishing between coagulase-positive and -negative staphylococci with sensitivities and specificities > or = 97% and only nine discrepancies.     

Toxoplasma gondii-infected cells are resistant to multiple inducers of apoptosis

Infection with certain intracellular pathogens, including viruses and bacteria, may induce host cell apoptosis. On the other hand, infection with some viruses inhibits apoptosis. Complex protozoan parasites, including Toxoplasma gondii and members of Plasmodium, Leishmania, and Microsporidia, are also obligate intracellular pathogens, yet relatively little is known regarding their subversion of host cell functions. We now report that cells infected with T. gondii are resistant to multiple inducers of apoptosis, including Fas-dependent and Fas-independent CTL-mediated cytotoxicity, IL-2 deprivation, gamma irradiation, UV irradiation, and the calcium ionophore beauvericin. Inhibition of such a broad array of apoptosis inducers suggests that a mechanism common to many, or perhaps all, apoptotic pathways is involved. The inhibitory activity requires live intracellular parasite and ongoing protein synthesis. Despite T. gondii-mediated inhibition of DNA fragmentation, infected cells can still be lysed by CTL.     

Anatomy of radical prostatectomy as defined by magnetic resonance imaging

PURPOSE: We examined and defined anatomical structures relevant to radical prostatectomy using magnetic resonance imaging. MATERIALS AND METHODS: Before radical prostatectomy, 15 men underwent high-resolution magnetic resonance imaging studies of their pelvic floors (fast spin echo, T2 weighting of 3- to 4-mm. contiguous or overlapping slices) in axial, coronal, and sagittal planes. RESULTS: Pubovesical ligaments, rather than the commonly reported puboprostatic ligaments, were observed attaching the bladder-prostate unit to the pubis. We suggest that the part of the urethra that extends from the apex of the prostate to the bulb of the penis, which is surrounded by the striated sphincter, should be termed the sphincteric urethra rather than the membranous urethra. Further, we found no evidence that supports the traditional concept of a urogenital diaphragm. The lower part of the striated urethral sphincter was flanked on its sides by the anterior recesses of the ischioanal fossae. The portion of the levator ani, which we have termed the puboanalis sling, flanked the apex of the prostate. The most anteromedial portion of this sling inserts into the perineal body and should be termed the puboperinealis. The terminal part of the gastrointestinal tract (the part continued beyond the levator ani) should be termed the anal canal, not the rectum, as used frequently in the urologic literature. Therefore, the initial plane of dissection in radical perineal prostatectomy passes along the anterior portion of the anal canal, not the rectum. CONCLUSION: We used magnetic resonance imaging to study male pelvic floor and perineal anatomy without the artifact of dissection. This study allowed us to devise a more precise nomenclature with respect to radical prostatectomy and, in so doing, to provide a better understanding of both the retropubic and the perineal operations.     

Insulin-like growth factor-1 (IGF-1) receptor-insulin receptor substrate complexes in the uterus. Altered signaling response to estradiol in the IGF-1(m/m) mouse

Some of the actions of estradiol occur through stimulation of growth factor pathways in target organs. Tyrosine-phosphorylated (Tyr(P)) insulin-like growth factor-1 receptor (IGF-1R) and the insulin receptor substrate (IRS)-1 are found in the uterus of mice treated with estradiol. Immunoprecipitates of uterine Tyr(P) IRS-1 contained both p85, the regulatory subunit of phosphatidylinositol (PI) 3-kinase, and PI 3-kinase catalytic activity. Estradiol also stimulated binding of IRS-1 and PI 3-kinase to the IGF-1R. Depletion of IRS-1 from uterine extracts reduced PI 3-kinase associated with the receptor, which suggests that binding of the enzyme to IGF-1R occurs primarily in a complex that also contains IRS-1. Following treatment with estradiol, formation of Tyr(P) IGF-1R, Tyr(P) IRS-1, and the p85.IRS-1 complex was very weak in the uterus of IGF-1(m/m) mice, which are severely deficient in IGF-1. This indicated that most, if not all, of the estradiol-stimulated Tyr phosphorylation of uterine IRS-1 originates from ligand activation of IGF-1R kinase. IRS-2 was also Tyr-phosphorylated in the normal uterus and bound more IGF-1R and p85 in response to estradiol; however, a marked decrease in levels of uterine IRS-2 occurred 12-24 h after treatment with estradiol. Since IRS-2 was present in IGF-1R precipitates and a recombinant form of IGF-1 (long R3 IGF-1) stimulated formation of Tyr(P) IRS-2, hormonal activation of this docking protein probably occurs through the IGF-1R. In summary, our findings show that estrogen activation of uterine IGF-1R kinase results in enhanced binding of p85 (PI 3-kinase) to IRS-1 and IRS-2. The formation of one or both of these complexes may be important for the potent mitogenic action of this steroid. That estradiol stimulated a decrease of IRS-2, but not of IRS-1, suggests that these docking proteins have different roles in hormone-induced signaling in the uterus.     

A prospective algorithm for the management of air leaks after pulmonary resection

BACKGROUND: Air leaks (ALs) are a common complication after pulmonary resection, yet there is no consensus on their management. METHODS: An algorithm for the management of chest tubes (CT) and ALs was applied prospectively to 101 consecutive patients who underwent elective pulmonary resection. Air leaks were graded daily as forced expiratory only, expiratory only, inspiratory only, or continuous. All CTs were kept on 20 cm of suction until postoperative day 2 and were then converted to water seal. On postoperative day 3, if both a pneumothorax and AL were present, the CT was placed to 10 cm H2O of suction. If a pneumothorax was present without an AL, the CT was returned to 20 cm H2O of suction. Air leaks that persisted after postoperative day 7 were treated with talc slurry. RESULTS: There were 101 patients (67 men); on postoperative day 1, 26 had ALs and all were expiratory only. Univariable analysis showed a low ratio of forced expiratory volume in 1 second to forced vital capacity (FEV1/FVC) (p = 0.005), increased age (p = 0.007), increased ratio of residual volume to total lung capacity (RV/TLC) (p = 0.04), increased RV (p = 0.02), and an increased functional residual capacity (FRC) (p = 0.02) to predict the presence of an AL on postoperative day 1. By postoperative day 2, 22 patients had expiratory ALs. After 12 hours of water seal, 13 of the 22 patients' ALs had stopped, and 3 more sealed by the morning of postoperative day 3. However, 2 of the 6 patients whose ALs continued experienced a pneumothorax. Five of the 6 patients with ALs on postoperative day 4 still had ALs on postoperative day 7, and all were treated by talc slurry through the CT. All ALs resolved within 24 hours after talc slurry. CONCLUSIONS: Most ALs after pulmonary resection are expiratory only. A low FEV1/FVC ratio, increased age, increased RV/TLC ratio, increased RV, and an increased FRC were predictors of having an ALs on postoperative day 1. Conversion from suction to water seal is an effective way of sealing expiratory AL, and pneumothorax is rare. If an expiratory AL does not stop by postoperative day 4 it will probably persist until postoperative day 7, and talc slurry may be an effective treatment.     

Conserved structural features between HLA-DO beta and -DR beta

HLA-DO is a non-classical MHC class II molecule presumed to play a specialized role in the antigen processing pathway. We have modeled the HLA-DO beta-chain and found its overall structure compatible with the one of DR beta. Functional studies further highlighted the similarity between these beta-chains of the class II family of proteins. Indeed, a mixed heterodimer composed of the DR alpha and a chimeric DO beta-chains presented bacterial superantigens to T cells and was shown to interact with CD4. The implications of such structural conservation for the in vivo functions of HLA-DO are discussed.     

Differential responses of pulmonary arteries and veins to histamine and 5-HT in lung explants of guinea-pigs

1. The mechanisms by which histamine and 5-HT differentially contract pulmonary arteries and veins are unclear. In lung explants from 26 guinea-pigs, we compared responses of pulmonary arteries and vein to histamine, 5-HT and KCI, and examined potential determinants for the differential responses. Lungs were filled with agarose, sectioned into approximately 1 mm thick slices, and vascular luminal areas measured by image analysis. 2. Histamine and 5-HT produced a concentration-dependent constriction in arteries and veins, greater in the latter. KCl constricted arteries and veins equally. 3. The histamine H1 antagonist chlorpheniramine (10(-4) M) abolished contractions to histamine; the H2 antagonist cimetidine enhanced maximal responses and sensitivity of arteries and veins to histamine, and diminished the differences between their maximal responses; the NO synthase inhibitor Nomega-nitro-L-arginine (L-NOARG) increased the maximal responses of arteries and veins, and the differences between their responses; indomethacin had no effect. 4. Contractions to 5-HT were abolished in arteries and markedly reduced in veins by the 5-HT2 antagonist ketanserin (10(-4) M); L-NOARG potentiated the maximal responses of arteries but not of veins; indomethacin increased the maximal responses of arteries but reduced them in veins. 5. By morphometry, arteries had a greater medial thickness and luminal diameter than veins. 6. The data suggest that in guinea-pigs, H2 receptors are responsible for the differential contractile responses of pulmonary arteries and veins to histamine, whereas endothelium-derived vasoactive substances are responsible for their differential contractile responses to 5-HT.     

Aloe barbadensis extracts reduce the production of interleukin-10 after exposure to ultraviolet radiation

Cutaneous exposure to ultraviolet radiation suppresses the induction of T cell mediated responses such as contact and delayed type hypersensitivity (DTH) by altering the function of immune cells in the skin and causing the release of immunoregulatory cytokines. Extracts of crude Aloe barbadensis gel prevent this photosuppression. Because the regulation of contact hypersensitivity and DTH responses differ, we investigated whether protection was afforded by a single or multiple agents in Aloe and the mechanism by which this material prevents suppression of DTH immunity. The ability of Aloe gel to prevent suppression of contact hypersensitivity responses to hapten decayed rapidly after manufacture. In contrast, agents that protected against systemic suppression of DTH responses to Candida albicans were stable over time. Oligosaccharides prepared from purified Aloe polysaccharide prevented suppression of DTH responses in vivo and reduced the amount of IL-10 observed in ultraviolet irradiated murine epidermis. To assess the effect of Aloe extracts on keratinocytes, Pam 212 cells were exposed in vitro to ultraviolet radiation and treated for 1 h with Aloe oligosaccharides. Culture supernatants were collected 24 h later and injected into mice. Supernatants from ultraviolet irradiated keratinocytes suppressed the induction of DTH responses, whereas Aloe oligosaccharide treatment reduced IL-10 and blocked the suppressive activity of the supernatants. These results indicate that Aloe contains multiple immunoprotective factors and that Aloe oligosaccharides may prevent ultraviolet induced suppression of DTH by reducing keratinocyte derived immunosuppressive cytokines.