Clinical evaluation of bioactive glass in the treatment of periodontal osseous defects in humans

The purpose of this study was to compare the use of bioactive glass to demineralized freeze-dried bone allograft (DFDBA) in the treatment of human periodontal osseous defects. Fifteen systemically healthy patients (6 males and 9 females, aged 30 to 63) with moderate to advanced adult periodontitis were selected for the study. All patients underwent initial therapy, which included scaling and root planing, oral hygiene instruction, and an occlusal adjustment when indicated, followed by re-evaluation 4 to 6 weeks later. Paired osseous defects in each subject were randomly selected to receive grafts of bioactive glass or DFDBA. Both soft and hard tissue measurements were taken the day of surgery (baseline) and at the 6-month re-entry surgery. The clinical examiner was calibrated and blinded to the surgical procedures, while the surgeon was masked to the clinical measurements. Statistical analysis was performed by using the paired Student's t test. The results indicated that probing depths were reduced by 3.07 +/- 0.80 mm with the bioactive glass and 2.60 +/- 1.40 mm with DFDBA. Sites grafted with bioactive glass resulted in 2.27 +/- 0.88 mm attachment level gain, while sites grafted with DFDBA had a 1.93 +/- 1.33 mm gain in attachment. Bioactive glass sites displayed 0.53 +/- 0.64 mm of crestal resorption and 2.73 mm bone fill. DFDBA-grafted sites experienced 0.80 +/- 0.56 mm of crestal resorption and 2.80 mm defect fill. The use of bioactive glass resulted in 61.8% bone fill and 73.33% defect resolution. DFDBA-grafted defects showed similar results, with 62.5% bone fill and 80.87% defect resolution. Both treatments provided soft and hard tissue improvements when compared to baseline (P < or = 0.0001). No statistical difference was found when comparing bioactive glass to DFDBA; however, studies with larger sample sizes may reveal true differences between the materials. This study suggests that bioactive glass is capable of producing results in the short term (6 months) similar to that of DFDBA when used in moderate to deep intrabony periodontal defects.     

Ward versus intensive care management of high-risk surgical patients

BACKGROUND: Selection of high-risk surgical patients for preoperative and perioperative admission to an intensive therapy unit (ITU) for enhancement of oxygen delivery may reduce postoperative morbidity and mortality rates. Limited resources may prevent admission of all suitable patients. This audit study examined whether it is possible to select patients most at risk and thus reduce surgical morbidity and mortality rates when ITU services are limited. METHODS: This was a retrospective audit comparing the actual outcomes of complications and death with predicted outcomes using the POSSUM score (Physiological and Operative Severity Score for the enUmeration of Mortality and morbidity) for 101 general surgical and vascular patients who would have fulfilled previously suggested criteria for preoperative admission to the ITU. Main outcome measures were the number of preoperative ITU admission criteria, American Society of Anesthesiologists (ASA) and POSSUM scores, preoperative oxygen delivery values, intravenous fluid therapy, length of ITU stay, length of hospital stay, postoperative complications and 28-day mortality. RESULTS: Medical staff allocated patients appropriately. There was a lower mortality rate than predicted from individual POSSUM scores. Patients who were admitted to the ITU before operation had the highest ASA scores, admission criteria and POSSUM scores; they also had significantly lower mortality and morbidity rates than predicted by the POSSUM scoring system. CONCLUSION: Patients with the greatest reduction in mortality and morbidity rates were admitted to the ITU before operation and had cardiovascular physiology 'optimized' before surgery.     

A condemnation of subcutaneous fasciotomy

Controversy exists regarding the indications and methods for lower-extremity fasciotomy. Two recent cases at our institution in which recurrent, acute limb-threatening ischemia occurred despite adequate fascial division have convinced us that in certain situations subcutaneous fasciotomy is clearly inadequate. In both patients, both of whom were young, intact healthy skin between the lower extent of the incision and the malleolus acted as a tourniquet, causing recurrent compartment syndrome as reperfusion edema occurred after initial repair. We believe that therapeutic fasciotomy in young patients with relatively noncompliant skin should include division of skin from the knee to the ankle on at least one side to prevent a tourniquet effect by intact skin at the ankle.     

Transient central hypothyroidism as a cause of failure to thrive in newborns and infants

The course of two neonates and one 4-month-old infant with laboratory and clinical evidence of central hypothyroidism is described. All three presented with failure to thrive and improved after L-T4 therapy. Early recognition and treatment of newborns and infants with central hypothyroidism is important to maximize the potential for growth and development. Two of the three infants have been documented to have transient central hypothyroidism of hypothalamic origin, not previously reported.     

Diamniotic placentation associated with omphalopagus conjoined twins: implications for a contemporary model of conjoined twinning

We have studied omphalopagus conjoined twins with a diamniotic monochorionic placenta. Although conjoined twins usually present in a single amniotic sac, one other example of diamniotic placenta has been reported in omphalopagus twins [Weston et al., 1990: Am J Med Genet 37:558-561]. Most theories concerning the pathogenesis of conjoined twinning exclude the possibility of diamniotic placentation. However, Spencer [1992: Teratology 45:591-602] recently elaborated a model for conjoined twinning based on duplication of organizing centers (primitive streaks) during gastrulation. We have considered the fate of embryonic membranes according to this model of omphalopagus twinning and show that diamniotic placentation is a predictable outcome.     

How well does number of parents explain unique variance in self-reported drug use?

Data from an anonymous survey of 3,690 adolescents were used to assess how much of the unique variance in adolescents' self-reported drug use was accounted for by number of parents in comparison to the adolescents' sex, age, social class, and peer drug use. Multiple regression revealed that the contribution of number of parents was small and nonsignificant compared to peer use, student age, parental occupation and remarriage, student sex, and parental unemployment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Antimicrobial prophylaxis for catheter-associated bacteriuria

We evaluated short-term systemic antimicrobial prophylaxis for catheter-associated bacteriuria in women undergoing elective gynecological operations in a prospective, controlled, double-masked study. Nine of 100 placebo-treated patients acquired bacteriuria during catheterization compared with 3 of 96 of the drug-treated group. However, at the time of hospital discharge, clean-voided urine specimens were positive as frequently in the drug-treated group (8 of 82 patients cultured) as in the placebo group (8 of 75 patients cultured). No difference in febrile morbidity due to bacteriuria was noted between the prophylaxis and placebo groups. The incidence of catheter-associated bacteriuria may be reduced by antimicrobial prophylaxis. However, because the protective effect is transient and is associated with the selection of resistant organisms, prophylaxis is not indicated for patients at low risk for acquired bacteriuria and in whom the sequelae of catheter-associated infections are infrequent.     

Absorption and magnetic circular dichroism spectra of nonequilibrium states of hemoproteins. III. Complexes of peroxidase

Absorption and magnetic curcular dichroism spectra of nonequilibrium states of peroxidase and its complexes with F-, N3-, CN- produced by reduction of oxidased forms of proteins by thermalysed electrons at 77 degrees K were studied. Mixtures of high spin and low spin ferroforms were found in nonequilibrium states of peroxidase and complexes with F- and N3-, the content of the high spin ferroform increasing as follows: N3- complex less than peroxidase less than fluorine complex. Only low spin ferroforms was found after low temperature reduction of the cyanide complex. The existence of the low spin ferroform in equilibrium states of peroxidase and its complex with F- was explained by location of iron near the porphyrine plane. In the case of azide and cyanide complexes the existence of the low spin form is due to the presence of these ligands in heme iron's coordination sphere. The temperature relaxation of all nonequilibrium forms was investigated and a possible mechanism of the process is proposed.     

Simple mathematical models with very complicated dynamics

First-order difference equations arise in many contexts in the biological, economic and social sciences. Such equations, even though simple and deterministic, can exhibit a surprising array of dynamical behaviour, from stable points, to a bifurcating hiearchy of stable cycles, to apparently random fluctuations. There are consequently many fascinating problems, some concerned with delicate mathematical aspects of the fine structure of the trajectories, and some concerned with the practical implications and applications. This is an interpretive review of them.