Day of week of procedure and 30 day mortality for elective surgery: retrospective analysis of hospital episode statistics.

OBJECTIVES: To assess the association between mortality and the day of elective surgical procedure. DESIGN: Retrospective analysis of national hospital administrative data. SETTING: All acute and specialist English hospitals carrying out elective surgery over three financial years, from 2008-09 to 2010-11. PARTICIPANTS: Patients undergoing elective surgery in English public hospitals. MAIN OUTCOME MEASURE: Death in or out of hospital within 30 days of the procedure. RESULTS: There were 27,582 deaths within 30 days after 4,133,346 inpatient admissions for elective operating room procedures (overall crude mortality rate 6.7 per 1000). The number of weekday and weekend procedures decreased over the three years (by 4.5% and 26.8%, respectively). The adjusted odds of death were 44% and 82% higher, respectively, if the procedures were carried out on Friday (odds ratio 1.44, 95% confidence interval 1.39 to 1.50) or a weekend (1.82, 1.71 to 1.94) compared with Monday. CONCLUSIONS: The study suggests a higher risk of death for patients who have elective surgical procedures carried out later in the working week and at the weekend.

Iron oxide-based nanoparticles with different mean sizes obtained by the laser pyrolysis: structural and magnetic properties.

Nano-sized iron oxide-based particles have been directly synthesized by the laser induced pyrolysis of a mixture containing iron pentacarbonyl/air (as oxidizer)/ethylene (as sensitizer). In this paper we further demonstrate the possibility to vary the chemical composition and the nanoparticle dimensions of the iron oxide-based materials by handling the oxidation procedure in the frame of the laser pyrolysis process. Thus, nanoparticles with major maghemite/magnetite content may change composition into mixtures with variable amounts of three components: major gamma-Fe2O3/Fe3O4 iron oxide, metallic Fe and cementite Fe3C. By X-ray diffraction (XRD) it is found that the relative proportion of these phases differs in function of the reaction temperature (laser power). As revealed by transmission electron microscopy (TEM), mean particle sizes between about 4 nm and 6 nm and between about 9 and 11 nm may be prepared by varying the oxidation procedure and the laser power, respectively. By the controlled heating of samples (maximum temperature 185 degrees C), increased crystallinity for the gamma-Fe2O3/Fe3O4 oxide phase was found as well as an increase of the mean particle diameters. The examination of the magnetization curves for samples obtained for different laser powers indicates notable differences in the magnetic behavior and parameters. The temperature dependent Mossbauer measurements confirm the formation of larger particles at higher laser power densities as well as the presence of inter-particle magnetic interactions. On this basis, the estimation of phase composition for the different representative samples is given.

Reliability of measurements of pressures applied on the foot during walking by a computerized insole sensor system.

OBJECTIVE: To evaluate the reliability of measurements of foot pressures while walking using the F-scan computerized system with various insole sensors. DESIGN: Ten healthy subjects were studied. Each used four different pairs of insoles while walking for three 6-second epochs per insole. Peak pressures were recorded at the hindfoot, midfoot, and forefoot and analyzed. Each insole was made of pressure-sensitive 25 mm 2 cells, embedded in protective backing, and scanned electronically every 50 to 100 msec. SETTING AND PARTICIPANTS: Conventional tile floor in a gait laboratory on 10 consecutive normal subjects. RESULTS: The mean +/- standard deviation peak pressure recorded at the hindfoot was 11.1 +/- 2.0 psi; at the midfoot, 3.5 +/- 1.5 psi; and at the forefoot, 11.3 +/- 2.6 psi. The intrasubject mean differences were 0.2 psi at the hindfoot, 0.4 psi at the midfoot, and 0.3 psi at the forefoot. The data suggest that variability between different insoles is not significant. CONCLUSION: The pressure data show these insoles to be sufficiently reliable for use in patients when knowledge of foot pressure distribution is important for the relief of pain, and for designing and assessing appropriate corrective measures to relieve excessive pressure on the foot and to prevent development of pressure ulcers.

Teenagers, young people and family planning: a survey in five Romanian high schools.

Family planning was for a long time prohibited in Romania. This has reduced the demand for contraceptives. Even though contraceptives were made accessible and their use promoted since the beginning of December 1989, abortion has still been the preferred form of fertility regulation, as the people of Romania are unaware of the advantages of contraception. The purpose of the present survey was to assess the level of sexual knowledge, attitudes and practice of teenagers and young people from urban areas of Romania and to identify if there was any significant difference in terms of age, education and sexual activity. A baseline examination was undertaken in which data were collected from 279 students who attended five high schools and six post high schools from the Moldavia cities, Iassy, Piatra-Neamt and Bîrlad. Students were asked to complete a self administered questionnaire, and a 97.5% response rate for the whole survey was achieved. Difference between answers were tested using chi-square test from 2x2 table and median test, average. A P-value <0.05 was considered to be significant. The study established that knowledge, attitudes and practice vary by age (adolescents (< or =19y) vs young people (>19y)) and education (high school vs post high school) in some regards. At the aggregate level, regarding knowledge, a statistically significant difference was found between adolescents and young people; but no statistically significant difference was found between high school and post high school students. Apart from lack of basic knowledge the study confirmed that many false beliefs regarding contraceptives are held by the survey participants. People who were sexually active were no better informed than the rest of survey participants, but they had a significantly higher percentage of positive attitudes regarding effectiveness of pills and withdrawal. Both, the knowledge and attitudes of students necessarily required appropriate sex education which, ideally should be introduced before young people become sexually active.

PIP: This survey aimed to explore the association between sexual knowledge, attitudes, and practices and selected sociodemographic factors among students. A baseline investigation was conducted among 279 students attending 5 high schools and 6 post-high schools from the cities of Iassy, Piatra-Neamt, and Birlad. A response rate of 97.5% was achieved after completing the self-administered questionnaire. The study indicated that sexual knowledge, attitudes, and practices vary by age and education. A significant difference on knowledge was noted between adolescents and young people, but was insignificant among high school and post-high school students. Apart from the lack of knowledge, the study confirmed that many false beliefs regarding family planning, particularly contraceptives, are held by the surveyed participants. In addition, sexually active participants have a higher percentage of positive attitudes towards the efficacy of pills and the withdrawal method. Knowledge and attitudes of students, as reflected in the study, necessitates appropriate sex education, which ideally should be introduced before they become sexually active.

Studies on the intermolecular forces involved in the antibody-antigen interactions, using V3 synthetic peptides and sera from HIV1 seropositive patients.

The nature of physical forces responsible for the antibody-antigen (Ab-Ag) reaction was analyzed in an original system, represented by synthetic peptides derived from the V3 consensus sequences of some HIV1 subtypes gp 120 and HIV1 positive human serum. For locating antigenic determines, flexibility, hydrophilicity and hydrophobicity profiles of the V3 peptides were analysed. The hydrophilicity indicates that V3 apex borders are involved in the first stage of the reaction. The flexibility and hydrophobicity suggest that the apex of the V3 loop (GPGR/Q) is involved in the stabilization of the complex by hydrophobic interactions. Further, we followed up the influence of the dielectric constant and of the pH upon the forces established between Ab and Ag. Modifications in the dielectric constant and pH reveal a significant contribution of electrostatic and van der Waals forces in securing the intermolecular complementarity. D2O produces the highest augmentation of the antibody affinity for the most hydrophilic peptides, while a very slight one was recorded for the most hydrophobic sequence. A high affinity of antibodies for the peptides MN, R and Z was registered at an acid pH, when their His residue was protonated. On the contrary, no influence was recorded in the case of the peptide A, which does not contain any His residue.

Tissue lipid peroxidation may be triggered by increased formation of bilirubin in vivo.

Following the administration of phenylhydrazine, cadmium chloride and ethanol to rats there was a marked increase in the concentration of liver lipid peroxides and a sharp decline in GSH levels. The oxidative stress generated by the action of these toxic compounds led to the induction of liver heme oxygenase, which exhibited a 3-fold increase in activity over the control value. Patients with various forms of liver disorders showed increased levels of plasma lipid peroxides as well as hyperbilirubinemia. In view of the known ability of bilirubin to cause lipid peroxidation in illuminated erythrocyte membranes, the results of the present paper suggest that in severely impaired liver, as in some liver diseases, lipid peroxides may be also produced by a mechanism involving heme oxygenase.

Considerations about the prophylactic role of T cell vaccination in HIV infection.

The AIDS epidemic in Romania has properties that are both common to countries of Eastern Europe and unique to Romania. The unique aspects include the large number of cases in children infected parenterally and a relatively low but steadily increasing number of HIV infected adults. Other groups of children and adults were also exposed at risk to acquire HIV by transfusion with unscreened blood or by multiple parenteral treatments with potentially contaminated needles. Our hypothesis was that a substantial number of people in area of high endemicity was "silently" infected but did not undergo specific immune response or clinical signs. In an attempt to explore the possibility that immunization with autologous proteins (consequence of multiple transfusions) can play a role in the protection from HIV infection or in slowing down the progression of disease, we compared the incidence of autoantibodies (anti-nuclear, smooth muscle and anti-HEp-2) in a group of long survivors children with AIDS, in HIV infected children with rapid evolution and in adults at risk for parenteral acquisition of blood borne viral disease. We analyzed also the incidence of some blood borne viral infections and the presence of anti-HLA antibodies in the same groups of patients. Our results do not support the suggestion that HIV infection or AIDS can be prevented, respectively, delayed by T-cell vaccination.

Preliminary results of HIV screening in sentinel facilities in Romania.

In the first months of 1994, 393 patients (random consecutive clinic attenders) from three sentinel clinics were tested for anti-V3 loop antibodies in ELISA with a branched synthetic peptide reproducing eight copies of full V3 sequence. Compared with a commercial HIV 1/2 ELISA kit the sensitivity of anti-V3 assay was 97.6% and the specificity 89.7%. The seroprevalence in women attending prenatal clinic was 7.54% and in children with multiple hospitalization record, 3.82%. Both heterosexual and parenteral transmission through unsafe medical practices fuel actual AIDS epidemic in Romania.

The variations of the serum IgD and of the circulant immune complexes in diabetic patients.

The levels of serum IgD and of the circulating immune complexes (CIC) were determined in 168 diabetic patients, of whom 78 with type 1, 59 with type 2 and 31 with the so-called "intermediary" type of the disease, in comparison with 124 non-diabetic subjects for IgD and 100 for CIC. The results revealed very low IgD titres (less than 1 mg%, considered undetectable) in almost 3/4 of the cases; values over 1 mg% were recorded mostly in the cases of type 1, followed by those of "intermediary" and of type 2 diabetes. The mean CIC values of 67.13 +/- 36.53 optic density units (O.D.U.) were significantly higher than in the non-diabetic controls. Certain differences with respect to age, diabetes type, duration of the disease and of the insulin therapy were also recorded. The data are interpreted with caution, further investigations being necessary to the assertion of definite conclusions.

[Quantitative and qualitative changes in the immunoglobulins of HIV-infected children]. / Modifications quantitatives et qualitatives des immunoglobulines chez les enfants infectés par le HIV.

In HIV-infected children impairment of B lymphocytes appears to precede the T cell deficiency, elevated but dysfunctional immunoglobulins being a hallmark of pediatric infection. Electrophoretic and immunochemical data obtained with samples from 91 cases of AIDS in children aged 7-36 months in P2 clinical stage are reported. In 21 children successive samples were obtained at each 3-4 months for a one-year follow-up. In electrophoresis low albumin level and marked increase of globulins level were noted. In immunodiffusion all Ig classes but especially IgG were increased. HI measles antibodies titers in all these samples were negative or very low in spite of measles vaccination positive record. Distinct from adult AIDS where absolute number of pan T and CD4 positive lymphocytes are good predictive markers, in pediatric AIDS estimation of quantitative and qualitative changes of immunoglobulins is useful for clinical diagnosis and follow-up of patients.

The significance of the peroxides increase in the plasma of the patients with liver failure.

200 patients with varied types of liver failure were biochemically and clinically investigated. Beside the usual biochemical analyses (transaminases, glutamyl transpeptidase, triglycerides, bilirubin), some special parameters such as lipid peroxides, glutathione, ceruloplasmin and the total antioxidative capacity of plasma were measured. High levels of lipid peroxides appear especially in severe cases of liver failure such as acute viral hepatitis, coma. The persistence of a high level of peroxides in plasma suggests the presence of severe, irreversible lesions. The increase of peroxides in the plasma is mainly due to the overridden production of antioxidative systems, localized especially in the liver. In severe liver failure, the mechanism of the increased formation of peroxides seems to involve bilirubin, due to induction of liver heme oxygenase. The data presented showed inverse correlations between the increase of peroxides and the decrease of glutathione and ceruloplasmin.

Relationship between the lead concentration in hair and occupational exposure.

The lead content of hair in workers occupationally exposed was correlated with the blood lead concentration. Determinations of lead in blood and hair were performed by electrothermal atomic absorption spectrophotometry in two exposed groups and a control group. A significant correlation was observed between the blood lead and hair lead concentrations, and a regression analysis showed an exponential accumulation of the lead content in hair, simultaneously with the increase of the values in blood. The colour of the hair and the age of the subject did not influence the lead accumulation in hair in the occupationally exposed subjects. The assessment of lead in hair is considered a useful screening test in estimating occupational exposure.

[Study of the incorporation of radioactive zinc in Saccharomyces cerevisiae aldolase]. / Studiul încorporarii zincului radioactiv in aldolaza din Saccharomyces cerevisiae

Saccharomyces cerevisiae aldolase concentrates from the culture medium containing ZnSO4 a large amount of Zn which becomes a component part of the enzyme molecular structure. This was made evident by adding to the culture medium 65ZnSO4 and measuring the radioactivity of the aldolase extracted by a Phillips single channel analyzer.

[Study of purified aldolase from Saccharomyces cerevisiae, using irradiated fructose-1,6-diphosphate]. / Investigarea aldolazei purificate din Saccharomyces cerevisiae cu ajutorul fructozo-1,6-difosfatului iradiat

The interaction of an electromagnetic field with the enzymatic substrate-- the sodium salt of fructose-1,6-disphosphate--induces in the latter a new type of physical transition S leads to S. The enzyme, in this case Saccharomyces cerevisiae aldolase, is able to reveal this new state of the substrate by an increase in its specific activity within well established irradiation times. Each enzyme is characterized by the tm (minimal irradiation time of the substrate) a tau (fixed time period) parameters that delimit the two signals. Purified S. cerevisiae aldolase has tm=5 sec. and tau=20 sec., in contrast to muscle aldolase (represented by class I aldolase) which has tm=15 sec. and tau=30 sec. This may be attributed to the fact that most of the enzymatic systems in S. cerevisiae are made up of several distinct molecular forms, involved in more metabolic pathways than in the animal tissue, therefore with various responses to the phenomenon of perturbation of the substrates.

[Clinical and biological aspects of chronic brucellosis]. / Delimitari clinice si biologice în bruceloza cronica

The present study refers to 53 cases of chronic brucellosis admitted to the clinic or followed up in an out-patient unit for ten years (1962-1971). There was a total of 946 days in hospital and 1688 days of occupational disability, about 40% of the patients necessitating repeated hospitalization because of the relapsing course of the disease. This group of cases presented the classical dominant features of an occupational anthropozoonoses (90.5%). Elements of visceral and tissular pathology, obviously conditioned in their structure by the stage of the disease, were found in cardiovascular, hepatic, nervous, osteoarticular, orchitic, ocular, cutaneous localizations, etc. Their associated character particularize the polyvisceral forms. The immunopathology of chronic brucellosis is marked by its dynamics and frequently dissociated character of the sero-allergic diagnostic reactions. Blood proteins behave unequally (hypoalbuminemia, hyperalpha1-, hyperalpha2- and hypergammaglobulinemia). There is still debate about the terapeutic attempts, although sigmamycin associated with cortisone derivatives reduce or temporize the relapsing evolution, opening up new therapeutical perspectives.