Comparative Survival Analysis of Urea Kinetic Based Indices

Background

Although urea kinetic modeling indices for measuring dialysis dose are recommended by world expert groups, it is not quite clear whether some of these are superior in predicting the outcome over others. This prospective, single-center study was carried out with the aim to compare predictive value of different indices and methods of measuring dialysis dose.

Methods

The analysis included 93 anuric patients having been on hemodialysis for at least 2 years who were followed-up for 75-months. The dialysis dose was measured by Kt/V (formal UKM, 3 and 2 urea samples), Kt/V (Daugirdas), Kt/V (Lowrie), eKt/V (Daugirdas), URR and TAC urea.

Results

Correlations between dialysis indices and survival time were significant for all indices (p<0.01) except for TAC. All indices, except for TAC urea, were significant predictors of mortality (multivariate Cox regression analysis; p<0.01) and differences of significant levels among these colinear parameters were small.

Conclusion

All examined indices except for TAC urea were highly predictive of patient mortality. Daugirdas and Lowrie simplified Kt/V indices are as predictive of all-cause mortality as more complex formal UKM methods in long-term patients on a 3×4h/week schedule.

Internal stress and defect-related free volume in submicrocrystalline Ni studied by neutron diffraction and difference dilatometry

A combined study of neutron diffraction and difference dilatometry on submicrocrystalline Ni prepared by high pressure torsion aims at studying the anisotropic behaviour during dilatometry and its relation to internal stress and structural anisotropy. Macroscopic stresses were undetectable in the dilatometer samples. Along with specific tests such as post cold-rolling, this shows that an observed anisotropic length change upon annealing is not caused by internal stress, but can be explained by the inherent microstructure, i.e. the anisotropic annealing of relaxed vacancies at grain boundaries of shape-anisotropic crystallites.

Investigation of the 3-D actinic flux field in mountainous terrain

During three field campaigns spectral actinic flux was measured from 290-500 nm under clear sky conditions in Alpine terrain and the associated O3- and NO2-photolysis frequencies were calculated and the measurement products were then compared with 1-D- and 3-D-model calculations. To do this 3-D-radiative transfer model was adapted for actinic flux calculations in mountainous terrain and the maps of the actinic flux field at the surface, calculated with the 3-D-radiative transfer model, are given. The differences between the 3-D- and 1-D-model results for selected days during the campaigns are shown, together with the ratios of the modeled actinic flux values to the measurements. In many cases the 1-D-model overestimates actinic flux by more than the measurement uncertainty of 10%. The results of using a 3-D-model generally show significantly lower values, and can underestimate the actinic flux by up to 30%. This case study attempts to quantify the impact of snow cover in combination with topography on spectral actinic flux. The impact of snow cover on the actinic flux was ~ 25% in narrow snow covered valleys, but for snow free areas there were no significant changes due snow cover in the surrounding area and it is found that the effect snow-cover at distances over 5 km from the point of interest was below 5%. Overall the 3-D-model can calculate actinic flux to the same accuracy as the 1-D-model for single points, but gives a much more realistic view of the surface actinic flux field in mountains as topography and obstruction of the horizon are taken into account.

New strategies for polymer development in pharmaceutical science--a short review

We are developing synthetic polymers for pharmaceutical and medical applications. These applications can be broadly grouped on how the polymer will be utilized e.g. material, excipient or molecule. Our focus is to develop polymers with more defined structures that are based on biological, physicochemical and/or materials criteria. Strategies are being developed to more efficiently optimize structure-property correlations during preclinical development. We describe two examples of our research on pharmaceutical polymer development: narrow molecular weight distribution (MWD) homopolymeric precursors which can be functionalized to give families of narrow MWD homo- and co-polymers, and hydrolytically degradable polymers.

Antimicrobial resistance of Streptococcus pneumoniae recovered from outpatients with respiratory tract infections in Germany from 1998 to 1999: results of a national surveillance study

Clinically significant pneumococcal isolates were prospectively collected from outpatients with respiratory tract infections by 19 different clinical microbiology laboratories in Germany. Resistance rates in a total of 961 isolates were as follows: penicillin, 6.6%; clarithromycin, 10.6%; tetracycline, 13.9%; and levofloxacin, 0.1%. Among 324 isolates from children, pneumococcal serotypes 19F (17.0%), 23F (13.0%), and 6B (11.7%) were the predominant types.

Does tuberculosis after kidney transplantation follow the trend of tuberculosis in general population?

Despite improvement in graft survival, infection continues to be an important cause of morbidity and mortality after kidney transplantation. We analyzed the clinical courses and outcomes of 16 transplanted patients with positive cultures for mycobacterium tuberculosis. In the course of a 20 year period, there were 13 cases of tuberculosis registered that developed in 456 patients who underwent kidney transplantation in our department, and in three refugees transplanted in other centers (a prevalence of 3.13%). Five of them developed tuberculous infections during 1997. Five patients had residual tuberculosis in preoperative chest X-ray, and specific pyelonephritis as an underlying kidney disease in two of them. All patients with treated with triple immunosuppressives. Before tuberculosis onset, 14 patients experienced one or more episodes of acute rejection and were treated with steroid pulses, ALG or OKT3. Tuberculosis was diagnosed after a period of 1.5 months to 10 years after transplantation. At the time of an infection, the graft function was normal in eight patients and chronic graft failure was evident in eight patients (sCr 210-700 micromol/L). The infection was pulmonary in 12 patients; urinary in two; disseminated in two; pulmonary and urinary, pulmonary and intestinal, and pancytopenia in one patient. All patients were treated with rifampicin and isoniazid in addition to ethambutol for the first two-month period. Treatment lasted from 1-22 months. With 14 patients favorable microbiological responses were registered. Two patients died within the first six months (both with disseminated disease), and the mortality rate was 14.3%. Throughout the followup period, the graft function remained stable and normal in eight patients who had normal graft function at the time of infection onset. Although six patients recovered, progressive graft failure developed and hemodialysis was restarted in one patient two months after antituberculous therapy introduction, and in two patients three years later. Four patients died 2-14 months after AT therapy withdrawal. The causes of death were severe liver failure, cerebrovascular insult and CMV.

Effect of topography on average surface albedo in the ultraviolet wavelength range

The reflectivity of the 22 km x 24 km region surrounding Sonnblick Observatory near Salzburg, Austria (3104-m altitude, 47.05 degrees N, 12.95 degrees E), was calculated with a three-dimensional albedo model. The average albedo of the region was calculated at 305 and 380 nm for different solar zenith angles, ground reflectances, and solar azimuth angles. To determine geometrical effects, we first carried out the simulations without taking account of the effects of the atmosphere. The ratio to the reflectivity of a corresponding flat surface area (area with the same ground characteristics) was always less than 1 and showed a decrease with increasing solar zenith angle and with diminishing ground reflectance. Even when the ground reflectance was 100%, the average albedo was less than 1. The effect of the atmosphere was then taken into consideration in these calculations and was found to diminish the reflected components. This diminishing effect was compensated for, however, by the scattered irradiance. Finally, simulations of real conditions (nonhomogeneous ground reflectivities) were performed for different snow lines in the Sonnblick region. The average albedos obtained when all the surroundings were covered with snow were 0.32-0.63 with low solar zenith angles and 0.38-0.77 with a 40 degrees solar zenith angle.

The survey of healthcare software in Yugoslavia

The aim of this study is to identify vendors of software packages applicable to health care system as well as to evaluate software packages offered to the health sector by a variety of sources, namely state owned software development companies, privately operated software development companies as well as sole traders. The approach undertaken was to preselect the potential suppliers via an initial targeted interview. Subsequently a questionnaire, consisting of 23 questions, was addressed to the selected vendors and suppliers. The response rate to the questionnaire was 58%. Investigation of 113 has revealed the non government software suppliers clearly lead in copyright ownership, IBM compatible personal computers were the platform of choice whereas majority of code was written utilising languages capable of supporting relational data base queries. The final outcome of the above study is a database of software packages and applications available to the health sector offering the health professionals and institutions guide lines and support in developing information systems, relevant subsystems and modules.

Personal identifying number as a unique patient identifier in database on clinically treated patients in Belgrade: its use, advantages and drawbacks

Database on clinically treated patients in Belgrade served as an example for analysis of possibilities for the use of Personal Identifying Number (PIN) as an Unique Patient Identifier. In the first part of the paper we analyzed filling up of the fields which contained data on PIN within complete databases in 1981, 1991 and 1996. Filling up of PIN was significantly changed in the three observed years: it was 18% in 1981; 68% in 1991, and 56% in 1996 respectively. Analysis of interactions among the chosen factors (type of hospital, demographic and social characteristics of patients, length of stay in hospital, manner of treatment, main diagnosis, treatment outcome) and measuring time, showed a different degree of statistical significance. In the second part of our paper we analyzed the unexpected decrease in filling up of PIN in 1996 (as compared to 1991) ussing the method of logistic regression, on 1% samples from the databases for the two respective years. On the basis of obtained models of filling up of UPI data, taken as dependent variable and the above factors (predictors) we analyzed the advantages and drawbacks of UPI application as an unique patient identifier.

Developing mortality patterns: robust modified generalized likelihood ratio algorithm for infant mortality rate change detection

A new robust modified generalized likelihood ratio algorithm, which enables the changes of mortality rates to be detected automatically, is applied. The procedure is based on the calculation of discrimination function using robust least squares estimates of AR mortality rates residuals. The feasibility of the approach is demonstrated with experimental data concerning infant mortality rate in Serbia.

Management of hospital discharge data in Belgrade

The paper presents a database on clinically treated patients in Belgrade, a computerized health-statistics information sub-system. It also analyses the organisation of report processing related to hospitalisation, types of indicators on hospital treatment (which are the result of such a processing) as well as their further utilisation on different levels of management within the system of health care in Belgrade.

Nutritional effects of the siege on new-born babies in Sarajevo

OBJECTIVE

To investigate the influence of maternal nutrition on perinatal mortality, morbidity, malformations and low birth weight (< 2500 grams).

DESIGN

All mothers and their babies born in Kosevo Hospital during three different time periods were sampled: September 1992 to February 1993 (pilot study), May 1993 to February 1994 (main study) and statistics compiled in 1991 (pre-war).

SETTING

Data were collected at the gynaecology and obstetric clinic, Kosevo hospital, city of Sarajevo.

SUBJECTS

A total of 920 babies were included in the pilot study, 1225 mothers of 1237 babies participated in the main study and birth data from 8676 babies born in 1991 were used as baseline data.

INTERVENTIONS

Birth outcome data were compiled for all three time periods. In the main study, a questionnaire was administered on arrival at the clinic in which mothers were asked to estimate their weight prior to pregnancy. Information on energy and protein intake was collected for all women by estimating weekly food intake during pregnancy. Mothers were weighed and had their heights measured within 12 hours of delivery. Women were divided into three groups based on their body mass index (BMI) using self-reported prepregnancy weight (underweight BMI < 21.5; normal weight BMI 21.5-25.6; overweight BMI > 25.6). Four groups were defined according to dietary intake during pregnancy (daily energy intake < 2755 kcal and 2755 + kcal; protein intake < 80 and 80 + grams).

RESULTS

Weight gain during pregnancy was low in overweight women (3.2 kg) compared with normal weight (10.4 kg) and underweight (11.7 kg) women. Underweight women had babies with the lowest mean birthweight (3072 grams) and the highest percentage of low birth weight babies (13.0%). Perinatal mortality increased from 15.8/1000 live births in 1991 (pre-war) to 36/1000 in May 1993-February 1994. Morbidity among babies increased from 3.4% to 8.2% in the same time period. There was a significant increase in babies born with malformations from 0.4% in the pre-war period to 3.0% in May 1993 to February 1994.

CONCLUSIONS

It is concluded that the war has had a deleterious effect on birth outcomes in Sarajevo.

Evaluation of the epidemiology of hepatitis B virus cross-infection in a maternity hospital

OBJECTIVE

To determine the hepatitis B infection risk in a university hospital of obstetrics and gynecology.

SETTING

The University Hospital of Obstetrics and Gynecology, The University of Sarajevo, Yugoslavia.

DESIGN

Staff members were divided into three groups: 73 doctors, 184 medical technicians working in delivery rooms, and 55 medical technicians working with postnatal care. The patients were 63 women, aged 17 to 39 years (mean = 26.11 years), pregnant for the first time and in the first stage of labor. Participants all had a negative history of hepatitis B and no known contact with the hepatitis B virus.

RESULTS

The incidence of hepatitis B infections among physicians, technicians, and postnatal care technicians was 1.36%, 3.8%, and 3.6%, respectively. The incidence among patients was 4.76%. The daily infection risk varied between 1% and 17% of all deliveries.

CONCLUSIONS

The risks of transmission of the hepatitis B virus to hospital workers in this setting is indeed high enough to make a case for hepatitis B vaccination in susceptible staff members. Even if vaccination of staff members is carried out, hygienic measures to prevent the transmission of bloodborne infection between patients and from patients to staff are of the utmost importance.

A new dry extract of cascara (Rhamnus purshiana D.C. bark)

The B.P. method of preparing a dry extract of cascara leads to significant breakdown of O-glycoside links in the active compounds. This is shown to be due to enzyme activity during percolation. A dry extract, containing most of the active glycosides originally present in the bark with no change in glycosylation status, can be prepared using boiling water as extracting solvent. A modification of the chemical assay process is recommended as well as the use of an official standardized extract with upper and lower limits for glycoside content.