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Biomedical subjects

I Steinberg

Publications and source records attributed to I Steinberg.

At least 19 recordsLinked to original sources
PubMed2005

Influence of mechanical-biological waste pre-treatment methods on the gas formation in landfills.

In order to minimise emissions and environmental impacts, only pre-treated waste should be disposed of. For the last six years, a series of continuous experiments has been conducted at the Institute WAR, TU Darmstadt, in order to determine the emissions from pre-treated waste. Different kinds of pre-treated waste were incubated in several reactors and various data, including production and composition of the gas and the leachate, were collected. In this paper, the interim results of gas production and the gas composition from different types of waste after a running time of six years are presented and discussed.

Biodegradation, Environmental↗
PubMed2005

Increase of the purification efficiency of biofilters by the use of a complementary ionisation step.

The biofilter and the ionisation system are two oxidative treatment techniques for purification of waste gas streams with low concentrations of volatile organic compounds. In this paper, the authors present the investigations of an ionisation technique aimed at increasing the efficiency of the reduction of the odorant concentration in waste gas streams from biological waste treatment plants. The objective is to enable advanced odour emission reduction and to adjust the existing biofilters to stricter requirements. In a first step, the odorous substances which are major contributors to the overall odorant concentration are identified on basis of various emission data sets with the help of a method of life cycle impact assessment. Thereby limonene, alpha-pinene, ethyl butyrate and dimethyl disulphide were identified as crucial indicators. In a second step, experimental investigations using limonene as a model compound were conducted to gain an understanding of the ionisation process itself and at last for the evaluation of the system.

Air Ionization↗
PubMed2005

Measurement of odour with focus on sampling techniques.

The treatment of waste and many manufacturing processes cause odour emissions. In order to prevent odours, the residents and businesses in the neighbourhood of such plants complain about odour, and it becomes necessary to reduce the emissions. To achieve that, the emissions have to be investigated and evaluated in a representative and reproducible manner. The DIN EN 13725 (2003) [DIN EN 13725. 2003. Luftbeschaffenheit--Bestimmung der Geruchsstoffkonzentration mit dynamischer Olfaktometrie--Air quality--Determination of odour concentration by dynamic olfactometry, Deutsche Fassung EN 13725:2003. Beuth Verlag, Berlin (DE)] provides a European standard for the measurement of odour. Nevertheless, the subject of sampling is not standardised; even though it has a substantial influence on the results of the measurements. In this paper, the odour measurement itself, as well as the different kinds of sampling methods (depending on the specific type of source), will be presented and discussed.

Chemistry Techniques, Analytical↗
PubMed2004

Ecological assessment of waste air treatment systems in the case of biological waste treatment.

In this paper, the authors present a technique aimed at increasing the efficiency of biological waste air treatment. The objective is to modify the existing biological waste air treatment systems (i.e. biofilters) to reduce the emitted substances and their potential environmental impacts. The principle of the ionization system is described, along with the first experiences of applying those methods during the rotting process. The investigated system is evaluated by means of life cycle impact assessment, with a focus on odour. It is demonstrated which of the measured substances (i.e. VOC) can potentially contribute to the odorant concentration. Further, it is shown which odour-intensive substances can be reduced by deploying ionization. Finally, the authors respond to the fact that the cleaning efficiency of ionization strongly depends on the humidity of the treated waste gas stream.

Bioreactors↗
PubMed2000

Clinical choices of antibiotics: judging judicious use.

Scientific literature widely documents the current overuse of antibiotics but often does not address the issue of the judicious use of antibiotics. Multiple analyses of prescribing patterns consistently reveal inappropriate prescribing of antibiotics, even when the clinician is aware of appropriate antibiotic use. In addition to overprescribing antibiotics, providers frequently address therapy failures by switching to same-class antibiotic agents. Additional investigations report that prescribing of antibiotics at the first office visit tends to increase, rather than decrease, costs and has marginal impact on patient outcomes. Patient education interventions, delivered prior to illness, can significantly reduce inappropriate use of antibiotics and reverse resistance trends. A variety of developments in antimicrobial use and resistance and newer antibiotic and respiratory infection management strategies are discussed.

Anti-Bacterial Agents↗
PubMed1997

Renal tolerance with the use of intralipid-amphotericin B in low-birth-weight neonates.

Amphotericin B is still the first-line therapy for neonatal fungal infections. With several comparative trials of intralipid-based amphotericin B (IL-AmB) demonstrating its clinical effectiveness and reduced renal toxicity in adults, we examined the renal tolerance and infection outcome in low-birth-weight infants in our 48-bed NICU treated with IL-AmB. Over 2 years, 52 patients (58 courses) received > or = 10 days of IL-AmB. Nineteen charts (23 episodes) were randomly accessed and reviewed. Mean birthweight = 747 grams, gestational age = 25.6 weeks, total IL-AmB dosage = 19.8 +/- 3.3 mg/kg (n = 23); 20 of these episodes were fungal culture positive (9 fungemias). Only one patient (who died during therapy) had a rise in creatinine of > 0.3 mg/dL. Overall, serum creatinine decreased significantly after Day 10 of IL-AmB therapy, from 0.93 +/- 0.42 mg/dL at baseline, to 0.54 +/- 0.24 after 19 days of therapy (p < 0.0001). Serial urine output, serum potassium and potassium supplementation data showed no significant differences from baseline. No interruption of therapy nor infusion reactions occurred. Only one death occurred attributable to fungal infection. Intralipid-amphotericin B may provide an effective alternative in the antifungal therapy of low birthweight neonates, without nephrotoxicity. Further prospective, comparative trials are warranted.

Amphotericin B↗
PubMed1996

Informatics integration in a medical residency program: early experiences.

In 1992, Informatics training was integrated into the medical residency program at Norwalk Hospital. The program objective was to familiarize the residents with clinical applications of information technology that could enhance their productivity in clinical practice. In its first year, the curriculum was theory oriented. Evaluation of the program at the end of the first year led to a significant restructuring of the program format and curriculum. The trainees did not find theory to be of immediate clinical value, in the second year the program emphasis was redirected toward the development of practical skills. Next year, in 1993, 'Informatics Clinics' were initiated to develop practical Informatics skills that would be useful in a clinical setting. This approach was more successful but did not offer a complete solution. The degree to which the concepts and methods learned are clinically utilized by residents will depend upon the degree of reinforcement provided in the clinical residency years. In addition, there is a need for the development of assessment standards for the evaluation of Informatics literacy levels. In the absence of assessment standards the level of Informatics literacy in medical graduates remains undetermined Consequently, it is difficult to determine whether the training received has transformed expectations into reality.

Connecticut↗
PubMed1987

The pharmacokinetics of antiarrhythmic agents in pregnancy and lactation.

The pharmacokinetics of various drugs may be profoundly altered during different stages of pregnancy, parturition, and lactation. Gastrointestinal absorption or bioavailability of drugs may vary due to changes in gastric secretion and motility. Various haemodynamic changes such as an increase in cardiac output, blood volume, and renal plasma flow may affect drug disposition and elimination. The increase in blood volume and total body water which occurs during pregnancy can alter the volume of distribution for various drugs. Although exact quantifications are not easy, these changes in pharmacokinetic parameters should be considered when dosing antiarrhythmic agents in pregnant women. Plasma protein concentrations and drug binding capacity are altered in the mother and fetus as pregnancy advances. With highly protein bound drugs, these changes may be clinically significant, as the pharmacological efficacy and toxicity are presumed to be related to the concentration of free drug in both the mother and fetus. In some instances, the fetus may be susceptible to greater drug toxicity as free drug concentrations may be underestimated by measurement of total drug concentrations. Changes in maternal drug metabolism and metabolism by the fetoplacental unit also contribute to alterations in the pharmacokinetics of drugs. As the placenta contains many metabolising enzymes, biotransformation of drugs at this site could potentially convert a drug into an active metabolite, or prevent fetal exposure to a toxic drug. Placental transfer of drugs, leading to toxicity in the fetus, is a major concern in the pharmacological management of the pregnant patient. The passage of individual drugs will vary depending on their apparent volumes of distribution, degree of protein binding the rates of metabolic conversion and excretion within the placenta and fetus, the pH difference between the maternal and fetal fluids, and maternal haemodynamic changes. Drug properties such as lipid solubility, protein binding characteristics, and ionisation constant (pKa) also influence the placental passage of drugs. For weakly basic antiarrhythmic agents, the fetal drug concentration may potentially exceed the maternal plasma concentration when the fetal pH is lowered as in the case of fetal acidosis; this is due to 'ion trapping'. Additionally, higher free drug concentrations of these basic drugs may exist, due to decreased alpha 1-acid glycoprotein concentration and binding affinity in the fetus. Lignocaine (lidocaine) has been shown to enter fetal plasma rapidly with fetal-maternal concentration ratios in the range of 0.52 to 0.66.(ABSTRACT TRUNCATED AT 400 WORDS)

Anti-Arrhythmia Agents↗
PubMed1986

Abatement of Sézary syndrome lesions following treatment with acyclovir.

Sézary syndrome is a malignant form of cutaneous T cell lymphoma in which patients characteristically present with generalized pruritic erythroderma and large numbers of circulating Sézary cells in the peripheral blood. Several previous studies have proposed that viruses may play a role in the cause of cutaneous T cell lymphoma. This report describes a 68-year-old man with Sézary syndrome who received a seven-day course of intravenous acyclovir for treatment of disseminated herpes zoster and was noted to have almost complete disappearance of generalized erythroderma and pruritus. Since acyclovir has been shown to selectively inhibit viral DNA polymerase, the observed clinical response is strong evidence that viruses play a role in the cause of cutaneous T cell lymphoma. Mechanisms that could explain the observed response are discussed, and further studies on the utility of antiviral agents for treatment of cutaneous T cell lymphoma and on possible inhibitory effects of acyclovir on retroviruses are recommended.

Acyclovir↗
PubMed1986

Vancomycin-induced neutropenia during treatment of osteomyelitis in an outpatient.

A case of vancomycin-associated neutropenia occurring during long-term outpatient therapy with vancomycin is described. Pharmacokinetic studies demonstrated that the patient's vancomycin serum levels were within an acceptable range during treatment. Eighteen other reported cases of vancomycin-associated leukopenia are discussed in brief. An immunologic mechanism has been proposed but a clear understanding is lacking. Patients receiving long-term vancomycin therapy should have their white blood cell counts periodically monitored.

Agranulocytosis↗
PubMed1985

Protein binding of disopyramide--displacement by mono-N-dealkyldisopyramide and variation with source of alpha-1-acid glycoprotein.

The binding of disopyramide to human serum proteins and human alpha-1-acid glycoprotein (AAG) was determined over a wide drug concentration range. Addition of 3.7 X 10(-6) mol litre-1 mono-N-dealkyldisopyramide caused a 20-100% increase in disopyramide free fraction. The disopyramide free fraction in AAG solutions prepared from various commercially available sources of alpha-1-acid glycoprotein varied up to 2.5 fold at corresponding disopyramide concentrations. Pronounced differences in the calculated binding constants (affinity and capacity) were observed among the commercially available AAG preparations. These findings suggest that binding studies should be performed in appropriately harvested human serum or plasma to avoid possible artifacts associated with the use of commercial preparations of alpha-1-acid glycoprotein for binding studies.

Binding, Competitive↗