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M Rudolph

Publications and source records attributed to M Rudolph.

At least 37 records · Page 2Linked to original sources
PubMed2000

ROBO-SIM: a simulator for minimally invasive neurosurgery using an active manipulator.

This application report describes the software system ROBO-SIM, which is a planning and simulation tool for minimally invasive neurosurgery. Using actual patient's datasets, ROBO-SIM includes all planning steps necessary. These are; defining the trepanation point for entry into the skull and the target point within the depth of the brain, checking the surgical track, performing virtual trepanations (virtual craniotomy), and defining sanctioned volumes for use with an intra-operative active manipulator. With the additional simulation part, neurosurgeons are able to simulate whole surgical interventions directly on the patient's anatomy using the same instruments as for the real operation. First tests with ROBO-SIM are performed on actual patient's datasets with ventricular tumours.

Computer Simulation↗
PubMed1999

Cancer incidence in a cohort of licensed pesticide applicators in Florida.

This study is a standardized incidence ratio (SIR) analysis of cancer incidence of licensed pesticide applicators in Florida, compared with that of Florida's general population. Through extensive data linkages, 33,658 applicators were assembled who had 1266 incident cancers and 279,397 person-years from January 1, 1975, to December 31, 1993. Disease risk from ethanol and tobacco use were significantly decreased. Among males, prostate cancer (SIR = 1.91; 95% confidence interval [CI], 1.72-2.13) and testicular cancer (SIR = 2.48; 95% CI, 1.57-3.72) were significantly elevated. No confirmed cases of soft tissue sarcoma (STS) were found, and the incidence of non-Hodgkin's lymphoma was not increased. There were few female applicators; nevertheless, cervical cancer incidence (SIR = 3.69; 95% CI, 1.84-6.61) was significantly increased, while the incidence of breast cancer was significantly decreased. Cancers that have been associated with estrogen disrupters were found in male, but not female, pesticide applicators. The lack of soft tissue sarcoma is at odds with prior literature associated with the use of phenoxy herbicides.

Adult↗
PubMed1999

Mortality in a cohort of licensed pesticide applicators in Florida.

OBJECTIVES: Although the primary hazard to humans associated with pesticide exposure is acute poisoning, there has been considerable concern surrounding the possibility of cancer and other chronic health effects in humans. Given the huge volume of pesticides now used throughout the world, as well as environmental and food residue contamination leading to chronic low level exposure, the study of possible chronic human health effects is important. METHODS: This was a retrospective cohort study, analysed by general standardised mortality ratio (SMR) of licensed pesticide applicators in Florida compared with the general population of Florida. A cohort of 33,658 (10% female) licensed pesticide applicators assembled through extensive data linkages yielded 1874 deaths with 320,250 person-years from 1 January 1975 to 31 December 1993. RESULTS: The pesticide applicators were consistently and significantly healthier than the general population of Florida. As with many occupational cohorts, the risks of cardiovascular disease and of diseases associated with alcohol and tobacco use were significantly lower, even in the subpopulations--for example, men, women, and licence subcategories. Among male applicators, prostate cancer mortality (SMR 2.38 (95% confidence interval (95% CI) 1.83 to 3.04) was significantly increased. No cases of soft tissue sarcoma were confirmed in this cohort, and non-Hodgkin's lymphoma was not increased. The number of female applicators was small, as were the numbers of deaths. Mortality from cervical cancer and breast cancer was not increased. Additional subcohort and exposure analyses were performed. CONCLUSIONS: Consistent with previous publications on farmers but at odds with current theories about the protective effects of vitamin D, prostate cancer was increased in these pesticide applicators. Female breast cancer was not increased despite theories linking risk of breast cancer with exposure to oestrogen disruptors--such as the organochlorines. The lack of cases of soft tissue sarcoma is at odds with previous publications associating the use of the phenoxy herbicides with an increased risk of these cancers.

Adult↗
PubMed1998

[Heparin-induced thrombocytopenia with unfractionated heparin. A prospective study of inpatient treatment of internal medicine patients].

AIM: To investigate the influence of unfractionated heparin on heparin-induced thrombocytopenia (HIT) type II. PATIENTS AND METHOD: In 162 patients with internal diseases treated therapeutically of prophylactically with unfractionated heparin (heparin sodium, heparin calcium), we carried out a prospective study to determine the incidence of HIT type I and II. 55.6% of the patients were female (n = 90) with an average age of 76.5 years (range: 25 to 96 years) and 44.4% male (n = 72) with an average age of 67.5 years (range: 17 to 93 years). A platelet count was taken regularly before the start of heparin treatment, on the first day of treatment and then every second day from day 5 to 20. Whenever HIT II was suspected, an HIPA test was performed. RESULT: Type I HIT occurred in 10%, type II in 3% of the cases. Two of the 5 patients with type II developed severe thrombotic complications. CONCLUSION: In view of the high incidence of HIT, regular platelet counts should always be carried out in patients receiving heparin treatment.

Adult↗
PubMed1998

Anti-inflammatory effect of hamamelis lotion in a UVB erythema test.

BACKGROUND: Although Hamamelis virginiana has long been used in the traditional treatment of skin diseases, there are few controlled clinical studies defining the extent of its anti-inflammatory action. OBJECTIVE: The anti-inflammatory efficacy of pH5 Eucerin aftersun lotion with 10% hamamelis distillate, the vehicle and a prior aftersun formulation were tested in 30 healthy volunteers using a modified UVB erythema test as model of inflammation. METHODS: Four UVB doses ranging from 1 to 2 MED were evaluated in each subject. Test fields on the back were treated occlusively for 48 h following irradiation. Chromametry and visual scoring were used to determine the degree of erythema in the treated fields and an untreated, irradiated control field 7, 24 and 48 h after irradiation. RESULTS: Erythema suppression ranged from approximately 20% of 7 h to 27% at 48 h in the hamamelis fields. A suppression of 11-15% was recorded in the fields treated with the other lotions. Significant differences were noted between hamamelis and these lotions. CONCLUSION: These data provide evidence for an anti-inflammatory action of the aftersun lotion with 10% hamamelis and support the usefulness of the UVB erythema test with multiple UV doses for the testing of nonsteroidal anti-inflammatory agents.

Adult↗
PubMed1998

Are preoperative antibiotics administered preoperatively?

Ideally antibiotics should be administered preoperatively within 2 hours of skin incision to ensure adequate tissue concentrations, especially when a vascular prosthesis is used. The quality of patient outcomes may be adversely affected when key processes, by degrees, fail to meet patient care objectives. This study was designed to incorporate the concepts of total quality management to determine how effectively this goal was achieved, and, after review of those measured results, what process improvements could be instituted to meet the established requirements for the administration of antibiotics. The study was then repeated on a yearly basis to determine what effect these improvement measures had on antibiotic administration. Three time periods were established for determining when antibiotics were administered. The "early" period was more than 2 hr preoperatively. "Preoperative" was from 2 hr before surgery until the time of incision and "perioperative" was after the time of incision. Group 1 consisted of the first 100 patients undergoing vascular procedures in 1992. After the data were collected, a multidisciplinary team of nurses, pharmacists, and surgeons was assembled to determine the step by step desired process flow from order received to actual medication administration. The team then reviewed each step of the process to identify variations relative to data obtained. An action plan was developed to implement the agreed upon improvement plan. After improvements were implemented, groups 2, 3, 4, and 5 consisted of the first 100 vascular procedures of 1993, 1994, 1995, and 1996. Group 1 had only 26% of antibiotics administered during the preoperative period and 74% during the perioperative period. Problems identified were: surgeons ordered the antibiotics when the patient was in the operating room, cefamandole and vancomycin required at least 1 hr to infuse, nurses were not aware of the need for preoperative infusion, and the pharmacy did not supply the antibiotics in a timely fashion. Educational inservices were held for all parties involved, and cefazolin was used in place of cefamandole because it could be given as a bolus. Results were: group 1, early, 0%; preoperative, 26%; perioperative, 74%; P = N/A; group 2, early, 0%, preoperative, 90%; perioperative, 10%; group 3, early, 7%; preoperative, 93%; perioperative, 0%; group 4, early 0%; preoperative, 100%; perioperative, 0%; and group 5, early, 0%; preoperative, 100%; perioperative, 0%; P = 0.0001 for groups 2-5 (versus group 1). It was surprising how often antibiotics were administered incorrectly in a busy vascular practice. By focusing on the process of care delivery, a continuous quality improvement team implemented simple changes that resulted in significant improvements. We are now conducting a study to determine what effect these process improvements had on our infection rate.

Antibiotic Prophylaxis↗
PubMed1995

Efficient gene transfer into human hepatocytes by baculovirus vectors.

Viral vectors are the most efficient tools for gene delivery, and the search for tissue-specific infecting viruses is important for the development of in vivo gene therapy strategies. The baculovirus Autographa californica nuclear polyhedrosis virus is widely used as a vector for expression of foreign genes in insect cells, and its host specificity is supposed to be restricted to arthropods. Here we demonstrate that recombinant A. californica nuclear polyhedrosis virus is efficiently taken up by human hepatocytes via an endosomal pathway. High-level reporter gene expression from heterologous promoters was observed in human and rabbit hepatocytes in vitro. Mouse hepatocytes and some other epithelial cell types are targeted at a considerably lower rate. The efficiency of gene transfer by baculovirus considerably exceeds that obtained by calcium phosphate or lipid transfection. These properties of baculovirus suggest a use for it as a vector for liver-directed gene transfer but highlight a potential risk in handling certain recombinant baculoviruses.

Animals↗
PubMed1995

Hepatocyte-specific binding of L/S-HBV particles expressed in insect cells.

The genome of hepatitis B virus (HBV) codes for three surface antigen proteins. Two of them are essential components of infectious viral particles. Whereas expression of the small (S) antigen led to formation of virus-like particles in different systems so far, secretion of neither the large antigen nor budding of virus-like particles containing both antigens could be observed. Using modified large antigen genes in dual expression vectors we were able to demonstrate secretion of virus-like particles in the baculovirus insect cell system. N-terminal fusion of an insect protein (melittin) derived signal sequence and destruction of the myristylation site resulted in secretion of the large antigen. Particles consisting of about 95% small and 5% large antigen bind specifically to hepatocytes. These pseudovirions could serve as a HBV vaccine and as a useful component of future hepatocyte-specific gene transfer vehicles.

Animals↗
PubMed1994

Borna disease virus: immunoelectron microscopic characterization of cell-free virus and further information about the genome.

The etiological agent of Borna disease, a persistent virus infection of the central nervous system with differently expressed symptomatology, was morphologically unknown. Here we provide the first convincing data on its phenotypic architecture. Salt-released virus comprising the biological parameters of Koch's postulates has an unsegmented single-stranded RNA. A dense band (1.22 g/cm3) in CsCl contains 90-nm particles which appear to be enveloped and a fraction of 50- to 60-nm particles. Labeling of the virions with neutralizing antisera and colloidal gold conjugates indicates that the 90-nm particles most likely represent the causative agent.

Animals↗
PubMed1993

Carboplatin-liposomes as activators of hematopoiesis.

Recombinant colony stimulating factors are studied in clinical trials with the purpose being the relief of the side effects of high dose chemotherapy and to make an optimized treatment regimen possible. The broad use of such factors is hindered by their relatively high costs, their short elimination half-lives, the occurrence of mild side effects, and the limitation of their action to the stimulation of mainly neutrophils. Therefore, exogenous preparations inducing an endogenous activation of hematopoiesis are being sought. In experiments in mice we have shown that carboplatin-liposomes injected intraperitoneally in a single dose of 100 mg/kg led to a strong two-peak increase in white blood cell counts. A maximum 10-fold elevation compared to controls of free carboplatin or empty liposomes was observed on day 2 and was probably due to the release and mobilization of cells from storage compartments. The second peak of about a 6-fold increase occurred on day 7-8 and can be seen as an indicator of bone marrow stimulation. Differentiation of blood cells revealed that neutrophils, lymphocytes and platelets multiplied. We presume that this effect of carboplatin-liposomes is due to a relatively fast uptake of these vesicles by macrophages as their natural target. Within these cells carboplatin is metabolized, leading to an almost total loss of antineoplastic activity against the murine P388 leukemia. Concomitantly, cytokines are apparently induced in and released from macrophages producing secondarily hematopoietic growth factors either directly or in combination with other cytokines. An involvement of macrophages is indicated by the fact that an intraperitoneal pretreatment of mice with zymosan caused a partial but significant suppression of hematopoietic stimulation. In an in vitro colony forming assay of serum of mice treated 1, 3, or 7 days with carboplatin-liposomes, the number of colonies increased 20-fold compared to serum from saline treated animals. Additionally, a combined intraperitoneal treatment of mice with 100 mg/kg of cyclophosphamide followed by carboplatin-liposomes one hour later demonstrated that prevention of cytostatic-induced leukopenia is possible by this method. Although the mechanism of stimulation of hematopoiesis by carboplatin-liposomes is still partially unknown our results suggest that there should be further development of such a preparation for possible use in the treatment of cancer or other inherited or acquired hematopoietic disorders.

Animals↗
PubMed1992

Analysis of [14C]-saterinone and its metabolites in dog plasma, urine and bile by high-performance liquid chromatography with radioactivity and fluorescence detection and by mass spectrometry.

An HPLC method was developed for the direct on-line radioactivity determination of [14C]-saterinone and its metabolites in biological canine fluids after intravenous and intraduodenal administration. After direct injection of 200 microliters of sample, the metabolites were separated on a semi-preparative reverse-phase column. The metabolites were identified by HPLC reference standards, enzymatic hydrolysis and mass spectrometry. Besides a small amount of unchanged saterinone, six metabolites could be detected, both in bile and urine. The main fraction (about 80-90% of the sum of detected metabolites) contained the phase II metabolites of saterinone, the sulphate and glucuronide. Ring hydroxylated saterinone and three metabolites that were not identified made up about 1-4% each. In plasma, only the major compounds could be detected because of the lower absolute concentrations. The metabolic pathway of saterinone in dogs was elucidated and compared with other species. Results from previous studies concerning a first-pass metabolism could be confirmed.

Animals↗
PubMed1992

Determination of moxonidine (BDF 5895) in plasma by gas chromatography-negative ion chemical ionization mass spectrometry.

For the measurement of the pharmacokinetic behaviour of moxonidine, 4-chloro-5-(2-imidazolin-2-yl-amino)-6-methoxy-2-methylpyrimidine, an extremely sensitive analytical method was needed. The GC-MS method developed is specific and reliably detects moxonidine plasma levels down to 40 pg ml-1. Using negative ion chemical ionization (NICI) the M- fragment of the ditrifluoromethyl benzamide derivative of moxonidine (m/z 721) and the [M-HCl]- fragment of the ditrifluoromethyl benzamide derivative of clonidine (internal standard, m/z 673) were monitored in the selected ion monitoring mode, ensuring a specific and sensitive detection of the compounds. The validation process carried out included assay precision, repeatability, linearity, accuracy, stability and estimation of the detection and determination limits. The plasma-level time-curves and pharmacokinetic parameters from two volunteers after oral administration of 0.2 mg moxonidine are presented and demonstrate the practicability of the method in, for example, clinical studies.

Antihypertensive Agents↗
PubMed1992

[Absolute bioavailability of beta-acetyldigoxin from tablets and drops in healthy subjects].

In a crossover design in random order 12 healthy male volunteers were given either beta-acetyldigoxin (Novodigal, CAS 5511-98-8) tablets, oral solution or i.v. application at a digoxin equivalent dose of 0.284 mg. To reach steady state each preparation was given for 10 days on a once-daily schedule. On days 8, 9 and 10 of each observation period blood was sampled to determine trough concentrations of digoxin in steady state. In addition, on day 10 blood was collected repeatedly at appropriate time intervals and urine was sampled concomitantly for 24 h. Trough values during steady state and 24 h AUC were used to calculate digoxin bioavailability for tablets and oral solution. From trough values, the mean bioavailability for beta-acetyldigoxin tablets was 91.2% (range 73.1-118.1) and for solution 93.8% (range 65.7-114.8). Using the AUCs 0-24 h at steady state bioavailability was calculated 77.7% for the tablets and 84.5% for the solution. Since trough values in steady state represent the body burden of digoxin which is supposed responsible for the therapeutic effect, trough values should be given priority for the determination of digoxin bioavailability from beta-acetyldigoxin tablets and solution. All formulations were well tolerated. No clinically relevant side effects were observed.

Acetyldigoxins↗
PubMed1991

[The concept of amnesia and quantitative assessment of amnesic disorders].

This article presents first a short historical overview of the different viewpoints concerning psychiatric approaches to define the concept "amnesia" (Ribot, Korsakow, K. Schneider, Bleuler, Bonhoeffer et al.). A generally accepted result is the differentiation between retrograde and anterograde amnesia. Research work of the last two decades has focussed on the experimental investigation of anterograde amnesia, the so-called amnesic syndrome. In this context four main factors responsible for memory performance are distinguished: encoding, retrieval, forgetting and interference. One of the main results of neuropsychological research in amnesia consists in having discovered a set of symptoms or features common to most if not all forms of amnesia. These features appear regardless of etiology and locus of lesion. This set or features is described in detail in the paper. On the basis of these amnesic features a clinical test was developed, the Berliner Amnesie Test (BAT). This standardized test can be used for the assessment from mild up to severe memory disorders.

Alzheimer Disease↗
PubMed1990

Determination of saterinone enantiomers in plasma samples with an internal standard using a Chiralcel OD column, fractionation and reversed-phase chromatography.

A specific and validated high-performance liquid chromatographic method was developed for the determination of the S-(-) and R-(+) enantiomers of saterinone. 1-[(4-cyano-1,2-dihydro-6-methyl-2-oxopyridin-5-yl)phenoxyl] -3-[4-(2- methoxyphenyl)piperazin-1-yl]propan-2-ol, in plasma at the low ng/ml level. The enantiomers of saterinone and an internal standard, 1-[(4-cyano-1,2-dihydro-6-methyl-2-oxo-pyridin-5-yl)phenoxy]-3-[4-(2- ethoxyphenyl)piperazin-1-yl]propan-2-ol, were chromatographed on a chiral Chiralcel OD stationary phase. However, the S-(-) enantiomers of saterinone and the internal standard were unresolved, as were the R-(+) enantiomers of both substances. Therefore, the two fractions were collected and each was separately resolved on an achiral Polyencap A reversed-phase column and quantified. The detection limit was 0.5 ng/ml of enantiomer, allowing the determination of plasma levels up to 36 h after oral administration of 90, 150 and 180 mg of saterinone to twelve subjects.

Administration, Oral↗
PubMed1990

Direct enantiomeric separation of saterinone by high-performance liquid chromatography.

A new method is described for the direct liquid chromatographic separation and determination of the enantiomers of saterinone, 1-[(4-cyano-1,2-dihydro-6-methyl-2-oxopyridinyl-5)-phenoxy]-3-[4-( 2- methoxyphenyl)piperazinyl-1]-propan-2-ol, using a Chiralcel OD column with methanol as eluent and a temperature set to 10 degrees C. Several lots of synthesized enantiomers were analysed for their enantiomeric purity of more than 99%, because of the excellent resolution (Rs = 2.2). Furthermore the enantiomeric ratio was determined in plasma samples after oral and intravenous administration of racemic saterinone.

Administration, Oral↗