Biomedical subjects

A Lehner

Publications and source records attributed to A Lehner.

At least 19 recordsLinked to original sources

PubMed2001

Ropivacaine in the horse: its pharmacological responses, urinary detection and mass spectral confirmation.

This report evaluates the pharmacological responses, urinary detection and mass spectral confirmation of ropivacaine in horses. Ropivacaine, a potent local anesthetic (LA) recently introduced in human medicine, has an estimated highest no-effect dose (HNED) of about 0.4 mg/site as determined in our abaxial sesamoid block model. Apparent ropivacaine equivalents were detectable by ELISA screening using a mepivacaine ELISA test after administration of clinically effective doses. Mass spectral examination of postadministration urine samples showed no detectable parent ropivacaine, but a compound indistinguishable from authentic 3-hydroxyropivacaine was recovered from these samples. The study shows that ropivacaine is a potent LA in the horse, that clinically effective doses can be detected in postadministration samples by ELISA-based screening, and that its major post administration urinary metabolite is 3-hydroxyropivacaine.

Amides↗

PubMed2001

Comparison of different approaches to quantify Staphylococcus aureus cells by real-time quantitative PCR and application of this technique for examination of cheese.

Two different real-time quantitative PCR (RTQ-PCR) approaches were applied for PCR-based quantification of Staphylococcus aureus cells by targeting the thermonuclease (nuc) gene. Purified DNA extracts from pure cultures of S. aureus were quantified in a LightCycler system using SYBR Green I. Quantification proved to be less sensitive (60 nuc gene copies/microl) than using a fluorigenic TaqMan probe (6 nuc gene copies/microl). Comparison of the LightCycler system and the well-established ABI Prism 7700 SDS with TaqMan probes revealed no statistically significant differences with respect to sensitivity and reproducibility. Application of the RTQ-PCR assay to quantify S. aureus cells in artificially contaminated cheeses of different types achieved sensitivities from 1.5 x 10(2) to 6.4 x 10(2) copies of the nuc gene/2 g, depending on the cheese matrix. The coefficients of correlation between log CFU and nuc gene copy numbers ranged from 0.979 to 0.998, thus enabling calculation of the number of CFU of S. aureus in cheese by performing RTQ-PCR.

Benzothiazoles↗

PubMed2000

Epidemiologic application of pulsed-field gel electrophoresis to an outbreak of Campylobacter jejuni in an Austrian youth centre.

We report the first documented Campylobacter jejuni outbreak in an Austrian youth centre. Sixty-four children were involved of which 38 showed classical signs of campylobacter gastroenteritis. Since unpasteurized milk distributed by a local dairy was suspected to be the source of infection, stool samples were collected from 20 cows providing the milk. Five of the cows tested positive for C. jejuni. These isolates together with 37 clinical samples were compared by pulsed-field-gel electrophoresis (PFGE). The PFGE patterns, using the restriction endonucleases SmaI and SalI, were identical for the human and bovine isolates. This finding confirmed that the outbreak was caused by the consumption of unpasteurized milk contaminated with C. jejuni.

Adolescent↗

PubMed2000

Single-strand conformation polymorphisms in the hly gene and polymerase chain reaction analysis of a repeat region in the iap gene to identify and type Listeria monocytogenes.

Two novel methods that allow the powerful identification of Listeria monocytogenes by polymerase chain reaction (PCR) and simultaneous differentiation by special electrophoresis formats are described. The first method involves a PCR-driven single-strand conformation polymorphism (SSCP-PCR) assay using a portion of the noncoding region of the hlv gene. The assay was evaluated with 120 genetically distinct L. monocytogenes strains of either foodborne or clinical origin. Distribution of listerial strains to at least 14 SSCP types was observed. In respect to the panel of strains, 39.7% were assigned to SSCP type 3, and 19% showed SSCP type 5. Further, SSCP type 1 was found in 7.5% of all strains, SSCP type 10 in 6.7%, and 5.8% each for SSCP types 6 and 7. The SSCP types 4, 9, and 11 were infrequently described in 2.55%, 3.3%, and 4.2%, respectively, of all isolates. At least 0.85% represented each of the SSCP types 2, 13, and 14, and 1.7% displayed SSCP types 8 and 12. In the second method, the internal threonine-asparagine repeat portion of the L. monocytogenes p60 protein was used for setting up a PCR-based identification and parallel differentiation assay. Ten different repeat types (RTs), according to different sizes of PCR products, were observed. Of 163 strains tested, 35.58% of samples were assigned to RT 1, 39.26% to RT 2, 3.68% to RT 3, 6.13% to RT 4, 4.29% to RT 5, 2.45% to RT 6, 5.52% to RT 7, 0.61% to RT 8, 0.61% to RT 9, and 1.83% to RT 10. The data suggest that both methods allow the simple identification and differentiation of L. monocytogenes isolates. Therefore, both the SSCP-PCR and the PCR-based identification and parallel differentiation assay could represent single-strand pretyping assays before laborious reference typing methods are applied.

Bacterial Proteins↗

PubMed1999

[The childhood ankle joint. Deformities, abnormalities and clinical variations].

The ankle joint unites high functionality with high load on a small surface. Congenital as well as acquired variations lead to a derangement of the complex concerted action of tendons, ligaments and joints. This causes dysfunction and the development of typical deformities. It is necessary to discriminate physiological variants, congenital, posttraumatic and tumoral variations for the differential diagnosis. In most instances this is only possible with the aid of radiological clarification. Congenital malformations in the region of the upper and lower ankle joint are generally rare. One disease is club foot, with malposition and deformity in the upper and lower ankle joint. Extreme malposition can also be found in talus verticalis and congenital hypoplasias and aplasias of fibula and tibia. A rather frequently found disease, which first occurs in the adolescence, is osteochondrosis dissecans.

Adolescent↗

PubMed1999

[Cogenital femoral defect. Indication, therapy and complication management].

Congenital femoral deficiencies remain a surgical challenge. There is no common classification: both radiological and clinical methods are recommended. Depending on the severity of the deformity, reconstructive and lengthening techniques are performed, while accompanying deformations are taken into consideration. In addition, amputation or fusion techniques together with orthotic devices are used. A total of 35 patients (37 extremities) with congenital femoral deficiencies have been treated at the Orthopaedic Hospital Vienna-Speising, from 1982 to 1998. 24 extremities were treated with reconstructive and/or lengthening techniques. Results and complications are reported.

Amputation, Surgical↗

PubMed1999

Mepivacaine: its pharmacological effects and their relationship to analytical findings in the horse.

Mepivacaine is a local anaesthetic drug that is widely used in equine medicine and is classified by the Association of Racing Commissioners International (ARCI) as a Class 2 foreign substance that may cause regulators to impose significant penalties if residues are identified in post-race urine samples. Therefore, an analytical/pharmacological database was developed for this agent and its metabolites. Using an abaxial sesamoid local anaesthetic model, it was determined that the highest no-effect dose (HNED) for its local anaesthetic effect was 2 mg. Using enzyme-linked immunosorbent assay (ELISA) screening, it was determined that subcutaneous (s.c.) administration of the HNED of mepivacaine to eight horses yielded a peak urinary concentration of apparent mepivacaine of 63 ng/mL 2 h after injection. The major identified metabolite recovered from equine urine after dosing with mepivacaine is 3-hydroxymepivacaine. Therefore, 3-hydroxymepivacaine was synthesized, purified and characterized, and a quantitative mass spectrometric method was developed for this metabolite as isolated from horse urine. Following subcutaneous injection of the HNED of mepivacaine, the concentration of 3-hydroxymepivacaine recovered from horse urine reached a peak of about 64.6 ng/mL at 4 h after administration as measured by GC/MS. The concentration of mepivacaine or its metabolites after administration of a HNED dose are detectable by mass spectral techniques. Within the limits of this research, the study suggests that recovery of concentrations less than about 65 ng/mL of 3-hydroxymepivacaine from post-race urine samples may not be associated with a recent LA effect of mepivacaine.

Anesthetics, Local↗

PubMed1999

Bupivacaine in the horse: relationship of local anaesthetic responses and urinary concentrations of 3-hydroxybupivacaine.

Bupivacaine is a potent local anaesthetic used in equine medicine. It is also classified as a Class 2 foreign substance by the Association of Racing Commissioners International (ARCI). The identification of residues in postrace urine samples may cause regulators to impose significant penalties. Therefore, an analytical/pharmacological database was developed for this medication. The highest no-effect dose (HNED) for the local anaesthetic effect of bupivacaine was determined to be 0.25 mg by using an abaxial sesamoid local anaesthetic model. Administration of the HNED of bupivacaine to eight horses yielded a peak urine concentration of apparent bupivacaine of 23.3 ng/mL 2 h after injection as determined with enzyme-linked immunosorbent assay (ELISA) screening. The major metabolite recovered from beta-glucuronidase-treated equine urine after dosing with bupivacaine is a hydroxybupivacaine, either 3-hydroxybupivacaine, 4-hydroxybupivacaine, or a mixture of the two. To determine which positional isomer occurs in the horse, 4-hydroxybupivacaine was obtained from Maxxam Analytics, Inc., and 3-hydroxybupivacaine was synthesized, purified, and characterized. Furthermore, a quantitative mass spectrometric method was developed for the metabolite as recovered from horse urine. Following subcutaneous injection of the HNED of bupivacaine, the concentration of the hydroxybupivacaine recovered from horse urine reached a peak of 27.4 ng/mL at 4 h after administration as measured by gas chromatography/mass spectrometry (GC/MS). It was also unequivocally demonstrated with ion chromatography that the hydroxybupivacaine metabolite found in horse urine is exclusively 3-hydroxybupivacaine and not 4-hydroxybupivacaine. The mean pH of the 4-h urine samples was 7.21; the mean urine creatinine was 209.5 mg/dL; and the mean urine specific gravity was 1.028. There was no apparent effect of pH, urine creatinine concentration, or specific gravity on the concentration of 3-hydroxybupivacaine recovered. The concentration of bupivacaine or its metabolites after administration of a HNED dose are detectable by mass spectrometric techniques. This study also suggests that recovery of concentrations less than approximately 30 ng/mL of 3-hydroxybupivacaine from postrace urine samples is unlikely to be associated with a recent local anaesthetic effect of bupivacaine.

Anesthetics, Local↗

PubMed1999

Detection and differentiation of Listeria spp. by a single reaction based on multiplex PCR.

The iap gene encodes the protein p60, which is common to all Listeria species. A previous comparison of the DNA sequences indicated conserved and species-specific gene portions. Based on these comparisons, a combination consisting of only five different primers that allows the specific detection and differentiation of Listeria species with a single multiplex PCR and subsequent gel analysis was selected. One primer was derived from the conserved 3' end and is specific for all Listeria species; the other four primers are specific for Listeria monocytogenes, L. innocua, L. grayi, or the three grouped species L. ivanovii, L. seeligeri, and L. welshimeri, respectively. The PCR method, which also enables the simultaneous detection of L. monocytogenes and L. innocua, was evaluated against conventional biotyping with 200 food hygiene-relevant Listeria strains. The results indicated the superiority of this technique. Thus, this novel type of multiplex PCR may be useful for rapid Listeria species confirmation and for identification of Listeria species for strains isolated from different sources.

Bacterial Proteins↗

PubMed1998

Lidocaine in the horse: its pharmacological effects and their relationship to analytical findings.

Lidocaine is a local anaesthetic agent that is widely used in equine medicine. It is also an Association of Racing Commissioners International (ARCI) Class 2 foreign substance that may cause regulators to impose substantial penalties if residues are identified in post race urine samples. Therefore, an analytical/pharmacological database was developed for this drug. Using our abaxial sesamoid local anaesthetic model, the highest no-effect dose (HNED) for the local anaesthetic effect of lidocaine was determined to be 4 mg. Using enzyme-linked immunosorbent assay (ELISA) screening, administration of the HNED of lidocaine to eight horses yielded peak serum and urine concentrations of apparent lidocaine of 0.84 ng/mL at 30 min and 72.8 ng/mL at 60 min after injection, respectively. These concentrations of apparent lidocaine are readily detectable by routine ELISA screening tests (LIDOCAINE ELISA, Neogen, Lexington, KY). ELISA screening does not specifically identify lidocaine or its metabolites, which include 3-hydroxylidocaine, dimethylaniline, 4-hydroxydimethylaniline, monoethylglycinexylidine, 3-hydroxymonoethylglycinexylidine, and glycinexylidine. As 3-hydroxylidocaine is the major metabolite recovered from equine urine, it was synthesized, purified and characterized, and a quantitative mass spectrometric method was developed for 3-hydroxylidocaine as recovered from horse urine. Following subcutaneous (s.c.) injection of the HNED of lidocaine, the concentration of 3-hydroxylidocaine recovered from urine reached a peak of about 315 ng/mL at 1 h after administration. The mean pH of the 1 h post dosing urine samples was 7. 7, and there was no apparent effect of pH on the amount of 3-hydroxylidocaine recovered. Within the context of these experiments, the data suggests that recovery of less than 315 ng/mL of 3-hydroxylidocaine from a post race urine sample is unlikely to be associated with a recent local anaesthetic effect of lidocaine. Therefore these data may be of assistance to industry professionals in evaluating the significance of small concentrations of lidocaine or its metabolites in postrace urine samples. It should be noted that the quantitative data are based on analytical methods developed specifically for this study, and that methods used by other laboratories may yield different recoveries of urine 3-hydroxylidocaine.

Anesthetics, Local↗

PubMed1997

Rapid screening of multiple forensic stains by SSCP analysis of HLA-DQ alpha amplification products.

Single strand conformation polymorphism (SSCP) analysis was performed with HLA-DQ alpha amplification products. The various HLA-DQ alpha genotypes reveal different SSCP patterns. These are reproducible in DNA preparations from unrelated persons with identical HLA-DQ alpha genotype. However, in one of the more frequent HLA-DQ alpha genotypes (1.1/4) two variant SSCP patterns were observed. SSCP analysis allows rapid low-cost screening of many specimens and is an alternative discrimination test of stains beside reverse dot blot hybridization.

Body Fluids↗

PubMed1995

Sex determination and DNA competition in the analysis of forensic mixed stains by PCR.

Sex determination of pure and mixed blood samples and stains was performed by amplification of the X-specific and Y-specific alphoid sequences by PCR (XY-PCR). From mixed blood samples with female DNA present in large excess of male DNA, the Y-specific sequence still amplified efficiently. In the analysis of vaginal secretions in a case of sexual assault, XY-PCR was performed to test the efficiency of the selective lysis procedure in order to investigate whether alleles found with other PCR systems were of male or female origin. Our studies with mixed blood samples revealed pronounced DNA competition in the HLA-DQ alpha and D1S80 PCR systems: the alleles from a minor DNA component could not be detected in the presence of a large excess of DNA from a second person.

Alleles↗

PubMed1991

[Not Available].

Explore the source record for details and available documents.

Anatomy↗

PubMed1983

Tension pneumocephalus after posterior fossa craniotomy: report of four additional cases and review of postoperative pneumocephalus.

Four cases of tension pneumocephalus after either posterior fossa craniotomy or translabyrinthine resection of acoustic neuroma with or without nitrous oxide anesthesia are described. Three of the operations were performed with the patient in the sitting position, and one was done with the patient in the lateral position. Of the three cases operated in the sitting position, no nitrous oxide was used at any time during anesthesia in one. Two patients failed to regain consciousness after the termination of anesthesia, and the other two developed the sudden onset of neurological symptoms 1 to 1.5 hours after the operation. In all cases computed tomography disclosed a large subdural collection of air. Re-exploration of the surgical wound or twist drill aspiration of the subdural air resulted in prompt recovery of neurological status in three patients, whereas the other patient's neurological status improved gradually without any specific treatment. The role played by nitrous oxide, the mechanisms by which air enters the intracranial space, the contributory factors, and the predisposing surgical conditions of tension pneumocephalus are reviewed and discussed. Dependent drainage of the cerebrospinal fluid, especially in a patient with coexisting hydrocephalus, seems to be the most important factor for the development of this complication.

Aged↗

PubMed1968