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Biomedical subjects

R Klein

Publications and source records attributed to R Klein.

At least 37 records · Page 2Linked to original sources

The GlideScope Video Laryngoscope: randomized clinical trial in 200 patients.

BACKGROUND: The GlideScope Video Laryngoscope is a new intubating device. It was designed to provide a view of the glottis without alignment of the oral, pharyngeal and tracheal axes. The aim of the study was to describe the use of the GlideScope in comparison with direct laryngoscopy for elective surgical patients requiring tracheal intubation. METHODS: Two hundred patients were randomly assigned to intubation by direct laryngoscopy using a Macintosh size 3 blade (DL, n=100) or intubation using the GlideScope (GS, n=100). Prior to intubation all patients were given a Cormack and Lehane (C&L) grade by a separate anaesthetist using a Macintosh size 3 blade. The patient was then intubated, using direct laryngoscopy or the GlideScope, by a different anaesthetist during which the larynx was inspected and given a laryngoscopy score. Time to intubate was measured. RESULTS: In the GS group, laryngoscopy grade was improved in the majority (28/41) of patients with C&L grade >1 and in all but one of patients who were grade 3 laryngoscopy (P<0.001). The overall mean time to intubate was 30 (95% CI 28-33) s in the DL group and 46 (95% CI 43-49) s in the GS group. The time to intubate for C&L grade 3 was similar in both groups, being 47 s for the DL group and 50 s for the GS group respectively. CONCLUSION: In most patients, the GlideScope provided a laryngoscopic view equal to or better than that of direct laryngoscopy, but it took an additional 16 s (average) for tracheal intubation. It has potential advantages over standard direct laryngoscopy for difficult intubations.

Adult↗

Diagnostic accuracy of atypical p-ANCA in autoimmune hepatitis using ROC- and multivariate regression analysis.

INTRODUCTION: Antineutrophil cytoplasmic antibodies (atypical p-ANCA) are detected at high prevalence in sera from patients with autoimmune hepatitis (AIH), but their diagnostic relevance for AIH has not been systematically evaluated so far. METHODS: Here, we studied sera from 357 patients with autoimmune (autoimmune hepatitis n=175, primary sclerosing cholangitis (PSC) n=35, primary biliary cirrhosis n=45), non-autoimmune chronic liver disease (alcoholic liver cirrhosis n=62; chronic hepatitis C virus infection (HCV) n=21) or healthy controls (n=19) for the presence of various non-organ specific autoantibodies. Atypical p-ANCA, antinuclear antibodies (ANA), antibodies against smooth muscles (SMA), antibodies against liver/kidney microsomes (anti-Lkm1) and antimitochondrial antibodies (AMA) were detected by indirect immunofluorescence microscopy, antibodies against the M2 antigen (anti-M2), antibodies against soluble liver antigen (anti-SLA/LP) and anti-Lkm1 by using enzyme linked immunosorbent assays. To define the diagnostic precision of the autoantibodies, results of autoantibody testing were analyzed by receiver operating characteristics (ROC) and forward conditional logistic regression analysis. RESULTS: Atypical p-ANCA were detected at high prevalence in sera from patients with AIH (81%) and PSC (94%). ROC- and logistic regression analysis revealed atypical p-ANCA and SMA, but not ANA as significant diagnostic seromarkers for AIH (atypical p-ANCA: AUC 0.754+/-0.026, odds ratio [OR] 3.4; SMA: 0.652+/-0.028, OR 4.1). Atypical p-ANCA also emerged as the only diagnostically relevant seromarker for PSC (AUC 0.690+/-0.04, OR 3.4). None of the tested antibodies yielded a significant diagnostic accuracy for patients with alcoholic liver cirrhosis, HCV or healthy controls. CONCLUSIONS: Atypical p-ANCA along with SMA represent a seromarker with high diagnostic accuracy for AIH and should be explicitly considered in a revised version of the diagnostic score for AIH.

Adolescent↗

Demonstration of antibodies to the chitin-binding mistletoe lectin (cbML) in tumor patients before and during therapy with an aqueous mistletoe extract.

Mistletoe extracts exert immunomodulatory properties in vivo and in vitro, and these effects have been related mainly to mistletoe lectin 1 (ML-1). Recently, a new chitin-binding mistletoe lectin (cbML) has been isolated and structurally characterized in these extracts. Aim of the present study was, therefore, to evaluate whether this cbML also affects immunocompetent cells and can for instance activate B-cells to produce anti-cbML-specific antibodies. Sera from patients with different tumors who were treated with the mistletoe extract ABNOBAviscum Mali (AM) 4 for at least 18 weeks were analysed before therapy and after 3, 6, 9, 12, 18, and 24 weeks. Sera were tested by ELISA against ML-1, -3, and cbML, isolated from a single mistletoe plant collected from an apple tree (Malus domestica). Eight of the 26 patients (31%) had IgG anti-cbML antibodies already before therapy, while only four had anti-ML-1 and -3 antibodies. Of the 18 anti-cbML negative patients before therapy 54% developed these antibodies during therapy, and there was a significant increase in anti-cbML antibody titers. In contrast, anti-ML-1 or -3-antibodies developed in almost 100% of the 25 patients being negative before therapy. These data indicate that cbML can induce immunological responses in patients treated with mistletoe extracts, although it seems to have lower antigenicity. Interestingly, anti-cbML antibodies can be observed in a low incidence also in individuals, not having yet received mistletoe therapy.

Adjuvants, Immunologic↗

Inversion within the haloalkaliphilic virus phi Ch1 DNA results in differential expression of structural proteins.

The sequence of phi Ch1 contains an open reading frame (int1) in the central part of its genome that belongs to the lambda integrase family of site-specific recombinases. Sequence similarities to known integrases include the highly conserved tetrad R-H-R-Y. The flanking sequences of int1 contain several direct repeats of 30 bp in length (IR-L and IR-R), which are orientated in an inverted direction. Here, we show that a recombination active region exists in the genome of phi Ch1: the number of those repeats, non-homologous regions within the repeat clusters IR-L and IR-R and the orientation of the int1 gene vary in a given virus population. Within this study, we identified circular intermediates, composed of the int1 gene and the inwards orientated repeat regions IR-L and IR-R, which could be involved in the recombination process itself. IR-L and IR-R are embedded within ORF34 and ORF36 respectively. As a consequence of the inversion within this region of phi Ch1, the C-terminal parts of the proteins encoded by ORF34 and 36 are exchanged. Both proteins, expressed in Escherichia coli, interact with specific antisera against whole virus particles, indicating that they could be parts of phi Ch1 virions. Expression of the protein(s) in Natrialba magadii could be detected 98 h after inoculation, which is similar to other structural proteins of phi Ch1. Taken together, the data show that the genome of phi Ch1 contains an invertible region that codes for a recombinase and structural proteins. Inversion of this segment results in a variation of these structural proteins.

Amino Acid Sequence↗

Retinal vessel wall signs and the 5 year incidence of age related maculopathy: the Blue Mountains Eye Study.

AIMS: To assess whether retinal arteriolar wall changes (focal narrowing and arteriovenous nicking) are associated with an increased 5 year risk of age related maculopathy (ARM). METHODS: The Blue Mountains Eye Study examined 3654 residents aged 49+ years living in a defined area, during 1992-4 (82.4% participation). After 5 years, 2335 surviving participants (75.1%) were re-examined during 1997-9. Retinal photographs were graded using the Wisconsin ARM grading system. Incident late (neovascular or atrophic) or early stage ARM was defined using a side by side grading method. Focal arteriolar narrowing (localised constricted arteriolar segments causing a sausage-like appearance), and arteriovenous (AV) nicking (constriction on both sides of the venule where crossed by an arteriole), were graded by comparison with standard photographs. All retinal vessels passing through a circumferential zone 0.5-1.0 disc diameters from the optic disc margin were measured from digitised images. Summarised estimates for central retinal arteriolar equivalent (CRAE) represent an average diameter of arterioles for that eye. Associations were assessed after adjusting for age, sex, smoking, mean arterial blood pressure, and other vascular risk factors. RESULTS: Of 2314 baseline participants at risk of late stage ARM, either late stage lesion developed in 34 participants (1.5%). Of 2203 at risk of early stage ARM, this sign developed in 197 participants (8.9%). Focal arteriolar narrowing was present at baseline in at least one eye of 162 survivors (6.9%) and severe AV nicking was present in 187 people (8.1%). Over 5 years, 4.9% of subjects with and 1.2% of those without focal narrowing developed either late stage ARM lesion, age adjusted relative risk (RR) 2.3, 95% confidence interval (CI) 1.0 to 5.1, multivariate adjusted odds ratios (OR) 2.1 (95% CI 0.9 to 4.9). Similarly, 3.7% of subjects with and 1.3% of those without severe AV nicking developed late ARM lesions, age adjusted RR 2.1 (95% CI 0.9 to 5.1), multivariate adjusted OR 2.2 (95% CI 0.9 to 5.6). Corresponding age adjusted RR and multivariate adjusted OR for development of early stage ARM were 1.4 (95% CI 0.9 to 2.0) and 1.3 (95% CI 0.8 to 2.1) for focal arteriolar narrowing, and 1.6 (95% CI 1.0 to 2.3) and 1.8 (95% CI 1.1 to 2.9) for severe AV nicking, respectively. No associations between baseline CRAE and 5 year incident late or early stage ARM were found. CONCLUSIONS: Although of borderline statistical significance, the consistent associations found in this study suggest that structural retinal arteriolar changes may either contribute to ARM progression or may share common pathological pathways with ARM.

Aged↗

Variation associated with measurement of retinal vessel diameters at different points in the pulse cycle.

BACKGROUND/AIMS: To assess the variability in retinal vessel measurements at different points in the pulse cycle. METHODS: A healthy white male aged 19 years had 30 digitised images taken at three distinct points in the pulse cycle over a one hour period. A pulse synchronised ear clip trigger device was used to capture images at the desired point in the pulse cycle. Two trained graders measured the retinal vessel diameter of one large arteriole, one large venule, one small arteriole, and one small venule 10 times in each of these 30 images. RESULTS: Within an image, variability was similar between graders, pulse point, and vessel type. Across images taken at the same point in the pulse period, the change from the minimum to maximum measurement was between 6% and 17% for arterioles and between 2% and 11% for venules. In addition, measurements of small vessels had greater changes than large vessels and no point in the pulse period was more variable than another. Ignoring pulse cycle increased variability across images in the large venule, but not in the other vessel types. Mixed effect models were fit for each of the vessel types to determine the greatest source of variability. Controlling for pulse point and grader, the largest source of variability for all four vessels measured was across images, accounting for more than 50% of the total variability. CONCLUSION: Measurements of large retinal venules is generally less variable than measurements of other retinal vessels. After controlling for pulse point and grader, the largest source of variation is across images. Understanding the components of variability in measuring retinal vessels is important as these techniques are applied in epidemiological studies.

Adult↗

Retinal microvascular changes and MRI signs of cerebral atrophy in healthy, middle-aged people.

OBJECTIVE: To examine the relation of retinal microvascular abnormalities and MRI signs of cerebral atrophy in healthy middle-aged people. METHODS: A population-based, cross-sectional study involved 1,684 persons aged 51 to 72 years who had cerebral MRI and retinal photography in 1993 to 1995. Sulcal and ventricular size were quantified from the MRI scans and coded as grades 0 to 9, with sulcal widening (SW) and ventricular enlargement (VE) defined as grades 3 or higher. The presence or absence of retinopathy, microaneurysms, hemorrhages, and other characteristics were defined from retinal photographs using a standardized protocol. Generalized arteriolar narrowing was defined from a computer-assisted measurement of arteriolar diameters from digitized photographs. RESULTS: Persons with retinopathy had higher sulcal (p = 0.001) and ventricular (p = 0.03) grades than persons without retinopathy. After adjusting for age, gender, race, mean arterial blood pressure, diabetes, cigarette smoking, common carotid artery intima-media thickness, and other vascular risk factors, retinopathy was significantly associated with SW (odds ratio [OR], 1.9; 95% CI, 1.2, 3.0) and VE (OR, 1.5; 95% CI, 1.0, 2.3). These associations persisted even in people without diabetes or hypertension (OR 1.9, 95% CI, 0.8, 4.4 for SW; OR 2.7, 95% CI, 1.2, 6.5 for VE). Other retinal arteriolar characteristics (arteriovenous nicking, focal and generalized arteriolar narrowing) were not related to sulcal or ventricular grade. CONCLUSIONS: In healthy, middle-aged people, retinopathy is independently associated with sulcal and ventricular enlargement on MRI. This finding is compatible with the hypothesis that microvascular characteristics may influence the development of cerebral atrophic changes.

Aging↗

Neuropathology and binding studies in anti-amphiphysin-associated stiff-person syndrome.

The authors report a 71-year-old woman with amphiphysin-associated paraneoplastic stiff-person syndrome, opsoclonus, and encephalopathy. The patient's symptoms temporarily responded to plasmapheresis in parallel with a decline of serum anti-amphiphysin antibody titers. Later, the encephalopathy progressed rapidly and the patient died. Binding studies and the detection of autoantibodies in the patient's CNS as well as the treatment response suggest a pathogenic role of the anti-amphiphysin antibodies.

Aged↗

Numerical modelling of the generation and transport of heat in a bottom ash monofill.

Municipal solid waste is incinerated to reduce its volume, toxicity and reactivity. Several studies have shown that the resulting bottom ash has a high exothermic capacity. Temperature measurements in municipal solid waste incineration (MSWI) bottom ash landfills have found temperatures up to 90 degrees C. Such high temperatures may affect the stability of the landfill's flexible polymer membrane liner (FML) and may also lead to an accelerated desiccation of the clay barrier. The purpose of this study was to gain detailed knowledge of temperature development under several disposal conditions in relation to the rate of ash disposal, the variation of layer thickness, and the environmental conditions in a modern landfill. Based on this knowledge, a simulation was developed to predict temperature development. Temperature development was simulated using several storage periods prior to the deposition and several modes of emplacement. Both the storage time and the mode of emplacement have a significant influence on the temperature development at the sensitive base of the landfill. Without a preliminary storage of the fresh quenched bottom ash, high temperatures at the bottom of a landfill cannot be avoided.

Air Movements↗

A very long ACTBP2 (SE33) allele.

Analysing a buccal swab we found a long allele in the STR system ACTBP2. For confirmation we sequenced the isolated PCR product and found a sequence structure common in alleles of type III. Based on the repeat array the new allele is assigned as allele "49".

Alleles↗

Intraabdominal abscess following open and laparoscopic appendectomy in the pediatric population.

BACKGROUND: Studies comparing intraabdominal abscess (IAA) rates following laparoscopic appendectomy (LA) and open appendectomy (OA) have shown conflicting results. METHODS: The charts of 324 children undergoing appendectomy were reviewed retrospectively to examine the incidence of IAA. RESULTS: Of the 324 appendectomies, 204 (63.0%) were completed laparoscopically and 119 (36.7%) were performed open. The conversion rate was 0.2% (1/324). Of the 15 (4.6%) IAAs, 7 occurred in the LA group (3.4%) and 8 occurred in the OA group (6.7%) [p = not significant (NS)]. The incidence of IAA for perforated appendicitis for LA was 15% (7/46) and that for OA was 10% (7/70) (p = NS). CONCLUSION: This study demonstrates no statistically significant difference in the rate of IAA among children following LA and OA. LA can be performed for perforated appendicitis without increasing the risk of IAA.

Abdominal Abscess↗

Management of municipal solid waste incineration residues.

The management of residues from thermal waste treatment is an integral part of waste management systems. The primary goal of managing incineration residues is to prevent any impact on our health or environment caused by unacceptable particulate, gaseous and/or solute emissions. This paper provides insight into the most important measures for putting this requirement into practice. It also offers an overview of the factors and processes affecting these mitigating measures as well as the short- and long-term behavior of residues from thermal waste treatment under different scenarios. General conditions affecting the emission rate of salts and metals are shown as well as factors relevant to mitigating measures or sources of gaseous emissions.

Air Pollution↗

The novel differentiation of human blood mononuclear cells into CD1a-negative dendritic cells is stimulated in the absence of exogenous cytokines by an extract prepared from pinecones.

The production of dendritic cells, both in-vivo and in-vitro, has become the intense focus of research activities. Common to many of these production protocols is the use of cytokines, typically granulocyte-monocyte colony stimulating factor and either interleukin 4 or tumor necrosis factor alpha or a combination of all three. Herein, we report our findings that a proprietary pinecone extract is capable of in a dose-dependent manner, and in the absence of exogenous cytokines, the rapid differentiation from peripheral blood mononuclear cells of mature CD1a-negative dendritic cells.

Animals↗

Methods for the in vitro determination of an individual disposition towards TH1- or TH2-reactivity by the application of appropriate stimulatory antigens.

In this study we performed several methods for the determination of cytokines (RT-PCR for the demonstration of cytokine mRNA and flow cytometry for the analysis of intracellular cytokines) and compared them with a recently established test system stimulating peripheral blood mononuclear cells (PBMC) with TH1- and TH2-relevant recall antigens and analysing type 1 and type 2 cytokines by ELISA. Aim of the study was therefore to evaluate the reliability of TH1/TH2 cytokine profiles in two individuals with different types of an allergic/atopic disposition: one of them showed a strong TH1/type 1-mediated tuberculin-reaction (subject A), the other (subject B) revealed elevated IgE-levels and eosinophil counts (TH2/type 2-mediated). PBMC were incubated with the type 1-antigen purified protein derivative (PPD) and the type 2-antigen tetanus-toxoid (TT) for seven days. From the comparison of ELISA with RT-PCR and flow cytometry-analysis it became evident that all three methods allowed the definition of subject A as a 'type 1-responder'. Subject B showed a pure type 2-response in the ELISA method; PCR and flow cytometry analysis revealed the simultaneous production of type 1- and type 2-cytokines resulting in a mixed type 1/type 2-profile. Active immunization of subject A with TT at the end of the observation period of 12 months resulted in a transient shift from type 1- to a mixed type 1/type 2-profile (simultaneous PPD-induced IFN-gamma- and TT-induced IL-5 production). From this pilot study based on clear cut clinical criteria concerning either a humoral or cellular immunological reactivity towards allergens/antigens it is suggested that the determination of type 1/type 2-cytokines by ELISA in supernatants of PBMC stimulated with type 1/type 2-relevant antigens is a useful approach for a better classification of 'type1-' or 'type 2-responder'.

Adult↗

Investigations on the re-establishment of the positive feedback of oestradiol during anoestrus in the bitch.

To test for the re-establishment of the positive feedback of oestradiol (E2) during anoestrus in the dog, the hypothalamo-pituitary-ovarian axis of five beagle bitches was challenged by treatments with oestradiol benzoate (EB), mimicking the course of the pro-oestric E2 secretion. Treatments in anoestrus started 7 days following the decline of progesterone (P) <1 ng/ml; they were repeated in 5 week intervals until onset of pro-oestrus; another treatment was performed during dioestrus 50 days after onset of the preceding pro-oestric bleeding. Each dog served as its own control by receiving vehicle-treatments in one of the following cycles. Each observation period covered a time window of 168 h and blood samples were collected for the determination of luteinizing hormone (LH), follicle-stimulating hormone (FSH) and E2 in 6 (0-24 h) and 8 h (24-168 h) intervals. In the control periods and as indicated by the parameters area under curve (AUC), basal and maximal values, the availability of LH, FSH and E2 decreased from dioestrus to early anoestrus to increase again during the course of anoestrus (p < 0.05), indicating a gradual desensitization of the hypothalamus towards the negative feedback of oestradiol. At all times treatments with EB lowered the availability of FSH (decreased AUC and basal levels). A delay in the occurrence of the first LH peak after treatments with EB (p < 0.001) and decreased maximal values (p < 0.001) indicated a suppression of the LH-release. In no case treatment with EB led to a pre-ovulatory like LH-surge. In each dog the last trial with EB in anoestrus passed over into pro-oestrus/oestrus, with a reduced AUC and peak value of the pre-ovulatory LH-surge being the only differences to the control group. The observed differences in the response of LH and FSH to treatments with EB point towards subtle differences in the mechanisms controlling the release of these two hormones during anoestrus. From the data obtained, it may be concluded that the time window for E2 to act via a positive feedback seems to be very small and restricted to the end of anoestrus, and that full follicular function is a pre-requisite to allow for this phenomenon.

Anestrus↗

Dramatic increase in bilirubin after ERCP - pethidine as a possible cause of drug-induced hepatitis.

We report on a 68-year-old female patient who was admitted with abdominal pain. Elevated lipase and CRP caused us to suspect pancreatitis. Because an enlarged pancreas head was found on ultrasound, an endoscopic retrograde cholangio- and pancreaticography was performed with a pethidine-containing premedication. Thereafter, bilirubin, gamma-glutamyl transpeptidase and alkaline phosphatase increased dramatically. There was also a moderate elevation of aspartate aminotransferase and alanine aminotransferase. A second endoscopic retrograde cholangio- and pancreaticography with the same premedication was performed in order to exclude an undetected concretion. This led to a further increase of bilirubin. An association with the drugs given as premedication was therefore suspected, and in fact, a hypersensitivity reaction towards pethidine was confirmed by the lymphocyte transformation test. We thus conclude that pethidine caused an immunologically mediated hepatic injury.

Adjuvants, Anesthesia↗

Rotational constraint in posterior-stabilized total knee prostheses.

Rotational stresses from box-post impingement have been implicated in the loosening of posterior-stabilized total knee prostheses. A bench model was constructed to assess the forces generated by tibiofemoral rotation. Rotational torque under load was measured in two different posteriorstabilized total knee prostheses using an axial-torsion load cell at 0 degrees, 20 degrees, and 40 degrees flexion over 20 degrees internal and external rotation. The Sigma posterior-stabilized prosthesis generated little torque through 5 degrees internal and external rotation. An increase in torque then occurred because of box-post impingement, generating peak torques of 17 to 18 N-m at 12 degrees to 14 degrees rotation. The bench model produced the same deformation of the polyethylene post as seen on retrieved specimens. The Scorpio posterior-stabilized prosthesis had a relatively continuous rise in generated torque from tibiofemoral conformity. Box-post impingement did not occur resulting in 32% lower torque between 12 degrees and 14 degrees rotation. Peak rotational torques of 15 to 16 N-m were reached at 19 degrees to 20 degrees rotation. Tibiofemoral conformity is the primary source of rotational constraint. Box-post impingement can be a source of additional rotational constraint. Depending on specific design features, small changes in relative tibiofemoral component rotation can more than double the generated torque. Axial rotation of the knee in vivo can generate substantial torque. Relative tibiofemoral rotational position is an important factor influencing component function and fixation.

Femur↗