Detection of methicillin-resistant Staphylococcus aureus and simultaneous confirmation by automated nucleic acid extraction and real-time PCR

A molecular assay for the simultaneous detection of a Staphylococcus aureus-specific gene and the mecA gene, responsible for the resistance to methicillin in staphylococci, was evaluated. The assay included an automated DNA extraction protocol conducted with a MagNA Pure instrument and real-time PCR conducted with a LightCycler instrument. The performance and robustness of the assay were evaluated for a suspension of methicillin-resistant S. aureus (MRSA) strain with a turbidity equivalent to a McFarland standard of 0.5, which was found to be the ideal working concentration. The specificity of the new molecular assay was tested with a panel of 30 gram-negative and gram-positive bacterial strains other than MRSA. No cross-reactivity was observed. In a clinical study, 109 isolates of MRSA were investigated. All clinical MRSA isolates gave positive results for the S. aureus-specific genomic target, and all but one were positive for the mecA gene. In conclusion, the new molecular assay was found to be quick, robust, and laborsaving, and it proved to be suitable for a routine molecular diagnostic laboratory.     

REACTIVITY OF LYMPHOCYTE SUBPOPULATIONS IN HUMAN MIXED LYMPHOCYTE CULTURE

Loss of antigenicity in the mixed lymphocyte culture (MLC) reaction of lymphocytes precultured at 22°C for 7–10 days was accompanied by a decrease in bone-marrow-derived lymphocytes (B cells) from 22 ± 1% to 13 ± 1%, and an increase in thymus-derived lymphocytes (T cells) from 65 ± 2% to 83 ± 1% (P < 0.001). Depletion of B cells from a fresh lymphocyte suspension by either antihuman immunoglobulin-coated column fractionation or by sheep red blood cell (SRBC) rosette formation resulted in a significant reduction of the cell's ability to stimulate in MLC (P < 0.001). Coating of lymphocytes with rabbit antihuman brain serum abrogated their ability to respond but not the ability to stimulate in MLC.     

Poly(2,5-dialkoxy-p-phenylene)s—synthesis and properties

The synthesis of poly(2,5-dialkoxy-p-phenylene)s (PPP) by palladium-catalyzed polycondensation of 2,5-dialkoxy-4-bromophenylboronic acids is described. Number-average degrees of polymerization of ca. 30 have been reached at best. The characterization of the polymers by NMR, IR, UV-VIS and fluorescence spectra, data on the bulk structure obtained by X-ray methods, melting behavior and thermal stability are reported. PPP's with long alkoxy side chains exhibit a layered phase structure, those with short or branched alkoxy side chains, cylindrical packing. Poly(2,5-dibutoxy-p-phenylene) was prepared with chain lengths 7 ≤ P_n ≤ 30. The polymer with P_n of 30 shows thermal transitions in the bulk phase at 182°C and 227°C. It forms an anisotropic melt above 227°C which only starts decomposing if heated above 300°C. The polymers of shorter chain length show isotropic melts, with the melting point strongly depending on chain length.     

Determination of Dissolved Oxygen in Heterogenous Systems Particularly in Emulsions and Oily Liquids

The content of dissolved oxygen was determined by four independent methods in a series of non-aqueous or heterogenous systems. The Lex-O₂-Content Analyzer represents a fast and simple apparatus that employs a coulometric oxygen assay with Hersch cell detection. A comparison of the results with different methods demonstrates the reliability of the Lex-O₂ in the determination of oxygen dissolved in heterogeneous or non-aqueous systems. Therefore, this apparatus can be recommended for the measurement of oxygen in oxygenator or perfusion fluids, as well as in blood substitutes or other oxygen transporting systems.     

Early biochemical and morphological changes of the rat adrenal medulla induced by xylitol

Long-term administration of high doses of xylitol and other polyols in rats has been associated with an increase in adrenal medullary hyperplasia and neoplasia. In order to exclude age-related factors and to differentiate between unspecific stress reactions and direct effects of the compound administered, a model was developed for quantifying early adrenomedullary responses. Male SD rats were fed xylitol (10% or 20% in the diet) for 2 and 8 weeks, and early biochemical changes were correlated with a stereological analysis of the adrenal medulla. At first, the in vivo rate of catecholamine (CA) biosynthesis was slightly decreased (at 2 weeks). This was followed by an increase in dopamine--hydroxylase (DBH) activity (at 8 weeks). By that time, the total chromaffin cell volume had increased and the number of chromaffin cells per reference volume had decreased in a dose-dependent way. The total number of chromaffin cells per adrenal gland showed a distinct tendency towards an increase. Adrenal epinephrine and norepinephrine contents were not altered, and both tyrosine hydroxylase and phenylethanolamine-N-methyltransferase activities remained unchanged. These data suggest that continued xylitol administration evoked an inhibitory effect on CA synthesis that, together with stimulation of the adrenal medulla brought about by the compound, resulted in compensatory medullary hypertrophy and hyperplasia.     

Significance of laboratory diagnostic study parameters of the hepatobiliary system in the evaluation of cardiovascular diseases--results of cross sectional and longitudinal studies in patients with suspicious cardiovascular findings in an epidemiologic follow-up study

With the help of an approx. 280 000 inhabitants check of x-ray-morphological suspects of a heart disease the laboratory parameters thymol turbidity test, zinc-sulphate turbidity test, total protein, serum protein electrophoresis and the enzymes "ASAT" and "ALAT" in longitudinal section and cross-section were examined in an intervention study during 5 years. All these parameters show standard values on the average, but compared to a healthy reference they showed significant differences, which relations to heart and vessel diseases could be deduced from. This referred especially to age-inverse behaviour of the transaminases only concerning male test persons. The examination of the longitudinal section confirmed exactly the results of the cross-section analysis. On the one hand it underlines the results got from the cross-section and in the second place it contributes to the efficient diagnostics by learning undone a repetition of these laboratory examinations during the period of 5 years with such a defined population. The relations of the particularities mentioned obviously refer to subclinical fields. Effects of therapy do not reflect in the laboratory findings.     

ACE inhibition reduces activity of the plasminogen/plasmin and MMP systems in the brain of spontaneous hypertensive stroke-prone rats

The spontaneously hypertensive stroke-prone rat (SHR-SP) is an experimental model of malignant hypertension which lead to secondary alterations of the extracellular matrix. Our aim was to determine ACE-inhibitor related changes of proteases involved in the reconstruction of the extracellular matrix in the brain. Twelve SHR-SP rats were randomized into two groups. Each group was treated with either an antihypertensive dose of ramipril or placebo for 6 months. Brain tissue plasminogen activator (t-PA) and urokinase (u-PA) were quantified by using casein-dependent plasminogen zymography, matrix metalloproteinase (MMP)-2 and MMP-9, by MMP-zymography, and tissue inhibitor of MMP (TIMP)-1 and -2, by reverse zymography. The amounts of u-PA, t-PA, and MMPs were significantly reduced in animals treated with ACE inhibitor. Plasminogen zymography showed a 39% reduction of u-PA in the basal ganglia (p < 0.0001); t-PA expression was reduced by 26% in the cortex and by 33% in the basal ganglia (p < 0.0001). MMP-2 expression was reduced by 15% in the cortex (p < 0.05) and by 10% in the basal ganglia (p < 0.05); MMP-9 expression significantly decreased by 37% in the cortex and by 25% in the basal ganglia (p < 0.0001 each). No differences were observed in the amount of TIMP-1 or TIMP-2. These findings provide new insights into the biochemical mechanisms underlying extracellular matrix proliferation and its modulation by ACE inhibitors. Therapeutic alterations that influence the proteolytic systems might prove important in the prevention of extracellular matrix accumulation and secondary microvascular vessel wall changes.     

Endoscopic cordectomy. a proposal for a classification by the Working Committee, European Laryngological Society

The European Laryngological Society is proposing a classification of different laryngeal endoscopic cordectomies in order to ensure better definitions of postoperative results. We chose to keep the word “cordectomy” even for partial resections because it is the term most often used in the surgical literature. The classification comprises eight types of cordectomies: a subepithelial cordectomy (type I), which is resection of the epithelium; a subligamental cordectomy (type II), which is a resection of the epithelium, Reinke’s space and vocal ligament; transmuscular cordectomy (type III), which proceeds through the vocalis muscle; total cordectomy (type IV); extended cordectomy, which encompasses the contralateral vocal fold and the anterior commissure (type Va); extended cordectomy, which includes the arytenoid (type Vb); extended cordectomy, which encompasses the subglottis (type Vc); and extended cordectomy, which includes the ventricle (type Vd). Indications for performing those cordectomies may vary from surgeon to surgeon. The operations are classified according to the surgical approach used and the degree of resection in order to facilitate use of the classification in daily practice. Each surgical procedure ensures that a specimen is available for histopathological examination. Received: 29 December 1998 / Accepted: 2 July 1999