Detection of Mycoplasma pneumoniae in serum specimens from patients with mycoplasma pneumonia by PCR

There are few data on detection of Mycoplasma pneumoniae from blood, serum or plasma, and systematic studies on this diagnostic approach in community-acquired pneumonia (CAP) are scarce. Compared to testing respiratory specimens, this approach has the advantages that it is less dependent on proper specimen collection, serum is easily stored and handled, and the pathogen is detected in a primary sterile site, where colonization can be ruled out. In this study, acute-phase serum specimens from 29 patients of Vienna University Hospital (treated between 11/1994 and 6/2004; female: 14, male: 15; median age: 31 years, range: 15-66 years) with CAP and serologically verified M. pneumoniae infection, who had not received anti-mycoplasma therapy prior to serum collection, were tested for M. pneumoniae by conventional PCR and real-time PCR. Conventional PCR yielded negative results for all specimens, but real-time PCR detected M. pneumoniae in 15/29 patient sera (52%). These findings indicate that M. pneumoniae is present in the bloodstream of a substantial proportion of patients with mycoplasma pneumonia. Despite the possible adherence of M. pneumoniae to human erythrocytes, the pathogen can be detected from serum, if a method with enhanced sensitivity is applied. However, the negative predictive value of PCR from serum with regard to etiological diagnosis is low. With regard to the potential clinical benefit of blood-based PCR diagnosis of mycoplasma pneumonia the diagnostic accuracy of this approach using either serum or whole-blood specimens should be addressed by large-scale studies.     

β Chain deficiency in three patients with dysfunctional C8 molecules

Structural and functional studies were performed on a dysfunctional C8 molecule present in the serum of two siblings and an unrelated individual. The C8 in these three sera exhibited a pattern of partial immunologic identity with C8 in normal serum but was devoid of functional activity. The C8 was immunoprecipitated from the three sera and from a control serum with an antihuman C8 antiserum and analyzed by SDS-PAGE using highly purified human C8 as a reference. A selective absence of a band of 62,000 mol. wt was observed in the immunoprecipitates from the sera containing dysfunctional C8. Experiments performed with the purified α-γ and γ subunits showed that the hemolytic activity of the C8 deficient sera could be reconstituted by the addition of the β chain but not the α-γ dimer. Binding of the dysfunctional C8 to C$\text{567}$ was excluded by the following observations: (1) EAC 1–7 treated with the C8 deficient sera and then washed could not be lysed after the addition of the β subunit and C9; and (2) the abnormal molecules did not interfere with the consumption of normal C8 by the soluble complex SC5b-7.     

Technical basis for magnetic resonance images

The spin-echo procedure is the basic technique in a magnetic resonance (MR) study (the magnetization vector is flipped by 90° onto the ortogonal plane to the main magnetic field). Very soon after the MR procedure was developed, it was pointed out how important it is to achieve the needed contrast with shorter repetition times (TRs) to reduce the imaging time. Recently, fast imaging techniques have been introduced (partial flip angles, short TRs, and the lack of 180° radiofrequency pulses to refocus the spins are their main characteristics; the spins are refocused by the application of a gradient reversal technique). These techniques are particularly needed in pediatric neuroradiology, where the examination time must be as short as possible. At present, partial flip-angle techniques are almost completely replacing the conventional spin-echo procedure, but the variations in flip angle could result in a change in contrast. For these reasons, conventional spin-echo techniques may still be useful in a routine MR study.Presented at the 11th Meeting of the European Society for Paediatric Neurosurgery, Naples 1988     

Thyroid carcinoma mimicking a toxic adenoma

A young woman with a thyroid papillary carcinoma behaving as an autonomously hyperfunctioning nodule is described. Only 17 similar patients have been seen in the past 25 years. It is emphasized that hyperthyroidism does not exclude malignant disease in hot nodules. This possibility suggests that all thyroid nodules, either cold or hot, require careful management. Therefore, in at risk cases, surgery could be the most useful treatment.     

Is there an abnormal fasting duodenogastric reflux in nonulcer dyspepsia?

A quantitatively and/or qualitatively abnormal duodenogastric reflux (DGR) could be involved in the pathogenesis of nonulcer dyspepsia (NUD). The aims of this prospective study were to look for (1) a pathological DGR profile during fasting and (2) an eventual correlation between DGR profile and clinical symptoms. Twenty-six NUD patients were investigated. Seven other operated patients with a surgical procedure facilitating DGR episodes and 27 healthy volunteers served as control groups. A clinical score was determined for each patient from a standardized questionnaire. Gastric aspiration was performed for 6 hr in fasting subjects. The aspirates were pooled into 17 samples. In each sample the concentration and the output of total bile acids was determined. If the concentration was larger than 30 mol/liter in pooled samples, the concentrations of free bile acids and the distribution of the conjugated bile acids was determined. The percentage of aliquots with a total bile acid concentration larger than 50 mol/liter (without upper limit), and the percentage with a concentration larger than 2500 mol/liter was also obtained. No significant difference was demonstrated between the healthy volunteers and NUD patients, whatever the parameter considered. However, there was a significant increase in each of the quantitative parameters for the group of operated patients in comparison with the NUD patient group. No significant correlation was found between the clinical score and the DGR profile in NUD patients. Apparently, DGR episodes do not play a primary role in the pathogenesis of NUD.Part of this work was presented at the 4th European Symposium on Gastrointestinal Motility, Krakow, Poland. September 22–24, 1988.Hepatogastroenterology, 35:178, 1988 (abstract).     

Reduction of cell proliferative activities of gastric stump adenomatous hyperplasias after bile reflux diversion in rats

Previously we reported the majority of lesions induced by bilereflux, in the absence of chemical carcinogens, in the rat remnantstomach to consist primarily of gastric type and secondarilyof intestinal type cells, and that they are reversible afterdiversion of bile reflux. The present study was designed toevaluate changes in proliferative activities in cells of eachtype under these conditions. The frequency of adenomatous hyperplasia(AH) induced in the gastric stump mucosa by duodenal contentreflux after Billroth II partial gastrectomy (BII) increaseduntil the 54th week of the experiment. Roux-en-Y (RY) surgicalprocedure which prevents duodenal reflux performed at the 24thor 36th week after BII led to a decrease in AH. Cell contentof the lesions was analyzed using routine H&E staining,immunohistochemical staining for pepsinogen isoenzyme 1 andhistochemical procedures for mucins (paradoxical concanavalinA, galactose oxidase Schiff and sialidase galactose oxidaseSchiff reactions) and proliferation in each compartment evaluatedby an immunohistochemical method using bromodeoxyuridine (BrdU)and a monoclonal antibody against BrdU. At the 54th week thenumber of BrdU-labeled cells per normal pyloric column was significantly(P < 0.05) increased to 10.63/pit after the BII operation,while it diminished to 5.23/pit after RY diversion, this beingthe same level as with the RY procedure alone. AH maintaineda high rate of BrdU incorporation at 12.7% after BII operation,which was also significantly reduced (P < 0.01) to 7.0% bythe RY surgery. The intestinal type cell showed highest (22.2%),the surface mucous type cell showed the next (16.5%) and thepyloric gland type cell showed lowest (5.2%) BrdU labeling indicesafter BII operation. All the cell types in AH showed similarproportional decreases in BrdU incorporation after RY diversion.Thus surgical intervention reverses the cell proliferation causedby bile reflux in the gastric stump.     

The influence of stimulus parameters on the visual field indices by automated projection perimetry

The various stimulus parameters offered by two standard automated projection perimeters [Humphrey Field Analyser 630 (HFA) and Octopus 2011, namely, stimulus size and location and the interaction of adaptation level and stimulus duration, were compared in a sample of 20 patients attending a glaucoma clinic using the visual field indices mean defect (MD), loss variance (LV), short-term fluctuation (SF) and corrected loss variance (CLV). LV and SF were greater with Octopus program 32 compared with Octopus program G1 (P < 0.02). No difference in the indices was found between stimulus sizes I and III for HFA program 30-2. MD was greater for program 30-2 compared with program 32 (P < 0.002) when expressed in terms of log (L/L) whereas LV (P < 0.02) and SF (P < 0.02) were greater for program 32. All differences were considered to be negligible in the clinical sense.     

Calcium channel modulation by dihydropyridines modifies sufentanil-induced antinociception in acute and tolerant conditions

Summary The study was aimed at elucidating the possible participation of l-type Ca²⁺ channel in the acute analgesic effect of an opiate and the development of tolerance to this action. Sufentanil, a selective p agonist, and two dihydropyridines, the Ca²⁺ antagonist nimodipine and the Ca²⁺ agonist Bay K 8644, were selected. The tail-flick test was used to assess the nociceptive threshold. In naive rats, nimodipine (200 g/kg) potentiated the analgesic effect of sufentanil reducing the ED₅₀ from 0.26 to 0.08 g/kg. Similar results were observed with its (–)-enantiomer Bay N 5248, while the (+) enantiomer Bay N 5247 was ineffective. Tolerance to the opiate was induced by chronic subcutaneous administration of sufentanil with minipumps (2 g/h, 7 days). In these conditions the dose-response curve to sufentanil was displaced to the right and the ED₅₀ was increased to 1.49 g/kg. In tolerant rats, nimodipine preserved its potentiating ability and prevented the displacement to the right of the sufentanil dose response-curve (ED₅₀ = 0.48 g/kg). When nimodipine was pumped (1 g/h, 7 days) concurrently with sufentanil, the development of tolerance to the opioid was not disturbed. However, the expression of tolerance was abolished and even the effect of acutely administered sufentanil was markedly potentiated (ED₅₀ = 0.03 g/kg). Similar experiments were performed with Bay K 8644. In naive rats, Bay K 8644 at a low dose (20 g/kg) that behaves as a calcium agonist, antagonized the analgesic effect of sufentanil (ED₅₀ = 0.58 g/kg), whereas at a high dose (200 g/kg) it potentiated this action (ED₅₀ = 0.15 g/kg). In tolerant rats, Bay K 8644 (20 g/kg) preserved its antagonizing ability inducing a displacement to the right of the sufentanildose-response curve (ED₅₀ = 4.2 g/kg). When Bay K 8644 was pumped (1 g/h, 7 days) concurrently with sufentanil, it enhanced the expression of tolerance to the opiate (ED₅₀ = 3.8 g/kg). These results suggest that the calcium fluxes through the l-type channel in neurones are functionally linked to the activation of the opiate receptor: the blockade of the channel increased the potency of sufentanil, whereas its activation reduced the potency of the opiate. In chronic experiments, DHPs concurrently administered with sufentanil did not affect the development of tolerance to the opiate. However, nimodipine prevented the expression of this phenomenon. Even more, the animals became hypersensitive to the opiate suggesting that the adaptative mechanisms induced by chronic opiate could be affected by chronic nimodipine.This work was supported by grants from Universidad de Cantabria-Caja Cantabria (1988) and Bayer AG, Wuppertal, FRGPredoctoral Fellow: Fondo de Investigaciones Sanitarias de la Seguridad Social.Send offprint requests to: M. A. Hurlé at the above address