Detection of virulence genes of Clostridium difficile by multiplex PCR

Antikainen J, Pasanen T, Mero S, Tarkka E, Kirveskari J, Kotila S, Mentula S, Könönen E, Virolainen‐Julkunen A‐R, Vaara M, Tissari P. Detection of virulence genes of Clostridium difficile by multiplex PCR. APMIS 2009; 117: 607–13. Clostridium difficile strains belonging to the PCR ribotype 027, pulse‐field gel electrophoresis (PFGE) type NAP1, toxinotype III and restriction endonuclease analysis group BI harbouring mutations in the tcdC gene and possessing binary toxin components A and B have been described to cause epidemics with increased morbidity and mortality. In the present study we developed a conventional multiplex PCR designed to detect selected virulence associated markers of the hypervirulent C. difficile PCR ribotype 027. The multiplex PCR assay detected the major toxins A and B, binary toxin components A and B as well as a possible deletion in the tcdC gene: a characteristic pattern of amplification products for the PCR ribotype 027 strains was detected. This rather simple method was specific for the screening of this hypervirulent C. difficile strain. The correlation between the multiplex PCR and PCR ribotyping methods was excellent. The sensitivity and specificity were 100% in our epidemiological situation. In conclusion, this multiplex PCR was found useful in the preliminary screening for the hypervirulent C. difficile PCR ribotype 027.     

The Feasibility of Fully Automated Pacemaker Advise in Treating Atrial Tachyarrhythmias

Background: Modern pacemakers continuously store significant cardiac‐related events. Interpreting these data and reprogramming the pacemaker can be time‐consuming and demands expert knowledge. A software‐based expert system, the therapy advisor (TA), was developed, which analyzes stored data and provides reprogramming recommendations. This study addresses whether pacemaker experts consider the messages that are automatically generated appropriate in the management of atrial tachyarrhythmias/atrial fibrillation (AT/AF). Methods: This observational, international, multicenter study follows 150 patients with suspected or documented atrial arrhythmias who received a dual‐chamber pacemaker (model Vitatron T‐70, Medtronic Inc., Minneapolis, MN, USA) incorporating the TA. The TA summarizes technical and clinical data stored in the pacemaker into key messages and may suggest programming changes. Twenty‐five cardiologists examined their patients per normal practice during two follow‐up visits. They reported the therapy changes they deemed necessary without initially reviewing the TA messages. Next, they rated their satisfaction with and the clinical relevance of the TA messages and recorded the final therapy changes. Results: The TA generated (mostly AT/AF‐related) main observations in 49% and programming advice in 33% of the patients. The experts rated 95% of the TA messages as satisfactory and deemed therapy changes necessary in roughly half the patients. Pacemaker changes in AT/AF therapy or general settings were prompted primarily by the diagnostic information stored in the device. Medication changes were mostly led by the symptoms reported by the patient. Conclusion: This study demonstrates that experienced cardiologists agree with 95% of the observations and programming suggestions that the TA automatically generates. (PACE 2010; 605–614)     

Biochemical characterization of variants of the Ehlers-Danlos syndrome type VI

Three variants of the Ehlers-Danlos syndrome type VI are described: a severe form with skeletal, dermal and ocular manifestations associated with a lack of hydroxylysine in skin and little lysyl hydroxylase activity in cultured fibroblasts; a similarly affected form with a nearly normal hydroxylsine content in skin, but with only little enzyme activity in cultured fibroblasts; and a predominantly ocular form with no biochemical abnormality in skin or cultured skin fibroblasts. The activities of prolyl 4-hydroxylase and the two hydroxylysyl glycosyltransferases were normal in all cases, and the failure to find lysyl hydroxylase activity was not due to altered solubility characteristics of the enzyme or to the presence of an enzyme inhibitor. The collagen produced in cell culture, however, was hydroxylated to a markedly higher extent than that found in skin. In both the mutant and control cells hydroxylation of lysyl residues was less sensitive to ascorbate deficiency than that of prolyl residues.     

Microvolt T-Wave Alternans During Exercise and Pacing in Patients with Acute Myocardial Infarction

Cardiac Arrhythmias and Risk Stratification after Myocardial infarction (CARISMA) is a prospective multicenter trial designed to document the incidence of cardiac arrhythmias after acute myocardial infarction (AMI), and to assess the predictive accuracy of various arrhythmic risk markers. In this substudy of the CARISMA trial, microvolt T-wave alternans (TWA) was assessed with specific equipment 6 weeks after AMI during bicycle exercise, atrial (A) pacing, and simultaneous ventricular and atrial (V + A) pacing in 80 patients with left ventricular ejection fraction (LVEF) <40%. The agreement between the acute test results was determined by overall proportion of concordance and the kappa statistic. Sustained TWA was observed in 24, 45, and 50% of the patients during the exercise test, A pacing, and V + A pacing, respectively. The number of indeterminate TWA was significantly lower during V + A pacing (n = 7) than exercise test (n = 34). The TWA concordance rate was 71% between exercise and V + A pacing (κ= 0.53, P = 0.001), 79% between exercise and A pacing (κ= 0.54, P < 0.001), and 95% between the two pacing modes (κ= 0.89, P < 0.001). Patients with positive TWA in all tests had lower LVEF (28 ± 7% vs 35 ± 9%, P < 0.01) and wider QT dispersion (99 ± 44 ms vs 67 ± 38 ms, P < 0.01) than those with inconsistent test result. The low number of indeterminate tests and high concordance between the test results indicate that V + A pacing may provide a valuable means to assess TWA in patients who cannot complete the exercise test.     

Collagen metabolism in normal and complicated pregnancy: changes in the aminoterminal propeptide of type III procollagen in serum

The turnover of type III collagen, a major constituent of the myometrium and the uterine cervix, during pregnancy was evaluated by monitoring serum antigens related to the aminoterminal propeptide of type III procollagen. Their concentration increased markedly towards term in most uncomplicated pregnancies, while their size distribution throughout the pregnancy resembled that seen in the sera of normal healthy persons. In some patients, however, the level remained low, indicating interindividual variation in the release into serum and metabolism of the propeptide. There were no distinct changes during or immediately after vaginal delivery. Values exceeding the reference range for uncomplicated pregnancies were found during weeks 28-37 in patients with pre-eclampsia, essential hypertension, intrahepatic cholestasis of pregnancy or twin pregnancy. Thus, pregnancy should be taken into account when evaluating results of the serum assay for the aminopropeptide and the use of this assay as an indicator of pregnancy complications warrants further study.     

Thallium Scintigraphy in Prediction of Occlusion of Bypass Grafts in Asymptomatic and Symptomatic Patients

ABSTRACT To evaluate thallium scintigraphy in predicting coronary artery bypass graft patency, exercise thallium scintigraphy and selective graft and native vessel angiograms were performed in 22 asymptomatic and 29 symptomatic consecutive patients three months after coronary artery bypass grafting (CABG). Twelve out of 22 asymptomatic patients (55%) had reversible thallium defects on postoperative images; in 10 patients the postoperative scans were normal. The graft patency was significantly lower in asymptomatic patients with abnormal thallium perfusion compared to those with normal perfusion after CABG (68% vs. 91%. p<0.05). The rate of graft patency in symptomatic patients was 66/87 (76%). Thallium scintigraphy was 77% sensitive and 78% specific in detecting one or more stenosed or occluded bypass grafts in patients without angina (accuracy 77%). When data from exercise electrocardiography were combined with scintigraphy, all but one patient with incomplete revascularization could be detected (positive predictive accuracy 92%). In symptomatic patients, thallium scintigraphy accurately predicted the presence or absence of graft occlusion in 24/29 (83%) cases. Thus, abnormal myocardial perfusion due to stenosis or occlusion of bypass grafts is common in both asymptomatic and symptomatic patients after CABG. Thallium scintigraphy together with exercise electrocardiography appear to be useful non-invasive methods in detecting painless myocardial ischemia and in predicting bypass graft occlusion after CABG.     

Paraganglion cells mimicking metastatic clear cell carcinoma

Four patients are presented whom normal paraganglion cells simulated metastases of clear cell carcinomas of the urogenital tract. The cells, located within and near the lumbar sympathetic ganglia, were initially interpreted by the pathologist as metastatic, but a later examination showed them to be normal paraganglion cells. One ganglion was also examined electron microscopically. Normal ganglion cells were seen, as were cells with intracytoplasmic osmophilic neurosecretory granules, confirming their paraganglionic origin. Awareness of the appearance of paraganglion cells in some instances is essential to avoid their misinterpretation as metastases of clear cell carcinomas.     

Complications Related to Permanent Pacemaker Therapy

This study evaluates complications related to permanent endocardial pacing in the era of modern pacemaker therapy. There is only limited information available about the complications related to modern cardiac pacing. Most of the existing data are based on the 1970s and are no longer valid for current practice. The recent reports on pacemaker complications are focused on some specific complication or are restricted to early complications. Thus, there are no reports available providing a comprehensive view of complications related to modern cardiac pacing. Four hundred forty-six patients, who received permanent endocardial pacemakers between January 1990 and December 1995 at Kuopio University Hospital, were reviewed retrospectively using patient records. Attention was paid to the occurrence of any complication during the implantation or follow-up. An early complication was detected in 6.7%, and 4.9% of patients were treated invasively due to the early complication. Late complication developed in 7.2% and reoperation was required in 6.3% of the patients. Complications related to the implantation procedure occurred in 3.1%. Inadequate capture or sensing was observed in 7.4% of the patients. Pacemaker infection was detected in 1.8% and erosion in 0.9% of the patients. An AV block developed in 3.6% (1.6%/year) patients who received an AAI(R)-pacemaker due to sick sinus syndrome. There was no mortality attributable to pacemaker therapy. A great majority (68%) of the complications occurred within the first 3 months after the implantation. Complications associated to modern permanent endocardial pacemaker therapy are not infrequent. Eleven percent of patients needed an invasive procedure due to an early or late complication.     

Reversal of Atrial Remodeling after Cardioversion of Persistent Atrial Fibrillation Measured with Magnetocardiography

Background : Atrial fibrillation (AF) causes electrical, functional, and structural changes in the atria. We examined electrophysiologic remodeling caused by AF and its reversal noninvasively by applying a new atrial signal analysis based on magnetocardiography (MCG).
Methods : In 26 patients with persistent AF, MCG, signal-averaged electrocardiography (SAECG), and echocardiography were performed immediately after electrical cardioversion (CV), and repeated after 1 month in 15 patients who remained in sinus rhythm (SR). Twenty-four matched subjects without history of AF served as controls. P-wave duration (Pd) and dispersion (standard deviation of Pd values in individual channels) and root mean square amplitudes of the P wave over the last 40 ms portions (RMS40) were determined.
Results : In MCG Pd was longer (122.8 ± 18.2 ms vs 101.5 ± 14.6 ms, P < 0.01) and RMS40 was higher (60.4 ± 28.2 vs 46.9 ± 19.1 fT) in AF patients immediately after CV as compared to the controls. In SAECG Pd dispersion was increased in AF patients. Mitral A-wave velocity and left atrial (LA) contraction were decreased and LA diameter was increased (all P < 0.01). After 1 month, Pd in MCG still remained longer and LA diameter greater (both P < 0.05), while RMS40 in MCG, Pd dispersion in SAECG, mitral A-wave velocity, and LA contraction were recovered.
Conclusions : Magnetocardiographically detected atrial electrophysiologic alterations in persistent AF diminish rapidly although incompletely during maintained SR after CV. This might be related to the known early high and late lower, but still existent tendency to AF relapses.