Yersinia enterocolitica impairs activation of transcription factor NF-kappaB: involvement in the induction of programmed cell death and in the suppression of the macrophage tumor necrosis factor alpha production.

In this study, we investigated the activity of transcription factor NF-kappaB in macrophages infected with Yersinia enterocolitica. Although triggering initially a weak NF-kappaB signal, Y. enterocolitica inhibited NF-kappaB activation in murine J774A.1 and peritoneal macrophages within 60 to 90 min. Simultaneously, Y. enterocolitica prevented prolonged degradation of the inhibitory proteins IkappaB-alpha and IkappaB-beta observed by treatment with lipopolysaccharide (LPS) or nonvirulent, plasmid-cured yersiniae. Analysis of different Y. enterocolitica mutants revealed a striking correlation between the abilities of these strains to inhibit NF-kappaB and to suppress the tumor necrosis factor alpha (TNF-alpha) production as well as to trigger macrophage apoptosis. When NF-kappaB activation was prevented by the proteasome inhibitor MG-132, nonvirulent yersiniae as well as LPS became able to trigger J774A.1 cell apoptosis and inhibition of the TNF-alpha secretion. Y. enterocolitica also impaired the activity of NF-kappaB in epithelial HeLa cells. Although neither Y. enterocolitica nor TNF-alpha could induce HeLa cell apoptosis alone, TNF-alpha provoked apoptosis when activation of NF-kappaB was inhibited by Yersinia infection or by the proteasome inhibitor MG-132. Together, these data demonstrate that Y. enterocolitica suppresses cellular activation of NF-kappaB, which inhibits TNF-alpha release and triggers apoptosis in macrophages. Our results also suggest that Yersinia infection confers susceptibility to programmed cell death to other cell types, provided that the appropriate death signal is delivered.

Natural radioactivity and external gamma radiation exposure at the coastal Red Sea in Egypt.

Radionuclides which present in different beach sands are sources of external exposure that contribute to the total radiation exposure of human. In this work, superficial samples of beach sand were collected from the Red Sea coastline (Ras Gharib, Hurghada, Safaga, Qusier and Marsa Alam areas) and at 20 km on Qena-Safaga road. The distribution of natural radionuclides in sand beach samples was studied by gamma spectrometry. The activity concentrations of primordial and artificial radionuclides in samples that are collected from the coastal environment of the Red Sea were 19.2 +/- 3 Bq kg(-1) for (210)Pb, 21.1 +/- 1 Bq kg(-1) for (226)Ra, 22.7 +/- 2 Bq kg(-1) for (238)U, 1.0 +/- 0.1 Bq kg(-1) for (235)U, 11.6 +/- 1 Bq kg(-1) for (228)Ra, 13.0 +/- 1 Bq kg(-1) for (228)Th, 12.4 +/- 1 Bq kg(-1) for (232)Th, 930 +/- 32 Bq kg(-1) for (40)K and 1.2 +/- 0.3 Bq kg(-1) for (137)Cs. The mean external gamma-dose rate was 62.5 +/- 3.2 nSv h(-1), 54.4 +/- 2.8 nGy h(-1) Ra equivalent activity (Ra(eq)) was 107 +/- 5.8 Bq kg(-1), 0.86 +/- 0.04 Bq kg(-1) for representative level index (I(gamma)) and effective dose rate was 0.067 +/- 0.003 mSv y(-1) in beach sand red sea, in air due to naturally occurring radionuclides.

Influence of grain size on radionuclide activity concentrations and radiological hazard of building material samples.

The knowledge of radioactivity content in various radionuclides in building materials plays an important role in health physics; therefore, we measured the amount of naturally occurring radionuclides in building material (sand, granite, marble, and limestone) samples of different grain sizes by using NaI (Tl) and MCA1024 gamma-ray spectrometers. Data analyses were performed to determine 226Ra, 232Th, and 4°K activity concentrations. The results revealed an inverse relationship between activity concentration and grain size of the samples. The radium equivalent activity (Raeq), representative level index I, and annual absorbed dose rate were calculated.

Simultaneous bilateral contrast transcranial doppler monitoring in patients with intracardiac and intrapulmonary shunts.

The prevalence of a right-to-left intracardiac shunt, demonstrated by echocardiography and transcranial Doppler sonography has been shown to be higher in stroke patients than in normal controls. The aim of this study was to assess the sensitivity and specificity of contrast transcranial Doppler sonography in comparison to transesophageal echocardiography in the detection and differentiation of intracardiac and intrapulmonary shunts and to correlate the transcranial Doppler findings with clinical outcome and morphological findings. Forty five consecutive stroke patients with suspected paradoxical embolism were entered into the study. In all 25 patients with middle cerebral artery stroke of the left (56%) or right (44%) territory and echocardiographic demonstrated patent foramen ovale (80%) or intrapulmonary shunt (20%), simultaneous bilateral transcranial Doppler sonography of the middle cerebral arteries was performed after contrast medium injection during rest and valsalva straining under standardized and optimized conditions. Overall sensitivity for the detection of a right-to-left shunt by contrast transcranial Doppler sonography was 97% and overall specificity was 70%. Bilateral appearance of microbubbles, microbubble count and time delay of microbubble appearance significantly increased after valsalva straining. In patients with intracardiac shunts, a significantly higher microbubble count (32 vs. 13 in patients with an intrapulmonary shunt) and a shorter time interval of microbubble appearance (11 vs. 14 s in patients with intrapulmonary shunts) was observed. There was no correlation between the side and numerical distribution of microbubble count and the location and severity of the current clinical symptoms, as well as between microbubble count and presence and hemispherical distribution of brain infarcts. Transcranial Doppler sonography is a highly sensitive method for the detection of right-to-left shunts, whether of cardiac or pulmonary location. However. no correlation was found between the side and number of microbubbles counted and the clinical symptomatology.

[Echocardiographic grading of cor pulmonale in chronic lung diseases]. / Echokardiographische Schweregradbeurteilung des Cor pulmonale bei chronischen Lungenerkrankungen.

The extent of right heart strain determines the prognosis of chronic lung disease. The value of a simple semiquantitative echocardiographic grading system for cor pulmonale was assessed in 69 patients (24 females, 45 males, age 61 +/- 12 years, ranging from 28-82 years) suffering from chronic lung disease. The patients were classified by echocardiography into four groups, Grade 0 consisting of those without evidence of right heart strain and three groups showing increasing severity of change (Grade I: right ventricular hypertrophy; Grade II: I + right ventricular dilation; Grade III: II + Dilation of the inferior vena cava). Echocardiographic investigation, at least from the subcostal view, and grading was possible in all patients. A correlation was found between the echocardiographic grading and the mean pulmonary artery pressure (PAP)-normal echo study 15.7 +/- 4.8; grade I 21.1 +/- 5.6; grade II 28.8 +/- 10.2; grade III 39.4 +/- 9.4 mmHg. In addition, patients with stress-induced pulmonary hypertension (PHT) were detected by Doppler echocardiography. 6 of 11 patients with latent PHT already showed evidence of cor pulmonale (4 Grade I and 2 Grade II). In 42 patients (61%) the systolic PAP was estimated by measuring the velocity of the tricuspid insufficiency jet with Doppler, and these data correlated closely with the invasive data (p < 0.001; r = 0.81). Doppler echocardiography for evaluation of cor pulmonale is feasible even in patients with chronic lung disease and limited acoustic windows. Semiquantitative grading correlates well with invasive data. Here, this technique is useful as a baseline study as well as for the follow-up of patients with chronic lung disease.

Evaluation of radioactive exposure from 137Cs in contaminated areas of Northern Ukraine.

The paper gives averages of 137Cs deposition densities in soils from three areas in Northern Ukraine measured 12 to 15 y following the Chernobyl accident: in an area near Narodici (75 km west of the Chernobyl nuclear power plant in the so-called zone II) heavily contaminated by the Chernobyl fall-out and in areas around Korosten and Zhitomir showing contamination levels to be much lower. The three areas exhibited very different 137Cs deposition densities of 2.2 MBq m(-2), 400 kBq m(-2), and 5 kBq m(-2), respectively. During a 1-y observation, measurements of the 137Cs transfer in the food chain to humans and 137Cs whole body contents dependent on the 137Cs daily intake were carried out under realistic conditions of the rural inhabitants who lived in settlements within zone II. Detailed investigations of components of the daily diet showed that the high 137Cs contamination levels found in soils of zone II do not affect in any way low 137Cs concentrations of all important agricultural products harvested and consumed by villagers. With regard to consumption habits of the population of zone II, mushrooms and wild berries were found to contribute more than 95% of the 137Cs daily intake to the 137Cs whole body content of about 12 kBq (with maximum values up to 760 kBq) measured in a group of inhabitants of zone II during a period from July 1998 to July 1999. The median of the annual dose of these inhabitants from external and internal exposures was 1.2 mSv y(-1) with a geometric standard deviation of 2.6. Excluding extreme habits, the geometric mean of the total exposure was 1.0 mSv y(-1) with a geometric standard deviation of 1.3.

[The Doppler echocardiographic assessment of left ventricular diastolic function in coronary heart disease]. / Dopplerechokardiographische Beurteilung der diastolischen linksventrikulären Funktion bei koronarer Herzkrankheit.

BACKGROUND AND OBJECTIVE: Changes in left ventricular (LV) diastolic function lead to characteristic changes in the transmitral flow profile as determined by Doppler echocardiography (DEC). Although DEC cannot provide direct quantitative measurement of LV filling pressures and is influenced by several factors, transmitral flow correlates well with LV haemodynamics. In this prospective study the results of transthoracic DEC were compared with haemodynamic parameters in patients with coronary heart disease (CHD) and their clinical value assessed. PATIENTS AND METHODS: 254 consecutive patients with CHD (67 women, 187 men, aged 62.5 +/- 8.5 years) underwent transthoracic DEC. The ratio of early to late diastolic velocity (VE/VA) and early diastolic deceleration time (DT) of the transmitral flow were measured as an indication of diastolic LV function. RESULTS: Patients with reduced LV compliance and increased filling pressure (LV end-diastolic pressure [LVEDP] > 15 mm hg) had a restrictive transmitral flow profile with a significantly higher than normal VE/VA and a shorter DT (1.35 +/- 0.84 vs. 0.86 +/- 0.26, P < 0.001; and 158 +/- 45 vs. 213 +/- 35, P < 0.001, respectively). VE/VA and DT also significantly correlated with LVEDP (r = 0.65, P < 0.001 and r = -0.60, P < 0.001 respectively). Sensitivity and specificity of an LVEDP of > 15 mm Hg were 67% and 84%, respectively, for a VE/VA of more than 1, and 65% and 91% for a DT of less than 170. The combination of the two parameters increased specificity to 97%. CONCLUSION: Determining the transmitral flow profile makes it possible noninvasively to obtain an indication of LV end-diastolic function. Patients with severe diastolic dysfunction and increased filling pressures are recognized with a high degree of specificity.

[Practical assessment using transmitral Doppler echocardiography for the evaluation of left ventricular filling pressure in patients with systolic ventricular dysfunction]. / Praktische Anwendung der transmitralen Dopplerechokardiographie zur Beurteilung der linksventrikulären Füllungsdrücke bei eingeschränkter systolischer Ventrikelfunktion.

Transmitral flow velocity profiles by Doppler echocardiography are strongly related to left ventricular diastolic properties. The aim of this study was to address the assessment of left ventricular filling pressures by transmitral flow velocity curves in patients with impaired systolic function. 90 patients (23 female, 67 men, age 60.0 +/- 9,9 a) with an ejection fraction < or = 45% either due to coronary artery disease (n = 67) or dilated cardiomyopathy (n = 23) were investigated by Doppler echocardiography prior to left heart catheterization. Early diastolic deceleration time (DT) and ratio of early to late diastolic peak velocities (VE/VA) were measured. Both, DT and VE/VA showed a significant correlation to left ventricular enddiastolic pressures (r = -0.79 respectively r = 0.73, p < 0.001 for all). According to DT three different transmitral flow patterns were identified. All patients with restrictive filling patterns (DT < 160) had elevated left ventricular filling pressures, whereas impaired relaxation (DT > 210) was a strong predictor of normal filling pressures. In patients with pseudonormal transmitral flow patterns (DT 160 to 210) filling pressures could not be predicted. Furthermore DT was strongly related to clinical signs of left heart failure. Doppler echocardiography gives useful additional information on left ventricular filling pressures in patients with systolic dysfunction.

[Current status and indications for contrast echocardiography]. / Stellenwert und Indikationen der Kontrastechokardiographie.

Due to newly developed techniques contrast echocardiography (CE) is less often applied today. As to reevaluate the usefulness and the indications for CE 7823 consecutive echocardiographic studies were analysed. In 638 (8%) of these studies CE was used. 379 patients showed signs of right ventricular overload, 58 due to a left-to-right shunt. Pressure overload due to pulmonary hypertension was found in 321 cases. CE enhanced doppler flow signals in tricuspid regurgitation and facilitated quantification of right heart dimensions. 259 patients were screened for patent foramen ovale (PFO), 94 after embolic events, and 165 because neurosurgical intervention in a sitting position was planned. So CE proved to be still indicated in the era of color flow doppler, especially for the detection of PFO.

[Doppler echocardiography in chronic right ventricular pressure load]. / Dopplerechokardiographie bei chronischer rechtsventrikulärer Druckbelastung.

Doppler-echocardiography (DEC) was performed before cardiac catheterization in 61 consecutive patients (25 women, 36 men; aged 59 +/- 10.6 years) with pulmonary hypertension. Chronic obstructive lung disease was its cause in 32, mitral valve disease in 16 and dilated cardiomyopathy in 13 patients. The subcostal approach was possible in all patients and a semiquantitative assessment into three degrees of severity determined from right ventricular wall thickness and size, as well as the diameter of the inferior vena cava. The severity grade was closely correlated with the level of pulmonary hypertension. In the absence of all signs of increased right ventricular load (grade 0) the mean pulmonary arterial pressure was 18.7 +/- 6.2 mm Hg, in grade I it was 15 and 22 mm Hg (only two patients), in grade II 29.9 +/- 11.9 and in grade III 41.1 +/- 8.6 mm Hg. 13 of the 21 patients in grade 0 or I had no manifest signs of pulmonary hypertension, but this was the case in only 6 of 22 in grade II and none in grade III. In 42 patients (69%) the systolic pulmonary artery pressure could be measured by DEC and it correlated well with the values obtained by cardiac catheterization (P < 0.001, r = 0.92). These findings show that DEC can provide semiquantitative and, in most cases, even exact evidence of chronic right ventricular overload.

[Quantitative determination of left ventricular myocardial perfusion with electron beam computerized tomography]. / Quantitative Bestimmung der linksventrikulären Myokardperfusion mittels EBCT.

Myocardial perfusion is one of the most important functional parameters of the heart. Presently various indirect methods are used to determine coronary blood flow or myocardial perfusion as inertgas-, thermodilution-, Doppler catheter- and radiopharmacological techniques. Electron-beam-computed-tomographical technology is able to perform CT data acquisition with a very short exposure time of 50 ms. Using this method it is not only possible to determine left ventricular volumes but also to measure myocardial perfusion in ml/100 g/min. The measurement of the left myocardial perfusion is performed using the short axis view. This position is obtained by moving the table 25 degrees to the patient's right and 15 degrees caudally. To determine the position of the left ventricle, a localization scan is obtained in multi-slice-mode using all for target-rings, thus obtaining 8 tomographic levels over 68 mm (each tomographic level having a slice thickness of 7 mm, with an interslice gap of 4 mm between each two adjacent tomographic levels). In this short axis position, using the multi slice flow mode with 3 target-rings and after administration of 50 ml of contrast medium intravenously with a flow of 3 ml/s, 6 tomographic levels are imaged. Each tomographic level is obtained 13 times at 80% of the R-R-interval at each 2 or 3 heart beat (ECG-gated). The left ventricular myocardial contrast enhancement is measured by drawing manually the outline of the left ventricular myocardium using time-density-software of the Imatron workstation. For calculation of the myocardial perfusion the so-called "slope method" is used and the results are expressed as the maximum slope of enhancement of the myocardium divided by the difference of the precontrast and peak CT-value in the left ventricle. The global myocardial perfusion is calculated as a mean of all evaluated tomographic levels. In this study left ventricular volumes as enddiastolic volume endsystolic volume and stroke volume were measured and ejection fraction and cardiac output calculated. The measurements were performed in the log axis view. This view is obtained by moving the table 15 degrees to the patients left in a horizontal position. In this long axis position 6 tomographic levels are imaged using the multi-slice-cine-mode with 3 target-rings after administration of 50 ml of contrast medium intravenously with a flow of 3 ml/s. Each tomographic level is obtained 13 times starting at 0% of the R-R-interval (ECG-triggering). The exposure time is 50 ms with an interscan time delay of 8 ms. In 9 studied patients of whom one had 3 significant coronary artery stenotic lesions (> 50%), 2 patients had each 2 non significant stenotic lesions (< 50%) and 6 revealed nearly normal coronary angiograms. The mean global myocardial perfusion was 70 ml/100 g/min (min.32 and max. 116 ml/100 g/min). This mean value of 70 ml/100 g/min is reflecting 5% of the cardiac output supposing that the mean heart weight of these patients was 300 g. In this study the mean of the left ventricular muscle mass determined by the use of EBCT was 130 g. A comparative evaluation of coronary angiographic findings in these patients with the measured myocardial perfusion values revealed, that is not sufficient to look only at the absolute values of the measured myocardial perfusion. Furthermore it seems to be necessary to interpret these perfusion values with respect to the calculated cardiac output. Additional studies of well defined patients groups are necessary to determine normal values of myocardial perfusion at rest in patients with and without coronary artery disease. This seems to be important as comparative analysis of myocardial scintigraphic and EBCT-studies is difficult because of methodical inherent differences. The results of this study suggest that despite the presence of some beam hardening artifacts it is possible to measure myocardial perfusion using EBCT in patients with suspected coronary artery disease in the

[Preoperative diagnosis of a patent foramen ovale: rational use of transthoracic and transesophageal contrast echocardiography]. / Präoperative Diagnostik eines offenen Foramen ovale. Rationaler Einsatz der transthorakalen und transösophagealen Kontrastechokardiographie.

BACKGROUND: The detection or ruling out of a patent foramen ovale (PFO) can be determined noninvasively by contrast echocardiography (CE). The transesophageal technique is superior to the transthoracic technique regarding sensitivity, whereas the specificity of both methods is equally high. This prospective study shows the rational use of transesophageal CE for the detection of a PFO, in patients without cardiovascular disorders. METHODS: 165 patients (92 female, 73 male, age 48 +/- 18 years) with planned neuro-surgery in a sitting position, underwent CE to rule out a PFO. If the CE was positive, an alternative position was selected in order to avoid a paradoxical air embolism. RESULTS: Initially, a transthoracic CE was performed in all patients resulting in 21 patients (13%) being positive and 39 patients (24%) being negative by sufficient image quality. A transesophageal CE was performed in 96 of the remaining 105 patients (63%). Here, further 25 patients showed a positive CE in the sense of a PFO. The combined use of transthoracic and transesophageal CE revealed a PFO in 46 of 165 patients (28%). CONCLUSION: The use of both, transthoracic and transesophageal CE is an efficient approach to the preoperative detection of a PFO in the sense of quality and economics. Depending upon the image quality, the use of a transesophageal examination could be avoided in one third of the cases.

Resistance to fracture of high-strength porcelain crowns versus metal ceramic crowns under different conditions.

Although the good appearance and biocompatibility of dental porcelains, failures are still of considerable concern because of the limited properties to all ceramic system. Physical properties that might be considered ideal include high strength, resistance to abrasion, and resistance to the hostile oral environment. Porcelain has been considered by many of its physical characteristic are similar to those of enamel. In 1983 a new modality of treatment, the etched porcelain restoration was introduced by Simonsen and Calamia. Numerous investigations have shown the strength of the etched porcelain bonded to composite resin and also the clinical success of this porcelain to be used as laminated veneers and etched inlays and onlays.