Nephrin loss in experimental diabetic nephropathy is prevented by deletion of protein kinase C alpha signaling in-vivo.

Albuminuria in diabetic nephropathy is due to endothelial dysfunction, a loss of negative charges in the basement membrane, and changes a of the slit-membrane diaphragm composition. We have recently shown that protein kinase C alpha (PKCalpha)-deficient mice are protected against the development of albuminuria under diabetic conditions. We here tested the hypothesis that PKCalpha mediates the hyperglycemia-induced downregulation of the slit-diaphragm protein nephrin. After 8 weeks of streptozotocin (STZ)-induced hyperglycemia the expression of glomerular nephrin was significantly reduced. In contrast, other slit-diaphragm proteins such as podocin and CD2AP were unaltered in diabetic state. In PKCalpha-/- mice, hyperglycemia-induced downregulation of nephrin was prevented. Podocin and CD2AP remained unchanged. In addition, the nephrin messenger RNA expression was also reduced in hyperglycemic wild-type mice but remained unaltered in PKCalpha-/- mice. We postulate that the underlying mechanism of the hyperglycemia-induced regulation of various proteins of the glomerular filtration barrier is a PKCalpha-dependent regulation of the Wilms' Tumor Suppressor (WT1) which previously has been shown to act as a direct transcription factor on the nephrin promoter. Our data suggest that PKCalpha activation may be an important intracellular signaling pathway in the regulation of nephrin expression and glomerular albumin permeability in the diabetic state.

Nephrin in human lymphoid tissues.

When nephrin, the protein product of NPHS1, was cloned, it was proposed to be specific for the kidney glomerular podocytes. Recently, however, new reports have emerged verifying additional nephrin expression sites, particularly the insulin-producing beta cells of the pancreas, as well as the central nervous system. In this study, we demonstrate nephrin expression in lymphoid tissues, specifically the tonsil, adenoid and lymph node. Nephrin mRNA expression levels were 4-fold higher in tonsils and adenoids than in thymus or B lymphocytes, and 20-fold higher than in T lymphocytes or monocytes, as shown by quantitative RT-PCR analysis. Anti-nephrin antibodies recognised a specific 165-kDa band in lysates of tonsil and adenoid. In immunofluorescence and immunohistochemichal stainings of adenoid and lymph node sections, nephrin-positive cells were detected in the germinal centres of the lymphoid follicles in a staining pattern typical for interdigitating cells. These results indicate a definite and additional presence of nephrin in lymphoid tissue.

Evaluation of innotrac aio! Second-generation cardiac troponin I assay: the main characteristics for routine clinical use.

The availability of a simple, sensitive, and rapid test using whole blood to facilitate processing and to reduce the turnaround time could improve the management of patients presenting with chest pain. The aim of this study was an evaluation of the Innotrac Aio! second-generation cardiac troponin I (cTnI) assay. The Innotrac Aio! second-generation cTnI assay was compared with the Abbott AxSYM first-generation cTnI, Beckman Access AccuTnI, and Innotrac Aio! first-generation cTnI assays. We studied serum samples from 15 patients with positive rheumatoid factor but with no indication of myocardial infarction (MI). Additionally, the stability of the sample with different matrices and the influence of hemodialysis on the cTnI concentration were evaluated. Within-assay CVs were 3.2%-10.9%, and between-assay precision ranged from 4.0% to 17.2% for cTnI. The functional sensitivity (CV = 20 %) and the concentration giving CV of 10% were approximated to be 0.02 and 0.04, respectively. The assay was found to be linear within the tested range of 0.063-111.6 mu g/L. The correlations between the second-generation Innotrac Aio!, Access, and AxSYM cTnI assays were good (r coefficients 0.947-0.966), but involved differences in the measured concentrations, and the biases were highest with cTnI at low concentrations. The second-generation Innotrac Aio! cTnI assay was found to be superior to the first-generation assay with regard to precision in the low concentration range. The stability of the cTnI level was best in the serum, lithium-heparin plasma, and lithium-heparin whole blood samples (n = 10 , decrease < 10 % in 24 hours at +20( degrees )C and at +4( degrees )C. There was no remarkable influence of hemodialysis on the cTnI release. False-positive cTnI values occurred in the presence of very high rheumatoid factor values, that is, over 3000 U/L. The 99th percentile of the apparently healthy reference group was

Spatial variation of Trichinella prevalence in rats in Finnish waste disposal sites.

Trichinellosis is 1 of the most widespread parasitic zoonoses in the world and can be lethal to humans. Trichinella spp. are also parasites of considerable economic importance. Because rats may play a role in the transmission of trichinellosis to swine and farmed wild boar, 767 brown rats (Rattus norvegicus Berkenhout) from 13 Finnish waste disposal sites were examined for Trichinella spp. by a HCl-pepsin digestion method. Trichinella spp. were found to be a common parasite in trapped rats (overall prevalence, 19%) detected in 12 of 13 dumps. Significant differences were observed between sites in the prevalence (0-49%) of Trichinella spp. Female rats were more often and more heavily infected than males, but age was not shown to be a risk factor for trichinellosis. In addition, positive correlation was demonstrated between rat population density and prevalence. Trichinella spiralis was identified by multiplex polymerase chain reaction in 28 rats. The median density of infection was 42 (range, 0.5-6,925) larvae/ g of host tissue, but neither the occurrence nor the density of the parasite was related to the physical condition of the animal.

Analytical performance of time-resolved fluorometry-based Innotrac Aio! cardiac marker immunoassays.

The results of an evaluation of the Innotrac Aio! cardiac markers are presented. This system is based on dry-chemistry, time-resolved fluorometry. All assay-specific reagents are dry-coated into assay-specific cups, and only the generic assay buffer is required. The levels of precision attained with pooled serum samples and control materials were acceptable for cTnI and CK-MB. Myoglobin assay showed higher CV, 5.6-9.5%. The linearity studies were performed in concentration ranges of 0.1-76 microg/L for cTnI, 0.7-450 microg/L for CK-MB and 0.6-1500 microg/L for myoglobin. The markers were found to be linear within the ranges tested. The correlation coefficient between the Aio! and AxSYM cTnI assays was 0.960, and the slope was 0.07. The correlation coefficients between the Aio! and AxSYM CK-MB and myoglobin assays were 0.995 and 0.971, respectively. They involved some differences in the measured concentrations (Aio! CK-MB was about 9% higher than AxSYM CK-MB, and Aio! myoglobin was 19% higher than AxSYM). Comparative studies with all the markers, using EDTA whole blood and lithium heparin plasma specimens and lithium heparin whole blood and plasma, yielded the following results: the slopes were close to 1.0 for all correlations, with the exception of that between CK-MB EDTA whole blood and lithium heparin (0.83). High correlation coefficients were obtained (> or = 0.97). The carryover results for all the cardiac markers were good, 0.0%, 0.0%, and 0.3% for cTnI, CK-MB, and myoglobin, respectively. The analytical detection limits were 0.01 microg/L for cTnI, 0.8 microg/L for CK-MB and 0.5 microg/L for myoglobin. The stability of the analytes in the lithium heparin samples at room temperature was also studied and was found to be decreased by from 10% (myoglobin and CK-MB) to 17% (cTnI) in 8 h. Innotrac Aio! provides a rapid and easy quantitative measurement of cardiac TnI, CK-MB, and myoglobin within < 18 min. This system is therefore suitable for use in emergency departments, coronary care units or central laboratory settings.

Effects of diclofenac in the prevention of pericardial effusion after coronary artery bypass surgery. A prospective, randomized study.

BACKGROUND: It is suggested that pericardial effusions after cardiac surgery can be managed with non-steroid anti-inflammatory drugs, but the efficacy of this therapy is not well established. This study was planned to evaluate the efficacy of the prophylactic use of diclofenac in the prevention of pericardial effusion after coronary artery bypass surgery. METHODS: In a prospective, randomized study, diclofenac sodium 50 mg was administered orally every 8 hours to 22 patients in the postoperative period. The control group consisted of 19 patients who were not given postoperatively either steroids or non-steroid anti-inflammatory drugs. RESULTS: Twelve patients of the diclofenac-treated group (54.5%) and 7 of the control group (36.8%) experienced supraventricular arrhythmias postoperatively. There was no statistically significant difference in the size of postoperative pericardial effusion as well as in the occurrence of pleural effusion in both groups. However, there was a higher rate of significant pericardial effusion (grade I-III) in the control group as compared with the diclofenac-treated group (52.6% vs 31.8%, p=ns). Based on chest X-ray findings, patients in the control group had higher incidence of pleural effusion either alone (42.1% vs 22.7%, p=ns) or combined with pericardial effusion (21.0% vs 13.6%, p=ns). Patients who received diclofenac had lower median C-reactive protein concentration (76.0+/-45.2 mg/L) than the patients of the control group (99.6+/-47.8 mg/L), (p=ns). CONCLUSIONS: The results of the present study suggest that diclofenac, even if without a striking effect, may lessen the degree of inflammatory reaction after cardiac surgery and may be useful in the prevention and in the management of early pericardial effusion after cardiac surgery.

Limited effects of heavy metal pollution on foraging and breeding success in the curlew (Numenius arquata).

We examined the effect of heavy metal pollution on the foraging success and breeding performance of the curlew (Numenius arquata) along a documented pollution gradient from a point source, and also by comparing foraging and breeding parameters between the polluted site and two non-polluted areas. Prey biomass and abundance, and foraging success did not vary along the pollution gradient, and were no less at the polluted site than in the non-polluted areas. Furthermore, there was no difference in adult weight during incubation between the polluted and non-polluted areas. There were also no differences in measures of breeding success along the pollution gradient, or between areas, which could be attributed to pollution per se. Egg shells from the polluted area had higher concentrations of heavy metals than in the non-polluted areas, and egg shells close to the pollution source were contaminated more than those further from it. However, there was no difference in calcium concentrations of egg shells or egg-shell thickness between areas. We conclude that in this study there were minimal immediate effects of heavy metal pollution on foraging and breeding success in the curlew.

Fatal occlusion of the left coronary main stem by a fragment from the femoral artery: a previously unreported complication of cardiac catheterization.

A 59-year-old man with grade III angina pectoris and 80% stenosis of the left anterior descending coronary artery developed an acute total occlusion of the artery during percutaneous transluminal coronary angioplasty (PTCA). Attempts at recanalisation and resuscitation were ineffective, and the patient died. The medico-legal autopsy revealed obstruction of left main coronary artery by a ringshaped piece of arterial wall that had been torn out of the femoral artery at the punction site and driven around the tip of the catheter into the orifice of the left coronary artery, filling it. This kind of complication of PTCA has not been described previously.

Effect of beta blockade on heart rate variability during vessel occlusion at the time of coronary angioplasty.

Beta blockers modify cardiovascular neural regulation, which may contribute to their protective effect against sudden cardiac death. To evaluate the effects of beta blockade on cardiovascular autonomic reactions caused by acute coronary occlusion in humans, heart rate (HR) variability was analyzed in the time and frequency domains immediately before and during balloon occlusion of a coronary artery in 116 patients randomly assigned to either chronic beta-blocker therapy (beta-blocker group) or no beta blockade (control group) during elective 1-vessel coronary angioplasty. Coronary occlusion (mean 112 seconds) caused a significant increase in both the high- and low-frequency components of HR variability in the control group (n = 58), from 2.7 +/- 1.6 to 3.4 +/- 1.7 (logarithmic units, p < 0.001) and from 4.3 +/- 1.3 to 4.8 +/- 1.5 (p < 0.01), respectively, whereas in the beta-blocker group (n = 58), the high-frequency power did not change during occlusion, but the low-frequency power increased from 3.9 +/- 1.4 to 4.4 +/- 1.4 (p = 0.01). Changes in high- and low-frequency components and HR were related to the change in systolic blood pressure during occlusion in the beta-blocker group (r = 0.53, p < 0.001; r = 0.34, p < 0.05; and r = -0.41, p < 0.01, respectively), but not in the control group (r = -0.17, r = -0.14, and r = 0.24, respectively). Thus, beta blockade attenuates the initial vagal activation associated with acute coronary occlusion and seems to maintain baroreflex-mediated cardiovascular control. The maintained integrity of baroreflex regulation and the alleviation of extreme autonomic reactions during beta blockade may modify the clinical outcome of acute coronary occlusion in a beneficial way.

Relation between heart rate variability and spontaneous and induced ventricular arrhythmias in patients with coronary artery disease.

OBJECTIVES: The aim of this study was to determine the relation between autonomic control of heart rate and the spontaneous occurrence and inducibility of ventricular arrhythmias in patients with coronary artery disease. BACKGROUND: Low heart rate variability increases the risk of arrhythmic events. It is not known whether impaired autonomic heart rate control reflects alterations in functional factors that contribute to the initiation of spontaneous arrhythmias or whether it is the consequence of an anatomic substrate for reentrant tachyarrhythmias. METHODS: Fifty-four patients with coronary artery disease with a history of sustained ventricular tachycardia (n = 25) or cardiac arrest (n = 29) were studied by 24-h ambulatory electrocardiographic recording and by programmed electrical stimulation. Heart rate variability was compared among the patients with and without spontaneous ventricular arrhythmias and with and without inducibility of sustained ventricular tachyarrhythmias. RESULTS: Eight patients had a total of 21 episodes of sustained ventricular tachycardia on Holter recordings. Standard deviation of RR intervals and low frequency and very low frequency components of heart rate variability were significantly blunted in patients with sustained ventricular tachycardias compared with those without repetitive ventricular ectopic activity (p < 0.05, p < 0.01 and p < 0.05, respectively). However, no significant alterations were observed in heart rate variability before the onset of 21 episodes of sustained ventricular tachycardia. Heart rate variability did not differ between the patients with or without nonsustained episodes of ventricular tachycardia. In patients with frequent ventricular ectopic activity, low frequency and very low frequency power components were significantly blunted compared with those with infrequent ventricular ectopic activity (p < 0.01 and p < 0.001, respectively). Heart rate variability did not differ significantly between the patients with and without inducible sustained ventricular tachyarrhythmias. CONCLUSIONS: Impaired very low and low frequency oscillation of heart rate reflects susceptibility to the spontaneous occurrence of ventricular arrhythmias but may not reflect the instantaneous triggers for life-threatening arrhythmias or a specific marker of the arrhythmic substrate for ventricular tachyarrhythmias.

Determinants of frequency domain measures of heart rate variability in the acute and convalescent phases of myocardial infarction.

OBJECTIVE: Low heart rate variability after acute myocardial infarction is associated with an increased risk of cardiac mortality. The aim of this study was to investigate the determinants of frequency domain measures of heart rate variability in acute myocardial infarction. METHODS: Heart rate variability in the frequency domain was compared in 43 patients in the early (0-12 h from the onset of pain) and convalescent (1 week after) phases of myocardial infarction and related to location (22 patients with anterior infarction and 21 patients with inferior infarction) and size of the infarct, occurrence of ventricular ectopic activity, and thrombolytic therapy. RESULTS: In the early phase of infarction all the power spectral components of heart variability were significantly lower in the patients with anterior infarcts than in those with inferior infarcts (p < 0.05 for all), but heart rate variability did not differ significantly between anterior and inferior infarct groups in the convalescent phase. High frequency power of heart rate variability was significantly lower in the convalescent phase than in the early phase in both the anterior and inferior infarction groups (p < 0.05 and p = 0.001, respectively), but other measures of variability did not change significantly. The ejection fraction was correlated with total power (p < 0.05), low frequency power (p < 0.01), and very low frequency power of heart rate variability (p < 0.05), and the low frequency and high frequency power components were significantly lower in the patients with non-sustained ventricular tachycardia than in those without repetitive ventricular activity in the convalescent phase of myocardial infarction (p < 0.05). Thrombolytic therapy had no influence on the measures of heart rate variability. CONCLUSIONS: The frequency domain measures of heart rate variability are mostly determined by the location of myocardial infarction in the early phase, whereas a correlation between heart rate variability and left ventricular function and arrhythmic propensity is more obvious in the convalescent phase.

Frequency domain measures of heart rate variability before the onset of nonsustained and sustained ventricular tachycardia in patients with coronary artery disease.

BACKGROUND: Low heart rate variability (HRV) is associated with an increased risk of arrhythmic death and ventricular tachycardia (VT). The purpose of this study was to examine whether there is a temporal relation between changes in HRV and the onset of spontaneous episodes of VT in patients at high risk of life-threatening arrhythmias. METHODS AND RESULTS: Components of HRV in the frequency domain were analyzed before the onset of 28 episodes of nonsustained VT (more than four impulses; duration < 30 seconds) and 12 episodes of sustained VT (> 30 seconds or requiring defibrillation) in 18 patients with coronary artery disease. Seven patients had survived cardiac arrest not associated with acute myocardial infarction, and 11 had a history of sustained VT. All frequency domain measures of HRV, i.e., total power (p < 0.001), high-frequency power (p < 0.05), low-frequency power (p < 0.01), very-low-frequency power (p < 0.01), and ultralow-frequency power (p < 0.05), were significantly lower before the onset of sustained VT than before nonsustained VT. Total power of HRV was also lower during the 1-hour period before the onset of sustained VT than the average 24-hour HRV (p < 0.05). An indirect correlation existed between the length of VT and the total power of HRV analyzed during the 15 minutes before the onset of VT (r = 0.54, p < 0.01). HRV had a trend toward increasing values before the onset of nonsustained VT (p < 0.01) but not before the sustained VT episodes. The ratio between low-frequency and high-frequency powers increased substantially before both nonsustained and sustained VT episodes (p = 0.06 and p = 0.05, respectively). The rate of VT or the coupling interval initiating the VT did not differ significantly between the nonsustained and sustained VT. CONCLUSIONS: Spontaneous episodes of VT are preceded by changes in HRV in the frequency domain. Divergent dynamics of HRV before the onset of nonsustained and sustained VT episodes may reflect differences in factors that can facilitate the perpetuation of these arrhythmias.

Changes in frequency domain measures of heart rate variability in relation to the onset of ventricular tachycardia in acute myocardial infarction.

The imbalance of the autonomic nervous function has been shown to contribute to the genesis of ventricular arrhythmias. Power spectral analysis of components of heart rate variability has the potential to quantify the cardiac autonomic tone during ambulatory electrocardiographic recording. We analysed the power spectral components of total power, very low frequency power (0.0033-0.04 Hz), low frequency (0.04-0.15 Hz) and high frequency (0.15-0.40 Hz) power in 12 consecutive patients accompanied with 27 episodes of ventricular tachycardia in acute myocardial infarction. The spectral areas were measured in 5-min periods preceding the onset of ventricular tachycardias. The total power of heart rate variability increased progressively before the onset of ventricular tachycardia episodes (P < 0.05). The increase of total power was mainly due to higher, very low frequency power at the onset rather than before the onset of ventricular tachycardia (P < 0.05). The trend towards adrenergic predominance at the onset of ventricular tachycardia was observed by an increase of average heart rate (P < 0.05) without concomitant increase in high frequency power. Thus, the occurrence of ventricular tachycardia is associated with changes in the power spectrum of heart rate variability suggesting alterations in autonomic tone at the onset of ventricular tachycardia in acute myocardial infarction.

Circadian variation of ventricular tachycardia in patients with coronary arterial disease.

Sudden cardiac death and ischaemic cardiac events occur in a circadian pattern. Because ventricular tachycardia is thought to play an important role in sudden cardiac death, the episodes of spontaneous ventricular tachycardias (greater than 3 consecutive beats) (n = 1314) were analysed from 24-hour long term electrocardiographic recordings in 34 patients with coronary arterial disease to determine whether circadian rhythm exists in spontaneous ventricular tachycardia. Twelve patients had suffered cardiac arrest, four patients had a history of syncope, and palpitation was the indication for electrocardiographic recordings in eighteen patients. Analysis using chronobiologic single cosinor method showed a significant circadian variation in the occurrence of ventricular tachycardia episodes with the peak occurring at 6 a.m. Similar circadian rhythm was also observed in the occurrence of the longest episode of ventricular tachycardia. Ischaemic ST-segment depression preceded the longest ventricular tachycardia episode only in one patient. Thus, a circadian rhythm occurs also in spontaneous episodes of ventricular tachycardia, a finding which is similar to that in sudden cardiac death.