Ratios of activated matrix metalloproteinase-9 to tissue inhibitor of matrix metalloproteinase-1 in wound fluids are inversely correlated with healing of pressure ulcers

Previous analyses of fluids collected from chronic, nonhealing wounds found elevated levels of inflammatory cytokines, elevated levels of proteinases, and low levels of growth factor activity compared with fluids collected from acute, healing wounds. This led to the general hypothesis that chronic inflammation in acute wounds produces elevated levels of proteinases that destroy essential growth factors, receptors, and extracellular matrix proteins, which ultimately prevent wounds from healing. To test this hypothesis further, pro- and activated matrix metalloproteinases (MMP-2 and MMP-9), tissue inhibitors of metalloproteinases (TIMP-1 and TIMP-2), and the ratios of MMPs/TIMPs were assayed in fluids and biopsies collected from 56 patients with chronic pressure ulcers. Specimens included ulcers treated for 0, 10, and 36 days with conventional therapy or with exogenous cytokine therapies. Quantitative assay data were correlated with the amount of healing. The average MMP-9/TIMP-1 ratio in fluids from 56 ulcers decreased significantly as the chronic pressure ulcers healed. Furthermore, the average MMP-9/TIMP-1 ratio was significantly lower for fluids collected on day 0 from wounds that ultimately healed well (> or =85% reduction in initial wound volume) compared with wounds that healed poorly (< 50% wound volume reduction). These data show that the ratio of MMP-9/TIMP-1 levels is a predictor of healing in pressure ulcers and they provide additional support for the hypothesis that high levels of MMP activity and low levels of MMP inhibitor impair wound healing in chronic pressure ulcers.     

Memory template comparison processes in anhedonia and dysthymia

Anhedonic subjects, potentially at risk for psychopathology because of a deficient ability to experience pleasure, have demonstrated a large N200 component in the event-related brain potential (ERP). The present experiment attempted to determine the psychological significance of this finding in light of Näätänen's (1990) distinction between N2a and N2b subcomponents. Anhedonics were contrasted with controls and dysthymics, an at-risk group reporting depression. Across groups, N2a was larger when a tone mismatched a longer run of preceding identical tones. Thus, an involuntary mismatch process appears to be intact in both at-risk groups. However, the three groups produced distinct N2bs as a function of stimulus sequence. The N2b finding for anhedonics is consistent with Knight's (1984, 1992) model of early stimulus processing deficits in schizophrenia.     

Transvenous Catheter Cryoablation for Treatment of Atrial Fibrillation:

Pulmonary vein (PV) isolation using radiofrequency (RF) ablation can induce PV stenosis. Cryoablation may offer a safer alternative energy source for PV isolation. PV isolation with cryoablation was attempted in 31 patients with paroxysmal atrial fibrillation (AF). Event monitors were used to measure the AF episode burden. Serial spiral CT scans were obtained to monitor PV stenosis pre- and postcryoablation. Cryoablation was immediately successful for PV isolation in 29 of 31 patients (94%), with 5.9 ± 1.2 months of follow-up. Additional RF ablation was performed for AF recurrences in seven patients. The remaining 22 patients with a single cryoablation procedure demonstrated a time-dependent, long-term reduction in the frequency of AF episodes. At 6 months of follow-up, 18 of 22 of cryo-treated only patients (82%) were free of symptomatic AF episodes, and antiarrhythmic drugs were discontinued in 12 of 22 patients. Serial spiral CT scans demonstrated no change in the cryo-treated PV ostial diameter. PV cryoablation was effective to control paroxysmal AF in most patients. Early recurrences of AF postcryoablation were common, though tended to resolve within 6 months postablation, consistent with a process of reverse atrial remodeling. Cryoablation of the PVs did not cause PV stenosis or other serious adverse events.     

A Unique Pulse Generator Safety Feature for Bipolar Lead Fracture

In this report, we describe two pacemaker dependent patients with outer-coil fractures in their bipolar ventncular leads who averted potentially calastrophic consequences because of a new safety feature incorporated into their puise generators (Intermedics Cosmos II, model 284–05). Both patients were asymptomatic; the malfunctions were discovered at routine pacemaker evaluation. Magnet application resulted in symptomatic loss of ventricular capture. In each instance, the pulse generator detected an outer-coil fracture and reprogrammed itself from bipolar DDD to unipolar DOO pacing to prevent loss of capture. Subsequent lead replacement resulted in resumption of normal function. We suggest that this feature be incorporaled into all devices with programmable polarity.     

Rapid Atrial Pacing Does Not Decrease the Atrial Defibrillation Threshold

The aim of the study was to evaluate the effect of preshock atrial pacing on the atrial defibrillation threshold (DFT) during internal cardioversion of AF. The implantable atrial defibrillator has been added to the therapeutic options for patients with recurrent episodes of persistent AF. Although the device is efficient in restoring sinus rhythm, patient discomfort is a limitation. Methods that lower the ADFT are needed. Eleven patients with AF underwent internal cardioversion. In a randomized, crossover design, ADFT testing was performed, applying a step-up protocol starting at 100 V. Rapid atrial pacing was performed with a right atrial catheter for 20 seconds at 90% of the average cycle length of the fibrillatory waves and was immediately followed by a biphasic defibrillation shock. At each energy level, pacing + shock was compared to shock only, until the level at which sinus rhythm was restored by both modes. The step-up protocol was thereafter repeated using the inverse sequence of the two modes. A total of 19 ADFTs were obtained. For 10 the ADFT was lower with pacing + shock, in 4 equal and in 5 higher, than with shock only. The ADFT (mean ± SD) with pacing + shock was   260 ± 84   V   (3.4 ± 2.9 J)   and did not differ from shock only:   268 ± 85   V   (3.8 ± 3.0 J) (P > 0.05)   . The coefficient of variation and the coefficient of reproducibility for pacing + shock was 16% and 60 V, respectively, and for shock only 17% and 61 V. Rapid atrial pacing did not influence the internal ADFT in AF. The randomized, crossover protocol used was reproducible between different modes, and seems useful when testing the impact of different interventions on the ADFT. (PACE 2003; 26[Pt. I]:1461–1466)     

Comparison of a Porous-Surfaced with a Totally Porous Ventricular Endocardial Pacing Electrode

Porous endocardial ventricular electrodes, re-cent innovations in cardiac pacing technology, have been shown to perform in a su-perior manner compared to conventional solid electrodes with respect to such parameters as stimulation threshold, sensed R-wave amplilude, and source im-pedance, This experimental study compared the electrophysiological performance of a porous-surfaced and a totally porous electrode, two fundamental design vari-ations of the porous eJectrode concept which are in current clinical use. Six porous-surfaced (1 mm length, 2.3 mm diameter, 8.8 mm² outer surface area, pores < 25 μn) and six totally porous (1.3 mm length, 2.0 mm diameter, 7,5 mm- outer surface area, pores 100 to 150 μm) flanged ventricular endocardial eleclrodes were implanted into the right ventricular apex of 12 dogs. Stimulation threshoids under constant current and constanl voltage conditions at pulse durations of 0.1, 0.25, 0.5, 0.75, 1.0, 1.5, and 2.0 milliseconds, sensed peak-to-peak R-wave amplitudes, and source impedance ivere measured at implant and at l, 4, 8, 12,16, 24, and 30 weeks (explant) thereafter. Analyses of voriance on the data for the strength-durolion curves at expiant and the threshold-time curves at l ms pulse duration indicated highly significant differ-ences between the performance of the two types of electrodes, the porous-surfaced electrodes displaying average Stimulation threshoids approximateiy 30% lower than the totally porous electrodes. Student's t tests indicated the magnitude of the sensed R-wave to be maintained over the 30 week period for the porous-surfaced electrodes but to decrease by about 20% for the totally porous electrodes. In addition, the chronic source impedance of the porous-surfaced electrodes was significtmtly Jess (about 257%) than that of the totally porous electrodes. These differences indi-cate better overall electrophysiological performance for the porous-surfaced electrodes as compared with the totally porous electrodes. Both types of electrodes, however, operate well within the limits of highly acceptable function and therefore rep-resent attractive designs for clinical use in endocardial pacing.     

The accuracy of nurses' estimates of their absenteeism

gaudine a & gregory c (2010) Journal of Nursing Management 18 , 599–605
The accuracy of nurses' estimates of their absenteeism Aim The purpose of the present study was to determine the accuracy of nurses’ self-reports of absence by examining: (1) the correlation, intra-class correlation, and Cronbach’s alpha for self-reported absence and absence as reported in organizational records, (2) difference in central tendency for the two measures of absence and (3) the percentage of nurses who underestimate their absence. Background Research on nurses’ absenteeism has often relied on self-reports of absence. However, nurses may not be aware of their actual absenteeism, or they may underestimate it. Method Self-reported absence from questionnaires completed by 215 Canadian nurses was compared with their absence from organizational records. Results There is a strong positive correlation, a strong intra-class correlation and Cronbach’s alpha for the two measures of absence. However, there is a difference in central tendency that is related to the majority of nurses in this study (51.1%) underestimating their days absent from work. Conclusions Research examining the predictors of absence may consider measuring absence with self-reports. Nevertheless, nurses demonstrated a bias to underestimate their absence. Implications for nursing management Feedback interventions to reduce absenteeism can be developed to include providing nurses with accurate information about their absence.     

Percutaneous Access of the Epicardial Space for Mapping Ventricular and Supraventricular Arrhythmias in Patients With and Without Prior Cardiac Surgery

Percutaneous Epicardial Access . Introduction: There is a paucity of data on the success rates of achieving percutaneous epicardial access in different groups of patients. Methods and Results: Percutaneous epicardial access was attempted in 137 patients having 149 procedures; 19 patients had supraventricular tachycardia (SVT), 25 patients had idiopathic VT and 93 patients had scar‐related ventricular tachycardia (VT). Ten patients had prior cardiac surgery. Successful epicardial access was achieved in 133 of 149 (89.3%) procedures. Access was achieved in 17 of 19 (89.5%) patients with SVT, all patients with idiopathic VT, 80 of 93 (86.0%) patients with scar‐related VT and in 2 (20%) patients with prior cardiac surgery. Attempted access failed in 16 patients; 8 had prior cardiac surgery and 3 had prior pericarditis. After an initial procedure, repeat access was attempted in 15 patients, 5.1 ± 5.4 months after initial epicardial mapping and ablation. Access was successful in 13 (86.7%) and failed in 2 patients who had pericarditis after their first procedure. Only 4 patients were given intrapericardial glucocorticoid at their first epicardial procedure. Prior cardiac surgery and a history of pericarditis predicted unsuccessful access (P < 0.01). Complications (9 patients) included pericardial bleeding (80–250 mL) and intraabdominal bleeding. Conclusions: In patients without prior cardiac surgery, percutaneous epicardial access can be obtained in the majority of patients. Prior cardiac surgery precludes access in the most patients and when possible adhesions may limit catheter movement. Repeat access is possible in the majority of patients without the installation of intrapericardial glucocorticoid at the first procedure. (J Cardiovasc Electrophysiol, Vol. 21, pp. 406–411, April 2010)     

Prospective Observations in the Clinical and Electrophysiological Characteristics of Intra‐Isthmus Reentry

ECG and EGM of IIR. Introduction: Intra‐isthmus reentry (IIR) is a circuit within the cavotricuspid isthmus (CTI). The purpose of this study is to prospectively define the electrogram and surface ECG characteristics of IIR, and its clinical implications. Methods and Results: Fourteen patients underwent electrophysiological studies and were found to have IIR. Detailed electrogram mapping of the CTI was available in all, electroanatomic mapping (EAM) in 8 of 14 (57%) patients. In all, entrainment mapping during tachycardia proved reentry, and showed that the anteroinferior CTI was out of the circuit and the septal CTI was in the circuit in 12 of 14 patients, whereas in 2, the circuit was confined within the mid and/or anteroinferior CTI. Fractionated potentials (FPs) spanning 34–71% of the tachycardia cycle length were recorded within the CTI in all, and double potentials were inscribed in 10 of 14 (71%). Analysis of the tricuspid annulus electrograms showed spontaneous shifts from a counterclockwise (CCW) to clockwise or fusion patterns. Surface ECGs showed either typical CCW pattern (12 patients) or atypical patterns (3 patients). The EAMs showed a focal pattern in 3, a CCW pattern in 5. The successful ablation site always occurred at the area with maximal FP duration. Over the same period, 33 of 384 (9%) patients who underwent ablation for CTI‐dependent flutter had prior successful CTI ablation, 7 of 33 (21%) were found to have IIR during the redo procedure. Conclusions: (1) Electrogram and ECG patterns of IIR frequently show atypical flutter. (2) IIR was successfully ablated in an area of the CTI associated with maximal duration of FPs. (3) IIR is a significant cause of “recurrent flutter” in patients with prior CTI ablation. (J Cardiovasc Electrophysiol, Vol. 21, pp. 1099‐1106)