Quantification of left ventricular internal flow from cardiac magnetic resonance images in patients with dyssynchronous heart failure

PURPOSE: To develop a method for quantifying left ventricular (LV) internal flow as a measure of dyssynchrony using standard cine cardiac magnetic resonance (CMR) images. MATERIALS AND METHODS: CMR images were obtained from 10 healthy controls and 10 patients with dyssynchronous heart failure (class III/IV, LV ejection fraction <35%, pattern seen in an electrocardiogram QRS duration > 150 msec). The LV volume was reconstructed and divided into 16 regions. Internal flow was defined as the sum of the regional volume changes minus the global volume change during each time step in the cardiac cycle. Internal flow fraction (IFF) was defined as the total internal flow as a percentage of stroke volume during systole (IFF(systole)), diastole (IFF(diastole)), or the whole cycle (IFF(whole)). RESULTS: IFF(whole) was significantly increased in the patients (9.9 +/- 5.0% vs. 1.5 +/- 0.5% in the controls, P < 0.001). An IFF(whole) threshold of 4% discriminated between patients and controls with 90% sensitivity and 100% specificity. IFF(diastole) (2.3 +/- 0.8%) was greater than IFF(systole) (0.8 +/- 0.5%) in the normal controls (P < 0.001) while the patients had similar IFF(diastole) (7.8 +/- 4.2%) and IFF(systole) (12.0 +/- 7.8%). CONCLUSION: Left ventricular internal flow fraction can be quantified from standard CMR images. In this preliminary study, Left ventricular internal flow fraction discriminated patients with dyssynchronous heart failure from normal controls with 95% accuracy.     

Effect of acute versus chronic theophylline administration on acute restraint stress-induced increase of pentylenetetrazol seizure threshold in mice

Various stressful paradigms were found to induce anticonvulsant effects in different seizure models. Methylxanthines, such as theophylline might contribute to the reduction of restraint-induced stress. Therefore, in this study the influence of acute restraint stress on pentylenetetrazol (PTZ) seizure thresholds as well as the effect of acute and chronic theophylline pretreatment on stress-induced modulation of the seizure threshold were assessed in mice. The onset of the three consecutive seizure phases: myoclonic twitch (MTW), generalized clonus (GNCL) and tonic hind limb extension (THE) was delayed after exposure to a 2 h restraint stress by 34%, 23% and 24%, respectively. In nonstressed mice, acute theophylline injection (100 mg/kg, i.p.) decreased the threshold only for THE. However, in stressed animals, the pretreatment with the methylxanthine significantly enhanced the dose of the convulsant producing the same seizure phase. In nonstressed mice, long-term theophylline treatment (50 mg/kg, twice daily for 14 days) increased PTZ threshold for all three seizure phases. In contrast, in chronically treated with theophylline mice exposed to restraint stress, significant decrease in the PTZ threshold for all seizure phases compared to control stressed animals have been observed. These results suggest that, depending on the treatment regimen (acute versus chronic), theophylline specifically and differentially modulates the anticonvulsant effect of restraint stress in mice.     

TVT-S in the U position��anatomical study

Introduction and hypothesis  

The objective is to describe the anatomical position of tension-free vaginal tape Secur (TVT-S) in the U position regarding possible injury and fixation site.     

Renal parenchymal thickness in children with solitary functioning kidney

Background

Reduced renal parenchymal thickness (PT) is a parameter used by clinicians to assess the degree of hydronephrosis. In patients with a congenital hydronephrotic solitary functioning kidney (SFK), PT is difficult to determine as there is no comparison with the contralateral kidney. The aim of this study was to obtain ultrasound measurements of PT in children with normal SFK and to compare these data with PT measurements in children with two functioning kidneys.

Methods

This was a prospective multicenter study carried out between 2006 and 2011 in which 236 children aged 11 days to 18.96 years with healthy SFK were examined. The SFK etiologies were unilateral renal agenesis or a nonfunctioning contralateral kidney, mostly due to multicystic dysplasia. In addition to determining other parameters, we measured PT in the middle third of the kidney by ultrasound. Correlations between PT and age, height and weight were assessed.

Results

Correlation analysis showed a positive correlation with renal PT for all parameters. The correlation coefficients for age, height and weight were 0.863, 0.873 and 0.874, respectively. In most age categories, the renal parenchyma was significantly thicker in the SFK than in two functioning kidneys.

Conclusions

Based on our results, we suggest that PT in the SFK is correlated with height, weight and age of the patient. Consequently, measurements of PT may be used for monitoring the development of the healthy SFK and may contribute to a more accurate assessment of the severity of SFK anomalies.     

Uremia causes endothelial progenitor cell deficiency

BACKGROUND: Circulating bone marrow-derived endothelial progenitor cells (EPCs) promote vascular repair. Their number in peripheral blood correlates with endothelial function and cardiovascular risk in humans. We explored whether uremia influences the number of EPCs. METHODS: We assessed circulating CD34+ hematopoietic progenitor cells in whole blood using flow cytometry and EPCs (in vitro assay) in 46 patients with advanced renal failure and in 46 age- and gender-matched healthy subjects. Further, the effect of uremia on EPC differentiation was studied in vitro and in vivo. RESULTS: Both in renal patients (r= 0.34, P < 0.02) and in healthy subjects (r= 0.32, P= 0.04) the number of EPCs was significantly correlated to the absolute number of CD34+ hematopoietic progenitor cells. Renal patients had significantly fewer EPCs than healthy subjects, however (167 +/- 15 cells/high power field vs. 235 +/- 17 cells/high power field; P < 0.05). Uremic serum significantly (P < 0.05) inhibited EPC differentiation and functional activity in vitro. Amelioration of uremia after institution of renal replacement therapy in patients with terminal renal failure also significantly (P < 0.05) increased the number of EPCs. CONCLUSION: Uremia inhibits differentiation of EPCs. This may impair cardiovascular repair mechanisms in patients with renal failure.     

Efficacy of speech aid prostheses for acquired defects of the soft palate and velopharyngeal inadequacy--clinical assessments and cephalometric analysis: a Memorial Sloan-Kettering Study

BACKGROUND: Restoration of speech after surgical resection for oropharyngeal cancer traditionally includes maxillofacial prosthetic intervention. Relatively few publications with objective speech outcomes exist. The purpose of this study was to evaluate speech outcome relative to the size of the surgical defect, the type of speech prosthesis, and the height and position of the speech bulb in relation to the posterior pharyngeal wall in the nasopharynx. METHODS: Fifty-five patients treated at the Memorial Sloan-Kettering Cancer Center Dental Service who underwent ablative cancer therapy were evaluated. All patients were 4 months or longer after surgery and were using a speech aid or obturator prosthesis at the time of the study. Speech samples for percent intelligibility and perceptual evaluation were collected and analyzed, in addition to aeromechanical measurements of palatopharyngeal function. Lateral cephalograms were taken while wearing the prosthesis using a radiopaque marker placed on the posterior aspect of the prosthesis for evaluating the height and position of the prosthesis obturator-speech bulb component. RESULTS: After adjustment for the differences between listeners, findings revealed that as the percentage of resection of palate or tongue increased, the intelligibility of speech decreased. Aeromechanical assessment of speech was the only outcome measure sensitive to the type of speech prosthesis. The position of the speech bulb component, as well as the angle measured, was correlated with the percent intelligibility. The amount of the prosthesis physically contacting the posterior pharyngeal wall was not significantly associated with any of the functional outcome measures. CONCLUSIONS: Speech aid and obturator prostheses contribute to a higher percentage of intelligible speech. A difference in intelligibility exists in relationship to the position of the prosthesis and the anterior tubercle of the atlas vertebrae (C1), both statistically and clinically. The position for optimal speech could not be specifically located mathematically (ie, 3 mm or 3 degrees inferior to the anterior tubercle of the atlas vertebrae) from the analysis. Subjective ratings of the efficacy of the obturator-speech bulbs by the clinicians did not correspond to the percent intelligibility. A strong statistical and clinical correlation exists supporting the efficacy of speech bulb-obturator intervention after velopharyngeal insufficiency for improved intelligibility of both words and sentences.     

Mechanics of wound healing and importance of Vacuum Assisted Closure in urology

PURPOSE: We discuss the mechanisms of wound healing and our experience with the Vacuum Assisted Closure device (Kinetic Concepts, Inc., San Antonio, Texas) for complex urogenital wounds. MATERIALS AND METHODS: The literature obtained from a Medline search on wound healing, wound failure and vacuum assisted closure was reviewed. In addition, we reviewed our experience with negative pressure wound therapy. RESULTS: Wound healing is a complex interaction between the reticuloendothelial and immune systems, in addition to correctable internal and external factors. Understanding the healing process improves outcomes and decreases patient morbidity. Negative pressure wound therapy has hastened wound healing and it adds significant improvement in the arsenal of choices available. CONCLUSIONS: Vacuum Assisted Closure is a therapeutic alternative that complements surgical and medical intervention in patients with complex wounds.