Age- and anatomy-related values of blood-brain barrier permeability measured by perfusion-CT in non-stroke patients.

BACKGROUND AND PURPOSE: The goal of this study was to determine blood-brain barrier permeability (BBBP) values extracted from perfusion-CT (PCT) using the Patlak model and possible variations related to age, gender, race, vascular risk factors and their treatment and anatomy in non-stroke patients. MATERIALS AND METHODS: We retrospectively identified 96 non-stroke patients who underwent a PCT study using a prolonged acquisition time up to 3 minutes. Patients' charts were reviewed for demographic data, vascular risk factors and their treatment. The Patlak model was applied to calculate BBBP values in regions of interest drawn within the basal ganglia and the gray and white matter of the different cerebral lobes. Differences in BBBP values were analyzed using a multivariate analysis considering clinical variables and anatomy. RESULTS: Mean absolute BBBP values were 1.2 ml 100 g(-1) min(-1) and relative BBBP/CBF values were 3.5%. Statistical differences between gray and white matter were not clinically relevant. BBBP values were influenced by age, history of diabetes and/or hypertension and aspirin intake. CONCLUSION: This study reports ranges of BBBP values in non-stroke patients calculated from delayed phase PCT data using the Patlak model. These ranges will be useful to detect abnormal BBBP values when assessing patients with cerebral infarction for the risk of hemorrhagic transformation.

Molecular weight of hydroxyethyl starch molecules influences coagulation profile measured by thrombelastography.

BACKGROUND: The consensus about the ideal intravenous fluid in trauma patients remains open. However, hypertonic saline and hydroxyethyl starch (HES) seems to have advantages in terms of immuno-modulatory and haemodynamic effects. Nevertheless clotting abnormalities are frequently reported in association with the use of HES. We investigated the influence of light, medium and heavy molecular weight (MW) hydroxyethyl starch (HES) on coagulation in 29 healthy subjects. METHODS: Ringer's lactate (RL) served as a control solution. Thrombelastography using Haemoscope's Thrombelastograph (TEG) hemostasis system was used to assess the effect of HES polymers and RL. TEG analysis was performed using recalcified native whole blood both with and without the addition of platelet activating factor IV (PAF IV) before and immediately after infusion of one of the solutions. RESULTS: Infusion of RL or one of the three HES solutions exerts an anticoagulant effect as demonstrated by a increase in clot formation time (R) and a decrease in maximum amplitude (MA), and the angle. The addition of PAF IV reversed these changes. CONCLUSIONS: This data indicate clear evidence of platelet activity per se or platelet interaction with the plasmatic coagulation system.

A simplified parameter of LV function in children with congenital heart disease.

Myocardial state in children with various congenital anomalies was assessed using pressured-derived parameters; Vmax and Vpm. A simple approach, based on the relationship between peak value of the first derivative of the left ventricular isovolumic pressure and its associated total pressure, for identifying patients with impaired myocardial function is described.

Familial coarctation of the aortic arch with bilateral ptosis: a new syndrome?

A Newfoundland family with the apparently unique syndrome of complex coarctation of the aortic arch, bilateral stenoses of the subclavian arteries, bilateral ptosis, sensorineural deafness, and bronchial asthma is reported. This syndrome appears to have affected at least four generations, and has the characteristics of autosomal dominant inheritance.

Successful one stage repair of coarctation of the aorta and aneurysm of the ascending aorta in a child.

A case of successful one stage repair of aortic coarctation and ascending aortic aneurysm in a 10 year old boy with cystic medial necrosis and congenital bicuspid aortic valve is presented. The patient underwent correction of both lesions at the same operation through two separate incisions. The coarctation was repaired first. The aortic valve was found to be hemodynamically normal and was not replaced. The patient leads a normal life at five and half years after operation and is playing ice hockey with no limitations. Close and long-term follow-up is considered essential in view of the potential complications.

Cuspal fracture resistance and microleakage of glass ionomer cements in primary molars.

The purpose of this study was to comparatively evaluate the fracture strength and microleakage among two new glass ionomer cements. One hundred and ten primary first and second molars were divided into two main groups, one group comprising of fifty teeth for microleakage evaluation and second group of sixty for fracture strength. Both the groups were subdivided equally into four based on the materials used, consisting of the same number of teeth respectively, in each. Two controls were used for cuspal fracture strength and an additional trial group was added for microleakage evaluation. Ideal, non retentive class II were prepared and restored with amalgam, Fuji IX, Fuji II LC and Vitremer. The statistical analysis revealed highly significant differences among all the subgroups except between subgroup 3 vs. 4 and 1 for cuspal fracture strength. Similarly microleakage values were significantly different statistically among sub groups 4 and 5 vs 1 and 2. The present study revealed that Fuji IX was the best in terms of cuspal fracture strength and Fuji IX with an additional application of light cure resin sealant gave the lowest degree of microleakage.

HIGH ALTITUDE PULMONARY OEDEMA - AN EXPERIENCE IN EASTERN HIMALAYA.

Three hundred and five cases of high altitude pulmonary oedema (HAPO) hospitalised in eastern Himalayan region have been analyzed. Incidence of HAPO was 5.5 per cent. Eighty per cent cases occurred during latter half of the year. Fifty six per cent of cases belonged to the third decade of life. HAPO cases occurred most commonly between the height of 2740 m to 5960 m. Eighty three per cent cases developed symptoms within 72 hours of induction to high altitude and 65.9 per cent suffered from the illness despite complete acclimatization. Breathlessness, headache and cough were the commonest symptoms. Tachycardia and tachypnoea was present in all cases. Twenty five per cent cases showed various ECG abnormalities. Mortality rate was 0.98 per cent.

ELECTROCARDIOGRAPHIC CHANGES IN VIRAL HEPATITIS.

Electrocardiograms of 322 patients with viral hepatitis were examined. Abnormal electrocardiograms were found in 229 patients (71.1%). The commonest abnormalities were T wave changes in 27 per cent. Other significant abnormalities were sinus bradycardia (13.7%), ST segment changes (5.7%), ventricular premature beats (2.5%) and U waves (6.5%). All the electrocardiographic abnormalities were transient and had no correlation with the severity or duration of illness.

Bilateral obturator hernia with intestinal obstruction: repair with a cigar roll technique.

Obturator hernia is an exceedingly rare pelvic hernia that occurs primarily in multiparous, elderly thin (>70 years of age) females. Here, we report a case of bilateral obturator hernia in an elderly female with high-grade small bowel obstruction repaired with a novel "cigar roll" technique.

Automatic polyp detection and measurement with computed tomographic colonography: A phantom study.

PURPOSE: The purpose of this study is to assess the performance of computer-aided detection (CAD) software in detecting and measuring polyps for CT Colonography, based on an in vitro phantom study. MATERIAL AND METHODS: A colon phantom was constructed with a PVC pipe of 3.8 cm diameter. Nine simulated polyps of various sizes (3.2mm-25.4mm) were affixed inside the phantom that was placed in a water bath. The phantom was scanned on a 64-slice CT scanner with tube voltage of 120 kV and current of 205 mAs. Two separate scans were performed, with different slice thickness and reconstruction interval. The first scan (thin) had a slice thickness of 1mm and reconstruction interval 0.5mm. The second scan (thick) had a slice thickness of 2mm and reconstruction interval of 1mm. Images from both scans were processed using CT Colonography software that automatically segments the colon phantom and applies CAD that automatically highlights and provides the size (maximum and minimum diameters, volume) of each polyp. Two readers independently measured each polyp (two orthogonal diameters) using both 2D and 3D views. Readers' manual measurements (diameters) and automatic measurements from CAD (diameters and volume) were compared to actual polyp sizes as measured by mechanical calipers. RESULTS: All polyps except the smallest (3.2mm) were detected by CAD. CAD achieved 100% sensitivity in detecting polyps ≥6mm. Mean errors in CAD automated volume measurements for thin and thick slice scans were 8.7% and 6.8%, respectively. Almost all CAD and manual readers' 3D measurements overestimated the size of polyps to variable extent. Both over- and underestimation of polyp sizes were observed in the readers' manual 2D measurements. Overall, Reader 1 (expert) had smaller mean error than Reader 2 (non-expert). CONCLUSION: CAD provided accurate size measurements for all polyps, and results were comparable to the two readers' manual measurements.

Dynamic perfusion CT assessment of the blood-brain barrier permeability: first pass versus delayed acquisition.

BACKGROUND AND PURPOSE: The Patlak model has been applied to first-pass perfusion CT (PCT) data to extract information on blood-brain barrier permeability (BBBP) to predict hemorrhagic transformation in patients with acute stroke. However, the Patlak model was originally described for the delayed steady-state phase of contrast circulation. The goal of this study was to assess whether the first pass or the delayed phase of a contrast bolus injection better respects the assumptions of the Patlak model for the assessment of BBBP in patients with acute stroke by using PCT. MATERIALS AND METHODS: We retrospectively identified 125 consecutive patients (29 with acute hemispheric stroke and 96 without) who underwent a PCT study by using a prolonged acquisition time up to 3 minutes. The Patlak model was applied to calculate BBBP in ischemic and nonischemic brain tissue. Linear regression of the Patlak plot was performed separately for the first pass and for the delayed phase of the contrast bolus injection. Patlak linear regression models for the first pass and the delayed phase were compared in terms of their respective square root mean squared errors (square root MSE) and correlation coefficients (R) by using generalized estimating equations with robust variance estimation. RESULTS: BBBP values calculated from the first pass were significantly higher than those from the delayed phase, both in nonischemic brain tissue (2.81 mL x 100 g(-1) x min(-1) for the first pass versus 1.05 mL x 100 g(-1) x min(-1) for the delayed phase, P < .001) and in ischemic tissue (7.63 mL x 100 g(-1) x min(-1) for the first pass versus 1.31 mL x 100 g(-1) x min(-1) for the delayed phase, P < .001). Compared with regression models from the first pass, Patlak regression models obtained from the delayed data were of better quality, showing significantly lower square root MSE and higher R. CONCLUSION: Only the delayed phase of PCT acquisition respects the assumptions of linearity of the Patlak model in patients with and without stroke.

Spin chains and channels with memory.

In most studies of quantum channels, it is assumed that the errors in each use of the channel are independent. However, recent investigations of the effect of memory or correlations in error have led to speculation that nonanalytic behavior may occur in the capacity. Motivated by these observations, we connect the study of channels with correlated error to the study of many-body systems. This enables us to use many-body theory to solve some interesting models of correlated error. These models can display nonanalyticities analogous to quantum phase transitions.

Bounds on multipartite entangled orthogonal state discrimination using local operations and classical communication.

We show that entanglement guarantees difficulty in the discrimination of orthogonal multipartite states locally. The number of pure states that can be discriminated by local operations and classical communication is bounded by the total dimension over the average entanglement. A similar, general condition is also shown for pure and mixed states. These results offer a rare operational interpretation for three abstractly defined distancelike measures of multipartite entanglement.

Length of insertion for pulmonary artery catheters to locate different cardiac chambers in patients undergoing cardiac surgery.

BACKGROUND: Although, guidelines related to length of insertion of a pulmonary artery catheter to reach a particular cardiac chamber are available, these are not backed by clinical studies. We measured the length of insertion of pulmonary artery catheters to locate the right ventricle, pulmonary artery and pulmonary capillary wedge positions in 300 adult patients undergoing elective cardiac surgery. METHODS: The pulmonary artery catheters were inserted using a standard technique through the right internal jugular vein. The right ventricle, pulmonary artery and wedge position of the catheter were confirmed by the characteristic waveforms, and the length of insertion to these points was measured. RESULTS: The right ventricle was reached at 24.6 (3) cm (95% CI 24.2-24.9 cm), pulmonary artery at 36 (4) cm (95% CI 35.6-36.5 cm) and wedge position at 42.8 (5.7) cm (95% CI 42.2-43.5 cm). The length of catheter to reach the right ventricle, pulmonary artery and wedge position was significantly more in patients undergoing valve surgery as compared with those undergoing coronary artery bypass grafting [26 (3.8) and 24 (2.5) cm; 38.5 (4.6) and 35 (3.2) cm; and 47.8 (6.9) and 41.2 (4.1) cm, respectively, P<0.001]. The length of insertion to reach pulmonary artery and pulmonary capillary wedge position was directly related to height of the patient (Pearson's correlation 0.157 and 0.15, respectively). CONCLUSIONS: We have provided the norms related to length of insertion of pulmonary artery catheter, which should be useful in accurate placement of the catheter and minimize complications related to coiling of the catheter.

Left-axis deviation in otherwise healthy children.

Eighteen children with left-axis deviation on the electrocardiogram but no other detected abnormalities are reported. The implications of this finding are discussed. No untoward cardiovascular events occurred during the period of follow-up and the electrocardiographic findings remained unchanged. This, therefore, appears to be a benign entity in the short term but longer follow-up is required before the ultimate prognosis can be determined.