White blood cell SPECT during active period of cluster headache and in remission

Background and purpose: Cluster headache (CH) is an episodic headache disorder characterized by recurrent, unilateral attacks of excruciating pain in the temporal/orbital region. The pathophysiology of CH is largely unknown although involvement of immunological mechanisms has been suggested. The aim of our study was to investigate whether patients with CH show signs of intracranial inflammation, when using white blood cell single‐photon emission computer tomography (WBC‐SPECT). Methods: We have examined 14 patients with CH, both in active period and in remission, and five control subjects at one occasion, with WBC‐SPECT. To be able to precisely define regions of interest (ROI:s) in the brain, all patients with CH and control subjects underwent magnetic resonance imaging (MRI) of the brain. Results: We found no significant difference in ^99mTc‐labeled WBC uptake between patients with CH in active period and controls. Furthermore, patients with CH in active period were not significantly different in uptake compared with patients with CH in remission. Conclusions: These results did not provide conclusive support for a hypothesis of a pathophysiological role of inflammation intracranially. Our conclusions are restricted to the advantages and limitations of the chosen method.     

The effect of sleep deprivation on objective and subjective measures of facial appearance

The faces of people who are sleep deprived are perceived by others as looking paler, less healthy and less attractive compared to when well rested. However, there is little research using objective measures to investigate sleep‐loss‐related changes in facial appearance. We aimed to assess the effects of sleep deprivation on skin colour, eye openness, mouth curvature and periorbital darkness using objective measures, as well as to replicate previous findings for subjective ratings. We also investigated the extent to which these facial features predicted ratings of fatigue by others and could be used to classify the sleep condition of the person. Subjects (n = 181) were randomised to one night of total sleep deprivation or a night of normal sleep (8–9 hr in bed). The following day facial photographs were taken and, in a subset (n = 141), skin colour was measured using spectrophotometry. A separate set of participants (n = 63) later rated the photographs in terms of health, paleness and fatigue. The photographs were also digitally analysed with respect to eye openness, mouth curvature and periorbital darkness. The results showed that neither sleep deprivation nor the subjects’ sleepiness was related to differences in any facial variable. Similarly, there was no difference in subjective ratings between the groups. Decreased skin yellowness, less eye openness, downward mouth curvature and periorbital darkness all predicted increased fatigue ratings by others. However, the combination of appearance variables could not be accurately used to classify sleep condition. These findings have implications for both face‐to‐face and computerised visual assessment of sleep loss and fatigue.     

A new application of pre-normalized principal component analysis for improvement of image quality and clinical diagnosis in human brain PET studies--clinical brain studies using [11C]-GR205171, [11C]-L-deuterium-deprenyl, [11C]-5-Hydroxy-L-Tryptophan, [11C]-L-DOPA and Pittsburgh Compound-B

Principal component analysis (PCA) is one of the most applied multivariate image analysis tool on dynamic Positron Emission Tomography (PET). Independent of used reconstruction methodologies, PET images contain correlation in-between pixels, correlations in-between frame and errors caused by the reconstruction algorithm including different corrections, which can affect the performance of the PCA. In this study, we have investigated a new approach of application of PCA on pre-normalized, dynamic human PET images. A range of different tracers have been used for this purpose to explore the performance of the new method as a way to improve detection and visualization of significant changes in tracer kinetics and to enhance the discrimination between pathological and healthy regions in the brain. We compare the new results with the results obtained using other methods. Images generated using the new approach contain more detailed anatomical information with higher quality, precision and visualization, compared with images generated using other methods.     

Electronic speckle pattern interferometry: a novel non-invasive tool for studying drug transport rate through free films.

In this work, Electronic Speckle Pattern Interferometry (ESPI) is presented as a non-invasive tool to study drug transport in controlled release systems. ESPI is shown to be a feasible tool to measure drug film permeability via comparison with an ordinary diaphragm cell. A specially designed cuvette was used in the release study: the polymeric film separated the donor and the receiving chambers of the cuvette to create a diffusion cell with no mixing in the two chambers. Thus, the cuvette mimicked a coated system immersed in a stagnant bulk liquid. Concentration profile data were obtained for the two compartments. Using these data, it was possible to visually discriminate between a film subject only to diffusion and a film subject to diffusion as well as osmotic effects. Moreover, using the concentration profile data collected at different time intervals, it was possible to follow the film properties in terms of drug permeability, thus studying how drug permeability depended on drug concentration. Compared to other measuring techniques, ESPI offers the advantages that no invasive measurements are needed, and that no sampling and calibration are required. Furthermore, the permeability can be measured with no influence of mass transfer in the boundary layers.     

Elevation of biochemical markers for myocardial damage prior to hospital admission in patients with acute chest pain or other symptoms raising suspicion of acute coronary syndrome

Abstract. Svensson L, Axelsson C, Nordlander R, Herlitz J (South Hospital, Stockholm; and Sahlgrenska University Hospital, Göteborg; Sweden). Elevation of biochemical markers for myocardial damage prior to hospital admission in patients with acute chest pain or other symptoms raising suspicion of acute coronary syndrome. J Intern Med 2003; 253: 311–319. Objectives. To evaluate the occurrence of elevation of serum biochemical markers for myocardial damage in the prehospital setting amongst patients who called for an ambulance due to a suspected acute coronary syndrome (ACS). Design. Prospective observational study. Subjects. All the patients who called for an ambulance due to suspected ACS. Setting. South Hospital's catchment area in Stockholm and in the Municipality of Göteborg, Sweden between January and November in the year 2000, were included. Interventions. On arrival of the ambulance crew, a blood sample was drawn for bedside analysis of serum myoglobin, creatine kinase MB and troponin I. A 12‐lead electrocardiogram (ECG) was simultaneously recorded. Main outcome measures. Elevation of biochemical markers prior to hospital admission. Results. In all, 511 patients participated on 538 occasions. Elevation of any biochemical marker was observed in 11% of all patients. The corresponding figure for patients developing myocardial infarction was 21%; for patients with myocardial ischaemia 8%; for patients with a possible myocardial ischaemia 4% and for patients with other diagnoses 5%. Amongst those who had a final diagnosis of acute myocardial infarction (AMI), 47% had ST‐elevation on initial ECG and 57% had either ST‐elevation or elevation of any biochemical marker. Conclusion. Bedside analysis of biochemical markers in serum is already feasible prior to hospital admission amongst patients with a suspected ACS. About 20% of patients with AMI have elevated biochemical markers at that stage. When found this data might increase the possibility of diagnosing an AMI very early in the course. However, false positives were found and whether this strategy will improve the triage of these patients in the prehospital setting remains to be proven.     

Increasing anastomosis safety and preventing abdominal adhesion formation by the use of polypeptides in the rat

Background and aims Postoperative adhesions can potentially be reduced using different anti-adhesive agents, though these drugs tend to compromise healing of an intestinal anastomosis. No method that significantly increases anastomosis safety is known at present. The aim of the study was to develop a concept of preventing postoperative adhesions using differently charged bioactive polypeptides, also considering healing and safety of an intestinal anastomosis.Methods An ileocolic anastomosis was performed under both “clean” and “septic” conditions in the rat. The treatment group received intraperitoneal poly-l-lysine and poly-l-glutamate, while controls received sodium chloride. Abdominal adhesions, anastomosis leakage and burst pressure were analysed after 1, 3, 5 and 7 days in the clean anastomosis model and after 7 days in the septic model.Results A significant decrease (p<0.01) in the amount of adhesions was seen in animals treated with polypeptides after 1, 3 and 5 days, while no difference was seen after 7 days. The anastomosis demonstrated a significantly higher burst pressure as evaluated at days 1 and 3 (p<0.05 and p<0.01, respectively) in the polypeptide-treated animals, while no difference was seen between the groups at day 5 or 7.Conclusion The use of differently charged polypeptides administered intraperitoneally after surgery resulted in a significant decrease in the extent of postoperative adhesions. Furthermore, an increase in intestinal anastomosis safety, based on improved burst pressure during the first 3 days, i.e. the critical period during the healing process, was noted. No adverse effects were seen in surgery during septic conditions.     

Elevated serum levels of S-adenosylhomocysteine, but not homocysteine, are associated with cardiovascular disease in stage 5 chronic kidney disease patients

OBJECTIVE: The putative role of sulfur amino acids such as homocysteine (tHcy) as cardiovascular risk factors is controversial in chronic kidney disease (CKD). Although, S-adenosylhomocysteine (SAH) levels have been linked to CVD in non-renal populations, such relationship has not been evaluated in CKD. DESIGN: Serum concentrations of S-adenosylmethionine (SAM), SAH and total homocysteine (tHcy) were determined by HPLC in 124 CKD stage 5 patients (GFR range 1-11 m/min) and 47 control subjects, and related to renal function, presence of CVD, inflammation and protein-energy wasting (PEW). RESULTS: The levels of SAM and SAH were higher in CKD patients than in controls. Both SAM (rho=-0.19; P<0.05) and SAH (rho=-0.37, P<0.001) were inversely related to GFR. The concentrations of SAH were significantly higher (P<0.001) in patients with CVD than in non-CVD patients, (683 (201-3057) vs 485 (259-2620) nmol/L; median (range)) as opposed to tHcy levels, which were lower in CVD patients. While SAH was not associated with the presence of inflammation or PEW, it was a significant contributor (OR; 4.9 (CI 1.8-12.8), P<0.001) to CVD in a multinomial logistic regression model (pseudo r(2)=0.31). CONCLUSION: Concentrations of serum SAH and SAM in CKD stage 5 patients are associated with renal function, but not with inflammation or PEW. Among the investigated sulfur amino acids, only SAH was independently associated with the presence of clinical signs of CVD. These findings suggest that while tHcy might be influenced by a number of confounding uremic factors, SAH levels may better reflect the putative increased cardiovascular risk of sulfur amino acid alterations in CKD patients.     

Cerebral microdialysis of patients with severe traumatic brain injury exhibits highly individualistic patterns as visualized by cluster analysis with self-organizing maps

OBJECTIVE: To analyze patterns of cerebral microdialysis in patients with traumatic brain injury and, with a neural network methodology, investigate pattern relationships to intracranial pressure and cerebral perfusion pressure. DESIGN: Retrospective. SETTING: University hospital, adult neurosurgical intensive care unit. PATIENTS: Twenty-six patients with severe traumatic brain injury. All consecutive traumatic brain injured patients (Glasgow Coma Scale < or =8) with microdialysis monitoring, analyzing glutamate, lactate, pyruvate, and glucose in both penumbral and nonpenumbral tissue. INTERVENTIONS: None; patients received the unit's standard neurointensive care procedure. MEASUREMENTS AND MAIN RESULTS: We used 2084 hrs of complete microdialysis data sets (eight markers) to train Kohonen self-organizing maps. The self-organizing map algorithm is a data-clustering method that reduces high-dimensional information to a two-dimensional representation on a grid (map), retaining local relationships in the data. Maps were colored (overlaid) for intracranial pressure, cerebral perfusion pressure, and outcome, to explore relationships with underlying microdialysis patterns. The maps exhibited a striking clustering of patients, with unique microdialysis patterns that were recognizable throughout the analysis period. This also held true for most microdialysis patterns characteristic of ischemia. These patients with ischemic patterns can have good outcomes, suggesting a disparity between microdialysis values and severity of traumatic brain injury. CONCLUSION: Using an artificial neural network-like clustering technique, Kohonen self-organizing maps, we have shown that cerebral microdialysis, in traumatic brain injury, exhibits strikingly individualistic patterns that are identifiable throughout the analysis period. Because patients form their own clusters, microdialysis patterns, during periods of increased intracranial pressure or decreased cerebral perfusion pressure, will be found within these clusters. Consequently, no common pattern of microdialysis can be seen among patients within the range of our data. We suggest that these individualistic patterns reflect not only metabolic states of traumatic brain injury but also local gradients seen with small volume sampling. Future investigation should focus on relating these patterns, and movement within and from clusters, to metabolic states of the complex pathophysiology of traumatic brain injury.     

Treatment and outcome in post-resuscitation care after out-of-hospital cardiac arrest when a modern therapeutic approach was introduced

BACKGROUND: The outcome among patients who are hospitalised alive after out-of-hospital cardiac arrest is still relatively poor. At present, there are no clear guidelines specifying how they should be treated. The aim of this survey was to describe the outcome for initial survivors of out-of-hospital cardiac arrest when a more aggressive approach was applied. PATIENTS: All patients hospitalised alive after out-of-hospital cardiac arrest in the Municipality of G?teborg, Sweden, during a period of 20 months. RESULTS: Of all the patients in the municipality suffering an out-of-hospital cardiac arrest in whom cardiopulmonary resuscitation (CPR) was attempted (n=375), 85 patients (23%) were hospitalised alive and admitted to a hospital ward. Of them, 65% had a cardiac aetiology and 50% were found in ventricular fibrillation. In 32% of the patients, hypothermia was attempted, 28% underwent a coronary angiography and 21% had a mechanical revascularisation. In overall terms, 27 of the 85 patients who were brought alive to a hospital ward (32%) survived to 30 days after cardiac arrest. Survival was only moderately higher among patients treated with hypothermia versus not (37% versus 29%; NS), and it was markedly higher among those who had early coronary angiography versus not (67% versus 18%; p<0.0001). CONCLUSION: In an era in which a more aggressive attitude was applied in post-resuscitation care, we found that the survival (32%) was similar to that in previous surveys. However, early coronary angiography was associated with a marked increase in survival and might be of benefit to many of these patients. Larger registries are important to further confirm the value of hypothermia in representative patient populations.