Functional Connectivity Analysis of Visually Evoked ERPs for Mild Cognitive Impairment: Pilot Study.

Mild cognitive impairment (MCI) is considered the early stage of Alzheimer's disease, characterized as mild memory loss. A novel method of functional connectivity (FC) analysis can be used to detect MCI before memory is significantly impaired allowing for preventative measures to be taken. FC examines interactions between EEG channels to grant insight on underlying neural networks and analyze the effects of MCI. Applying FC method of weighted phase lag index (wPLI) to P300 ERPs provided insight on the link between the pathology of Alzheimer's disease and cognitive loss. wPLI was analyzed per frequency band (θ, α, µ, ß) and by channel combination groups (intra-hemispheric short, intra-hemispheric long, inter-hemispheric short, inter-hemispheric long, transverse). MCI was found to have a statistically significant lower ΔwPLIP300 compared to normal controls in the µ intra-hemispheric short (p = 0.0286), µ intra-hemispheric long (p = 0.0477), µ inter-hemispheric short (p = 0.0018) and the α intra-hemispheric short (p = 0.0423). Results indicate a possible deficiency in the dorsal visual processing pathway among MCI subjects as well as an unbalanced coordination between the two hemispheres.

Effects of chlorine particle concentration on the human airway.

For COVID-19, chlorine has lately been utilised as a home disinfectant. Given that chlorine is hazardous to the human airway, the current research investigates the effects of chlorine mass fraction and droplet size on the human airway. The effects are investigated at chlorine mass ratios of 2% (24 ppm), 10% (120 ppm), 15% (180 ppm), and 20% (240 ppm), as well as chlorine particle diameters of 10 nm, 20 nm, 30 nm, and 50 nm, and three inhalation rates (15 l/min, 30 l/min, and 60 l/min). The results reveal that when the chlorine mass fraction is 2% and the inhalation rate is low, the chlorine volume fraction decreases. Furthermore, at 2% chlorine and a rapid breathing rate, chlorine particles are accelerated to escape into the lungs.

A new, simple operative approach for bilateral inguinal hernia repair in girls: A single transverse supra-pubic incision.

BACKGROUND: Inguinal hernia repair remains one of the most common operations performed by pediatric surgeons. We described a new surgical approach for treating bilateral inguinal hernias in girls through a small single transverse supra-pubic incision. MATERIALS AND METHODS: A new approach was performed on female children 12-years-old and younger with bilateral inguinal hernias between January 2005 and April 2012. TECHNIQUE: A single transverse suprapubic incision (1-1.5 cm) was made. Using sharp and blunt dissection bilateral hernias were exposed and repaired using a standard high ligation. RESULTS: Ninety-nine girls with a preoperative clinical diagnosis of bilateral inguinal hernia were included. Median age was 2 years (range: 1 month to 12 years). All patients underwent general anesthesia. Median operative time was 12 minutes (range 5-22). There were no intra-operative complications or misdiagnosis. Two patients had bilateral sliding hernias and the remainder had indirect hernias. Post-operatively two patients developed non-expanding small hematomas, both treated non-operatively without sequelae. There were zero hernia recurrence and median follow-up was 5 years (range: 1-8 years) on 99% of patients. CONCLUSION: We described a new, safe, simple, and rapid approach for bilateral inguinal hernia repair in female pediatric population. A single transverse suprapubic skin incision was adequate for exposing both inguinal regions with excellent postoperative results.

The value of PET scan (and MRI and Wada test) in patients with bitemporal epileptiform abnormalities.

BACKGROUND: Lateralization remains difficult in patients with bitemporal epileptiform abnormalities. OBJECTIVE: To evaluate the reliability of the interictal fluorodeoxyglucose F18-positron emission tomographic (PET) scan in this setting. METHODS: We analyzed PET scan findings in 25 patients who required bilateral depth electrodes for lateralization of temporal lobe epilepsy. The contribution of magnetic resonance imaging and the intracarotid amobarbital procedure was also analyzed. RESULTS: Positron emission tomographic scan revealed lateralized hypometabolism in 15 patients. This was in agreement with the depth evaluation in 10 cases (67%). In five cases (33%), the PET and depth findings were in disagreement, with no predominant side of seizure origin by depth electroencephalography (EEG) in four cases and PET lateralization opposite to depth findings in one case. In 10 of the 25 patients, PET scans could not lateralize hypometabolism to one temporal lobe, of which six were confirmed by depth EEG not to have a predominant side of seizure onset. The overall sensitivity of PET for concordant lateralized seizure onset was 67%. Ten of 14 patients who underwent a lobectomy had a successful outcome, including three of four patients whose temporal lobe epilepsy was lateralized by depth EEG but not by PET. One patient had PET lateralization opposite to the depth EEG and side of surgery and failed to improve. CONCLUSIONS: In this highly selected group of patients, the lateralizing value of PET and magnetic resonance imaging was somewhat diminished, and the intracarotid amobarbital procedure was not found useful for lateralization. Positron emission tomography and magnetic resonance imaging, when pointing to the side opposite depth EEG, may indicate a poor prognosis.

Comparison and spacial correlation of interictal HMPAO-SPECT and FDG-PET in intractable temporal lobe epilepsy.

The respective contribution of interictal HMPAO-SPECT and FDG-PET to the imaging of the epileptogenic zone in intractable temporal lobe epilepsy is not known. Ten consecutive patients with drug resistant focal epilepsy of temporal lobe origin were studied with prolonged noninvasive video-EEG monitoring, magnetic resonance imaging, interictal FDG-PET and HMPAO-SPECT. Five patients demonstrated unitemporal and 5 patients bitemporal interictal and/or ictal EEG epileptiform abnormalities. We developed a 3-dimensional semiquantitative method for interpretation and comparison of FDG-PET and HMPAO-SPECT using a 15-compartment model of the temporal lobe. In all 5 patients with unilateral epileptogenicity, interictal hypometabolism and hypoperfusion were recorded on the side of the EEG abnormalities without discrepancy between PET and SPECT. The severity and the extent of focal abnormalities were consistently greater on PET than on SPECT, in agreement with previously well documented better 'sensitivity' of PET. Among the 5 patients with bitemporal epileptogenicity, results of SPECT and PET were convergent in only 2 cases. In this group, SPECT abnormalities appeared more profound but either SPECT or PET were not constantly correlated with the side of predominant EEG epileptogenicity. Abnormalities on PET and SPECT were more frequently limited to mesiobasal structures among cases with unilateral epileptogenicity and tended to involve neocortical structures in bitemporal cases. We conclude that interictal FDG-PET and HMPAO-SPECT provide the same type of information on the side of the epileptogenic zone in cases with clearly unilateral epileptogenicity, with abnormalities more intense and more extensive on PET.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical outcome of cardiac patients with negative thallium-201 SPECT and positive rubidium-82 PET myocardial perfusion imaging.

In a previous comparison of 202 consecutive patients who underwent myocardial perfusion imaging with both 201Tl SPECT and 82Rb PET, 27 patients were identified as having true-positive 82Rb images, but false-negative 201Tl images. The purpose of this report is to determine the effect of correct image interpretation of coronary artery disease on the final management of those patients and compare it to the previous management scheme wherein a negative image was usually accepted as the end point unless clinical symptoms dictated otherwise. A follow-up study of the clinical course and outcome of these studies showed that 63% (17/27) of the patients with a true-positive 82Rb PET image were recommended for revascularization procedures. It is doubtful that this majority of patients would have received either surgical or interventional management based on the false-negative 201Tl SPECT procedure alone.

Presurgical evaluation of temporal lobe epilepsy using interictal temporal spikes and positron emission tomography.

OBJECTIVE: Our goal was to determine the role of fludeoxyglucose F 18-positron emission tomography (18FDG-PET) and interictal temporal spikes in lateralizing the epileptogenic region in patients who (1) were diagnosed as having temporal lobe epilepsy based on clinical symptoms and exclusively temporal interictal spikes and (2) did not have a structural lesion on magnetic resonance imaging. DESIGN: This was a retrospective study of 40 consecutive patients fulfilling the above criteria who underwent 18FDG-PET scanning. A firm electrophysiologic diagnosis and 1 complete year of postsurgical follow-up, where applicable, were required. Outcome measures included surgical outcome and final electrophysiologic diagnosis. RESULTS: Unilateral, interictal temporal spikes (ITS) were present in 33 (82.5%) of 40 patients. Seven patients (17.5%) had bitemporal, independent spikes. Thirty-one (77.5%) of 40 patients had unilateral temporal hypometabolism (TH). Twenty-eight (70%) patients had concordant TH and ITS. One year after surgery, 31 of 33 patients with unilateral ITS were greatly improved; two of five who had bitemporal ITS showed similar improvement. In 28 patients, unilateral TH and unilateral ITS were concordant. The paired result always concurred with the final neurophysiologic assessment. Surgical outcome between patients with 18FDG-PET showing unilateral TH (26 of 30 greatly improved) and those not showing unilateral TH (six of eight greatly improved) was not significantly different. CONCLUSION: In temporal lobe epilepsy not associated with a mass lesion, unilateral ITS are reliable lateralizing features and suggest a good surgical outcome. Use of 18FDG-PET provides corroborative lateralizing information but 18FDG-PET that fails to show unilateral TH does not preclude a good surgical outcome.

Tracer kinetics of 15-(ortho-123/131I-phenyl)-pentadecanoic acid (oPPA) and 15-(para-123/131I-phenyl)-pentadecanoic acid (pPPA) in animals and man.

The human myocardium retains oPPA as opposed to pPPA. Therefore turnover of oPPA was compared with that of pPPA in rat hearts and in man, the latter by using substrates double-labeled with 123/131I and 14C. Moreover, substrate binding to coenzyme-A was tested in vitro. In rats, oPPA remained mainly in the pool of free fatty acids, as opposed to pPPA, which was metabolized by mitochondrial beta-oxidation. Binding to coenzyme-A at maximum was 62% for oPPA, 81% for pPPA and 90% for palmitic acid. In man, after i.v. and intracoronary injection of double-labeled oPPA, the two radionuclides reappeared together in venous blood and in coronary sinus respectively, in an unchanged ratio but at a significantly lower rate than with pPPA. It can be concluded that oPPA is bound to coenzyme-A and is retained in the cytosolic lipid pool, while pPPA is metabolized by mitochondrial beta-oxidation. A dual-tracer application of oPPA and pPPA has the potential of being a specific probe for the function of the carnitine shuttle.

Nuclear medicine studies of aging: X. Relationship of liver and spleen lengths at age 65 years and older.

For 3 groups of patients aged 65 years or greater, liver and spleen lengths were measured from calibrated radiocolloid images. Length relationships between liver (L) and spleen (S) were examined in terms of S as a function of L, as well as (S/L) and (L-S) vs S or L. Liver and spleen lengths were the least well correlated in these patients. The S/L ratio vs S produced the most significant correlation in all 3 groups. This suggests a complex but describable relationship between liver and spleen lengths in the overall aging population, and provides a baseline for comparing the effects of various diseases on S and L.

Radiopharmaceuticals for studying cardiac metabolism.

(1) Metabolism is the link between myocardial blood flow and physiological performance of the heart. (2) Metabolic myocardial radiopharmaceuticals have the potential to identify metabolic alterations unique to a given intrinsic cardiac disease (e.g. cardiomyopathies), to assess acute metabolic changes or in delineating a specific chronic metabolic defect (e.g. coronary artery disease). (3) Two approaches can be employed to evaluate in vivo myocardial utilization of subtracts: (a) use of radiolabeled "physiologic" substrates e.g. positron emitting 11C-palmitic acid was successfully employed for assessing the in vivo metabolic sequelae of myocardial ischemia, infarction and cardiomyopathies, and (b) use of modified tracers which enter known metabolic pathways. However, because of their unique structure, metabolism of the tracer stops at a certain state thus leaving the radiolabel trapped in the cell, e.g. [18F]FDG for measuring glucose metabolic rate in the human brain and myocardium. (4) Among the radiopharmaceuticals for planar and single photon tomography, the para and the ortho isomers of 123I-phenyl iodoheptadecanoic acids and their beta-methyl derivatives are the most promising tracers for myocardial metabolic studies. (5) Ortho-(123I-phenyl)-pentadecanoic acid (o-IPPA) human myocardial uptake was rapidly and markedly elevated in well perfused segments; myocardial turnover was strikingly prolonged, suggesting some "trapping" phenomenon, resulting in excellent scintigrams. This is in contrast to the relatively shorter clearance of the para isomer from the myocardium. (6) 11C-Palmitic acid and [18F]FDG are the most widely used for PET scanning for following myocardial metabolism. The most important clinical application of these agents is predicting viability of ischemic myocardium. (7) A significant proportion of fixed perfusion defects seen on thallium studies can be demonstrated to be viable myocardium on PET scans using metabolic agents. If the markers of perfusion alone are relied on to assess tissue viability, the extent of salvageable myocardium may be underestimated. The demonstration of myocardial viability is crucial in the decision of the optimal treatment of the disease.

Role of a nonsteroidal anti-inflammatory agent, ibuprofen, in coronary revascularization after acute myocardial infarction.

The efficacy of using a nonsteroidal anti-inflammatory agent such as ibuprofen for the salvage of ischemic and reperfused myocardium was investigated by examining its ability to improve global and regional functions as well as to preserve high-energy phosphate compounds and inhibit creatine kinase release from an isolated in-situ pig heart subjected to 1 h of normothermic regional ischemia followed by 1 h of global hypothermic arrest and 1 h of normothermic reperfusion. Preperfusion of the heart for 15 min prior to ischemic insult with 50 microM ibuprofen failed to mitigate the myocardial reperfusion injury. Ibuprofen, however, functioned as an anti-inflammatory agent, as judged by its ability to inhibit the influx of indium-111-labeled polymorphonuclear leukocytes and chromium-51 (51Cr)-labeled platelets into the ischemic and reperfused heart. It also blocked the cyclooxygenase pathway, as evidenced by the significant reduction of 6-keto-prostaglandin F1 alpha and thromboxane B2 concentrations in the perfusate. Inhibition of cyclooxygenase resulted in increased accumulation of nonesterified fatty acids, particularly arachidonic acid, in the heart. These results suggest that although ibuprofen can inhibit polymorphonuclear leukocyte and platelet influx into the ischemic and reperfused heart, it causes further damage to the already ischemic heart by reducing prostacyclin concentration and increasing free fatty acids in the heart.

[Detection by echocardiography of a thrombus of the right cavities in acute pulmonary embolism]. / Détection par échocardiographie de thrombus des cavités droites dans l'embolie pulmonaire aiguë.

Echocardiography evaluates the severity of acute pulmonary embolism from its repercussions on haemodynamics. However, many authors have reported the discovery of thrombosis in the right heart cavities of patients with acute pulmonary embolism. In order to assess the frequency of intracavitary thrombosis and to evaluate the practical problems it raises, we have systematically examined by echocardiography 84 patients hospitalized for severe, acute pulmonary embolism (mean Miller's score: 21). In this series of 39 men and 45 women (mean age 62 years), 9 thrombi were detected, i.e. an incidence of 11%. Depending on the ultrasonographic images they presented, these patients were divided into two groups: 1. Six patients with low mobility thrombi attached to the cardiac wall. All benefited from a medical treatment consisting of heparin in 4 cases and a thrombolytic drug in 2 cases. There was no clinical evidence of recurrent embolism. Echocardiography showed complete disappearance of the thrombi in 5 of these 6 patients and partial regression under heparin therapy in one. 2. Three patients with a large and mobile thrombus threatening to prolapse through the tricuspid valve during atrial systole. It seemed rational to regard such thrombi as carrying a high risk of embolism with recurrences, especially since they had formed in patients already with severe pulmonary embolism. This view was confirmed by a search in the literature which yielded a 40% death rate figure when these thrombi were associated with pulmonary embolism. This high mortality, however, can be reduced by diagnostic and therapeutic measures.(ABSTRACT TRUNCATED AT 250 WORDS)

15-(ortho-123I-phenyl)-pentadecanoic acid, a new myocardial imaging agent for clinical use.

The result of previous experiments in rodents indicated different kinetics for the para- and ortho-isomers of 15-(iodophenyl)-pentadecanoic acid (p-IPPA, o-IPPA), with o-IPPA showing an enhanced rate of washout. To test the relevance of this phenomenon for clinical diagnosis, 15 fasting male patients with confirmed coronary heart disease (1-VD/7, 2-VD/4, 3-VD/4) were investigated under exercise. Serial images were recorded at a rate of 3 frames min-1 for 70 to 90 min, corrected for tracer in blood and compared with thallium-201 images obtained from these patients within less than 2 weeks. Time-activity curves were also taken from the peripheral blood. Ortho-IPPA was well taken up by healthy myocardium and, contrary to rodents, retained with elimination half times longer than 200 min. A decreased myocardial uptake was seen which was very similar to the pattern obtained with thallium. Ortho-IPPA was eliminated from the blood to less than 10% at 4 min. Almost all radioactivity was in the organic phase (greater than 95% at 5 min) and chromatography showed only one major peak (o-IPPA) indicative of minimal organic catabolism.