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PubMed1989

Assessment of the intrinsic contractile state within an area of myocardium.

Afterload independent, inotropic state sensitive indices of regional function were sought in 31 canine hearts instrumented with piezoelectric crystals to depict trapezoidal areas in the left anterior descending and circumflex arterial beds. Control and postinterventional end-systolic pressure versus regional length and area relationships and regional stroke work versus end-diastolic length and area relationships were inscribed during incremental volume loading on right heart bypass. Hearts were randomized to undergo afterload variation with phenylephrine infusion, contractility augmentation by calcium chloride, or 20 minutes of ischemia in the region of the left anterior descending artery with 30 minutes of reperfusion. All relationships were linear before and after each intervention (mean r = 0.726 to 0.974). The slopes of each correlation were interpreted to quantify intrinsic regional contractility, and all were afterload insensitive (unaffected by phenylephrine). Regional stroke work versus end-diastolic area and length relationships were depressed 55% and 62%, respectively, after ischemia (p less than 0.001 each), whereas neither end-systolic pressure versus regional area nor regional length was significantly altered. Calcium chloride increased regional stroke work versus area 45% in both arterial beds, but significantly increased the other indices only in the left anterior descending and not the left circumflex region. Unlike previous studies of global contractility, correlation of end-systolic events alone did not reliably discriminate perturbations in regional function. The superiority of regional stroke work versus end-diastolic area may be due to incorporating pressure-area changes during the entire cardiac cycle and obviating variability owing to crystal orientation inexactly parallel to fiber shortening.

Animals↗

PubMed1986

[Sclerosing stromal tumor of the ovary].

A 20-year-old woman had the complaints of a tumor in the lower abdominal region and irregular menstruation. A spherical tumor measuring 7 X 6 X 3.5 cm in the great dimension was removed from the left ovary. The cut surface showed a lobular pattern and cystic degeneration in some areas. Histological examination revealed edematous areas and highly cellular areas. The cells were variable in size and shape. Round cells resembled signet-ring cells in places. By PAS reaction and alcian blue stain, these cells were found to be negative, but by Sudan III stain, positive. Postoperatively, the patient complained of genital bleeding for five days. Subsequently, her menstrual pattern returned to normal.

Adult↗

PubMed1996

Low myocardial temperatures are associated with postoperative conduction defects after coronary artery bypass surgery.

The incidence and significance of postoperative conduction defects after coronary artery bypass surgery were investigated prospectively in 181 patients. Several pre- and perioperative variables, especially the temperature in three regions of the myocardium, were recorded as explanatory variables. The incidence of conduction defect(s) in the immediate postoperative electrocardiogram (ECG) was 55.8%, and 35.9% of the patients had a conduction defect when leaving hospital. Two patients had a permanent third degree atrioventricular (AV) block. Five pacemakers were implanted. Left main coronary artery stenosis was more common (P < 0.01), and the perioperative myocardial temperatures (P < 0.05-0.01) were lower in patients with conduction defects. These patients had also low postoperative cardiac output more often (P < 0.001), their creatine kinase myocardial (MB) fraction values were higher (P < 0.01), and they stayed in hospital longer (P < 0.05). Right bundle branch block had no significant association with the studied variables.

Bundle-Branch Block↗

PubMed1988

Cardiovascular effects of diltiazem in the dog.

The effects of two bolus injections (0.2 mg kg-1) and two infusion rates (0.2 mg min-1 and 0.4 mg min-1) of diltiazem on global and regional left (LV) and right ventricular (RV) performance (ultrasonic dimension technique), on coronary (electromagnetic flow meters) and systemic haemodynamics, and on electrophysiology (PR, QRS, QTc intervals) were studied in eight open-chest dogs anaesthetized with droperidol and fentanyl. The two bolus injections of diltiazem resulted in plasma concentrations of 688 +/- 115 and 650 +/- 85 ng ml-1 (means +/- SE), respectively, and caused substantial decreases in systemic and coronary vascular resistances, and in aortic pressure, and increases in LV segment shortening, stroke volume and aortic flow. Electrophysiological variables were little affected. At the low infusion rate (plasma concentration 140 +/- 23 ng ml-1) coronary and systemic vasodilatation occurred, but global and regional RV and LV performance were little affected. PR interval increased by 15%. At the higher infusion rate (plasma concentration 282 +/- 33 ng ml-1) coronary and systemic vasodilatation were maintained. Aortic pressure decreased slightly. Whereas LV end-diastolic and end-systolic dimensions remained unchanged, they increased in the RV. In addition, the PR interval increased by 35%, and three animals developed atrioventricular block type I. The data indicate that diltiazem is a potent coronary and systemic vasodilator with little effect on global RV and LV performance. However, at a higher infusion rate RV dimensions clearly tend to increase, and conduction abnormalities develop.

Animals↗

PubMed1991

A morphometric quantitation of developmental changes in elastic fibers in rat lung parenchyma: variability with lung region and postnatal age.

Elastin has long been thought to play a pivotal role in alveolar septal development by providing the structural framework around which new alveoli develop in the immature lung. This theory was derived from observations that the dramatic increase in lung elastin and alveolar septal development occurred during the same time period, days 4 to 13 in the rat. Using stereologic techniques, we evaluated volume density of respiratory tissue in parenchyma and total length of parenchymal elastic fibers in the lungs of neonatal rats ranging in age from 4 to 26 days. Lung tissue was obtained from each of the four right lung lobes and from the upper, middle, and lower regions of the left lung. When changes in these two parameters in the lung as a whole were considered by averaging values for each of the seven regions, a continuous increase was observed in both the volume of parenchymal tissue in parenchyma and the total length of elastic fibers from days 4 to 22. A significant correlation was found between the volume of respiratory tissue in parenchyma and the length of parenchymal elastic fibers from days 4 to 26, supporting the existing theory that a causal relationship exists between these two parameters. A comparison of the ratios of elastic fiber length to volume density of respiratory tissue in parenchyma (Lv/Vrp) from each of the seven lung regions sampled indicated a significant variability in Lv/Vrp within different regions of the same lung. In addition, the effects of postnatal age and lung region on Lv/Vrp were interdependent; the lung regions that differed with respect to the length density of elastic fibers varied with postnatal age.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗

PubMed1982

DNA of herpesvirus pan, a third member of the Epstein-Barr virus-Herpesvirus papio group.

The DNA of herpesvirus pan, a primate B-lymphotropic herpesvirus, shares about 40% well-conserved sequence relatedness with Epstein-Barr virus (EBV) and herpesvirus papio DNAs. Labeled cloned fragments from the EBV recombinant DNA library were cross hybridized to blots of EcoRI, XbaI, and BamHI restriction endonuclease fragments of herpesvirus pan DNA to identify and map homologous sequences in the herpesvirus pan genome. Regions of colinear homology were demonstrated between 6 x 10(6) daltons and 108 x 10(6) daltons in the DNAs. The structural organization of herpesvirus pan DNA was similar to the format of Epstein-Barr virus and herpesvirus papio DNAs. The DNA consists of two domains of largely unique sequence complexity, a segment US of 9 x 10(6) daltons and a segment UL of 88 x 10(6) daltons. US and UL are separated by a variable number of tandem repetitions of a sequence IR (2 x 10(6) daltons). There was homology between DNA which mapped at 26 to 28 x 10(6) daltons and 93 to 95 x 10(6) daltons in UL. The terminal reiteration component, TR, of herpesvirus pan DNA and sequences which mapped to the left of 6 x 10(6) daltons and to the right of 108 x 10(6) daltons had no detectable homology with the corresponding regions of Epstein-Barr virus DNA.

Base Sequence↗

PubMed1995

Non-dominant dorsal-prefrontal activation during chess problem solution evidenced by single photon emission computerized tomography (SPECT).

Expert chess players can recall meaningful chess positions with extraordinary precision in comparison with inexperienced players. We hypothesized, therefore, that their mental performance during chess deliberation could be an appropriate target for single photon emission computerized tomography (SPECT) studies. We studied cerebral activation with 1110 MBq 99mTc-Bicisate SPECT in five expert male chess players during mental solution of a complex chess problem. Region of interest (ROI) analysis, in comparison with average weighted cerebellar counts, showed activation by 10% or more, of the non dominant prefrontal area (right in four dominant right handed players, left in one dominant left handed player) and by 2-6% in the non-dominant middle temporal areas. Maximum variability of ROI analysis versus cerebellar counts in test/retest evaluation is in our laboratory, as in others, 1.5%. Our results are in agreement with neuropsychological studies suggesting that the non-dominant hemisphere is specialized for chess skill, and show that non-dominant prefrontal and temporal lobe activation during chess deliberation can be detected by SPECT.

Adult↗

PubMedDate not supplied

Effects of ganglionic blockade on noradrenaline release and cell injury in the acutely ischemic rat myocardium.

We investigated the mechanisms responsible for ischemia-induced myocardial noradrenaline release in pentobarbitone-anaesthetized rats with left coronary artery occlusion. By means of tissue analysis of catecholamines and the Hillarp-Falck fluorescence histochemical technique for visualizing catecholamines in tissues, we studied the effect of a ganglionic blocker (chlorisondamine 0.1 mg/kg i.v.) on the ischemia-induced changes of the myocardial adrenergic nerve endings. In addition, the myocardial creatine kinase activity and potassium content were determined to estimate the extent of ischemic cell injury. In rats treated with either saline or chlorisondamine, the tissue noradrenaline content of the ischemic left ventricle was markedly reduced after 2.5 h of coronary ligation. In saline-treated rats 0.5 h of ischemia caused a slight decrease in left ventricular noradrenaline content, and this tended to be even less marked in chlorisondamine-treated animals. The changes in catecholamine fluorescence of the acutely ischemic myocardium seen after ganglionic blockade were essentially the same in both groups, but the size of the regions with reduced catecholamine fluorescence was more variable in the chlorisondamine-treated rats. Chlorisondamine caused a reduction in arterial blood pressure and heart rate and tended to reduce the degree of ischemic cell damage. We conclude that in our model the decrease in myocardial noradrenaline content after 2.5 h of ischemia is largely due to a local, nerve impulse--independent release of noradrenaline caused by ischemic changes in the tissue. The acute release of noradrenaline seen during 0.5 h of ischemia may be the combined result of local, ischemia-induced release of noradrenaline and an increased sympathetic nerve activation of the heart.

Animals↗

PubMed2004

The feasibility of measuring three-dimensional facial morphology in children.

OBJECTIVE: An investigation to determine the feasibility of measuring soft tissue morphology in children using a three-dimensional laser-scanning device. DESIGN: Prospective clinical trial. SETTING AND SAMPLE POPULATION: University of Wales, College of Medicine and one secondary school in the South Wales region. Sixty live subjects (30 adults, 30 children) were recruited in the study. EXPERIMENTAL VARIABLES: Laser scanned images of the subjects were obtained under a reproducible and controlled environment with two Minolta Vivid 900 (Osaka, Japan) optical laser-scanning devices assembled as a stereo-pair. A set of left and right scanned images was taken for each subject and each scan took an average of 2.5 s. These scanned images were processed and merged to form a composite three-dimensional soft tissue reproduction of the subjects using commercially available reverse modelling software. OUTCOME MEASURE: The shell deviations between left and right scan of each patient were recorded and analysed for differences. These differences determined whether the subjects could remain still during the time of the scans. RESULTS: The results showed that the mean differences between shell deviations for the adult scans and children scans were 0.25 +/- 0.09 and 0.30 +/- 0.09 mm, respectively. Paired t-tests showed that the mean error between subject groups was 0.05 +/- 0.15 mm indicating that there was no difference between the two subject groups (p = 0.18). CONCLUSION: The technique as described is clinically reproducible for children and adults and can be used for studies assessing facial changes due to growth or clinical intervention.

Adult↗

PubMed1978

Choline acetyltransferase activity in rat heart after transplantation.

Choline acetyltransferase (CAT) catalyzes the biosynthesis of acetylcholine according to the chemical equation: Acetyl-CoA + Choline in equilibrium Acetylcholine + CoA. To demonstrate the neuronal relationship of this enzyme, CAT activity was measured in hearts to which the extrinsic innervation was completely interrupted by extirpation of the heart from a donor animal and transplantation in a heterotopic position into the recipient's abdominal cavity. After the animals were killed at 8 days, enzyme activity in the transplanted hearts was measured and compared with that of the recipient. Choline acetyltransferase activity decreased 98% in the right atrium of the transplanted denervated hearts, 94% in the SA node, 87% in the left atrium, 80% in the right ventricle, and about 50% in the interventricular septum and left ventricle. These data show that sectioning the extrinsic parasympathetic innervation to the heart results in variable decreases in CAT activity, a finding which confirms that CAT activity is related to the extrinsic cholinergic innervation. The extrinsic (preganglionic) component of the parasympathetic system is nonuniform and supplies predominantly the specialized regions of the heart with conduction tissue. The residual enzyme activity is related to intrinsic (postganglionic) parasympathetic neurons. The intrinsic component is uniformly distributed to both specialized and contractile regions of the heart.

Animals↗

PubMed1997

Segmental analysis of color kinesis images: new method for quantification of the magnitude and timing of endocardial motion during left ventricular systole and diastole.

BACKGROUND: We describe a method for objective assessment of left ventricular (LV) endocardial wall motion based on Color Kinesis, a new echocardiographic technique that color-encodes pixel transitions between blood and myocardial tissue. METHODS AND RESULTS: We developed a software that analyzes Color Kinesis images and provides quantitative indices of magnitude and timing of regional endocardial motion. Images obtained in 12 normal subjects were used to evaluate the variability in each index. Esmolol, dobutamine, and atropine were used to track variations in LV function in 14 subjects. Objective evaluation of wall motion was tested in 20 patients undergoing dobutamine stress testing. Regional fractional area change, displacement, and radial shortening were displayed as histograms and time curves. Global function was assessed by calculating magnitude and timing of peak ejection or filling rates and mean time of ejection or filling. Patterns of endocardial motion were consistent between normal subjects. Fractional area change and peak ejection rate decreased with esmolol and increased with dobutamine. Time to peak ejection and mean time of contraction were prolonged with esmolol and shortened with dobutamine. Using atropine, we proved that our findings with dobutamine were not secondary to its chronotropic effects. Dobutamine induced regional wall motion abnormalities in 10 patients in 38 segments diagnosed conventionally. Segmental analysis detected abnormalities in 36 of these 38 segments and in an additional 5 of 322 segments. CONCLUSIONS: Analysis of Color Kinesis images allows fast, objective, and automated evaluation of regional wall motion sensitively enough to evaluate clinical dobutamine stress data. This method has significant potential in the diagnosis of myocardial ischemia.

Adrenergic beta-Agonists↗

PubMed2002

Variability of contractile reserve in hibernating myocardium: dependence on the method of inotropic stimulation.

OBJECTIVE: Contractile reserve during graded beta-adrenergic stimulation identifies viability in patients with left ventricular dysfunction. Nevertheless, contractile reserve is frequently absent in viable, chronically dysfunctional myocardium with reduced resting flow (hibernating myocardium). The goal of this study was to evaluate the mechanisms responsible for limited contractile reserve in hibernating myocardium. METHODS: Pigs were chronically instrumented with a left anterior descending coronary artery (LAD) stenosis to produce hibernating myocardium; and regional flow, function and hemodynamics were assessed during graded beta-adrenergic stimulation (epinephrine). RESULTS: The chronic LAD stenosis produced a critical reduction in coronary flow reserve with regional reductions in resting subendocardial flow (0.69+/-0.05 vs. 1.03+/-0.11 ml/min/g in shams, P<0.05) and wall thickening (2.0+/-0.4 vs. 4.3+/-0.4 mm in shams, P<0.05), consistent with hibernating myocardium. In sham controls, LAD flow and function increased during graded, steady-state increases in epinephrine. Nevertheless, despite similar external determinants of demand in animals with hibernating myocardium, neither subendocardial flow (peak response: 0.66+/-0.14 and peak dose: 0.58+/-0.13 ml/min/g, respectively) nor wall thickening (3.0+/-0.5 and 2.5+/-0.6 mm, respectively) increased during graded epinephrine infusion. However, during a transient epinephrine infusion to the maximum dose used in the graded protocol, flow remained unchanged (0.80+/-0.06 to 0.85+/-0.08 ml/min/g) but wall thickening improved (2.3+/-0.4 to 4.1+/-0.6 mm, P<0.05). CONCLUSIONS: These data indicate that variability in contractile reserve in hibernating myocardium is at least partly related to the protocol used for beta-adrenergic stimulation. The blunted steady-state responses to beta-adrenergic stimulation raise the possibility that, like moderate supply-induced ischemia, an exquisite matching between flow and function develops during moderate demand-induced ischemia. This prevents metabolic deterioration in hibernating myocardium but limits contractile function during increases in the external determinants of myocardial metabolism.

Adrenergic beta-Agonists↗

PubMed1997

Detection of left ventricular systolic and diastolic abnormalities in patients with coronary artery disease by color kinesis.

BACKGROUND: Color kinesis (CK) is a recently developed echocardiographic technique based on acoustic quantification that automatically tracks and displays endocardial motion in real time and has been used in initial studies to improve the evaluation of global and regional wall motion. HYPOTHESIS: For further validation of the use of CK for analysis of segmental ventricular dysfunction, we assessed its sensitivity and specificity for detection of regional systolic and diastolic wall motion abnormalities in patients with coronary artery disease (CAD). METHODS: Two-dimensional (2-D) echocardiography and CK were used to study 15 normal subjects and 63 patients with technically good quality echocardiographic tracings, who underwent coronary arteriography within 1 month of echocardiography. Significant (> 70% luminal diameter stenosis) CAD was present in 50 patients (79%). RESULTS: Color kinesis tracked endocardial motion accurately in 93% of left ventricular segments. Wall motion score, systolic segmental endocardial motion (SEM), and the time of systolic SEM (tSEM) and diastolic (tDEM) segmental endocardial motion were calculated. Intra- and interobserver variability were within narrow limits. SEM and tSEM were significantly lower and tDEM was significantly higher in the patient population than in the control group (p < 0.001). Comparison between CK and 2-D echocardiography showed a correlation coefficient of 0.81 between the two techniques. The score was identically graded in 74% of segments, with concordance of 82% in diagnosing segments as abnormal. Interobserver concordance was 86% for CK (r = 0.85) and 81% for 2-D echocardiography (r = 0.80). The sensitivity and specificity of systolic and diastolic CK parameters for the detection of CAD were 88 and 92% and 77 and 85%, respectively. The positive predictive values were 93 and 96%, respectively, the negative predictive values were 63 and 73%, respectively, and the overall accuracy was 86 and 91%, respectively. CONCLUSIONS: Our data suggest that CK is a feasible and sensitive technique for identifying regional systolic as well as diastolic wall motion abnormalities in patients with CAD.

Adult↗

PubMed2000

Organochlorines and bone mineral density in Swedish men from the general population.

Persistent organochlorines (POCs), such as polychlorinated biphenyls (PCBs) and DDT, are present at relatively high concentrations in food and show estrogenic, anti-estrogenic or anti-androgenic activity in biological test systems. Because bone mineral density (BMD) in men is influenced by sex hormones, we looked for associations between BMD and serum concentrations of POCs in 115 men (mean age 63 years, range 40-75 years) from the general Swedish population. Ten PCB congeners, five DDT isomers, hexachlorobenzene, three hexachlorocyclohexane isomers, trans-nonachlor and oxychlordane were analyzed by gas chromatography. Quantitative bone measurements were performed by dual-energy X-ray absorptiometry at three sites: whole body, the L2-L4 region of the lumbar spine, and the neck region of the proximal femur, as well as by quantitative ultrasound on the left os calcis (broadband ultrasound attenuation (BUA) and speed of sound (SOS)). After adjustment for confounding factors in linear regression analyses we found no strong association between serum concentrations of single POCs and the five BMD and ultrasound variables. When POCs were grouped according to hormonal activity (estrogenic, anti-estrogenic, anti-androgenic) and the study subjects were divided into organochlorine concentration quartiles, a weak association was indicated between increased serum concentrations of p,p'-DDE (antiandrogenic) and decreased BMD, BUA and SOS. This may suggest that p,p'-DDE could cause negative effects on bone density, but the findings might also be due to chance since multiple comparisons were made in the statistical analysis. Overall our results do not suggest that the studied POCs caused major effects on bone density in our study group.

Adult↗

PubMed1999

Inhibitory control of competing motor memories.

The ability to inhibit previously learned visuomotor associations is essential for efficient learning of novel behaviors. While the neural basis of the system that might control interactions between competing motor memories is not known, it has been demonstrated that animals with ventral and orbital prefrontal cortex (PFC) deficits have particular difficulties in learning to withhold responses to previously conditioned sensory stimuli. Here we measured regional cerebral blood flow (rCBF), using positron emission tomography, during learning of a novel motor task that required inhibition of a previously learned motor memory. Subjects (n=24) learned reaching movements in a force field (field A). After a variable time interval, some subjects (n=15) learned to reach in a field with a reversed pattern of forces (field B). When the time interval was short (10 min), learning in field B was coincident with a reactivation of regions that had become initially activated during learning in field A: the left putamen and bilaterally in the dorsolateral PFC. Behaviorally, this was accompanied with perseveration that lasted for hundreds of movements, suggesting an instantiation of the internal model for field A during learning in field B. Neither the reactivation nor the perseveration were observed in a different group of subjects that learned field B at 5.5 h. We found that the regions which significantly differentiated the two groups during learning of B were in the ventrolateral PFC (bilaterally): there were sharp decreases in rCBF here in the 5.5 group but not in the 10-min group. At 5.5 h motor learning again involved the striatum, but this time in the left caudate. Neither the caudate nor the ventral PFC had exhibited learning-related activity in field A. Instead, they showed changes in rCBF during the reversal of the learning problem when the previously acquired motor memory was successfully gated. The results demonstrate that: (1) perseveration of a competing motor memory may be linked to reactivation of the neural circuit that participated in acquiring that memory, and (2) the ventral PFC may play an important role in the inhibitory control of the competing motor memory.

Adult↗

PubMed1998

EEG activity and heart rate during recall of emotional events in hypnosis: relationships with hypnotizability and suggestibility.

The purpose of the present research was to find physiological and cognitive correlates of hypnosis, imaginative suggestibility and emotional experiences. After the administration of a standard hypnotic induction, the EEG and heart rate (HR) were recorded during self-generated happy and sad emotions using a relaxation condition as a control. Physiological recordings were also obtained during three eyes-open and eyes-closed baseline periods: (1) waking rest; (2) early-rest in hypnosis (just after the hypnotic induction); (3) late-rest hypnosis (at the end of hypnotic condition). EEG was recorded at frontal (F3, F4), central (C3, C4), and posterior sites (middle of O1-P3-T5 and O2-P4-T6 triangles). Using log transform of mean spectral amplitude, eight EEG frequency bands (4-44 Hz) were evaluated. High hypnotizable subjects, as compared to the lows, produced a higher theta1 amplitude (4-6 Hz) across both left- and right-frontal and right-posterior areas. These subjects also produced smaller alpha1 amplitude (8.25-10 Hz) over both left and right frontal recording sites. High suggestible subjects, during resting conditions, disclosed higher theta2 (6.25-8 Hz) and alpha1 amplitudes in eyes-closed as compared to an eyes-open condition than did low suggestible subjects. High suggestible subjects also showed, in hypnosis-rest condition, higher 40-Hz amplitudes (36-44 Hz) and HR activity than did low suggestible subjects. Hypnotizability and not suggestibility was found to moderate emotional processing: high hypnotizable individuals self-reported greater levels of emotional experiences than did low hypnotizables especially in terms of negative emotion. High hypnotizables, during processing of emotional material, also disclosed opposite 40-Hz hemispheric asymmetries over anterior and posterior regions of the scalp. These subjects during happiness showed an increased production of 40-Hz activity in the left frontal and central regions of the scalp, while during sadness they showed an increased activity in the right central and posterior regions. The hemispheric asymmetries for relaxation condition were similar, but less marked, to those obtained for happiness. No significant interactions involving both hypnotizability and imaginative suggestibility were found for physiological variables considered in this study. This demonstrates that hypnotizability and suggestibility reflect different underlying psychophysiological activities.

Adult↗

PubMed1993

Inhaled nitric oxide for the adult respiratory distress syndrome.

BACKGROUND: The adult respiratory distress syndrome is characterized by pulmonary hypertension and right-to-left shunting of venous blood. We investigated whether inhaling nitric oxide gas would cause selective vasodilation of ventilated lung regions, thereby reducing pulmonary hypertension and improving gas exchange. METHODS: Nine of 10 consecutive patients with severe adult respiratory distress syndrome inhaled nitric oxide in two concentrations for 40 minutes each. Hemodynamic variables, gas exchange, and ventilation-perfusion distributions were measured by means of multiple inert-gas-elimination techniques during nitric oxide inhalation; the results were compared with those obtained during intravenous infusion of prostacyclin. Seven patients were treated with continuous inhalation of nitric oxide in a concentration of 5 to 20 parts per million (ppm) for 3 to 53 days. RESULTS: Inhalation of nitric oxide in a concentration of 18 ppm reduced the mean (+/- SE) pulmonary-artery pressure from 37 +/- 3 mm Hg to 30 +/- 2 mm Hg (P = 0.008) and decreased intrapulmonary shunting from 36 +/- 5 percent to 31 +/- 5 percent (P = 0.028). The ratio of the partial pressure of arterial oxygen to the fraction of inspired oxygen (PaO2/FiO2), an index of the efficiency of arterial oxygenation, increased during nitric oxide administration from 152 +/- 15 mm Hg to 199 +/- 23 mm Hg (P = 0.008), although the mean arterial pressure and cardiac output were unchanged. Infusion of prostacyclin reduced pulmonary-artery pressure but increased intrapulmonary shunting and reduced the PaO2/FiO2 and systemic arterial pressure. Continuous nitric oxide inhalation consistently lowered the pulmonary-artery pressure and augmented the PaO2/FiO2 for 3 to 53 days. CONCLUSIONS: Inhalation of nitric oxide by patients with severe adult respiratory distress syndrome reduces the pulmonary-artery pressure and increases arterial oxygenation by improving the matching of ventilation with perfusion, without producing systemic vasodilation. Randomized, blinded trials will be required to determine whether inhaled nitric oxide will improve outcome.

Adolescent↗

PubMed2003

Progressive non-fluent aphasia is associated with hypometabolism centred on the left anterior insula.

Progressive non-fluent aphasia (PNFA) is a syndrome in which patients lose the ability to communicate fluently in the context of relative preservation of single word comprehension and non-linguistic cognitive abilities. Neuroimaging in case studies with PNFA has failed to identify a consistent neural substrate for the language disorder. In this study of a group of patients (n=10) whose presenting complaint was progressive dysfluency, resting cerebral metabolism was measured using [18F]fluorodeoxyglucose-PET and analysed with the technique of statistical parametric mapping (SPM). Regional atrophy was assessed with voxel-based morphometry (VBM). Seven patients had a 'pure' PNFA syndrome, while the remaining three had additional features of a more pervasive dementia. Compared with controls, the patients showed hypometabolism in several regions that, most notably, included the left anterior insula/frontal opercular region. The VBM analysis revealed only one small area of atrophy in the left peri-Sylvian region. Analysis of the pure PNFA cases (n=7) relative to controls yielded qualitatively similar results to those of the whole group, suggesting that these cases were also at risk of a more generalized dementia, a finding borne out in subsequent follow-up of two cases to date. The PNFA group was then compared with a group with Alzheimer's disease (n=10) whose clinical profile did not include non-fluent aphasic features. In this analysis, the only persisting hypometabolic region was that centred over the left anterior insula. VBM did not identify any regional differences in atrophy between PNFA and Alzheimer's disease. In the light of current theories of fluent language production, the findings offer anatomical evidence that the breakdown in fluency is due to a motor articulatory planning deficit (speech apraxia) combined with a variable degree of agrammatism.

Aged↗