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PubMed1983

The effect of halothane anesthesia on myocardial necrosis, hemodynamic performance, and regional myocardial blood flow in dogs following coronary artery occlusion.

The effect of halothane anesthesia on myocardial necrosis resulting from coronary artery ligation was examined in 28 anesthetized mongrel dogs. In 18 dogs, the left anterior descending coronary artery (LAD) was ligated immediately proximal to the first apical diagonal branch, and 1 h later the dogs were assigned randomly either to receive halothane, 0.5-1.0% inspired in room air for 12 h (n = 10) or to awaken without further intervention (control, n = 8). Infarct size was measured by staining the myocardium with triphenyl tetrazolium chloride 24 h after LAD ligation. Infarct size in halothane-treated dogs was 17.8 +/- 2.0% of the left ventricle, compared with 27.3 +/- 3.3% in control dogs (P less than 0.05). Myocardial salvage was present transmurally but was greatest in epicardial regions. In 10 additional dogs, hemodynamic variables (heart rate, arterial pressure, left ventricular end-diastolic pressure, peak left ventricular dP/dt, tension-time index, and rate-pressure product) were measured or calculated, and radionuclide-labeled microspheres were injected for measurement of cardiac output and regional myocardial blood flow (RMBF). Thirty minutes after LAD ligation and after initial hemodynamic measurements and microsphere injection, these dogs were assigned randomly to receive either halothane, 1.0%, inspired in room air (n = 5) or no intervention (control, n = 5). After 15 min of halothane inhalation (45 min after LAD ligation in control dogs), measurements were repeated. Halothane inhalation reduced heart rate, arterial pressure, and indexes of left ventricular contractile and pump performance. During halothane treatment, RMBF declined in normal myocardium but not in ischemic regions, while neither normal nor ischemic zone RMBF changed in control dogs. Systemic vascular resistance was unchanged in either group. Thus, halothane was associated with a 35% smaller myocardial infarct, transmural myocardial salvage, reduced heart rate, reduced left ventricular contractile and pump performance, reduced RMBF to nonischemic regions, and unchanged RMBF in the ischemic myocardium.

Anesthesia, Inhalation↗

PubMed2007

Advanced quantitative echocardiography in arrhythmogenic right ventricular cardiomyopathy.

BACKGROUND: Arrhythmogenic right ventricular (RV) cardiomyopathy (ARVC) is a regional disease of the RV myocardium with variable degrees of left ventricular involvement. Three-dimensional echocardiography and Doppler tissue imaging (DTI) are new echocardiographic modalities for the evaluation of global and regional function, but the diagnostic potential remains to be assessed. METHODS: Twenty patients with previously established ARVC were evaluated by 3-dimensional echocardiography and DTI, and compared with 32 age- and sex-matched control subjects. RESULTS: Using 3-dimensional echocardiography, patients with ARVC had a decreased RV ejection fraction (0.47 +/- 0.08 vs 0.53 +/- 0.05, P < .01), and a decreased peak lateral systolic annular velocity by pulsed wave imaging of both the RV (11.9 +/- 2.6 vs 15.1 +/- 3.7 cm/s, P < .01) and the left ventricle (7.0 +/- 2.6 vs 9.5 +/- 1.9 cm/s, P < .01). DTI showed decreased regional systolic strain, but with wide variation in the measurements. CONCLUSION: Three-dimensional echocardiography identifies decreased RV ejection fraction in ARVC. Assessment of regional contractility by DTI is limited by wide variation. Echocardiographic evaluation of the longitudinal motility appears to be a sensitive marker of preclinical left ventricular involvement.

Adult↗

PubMed1998

The genomic sequence analysis of the left and right species-specific terminal region of a cowpox virus strain reveals unique sequences and a cluster of intact ORFs for immunomodulatory and host range proteins.

Sequencing and computer analysis of the left (52,283 bp) and right (49,649 bp) variable DNA regions of the cowpox virus strain GRI-90 (CPV-GRI) has revealed 51 and 37 potential open reading frames (ORFs), respectively. Comparison of the structure-function organization of these DNA regions of CPV-GRI with those previously published for corresponding regions of genomes of vaccinia virus, strains Copenhagen (VAC-COP) and Western Reserve (VAC-WR); and variola major virus, strains India-1967 (VAR-IND), Bangladesh-1975 (VAR-BSH); and alastrim variola minor virus, strain Garcia-1966 (VAR-GAR), was performed. Within the left terminal region under study, an extended DNA sequence (14,171 bp), unique to CPV, has been found. Within the right region of the CPV-GRI genome two segments, which are unique to CPV DNA (1579 and 3585 bp) have been found. Numerous differences have been revealed in the genetic structure of CPV-GRI DNA regions, homologous to fragments of the genomes of the above-mentioned orthopoxvirus strains. A cluster of ORFs with structural similarity ot immunomodulatory and host range function of other poxviruses have also been detected. A comparison of the sequences of ORF B, crmA, crmB, crmC, IMP, and CHO hr genes of CPV Brighton strain (CPV-BRI) with the corresponding genes in strain GRI-90 have revealed an identity at the amino acid level ranging from 82 to 96% between the two strains. The findings are significant in light of the recent demonstration of CPV as an important poxvirus model system to probe the precise in vivo role(s) of the unique virally encoded immunomodulatory proteins. Also, the presence of a complete and intact repertoire of immunomodulatory proteins, ring canal proteins family, and host range genes indicates that CPV may have been the most ancient of all studied orthopoxviruses.

Amino Acid Sequence↗

PubMed2006

A systematic multiple stage surgical approach for attainment of satisfactory and favourable surgical results in an extremely severe von Recklinghausen's disease, elephantiasis neurofibromatosa.

This disease was first described by von Recklinghausen and Festscher and has been known as the von Recklinghausen's disease or neurofibromatosis (NF). Numerous articles have been published on this subject where majority of the authors have stressed their difficulty in achieving favourable surgical results. This disease is pathologically accepted to be of neuroectodermal origin with a positive family history in approximately 50% of the cases, autosomal dominant trait and is known to involve the periorbital regions, orbit (preoperative CT scan: upper left and right photographs), temporal region to a variable extent, mid-facial region to the mandibular region. The indicated treatment for this disease is surgery including cranio-maxillofacial surgery even though re-evaluation of the conventional methods of surgery should be considered. This particular case is an extremely difficult and challenging case for any reconstructive plastic surgeon and required extensive preoperative planning. The systematic multiple stage surgical approach for an extremely severe von Recklinghausen's disease, elephantiasis neurofibromatosa is presented and discussed in detail.

Anesthesia, General↗

PubMed1999

Herpesvirus ateles gene product Tio interacts with nonreceptor protein tyrosine kinases.

Herpesvirus ateles is a gamma-2-herpesvirus which naturally infects spider monkeys (Ateles spp.) and causes malignant lymphoproliferative disorders in various other New World primates. The genomic sequence of herpesvirus ateles strain 73 revealed a close relationship to herpesvirus saimiri, with a high degree of variability within the left terminus of the coding region. A spliced mRNA transcribed from this region was detected in New World monkey T-cell lines transformed by herpesvirus ateles in vitro or derived from T cells of infected Saguinus oedipus. The encoded viral protein, termed Tio, shows restricted homology to the oncoprotein StpC and to the tyrosine kinase-interacting protein Tip, two gene products responsible for the T-cell-transforming and oncogenic phenotype of herpesvirus saimiri group C strains. Tio was detectable in lysates of the transformed T lymphocytes. Dimer formation was observed after expression of recombinant Tio. After cotransfection, Tio was phosphorylated in vivo by the protein tyrosine kinases Lck and Src and less efficiently by Fyn. Stable complexes of these Src family kinases with the viral protein were detected in lysates of the transfected cells. Binding analyses indicated a direct interaction of Tio with the SH3 domains of Lyn, Hck, Lck, Src, Fyn, and Yes. In addition, tyrosine-phosphorylated Tio bound to the SH2 domains of Lck, Src, or Fyn. Thus, herpesvirus ateles-encoded Tio may contribute to viral T-cell transformation by influencing the function of Src family kinases.

Amino Acid Sequence↗

PubMedDate not supplied

Reduction in regional cerebral metabolic rate of oxygen during human aging.

To investigate changes in cerebral circulation and oxygen metabolism during aging, regional cerebral blood flow (rCBF), regional oxygen extraction fraction (rOEF), regional cerebral metabolic rate of oxygen (rCMRO2) and regional cerebral blood volume (rCBV) were measured using the 15O labelled gas inhalation technique and a multi-slice positron emission tomograph (PET) in 22 healthy volunteers, aged from 26 to 64 years old. The measurements were performed with subjects at rest, without sensory deprivation. The values of rCBF, rOEF, rCMRO2 and rCBV in more than 40 anatomical structures of the brain were evaluated by studying a large series of scans in each region of interest after the functional PET image had been anatomically identified using x-ray computed tomographic images corresponding to the PET. In mean gray values, only CMRO2 showed significant reduction with age. rCMRO2 significantly decreased with age only in the supratentrium, and much more in the left hemisphere. Especially remarkable was rCMRO2 reduction in the left caudate region. Both CBF and OEF were variable and less age-dependent. It was concluded that CMRO2 could be reflecting healthy brain aging most properly.

Adult↗

PubMed1982

An improved method of right ventricular gated equilibrium blood pool radionuclide ventriculography.

Gated blood pool radionuclide ventriculography provides a means for obtaining repeated studies of both cardiac ventricles with a single dose of radionuclide. Quantitative assessment of right ventricular (RV) function using this technique has been complicated by several technical problems. We describe a new method of RV blood pool analysis which attempts to solve these problems using well-established concepts for left ventricular (LV) blood pool analysis: (1) variable regions of interest; (2) computer edge detection with operator intervention; and (3) computer selected background. Results showed a strong linear correlation between gated first pass RV ejection fraction (RVEF) and the gated blood pool RVEF (n = 22; r = 0.93; blood pool RVEF = 0.03 + 0.89 X first pass RVEF; Sy.x = 0.04). There was also a strong linear correlation between LV and RV stroke counts in patients without valvular regurgitation, intracardiac shunts, or ventricular aneurysms (n = 19; r =0.86; RV counts = 72 + 0.94 X LV counts; Sy.x = 116). In terms of both of these validation standards this method proved superior to three published methods of RV blood pool analysis that used hand-drawn regions, and is suitable for analysis of rest, exercise, and intervention studies of RV function.

Adult↗

PubMed1996

Regional left atrial stasis during atrial fibrillation and flutter: determinants and relation to stroke.

OBJECTIVES: This study sought to 1) determine the location of left atrial stasis during atrial arrhythmia; 2) define the degree of stasis associated with significant risk of stroke; and 3) identify clinical or transthoracic echocardiographic data useful for predicting left atrial stasis. BACKGROUND: Prior studies suggest that stroke during atrial arrhythmia is related to stasis in either the body of the left atrium or the appendage. Recent data indicate that appendage stasis is associated with appendage thrombus formation, but stroke during atrial arrhythmia occurs frequently in the absence of appendage stasis. METHODS: Blood flow velocity was measured in multiple sites in the body of the left atrium and in the appendage by transesophageal pulsed wave Doppler echocardiography in 89 patients with atrial fibrillation or flutter. Regional velocities were related to the frequency of probable embolic stroke and to clinical and transthoracic echocardiographic variables. RESULTS: The lowest velocity region was either the posterior left atrium or the appendage. Stroke frequency increased progressively and steeply with velocity < 15 cm/s in either region; this cutoff value had an 87% sensitivity and 40% specificity for stroke. Factors related to stasis were low left atrial ejection fraction, mitral regurgitation < 3+, fibrillation (vs. type I flutter), left ventricular dilation and mitral valve area < 2.0 cm2. CONCLUSIONS: Posterior left atrial stasis appears to be as important as appendage stasis for the risk of stroke, which increases steeply with lower blood flow velocity in either region. Patients likely to have severe stasis during atrial arrhythmia are those with left ventricular dilation and low atrial ejection fraction accompanying left atrial dilation. Direct measurement of atrial velocity by transesophageal echocardiography appears to be useful for the identification of patients at risk for stroke during atrial arrhythmia.

Aged↗

PubMed1985

Artifactual regional gray level variability in contrast-enhanced two-dimensional echocardiographic images: effect on measurement of the coronary perfusion bed.

The purpose of this study was to determine the extent of regional variability of image echocardiographic amplitude (expressed as gray level variability) in contrast-enhanced two-dimensional echocardiographic images, and to assess the effect of such baseline gray level variability on quantitation of the coronary perfusion bed. In 10 anesthetized closed chest dogs, short-axis papillary muscle echocardiographic images were obtained during control preinjection conditions and during injection of three contrast agents into the left main coronary artery with and without circumflex artery occlusion. Regional echocardiographic amplitude variation was measured by computer-based videodensitometric analysis of mean gray levels in four myocardial regions after cavity (background) gray level subtraction. To determine the effect of regional gray level variability on quantitation of the coronary perfusion bed, the contrast-enhanced left anterior descending artery perfusion bed was measured by two methods. The circumferential method ignored myocardial contrast inhomogeneity by measuring the circumferential extent of contrast enhancement, whether or not the enhancement by contrast medium extended transmurally. The exact method measured only the area of myocardium actually enhanced by contrast medium, which often did not extend transmurally. The perfusion beds determined by the two echocardiographic methods were compared with the anatomic perfusion bed determined by postmortem barium-gelatin coronary arteriography. Regional gray levels varied qualitatively and quantitatively in the control state (before contrast injection), with lateral regions being less bright than axial regions. After injection of contrast medium, brightness increased in all regions, the axial regions brightening most.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed2001

Mapping cortical asymmetry and complexity patterns in normal children.

This study reports the first comprehensive three-dimensional (3D) maps of cortical patterns in children. Using a novel parametric mesh-based analytic technique applied to high-resolution T1-weighted MRI scans, we examined age (6-16 years) and gender differences in cortical complexity (the fractal dimension or complexity of sulcal/gyral convolutions) and asymmetry of 24 primary cortical sulci in normally developing children (N=24). Three-dimensional models of the cerebral cortex were extracted and major sulci mapped in stereotaxic space. Given the documented age-related changes in frontal lobe functions and several neuroimaging studies that have reported accompanying volumetric changes in these regions, we hypothesized that, with age, we would find continued modifications of the cerebrum in frontal cortex. We also predicted that phylogenetically older regions of the cerebrum, such as olfactory cortex, would be less variable in anatomic location across subjects and with age. Age-related increases in cortical complexity were found in both left and right inferior frontal and left superior frontal regions, possibly indicating an increase in secondary branching with age in these regions. Moreover, a significant increase in the length of the left inferior frontal sulcus and a posterior shifting of the left pre-central sulcus was associated with age. Three-dimensional asymmetry and anatomic variability maps revealed a significant left-greater-than-right asymmetry of the Sylvian fissures and superior temporal sulci, and increased variance in dorsolateral frontal and perisylvian areas relative to ventral regions of the cortex. These results suggest increases in cortical complexity and subtle modifications of sulcal topography of frontal lobe regions, likely reflecting ongoing processes such as myelination and synaptic remodeling that continue into the second decade of life. More studies in a larger sample set and/or longitudinal design are needed to address the issues of normal individual variation and sulcal development.

Adolescent↗

PubMed2002

Early anti-remodeling effect of labetalol in the congestive heart failure model induced by aortic constriction in the guinea pig.

We investigated the effects of the beta1-beta2-alpha1-blocker, labetalol, in the congestive heart failure (CHF) model induced by aortic constriction in the guinea pig. One hundred days after aortic constriction, 52 animals were given either placebo, labetalol 2 mg/kg/d, or labetalol 20 mg/kg/d for 60 days. Eighteen sham-operated animals were used as controls. Investigations were performed at the end of the treatment period. Compared with sham-operated animals, banded animals receiving placebo showed signs of overt CHF with cardiac, systemic and regional (mesenteric and femoral) hemodynamic dysfunction, and pulmonary and hepatic congestion. An increase in whole heart, atria, and left and right ventricle weights associated with left ventricular cavity enlargement and left and right ventricular wall thickening indicated a remodeling process. Compared with placebo, labetalol did not significantly modify cardiac, systemic, or regional hemodynamic variables but significantly decreased pulmonary and hepatic congestion. Labetalol significantly reduced left ventricular cavity area (-10 and -20% after 2 and 20 mg/kg, respectively) and left ventricular (-4 and -16%) and right ventricular (-4 and -19%) wall thickness. In conclusion, labetalol induced partial regression of cardiac remodeling before hemodynamic improvement. This early anti-remodeling effect could play a role in the favorable effects observed with beta1-beta2-alpha1-blockers in humans.

Adrenergic beta-Antagonists↗

PubMed1993

Heterogeneity of the early outward current in ventricular cells isolated from normal and hypertrophied rat hearts.

1. The nature, magnitude and kinetics of the 4-aminopyridine-sensitive early outward current (Ito) were analysed in isolated ventricular myocytes from the septum, the apex and the left ventricular free wall of rat ventricles using the whole-cell voltage clamp method. The modulatory effect of pressure overload-induced cardiac hypertrophy on the regional variations of Ito was assessed in each topographical class of cells. 2. Voltage clamp experiments were performed at room temperature (20-25 degrees C) in the absence of Na+ on both sides of the membrane and in the presence of 3 mM CoCl2. Ito was studied from a holding potential of -80 mV and determined by subtraction of total outward currents elicited by the same protocols in the presence of 3 mM 4-aminopyridine (4-AP) from those obtained in its absence. 3. In normal hearts, membrane passive properties were very similar in each topographical class of cells. Our results confirmed that the predominant early outward current in rat ventricular cells was 4-AP-sensitive, time and voltage dependent, and demonstrated that the magnitude of the current varied on a regional basis: current density of Ito in left ventricular free wall cells (30.1 +/- 9.2 pA/pF at +60 mV) was larger than in apex cells (20.2 +/- 1.7 pA/pF) or in septum cells (11.9 +/- 3.3 pA/pF). We noticed a larger variability in data from left ventricular free wall compared with other regions. 4. No shift in steady-state voltage dependence of Ito activation and inactivation was found. However, the maximal computed chord conductances were (in microS/pF): 0.18 +/- 0.07 for left ventricular free wall cells, 0.13 +/- 0.02 for apex cells, and 0.08 +/- 0.02 for septum cells. These findings might reflect a differential distribution in functional channel densities. 5. No difference in voltage-dependent Ito activation kinetics was present with respect to topography. However, inactivation time constants in septum were longer than those of both other groups. 6. Left ventricular hypertrophy was induced by abdominal aortic constriction and its effects compared to the findings from normal rats. Hypertrophied cells had similar resting potentials but higher capacitance values than normal cells. Although Ito magnitude appeared not to be modified, the current density-voltage curves were slightly shifted to more positive potentials and significantly decreased as compared to normal cells (in pA/pF, at +60 mV): 8.4 +/- 5.0 in the left free wall group, 11.6 +/- 2.0 in the apex group, and 3.8 +/- 1.5 in the septum group.(ABSTRACT TRUNCATED AT 400 WORDS)

4-Aminopyridine↗

PubMedDate not supplied

Quantitative echocardiographic analysis of global and regional left ventricular function: a problem revisited.

We recorded two-dimensional echocardiograms simultaneously with the respiration measurements of 20 normal subjects and 20 patients with anterior myocardial infarction. The apical long-axis and four-chamber views were quantitatively analyzed. Measurement variability of global ejection fraction and regional ejection fraction of 100 regions was calculated during inspiration and at end-expiration for two observers. To minimize variability, the endocardial contour was redefined and traced with an improved computer-assisted tracing system. Variability (absolute mean difference) between two beats at end-expiration was significantly less than during inspiration (p less than 0.05): for ejection fraction the variability at end-expiration was 3.4% and the variability during inspiration was 6.4% (mean, 54%; SD, 7%); for regional ejection fraction the variability at end-expiration was 11.8% and the variability during inspiration was 21.5% (mean, 56%; SD, 15%). Intraobserver and interobserver variability values of one beat at end-expiration for ejection fraction were 3.1% and 3.8%, respectively, and 9.5% and 12.8%, respectively, for regional ejection fraction. Variability in patients with myocardial infarction was comparable. This method of recording respiration and analyzing left ventricular function at end-expiration, with a new contour definition and tracing system, provides a measurement variability that is considerably less than that reported in previous echocardiographic studies and that is comparable to angiographic methods.

Adult↗

PubMed1989

Prolonged abnormalities of left ventricular diastolic wall thinning in the "stunned" myocardium in conscious dogs: time course and relation to systolic function.

Myocardial reperfusion after reversible ischemia is known to be associated with prolonged abnormalities of systolic contractile function (myocardial "stunning"). However, no information is available regarding the recovery of diastolic function in the stunned myocardium in the conscious state. Accordingly, 10 conscious dogs instrumented with pulsed Doppler thickening probes underwent a 15 min occlusion of the left anterior descending coronary artery followed by 7 days of reperfusion. Regional systolic function was assessed as net systolic thickening fraction. Left ventricular regional diastolic properties were estimated from two variables: the mean rate to half end-diastolic thinning and the late diastolic thinning fraction. Both indexes of diastolic function remained severely impaired after restoration of flow. In general, the recovery of the mean rate to half end-diastolic thinning and of the late diastolic thinning fraction paralleled the recovery of systolic thickening, but the impairment of the mean rate to half end-diastolic thinning was more marked than that of the late diastolic thinning fraction. At 4 h of reperfusion, the values for the mean rate to half end-diastolic thinning and the late diastolic thinning fraction (expressed as percent of baseline) were 57 +/- 5% (p less than 0.001 versus baseline) and 79 +/- 7% (p less than 0.05), respectively, whereas systolic thickening fraction averaged 52 +/- 10% (p less than 0.001). At 24 h, the mean rate to half end-diastolic thinning and the late diastolic thinning fraction were no longer significantly different from baseline, whereas systolic thickening fraction remained decreased at 82 +/- 4% (p less than 0.001) and returned to control values by 48 h. This study demonstrates the presence of profound, prolonged abnormalities of regional diastolic wall thinning after a brief episode of ischemia in the conscious state and expands the concept of myocardial stunning from the traditional notion of impaired systolic performance to that of a global derangement in mechanical function that involves both systolic and diastolic properties.

Animals↗

PubMed1988

Role of endogenous prostacyclin in myocardial blood flow regulation distal to a severe coronary stenosis.

To test the hypothesis that endogenous prostacyclin is required to maintain reduced arteriolar tone distal to a severe coronary arterial stenosis under basal conditions and during challenge with a vasoconstrictor eicosanoid such as thromboxane A2 10 closed chest, domestic swine were prepared with an artificial stenosis, which reduced the luminal diameter of the left anterior descending coronary artery by 80%. Haemodynamic variables, regional myocardial blood flow (microsphere method), and lactate metabolism were measured at control (1); after infusion of U46619 (thromboxane A2 mimetic) distal to the stenosis at 1 microgram.min-1 for 10 min and 5 micrograms.min-1 for 10 min; at control (2); after indomethacin infusion distal to the stenosis; and after repeat infusion of U46619. At the end of the study the animal hearts were removed and their coronary vessels harvested for in vitro determination of prostacyclin (PGI2) production. Regional myocardial blood flow in all layers of the heart distal to the stenosis did not change compared with control during the initial 1 microgram.min-1 dose of U46619 but was reduced significantly after the 5 micrograms.min-1 dose (approximately 20% vs control). Distal zone flow (all layers) returned to baseline at control (2) and remained unchanged after indomethacin infusion. Although distal zone flows were reduced significantly in response to the second 5 micrograms.min-1 dose, the reduction in each layer after indomethacin was comparable to that observed with the 5 micrograms.min-1 dose before indomethacin infusion. Finally, the in vitro production of PGI2 by coronary vessels was considerably impaired by indomethacin infusion.(ABSTRACT TRUNCATED AT 250 WORDS)

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗

PubMed2004

Contrast echocardiography: clinical utility for the evaluation of left ventricular systolic function.

Despite continued improvements in imaging technology, transthoracic echocardiography does not reliably provide images adequate for interpretation in all patients. In these patients, the administration of ultrasound contrast agents can markedly enhance the diagnostic utility of the test. Contrast echocardiography relies on the ultrasound detection of contrast agents composed of encapsulated microbubbles that are generally smaller than red blood cells. Intravenous administration of microbubble contrast agents results in left ventricular opacification and facilitates delineation of the endocardial border. This procedure has been shown to consistently increase the number of myocardial segments that can be interpreted, to improve accuracy of assessing regional and global left ventricular function, to decrease interinterpreter variability, to increase interpreter confidence, and to be a cost-effective strategy. Accordingly, patient selection for contrast echocardiography should be based not only on adequacy of the baseline images, but also on the clinical question being asked.

Chemistry, Pharmaceutical↗

PubMed1996

Characterization of a large chromosomal "high-pathogenicity island" in biotype 1B Yersinia enterocolitica.

Pathogenic Yersinia spp. can be subdivided into highly pathogenic (high-pathogenicity) and low-pathogenicity strains. Several genes specific for the high-pathogenicity strains are clustered on a chromosomal fragment designated a "high-pathogenicity island" (HPI). In the present work, the HPI of biotype 1B strain Ye 8081 of Y. enterocolitica was characterized. We demonstrate important differences from the HPI of Y. pestis. The HPI of Y. enterocolitica is smaller (45 kb) and is not flanked by insertion sequences. A copy of the gene coding for the tRNA-Asn is present at one extremity of the HPI and may, as in uropathogenic Escherichia coli, participate in the excision of the island. In addition to the genes encoding the yersiniabactin-pesticin receptor and the high-molecular-weight protein 2, four repeated sequences are present on the HPI of Y. enterocolitica. At least two of them are insertion elements: previously described IS1328 and newly characterized IS1400. Comparison of the HPI of strain Ye 8081 with that of other Y. enterocolitica strains of biotype 1B indicates that most of the island is conserved, apart from 15 kb at the left-hand end which is variable, especially in the region where three repeated sequences are clustered.

Amino Acid Sequence↗

PubMed1971

Closed head trauma and aphasia.

A prospective study has been done on the relationship between closed head trauma and aphasia. The most frequent type of aphasia seen after closed head injury is an anomic aphasia. This aphasia is often associated with other defects of higher cortical function. The second most common type of aphasia is a Wernicke's aphasia. Other types of aphasia were not seen in this study. The areas of the head which when injured produce aphasia are the right orbitofrontal region and the left temporoparietal region. The prognosis for recovery appeared highly variable.

Adult↗