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At least 487 records · Page 27Linked to original sources

Morphology of left anterior descending coronary territory lesions as a predictor of anterior myocardial infarction: a CASS Registry Study.

Despite a growing awareness of the correlation of coronary artery stenoses morphology with clinical syndromes, no comprehensive, prospective analysis of the implications of stenosis morphology on risk of myocardial infarction has been reported. Angiograms from 118 patients, representative of the 4.9% of medically treated Coronary Artery Surgery Study (CASS) patients who during subsequent 3 year follow-up study had an anterior myocardial infarction, were matched on the basis of arteriographic anatomy and disease with 141 patients who did not have an anterior infarction. Angiograms from these 259 patients with 557 left anterior descending artery stenoses were reviewed without knowledge of clinical outcome. Conditional regression analyses were performed to determine the importance of stenosis morphology, relative to computer-determined stenosis severity and other clinical variables, in the prediction of risk of infarction. Univariate analysis revealed luminal roughness (odds ratio 4.5; p = 0.001) and lesion length (odds ratio 1.7 per unit length; p = 0.007) to be highly correlated with future risk of infarction. Multivariate analysis revealed left anterior descending artery percent stenosis greater than or equal to 50%, lesion roughness, left circumflex artery stenosis and smoking, in that order, to be predictive of anterior myocardial infarction, whereas 22 other morphologic variables were not independently predictive of outcome. The importance of stenosis roughness may relate to its propensity for thrombogenesis and should be considered in clinical decision making.

Angiography↗

Computer graphics editor GSE and some of its applications in morphology.

A simple, vector-based graphics editor, designed for experimental data presentation, schematics, large structured chemical formulae etc. in a modest IBM PC, MS DOS environment is described. Its applications in semi-automatic image analysis, especially in the implementation of design-based stereological methods for estimating global geometrical characteristics of studied samples and in 3D volume reconstruction from serial sections are discussed.

Computer Graphics↗

[Method of studying renal morphology in hypertensive patients with and without renal artery stenosis].

UNLABELLED: Although the size of the kidney is still the most commonly used as morphological parameter, it is not enough sensitive for early detection of ischemic nephropathy. PURPOSE: To study a novel method of renal morphology analysis using spiral computed tomography angiography (CTA) in hypertensive patients with or without unilateral atheromatous renal artery stenosis (RAS). METHODS: Forty-nine hypertensive patients suspected RAS underwent spiral CTA. Arteriography showed significant RAS in 26 patients. Renal length, 3 upper and 3 lower cortical thicknesses were measured in 46 control kidneys (C) i.e. 23 patients without RAS (group 1), in 26 stenosed (S) and in 26 opposite kidneys (OPP) i.e. 26 patients with unilateral RAS (group 2). Mean cortical thickness (MCT), cortical area (CA), medullary length (ML) were calculated in the same groups. The reproducibility and agreement of measurements were investigated in two groups. The demographic parameters (age, sex, bodymass index, and history of hypertension) were correlated with morphological parameters in group 1. RESULTS: The reproducibility and agreement of measurements were confirmed (R2 = 0.53 to 0.93) except for anterosuperior thickness. The C kidneys were of comparable morphology: MCT (mm) = 9.1 +/- 0.6; 9.2 +/- 1.0, CA (mm2) = 950 +/- 119; 934 +/- 157, ML (mm) = 85 +/- 11. In group of Opp kidneys, MCT = 7.9 +/- 1.4 mm, CA = 806 +/- 210 mm2, ML = 84 +/- 13 mm. In group of S kidneys, MCT = 6.6 +/- 1.6 mm, CA = 612 +/- 193 mm2, ML = 77 +/- 14 mm. Demographic parameters were not correlated to renal morphology. CONCLUSION: Spiral CTA is a suitable method to study renal morphology. Cortical thickness and medullary length could be used to obtain a reliable diagnosis of early ischemic nephropathy.

Adult↗

Computerized automated morphometric assay including frequency estimation of pentachlorophenol induced nuclear anomalies (micronucleus) in catfish Heteropneustes fossilis.

An in vivo study of the effects of pentachlorophenol was carried out with a pre-acclimatized fish species, Heteropneustes fossilis, using four sub-lethal concentrations, 0.1, 0.2, 0.3 and 0.4 ppm, and three sampling times, 48, 72 and 96 h. Cytogenetic preparations were stained by the haematoxylin-eosin technique. The incidence of micronuclei was scored by a manual and an automated method. Small-sized micronuclei appeared in the cytoplasm in addition to the main nucleus. The frequency of micronucleated erythrocytes peaked at 4 days (96 h) exposure. The percentage of single micronuclei increased with longer exposures. The Mann-Whitney U test showed all micronuclei frequencies were significantly different from control (P<0.05). No statistical difference was observed between scores obtained by the manual and automated methods. A linear relationship between the percentage of micronucleated erythrocytes and dose was confirmed at all levels. Computer image analysis of morphological variations of erythrocytes indicated a 1:5 ratio of micronuclei and main nucleus accompanied by a reduction in cell volume by 600 dot units. Pentachlorophenol-mediated genotoxicity was confirmed in this fish for the first time. Possible consequences of genotoxicity and cytotoxicity are discussed.

Animals↗

The significance of microemboli detection by means of transcranial Doppler ultrasonography monitoring in carotid endarterectomy.

PURPOSE: Carotid endarterectomy (CEA) performed with continuous transcranial Doppler monitoring provides a unique opportunity to determine the number of cerebral microemboli and to relate their occurrence to the surgical technique. The purpose of this study was to assess in CEA the impact of cerebral microembolism on clinical outcome and brain architecture. We also evaluated the influence of the audible transcranial Doppler signal on the surgeon and his or her technique. METHODS: In a prospective series of 301 patients, CEA was monitored with electroencephalography and transcranial Doppler ultrasonography of the ipsilateral middle cerebral artery. Preoperative and intraoperative risk factors were entered in a logistic regression analysis program to assess their correlation with cerebral outcome. To evaluate the impact of cerebral microembolism on brain architecture, we compared preoperative and postoperative computed tomography scans or magnetic resonance images of the brain in two subgroups of 58 and 40 patients, respectively. RESULTS: Seven (2.3%) patients had intraoperative transient ischemic symptoms, three (1%) had intraoperative strokes, 1 (0.3%) had transient ischemic symptoms after operation, and 10 (3.3%) had postoperative strokes. Four (1.3%) patients died. Microemboli (> 10) noticed during dissection were related to both intraoperative (p < 0.002) and postoperative (p < 0.02) cerebral complications. Microemboli that occurred during shunting were also related to intraoperative complications (p < 0.007). Microembolism never resulted in new morphologic changes on postoperative computed tomography scans. On the contrary, the phenomenon of more than 10 microemboli during dissection was significantly (p < 0.005) related to new hyperintense lesions on postoperative T2-weighted magnetic resonance images. CONCLUSIONS: During CEA the presence of microembolism (> 10 microemboli) during dissection shows a statistically significant relationship with perioperative cerebral complications and with new ischemic lesions on magnetic resonance images of the brain. Moreover, microembolism during shunting is also related to intraoperative complications. Surgeons can be guided by the audio Doppler and emboli signals by changing their technique. This change may result in a decrease of microembolism and consequently in a decline of the intraoperative stroke rate.

Adult↗

Quantitative analysis of radiation-induced changes in sperm morphology.

When developing spermatogenic cells are exposed to radiation, chemical carcinogens or mutagens, the transformation in the morphology of the mature sperm can be used to determine the severity of the exposure. In this study five groups of mice with three mice per group received testicular doses of X irradiation at dosage levels ranging from 0 rad to 120 rad. A random sample of 100 mature sperm per mouse was analyzed five weeks later for the quantitative morphologic transformation as a function of dosage level. The cells were stained with gallocyanin chrome alum (GCA) so that only the DNA in the sperm head was visible. The ACUity quantitative microscopy system at Lawrence Livermore National Laboratory was used to scan the sperm at a sampling density of 16 points per linear micrometer and with 256 brightness levels per point. The contour of each cell was extracted using conventional thresholding techniques on the high-contrast images. For each contour a variety of shape features was then computed to characterize the morphology of that cell. Using the control group and the distribution of their shape features to establish the variability of a normal sperm population, the 95% limits on normal morphology were established. Using only four shape features, a doubling dose of approximately 39 rad was determined. That is, at 39 rad exposure the percentage of abnormal cells was twice that occurring in the control population. This compared to a doubling dose of approximately 70 rad obtained from a concurrent visual procedure.

Animals↗

Differentiation of two Oesophagostomum spp. from pigs, O. dentatum and O. quadrispinulatum, by computer-assisted image analysis of fourth-stage larvae.

A method was developed to differentiate between fourth-stage larvae (L4) of two species of porcine nodular worms, Oesophagostomum dentatum and O. quadrispinulatum, by computer-assisted analysis of digitised microphotographs of L4 grown in vitro for various time periods and of L4 ex vivo. The overall lengths of the larvae and the lengths of the oesophagus as well as parameters describing the shape of the oesophagus and buccal capsule were measured and a formula based on these parameters was developed that could differentiate between the two species on the basis of the morphometric data. It was demonstrated that morphometry can produce unbiased data which can be employed for the calculation of indices suitable for the differentiation of morphologically different specimens. Computer-based techniques facilitate the processing of the complex data and offer the option for automation of measurements for routine applications.

Animals↗

The effect of arterial clamp duration on endothelial injury: an experimental study.

BACKGROUND: Arterial clamp-related endothelial damage was investigated in an animal model to quantify the surface area of endothelial disruption. The influence of the duration of clamp application on this damage was evaluated. METHODS: Four identical angled DeBakey vascular clamps were applied on each of eight carotid arteries in four heparinized adult sheep for durations of 15, 30, 45 and 60 min. The applied clamping forces were measured and kept constant. After the last clamp was removed, the areas of endothelial loss were identified by in vivo staining with Evan's blue dye. The vessels were excised and the blue stained areas measured by computer-assisted analysis. The morphological appearance of the specimens was assessed by scanning electron microscopy. RESULTS: Endothelial damage following clamping for 15 min (10.6 +/- 4.3 mm2) was significantly less than for 30 min (19.0 +/- 4.7 mm2), 45 min (19.8 +/- 4.6 mm2) and 60 min (20.4 +/- 4.9 mm2, P = 0.005), but there were no significant differences between the areas of endothelial loss observed for 30, 45, and 60 min. These results corresponded to the damage seen using scanning electron microscopy, which showed partial disruption of endothelium at 15 min compared to more complete destruction at longer durations. CONCLUSIONS: Evan's blue staining combined with computer-assisted surface area measurement is an accurate method for quantifying endothelial damage. The extent of damage caused by vascular clamps is partly time-dependent, being less for 15 min than for 30 min of clamping, but not significantly increasing for durations greater than 30 min.

Animals↗

Stent graft repair in the aortic arch and descending thoracic aorta: a 4-year experience.

BACKGROUND: Thoracic aortic aneurysms (TAAs) and type B aortic dissections (ADs) are relatively frequent, serious conditions that are often managed nonoperatively because of perceived poor outcome of standard surgical reconstruction. Recently developed stent graft techniques represent a more attractive, less invasive option. We sought to determine the technical feasibility and safety of endovascular repair in the thoracic aorta with a retrospective review of our experience with such an approach. METHODS: Forty-seven patients received thoracic stent graft implants during the 4-year period ending March 31, 2002. All patients signed an Institutional Review Board-approved informed consent. Thirty-one patients had TAAs, and 16 had ADs. Device design and implant strategy were on the basis of evaluation of morphology with angiography and computed tomographic scan. The procedures were done with fluoroscopic guidance, with local anesthesia in five cases, spinal anesthesia in 19 cases, and general anesthesia in 23 cases. Endovascular access was achieved with femoral cutdown in 41 cases and a temporary iliac conduit in six cases. A Talent patient-specific device, with 4-mm to 6-mm oversize, was used in all. Proximal endograft attachment was in the descending thoracic aorta in 16 cases, parasubclavian in 21 cases, and the suprasubclavian aorta in 10 cases. Eight patients had adjunctive cervical reconstruction to transpose or revascularize the left subclavian or left common carotid arteries, enabling more proximal endograft attachment in the aortic arch. RESULTS: Access failure occurred in one patient (2.1%). One patient (2.1%) died within 30 days of access-related iliac artery rupture. Another death occurred at 60 days from a ruptured thoracoabdominal aneurysm with type I endoleak. No instances of paraplegia, stroke, or surgical conversion were seen. Five patients (TAA) were found to have endoleak on 30-day computed tomographic scan. Repair of type I endoleak was undertaken in three cases at 1, 4, and 6 months. Eight patients (17%) had adverse events within the first 30 days. Length of follow-up ranged from 1 to 44 months, with a mean of 18 months. Two patients were lost to follow-up, and one withdrew from the study. Four additional mortalities were observed, none related to the endograft or aortic pathology. CONCLUSION: Stent graft repair of TAA and AD is feasible and can be achieved with technical success and relatively low rates of perioperative morbidity and mortality. The Talent customized design proved versatile in various morphologies. More information is needed on indications, clinical efficacy, and long-term results.

Adult↗

Sperm abnormalities and histopathological changes in the testes in Crj:CD(SD)IGS rats.

In this study, morphological examination and computer-assisted sperm analysis (CASA) of epididymal spermatozoa in non-treated Crj:CD(SD)IGS rats were performed, and the relationship between the data obtained and the retention of step 19 spermatids in Stage IX to XI seminiferous tubules was examined. Retention of step 19 spermatids in Stage IX to XI seminiferous tubules was observed in all 50 untreated males, and the incidence ranged from 3.3% to 100%. Eighteen animals showed a high incidence of retention (74.7 +/- 14.2%, HIR for short), and the others showed a low incidence (24.9 +/- 11.0%, LIR for short). Although the incidence of retention in Stage X and XI seminiferous tubules was very low in LIR males, it was high in HIR males (1.8 +/- 3.0% vs 58.6 +/- 23.2%). Morphological abnormalities of sperms in the caudal region of the epididymis, mainly amorphous head and no head, were more frequently observed in HIR males than in LIR males (36.2 +/- 28.5% vs 1.8 +/- 1.2%). Sperm analysis also revealed some differences between HIR and LIR males: sperm motility in HIR males was severely lower than that in LIR males, and sperm velocity, beat/cross frequency and amplitude of lateral head displacement in HIR males were lower than the corresponding values in LIR males. In summation, retention of step 19 spermatids frequently occurred in the non-treated Crj:CD(SD)IGS males, and a relationship between the retention of these spermatids and sperm abnormalities, such as morphologically abnormal sperms, low motility and other items revealed by sperm analysis (CASA), was suggested.

Animals↗

Total cytoplasmic volume as biomarker of fragmentation in human embryos.

PURPOSE: To use computer-controlled, multilevel embryo morphology analysis to quantify the reduction in cytoplasmic volume from the zygote stage to the combined volume of the individual blastomeres as an expression for the degree of fragmentation. METHODS: Zygotes and their corresponding embryos from patients referred to ICSI treatment were analyzed. Sequences of digital images were taken focussing at 5-microm intervals through the zygotes and embryos. Assessment of cytoplasmic volumes and fragmentation were based on these sequences. RESULTS: The mean cytoplasmic reduction of the embryos were significant linear increasing with increasing degree of fragmentation assessed by traditional evaluation (P < 0.001). Embryos scored to be highly fragmented had on average a cytoplasmic reduction of 63% larger than embryos assessed to have no fragmentation. In total, 68% of the embryos had a cytoplasmic reduction lying within their allocated fragmentation group. CONCLUSION: Assessment of embryonic fragmentation based on computer-controlled, multi-level embryo analysis of the blastomere volumes expressed in relation to the volume of the preceding zygote may allow a more precise and standardized evaluation of fragmentation than the traditional fragmentation assessment.

Cytoplasm↗

Importance of different nuclear morphologic patterns in grading prostatic adenocarcinoma. An expanded model for computer graphic filters.

The aim of this work was to continue the development of an interactive workstation for the nuclear grading of prostatic lesions by including a large range of nuclear patterns. A previous model was based on four groups: hyperplasia, Mostofi grade 1, Mostofi grade 2 and Mostofi grade 3. Each group included the most common nuclear patterns of the lesions. One set used to test the model included cases showing patterns different from the typical ones of the model. Poor results were obtained for low and medium grades. A review of all the cases in our database led to the conclusion that different nuclear patterns can belong to the same "nuclear grade." Thus, in this work the model was expanded to include six groups: hyperplasia, two subgroups for Mostofi grade 1, two subgroups for Mostofi grade 2 and Mostofi grade 3. A set of 900 nuclei, 150 in each group, was selected to test the model. An additional 300 nuclei, 50 in each group, were used for a test set. The overall success rate for classifying the nuclei in the test set using the new model was 93% as compared to a rate of 71% obtained for the similar test set, described above, using the previous model. Moreover, correlating karyometric features with nuclear morphology indicated a role for nucleoli in nuclear grading. The good results obtained with large and heterogeneous sets of cases indicate that the procedures used to develop this model may be adapted for the development of models for the nuclear grading of other tumors.

Adenocarcinoma↗

Voltage-clamp analysis and computer simulation of a novel cesium-resistant A-current in guinea pig laterodorsal tegmental neurons.

Increased firing of cholinergic neurons of the laterodorsal tegmental nucleus (LDT) plays a critical role in generating the behavioral states of arousal and rapid eye movement sleep. The majority of these neurons exhibit a prominent transient potassium current (IA) that shapes firing but the properties of which have not been examined in detail. Although IA has been reported to be blocked by intracellular cesium, the IA in LDT neurons appeared resistant to intracellular cesium. The present study compared the properties of this cesium-resistant current to those typically ascribed to IA. Whole cell recordings were obtained from LDT neurons (n = 67) in brain slices with potassium- or cesium-containing pipette solutions. A transient current was observed in cells dialyzed with each solution (KGluc-85%; CsGluc-79%). However, in cesium-dialyzed neurons, the transient current was inward at test potentials negative to about -35 mV. Extracellular 4-aminopyridine (4-AP; 2-5 mM) blocked both inward and outward current, suggesting the inward current was reversed IA rather than an unmasked transient calcium current as previously suggested. This conclusion was supported by increasing [K]o from 5 to 15 mM, which shifted the reversal potential positively for both inward and outward current (+17.89 +/- 0.41 mV; mean +/- SE). Moreover, recovery from inactivation was rapid (tau = 15.5 +/- 4 ms; n = 4), as reported for IA, and both inward and outward transient current persisted in calcium-free solution [0 calcium/4 mM ethylene glycol-bis(beta-aminoethyl ether)-N,N,N', N'-tetraacetic acid; n = 4] and during cadmium-blockade of calcium currents (n = 3). Finally, the transient current was blocked by intracellular 4-AP indicating that adequate dialysis occurred during the recordings. Thus the Cs-resistant current is a subthreshold IA. We also estimated the voltage-dependence of activation (V1/2 = -45.8 +/- 2 mV, k = 5.21 +/- 0.62 mV, n = 6) and inactivation (V1/2 = -59. 0 +/- 2.38 mV, k = -5.4 +/- 0.49 mV, n = 3) of this current. Computer simulations using a morphologically accurate model cell indicated that except for the extreme case of only distal A-channels and a high intracellular resistivity, our parameter estimates were good approximations. In conclusion, guinea pig LDT neurons express subthreshold A-channels that are resistant to intracellular cesium ions. This suggests that these channels differ fundamentally in their ion permeation mechanism from those previously studied. It remains to be determined if Cs+ resistance is common among brain A-channels or if this property is conferred by known A-channel subunits.

4-Aminopyridine↗

Leiomyosarcoma metastatic to the liver: CT appearance.

Leiomyosarcoma is an uncommon malignancy that metastasizes to the liver and lungs. Each of the three cases of leiomyosarcoma metastatic to the liver examined by computed tomography demonstrated similar morphologic and dynamic characteristics. Common features included hepatomegaly and large, circumscribed "cannonball" lesions that distorted normal hempatic architecture. These larger metastases were sharply defined with central necrosis and were accentuated by contrast enhancement of normal surrounding liver. Smaller perfused metastases often became isodense following contrast medium administration. This combination of features and effects should alert one to the possible diagnosis of metastatic leiomyosarcoma and cautions against underestimating the extent of disease by having precontrast control scans for comparison.

Aged↗

Computed tomographic evaluation of the role of craniofacial and upper airway morphology in obstructive sleep apnea in Chinese.

OBJECTIVES: To evaluate the relationship between cephalometric parameters, upper airway morphological factors and obstructive sleep apnea (OSA) in Chinese subjects. DESIGN: Polysomnogram (PSG) were performed and scored using standard criteria. Supine lateral cephalometric parameters and pharyngeal cross-sectional areas at the level of velopharynx (VA) and hypopharynx (HA) were measured from computed tomographic scans. The roles of these parameters and other anthropometric/demographic characteristics in OSA (apnea hypopnea index, AHI > or = 5) and their relationship with severity of OSA were explored by multiple logistic and multinominal regression analysis. RESULTS: Ninety-two subjects, ranging from normal (n = 36), mild/moderate OSA (n = 34) to severe OSA (n = 22), were evaluated. Compared with normal subjects, OSA subjects were heavier (body mass index 27 vs. 24 kg/m2) and older (47 vs. 42 years of age); had smaller VA size and VA to HA ratio, lower positioned hyoid bone, longer and thicker soft palate, and more retropositioned mandible relative to maxilla. After controlling for body mass index and age, subjects with severe OSA (AHI > 30) had more retropositioned mandible relative to maxilla (odds ratio, OR 1.31, P = 0.044) and longer soft palate (OR 1.16, P = 0.01), while those with mild/moderate OSA had larger VA to HA ratio (OR 0.17, P = 0.018). CONCLUSIONS: Craniofacial factors and upper airway morphology contributed to severity of OSA in Chinese subjects. Having controlled for obesity, more retropositioned mandible was associated with more severe OSA.

Cephalometry↗

[MRI diagnosis of bone tumors].

Diagnosis of bone tumours is still based on plain films and, if necessary, computed tomography because crucial morphologic criteria such as ossification of tumour matrix, patterns of bone destruction and formation of new bone are not clearly visualized by MRI. Only in a few cases is MRI helpful for characterization of bone lesions. Although MRI is of limited value for differential diagnosis of bone tumours, it may be very helpful for planning of biopsy or surgery by virtue of its ability to demonstrate tumour extent and soft tissue changes. For local staging and follow-up of primary bone tumours MRI is clearly the method of choice. MRI strategy should be coordinated with clinical requirements in order to ensure optimum evaluation of tumour extent, effectiveness of chemotherapy and detection of local recurrence.

Bone Neoplasms↗

A mathematical model for the morphology of the pulmonary acinus.

A computational method is proposed for the construction of a three-dimensional space-filling model of an acinar ventilatory unit. Its geometry consists of truncated octahedra arranged in a cuboidal block. The ducts and alveoli are formed by opening specific common faces between polyhedra. The branching structure is automatically computed using algorithms solely to maximise the number of alveoli and minimise the average path lengths; it is not formed with reference to published experimental data. Properties of the model such as the total alveolar and ductal volumes, the distribution of individual path lengths to the alveolar sacs, and the average number of ducts per generation are calculated. The predicted morphology of the model compares well with published data for rat lungs.

Algorithms↗

Inflammatory lesions of the basal ganglia and thalamus: review of twenty-one cases.

We report a series of 21 patients with basal ganglia and thalamic granulomas or abscesses treated over 7 years. Among them, 15 were tubercular, 5 were pyogenic, and 1 was fungal. Pyogenic abscesses, usually hematogenous, also occurred secondary to osteomyelitis of the skull and chronic otitis media. The fungal abscess developed in a nonimmunocompromised patient with no intercurrent malignancy. Evidence of tuberculosis elsewhere in the body was detected in only 7 patients with tuberculomas. The computed tomographic (CT) image morphology characterizing an abscess or a tuberculoma was present in all except 2 patients with tuberculomas. The fungal abscess resembled a malignant glioma. The only hospital mortality occurred in a deeply unconscious patient with a thalamic pyogenic abscess. A 12-month or longer follow-up in 16 patients showed that 3 continued to be handicapped neurologically, and 2 died 13 and 16 months later, respectively. We conclude that inflammatory lesions at these sites are not uncommon and that CT scans are diagnostic in the great majority. Doubtful diagnosis merits stereotactic aspiration or biopsy of the lesion. Satisfactory results follow adequate medical therapy.

Adolescent↗