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At least 937 records · Page 52Linked to original sources
PubMed1996

[Evaluation of reconstruction arc in myocardial SPECT imaging using a cardiac phantom--comparison between 360 degrees and 180 degrees arcs].

In order to investigate the effect of reconstruction arc on myocardial SPECT images, a series of phantom studies was performed with and without plastic chambers simulating perfusion defects using 201Tl and 99mTc. Coefficient of variations (CV) of the counts among the ROIs and defect contrast were evaluated in 360 degrees and 180 degrees images reconstructed from the same 360 degrees projection data. Reconstruction processes were identical for all images. In the absence of defects, the CV of the counts were approximately the same in 360 degrees and 180 degrees images. The CV of the counts in the 360 degrees 201Tl image, among 4 defects located on the anterior, lateral, inferoposterior, and septal walls, was superior to those in the 180 degrees images. In contrast, in the 99mTc images, the CV of the counts among the 4 defects in the 180 degrees image was superior to those of the 360 degrees image. The defect contrast was changed both by the location of the defect and by the reconstruction arc (201Tl, 99mTc). The defect contrast of the 180 degrees images, in both 201Tl and 99mTc experiments, was closer to the true contrast value as calculated by the count ratio between myocardium and defect. Although the defect contrast in the anterior, lateral and septal walls was more emphasized in the 180 degrees images, the defect contrast in the inferoposterior wall was less emphasized in the 180 degrees images compared to the 360 degrees (201Tl, 99mTc).

Heart↗
PubMedDate not supplied

Reconstruction of the lower eyelid by third eyelid lateral advancement and local transposition cutaneous flap after "en bloc" resection of squamous cell carcinoma in 5 cats.

OBJECTIVE: To describe a novel technique for blepharoplasty to cover a tissue defect involving >/=50% of the lower eyelid. STUDY DESIGN: Prospective clinical study. ANIMALS: Five cats with lower eyelid squamous cell carcinoma (SCC). METHODS: En bloc resection of SCC by removing >/=50% of the lower lid with either the medial or lateral canthus was performed without other adjunctive treatment for SCC. The lid defect was reconstructed with a transposition skin flap derived from the frontal (medial defect) or temporal (lateral defect) region. The third eyelid was advanced laterally without dissection from its insertion; its outer conjunctival layer was removed, and the skin flap was sutured with single interrupted sutures dorsally over the nictitating membrane, ventrally to the cutaneous edge of the surgical wound and medially or laterally (depending on the canthus removed) to the skin of the remaining lower lid. RESULTS: Satisfactory cosmetic and functional results were achieved and the Schirmer tear tests were normal. In 2 cats, the skin flap needed monthly hair trimming to avoid corneal lesions. CONCLUSIONS: After en bloc resection of SCC involving >/=50% of the lower eyelid, reconstruction can be achieved by relocation of the third eyelid and use of a cutaneous transposition flap sutured to the scarified external surface of the third eyelid. Eyelid apposition and lacrimal function were preserved. CLINICAL RELEVANCE: Blepharoplasty using a cutaneous transposition flap sutured to the scarified surface of a relocated third eyelid should be considered for reconstruction of lower eyelid defects with >/=50% tissue loss of the lid margin.

Animals↗
PubMed1982

Evoked potentials in the evaluation of visual field defects due to chiasmal or retrochiasmal lesions.

We used monocular full-field and hemifield pattern reversal stimulation to study visual evoked potentials (VEPs) in 20 patients with confirmed defects of the visual pathways. In 10 of 12 patients with homonymous field defects, it was possible to lateralize the brain lesion but not to predict the site of the lesion within the hemisphere. In four of eight patients with bitemporal field defects, VEPs suggested involvement at the chiasmal level. In the remaining cases, VEPs provided no correlation with perimetric and radiologic findings. We found that VEPs usually corroborated other diagnostic studies but subtle defects were not detected reliably, and large hemianopic defects were occasionally not lateralized accurately. VEP analysis is therefore of only limited value in assessment for clinical purposes of patients with homonymous or bitemporal hemianopias.

Adolescent↗
PubMed1994

[A case of occipital lobe epilepsy following cerebral infarction].

We report a rare case of occipital lobe epilepsy following cerebral infarction in bilateral occipital lobes. The patient is a seventeen-year-old female, who had cerebral infarction in bilateral occipital regions a few days after an open-heart surgery at 15 years of age. Thereafter she sometimes complained of visual field defects and ictal amaurosis. Seventeen months later, she developed a tonic seizure with ictal amaurosis, visual field defects and head deviation. On admission, results of the neurological examinations were all normal with the exception of peripheral visual field defects. Scalp electroencephalographic (EEG) findings showed paroxysmal discharges that were more prominent in the frontal to parietal leads than in the occipital leads. Sometimes the laterality of paroxysmal discharges changed. Her visual defects were diagnosed as psychogenic activity by the ophthalmological visual fields test. Simultaneous recordings of pattern reversal visual evoked potential (VEP) and electroretinograms (ERG) showed normal in 15 minute checks, but prolongation of bilateral P100 latency in 30 minute checks. These findings suggested that peripheral visual fields were disturbed. In this case, EEG findings and the initial symptoms of amaurosis and visual fields defect suggested occipital epilepsy following cerebral infarction in bilateral occipital lobes. We wish to emphasize that simultaneous VEP and ERG recording is a useful diagnostic tool for estimating visual functions.

Adolescent↗
PubMed2005

[The use of bone substitute materials in apitectomy of anterior teeth].

The authors present cases of treatment of 16 teeth in 12 patients with cystis in the region of apical root. The bone defects were filled in with using bone substitute materials Bio-Oss and membranes Bio-Gide. Two years later all the bone defects were filled in with new tissue and any incidence of complications appeared.

Adult↗
PubMed2005

Management of defects in the groin, thigh, and pelvic region with modified contralateral TRAM/VRAM flaps.

In patients with sarcomas, or regional recurrence of the disease, radical resection and radiation therapy is indicated to achieve cure or palliation. As a result of radical surgery, extensive radiation, or infection in the pelvic, groin or thigh region, the development of large pelvic / groin / thigh defects present a difficult surgical problem. Musculocutaneous deep epigastric island-flaps, as a modification of the extended deep inferior epigastric flap, described by Taylor et al. in 1983, are an attractive option for a successful reconstruction for this defect localisation. Two technical modifications of the contralateral extended deep inferior epigastric island-flap permitted an adequate tailoring to a defect in the posterior lateral pelvic or groin-thigh region, and avoided the drawbacks of other loco-regional or microsurgical flaps in previously irradiated fields. The skin island reached the posterior lateral pelvic region, groin or thigh. The muscular portion of this flap was suited to fill the soft tissue defects in these critical areas. These so modified flaps represent an instrument, which in selected cases may be an interesting alternative tool for closure of complex defects. No significant functional impairment secondary to the flap procedures was noted in our patients.

Bone Neoplasms↗
PubMed1995

Orthodontic movement through a repaired buccal alveolar fracture: a case report.

Orthodontic treatment in adults often involved the extraction of a lower central incisor. The extraction of these teeth can be problematic. Some factors that can influence successful treatment include: difficult access for actual tooth removal; the existing contour and bulk of the alveolar ridge; the buccal tooth position; and the inclination of the tooth in the alveolus. A patient who had a lower central incisor removed experienced a buccal alveolar fracture because of thin buccal plate. Upon healing there was a buccal defect that prevented the later tooth movement that would have closed the extraction site. The area was grafted with a demineralized freeze dried bone allograft to provide a matrix for osteoinduction. Gore-Tex was used as the physical barrier. After 6 months, the extraction side was closed by passing the lateral incisor through the graft site. The result was good tooth alignment and slight horizontal bone loss in the defect area.

Adult↗
PubMed1996

Motor neuron degeneration induced by excitotoxin agonists has features in common with those seen in the SOD-1 transgenic mouse model of amyotrophic lateral sclerosis.

A superoxide dismutase 1 (SOD-1)genetic defect has been identified in familial amyotrophic lateral sclerosis (ALS) and motor neuron degeneration has been described in SOD-1 transgenic mice. Because an excitotoxic mechanism has been implicated in ALS, we undertook studies to provide a description of excitotoxic degeneration of spinal motor neurons for comparison with the degenerative process observed in SOD-1 transgenic mice. Excitotoxin agonists selective for each of the three major types of inotropic glutamate receptors were applied directly onto the lumbar spinal cord of 21-day old rats following posterior laminectomy. N-methyl-D-aspartate (NMDA) preferentially affected dorsal horn neurons, whereas the non-NMDA agonist, kainic acid, preferentially affected motor neurons. Cytopathological changes in motor neurons closely resembled those described in SOD-1 mice. These changes consist of massively swollen dendritic processes in the presence of well-preserved presynaptic axon terminals; cell bodies of motor neurons filled with vacuoles that originate both from endoplasmic reticulum and mitochondria; pleomorphic changes in mitochondria; axons of motor neuron becoming swollen proximally with accumulation of vacuoles, organelles, filaments, and degeneration products in the swollen segment. The observed changes in motor axons resemble changes described in the spinal cord of ALS patients. These findings are consistent with the proposal that motor neuron degeneration in ALS may be mediated by an excitotoxic process involving hyperactivation with non-NMDA glutamate receptors.

Amyotrophic Lateral Sclerosis↗
PubMed2005

End-to-side nerve grafting of the tibial nerve to bridge a neuroma-in-continuity.

Standard treatment for a neuroma-in-continuity with partial retained function is neurolysis with or without grafting. The present study tests the outcome of a novel partial nerve lesion bypassed with an end-to-side bridge graft, intended to increase the number of axons crossing the defect while not disturbing intact axons. An 8-mm portion of tibial nerve was resected in 20 rats. Three weeks later, half had the defect repaired with an end-to-side bridge allograft and perineurial windows; controls had only neurolysis. Recovery was evaluated using walking-track analysis, allodynia testing, muscle weight ratios, and histology at 8 weeks. No significant differences in motor or sensory functional recovery were noted between the two groups. Histology showed good axonal regeneration through the defect in all specimens. The experimental group also had regenerated axons in the bridge graft, but their maturity was less advanced, presumably due to delays in regeneration.

Animals↗
PubMed1982

How accurate is the ultrasonic estimation of ventricular septal defect size?

The relationship between the size of ventricular septal defects estimated from ultrasonic images and the actual size of the ventricular septal defects is currently unknown. Our goal was to image simulated defects of known size under conditions as physiological as possible with several two-dimensional ultrasonic instruments. The study was not viewed as a contest between instruments. A static heart model we tested consisted of a simulated chest wall-right ventricular anterior wall, a human septum or muscular septal equivalent, and a simulated left ventricular posterior wall. Model tissues were placed in holders in a water bath for imaging at 90 degrees and 180 degrees with respect to the ventricular septal defect. These angles tested the lateral and axial resolution necessary for imaging simulated ventricular septal defects. Actual ventricular septal defect sizes ranged from 5 to 17.5 mm. Images were obtained with a 30 degrees, 3.5-MHz, mechanical sector scanner, a 2.4-MHz range focused phased array, and a prototype transmit and dynamically focused, 3.5-MHz phased array. Image quality of the defect varied at 90 degrees but was generally poor at 180 degrees. For studies conducted at 180 degrees, phased arrays imaged sharp defect edges for larger holes, but the mechanical sector scanner did not. Signal attenuation appeared to be the major limiting factor for axial resolution. For imaging at 90 degrees, the mechanical sector scanner approximated the actual defect size less 4 mm. The prototype phased array scanner approximated the defect size less 4 to 6 mm. With the range focused, phased array, imaged size was always less than one half actual size. The smallest defect imaged with our simulation with any instrument was 7 mm. These data or their regression equation should not be used to compute the actual size of a clinical ventricular septal defect, since different machines, transducers, and situations might alter the exact relationship between imaged and actual defect size. However, the data led to the conclusion that imaged size of a defect is instrument and transducer dependent and is always smaller than actual defect size.

Animals↗
PubMed2001

Tc-99m MDP, thallium-201 chloride and Tc-99m MAG3 renal uptake in subacute and chronic radiation nephritis compared.

The authors present a comparison of the findings for thallium-201 (Tl-201), Tc-99m MAG3 and Tc-99m MDP in subacute and chronic radiation nephritis in a 9-yr-old boy who was treated by radiation therapy for alveolar rhabdomyosarcoma of the left chest wall by a radiation port that partially included the left kidney. Tl-201 imaging three and six months later showed a cortical defect in the left kidney due to radiation nephritis. Tc-99m MDP scan showed increased uptake on both occasions, but more marked in the subacute period than in the chronic period. Tc-99m MAG3 showed decreased concentration and increased cortical retention three months later. Six months after the radiation therapy, a cortical defect corresponding to the cortical area that showed increased parenchymal retention was more prominent in the Tc-99m MAG3 scan. In the present case, Tc-99m MDP, Tl-201 and Tc-99m MAG3 findings may provide useful information for understanding pathophysiological damage in the kidney after radiation.

Child↗
PubMed2004

Transient giant R-wave, right axis deviation, and intraventricular conduction delay during exercise treadmill testing: a case report.

A 53 year old man complained of chest pain during an exercise treadmill test. Electrocardiogram revealed transient giant R-wave, right-axis deviation, intraventricular conduction delay, and ST-segment elevation in the inferolateral leads. Subsequent coronary angiography showed an 80% lesion in mid part of a nondominant left circumflex artery, whereas the other coronary arteries had mild atherosclerosis only. Percutaneous coronary intervention and stenting was performed on the left circumflex artery lesion. A follow-up exercise thallium scan 3 months later still showed an intermediate-sized, mild reversible perfusion defect in the inferior and lateral wall but the giant R-wave ECG pattern was not inducible anymore. Restudy coronary angiography showed no in-stent restenosis, but there was disease progression in the midpart of the right coronary artery. The initial electrocardiographic pattern is typical of the "giant R-wave syndrome." Severe coronary spasm superimposed on the underlying mild atherosclerotic lesion of the right coronary artery is hypothesized to be the cause of the initial event. Ad hoc direct stenting was performed on the right coronary artery lesion. The patient remained symptom-free with a normal thallium scan 9 months later.

Angina Pectoris, Variant↗
PubMed1997

A regional approach to reconstruction of the upper lip.

PURPOSE: This articles reviews the results obtained when cheek or lower lip flaps, or a combination of these flaps, are used for the reconstruction of defects of the upper lip. PATIENTS AND METHODS: Twenty-four cases of either partial or total full-thickness defects of the upper lip were reconstructed. Four cases with lateral full-thickness partial defects were reconstructed by advancing a cheek flap using the Bernard-Burow method. In five cases, defects located at the junction of the upper lip and the cheek were reconstructed with an Estlander flap. Four patients with a tight upper lip were corrected with an Abbé flap. In two cases, a modified mucomuscular Abbé flap was used for reconstruction of a vermilion defect of the upper lip. Nine patients with subtotal or total full-thickness defects of the upper lip were reconstructed with a combination of bilateral or unilateral cheek flaps using either the Bernard-Burow or Dieffenback method and T-shaped or oblong Abbé flap. RESULTS: All regional flaps healed uneventfully, and the function of reconstructed upper lips had recovered within 2 years postoperatively. CONCLUSION: Use of regional flaps to reconstruct partial or total full-thickness defects of the upper lip can usually achieve satisfactory functional and esthetic results.

Adolescent↗
PubMed1993

Wave plate osteosynthesis as a salvage procedure.

The load axis of the curved-shaped proximal femur lies not inside, but outside the bone. Therefore high bending forces are acting, the medial cortex absorbing pressure, the lateral cortex absorbing tension. In a transverse fracture, a laterally applied plate will absorb the tensile stresses, the medial cortex the pressure forces. When medial butress due to bony defect is missing, the laterally applied plate is subjected to cycling bending and will undergo fatigue fracture. This dilemma is compensated by a wave-plate with bone graft: The compression forces are detoured to the lateral cortex and the plate is again subjected to tension. Furthermore since the plate is standing away from the bone, the plate does not disturb the blood supply at the fracture side and bone healing.

Adult↗
PubMed1998

Reconstruction after temporal bone resection.

Reconstruction of soft tissue defects after temporal bone resection can vary from simple closure of the external auditory canal to complex flap coverage of extensive defects. Between 1987 and 1996, 34 patients underwent lateral skull base resections and reconstruction for invasive carcinoma of the temporal bone. Seven underwent sleeve resection and/or radical mastoidectomy. Sleeve resection was managed with tympanoplasty, canalplasty, or obliteration of the external auditory canal (10). There were 24 lateral temporal bone resections and four subtotal temporal bone resections. Larger defects created by lateral and subtotal temporal bone resections required closure with a combination of temporalis flaps and local rotational cutaneous flaps (13). Lower island trapezius flaps (five), free flaps (four), and pectoralis major flaps (two) were also used. Indications and efficacy of each method are discussed, and treatment outcomes are presented.

Adult↗
PubMed2001

Recovery from arterial growth delay reduces penetrance of cardiovascular defects in mice deleted for the DiGeorge syndrome region.

Chromosome 22q11.2 heterozygous deletions cause the most common deletion syndrome, including the DiGeorge syndrome phenotype. Using a mouse model of this deletion (named Df1) we show that the aortic arch patterning defects that occur in heterozygously deleted mice (Df1/+) are associated with a differentiation impairment of vascular smooth muscle in the 4th pharyngeal arch arteries (PAAs) during early embryogenesis. Using molecular markers for neural crest, endothelial cells and vascular smooth muscle, we show that cardiac neural crest migration into the 4th arch and initial formation of the 4th PAAs are apparently normal in Df1/+ embryos, but affected vessels are growth-impaired and do not acquire vascular smooth muscle. As in humans, not all deleted mice present with cardiovascular defects at birth. However, we found, unexpectedly, that all Df1/+ embryos have abnormally small 4th PAAs during early embryogenesis. Many embryos later overcome this early defect, coincident with the appearance of vascular smooth muscle differentiation, and develop normally. Embryos born with aortic arch patterning defects probably represent a more severely affected group that fails to attain sufficient 4th PAA growth for normal remodelling of the PAA system. Our data indicate that Df1/+ embryos are able to overcome a localized arterial growth impairment and thereby reduce the penetrance of birth defects.

Animals↗
PubMed1976

Diagnostic value of the water-drinking test in early detection of simple glaucoma.

A series of 64 patients (119 eyes) subjected 10 years previously to water provocative tests on a suspicion of simple glaucoma were followed up. At that time the intraocular tension exceeded 20 mmHg, but there were no optic disc changes and no visual field defects. The follow-up examination comprised ophthalmoscopy, visual acuity, gonioscopy, intraocular tension, and perimetry. Setting a rise of 8 mmHg as the lower limit, the water provocative test ten years previously had been positive in 31 eyes. Nine of these developed glaucomatous visual field defects despite treatment (29 per cent). The test had been negative in 88 eyes. Of these, 21 (24 per cent) developed glaucomatous visual field defects. The water-drinking test was negative in 70 per cent of the eyes which subsequently developed visual field defects and negative in 75 per cent of those in which no defects developed. Thus the test was neither of diagnostic nor of prognostic value. All the eyes with a positive test which later developed visual field defects had been treated, whereas 57 per cent of the eyes with a negative test which subsequently developed visual field defects had received no treatment. This indicated that a negative water-drinking test gave a false security. It is shown that an alteration of the lower limit of a tension rise does not render the water provocative test any more useful.

Drinking↗
PubMed2006

Left ventricular free wall impeding rupture in post-myocardial infarction period diagnosed by myocardial contrast echocardiography: case report.

BACKGROUND: Left ventricular free wall rupture occurs in up to 10% of the in-hospital deaths following myocardial infarction. It is mainly associated with posterolateral myocardial infarction and its antemortem diagnosis is rarely made. Contrast echocardiography has been increasingly used for the evaluation of myocardial perfusion in patients with acute myocardial infarction, with important prognostic implications. In this case, we reported its use for the detection of a mechanical complication following myocardial infarction. CASE PRESENTATION: A 50-year-old man with acute myocardial infarction in the lateral wall underwent myocardial contrast echocardiography for the evaluation of myocardial perfusion in the third day post-infarction. A perfusion defect was detected in lateral and inferior walls as well as the presence of contrast extrusion from the left ventricular cavity into the myocardium, forming a serpiginous duct extending from the endocardium to the epicardial region of the lateral wall, without communication with the pericardial space. Magnetic resonance imaging confirmed the diagnosis of impending rupture of the left ventricular free wall. While waiting for cardiac surgery, patient presented with cardiogenic shock and died. Anatomopathological findings were consistent with acute myocardial infarction in the lateral wall and a left ventricular free wall rupture at the infarct site. CONCLUSION: This case illustrates the early diagnosis of left ventricular free wall rupture by contrast echocardiography. Due to its ability to be performed at bedside this modality of imaging has the potential to identify this catastrophic condition in patients with acute myocardial infarction and help to treat these patients with emergent surgery.

Echocardiography↗