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Biomedical subjects

A Yellin

Publications and source records attributed to A Yellin.

At least 37 records · Page 2Linked to original sources
PubMed1998

Reconstruction of the sternum and chest wall with methyl methacrylate: CT and MRI appearance.

The aim of our study was to define the appearance of methyl methacrylate grafts replacing resected sternum and ribs on CT and MRI and how the sternal graft may mimic an abnormally sclerotic sternum on CT images. We reviewed the CT scans of nine patients who had undergone chest wall resection (eight with malignant and one with benign disease) and reconstruction with a composite of methyl methacrylate and Marlex mesh graft. One of them had an MRI study as well. The size, shape and CT attenuation were assessed on mediastinal and bone window settings. The sternal graft was seen on mediastinal and even better on bone windows as an abnormally wide, irregularly shaped structure, somewhat denser than the normal sternum. The chest wall prosthesis replacing resected ribs was seen as a continuous dense structure and of similar attenuation as that of the sternal graft. On MRI the prosthesis appeared as a well-defined structure with no signal. Reconstruction of the chest wall with methyl methacrylate appears on CT as a diffusely dense sclerotic bone lesion not unlike a malignant lesion. The possibility of a graft has to be included in the differential diagnosis in these cases.

Adolescent↗
PubMed1997

The prognostic application of cytokeratin typing of nonsmall cell lung carcinoma. A retrospective study.

BACKGROUND: In a previous study, the authors used a variety of anticytokeratin monoclonal antibodies to show that a large proportion of lung tumors cytologically diagnosed as squamous cell carcinoma contain cells expressing simple epithelial cytokeratins, suggesting that these tumors have their origin in adenocarcinoma. These findings raised the possibility that cytokeratin (CK) typing might have a diagnostic capacity not attainable by standard histopathology. The aim of the current study was to assess the value of CK typing for this purpose by determining the correlation between the diagnosis of lung tumors based on CK typing and the survival rate of the patients. METHODS: Paraffin embedded tissue sections of 66 nonsmall cell lung carcinoma (NSCLC) specimens were examined. These included 18 adenocarcinomas, 32 squamous cell carcinomas, and 16 undifferentiated carcinomas, all diagnosed surgically and histopathologically, and further classified as either Stage I or II. CK typing was performed using the streptavidin-biotin-peroxidase method, employing the following anti-CK monoclonal antibodies: Ks.B.17 (which reacts with CK 18), A3-3 (which reacts with CK 13), and E5-9 (which reacts with CK 10). RESULTS: Comparison between the 5-year survival rates (5 ysr) of patients with different NSCLC indicated that all types of Stage II tumors had a much poorer prognosis than Stage I tumors. Differences found in the 5 ysr among patients with different types of Stage I tumors were not statistically significant (adenocarcinomas, 33% 5 ysr; squamous cell carcinomas, 59% 5 ysr; undifferentiated carcinomas, 36% 5 ysr; all diagnosed by conventional histopathology). Similarly, no significant differences were noted in 5 ysr between patients with tumors stained positively or negatively with monoclonal antibodies A3-3 or E5-9 (anti-CK 13 and anti-CK 10, respectively). In contrast, highly significant differences (P = 0.002) were found in the 5 ysr between patients with Stage I tumors positively or negatively stained with monoclonal antibody Ks.B.17 (23% vs. 75% 5 ysr, respectively) regardless of the histologic types of tumors. Especially informative was a combination of immunohistochemical and histologic diagnoses, with best survival rates (87% 5 ysr) in Ks.B.17 negative tumors histologically diagnosed as Stage I squamous cell carcinomas and worst survival rates (14% 5 ysr) in Ks.B.17 positive tumors diagnosed as adenocarcinomas. CONCLUSIONS: The current study showed that CK 18 typing of lung tumors can provide a more accurate diagnosis and therefore facilitate the planning of more suitable therapeutic approaches.

Adenocarcinoma↗
PubMed1997

Evaluation of penetrating injuries of the neck: prospective study of 223 patients.

The objective of this study was to assess the role of clinical examination, angiography, color flow Doppler imaging, and other diagnostic tests in identifying injuries to the vascular or aerodigestive structures in patients with penetrating injuries to the neck. A prospective study was made of patients with penetrating neck injuries. All patients had a careful physical examination according to a written protocol. Stable patients underwent routine four-vessel angiography and color flow Doppler imaging. Esophagography and endoscopy were performed for proximity injuries. The sensitivity, specificity, and predictive values of physical examination, color flow Doppler studies, and other diagnostic tests were assessed during the evaluation of vascular and aerodigestive tract structures in the neck. Altogether 223 patients were entered in the study. After physical examination 176 patients underwent angiography and 99 of them underwent color flow Doppler imaging. Angiographic abnormalities were seen in 34 patients for an incidence of 19.3%, but only 14 (8.0%) required treatment. Color flow Doppler imaging was performed on 99 patients with a sensitivity of 91.7%, specificity 100%, positive predictive value (PPV) 100%, and negative predictive value (NPV) 99%. These values were all 100% when only injuries requiring treatment were considered. None of the 160 patients without clinical signs of vascular injury had serious vascular trauma requiring treatment (NPV 100%), although angiography in 127 showed 11 vascular lesions not requiring treatment. "Hard" signs on clinical examination (large expanding hematomas, severe active bleeding, shock not responding to fluids, diminished radial pulse, bruit) reliably predicted major vascular trauma requiring treatment. Among 34 of the 223 total patients (15.2%) admitted with "soft" signs, 8 had angiographically detected injuries, but only one required treatment. An esophagogram was performed on 98 patients because of proximity injuries (49 patients) or suspicious clinical signs (49 patients), and two of them showed esophageal perforations. None of the 167 patients without clinical signs of esophageal trauma had an esophageal injury requiring treatment. It was concluded that physical examination is reliable for identifying those patients with penetrating injuries of the neck who require vascular or esophageal diagnostic studies. Color flow Doppler imaging is a dependable alternative to angiography. An algorithm for the initial assessment of neck injuries is suggested.

Algorithms↗
PubMed1997

Exostosis of a rib causing laceration of the diaphragm: diagnosis and management.

A 17-year-old boy presented with spontaneous hemothorax due to a puncture wound of the diaphragm by an inward facing exostosis of the rib. Diagnosis was made by computed tomographic scan, and the patient underwent a video-assisted thoracoscopic procedure to remove the exostosis. This is only the eighth reported case of an exostosis causing hemothorax.

Adolescent↗
PubMed1997

Absence of p53 mutations in malignant mesotheliomas.

Mutations in the p53 gene are the most common genetic alterations found in human malignancies. In this study, a search was done for mutations in the conserved regions of the p53 gene in malignant mesotheliomas. Thirteen malignant mesotheliomas collected over the preceding 12 yr and maintained in paraffin blocks were examined by polymerase chain reaction (PCR) followed by both single-strand conformation polymorphism (SSCP) and denaturing gradient-gel electrophoresis (DGGE). Direct sequence analysis was performed in cases suspected for mutations. No mutations in exons 5 to 8 of the p53 gene were detected. Our results suggest that malignant transformation of human mesothelioma cells does not require inactivation of p53 by point mutations in the conserved regions of the gene.

Adult↗
PubMed1996

Management options in vertebral artery injuries.

The treatment of 22 patients with vertebral artery injuries was reviewed. Only four patients required an emergency operation. Most of the injuries (13 of 22) were successfully managed by observation. Five patients were managed by angiographic embolization which was successful in three. In three patients with an aneurysm and arteriovenous fistula, proximal embolization of the vascular lesion was not adequate and a suboccipital craniectomy was required for distal ligation. Most vertebral artery injuries can safely be managed without an operation, or by angiographic embolization. Surgical intervention should be reserved for patients with severe bleeding or where embolization has failed.

Adolescent↗
PubMed1996

Re-expansion pulmonary oedema following spontaneous pneumothorax.

Re-expansion pulmonary oedema may occur after chest tube drainage of pneumothorax and can give rise to cardiopulmonary manifestations which range from the mild to the severe. In order to evaluate the prevalence and the clinical manifestations of this complication, all patients with spontaneous pneumothorax managed with chest tube drainage were evaluated over an 8-yr period (1986-1994). A chest radiograph was performed routinely in all patients within 4 h of tube insertion. Lung expansion and the appearance of infiltrates within the lungs were investigated specifically. Re-expansion oedema was noted in three of 320 episodes (0.9%). Two of the three patients needed rapid and extensive clinical treatment.

Adult↗
PubMed1996

Pediatric craniocerebral wounds from plastic bullets: prognostic implications, course, and outcome.

OBJECTIVE: To review our experience with craniocerebral injuries caused by plastic bullets, and to delineate prognostic factors for outcome. DESIGN: Retrospective case series of 29 patients presenting with plastic bullet-induced craniocerebral lesions. SETTING: Pediatric intensive care department of a tertiary care center. MEASUREMENTS AND MAIN RESULTS: Outcome was poor in 10 patients, good in 11, and two and six patients were moderately and severely disabled, respectively. Statistical analysis showed prognostic significance of the admission Glasgow Coma Scale score, computed tomographic findings of intraventricular hemorrhage and midline shift, and metabolic studies including hypokalemia and hyperglycemia. CONCLUSIONS: Plastic bullet-induced craniocerebral injuries carry a lower morbidity and mortality rate compared with other gunshot wounds. However, plastic bullets do incur a significant risk of injury. Their use should be carefully regulated.

Adolescent↗
PubMed1996

Radiation pneumonitis complicating mediastinal radiotherapy postpneumonectomy.

Radiation pneumonitis is a well-characterized clinicopathological syndrome. The severity of radiation-induced lung injury correlates, among other factors, with the extent of lung volume incorporated within the field of radiation. The present article describes the cases of two patients with radiation pneumonitis following pneumonectomy and mediastinal radiotherapy. Postpneumonectomy pulmonary-mediastinal shift of the remaining lung towards the operated side, with inclusion of lung parenchyma within the "mediastinal" radiation portals, resulted in a substantial (albeit clinically unsuspected) radiation pneumonitis. Chest computed tomography in the postpneumonectomy patient may be helpful to evaluate the degree of pulmonary-mediastinal shift and optimization of the radiotherapy field.

Combined Modality Therapy↗
PubMed1995

Penetrating injuries of the neck in patients in stable condition. Physical examination, angiography, or color flow Doppler imaging.

BACKGROUND: The initial assessment of penetrating injuries of the neck is controversial, with angiography remaining the gold standard for identifying vascular injuries. Recent reports suggest that physical examination might be an accurate way to evaluate these injuries. Color flow Doppler imaging has been used with promising results to assess extremity injuries, but the role of color flow Doppler imaging in neck injuries has not been studied. OBJECTIVE: To evaluate and compare the roles of physical examination, color flow Doppler imaging, and angiography in the identification and management of penetrating neck injuries. STUDY DESIGN: A prospective study of patients in stable condition with penetrating injuries of the neck. All study patients were examined according to a written clinical protocol and subsequently underwent angiography and color flow Doppler imaging. The sensitivity and specificity of physical examination and color flow Doppler imaging were compared with those of angiography. RESULTS: Eighty-two patients fulfilled the criteria for inclusion in the study. Angiography demonstrated vascular lesions in 11 patients (13.4%), but only two (2.4%) of them required treatment. Serious injuries were detected or suspected during physical examination, but six lesions not requiring treatment were missed. When injuries not requiring treatment were excluded, the sensitivity was 100% and the specificity was 91%. With color flow Doppler imaging, 10 of the 11 injuries were identified, for a sensitivity of 91% and a specificity of 98.6%. The sensitivity and specificity were 100% for clinically important lesions. CONCLUSION: The combination of a careful physical examination and color flow Doppler imaging provides a reliable way to assess penetrating neck trauma and may be a safe alternative to routine contrast angiography.

Adolescent↗
PubMed1994

Human endothelial cells are defective in diabetic vascular disease.

Diabetic vascular disease is characterized pathologically by endothelial cell (EC) hyperplasia and basement membrane (BM) thickening. One key question regarding the pathogenesis of diabetic vascular disease is whether the EC or BM or both are primarily defective and responsible for these pathological changes. Previous studies, which took the approach of creating artificial diabetic conditions, have been inconclusive. It is known, however, that the extracellular matrix may be altered by glycosylation as a result of hyperglycemia, thereby altering EC function. To begin to address this question and more closely mimic the situation in vivo, we characterized human diabetic EC harvested from insulin-dependent diabetic mothers (IDDM) at the cellular and molecular levels. Human EC were isolated from both normal and IDDM umbilical cords and cellular functions evaluated using standard assays of attachment (% attached cells), proliferation (cpm/cell), resistance to detachment under shear stress (number of cells remaining attached), and glucose uptake (cpm/2 X 10(4) cells). Gene expression of major BM components (collagen type IV, laminin beta 1, and laminin beta 2) was quantified by Northern analysis. Diabetic EC demonstrated increased proliferation (two- to eightfold compared to normals), were 20-40% less resistant to shear stress and took up glucose 10-15% more slowly than normal EC. Furthermore, Northern analysis showed that the expression of major BM components was increased by an average of 10-18% in diabetic cells compared to normal cells. These results were consistent with in vivo observations and previously published data.(ABSTRACT TRUNCATED AT 250 WORDS)

Basement Membrane↗