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Biomedical subjects

P Som

Publications and source records attributed to P Som.

At least 19 recordsLinked to original sources
PubMed2001

Failed medialization laryngoplasty: management by revision surgery.

OBJECTIVE: The purpose of this study was to evaluate the cause of immediate and late medialization laryngoplasty failures and to describe their management. METHODS: A retrospective analysis was performed in 20 patients who underwent revision surgery after failed medialization laryngoplasty. Analysis was based on preoperative spiral CT scan, preoperative and postoperative videostrobolaryngoscopy, and phonatory function measures. RESULTS: Three major types of failures were identified. The most common problem was arytenoid rotation with a persistent posterior glottic gap (11 of 20). Malposition or wrong size of the implants resulted in a lateralized vocal fold or false vocal fold medialization (6 of 20). Three patients had implants that were extruding. Late atrophy and bowing resulted in a glottal gap (2 of 20). One patient had fibrosis around the implant requiring removal. Spiral CT scan of the larynx located the implant precisely and showed the degree of arytenoid rotation. Patients with arytenoid rotation and posterior gap had revision medialization combined with arytenoid adduction. Revision medialization was performed in 11 patients, arytenoid adduction in 12 patients, lipoinjection in 2 patients, and 4 implants were removed. The voice was improved in 15 patients. Improved voice was correlated with improved phonation time and reduced phonatory airflow rates. CONCLUSION: Immediate and late failures of medialization laryngoplasty are due to several possible causes. Revision surgery is feasible and highly successful. To select between the surgical alternatives work up should include preoperative analysis of vocal function, videostrobolaryngoscopic analysis, and spiral CT of the larynx.

Adult↗
PubMed2000

Radiolabeling brachytherapy sources with Re-188 through chelating microfilms: stents.

Rhenium-188 (Re-188, T(1/2) = 17 h) emits beta particles (E(max) = 2. 12 MeV) having an ideal range for intravascular brachytherapy and certain cancer brachytherapies. Re-188 was attached to metal wafers and stents via a chelating microfilm, and these brachytherapy sources characterized in vitro and in vivo. To prepare the sources, a siloxane film containing reactive amines was plasma deposited on the metal, a chelating microfilm conjugated to the amines, and the chelating microfilm used to attach Re-188. Re-188 was selectively bound to materials coated with the chelating microfilm. Binding correlated with the amount of radionuclide used. Wafers (1 cm(2)) bound up to 62.9 MBq (1.7 mCi) of Re-188 with yields generally near 30%. Stents bound up to 26.6 MBq (720 microCi). Typically, stents were labeled to bind 4-12 MBq and deposit 10-30 Gy at 2 mm in the arterial wall. In phantom studies, the longer nitinol stents deposited doses of 2.3 Gy/MBq (0.085 Gy/microCi), while shorter stainless steel stents deposited 4.62 Gy/MBq (0.171 Gy/microCi). After placement in arteries of pigs, only the Re-188-stents were detected by scintigraphy at times up to 24 h. Scintigraphy did not detect activity in other organs. Blood sampling (0.1-24 h) detected maximum radioactivity (up to 388 cpm/mL/100micro Ci) at 6 h. We conclude that on-demand radiolabeling of stents and other brachytherapy sources with Re-188 can be performed routinely.

Biocompatible Materials↗
PubMed2000

A clinicopathological study of sinonasal neuroendocrine carcinoma and sinonasal undifferentiated carcinoma.

OBJECTIVE: Sinonasal undifferentiated carcinoma (SNUC) and sinonasal neuroendocrine carcinoma (SNEC) are relatively newly recognized, rare entities requiring further clinicopathological analysis to advance our understanding and determine prognostic distinctions between them. STUDY DESIGN: Retrospective chart review. METHODS: Cases were retrieved from the Copath system. One patient was seen in consultation from an outside institution. Histological and immunohistochemical findings, patient demographics, treatment regimens, and outcomes were analyzed and compared. RESULTS: Ten patients (7 men, 3 women) ranging in age from 17 to 58 years (mean age, 44.7 y) were included. Four patients were classified with SNEC, six as having SNUC. The predominant site was the superior nasal cavity or ethmoids (seven cases), followed by the maxilla (four cases). Disease in four patients was clinically staged as N1 (three with SNUC, one with SNEC), and in six patients as NO (three with SNEC, three with SNUC). Of the nine patients who were treated initially with surgical resection, seven received postoperative radiation therapy alone, one received postoperative radiation and chemotherapy, and one had only limited postoperative chemotherapy. One patient was treated with radiation therapy and chemotherapy alone, without surgical resection. Follow-up was obtained ranging from 6 to 108 months (mean period, 26.4 mo). Three patients died of disease 10, 14, and 41 months, respectively, after diagnosis. Three patients had persistent disease at 6, 9, and 21 months, respectively, two of them with distant metastases. Four patients were disease free after 6, 18, 31, and 108 months, respectively. CONCLUSIONS: SNUC and SNEC are both aggressive tumors, usually presenting in middle age as a nasal mass. Both tumors have the capacity to metastasize locally and distantly, and both can result in poor outcomes. This small series precludes a demographic or prognostic distinction between the two groups.

Adolescent↗
PubMed1999

Granular cell tumor of the parotid.

A case of granular cell tumor of the major salivary glands is presented. This tumor appeared as an expansive multinodular mass that arose from facial nerve trunks. The presenting symptoms of facial pain and paresis and the intraoperative findings of tumor adhesion to nerves led to the clinical impression of malignancy. At intraoperative consultation, the tumor resembled an acinic cell carcinoma. Pathologists should be aware that granular cell tumors may involve the major salivary glands and that it should be considered in the diagnostic differential diagnosis.

Female↗
PubMed1999

Sialoblastoma: clinicopathological/immunohistochemical study.

Sialoblastoma is an extremely rare salivary tumor diagnosed at birth or shortly thereafter with significant variability in histologic range and clinical course, so that for an individual case it may be difficult to predict the most appropriate therapy. We detail the case of a toddler noted to have a firm 1-2-cm mass in the left cheek at 21 months. Parotidectomy was performed at 26 months, revealing a sialoblastoma; the resection margins were positive. During the next 10 months, the mass recurred or persisted, necessitating numerous procedures. The tumor was composed of basaloid cells with fine chromatin and other more mature cuboidal epithelial cells. Ductules and solid organoid nests with some tendency toward peripheral pallisading were also noted. There was no perineural invasion; necrosis initially was sparse but increased over time. The mitotic rate also increased from 6 to 7/10 high-power fields in the first resection to 20/10 high-power fields in the last resection. Nuclear pleomorphism increased with time. The MiB1 proliferative index revealed a dramatic increase in the number of labeled nuclei: from 3 cells/10 high-power fields in the first specimen to 94 cells/10 high-power fields for the last specimen. Cytokeratin accentuated the ductal structures. S-100 showed a diffuse staining pattern, with darker staining of the spindled myoepithelial cells. The Her-2-neu protein showed moderate cytoplasmic staining, whereas the p53 showed only occasional labeling of nuclei. This is the first case of sialoblastoma with evidence of increasing anaplasia based on increasing proliferative capacity. Therefore, the distinction between benign and malignant sialoblastomas may not be as well defined as previously thought. The patient's prognosis is likely to be determined by the tumor grade as well as the stage at presentation and the extent of resection.

Biomarkers, Tumor↗
PubMed1999

The back door: venous-mediated metastasis into cervical lymph nodes as an alternative metastatic pathway for oropharyngeal squamous cell carcinoma.

Circulating lymphocytes may home to lymph nodes (LNs) via paracortical postcapillary venules, high-endothelial venules (HEVs) that recognize circulating lymphocytes, enabling them to migrate into nodal cortical/paracortical regions. Our goal was to find any histologic, immunohistochemical, or in vitro evidence to support the hypothesis that squamous cell carcinoma (SCC) may gain access to LNs via an alternative venolymphatic pathway. Slides from 67 neck dissections with SCC were studied. Standard criteria for lymphatic-mediated metastasis were used; criteria for evidence ofvenolymphatic metastasis were tumor nests localized to the paracortical regions, directly contiguous to HEVs but not marginal sinuses. Cases in which LN architecture was obliterated by metastases were excluded. A modified Stamper-Woodruff assay, which assesses HEV binding, incubated cell lines from oral carcinomas and lung adenocarcinomas with fresh frozen LN sections. Double-blinded cell counts were performed by two observers and analyzed by Student's t test. Immunohistochemical examination was undertaken on 19 paraffin-embedded cases with the monoclonal antibody, MoAb CD44v6, to discover whether expression of this adhesion molecule correlated with metastatic pattern. Twenty-nine cases (66%) revealed evidence only for the LN route of metastasis; 4 cases (9%) were classified as venolymphatic metastasis; 11 cases (25%) showed evidence for both pathways. The Stamper-Woodruff assay confirmed that SCC cells preferentially bound to HEV within cervical LN sections more than did adenocarcinoma cells (P = .02). Strong staining to MoAb CD44v6 was seen in 18 (95%) of 19 SCCs with a membranous pattern. Occasionally, CD44v6 highlighted tumor emboli adjacent to HEVs, but no overall correlation could be made between CD44v6 expression and pattern of spread. Tumor metastasis via lymphatic channels is the predominant mode of metastatic spread, but the venolymphatic route is a plausible alternative pathway. The preferential attachment of SCC cells to HEVs supports this theory.

Cell Adhesion↗
PubMed1998

Benign intratracheal thyroid: a possible cause for preoperative overstaging.

We report a rare case of intratracheal thyroid ectopia in the setting of papillary thyroid carcinoma, resulting in the preoperative clinical impression of an aggressive, high-stage tumor. A 24-year-old opera singer presented with complaints of a gagging or choking sensation. The results of computed tomography revealed a mass in the left thyroid lobe with multiple small calcifications consistent with papillary thyroid carcinoma as well as a soft tissue mass in the adjacent left tracheal lumen thought to be direct invasion by the thyroid tumor. A total thyroidectomy was performed including excision of half of the first and second tracheal cartilages and the lower portion of the hemicricoid cartilage. The final histological findings revealed that the intratracheal component was composed of benign thyroid tissue and strands of benign thyrocytes coursed through the first tracheal membrane. Intratracheal thyroid ectopia is a rare symptomatic occurrence with a striking female predisposition. We have identified 23 cases of intratracheal thyroid ectopia from the literature. They occur most often at the level of the cricoid, usually posteriorly with a slight predisposition for the left side. Continuity between the intratracheal component and the thyroid lobe may be seen. Clinicians and pathologists must be aware of this entity to avoid mistaking it for evidence of thyroid invasion by a malignant neoplasm.

Adult↗
PubMed1996

Biodistribution and clearance of 99mTc-labeled Arg-Gly-Asp (RGD) peptide in rats with ischemic acute renal failure.

Based on the previous demonstration of a renoprotective effect of arginine-glycine-aspartic acid (RGD) peptides in acute renal failure, experiments were designed to test the distribution and renal accumulation of the peptide. To accomplish this goal, in this study, RGD peptide was radiolabeled and its biodistribution and renal accumulation was determined in rats with ischemic acute renal failure (ARF). 99mTc-RGD with or without 111In-DTPA were injected intravenously in control and ARF rats. Various organs were dissected at different times after injection and subjected to gamma-scintillation counting and autoradiography (ARG). Blood clearance of 99mTc-RGD was rapid, with t1/2 < 10 min, and unchanged in ARF compared with control rats. Kidneys retained the largest portion of the injected dose in both control and ARF rats, as detected using scintillation counting and whole-body ARG (10.56 +/- 1.05% and 10.12 +/- 3.16% injected dose/g wet weight, respectively). Renal ARG revealed a significant increase in binding to the cortex in ARF kidneys, compared with that of control kidneys. Given the differences in renal blood flow and GFR in control and postischemic kidneys, the next series of experiments was performed with two radiopharmaceuticals, 99mTc-RGD and 111In-DTPA. The ratio of 99mTc-RGD:111In-DTPA was increased more than three-fold in ARF kidneys compared with control kidneys (2.7 +/- 0.15 versus 0.8 +/- 0.19, respectively). The results indicate that (1) RGD peptide undergoes a rapid clearance predominantly via the renal route; (2) despite a significant reduction in the renal perfusion, 99mTc-RGD peptide accumulates in the postischemic kidney; (3) this is consistent with the hypothesis on the involvement of RGD-recognizing integrins in the development of tubular obstruction in renal ischemia.

Acute Kidney Injury↗
PubMed1995

Imaging of multiple bilateral parotid gland oncocytomas.

Oncocytoma of the salivary glands is a rare tumor that usually follows a benign course and, in most cases, can be cured by surgical resection. The authors report a rare case of multiple bilateral parotid oncocytomas that presented clinically with two palpable parotid masses. Both CT and MRI scans demonstrated multiple masses in each parotid gland. The tumors exhibited intense uptake and prolonged retention of Tc-99m pertechnetate. The diagnosis was confirmed by fine needle aspiration. Sialoscintigraphy is a simple and noninvasive procedure that can usually separate benign entities like Warthin tumor and oncocytoma of the salivary glands from malignant tumors, and significantly affect the course of treatment.

Adenoma, Oxyphilic↗
PubMed1994

Evaluation and management of congenital cervical teratoma. Case report and review.

Congenital cervical teratoma can be clinically dramatic, although essentially benign. Prognosis is good provided that the airway is quickly stabilized and resection is not delayed. We present a case of massive cervical teratoma diagnosed using antenatal magnetic resonance imaging. The child was maintained on maternal circulation after cesarean section until successfully intubated, with a second team ready for emergent bronchoscopy or tracheotomy. After delivery, the lesion grew rapidly with persistent bleeding; biopsy revealed a benign, immature teratoma. On computed tomography all anatomy ventral to the vertebrae was obliterated. At surgery, however, the tumor was easily resected. The literature is reviewed, with attention to malignancy in neonatal cervical teratoma. Surgery was delayed because of the aggressive imaging appearance and rapid growth. This case suggests that when evaluating neonatal tumors, the standard criteria for infiltration and resectability may require modification.

Adult↗
PubMed1994

Spatial and temporal distribution of cocaine and effects of pharmacological interventions: wholebody autoradiographic microimaging studies.

Whole body timed distribution of pharmacological doses of 14C-cocaine was studied in rats using quantitative autoradiographic microimaging. Rapid, intense uptake was seen in the brain, spinal cord, adrenals and nuchal brown fat pad. Clearance of cocaine was fastest from the cerebellum. Cortex activity reached soft tissue activity within 20 min. Uptake in the heart and adrenals was very intense following the same time course as in the brain. Kidney activity increased gradually at the same time as in the liver, probably representing specific binding as well as an excretory pathway of cocaine. Desipramine decreased uptake in the heart and adrenals and a piperazine derivative (GBR 12909) caused decreased uptake in the brain, heart and adrenals. Scopolamine, pentobarbital and cold cocaine caused decreased uptake in all organs and increased uptake (excretion) in the liver. Thus, cocaine appears to bind in the brain to the dopamine transporter and to a lesser extent to transporters for norepinephrine and serotonin. In the heart cocaine binds to norepinephrine, serotonin and dopamine. The targeting of cocaine to specific organs and the time sequence correspond to the pharmacological effects of cocaine.

Adipose Tissue, Brown↗
PubMed1994

Quantitative autoradiographic measurement of cocaine-induced regional myocardial metabolic changes in hypertensive rats.

A rat model of hypertensive cardiomyopathy was studied to evaluate the acute effects of cocaine on the myocardium. Using autoradiographic microimaging techniques, myocardial perfusion (201Tl) and energy substrate utilization (glucose: [14C]2-fluoro-2-deoxy-D-glucose-[14C]2DG and fatty acid (15-[p-iodophenyl])-3-R,S-methyl pentadecanoic acid-[131I]BMIPP) were studied in Dahl strain salt-sensitive normotensive and hypertensive rats with and without intravenous cocaine. The right ventricle, septum, endocardium and epicardium of the left ventricle were analyzed. Increased perfusion (18%) was seen in the myocardium of the hypertensive rats as compared to the normotensive rats. There was higher [14C]2DG (254%) and lower fatty acid (13.2%) uptake in the hypertensive rats, indicative of a shift from aerobic to anaerobic substrate utilization. In cocaine-treated normotensive rats, a generalized decrease in myocardial perfusion (30%) and increased glucose metabolism (89%) was seen. In cocaine-treated hypertensive rats, the increased myocardial perfusion (16%) was heterogeneous and was more pronounced in septum and epicardium. The endocardium and epicardium in the hypertensive rats showed an overall increase (23%) in glucose utilization after cocaine which was not as dramatic as was seen in the normotensive heart and a slight increase in fatty acid utilization. These results are consistent with prior observations that under pressure overload the myocardium responds non-uniformly. It may well be that the hypertensive cardiomyopathic heart is unable to respond to the challenge of cocaine by further increasing glucose utilization. These data obtained in an animal model of hypertension seem to indicate that hypertension may increase the risk of cardiac complications related to cocaine.

Animals↗
PubMed1993

Myocardial accumulation of iodinated beta-methyl-branched fatty acid analog, [125I](p-iodophenyl)-3-(R,S)-methylpentadecanoic acid (BMIPP), and correlation to ATP concentration--II. Studies in salt-induced hypertensive rats.

This study investigates the possible relationship between myocardial [125I]BMIPP accumulation and ATP concentration, in the salt-induced hypertensive Dahl-strain rats. [125I]BMIPP accumulation in the myocardium was inversely related to the degree of hypertension. On the other hand, ATP levels increased in the myocardium of rats with higher blood pressure showing an inverse relationship with BMIPP accumulation. Further studies are required for elucidating these possible inter-related phenomena.

Adenosine Triphosphate↗
PubMed1993

Abscess scintigraphy with 99mTc-human immunoglobulin (IgG) using a one-step labeling method.

It was shown earlier that non-specific human gamma globulin (IgG) labeled with 111In can be used as an agent for abscess localization. We describe experimental results with 99mTc-IgG in animals bearing abscesses and tumors using a one-step labeling method with 99mTc. We studied this compound in several animal models: mice bearing turpentine abscesses and subcutaneously transplanted sarcomas, in rats with turpentine or E. coli abscesses and intracerebrally implanted gliomas and in rabbits with E. coli or turpentine abscesses. Blood clearance was studied in dogs. It was found that the absolute concentration of 111In-IgG in abscess and tumor was higher than that of 99mTc-IgG. However, the abscess-to-tumor ratio was higher for 99mTc-IgG. The 99mTc-IgG images were of high quality and abscesses could be detected as early as 30 min post-injection (p.i.). It appears that 99mTc-IgG has many potential advantages over 111In-IgG because of better physical properties of 99mTc, simpler preparation, lower cost and greater availability and the possibility of using higher 99mTc doses.

Abscess↗
PubMed1992

Paraganglioma of the inferior laryngeal paraganglia. A case report.

Laryngeal paragangliomas are uncommon, usually benign neoplasms. The overwhelming majority of these tumors are supraglottic, arising from the superior laryngeal parasympathetic paraganglia. Few paragangliomas of the infraglottic region have been described. We describe the case of a 35-year-old man with a family history of carotid body tumors who presented with an infraglottic paraganglioma.

Adult↗
PubMed1992

Laryngeal chondrosarcomas: a clinicopathologic study of 11 cases, including two "dedifferentiated" chondrosarcomas.

Laryngeal chondrosarcomas are uncommon, and those that contain a distinct, nonchondroid, high-grade spindle cell sarcoma (the so-called "dedifferentiated" chondrosarcoma or chondrosarcoma with additional malignant mesenchymal component [CAMMC]) are extremely rare. Laryngeal CAMMC merit special attention, as CAMMC in other sites portends a poor prognosis. Eleven patients with laryngeal chondrosarcomas are reported on; 2 of these patients had CAMMC. On follow-up, 3 of the 11 patients had recurrences. The first had recurrence 4 and 11 years after tumor enucleation; that patient died disease free 2 years after salvage total laryngectomy. The second had recurrence 2 years after partial laryngectomy and was lost to follow-up after salvage total laryngectomy. The last patient recurred 13 years after partial laryngectomy and underwent salvage total laryngectomy; that patient was one of the two who developed CAMMC, and he also developed stomal recurrence of the "dedifferentiated" component 3 years after total laryngectomy. The other 8 patients are disease free after partial laryngectomy (6) or total laryngectomy (2) 10 months to 12 years later (mean: 51 months). This includes the 1 other patient with CAMMC, who is disease free 60 months after total laryngectomy. Laryngeal CAMMC has been shown, in at least one of the two patients, to be associated with a poor outcome. Patients with recurrent laryngeal chondrosarcomas do not have a poorer outcome after salvage total laryngectomy. The authors advocate partial laryngectomy if technically feasible.

Adult↗