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Biomedical subjects

M Huntrakoon

Publications and source records attributed to M Huntrakoon.

At least 19 recordsLinked to original sources
PubMed1996

Hibernoma.

Hibernoma is a rare, benign soft tissue tumor composed of brown fat. A 42-year-old white man presented with an enlarging soft tissue mass located in his left medial thigh. This was evaluated radiographically by CT as well as MR imaging. An open biopsy revealed a hibernoma. The mass was subsequently excised in its entirety, maintaining a cuff of normal tissue. The patient has done very well postoperatively. Although nearly 100 cases have been reported, this case is presented to review the clinical and pathological presentation of this tumor and to describe its MR imaging characteristics.

Adult↗
PubMed1994

Leiomyosarcoma of the vulva: report of a case.

A 52-year-old female presented with a progressively enlarging vulvar mass. Pathological evaluation revealed a high-grade vulvar leiomyosarcoma. Immunohistochemical and ultrastructural studies were performed to support the diagnosis. In an effort to better understand the biology of this tumor additional immunohistochemical studies for the protein product of p53 tumor suppressor gene and estrogen receptor expression by tumor cells, as well as the type of immune cells infiltrating the tumor were performed. Tumor cells showed an overexpression of p53 protein and were estrogen receptor-positive. Macrophages and T and B lymphocytes infiltrated the tumor in moderate numbers with occasional lymphoid aggregate formation. This study is the first attempt to better understand the biology of these tumors.

B-Lymphocytes↗
PubMed1994

Comparative age-related acute and chronic pulmonary oxygen tolerance in rats.

Young rats are thought to be more tolerant to hyperoxia. We propose that this may not be proven and depends on how tolerance is defined. We assessed oxygen tolerance in Sprague-Dawley rats from birth to maturity by comparing survival, lung water, antioxidant enzyme activity, lung morphometrics, heart weight, and arterial blood gases in newborn and 27-, 44-, 48-, and 96-day-old rats exposed to 100% O2 or room air for 22 days. Some 96-day-old rats (rest group) received only 50% O2 between 48 and 72 h. Mortality after 5 days of O2 was 0% in newborn and 27-day-old rats and 27% in 44-day-old rats but was > 80% in 48- and 96-day-old rats. Between 5 and 22 days, the death rate was 100% in newborns, 25% in 27-day-old rats, and 0% in 44- to 96-day-old rats. Death occurred when lung water was > 84% except in newborns, which tolerated high lung water for the first 7 days. In chronically exposed 44- and 96-day-old rats, lung water returned to normal. Enzyme activity increased with O2 at all ages but did not relate to survival. In 96-day-old rats, the initial increase was suppressed on day 3. All chronically O2-exposed rats had minimal nonvascular parenchymal changes but developed right ventricular hypertrophy and increased alveolar ductal artery muscularization and lost alveolar capillaries. The most mature rats were least affected. In O2, there was pulmonary insufficiency the first 3 days, followed by recovery, and later hypercarbia and decreased arterial PO2. We conclude that young rats, 0-44 days old, are more O2 tolerant for 5 days. More mature animals, surviving 5 days, are more tolerant to chronic exposure.

Aging↗
PubMed1994

Subcapital fractures of the femoral neck: prevalence and cause of radiographic appearance simulating pathologic fracture.

OBJECTIVE: Subcapital fractures of the femoral neck are common in elderly persons who have osteoporosis. Occasionally, radiographs of the hip in these patients show a radiolucency in the superolateral, subcapital region of the femoral neck that mimics the features of a pathologic fracture. Our purpose was to determine the prevalence of this finding and the anatomic variations of fracture alignment that cause this appearance. MATERIALS AND METHODS: All subcapital nonpathologic hip fractures (n = 111) that occurred at our institution during a 5-year period were reviewed. Radiographs were available in 100 of these cases. Review of intraoperative biopsy specimens, available in 69 patients, revealed no evidence of neoplasm in any case. In the other patients, follow-up radiographs, clinical evaluation, and pathology reports were used to exclude neoplastic involvement. Preoperative radiographs were analyzed for the presence of findings suggesting a pathologic fracture. Fracture configuration was classified by using the Garden staging system. Cadaveric femurs (n = 6) were fractured and studied radiographically. RESULTS: Seventeen (17%) of the 100 subcapital fractures had a radiographic appearance similar to that of a pathologic fracture. This finding occurred only with Garden stage III fractures (n = 7, 32% of Garden stage III fractures) or Garden stage IV fractures (n = 10, 24% of Garden stage IV fractures). Study of the cadaveric femoral specimens showed that the radiographic appearance simulating a pathologic fracture was primarily caused by external rotation of the distal fracture fragment and was accentuated by displacement between fracture fragments. CONCLUSION: The radiographic appearance of subcapital fractures of the femoral neck unrelated to neoplasm is often similar to that of pathologic fractures. This appearance is caused primarily by rotation of the fracture fragments, and the finding is accentuated by displacement. Recognition of the appearance of subcapital hip fractures mimicking pathologic fractures and knowledge of the cause of this finding are important for prescribing appropriate treatment.

Adolescent↗
PubMed1992

Titanium-induced arthropathy associated with polyethylene-metal separation after total joint replacement.

Complications of total joint replacements are not infrequent. The authors describe five patients with displacement of the polyethylene component in two knee (metal-backed patellar component) and three hip joint replacements. Clinical, radiographic, surgical, and pathologic findings were reviewed in all cases. Conventional radiographs revealed abnormal position of the metal components in all patients and opaque curvilinear periarticular deposits in four. Arthropathy caused by deposition of small titanium particles from metal friction (in the absence of interposed polyethylene) was pathologically proved to correspond to the periarticular opacity. The subtle radiolucent polyethylene component was identified in all patients; adequate visualization in some cases may necessitate imaging with additional methods such as magnification, phosphor plate, and soft-tissue radiographic techniques; conventional tomography; and arthrography. Early recognition of these abnormalities in patients with painful joint replacements may allow less extensive surgical revision and prevent development of titanium-induced arthropathy.

Aged↗
PubMed1992

Identification of donor melanoma in a renal transplant recipient.

A patient with chronic renal failure received a closely matched cadaveric kidney. Approximately 3 months after transplantation, the patient developed a metastatic malignant melanoma. A large retroperitoneal mass consisting of large pleomorphic polygonal neoplastic cells was found close to the donated kidney. This tumor was diagnosed as a malignant melanoma. DNA analysis of this tumor, the donated kidney, and the recipient indicated that the melanoma originated from the donor. Although this is not the first report of a donated melanoma, it is the first report of definitive DNA analysis of the origin of the malignant cells.

DNA, Neoplasm↗
PubMed1991

Immunocytochemical studies of subtypes of pulmonary endocrine cells in diethylnitrosamine-treated rabbits.

New Zealand White rabbits were injected subcutaneously with 20 mg/kg body weight of diethylnitrosamine (DEN), twice per week, starting when they were 1 week old. The animals were sacrificed 6 to 12 months after the first injection and lung tissues were processed for light microscopy. Using serotonin (5HT) and neuron specific enolase (NSE) as markers for the endocrine cells, tissue sections were stained immunocytochemically by the avidin-biotin complex method. Numerous neuroepithelial bodies (NEBs) positive for 5HT, but negative for NSE, were seen in the alveolar duct regions of DEN-treated rabbits. On the other hand, an increased number of solitary endocrine cells immunoreactive for NSE was found in bronchial or bronchiolar epithelia. The results indicate that DEN induced increases in two distinct types of endocrine cells: the component cells of NEBs are positive for 5HT and solitary cells are positive for NSE.

Animals↗
PubMed1990

Bilateral choroidal neonatal neuroblastoma.

We treated a bilateral, well-differentiated neuroblastoma of the choroid in a patient who had congenital abdominal neuroblastoma. Although orbital metastasis of neuroblastoma is common, intraocular metastasis is not. In our patient, there was no amplification of the N-myc oncogene in the tumor of either eye. This is consistent with early-stage primary neuroblastoma. Histologically, the tumors were identical in each eye and well differentiated with Homer Wright rosettes; most neuroblastoma metastases have few rosettes and are composed of more undifferentiated, anaplastic cells. We believe that our patient had bilateral primary tumors and not metastatic tumors.

Choroid Neoplasms↗
PubMed1990

Chromosomal abnormalities in clear cell sarcoma. Implications for histogenesis.

Cytogenetic analysis was performed on three specimens of clear cell sarcoma, a rare neoplasm of uncertain histogenesis. Chromosomal analysis of clear cell sarcoma has not been reported previously. Two of the specimens analyzed consisted of the primary foot lesion and subsequent lymph node metastasis in a 29-year-old male. The other specimen was a primary foot lesion in a 61-year-old male. Clonal abnormalities were detected in all three of the specimens. The significance of these results with regard to the origin of this uncommon neoplasm is discussed.

Adult↗
PubMed1990

The significance of eosinophils in mild and moderate acute cardiac allograft rejection.

The presence of eosinophils has previously been associated with severe acute cardiac allograft rejection. This appears to be a relatively uncommon finding, judging from our experience and the paucity of information appearing in literature. We report three cases where a prominent infiltrate of eosinophils was noted on endomyocardial biopsy following cardiac transplantation. There was no evidence of severe acute rejection in any of these three patients, and one patient had only mild acute rejection without even focal myocardial necrosis. An infiltrate, which includes eosinophils, does not appear to be restricted to severe acute cardiac allograft rejection. Therefore, when eosinophils are noted in endomyocardial biopsy specimens, decisions to revise the immunosuppressive regimen of cardiac transplant recipients should continue to be based upon established conventional histologic criteria.

Acute Disease↗
PubMed1989

Misalignment of lung vessels and alveolar capillary dysplasia: a cause of persistent pulmonary hypertension.

Two infants with fatal persistent pulmonary hypertension are described. Morphologically there was misalignment of the lung vessels, with the veins and the arterioles anomalously related, often sharing the same adventitial sheet. The capillaries did not make contact with the alveolar epithelium. The arterioles had increased medial muscle, and there was extension of the arteriolar muscularization to the precapillary level. The fraction of the parenchyma that was septal and connective tissue was increased. The acini had a decreased complexity, with immature alveoli and with a decreased radial alveolar count. The cause appeared to be related to abnormal capillary and venous plexus formation and migration. This syndrome seems to be identical with that described in three previous reports and probably represents a specific cause of persistent pulmonary hypertension.

Arterioles↗
PubMed1989

Small renal neoplasms: clinical, pathologic, and imaging features.

Small renal neoplasms are being found more often because of the widespread use of abdominal CT and sonography. Little is known about their natural history. We therefore retrospectively reviewed clinical, pathologic, and imaging findings in 22 patients with surgically confirmed solitary renal neoplasms that were 3 cm or less in diameter. Eighteen lesions were first found by CT, three by sonography, and one by IV urography. Three lesions were discovered because the patients had hematuria. Nineteen were incidental radiologic diagnoses in patients without renal symptoms. Of 22 neoplasms, 15 (68%) were renal cell carcinomas, six (27%) were oncocytomas, and one (5%) was a lymphoma. Fourteen (93%) of the 15 carcinomas were confined to the kidney, and one showed microscopic capsular invasion. Metastases did not develop in any patient with carcinoma, indicating that small carcinomas usually have good prognoses. Patients with carcinomas had a mean follow-up of 42 months. All neoplasms were visible on CT. However, characterization of these lesions sometimes required a combination of CT and sonography and occasionally angiography. The carcinomas, oncocytomas, and solitary renal lymphoma could not be distinguished radiologically. Small renal neoplasms are most often found incidentally by CT performed in patients without renal complaints. Most are low-stage carcinomas, and some are oncocytomas.

Adenoma↗
PubMed1989

Diethylnitrosamine-induced pulmonary endocrine cell hyperplasia and its association with adenomatosis and adenocarcinoma in rabbits.

Pulmonary endocrine cells are suspected of being the precursors for small cell carcinoma of the lung (SCCL). The purpose of this study was to determine whether Diethylnitrosamine (DEN) can induce SCCL in rabbits. New Zealand white rabbits were injected subcutaneously with 20 mg/kg body weight of DEN, twice per week, starting when they were 1 week old. Controls received saline vehicle only. The animals were sacrificed 6 to 8.5 months after the first injection and lung tissues were processed for light microscopy. Using serotonin (5-HT) as a marker for the endocrine cells, tissue sections were stained immunohistochemically by the avidin-biotin complex method. In both control and DEN-treated animals, serotonin-immunoreactive cells organized into neuroepithelial bodies (NEBs). There was an apparent increase in the size, number, and stainability of NEB in DEN-injected animals. A majority of these NEBs were localized in the alveolar duct region. Small foci of adenomatosis and well-differentiated adenocarcinomas, which sometimes coexisted with hyperplastic pulmonary endocrine cells, were also found in the DEN-treated rabbits.

Adenocarcinoma↗
PubMed1988

Mucinous carcinoma of the breast: recurrence 30 years after mastectomy.

We have reported a case of mucinous breast carcinoma that recurred in the form of lung and lymph node metastases 30 years after definitive resection. This case emphasizes the indolent nature of this neoplasm and the need to lengthen the period of follow-up for patients with this form of cancer.

Adenocarcinoma, Mucinous↗
PubMed1988

Morphologic response of rat Leydig cells to hemicastration.

Hemiorchidectomized rats were followed up to 15 days postsurgery for morphologic evaluation of compensatory testicular response and its correlation to serum testosterone levels. Although gross compensatory testicular hypertrophy (CTH) was not noted, an enlarged interstitium was observed with hypertrophy and hyperplasia of Leydig cells with morphologic changes suggestive of increased cellular activity. These histologic changes were accompanied by compensatory testicular hypersecretion (CTHS) illustrated by the return of the serum testosterone levels to near the intact-control value in the later groups. Ultrastructural studies of the Leydig cells indicated an increase in the amount of smooth endoplasmic reticulum as an underlying mechanism for this response. In view of the previously reported normal serum luteinizing hormone levels after hemicastration, the compensatory hyperactivity/hypersecretion should be considered primarily an intrinsic Leydig cell response, not related to changes in the hypothalamo-hypophyseal axis.

Animals↗
PubMed1988

Congenital fibromatosis (myofibromatosis) of the orbit: a rare cause of proptosis at birth.

A full-term infant boy had proptosis OS at birth: A large solid tumor mass was found by examination and computed tomographic scan in the orbit and extended intracranially. Biopsy showed spindle-shaped tumor cells that, with electron microscopy, proved to be myofibroblasts. Congenital fibromatosis (myofibromatosis) is a benign localized tumor of which this case is a striking example.

Exophthalmos↗
PubMed1988

Premortem histologic evidence of chronic vascular rejection obtained from percutaneous endomyocardial biopsy: report of a case.

Chronic rejection is characterized by obliterative arteritis of coronary arteries and their branches in the form of myointimal proliferation and diffuse tubular atherosclerosis. Chronic rejection is more difficult to detect than discrete focal obstructive lesions by coronary angiography. We report a case of a 51-year-old woman in whom a biopsy of the right ventricle 14 months after heart transplantation revealed convincing histologic evidence of chronic rejection. A subsequent biopsy of the left ventricle showed subendocardial infarct. Necropsy findings confirmed coronary artery changes of chronic rejection, as well as diffuse subendocardial infarction, which had been suspected clinically. The finding of a small arteriole in a biopsy was fortuitous. However, if such a vessel is present and shows obliterative arteritis, this demonstrates that a premortem histologic diagnosis of chronic rejection is possible.

Biopsy↗