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Biomedical subjects

J R Marti

Publications and source records attributed to J R Marti.

9 recordsLinked to original sources
PubMed1994

Tall cell papillary thyroid cancer: incidence and prognosis.

BACKGROUND: The tall cell variant (TCV) of papillary thyroid cancer is reported to have a poor prognosis. This study examines the incidence and end result of surgical treatment of TCV. METHODS: In this study, 240 thyroid cancers treated over a 23-year period at two hospital centers are reviewed. A total of 153 patients with papillary cancer were available for follow-up. All microscopic slides were re-examined. RESULTS: Of the total 183 papillary cancers, 19 (10.4%) were TCV. The remainder were usual papillary or other papillary cancer variants. Patient age, tumor size, lymph node and soft-tissue involvement, recurrence, and death rates were evaluated. Multivariate statistical analysis disclosed that TCV histology, as well as age and tumor size, were significant predictors of recurrence. CONCLUSION: Despite a high rate of recurrence in TCV cases over age 50 (6/9), there were no recurrent TCVs in cases under age 50 (0/8). Pathologists and surgeons must develop an increased awareness of this entity and implications for more radical treatment in the older age group.

Adult↗
PubMed1991

Major salivary gland lymphoepithelial lesions and the acquired immunodeficiency syndrome.

Presently, there is no consensus regarding the most appropriate diagnostic and therapeutic approach to patients with human immunodeficiency virus (HIV)-associated lymphoepithelial lesions of the major salivary glands. A retrospective review of 60 consecutive patients with lymphoepithelial lesions is presented. Thirty-eight cases were associated with HIV infection. Lesions associated with HIV infection were usually bilateral, multiple, cystic, and associated with lymphadenopathy. In contrast, in those cases without HIV infection, the lesions tended to be solitary and solid. In the HIV-infected group, treatment included surgery, radiotherapy, zidovudine (AZT), and/or cyst aspiration. All therapeutic regimens, other than aspiration alone, were found to be effective. Eighteen of the patients with HIV infection developed the acquired immunodeficiency syndrome (AIDS) during the study period. Surgical treatment is probably not necessary in the majority of HIV-associated cases. Depending upon individual circumstances, treatment with AZT or low-dose radiotherapy is recommended. A diagnostic and therapeutic algorithm is presented as a guide to the management of future cases.

AIDS-Related Complex↗
PubMed1984

Carcinoma of the breast with pseudosarcomatous metaplasia.

Twenty-six cases of breast carcinoma demonstrating pseudosarcomatous metaplasia are described, and their clinical and pathologic aspects are correlated. The metaplastic elements include mature and immature bone, cartilage, myxoid stroma, loose fibromyxoid and dense spindle-cell stroma, and anaplastic stroma with giant cell features. Light and electron microscopic examination demonstrated an orderly sequence of transformation and dedifferentiation of epithelial cells to become undifferentiated mesenchymal cells. These tumors are more aggressive than purely epithelial carcinomas. The overall survival rate was 44%. Five-year survival figures for TNM Stages I, II, and III lesions were 56%, 26%, and 18%, respectively. The incidence of lymph node metastasis was 25% despite the large size of many of these tumors. Systemic metastases replicated the range of metaplastic elements seen in the primary site. Patients with tumors composed predominantly of pseudosarcomatous elements had worse prognoses than those with predominantly epithelial components (28% versus 62%, 5-year survival).

Adult↗
PubMed1982

Aspartate carbamoyltransferase activity, drug concentrations, and pyrimidine nucleotides in tissue from patients treated with N-(phosphonacetyl)-L-aspartate.

Biopsy specimens were obtained from patients treated with N-(phosphonacetyl)-L-aspartate (PALA) in a phase I clinical trial. Activities of aspartate carbamoyltransferase (ACTase), the target enzyme, in ten specimens before treatment varied from 0.4 to 1.7 units/mg. PALA was measured in protein-free extracts of thirteen specimens by inhibition of rat ACTase. At 1.5 to 145 hr after doses of 1 to 6 g/m2, PALA concentrations were 0.9 to 89 micrograms/g; at 4 hr or later the tissue concentrations were similar to those in plasma (five samples). The observed inhibition of ACTase (17-87%) correlated with the PALA concentrations. Pyrimidine nucleotides were decreased (relative to purine nucleotides) in nine to ten specimens, by 16-72%. ACTase partially purified from human spleen had a Km for carbamoyl phosphate of 20.6 microM and the Ki for PALA was 0.011 microM. The results suggest that inhibition of ACTase by PALA affects the concentration of pyrimidine nucleotides in human tumors in a dose-dependent manner.

Antimetabolites, Antineoplastic↗
PubMed1980

Pharmacological disposition of N-(phosphonacetyl)-L-aspartate in humans.

The pharmacological disposition of N-(phosphonacetyl)-L-aspartate (PALA), an antitumor transition state analog currently in clinical trial, has been studied in 19 patients after i.v. administration of the agent at doses ranging from 800 to 5000 mg/sq m; PALA in biological specimens was assayed enzymatically, advantage being taken of its inhibition of L-aspartate carbamoyltransferase (EC 2.1.3.2) PALA disappeared from plasma biexponentially, with an average terminal t 1/2 of 5.3 hr. It was excreted in the urine unchanged; the 24-hr cumulative excretion was 85% of the administered dose. The average total clearance was 1.60 ml/kg/min and was linearly related to creatinine clearance, suggesting that in humans PALA is essentially cleared by glomerular filtration. The apparent volume of distribution of PALA was 309 ml/kg, approximately the sulfate space in humans. PALA penetrated into the central nervous system only to a limited extent. Tumor L-aspartate carbamoyltransferase activity was also measured before and 1.5 hr to 6 days after PALA administration; in all eight studies, a notable decrease in enzyme activity was observed.

Aspartate Carbamoyltransferase↗
PubMedDate not supplied

Synchronicity, multicentricity, and metachronicity of head and neck cancer.

Two hundred patients with squamous carcinoma of the head and neck were evaluated prospectively for synchronous second primary tumors. Complete head and neck examination, chest x-ray, and barium study (when indicated) revealed synchronous tumors of the upper aerodigestive tract in 24 patients (12%). Eleven patients had a second primary in the head and neck area. Nine patients had carcinoma of the lung, while four had carcinoma of the esophagus. Seven patients had a second primary outside the upper aerodigestive tract either in large bowel or prostate. During the period of this study, an additional 13 patients were seen with metachronous tumors 1-12 years after initial treatment of their index tumor. Most of these metachronous tumors were in the lung and esophagus and were noted within 1-3 years of treatment of the primary head and neck cancer. Detection of synchronous second primary is very important for prognosis and management of the index tumor, while early diagnosis of metachronous lesion is crucial in the follow-up of these patients.

Carcinoma, Squamous Cell↗