PubMed Health⌕ Search

Biomedical subjects

B Mackay

Publications and source records attributed to B Mackay.

At least 91 records · Page 5Linked to original sources
PubMed1984

Enteric-type adenocarcinoma of the nasal cavity. An electron microscopic and immunocytochemical study.

A primary adenocarcinoma of the nasal cavity with light microscopic, electron microscopic, and immunocytochemical features of an enteric-type carcinoma is presented. The carcinoma contained a variety of dense-core granules similar to those seen in enterochromaffin cells of different functional types. Some granules demonstrated an immunoreactivity with serotonin, cholecystokinin, gastrin, somatostatin and leu-enkephalin antibodies. It is suggested that the endocrine cells in the neoplasm belong to the non-neuroectodermal paraneurone system.

Adenocarcinoma↗
PubMed1984

Occult Cushing's disease presenting with acute psychosis.

A 37-year-old woman presented with acute psychosis and cognitive impairment. Skull x-ray showed an enlarged sella turcica with erosion of the floor. Endocrinologic workup suggested the diagnosis of Cushing's disease and hyperprolactinemia. She had no cushingoid feature, and the only physical sign was mild generalized obesity. She showed a paradoxic response to dexamethasone suppression, and underwent trans-sphenoidal resection of a pituitary macroadenoma. Electron microscopy showed the tumor to be a Crooke's cell adenoma. Results of immunohistochemical staining were positive only for ACTH and beta-endorphin. The neuropsychiatric manifestations resolved after surgery.

Adenoma↗
PubMed1984

A comparison of cardiac biopsy grades and ejection fraction estimations in patients receiving Adriamycin.

One hundred fifty-eight patients receiving Adriamycin underwent 226 transjugular biopsy procedures. The specimens were evaluated by electron microscopy for evidence of drug-related cardiotoxicity. Ejection fraction determinations using echocardiographic or nuclear techniques at rest were available for 69% and 81% of the patients, respectively. Analysis of the data revealed a correlation between cumulative Adriamycin dose and biopsy grade (p less than 0.02). No similar relationship existed between cumulative Adriamycin dose and ejection fractions obtained at rest or between biopsy grades and ejection fractions. In patients who underwent serial endomyocardial biopsies and serial ejection fraction determinations, the correlation between changes in biopsy grade and ejection fraction was poor. A change in resting ejection fraction detected by either method did not reliably predict a change in biopsy grade. The poor correlation between ejection fractions and biopsy grades could be due in part to the sensitivity and specificity of the Adriamycin-related structural changes in contrast to the wider range of disease processes that can affect myocardial function, and to the fact that structural changes often precede the ejection fraction abnormalities. The greater sensitivity and specificity of the biopsy grade should prove useful in reducing the risks associated with evaluating new anthracyclines and potential myocardial protectors of Adriamycin toxicity.

Biopsy↗
PubMed1984

Increased therapeutic index of weekly doxorubicin in the therapy of non-small cell lung cancer: a prospective, randomized study.

One hundred patients with non-small cell lung cancer were entered into a randomized evaluation of two schedules of doxorubicin combined with ftorafur, cyclophosphamide, and cisplatin (FACP). Doxorubicin was given either weekly at 20 mg/m2, or every three weeks (standard) at 60 mg/m2. Fifty-two patients were randomized to the FACP/weekly doxorubicin arm and 48 patients to the FACP/standard doxorubicin arm. The FACP/weekly doxorubicin regimen was associated with higher complete and partial remission rates (31% versus 19%), longer response duration (median, 33 versus 21 weeks), and longer survival duration for responders (median, 58 versus 50 weeks). These differences were not significant. Less neutropenia (p = 0.01) and less infectious morbidity (p = 0.05) were observed in the FACP/weekly doxorubicin arm. Twenty-eight patients underwent 35 endomyocardial biopsies to assess doxorubicin-induced cardiotoxicity. Sixteen biopsies were performed in 12 patients receiving cumulative doxorubicin doses ranging from 250 to 1,190 mg/m2 within the FACP/weekly doxorubicin arm. Nineteen biopsies were performed in 16 patients receiving cumulative doxorubicin doses ranging from 250 to 540 mg/m2 within the FACP/standard doxorubicin regimen. The FACP/weekly doxorubicin regimen was associated with significantly lower cardiotoxicity scores (p = 0.01). This study indicates that weekly administered doxorubicin is as effective and less cardiotoxic than the standard schedule.

Adenocarcinoma↗
PubMed1983

Small cell carcinomas of the parotid gland. A clinicopathologic study of three cases.

Clinical, histological and ultrastructural features of three small cell carcinomas arising in the parotid gland are presented. The light microscopic appearance of two of the neoplasms suggested neuroendocrine cell derivation, confirmed by electron microscopy in both instances. The fine structure of the third neoplasm suggested intercalated duct cell differentiation. The possibility that both types of neoplasm may arise from the same primitive precursor cell is considered. The findings from this study confirm the occurrence of two different types of small cell carcinoma of salivary gland origin. A distinction between duct cell and neuroendocrine subtypes may be impossible by conventional light microscopic evaluation.

Aged↗
PubMed1983

Laryngeal paraganglioma. Report of two tumors with immunohistochemical and ultrastructural analysis.

Paraganglionic tumors of the larynx are uncommon neoplasms and their secretory products have rarely been elucidated. We saw two patients whose laryngeal paragangliomas were examined with an electron microscope and by the use of immunocytochemical techniques. Both tumors manifested positive immunoreactivity against calcitonin and vasoactive intestinal polypeptide. One of the paragangliomas was immunoreactive against carcinoembryonic antigen and pursued a biologically malignant course. Our observations suggest the coexistence of amines and hormonal polypeptides in cells of paraganglionic tumors and demonstrate the multihormonal nature of these tumors.

Aged↗
PubMed1983

Large cell lymphoma with microvillus-like projections: an ultrastructural study.

On many of the cells of each of the 10 large cell lymphomas we studied, electron microscopy demonstrating slender peripheral cytoplasmic projections that simulated microvilli. They varied in number, but, when numerous, easily could be misinterpreted as evidence of adenocarcinoma. Immunoperoxidase staining confirmed the presence of monoclonal cytoplasmic immunoglobulin in four of 10 cases. Stains for muramidase were negative in every case. Because nine of the 10 cases were of presumed B-cell lineage, the lymphoma cells are compared to transformed lymphocytes from the follicular centers of reactive lymph nodes.

Adenocarcinoma↗
PubMed1983

Clear cell islet cell tumor.

A patient with an islet cell tumor presented initially with a supra-renal mass that histologically had an extensive clear cell component. Electron microscopic and immunocytochemical findings were essential to prove that the extrapancreatic mass with clear cells was an unusual metastatic manifestation of an islet cell tumor. Both the pancreatic and extrapancreatic tumor cells contained neurosecretory granules and produced vasoactive intestinal polypeptide and substance P. The clear cell morphology was due to the accumulation of lipid and glycogen and cytoplasmic swelling.

Adenoma, Islet Cell↗
PubMed1983

Association between neuroendocrine (Merkel cell) carcinoma and squamous carcinoma of the skin.

Among 32 neuroendocrine carcinomas of the skin, 11 were from patients with previous or concomitant squamous carcinoma. The medical records and pathologic material for these 11 cases were reviewed, and the diagnosis of neuroendocrine carcinoma was confirmed in each instance by electron microscopy. In two cases, the squamous and neuroendocrine carcinomas were admixed, but each preserved its identity and transition between the two was not identified. Despite the lack of evidence for origin from a single cell, the observations nevertheless indicate a common carcinogenetic influence for squamous and neuroendocrine carcinomas of the skin.

Adenocarcinoma↗
PubMed1982

Neurosarcomatous transformation in malignant melanoma: an ultrastructural study.

Six cases of desmoplastic melanoma were studied by light and electron microscopy. The tumors fulfilled one or more of the following criteria: (1) having the presence of atypical intraepidermal melanocytic proliferation bordering the primary lesions; (2) an antecedent history of melanoma at the site of recurrence; (3) a metastatic lesion in the direct lymphatic drainage route of a previously excised melanoma. Premelanosomes were not identified in the neoplastic cells. Ultrastructural features common to the six tumors were interpreted as evidence of Schwann cell differentiation, i.e., neurosarcomatous transformation occurring in malignant melanoma. The ultrastructural findings provide further support for the concept that melanocytic lesions may simulate tumors of Schwann cell origin, presumably reflecting the common embryologic origin of the two cell types from the neural crest.

Adult↗
PubMed1982

Neuroblastomas and neuroendocrine carcinomas of the nasal cavity: a proposed new classification.

The histologic characteristics of 29 nasal tumors previously diagnosed as neuroblastomas, unclassified carcinomas, or unclassified malignant neoplasms were reviewed. Electron microscopy was performed in 17. Nine tumors were neuroblastomas; six of these were classical neuroblastomas while the other three exhibited olfactory differentiation in addition to the classical neuroblastoma component. Areas of ganglioneuroblastoma were found in the metastasis of one of the three olfactory neuroblastomas. Twenty tumors were classified as neuroendocrine carcinoma because all showed a neuroendocrine pattern with remarkably uniform cells growing from benign glandular epithelium; membrane bound granules were present in the cytoplasm of cells of the ten cases in this group examined by electron microscopy. The mean age of the patients with neuroblastomas was 20 years; survival in this group was 75% at five and seven years, respectively, and 67% at ten years. Recurrences, metastasis, and death occurred within 3 years of diagnosis. There was a low percentage (25%) of multiple recurrences. The metastases were located in cervical lymph nodes, brain and spine. The mean age of the patients with neuroendocrine carcinoma was 50 years. Survival was 100% at five years, 88% at seven years, and 77% at ten years. Recurrences and metastasis in 70% of the cases occurred later than the third year. Multiple recurrences were present in 54% of the cases. The metastases affected lymph nodes, brain and spine in all cases except in one in which lungs and femur were involved. In the latter case adenocarcinoma was also present in addition to the neuroendocrine carcinoma. Three patients died, all more than five years from the time of diagnosis. No correlation was found between staging and prognosis in either group, except for Stage I disease.

Cell Differentiation↗
PubMed1982

Adriamycin therapy by continuous intravenous infusion in patients with metastatic breast cancer.

Patients with metastatic breast cancer previously treated with non-Adriamycin containing chemotherapy were treated with Adriamycin at a dose of 60 mg/m2 administered as a continuous infusion through a central venous catheter. The duration of Adriamycin infusion was escalated by 100% increments from 24-96 hours, but the majority of patients were maintained on 96-hour infusions. Thirteen of 27 patients achieved objective response (1 CR, 12 PR), six improved, and eight failed to respond to Adriamycin. Administration of Adriamycin by infusion led to a decrease in the severity of nausea and vomiting, but had no effect on myelosuppression and alopecia secondary to Adriamycin. The cardiac toxicity of Adriamycin was reduced in patients who received maintenance therapy with 96-hour infusions of Adriamycin.

Adult↗
PubMed1982

Immunoperoxidase localization of prostatic acid phosphatase in prostatic carcinoma with sarcomatoid changes.

Immunoperoxidase staining of tissue for prostatic acid phosphatase has been useful in confirming the prostatic origin of metastatic deposits. This technique was used on the prostate tumors of 2 patients to differentiate between a true carcinosarcoma and a pure epithelial carcinoma with sarcomatoid changes. Positive staining for prostatic acid phosphatase in both the sarcomatoid element, as well as the area of well-differentiated carcinoma, confirmed the common epithelial cell origin of these components. Electron microscopy further confirmed these findings by demonstrating desmosomes in the sarcomatoid areas. Although each type of tumor is rare, differentiation between true carcinosarcomas and true carcinomas with sarcomatoid changes is important to elucidate further their different clinical behaviors and responses to therapy.

Acid Phosphatase↗