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Biomedical subjects

A M Magliocco

Publications and source records attributed to A M Magliocco.

10 recordsLinked to original sources

Molecular mechanisms of hepatic metastasis in colorectal cancer.

BACKGROUND: Colorectal cancer currently accounts for 11% of all cancers in the United States and is the second leading cause of cancer-related death, with the majority of deaths attributable to hepatic metastases. Many new studies are elucidating the complex molecular factors involved in this event, which could be used to generate clinically applicable screening and therapeutic tools. METHODS: An initial Pubmed and Medline literature search using keywords such as, molecular factor, colorectal cancer, hepatic metastasis/es, and main headings, such as angiogenesis, was reviewed. Since there are many molecular factors involved in this process not all could be included in this review. The list of discussed gene products was limited to the most studied factors, identified by the number of references in the literature search, and additional recently discovered gene products with in-vivo evidence of strong metastasis association. RESULTS: Twenty molecular factors were identified and included in the discussion of this review article. The molecular factors were separated into four groups based on their function, they are: proteolysis, adhesion, angiogenesis, and cell survival. All factors have a promising role as a screening or therapeutic target. CONCLUSION: This review has identified the many recent advances in elucidating the pathways involved in colorectal cancer hepatic metastasis. By better understanding the many complex molecular events involved in metastasis, novel screening and therapeutic tools may be developed with the ultimate goal of preventing metastasis and increasing patient survival.

Apoptosis Regulatory Proteins↗

Regulation of plasmin-dependent fibrin clot lysis by annexin II heterotetramer.

In a previous report we showed that plasmin-dependent lysis of a fibrin polymer, produced from purified components, was totally blocked if annexin II heterotetramer (AIIt) was present during fibrin polymer formation. Here, we show that AIIt inhibits fibrin clot lysis by stimulation of plasmin autodegradation, which results in a loss of plasmin activity. Furthermore, the C-terminal lysine residues of its p11 subunit play an essential role in the inhibition of fibrin clot lysis by AIIt. We also found that AIIt binds to fibrin with a K(d) of 436 nm and a stoichiometry of about 0.28 mol of AIIt/mol of fibrin monomer. The binding of AIIt to fibrin was not dependent on the C-terminal lysines of the p11 subunit. Furthermore, in the presence of plasminogen, the binding of AIIt to fibrin was increased to about 1.3 mol of AIIt/mol of fibrin monomer, suggesting that AIIt and plasminogen do not compete for identical sites on fibrin. Immunohistochemical identification of p36 and p11 subunits of AIIt in a pathological clot provides important evidence for its role as a physiological fibrinolytic regulator. These results suggest that AIIt may play a key role in the regulation of plasmin activity on the fibrin clot surface.

Animals↗

Ovarian cancer gene therapy: repeated treatment with thymidine kinase in an adenovirus vector and ganciclovir improves survival in a novel immunocompetent murine model.

OBJECTIVE: Our purpose was to assess the effect of multiple injections of the system of herpes simplex virus thymidine kinase in an adenovirus vector and ganciclovir on survival in a murine model of human epithelial ovarian cancer. STUDY DESIGN: In this work we tested the ability of the system of thymidine kinase delivered by an adenovirus vector and ganciclovir to treat ovarian cancer in a novel murine model for epithelial ovarian cancer, SaskMouse. SaskMouse was developed by injecting LM-1 cells, a murine epithelial ovarian cancer cell line, intraperitoneally into a syngeneic C57BL/6N x C3H/He mouse strain. The cells developed into multiple cancer implants on different abdominal organs, leading to ascites and rapid death. The model has an intact immune system, as evidenced by the inability of different human cancer cells to develop into cancers when injected into the mice intraperitoneally. RESULTS: The system of thymidine kinase delivered by an adenovirus vector and ganciclovir was applied to SaskMouse. Mice were either untreated (group 1), treated with one intraperitoneal injection of adenovirus- thymidine kinase at 250 plaque-forming units/cell (group 2), or treated with two intraperitoneal injections of adenovirus-thymidine kinase at 250 plaque-forming units/cell on days 0 and 23 (group 3). Survivals were 23 +/- 2, 27 +/- 2, and 35 +/- 4 days, respectively (P <.05). Antiadenoviral antibodies were assayed both in the serum and in the peritoneal fluid of treated mice. Despite high antibody titers in serum, there were no detectable antibodies in the peritoneal fluid. CONCLUSION: Our data suggest that multiple intraperitoneal injections of the combination of thymidine kinase delivered by an adenovirus vector and ganciclovir are effective in prolonging survival in the presence of ovarian cancer. There are potential implications for other abdominal malignancies.

Adenoviridae↗

p53, ErbB2, and TAG-72 expression in the spectrum of ductal carcinoma in situ of the breast classified by the Van Nuys system.

CONTEXT: The Van Nuys (VN) classification system for ductal carcinoma in situ (DCIS) of the breast is a simplified morphology-based system that uses the presence of nuclear pleomorphism and comedo-type necrosis to stratify DCIS lesions into 3 prognostic groups. OBJECTIVE: To determine if there is an underlying biological basis that correlates with the morphologic aspects of the VN classification system. DESIGN: We evaluated the expression of markers implicated in the development of breast cancer (p53, ErbB2, and TAG-72) in DCIS classified with the VN system. Forty-five cases of pure DCIS were classified as 8 cases of VN1, 7 cases of VN2, and 30 cases of VN3. p53, ErbB2, and TAG-72 antigen expression was measured by immunohistologic means in each of the cases. RESULTS: Nuclear accumulation of p53 was only observed in VN3 (30%). ErbB2 overexpression was found only in VN2 (14%) and VN3 (43%). TAG-72 expression was observed in all categories of lesions but was more frequent in VN2 (71%) and VN3 (70%) compared with VN1 (25%). It appears that overexpression of ErbB2 and p53 are features associated with the high-grade lesions. CONCLUSION: The simplified VN classification system for DCIS has a clear underlying biological basis as evidenced by differential expression of tumor-associated antigens in each of the 3 morphologic categories. These differences may contribute to the differential clinical behavior of the separate groups.

Antigens, Neoplasm↗

Cortical blindness as a manifestation of hypomagnesemia secondary to cisplatin therapy: case report and review of literature.

Cisplatin is widely used in the treatment of solid tumors and is known to have a number of side effects including hypomagnesemia. We present a case report of a patient with a Stage IIA carcinoma of the cervix who initially was treated with radiotherapy and cisplatin and subsequently presented with sudden onset of blindness. The diagnosis was uncertain but the possibility of functional blindness was considered. Serum magnesium was low. Correction of this electrolyte abnormality resolved this profound visual symptom. This case emphasizes the importance of serially observing cisplatin-treated patients for the possible development of the clinical syndrome of magnesium deficiency.

Antineoplastic Agents↗

Genome scanning detects genetic alterations in human ovarian carcinoma.

Genome scanning, originally used to detect mouse mutations, is a technique which can rapidly identify differences between genomic DNA samples. The procedure is essentially a high resolution Southern analysis using a probe that hybridizes to a medium copy number (1000-2000 copies per haploid genome) repetitive element naturally dispersed throughout the genome. This technique detects genetic changes (primarily large scale genetic changes, e.g., amplifications and deletions) as differences in hybridization band intensity. The use of a probe derived from an endogenous human retroviral-like repetitive sequence, the RTVL-H element, has made genome scanning in humans feasible. In this report, the genome scanning technique was used to evaluate genomic DNA extracted from 14 frozen ovarian tumors. These included 8 high grade serous cystadenocarcinomas, 2 endometrioid carcinomas, one malignant mixed mullerian tumor, 2 Krukenberg tumors, and one tumor where histological classification was unavailable. Band amplifications were identified in 11 cases, with the most prominent amplifications observed in the high grade serous cystadenocarcinomas. In some of the cases, the amplifications involved bands of identical molecular size suggesting that similar underlying changes occurred in different tumors and are potentially associated with specific histological tumor types or clinical behavior. Band deletions were also observed in one endometrioid tumor where blood leukocyte genomic DNA was available from the same patient, allowing a direct comparison.

DNA Probes↗

Varicella embryopathy.

Varicella embryopathy is a rare entity afflicting infants born to mothers who have contracted varicella during the first 20 weeks of pregnancy. The teratogenicity of varicella has not been established from epidemiologic studies, but isolated case reports describe characteristic malformations following early maternal infection. We describe a male neonate delivered at 40 weeks' gestation to a 26-year-old grava 2, para 2 mother who developed varicella during the first trimester. The infant lived 7 days and died of bronchopneumonia. At postmortem examination there was growth retardation, multiple cicatricial skin lesions, flexion contractures of all major joints, hypoplastic right diaphragm, bilateral hydroureters and mucosal fibrosis of the trachea, as well as intestinal fibrosis and colonic stricture. The brain contained areas of cystic necrosis involving the frontal, parietal, temporal, and occipital lobes, with generalized ventriculomegaly. The midbrain, pons, and medulla were hypoplastic. There was denervation atrophy of muscles of the lower limbs and loss of dorsal root ganglia as well as of neurons of the anterior horn of the spinal cord. The cerebral white matter was degenerated, with proliferation of reactive astrocytes. Chorioretinitis was not observed. Immunocytochemical stains using two commercially available antivaricella antibodies were negative in all tissues examined. The sporadic nature and pathogenesis of the varicella embryopathy, which may have been caused by focal defects in the fetal T-cell immune response, are discussed.

Abnormalities, Multiple↗

Granulocytic sarcoma of the ovary. An unusual case presentation.

We report an unusual occurrence of granulocytic sarcoma presenting as an ovarian mass in a 46-year-old woman with a history of dysplastic nevus syndrome. During workup of the ovarian mass, the diagnosis of acute myelogenous leukemia was made. A fine-needle aspirate of the ovarian mass showed granulocytic sarcoma. The patient died of complications of the acute leukemia a short time later. A postmortem examination was performed, which confirmed the nature of the ovarian mass as a granulocytic sarcoma. Material was obtained for flow cytometry, immunohistochemical and histochemical studies, and electron microscopy. Ploidy analysis of the tumor showed it to be diploid with an S phase of 4.8% and a G2 + M ratio of 0.5%. To our knowledge, there is only one previous report of a primary ovarian presentation of granulocytic sarcoma, and only four cases in which granulocytic sarcoma was diagnosed by fine-needle aspiration cytology. The association between dysplastic nevus syndrome and acute myeloid leukemia in this case is discussed with reference to a review of the metachronous association between melanoma and leukemia as described in the literature.

Biopsy, Needle↗

Absence of varicella zoster DNA in varicella embryopathy tissue utilizing the polymerase chain reaction.

We have previously examined a case of varicella embryopathy (VE) occurring in a 41-week gestational age infant, showing some of the most severe lesions reported to be associated with the syndrome to date. A previous survey of the postmortem tissue with two anti-varicella zoster antibodies was negative. It was hypothesized that if varicella-zoster virus (VZV) was associated with VE, a latent viral infection might be expected, similar to that occurring in adults infected with VZV. Subsequently, an attempt was made to identify DNA encoding three separate and specific VZV genes using the highly sensitive polymerase chain reaction from formalin-fixed tissues of the central nervous system including cerebral cortex, cerebellum, and brainstem, in addition to frozen tissue of liver, adrenal, and thymus. Although amplifications utilizing primers for a normal human DNA sequence (ME491) demonstrated the ability of the samples to serve as a target for the PCR, none of the samples contained amplifiable VZV DNA. Substitution of biotin 11-dUTP in the PCR and subsequent detection of the biotinylated amplimers resulted in a large increase of the sensitivity of the PCR amplimer detection, but still failed to detect the presence of VZV DNA in the samples. The most likely explanation for these findings suggests a complete destruction of fetal tissue tropic for VZV with a subsequent inability for a latent VZV infection to be established.

Abnormalities, Multiple↗