PubMed Health⌕ Search

Biomedical subjects

M V Viola

Publications and source records attributed to M V Viola.

At least 19 recordsLinked to original sources
PubMed1992

c-Ki-ras mutations in dysplastic fields and cancers in ulcerative colitis.

A sensitive restriction fragment length polymorphism assay and DNA sequencing were used to detect c-Ki-ras mutations in 56 specimens of colonic epithelium from 18 patients with chronic ulcerative colitis. Mutations were not detected in biopsy specimens that were negative or indefinite for dysplasia. In 4 of 8 patients with high-grade dysplasia, a c-Ki-ras codon 12 or 13 mutation was detected. In three colectomy specimens, a wide area of dysplastic cells (greater than 10 cm2) contained a specific ras mutation. In two of these specimens, an invasive cancer contained a c-Ki-ras mutation identical to that found in adjacent dysplastic epithelium. These studies indicate that mutations of c-Ki-ras may be an excellent molecular genetic marker to map dysplastic fields and invasive cancer in ulcerative colitis.

Base Sequence↗
PubMed1991

A method to detect ras point mutations in small subpopulations of cells.

Biochemical assays for ras mutations are capable of detecting a mutant allele only if it is present in at least 5% of cells tested. Further, ras mutation assays which utilize the polymerase chain reaction (PCR) are unable to distinguish a ras mutation in a small population of cells from mutations resulting from Taq DNA polymerase base misincorporation. We used a standard restriction fragment length polymorphism assay of PCR-amplified c-Ki-ras to detect codon 12 mutations in tumor cells and found a cumulative error frequency for Taq DNA polymerase of one codon 12 mutation per 2 X 10(4) molecules of total amplification product. The Taq polymerase-induced mutations were found to be multiple base transitions and represented a constant proportion of the amplification product at each step of the PCR. The ability to detect the in vitro generated mutation was dependent on the number of thermal cycles and the sensitivity of the detection assay. With these considerations in mind, we developed a two-step RFLP assay in which the thermal cycle number was kept low and molecules containing mutations at codon 12 were selectively amplified in the second step. We were able to detect a ras mutation occurring in 1 per 1000 cells (a two log improvement over standard RFLP methods) without detecting mutations resulting from Taq DNA polymerase infidelity.

Base Sequence↗
PubMed1989

Protooncogene structure in the cancer family syndrome.

Protooncogene loci in constitutional DNA from affected members of a kindred with the cancer family syndrome were studied by Southern blot hybridization analysis. No structural rearrangements or amplification of 16 protooncogenes were detected. These studies demonstrated that gross structural alteration of the tested protoocongenes is not responsible for cancer susceptibility in this syndrome.

Chromosome Mapping↗
PubMed1989

Protein A immunotherapy in the treatment of cancer: an update.

Protein A, a naturally occurring Staphylococcus aureus cell surface protein, has the unusual property of binding circulating immune complexes and immunoglobulin G with high avidity. CIC have played a major role in cancer-associated immunosuppression. Thus, removal of the immunosuppressive agents, ie, the CIC, may lead to a modulation of the immunosuppression and a liberation of the immune system to perform an antitumor effect. In animal studies, protein A has been used in extracorporeal immunoadsorption columns and treatments have resulted in tumor shrinkage and antiviral responses. Our group developed a multicenter clinical trial to assess toxicity and antitumor responses with this biologic response modifier alone. This is an update of our original trial. We have now treated 142 patients for a total of 1,306 treatments. The patients consisted of 74 males and 68 females. Their age ranged from 7 to 83 years, with a mean of 50 years. The Karnofsky performance index values ranged from 40 to 95, with a mean of 80. Patients who received seven or more treatments were considered eligible for tumor response assessment, and all patients with one or more treatments were eligible for toxicity assessment. Thus, there were 101 patients eligible for tumor response and 142 eligible for toxicity response. The total response rate was 22 patients or 21.8% (partial remission [PR], 12 patients, 12%; less than PR, 10 patients, 10%). Response rates were similar in the 13 treatment centers. Toxicity was assessed in 142 patients. One thousand three hundred six treatments were assessed for treatment toxicity.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical Trials as Topic↗
PubMed1988

Normal G2 chromosomal radiosensitivity and cell survival in the cancer family syndrome.

Recent reports have suggested that elevated chromosomal aberration yields following X-irradiation of skin fibroblasts in the G2 phase of the cell cycle are characteristic of affected members of cancer-prone families. These studies propose that this phenomenon is a consequence of impaired DNA repair and might be a useful predictor of genetic susceptibility to cancer. We have tested G2 chromosomal X-ray sensitivity in skin fibroblasts and peripheral blood lymphocytes from members of a kindred with the cancer family syndrome, a disorder in which susceptibility to colon cancer and other epithelial cancers is inherited in an autosomal dominant pattern. Further, using a cell survival assay, we tested cancer family syndrome skin fibroblasts for sensitivity to four classes of mutagens, including X-rays. In the assays used, skin fibroblasts and lymphocytes from both affected and unaffected family members exhibited responses indistinguishable from normal controls. Karyotypic analysis of lymphocytes and fibroblasts revealed no consistent constitutional cytogenetic abnormality. Thus, affected patients with the cancer family syndrome do not have increased sensitivity to irradiation and chemical mutagens and lack a germ-line chromosomal defect.

Cell Survival↗
PubMed1988

Protein A immunoadsorption in the treatment of malignant disease.

Circulating immune complexes (CIC) are known to be present in cancer patients and are responsible for much of the cancer-associated immunosuppression. Removal or modulation of these "blocking factors" can reverse the immunosuppression. Protein A from Staphylococcus aureus has the unusual property of binding to CIC with high avidity. Use of protein A as an immunoadsorbent in extracorporeal immunotherapy affinity columns has resulted in antitumor and antiviral responses in animals. Our group developed a multicenter trial to assess toxicity and antitumor response with this biologic response modifier alone. Overall, 24% (21 of 87 patients) had objective tumor regressions including both partial responses (PR) and less than PR. No complete responses (CR) were observed. Responses were observed in acquired immune deficiency syndrome (AIDS)-related Kaposi's sarcoma (six of 17 PR; two of 17 less than PR; overall, 47%), breast adenocarcinoma (five of 22 PR; three of 22 less than PR; overall response, 36%), colon adenocarcinoma, (one PR, one less than PR; overall response, 11%), and non-oat cell lung carcinoma (two of seven less than PR). The procedure was well tolerated and could be performed on an outpatient basis. No adverse reaction was observed in 735 of 1,113 treatments (66%). The most common adverse effect was an "influenza-like" syndrome consisting of fever and chills. Pain was present in 12% of the patients. There were no study-related deaths. Serum IgG and CIC levels did not statistically change due to therapy in responding or nonresponding patients. Complement levels remained within the normal range. Liver and renal tests remained stable throughout the study. In summary, protein A immunoadsorption of plasma is well tolerated in the outpatient clinic, has demonstrated antitumor activity in resistant solid tumors, and functions as a biologic response modifier.

Adolescent↗
PubMed1987

ras p21 expression in the progression of breast cancer.

The differential expression of the ras oncogene product p21 in the primary tumor, regional nodes, and distant metastatic sites in patients with disseminated breast cancer was examined to define the biologic and clinical significance of the ras oncogene in the progression of breast cancer. The avidin-biotin peroxidase complex method was used on formalin-fixed, paraffin-embedded tissues from 16 patients with metastatic disease. The primary antibody used in this protocol was RAP-5, an anti-p21 murine monoclonal IgG2a. p21 antigen staining was similar in the primary tumor and regional nodes from the same patient (P less than 0.05), but the staining of distant metastases was more variable. Expression of ras p21 was consistently increased in invasive components of the primary tumor as compared with intraductal tumor. In addition, a high level of p21 expression was seen in tumor emboli in lymphatics and blood vessels as compared with contiguous tumor in parenchymal tissue. Although p21 staining is present in aggressive primary breast cancers and most metastatic sites, our findings indicate that markedly enhanced p21 expression is associated with the earlier stages (invasion and dissemination) of aggressive breast cancers.

Breast Neoplasms↗
PubMed1987

Microinjection of ras p21 induces a rapid rise in intracellular pH.

Quiescent mouse NIH 3T3 cells responded to microinjection of activated ras p21 with a rapid and sustained rise in intracellular pH (approximately 0.17 pH units). The p21-induced pH change was inhibited by amiloride treatment or growth of cells in medium low in sodium, suggesting a role for the Na+/H+ antiporter. Amiloride was found to suppress p21-induced mitosis, also.

Amiloride↗
PubMed1986

Expression of ras oncogene p21 in prostate cancer.

The major neoplastic transformation-inducing genes of human solid tumors are members of the ras oncogene family. We used an immunohistochemical assay to assess expression of both the unaltered and the mutated ras oncogene protein (p21) in normal and neoplastic prostatic cells. With the concentration of monoclonal antibody used in this study, epithelial and stromal cells from subjects with normal prostates and from 19 patients with benign prostatic hyperplasia were negative for p21 antigen. This antigen was detected in 2 of 6 prostates with Grade I carcinoma, 4 of 6 with Grade II, and all of 17 with higher grades. A semiquantitative immunohistochemical method demonstrated that expression of the p21 antigen in a carcinoma strongly correlated with nuclear anaplasia and was inversely related to the degree of glandular differentiation. However, markedly anaplastic tumors were often more heterogeneous in expression of p21 and contained areas of low staining for the antigen. Comparison of p21 antigen with tumor carcinoembryonic antigen and prostate-specific antigen demonstrated that ras p21 was the only phenotypic marker that correlated with histologic tumor grade. Thus, ras oncogene p21 may represent a new class of biologically relevant tumor markers and may be a useful adjunct to histopathologic examination in determining the prognosis of patients with prostate cancer.

Antigens, Neoplasm↗
PubMed1986

A comparison of tumor-related antigens in male and female breast cancer.

A retrospective analysis was undertaken in which 15 female and 15 male breast cancers were matched by age, stage, estrogen receptor status, and histologic type. Our protocol compares male and female breast cancers for reactivity with antibodies against tumor-associated antigens known to be present on female breast cancer cells. Formalin-fixed sections of each primary tumor were reacted in the ABC immunoperoxidase assay against antibodies B72.3 and DF.3 and an antibody to the ras p21 antigen. Reactivity to B72.3 and DF.3 was similar. However, the ras p21 antigen was expressed to a significantly greater extent in female breast cancers (p = .0008). Thus, although there are similarities in antigenic phenotype of male and female breast cancers, some female breast cancers may have a different pathogenesis as demonstrated by increased amounts of a specific oncogene product.

Adult↗
PubMed1986

Elevated ras oncogene expression correlates with lymph node metastases in breast cancer patients.

The protein product of the ras cellular oncogene(s) (p21) was assayed in primary breast carcinomas from two groups of patients who had different axillary lymph node status. Using an immunohistochemical assay, the intensity and percent of neoplastic cells demonstrating ras p21 antigen staining were significantly higher in the primary tumors from patients with lymph nodes positive (LN+) for malignancy (20 patients) compared with the lymph node negative (LNO) group (21 patients). The expression of p21 also correlated with tumor size. Age and estrogen receptor status did not influence p21 staining. The antigen expression of p21 was similar in intensity and distribution in the primary tumor and regional lymph node metastases. Enhanced expression of p21 in primary breast cancers that metastasize to regional nodes indicates that ras p21 may be a determinant of the malignant potential of breast cancer cells and may represent a new class of more biologically relevant tumor markers.

Antibodies, Monoclonal↗
PubMed1979

Identifying the primary site in metastatic cancer of unknown origin. Inadequacy of roentgenographic procedures.

Two hundred sixty-six patients with metastatic nonsquamous carcinoma of unknown origin underwent upper and lower gastrointestinal series, intravenous pyelograms, and chest roentgenograms (CR) for location of a primary cancer site. Of 129 identified cancer sites, only 22 were verified antemortem, whereas necropsy disclosed 25 cases with false-positive examination results. The CR patterns thought typical for lung cancer (eg, single mass lesion and hilar or mediastinal adenopathy) were often shown (43%) to represent metastatic lesions. Because contrast roentgenographic studies are costly, uncomfortable, of low yield, and often misleading, they should be limited to cases with specific organ dysfunction.

Adenocarcinoma↗
PubMed1979

Solar cycles and malignant melanoma.

There has been a sixfold increase in the incidence of malignant melanoma in the State of Connecticut during the past forty years. Superimposed on a steady incidence rise are cycles of markedly increased incidence rates which follow periods of maximum sunspot activity. We propose that the effect of sunspot cycles on human melanoma occurrence is mediated by modulation of stratospheric ozone and thus indirectly affects UV flux at the earth's surface. This hypothesis would predict a time lag in melanoma incidence cycles, relative to sunspot activity, with increasing distance from polar caps. This appears to be the case. The increase in melanoma incidence related to a given reduction in ozone depletion in this hypothesis, is in great excess of existing models relating anthropogenic ozone depletion and skin cancer.

Connecticut↗
PubMed1979

Lymphocyte adherence in multiple sclerosis.

It has been reported that peripheral blood lymphocytes from patients with multiple sclerosis (MS) adhere to measles-infected human epithelial cells in significantly greater numbers than do lymphocytes from healthy volunteers or patients with other neurologic diseases. We have confirmed this observation in three separate studies, and have investigated the relationship of lymphocyte adherence to the clinical state. Lymphocyte adherence determination values correlated with the degree of certainty of the clinical diagnosis of MS, and lymphocyte adherence values in individual patients increased during clinical exacerbations. Judicious use of this test may facilitate the diagnosis of MS.

Epithelium↗