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Biomedical subjects

R Pillai

Publications and source records attributed to R Pillai.

At least 91 records · Page 5Linked to original sources
PubMed1992

Oncogenes and oncoproteins as tumor markers.

A major problem in the management of patients with cancer is the lack of specific tumor markers for the early detection, the accurate prediction of biological behavior and for accurate assessment of prognosis. A new and exciting answer to this problem may now become available following the discovery of specific genes associated with malignancy. The role of such genes and their products are now being identified and their role in cancer is under intense investigation. On a clinical level, these genes and their products may allow us to improve our understanding of disease etiology and provide more precise diagnostic, prognostic and therapeutic characterization of individual tumors. This paper discusses the possibilities of using the altered expression of oncogenes and tumor suppressor genes and their products in neoplastic tissues as markers for the diagnosis and prognosis of malignant disease. These data support the view that detailed analysis of such gene expression has the potential to predict a tumor's behavior as well as the response to different treatment modalities.

Biomarkers, Tumor↗
PubMed1992

Thrombolysis and postinfarction ventricular septal rupture.

We studied all patients with postinfarction ventricular septal rupture referred to the Oxford Heart Centre for operation over a 4 1/2-year period. Twenty one women and 8 men were admitted to the Centre, 13 of whom had received streptokinase and 16 of whom had not. The median interval between symptomatic onset of myocardial infarction and the development of septal rupture was 24 hours for those treated by early thrombolysis (all streptokinase) and six days for those who were not. Of the 26 patients who underwent surgical repair, three were operated on less than 36 hours after streptokinase infusion, in one case within 12 hours of thrombolytic treatment. Macroscopic observation of the disintegrating myocardium showed muscle bundles dissected by blood rendered incoagulable by thrombolytic treatment, together with the histologic features of reperfusion injury. The overall surgical mortality rate for the streptokinase group was 33% and for the others 21%. The patient operated on within 12 hours of thrombolytic treatment recovered uneventfully. Six of seven surgical deaths were caused by left ventricular or biventricular failure and one by gastrointestinal hemorrhage. All survivors were in New York Heart Association classes II or III between 2 weeks and 4 1/2 years after operation. We conclude that thrombolysis leads to early breakdown of the interventricular septum after acute myocardial infarction but does not preclude early repair.

Aged↗
PubMed1991

Lymphocyte subset distribution after radiation therapy for cancer of the uterine cervix. Possible prognostic implications and correlation with disease course.

An analysis of lymphocyte subpopulations was done in patients with cancer of the uterine cervix before and at different intervals after the commencement of radiation therapy. A common feature was a duration of T-cell and B-cell lymphopenia after therapy. The findings relating to the T-cell subsets were interesting. Although the CD4/CD8 ratio remained unchanged in Stages I/IIA for 24 months after treatment, patients with Stages IIB and III showed a lowering of the ratio immediately after treatment. Distinctive patterns of lymphocyte subset distribution were seen in a comparison between patients who were disease-free and those with recurrent disease. The CD4+ cell counts and CD4/CD8 ratio differed between the two groups, with consistent lowered values during the follow-up associated with recurrent disease. This study demonstrates the effects of radiation therapy in altering lymphocyte subset distribution, resulting in characteristic patterns which could be used as clinical and prognostic indicators.

Antibodies, Monoclonal↗
PubMed1991

Oncogene expression and oral cancer.

Cancer of the oral cavity remains a major problem in the United States as well as in many other countries, some of which record as much as 30% of all their cancers to be in the oral region. Despite numerous advances in the fields of epidemiology and etiology, little is known of the molecular basis of oral cancer. Advances in the field of oncogenes have produced a tool to study the different stages of carcinogenesis, including transition from premalignant to malignant stages. These strategies have direct relevance to oral cancer where the premalignant stage is well defined. Preliminary studies into the expression and function of oncogenes suggest abnormalities including individual and multiple amplification of three or more types of these genes. This review briefly describes the concept of oncogenes, and their possible role in the development of neoplasia and specifically on studies in oral cancer.

Animals↗
PubMed1991

AIDS, drugs of abuse and the immune system: a complex immunotoxicological network.

Two of the most interesting questions often asked about AIDS is why many people do not become immunodeficient or get complicating disease when first infected with Human Immunodeficiency Virus (HIV) and what are the "risk factors" making some individuals more susceptible to the disease. A large majority of people with AIDS have a well established history of drug and alcohol abuse. Both drugs of abuse and alcohol have immunotoxic properties as evidenced by a number of studies. These include marked changes in the cellular, humoral and other components of the immune defense mechanism. Such a compromise of the immune system can render it susceptible to the development of AIDS after HIV infection. This paper reviews the evidence suggesting possible links between substance abuse and its immunotoxicology, and their possible roles in the pathogenesis of AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Immunological abnormalities in oral precancers.

Cancer of the oral cavity constitutes approximately 30% of all malignancies in India today. Many oral cancers first present as a precancerous lesion and hence it is important to understand the biological factors associated with such lesions. The immune system and its functioning is a significant element in the development of cancer. Considerable evidence exists suggesting that the immune response plays a role in regulating the development and growth of oral precancers. This paper reviews the various immunological abnormalities associated with oral precancers including cell surface changes, alterations in cell mediated immune reactions and humoral immune abnormalities.

Antibody Formation↗
PubMed1991

Oncogene expression and prognosis in cervical cancer.

Cancer of the uterine cervix accounts for 80-85% of all female genital tract malignancies in India and also remains a major problem for oncologists in other parts of the world. A major concern regarding the disease is the lack of specific tumor markers for early detection, for accurate prediction of biological behaviour and for accurate assessment of prognosis. A new and exciting answer to this issue may now be available with the description of specific oncogenes and oncoproteins associated with this malignancy. On a clinical level these genes and their products may allow us to improve our understanding of disease etiology, and provide more precise diagnostic, prognostic and therapeutic characterization of individual tumors. This paper discusses the possibilities of using altered expression of oncogenes and their products in neoplastic tissue as markers for the diagnosis and prognosis of cervical cancer. These data support the view that detailed analysis of such gene expression has the potential to predict tumor behavior.

Female↗
PubMed1991

Cocaine immunotoxicity: abnormal cytokine production in Hispanic drug users.

Peripheral blood lymphocytes from 47 Hispanic poly-drug users with a history of cocaine abuse were analyzed for in vitro production of interleukin-1 (IL-1), interleukin-2 (IL-2), gamma-interferon (IFN) and plasma levels of soluble IL-2 receptor (SIL-2R). Cocaine use was confirmed and quantified by analysis of hair and urine samples, and subjects were grouped into 3 based on the extent of cocaine metabolites detected. No significant differences in IL-1 and IFN production were seen between the 3 groups. However, subjects with higher levels of cocaine in hair also showed higher levels of IL-2. In addition, a positive correlation was seen between cocaine concentrations and IL-2 levels. A corresponding negative correlation was seen between cocaine levels and levels of plasma SIL-2R. These findings suggest modulation of the IL-2 network by cocaine in poly-drug users.

Adolescent↗
PubMed1991

Stimulation of natural killer cell activity by murine retroviral infection and cocaine.

The effects of cocaine and murine AIDS on natural killer (NK) cell activity in C57BL/6 mice was studied. Cocaine may play a major role in the development and progression to AIDS in the human population. Chronic intraperitoneal injection of cocaine was shown to cause an increase in NK cell activity over those of saline-treated animals. Infection with LP-BM5 murine leukemia retrovirus was also shown to increase NK cell activity. NK cell activity was increased in retrovirally infected mice treated with cocaine beyond that of mice treated with cocaine alone. This study indicates an important immunomodulatory effect of cocaine on NK cell activity, especially when combined with the effects caused by retroviral infection.

Adjuvants, Immunologic↗
PubMed1991

Immunotoxicity of poly-drug use: abnormalities in the active and high-affinity CD2 antigen (E-rosette receptor) bearing T-lymphocytes.

The E-rosetting profiles of T-cells were studied in 47 subjects with a history of poly-drug and alcohol abuse, and compared with 15 normal controls. No change was evident in numbers of total rosette-forming cells (TRFC). However, there was reduction in active and high-affinity rosette-forming cells (ARFC and HARFC). These two subsets of CD2-antigen-bearing T-cells are considered as immunocompetent surveillance cells. Thus the abnormality associated with them could be due to the combined immunotoxic effects of substance abuse, modulating the immune status of drug users.

Adult↗
PubMed1991

Diagnostic delay and outcome in surgery for type A aortic dissection.

Twenty-two patients with acute type A aortic dissection presented to this hospital over a three-year period. The initial diagnosis was incorrect in 12 (54.5 per cent) and in 11 of these the error occurred in peripheral hospitals before referral. This diagnostic mistake lead to a delay in surgical treatment of 2-9 days (median 5 days). Three deaths occurred without surgery, and two of these could have been considered for repair if the correct diagnosis had been made earlier. In the surgically treated group, a 30-day survival of 16 out of 19 (84.2 per cent) was achieved and the three deaths were all related to late referral. Two died because of bowel infarction and one because of respiratory failure. An increased general awareness of acute aortic dissection is necessary as early diagnosis, before the onset of irreversible ischaemic events, allows a high surgical success rate.

Acute Disease↗
PubMed1990

Leukocyte depletion results in excellent heart-lung function after 12 hours of storage.

Extended preservation of the heart-lung block for 12 hours in a bovine model of heart-lung transplantation was achieved using donor core cooling, static hypothermic storage, and reperfusion on cardiopulmonary bypass with leukocyte-depleted (LD) blood. Orthotopic heart-lung transplantation was performed with (n = 4, LD group) or without (n = 4, control group) LD blood during cardiopulmonary bypass. Postoperative measurements of cardiopulmonary function were made at 2, 4, and 6 hours after reperfusion. Only 2 animals (50%) of the control group survived more than 2 hours, whereas all animals in the LD group survived the study period. Arterial oxygen tension on 100% oxygen was 535.63 +/- 64.96 mm Hg and 146.45 +/- 90.9 mm Hg in the LD and control groups, respectively, at 2 hours (p less than 0.5) and 524.3 +/- 73.32 and 147.9 +/- 255.67 mm Hg at 6 hours. Pulmonary artery systolic pressure-to-systemic pressure ratio was 0.49 +/- 0.08 and 0.62 +/- 0.35 at 2 and 6 hours in the LD group. Extravascular lung water was 17.81 +/- 0.02 mL/kg (control group) and 11.28 +/- 9.15 mL/kg (LD group) at 2 hours. At reperfusion, the mean neutrophil count was 27 +/- 27 and 764 +/- 635 x 10(9)/L in the LD and control groups, respectively. This novel approach of leukocyte depletion during reperfusion after heart-lung preservation resulted in excellent cardiac and pulmonary protection.

Animals↗