Biomedical subjects

V A Ngu

Publications and source records attributed to V A Ngu.

At least 19 recordsLinked to original sources

PubMed1997

The viral envelope in the evolution of HIV: a hypothetical approach to inducing an effective immune response to the virus.

The human immunodeficiency virus (HIV) is 'perceived' by the host immune system as partly-self because of the presence of host cell wall membrane on the viral envelope. This perception leads to an ineffective immune response to the virus. It is proposed that only viral core antigens without the envelope will be perceived as non-self by the host immune system and can provoke an effective immune response. In normal uninfected persons, core antigens could therefore serve as a vaccine. In HIV infected persons, uncommitted immunocytes from the peripheral leucocytes freed from antibodies will in vitro process autologous viral core antigens as non-self antigens and lead to an effective immune response against the HIV when reinjected into the patient. The use of autologous viral core antigens provides, at the same time, a means for testing viral core antigens as possible vaccines without any risk to a third person. This immunotherapy of the HIV, when confirmed, will support core antigens as possible vaccines and could also be applied to the large group of retroviral and other enveloped viruses that cause chronic infections and malignant tumours in man and animals, with considerable benefits to human and animal health.

AIDS Vaccines↗

PubMed1996

Testes tumors in a Sub-Saharan African city (Yaounde). Incident cases and histopathology.

OBJECTIVES: To determine the histologic types of testicular tumors and identify associated risk factors. METHODS: Data on clinical presentation, age, race, history of cryptorchidism or testicular trauma and histologic types, on each patient with testis tumor, were abstracted from medical records and the pathology register. RESULTS: Of 14 tumors, 11 were malignant. Five were Burkitt's and 2 non-Burkitt's lymphomas, 1 plasmocytoma and 3 seminomas. None of the seminomas occurred in black Africans. CONCLUSION: The epidemiology and histology of testis tumors in Yaounde differs considerably from other reported series. Burkitt's lymphoma is the commonest tumor. This alters the approach to the management of testicular masses. Race and geography seem to be important in the occurrence of testes tumors.

Adult↗

PubMed1994

Chronic infections from the perspective of evolution: a hypothesis.

No satisfactory explanation has so far been given for the persistence in the body sometimes, of various microorganisms-bacteria, parasites, fungi and viruses-in spite of their foreign antigens and a competent immune system. It has been proposed as an explantation that these microorganisms, in the course of evolution, have concealed their true antigens from the immune system. Free living microorganisms concealed their true antigens when the heat of the sun, with the threat of dehydration, induced the development in surviving mutants of a lipid coat to reduce surface water losses. This coat enveloped the microorganisms, concealing their true antigens. Viruses that cause chronic infections concealed their true antigens beneath a viral envelope derived from host cell. Exposing the true antigens on microorganisms and viruses with suitable lipid solvents and re-introducing the microorganisms and viruses so treated into the host as a kind of vaccine, should provoke a new immune response effective in eliminating the pathogens concerned from the body and in preventing future infections. In this way, pathogens could be used to treat and prevent certain infectious diseases. The above procedure should have significant benefits for human and animal health.

Animals↗

PubMed1992

Human cancers and viruses: a hypothesis for immune destruction of tumours caused by certain enveloped viruses using modified viral antigens.

Certain viruses which have been identified as possible aetiological agents of human malignant tumours have 2 common characteristics: a) they persist in the human body for long periods despite the presence of antibodies to them and b) they all possess viral envelopes. The envelopes, consisting of phospho-lipoproteins are derived from host cells viz nuclear envelope in the case of DNA viruses, and the cell membrane in the case of RNA viruses. These host cell elements on the viral envelope modify the antigenicity of the specific surface antigens which are now perceived by the host immune system as partly self. This in turn blackmails the immune system, if it is to avoid serious auto-immune disease, into producing compromise and ineffective antibodies. The hypothesis proposes the dissolution of the viral envelope in vitro and the re-introduction of the viral core into the host. This should provoke a new uncompromised immune response because it will be directed at the viral core only. This response should eliminate the viral core and with it, the whole enveloped virus, as well as the malignant tumour cells which carry the viral genome derived essentially from the viral core. This approach should introduce a new method for treating and preventing tumours caused by enveloped viruses and the chronic diseases caused by such viruses.

Antibodies, Viral↗

PubMed1990

Fever: thermodynamics applied to the leucocyte.

A fever, by raising the temperature of leucocytes, accelerates and so enhances their antimicrobial action against infections. This is in keeping with thermodynamic principles which apply to chemical and biochemical reactions. In keeping with the same thermodynamic principles, when the temperature of matter is raised, at certain critical temperatures its form and behaviour change dramatically and radically. Visible water, for example, boils at 100 degrees C into invisible steam. By analogy to such dramatic changes of behaviour it has been proposed as a hypothesis, that when the temperature of the leucocyte is raised in vitro to the extreme limit just before it dies, its behaviour will also change in a radical and dramatic manner to produce a totally new class of antimicrobial substances or antibiotics, called leucocyte derived antibiotics, LDA. The new LDA should have a wide spectrum of action against infecting micro-organisms including viruses that provoke a fever in the body. They should also have some anti-tumour effects in patients providing such leucocytes. Preliminary observations suggest that when the temperature of leucocytes is raised in vitro to the point of near cell death they can indeed produce new antimicrobial and antitumoral substances.

Fever↗

PubMed1981

Clinical experience with autobiotherapy of malignant tumor disease: a preliminary report.

It has been proposed that the elimination of excess scar tissue from the body is achieved by specialized killer cells, which are activated by vascular changes in the scar tissue. The malignant tumor is, according to this theory, considered to be a special type of excess scar tissue of fetal or near fetal age, the fetal blood supply of which prevents the activation of those specialized killer cells which were believed to eliminate excess scar tissue. Therefore, it is assumed that if the specialized killer cells of a malignant tumor patient are activated artificially, they would cause malignant tumor regression in vivo. This method of treatment is called autobiotherapy because it utilizes biological products from the patient to treat his own malignant tumor. Preliminary evidence is presented in support of autobiotherapy of malignant tumor disease.The peripheral leucocytes of 27 malignant tumor patients were activated separately by incubation in a serum-free medium containing the respective tumor cells or material. The effect of the injection of the activated leucocytes or their products, termed tumor leucocyte cultures (TLC), was studied in five patients with Kaposi sarcoma, five with carcinoma of the breast, four with carcinoma of the cervix, three with soft tissue sarcoma, two with carcinoma of the lung, two with carcinoma of the maxillary antrium, and a miscellaneous group of six patients. In 52 percent of cases, there was significant tumor regression. Tumor regression was most marked in patients with Kaposi sarcoma, carcinoma of the cervix, pharynx, and pancreas, one patient with a slow growing fibrosarcoma, one patient with a metastatic breast carcinoma, and also in one patient with myelogenous leukemia. However, not all the types of tumor studied responded satisfactorily to autobiotherapy. The reasons for the differences in response to autobiotherapy remain to be determined. Even so, the positive results obtained indicate that autobiotherapy is worthy of further research as an alternative in controlling malignant tumor disease.

Adult↗

PubMed1973