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Biomedical subjects

J W Shields

Publications and source records attributed to J W Shields.

At least 37 records · Page 2Linked to original sources
PubMed1997

The XI AIDS conference and HIV-1 lymphopathy.

The random reverse transcription of HIV-1 RNA into the genes of large dividing lymphocytes and transport of integrated proviral DNA within and between persons via migratory small cytoplasm depleted lymphocytes derived therefrom causes deterioration of the entire lymphopoietic system. Secondary results are progressive failure in homeostasis, loss of sensitivity to potentially therapeutic drugs, and inability to produce preventive vaccines. The world-wide prevention of HIV-1 sickness and other lymphopathic retroviral diseases will depend on greater individual cooperation, especially with respect to minimizing the numbers of infected lymphocytes which migrate between persons through blood, semen, uterine endocervical secretions and maternal colostrum.

AIDS-Related Complex↗
PubMed1994

Lymph, lymphomania, lymphotrophy, and HIV lymphocytopathy: an historical perspective.

From 1578-1628, Fabricius and his pupils, Asellius and Harvey, sequentially laid the foundations for the modern sciences of comparative anatomy, lymphology and circulation, as well as a state of lympho-philia or "-mania" which persists to the present time. Lymphomania persists because there remains a fundamental controversy and ignorance about the precise functions of lymph, lymphatics, lymph glands, lymphocytes, and the bursa of Fabricius. In 1778, William Hewson deduced that lymph effluent from lymph glands contains globular particles essential to normal body growth and tissue repair. In 1878, Claude Bernard recognized that lymph is a composite emanating from all body cells which forms the circulating blood plasma in order to sustain homeostasis throughout the internal milieu. From 1890-1960, many observers confirmed older concepts that lymph, lymph glands, and lymphocytes develop to nourish and regulate cell growth throughout the body. However, since 1960 characterization of "T-" and "B-" cells, respectively derived from thymus and the avian bursa, has revolutionized conceptual immunology, almost to the exclusion of older trophic concepts of lymph, lymph gland and lymphocyte functions. Therefore, homeostasis is considered here in terms of lymph circulation from and to respiring cells, as well as in homeostatic "failures" commonly found in persons infected with lymphotropic retroviruses.

AIDS-Related Complex↗
PubMed1993

Morpho-physiological function and role of omental milky spots as omentum-associated lymphoid tissue (OALT) in the peritoneal cavity.

The morpho-physiological function and role of milky spots in the greater omentum are reviewed. These milky spots are composed of cellular aggregations of mesenchymal cells, mainly macrophages and lymphocytes, surrounding capillary convolutions termed omental glomeruli. Initial lymphatics of the omentum begin at the milky spots and drain into lymph collectors. The lymphatic capillaries in the omental milky spots take part in the absorption of various substances from the peritoneal cavity. Omental milky spots probably act as the first line of defense in the peritoneal cavity and therefore are immunologically important. In human infants, most of the cells in these milky spots are macrophages (49%); less common are B lymphocytes (29%) and T lymphocytes (12%). Whereas macrophages form clusters near the peritoneal surface of the milky spots and are oriented toward the peritoneal cavity for migration, clusters of B and T lymphocytes are typically found in periarteriolar locations within the milky spots. This cell zonation facilitates phagocytosis and processing of circulating antigens and foreign bodies which emanate from the peritoneal cavity. During inflammation, the number and size of omental milky spots dramatically increase, and some develop germinal centers within the lymphatic follicles and produce antibodies. During intraperitoneal immunotherapy, the omental milky spots and their cellular elements may be activated by intraperitoneal administration of biological response modifiers, and thereby represent an important immunoregulatory system for the peritoneal cavity. Omental milky spots are also closely linked to the dissemination of cancer cells. Thus, intraperitoneally inoculated experimental tumor cells selectively invade the milky spots and proliferate there to form tumor nodules. This occurrence is relevant to clinical practice where nodular metastases to the omentum are common. Omental milky spots are analogous to regional lymph nodes and as such are the omentum-associated lymphoid tissues and participate in intraperitoneal immune reactions.

Animals↗
PubMed1992

Lymph, lymph glands, and homeostasis.

Under aerobic conditions every respiring cell in the human body normally consumes oxygen to burn food and produce stoichiometric quantities of water which dissolves carbon dioxide and less soluble cell products. The effluent water and solutes appear in the form of lymph in the interstices between cells. The lymph effluent from all respiring cells flows to become the circulating lymph and blood plasma which coordinately sustain a steady state of homeostasis throughout the internal milieu. As a result, every living cell served by the vascular system has equal opportunity to partake of water and solutes emanating from or absorbed by remaining cells. Solute quantities available depend on cell location, regional plasma flow, local vascular permeability, molecular size, configuration, solubility and concentration, as well as avid cell receptors. Proportional to oxygen consumption, organized lymph glands develop in environments of relatively high oxygen tension around regional arteries to filter and process lymph coming from regional cells, and to produce effluent lymph rich in soluble globulins extruded by local mononuclear cells (especially macrophages, plasmacytes, lymphocytes), along with suspended small cytoplasm-poor lymphocytes. In turn, such dissolved globulins and remarkably motile small lymphocytes help feed, regulate growth and provide immunity to remaining cells. The lymph effluent from lymph glands and residua from capillary filtrates, along with newly absorbed solvent water, join the blood circulation during pulmonary inspiration in volumes proportional to the volume of air inspired with each breath.

Animals↗
PubMed1989

Lymphocyte emperipolesis in AIDS.

Excepting sperm, lymphocytes are the most motile cells within and outside of the body in mammals. In the body, lymphocytes are the primary victims of the Acquired Immune Deficiency Syndrome (AIDS). This photo-essay illustrates that migrant lymphocytes outside of the body are the primary vectors of AIDS spread.

Acquired Immunodeficiency Syndrome↗
PubMed1980

Central lymph propulsion.

Dissections reveal that each lymphatic organ characteristic of species is supplied with lymph hearts, smooth muscles, or striated muscles whose contractions (along with tranmitted arterial pulsations and changing gravitational forces) coordinately propel lymph centrally during breathing, swallowing, food absorption and joint flexion. In aquatic vertebrates and amphibians lymph hearts, closely related to the gills, propel central lymph into the jugular veins. In aerial vertebrates with well-developed lungs, the striated muscles which enable ventilation, propel central lymph into large veins coursing through the thoracic inlet at rates commensurate with oxygen consumption under normal conditions.

Amphibians↗
PubMed1979

Cytoclasmosis in central lymph production.

Electron microscopic observations and ancillary data are reviewed to show that lymphatic organs produce quantities of central lymph by releasing cytoplasm-depleted cells into colloidal hydrosols produced by cell fragmentation (cytoclasmosis).

Animals↗