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Biomedical subjects

W J Richtsmeier

Publications and source records attributed to W J Richtsmeier.

At least 55 records · Page 3Linked to original sources
PubMed1988

The versatile midface degloving approach.

The exposure obtained using the degloving approach is superb and the absence of resultant facial scar or deformity provides a dramatic new addition to the otolaryngologist's surgical repertoire. The advantages of the degloving technique in exposure of the midface, nasal cavities, paranasal sinuses, nasopharynx, skull base, and clivus have led to its increasing importance in the otolaryngology literature. Within 2 years of the technique's introduction in our department, it had been used 48 times for a wide variety of problems, including inverting papilloma, juvenile angiofibroma, chordoma and selected cases of fungal disease of the sinuses. This article describes the procedure, reports the results from a panel of 48 patients, and discusses potential complications. The authors' experience with this procedure indicates that it should become a procedure of choice for management of inverting papilloma and juvenile angiofibroma, as well as a major alternative method in many other circumstances.

Face↗
PubMed1988

Induction of HLA-DR antigen on human squamous carcinoma by recombinant interferon gamma.

The antigen recognition system which plays the major role in immunologic attraction mechanisms, including graft rejection, is the class II major histocompatibility complex containing the HLA-DR locus. Few types of cells constitutively express this antigen, as it is a potent immunological activating signal usually confined to antigen processing cells, activated lymphocytes, and endothelium. Using indirect immunofluorescence, we have observed induction of the HLA-DR glycoprotein in selected head and neck squamous cell carcinoma tissue cultures treated with recombinant interferon gamma. This occurs in concert with growth arrest and morphological changes after rHuIFN-gamma treatment. This report describes the induction of a surface antigen that may have profound prognostic significance. Understanding the kinetics of HLA-DR induction will aid in the design and assessment of adoptive immunotherapy with rHuIFN-gamma.

Carcinoma, Squamous Cell↗
PubMed1987

In vivo nutrient uptake by head and neck cancers.

The arteriovenous uptake differences for glucose, lactate, pyruvate, beta-hydroxybutyrate, and acetoacetate were measured in vessels across squamous cell carcinomas in ten selected patients with tumors of the head and neck. All tumors measured took up glucose, pyruvate, beta-hydroxybutyrate, and acetoacetate. They could either produce, take up, or maintain a constant level of lactate. These tumors demonstrate a heterogeneous affinity for various metabolites, including ketone bodies which are elevated in the nutritionally depleted, tumor-burdened patient.

3-Hydroxybutyric Acid↗
PubMed1987

Tinnitus--the initial evaluation.

Initial evaluation of patients with tinnitus presents a challenge to the otolaryngologist's skills, knowledge, and judgment. History-taking, physical examination, and the ordering of initial laboratory tests should be orchestrated to efficiently evaluate patients with tinnitus. By the end of this initial evaluation, major decisions have to be made in regard to the employment of additional expensive and possibly invasive diagnostic tests. We present an outline to expedite the initial evaluation of patients with tinnitus as their major concern.

Audiometry↗
PubMed1987

Epstein-Barr virus-associated malignancies.

The infectious aspects of cancer in humans were epidemiologically pioneered by Dr. David Burkitt through his observations of lymphomatous tumors seen in children in equatorial Africa. Years, later, the Epstein-Barr virus (EBV) was shown to be intimately associated with such tumors and is now recognized as a component of some B-cell lymphomas and nasopharyngeal carcinoma. Still the questions of an active, passive, or accessory role persist. The ability of this virus to cause immunosuppressive hemopoietic disturbances in individuals infected with EBV but not developing cancer raise questions about host susceptibility, host immune response, and possible coconspiring, infectious, oncogenic agents. Recent associations of EBV antibody found in diseases, such as squamous cell carcinoma of the head and neck and acquired immunodeficiency syndromes, point to its possible accessory role as an immunosuppressive agent. The ability of EBV to spread by extracellular and intracellular mechanisms demonstrates its variable infectious potential. Numerous EBV-transformed human cell lines attest to its ability to confer "immortality" with uncontrolled growth patterns. This review critically examines the association of EBV with various malignancies, the type of evidence which links it there, and the implications for further investigations and therapy.

Burkitt Lymphoma↗
PubMed1987

The physiology and immunology of the pharyngeal lymphoid tissue.

The immunologic structure and function of the parapharyngeal lymphoid tissue are presented. The antigen-processing activities of the tonsils are compared to those of the adenoids and other mucosal-associated lymphoid tissues. Both immunoglobin synthesis and secretion as well as T-lymphocyte activities are described.

Adenoids↗
PubMed1986

In vivo anergy reversal with cimetidine in patients with cancer.

Impaired cell-mediated immune response is commonly seen in patients with squamous cell carcinoma of the head and neck. This immune defect has been associated with poor clinical performance. Recent evidence indicates an immunoregulatory action for cimetidine. For this reason, the effect of this medication on delayed hypersensitivity reactions in previously untreated patients with squamous cell carcinoma of the head and neck was studied. Patients hyporesponsive to an initial skin test battery were treated with cimetidine. A statistically significant increase in delayed hypersensitivity responses on repeated skin testing during cimetidine hydrochloride therapy was observed. Four of these patients who converted their skin tests while receiving cimetidine were again studied one to two weeks after cessation of therapy. All four returned to their precimetidine treatment status. These skin test response results suggest that histamine-mediated suppression of immune response occurs in patients with head and neck cancer. Cimetidine should be considered as an immunomodulator in patients with squamous cell carcinoma of the head and neck.

Aged↗
PubMed1986

Alpha-interferon: differential suppression of colony growth from human erythroid, myeloid, and megakaryocytic hematopoietic progenitor cells.

The effect of varying concentrations of interferon-alpha (IFN-alpha) on the in vitro colony growth from all single-lineage human hematopoietic colony-forming progenitor cells was evaluated. IFN-alpha was tested at concentrations of 0, 2, 20, and 200 U/ml in optimally stimulated bone marrow cultures from each of 4 volunteer donors. Substantial donor-to-donor variability and distinct, lineage-specific patterns of stem cell sensitivity to IFN-alpha were observed. In the erythroid series, the more primitive progenitor or burst-forming unit (BFU-E) was substantially more resistant to growth inhibition at low IFN-alpha concentrations than the mature colony-forming unit (CFU-E). Colony growth by the megakaryocyte progenitor cell (CFU-Meg) was decreased by all concentrations of IFN-alpha which produced a biphasic, inhibitory dose response. The response of the colony-forming unit granulocyte/macrophage (CFU-GM) was heterogeneous among the donors tested. CFU-GM growth from 2 donors was insensitive to IFN-alpha at all concentrations. Conversely, CFU-GM from the other 2 donors manifested a steep dose-response curve that was similar to that of the CFU-E. These data demonstrate a heterogeneity of progenitor cell sensitivity to growth suppression by IFN-alpha which appears to be influenced by (i) hematopoietic lineage, (ii) degree of differentiation of the progenitor cell, and (iii) individual variability.

Colony-Forming Units Assay↗
PubMed1985

The effect of split virus influenza vaccination on theophylline pharmacokinetics.

The effects of split virus influenza vaccine on the pharmacokinetics of theophylline and the in vivo and in vitro induction of interferon were studied in 23 volunteers. No effect on the total body clearance, half-life, or mean residence time of theophylline was found as a result of influenza virus vaccine. Additionally, no interferon activity was detected in vivo for as long as 24 h after vaccination. Finally, no production of interferon occurred in tonsil or peripheral lymphocyte cultures inoculated with split virus vaccine. We conclude that split virus influenza vaccine does not affect theophylline pharmacokinetics. In addition, we find no evidence that split virus influenza vaccine functions as an interferon inducer in humans.

Adolescent↗
PubMed1985

Interferon sensitivity of fibroblast cell cultures derived from patients with neoplasms of the head and neck.

Interferon (IFN) is a protein with antiviral activity that has been shown to inhibit the growth of many different types of cells. We have measured the IFN sensitivity of nine cell cultures isolated from patients with squamous cell carcinoma and one with malignant melanoma of the head and neck. Normal-appearing fibroblast cultures isolated from these tissues appear quite sensitive to the antiviral effects of IFN. When the encephalomyocarditis virus yield reduction assay is used, these diploid cells are as sensitive to IFN-alpha as are newborn foreskin fibroblast cultures. A similar antiviral effect is seen with IFN-gamma. These cells are relatively insensitive to the antigrowth effect of both IFN preparations as measured by 3H thymidine incorporation and direct observations of cell growth. This is the same relative sensitivity as fibroblasts derived from normal patients. Since these cells are at least 100 times less sensitive to the antigrowth action of the IFNs, it appears unlikely that the IFNs play a significant role in the control of normal fibroblast growth, in contrast to the sensitivity of malignant cell lines.

Carcinoma, Squamous Cell↗
PubMed1984

Dendritic cell identification in head and neck lymphoid tissue. Newly recognized cells control T-lymphocyte functions.

The physiologic measurements of a subpopulation of mononuclear cells derived from head and neck lymphoid tissues are similar to those of dendritic cells are described. Dendritic cells are a subpopulation of bone marrow-derived leukocytes that were originally identified in rodents and now described in man as having central control of T-lymphocyte functions. We describe a technique for the enrichment of dendritic cells obtained from tonsils utilizing a bovine serum albumin (BSA) gradient and note that they have the light and electron microscopic appearance of dendritic cells. The measured oxidative mitogenic response and interferon-gamma production in complete leukocyte cultures was compared with BSA gradient-separated preparations. The denser cells, comprised mostly of normal appearing lymphocytes, would not undergo a mitogenic response nor produce normal amounts of interferon when stimulated unless the dendritic cell-rich, less-dense fraction, was added back. The dendritic cells derived from tonsils seem to behave as a potent accessory cell for these T-lymphocyte-associated functions.

Animals↗
PubMed1984

Interferon--present and future prospects.

The interferons are a group of proteins that have inspired a new era of investigation into biological modification. The interferons are now divided into subgroups characterized by chemical means and correspond to different biological responses which can be observed in terms of the inducer used, and the timing of the response. Identified originally as antiviral agents when homologous cell systems were treated prior to infection, new studies have extended these observations to place the interferons in a central role as a strong force in the regulation of immunologic responses. A marriage of interferonology and cell immunology is enlarging both our understanding of the action of these proteins and our ability to follow the course of an illness and eventually to control its outcome . Genetic engineering has provided a way to process quantities of interferon and provided the molecular sequence of all three classes of IFN including a model of the active site for IFN-alpha. The offshot of the technology developed to study the intracellular processes after interferon treatment have already led to increased sensitivity to detect virally treated diseases. Both the variety of the interferon inducers and the scope of parasites in which it can exert its influence provide a frontier of biological investigation which has at the root of its nature the very secret of life. In addition to cellular phenomena, the positive effects on tumor-bearing organisms and the ill effects on infant animals highlight the potential power of the interferons.

Bacterial Infections↗
PubMed1979

Actinomycosis of the head and neck.

Actinomycosis has been known to involve virtually every anatomic site in the body; those infections involving the head and neck will be reviewed. Actinomycosis of the head and neck has many presentations; it may disguise itself as a tumor or present as a draining abscess which has failed to reveal an infectious agent as its etiology. With more recent attention directed toward the detection of anaerobic organisms especially in the cervicofacial region, this diagnosis is being made more frequently. In this review, a discussion of the bacteriology of Actinomyces, including a review of its taxonomy, morphology, growth requirements, and biochemistry, will be presented. Recommendations are made to clinicians and laboratory personnel who handle such specimens in order that they might obtain maximum information. In addition, infections which mimic or accompany actinomycosis will be reviewed. The diagnosis and management of this infection, including the physical exam, X-ray and laboratory tests, and collection and handling of specimens, as well as the surgical and antibiotic therapy will be discussed in depth. The variety of clinical presentations with their differential diagnosis is used to illustrate the complexity of this disease.

Actinomycosis↗
PubMedDate not supplied

Human interferon production in tonsil and adenoid tissue cultures.

Using Sendai virus as an inducer, tonsil lymphocytes produce alpha interferon (IFN-alpha) 1,000 times more potent than that reportedly induced using Newcastle disease virus in such lymphoid tissue. Alpha and gamma interferons can be produced from tonsil and adenoid lymphocyte cultures in amounts comparable with those produced from cultures of pooled peripheral blood lymphocytes. Lymphocytes from both tonsils and adenoids are equal in the amount of IFN each produces. The IFN-producing potential of lymphocytes appears constant in humans between the ages of 3 and 38 years and is not adversely affected during the first trimester of pregnancy. Since approximately one billion lymphocytes are obtained from each of these tissues, they represent a potential source of significant quantities of IFN for investigational use.

Adenoids↗