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Biomedical subjects

R Hong

Publications and source records attributed to R Hong.

At least 163 records · Page 9Linked to original sources

Fatal graft-versus-host disease after a small leukocyte transfusion in a patient with lymphoma and varicella.

A child with a poorly differentiated lymphoma developed varicella while being treated with maintenance chemotherapeutic agents. He received a transfusion of nonirradiated leukocytes from 1 unit of whole blood donated by a healthy volunteer who had recently recovered from varicella. The clinical course of varicella was aborted, but a classic graft-versus-host reaction developed and ultimately proved fatal. The host may have presented a large population of antigen-bearing cells to an infusion of presensitized immunocompetent donor cells, leading to an overwhelming aggressor lymphocyte reaction. We speculate that a modified approach using irradiated donor cells could be of benefit in the treatment of varicella infections in the immunosuppressed host.

Chickenpox↗

Successful transplantation of the thymus in Nezelof's syndrome.

A 6-month-old girl with congenital thymic dysplasia or Nezelof's syndrome (lack of T cell function and normal levels of immunoglobulins) was given a transplant of a human thymus gland from a 14-week-old fetus and is surviving 36 months after transplant. Her clinical condition is the principal index of the success of the transplant since most in vitro and in vivo data indicate a full immunologic restoration has not been achieved. However, the number of E-rosettes in the peripheral blood has increased, the number of surface immunoglobulin-bearing cells has decreased, but there is little improvement in mitogen responsitivity. Immunoglobulin levels have increased with age, but there is no demonstrable specific antibody activity. Nevertheless, she remains free of infection, living in an unprotected environment.

Female↗

Circulating thymic-hormone activity in congenital immunodeficiency.

Circulating thymic-hormone activity was assayed by measuring Thy 1-2 antigen induction on null lymphocytes from athymic mice incubated with human plasma or serum. Plasma from 19 normal children aged under 10 had inductive activity equivalent to 10-6-16-2 ng thymopoitin/ml. Plasma from 15 infants were severe combined immuno-deficiency, 2 of whom had appreciable immunoglobulin synthesis, and from 2 infants with DiGeorge syndrome had little or no inductive activity. Successful reconstitution with thymus or bone-marrow grafts and with red-cell infusions (if adenosine-deaminase deficiency is present) was followed by a rise in circulating thymic-hormone activity.

Agammaglobulinemia↗

Thymocyte-macrophage roles in autoimmune diseases.

Thymocytes and macrophages can be involved in the generation and perpetuation of autoimmune disorders in many ways. Evidence continues to mount for their active role. Although a significant association seems likely, one should remember that B cells and complement-directed granulocyte destruction may be equally if not more important. Furthermore, a combination of processes is not precluded by any fundamental biological law. Appropriate and effective therapy requires acceptance of this concept and further studies should attempt to define the interrelationships of these processes and focus upon methodology to determine their relative roles in a given situation.

Animals↗

Quantitation of urinary immunogloublins by a double antibody technique.

A double antibody method for quantitation of urinary immunoglobulins that is sensitive enough to avoid the need for urine concentrations has been developed. The first antibody is goat antiserum monospecific for the heavy chains of IgA, IgG, and IgM. The second, and precipitating, antibody is developed in rabbits made tolerant to human IgG. Normal values for male and female children and adults are presented. Elevated levels of urinary IgA and IgG were found after urinary tract infection.

Adult↗

Reconstitution of B and T lymphocyte function in severe combined immunodeficiency disease after transplantation with thymic epithelium.

A patient with severe combined immunodeficiency has been given a transplant of thymic epithelium obtained from short-term culture of normal human thymus. 4 wk after transplantation immunoglobulin was detected and the patient now has normal levels of the three main classes. Functional antibodies of four specificities have been detected. An increase in reactivity to allogeneic cells and phytohaemagglutinin has been observed, with an increase in E rosettes; a positive delayed skin test to candida antigen is now present. The patient has shown reversal of wasting and has been free of infection for 7 months since receiving the transplant. It appears that under certain circumstances thymic epithelium reconstitutes both T and B cell functions.

B-Lymphocytes↗

Chronic cytomegalovirus infection, immunodeficiency, and monoclonal gammopathy-antigen-driven malignancy?

An infant with severe combined immunodeficiency had normal numbers of lymphocytes which bore E rosette and surface Ig markers in an appropriate distribution. However, only minimal responsivity to in vitro stimulation by mitogens and allogenic cells, and none to antigens could be elicited; functional antibody responses were also nil, except to cytomegalovirus. Intrauterine-acquired cytomegalovirus may have caused his immune dysfunction, although the possibility of a postnatal infection cannot be excluded. Therapy with transfer factor and thymus transplantation was unsucessful in restoring immunity and may have aggravated a pre-existing monoclonal gammopathy. It is possible that the monoclonal protein was derived from B-cells transplacentally received from the patients mother.

Antibody Formation↗

Synthesis of secretory component by human colon cancer cells.

Colon carcinoma, established in long-term tissue culture, has been shown to synthesize secretory component (SC). These molecules can be demonstrated both on the cell surface and in the cytoplasm by immunofluorescence. Regeneration of SC was demonstrable after trypsinization of the cells. In culture, two lines of carcinoma epithelium were shown to incorporate (14C) leucine into newly synthesized SC. These cell lines should provide useful preparations for studying the details of immunoglobulin-SC interactions.

Cell Line↗

Morula forms of E rosettes: distribution, specific inhibition, and enhancement.

Rosetts-forming cells (RFC) with more than 10 sheep red blood cells (SRBC's) per cell defined as morula-forming cells (MFC) were studied in human lymphoid organs and in the peripheral blood (PBL). MFC are most common in the thymus (more than 50%) and the frequency is much less in peripheral lymphoid tissues and in the blood (29.8% in those less than 5 years old; 14.9% in adults). There is very slight decrease in total RFC in PBL over age 5, but the changes in MFC are quite striking. Treatment with antihuman thymus antiserum (ATS) and with anti-human lymphoblastic antiserum (ATL) resulted in significant inhibition of total rosette and morula rosette formation. No inhibition was seen using normal brain antiserum, anti-IgM antiserum, or anti-L chain antiserum. In two patients with chronic lymphocytic leukemia and in some cases of thymic deficiency the ratio of MFC to total RFC was unusually high. After culture with phytohemagglutinin (PHA) and conversion to blast forms or after surface peturbation by papain or freeze-thaw treatment, MFC numbers were increased.

Humans↗