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Biomedical subjects

K Lennert

Publications and source records attributed to K Lennert.

At least 181 records · Page 10Linked to original sources
PubMed1976

[Malignant and benign lymphomas of the eye, eyelid, and orbit (author's transl)].

Twenty-three lymphomas of the eye, eyelid, and orbit were chosen study from biopsy material of the Department of Pathology, University of Kiel, and the Lymph Node Registry in Kiel. There were 12 malignant non-Hodgkin's lymphomas and 11 benign lymphomas. Catamnestic examination confirmed the histologic diagnosis in all 11 cases of benign lymphoma. Eleven of the malignant lymphomas represented immunocytomas and were therefore a low-grade malignancy. In contrast, there was only one case of malignant lymphoma of high-grade malignancy, which was diagnosed as centroblastic lymphoma. The immunocytoma was retrobulbar in one third of our cases and conjuctival in only 2 cases, whereas benign lymphoma had developed in the conjunctiva in 7 of 11 cases. Immunocytoma represents a tumor composed of lymphocytes and plasma cells or plasmacytoid cells. PAS-positive globular inclusions are usually found in the nucleus and/or cytoplasm of the plasma cells or plasmacytoid cells.

Adult↗
PubMed1976

Lymphoblastic lymphoma of convoluted or acid phosphatase type-a tumor of T precursor cells.

Five lymphatic neoplasms with strong focal acid phosphatase reactivity were selected from a group of acute lymphocytic leukemias and lymphoblastic lymphomas. All five cases showed an anterior mediastinal mass and exhibited identical morphology. This type of lymphoma has been described by Lukes under the term "malignant lymphoma of convoluted lymphocytes". Analysis of surface membrane receptors revealed that the tumor cells lacked surface immunoglobulin and receptors for Fc-fragment, but possessed receptors for complement (C3), untreated SRBC (ES) and SRBC treated with neuraminidase (ESN). By applying a mixed rosette assay using nucleated chicken erythrocytes coated with antibodies and C3, and denucleated ESN, it was found that a considerable number of tumor cells in all five cases formed mixed rosettes, i.e. that they bore the C3 receptor characteristic of B cells and simultaneously the E receptor characteristic of T cells. Thus the tumor cells resembled immature thymocytes of 10-15 weeks' gestation, which also show focal acid phosphatase reactivity and simultaneous expression of C3 and E receptors.

Acid Phosphatase↗
PubMed1976

Attempts to demonstrate virus-specific sequences in human tumors. IV. EB viral DNA in European Burkitt lymphoma and immunoblastic lymphadenopathy with excessive plasmacytosis.

Various biopsies from different European malignant lymphomas, two biopsies from nasopharyngeal carcinomas, and material from non-neoplastic lymph nodes were assayed for the presence of Epstein-Barr virus (EBV) DNA by nucleic acid hybridization. Reassociation kinetics of in vitro-labelled EBV DNA were studied in the presence of tumor DNA. The lymphomas tested included among others follicular lymphomas, germinocytomas, immunoblastic lymphomas and lymphoplasmacytoid immunocytomas. Epstein-Barr viral DNA was demonstrated within the two nasopharyngeal carcinoma biopsies as expected. A histologically typical Burkitt lymphoma as well as an immunoblastic lymphadenopathy with excessive plasmacytosis also contained EBV-DNA. The Burkitt biopsy revealed about 15 EBV genome equivalents per cell. Antibodies against EBV-specific antigens were highly elevated in the serum of this patient. The material of the patient with immunoblastic lymphadenopathy contained 2-3 EBV genome equivalents per cell.

Aged↗
PubMed1976

Sinus histiocytosis with massive lymphadenopathy: fifteen new cases.

Fifteen cases of chronic lymphadenitis with massive hemophagocytic sinus histiocytosis were analyzed. Fourteen patients were whites, 13 were Europeans, and 11 were males; 10 patients were under 10, 4 were over 20, and 2 over 60 years old. The oldest patient died; all other either healed without therapy or are in excellent condition. We studied the cytologic features of lymph node imprints. A 5-year-old girl was examined more thoroughly. High antibody titers to Klebsiella antigens were found repeatedly. The patient also had a constant lymphocytopenia. Phytohemagglutinin-induced blast transformation and lymphotoxin production were within normal limits. No serum Epstein-Barr virus-antibodies could be detected.

Adolescent↗
PubMed1976

Leukemic anaplasias reflecting physiologic cytogenesis of myeloid system.

Naphthol AS-D chloroacetatesterase activity in peripheral blood granulocytes is confined to neutrophils which are all positive and to a minor part of monocytes. Its occurance in eosinophils and basophils indicate a myeloproliferative disease. This chemical property can reliably be applied to separate neoplastic from reactive forms of quantitative and qualitative leukocyte alterations. The developmental line of this specific myeloid cellular attribut has been presented to elucidate its diagnostic significance and its validity as proof for existence of a common promyelocyte from which neutrophils, monocytes, basophils and eosinophils originate.

Basophils↗
PubMed1975

The immunological significance of cellular infiltrates in chronic rejection of human kidney transplants.

Fifteen transplanted human kidneys with clinical and histological signs of chronic rejection were examined microscopically for cellular infiltration. Three normal kidneys were used as a reference. All infiltrating cells were classified and counted. The average number of cells per 10 microscopic fields was called the relative density of cellular infiltrates. Differences in the densities of different cell classes and changes in the cellular infiltration of the grafts were regarded as cellular expressions of the immune response. Summarizing our results, we conclude that: 1) the chronic immunological rejection of transplanted human kidneys is essentially caused by immunocompetent cells; 2) plasma cells develop in the graft itself; 3) the immunocompetent cell population tends to be purely and simply made up of plasma cells; 4) therefore, the true "effector cell" among the immunocompetent cells may be the plasma cell--at least in the chronic rejection of transplanted human kidneys. Cleaved lymphocytes were the most frequent of the infiltrating cells found in the transplants. However, their role is not yet clear.

Cell Count↗
PubMed1975

[Immunoblastic adenopathy: clinical features, treatment and prognosis (author's transl)].

Clinical features, response to treatment and prognosis of 50 cases of immunoblastic lymph-adenopathy are reviewed. Most of the patients presented with generalized lymphadenopathy, hepatomegaly and/or splenomegaly, and fever. Hyperergic reactions such as pruritus, skin rash or eosinophilia were frequent. Erythrocytic sedimentation rate was increased by differing amounts. In some cases there was a polyclonal increase in immunoglobulins, while in others there was a reduction. Proven hypersensitivity to a wide spectrum of drugs was present in nine cases. Prognosis is uncertain: almost half of the patients died within one to forty-two months, some perhaps as a result of massive chemotherapy and/or radiotherapy. Best management probably is symptomatic treatment alone or with small doses of corticoids or immunosuppressives, supplemented by antibiotics. It is concluded that immunoblastic lymphadenopathy represents a hyperimmune reaction and is not, despite the high death-rate, a true malignant lymphoma.

Adult↗
PubMed1975

Morphology and classification of malignant lymphomas and so-called reticuloses.

There is general agreement as to the definition and subclassification of Hodgkin lymphomas, which is acceptable for practical reasons. However, the nature of the different types of Hodgkin lymphomas needs further consideration. On the other hand, today we are as far from agreement on non-Hodgkin lymphomas as ever before. Earlier European and American classifications have now to be reconsidered in the light of modern concepts of experimental immunology. It has become necessary to apply immunochemical and immunomorphological methods in addition to histological, histochemical, cytological, and ultrastructural techniques. Only such a complex approach has been able to provide new insight into the functional properties of the tumor cells. The result was a new lymphoma classification, which conforms to LUKES' concept in many respects. It was fundamentally accepted by a group of European lymphoma experts and has been condensed and modified in order to be applicable by as many lymphoma centers as possible. It has received the name "Kiel Classification" 1974. The main principles of the classification are as follows: 1. A distinction is made between malignant lymphomas of low-grade and those of high-grade malignancy; "-cytic", "-blastic" m.l. 2. The terms "sarcoma" and "leukemia" are avoided. All types of malignant lymphoma can be leukemic, however with differnt frequencies. All B-cell lymphomas can also show a monoclonal immunoglobulin increase ("paraproteinemia") in the blood, mostly of IgM. So-called macroglobulinemia of Waldenström is therefore not itself an etity, but instead a clinical syndrome. It has been shown that so-called reticulosarcoma is derived from immunoblasts, not from reticulum cells or histiocytes. The group of reticuloses also needs reconsideration. The term "reticulosis" is cytologically incorrect in most cases. Otherwise it refers to a group of diseases which we do not yet understand.

B-Lymphocytes↗
PubMed1975

Cytological and functional criteria for the classification of malignant lymphomata.

The subtle morphology and functional properties of cells are the best parameters to use for their definition. This is also true for the corresponding tumours, especially malignant lymphomata. In studies of 106 cases of malignant lymphoma we therefore applied as morphological methods haematological staining (Giemsa in sections and imprints) and electron microscopic analysis. As functional criteria we used the nonspecific esterase reaction to define tumours of histiocytes and an estimation of the immunoglobulin content of tissue extracts and single cells to define tumours of B lymphocytes and their derivatives. By combining all of these methods it was possible to propose a new classification. Whereas not one histiocytic malignant lymphoma ("reticulosarcoma") was found in the series, at least most of the malignant lymphomata investigated seemed to be derived from the B lymphocyte system. The following types are distinguished: (1) Chronic lymphocytic leukaemia; (2) diffuse germinocytoma (malignant lymphoma, lymphocytic, intermediate); (3) germinoblastoma (follicular, follicular and diffuse, diffuse; sclerotic, nonsclerotic) which can show a transition into germinoblastic sarcoma; (4) immunoblastic sarcoma of the B cell type (previously called reticulo-sarcoma); (5) lymphoplasmocytoid immunocytoma, which may be associated with Waldenstrom's macroglobulinaemia and can show a mixed cellularity; (6) lymphoblastic (paraleukoblastic) sarcoma and leukaemia, which are, at least in most cases, probably neoplasias of germinoblasts. All of these lymphomata can produce immunoglobulins. Sixty-seven cases showed an Ig increase in the tumour. This was mostly IgM, but sometimes IgG, IgA, IgD and/or IgE. A morphological equivalent of even abnormal Ig secretion is the globular positive (diastase resistant) PAS reaction in lymphoid cells (not in the histiocytes) in paraffin sections, which we found in 43 cases. Only 19 of the 63 cases with an IgM increase in the tumour showed an increase of IgM in the serum. Waldenström's macroglobulinaemia is a facultative symptom of morphologically different malignant lymphomata and should therefore be considered only as a clinical syndrome and not as a nosological entity.

B-Lymphocytes↗