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Biomedical subjects

U Schmid

Publications and source records attributed to U Schmid.

At least 73 records · Page 4Linked to original sources

Determination of intracellular pyridine nucleotide levels by bioluminescence using anaerobic bacteria as a model.

An assay for the determination of NAD(P)+ and NAD(P)H in extracts from the obligate anaerobe bacterium Thermoanaerobacter finnii is developed and the strategy for this development is described. This assay performed with constant FMN reductase (EC 1.6.8.1) and luciferase (EC 1.14.14.3) concentrations has been shown to detect as low as 1 pmol pyridine nucleotide. With this assay recovery, efficiency of extraction, reliability, and detection limit of the procedures were determined. To our knowledge this is the first bioluminometric assay for the determination of pyridine nucleotide levels in bacterial extracts.

Adenine Nucleotides↗

Follicular lymphoid hyperplasia of the skin with high content of Ki-1 positive lymphocytes.

We report the case of a spontaneously regressing lymphocytic lesion on the neck of a 76-year-old man. Routine histopathological examination revealed a heterogeneous infiltrate composed of both lymphoid follicles and preferentially perifollicular and interfollicular sheets of large atypical cells. Immunohistologically, large atypical cells were positive for Ki-1/Ber-H2 (CD30), anti-Il-2 (CD25), Ber T9, anti-HLA-DR, Leu-5b (CD2), T3 (CD3), Leu-3 (CD4), Leu-1 (CD5) and, occasionally, Leu-M1 (CD15); that is, they showed an arrangement and immunophenotype similar to those of perifollicular Ki-1 positive cells in reactive lymphoid tissue. In contrast, antibodies To15 (CD22), anti-immunoglobulins, and anti-CALLA (CD10) stained polyclonal B-cells restricted to lymphoid follicles and small clusters representing remnants of follicles. We suggest that this lesion be termed "follicular lymphoid hyperplasia of the skin with high content of activated T-helper cells."

Aged↗

Melanoma targeting with a cocktail of monoclonal antibodies to distinct determinants of the human HMW-MAA.

The monoclonal antibodies (MoAbs) 149.53, 225.28, and 763.74 which recognize distinct and spatially distant determinants of the human high molecular weight-melanoma associated antigen (HMW-MAA) do not influence the binding of each other to cultured human melanoma cells. In vitro incubation of melanoma cells with a combination of the three 125I-labeled anti-HMW-MAA MoAbs results in a marked additive binding only when the MoAbs are used at saturating concentrations. Injection of the combination of the three 125I-labeled MoAbs (up to 300 micrograms per mouse) into human melanoma-bearing nude mice does not increase the amount of radioactivity specifically localized in melanoma lesions above the level observed upon injection of corresponding doses of individual MoAbs. These results may reflect the low concentration of MoAbs which reaches tumor lesions in vivo. Therefore, administration of combinations of MoAbs to distinct determinants of HMW-MAA may not increase the sensitivity of immunoscintigraphy to visualize lesions in patients with melanoma.

Animals↗

Identification of plasmacytoid T cells in lymphoid hyperplasia of the skin.

Well-defined clusters of plasmacytoid T cells were identified in two cases of lymphoid hyperplasia of the skin. With the use of paraffin-embedded and frozen sections and 46 different antibodies, the antigenic profile of plasmacytoid T cells was obtained. Corresponding to plasmacytoid T cells in reactive and neoplastic lymph node conditions, plasmacytoid T cells of the skin were devoid of most T-cell-restricted differentiation antigens CD2, CD3, CD5, and CD8 while expressing monocyte/macrophage-related antigens recognized by Ki-M6 and Ki-M7. In addition, plasmacytoid T cells were positive for CD4, CD45, HLA class II antigens (HLA-DR, Leu-10, MB3, LN2, LN3) and the transferrin receptor. Furthermore, they reacted with anti-Leu-8, MB1, Ki-B3 (CD45R), and MT1. Thus plasma-cytoid T cells are considered to be mononuclear cells with monocyte/macrophage differentiation rather than T lymphocytes. In addition, our findings substantiate the concept that plasmacytoid T cells may function as a hitherto unrecognized subgroup of antigen-presenting cells in the skin.

Antibodies, Monoclonal↗

[Primary non-Hodgkin's lymphoma of the muscles].

On the basis of two personal observations and of 18 published cases, a review of primary non-Hodgkin lymphoma originating in the skeletal muscle is presented. The disease mainly affects persons in the seventh decade. Ninety-five percent of the tumors occur in the extremities, with 75% in the lower extremities. Most lymphomas were of low grade malignancy, with intermediate and high grade tumors accounting for 45% of cases. Reliable differentiation of NHL from other small round cell tumors of the soft tissues, such as rhabdomyosarcoma or Ewing sarcoma, and from metastatic carcinoma, is mandatory for therapeutic purposes. Diagnosis can be established by light microscopy alone in most patients. In doubtful cases immunohistochemistry may be required.

Combined Modality Therapy↗

Immunostaining in atypical fibroxanthoma of the skin.

We have studied 12 cases of cutaneous atypical fibroxanthoma using immunohistochemistry to demonstrate lysozyme, alpha-1-antitrypsin, S-100-protein, receptors for peanut agglutinin, and intermediate filaments. Results were compared with immunostaining in 24 cases of other so-called fibrohistiocytic tumours. In addition 2 cases of atypical fibroxanthoma and 6 cases of fibrohistiocytic tumours were stained by monoclonal antibodies specific for the monocyte cell lineage (Ki-M1, Ki-M2, Ki-M6, Ki-M7, Ki-M8, OKM-1 and Leu-M1) and double-stained by monocyte-markers and Ki-67. The immunophenotype of atypical fibroxanthoma was rather similar to the marker profile found in malignant fibrous histiocytoma. All atypical fibroxanthomas were positive for vimentin and negative for epithelial markers. Monocyte lineage-specific determinants could be demonstrated in varying amounts in cells suggestive of being reactive. In contrast proliferating--Ki-67 positive--cells did not express monocyte/macrophage related antigens in atypical fibroxanthoma and malignant fibrous histiocytoma both. As to the histogenesis of these tumours our findings speak in favour of a derivation from primitive mesenchymal cells rather than from histiocytes.

Aged↗

[Myeloproliferative syndrome and acute febrile neutrophilic dermatosis (Sweet's syndrome)--a rare association].

The case is reported of a 73-year-old man presenting with a history arthralgia, conjunctivitis, fever and typical lesions of acute febrile neutrophilic dermatosis (Sweet's syndrome). Due to massive leukocytosis, an unclassifiable myeloproliferative disorder was later diagnosed. The disease responded well to hydroxyurea but only partly to steroids. The case demonstrates the necessity of close hematologic follow-up in Sweet's syndrome, since some 10% of patients develop hematologic malignancies weeks or months later.

Acute Disease↗

[Predictive value of additional immunohistochemical studies in histological diagnosis].

No exact information exists on the diagnostic value of immunohistochemistry applied to the routine material of an institute of surgical pathology. For this reason 390 cases additionally investigated by immunohistochemistry were analyzed retrospectively. This method was applied to 0.5% of all biopsies studied morphologically. On average 4.4 antisera per case were used. 352 cases (90.3%) initially diagnosed by morphology alone (16 benign lesions of debatable type, 111 lesions not clearly defined as benign or malignant, 225 malignant tumours of unknown subtype) could be clarified by immunohistochemistry. To obtain reliable results specific application of immunohistology and a clearcut formulation of the question are necessary. If these criteria are fulfilled immunohistochemistry represents a powerful tool in surgical pathology.

Adolescent↗

Further observational data on the behavioral and social world of institutions for the aged.

This study is an extension of previous observational work on the social ecology of dependence and independence in the institutionalized elderly. Observations of everyday, naturally occurring interactions between elderly residents of two different long-term institutions and their social partners were extended such that, aside from the identification of type of behavior, the dyadic form and continuity of each behavior was specified. The following were among the major results: (a) Previously found interaction patterns between elderly residents and their social partners, replicated in both a nursing home and a home for the chronically ill, supported the notion of discrepant social ecologies for dependent versus independent behaviors of residents: (b) specification of each behavioral act as to its dyadic form underscored the fact that the interactions were controlled largely by social partners and not by the elderly residents; (c) coding continuity or discontinuity of behavior suggested that independent behaviors were maintained by chaining; and (d) elderly residents in the home for the chronically ill evinced, as expected, more dependence-related behaviors.

Activities of Daily Living↗

Bone-marrow plasmocytosis--an immunohistological study.

Bone-marrow biopsies and smears from 59 patients with reactive plasmocytosis (22), multiple myeloma (24), solitary plasmocytoma (3) and monoclonal gammopathy of undetermined significance (MGUS) (10) were examined. To demonstrate cytoplasmic immunoglobulin the immunoperoxidase method was applied and evaluated quantitatively. Immunohistology yielded different ranges in kappa/lambda ratio for reactive plasmocytosis (0.4-3.5), multiple myeloma (less than or equal to 0.1 and greater than or equal to 11.2) and MGUS (0.2-3.0). As a result this method seems to be helpful in characterizing a plasmocytosis and distinguishing overt myeloma from monoclonal gammopathy of undetermined significance and reactive plasmocytosis. A differentiation of monoclonal gammopathy of undetermined significance from reactive plasmocytosis is not possible histologically and immunohistologically.

Adult↗

Immunocytochemical characterization of lymphocytes in benign and malignant lymphocyte-rich serous effusions.

The cytological diagnosis of malignant Lymphoma in serous effusions can be difficult because reactive lymphocytes may be morphologically indistinguishable from malignant cells in lymphocytic and other low grade Non-Hodgkin's lymphomas. As a result of the present study, diagnostic accuracy can be improved by means of B- and T-cell enumeration using an immunoalkaline-phosphatase method (IAP). 30 cytological specimens, including 28 pleural, 1 pericardial and 1 ascitic fluids, were studied with a panel of monoclonal anti B- and anti T-cell antibodies (PAN B, kappa, lambda, T1, T2, OKT4, T8). Reactive lymphocytic effusions were characterized by a predominance of T cells constituting greater than or equal to 80% of all lymphocytes with an excess of helper/inducer cells (mean helper to suppressor ratio 3.0) and by a surface kappa to surface lambda ratio of 1.6 on B-cells. Tuberculous effusions showed a similar distribution of lymphocyte-subpopulations whilst most of the carcinomatous fluids showed a lower percentage of T cells (lowest value 67%) and lower Th: Ts ratio (mean 2.0). Lymphoid cells in samples of five B-cell lymphomas were characterized by T-cell depression (less than 70%). B-cells in three cases expressed clear cut light chain monoclonality which was at least suggested in the other two cases. Lymphoid cells from two cases of Hodgkin's disease expressed an indistinct immunological pattern. Labelling of cytoplasmic immunoglobulins (heavy and light chains) using the peroxidase antiperoxidase method (PAP) may be important to characterize neoplasms of the plasma cell series. It is concluded that the chosen panel of antibodies in combination with IAP labelling method may be of great value in identifying B-cell lymphomas. The technique can be used in the routine laboratory and storage of unlabelled and labelled slides over long periods is possible.

Antibodies, Monoclonal↗

Evidence of vascular differentiation in anaplastic tumours of the thyroid--an immunohistological study.

Sixteen cases of anaplastic carcinoma (ACA) and 4 cases of malignant haemangioendothelioma (HAE) of the thyroid were studied by light microscopy and immunohistochemistry. Seven cases of ACA and 3 cases of HAE were characterized by coexpression of immunohistological features of epithelial and vascular endothelial cells. Expression of vimentin was common to all tumours investigated. The present study provides evidence that ACA and HAE are partially closely related tumours showing alternating differentiation. This speaks in favour of a common neoplastic cell with the potential for epithelial and vascular endothelial differentiation.

Adenocarcinoma↗

Lymph-node infarction and malignant lymphoma: a multicentre survey of European, English and American cases.

A multicentre study of 51 cases of lymph-node infarction seen in the 30-year period 1956 to 1985 was conducted in order to assess both the short- and long-term prognostic implications of the condition. In 14 cases malignant lymphoma was found synchronously with the infarct. Of the remaining 37 patients with apparently 'benign' lymph-node infarction only six showed manifestations of malignant lymphoma in the follow-up time studied (mean = 48 months; range 1-156 months). These subsequent malignant lymphomas all occurred within 2 years of the lymph-node infarction. A postal enquiry and collation of other cases in the medical literature indicates that a minority (26 of 81) have developed malignant lymphoma, and that these lymphomas, too, have all appeared within 2 years. Thorough examination of both the infarcted lymph nodes and others resected at the same time is mandatory in order to exclude concomitant or underlying malignant lymphoma. Two years after lymph-node infarction the risk of malignant lymphoma is negligible.

Adolescent↗

Follicular malignant non-Hodgkin's lymphoma with pronounced plasmacytic differentiation: a plasmacytoma-like lymphoma.

A case of follicular centroblastic-centrocytic lymphoma with an unusually pronounced plasmacytic component occurring in the gingiva and cervical lymph nodes of a 74-year-old male patient is described. Immunohistological analysis revealed a monotypic intracytoplasmic immunoglobulin pattern (IgM/lambda). The relation between follicular malignant non-Hodgkin's lymphomas and extramedullary plasmacytome is discussed. In the present case the tumour may represent the development of an autonomous plasma cell clone within a follicular centroblastic-centrocytic lymphoma.

Aged↗

[Malignant testicular tumor treated with cytostatic drugs in a case of kidney transplantation for familial cystic kidney].

The case is presented of a 29-year-old male who developed embryonal testicular carcinoma two months after successful transplantation of a cadaver kidney because of end stage renal disease due to polycystic disease. After surgical removal of the carcinoma and 3 courses of chemotherapy with bleomycin and vinblastine, complete remission was induced which has now lasted for 14 months. In addition to the usual toxicity of cytotoxic therapy, transplant function decreased intermittently but renal function recovered under close monitoring and dose-adaptation of immunosuppressive medication with cyclosporin and prednisolone.

Adult↗