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Biomedical subjects

H Stein

Publications and source records attributed to H Stein.

At least 163 records · Page 9Linked to original sources
PubMed1998

Targeting of saporin to Hodgkin's lymphoma cells by anti-CD30 and anti-CD25 bispecific antibodies.

CD25 and CD30 represent suitable target molecules for bispecific antibody (bimAb)-driven toxin delivery to lymphoid tumour cells. We describe two new anti-CD30/anti-saporin bimAbs (termed CD30 x sap1 and CD30 x sap2), produced by hybrid hybridomas, which react against non-cross-reactive epitopes of the saporin molecule, and compared their effect with a bimAb reacting with saporin and with CD25 (CD25 x sap1). In a protein synthesis inhibition assay these bimAbs were able to enhance saporin toxicity (IC50 = 8.5 x 10(-9) M in the absence of mAbs) with a similar activity: in the presence of 10(-9) M CD30 x sap1 bimAb the IC50 was 2.75 x 10(-11) M, whereas with CD30 x sap2 bimAb the IC50 was 6.5 x 10(-11) M and CD25 x sap1 bimAb displayed an IC50 of 3 x 10(-11) M (as saporin). The combined use of the two anti-CD30 bimAbs further increased cytotoxicity by 100-fold, resulting in an IC50 of 1.9 x 10(-13) M. A slightly less efficient improvement was obtained by combining the CD25 x sap1 bimAb with the CD30 x sap2 bimAb directed against a different toxin epitope (saporin IC50 to 7 x 10(-13) M). In contrast, no synergistic effect was observed using the combination of the anti-CD25 bimAb with the anti-CD30 bimAb reacting with the same epitope of saporin (IC50 = 4.5 x 10(-11) M). Analysis of FITC-saporin binding to L540 cells by flow cytometry demonstrated that the appropriate combinations of the two anti-CD30/anti-saporin bimAbs or of the anti-CD30/anti-saporin and anti-CD25/anti-saporin bimAbs had a cooperative effect on the binding of the ribosome-inactivating protein (RIP) to the cells, when compared with single bimAbs.

Antibodies, Bispecific↗
PubMed1998

Articular cartilage of the rabbit knee after synovectomy: a scanning electron microscopy study.

We sought to study the effect of synovectomy on the surface morphology of articular cartilages of the rabbit knee using scanning electron microscopy (SEM). Fifteen rabbits were surgically synovectomised and allowed to regenerate their synovia during time intervals ranging from 3 to 44 wk. Cartilage specimens were shaved from 5 distinct articular sectors of synovectomised, contralateral and sham-operated knees and prepared for SEM using tannic acid. Applying structural reinforcement by tannic acid was found to secure the in vivo surface morphology of the cartilages and thus production of surface irregularities during preparation was excluded. The surface morphology of cartilages both from the synovectomised and contralateral joints was found to differ from that of intact healthy rabbits. A 'chaotic' nature of the altered cartilaginous morphology persisted as late as 44 wk postsynovectomy. Cartilages from sham-operated joints did not differ detectably from normal cartilages.

Animals↗
PubMed1998

In situ upregulation of IL-10 reflects the activity of human glomerulonephritides.

A reciprocal regulation between the expression of tumor necrosis factor (TNF)-alpha and interleukin (IL)-10, demonstrated in monocytes and mesangial cells, provides a rationale for new therapeutic approaches in glomerulonephritis (GN). Administration of IL-10 to mice with antibody-mediated GN attenuated the severity of glomerular lesions. Recently, however, it has been shown that the genetically determined predominance of Th1 or Th2 cytokines results in different glomerular responses to the same planted antigen, but in an equally severe impairment of renal function. We looked for the expression of IL-10 and TNF-alpha in 111 renal biopsy specimens with proliferative and nonproliferative forms of GN and in 10 control kidneys, by means of immunocytochemistry, in situ hybridization, or reverse-transcriptase polymerase chain reaction (RT-PCR). Six patients had acute endocapillary GN (AGN), 10 patients had pauci-immune GN due to microscopic polyangiitis (MP), 48 patients had immunoglobulin-A (IgA)-GN, 18 patients had idiopathic membranous GN (IMGN), 12 patients had minimal change disease (MCD), and 13 patients had focal segmental glomerulosclerosis (FSGS) and four other forms of GN. Antibodies against monocytes (CD14) and macrophages (CD68) were applied to attribute the expression of TNF-alpha and IL-10 to resident renal or infiltrating cells. We show that mRNAs for TNF-alpha and IL-10 are detected by RT-PCR and in situ hybridization in the normal kidney. A constitutive expression of TNF-alpha protein is observed in mesangial cells, smooth muscle cells in renal arteries, and in the interstitium. A trace immunoreactivity for IL-10 is restricted to arterial smooth muscle cells, distal tubular epithelial cells, and some interstitial cells. Upregulation of both cytokines is found in glomerular diseases. The expression of TNF-alpha increases in mesangial areas in MCD, IMGN stages I/II, and IgA-GN with minor glomerular abnormalities, that is, under conditions with a generally well-preserved glomerular structure. Conversely, marked glomerular proliferation in IgA-GN and, particularly, acute vascular lesions in MP, are accompanied by a significant upregulation of IL-10 (at the mRNA and protein level). Patients with nephrotic-range proteinuria show a significant increase in tubulointerstitial expression of IL-10, whereas the immunoreactivity for TNF-alpha reflects the extent of interstitial fibrosis. Thus, our results confirm previous suggestions that proinflammatory and antiinflammatory cytokines are produced in situ by resident renal cells and contribute to the natural course of human GN.

Adult↗
PubMed1998

Workshop report on Hodgkin's disease and related diseases ('grey zone' lymphoma).

Despite advances in immunohistochemistry and molecular biology, the distinction between classical Hodgkin's lymphoma and related diseases such as nodular lymphocyte-predominant Hodgkin's disease, T-cell rich large B-cell lymphoma or anaplastic large cell lymphoma has remained difficult in rare cases. Lack of clear-cut diagnostic criteria represents a problem for both the pathologist and the clinician. To delineate this 'grey zone' between classical Hodgkin's lymphoma and non-Hodgkin's lymphoma (NHL) and to develop criteria for classification of such cases, 12 expert hematopathologists each submitted one to five borderline cases to a workshop. Cases were reviewed and classified at a multiheaded microscope and criteria were established for the diagnosis of questionable cases. Well established entities such as classical Hodgkin's lymphoma, anaplastic large-cell lymphoma and TCRBCL were defined more strictly and cases with unusual morphology or antigen expression could be identified. A distinctive subset of cases representing mediastinal large B-cell lymphomas with features of Hodgkin's lymphoma was identified.

Diagnosis, Differential↗
PubMed1998

Ilizarov external fixation in the management of bilateral, highly complex blast injuries of lower extremities: a report of two cases.

Because of their complexity, war injuries inflicted by a blast mechanism often require tailoring of treatment to attain a more individualized solution. We report two cases of bilateral, severely mangled lower limbs with open tibial fractures and crush injuries to the feet. In each case, one limb had to be amputated below the knee, but the other limb was saved by immediate stabilization in a tubular external fixation frame crossing the knee; the frame was later replaced by a hybrid ring fixation frame with a freely moving knee. Such incidences are rare, and the particular management detailed here has not previously been reported in the literature.

Adult↗
PubMed1998

Hyperbaric oxygen therapy for cutaneous/soft-tissue zygomycosis complicating diabetes mellitus.

A 24-year-old female diabetic patient was hospitalized because of ketoacidosis and a necrotic wound on the hand. Debridement and antibiotic therapy failed to halt the process. After demonstration of Mucor in cultures from the wound, the patient underwent extensive surgery and amphotericin B was administered. When the necrotic process continued despite these measures, adjunctive hyperbaric oxygen (100% O2 at 2.5 ATA for 90 minutes) was administered daily for a total of 21 treatment sessions. She gradually improved, and at 2 months follow-up most of the wound had healed. Although the mortality rate of cutaneous/soft-tissue zygomycosis is markedly lower than that of the rhinocerebral form, morbidity is still considerably high. Successful use of hyperbaric oxygen has been reported in rhinocerebral zygomycosis, and it may have been of benefit in this high-risk patient by preventing local and systemic spreading of the fungus. This report is the first case of the use of hyperbaric oxygen for cutaneous/soft-tissue zygomycosis. It is suggested that hyperbaric oxygen be considered for this indication in diabetic patients as an adjunct to surgery and amphotericin B.

Adult↗
PubMed1998

Improved polymerase chain reaction detection of clonally rearranged T-cell receptor beta chain genes.

A new method for the detection of all known possible rearrangements at the variable (V), diversity (D), and joining (J) segments of the T-cell receptor beta chain (TcR beta) gene in tissue DNA extracts is described that involves two polymerase chain reactions (PCRs). The first PCR round (screening PCR) allowed the identification of the J beta segment involved in a clonal rearrangement. A J beta-primer was used for the second PCR (J beta-specific PCR), recognizing the J beta segment identified in the screening PCR in combination with a consensus V beta primer. This PCR generated prominent and short amplificates suitable for direct sequence analysis because of their low background. Using this approach, clonal TcR beta gene rearrangements were able to be demonstrated in all T-cell lines (n = 7) and in all peripheral T-cell lymphomas (n = 33) analyzed. No clonal TcR beta gene rearrangements were found in any of the normal tissues studied nor in any B-cell non-Hodgkin lymphomas. This method is applicable to DNA from fresh frozen tissues, and, after the TcR beta rearrangement of a patient's malignant T-cell clone has been identified by the screening PCR, DNA can also be detected in follow-up formalin-fixed paraffin-embedded samples by the J beta-specific PCR with high sensitivity and specificity.

Clone Cells↗
PubMed1998

Expression patterns of cyclin D1 and related proteins regulating G1-S phase transition in uveal melanoma and retinoblastoma.

BACKGROUND/AIMS: A checkpoint mechanism in late G1, whose regulation via loss of retinoblastoma protein (pRB) or p16, or overexpression of cyclin D1 or cyclin dependent kinase 4 (CDK4), has been proposed to constitute a common pathway to malignancy. The aims of this study were (a) to compare markers of cell cycle G1-S phase transition in an intraocular tumour with known pRB deficiency (retinoblastoma) and compare it with one with an apparently functional pRB (uveal melanoma); (b) to determine if one of these markers may have a role in the pathogenesis of uveal melanoma; and (c) to determine if there is a difference in cell cycle marker expression following treatment of uveal melanoma and retinoblastoma. METHODS: 90 eyes were enucleated from 89 patients for retinoblastoma (n = 24) or for choroidal or ciliary body melanoma (n = 66). Conventional paraffin sections were assessed for cell type and degree of differentiation. Additional slides were investigated applying standard immunohistochemical methods with antibodies specific for cyclin D1 protein, pRB, p53, p21, p16, BCL-2, and MIB-1. RESULTS: Cyclin D1 protein and pRB were negative in retinoblastoma using the applied antibodies. In contrast, cyclin D1 protein expression was observed in 65% of uveal melanomas; a positive correlation between cyclin D1 cell positivity and tumour cell type, location, growth fraction, as well as with pRB positivity was observed. p53, p21, and p16 could be demonstrated in both tumours. An inverse relation between p53 and p21 expression was demonstrated in most choroidal melanomas and in some retinoblastomas. Apart from a decrease in the growth fractions of the tumours as determined by MIB-1, a significant difference in the expression of G1-S phase transition markers in vital areas of uveal melanoma and retinoblastoma following treatment with radiotherapy and/or chemotherapy was not observed. CONCLUSION: Retinoblastomas and uveal melanomas, two tumours of differing pRB status, differ also in their immunohistochemical pattern for markers of the G1-S phase transition of the cell cycle. The results of the present study support the concept of (a) an autoregulatory loop between pRB and cyclin D1 in tumours with a functional pRB and the disruption of this loop in the presence of pRB mutation, as well as (b) a checkpoint mechanism in late G1, whose regulation via loss of p16 or pRB, or overexpression of cyclin D1 constitutes a common pathway to malignancy. Further, the results raise the possibility of cyclin D1 overexpression having a role in the pathogenesis of uveal melanoma.

Adolescent↗
PubMed1998

Mantle-cell lymphomas have more widespread disease and a slower response to chemotherapy compared with follicle-center lymphomas: results of a prospective comparative analysis of the German Low-Grade Lymphoma Study Group.

PURPOSE: To compare mantle-cell lymphomas (MCLs) and follicle-center lymphomas (FCLs) for their features of clinical presentation, response to chemotherapy, and prognosis on the basis of a prospective randomized clinical trial. PATIENTS AND METHODS: Patients with MCL and FCL who entered onto the prospective randomized comparison of cyclophosphamide, vincristine, and prednisone (COP) versus prednimustine and mitoxantrone (PmM) followed by a second randomization for interferon (IFN) maintenance versus observation only. RESULTS: One hundred sixty-five of 234 patients had FCL and 45 of 234 patients had MCL. With FCL, both sexes were equally affected (men, 47%); patients with MCL were predominantly men (78%; P < .0004) and had a higher median age (64 v 53 years; P < .0001). Patients with MCL also had more widespread disease, reflected by the proportion of patients with two or greater extranodal manifestations (43% v 21%; P < .005) and nine or greater involved nodal areas (64% v 45%; nonsignificant [NS]). Response to chemotherapy was significantly lower in patients with MCL (complete remission [CR] + partial remission [PR], 69% v 88%; P < .05) and occurred at a slower pace. Patients with MCL also had a shorter event-free interval (median, 8 v 24 months; P < .0001) and overall survival (median, 28 v 77 months; P < .0001). In both subtypes, however, patients with less than two residual lymphoma manifestations in remission experienced a relatively good prognosis with an estimated 5-year survival of greater than 60% for MCL and greater than 75% for FCL. CONCLUSION: MCL and FCL differ substantially in their features of presentation, response to chemotherapy, and long-term prognosis. The extent of residual disease after completion of chemotherapy discriminates patients with different prognosis and may be used for the stratification of postremission strategies.

Adult↗
PubMed1998

What do adult attachment scales measure?

Research suggests that attachment patterns can be measured as early as 12 months of age and that in the absence of major environmental change, they persist into adulthood. Evolving from three traditions, a number of assessment tools have been developed to study adult attachment. They range from semiclinical interviews to brief questionnaires and explore different relationship domains, from retrospective accounts of childhood experience to current romantic relationships. After exploring the theoretical background of the study of adult attachment, the authors review the format and the psychometric properties of several measures. Studies that compare measures are described. The article concludes with a discussion of unresolved questions about adult attachment that emerge from various measurement perspectives.

Adult↗
PubMed1997

Origin of nodular lymphocyte-predominant Hodgkin's disease from a clonal expansion of highly mutated germinal-center B cells.

BACKGROUND: The atypical cells of nodular lymphocyte-predominant Hodgkin's disease, designated lymphocytic and histiocytic (L&H) cells, have a B-cell phenotype. To clarify the clonality of these cells, we studied rearranged immunoglobulin genes for the variable region of the heavy chain (V[H] genes) in individual L&H cells from 11 patients with nodular lymphocyte-predominant Hodgkin's disease. We also studied the expression of immunoglobulin light chains by those cells in six of the same patients. METHODS: Single CD20+ L&H cells were isolated from frozen sections by a technique of micromanipulation. The rearranged V(H) genes of these cells were amplified by the polymerase chain reaction (PCR), sequenced, and compared with germ-line V(H) genes. Immunoglobulin light-chain messenger RNA (mRNA) was detected by in situ hybridization. RESULTS: Of 615 L&H cells isolated from all the frozen sections, 160 yielded PCR products. In each of the 11 patients, the L&H cells that could be evaluated had identically rearranged V(H) genes, whether they were isolated from the same nodule, different nodules, or different blocks of tissue. All the V(H) sequences derived from the L&H cells were highly mutated (7.5 to 27.2 percent). In two cases the coding capacity of the V(H) genes was completely or partially disrupted by mutations. Intraclonal diversity was found in six cases, and monotypic immunoglobulin light-chain mRNA was found in six. CONCLUSIONS: The L&H cells of nodular lymphocyte-predominant Hodgkin's disease represent a monoclonal expansion of B cells. The high load of V(H) gene mutations and signs of intraclonal diversity suggest a relation between L&H cells and germinal-center B cells at the centroblastic stage of differentiation.

B-Lymphocytes↗
PubMed1997

Autocrine interleukin-1 receptor antagonist can support malignant growth of glioblastoma by blocking growth-inhibiting autocrine loop of interleukin-1.

In situ hybridization (ISH) of human glioblastoma tissue sections revealed expression of interleukin-1 (IL-1)alpha and/or beta and IL-1 receptor types I and II (IL-1R I and II) in the majority of cases evaluable. To understand the function of IL-1-family members in human glioblastomas, we have studied 6 glioblastoma cell lines. RT-PCR, ISH, ELISA and 125I-IL-1-binding assays revealed expression of IL-1 and high-affinity receptors for human (h)IL-1 in all but 1 cell line. Using a colony growth assay in semi-solid media for testing serial plating efficacy (PE, number of colonies per number of cells seeded in %), only the IL-1R-negative cell line was not influenced by recombinant human (rh)IL-1alpha or -beta, whereas IL-1 down-regulated the self-renewal of clonogenic cells of the other glioblastomas. Tritiated thymidine uptake was down-regulated by rhIL-1 in all cell lines studied. Cell viability remained unchanged by rhIL-1. Wherever growth modulation by rhIL-1 was detected, it could be reversed by either soluble IL-1R I or II or by rhIL-1 receptor antagonist (ra). IL-1ra not only was able to reverse rhIL-1-induced growth modulation but alone could modulate glioblastoma growth in comparison with control in cell lines producing IL-1. Our results show the presence of public autocrine loops for IL-1 leading to growth inhibition in some glioblastomas. To understand these loops, we have studied expression and function of IL-1ra in glioblastomas. ISH of human glioblastoma tissue sections revealed expression of hIL-1ra in all 8 cases evaluable. In 4 of 6 cell lines, IL-1ra was found in the supernatant under constitutive conditions, the IL-1R-negative line being among the 2 non-producers. The other non-producing cell line, HTB 17, showed expression of hIL-1R II. Most interestingly, a neutralizing antibody against IL-1ra down-regulated growth of IL-1- and IL-1ra-producing glioblastoma cells to approx. 30% of the controls. Thus, public autocrine loops for IL-1 in human glioblastomas exist and result in growth inhibition. An autocrine production of IL-1-antagonizing molecules such as IL-1ra by these tumors can counteract this IL-1 function and represent a basic escape mechanism supporting malignant growth in some glioblastomas.

Binding Sites↗