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Biomedical subjects

R Stein

Publications and source records attributed to R Stein.

At least 181 records · Page 10Linked to original sources
PubMed1994

Multifocal renal cell tumors: a retrospective analysis of 56 patients treated with radical nephrectomy.

In this retrospective analysis of 56 patients with multifocal renal cell tumors the effect of secondary tumors on the prognosis was examined and the incidence of tumors in the contralateral kidney was evaluated. All of the primary tumors were renal cell carcinomas, the majority of which had a local tumor stage of pT2 (31 cases, 55.3%) and a cytological grading of 1 (23 cases, 41%). The mean size of the secondary tumors was 1.0 cm. An additional tumor was diagnosed in 23 patients (41%), 2 to 5 secondary tumors in 23 (41%) and more than 5 additional tumors in 10 (18%). The overall 5-year survival rates were 69.4%, 72.2% and 40%, respectively (p = 0.313). Histopathological differentiation of the additional lesions revealed 23.2% renal cell carcinomas, 71.4% adenomas and 5.3% renal tumors of "doubtful dignity," with overall 5-year survival rates of 67.2% for adenomas, and 60.6% for carcinomas and renal tumors of "doubtful dignity" (p = 0.546). After a mean followup of 60 months 33 patients (58.9%) were alive without evidence of disease, 1 (1.7%) was alive with tumor progression, 8 (14.2%) died of the disease and 14 (25%) died of other causes; only 1 patient presented with a tumor in the contralateral kidney (incidence 1.7%). Thus, the overall 5-year survival rate for the entire group was 66.0% and the histopathological parameters of the additional tumors had no effect on the prognosis of the patients.

Adenoma↗
PubMed1994

The fate of the adult exstrophy patient.

Between 1968 and 1993, 101 patients with bladder exstrophy or incontinent epispadias underwent surgery at our hospital. The standard procedure was ureterosigmoidostomy and additional genital reconstruction. Of the 56 patients who have reached adulthood 45 could be interviewed regarding social integration, sexuality and fertility. All patients have a functioning urinary diversion. Of the 45 patients questioned 41 have completed vocational training or are currently in training, 3 are unemployed and 1 lives at a therapeutic center. Among the patients 29 are married or have a steady partner. All women engage in sexual intercourse and 2 have delivered 3 children by cesarean section. All men achieve erection. Of the 28 men who underwent reconstruction of the external genitalia 11 have a penile deviation, which is distressing in only 2. Only 3 of the men are dissatisfied with the cosmetic result and 33% had epididymitis, necessitating 2 orchiectomies and 3 vasectomies. No patient with reconstruction of the external genitalia can ejaculate normally or has fathered children, whereas all 5 who did not undergo genital reconstruction had normal ejaculation and 2 have fathered children. Male patients with genital reconstruction and closure of the urethra have a high risk of infertility. Our patients demonstrate that the cosmetic results after genital reconstruction are satisfactory. However, in male patients, surgery is performed at the expense of fertility. Because this corrective procedure is usually performed during childhood, the parents must be informed of these consequences before surgical correction.

Adolescent↗
PubMed1994

c-jun inhibits transcriptional activation by the insulin enhancer, and the insulin control element is the target of control.

Selective transcription of the insulin gene in pancreatic beta cells is regulated by its enhancer, located between nucleotides -340 and -91 relative to the transcription start site. One of the principal control elements within the enhancer is found between nucleotides -100 and -91 (GCCATCTGCT, referred to as the insulin control element [ICE]) and is regulated by both positive- and negative-acting transcription factors in the helix-loop-helix (HLH) family. It was previously shown that the c-jun proto-oncogene can repress insulin gene transcription. We have found that c-jun inhibits ICE-stimulated transcription. Inhibition of ICE-directed transcription is mediated by sequences within the carboxy-terminal region of the protein. These c-jun sequences span an activation domain and the basic leucine zipper DNA binding-dimerization region of the protein. Both regions of c-jun are conserved within the other members of the jun family: junB and junD. These proteins also suppress ICE-mediated transcription. The jun proteins do not appear to inhibit insulin gene transcription by binding directly to the ICE. c-jun and junB also block the trans-activation potential of two skeletal muscle-specific HLH proteins, MyoD and myogenin. These results suggests that the jun proteins may be common transcription control factors used in skeletal muscle and pancreatic beta cells to regulate HLH-mediated activity. We discuss the possible significance of these observations to insulin gene transcription in pancreatic beta cells.

Animals↗
PubMed1994

Isolation and characterization of a novel transcription factor that binds to and activates insulin control element-mediated expression.

Pancreatic beta-cell-type-specific transcription of the insulin gene is principally regulated by a single cis-acting DNA sequence element, termed the insulin control element (ICE), which is found within the 5'-flanking region of the gene. The ICE activator is a heteromeric complex composed of an islet alpha/beta-cell-specific factor associated with the ubiquitously distributed E2A-encoded proteins (E12, E47, and E2-5). We describe the isolation and characterization of a cDNA for a protein present in alpha and beta cells, termed INSAF for insulin activator factor, which binds to and activates ICE-mediated expression. INSAF was isolated from a human insulinoma cDNA library. Transfection experiments demonstrated that INSAF activates ICE expression in insulin-expressing cells but not in non-insulin-expressing cells. Cotransfection experiments showed that activation by INSAF was inhibited by Id, a negative regulator of basic helix-loop-helix (bHLH) protein function. INSAF was also shown to associate in vitro with the bHLH protein E12. In addition, affinity-purified INSAF antiserum abolished the formation of the activator-specific ICE-binding complex. Immunohistochemical studies indicate that INSAF is restricted in terms of its expression pattern, in that INSAF appears to be detected only within the nuclei of islet pancreatic alpha and beta cells. All of these data are consistent with the proposal that INSAF is either part of the ICE activator or is antigenically related to the specific activator required for insulin gene transcription.

Amino Acid Sequence↗
PubMed1994

Glucose-induced transcription of the insulin gene is mediated by factors required for beta-cell-type-specific expression.

The insulin gene is expressed exclusively in pancreatic islet beta cells. The principal regulator of insulin gene transcription in the islet is the concentration of circulating glucose. Previous studies have demonstrated that transcription is regulated by the binding of trans-acting factors to specific cis-acting sequences within the 5'-flanking region of the insulin gene. To identify the cis-acting control elements within the rat insulin II gene that are responsible for regulating glucose-stimulated expression in the beta cell, we analyzed the effect of glucose on the in vivo expression of a series of transfected 5'-flanking deletion mutant constructs. We demonstrate that glucose-induced transcription of the rat insulin II gene is mediated by sequences located between -126 and -91 bp relative to the transcription start site. This region contains two cis-acting elements that are essential for directing pancreatic beta-cell-type-specific expression of the rat insulin II gene, the insulin control element (ICE; -100 to -91 bp) and RIPE3b1 (-115 to -107 bp). The gel mobility shift assay was used to determine whether the formation of the ICE- and RIPE3b1-specific factor-DNA element complexes were affected in glucose-treated beta-cell extracts. We found that RIPE3b1 binding activity was selectively induced by about eightfold. In contrast, binding to other insulin cis-acting element sequences like the ICE and RIPE3a2 (-108 to -99 bp) were unaffected by these conditions. The RIPE3b1 binding complex was shown to be distinct from the glucose-inducible factor that binds to an element located between -227 to -206 bp of the human and rat insulin I genes (D. Melloul, Y. Ben-Neriah, and E. Cerasi, Proc. Natl. Acad. Sci. USA 90:3865-3869, 1993). We have also shown that mannose, a sugar that can be metabolized by the beta cell, mimics the effects of glucose in the in vivo transfection assays and the in vitro RIPE3b1 binding assays. These results suggested that the RIPE3b1 transcription factor is a primary regulator of glucose-mediated transcription of the insulin gene. However, we found that mutations in either the ICE or the RIPE3b1 element reduced glucose-responsive expression from transfected 5'-flanking rat insulin II gene constructs. We therefore conclude that glucose-regulated transcription of the insulin gene is mediated by cis-acting elements required for beta-cell-type-specific expression.

Animals↗
PubMed1994

XIHbox 8, an endoderm-specific Xenopus homeodomain protein, is closely related to a mammalian insulin gene transcription factor.

The cis-acting sequences that mediate insulin gene expression exclusively in pancreatic islet beta-cells are localized within the 5'-flanking region between nucleotides -340 and -91. We have identified an evolutionarily conserved, A+T-rich element at -201/-196 basepairs in the rat insulin II gene that is essential for efficient expression in beta-cells. Affinity-purified antibody to the XIHbox 8 protein super-shifted the major beta-cell-activator factor complex binding to the -201/-196 element. XIHbox 8 is a Xenopus endoderm-specific homeodomain protein whose expression is restricted to the nucleus of endodermal cells of the duodenum and developing pancreas. Antibody to XIHbox 8 specifically interacts with a 47-kilodalton protein present in this DNA complex. Immunohistochemical studies revealed XIHbox 8-like proteins within the nucleus of almost all mouse islet beta-cells and a subset of islet alpha- and beta-cells. These results are consistent with the proposal that an XIHbox 8-related homeoprotein of 47 kilodalton is required for expression of the mammalian insulin gene in beta-cells. Experiments conducted with antiserum raised to somatostatin transcription factor-1 (STF-1), a recently isolated mammalian XIHbox 8-related homeoprotein, indicate that the STF-1 protein is the mammalian homolog of Xenopus XIHbox 8.

Amino Acid Sequence↗
PubMed1993

Specificity and properties of MAb RS7-3G11 and the antigen defined by this pancarcinoma monoclonal antibody.

The murine monoclonal antibody (MAb) RS7-3G11 is an IgG1 with pancarcinoma reactivity, which has been raised against human squamous-cell carcinoma of the lung. Immunoperoxidase staining of frozen tissue sections demonstrated that the antigen defined by RS7-3G11 is present in tumors of the lung, stomach, bladder, breast, ovary, uterus and prostate. The rate and extent of internalization of RS7-3G11 into Calu-3, an adenocarcinoma of the lung cell line, was investigated using unconjugated MAb, followed by fluorescence labelling, and by binding 125I-RS7-3G11 followed by acid removal of surface-bound antibody. Rapid internalization of MAb RS7-3G11 into target cells was observed. Antibody internalization was noted at 30 min, and by 2 hr virtually all MAb RS7-3G11 was internal. Although MAb RS7-3G11 was raised against non-small-cell carcinoma of the lung, ME-180, a cervical-carcinoma cell line, expresses higher quantities of the antigen than the lung-carcinoma cell lines. Due to the higher antigen density in ME-180 cells, this line was used for immunoprecipitation studies and antigen purification. Immunoprecipitation studies using the ME-180 cervical-carcinoma cell line metabolically labeled with [3H]leucine or [3H]glucosamine demonstrated that the antigen defined by RS7-3G11 is a glycoprotein of M(r) 46 kDa. Deglycosylation by treatment with endoglycosidase-F resulted in a protein with a M(r) of 35 kDa. RS7-3G11-antigen was purified from ME-180 tissue-culture cells using affinity-column chromatography. By SDS-PAGE it was seen that the antigen was highly purified. The major band appeared at M(r) of 45 to 48 kDa. This result is in agreement with the immunoprecipitation studies. The broad band observed in the SDS-PAGE is typical of many glycoproteins, and suggests heterogeneity of glycosylation. Chemical and enzymatic treatments of the antigen, followed by Western blot analyses, suggest that the RS7-3G11 antigenic determinant is composed of a conformation-dependent peptide.

Animals↗
PubMed1993

Biochemical and immunological characterization of the human carcinoma-associated antigen MH 99/KS 1/4.

We have characterized the 38-kDa transformation-associated membrane glycoprotein MH 99, whose expression is highly elevated in many epithelial malignancies. A spontaneous cleavage of MH 99 into a 32- and a 6-kDa chain in some carcinoma cell lines was recently shown. Sequence homologies to nidogen, a matrix-adhesion molecule, support the suggestion of a receptor-like function. In this study, we characterized biochemical and immunogenic aspects of MH 99. Transformed epithelial cell lines which do not spontaneously cleave MH 99 were exposed to 8 proteases with distinct specificities. Each of the enzymes produced similar specific fragmentation into chains of about 30 to 32 and 6 kDa, indicating a characteristic cleavage site of MH 99. The fragments were not distinguishable from those in carcinoma cells showing spontaneous cleavage of MH 99. The specific fragmentation depends on the localization in intact membranes and is not shared by other membrane proteins. N-glycosylation of MH 99 of about 4 kDa was exclusively found on the 32-kDa fragment. Characterization of antigenic epitopes was performed using 16 different monoclonal antibodies (MAbs). Only 2 independent determinants were found. One is located on the 32-kDa chain and is recognized only by the MM 104 MAb. The other 15 antibodies bind to a dominant epitope on the 6-kDa fragment which can be divided into 3 overlapping sub-epitopes. The unique features of MH 99 indicate that its immunogenic epitopes are mainly located at its 6-kDa chain, and support the suggestion of a transformation-associated cell-surface receptor which might be proteolytically regulated.

Animals↗
PubMed1993

Treatment of the anemia of myelodysplastic syndromes using recombinant human granulocyte colony-stimulating factor in combination with erythropoietin.

We treated myelodysplastic syndrome patients (MDS) with both recombinant human granulocyte colony-stimulating factor (G-CSF) and recombinant human erythropoietin (EPO) to determine whether such combination therapy resulted in improvement of their anemias. Twenty-four of 28 patients begun on study completed the protocol and were evaluable for erythroid responses. Therapy was initiated with G-CSF at 1 micrograms/kg administered by daily subcutaneous injection and adjusted to either normalize or double the neutrophil count. EPO was then administered by daily subcutaneous injection at a dose of 100 U/kg and dose-escalated to 150 and 300 U/kg every 4 weeks while continuing the G-CSF. Changes in absolute reticulocyte count, hematocrit level, and need for RBC transfusions were compared with pretreatment values as well as other blood cell counts. Ten of 24 patients (42%) had erythroid responses, whereas all patients had neutrophil responses. Six previously transfused patients no longer required RBC transfusions during the treatment period. Erythroid responses were found to be independent of patient age, French-American-British subtype, duration of disease, prior RBC transfusion requirements, or cytogenetic abnormalities at presentation. Pretreatment serum EPO levels were lower in erythroid-responding as compared with nonresponding patients (median 157 v 600 U/L; P = .05). The combined treatment modality was generally well tolerated. We conclude that a substantial percentage of MDS patients had both erythroid and myeloid responses when treated with the combination of G-CSF and EPO.

Adult↗
PubMed1993

Epitope specificity of the anti-(B cell lymphoma) monoclonal antibody, LL2.

LL2 is a murine monoclonal antibody IgG2a reactive with B cells and non-Hodgkin's B-cell lymphoma, which, in a radioiodinated form, induces responses in lymphoma patients [Goldenberg et al. (1991) J Clin Oncol 9:548-564]. In this report we identify LL2 as a member of the CD22 cluster. The molecular size of the antigen, its expression profile, and competitive blocking studies were used to establish this identification. By Western blot analysis and immunoprecipitation studies using the Raji Burkitt's lymphoma cell line metabolically labelled with [3H]leucine, the LL2 antigen was determined to correspond to a molecular mass of 140 kDa. The molecular mass of the LL2 antigen, and the B-cell-restricted reactivity of the LL2 antibody, were consistent with both the CD21 and CD22 clusters. To assess additional similarities and differences between LL2 and anti-CD22 and anti-CD21, the binding of these mAb to cultured cell lines, Nalm-6 and Molt-4, was compared by flow cytometry. The binding profile of LL2 on these cell lines was consistent with anti-CD22, but not anti-CD21. Sequential immunoprecipitation and cross-blocking studies with anti-CD22 monoclonal antibodies recognizing established CD22 epitopes were performed to confirm that LL2 reacts with CD22 and to determine which epitope LL2 recognizes. Binding of 131I-LL2 to Raji cells is inhibited over 90% by prior incubation of the target cells with unlabelled RFB4, indicating that LL2 belongs to the same epitope group as RFB4, i.e., epitope B.

Antibodies, Monoclonal↗
PubMed1993

A randomised study of carboplatin vs sequential ifosfamide/carboplatin for patients with FIGO stage III epithelial ovarian carcinoma. The London Gynaecologic Oncology Group.

In a study designed to compare response rates of patients with stage III epithelial ovarian carcinoma to ifosfamide and carboplatin, 152 patients were randomised to receive either sequential therapy with three cycles of ifosfamide followed by three cycles of carboplatin, or to six cycles of single agent carboplatin. Ifosfamide was given every 3 weeks in a dose of 5 gm m-2 as a 24 h infusion with mesna, 1 gm m-2 by i.v. bolus prior to ifosfamide, 3 gm m-2 with ifosfamide, and 1 gm m-2 as an 8 h infusion after ifosfamide. Carboplatin was given in a dose of 400 mg m-2 by short i.v. infusion every 4 weeks. Sixty-eight evaluable patients were randomised to sequential ifosfamide/carboplatin, and 67 to single agent carboplatin. Median follow-up is 36 months (range 5.5-82.3). After three cycles of treatment two patients in the ifosfamide/carboplatin arm achieved complete remission (CR), and 12 partial remission (PR) for an overall response rate of 29%, whereas in the carboplatin arm ten patients achieved CR, and 23 PR, for an overall response rate of 63% (P = 0.0008). Seven of 15 patients with progressive disease, and nine of 20 patients with stable disease at the initial response evaluation, following three cycles of ifosfamide, subsequently responded to carboplatin therapy so that the final response rate to the complete regimen was 65% for the ifosfamide/carboplatin arm, compared to 71% for the carboplatin arm (NS). For the ifosfamide/carboplatin arm, median recurrence free survival and overall survival were 14.1 months and 18.7 months. Corresponding figures for the carboplatin arm were 14.5 months and 21.5 months (NS). Both treatments were generally well tolerated. However 47% of patients in the ifosfamide/carboplatin arm developed alopecia sufficient to require a wig, compared to only 2% in the carboplatin arm. Ifosfamide is clearly less effective, and more toxic than carboplatin. Ifosfamide failures can however be effectively salvaged by subsequent carboplatin treatment. Ifosfamide cannot be recommended for single agent therapy in ovarian carcinoma, however the combination of carboplatin plus ifosfamide might be a suitable treatment to be tested in a future randomised study against carboplatin alone.

Adult↗
PubMed1993

Prognostic parameters of renal cell carcinoma. Clinicopathologic and DNA image cytometric analysis in 133 pT3a cases.

In 133 cases of patients with renal cell carcinoma which infiltrated locally into the renal fatty tissue (stage pT3a, TNM classification of 1987), the prognostic potential of the following parameters was investigated: symptoms, patient's age at the time of operation, tumor size and localization, grade of malignancy, cell type, growth pattern, and prognostic score according to Störkel et al. [Eur Urol 1990;18(suppl 2):36]. Additionally, automated image analysis DNA cytometry was performed on 110/133 carcinomas. After an average observation period of 3.6 years (maximum 10.1 years), 59 (44.4%) of the patients died of their tumors. The cause-specific 5- and 10-year survival rates were 51.3 and 29.1%, respectively. Statistically significant differences (p < 0.05) within the individual parameters were found only for the grade of malignancy and the corresponding prognostic score. Using DNA cytometry, 13 types of renal cell carcinoma were differentiated; 90% of the tumors contained aneuploid cells. Significant differences between these relative to prognosis did not exist. In the case of locally advanced renal cell carcinoma, the DNA histogram does not seem to be superior to conventional prognostic criteria.

Adult↗
PubMed1992

Dissociation between release and gene expression of gonadotropin alpha-subunit in gonadotropin-releasing hormone-stimulated alpha T3-1 cell line.

The alpha T3-1 cell line which was derived by targeted tumorigenesis in transgenic mice [Windle et al. (1990) Mol. Endocrinol. 4, 597-603] possesses high-affinity binding sites for GnRH analogs coupled to enhanced phosphoinositide turnover and phospholipase D activity. Incubation of alpha T3-1 cells with [D-Trp6]-GnRH analog (GnRH-A) resulted in a rapid increase in gonadotropin alpha-subunit mRNA levels which was detected already at 30 min of incubation (0.1 nM GnRH-A, 3-fold, p < 0.01). The effect diminished with time to reach basal levels at about 12 h of incubation, with a secondary rise in alpha mRNA levels between 12 and 24 h of incubation. Addition of the protein kinase C activator 12-O-tetradecanoylphorbol 13-acetate (TPA, 100 ng/mL) or the Ca2+ ionophore ionomycin (1 microM) to alpha T3-1 cells also resulted in a rapid increase in alpha-subunit mRNA levels. Surprisingly, GnRH-induced alpha-subunit release was detected only after a lag of 4 h of incubation. Thus, dissociation between exocytosis and gene expression can be demonstrated in GnRH-stimulated alpha T3-1 cell line.

Animals↗
PubMed1992

A double-blind study of the efficacy of metronidazole gel in the treatment of malodorous fungating tumours.

A double-blind placebo-controlled trial was undertaken to assess the value of topical metronidazole gel preparation in the palliation of the offensive odour of fungating tumours. This 5 day trial was followed by a 6 day period during which all patients received the active gel. Subjective odour assessments were performed by both patients and medical staff. 11 patients were entered and the randomisation was then halted because of an obvious overall benefit over the whole 11 days. There was a non-significant trend in favour of the active treatment during the initial double-blind placebo-controlled phase of the trial, and no side-effects were observed.

Administration, Topical↗
PubMed1992

Conservative surgery of renal cell tumors in 140 patients: 21 years of experience.

Operative method, course and complications were analyzed retrospectively in 140 patients who underwent a conservative operation for renal tumor between June 1969 and December 1990. In 53 patients (20 women and 33 men, mean age 61.2 years, range 38 to 77 years, with 49 renal cell carcinomas and 4 benign renal tumors) there was an imperative indication for an organ preserving operation because nephrectomy would have made dialysis obligatory. In 87 patients (29 women and 58 men, mean age 53.7 years, range 27 to 74 years, with 72 renal cell carcinomas and 15 benign renal tumors) the tumor was conservatively resected in the presence of a normal contralateral unit (elective indication) and 68 of these patients (78%) were symptom-free. In the imperative group 32 of 49 patients (65.3%) with renal cell carcinoma had no evidence of disease after a mean followup of 4.6 years. Known metastases were present in 4 of 7 patients who died of the tumors in this group. In 3 patients with an imperative indication for conservative surgery a second tumor occurred in the kidney: 2 were treated with further parenchyma sparing operations, while in 1 with poor physical condition no further measures were possible. Of 72 patients with renal cell carcinoma who underwent an elective operation 68 (94.4%) had no signs of tumor progression after a mean followup of 3.3 years. One patient died of tumor metastases, and 2 (2.7%) had tumor recurrence in the kidney requiring nephrectomy and enucleation, respectively. The 5-year cause-specific survival rates for the imperative and elective groups were 84% and 96%, respectively. Patients with a local stage T3 tumor were characterized by a significantly worse survival curve than those with a stage T1 or T2 tumor but no significant difference was noted among the various grades of differentiation.

Adult↗
PubMed1992

Haematological effects of radioimmunotherapy in cancer patients.

The haematologic effects of radioimmunotherapy (RAIT) in cancer patients have been studied in order to better understand the aetiology of RAIT-associated myelosuppression. Evaluations were performed on patients treated with 131I-anti-carcinoembryonic antigen (CEA) and 131I-LL2, a monoclonal antibody (MAb) reactive with non-Hodgkin's B-cell lymphoma. Both groups of patients experienced decreases in WBC and platelets. Nadirs were observed 42-51 d post first injection in the lymphoma patients, and 49-66 d post first injection (30-43 d post high-dose therapeutic injection) in the carcinoma patients. Within the WBC population, B cells were the most radiosensitive. The evaluations of the binding of these MAbs to peripheral blood cells and the effect of RAIT on lymphocyte subpopulations indicated a drop of 26-92% in the percentage of B lymphocytes within 1 week following treatment with both 131I-LL2 and 131I-anti-CEA MAbs even though only LL2 binds to B cells. The percentage of T lymphocytes was not affected by the 131I-antibody treatments. These observations suggest that the marked drop in circulating B lymphocytes and platelets after the administration of radioiodinated antibodies is a nonspecific radiation effect, and not necessarily related to the binding of MAb to normal B cells. Thus, among WBCs, B cells are uniquely radiosensitive, and will be unusually affected by antibody-directed internal radiation.

Adult↗