[Mastocytosis and osteoporosis].
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Female↗
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Phase I-II vinorelbine (Navelbine) by continuous infusion in patients with metastatic breast cancer: cumulative toxicities limit dose escalation.
Vinorelbine (Navelbine) has significant activity against breast carcinoma and is less neurotoxic than vinblastine. Because vinblastine has improved activity when administered by continuous infusion, we conducted a Phase I-II study to determine the maximum tolerated dose (MTD) of vinorelbine when given by continuous infusion and the response rates to it in heavily pretreated metastatic breast cancer patients. Between April 1994 and August 1997, 87 patients were entered in the study. All were female and had proven metastatic breast cancer. Ninety-five percent of them had received prior doxorubicin treatment, and 74% had received prior paclitaxel treatment. In Phase I of the study, all patients received 8 mg of vinorelbine by intravenous (i.v.) bolus followed by a continuous infusion of vinorelbine over 96 hr. When the MTD was determined, patients were entered in the Phase II arm to assess treatment responses and cumulative toxic reactions. In the Phase I arm (43 patients, 182 cycles), we determined the MTD of vinorelbine to be 8 mg by i.v. bolus followed by a continuous infusion of 11 mg/m2/day over 4 days. The dose-limiting toxic reaction was grade 3-4 granulocytopenia in 35% of the cycles and neutropenic fever in 15% of the cycles. Forty-four patients (193 cycles) were treated at the MTD. Seven (16%) of them had a response (2 complete responses, 5 partial responses). The median durations of response and survival were 4.3 and 8.6 months, respectively. However, cumulative toxic reactions (neutropenic fever and stomatitis) in 22 patients (50%) required dose reductions. A continuous infusion of vinorelbine can be safely administered but with a narrow therapeutic index because of cumulative toxic reactions. We recommend a modified MTD of vinorelbine: 8 mg by i.v. bolus followed by a continuous infusion of 10 mg/m2/day over 4 days. However, this treatment schedule offers no apparent advantage over the commonly used weekly vinorelbine schedule.
Adult↗
Expression of BAG-1 and BcL-2 proteins before and after neoadjuvant chemotherapy of locally advanced breast cancer.
It has been suggested that expression of anti-apoptotic proteins such as Bcl-2 or BAG-1 may confer cellular resistance to chemotherapy. A corollary of this hypothesis is that expression of these proteins may predict clinical response to treatment and that Bcl-2- or BAG-1-positive cells may selectively be enriched in postchemotherapy tissue specimens. The goal of this exploratory pilot study was to assess these two predictions by using immunohistochemistry in 29 paired pre- and postchemotherapy breast tissue specimens obtained from patients who underwent preoperative doxorubicin-based chemotherapy. All breast cancers expressed BAG-1 protein, and, in individual tumors, 40-100% of neoplastic cells stained positive for this protein. Homogenous cytoplasmic staining was typically observed, though neoplastic cells also showed nuclear staining in many specimens. We found no correlation between prechemotherapy expression of BAG-1 and subsequent pathological response to cytotoxic therapy. Paired pre- and posttreatment specimens showed similar levels of BAG-1 expression when residual tumor could be assessed. Bcl-2 was expressed in 55% of cancers and was localized to the cytoplasm. Absence of Bcl-2 expression in prechemotherapy specimens was associated with more frequent complete pathological response (58% vs. 20%; p = 0.04). However, similar to BAG-1, no difference between pre- and posttherapy expression of Bcl-2 was observed in neoplastic cells in paired tissue specimens. These observations suggest that BAG-1 contributes an important cellular function to breast epithelial cells, which is reflected by its ubiquitous expression in these tissues. However, it does not appear to determine response to doxorubicin-based chemotherapy. In contrast, lack of Bcl-2 expression was associated with a higher probability of complete pathological response to doxorubicin-based chemotherapy.
Adult↗
Effect of vitamin E on glutathione-dependent enzymes.
Reactive oxygen species and various electrophiles are involved in the etiology of diseases varying from cancer to cardiovascular and pulmonary disorders. The human body is protected against damaging effects of these compounds by a wide variety of systems. An important line of defense is formed by antioxidants. Vitamin E (consisting of various forms of tocopherols and tocotrienols) is an important fat-soluble, chain-breaking antioxidant. Besides working as an antioxidant, this compound possesses other functions with possible physiological relevance. The glutathione-dependent enzymes form another line of defense. Two important enzymes in this class are the free radical reductase and glutathione S-transferases (GSTs). The GSTs are a family of phase II detoxification enzymes. They can catalyze glutathione conjugation with various electrophiles. In most cases the electrophiles are detoxified by this conjugation, but in some cases the electrophiles are activated. Antioxidants do not act in isolation but form an intricate network. It is, for instance, known that vitamin E, together with glutathione (GSH) and a membrane-bound heat labile GSH-dependent factor, presumably an enzyme, can prevent damaging effects of reactive oxygen species on polyunsaturated fatty acids in biomembranes (lipid peroxidation). This manuscript reviews the interaction between the two defense systems, vitamin E and glutathione-dependent enzymes. On the simplest level, antioxidants such as vitamin E have protective effects on glutathione-dependent enzymes; however, we will see that reality is somewhat more complicated.
Animals↗
The HB-6, CDw75, and CD76 differentiation antigens are unique cell-surface carbohydrate determinants generated by the beta-galactoside alpha 2,6-sialyltransferase.
Expression of the beta-galactoside alpha 2,6-sialyltransferase (alpha 2,6-ST) was shown to regulate the generation of multiple cell-surface differentiation antigens (Ags) that may be necessary for lymphocyte function. A new mAb was produced, termed HB-6, that was shown to identify a novel neuraminidase-sensitive cell-surface Ag expressed by subpopulations of human lymphocytes and erythrocytes. In attempting to isolate a cDNA encoding the HB-6 antigen by expression cloning, a cDNA encoding the alpha 2,6-ST (EC 2.4.99.1) was obtained. Since expression of the alpha 2,6-ST protein was shown to be limited to the Golgi apparatus, the cell-surface HB-6 Ag was demonstrated to be the product of alpha 2,6-ST activity. Interestingly, alpha 2,6-ST expression also generated two other neuraminidase-sensitive lymphocyte cell-surface differentiation Ags, CDw75, and CD76. The HB-6, CDw75, and CD76 mAb identified distinct Ags that were differentially expressed by different B cell lines and exhibited different patterns of expression in tissue sections. These results indicate that alpha 2,6-ST expression is a critical regulatory step in the formation of the Ags that are recognized by these mAb, and that an alpha 2,6-linked sialic acid residue is an essential component of each Ag. Thus, expression of a single ST can result in the generation of multiple distinct antigenic determinants on the cell surface which can be distinguished by mAb and may have regulatory roles in lymphocyte function.
Amino Acid Sequence↗
MyoD-positive myoblasts are present in mature fetal organs lacking skeletal muscle.
The epiblast of the chick embryo gives rise to the ectoderm, mesoderm, and endoderm during gastrulation. Previous studies revealed that MyoD-positive cells were present throughout the epiblast, suggesting that skeletal muscle precursors would become incorporated into all three germ layers. The focus of the present study was to examine a variety of organs from the chicken fetus for the presence of myogenic cells. RT-PCR and in situ hybridizations demonstrated that MyoD-positive cells were present in the brain, lung, intestine, kidney, spleen, heart, and liver. When these organs were dissociated and placed in culture, a subpopulation of cells differentiated into skeletal muscle. The G8 antibody was used to label those cells that expressed MyoD in vivo and to follow their fate in vitro. Most, if not all, of the muscle that formed in culture arose from cells that expressed MyoD and G8 in vivo. Practically all of the G8-positive cells from the intestine differentiated after purification by FACS. This population of ectopically located cells appears to be distinct from multipotential stem cells and myofibroblasts. They closely resemble quiescent, stably programmed skeletal myoblasts with the capacity to differentiate when placed in a permissive environment.
Animals↗
Studies on proinsulin and proglucagon biosynthesis and conversion at the subcellular level. I. Fractionation procedure and characterization of the subcellular fractions.
Anglerfish islets were homogenized in 0.25 M sucrose and separated into seven separate subcellular fractions by differential and discontinuous density gradient centrifugation. The objective was to isolate microsomes and secretory granules in a highly purified state. The fractions were characterized by electron microscopy and chemical analyses. Each fraction was assayed for its content of protein, RNA, DNA, immunoreactive insulin (IRI), and immunoreactive glucagon (IRG). Ultrastructural examination showed that two of the seven subcellular fractions contain primarily mitochondria, and that two others consist almost exclusively of secretory granules. A fifth fraction contains rough and smooth microsomal vesicles. The remaining two fractions are the cell supernate and the nuclei and cell debris. The content of DNA and RNA in all fractions is consistent with the observed ultrastructure. More than 82 percent of the total cellular IRI and 89(percent) of the total cellular IRG are found in the fractions of secretory granules. The combined fractions of secretory granules and microsomes consistently yield >93 percent of the total IRG. These results indicate that the fractionation procedure employed yields fractions of microsomes and secretory granules that contain nearly all the immunoassayable insulin and glucagons found in whole islet tissue. These fractions are thus considered suitable for study of proinsulin and proglucagon biosynthesis and their metabolic conversion at the subcellular level.
Animals↗
Studies on proinsulin and problucagon biosynthesis and conversion at the subcellular level. II. Distribution of radioactive peptide hormones and hormone precursors in subcellular fractions after pulse and pulse-chase incubation of islet tissue.
Anglerfish proinsulin and insulin were selectively labeled with [(14)C]isoleucine, while proglucagon, conversion intermediate(s), and glucagon were selectively labeled with[(3)H]tryptophan. After various periods of continuous or pulse-chase incubation, islet tissue was subjected to subcellular fractionation. Fraction extracts were analyzed by gel filtration for their content of precursor, conversion intermediate(s), and product peptides. Of the seven subcellular fractions prepared after each incubation, only the microsome and secretory granule fractions yielded significant amounts of labeled insulin-related and glucagon-related peptides. After short-pulse incubations, levels of both [(14)C]proinsulin and [(3)H]proglucagon (mol wt approximately 12,000) were highest in the microsome fraction. This fraction is therefore identified as the site of synthesis. With increasing duration of continuous incubation or during chase incubation in the absence of isotopes, proinsulin, proglucagon, and conversion intermediate(s) are transported to secretory granules. Conversion of proinsulin to insulin and proglucagon to a approximately 4,900 mol wt conversion intermediate and 3,500 mol wt glucagon occurs in the secretory granules. Converting activity also was observed in the microsome fraction. The recovery of most of the incorporated radioactivity in microsome and secretory granule fractions indicates that the newly synthesized islet peptides are relegated to a membrane-bound state soon after synthesis at the RER is completed. This finding supports the concept of intracisternal sequestration and intragranular maintenance of peptides synthesized for export from the cell of origin.
Animals↗
Heterogeneity of the cellular immune response. I. Kinetics of lymphocyte stimulation during sensitization and recovery from tolerance.
Lymph node cells from guinea pigs immunized with HSA in complete Freund's adjuvant were grown in cultures containing different concentrations of specific antigen. Stimulation of thymidine incorporation was induced with progressively lower concentrations of HSA at successive intervals after sensitization. Moreover, the intensity of delayed skin reactions and the magnitude of stimulation in vitro increased over the same interval. These events are considered compatible with an evolution of the cellular immune response resulting from the selection of lymphoid cells by decreasing concentrations of antigen in vivo. Cells from animals rendered tolerant to HSA failed to respond to specific antigen in culture. As tolerance waned, stimulation was achieved at high but not low antigen concentrations. Tolerance, measured by cutaneous reactivity or by lymphocyte stimulation, was less readily induced in animals sensitized with adjuvant containing a reduced concentration of mycobacteria. Lymph nodes from these animals contained a large population of cells reactive at high antigen concentration, presumably less susceptible to the toleragenic effect of intravenous antigen. The dissociation of delayed hypersensitivity and antibody formation observed early in the immune response and upon recovery from tolerance has permitted correlation of lymphocyte stimulation with delayed hypersensitivity and cutaneous basophil hypersensitivity respectively.
Animals↗
Heterogeneity of the cellular immune response. II. The role of adjuvant, lymphocyte stimulation in cutaneous basophil hypersensitivity.
Antigen-mediated stimulation of thymidine incorporation was demonstrated in lymph node cells from guinea pigs immunized with 100 microg human serum albumin in either Freund's incomplete or Freund's complete adjuvant. Animals receiving HSA in IFA exhibited both cutaneous basophil (Jones-Mote) hypersensitivity and lymphocyte stimulation at 1, but not at 6 wk after immunization. Significant stimulation required >/= 10 microg HSA/ml of culture. Sensitization with HSA in CFA produced delayed hypersensitivity and permitted lymphocyte stimulation at both 1 and 6 wk. Stimulation was observed with as little as 0.1 microg HSA/ml at the later interval. Administration of 5 mg HSA intravenously at the time of sensitization with 100 microg HSA in IFA reduced but did not eliminate both CBH and lymphocyte stimulation at 1 wk. Antigen-specific inhibition of macrophage migration could be demonstrated with exudates from animals immunized with HSA in CFA, but not with HSA in IFA at 3 wk after sensitization. HSA was cleared from depots of CFA and IFA at similar rates, but significantly more antigen appeared in the plasma and subsequently in the draining lymph nodes following administration in IFA. Conversely, accumulated antigen disappeared more rapidly following CFA immunization.
Albumins↗
A nosocomial outbreak of fluoroquinolone-resistant Streptococcus pneumoniae.
Over the course of a 20-month period, in a hospital respiratory ward in which ciprofloxacin was often used as empirical antimicrobial therapy for lower respiratory tract infections (LRTIs), 16 patients with chronic bronchitis developed nosocomial LRTIs caused by penicillin- and ciprofloxacin-resistant Streptococcus pneumoniae (serotype 23 F). The minimum inhibitory concentration (MIC) of ciprofloxacin for all isolates from the first 9 patients was 4 microg/mL, in association with a parC mutation. Isolates from the subsequent 7 patients all had a ciprofloxacin MIC of 16 microg/mL, in association with an additional mutation in gyrA. The MICs for this isolate were 8 microg/mL of levofloxacin (resistant), 2 microg/mL of moxifloxacin and gatifloxacin (intermediately resistant), and 0.12 microg/mL of gemifloxacin. This outbreak demonstrates the ability of S. pneumoniae to acquire multiple mutations that result in increasing levels of resistance to the fluoroquinolones and to be transmitted from person to person.
Aged↗
Fluoroquinolone-resistant Streptococcus pneumoniae, an emerging but unrecognized public health concern: is it time to resight the goalposts?
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Drug Resistance, Bacterial↗
Use of water jet resection in organ-sparing kidney surgery.
BACKGROUND AND PURPOSE: The morbidity of organ-sparing renal surgery is related to intraoperative hemorrhaging and secondarily to urinary fistulae and urinoma. Various tools have been developed for gentle transection and precise control of bleeding. Water jet technology is already established in clinical practice for surgery of the liver and other parenchymatous organs. We report our clinical experience with a new water jet resection device in kidney surgery and the histologic effects of water jet resection on kidney tissue. PATIENTS AND METHODS: A series of 24 patients underwent open surgery for renal-cell carcinoma, nephrolithiasis, complicated cysts, or oncocytoma. In tumor patients, a partial nephrectomy; in two stone patients, a nephrolithotomy; and in the third stone patient, a lower-pole resection were performed. The cysts and the oncocytoma were enucleated in toto. In one patient, an endoscopic pyeloplasty was performed because of ureteropelvic stenosis. Tissue samples were investigated histologically using standard light microscopy after hematoxylin-eosin staining and compared with those subjected to thermal dissection techniques. RESULTS: The water jet produced a corridor in the desired dissection line without interfering with the intrarenal vessels and pelvicalical system. This way, precise hemostasis was possible, and damages to the surrounding tissue was avoided. Resection took between 14 and 40 minutes with minimal intraoperative blood loss. No significant postoperative complications occurred. Histologic evaluation demonstrated a sharp dissection line without thermal alterations or deep necrosis. Only a small disruption zone could be seen at the margins of the dissection. CONCLUSIONS: Water jet resection is a gentle method for dissection of kidney tissue. Histologic examination confirmed minimal traumatic parenchymal alteration. In our opinion, the water jet dissector is a useful device for renal transection in organ-sparing kidney surgery.
Carcinoma, Renal Cell↗
Enrichment and selection of hybrid hybridomas by Percoll density gradient centrifugation and fluorescent-activated cell sorting.
Hybrid hybridomas, producing bi-specific monoclonal antibodies that react with horseradish peroxidase and human IgA1 were isolated by sorting the double-fluorescent cells on single-cell basis after fusion of two hybridomas, previously labelled green or red by octadecylamine-FITC or -TRITC, respectively. The double-fluorescent fused cells were significantly different in AXL (size) and RAS (internal structure) distribution compared with the (non-fused) mono-fluorescent cells. The percentage of double-fluorescent cells and the viability of these cells could be increased by Percoll density gradient centrifugation. As a result, there was an 8-fold increase of total isolated hybrid hybridomas (up to 30% of all tested clones) compared to isolations without Percoll density gradient centrifugation. All the isolated hybrid hybridoma clones had similar amounts of DNA, equal to the sum of the DNA of both parental hybridomas.
Antibodies, Monoclonal↗
Coexpression of the HER-2 gene product, p185HER-2, and epidermal growth factor receptor, p170EGF-R, on epithelial ovarian cancers and normal tissues.
Monoclonal antibodies (MAbs) and immunoconjugates reactive with different antigens expressed by neoplastic cells can inhibit tumor growth. Use of these agents in combination with one another or with chemotherapy can exert additive or synergistic cytotoxicity against tumor cells. An augmented therapeutic activity with favorable therapeutic index might be attained when coexpression is observed on tumor cells, but not in normal tissues. In this study frozen sections of 19 ovarian cancers (2 stage I, 10 stage III, 2 stage IV, and 5 recurrent), as well as 29 normal tissues, were evaluated by immunohistochemistry using 11 distinct MAbs against HER-2/p185 and 2 antibodies against EGF-R/p170 to assess coexpression of these receptors. HER-2/p185 expression was detected in 5 to 100% of ovarian cancers and 0 to 50% of normal ovarian epithelia, depending on the antibody used. EGF-R/p170 expression was detected in approximately 70% of cancers and 40% of normal ovaries by both antibodies. Coexpression of p185 and p170 was observed in 47-68% of ovarian cancers and 9-18% of normal ovarian epithelial specimens depending upon the combination of antibodies used. Staining of 273 specimens from 29 normal tissues indicated that coexpression of HER-2 and EGF-R is rare. Normal tissues that coexpressed both receptors in > or =50% of the cases included cervix, endometrium, esophagus, skin, and prostate. These data confirm that HER-2 and EGF-R are more frequently expressed in advanced ovarian cancers than in normal ovarian epithelium and a significant fraction of these tumors coexpress both HER-2 and EGF-R.
Antibodies, Monoclonal↗
Clinical experience with CD3 x CD19 bispecific antibodies in patients with B cell malignancies.
In extensive preclinical testing, a CD3 x CD19 bispecific antibody (BsAb) induced killing of malignant B cells by resting T cells even in an autologous situation. In a 14 day clonogenic assay using a CD19+ pre-B cell line (REH), BsAb required repeated administration together with IL-2 to achieve a 5 log kill by resting peripheral blood T cells. Intravenously administered BsAb in an intrapatient dose escalation study of 3 patients with B cell non-Hodgkin's lymphoma showed limited toxicity (WHO grade II fever and chills) due to tumor necrosis factor-alpha (TNF-alpha) release by T cells. Pharmacokinetics with 2.5 mg BsAb showed peak levels of 200-300 micrograms/ml and a t1/2 of 10.5 h. The next patient, with chronic lymphocytic leukemia (CLL), received 0.6 mg BsAb/m2 as an i.v. infusion preceded by 1 MU IL-2/m2 s.c. Improved T cell activation was noted, as indicated by an increase in IFN-gamma, IL-6, IL-8, and IL-10, in addition to high TNF-alpha increases. TNF-alpha increases were highest on the first day. Toxicity remained restricted to grade II fever and chills, observed every day after the infusion of BsAb. No clear clinical effects were seen in this chemotherapy-resistant CLL patient with a high tumor burden. If subsequent patients also show limited toxicity, treatment of patients with a lower tumor load seems to be warranted to evaluate the efficacy of CD3 x CD19 BsAb therapy.
Animals↗
A comparison of immunohistochemistry, two-color immunofluorescence, and flow cytometry with cell sorting for the detection of micrometastatic breast cancer in the bone marrow.
A significant percentage of women with primary breast cancer have micrometastatic disease in the bone marrow. Bone marrow involvement may be an adverse prognostic factor, and more aggressive therapy may be indicated for these patients. There are a number of different techniques and antibodies used to detect tumor cells in the bone marrow. We used the same panels of four antibreast cancer antibodies and compared three immunodetection techniques: two-color immunofluorescence, immunohistochemical staining, and fluorescence-activated cell sorting with cytologic examination of the sorted cells. The two-color immunofluorescence technique was superior and consistently detected one tumor cell contaminating one million normal bone marrow cells and had no reactivity with normal bone marrow.
Bone Marrow Neoplasms↗
Determination of proliferation index with MIB-1 in advanced ovarian cancer using quantitative image analysis.
A new monoclonal antibody, MIB-1, reacts with the same epitope recognized by Ki-67. The authors investigated the feasibility of using image analysis to quantitate the MIB-1 staining (proliferation index [PI]) of epithelial ovarian cancers. The PI was determined in 50 advanced-stage primary ovarian cancers. Paraffin sections were immunostained with the MIB-1 monoclonal antibody, and the PI was calculated using a CAS 200 image analyzer. Among 36 stage III ovarian carcinomas, the median PI was 15.1%, compared with 18.9% in 14 stage IV cancers (P = .47). Based on exploratory methods, a cutoff point of 7% best dichotomized these patients into two prognostic groups. Of 39 patients whose cancers had a high MIB-1 expression (> or = 7%), the median survival was 16.5 months, which differed significantly (P = .01) from the median survival of 33.2 months observed in the 11 patients whose tumors demonstrated low MIB-1 expression (< 7%). Using MIB-1 as a binary variable, a strong correlation was found between overexpression of c-erbB-2 (2+ and 3+) and MIB-1 > or = 7% (P = .001). No relationship was found between PI and histologic grade. Further studies are warranted to investigate the relationship between MIB-1, PI expression, and other known clinicopathologic and genetic features of early- and late-stage ovarian cancer.
Antibodies, Monoclonal↗