Social, Racial, and Cultural Considerations in Hypertension in Older Adults.

Black and Hispanic older adults in the United States have higher prevalence of hypertension, less adequate treatment, less consistent blood pressure control, and worse cardiovascular outcomes than their white counterparts. Genetic differences are insufficient to explain these disparities-various social, economic, and environmental factors notably contribute. Racial and ethnic differences in living circumstances, household income, access to appropriate care, food security, educational attainment, and tobacco use all negatively impact long-term hypertension outcomes in minoritized older adults. To remedy these inequities, the search for solutions must include a complete assessment of the social, racial, and cultural components of the problem.

Evolutionary model selection with a genetic algorithm: a case study using stem RNA.

The choice of a probabilistic model to describe sequence evolution can and should be justified. Underfitting the data through the use of overly simplistic models may miss out on interesting phenomena and lead to incorrect inferences. Overfitting the data with models that are too complex may ascribe biological meaning to statistical artifacts and result in falsely significant findings. We describe a likelihood-based approach for evolutionary model selection. The procedure employs a genetic algorithm (GA) to quickly explore a combinatorially large set of all possible time-reversible Markov models with a fixed number of substitution rates. When applied to stem RNA data subject to well-understood evolutionary forces, the models found by the GA 1) capture the expected overall rate patterns a priori; 2) fit the data better than the best available models based on a priori assumptions, suggesting subtle substitution patterns not previously recognized; 3) cannot be rejected in favor of the general reversible model, implying that the evolution of stem RNA sequences can be explained well with only a few substitution rate parameters; and 4) perform well on simulated data, both in terms of goodness of fit and the ability to estimate evolutionary rates. We also investigate the utility of several distance measures for comparing and contrasting inferred evolutionary models. Using widely available small computer clusters, our approach allows, for the first time, to evaluate the performance of existing RNA evolutionary models by comparing them with a large pool of candidate models and to validate common modeling assumptions. In addition, the new method provides the foundation for rigorous selection and comparison of substitution models for other types of sequence data.

Altered profiles in nuclear matrix proteins associated with DNA in situ during progression of breast cancer cells.

Nuclear matrix proteins (NMPs) show promise as informative biomarkers in following the pathogenesis of breast cancer. The nuclear matrix is a dynamic RNA-protein network involved in the organization and expression of chromatin. Cisplatin, which preferentially cross-links nuclear matrix proteins to DNA in situ, may be used to identify NMPs that organize and/or regulate the processing of DNA. In this study, we analyzed the nuclear matrix proteins from an estrogen receptor-positive breast cancer cell line panel consisting of MCF-7, MIII, LCC1, and LCC2 cell lines. This cell line panel reflects the stages of malignant progression in breast cancer. Proteins isolated from nuclear matrices and proteins cross-linked to nuclear DNA in situ with cisplatin were analyzed by two-dimensional gel electrophoresis. Specific changes in nuclear matrix proteins bound to nuclear DNA were identified. In concordance with estrogen independence and antiestrogen insensitivity, a loss in cisplatin cross-linking of specific NMPs to nuclear DNA was observed. Our results suggest that progression of breast cancer is accompanied by a reorganization of chromosomal domains, which may lead to alterations in gene expression.

CAMPATH-1M T-cell depleted BMT for SCID: long-term follow-up of 19 children treated 1987-98 in a single center.

BACKGROUND: SCID can be cured by BMT. Depletion of mature T cells from BM has enabled HLA non-identical stem-cell transplantation. We report the outcome of 30 patients treated with 37 T-cell depleted BMT procedures using CAMPATH-1M in vitro between 1987-98 in a single center. METHODS: Immune reconstitution and quality-of-life were assessed in 19 longterm survivors. All but two received pre-transplant conditioning. T- and B-cell chimerism, numbers and function were analyzed during a median follow-up of 5.3 years (range 1.33-12). RESULTS: The overall engraftment rate was 59%, six children required repeated BMT and the survival rate was 63%. All have donor T cells, 58% normal T-cell numbers and 74% normal T-cell function. Of 17 evaluated, 16 patients (94%) have normal IgM and IgG levels, and production of specific Abs to protein Ags, but only 5/16 (31%) have a good response to pneumococcal polysaccharide. Early and late post-BMT complications were rare and there were no delayed deaths. Only one child continues on long-term i.v. Ig 4-years post-BMT. Eleven children died (37%). DISCUSSION: CAMPATH-1M T-cell depleted BMT for SCID resulted in 63% survival. Deaths of 11 children were mainly due to pre-existing infections. Seventeen of 19 long-term survivors have normal immune function and good quality-of-life.

Nuclear matrix proteins associated with DNA in situ in hormone-dependent and hormone-independent human breast cancer cell lines.

The nuclear matrix is a dynamic RNA-protein complex that organizes chromatin and regulates nuclear DNA metabolism. Nuclear matrix proteins informative in the diagnosis of cancer have been identified. Here, the nuclear matrix breast cancer proteins (NMBCs) cross-linked to nuclear DNA in situ with cisplatin in human breast cancer cell lines were analyzed by two-dimensional gel electrophoresis. We identified NMBCs that were differentially associated with nuclear DNA of hormone-dependent and -independent breast cancer cell lines. Three DNA cross-linked NMBCs were found to be exclusive to estrogen receptor-positive, hormone-dependent breast cancer cells, whereas two NMBCs were observed only in estrogen receptor-negative, hormone-independent breast cancer cells. Changes in these NMBCs were observed when hormone-dependent breast cancer cells became hormone independent. Furthermore, we show that the intermediate filament protein vimentin is associated with the nuclear DNA of MDA-MB-231 breast cancer cells, an estrogen receptor-negative, hormone-independent breast cancer cell line with high metastatic potential. These nuclear matrix DNA-binding proteins may play important roles in breast tumorigenesis.

Signal transduction pathways and chromatin structure in cancer cells.

Molecular mechanisms controlling gene expression include cell shape, mechanical and chemical signal transduction pathways, chromatin remodeling, and DNA methylation. In this article, we will review the contribution of these molecular mechanisms and structural alterations in the malignant transformation of cells. The mechanical signaling pathway consists of the tissue matrix system that links together the three-dimensional skeletal networks, the extracellular matrix, cytoskeleton, and nuclear matrix. The cytoskeleton array is a dynamic system that transmits signals from the cell exterior to nuclear DNA. The composition and function of this mechanical signaling pathway is altered in cancer cells. Chemical signaling pathways such as the Ras/mitogen-activated protein kinase (MAPK) pathway stimulate the activity of kinases that modify transcription factors, histones, and chromatin remodeling factors. Oncoproteins deregulating this signaling pathway set in motion a series of events that cumulate to chromatin remodeling and aberrant gene expression. J. Cell. Biochem. Suppl. 35:27-35, 2000.

Organization of chromatin in cancer cells: role of signalling pathways.

The role of mechanical and chemical signalling pathways in the organization and function of chromatin is the subject of this review. The mechanical signalling pathway consists of the tissue matrix system that links together the three-dimensional skeletal networks, the extracellular matrix, cytoskeleton, and nuclear matrix. Intermediate filament proteins are associated with nuclear DNA, suggesting that intermediate filaments may have a role in the organization of chromatin. In human hormone-dependent breast cancer cells, the interaction between cytokeratins and chromatin is regulated by estrogens. Transcription factors, histone acetyltransferases, and histone deacetylases, which are associated with the nuclear matrix, are components of the mechanical signalling pathway. Recently, we reported that nuclear matrix-bound human and chicken histone deacetylase 1 is associated with nuclear DNA in situ, suggesting that histone deacetylase has a role in the organization of nuclear DNA. Chemical signalling pathways such as the Ras/mitogen-activated protein kinase (Ras/MAPK) pathway stimulate the activity of kinases that modify transcription factors, nonhistone chromosomal proteins, and histones. The levels of phosphorylated histones are increased in mouse fibroblasts transformed with oncogenes, the products of which stimulate the Ras/MAPK pathway. Histone phosphorylation may lead to decondensation of chromatin, resulting in aberrant gene expression.

Delayed engraftment and mixed chimerism after HLA-identical sibling donor BMT in Fanconi anaemia.

A 12-year-old girl with Fanconi anaemia (FA) received a bone marrow transplant from her HLA-identical brother following conditioning with cyclophosphamide (20 mg/kg), thoraco-abdominal radiation (TAI) (4 Gy) and equine anti-thymocyte globulin (ATG) (90 mg/kg). Engraftment was delayed and initially tenuous, and was followed by mixed chimerism (MC) over a follow-up period of 2 years. DNA analysis of engraftment was performed on whole peripheral blood and on separated granulocytes, B and T lymphocytes using PCR detection of CA tandem repeat polymorphisms. At 10 weeks post BMT, granulocytes were predominantly donor, but B and T lymphocytes recipient, in origin. Over the subsequent 90 weeks, granulocytes and B lymphocytes were donor-derived, whilst T cells showed persistent MC but with an increasing donor component. Marrow haemopoietic function (Hb, ANC and platelet count) improved gradually in parallel with a rise in the proportion of donor lymphocyte engraftment. We postulate that a population of recipient lymphocytes survived conditioning and in turn delayed the development of full donor chimerism. Although transient MC has been described after allogeneic BMT in FA, its association with delayed engraftment, and persistence for more than 1 year post BMT, has not been documented clearly.

Estrogen regulates the association of intermediate filament proteins with nuclear DNA in human breast cancer cells.

In a previous study we showed that the levels of the intermediate filament proteins, cytokeratins 8, 18, and 19, in the nuclear matrix-intermediate filament (NM-IF) fraction from the hormone-dependent and estrogen receptor (ER)-positive human breast cancer cell line T-47D5 were regulated by estrogens. In contrast, estrogens did not regulate the cytokeratins in the NM-IF fraction of the hormone-independent and ER-positive cell line, T5-PRF. In this study, human breast cancer cells were treated with cis-diamminedichloroplatinum to cross-link protein to nuclear DNA in situ, and proteins bound to DNA were isolated. We show that cytokeratins 8, 18, and 19 of T-47D5 and T5-PRF were associated with nuclear DNA in situ. The levels of the cytokeratins 8, 18, and 19 bound to nuclear DNA or associated with the cytoskeleton of T-47D5 human breast cancer cells decreased when estrogens were depleted or the pure antiestrogen ICI 164,384 was added. In contrast, the cytokeratin levels associated with nuclear DNA or cytoskeleton were not significantly affected by estrogen withdrawal or antiestrogen administration in T5-PRF cells. These observations suggest that estrogen regulates the organization of nuclear DNA by rearrangement of the cytokeratin filament network in hormone-dependent, ER-positive human breast cancer cells and that this regulation is lost in hormone-independent, ER-positive breast cancer cells.

Chromatin, nuclear matrix and the cytoskeleton: role of cell structure in neoplastic transformation (review).

Aberrant nuclear and cellular structures are hallmarks of malignant transformation. Thus it is not surprising that the three-dimensional structure of the cell both affects and is affected by changes in gene expression. Here we review the role of the cytoskeleton, nuclear matrix, and chromatin structure in the genesis of cancer. The shape of a cell is governed by a dynamic tissue matrix, which includes extracellular matrix, cytoskeleton and nuclear matrix. Mechanical and chemical signals are transmitted to the nucleus, resulting in alterations in the three-dimensional chromatin organization of genes. The signal transduction pathways affect histone modifications, such as acetylation and phosphorylation, resulting in a relaxed chromatin structure observed in oncogene-transformed cells.

In situ cross-linking by cisplatin of nuclear matrix-bound transcription factors to nuclear DNA of human breast cancer cells.

Cisplatin is an antitumor drug that is used to treat several types of cancers. In this study, we analyzed the proteins that were cross-linked to DNA in situ in MCF-7 human breast cancer cells incubated with cisplatin. We show that cisplatin cross-links nuclear matrix proteins to DNA. In immunoblotting experiments, we found that nuclear matrix-associated transcription factors and cofactors (estrogen receptor, HET/SAF-B, hnRNP K, and histone deacetylase 1) were cross-linked to nuclear DNA. These transcription factors and cofactors have essential roles in the regulation of genes involved in the proliferation of breast cancer cells and in the organization and structure of chromatin. We applied a novel protocol to demonstrate that the nuclear matrix-bound transcription factors/cofactors were cross-linked to DNA fragments attached to the nuclear matrix. These results suggest that the cross-linking of nuclear matrix-associated transcription factors and cofactors to DNA may be one of the mechanisms by which cisplatin inhibits transcription and replication processes.

Randomized study of growth factors post-peripheral-blood stem-cell transplant: neutrophil recovery is improved with modest clinical benefit.

PURPOSE: To evaluate the clinical value of growth factors (GFs) with peripheral-blood stem cells (PBSC) collected following mobilization with GFs, we randomized patients to receive or not to receive GFs following transplant. PATIENTS AND METHODS: Thirty-seven patients were apheresed after receiving the combination of granulocyte colony-stimulating factor (G-CSF) with granulocyte-macrophage colony-stimulating factor (GM-CSF) at doses of 10 micrograms/kg/d and 5 micrograms/kg/d, respectively, for 6 days before apheresis and during a median of 4 days of collections. One day after the infusion of autologous marrow and PBSC, patients were randomly assigned to receive no GFs or a combination of G-CSF (7.5 micrograms/kg/d) and GM-CSF (2.5 micrograms/kg/d), both as a 2-hour intravenous (i.v.) infusion twice per day until the neutrophil count was greater than 1,500/microL. RESULTS: The median days to recovery to an absolute neutrophil count (ANC) of 100/microL (9 v 11.5, P = .0005), 500/microL (10 v 16, P = .0004), or 1,000/microL (12 v 21, P = .0008) was shortened with the use of GFs, post-PBSC infusion. In addition, the duration of hospitalization was shorter (19 v 21 days, P = .0112) in the arm receiving GFs post-PBSC infusion. There was no significant difference between the two study arms in the duration of fever, documented septic episodes, or RBC or platelet transfusion requirements. CONCLUSION: Despite faster neutrophil recovery and shortened duration of hospitalization with GFs administered after PBSC transplantation, the measured clinical variables of febrile days, septic episodes, and transfusion requirements were similar between the study arms. The use of GFs post-PBSC transfusion is associated with a modest clinical benefit.

Design of preparative regimens for stem cell transplantation in breast cancer.

We have evaluated tandem cycles of a tri-drug combination, termed CVP (cyclophosphamide, etoposide [VP-16], and cisplatin [Platinol]), at four levels in more than 300 patients with various types of tumors. Tandem CVP appears to be at least therapeutically equivalent to alternatives. A second potentially non-cross-resistant combination of mitoxantrone and thiotepa (MT), with or without etoposide, has been used in sequence following CVP to improve long-term, disease-free survival in patients who have multiple metastatic sites, who relapse shortly after adjuvant therapy, or who show other unfavorable clinical features. A combination of MT and etoposide (MVT) achieved an overall response rate of 61% in 32 patients with metastatic or refractory breast cancer. The etoposide was then eliminated to decrease the major toxicities of this regimen. MT was subsequently given to 37 evaluable patients prior to bone marrow infusion. The overall response rate was 48.5% Thirty patients with metastatic breast cancer were then treated with induction therapy, a cycle of CVP, and then a cycle of MT. Given the low complete remission (CR) rate to induction therapy in these patients, the CR rate achieved with CVP-MT was encouraging. Further studies are ongoing.

Allogeneic bone marrow transplantation for hematological malignancies following etoposide, cyclophosphamide, and fractionated total body irradiation.

Forty-three patients received etoposide, cyclophosphamide, and fractionated total body irradiation before allogeneic marrow transplantation. Fifteen patients had chronic myelogenous leukemia in chronic phase or acute leukemia in first remission (standard risk) and twenty-eight patients with more advanced disease (high risk). All patients received etoposide 1,500 mg/m2 intravenously on day -8, cyclophosphamide 60 mg/kg/day intravenously on days -7 and -6, and total body irradiation at 170 cGy twice a day on days -3, -2, and -1. During the first 100 days 12 high risk patients (43%) died from causes unrelated to relapse while none of the standard risk patients died. Renal and hepatic dysfunction were also significantly increased during the first 14 days in the high risk group. The addition of 1,500 mg/m2 of etoposide to the cyclophosphamide and total body irradiation was well tolerated for patients with standard risk. However, the regimen was poorly tolerated with high mortality in patients with more advanced disease.

Influence of mobilized peripheral blood cells on the hematopoietic recovery by autologous marrow and recombinant human granulocyte-macrophage colony-stimulating factor after high-dose cyclophosphamide, etoposide, and cisplatin.

Peripheral blood cells (PBC) can hasten hematopoietic recovery after high-dose chemotherapy. To determine if PBC apheresed after mobilization further enhance hematopoietic recovery over that achieved with autologous bone marrow (ABM) and recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF), 14 patients with metastatic solid tumors were supported by ABM and rhGM-CSF during the first course of high doses of cyclophosphamide, etoposide, and cisplatin (CVP) and 11 of these 14 patients by mobilized PBC with ABM and rhGM-CSF during the second CVP. Each patient served as his or her own control. Identical doses of CVP were administered in both courses: cyclophosphamide 5.25 g/m2, etoposide 1,200 mg/m2, and cisplatin 165 to 180 mg/m2. PBC were collected on day 10 after mobilization with cyclophosphamide (3 g/m2) intravenously (IV) on day 1, doxorubicin (50 mg/m2) as a continuous IV infusion over 48 hours starting day 2, and rhGM-CSF as a daily 4-hour IV infusion starting day 4 at 0.6 mg/m2 for 14 days. Comparing recovery in the 11 patients to receive two cycles of therapy, the median days to an absolute neutrophil count of 0.1 x 10(9)/L and 0.5 x 10(9)/L were not statistically significant between the two courses; neither was there a difference in the incidence of fever and bacteremia. The median number of days to platelet count of 0.02 x 10(12)/L unmaintained by platelet transfusion was 20 from marrow infusion for course 1 and 16 for course 2 (P = .059). The median number of days to a platelet count of 0.05 x 10(12)/L was significantly shortened: 24 and 19 days for courses 1 and 2, respectively (P = .045). Patients who received PBC required fewer number of platelet transfusions. Extramedullary toxicities were not different between the groups. Our finding of enhanced early recovery of platelets and reduced platelet transfusion requirement is in concordance with other studies.

Autologous bone marrow transplantation in solid tumors.

Recent studies in autologous bone marrow or peripheral blood transplantation in solid tumors are discussed. The toxicity and activity of high-dose cisplatin or carboplatin combined with etoposide and other drugs are described. The results of trials in nonseminomatous germ cell tumors, neuroblastoma, ovarian cancer, and brain tumors are detailed and discussed. The impressive antitumor activities noted in certain subgroups should lead to an early application of these strategies before drug resistance becomes prevalent.

An effective acute graft-vs.-host disease prophylaxis with minidose methotrexate, cyclosporine, and single-dose methylprednisolone.

Cyclosporine and methotrexate at standard doses (15 mg/m2 on day 1 and 10 mg/m2 on days 3, 6, and 11, total 45 mg/m2) are effective in the prophylaxis of acute graft-vs.-host disease. However, the combination has significant early toxicities with delayed engraftment, increased mucositis, and hepatotoxicity. We modified the combination by adding single-dose methylprednisolone and lowered the total dose of methotrexate to 35 mg/m2 (5 mg/m2 on days 1, 3, and 6, and then 10 mg/m2 on days 11 and 18) and then to 20 mg/m2 (5 mg/m2 on days 1, 3, 6, and 11) in an attempt to decrease these side effects in two sequential consecutive groups of patients. We demonstrated that the modified regimens maintained the efficacy with reduced toxicities. The rate of engraftment was comparable to cyclosporine alone and the hepatotoxicity was reduced with reduced doses of methotrexate. Factors such as early immunosuppression of the host, intravenous immunoglobulin, the timing of steroid administration, nucleotide free diet and germ free environment may contribute to the effectiveness of the combination and permit reduction of methotrexate dose.

Prophylaxis of cytomegalovirus infection with ganciclovir in allogeneic marrow transplantation.

Cytomegalovirus (CMV) infection is one of the most common causes of morbidity and mortality after allogeneic marrow transplantation. We studied 14 consecutive CMV-seropositive patients adding ganciclovir (2.5 mg/kg i.v. every 8 hours for 7 days prior to transplant and 6 mg/kg three times a week after neutrophils became greater than 0.5 x 10(9)/l and the patients were platelet transfusion-independent until d 70) to our previous prophylaxis regimen which consisted of intravenous immunoglobulin and acyclovir. The result was compared with 30 consecutive patients whom we studied with our previous regimen. The addition of ganciclovir did not cause any extra toxicities. The incidence of interstitial pneumonitis and cumulative probability of CMV excretion in the first 100 d post-transplantation was significantly reduced (p = 0.038 and p = 0.035 respectively). The result shows that addition of ganciclovir significantly decreased the incidence of CMV infection in the early post-transplantation period.

Impact of autologous bone marrow infusion on hematopoietic recovery after high-dose cyclophosphamide, etoposide, and cisplatin.

Because of potential tumor contamination and inadequacy of current purging technique of bone marrow in patients with solid tumors, we investigated an alternative approach to high-dose therapy without autologous bone marrow (ABM) infusion. Three levels of nonmyeloablative doses of cyclophosphamide 4.5 to 5.25 g/m2, etoposide 750 to 1,200 mg/m2, and cisplatin 120 to 165 mg/m2 (CVP) were administered to patients with metastatic solid tumors. Patients were randomized to ABM (n = 46) or no-ABM (NABM) (n = 46) infusion after CVP to study the impact of ABM on hematopoietic recovery, morbidity, and mortality. All patients had ABM harvested, underwent conventional chemotherapy, and then received CVP. Seventy-three patients received two courses of similar doses. The following were the median days to absolute neutrophil count (ANC) of 0.1 x 10(9)/L: for the ABM arm, 19, 21, and 19 and for the NABM arm, 23, 20, and 21 at levels 1, 2, and 3, respectively, during course 1 (P = .01, .80, and .01, respectively). During course 2, ANCs to 0.1 x 10(9)/L and 0.5 x 10(9)/L were attained significantly faster at levels 1 and 3 in the ABM arm. ANC to 1.0 x 10(9)/L was comparable in both arms. Incidence of infection and duration of fever were similar in both arms. Although mortality and the incidence of delayed hematopoietic recovery were more frequent in the NABM arm, this was not statistically significant. Platelet recovery was consistently prolonged in course 2 in both arms, with demonstrable benefit of ABM in course 2 when dose levels were collectively considered. We conclude that (1) ABM enhanced recovery of ANC to 0.1 x 10(9)/L; (2) ABM did not decrease the incidence of infections and the duration of fever; and (3) CVP can be safely given without ABM to carefully selected patients.