After rehabilitation: meeting the long-term needs of persons with traumatic brain injury

Many survivors of traumatic brain injury have significant needs for long-term support. The rehabilitation professions, including occupational therapy, have begun to recognize these needs more fully during the last decade. The literature describes various models of supported living that provide housing, support services, and vocational assistance; however, these programs are not widely available due to limitations in public funding and inadequate insurance coverage for long-term care. Occupational therapists can contribute a broad expertise to the provision of supported living services, and the profession is encouraged to provide leadership and advocacy with respect to the long-term care needs of survivors of traumatic brain injury.

The leukemic myeloid cell line OMA-AML-1: an in vitro model of hematopoietic cell differentiation

The OMA-AML-1, acute myelogenous leukemia cell line is unique in that it spontaneously maintains both a CD34+ precursor cell compartment and a CD15+ differentiating cell compartment in vitro. A third transitional cell type with co-expression of CD34 and CD15 can also be identified in in vitro cultures. The cell line shows dynamic fluctuations in the relative sizes of these three cell compartments in suspension culture. In contrast, OMA-AML-1 fails to show phenotypic or morphologic evidence of differentiation when grown subcutaneously in immunodeficient mice. OMA-AML-1 responds to a number of hematopoietic cytokines. Delineation of cytokine responses on FACS isolated populations of CD34+ versus CD15+ cells demonstrated that proliferative responses occurred primarily at the level of the precursor cell (CD34+) while the production of endstage eosinophils occurred within the CD15+ compartment. OMA-AML-1 mimics a number of features of normal hematopoiesis and is proving to be a useful in vitro model for the study of hematopoietic differentiation.

High-dose therapy and peripheral blood progenitor cell transplantation: effects of recombinant human granulocyte-macrophage colony-stimulating factor on the autograft

Between June 1989 and June 1992, 144 patients participated in sequential clinical trials using peripheral blood progenitor cells (PBC) as their sole source of hematopoietic rescue following high-dose chemotherapy. All patients had received prior extensive combination chemotherapy and had marrow defects that precluded autologous bone marrow transplantation (ABMT). PBC were collected according to a single apheresis protocol. The initial 86 patients (group 1) had PBC collected without mobilization. Beginning in April 1991, PBC were mobilized solely with recombinant human granulocyte-macrophage colony-stimulating factor (rHuGM-CSF). Thirty-four patients (group 2) received rHuGM-CSF at a dose of 125 micrograms/m2/d by continuous intravenous infusion, and 24 patients (group 3) received rHuGM-CSF at a dose of 250 micrograms/m2/d by continuous intravenous infusion. Patients underwent at least six aphereses and had a minimum of 6.5 x 10(8) mononuclear cells (MNC)/kg collected. Cytokines were not routinely administered immediately after transplantation. A median of nine aphereses were required to collect PBC in group 1 and seven aphereses for groups 2 and 3 (P = .03). The time required to recover 0.5 x 10(9)/L granulocytes after transplant was significantly shorter (P = .0004) for the mobilized groups; the median time to recovery was 26 days for group 1, 23 days for group 2, and 18 days for group 3. Transplantation of PBC mobilized with rHuGM-CSF resulted in a shorter time to platelet (P = .04) and red blood cell (P = .01) transfusion independence. Mobilization with rHuGM-CSF alone resulted in efficient collection of PBC, that provided rapid and sustained restoration of hematopoietic function following high-dose chemotherapy. Mobilization of PBC with rHuGM-CSF alone is an effective method for patients who have received prior chemotherapy and have bone marrow abnormalities.

T-cell reconstitution by molecular, phenotypic, and functional analysis in the thymus, bone marrow, spleen, and blood following split-dose polychemotherapy and therapeutic activity for metastatic breast cancer in mice

We examined the effect of a maximum tolerated, split-dose chemotherapy protocol of cyclophosphamide, cisplatin, and 1,3-bis (2-chloroethyl)-1-nitrosourea (BCNU) on neutrophil and lymphocyte subpopulations in the peripheral blood leukocytes (PBLs), thymus, bone marrow, and spleen. It was found that this protocol of polychemotherapy, modeled after the induction protocol used with autologous bone marrow transplantation (AuBMT) for breast cancer, suppressed both B- and T-cell populations and T-cell function at times when the absolute neutrophil count had returned to normal or supernormal numbers. We observed an organ- and phenotype-specific T- and B-cell recovery to normal levels following chemotherapy. However, despite normalization of cellularity and phenotype frequency, splenic lymphocytes remained unable to respond to normally concanavalin A (ConA). This polychemotherapy protocol in mice with an extensive experimental metastasis mammary tumor burden, was a dose lethal to 20% of the test group, which could be overcome with treatment by BMT and rHu interleukin (IL)-7. Furthermore, therapy with the T-cell augmenting agent rHu IL-7 had additive therapeutic activity and significantly prolonged survival beyond that of chemotherapy and BMT although it did not cure any mice with a heavy tumor burden. In summary, these studies demonstrate an organ-specific and selective polymorphonuclear neutrophil and T- and B-cell reconstitution following multidrug, split-dose chemotherapy on tissue and PBL populations, and a chronic depression in T-cell function, which when modified can result in significant therapeutic activity.

Age differences in summarizing descriptive and procedural texts

This study compared young and older adults' summaries of expository texts under the hypothesis that older adults would be more experienced, hence more accurate, at summarizing texts. Two types of expository texts were used: procedural and descriptive texts. The texts were read by a panel of judges who wrote summaries of each text and identified the central ideas of each text; the judges' summaries were used to prepare lists of the central ideas of each text and to write standard summaries of each text. The participants read four texts, two orally and two silently, and then wrote summaries, which were limited to 50 words. Words-per-minute reading times were collected and the summaries were scored on two measures of content, how many ideas were reproduced from the original texts and the proportion of central ideas that were reproduced, and two measures of length, the number of sentences and the number of words. Although the older adults read more slowly than the young adults, the older adults reproduced more total and central ideas than the young ideas.

OMA-AML-1: a leukemic myeloid cell line with CD34+ progenitor and CD15+ spontaneously differentiating cell compartments

OMA-AML-1 was established from a patient with acute myelomonocytic (M4) leukemia at fifth relapse when blasts were greater than 85% CD34+, CD15-. Leukemic cells were established in suspension culture and independently grown as subcutaneous tumors in SCID mice. Cells growing in suspension culture underwent differentiation by phenotypic and morphologic criteria. In contrast, cells grown as subcutaneous solid tumors in SCID mice maintained progenitor cell characteristics with high-density CD34 expression and lack of morphologic differentiation. A tendency toward differentiation to CD15+, CD34- cells in vitro and self-renewal of CD34+, CD15- cells in vivo was consistently demonstrated regardless of whether cells were initially grown in vitro or in vivo. The cell line maintains both a CD34+, CD15- progentitor cell pool and a non-overlapping, CD15+, CD34- differentiating cell compartment after more than 1 year in continuous culture. Cell cycle analysis and cloning experiments were consistent with terminal differentiation occurring in the CD15+, CD34- population. The cell line shows concentration-dependent proliferative responses to interleukin (IL)-3, granulocyte-macrophage colony-stimulating factor (GM-CSF), and IL-6, but not to granulocyte CSF (G-CSF). OMA-AML-1 appears to mimic several features of normal myeloid hematopoiesis and should prove useful for the study of normal and malignant myeloid differentiation.

DNA methylation inhibits transcription of procollagen alpha 2(I) promoters

Our previous studies have demonstrated that a 2-[N-(acetoxyacetyl)amino]fluorene-transformed rat epithelial-like cell line, W8, contains a transcriptionally inactive alpha 2(I) gene with a hypermethylated promoter/first-exon region. We have cloned the rat promoter/first-exon region (-211 to +207) from W8 cells and their parent cell line, K16, which expresses alpha 2(I) collagen. There were no sequence differences between the clones from the two cell lines, indicating that a mutation was not responsible for transcriptional inhibition. The alpha 2(I) rat promoters were cloned upstream of the chloramphenicol acetyltransferase gene. Both constructs were equally active in both cell lines, suggesting that trans-activating factors for alpha 2(I) transcription are present in W8 cells. Finally, methylation of plasmids at all CpG sites with SssI methylase completely inhibited transcription using alpha 2(I) promoters, but methylation did not inhibit simian-virus-40 promoter-driven transcription. Certain methylation sites partially inhibit promoter activity. An HhaI methylation site inhibited transcriptional activity of the alpha 2(I) promoter 8-fold, whereas methylation at the HpaII site in the rat alpha 2(I) promoter did not decrease transcriptional activity. This provides further evidence that methylation at specific sites in the collagen alpha 2(I) promoter is responsible for the inactivation of transcription in W8 cells.

Are the stray 60-Hz electromagnetic fields associated with the distribution and use of electric power a significant cause of cancer?

The putative causal relation between ambient low-frequency (50 or 60 Hz) electromagnetic fields (necessarily present in living and working environments because of our ever increasing use of electrical devices) and cancer, especially leukemia, can be tested on the large scale by examining historical data on the growth of the generation and consumption of electric power since 1900 and corresponding data on cancer death and incidence rates. The United States per capita generation and residential consumption of electric power have grown roughly exponentially since 1900; total per capita generation has increased by a factor of 10 since 1940, and per capita residential consumption has increased by a factor of 20 in the same period. The ubiquitous stray fields from power distribution lines and internal and external wiring in buildings have grown in the same proportions. In contrast to the explosive increase in the generation and use of electricity, the age-adjusted cancer death rate for the population as a whole shows only a slight rise since 1900. When respiratory cancers (largely caused by tobacco use) are subtracted, the remaining death rate has actually fallen since 1940. That the death rate may have fallen because of better diagnosis and treatment, despite a rising incidence rate, is not substantiated, especially for leukemia, including childhood leukemia, where the incidence rate has been constant or declining slightly for the past 25 yr. The absence of any appreciable change in the national cancer incidence rates during a period in which residential use of electric power has increased dramatically shows that the associated stray 50- or 60-Hz electromagnetic fields pose no significant hazard to the average individual.

In vivo administration of antibody to interleukin-5 inhibits increased generation of eosinophils and their progenitors in bone marrow of parasitized mice

Bone marrow of mice parasitized with Nippostrongylus brasiliensis showed increased numbers of eosinophils as early as 4 days after infection. By day 7, their bone marrow also contained elevated numbers of progenitors that form small eosinophil colonies (20 to 50 cells) in soft agar cultures supplemented with interleukin-5 (IL-5). However, when mice were infused with anti-IL-5 antibodies at the time of infection, the number of recognizable eosinophils present in bone marrow remained low and eventually dropped below normal levels. The antibody treatment also prevented increased generation of IL-5-responsive precursors capable of differentiating into mature eosinophils in liquid culture and inhibited the generation of progenitor cells capable of forming small eosinophil colonies or clusters in soft agar cultures. The results of these in vivo experiments directly show that IL-5 is an essential regulatory molecule required for the bone marrow-dependent phase of a parasite-induced eosinophilia.

The influence of advertising on tobacco consumption: some problems with Chetwynd et al.'s analysis

In a recent study of the relationship between cigarette advertising and the aggregate consumption of cigarettes in New Zealand between 1973 and 1985, Chetwynd et al. (1988) argue that quarterly data suggest that advertising affects overall consumption of cigarettes with an elasticity of +0.07. In addition, they argue that advertising has a 'carry over' effect of about four quarters on current consumption. These results are potentially important for two reasons. Although the evidence is mixed, the conventional view is that cigarette advertising affects brand choice among smokers but not aggregate demand for cigarettes. Chetwynd et al.'s results, (hereafter, Chetwynd) contradict this traditional view. Secondly, if advertising does increase the aggregate demand for cigarettes, then a public policy banning cigarette advertising might reduce aggregate demand for cigarettes. Unfortunately, the Chetwynd, study is sufficiently flawed with conceptual and econometric problems that their inference that advertising increases cigarette demand is questionable. Certainly cigarette advertising may increase or decrease cigarette consumption. The point we wish to make is that, any inference one way or the other based on the results of Chetwynd, cannot be viewed as well-grounded in either scientific methodology or statistical principles.

PaperChase: computerized bibliographical retrieval for the physician

PaperChase is a computer program that permits any physician or scientist to search the National Library of Medicine's MEDLINE data base of references to the biomedical literature. Written for the clinician rather than for the search librarian, PaperChase permits the user to search the entire MEDLINE collection of over 5,000,000 references published in 4,000 biomedical journals dating back to 1966. PaperChase is now available throughout the world to anyone who has a computer terminal or personal computer, and a modem. No special training is needed for a successful search. There is no user's manual. Users can search by title word, Medical Subject Heading, author's name, journal title, year of publication, language of publication, or any combination of the above. Users can read abstracts online, and they can request that a photocopy of the full text of any article be mailed to them.

Comparison of the growth and metastasis of four human intestinal tumor cell line xenografts

The growth and metastasis of four human intestinal tumor cell lines: one duodenal adenocarcinoma (HTB-40) and three adenocarcinomas of the colon (CCL-218, CCL-222 and HT-29) have been compared in vitro and in vivo in nude mice. HTB-40 was the fastest growing cell line in vitro with a doubling time (DT) of 14.8 h. CCL-218 and CCL-222 grew more slowly in vitro with doubling times of 21.6 and 22.8 hours, respectively. All three of these tumors grew more slowly in vivo with doubling times ranging from 39.1 h (CCL-218 in male nude mice) to 65.3 h (CCL-222). The growth of CCL-218 cells was significantly slower in female nude mice DT 51.0 h). HT-29 was the slowest growing in vitro (DT 23.8 h) and in vivo (DT about 100 h). HT-29 also showed the greatest discrepancy between its DT measured in vivo as compared to in vitro, suggesting a greater clonogenic cell loss from HT-29 tumors in vivo. Histologic evaluation of these tumors grown subcutaneously in nude mice showed all to be anaplastic and to produce liver micrometastases. However, more extensive abdominal and liver metastases were observed in the nude mice injected with HT-29 cells, and some of these metastases had morphologic features of moderately well-differentiated epithelium. These results indicate the usefulness of the HT-29 tumor cell line as an experimental model of metastasis from a human colonic adenocarcinoma.

Cell surface properties associated with malignancy of metastatic large cell lymphoma cells

The highly malignant and metastatic RAW117-H10 cell line was developed by in vivo selection from the Abelson leukemia virus induced parental RAW117-P lymphoma. In this study we have characterized these cell lines with regard to their expression of lymphocyte and macrophage differentiation antigens, adherence, phagocytic properties, binding of various lectins, binding of antibodies to glycolipid asialo-monoganglioside, and the role of butanol extractable cell surface molecules to determine if any of these cell surface properties are associated with the malignant potential of RAW117-H10 cells. The only major difference in immunological phenotypes between RAW117-P and RAW117-H10 cells was an increased expression of Thy-1 molecules by the latter. However, the highly malignant RAW117-H10 cells bound significantly less concanavalin A, Ricinia communis agglutinin, succinylated wheat germ agglutinin, and particularly anti-asialomonoganglioside than their parental counterpart and were resistant to natural killer cell mediated cytolysis. Removal of butanol extractable cell surface molecules significantly decreased the malignancy of RAW117-H10 cells and increased their susceptibility to natural killer cell mediated cytolysis. The butanol treated RAW117-H10 cells regained high in vivo malignancy when recultured for 3 days to permit regeneration of their cell surface components. The butanol extracted RAW117-H10 cells still expressed high levels of Thy-1 indicating that this most probably represented "inappropriate" antigen expression. Since the expression of lymphocyte differentiation antigens did not correlate with the malignant behavior of the cells, we postulate that these antigenic differences merely represent phenotypic variation. The decreased malignant potential of the butanol treated RAW117-H10 cells did correlate with increased cell surface anti-asialomonoganglioside binding (glycolipid) and increased natural killer cell susceptibility.

Severe steroid responsive pneumonitis associated with pyoderma gangrenosum and ulcerative colitis

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