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Biomedical subjects

C Snow

Publications and source records attributed to C Snow.

At least 91 records · Page 5Linked to original sources
PubMed1996

Phase I study of high-dose etoposide phosphate in man.

Etoposide is a widely used cytotoxic agent with a broad spectrum of activity in human malignancies. This agent has been incorporated into many transplant regimens although toxicity occurs because of its poor water solubility and toxic excipients. Etoposide phosphate, a water soluble prodrug of etoposide, has been studied at conventional dosages in man and shown to have advantages over the parent compound. We have extended our previous experience with this new agent to evaluate the levels needed in transplantation protocols. This phase I study of intravenous high-dose etoposide phosphate over 2 h on days 1 and 2 was designed to determine whether or not dose linearity between the amount of etoposide phosphate administered to patients and generation of etoposide in vivo as seen with conventional dosages of this agent would be present at transplant-dose levels. In addition, the toxicities of these dose levels with the short infusion schedule were defined. A conservative dose escalation scheme was chosen based upon prior knowledge of etoposide. Thirty-one patients (19 male, 12 female) with CALGB performance status 0-1 with a variety of solid tumors entered this study. The patients were treated with dose levels of etoposide phosphate given as the etoposide-equivalent doses of 250, 500, 750, 1000, 1200, 1400, and 1600 mg/m2/day in 250-400 ml of normal saline given as an intravenous infusion over 2 h on days 1 and 2 every 28 days. After the maximal tolerated dose level was determined on this schedule, additional patients received etoposide phosphate as a 4 h infusion on both days in an attempt to reduce toxicities. G-CSF (5 micrograms/kg/day) was administered subcutaneously to all patients from day 3 until the WBC > or = 10000/microliters. Nonhematologic toxicity was considered to be dose limiting. Serial plasma samples for pharmacokinetics were obtained from patients on day 1 of cycle 1. For the 2 h infusion, the maximum tolerated dose of etoposide phosphate was 1000 mg/m2/day x 2 with dose limiting mucositis. In the small number of patients studied, the maximum tolerated dose was reached for the 4 h infusion at 1400 mg/m2/day of drug, again due to mucositis. Other toxicities, despite the rapid infusion schedule, were modest with transient mild headache being most common. At the highest doses etoposide phosphate was efficiently and rapidly dephosphorylated to etoposide. Etoposide generated by dephosphorylation of etoposide phosphate had plasma disposition curves characteristic of etoposide administered parenterally. One partial response occurred in a patient with small cell lung cancer. Etoposide phosphate can be rapidly infused in modest fluid volumes at dosages required for transplantation protocols with minimal acute side-effects. On a 2 h schedule, mucositis becomes the dose limiting nonhematologic toxicity. Mucositis seems to correlate with peak dose levels of the drug rather than total drug administered. On a 4 h infusion schedule given sequentially for 2 days, the maximum tolerated dosage could be increased 40% compared to the 2 h schedule. The relative ease of administration and the rapid conversion of this prodrug into etoposide should make it useful in high-dose therapy settings.

Adult↗
PubMed1995

Technology keeps food costs on diet.

In the past when a patient missed a meal at Good Samaritan Hospital in Cincinnati, nurses often had to interrupt their work and rush down to the kitchen for the tray. Now, the nurses can call the food service and request that SAM bring it up. Not quite R2D2, but versatile nonetheless, SAM is a cordless, programmable robotic courier that keeps going until its 24-volt batteries need recharging.

Food Service, Hospital↗
PubMed1995

Early intervention for back-injured nurses at a large Canadian tertiary care hospital: an evaluation of the effectiveness and cost benefits of a two-year pilot project.

This study evaluated a two-year multidisciplinary early intervention pilot programme for back-injured nurses employed at a large teaching hospital, using a pre- versus post-programme analysis. The purpose was to ascertain whether this programme could reduce the incidence, morbidity, time lost and cost due to back injuries in the 250 nurses employed on ten targeted high-risk wards. Injuries in the remaining 1395 nurses employed on the other 45 wards were monitored concurrently for comparison. The programme consisted of prompt assessment, treatment and rehabilitation through modified work. Evaluative data were gathered by one research nurse on standardized forms at the time of injury, weekly until return to work, and at a six-month follow-up. Time lost and cost data for up to one-year post-injury were derived from workers' compensation statements. Compared to the two years prior to introduction of the programme, the rates of back injuries and lost-time back injuries decreased by 23% and 43%, respectively, on the targeted wards, while these increased on the control wards. Combined expenditure was 32% lower per injury and 34% lower per lost-time injury for those in the targeted group who consented to take part in the programme compared to their counterparts on the control wards, as the increased assessment and treatment costs per case attributable to the programme were more than offset by the savings in lower compensation (wage loss) costs. This programme thus reduced the incidence and time lost due to back injuries and was cost-beneficial.

Back Injuries↗
PubMed1995

The epidemiology of back injuries in nurses at a large Canadian tertiary care hospital: implications for prevention.

Two years of prospective data on 416 back injuries were gathered at a 1100-bed acute and tertiary care hospital to assist target prevention efforts. The rate of injury among 1645 nurses was found to be highest for those working on orthopaedic, medicine, neurology, spinal and surgery wards, indicating priorities for prevention. In fact, 51% of the orthopaedic nurses sustained at least one back injury during the two-year period. Gender did not significantly affect the risk of back injury; however, injuries were slightly more common in nurses with less seniority and younger nurses were found to be at significantly increased risk of back injury. Almost 63% of the back injuries which occurred in nurses working 8 h shifts on the high-risk wards occurred during the first two hours of the shift. Lifting and transferring patients with assistance were the two most common mechanisms for back injury (22.6% and 23.3%, respectively). In total, injured nurses attributed 52.3% of their injuries to inadequate training; inadequate staffing was given as the primary reason for 13.8% of the injuries. The results suggest that training in the indications for and use of mechanical devices for lifting/transferring patients requires intensification, and a 'warm-up' period should also be considered in the face of injuries occurring early in the shift if work activities cannot be evenly planned.

Adult↗
PubMed1993

Injury prevention instruction in the emergency department.

STUDY OBJECTIVE: To describe preventable pediatric injuries and the proportion receiving documented injury prevention instruction by emergency department personnel. DESIGN: Retrospective chart review. SETTING: A rural Level I trauma center. TYPES OF PARTICIPANTS: All injured children aged birth through 15 years presenting to our hospital from January 1, 1987, through December 31, 1987. MEASUREMENTS AND MAIN RESULTS: During the study period, 1,449 injuries presented to the trauma center. Motor vehicle crashes caused the largest number of preventable injuries (71), although the proportion of preventable injuries was higher among poisonings, burns, and pedestrian-automobile collisions. Among the 1,313 patients available to ED personnel at discharge, injury prevention instruction was indicated in 27% of cases but documented in the medical record in only 3%. ED personnel were more likely to document instruction for preventing poisoning than other causes of injury. CONCLUSION: Most preventable pediatric injuries treated and released by ED personnel do not receive documented injury prevention instruction.

Adolescent↗
PubMed1992

The wheat and the chaff: or four confusions regarding CHILDES.

Edwards (1992) presents a set of examples from the Child Language Data Exchange System (CHILDES) as prototypes of bad transcription practice. Her discussion is based upon four basic confusions. First, Edwards confuses old and discarded versions of CHAT with current CHAT. Second, she confuses the relation between CHAT standards with the implementation of these standards during the process of reformatting older corpora. Third, she confuses transcription for automatic analysis with transcription for documentation. Fourth, she confuses the CHAT guidelines with the larger CHILDES system. We argue that these confusions have misled Edwards into developing an overly rigid set of principles for data analysis which, if followed literally, could choke off progress in the analysis of spontaneous language samples.

Archives↗
PubMed1990

The Child Language Data Exchange System: an update.

In a previous issue of this Journal, MacWhinney & Snow (1985) laid out the basic sketch for an international system for exchanging and analysing child language transcript data. This system--the Child Language Data Exchange System (CHILDES)--has developed three major tools for child language research: (1) the CHILDES database of transcripts, (2) the CHAT system for transcribing and coding data, and (3) the CLAN programs for analysing CHAT files. Here we sketch out the current shape of these three major tools and the organizational form of the CHILDES system. A forthcoming book (MacWhinney, in press) documents these tools in detail.

Child↗
PubMed1987

Differences of T-cell activation by the anti-CD3 antibodies Leu4 and BMA030.

Two anti-CD3 antibodies and their Fab/F(ab')2 fragments were compared with regard to their requirement for secondary signals and generations of intracellular messengers. The anti-CD3 antibody BMA030 was found to require monocyte contact to elicit T-cell mitogenesis. Cross-linking by plastic-bound goat anti-mouse antibodies (panning) failed to activate T cells, even in the presence of recombinant IL-1 or IL-2. In contrast, crosslinking of the anti-CD3 antibody Leu4 or Leu4 fragments was mitogenic in monocyte-free cultures. Measurements of intracellular Ca2+ ([Ca2+]i) and generation of inositol phosphates revealed that binding (+/- panning) of BMA030, Leu4, and their F(ab')2 fragments generated similar amounts of intracellular messengers and thus failed to explain the different responsiveness to passive crosslinking. Since the generation of these messengers was not necessarily followed by proliferation but was always observed when mitogenesis occurred, we conclude that the elevation of [Ca2+]i and the production of inositol phosphates are required but not sufficient to trigger mitogenesis.

Adult↗
PubMed1986

Sex-dependent local cellular immunity to alloantigens.

A local component of cellular immunity was detected in mice that had been immunized against histocompatibility antigens. The status of this local immunity was determined using a node-onto-kidney (NOK) assay in which lymph nodes draining the site of immunization as well as distant (nondraining) lymph nodes of the immunized mice were grafted onto the kidneys of mice of the immunizing strain. In this assay, the weight gained by each node piece was taken as a measure of its immunological responsiveness. The responsiveness of a draining lymph node was directly compared with that of a distant node after both had been grafted onto the same host kidney. We consistently found that the draining lymph nodes of immunized male mice were more responsive than their distant nodes, whereas the draining lymph nodes of immunized female mice were less responsive than their distant nodes. Male mice were converted to the female pattern of hyporesponsiveness in the draining nodes by performing bilateral orchidectomy, suggesting that the male pattern depends upon the presence of testicular hormones. Additional studies showed there was a significant reduction in the reactivity of uterine draining lymph nodes during both syngeneic and allogeneic pregnancy, raising the possibility that the female pattern of hyporesponsiveness facilitates fetal survival by reducing the maternal immune response to fetal antigens and alloantigens during pregnancy.

Animals↗
PubMed1981

Local cellular immunity in the draining lymph nodes of mice after immunization with histocompatibility alloantigens.

Mice immunized with allogeneic cells exhibit a local component of cellular immunity that is confined to lymph nodes draining the site of immunization. After immunization of C3H mice by skin grafting or by i.p. or footpad injection of F1 hybrid spleen cells, draining lymph nodes show increased responsiveness toward the immunizing histocompatibility determinants for at least 3 months after immunization. This local component of immunity is not detected in a traditional graft-versus-host (GVH) assay of splenomegaly. To demonstrate this immunity, we used a GVH assay in which pieces of whole lymph nodes were grafted onto F1 hybrid host kidneys. The enlargement of each grafted node piece is taken as the measure of its immunological responsiveness. We interpret our results to indicate that this node-onto-kidney assay detects the contribution of a relatively immobile donor cell population that exerts its effects in lymph nodes local to, but not distant from, the site of immunization.

Animals↗