Simulated shuttle egress: comparison of two Space Shuttle protective garments

BACKGROUND

In a previous study from our laboratory, we observed carbon dioxide (CO2) accumulation in the helmet of the NASA Launch and Entry Suit (LES) during a simulated emergency egress from the Space Shuttle. Of 12 subjects, 8 were unable to complete the egress simulation with a G-suit inflation pressure of 1.5 psi. The purpose of this report was to compare CO2 accumulation and egress walking time in the new Advanced Crew Escape Suit (ACES) with that in the LES.

METHODS

Four male subjects who previously were unable to complete the egress in the LES performed a simulated egress while wearing the ACES with the G-suit inflated to 1.5 psi. The egress simulation consisted of 6 min of seated rest, 2 min of standing, and 5 min of walking on a treadmill at 1.56 m x s(-1) (3.5 mph) and 0% grade. The helmet visor was closed with the subjects receiving 100% oxygen throughout the simulation. Inspired CO2 and walking time were measured.

RESULTS

The rate of CO2 accumulation was significantly less (ACES: 0.53 +/- 0.03, LES: 1.07 +/- 0.15 %CO2 x min(-1); p = 0.05) and walk time was greater in the ACES (ACES: 5.0 +/- 0.0, LES: 2.7 +/- 0.2 min; p = 0.002).

CONCLUSIONS

Changes in the design of the ACES from the LES resulted in a decreased rate of CO2 accumulation and an improved egress walking time compared with the LES.

Activity of the leukocyte NADPH oxidase in whole neutrophils and cell-free neutrophil preparations stimulated with long-chain polyunsaturated fatty acids

Fish oils are known for their anti-inflammatory effects. In this paper we investigated the influence of eicosapentaenoic acid and docosahexaenoic acid (omega-3 fatty acids), as well as docosapentaenoic acid, a metabolic product of omega-3 fatty acid metabolism, on O2(-)-production catalyzed by the NADPH oxidase in whole neutrophils and in a cell-free system consisting of neutrophil membranes and cytosol. As a standard we used arachidonic acid (an omega-6 fatty acid) found in a high proportion in the Western diet, and known as an effective activator of the oxidase in both systems. Our data show that with omega-3 fatty acids, the O2(-)-production in both systems is reduced as compared to the effect of arachidonic acid. The effects are more pronounced with increasing carbon chain length and increasing numbers of double bonds. Our results suggest another mechanism besides the inhibition of eicosanoid and cytokine production to explain the beneficial effects of fish oils in reducing inflammation.

Maximal exercise as a countermeasure to orthostatic intolerance after spaceflight

Previous investigators have suggested that maximal exercise performed 24 h before the end of bed rest, a spaceflight analog, restores prebed rest plasma volume, baroreflex responses, and orthostatic tolerance.

PURPOSE

In this case report, we examined the effect of a similar exercise protocol 24 h before a Shuttle landing on the orthostatic responses of four crewmembers (EX) after spaceflights of 8-14 d. Four additional crewmembers (CON) served as controls and did not perform exercise during the final day of the flight.

METHODS

Each crewmember performed a 10-min stand test approximately 10 d before launch (L-10) and within 1-2 h of landing (R+0). Cardiac stroke volume was measured (Doppler ultrasound) supine and during each min of standing for three EX and three CON subjects.

RESULTS

Preflight, all crewmembers completed the stand test and each group had similar heart rate and blood pressure responses. Postflight, all subjects also completed the 10-min stand test. Each group had similarly elevated supine and standing heart rates, elevated diastolic and mean arterial blood pressures, and reduced pulse pressures compared to L-10. However, postflight cardiac output, mean +/- SEM, (EX: 4.5+/-0.6 L x min(-1); CON: 3.1+/-0.3 L x min(-1)) and stroke volume (EX: 43+/-7 mL x beat; CON: 30+/-6 mL x beat) were higher after 10 min standing in the EX subjects compared to CON subjects.

CONCLUSIONS

For these four crewmembers, maximal exercise performed 24 h before landing may have helped maintain stroke volume but did not maintain heart rate and blood pressure responses during standing compared to preflight.

Total artificial nutrition is associated with major changes in the fecal flora

BACKGROUND

Animal studies have demonstrated dramatic changes in the intestinal flora during total enteral (TEN) or parenteral (TPN) nutrition.

AIM OF THE STUDY

To assess the impact of TEN and TPN on human intestinal microflora.

METHODS

Eight patients on fiber-free TEN, five patients on TPN, and ten controls were studied. Fecal bacteria were identified and numbered (logCFU/g feces), and fecal short-chain fatty acids (SCFAs) were measured in stool samples, by gas-liquid chromatography.

RESULTS

In TEN patients, compared to controls (P < 0.01), aerobes were increased (8.46 +/- 0.24) while anaerobes were decreased (5.79 +/- 0.84). In TPN patients, both aerobes and anaerobes were decreased compared to controls (5.64 +/- 0.27 and 5.31 +/- 1.09 respectively, P < 0.01). Total SCFAs were lower in TPN patients than in TEN patients (48.3 +/- 16.6 vs 118.6 +/- 24.1 mmol/kg, P < 0.05).

CONCLUSIONS

Both TPN and TEN induce modifications in the intestinal microflora. During TPN, a homogeneous decrease occurs in both aerobic and anaerobic bacteria. TEN decreases only anaerobic bacteria, while aerobic bacteria are increased. This imbalance may play a role in the pathophysiology of TEN-induced diarrhea.

Virtual reality as a distraction intervention for older children receiving chemotherapy

The purpose of this pilot study was to describe the perceived effectiveness and feasibility of using virtual reality (VR) as a distraction intervention for children, aged 10-17, receiving outpatient chemotherapy. Treatments for cancer are intensive and difficult to endure. Distraction interventions are effective because the individual concentrates on pleasant or interesting stimuli instead of focusing on unpleasant symptoms. VR is a computer-simulated technique allowing an individual to hear and feel stimuli that correspond with a visual image. Evaluation of the VR intervention demonstrated positive outcomes. Eighty-two percent of the children (n = 11) indicated the chemotherapy treatment with the VR was better than previous chemotherapy treatments. All subjects responded positively when asked if they would like to use the VR again. The intervention was easy to implement, did not require practice to be effective, and required minimal nursing time. Results from this pilot study suggest that VR as a distraction intervention has the potential to enhance positive clinical outcomes. This intervention warrants further investigation with both pediatric and adult populations.

Activation of retinoic acid receptor alpha is sufficient for full induction of retinoid responses in SK-BR-3 and T47D human breast cancer cells

Retinoid signaling via retinoic acid (RA) and retinoid X receptors (RARs and RXRs) regulates mammary epithelial cell growth and differentiation. Loss of RAR-beta might represent an early event during breast carcinogenesis. Higher differentiated, estrogen-dependent, estrogen receptor (ER)-positive (ER+) mammary carcinoma cells have been found to contain relatively high levels of RAR-alpha and to be responsive to retinoids, whereas most undifferentiated, estrogen-independent, ER-negative (ER-) cells are characterized by low RAR-alpha expression and by retinoid resistance. In contrast, RAR-gamma is detectable at equal levels in both ER+ and ER- cells. In the present investigation, we directly examined the relative contribution of the distinct retinoid receptors to the retinoid response of breast cancer cells by comparing the effects of low concentrations of specific retinoids, which selectively activate individual receptor subtypes, on growth, cell cycle distribution, apoptosis, and on the autoregulation of RAR-alpha and RAR-gamma in ER- SK-BR-3 and ER+ T47D breast cancer cells. In vitro growth activity was determined by using a colorimetric cell viability assay and analysis of cell cycle distribution, and apoptosis was performed by flow cytometry of propidium iodide-stained or fluorescent Annexin V-labeled cells, respectively, whereas expression of RAR-alpha and RAR-gamma was determined by Northern blotting. Both cell lines are retinoid sensitive and express high amounts of RAR-alpha, RAR-gamma, and RXR-alpha. RAR-alpha-selective compounds (AM80 and AM580) inhibit cell growth, induce G1 arrest, stimulate apoptosis, and up-regulate RAR-alpha and RAR-gamma mRNA as efficiently as RAR/RXR-pan-reactive (9-cis RA) and RAR-pan-reactive retinoids (all-trans RA, TTNPB). Remarkably, an RAR-alpha antagonist (Ro 41-5253) not only blocks the RAR-alpha-selective agonists but also the pan-reactive compounds. In contrast, RAR-13-selective (CD417), RAR-gamma-selective (CD437/AHPN), and RXR-alpha-selective (Ro 25-7386) retinoids exert no effects on the examined parameters. Thus, our results support the idea that RAR-alpha is the crucial receptor mediating the biological effects during retinoid signaling in both ER- SK-BR-3 and ER+ T47D human breast cancer cells.

Resting energy expenditure in chronic hepatitis C

BACKGROUND/AIMS

Hypermetabolism is considered to be of clinical interest in liver disease and in several chronic viral infections. Whether resting energy expenditure (REE) increases during chronic hepatitis C is not known. Our aims were: (a) to determine the metabolic state of patients with chronic hepatitis C, and (b) to evaluate the effects of interferon therapy on REE.

METHODS

Forty-seven patients and 20 controls were studied. Sixteen patients failed to respond to interferon and 12 patients stopped the treatment during the first 2 months for various reasons. The 19 responders all received 1 year of interferon. REE (indirect calorimetry) and fat-free mass (FFM, bioelectric impedance analysis) were evaluated before (day 0) and after 90, 180, and 360 days of interferon. The virus load was evaluated in patients before treatment.

RESULTS

On day 0, REE expressed as a ratio of FFM (REE/FFM) was higher in patients than in controls (129.2 +/- 14.7 vs 117.9 +/- 9.6 kJ kg FFM(-1) 24 h(-1), p<0.01), and was positively correlated with the viral load (r=0.45, p=0.01). On day 90, REE/FFM had significantly decreased in responders but it did not decrease in non-responders (p<0.01). In responders, REE/FFM on days 180 and 360 was similar to that of the controls.

CONCLUSIONS

Chronic hepatitis C induces hypermetabolism that is normalized by interferon therapy in responders. The underlying mechanisms of chronic hepatitis C-induced hypermetabolism and its clinical relevance remain to be determined.

Supine lower body negative pressure exercise during bed rest maintains upright exercise capacity

Bed rest and spaceflight reduce exercise fitness. Supine lower body negative pressure (LBNP) treadmill exercise provides integrated cardiovascular and musculoskeletal stimulation similar to that imposed by upright exercise in Earth gravity. We hypothesized that 40 min of supine exercise per day in a LBNP chamber at 1.0-1.2 body wt (58 +/- 2 mmHg LBNP) maintains aerobic fitness and sprint speed during 15 days of 6 degrees head-down bed rest (simulated microgravity). Seven male subjects underwent two such bed-rest studies in random order: one as a control study (no exercise) and one with daily supine LBNP treadmill exercise. After controlled bed-rest, time to exhaustion during an upright treadmill exercise test decreased 10%, peak oxygen consumption during the test decreased 14%, and sprint speed decreased 16% (all P < 0.05). Supine LBNP exercise during bed rest maintained all the above variables at pre-bed-rest levels. Our findings support further evaluation of LBNP exercise as a countermeasure against long-term microgravity-induced deconditioning.

Quality of life in long-term home enteral nutrition patients

BACKGROUND AND AIMS

Few data are available on the quality of life of home enteral nutrition (HEN) patients. This study was designed to assess both the quality of life of long-term HEN patients and the evolution of quality of life after initiation of HEN.

METHODS

Quality of life-related parameters were analysed in 38 patients (24M, 14F) aged 56 +/- 5 years who had been on HEN for more than 2 months (mean 25 +/- 5 months). Patients or close relatives were asked to answer a subjective assessment questionnaire, and patients with normal consciousness (n+ 24) answered the self-administered SF-36 and EuroQol questionnaires.

RESULTS

Since the initiation of HEN, patients had spent 1.9 +/- 0.5% of the time in the hospital, in 54% of cases because of HEN-related complications. Analysis of the generic questionnaires revealed poorer quality of life parameters in comparison to a general population, although better results were sometimes observed in younger patients (under 45 years), patients without cancer, and patients with more than one care-giver. Nevertheless, the patients' subjective assessment of the changes in their quality of life since beginning HEN was generally good, with most patients reporting improved or stable mental and physical well-being.

CONCLUSIONS

Quality of life is poor in HEN patients, but subgroups of patients who score better in some quality of life dimensions can be identified. Most patients describe an improvement in their quality of life following the initiation of HEN that needs to be confirmed by a prospective study.

Use of nutritional scores to predict clinical outcomes in chronic diseases

Many hospitalized patients are malnourished, and the relationship between malnutrition and patient outcome is well established. To determine which patients are at nutritional risks, clinical scores are probably more accurate than using a single nutritional parameter. Among the numerous scores published, both the Prognostic Nutritional Index and the Subjective Global Assessment were prospectively validated. One is based on objective measurements, whereas the second is based on medical history and physical examination. The Nutritional Risk Index has been used in many studies including the "Veterans Study." The Mini Nutritional Assessment is a promising score for evaluating malnutrition in the elderly. The development of nutritional scores for use by nurses may facilitate screening of a large number of hospitalized patients.

Inflight exercise affects stand test responses after space flight

PURPOSE

The purpose of this study was to determine whether exercise performed by Space Shuttle crew members during short-duration space flights (9-16 d) affects the heart rate (HR) and blood pressure (BP) responses to standing within 2-4 h of landing.

METHODS

Thirty crew members performed self-selected inflight exercise and maintained exercise logs to monitor their exercise intensity and duration. Two subjects participated in this investigation during two different flights. A 10-min stand test, preceded by at least 6 min of quiet supine rest, was completed 10-15 d before launch (PRE) and within 4 h of landing (POST). Based upon their inflight exercise records, subjects were grouped as either high (HIex: > or = 3 times/week, HR > or = 70% HRmax, > or = 20 min/session, N = 11), medium (MEDex: > or = 3 times/week, HR < 70% HRmax, > or = 20 min/session, N = 10), or low (LOex: < or = 3 times/week, HR and duration variable, N = 11) exercisers. HR and BP responses to standing were compared between groups (ANOVA, P < or = 0.05).

RESULTS

There were no PRE differences between the groups in supine or standing HR and BP. Although POST supine HR was similar to PRE, all groups had an increased standing HR compared with PRE. The increase in HR upon standing was significantly greater after flight in the LOex group (36 +/- 5 bpm) compared with HIex or MEDex groups (25 +/- 1 bpm; 22 +/- 2 bpm). Similarly, the decrease in pulse pressure (PP) from supine to standing was unchanged after space flight in the MEDex and HIex groups but was significantly greater in the LOex group (PRE: -9 +/- 3; POST: -19 +/- 4 mm Hg).

CONCLUSIONS

Thus, moderate to high levels of inflight exercise attenuated HR and PP responses to standing after space flight.

Involvement of nuclear steroid/thyroid/retinoid receptors and of protein kinases in the regulation of growth and of c-erbB and retinoic acid receptor expression in MCF-7 breast cancer cells

Nuclear steroid/thyroid/retinoid receptors and c-erbB membrane receptor tyrosine kinases control epithelial growth and differentiation. Retinoid receptors can dimerize with the vitamin D receptor, the glucocorticoid receptor or the thyroid receptor. Furthermore, multiple c-erbB receptor dimers have been identified. It has been shown that some of these receptor pathways communicate with each other via cross-connected regulatory networks. Molecular interactions between retinoid receptors or estrogen receptors (ER) and c-erbB-2, and between ER and retinoic acid receptor(RAR)-alpha have been reported. Here, we demonstrate the effects of steroids/thyroids/retinoids and of activators of protein kinase A (forskolin, Forsk) and C (12-O-tetradecanoylphorbol-13-acetate, TPA), on growth and expression of c-erbB and RARs in MCF-7 breast cancer cells, which contain high levels of RAR-alpha and -gamma, and which express significant amounts of c-erbB-2 and -3. All trans-retinoic acid (tRA), the anti-estrogen ICI 182 780 (ICI), Forsk and TPA reduced, whereas triiodothyronine and 17beta-estradiol (E2) stimulated cell growth. Flow cytometry revealed that tRA and E2 reduced c-erbB-2 and -3, whereas tamoxifen, Forsk and TPA up-regulated c-erbB-2. c-erbB-3 was co-regulated with c-erbB-2. Northern analysis demonstrated that RAR-alpha was down-regulated by dexamethasone, ICI, and TPA, whereas vitamin D3 and E2 up-regulated RAR-alpha. RAR-gamma expression was less responsive to such treatment, being reduced only by ICI and Forsk. These data indicate that nuclear receptor and protein kinase signaling communicate with each other and control the expression of RARs and c-erbB receptors. Efficient growth control requires the coordinated interplay of both receptor systems.

A comparison of the bioavailabilities of oral and intravenous ethanol in healthy male volunteers

OBJECTIVES

Ethanol (EtOH), the antidote for methanol and ethylene glycol, is administered by the oral (PO) and intravenous (IV) routes. Serum concentrations (SCs) of 100 mg/dL or more are targeted for clinical effect. This study was completed to validate the assumption that there are minimal differences in SC achieved between these two routes.

METHODS

Twenty healthy male volunteers were randomized to receive either PO or IV EtOH. Subjects abstained from EtOH for 48 hours before each phase. After a seven-day washout period, the subjects crossed over to the other group. Inclusion criteria were no history of medical problems, age between 21 and 40 years, and actual body weight within 10% of ideal weight. Baseline EtOH SCs were obtained before participation in each phase. Two hours after a standard breakfast, the subjects received 700 mg/kg of PO or IV EtOH. PO EtOH was administered as a 20% solution in juice over 10 minutes. IV EtOH, controlled by an infusion pump, was administered as a 10% solution over 30 minutes. Blood was drawn for EtOH SCs at 45, 75, 105, 135, 165, 225, 285, and 345 minutes after start of the dose.

RESULTS

All initial EtOH SCs were 0. EtOH SCs were higher after IV administration. Mean peak SC was 103.6 mg/dL after IV administration and 71.3 mg/dL after PO administration (p<0.0001). Mean time to peak was 46.5 minutes after IV administration and 103.5 minutes after PO administration (p<0.0001). Total area under the curve was 17,440 min-mg/dL after IV administration and 13,875 min-mg/dL after PO administration (p<0.003). The order of treatments did not affect results (p>0.1).

CONCLUSION

Significant differences exist between the SCs of EtOH as well as the times to peak SC after PO and IV administrations.

Biomarkers of liver regeneration allow early prediction of hepatic recovery after acute necrosis

Acute toxic hepatic necrosis is common and may be fatal. Predicting clinical outcome may be aided by following serum markers that could indicate recovery or may signify massive (substantial) destruction of functional liver mass. Previously, in a published case of chloroform poisoning, we serially assayed serum biomarkers of hepatocellular necrosis (aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, lactate dehydrogenase) and markers of hepatocellular regeneration (alpha-fetoprotein, retinol-binding protein, gamma-glutamyl transferase, and des-gamma-carboxyprothrombin). We noted a decline in necrotic markers and a synchronous elevation in regenerative markers, which could be suggestive of a favorable outcome in similar cases. We now report 6 Amanita mushroom poisonings with favorable outcome and 2 fatal acetaminophen poisonings in which the same markers were observed. Our results further support our hypothesis that a sustained decline in serum markers of hepatocyte necrosis with a concurrent elevation in regenerative markers could aid in prediction of favorable outcome in patients with acute liver injury.

Teaching emergency medicine residents evidence-based critical appraisal skills: a controlled trial

STUDY OBJECTIVES

To compare the performance of an evidence-based medicine (EBM) approach and a traditional approach to teaching critical appraisal skills to emergency medicine residents.

METHODS

This was a prospective, case-controlled trial of 32 emergency medicine residents (16 control and 16 intervention). Intervention residents were exposed to a monthly, 1-hour journal club using an EBM approach to critical appraisal over the course of 1 year. Control residents were exposed to a traditional, unstructured journal club, also monthly. Both groups were given a factitious article to evaluate in an essay format before and after the 12-month study period. The Wilcoxon rank sum test was used to compare mean improvement in test scores for each group.

RESULTS

The mean improvement in test scores was 1.80 for the control group and 1.53 for the intervention group; these values were not significantly different (P =.90). The difference in mean change in test score between the 2 groups was.27 points.

CONCLUSION

Compared with a traditional approach, an EBM approach to teaching critical appraisal did not appear to improve the critical appraisal skills of emergency medicine residents. However, because of the small number of subjects studied, small differences in critical appraisal skill improvement cannot be ruled out.

Inhibition of proliferation and induction of apoptosis in soft tissue sarcoma cells by interferon-alpha and retinoids

Uncontrolled proliferation and a defect of apoptosis constitute crucial elements in the development and progression of tumours. Among many other biological response modifiers known to influence these mechanisms, the efficacy of retinoids and interferons in the treatment of various malignant entities is currently matter of discussion. In the present study, we have investigated the effects of 9-cis-retinoic acid (9cRA), 13-cis-retinoic acid (13cRA), all-trans-retinoic acid (tRA) and interferon-alpha on proliferation and apoptosis of human soft tissue sarcoma (STS) cell lines HTB-82 (rhabdomyosarcoma), HTB-91 (fibrosarcoma), HTB-92 (liposarcoma), HTB-93 (synovial sarcoma) and HTB-94 (chondrosarcoma) in relation to p53 genotype as well as p53 expression. HTB-91, HTB-92 and HTB-94 STS cells exhibited mutant p53, whereas wild-type p53 was found in HTB-93 STS cells, and a normal p53 status in HTB-82 STS cells, carrying a silent point mutation only. Interferon-alpha, irrespective of p53 status, inhibited the proliferation of all five cell lines dose- and time-dependently. Similarly, 9cRA, 13cRA and tRA decreased the proliferation of HTB-82 and HTB-93 STS cells, whereas the proliferation of p53-mutated HTB-91, HTB-92 and HTB-94 STS cells remained unchanged. Furthermore, only 9cRA and tRA were capable of inducing apoptosis in HTB-82 and HTB-93 STS cells, whereas HTB-91, HTB-92 and HTB-94 STS cells did not undergo apoptosis under the influence of 9cRA or tRA. Retinoic acid receptor (RAR)-alpha and RAR-beta mRNA were not detectable by Northern blot analysis in the five STS cell lines, whereas mRNA for the universal retinoic acid receptor, RAR-gamma, was expressed in all STS cell lines indicating that retinoid resistance was not associated with a lack of RAR expression. Apoptosis was not induced by interferon-alpha or 13cRA in any of the five STS cell lines tested. Our results indicate that within the panel of tested STS cell lines, inhibition of proliferation and induction of apoptosis result from different mechanisms which differ in their dependence upon the presence of intact p53.

Expression of c-erbB-4/HER4 is regulated in T47D breast carcinoma cells by retinoids and vitamin D3

Nuclear steroid/retinoid and memgbrane c-erbB receptor tyrosine kinase signaling control proliferation and differentiation of mammary epithelial cells. Recently, we reported that retinoic acids are efficient repressors of c-erbB-2 and -3, but not of c-erbB-1 gene expresson. Here we demonstrate that retinoid acid- mediated growth inhibition is accompanied with reduced expression of c-erbB-4/HER4 in T47D breast cancer cells as determined by FACS, Western, and RT-PCR. All-trans and 9-cis retinoic acid reduce c-erbB-4 expression to 30%-60% of control, depending on the concentration. Dexamethasone (Dex) is inactive on D3 (D3), in contrast, acts as a strong inducer, elevation more that twofold at the mRNA, but does not significantly affect cell growth. We concolude that retinoic acids are efficient growth inhibitors and repressors of cell growth and c-erbB-4, whereas D3 represents a highly efficient inducer of c-erbB-4 expression with affecting cell proliferation.

Retinoids control the expression of c-erbB receptors in breast cancer cells

Nuclear retinoid and membrane c-erbB receptors participate in signal transduction systems that control mammary epithelial cell proliferation and differentiation. Recently, we demonstrated that c-erbB receptor activation stimulates retinoic acid receptor-alpha expression. We now report that retinoids reduce SK-BR-3 breast cancer cell growth by inhibiting the cell cycle and by inducing apoptosis. This is accompanied with reduced c-erbB expression as determined by FACS, Western, Northern, RT-PCR, and reporter assays. All-trans (ATRA) and 9-cis retinoic acid (9cRA) reduce c-erbB-1 protein to 50-100%, c-erbB-2 to 20-30%, and c-erbB-3 to 10-50% of control, depending on the concentration, respectively, without influencing the tyrosine phosphorylation status. Down-regulation of c-erbB-2 and -3 was seen at all levels analyzed, whereas c-erbB-1 mRNA remained unchanged. Retinoic acid-mediated down-regulation of growth and c-erbB-2 and -3 expression was also seen in MCF-7 cells. We conclude that retinoic acids are efficient repressors of c-erbB-2 and -3 gene expression, whereas c-erbB-1 is not markedly affected.

Effects of retinoic acid and fenretinide on the c-erbB-2 expression, growth and cisplatin sensitivity of breast cancer cells

We investigated the effects of all-trans retinoic acid (ATRA) and fenretinide (4-HPR) on c-erbB-2 expression in SK-BR-3, BT-474 and MCF-7 breast cancer cells and on the growth, differentiation, apoptosis and cisplatin (CDDP) sensitivity of SK-BR-3 cells. It has been reported that oestrogen inhibits c-erbB-2 in oestrogen receptor-positive breast cancer cells. Using ELISA, Western and Northern analysis we have demonstrated that ATRA and 4-HPR exert similar effects down-regulating c-erbB-2 protein and mRNA in c-erbB-2-overexpressing SK-BR-3 and BT-474 and in normally expressing MCF-7 cells. Both retinoids inhibit SK-BR-3 cell growth. ATRA induces cellular enlargement and flattening, suggesting epithelial differentiation. 4-HPR causes nuclear and cytoplasmic condensation, DNA fragmentation and externalization of phosphatidylserine, indicating apoptosis. c-erbB-2 expression/activity has been linked to sensitivity against CDDP. Therefore, combinations of ATRA or 4-HPR with CDDP were tested for their anti-proliferative activity. Retinoid-conditioned cells were either exposed to retinoid and CDDP (schedule I, 'continuous retinoid treatment') or to CDDP alone (schedule II, 'retinoid pretreatment'). This retinoid-conditioning followed by CDDP +/- retinoid yields stronger growth inhibition compared with unconditioned cells, which were exposed to CDDP +/- retinoid (schedule III, 'no retinoid pretreatment'). The inefficacy of schedule III indicates that retinoid-conditioning is essential for the improvement of the antiproliferative effect. The interactions in schedules I and II are synergistic for ATRA and CDDP, but slightly antagonistic for 4-HPR and CDDR However, 4-HPR + CDDP is more effective in growth inhibition than each drug alone.

Gatekeepers: a missed opportunity for safe transport

OBJECTIVE

To assess whether contact with a health care provider or gatekeeper increases the use of an ambulance for patients with acute chest pain.

METHODS

A convenience sample of adults > or =40 years of age presenting with a chief complaint of chest pain were interviewed by trained personnel regarding transport used to come to the ED. The study was performed at the ED of an urban university hospital. Patients with hemodynamic instability and those receiving thrombolytics or emergency angioplasty were excluded. Patients were asked about access to a primary health care provider and contact with a provider regarding this ED visit, including instructions given for transportation.

RESULTS

Of the 450 interviewed patients, 42% arrived by ambulance. Those who had contact with a health care provider prior to the ED visit were less likely to come by ambulance than those without contact, 31% vs 51% (p < 0.001). Of the patients who had cardiac enzymes obtained to work up for their chest pain, 34% with health provider contact vs 57% without health provider contact arrived by ambulance (p < 0.001). Of those with acute myocardial infarction, 30% with health provider contact vs 66% without health provider contact came by ambulance (p < 0.03). Patients who recalled transport instructions from their providers tended to follow those instructions. The majority of patients who recalled no specific transport instructions arrived by personal automobile.

CONCLUSION

Of patients presenting to an ED for evaluation of chest pain, those who made contact with a health care provider were less likely to arrive via ambulance.

Definition of emergency medicine

This SAEM position paper clarifies the role of emergency medicine in health care delivery. It builds upon the working definition of emergency medicine developed by the American College of Emergency Physicians in 1994 by describing the health care role of emergency physicians (EPs). EPs are first-contact providers who care for all patients regardless of age, gender, time of presentation, or ability to pay. They remain the only continuously accessible specialty for patients seeking help and solace in the health care system. They are an essential link in the health care continuum between primary care physicians, specialists, the out-of-hospital system, the patient, inpatient services, and communication services. The EP's role is in organizing and monitoring the emergency care delivery system. Part of this role is to better align the health care provider training and ability with the specific medical needs of a patient. The emergency health care system remains the essential medical safety net for all individuals needing care in this country.

Cocaine balloon aspiration: successful removal with bronchoscopy

Ingestion of balloons containing illicit substances along with the potential toxic sequelae associated with these ingestions have been described in the literature. This report describes the successful bronchoscopic retrieval of a cocaine balloon after aspiration. A 39-year-old man was witnessed swallowing several balloons that were thought to contain heroin. Shortly after ingestion, the patient became unconscious and required nasotracheal intubation. Before intubation, several balloons were removed from the oropharynx. Naloxone 4 mg was administered en route to the emergency department (ED). Following naloxone, the patient awoke and became agitated and combative. On arrival in the ED, midazolam, succinylcholine, and vecuronium were required to manage his combativeness. Vital signs were: heart rate, 130 beats/min; blood pressure, 128/86 mm Hg; respirations, 12 breaths/min; temperature, 96.5 degrees F. A balloon and balloon tip were removed during lavage. Whole bowel irrigation with a polyethylene glycol electrolyte solution was initiated. A right upper lobe infiltrate was identified on chest X-ray and aspiration of a balloon was suspected. At bronchoscopy, a small yellow, intact balloon visualized in the basilar segment of the right lower lobe was removed. Toxicologic analysis of the balloon contents found cocaine. The rest of the patient's hospital course was unremarkable and he was discharged 5 days after admission. This case brings to light the potential concerns, such as respiratory compromise, associated with aspiration of small balloons in the body stuffer. Additionally, the potential for the development of toxicity if the balloon ruptures and toxin absorption occurs through through the lungs should be considered. Emergency physicians and toxicologists should be aware of this significant complication of packet ingestion in the body packer or stuffer and be prepared to intervene early during the course of the patient's treatment.

Frequent users of the emergency department: can we intervene?

OBJECTIVE

To determine whether the use of individualized patient care plans and multidisciplinary case management would decrease ED utilization by frequent ED users.

METHODS

The authors performed a prospective, randomized clinical trial of the impact of a care plan on ED use by adults with frequent ED visits. Patients with > 10 ED visits to a university hospital in 1993 were identified. Patients were matched for age, sex, and number of visits and then randomized into 2 groups. The control group received standard emergency care. The treatment group was managed by a multidisciplinary team and treated in the ED according to individualized care plans. ED use was tracked at the university hospital and at the other 5 community hospitals in the city.

RESULTS

Of the 70 enrolled patients, 25 of 37 control patients and 27 of 33 treatment patients made visits to the university hospital during the 1-year study period. Only those patients with follow-up visits were included in the data analysis. Patients remaining in the control group made 247 total visits (range 1-65) to the university hospital and 179 total visits (range 0-38) to the community hospitals during the study period. Patients in the treatment group made 320 total visits (range 1-72) to the university hospital and 254 total visits (range 0-135) to the community hospitals during the study period. There was no significant difference in the median number of visits made to either the university hospital or the community hospitals by the patients in the control group and those in the treatment group.

CONCLUSIONS

The use of individualized care plans and case management did not significantly decrease ED utilization by frequent ED users. However, the impact of individualized care plans and case management on other quality-of-care measures (e.g., patient satisfaction, ED length of stay, hospitalizations, primary care visits, and health care costs) remains to be determined.