STAT3 protects hematopoietic stem cells by preventing activation of a deleterious autocrine type-I interferon response

Hematopoietic stem and progenitor cells (HSPCs) maintain blood-forming and immune activity, yet intrinsic regulators of HSPCs remain elusive. STAT3 function in HSPCs has been difficult to dissect as Stat3-deficiency in the hematopoietic compartment induces systemic inflammation, which can impact HSPC activity. Here, we developed mixed bone marrow (BM) chimeric mice with inducible Stat3 deletion in 20% of the hematopoietic compartment to avoid systemic inflammation. Stat3-deficient HSPCs were significantly impaired in reconstitution ability following primary or secondary bone marrow transplantation, indicating hematopoietic stem cell (HSC) defects. Single-cell RNA sequencing of Lin-ckit+Sca1+ BM cells (LSKs) revealed aberrant activation of cell cycle, p53, and interferon (IFN) pathways in Stat3-deficient HSPCs. Stat3-deficient LSKs accumulated γH2AX and showed increased expression of DNA sensors and type-I IFN (IFN-I), while treatment with A151-ODN inhibited expression of IFN-I and IFN-responsive genes. Further, the blockade of IFN-I receptor signaling suppressed aberrant cell cycling, STAT1 activation, and nuclear p53 accumulation. Collectively, our results show that STAT3 inhibits a deleterious autocrine IFN response in HSCs to maintain long-term HSC function. These data signify the importance of ensuring therapeutic STAT3 inhibitors are targeted specifically to diseased cells to avoid off-target loss of healthy HSPCs.

Natural History of Histopathologic Changes in Cardiomyopathy of Golden Retriever Muscular Dystrophy

Background

Duchenne muscular dystrophy (DMD) is an X-linked inherited myopathy that causes progressive skeletal and cardiac muscle disease. Heart lesions were described in the earliest DMD reports, and cardiomyopathy is now the leading cause of death. However, diagnostics and treatment for cardiomyopathy have lagged behind those for appendicular and respiratory skeletal muscle disease. Most animal model studies have been done in the mdx mouse, which has a relatively mild form of cardiomyopathy. Dogs with the genetically homologous condition, Golden Retriever muscular dystrophy (GRMD), develop progressive cardiomyopathy analogous to that seen in DMD. Previous descriptive studies of GRMD cardiomyopathy have mostly been limited to selective sampling of the hearts from young dogs.

Methods and Results

We systematically assessed cardiac lesions in 31 GRMD and carrier dogs aged 3 to 76 months and a separate cohort of 2–10-year-old normal hounds. Both semi-quantitative lesion scoring and quantitation of the cross-sectional area of fibrosis distinguished dogs with GRMD disease from normal dogs. The carriers generally had intermediate involvement but had even greater fibrosis than GRMD dogs. Fatty infiltration was the most prominent feature in some older GRMD dogs. Vascular hypertrophy was increased in GRMD dogs and correlated positively with lesion severity. Purkinje fiber vacuolation was also increased but did not correlate with lesion severity. Histopathologic changes correlated with late gadolinium enhancement on cardiac MRI.

Conclusion

These features are generally compatible with those of DMD and further validate GRMD as a useful model to study cardiomyopathy pathogenesis and treatment. Additionally, the nature of some degenerative lesions suggests that functional hypoxia or non-thrombotic ischemia may contribute to disease progression.

Do written diagnosis-treatment recommendations on microbiological test reports improve the management of Staphylococcus aureus bacteremia? A single-center, retrospective, observational study

The objective of this study was to assess the impact of microbiological test reports that provide specific written recommendations on the appropriate management of Staphylococcus aureus bacteremia (SAB). We performed a retrospective analysis of laboratory and clinical data of all SAB patients treated at one German University hospital, 2012-2015. Among 467 included patients, methicillin-resistant S. aureus (MRSA) accounted for 15.2% of all SAB cases. All-cause in-hospital mortality was 25.2%, and was significantly elevated in individuals aged >55 years, in MRSA bacteremia and if the source of infection remained unidentified. Focus identification was achieved in 71.1%, with the most prevalent foci being catheter-associated bloodstream infection (23.1%), soft tissue infection (15.4%), osteomyelitis (5.1%) and endocarditis (4.9%). Standardized written recommendations on microbiological test reports led to a significant increase of transesophageal echocardiography, additional imaging studies for focus identification and more frequent follow-up blood cultures, but no significant effect on mortality was observed.

Trypanosoma cruzi infection in a zoo-housed red panda in Kansas

A 9-y-old, zoo-housed, male red panda (Ailurus fulgens) became progressively lethargic and inappetent over a 1-wk period. Physical examination was unremarkable. A complete blood count showed mild normocytic, normochromic, non-regenerative anemia with the presence of trypomastigote organisms, consistent with a Trypanosoma sp. The organism was confirmed later as Trypanosoma cruzi lineage TcI via PCR and genome sequencing. The panda was initially treated supportively; however, its clinical status within 24 h from presentation deteriorated, and euthanasia was elected. Autopsy showed severe systemic T. cruzi infection with the presence of amastigotes in the heart, brain, peripheral nerves, skeletal muscles, tongue, liver, and testes. We used genome sequencing and serology in identifying the agent.

ESPEN guidelines on definitions and terminology of clinical nutrition

BACKGROUND

A lack of agreement on definitions and terminology used for nutrition-related concepts and procedures limits the development of clinical nutrition practice and research.

OBJECTIVE

This initiative aimed to reach a consensus for terminology for core nutritional concepts and procedures.

METHODS

The European Society of Clinical Nutrition and Metabolism (ESPEN) appointed a consensus group of clinical scientists to perform a modified Delphi process that encompassed e-mail communication, face-to-face meetings, in-group ballots and an electronic ESPEN membership Delphi round.

RESULTS

Five key areas related to clinical nutrition were identified: concepts; procedures; organisation; delivery; and products. One core concept of clinical nutrition is malnutrition/undernutrition, which includes disease-related malnutrition (DRM) with (eq. cachexia) and without inflammation, and malnutrition/undernutrition without disease, e.g. hunger-related malnutrition. Over-nutrition (overweight and obesity) is another core concept. Sarcopenia and frailty were agreed to be separate conditions often associated with malnutrition. Examples of nutritional procedures identified include screening for subjects at nutritional risk followed by a complete nutritional assessment. Hospital and care facility catering are the basic organizational forms for providing nutrition. Oral nutritional supplementation is the preferred way of nutrition therapy but if inadequate then other forms of medical nutrition therapy, i.e. enteral tube feeding and parenteral (intravenous) nutrition, becomes the major way of nutrient delivery.

CONCLUSION

An agreement of basic nutritional terminology to be used in clinical practice, research, and the ESPEN guideline developments has been established. This terminology consensus may help to support future global consensus efforts and updates of classification systems such as the International Classification of Disease (ICD). The continuous growth of knowledge in all areas addressed in this statement will provide the foundation for future revisions.

Diagnostic criteria for malnutrition - An ESPEN Consensus Statement

OBJECTIVE

To provide a consensus-based minimum set of criteria for the diagnosis of malnutrition to be applied independent of clinical setting and aetiology, and to unify international terminology.

METHOD

The European Society of Clinical Nutrition and Metabolism (ESPEN) appointed a group of clinical scientists to perform a modified Delphi process, encompassing e-mail communications, face-to-face meetings, in group questionnaires and ballots, as well as a ballot for the ESPEN membership.

RESULT

First, ESPEN recommends that subjects at risk of malnutrition are identified by validated screening tools, and should be assessed and treated accordingly. Risk of malnutrition should have its own ICD Code. Second, a unanimous consensus was reached to advocate two options for the diagnosis of malnutrition. Option one requires body mass index (BMI, kg/m(2)) <18.5 to define malnutrition. Option two requires the combined finding of unintentional weight loss (mandatory) and at least one of either reduced BMI or a low fat free mass index (FFMI). Weight loss could be either >10% of habitual weight indefinite of time, or >5% over 3 months. Reduced BMI is <20 or <22 kg/m(2) in subjects younger and older than 70 years, respectively. Low FFMI is <15 and <17 kg/m(2) in females and males, respectively. About 12% of ESPEN members participated in a ballot; >75% agreed; i.e. indicated ≥7 on a 10-graded scale of acceptance, to this definition.

CONCLUSION

In individuals identified by screening as at risk of malnutrition, the diagnosis of malnutrition should be based on either a low BMI (<18.5 kg/m(2)), or on the combined finding of weight loss together with either reduced BMI (age-specific) or a low FFMI using sex-specific cut-offs.

A history of the term radical behaviorism: From Watson to Skinner

This paper describes the origins and evolution of the term radical behaviorism. John B. Watson's coining of behaviorism in 1913 is presented first, followed by a discussion of the uses of "radical" within psychology during these early years. When the term radical behaviorism first emerged in the early 1920s, its referent was Watson's behaviorism, most specifically his stance on consciousness. In the 1930s, B. F. Skinner described his own position with the term radical behaviorism in an unpublished manuscript, and then in 1945 first referred in print to his views as such. Today, radical behaviorism is generally applied to Skinner's views alone. The paper concludes with a brief discussion of a similarity in Watson's and Skinner's positions on consciousness, which seems a possible historical and philosophical connection between their respective radical behaviorisms.

The history of behavior analysis: Some historiography and a bibliography

This article has two main purposes. First, it introduces the discipline of historiography and, second, it provides a selected bibliography on the history of behavior analysis. In introducing the former in the context of the latter, four important methodological considerations involved in the process and product of historiography are described: The sources from which historical materials are drawn (i.e., primary, secondary, and tertiary) and three dimensions along which historiography is conducted and evaluated-internalist vs. externalist, great person vs. Zeitgeist, and presentist vs. historicist. Integrated throughout are four purposes for the historiography of behavior analysis, as well as an overview of the topics covered in the extant literature. The manuscript concludes with a listing of current bibliographic material by publication type and topic.

Sequences of spaced responses: Behavioral units and the role of contiguity

Sequences of temporally spaced responses were reinforced to investigate the effects of delay of reinforcement on the formation of functional behavioral units. In Experiment 1, rats' two- and three-response demarcated sequences of left and right lever presses were reinforced such that different response distributions would occur depending on whether the sequences themselves or individual responses were functional units. The matching law could thus be obeyed either by individual responses or by sequences, but not by both; intermediate results were possible. Both regular (nonretractable) and retractable levers were used; the retractable levers precluded the occurrence of insufficiently spaced responses. At a minimum interresponse time of 5 s for regular levers and 7 s for retractable ones, matching results were intermediate, with greater evidence of sequence conditionability in the two-response sequences than in the three-response sequences. In Experiment 2, the required minimum interresponse spacing for two-response retractable-lever sequences was varied in an attempt to locate the sequence matching threshold. This attempt was unsuccessful, but the sequences (instead of individual responses) more closely obeyed the matching law. In the shortest spaced condition, conditional probability data on Lag 1 sequence emission order showed marked, highly similar patterning for all rats, indicating sequential control of the sequences. Post hoc definition of the behavioral unit in these studies is ambiguous. Although reinforcement contiguity was important, aspects of the results could support both molar- and molecular-level interpretations.

Esophageal varices in chronic intestinal insufficiency in absence of portal hypertension or liver cirrhosis: case report

We report the case of a 62-year-old man with short-bowel syndrome, referred for intestinal transplantation, who had esophageal varices (EV) due to superior vena cava (SVC) thrombosis. Pretransplantation work-up revealed protein S deficiency. Results of liver function tests were normal. Upper endoscopy showed grade II to III EV in the upper and middle segments of the esophagus. Computed tomography demonstrated thrombosis of the jugular, subclavian, and SVC veins and marked collateral vessels in the chest. Transient elastography yielded normal findings. A liver biopsy specimen showed a normal aspect of the liver, without fibrosis or liver cirrhosis. Presence of EV in a patient with chronic intestinal insufficiency may be related to collateral venous circulation associated with SVC thrombosis in the absence of portal hypertension. In this situation, an isolated intestinal graft is indicated.

Consensus definition of sarcopenia, cachexia and pre-cachexia: joint document elaborated by Special Interest Groups (SIG) "cachexia-anorexia in chronic wasting diseases" and "nutrition in geriatrics"

Chronic diseases as well as aging are frequently associated with deterioration of nutritional status, loss muscle mass and function (i.e. sarcopenia), impaired quality of life and increased risk for morbidity and mortality. Although simple and effective tools for the accurate screening, diagnosis and treatment of malnutrition have been developed during the recent years, its prevalence still remains disappointingly high and its impact on morbidity, mortality and quality of life clinically significant. Based on these premises, the Special Interest Group (SIG) on cachexia-anorexia in chronic wasting diseases was created within ESPEN with the aim of developing and spreading the knowledge on the basic and clinical aspects of cachexia and anorexia as well as of increasing the awareness of cachexia among health professionals and care givers. The definition, the assessment and the staging of cachexia, were identified as a priority by the SIG. This consensus paper reports the definition of cachexia, pre-cachexia and sarcopenia as well as the criteria for the differentiation between cachexia and other conditions associated with sarcopenia, which have been developed in cooperation with the ESPEN SIG on nutrition in geriatrics.

Effects of virtual reality on symptom distress in children receiving chemotherapy

This study tested the premise that virtual reality (VR) as a distraction intervention could mitigate chemotherapy-related symptom distress in children with cancer aged 10-17 years. Cancer treatments 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 as a distraction intervention is both immersive and interactive. For this study the individual wore a Virtual IO(R) headset during a single intravenous chemotherapy treatment. Participants chose one of three commercially available, CD ROM-based scenarios: Magic Carpet, Sherlock Holmes Mystery, and Seventh Guest(R). An interrupted time series design with removed treatment was used to answer these research questions: (1) Is VR an effective distraction intervention for reducing chemotherapy-related symptom distress in children? and (2) Does VR have a lasting effect? The convenience sample consisted of 11 children receiving outpatient chemotherapy. The Symptom Distress Scale (SDS) and the State-Trait Anxiety Inventory for Children (STAIC-1) were used to measure the dependent variable of symptom distress. Repeated-measures ANOVA were used for data analysis. Data analysis of the SDS suggested that the VR intervention was effective at reducing the level of symptom distress immediately following the chemotherapy treatment (p <.10), but did not have a lasting effect. Analysis of the STAIC-1 demonstrated high levels of anxiety during the initial chemotherapy treatment that decreased during subsequent treatments. State anxiety levels were not influenced by the VR intervention. This study supports the application of VR as a distraction intervention.

Almond Replant Disease and Its Management with Alternative Pre-Plant Soil Fumigation Treatments and Rootstocks

Trials were conducted in orchards near Chico, CA and microplots near Parlier, CA to examine symptoms and control measures for a replant disease (RD) on almond (Prunus dulcis). In the orchard trials, areas with a recent history of severe RD were cleared, given soil fumigation treatments in the fall, and replanted with almond trees on various rootstocks the following winter. The replants in nonfumigated soil developed severe RD (stunting, wilting, chlorosis, defoliation) by the following summer, while those in most fumigated treatments remained healthy. Trees in nonfumigated soil developed smaller trunk diameters and fewer healthy roots ≤1 mm diameter, compared with the healthy trees. Almond developed RD on all rootstocks evaluated (Marianna 2624, Lovell, and Nemaguard), but the trees on Marianna 2624 were the most severely affected. Pre-plant tree-site (spot) fumigation treatments with methyl bromide (MB), chloropicrin (CP), 1,3-dichloropropene (1,3-D), 1,3-D + CP, iodomethane, and iodomethane + CP all prevented severe RD. Broadcast soil fumigation with CP also was effective, but broadcast MB and 1,3-D were ineffective. In microplots filled with RD-conducive soil, CP was more potent than MB for prevention of RD on Nemaguard peach. There was no association between nematodes and RD in orchard or microplot trials. The RD apparently was mediated by a biological agent(s) other than nematodes and can be prevented by appropriate fumigation with CP or other MB alternatives.

Emergency department management of mild traumatic brain injury in the USA

OBJECTIVE

To describe the emergency department (ED) management of isolated mild traumatic brain injury (TBI) in the USA and to examine variation in care across age and insurance types.

METHODS

A secondary analysis of ED visits for isolated mild TBI in the National Hospital Ambulatory Medical Care Survey 1998-2000 was performed. Mild TBI was defined by International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9) codes for skull fracture, concussion, intracranial injury (unspecified), and head injury (unspecified). Available ED care variables were analysed by patient age and insurance categories using multivariate logistic regression.

RESULTS

The incidence of isolated mild TBI cases attending ED was 153,296 per year, or 56.4/100,000 people. Of the patients with isolated mild TBI, 44.3% underwent computed tomography, 23.9% underwent other non-extremity, non-chest x rays, 17.1% received wound care and 14.1% received intravenous fluids. However, only 43.8% had an assessment of pain. Of those with documented pain, only 45.5% received analgesics in the ED. Nearly 38% were discharged without recommendations for specific follow up. Several aspects of ED care varied by age but not by insurance type.

CONCLUSION

Substantial ED resources are devoted to the care of isolated mild TBI. The present study identified deficiencies in and variation around several important aspects of ED care. The development of guidelines specific for mild TBI could reduce variation and improve emergency care for this injury.

Strength gains following different combined concentric and eccentric exercise regimens

BACKGROUND

Loss of muscle strength and cross-sectional area is a well-recognized consequence of spaceflight. Existing countermeasures have not been fully effective in preventing muscle weakness and atrophy in microgravity. Resistance exercise programs that consist of both eccentric and concentric actions have resulted in strength and muscle mass gains in ground-based studies.

HYPOTHESES

1) A concentric/eccentric combination exercise regimen (with a bias of either concentric or eccentric exercise) will result in a greater strength gain than concentric exercise alone; and 2) an eccentrically biased regimen will result in the greatest strength gain of all.

METHODS

The 31 subjects were randomly assigned to one of three isokinetic exercise groups (CON-ECC: 75% concentric and 25% eccentric; ECC-CON: 75% eccentric and 25% concentric; CON: 100% concentric); each subject trained the right leg 3 d per week for 5 wk. Pre- and post-training isokinetic concentric/ eccentric strength tests and DEXA scans assessed changes in muscle strength and/or mass.

RESULTS

All three groups showed an increase in eccentric muscle strength with the CON group showing the smallest gain (10.1%). Significantly larger gains were noted in the two combination groups (19.5%, 18.1%; p < 0.042), with the largest gains in eccentric strength. No significant change was noted in muscle mass.

CONCLUSIONS

A resistance exercise protocol which includes eccentric as well as concentric exercise, particularly when the eccentric exercise is emphasized, appears to result in greater strength gains than concentric exercise alone. Findings suggest eccentric exercise may be an important component of the in-flight resistance exercise protocol for long-duration spaceflight.

Fatigue is associated with high circulating leptin levels in chronic hepatitis C

BACKGROUND AND AIMS

Fatigue is a frequent and disabling symptom reported by patients with chronic hepatitis C (CHC). Its mechanism is poorly understood. Recent attention has focused on the role of leptin and energy expenditure in CHC. Our aims were to analyse fatigue in CHC and to determine its relationship with disease activity, resting energy expenditure (REE), circulating leptin, and tumour necrosis factor alpha (TNF-alpha).

METHODS

Seventy eight CHC patients, 22 healthy controls, and 13 primary biliary cirrhosis (PBC) patients underwent measurements of REE, body composition, leptin, and TNF-alpha. All subjects completed the fatigue impact scale (FIS) questionnaire. A liver biopsy and viral load measurements were performed in all patients.

RESULTS

Thirty eight of 78 CHC patients considered fatigue the worst or initial symptom of their disease. The fatigue score of patients was significantly higher than that of controls (53.2 (40.1) v 17.7 (16.9); p<0.0001) and was more pronounced in females (p=0.003). Leptin was increased significantly in CHC patients compared with controls (15.4 (20.7) v 6.4 (4.1) ng/ml; p<0.05). In CHC patients, the fatigue score correlated significantly with leptin corrected for fat mass (r=0.30, p=0.01). This correlation increased when the physical domain of fatigue was included (r=0.39, p=0.0009). Furthermore, a similar positive correlation was found in PBC patients (r=0.56, p=0.04). No correlation was found between fatigue and age, REE, liver function tests, viral load, or the METAVIR score in CHC patients.

CONCLUSIONS

Fatigue is present in CHC patients and is more pronounced in females. The FIS questionnaire is clinically relevant and may be useful for future therapeutic trials aimed at reducing fatigue. Fatigue may be partly mediated by leptin.

Invited review: gender issues related to spaceflight: a NASA perspective

This minireview provides an overview of known and potential gender differences in physiological responses to spaceflight. The paper covers cardiovascular and exercise physiology, barophysiology and decompression sickness, renal stone risk, immunology, neurovestibular and sensorimotor function, nutrition, pharmacotherapeutics, and reproduction. Potential health and functional impacts associated with the various physiological changes during spaceflight are discussed, and areas needing additional research are highlighted. Historically, studies of physiological responses to microgravity have not been aimed at examining gender-specific differences in the astronaut population. Insufficient data exist in most of the discipline areas at this time to draw valid conclusions about gender-specific differences in astronauts, in part due to the small ratio of women to men. The only astronaut health issue for which a large enough data set exists to allow valid conclusions to be drawn about gender differences is orthostatic intolerance following shuttle missions, in which women have a significantly higher incidence of presyncope during stand tests than do men. The most common observation across disciplines is that individual differences in physiological responses within genders are usually as large as, or larger than, differences between genders. Individual characteristics usually outweigh gender differences per se.

From single site to societal belief: the impact of pediatric oncology nursing research

This review describes the evolution of pediatric oncology nursing research over the past 25 years. It highlights practice-changing contributions from single-site studies and from multisite trials and discusses strategies for interdisciplinary collaboration. Technological advances that will alter the way in which studies are conducted and findings are disseminated will influence the future of nursing research. Studies implemented by pediatric nurse researchers will continue to influence practice and change how we, and others, view the experience of childhood cancer.

Outcome of patients treated with home enteral nutrition

BACKGROUND

The aims of this study were to prospectively analyze the 1-month mortality and long-term outcome of home enteral nutrition (HEN) patients in order to determine the benefits of this treatment.

METHODS

Between 1990 and 1996, 417 patients, aged 64 +/- 25 years, were discharged on HEN and followed up until December 31, 1998, when outcome was assessed, which allowed us to determine survival probabilities and conditions associated with survival.

RESULTS

The mean duration of HEN was 242 +/- 494 days, with a 24- to 103-month follow-up. Probabilities of being alive at 1 month, 1 year, and 5 years were 80%, 41.7%, and 25%, respectively. Factors associated with death were dementia, neurologic disease, head and neck cancer, AIDS, and age over 70 years. A total of 5.5% of patients remained dependent on HEN, 32.6% resumed full oral nutrition, 20.2% of patients died during the first month on HEN, and 35% died after more than 1 month on HEN (219 +/- 257 days). A total of 6.7% of patients stopped HEN for other reasons.

CONCLUSIONS

HEN provides well-tolerated long-term nutritional support in many patients. However, because of their likelihood of being old and the nature of the underlying disease, these patients as a group tend to have a modest prognosis. This calls for the determination of more accurate selection criteria, and the measurement of the impact of HEN on quality of life.

Ageing and muscle: the effects of malnutrition, re-nutrition, and physical exercise

Because of the metabolic changes caused by ageing, malnutrition is accompanied by a preferential loss of fat-free mass in the elderly, and it exaggerates the physiological loss of body cell mass, muscle mass and muscle function observed in the aged. Exercise training has positive anabolic effects even in the frail elderly, and may improve the effect of re-nutrition in malnourished elderly patients.

Simulated shuttle egress: role of helmet visor position during approach and landing

BACKGROUND

We previously reported that carbon dioxide (CO2) rapidly accumulates in the helmet of the NASA Launch and Entry Suit (LES) during a simulated egress from the Space Shuttle following 6 min of visor-closed seated rest to simulate approach and landing. The purpose of this study was to determine if CO2 accumulation and walking time in the LES would be improved by helmet visor-open rather than visor-closed seated rest prior to the performance of the simulated egress.

METHODS

Wearing the LES, 12 male subjects performed 4 laboratory egress simulations consisting of 6-min seated rest, 2-min stand, and 5-min walk at 1.56 m x s(-1) (3.5 mph). During seated rest, subjects sat either with the visor open, breathing room air until the visor was closed on standing, or with the visor closed for the duration of the simulation. For all visor-closed operations 100%, O2 was supplied. The G-suit was either deflated (0.0 psi) or inflated to 1.5 psi. Inspired CO2 and walking time were measured. Data were analyzed at the end of seated rest, standing, and after 5 min of walking at 0.0 psi or after 2 min of walking at 1.5 psi (>90% of data available).

RESULTS

Walk time was not different following visor-open (0.0 psi: 5.0 +/- 0.0; 1.5 psi: 3.4 +/- 0.3 min) or visor-closed (0.0 psi: 4.8 +/- 0.2; 1.5 psi: 3.5 +/- 0.4 min) seated rest at either G-suit pressure. Inspired CO2 levels were not different between the two conditions during walking at 5 min at 0.0 psi (p = 0.50; Open: 4.39 +/- 0.14; Closed: 4.48 +/- 0.18%) or at 2 min at 1.5 psi (p = 0.53; Open: 3.59 +/- 0.12; Closed: 3.65 + 0.21%).

CONCLUSIONS

Visor position during seated rest immediately preceding the egress walk had no effect on inspired CO2 or walking time.

[Atrophic polychondritis associated with ulcerative colitis]

We report the case of a 46-year-old patient in whom ulcerative colitis had been diagnosed three years ago. He was admitted to the hospital for swelling of the nose. Clinical course and complementary exams led us to diagnose atrophic polychondritis. Twelve cases of such an association have been published so far.

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.