Epigenetic processes associated with neonatal spinal transection

In early development, the spinal cord in healthy or disease states displays remarkable activity-dependent changes in plasticity, which may be in part due to the increased activity of brain derived neurotrophic factor (BDNF). Indeed, BDNF delivery has been efficacious in partially ameliorating many of the neurobiological and behavioral consequences of spinal cord injury (SCI), making elucidating the role of BDNF in the normative developing and injured spinal cord a critical research focus. Recent work in our laboratory provided evidence for aberrant global and locus-specific epigenetic changes in methylation of the Bdnf gene as a consequence of SCI. In the present study, animals underwent thoracic lesions on P1, with cervical and lumbar tissue being later collected on P7, P14, and P21. Levels of Bdnf expression and methylation (exon IX and exon IV), in addition to global methylation levels were quantified at each timepoint. Results indicated locus-specific reductions of Bdnf expression that was accompanied by a parallel increase in methylation caudal to the injury site, with animals displaying increased Bdnf expression at the P14 timepoint. Together, these findings suggest that epigenetic activity of the Bdnf gene may act as biomarker in the etiology and intervention effort efficacy following SCI.

Nasal airway inflammatory responses and pathogen detection in infants with cystic fibrosis

BACKGROUND

Detecting airway inflammation non-invasively in infants with cystic fibrosis (CF) is difficult. We hypothesized that markers of inflammation in CF [IL-1β, IL-6, IL-8, IL-10, IL-17A, neutrophil elastase (NE) and tumor necrosis factor (TNF-α)] could be measured in infants with CF from nasal fluid and would be elevated during viral infections or clinician-defined pulmonary exacerbations (PEx).

METHODS

We collected nasal fluid, nasal swabs, and hair samples from 34 infants with CF during monthly clinic visits, sick visits, and hospitalizations. Nasal fluid was isolated and analyzed for cytokines. Respiratory viral detection on nasal swabs was performed using the Luminex NxTAG® Respiratory Pathogen Panel. Hair samples were analyzed for nicotine concentration by reverse-phase high-performance liquid chromatography. We compared nasal cytokine concentrations between the presence and absence of detected respiratory viruses, PEx, and smoke exposure.

RESULTS

A total of 246 samples were analyzed. Compared to measurements in the absence of respiratory viruses, mean concentrations of IL-6, IL-8, TNF-α, and NE were significantly increased while IL-17A was significantly decreased in infants positive for respiratory viruses. IL-17A was significantly decreased and NE increased in those with a PEx. IL-8 and NE were significantly increased in infants with enteric pathogen positivity on airway cultures, but not P. aeruginosa or S. aureus. Compared to those with no smoke exposure, there were significantly higher levels of IL-6, IL-10, and NE in infants with detectable levels of nicotine.

CONCLUSIONS

Noninvasive collection of nasal fluid may identify inflammation in infants with CF during changing clinical or environmental exposures.

In children, the microbiota of the nasopharynx and bronchoalveolar lavage fluid are both similar and different

RATIONALE

Sputum and bronchoalveolar lavage fluid (BALF) are often obtained to elucidate the lower airway microbiota in adults. Acquiring sputum samples from children is difficult and obtaining samples via bronchoscopy in children proves challenging due to the need for anesthesia and specialized procedural expertise; therefore nasopharyngeal (NP) swabs are often used as surrogates when investigating the pediatric airway microbiota. In adults, the airway microbiota differs significantly between NP and BALF samples however, minimal data exist in children.

OBJECTIVES

To compare NP and BALF samples in children undergoing clinically indicated bronchoscopy.

METHODS

NP and BALF samples were collected during clinically indicated bronchoscopy. Bacterial DNA was extracted from 72 samples (36 NP/BALF pairs); the bacterial V1-V3 region of the 16S rRNA gene was amplified and sequenced on the Illumina Miseq platform. Analysis was performed using mothur software.

RESULTS

Compared to NP samples, BALF had increased richness and diversity. Similarity between paired NP and BALF (intra-subject) samples was greater than inter-subject samples (P = 0.0006). NP samples contained more Actinobacteria (2.2% vs 21%; adjusted P = 1.4 × 10^-6 ), while BALF contained more Bacteroidetes (29.5% vs 3.2%; adjusted P = 1.2 × 10^-9 ). At the genus level several differences existed, however Streptococcus abundance was similar in both sample types (NP 37.3% vs BAL 36.1%; adjusted P = 0.8).

CONCLUSION

Our results provide evidence that NP samples can be used to distinguish differences between children, but the relative abundance of organisms may differ between the nasopharynx and lower airway in pediatric patients. Studies utilizing NP samples as surrogates for the lower airway should be interpreted with caution.

Prevalence of headshaking within the equine population in the UK

REASON FOR PERFORMING STUDY

Headshaking in horses has been reported to be most commonly due to idiopathic neuropathic facial pain (trigeminal-mediated headshaking). The prevalence of headshaking in horses in the UK is unknown.

OBJECTIVES

To estimate owner-reported prevalence of headshaking in horses in the UK and to report their case background and disease characteristics, as reported by owners.

STUDY DESIGN

Cross-sectional web based owner questionnaire.

METHODS

The questionnaire was advertised online via social media, horse forums, veterinary websites and equestrian magazines from 17th June 2016, until >1000 responses had been obtained. All UK horse owners were eligible to complete the questionnaire, however only one questionnaire could be completed per owner.

RESULTS

The estimated prevalence of owner-reported headshaking in the sample population of horses (n = 1014), within the last year, was 4.6% (95% confidence interval 3.5-6.1), whereas 6.2% (95% confidence interval 4.9-7.9) of horses were reported by their owners to have shown signs of headshaking at any time-point since ownership. There was no association of sex or breed. Nineteen percent of headshaking horses were reported to show headshaking at rest. Fewer than one-third (30.2%, n = 19) of headshaking horses had been examined by a veterinarian for headshaking. Of horses seen by a veterinarian, the cause for headshaking remained unknown in the majority of cases (57.9% responses) and trigeminal-mediated headshaking was reported as a diagnosis in just one case.

MAIN LIMITATIONS

The accuracy in data reporting by horse owners was not verified in this study. There may be a potential for bias towards over-reporting due to the nature of survey participation.

CONCLUSIONS

Within this sample, owner-reported prevalence of signs of headshaking within the last year, in horses in the UK was 4.6%. Over two-thirds of owners of headshaking horses did not seek veterinary intervention for headshaking. Trigeminal-mediated headshaking was rarely reported by owners as a diagnosis.

Differential effects of hydrocortisone, prednisone, and dexamethasone on hormonal and pharmacokinetic profiles: a pilot study in children with congenital adrenal hyperplasia

Background

Little is known about the comparative effects of different glucocorticoids on the adrenal and growth hormone (GH) axes in children with congenital adrenal hyperplasia (CAH). We sought to compare the effects of hydrocortisone (HC), prednisone (PDN), and dexamethasone (DEX) in children with classic CAH and to investigate a potential role of pharmacogenetics.

Methods

Subjects were randomly assigned to three sequential 6-week courses of HC, PDN, and DEX, each followed by evaluation of adrenal hormones, IGF-1, GH, and body mass index (BMI). Single nucleotide polymorphism (SNP) analysis of genes in the glucocorticoid pathway was also performed.

Results

Nine prepubertal subjects aged 8.1 ± 2.3 years completed the study. Mean ACTH, androstenedione, and 17-hydroxyprogesterone (17-OHP) values were lower following the DEX arm of the study than after subjects received HC (p ≤ 0.016) or PDN (p ≤ 0.002). 17-OHP was also lower after HC than PDN (p < 0.001). There was no difference in IGF-1, GH, or change in BMI. SNP analysis revealed significant associations between hormone concentrations, pharmacokinetic parameters, and variants in several glucocorticoid pathway genes (ABCB1, NR3C1, IP013, GLCCI1).

Conclusions

DEX resulted in marked adrenal suppression suggesting that its potency relative to hydrocortisone and prednisone was underestimated. SNPs conferred significant differences in responses between subjects. Although preliminary, these pilot data suggest that incorporating pharmacogenetics has the potential to eventually lead to targeted therapy in children with CAH.

Raising the Level of Nursing Involvement in the National Precision Medicine Initiative: An Example

PURPOSE

The Precision Medicine Initiative (PMI) goal of ushering in a new and more effective era of health care that benefits all Americans requires two critical and interdependent components: a cohort assembly of 1 million or more Americans who reflect the diversity of the United States of America and an interdisciplinary workforce that includes nursing. The purpose of this article is to provide an example of nursing involvement in PM, specifically as related to gathering biospecimens (saliva) from vulnerable, understudied adolescents with disruptive behavior disorders and their family members.

SOURCE(S)

First, we provide a brief description of important concepts related to PM as well as current roles of nurses in PM. Then, we share lessons learned from our feasibility study aimed at increasing the diversity of our statewide cohort assembly that has provided biospecimens for the Indiana Biobank.

CONCLUSION

Nurses can definitely contribute to biobanks in support of the PMI. This article is a call to action for nurses to take their rightful place in PM.

Interest in health information exchange in ambulatory care: a statewide survey

OBJECTIVE

Assess the interest in and preferences of ambulatory practitioners in HIE.

BACKGROUND

Health information exchange (HIE) may improve the quality and efficiency of care. Identifying the value proposition for smaller ambulatory practices may help those practices engage in HIE.

METHODS

Survey of primary care and specialist practitioners in the State of Colorado.

RESULTS

Clinical data were commonly (always [2%], often [29%] or sometimes [49%]) missing during clinic visits. Of 12 data types proposed as available through HIE, ten were considered "extremely useful" by most practitioners. "Clinical notes/consultation reports," "diagnosis or problem lists," and "hospital discharge summaries" were considered the three most useful data types. Interest in EKG reports, diagnosis/problem lists, childhood immunizations, and discharge summaries differed among ambulatory practitioner groups (primary care, obstetrics-gynecology, and internal medicine subspecialties).

CONCLUSION

Practitioners express strong interest in most of the data types, but opinions differed by specialties on what types were most important. All providers felt that a system that provided all data types would be useful. These results support the potential benefit of HIE in ambulatory practices.

Stapled versus sutured gastrointestinal anastomoses in the trauma patient: a multicenter trial

BACKGROUND

Construction of gastrointestinal anastomoses utilizing stapling devices has become a familiar procedure. In elective surgery, studies have shown no significant differences in complications between stapled and sutured anastomoses. Controversy has recently arisen regarding the accurate incidence of complications associated with anastomoses in the trauma patient. The objective of this multi-institutional study was to determine whether the incidence of postoperative complications differs between stapled and sutured anastomoses following the emergent repair of traumatic bowel injuries.

METHODS

Using a retrospective cohort design, all trauma registry records from five Level I trauma centers over a period of 4 years were reviewed.

RESULTS

A total of 199 patients with 289 anastomoses were identified. A surgical stapling device was used to create 175 separate anastomoses, while a hand-sutured method was employed in 114 anastomoses. A complication was defined as an anastomotic leak verified at reoperation, an intra-abdominal abscess, or an enterocutaneous fistula. The mean abdominal Abbreviated Injury Scale score and Injury Severity Score were similar in the two cohort groups. Stapling and suturing techniques were evenly distributed in both small and large bowel repairs. Seven of the total 175 stapled anastomoses and none of the 114 hand-sewn anastomoses resulted in a clinically significant leak requiring reoperation (RR = undefined, 95% CI 1.08-infinity, p = 0.04). Each anastomotic leak occurred in a separate individual. Nineteen stapled anastomoses and four sutured anastomoses were associated with an intra-abdominal abscess (RR = 2.7, 95% CI 0.96-7.57, p = 0.04). Enterocutaneous fistula formation was not statistically associated with either type of anastomoses (stapled cohort = 3 of 175 and sutured cohort = 2 of 114). Overall, 22 (13%) stapled anastomoses and 6 (5%) sutured anastomoses were associated with an intra-abdominal complication (RR = 2.08, 95% CI 0.89-4.86, p = 0.076).

CONCLUSION

Anastomotic leaks and intra-abdominal abscesses appear to be more likely with stapled bowel repairs compared with sutured anastomoses in the injured patient. Caution should be exercised in deciding to staple a bowel anastomosis in the trauma patient.

Growth hormone regulates phosphorylation and function of CCAAT/enhancer-binding protein beta by modulating Akt and glycogen synthase kinase-3

Growth hormone (GH) regulates transcription factors associated with c-fos, including C/EBPbeta. Two forms of C/EBPbeta, liver-activating protein (LAP) and liver inhibitory protein (LIP), are dephosphorylated in GH-treated 3T3-F442A fibroblasts. GH-induced dephosphorylation of LAP and LIP is reduced when cells are preincubated with phosphatidylinositol 3'-kinase (PI3K) inhibitors. GH activates Akt and inhibits glycogen synthase kinase-3 (GSK-3). Lithium, a GSK-3 inhibitor, increases GH-dependent dephosphorylation of LAP and LIP. Both are in vitro substrates of GSK-3, suggesting that GSK-3 inactivation contributes to GH-promoted dephosphorylation of C/EBPbeta. Alkaline phosphatase increases binding of LAP homodimers and decreases binding of LIP homodimers to c-fos, suggesting that dephosphorylation of C/EBPbeta modifies their ability to bind DNA. Both alkaline phosphatase- and GH-mediated dephosphorylation comparably increase binding of endogenous LAP in 3T3-F442A cells. In cells overexpressing LAP and GSK-3, LAP binding decreases, suggesting that GSK-3-mediated phosphorylation interferes with LAP binding. Expression of constitutively active GSK-3 reduced GH-stimulated c-fos promoter activity. These studies indicate that PI3K/Akt/GSK-3 mediates signaling between GH receptor and the nucleus, promoting dephosphorylation of C/EBPbeta. Dephosphorylation increases binding of LAP complexes to the c-fos promoter and may contribute to the participation of C/EBPbeta in GH-stimulated c-fos expression.

p300 coactivates the adipogenic transcription factor CCAAT/enhancer-binding protein alpha

Despite the knowledge that CCAAT/enhancer-binding protein alpha (C/EBPalpha) plays an important role in preadipocyte differentiation, our understanding of how C/EBPalpha interacts with nuclear proteins to regulate transcription is limited. Based on the hypothesis that evolutionarily conserved regions are functionally important and likely to interact with coactivators, we compared the amino acid sequence of C/EBPalpha from different species (frog to human) and identified four highly conserved regions (CR1-CR4) within the transactivation domain. A series of amino-terminal truncations and internal deletion constructs were made creating forms of C/EBPalpha which lack single or multiple conserved regions. To determine which regions of the C/EBPalpha transactivation domain are important in its ability to induce spontaneous differentiation of 3T3-L1 preadipocytes, we infected preadipocytes with expression vectors encoding the C/EBPalpha conserved region mutants and observed their ability to induce differentiation. We found that CR2 fused to the DNA binding domain is able to induce spontaneous differentiation independent of the other conserved regions. However, CR2 was not necessary for the adipogenic action of C/EBPalpha because a combination of CR1 and CR3 can also induce adipogenesis. Because the transcriptional coactivator p300 participates in the signaling of many transcription factors to the basal transcriptional apparatus, we examined whether functional interaction exists between C/EBPalpha and p300. Cotransfection of p300 with p42C/EBPalpha results in a synergistic increase in leptin promoter activity, indicating that p300 acts as a transcriptional coactivator of C/EBPalpha. Analyses using C/EBPalpha conserved region mutants suggest that multiple regions (CR2 and CR3) of the C/EBPalpha transactivation domain functionally interact with p300.

Spectroelectrochemical sensing based on multimode selectivity simultaneously achievable in a single device. 9. Incorporation of planar waveguide technology

Incorporation of planar waveguide technology into a spectroelectrochemical sensor is described. In this sensor design, a potassium ion-exchanged BK7 glass waveguide was over-coated with a thin film of indium tin oxide (ITO) that served as an optically transparent electrode. A chemically selective film was spin-coated on top of the ITO film. The sensor supported five optical modes at 442 nm and three at 633 nm. Investigations on the impact of the ITO film on the optical properties of the waveguide and on the spectroelectrochemical performance of the sensor are reported. Sensing was based on the change in attenuation of light propagated through the waveguide resulting from an optically absorbing analyte. By applying either a triangular or square wave excitation potential waveform, electromodulation of the optical signal has been demonstrated with Fe(CN)6(3-/4-) as a model electroactive couple that partitions into a PDMDAAC-SiO2 film [where PDMDAAC = poly(dimethyldiallylammonium chloride)] and absorbs at 442 nm.

Predictors of operative outcome in patients with human immunodeficiency virus infection and acquired immunodeficiency syndrome

BACKGROUND

Plasma viral load has recently been associated with clinical outcome in patients with human immunodeficiency virus (HIV) infection and acquired immunodeficiency syndrome (AIDS). We hypothetized that, in addition to CD4 lymphocytes, plasma HIV-1 RNA counts are predictive of postoperative outcome.

METHODS

HIV-infected and AIDS patients admitted to a major teaching hospital requiring invasive or surgical procedures were retrospectively analyzed for postoperative outcome. Preoperative and postoperative immune cell counts including plasma HIV-1 RNA counts were recorded. Chi-square analysis, Fisher's exact test, and multivariate regression were performed with statistical significance P </=0.05.

RESULTS

Fifty-five consecutive patients between 14 and 62 years of age were admitted in a 1-year period and underwent 64 diagnostic and therapeutic procedures. Fourteen (22%) postoperative infections and 18 (28%) complications other than infection, with an overall mortality of 11%, were documented. Total preoperative white blood cell count ([WBC] P <0.01), preoperative percent lymphocyte count (P <0.01), absolute postoperative CD4 lymphocyte count (P <0.01), and postoperative plasma viral load (P <0.0001) are associated with mortality. Multivariate regression indicated that postoperative percent CD4 lymphocyte count is an independent predictor of both postoperative infection and other complications (P <0.05, R = 0.848, power = 0.9911), while the decrement in percent CD4 lymphocyte count is an independent predictor of postoperative complications other than infection (P <0.05, R = 0.596, power = 0.7838).

CONCLUSIONS

In accordance with the medical literature for clinical outcome in HIV-infected and AIDS patients, both immune cell counts and HIV-1 RNA counts were found to associate with postoperative mortality. However, the postoperative and decrement in percent CD4 lymphocyte proved to be the independent predictors of postoperative complications.

Inhibition of adipogenesis by Wnt signaling

Wnts are secreted signaling proteins that regulate developmental processes. Here we show that Wnt signaling, likely mediated by Wnt-10b, is a molecular switch that governs adipogenesis. Wnt signaling maintains preadipocytes in an undifferentiated state through inhibition of the adipogenic transcription factors CCAAT/enhancer binding protein alpha (C/EBPalpha) and peroxisome proliferator- activated receptor gamma (PPARgamma). When Wnt signaling in preadipocytes is prevented by overexpression of Axin or dominant-negative TCF4, these cells differentiate into adipocytes. Disruption of Wnt signaling also causes transdifferentiation of myoblasts into adipocytes in vitro, highlighting the importance of this pathway not only in adipocyte differentiation but also in mesodermal cell fate determination.

Glycogen synthase kinase 3 is an insulin-regulated C/EBPalpha kinase

CCAAT/enhancer binding protein alpha (C/EBPalpha) is a transcription factor involved in creating and maintaining the adipocyte phenotype. We have shown previously that insulin stimulates dephosphorylation of C/EBPalpha in 3T3-L1 adipocytes. Studies to identify the insulin-sensitive sites of phosphorylation reveal that a C/EBPalpha peptide (amino acids H215 to K250) is phosphorylated on T222, T226, and S230 in vivo. The context of these phosphoamino acids implicates glycogen synthase kinase 3 (GSK3), whose activity is known to be repressed in response to insulin, as a potential kinase for phosphorylation of T222 and T226. Accordingly, GSK3 phosphorylates the predicted region of C/EBPalpha on threonine in vitro, and GSK3 uses C/EBPalpha as a substrate in vivo. In addition, the effect of pharmacological agents on GSK3 activity correlates with regulation of C/EBPalpha phosphorylation. Treatment of 3T3-L1 adipocytes with the phosphatidylinositol 3-kinase inhibitor wortmannin results in phosphorylation of C/EBPalpha, whereas treatment with the GSK3 inhibitor lithium results in dephosphorylation of C/EBPalpha. Collectively, these data indicate that insulin stimulates dephosphorylation of C/EBPalpha on T222 and T226 through inactivation of GSK3. Since dephosphorylation of C/EBPalpha in response to lithium is blocked by okadaic acid, strong candidates for the T222 and T226 phosphatase are protein phosphatases 1 and 2a. Treatment of adipocytes with insulin alters the protease accessibility of widespread sites within the N terminus of C/EBPalpha, consistent with phosphorylation causing profound conformational changes. Finally, phosphorylation of C/EBPalpha and other substrates by GSK3 may be required for adipogenesis, since treatment of differentiating preadipocytes with lithium inhibits their conversion to adipocytes.

An introductory therapeutic modality for restoring implants and natural teeth using conus crowns: a 5-year case report

The advent of cylindric titanium implants and the prevalence of periodontal disease have necessitated a restoration that facilitates the performance of oral physiotherapy. The use of the conical crown as a metallic covering over natural teeth and implants--with a suprastructure that is retained through a specific degree of convergence without cement or screws--allows access for enhanced oral hygiene practices, while providing for esthetic and functional goals.

Jejunostomy tube feedings should not be stopped in the perioperative patient

BACKGROUND

Anesthetic standard of care is to restrict oral intake for 8 hours before elective surgery. There is no research addressing appropriate preoperative discontinuation of jejunostomy tube (J-tube) feedings. We hypothesized that patients could be fed safely, via a J-tube, until the time of surgery.

METHODS

Patients admitted to a Level I Trauma Center, having J-tubes and undergoing a nonabdominal operation, were prospectively evaluated. Group I patients received J-tube feedings until transport to the operating room. Group II patients had tube feedings discontinued for at least 8 hours before surgery. Data were compared using the Student's t test and contingency table analysis.

RESULTS

There were 46 patients in group I and 36 in group II. There was no incidence of aspiration. Patient groups did not differ in age, mortality, length of stay, injury severity score, or ventilator days. Group I patients had tube feedings discontinued for fewer hours before and after surgery than group II patients (before surgery: 1.40 +/- 1.20 vs 11.61 +/- 5.01, respectively; p < .001; after surgery: 2.99 +/- 7.49 vs 7.11 +/- 9.03, respectively; p = .043); received more kilocalories/ grams of protein on the day of surgery (group I vs group II, 1676.15/89.57 +/- 1133.21/38.04 vs 791.14/57.58 +/-498.66/79.87, respectively; p = .001/p = .032) and more kilocalories/grams of protein on the first postoperative day (group I vs group II, 1580.74/92.57 +/- 600.53/37.96 vs 1152.47/63.53 +/- 733.96/39.40, respectively; p = .006/p = .001).

CONCLUSIONS

Patients receiving J-tubes who are undergoing nonabdominal operations may safely continue enteral nutrition at maximum protein and caloric intake until surgery.

CCAAT/enhancer-binding protein beta (C/EBPbeta) and C/EBPdelta contribute to growth hormone-regulated transcription of c-fos

Using the c-fos enhancer as a model to analyze growth hormone (GH)-promoted gene expression, the roles of CCAAT/enhancer-binding proteins (C/EBPs) in GH-regulated transcription were investigated. In 3T3-F442A fibroblasts stably expressing the c-fos promoter mutated at the C/EBP binding site upstream of luciferase, c-fos promoter activity is stimulated by GH 6-7-fold; wild type c-fos promoter shows only a 2-fold induction by GH. This suggests that C/EBP restrains GH-stimulated expression of c-fos. Electrophoretic mobility shift assays with nuclear extracts from 3T3-F442A cells indicate that GH rapidly (2-5 min) increases binding of C/EBPbeta and C/EBPdelta, to the c-fos C/EBP binding site. Both liver activating protein (LAP) and liver inhibitory protein (LIP), forms of C/EBPbeta, are detected in 3T3-F442A cells by immunoblotting. GH increases the binding of LAP/LAP and LAP/LIP dimers. Overexpression of LIP interferes with GH-promoted reporter expression in CHO cells expressing GH receptors, consistent with the possibility that LIP restrains GH-stimulated c-fos expression. Overexpression of LAP elevates basal luciferase activity but does not influence promoter activation by GH, while overexpressed C/EBPdelta elevates basal promoter activity and enhances the stimulation by GH. GH stimulates the expression of mRNA for C/EBPbeta and -delta and increases levels of C/EBPdelta. Although C/EBPbeta is not detectably altered, GH induces a shift to more rapidly migrating forms of LIP and LAP upon immunoblotting. Treatment of extracts from GH-treated cells with alkaline phosphatase causes a shift of the slower migrating form to the rapidly migrating form, consistent with GH promoting dephosphorylation of LIP and LAP. These studies implicate C/EBPbeta and -delta in GH-regulated gene expression. They also indicate that GH stimulates the binding of C/EBPbeta and -delta to the c-fos promoter and promotes the dephosphorylation of LIP and LAP. These events may contribute to the ability of C/EBPbeta and -delta to regulate GH-stimulated expression of c-fos.

Biochemical characterization of alpha-ketooxadiazole inhibitors of elastases

A series of alpha-ketooxadiazole compounds was prepared and evaluated in vitro as potential inhibitors of human neutrophil elastase (HNE), proteinase-3 (PR-3), and porcine pancreatic elastase (PPE). Several compounds have been found to be very potent, fast, reversible, and selective inhibitors of HNE with Ki values below 100 pM. The highest kon value exceeded 10(7) M(-1) s(-1). Some alpha-ketooxadiazoles were also very effective against PR-3 and PPE with Ki values in the range of 5(-10) nM and 0.1(-2) nM, respectively. The two rings, 1,2,4- and 1,3,4-oxadiazole, are amenable to substitutions, extending the P' side of the inhibitor and allowing additional binding interactions at S' subsites of the enzyme. Nonpeptidic HNE inhibitors containing the oxadiazole heterocycle displayed promising oral bioavailability.

Carboxyhemoglobin elevation in trauma victims

BACKGROUND

Products of the hemeoxygenase enzyme include carboxyhemoglobin (COH) and bilirubin, which have protective effects in stressed states. Hemeoxygenase-1 enzyme up-regulates in states of oxidative stress. We hypothesized that COH is elevated in septic trauma patients compared with nonseptic patients.

METHODS

A prospective study was carried out at a Level I trauma center involving all patients admitted to the trauma intensive care unit. During a 3.5-month period, 45 patients were enrolled, with 76 samples being drawn on admission and at later time points. The samples were classified as septic (Bone's criteria), stressed (based on expired gas analysis), or nonstressed nonseptic. Correlations with Acute Physiology and Chronic Health Evaluation III score, white blood cell count, temperature, partial pressure of oxygen, and percentage of inspired oxygen were evaluated.

RESULTS

COH levels in samples drawn from patients presenting in shock (systolic blood pressure < or =90 mm Hg) were significantly higher than levels in samples from patients not in shock (systolic blood pressure >90 mm Hg) (3.27+/-1.09 vs. 2.75+/-0.64; p = 0.013). Samples from septic patients with infection were associated with significantly higher Injury Severity Scores (34.1+/-11.2 vs. 21.8+/-18.3; p< or =0.05) and a lower percentage of inspired oxygen (41.6+/-10.3 vs. 61.0+/-26.3; p< or =0.05).

CONCLUSION

COH was significantly elevated in samples drawn during stress, sepsis, and shock states. There was overlap between sepsis and stress COH sample values, limiting the clinical usefulness of the assays in predicting sepsis. Further studies focusing on hemeoxygenase-1 expression and the role of its by-products in the outcomes of trauma patients are warranted.

Central nervous system metabolic and physiologic effects of laparoscopy

We set out to determine whether the increases in intracranial pressure (ICP) associated with CO2 insufflation had any metabolic effect on the central nervous system in a head injury when compared with gasless laparoscopy (GL). To test this hypothesis, we looked at both the ICP and jugular bulb venous saturation (JVS), with and without a coexisting cerebral mass lesion. Twenty-five kilogram male pigs had tracheostomy, epidural balloon, pulmonary arterial catheter, arterial line, and jugular bulb catheter placed. Intravenous Pentobarbital was used for anesthesia. Either CO2 laparoscopy (CL; n=7) or GL (n=7) were performed both with and without an epidural balloon inflated to a baseline ICP of 25. Data were analyzed using the Student's t test with a P value <0.05 being significant. Cerebral perfusion pressure and most hemodynamic values did not differ. Both central venous pressure and peak inspiratory pressure were significantly elevated whenever CO2 insufflation took place, reflecting an increased intrathoracic pressure. When comparing both study groups, the partial pressure of CO2 did not differ. CL increases ICP significantly above the gasless group in our head injury model. This is most likely secondary to increased intrathoracic pressure. The question still remains whether these changes are clinically significant. We could not demonstrate significant metabolic effects secondary to laparoscopy. In patients suffering head injury, GL rather than CL might be safer to avoid ICP elevation. Additional studies looking at central nervous system metabolic and objective histopathologic effects should be undertaken with larger numbers of study animals.

Rapid sequence induction for intubation by an aeromedical transport team: a critical analysis

Airway control is the initial priority in the management of the injured patient. The purpose of this investigation was to evaluate the experience of an aeromedical transport team in the utilization of rapid sequence induction (RSI) for endotracheal intubation in the prehospital setting. Records of a consecutive series of injured patients undergoing RSI between June 1988 and July 1992 by a university-based aeromedical transport team were reviewed for demographics, intubation mishaps, and pulmonary complications. The relationship between intubation mishaps and pulmonary complications was analyzed. Eighty-four patients were studied with a mean age of 30.8 +/- 15.3 years. The mean Revised Trauma Score was 11.3 +/- 2.4, and the mean Injury Severity Score (ISS) was 19.6 +/- 11.5. Intubation mishaps occurred in 15 patients (18%), and pulmonary complications developed in 22 (29%) of the 75 patients surviving longer than 24 hours. There was no relationship between intubation mishaps and pulmonary complications. Abbreviated Injury Scale (AIS) face score was significantly higher in patients with intubation mishaps, compared with patients without mishaps (1.1 +/- 1.2 and 0.5 +/- 0.9, respectively, P < .05, Wilcoxon rank-sum). ISS and AIS chest were higher in patients with pulmonary complications, compared with those without (25.7 +/- 12.6 and 17.4 +/- 10.3 and 2.2 +/- 1.8 and 1.0 +/- 1.5, ISS and AIS respectively; P < .05, Wilcoxon rank-sum). Eighty-one patients (96%) underwent successful RSI, 73 (87%) on the first attempt. Failure to intubate occurred in three patients (4%). Performed under strict protocol by appropriately trained aeromedical transport personnel, RSI is an effective means to facilitate endotracheal intubation in the injured patient requiring definitive airway control. Pulmonary complications were related to injury severity and not to intubation mishaps.

Therapeutic actions of cyclosporine and anti-tumor necrosis factor alpha in collagen-induced arthritis and the effect of combination therapy

OBJECTIVE

To define the mechanisms of action of 2 novel drugs, cyclosporine and anti-tumor necrosis factor alpha (TNFalpha), in collagen-induced arthritis and to determine the effect of combination therapy.

METHODS

Type II collagen-immunized DBA/1 mice with established arthritis were treated with cyclosporine alone, anti-TNFalpha alone, cyclosporine plus anti-TNFalpha, or saline.

RESULTS

Cyclosporine was found to ameliorate arthritis, suppress interferon-gamma (IFNgamma) production by CD4+ T cells, and reduce TNFalpha expression in arthritic joints. However, cyclosporine did not directly inhibit TNFalpha production by macrophages, indicating that the decrease in TNFalpha expression observed in vivo was probably an indirect consequence of the reduction in type 1 T helper cell activity. Anti-TNFalpha also reduced IFNgamma production by T cells, indicating that TNFalpha is involved in the cellular immune response to collagen. Combined treatment with cyclosporine plus anti-TNFalpha had an additive therapeutic effect.

CONCLUSION

Although cyclosporine and anti-TNFalpha target different points in the inflammatory pathway, there is an overlap in the consequences of their actions in vivo.

A role for the p38 mitogen-activated protein kinase/Hsp 27 pathway in cholecystokinin-induced changes in the actin cytoskeleton in rat pancreatic acini

Cholecystokinin (CCK) and other pancreatic secretagogues have recently been shown to activate signaling kinase cascades in pancreatic acinar cells, leading to the activation of extracellular signal-regulated kinases and Jun N-terminal kinases. We now show the presence of a third kinase cascade activating p38 mitogen-activated protein (MAP) kinase in isolated rat pancreatic acini. CCK and osmotic stress induced by sorbitol activated p38 MAP kinase within minutes; their effects were dose-dependent, with maximal activation of 2.8- and 4.4-fold, respectively. The effects of carbachol and bombesin on p38 MAP kinase activity were similar to those of CCK, whereas phorbol ester, epidermal growth factor, and vasoactive intestinal polypeptide stimulated p38 MAP kinase by 2-fold or less. Both CCK and sorbitol also increased the tyrosyl phosphorylation of p38 MAP kinase. Using the specific inhibitor of p38 MAP kinase, SB 203580, we found that p38 MAP kinase activity was required for MAP kinase-activated protein kinase-2 activation in pancreatic acini. SB 203580 reduced the level of basal phosphorylation and blocked the increased phosphorylation of Hsp 27 after stimulation with either CCK or sorbitol. CCK treatment induced an initial rapid decrease in total F-actin content of acini, followed by an increase after 40 min. Preincubation with SB 203580 significantly inhibited these changes in F-actin content. Staining of the actin cytoskeleton with rhodamine-conjugated phalloidin and analysis by confocal fluorescence microscopy showed disruption of the actin cytoskeleton after 10 and 40 min of CCK stimulation. Pretreatment with SB 203580 reduced these changes. These findings demonstrate that the activation of p38 MAP kinase is involved not only in response to stress, but also in physiological signaling by gastrointestinal hormones such as CCK, where activation of Gq-coupled receptors stimulates a cascade in which p38 MAP kinase activates MAP kinase-activated protein kinase-2, resulting in Hsp 27 phosphorylation. Activation of p38 MAP kinase, most likely through phosphorylation of Hsp 27, plays a role in the organization of the actin cytoskeleton in pancreatic acini.

Efficacy of the motor component of the Glasgow Coma Scale in trauma triage

BACKGROUND

National guidelines recommend that patients with Glasgow Coma Scale (GCS) scores of less than 14 be triaged to trauma centers. We hypothesized that the motor component of the GCS (GCSM) would be equally sensitive as the total GCS in head injury triage.

METHODS

A 2-year retrospective review of 3,235 injured adults transported directly to a Level I trauma center.

RESULTS

One thousand four hundred ten patients (44%) had prehospital GCS scores recorded. GCSM was found to have a sensitivity of 0.90 for Abbreviated Injury Scale (AIS) score = 5 head injury and 0.61 for AIS score > 3 injury, whereas the GCS had sensitivities of 0.92 and 0.62, respectively (p = not significant). Specificities were equal at 0.85 for AIS score = 5 and 0.89 for AIS score > 3.

CONCLUSION

GCSM is equivalent to GCS for prehospital triage, and in view of its simplicity it should replace the GCS in triage schemes.

Ureteral trauma: preoperative studies neither predict injury nor prevent missed injuries

BACKGROUND

Ureteral injuries are uncommon, and the necessity, accuracy, and optimal use of perioperative testing remains unknown. Delays in diagnosis have also been associated with significant morbidity, including loss of renal function.

STUDY DESIGN

The records of all patients (n = 20) admitted with ureteral injuries to two Level I trauma centers during a 5-year period were reviewed. Data collected included patient demographics, mechanism of injury, degree of associated injuries, and presence of gross or microscopic hematuria. The use of any pre- or intraoperative testing was specifically noted. The location of the ureteral injury was obtained from the operative notes. The morbidity and mortality associated with ureteral injuries in the primarily diagnosed and the delayed groups were assessed. Presenting signs and symptoms, diagnostic testing, and the urologic management of the patients in the delayed group were reviewed.

RESULTS

All patients were men whose ages ranged from 15 to 72 years, with a mean age of 29. The mechanisms of injury were gunshot wounds in 15, stab wounds in 4, and blunt vehicular trauma in 1. Excluding other urologic injuries, the incidence of hematuria related to the ureteral injury alone was 53%. A total of 10 pre- and intraoperative studies were performed, only 2 demonstrated the ureteral injury. Seventeen patients had their injuries diagnosed primarily. In this group, the ureter was repaired by suturing and stenting in 12, suturing without a stent in 1 and ureterocystostomy in 4. Delayed diagnosis of their ureteral injuries occurred in three patients. All three missed injuries occurred in the upper portion of the left ureter. All ureters were successfully repaired. There were no mortalities in this group, nor did any patient require a nephrectomy.

CONCLUSIONS

Direct visualization of the injury is the best and most accurate diagnostic modality in ureteral trauma. These results reinforce that a thorough exploration of all retroperitoneal hematomas after penetrating trauma remain an integral part of the total abdominal exploration for trauma.

Regulation of CCAAT/enhancer binding protein alpha (C/EBP alpha) gene expression by thiazolidinediones in 3T3-L1 adipocytes

Thiazolidinediones are a class of antidiabetic drugs that induce preadipocyte differentiation by binding and activating peroxisome proliferator-activated receptor gamma 2. Although thiazolidinediones are commonly thought of as insulin-sensitizing agents, these drugs have opposing and antagonistic effects to that of insulin on CCAAT/enhancer binding protein alpha (C/EBP alpha) gene expression in fully differentiated 3T3-L1 adipocytes. Thiazolidinediones induce expression of C/EBP alpha mRNA and protein, while insulin stimulates a rapid decline in C/EBP alpha mRNA and protein. When added in combination, thiazolidinediones block the suppression of C/EBP alpha mRNA by insulin; however, thiazolidinediones do not block the insulin-induced decline in GLUT4 mRNA, indicating that repression of C/EBP alpha mRNA is not required for insulin to suppress expression of a C/EBP alpha-responsive gene such as GLUT4. Instead, insulin may regulate GLUT4 mRNA by inactivating C/EBP alpha through dephosphorylation as well as by inducing the expression of the dominant-negative form of C/EBP beta (liver inhibitory protein), since both of these processes occur in the presence of thiazolidinediones.

Suppression of TNF-alpha expression, inhibition of Th1 activity, and amelioration of collagen-induced arthritis by rolipram

Rolipram is a type IV phosphodiesterase inhibitor that suppresses inflammation and TNF-alpha production. As anti-TNF-alpha therapy is effective in rheumatoid arthritis, we investigated the effect of rolipram on collagen-induced arthritis (CIA), a murine model of rheumatoid arthritis. Rolipram was administered after the onset of clinical arthritis at doses of 0.5, 3, 5, or 10 mg/kg twice daily, with a dose-dependent therapeutic effect on clinical severity and joint erosion. Immunohistochemical analysis of joints of rolipram-treated mice revealed 67% reduction in TNF-alpha-expressing cells compared with control arthritic mice. In vitro studies using bone marrow-derived macrophages confirmed that rolipram directly suppressed TNF-alpha and IL-12 production following stimulation with IFN-gamma and LPS. The effect of rolipram on T cell activity was studied by measuring Th1/Th2 cytokine production by collagen-stimulated draining lymph node cells from arthritic mice treated in vivo with rolipram. Rolipram reduced IFN-gamma production and increased IL-10, indicating that rolipram down-regulated the ongoing Th1 response to type II collagen. Finally, the effect on CIA of combination therapy was studied using rolipram plus either anti-TNF-alpha or anti-CD4 mAbs. Rolipram plus anti-TNF-alpha was not therapeutically additive, whereas rolipram plus anti-CD4 mAb was clearly additive. This result indicates that the therapeutic effects of rolipram overlap with TNF-alpha blockade, but are complementary to anti-CD4 treatment. It is therefore proposed that a major mechanism of action of rolipram in CIA is suppression of TNF-alpha activity. These findings suggest that type IV phosphodiesterase inhibitors may be effective in pathologic conditions, such as RA, with overexpression of TNF-alpha.

Suppression of TNF-alpha expression, inhibition of Th1 activity, and amelioration of collagen-induced arthritis by rolipram

Rolipram is a type IV phosphodiesterase inhibitor that suppresses inflammation and TNF-alpha production. As anti-TNF-alpha therapy is effective in rheumatoid arthritis, we investigated the effect of rolipram on collagen-induced arthritis (CIA), a murine model of rheumatoid arthritis. Rolipram was administered after the onset of clinical arthritis at doses of 0.5, 3, 5, or 10 mg/kg twice daily, with a dose-dependent therapeutic effect on clinical severity and joint erosion. Immunohistochemical analysis of joints of rolipram-treated mice revealed 67% reduction in TNF-alpha-expressing cells compared with control arthritic mice. In vitro studies using bone marrow-derived macrophages confirmed that rolipram directly suppressed TNF-alpha and IL-12 production following stimulation with IFN-gamma and LPS. The effect of rolipram on T cell activity was studied by measuring Th1/Th2 cytokine production by collagen-stimulated draining lymph node cells from arthritic mice treated in vivo with rolipram. Rolipram reduced IFN-gamma production and increased IL-10, indicating that rolipram down-regulated the ongoing Th1 response to type II collagen. Finally, the effect on CIA of combination therapy was studied using rolipram plus either anti-TNF-alpha or anti-CD4 mAbs. Rolipram plus anti-TNF-alpha was not therapeutically additive, whereas rolipram plus anti-CD4 mAb was clearly additive. This result indicates that the therapeutic effects of rolipram overlap with TNF-alpha blockade, but are complementary to anti-CD4 treatment. It is therefore proposed that a major mechanism of action of rolipram in CIA is suppression of TNF-alpha activity. These findings suggest that type IV phosphodiesterase inhibitors may be effective in pathologic conditions, such as RA, with overexpression of TNF-alpha.

Signaling pathways through which insulin regulates CCAAT/enhancer binding protein alpha (C/EBPalpha) phosphorylation and gene expression in 3T3-L1 adipocytes. Correlation with GLUT4 gene expression

Treatment of 3T3-L1 adipocytes with insulin (IC50 approximately 200 pM insulin) or insulin-like growth factor-1 (IC50 approximately 200 pM IGF-1) stimulates dephosphorylation of CCAAT/enhancer binding protein alpha (C/EBPalpha), a transcription factor involved in preadipocyte differentiation. As assessed by immunoblot analysis of one- and two-dimensional PAGE, insulin appears to dephosphorylate one site within p30C/EBPalpha and an additional site within p42C/EBPalpha. Consistent with insulin causing dephosphorylation of C/EBPalpha through activation of phosphatidylinositol 3-kinase, addition of phosphatidylinositol 3-kinase inhibitors (e.g. wortmannin) blocks insulin-stimulated dephosphorylation of C/EBPalpha. In the absence of insulin, wortmannin or LY294002 enhance C/EBPalpha phosphorylation. Similarly, blocking the activity of FKBP-rapamycin-associated protein with rapamycin increases phosphorylation of C/EBPalpha in the absence of insulin. Dephosphorylation of C/EBPalpha by insulin is partially blocked by rapamycin, consistent with a model in which activation of FKBP-rapamycin-associated protein by phosphatidylinositol 3-kinase results in dephosphorylation of C/EBPalpha. The dephosphorylation of C/EBPalpha by insulin, in conjunction with the insulin-dependent decline in C/EBPalpha mRNA and protein, has been hypothesized to play a role in repression of GLUT4 transcription by insulin. Consistent with this hypothesis, the decline of GLUT4 mRNA following exposure of adipocytes to insulin correlates with dephosphorylation of C/EBPalpha. However, the repression of C/EBPalpha mRNA and protein levels by insulin is blocked with an inhibitor of the mitogen-activated protein kinase pathway without blocking the repression of GLUT4 mRNA, thus dissociating the regulation of C/EBPalpha and GLUT4 mRNAs by insulin. A decline in C/EBPalpha mRNA and protein may not be required to suppress GLUT4 transcription because insulin also induces expression of the dominant-negative form of C/EBPbeta (liver inhibitory protein), which blocks transactivation by C/EBP transcription factors.

T cell receptor-induced phosphorylation of Sos requires activity of CD45, Lck, and protein kinase C, but not ERK

Stimulation of the T cell antigen receptor (TCR) activates signaling pathways involving protein kinases, phospholipase Cgamma1, and Ras. How these second messengers interact to initiate distal activation events is an area of intense scrutiny. In this report, we confirm that TCR ligation results in phosphorylation of Sos, a guanine nucleotide exchange factor for Ras. This requires expression of both the CD45 tyrosine phosphatase and the Lck protein tyrosine kinase and depends upon signaling via protein kinase C. In contrast to previous studies examining requirements for Sos phosphorylation following insulin and epidermal growth factor receptor engagement, we show that TCR-induced phosphorylation of Sos does not require activation of the mitogen-activated protein kinase/extracellular-signal regulated kinase (MEK/ERK) pathway. However, the basal phosphorylation of Sos in T cells is affected by either MEK or MEK-dependent kinases. Although Sos phosphorylation results in its dissociation from Grb2 following insulin stimulation in Chinese hamster ovary cells, TCR engagement on the Jurkat T cell line fails to elicit a similar effect. These data demonstrate that the kinases responsible for Sos phosphorylation differ following ligation of various cell surface receptors and that the consequences of Sos phosphorylation relies, at least in part, on sites of its phosphorylation.

Three domains of SLP-76 are required for its optimal function in a T cell line

We and others have shown that overexpression of SLP-76 augments TCR-stimulated IL-2 promoter activity in the Jurkat T cell line. In this report we investigate the signaling mechanisms through which SLP-76 mediates its effect on T cell activation. We show that overexpressed SLP-76 acts downstream of TCR-stimulated protein tyrosine kinases, but does not affect calcium signaling. Overexpression of SLP-76 does, however, augment TCR stimulation of both ERK (extracellular signal-regulated kinase) activity and a reporter construct driven by activating protein-1 binding sites. Structure/function analysis reveals that three distinct regions of SLP-76, each important for protein associations, are required for augmentation of TCR-induced nuclear factor-AT activity. These data suggest that SLP-76 functions as an adapter molecule that requires three unique domains to link proximal TCR signals in T cells.

Three domains of SLP-76 are required for its optimal function in a T cell line

We and others have shown that overexpression of SLP-76 augments TCR-stimulated IL-2 promoter activity in the Jurkat T cell line. In this report we investigate the signaling mechanisms through which SLP-76 mediates its effect on T cell activation. We show that overexpressed SLP-76 acts downstream of TCR-stimulated protein tyrosine kinases, but does not affect calcium signaling. Overexpression of SLP-76 does, however, augment TCR stimulation of both ERK (extracellular signal-regulated kinase) activity and a reporter construct driven by activating protein-1 binding sites. Structure/function analysis reveals that three distinct regions of SLP-76, each important for protein associations, are required for augmentation of TCR-induced nuclear factor-AT activity. These data suggest that SLP-76 functions as an adapter molecule that requires three unique domains to link proximal TCR signals in T cells.

Bradykinin antagonists in human systems: correlation between receptor binding, calcium signalling in isolated cells, and functional activity in isolated ileum

The determination of the relationship between ligand affinity and bioactivity is important for the understanding of receptor function in biological systems and for drug development. Several physiological and pathophysiological functions of bradykinin (BK) are mediated via the B2 receptor. In this study, we have examined the relationship between B2 receptor (soluble and membrane-bound) binding of BK peptidic antagonists, inhibition of calcium signalling at a cellular level, and in vitro inhibition of ileum contraction. Only human systems were employed in the experiments. Good correlations between the studied activities of BK antagonists were observed for a variety of different peptidic structures. The correlation coefficients (r) were in the range of 0.905 to 0.955. In addition, we analyzed the effect of the C-terminal Arg9 removal from BK and its analogs on B2 receptor binding. The ratios of binding constants (Ki(+Arg)/Ki(-Arg)) for the Arg9 containing compounds and the corresponding des-Arg9 analogs varied from about 10 to 250,000. These ratios strongly depend on the chemical structures of the compounds. The highest ratios were observed for two natural agonist pairs, BK/des-Arg9-BK and Lys0-BK/des-Arg9-Lys0-BK.

Secondary emergency department triage (supertriage) and trauma team activation: effects on resource utilization and patient care

BACKGROUND

Not all field triage patients need full trauma team activation. Secondary emergency department (ED) triage (supertriage), a clinical and anatomic screen, determines trauma team versus ED management. The purpose was to study the effects of supertriage on injury severity and disposition by patients managed with and without team activation.

METHODS

Observational study of consecutive patients transported for alert consideration undergoing supertriage by a trauma nurse. Chart review was performed for disposition and Injury Severity Score. Contingency table or t test with p < or = 0.05 was used for data analysis.

RESULTS

One hundred ninety patients were screened; 74% of the 54 with positive supertriage and team activation needed the operating room in 24 hours or the intensive care unit versus 46% of cases with negative supertriage managed in the ED and admitted (p = 0.015). Of the 35 admitted ED patients, 10 required the operating room and 6 required the intensive care unit.

CONCLUSIONS

Supertriage identified a majority requiring team activation; however, resources must be available for the seriously injured not meeting field or hospital triage criteria.

In vitro studies of a bradykinin B1/B2 antagonist linked to a human neutrophil elastase inhibitor; a heterodimer for the treatment of inflammatory disorders

Inflammatory disorders typically have a complex etiology and involve a multitude of inflammatory mediators, and hence, a polytherapeutic approach to these diseases would seem appropriate. In certain chronic inflammatory conditions, we believe that bradykinin (BK) and human neutrophil elastase (HNE) are cooperatively involved. We have previously synthesized compounds with inhibitory activity toward both the BK B2 receptor and HNE. The present study describes single compounds designed to incorporate HNE inhibitory activity and BK B1 and B2 antagonist activity. A proprietary HNE inhibitor (HNEI, CP-955) was directly linked via amide bond formation to a peptide-based combined BK B1/B2 antagonist (B-9430). Three compounds were made using different linking positions in the antagonist peptide. For all compounds, B1 and B2 receptor binding in human cloned receptors was at least 10-fold less than that of B-9430, whereas in the in vitro guinea pig ileum B2 receptor functional assay, the compounds had potencies equivalent to B-9430. Compound I was found to have a fourfold increase in HNEI activity compared with CP-955, whereas compounds II and III were inactive. These data clearly demonstrate that it is possible to retain BK B1/B2 receptor antagonist and HNE activity in a heterodimer.

Surface expression of hemopoietic cell phosphatase fails to complement CD45 deficiency and inhibits TCR-mediated signal transduction in a Jurkat T cell clone

Previous studies have shown that the protein tyrosine phosphatase CD45 is required for initiation of signal transduction through several lymphoid receptors. In contrast, there is increasing evidence that another protein tyrosine phosphatase, hemopoietic cell phosphatase (known as HCP, SHP, PTP1C, SHPTP-1, or PTPN6), is a negative regulator of signaling in hemopoietic cells. To determine the effect of HCP on signal transduction through the TCR, HCP was expressed as a chimeric molecule with extracellular and transmembrane domains of the HLA-A2 molecule (A2/HCP) on wild-type Jurkat T cells and the CD45-deficient variant, J45.01. In this report, we show that expression of A2/HCP, unlike A2 chimeras containing the enzymatic regions of CD45, fails to rescue TCR-mediated signal transduction in J45.01. Furthermore, expression of A2/HCP on wild-type Jurkat T cells results in diminished inositol phosphate production following TCR ligation as well as markedly diminished nuclear factor of activated T cells promoter activity. Surprisingly, however, TCR-mediated tyrosine phosphorylation of phospholipase C gamma 1 remains intact in the Jurkat cells expressing the A2/HCP chimera. These experiments provide further evidence that HCP can serve a negative regulatory role in receptor-mediated signaling in immune cells. Additionally, our studies suggest that surface expression of HCP in T cells may provide a means to identify phosphotyrosine-containing proteins that are required for coupling signaling pathways initiated by ligation of the T cell Ag receptor.

Surface expression of hemopoietic cell phosphatase fails to complement CD45 deficiency and inhibits TCR-mediated signal transduction in a Jurkat T cell clone

Previous studies have shown that the protein tyrosine phosphatase CD45 is required for initiation of signal transduction through several lymphoid receptors. In contrast, there is increasing evidence that another protein tyrosine phosphatase, hemopoietic cell phosphatase (known as HCP, SHP, PTP1C, SHPTP-1, or PTPN6), is a negative regulator of signaling in hemopoietic cells. To determine the effect of HCP on signal transduction through the TCR, HCP was expressed as a chimeric molecule with extracellular and transmembrane domains of the HLA-A2 molecule (A2/HCP) on wild-type Jurkat T cells and the CD45-deficient variant, J45.01. In this report, we show that expression of A2/HCP, unlike A2 chimeras containing the enzymatic regions of CD45, fails to rescue TCR-mediated signal transduction in J45.01. Furthermore, expression of A2/HCP on wild-type Jurkat T cells results in diminished inositol phosphate production following TCR ligation as well as markedly diminished nuclear factor of activated T cells promoter activity. Surprisingly, however, TCR-mediated tyrosine phosphorylation of phospholipase C gamma 1 remains intact in the Jurkat cells expressing the A2/HCP chimera. These experiments provide further evidence that HCP can serve a negative regulatory role in receptor-mediated signaling in immune cells. Additionally, our studies suggest that surface expression of HCP in T cells may provide a means to identify phosphotyrosine-containing proteins that are required for coupling signaling pathways initiated by ligation of the T cell Ag receptor.

Reintubation as an outcome predictor in trauma patients

STUDY OBJECTIVE

Determine reintubation rate, identify its cause, and detail adverse outcomes from reintubation.

DESIGN

Retrospective review of extubation failures in the trauma ICU.

SETTING

University hospital and regional trauma center.

PATIENTS

Four hundred five patients arriving intubated or requiring intubation during hospitalization after 2,516 traumatic injury admissions over 18 months.

INTERVENTIONS

None.

RESULTS

Reintubation incidence was 7% (27 times per 405 patients). Comparative mortality of the reintubated group (2/24 = 8%) is similar to overall trauma center mortality (224/2516 = 6.5%), but less than the cohort of patients admitted to the hospital intubated (63/405 = 16%). Reintubated patients had an increased frequency of stridor than reported previously (33%), and an increased tracheostomy rate (62% vs 30%). Stridor was not predictable from injury severity score, Glasgow coma score, age, sex, length of intubation, or place of intubation. Pulmonary complications (atelectasis, tracheobronchitis, pneumonia) developed in half of reintubated patients; stridorous patients did not have an increased rate of pulmonary complications.

CONCLUSION

Reintubation in trauma ICU patients does not predict poor outcome.

Tyrosines 113, 128, and 145 of SLP-76 are required for optimal augmentation of NFAT promoter activity

SLP-76 (SH2 domain leukocyte protein of 76 kDa) is a recently identified substrate of the TCR-stimulated protein tyrosine kinases that functions in the signal transduction cascade linking the TCR with IL-2 gene expression. In this report, we demonstrate that engagement of the TCR results in tyrosine phosphorylation of SLP-76 in its amino-terminal acidic region. Two tyrosines (Y113 and Y128) fall within an identical five amino-acid motif and are shown to be phosphorylated upon TCR ligation. Although mutation of either Y113 and Y128 has a minimal effect on SLP-76 function, mutation of both residues decreases significantly the ability of SLP-76 to promote T cell activation. A third tyrosine within the amino-terminal region (Y145) appears to be the most important for optimal SLP-76 function, as altering it alone to phenylalanine has a potent impact on SLP-76 augmentation of NFAT promoter activity.

Tyrosines 113, 128, and 145 of SLP-76 are required for optimal augmentation of NFAT promoter activity

SLP-76 (SH2 domain leukocyte protein of 76 kDa) is a recently identified substrate of the TCR-stimulated protein tyrosine kinases that functions in the signal transduction cascade linking the TCR with IL-2 gene expression. In this report, we demonstrate that engagement of the TCR results in tyrosine phosphorylation of SLP-76 in its amino-terminal acidic region. Two tyrosines (Y113 and Y128) fall within an identical five amino-acid motif and are shown to be phosphorylated upon TCR ligation. Although mutation of either Y113 and Y128 has a minimal effect on SLP-76 function, mutation of both residues decreases significantly the ability of SLP-76 to promote T cell activation. A third tyrosine within the amino-terminal region (Y145) appears to be the most important for optimal SLP-76 function, as altering it alone to phenylalanine has a potent impact on SLP-76 augmentation of NFAT promoter activity.

Tyrosine phosphorylation of Grb2-associated proteins correlates with phospholipase C gamma 1 activation in T cells

Ligation of the T-cell antigen receptor (TCR) results in the rapid activation of several protein tyrosine kinases, with the subsequent phosphorylation of numerous cellular proteins. We investigated the requirement for tyrosine phosphorylation of proteins which bind the Grb2 SH2 domain in TCR-mediated signal transduction by transfecting the Jurkat T-cell line with a cDNA encoding a chimeric protein designed to dephosphorylate these molecules. Stimulation of the TCR on cells expressing this engineered enzyme fails to result in sustained tyrosine phosphorylation of a 36-kDa protein likely to be the recently cloned pp36/Lnk. Interestingly, TCR ligation of the transfected cells also fails to induce soluble inositol phosphate production and intracellular calcium mobilization, although receptor-mediated tyrosine phosphorylation of phospholipase C gamma 1 still occurs. TCR-mediated Ras and mitogen-activated protein kinase activation remain intact in cells expressing the engineered phosphatase. These data demonstrate that tyrosine phosphorylation of a protein(s) which binds the SH2 domain of Grb2 correlates with phospholipase C gamma 1 activation and suggest that such a phosphoprotein(s) plays a critical role in coupling the TCR with the phosphatidylinositol second-messenger pathway.

Infant survival after cesarean section for trauma

HYPOTHESIS

Emergency cesarean sections in trauma patients are not justified and should be abandoned.

SETTING AND DESIGN

A multi-institutional, retrospective cohort study was conducted of level 1 trauma centers.

METHODS

Trauma admissions from nine level 1 trauma centers from January 1986 through December 1994 were reviewed. Pregnant women who underwent emergency cesarean sections were identified. Demographic and clinical data were obtained on all patients undergoing a cesarean section. Fetal distress was defined by bradycardia, deceleration, or lack of fetal heart tones (FHTs). Maternal distress was defined by shock (systolic blood pressure < 90) or acute decompensation. Statistical analyses were performed.

RESULTS

Of the 114,952 consecutive trauma admissions, more than 441 pregnant women required 32 emergency cesarean sections. All were performed for fetal distress, maternal distress, or both. Overall, 15 (45%) of the fetuses and 23 (72%) of the mothers survived. Of 33 fetuses delivered, 13 had no FHTs and none survived. Twenty infants (potential survivors) had FHTs and an estimated gestational age (EGA) of greater than or equal to 26 weeks, and 75% survived. Infant survival was independent of maternal distress or maternal Injury Severity Score. The five infant deaths in the group of potential survivors resulted from delayed recognition of fetal distress, and 60% of these deaths were in mothers with mild to moderate injuries (Injury Severity Score < 16).

CONCLUSIONS

In pregnant trauma patients, infant viability is defined by the presence of FHTs, estimated gestational age greater than or equal to 26 weeks. In viable infants, survival after emergency cesarean section is acceptable (75%). Infant survival is independent of maternal distress or Injury Severity Score. Sixty percent of infant deaths resulted from delay in recognition of fetal distress and cesarean section. These were potentially preventable. Given the definition of fetal viability, our initial hypothesis is invalid.

Implication of the GRB2-associated phosphoprotein SLP-76 in T cell receptor-mediated interleukin 2 production

Recently we described the molecular cloning of SLP-76, a hematopoietic cell-specific 76-kD protein that was first identified through its association with GST/Grb2 fusion proteins. The primary sequence of SLP-76 predicts a protein of 533 amino acids comprising an amino-terminal region with numerous potential tyrosine phosphorylation sites, a central region rich in proline residues, and a single carboxy-terminal SH2 domain. Here we demonstrate formally that Grb2 associates with unphosphorylated SLP-76 and map the Grb2 binding site on SLP-76 undergoes rapid tyrosine phosphorylation and associates with tyrosine phosphoproteins of 36, 62, and 130 kD. In vitro experiments show that the SH2 domain of SLP-76 associates with the 62- and 130-kD proteins and additionally with a serine/threonine kinase. Finally, we demonstrate that transient overexpression of SLP-76 results in dramatically enhanced TCR-mediated induction of nuclear factor of activated T cells (NFAT) and interleukin (IL) 2 promoter activity; and we provide evidence that a functional SLP-76 SH2 domain is required for this effect. Our data document the in vivo associations of SLP-76 with several proteins that potentially participate in T cell activation and implicate SLP-76 itself as an important molecule in TCR-mediated IL-2 production.