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Biomedical subjects

J E Manning

Publications and source records attributed to J E Manning.

At least 19 recordsLinked to original sources
PubMed2001

The ubiquitin-proteasome pathway plays an essential role in proteolysis during Trypanosoma cruzi remodeling.

Here, we document for the first time the presence of the 26S proteasome and the ubiquitin pathway in a protozoan parasite that is in an early branch in the eukaryotic lineage. The 26S proteasome of Trypanosoma cruzi epimastigotes was identified as a high molecular weight complex (1400 kDa) with an ATP-dependent chymotrypsin-like activity against the substrate Suc-LLVY-Amc. This activity was inhibited by proteasome inhibitors and showed same electrophorectic migration pattern as yeast 26S proteasome in nondenaturating gels. About 30 proteins in a range of 25-110 kDa were detected in the purified T. cruzi 26S proteasome. Antibodies raised against the AAA family of ATPases from eukaryotic 26S proteasome and the T. cruzi 20S core specifically recognized components of T. cruzi 26S. To confirm the biological role of 26S in this primitive eukaryotic parasite, we analyzed the participation of the ubiquitin (Ub)-proteasome system in protein degradation during the time of parasite remodeling. Protein turnover in trypomastigotes was proteasome and ATP-dependent and was enhanced during the transformation of the parasites into amastigotes. If 20S proteasome activity is inhibited, ubiquitinated proteins accumulate in the parasites. As expected from the profound morphological changes that occur during transformation, cytoskeletal proteins associated with the flagellum are targets of the ubiquitin-proteasome pathway.

Acetylcysteine↗
PubMed2001

SOCS-1, a negative regulator of the JAK/STAT pathway, is silenced by methylation in human hepatocellular carcinoma and shows growth-suppression activity.

Hepatocellular carcinoma (HCC) is a major cause of cancer death, but the molecular mechanism for its development beyond its initiation has not been well characterized. Suppressor of cytokine signaling (SOCS-1; also known as JAB and SSI-1) switches cytokine signaling 'off' by means of its direct interaction with Janus kinase (JAK). We identified aberrant methylation in the CpG island of SOCS-1 that correlated with its transcription silencing in HCC cell lines. The incidence of aberrant methylation was 65% in the 26 human primary HCC tumor samples analyzed. Moreover, the restoration of SOCS-1 suppressed both growth rate and anchorage-independent growth of cells in which SOCS-1 was methylation-silenced and JAK2 was constitutively activated. This growth suppression was caused by apoptosis and was reproduced by AG490, a specific, chemical JAK2 inhibitor that reversed constitutive phosphorylation of STAT3 in SOCS-1 inactivated cells. The high prevalence of the aberrant SOCS-1 methylation and its growth suppression activity demonstrated the importance of the constitutive activation of the JAK/STAT pathway in the development of HCC. Our results also indicate therapeutic strategies for the treatment of HCC including use of SOCS-1 in gene therapy and inhibition of JAK2 by small molecules, such as AG490.

Antineoplastic Agents↗
PubMed2001

Selective aortic arch perfusion with hemoglobin-based oxygen carrier-201 for resuscitation from exsanguinating cardiac arrest in swine.

OBJECTIVE: The prospects for resuscitation after blunt traumatic cardiac arrest are dismal. Selective aortic arch perfusion (SAAP) with a hemoglobin-based oxygen carrier (HBOC-201) offers a potentially effective therapy. This study evaluated the acute cardiovascular and metabolic effects of SAAP with HBOC-201 in an exsanguination model of cardiac arrest. DESIGN: Randomized, controlled, laboratory investigation. SETTING: University research laboratory. SUBJECTS: Domestic swine, 25-39 kg. INTERVENTIONS: Partial resection of four liver lobes rapidly led to profound hemorrhagic shock and subsequent cardiac arrest at 10-13 mins. At 15 mins, swine were randomized to receive either SAAP with oxygenated lactated Ringer's (LR) solution (n = 6) or SAAP with oxygenated HBOC-201 (n = 6) at a rate of 10 mL x kg(-1) x min(-1) until return of spontaneous circulation with a mean aortic pressure of 60 mm Hg (8.0 kPa) was achieved. Epinephrine (0.005 mg/kg) was given via intra-aortic route every 30 secs as needed to promote return of spontaneous circulation beginning at 18 mins after onset of liver injury (3 mins after beginning SAAP). MEASUREMENTS AND MAIN RESULTS: Mean aortic pressure, cardiac output, total blood loss, and time of arrest were similar for both groups before SAAP therapy. In the SAAP-HBOC group, return of spontaneous circulation with a sustained mean aortic pressure of 60 mm Hg (8.0 kPa) was achieved in six of six swine at 1.9 +/- 0.3 mins of SAAP, and none of these swine required epinephrine. In the SAAP-LR group, no swine (from a total of six) achieved return of spontaneous circulation before intra-aortic epinephrine administration, and only two of six swine had brief return of spontaneous circulation with an mean aortic pressure of 60 mm Hg (8.0 kPa) after intra-aortic epinephrine that was sustained for <10 mins. One-hour survival was five of six in the SAAP-HBOC group and none of six in the SAAP-LR group (p <.05, Fisher's exact test). CONCLUSION: SAAP with oxygenated HBOC-201 rapidly restored viable cardiovascular function after exsanguinating cardiac arrest in this swine model of liver injury with profound hemorrhagic shock.

Animals↗
PubMed2000

Paraflagellar rod proteins administered with alum and IL-12 or recombinant adenovirus expressing IL-12 generates antigen-specific responses and protective immunity in mice against Trypanosoma cruzi.

Successful vaccination of mice against an otherwise lethal challenge with the Peru strain of Trypanosoma cruzi necessitates the induction of a strong cell mediated immune response. Previously, immunization of mice with the paraflagellar rod proteins from Trypanosoma cruzi90% reduction in parasitemia in immunized mice challenged with the bloodstream stage of Trypanosoma cruzi.

Adenoviridae↗
PubMed2000

Cardiopulmonary and cerebral resuscitation.

The future of cardiopulmonary resuscitation lies in new technologies for monitoring and generating vital organ perfusion during cardiac arrest and the post-resuscitation phase and in pharmacologic agents that will enhance ROSC and reverse ischemia-reperfusion injury. ROSC is the first step toward survival, so interventions that improve ROSC deserve further investigation. Long-term survival with good neurologic recovery is the critical endpoint. Interventions recommended for clinical practice must therefore demonstrate improved long-term survival. The resources required to provide many of the interventions discussed in this article, principally invasive perfusion technologies, cannot be justified unless there is clear benefit. The allocation of such resources to provide intensive resuscitation and post-resuscitation support will need to be addressed from medical and societal viewpoints.

Anti-Arrhythmia Agents↗
PubMed2000

Bovine hemoglobin-based oxygen carrier (HBOC-201) for resuscitation of uncontrolled, exsanguinating liver injury in swine. Carolina Resuscitation Research Group.

In the setting of rapidly exsanguinating hemorrhage, resuscitation with intravenous (i.v.) crystalloid solution may not sustain survival before availability of allogenic blood transfusion and surgery. This study tested the hypothesis that bovine hemoglobin-based oxygen carrier, HBOC-201, would improve resuscitation and extend early survival from exsanguinating hemorrhage. This study simulated the prehospital scenario of rapidly exsanguinating hemorrhage with prolonged prehospital time and lack of blood availability. Severe hemorrhagic shock was induced in swine by using multiple liver lacerations. At 9 min after the onset of bleeding, swine were randomized to receive approximately 10 mL/kg/min of i.v. lactated Ringer's solution (n = 10) or HBOC-201 (n = 7) to achieve a mean aortic pressure (MAP) of 60 mmHg. Thereafter, infusion rate was adjusted to maintain MAP at 60 mmHg for up to 2 h. All animals were initially successfully resuscitated. The results showed 2-h survival was 1 of 10 with lactated Ringer's and 7 of 7 with HBOC-201 (P = 0.0004). Nine lactated Ringer's swine had cardiovascular collapse at 36 +/- 10 min. Lactate at 30 min was 18 +/- 3 mmol/L with lactated Ringer's and 12 +/- 2 mmol/L with HBOC-201 (P < 0.05). Hematocrit was <1% in 9 of 10 lactated Ringer's and 6 of 7 HBOC-201 animals. These data indicate that HBOC-201 improved early survival and stabilized hemodynamic and metabolic parameters vs. lactated Ringer's in this swine model of liver injury with uncontrolled, lethal hemorrhage that simulates the prehospital care environment where allogenic blood is unavailable.

Animals↗
PubMed1999

Cloning of a surface membrane glycoprotein specific for the infective form of Trypanosoma cruzi having adhesive properties to laminin.

Trypomastigotes of Trypanosoma cruzi express a set of surface glycoproteins known, collectively, as Tc-85. A monoclonal antibody to these proteins, named H1A10, inhibits (50-90%) in vitro parasite interiorization into host cells, thus implicating these glycoproteins in the infection process. Two DNA inserts, a genomic DNA fragment and a full-length cDNA encoding the H1A10 epitope, have now been cloned and characterized. Results show that both have high sequence identity with all reported members of the gp85/trans-sialidase gene family, although the H1A10 epitope exists only in the Tc-85 subset of the family. The epitope has been mapped by competition of antibody binding to a Tc-85 recombinant protein with peptides having sequences predicted by the Tc-85 DNA sequence, which contains also putative N-glycosylation sites and COOH-terminal glycosylphosphatidylinositol anchor insertion sites, as expected, since an N-glycan chain and a glycosylphosphatidylinositol anchor have been characterized previously in the Tc-85 subset. The protein encoded by the full-length cDNA insert binds to cells and in vitro to laminin, but not to gelatin or fibronectin, in a saturable manner. For the first time it was possible to assign a defined ligand to a sequenced glycoprotein belonging to the gp85 family. This fact, together with the reported binding of family members to cell surfaces, reinforces the hypothesis that this family encodes glycoproteins with similar sequences but differing enough as to bind to different ligands and thus forming a family of adhesion glycoproteins enabling the parasite to overcome the barriers interposed by cell membranes, extracellular matrices, and basal laminae.

Amino Acid Sequence↗
PubMed1999

Immunization of mice with a TolA-like surface protein of Trypanosoma cruzi generates CD4(+) T-cell-dependent parasiticidal activity.

The gene family encoding a trypomastigote-specific protein restricted to the part of the flagellum in contact with the cell body of the trypomastigote form of Trypanosoma cruzi has been isolated, characterized, and expressed in a baculovirus expression system. The gene family contains three tandemly repeated members that have 97 to 100% sequence identity. The predicted protein encoded by the gene family has both significant amino acid sequence identity and other physical and biological features in common with the TolA proteins of Escherichia coli and Pseudomonas aeruginosa. Based on these similarities, we have designated this gene family tolT. Immunization of mice with recombinant TolT generates a population of CD4(+) T lymphocytes that recognize T. cruzi-infected macrophages, resulting in the production of gamma interferon (IFN-gamma), which leads to NO production and a 50 to 60% reduction in parasite numbers compared to that seen with infected macrophages incubated with naive T cells. This population of T cells also produces both IFN-gamma and interleukin 2 (IL-2) but not IL-4 or IL-5 when incubated with spleen cells stimulated with TolT antigen, indicating that they are of the T-helper 1 type. T cells from mice chronically infected with T. cruzi also produce significant levels of IFN-gamma when cocultured with macrophages and either TolT protein or paraflagellar rod protein, indicating that both of these flagellar proteins produce positive T-cell responses in mice chronically infected with T. cruzi.

Animals↗
PubMed1998

Evidence for four distinct major protein components in the paraflagellar rod of Trypanosoma cruzi.

The major structural proteins present in the paraflagellar rod of Trypanosoma cruzi migrate on SDS-polyacrylamide gels as two distinct electrophoretic bands. The gene encoding a protein present in the faster migrating band, designated PAR 2, has been identified previously. Here we report the isolation and partial characterization of three genes, designated par 1, par 3, and par 4, that encode proteins present in the two paraflagellar rod protein bands. Peptide-specific polyclonal antibodies and monoclonal antibodies against the four proteins encoded by these genes shows that PAR 1 and PAR 3 are present only in the slower migrating paraflagellar rod band, and that PAR 2 and PAR 4 are present only in the faster migrating band. Analysis of the nucleotide sequence of these genes and the amino acid sequence of the conceptual proteins encoded by them indicates that par 2 shares high sequence similarity with par 3 and both are members of a common gene family, of which par 1 may be a distant member. Analysis of gene copy number and steady-state RNA levels suggest that the close stoichiometric ratio of the four PAR proteins is likely maintained by homeostatic regulation of RNA levels rather than gene dosage.

Amino Acid Sequence↗
PubMed1998

Significance of fetal intracardiac echogenic foci in relation to trisomy 21: a prospective sonographic study of high-risk pregnant women.

OBJECTIVE: The aim of the study was to determine if an association exists between intracardiac echogenic foci in the second-trimester fetus and trisomy 21. SUBJECTS AND METHODS: Over a 2-year period, targeted fetal sonography was performed for various indications in 1593 second-trimester high-risk pregnant women. Presence or absence of echogenic foci was recorded for each fetus. Amniocentesis for karyotype analysis was performed in 901 subjects immediately after sonography. The findings of these 901 subjects formed the basis of this report. RESULTS: Intracardiac echogenic foci were present in the left ventricle of 24 (3%) of the 901 fetuses. Three (13%) of these 24 fetuses had trisomy 21; no chromosomal abnormalities were found in the other 21 fetuses. Karyotype analysis revealed trisomy 21 in 14 (2%) of the remaining 877 fetuses who did not exhibit intracardiac echogenic foci. The sensitivity, specificity, positive predictive values, and negative predictive values for intracardiac echogenic foci in predicting trisomy 21 were 18%, 98%, 13%, and 98%, respectively. The association of intracardiac echogenic foci and trisomy 21 was significant (p < .009) by the two-tailed Fisher's exact test. CONCLUSION: In a high-risk obstetric population, the association between fetal intracardiac echogenic foci and trisomy 21 was statistically significant. Therefore, women carrying fetuses with intracardiac echogenic foci should be informed of the statistical association with trisomy 21.

Adolescent↗
PubMed1997

Protection of mice against Trypanosoma cruzi by immunization with paraflagellar rod proteins requires T cell, but not B cell, function.

Previous studies have shown that immunization of mice with the paraflagellar rod proteins (PAR) of Trypanosoma cruzi induces an immune response capable of protecting mice against an otherwise lethal challenge with this parasite. Herein, we define immunologic responses that do or do not play a critical role in PAR-mediated protection. Firstly, PAR-immunized Ab-deficient (muMT) strain mice survived an otherwise lethal T. cruzi challenge, indicating that a B cell response is not required for PAR-induced immunity. However, beta2m -/- mice, which are severely deficient in MHC class I and TCR alphabeta+ CD8+ CD4- T cells, did not survive challenge infection following PAR immunization, indicating that MHC class I/CD8+ T cell function is necessary for protection induced by PAR immunization. Surprisingly, PAR-immunized mice depleted of CD4+ T cells survived a T. cruzi challenge for >84 days postinfection while maintaining a parasitemia that is generally thought to be lethal (i.e., >10(6) trypomastigotes/ml), thus associating CD4+ T cell function with the process of parasite clearance. Consistent with this association, CD4+ T cells from PAR-immunized mice released INF-gamma and stimulated T. cruzi-infected macrophages to release nitric oxide. The importance of IFN-gamma in PAR-induced protective immunity is further indicated by the observation that PAR-immunized INF-gamma knockout mice developed an extremely high parasitemia and did not survive a challenge infection. Thus, while Ab-mediated immune mechanisms are not required for protection induced by PAR immunization, T cell responses are necessary for both elimination of bloodstream parasites and survival.

Animals↗
PubMed1997

Selective aortic arch perfusion during cardiac arrest: enhanced resuscitation using oxygenated perflubron emulsion, with and without aortic arch epinephrine.

STUDY OBJECTIVE: To evaluate selective aortic arch perfusion (SAAP) with an oxygenated fluorocarbon emulsion, with and without aortic arch epinephrine during cardiac arrest. METHODS: This randomized, controlled study, undertaken at a university research laboratory, involved 15 mixed-breed dogs. After 10 minutes of ventricular fibrillation and 30 seconds of CPR, the dogs were randomized to three groups, each comprising five dogs. Group 1 (controls) dogs were given CPR and intravenous epinephrine, .01 mg/kg, at 10.5 minutes and then every 3 minutes. Group 2 dogs (IVE-SAAP) were treated with CPR and intravenous epinephrine (IVE) in the same fashion as the control group but were also subjected to SAAP with 275 mL of oxygenated 60% wt/vol perflubron emulsion over 30 seconds. Group 3 dogs (AoE-SAAP) received the same treatment as the IVE-SAAP group, except that the first epinephrine dose was given intraaortically. RESULTS: Coronary perfusion pressure (CPP) increased during SAAP in both the IVE-SAAP and AoE-SAAP groups but was greater in the AoE-SAAP group. CPR diastolic CPP after SAAP was significantly greater in the AoE-SAAP group than in the control group. Return of spontaneous circulation (ROSC) occurred in two control dogs, all five IVE-SAAP dogs, and all five AoE-SAAP dogs. The time elapsed from the initiation of CPR to ROSC was 6.1 +/- 1.9 minutes in the AoE-SAAP group, compared with 11.0 +/- 5.8 minutes in the IVE-SAAP group. CONCLUSION: SAAP with oxygenated perflubron emulsion improved ROSC, both with and without aortic arch epinephrine. The combination of SAAP with perflubron emulsion and aortic arch epinephrine resulted in higher CPP and more rapid ROSC.

Animals↗
PubMed1997

Selective aortic arch perfusion using serial infusions of perflubron emulsion.

OBJECTIVE: To determine whether selective aortic arch perfusion (SAAP) using serial infusions of oxygenated perflubron emulsion combined with aortic epinephrine (AoE) administration is more effective than conventional therapy in treating cardiac arrest. METHODS: An experimental cardiac arrest model (10 min ventricular fibrillation and 2 min CPR) was used with 12 mixed-breed canines, randomized into 2 groups: control (n = 6), CPR and IV epinephrine, 0.01 mg/kg, at 12 min and then every 3 min; or AoE-SAAP (n = 6), CPR and aortic epinephrine, 0.01 mg/kg, at 12 min and then every 3 min, and serial SAAP with oxygenated 60% weight/volume (w/v) perflubron emulsion as follows: 300 mL over 30 sec at 12 min as continuous SAAP without CPR; 150 mL over 20-30 sec at 15 min and 18 min as pulsed diastolic SAAP during CPR. RESULTS: AoE-SAAP resulted in increased coronary perfusion pressure (CPP) and return of spontaneous circulation (ROSC) compared with control. CPR-diastolic (release phase) CPP during pulsed diastolic SAAP was similar to or greater in magnitude than the CPP generated during the initial SAAP infusion without CPR. ROSC for control was 0/6 and for AoE-SAAP was 4/6 (p < 0.05, Fisher's exact test). Time from initiation of CPR to ROSC with a sustained systolic aortic pressure > 60 mm Hg was 8.0 +/- 1.2 min in the 4 resuscitated AoE-SAAP animals. CONCLUSION: The combination of AoE with SAAP infusions of oxygenated perflubron emulsion was more effective than conventional resuscitation therapy. Pulsed diastolic SAAP is a promising method for performing SAAP.

Analysis of Variance↗
PubMed1996

Trypanosoma cruzi: protective immunity in mice immunized with paraflagellar rod proteins is associated with a T-helper type 1 response.

We have examined the ability of mice to survive a lethal challenge with the parasitic hemoflagellate, Trypanosoma cruzi, following immunization with paraflagellar rod proteins (PAR) 1 and 2 either alone or in combination with the following adjuvants: Freund's, alum, QS-21, Ribi-700, or IL-12. PAR administered subcutaneously (sc) in combination with Freund's or alum provided significant protection, 100 and 83%, respectively, against a T. cruzi challenge. In contrast, PAR in combination with QS-21, Ribi-700, IL-12, or Freund's administered intraperitoneally (ip) or PAR alone provide no protection against a challenge. PAR-specific serum antibody titers and isotype profiles for several of the immunization regimens were determined, and no positive correlation could be seen between a protective immune response and either antibody titer or the subclass of antibody induced. We also examined the ability of PAR to stimulate T cells from the spleen and lymph nodes of mice immunized with PAR in combination with Freund's (sc), Freund's (ip), alum, or Ribi-700. Each of the adjuvants strongly enhanced the ability of enriched T cells to proliferate in a PAR-specific fashion, suggesting no obvious correlation between PAR-specific T cell activation and protection. However, examination of the cytokine profiles of the stimulated T cell groups showed that the protective groups differed from the nonprotective groups. While all four groups showed low levels of IL-10, the Freund's (sc) and alum groups had higher levels of IFN-gamma and IL-2 than Freund's (ip) and Ribi-700 groups, and most strikingly, no IL-4 could be detected in either the Freund's (sc) or the alum group, in contrast to significant levels of IL-4 in both the Freund's (ip) and the Ribi-700 group. These findings indicate that protective immunity in mice immunized with PAR is associated with a Th1-type response.

Adjuvants, Immunologic↗
PubMed1996

Effect of selective aortic arch perfusion on median frequency and peak amplitude of ventricular fibrillation in a canine model.

STUDY OBJECTIVE: To determine whether the computer-derived measures of median frequency or peak amplitude of ventricular fibrillation (VF), obtained by fast Fourier transform of the VF waveform, change during selective aortic arch perfusion in a canine model of cardiac arrest. METHODS: Eight mongrel dogs (including 4 control animals) were sedated, intubated, catheterized, and instrumented to record the electrocardiogram (digitally at 100 Hz, filtered with a finite impulse response filter at 2 Hz), right atrial pressure, and aortic pressure during resuscitation in a model of VF-induced cardiac arrest. After 10 minutes of VF-induced arrest, cardiopulmonary resuscitation (CPR) with a mechanical chest compression device was initiated. Beginning 2 minutes later, the 4 study animals received, every 2 minutes, 45 seconds of selective aortic arch perfusion (SAAP) with autologous blood infusions under high pressure. Defibrillation was attempted after 3 minutes of CPR and every minute thereafter. Both study and control groups received standard-dose epinephrine (.01 mg/kg) every 3 minutes by means of an intraaortic catheter. The median frequency, peak amplitude, and coronary perfusion pressure (CPP) during the 5-second period just before defibrillation were obtained with the use of computer algorithms. RESULTS: All SAAP animals and 1 control animal were resuscitated. Baseline measures of median frequency (8.4 +/- 1.5 versus 6.6 +/- 1.0 Hz) and peak amplitude (.18 +/- .05 versus .36 +/- .13 mV) were not different between the SAAP and control groups, respectively, at the start of CRP. SAAP infusion resulted in significant increases in the SAAP group compared with the control group: median frequency, 9.6 +/- .4 versus 7.3 +/- 1.4 Hz; peak amplitude, .74 +/- .21 versus .39 +/- .15 mV; and CPP, 40.5 +/- 7.1 versus 18.0 +/- 15.0 mm Hg, respectively. Median frequency correlated with CPP (r2 = .67). Peak amplitude did not correlate with CPP (r2 = .06). CONCLUSION: Median frequency and peak amplitude increase with SAAP during cardiac arrest in a canine model. This method of resuscitation was reliable in allowing restoration of a stable perfusing rhythm after defibrillation. Changes in measures of peak amplitude and median frequency may reflect interventions that enhance the likelihood of successful defibrillation and may thereby offer a noninvasive means of monitoring interventions during cardiac arrest.

Animals↗
PubMed1996

Factors associated with prolongation of transport times of emergency pediatric patients requiring transfer to a tertiary care center.

PURPOSE: The purpose of this study was to determine factors associated with longer times to transport of emergency pediatric patients requiring tertiary care. DESIGN: Retrospective case series. SETTING: Emergency pediatric transport service. PARTICIPANTS: Infants and children transported by the transport service at the University of North Carolina Hospitals at Chapel Hill from January 1, 1988, to December 31, 1990. MAIN MEASUREMENTS: The time-to-request, the time from patient arrival at the referring hospital to the time when the request for transfer was received, and the ground time, defined as the time between the transport team's arrival at the referring hospital and their departure, were recorded for each transported patient. RESULTS: Three hundred consecutive children 0 to 16 years (61% male) were transferred. Time-to-request was shorter for trauma patients (median 62 minutes, quartiles 29 and 153 minutes) than for medical patients (median 172 minutes, quartiles 83 and 508 minutes) (P = 0.0001). Infants, children, and adolescents had similar times-to-request of 147 minutes, 129 minutes, and 128 minutes, respectively (P = 0.91). Increased ground times were associated with diagnosis category (median of 40 minutes for medical patients vs 29 minutes for trauma patients) (P = 0.0001), with younger age (median of 46 minutes for infants, 35 minutes for children, and 28 minutes for adolescents) (P = 0.0001), and with the performance of major procedures (median of 35 minutes if no procedures were performed, 38 minutes if one procedure was performed, and 54 minutes if two procedures were performed) (P = 0.039). After the transport team arrived, 13% (40/300) of patients required at least one major procedure prior to transport. CONCLUSIONS: Increased time-to-request for patients with medical diagnoses, increased ground times for younger patients and patients with medical diagnoses, and failure to perform necessary procedures contribute to a prolongation of the time-to-transport of emergency pediatric patients. The magnitude of the impact of these longer transport times on outcome is unknown.

Academic Medical Centers↗
PubMed1995

Male-specific lethal 2, a dosage compensation gene of Drosophila, undergoes sex-specific regulation and encodes a protein with a RING finger and a metallothionein-like cysteine cluster.

In Drosophila the equalization of X-linked gene products between males and females, i.e. dosage compensation, is the result of a 2-fold hypertranscription of most of these genes in males. At least four regulatory genes are required for this process. Three of these genes, maleless (mle), male-specific lethal 1 (msl-1) and male-specific lethal 3 (msl-3), have been cloned and their products have been shown to interact and to bind to numerous sites on the X chromosome of males, but not of females. Although binding to the X chromosome is negatively correlated with the function of the master regulatory gene Sex lethal (Sxl), the mechanisms that restrict this binding to males and to the X chromosome are not yet understood. We have cloned the last of the known autosomal genes involved in dosage compensation, male-specific lethal 2 (msl-2), and characterized its product. The encoded protein (MSL-2) consists of 769 amino acid residues and has a RING finger (C3HC4 zinc finger) and a metallothionein-like domain with eight conserved and two non-conserved cysteines. In addition, it contains a positively and a negatively charged amino acid residue cluster and a coiled coil domain that may be involved in protein-protein interactions. Males produce a msl-2 transcript that is shorter than in females, due to differential splicing of an intron of 132 bases in the untranslated leader. Using an antiserum against MSL-2 we have shown that the protein is expressed at a detectable level only in males, where it is physically associated with the X chromosome. Our observations suggest that MSL-2 may be the target of the master regulatory gene Sxl and provide the basic elements of a working hypothesis on the function of MSL-2 in mediating the 2-fold increase in transcription that is characteristic of dosage compensation.

Amino Acid Sequence↗