An Arabidopsis gene regulatory network for secondary cell wall synthesis.

The plant cell wall is an important factor for determining cell shape, function and response to the environment. Secondary cell walls, such as those found in xylem, are composed of cellulose, hemicelluloses and lignin and account for the bulk of plant biomass. The coordination between transcriptional regulation of synthesis for each polymer is complex and vital to cell function. A regulatory hierarchy of developmental switches has been proposed, although the full complement of regulators remains unknown. Here we present a protein-DNA network between Arabidopsis thaliana transcription factors and secondary cell wall metabolic genes with gene expression regulated by a series of feed-forward loops. This model allowed us to develop and validate new hypotheses about secondary wall gene regulation under abiotic stress. Distinct stresses are able to perturb targeted genes to potentially promote functional adaptation. These interactions will serve as a foundation for understanding the regulation of a complex, integral plant component.

The effect of a topical combination of clonidine and pentoxifylline on post-traumatic neuropathic pain patients: study protocol for a randomized, double-blind placebo-controlled trial.

BACKGROUND: First-line pharmacotherapy for neuropathic pain entails the use of systemic antidepressants and anticonvulsants. These drugs are not optimally effective and poorly tolerated, especially for older patients with comorbid conditions. Given the high number of such patients, there is a need for a greater repertoire of safer and more effective analgesics. Clonidine and pentoxifylline are vasodilator agents that work synergistically to enhance tissue perfusion and oxygenation. The topical administration of these drugs, individually and in combination, has shown anti-nociceptive properties in rodent models of neuropathic pain. A topically-administered combination of clonidine and pentoxifylline also effectively reduced the intensity of both spontaneous and evoked pain in healthy volunteers with experimentally-induced neuropathic pain. The next step in advancing this formulation to clinical use is the undertaking of a phase II clinical study to assess its efficacy and safety in neuropathic pain patients. METHODS/DESIGN: This is a study protocol for a randomized, double-blind, placebo-controlled, phase II clinical trial with a cross-over design. It is a single-centered, 5-week study that will enroll a total of 32 patients with post-traumatic peripheral neuropathic pain. Patients will be treated topically with either a combination of clonidine and pentoxifylline or placebo for a period of 2 weeks each, in randomly assigned order across patients, with an intervening washout period of 1 week. The primary outcome measures of the study are the intensity of spontaneous pain recorded daily in a pain diary with a visual analog scale, and the degree of mechanical allodynia evoked by a brush stimulus. The secondary outcome measures of the study include scores of pain relief and change in the area of punctate hyperalgesia. This trial has been prospectively registered with ClinicalTrials.gov on November 1, 2017. ClinicalTrials.gov Identifier: NCT03342950 . DISCUSSION: The analgesic use of topical treatment with clonidine and pentoxifylline in combination has not been investigated in post-traumatic neuropathic pain. This study could generate the first evidence for the efficacy and safety of the formulation in alleviating pain in patients with neuropathic pain. Furthermore, this trial will provide objective grounds for the investigation of other agents that enhance tissue oxygenation in the topical treatment of peripheral neuropathic pain. TRIAL REGISTRATION: This trial has been registered with ClinicalTrials.gov owned by NIH's US National Library of Medicine. ClinicalTrials.gov NCT03342950 . Registered on November 1, 2017 (trial was prospectively registered). PROTOCOL VERSION AND IDENTIFIERS: This is protocol version 5, dated June 2018. McGill University Health Center (MUHC) Reaseach Ethics Board (REB) identification number: TTNP 2018-3906.

The sua8 suppressors of Saccharomyces cerevisiae encode replacements of conserved residues within the largest subunit of RNA polymerase II and affect transcription start site selection similarly to sua7 (TFIIB) mutations.

Mutations in the Saccharomyces cerevisiae sua8 gene were found to be suppressors of an aberrant ATG translation initiation codon in the leader region of the cyc1 gene. Analysis of cyc1 transcripts from sua8 mutants revealed that suppression is a consequence of diminished transcription initiation at the normal start sites in favor of initiation at downstream sites, including a site between the aberrant and normal ATG start codons. This effect is not cyc1 gene specific since initiation at other genes, including ADH1, CYC7, and HIS4, was similarly affected, although initiation at HIS3 and SPT15 was unaffected. The SUA8 gene was cloned and partially sequenced, revealing identity to RPB1, which encodes the largest subunit of RNA polymerase II. The sua8 suppressors are the result of single amino acid replacements of highly conserved residues. Three replacements were found either within or immediately preceding homology block D, and a fourth was found adjacent to homology block H, indicating that these regions play a role in defining start sites in vivo. Nearly identical effects on start site selection were observed for sua7 suppressors, which encode altered forms of TFIIB. Synthetic lethality was associated with double sua7 sua8 suppressor mutations, and recessive sua7 mutants failed to fully complement recessive sua8 mutants in heterozygous diploids (nonallelic noncomplementation). These data indicate that the largest subunit of RNA polymerase II and TFIIB are important determinants of transcription start site selection in S. cerevisiae and suggest that this function might be conferred by interaction between these two proteins.

Antibodies to Phosphatidylserine/Prothrombin Complex in Antiphospholipid Syndrome: Analytical and Clinical Perspectives.

Antiphospholipid syndrome (APS) is an autoimmune disorder characterized by thrombosis and/or pregnancy-related morbidity accompanied by persistently positive antiphospholipid antibodies (aPL). Current laboratory criteria for APS classification recommend testing for lupus anticoagulant as well as IgG and IgM anticardiolipin, and beta-2 glycoprotein I (anti-ß2GPI) antibodies. However, there appears to be a subset of patients with classical APS manifestations who test negative for the recommended criteria aPL tests. While acknowledging that such patients may have clinical features that are not of an autoimmune etiology, experts also speculate that these "seronegative" patients may test negative for relevant autoantibodies as a result of a lack of harmonization and/or standardization. Alternatively, they may have aPL that target other antigens involved in the pathogenesis of APS. In the latter, autoantibodies that recognize a phosphatidylserine/prothrombin (PS/PT) complex have been reported to be associated with APS and may have diagnostic relevance. This review highlights analytical and clinical attributes associated with PS/PT antibodies, taking into consideration the performance characteristics of criteria aPL tests in APS with specific recommendations for harmonization and standardization efforts.

Towards an open grapevine information system.

Viticulture, like other fields of agriculture, is currently facing important challenges that will be addressed only through sustained, dedicated and coordinated research. Although the methods used in biology have evolved tremendously in recent years and now involve the routine production of large data sets of varied nature, in many domains of study, including grapevine research, there is a need to improve the findability, accessibility, interoperability and reusability (FAIR-ness) of these data. Considering the heterogeneous nature of the data produced, the transnational nature of the scientific community and the experience gained elsewhere, we have formed an open working group, in the framework of the International Grapevine Genome Program (www.vitaceae.org), to construct a coordinated federation of information systems holding grapevine data distributed around the world, providing an integrated set of interfaces supporting advanced data modeling, rich semantic integration and the next generation of data mining tools. To achieve this goal, it will be critical to develop, implement and adopt appropriate standards for data annotation and formatting. The development of this system, the GrapeIS, linking genotypes to phenotypes, and scientific research to agronomical and oeneological data, should provide new insights into grape biology, and allow the development of new varieties to meet the challenges of biotic and abiotic stress, environmental change, and consumer demand.

Utilization of putrescine by Streptococcus pneumoniae during growth in choline-limited medium.

Polyamines such as putrescine are small, ubiquitous polycationic molecules that are required for optimal growth of eukaryotic and prokaryotic cells. These molecules have diverse effects on cell physiology and their intracellular content is regulated by de novo synthesis and uptake from the environment. The studies presented here examined the structure of a putative polyamine transporter (Pot) operon in Streptococcus pneumoniae (pneumococcus) and growth of pneumococci in medium containing putrescine substituted for choline. RT-PCR experiments demonstrated that the four genes encoding the Pot system are co-transcribed with murB, a gene involved in an intermediary step of peptidoglycan synthesis. Pneumococci grown in chemically-defined media (CDM) containing putrescine without choline enter logarithmic phase growth after 36-48 hs. However, culture density at stationary phase eventually reaches that of choline-containing medium. Cells grown in CDM-putrescine formed abnormally elongated chains in which the daughter cells failed to separate and the choline-binding protein PspA was no longer cell-associated. Experiments with CDM containing radiolabeled putrescine demonstrated that pneumococci concentrate this polyamine in cell walls. These data suggest that pneumococci can replicate without choline if putrescine is available and this polyamine may substitute for aminoalcohols in the cell wall teichoic acids.

Intermittent injection vs patient-controlled analgesia for sickle cell crisis pain. Comparison in patients in the emergency department.

BACKGROUND: --The purpose of this study is a prospective assessment of morphine sulfate administration by intermittent intravenous (IV) injections (Int-IV) vs patient-controlled analgesia (PCA) in patients in the emergency department (ED) with sickle cell crisis pain. METHODS: --Patients were at bed rest and received intravenous hydration. Linear analog scale for pain intensity and verbal pain scale, level of alertness, and vital signs were assessed prior to therapy, every 60 minutes thereafter, and at the time of discharge from the ED. Patients were randomized to Int-IV or PCA. During phase 1, patients in the Int-IV group received morphine sulfate 4 mg IV every 30 to 60 minutes as necessary for a linear analog scale for pain intensity greater than 50 mm. The patients in the PCA group received morphine sulfate 2 mg bolus then 1.0 mg with a 6-minute lockout. During phase 2, patients in the Int-IV group received morphine sulfate 8 mg IV every 30 to 60 minutes as necessary for a linear analog scale for pain intensity greater than 50 mm. The patients in the PCA group received morphine sulfate 5 mg bolus then 2.7 mg with a 10-minute lockout. Data were analyzed by unpaired t test, general linear modeling, Mann-Whitney U test, and chi 2 test. RESULTS: --During phase 1, 10 patients (28.3 +/- 7.3 years) received Int-IV and 10 patients (33.9 +/- 12.5 years) received PCA. Treatment groups did not differ significantly regarding duration of pain, amount of morphine administered, linear analog scale for pain intensity, verbal pain scale, level of alertness, or vital signs except for a significantly lower final respiratory rate with Int-IV. In phase 2, 12 patients (28.4 +/- 5.6 years) received Int-IV and 13 patients (26.8 +/- 8.1 years) received PCA. The PCA groups had a significantly shorter elapsed time between onset of pain and treatment (7.3 +/- 6.5 hours) when compared with the Int-IV group (18 +/- 16.9 hours). Treatment groups did not differ significantly with respect to total amount of morphine administered, linear analog scale for pain intensity, verbal pain scale, vital signs, or level of alertness. The PCA group had a significant reduction in length of stay in the ED during phase 2 when compared with phase 1. The ED discharge rate and the incidence of side effects did not differ significantly between groups. CONCLUSION: --At both the low- and high-dose regimens, PCA is equally safe and effective and may be used in place of Int-IV administration of morphine in the ED treatment of sickle cell crisis pain.

Dissociation of the Jak kinase pathway from G-CSF receptor signaling in neutrophils.

Activation of the granulocyte colony-stimulating factor receptor (G-CSFR) induces rapid tyrosine phosphorylation of multiple intracellular substrates in proliferating cells and nonproliferating, terminally differentiated neutrophils. The kinases that couple ligand binding to tyrosine phosphorylation of cellular substrates by the G-CSFR with activation of specific functional programs are largely unknown. In this study, we examined early signaling events in proliferating and terminally differentiated cells following G-CSF stimulation to determine whether identical signaling cascades are activated. In murine Ba/F3 cells transfected with the human G-CSFR and NFS-60 cells constitutively expressing the murine G-CSFR, G-CSF induced tyrosine phosphorylation and activation of Jak1, Jak2, and Tyk2. Tyrosine phosphorylation of Stat3 and, to a lesser extent, Stat1 was also detected following G-CSF stimulation. Using a mitogenically incompetent human G-CSFR mutant in which Pro639 and Pro641 were substituted by alanine, the box 1 PDP motif was found to be required for activation of Jak kinases, tyrosine phosphorylation of the G-CSFR, and recruitment of Stat proteins. Notably, no activation of Jak1, Jak2, Tyk2, Stat1, or Stat3 was observed in neutrophils following G-CSF stimulation. In addition, there was no detectable activation in neutrophils of the recently cloned Jak3 kinase, which has been reported to be expressed at high levels as myeloid cells undergo terminal neutrophilic maturation. These results indicate a lack of involvement of Jak kinases in signaling by the G-CSFR in neutrophils, and suggest utilization of alternative signal transduction pathways distinct from those in proliferating cells. Activation of the Jak-Stat pathway correlates with proliferative signaling by the G-CSFR and requires the membrane-proximal box 1 PXP motif, which is conserved in members of the cytokine receptor superfamily.

Extragenic suppressors of a translation initiation defect in the cyc1 gene of Saccharomyces cerevisiae.

The cycl-362 allele contains a point mutation that generates an aberrant AUG codon upstream of the normal CYC1 translation initiation codon. Mutants containing this allele express only about 2% of normal iso-1-cytochrome c, presumably due to translation initiation at the upstream AUG, termination at a UAA sequence six codons downstream, and failure to reinitiate at the normal AUG codon two nucleotides later. Both intragenic and extragenic revertants of cycl-362, expressing elevated levels of iso-1-cytochrome c, have been isolated simply by selecting for growth on lactate medium. Here we describe an improved method for isolating and readily distinguishing cis- from trans-acting suppressors of the upstream AUG. Eight different genes, designated sua1-sua8, are represented in our current collection of extragenic suppressors; all are recessive and enhance iso-1-cytochrome c levels to 10-60% of normal. None of the sua genes is allelic to SUI2 or sui3, which encode eIF-2 alpha and eIF-2 beta, respectively, or to SUI1. Many of the suppressors exhibit pleiotropic phenotypes, including slow growth, cold (16 degrees C) and heat (37 degrees C) sensitivity. These phenotypes have been exploited to clone the SUA5, SUA7 and SUA8 genes, which are presently being characterized. The structure of cyc1-362 and the number of sua genes already uncovered suggest that the SUA genes are likely to encode factors affecting several different cellular processes, including translation initiation, mRNA stability and possibly transcription start site selection.

Exploiting tumor hypoxia through bioreductive release of diffusible cytotoxins: the cobalt(III)-nitrogen mustard complex SN 24771.

PURPOSE: To assess the oxygen dependence of a novel cobalt-nitrogen mustard complex, SN 24771, designed to release a diffusible cytotoxic metabolite in hypoxic tumor microenvironments. METHODS AND MATERIALS: Oxygen dependence of cell killing was assessing in well-stirred single cell suspensions obtained by enzymatic dissociation of EMT6 spheroids, using a sensitive oxygen electrode to measure oxygen concentrations in solution. Cell killing in intact EMT6 spheroids was also compared with that in single cell suspensions. RESULTS: Cytotoxicity of SN 24771 in single cell suspensions was inhibited by very low concentrations of oxygen. The C50 value (O2 required for 50% inhibition of log cell kill) was ca. 0.02% O2 at 1 h, and the K value (O2 required to give a cytotoxic potency equal to the average of that at zero and infinite O2) was of a similar order. However, intact spheroids were much more sensitive to SN 24771 than could be accounted for by the K curve for single cell suspensions, this estimate being based on published data for the oxygen concentration profile in these spheroids. CONCLUSION: The cytotoxicity of SN 24771 is inhibited appreciably at oxygen concentrations which are too low to provide radiosensitization. In this respect, SN 24771 resembles organic bioreductive drugs such as quinones and nitroaromatic compounds. However, the extensive killing observed in multicellular spheroids is consistent with release of a diffusible nitrogen mustard on reduction. Bioreductive drugs with a low K value for activation, but which release a diffusible cytotoxin, may have desirable properties as tumor radiosensitizers.

Hypoxia-selective antitumor agents. 7. Metal complexes of aliphatic mustards as a new class of hypoxia-selective cytotoxins. Synthesis and evaluation of cobalt(III) complexes of bidentate mustards.

Nitrogen mustards coordinated to Co(III) are potential hypoxia-selective cytotoxins, since one-electron reduction to the Co(II) complexes greatly labilizes the Co-N bonds, causing the release of activated aliphatic mustards which can act as diffusible cytotoxins. Two series of Co(III) complexes of the bidentate bisalkylating nitrogen mustard ligands N,N'-bis(2-chloroethyl)-ethylenediamine (BCE) and N,N-bis(2-chloroethyl)ethylenediamine (DCE) have been synthesized and evaluated for their hypoxia-selective cytotoxicity against AA8 cells in vitro. The complexes also bear two 3-alkylpentane-2,4-dionato (acac) auxiliary ligands; cyclic voltammetry studies show that variation of the alkyl group in the auxiliary ligands alters the reduction potentials of the complexes (within a series) over a range of about 150 mV. In both series, the patterns of cytotoxicities of the cobalt complexes were broadly similar to those of the respective free ligands, suggesting that the cytotoxicity of these compounds is due to release of the free ligands. The nonsymmetrical ligand DCE and its cobalt complexes were 1 order of magnitude more cytotoxic than the corresponding BCE compounds. Although the unsubstituted acac/DCE complex showed no hypoxic selectivity against repair-deficient UV4 cells in a stirred suspension culture assay, the methyl and ethyl analogues showed substantial selectivity. The results may indicate a narrow range of acceptable reduction potential, with an optimum close to that for the methyl analogue (E1/2 = -305 mV). The methyl analogue also shows hypoxic selectivity against repair-proficient cell lines (e.g., AA8 and EMT6) and has high activity against EMT6 cells in intact spheroids, suggesting that the released DCE is capable of back-diffusion from the hypoxic core of the spheroid. This work shows that metal complexes of nitrogen mustards have significant hypoxia-selective cytotoxicity toward mammalian cells in cell culture and are a new general class of hypoxia-selective cytotoxins.

Blunt trauma resuscitation: the old can respond.

HYPOTHESIS: Old and young trauma patients are capable of hyperdynamic response during standardized shock resuscitation. DESIGN: The responses of old and young trauma patients resuscitated using a standardized protocol are compared in an inception cohort study. A standardized resuscitation protocol was used to attain and maintain an oxygen delivery index of 600 mL/min x m2 or greater (DO2I > or = 600) for the first 24 hours in the intensive care unit. Interventions, responses, and outcomes for old (> or = 65 years) and young (<65 years) patients are described. Data were analyzed using analysis of variance, the chi2 test, and the t test; P<.05 was considered significant. SETTING: A 20-bed shock trauma intensive care unit in a regional level I trauma center. PATIENTS: Patients at high risk of postinjury multiple organ failure, ie, major organ or vascular injury and/or skeletal fractures, initial base deficit of 6 mEq/L or greater, need for 6 units or more of packed red blood cells in the first 12 hours, or age of 65 years or older with any 2 previous criteria. INTERVENTIONS: Pulmonary artery catheter, crystalloid fluid infusion, packed red blood cell transfusion, and moderate inotrope support, as needed in that sequence, to attain DO2I > or = 600. MAIN OUTCOME MEASURES: Intensive care unit length of stay and survival. RESULTS: During 19 months ending June 1999, 12 old patients (58% male; age, 76 +/- 2 years [mean +/- SEM] [P<.0011; Injury Severity Score, 20 +/- 2 [P=.02]) and 54 young patients (61% male; age, 37 +/- 2 years; Injury Severity Score, 32 +/- 2) were resuscitated. Initially, for old patients (cardiac index, 2.0 +/- 0.2 L/min x m2) and for young patients (cardiac index, 3.0 +/- 0.2 L/min x m2; P=.01), 24-hour volumes were as follows: 16 +/- 3 L of crystalloid and 12 +/- 3 units of packed red blood cells for the old patients and 21 +/- 2 L of crystalloid and 19 +/- 2 units of packed red blood cells for the young patients. For old patients, 9 (75%) attained DO2I > or = 600, and 11 (92%) survived 7 or more days and 5 (42%) 30 or more days. For young patients, 45 (83%) attained the DO2I goal, and 48 (89%) survived 30 or more days. Intensive care unit length of stay was 25 +/- 9 days for the old patients and 23 +/- 2 days for the young patients. CONCLUSIONS: Elderly patients have initially depressed cardiac index but generate hyperdynamic response. Although ultimate outcome is poorer than in the younger cohort, resuscitation is not futile.

Delayed complications of nonoperative management of blunt adult splenic trauma.

OBJECTIVE: To determine the incidence and type of delayed complications from nonoperative management of adult splenic injury. DESIGN: Retrospective medical record review. SETTING: University teaching hospital, level I trauma center. PATIENTS: Two hundred eighty patients were admitted to the adult trauma service with blunt splenic injury during a 4-year period. Men constituted 66% of the population. The mean (+/-SEM) age was 32.2+/-1.0 years and the mean (+/-SEM) Injury Severity Score was 22.8+/-0.9. Fifty-nine patients (21%) died of multiple injuries within 48 hours and were eliminated from the study. One hundred thirty-four patients (48%) were treated operatively within the first 48 hours after injury and 87 patients (31%) were managed nonoperatively. MAIN OUTCOME MEASURES: We reviewed the number of units of blood transfused, intensive care unit length of stay, overall length of stay, outcome, and complications occurring more than 48 hours after injury directly attributable to the splenic injury. RESULTS: Patients managed nonoperatively had a significantly lower Injury Severity Score (P<.05) than patients treated operatively. Length of stay was significantly decreased in both the number of intensive care unit days as well as total length of stay (P<.05). The number of units of blood transfused was also significantly decreased in patients managed nonoperatively (P<.05). Seven patients (8%) managed nonoperatively developed delayed complications requiring intervention. Five patients had overt bleeding that occurred at 4 days (3 patients), 6 days (1 patient), and 8 days (1 patient) after injury. Three patients underwent splenectomy, 1 had a splenic artery pseudoaneurysm embolization, and 1 had 2 areas of bleeding embolization. Two patients developed splenic abscesses at approximately 1 month after injury; both were treated by splenectomy. CONCLUSION: Significant numbers of delayed splenic complications do occur with nonoperative management of splenic injuries and are potentially life-threatening.

The effect of the nitroimidazole drug dimetridazole on microaerophilic campylobacters.

Dimetridazole, a nitroimidazole drug reported to act only on obligately anaerobic micro-organisms, is widely used for the prevention and treatment of swine dysentery. Forty-four strains of the microaerophilic bacterium Campylobacter coli isolated from either healthy or diseased pigs, and a strain of Campylobacter fetus, were all sensitive to dimetridazole. The sensitivities (minimal inhibitory concentration less than 10 microng per ml) were similar to those of anaerobic bacteria. Dimetridazole inhibited growth of campylobacters in a shaken culture in air, but did not inhibit uptake of oxygen. Inhibition of growth appeared to result from an inhibition of nucleic-acid synthesis and does not seem to depend upon interference with electron transport in the catabolism of pyruvate.

Antenatal assessment of twin gestation.

We have identified that twin gestation presents considerable risks to the well-being of both infants that can be traced to either related maternal or intrinsic fetoplacental factors. A protocol for the assessment of twin gestation is established, beginning with a basis in ultrasound identification of twinning and correct gestational dating. Because most hazards for twins are related to abnormal growth, discrepant growth between twins, and abnormalities of placentation, the approach to assessing well-being requires good serial biometry of twins. This critical review addresses the individual and combined application of standard tests used for evaluation of intrauterine health in single pregnancies: (1) ultrasound fetal growth curves; (2) Doppler velocimetry of the umbilical artery; (3) nonstress tests; (4) amniotic fluid assessment and (5) biophysical profile testing. The best current evidence suggests that there are clear deficiencies in the basis for growth nomograms for twin gestations, and with the exception of femur length, most individual anatomic measurements start to deviate from singleton standards between 21 and 30 weeks' gestation. Regardless of formulae used, estimated fetal weight provides the best discriminator for discordant growth. Dynamic assessment of fetal well-being is best provided by a combination of Doppler velocimetry and nonstress testing. Semiquantitative amniotic fluid assessment, other than establishing pathological conditions (eg, twin transfusion syndrome), is problematic and difficult to reproduce. Inadequate data exist to establish the value of the biophysical profile in twins. Given the limitations of present knowledge, serial assessment of twins beginning in the midtrimester with ultrasound observation, and adding combinations of Doppler velocimetry and nonstress testing in the third trimester, seems to represent the most reasonable current clinical approach to twin well-being.

Vacuum-assisted wound closure provides early fascial reapproximation in trauma patients with open abdomens.

BACKGROUND: Damage control and decompressive laparotomies salvage severely injured patients who would have previously died. Unfortunately, many of these patients develop open abdomens. A variety of management strategies exist. The end result in many cases, however, is a large ventral hernia that requires a complex repair 6 to 12 months after discharge. We instituted vacuum-assisted wound closure (VAWC) to achieve early fascial closure and eliminate the need for delayed procedures. METHODS: For 12 months ending June 2000, 14 of 698 trauma intensive care unit admissions developed open abdomens and were managed with VAWC dressing. This was changed every 48 hours in the operating room with serial fascial approximation until complete closure. RESULTS: Fascial closure was achieved in 13 patients (92%) in 9.9 +/- 1.9 days, and 2.8 +/- 0.6 VAWC dressing changes were performed. There were 2 wound infections, no eviscerations, and no enteric fistulas. CONCLUSIONS: Use of VAWC can safely achieve early fascial closure in more than 90% of trauma patients with open abdomens.

Bis-tropolonato derivatives of cobalt(III) complexes of bidentate aliphatic nitrogen mustards as potential hypoxia-selective cytotoxins.

A series of cobalt(III) complexes, [Co(trop)2(L)]+, where trop is the tropolonate anion and L is a bidentate amine or nitrogen mustard, have been prepared as potential hypoxia-selective cytotoxins (L = BEE, N,N'-diethylethylenediamine; DEE, N,N-diethylethylenediamine; BCE, N,N'-bis(2-chloroethyl)ethylenediamine; DCE, N,N-bis(2-chloroethyl)ethylenediamine). The 1H NMR and 13C{1H} NMR spectra of the complexes were assigned on the basis of chemical shift considerations, 2D NMR studies (including 13C-1H and 1H-1H COSY correlation experiments), and comparison to the related, known acetylacetonato (acac) complexes [Co(acac)2(L)]+. An x-ray crystal structure determination of the analogue [Co(trop)2(BEE)]ClO4 showed it to be the delta SS/lambda RR enantiomeric pair of diastereomers. The tropolonato complexes have significantly higher reduction potentials than the corresponding acac complexes, suggesting more facile cellular reduction. In agreement with this, the mustard complexes have IC50 values in cells little different to those of the free mustards even under aerobic conditions, and do not show hypoxic selectivity in a clonogenic assay under conditions where the corresponding 3-methylacac complex of DCE showed significant selectivity.

Ethanol modulates cocaine-induced behavioral change in inbred mice.

We recently conducted a study of the behavioral effects of combined cocaine and ethanol in genetically defined mice. Male and female C57BL/6 (B6) and DBA/2 (D2) were tested in an automated activity monitor on 2 consecutive days. On day 1, all animals received an IP injection of sterile saline and were placed into the activity monitor for 30 min. Behaviors measured were total distance traveled, stereotypy, nosepokes, and wall-seeking. On day 2, all animals were tested again for 15 min following injection of one of the following: saline, 10% v/v ethanol at 2.0 g kg(-1) or 2.0 g kg(-1) ethanol plus 5, 15, or 30 mg kg(-1) cocaine. Cocaine alone at the same doses was injected into separate groups of animals. For the B6 strain, the overall effect of ethanol was to reduce cocaine-induced locomotor stimulation; no consistent effect of ethanol on cocaine-induced locomotion was observed in D2 mice. Cocaine-induced inhibition of nosepokes in both strains and sexes was partially reversed by ethanol. Ethanol also partially reversed cocaine-elevated stereotypy in both strains and both sexes. In B6 mice, cocaine-increased wall seeking tended to be reversed by coadministration of ethanol, whereas no consistent pattern was observed in the D2s. Results from this study suggest that the several measures affected by cocaine (locomotor activity, stereotypy, exploration, thigmotaxis) were, in turn, differentially affected by concurrent treatment with ethanol. Furthermore, our results point to genetic-based differences in ethanol's effects on cocaine-related behaviors. We address the implications for combined ethanol and cocaine use in humans.

An unusual case of cardiac tamponade.

A 29-year-old woman with Ebstein's anomaly on anticoagulant therapy presented with chest pain. A diagnosis of pericarditis was made once a myocardial infarction and pulmonary embolus had been excluded. She was discharged but returned shortly thereafter with fever, tachypnea and tachycardia. A repeat chest film disclosed that the cardiac silhouette had enlarged greatly since prior admission. Despite the absence of pulsus paradoxus, right heart catheterization confirmed the clinical suspicion of pericardial tamponade.

The nonstress test. Reassessment of the "gold standard".

The NST is simpler, less invasive, less time-consuming, and less expensive than its predecessor, the CST. It may be conducted in the outpatient setting with less skilled personnel. If the NST is to remain an important diagnostic modality, the issues of interpretative criteria, test conditions, and population composition must be reconsidered. In the future, authors must specify these data in detail and present their parameters of sensitivity, specificity, predictive values, and prevalence clearly. They also would be well advised to consider the value of adding other FHR information, such as baseline rate and variability to their interpretative criteria. Because clinical management--i.e., whether or not to intervene--may be influenced by or directly follow the outcome of an NST, it is even more important that such critical questions be addressed. The testing process should be cost effective, accurate, and sensitive enough to detect pregnancies at risk, yet specific enough to identify pregnancies that will have a good outcome. We believe that the issue of stand-alone NSTs should be examined for all indications and gestational ages commonly encountered. In our laboratory, current practice suggests that most conditions, at most gestational ages, benefit from an approach that combines the NST with amniotic fluid assessment and that uses age-adjusted standards to avoid misclassification of normal infants.