Sigh Ventilation in Patients With Trauma: The SiVent Randomized Clinical Trial

Importance

Among patients receiving mechanical ventilation, tidal volumes with each breath are often constant or similar. This may lead to ventilator-induced lung injury by altering or depleting surfactant. The role of sigh breaths in reducing ventilator-induced lung injury among trauma patients at risk of poor outcomes is unknown.

Objective

To determine whether adding sigh breaths improves clinical outcomes.

Design, Setting, and Participants

A pragmatic, randomized trial of sigh breaths plus usual care conducted from 2016 to 2022 with 28-day follow-up in 15 academic trauma centers in the US. Inclusion criteria were age older than 18 years, mechanical ventilation because of trauma for less than 24 hours, 1 or more of 5 risk factors for developing acute respiratory distress syndrome, expected duration of ventilation longer than 24 hours, and predicted survival longer than 48 hours.

Interventions

Sigh volumes producing plateau pressures of 35 cm H2O (or 40 cm H2O for inpatients with body mass indexes >35) delivered once every 6 minutes. Usual care was defined as the patient's physician(s) treating the patient as they wished.

Main Outcomes and Measures

The primary outcome was ventilator-free days. Prespecified secondary outcomes included all-cause 28-day mortality.

Results

Of 5753 patients screened, 524 were enrolled (mean [SD] age, 43.9 [19.2] years; 394 [75.2%] were male). The median ventilator-free days was 18.4 (IQR, 7.0-25.2) in patients randomized to sighs and 16.1 (IQR, 1.1-24.4) in those receiving usual care alone (P = .08). The unadjusted mean difference in ventilator-free days between groups was 1.9 days (95% CI, 0.1 to 3.6) and the prespecified adjusted mean difference was 1.4 days (95% CI, -0.2 to 3.0). For the prespecified secondary outcome, patients randomized to sighs had 28-day mortality of 11.6% (30/259) vs 17.6% (46/261) in those receiving usual care (P = .05). No differences were observed in nonfatal adverse events comparing patients with sighs (80/259 [30.9%]) vs those without (80/261 [30.7%]).

Conclusions and Relevance

In a pragmatic, randomized trial among trauma patients receiving mechanical ventilation with risk factors for developing acute respiratory distress syndrome, the addition of sigh breaths did not significantly increase ventilator-free days. Prespecified secondary outcome data suggest that sighs are well-tolerated and may improve clinical outcomes.

Trial Registration

ClinicalTrials.gov Identifier: NCT02582957.

Trial Participation and Outcomes Among English-Speaking and Spanish-Speaking Patients With Appendicitis Randomized to Antibiotics: A Secondary Analysis of the CODA Randomized Clinical Trial

Importance

Spanish-speaking participants are underrepresented in clinical trials, limiting study generalizability and contributing to ongoing health inequity. The Comparison of Outcomes of Antibiotic Drugs and Appendectomy (CODA) trial intentionally included Spanish-speaking participants.

Objective

To describe trial participation and compare clinical and patient-reported outcomes among Spanish-speaking and English-speaking participants with acute appendicitis randomized to antibiotics.

Design, Setting, and Participants

This study is a secondary analysis of the CODA trial, a pragmatic randomized trial comparing antibiotic therapy with appendectomy in adult patients with imaging-confirmed appendicitis enrolled at 25 centers across the US from May 1, 2016, to February 28, 2020. The trial was conducted in English and Spanish. All 776 participants randomized to antibiotics are included in this analysis. The data were analyzed from November 15, 2021, through August 24, 2022.

Intervention

Randomization to a 10-day course of antibiotics or appendectomy.

Main Outcomes and Measures

Trial participation, European Quality of Life-5 Dimensions (EQ-5D) questionnaire scores (higher scores indicating a better health status), rate of appendectomy, treatment satisfaction, decisional regret, and days of work missed. Outcomes are also reported for a subset of participants that were recruited from the 5 sites with a large proportion of Spanish-speaking participants.

Results

Among eligible patients 476 of 1050 Spanish speakers (45%) and 1076 of 3982 of English speakers (27%) consented, comprising the 1552 participants who underwent 1:1 randomization (mean age, 38.0 years; 976 male [63%]). Of the 776 participants randomized to antibiotics, 238 were Spanish speaking (31%). Among Spanish speakers randomized to antibiotics, the rate of appendectomy was 22% (95% CI, 17%-28%) at 30 days and 45% (95% CI, 38%-52%) at 1 year, while in English speakers, these rates were 20% (95% CI, 16%-23%) at 30 days and 42% (95% CI 38%-47%) at 1 year. Mean EQ-5D scores were 0.93 (95% CI, 0.92-0.95) among Spanish speakers and 0.92 (95% CI, 0.91-0.93) among English speakers. Symptom resolution at 30 days was reported by 68% (95% CI, 61%-74%) of Spanish speakers and 69% (95% CI, 64%-73%) of English speakers. Spanish speakers missed 6.69 (95% CI, 5.51-7.87) days of work on average, while English speakers missed 3.76 (95% CI, 3.20-4.32) days. Presentation to the emergency department or urgent care, hospitalization, treatment dissatisfaction, and decisional regret were low for both groups.

Conclusions and Relevance

A high proportion of Spanish speakers participated in the CODA trial. Clinical and most patient-reported outcomes were similar for English- and Spanish-speaking participants treated with antibiotics. Spanish speakers reported more days of missed work.

Trial Registration

ClinicalTrials.gov Identifier: NCT02800785.

Outcomes of Restricted versus Liberal Post-Operative Antibiotic Use in Patients Undergoing Appendectomy: A DOOR/RADAR Post Hoc Analysis of the EAST Appendicitis MUSTANG Study

Background: There is no consensus on the duration of antibiotic use after appendectomy. We hypothesized that restricted antibiotic use is associated with better clinical outcomes. Patients and Methods: We performed a post hoc analysis of the Eastern Association for the Surgery of Trauma (EAST) Multicenter Study of the Treatment of Appendicitis in America-Acute, Perforated, and Gangrenous (MUSTANG) study using the desirability of outcome ranking/response adjusted for duration of antibiotic risk (DOOR/RADAR) framework. Three separate datasets were analyzed based on restricted versus liberal post-operative antibiotic groups: simple appendicitis (no vs. yes); complicated appendicitis, only four days (≤24 hours vs. 4 days); and complicated appendicitis, four or more days (≤24 hours vs. ≥4 days). Patients were assigned to one of seven mutually exclusive DOOR categories RADAR ranked within each category. DOOR/RADAR score pairwise comparisons were performed between all patients. Each patient was assigned either 1, 0, or -1 if they had better, same, or worse outcomes than the other patient in the pair, respectively. The sum of these numbers (cumulative comparison score) was calculated for each patient and the group medians of individual sums were compared by Wilcoxon rank sum. Results: For simple appendicitis, the restricted group had higher median sums than the liberal group (552 [552,552] vs. -1,353 [-1,353, -1,353], p < 0.001). For both complicated appendicitis analyses, the restricted group had higher median sums than the liberal: only 4 (196 [23,196] vs. -121 [-121, -121], p < 0.02) and 4 or more (660 [484,660] vs -169 [-444,181], p < 0.001). Conclusions: Restricted post-operative antibiotic use in patients after appendectomy is a dominant strategy when considering treatment effectiveness and antibiotic exposure.

New Pathogenesis Mechanisms and Translational Leads Identified by Multidimensional Analysis of Necrotizing Myositis in Primates

A fundamental goal of contemporary biomedical research is to understand the molecular basis of disease pathogenesis and exploit this information to develop targeted and more-effective therapies. Necrotizing myositis caused by the bacterial pathogen Streptococcus pyogenes is a devastating human infection with a high mortality rate and few successful therapeutic options. We used dual transcriptome sequencing (RNA-seq) to analyze the transcriptomes of S. pyogenes and host skeletal muscle recovered contemporaneously from infected nonhuman primates. The in vivo bacterial transcriptome was strikingly remodeled compared to organisms grown in vitro, with significant upregulation of genes contributing to virulence and altered regulation of metabolic genes. The transcriptome of muscle tissue from infected nonhuman primates (NHPs) differed significantly from that of mock-infected animals, due in part to substantial changes in genes contributing to inflammation and host defense processes. We discovered significant positive correlations between group A streptococcus (GAS) virulence factor transcripts and genes involved in the host immune response and inflammation. We also discovered significant correlations between the magnitude of bacterial virulence gene expression in vivo and pathogen fitness, as assessed by previously conducted genome-wide transposon-directed insertion site sequencing (TraDIS). By integrating the bacterial RNA-seq data with the fitness data generated by TraDIS, we discovered five new pathogen genes, namely, S. pyogenes 0281 (Spy0281 [dahA]), ihk-irr, slr, isp, and ciaH, that contribute to necrotizing myositis and confirmed these findings using isogenic deletion-mutant strains. Taken together, our study results provide rich new information about the molecular events occurring in severe invasive infection of primate skeletal muscle that has extensive translational research implications.IMPORTANCE Necrotizing myositis caused by Streptococcus pyogenes has high morbidity and mortality rates and relatively few successful therapeutic options. In addition, there is no licensed human S. pyogenes vaccine. To gain enhanced understanding of the molecular basis of this infection, we employed a multidimensional analysis strategy that included dual RNA-seq and other data derived from experimental infection of nonhuman primates. The data were used to target five streptococcal genes for pathogenesis research, resulting in the unambiguous demonstration that these genes contribute to pathogen-host molecular interactions in necrotizing infections. We exploited fitness data derived from a recently conducted genome-wide transposon mutagenesis study to discover significant correlation between the magnitude of bacterial virulence gene expression in vivo and pathogen fitness. Collectively, our findings have significant implications for translational research, potentially including vaccine efforts.

Comparative effectiveness of primary tumor resection in metastatic colon cancer: An instrumental variable analysis

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Background: Although the safety of chemotherapy without primary tumor resection (PTR) has been established, questions remain regarding potential survival benefit with PTR. The purpose of this study was to compare mortality with and without PTR among patients with unresectable metastatic colon cancer using nationwide hospital based cancer registry data. Methods: An observational study was conducted of patients with stage 4 colon cancer identified from the National Cancer Data Base (2003-2005). Patients who underwent metastectomy were excluded. Patient, treatment, and hospital data were analyzed. Multivariate Cox regression stratified by receipt of chemotherapy was performed to compare survival with and without PTR. To account for treatment selection bias, Propensity Score Weighting (PSW) and Instrumental Variable (IV) analyses, using hospital-level PTR rate as the instrument, were performed. In order to account for the potential bias associated with early comorbidity or disease burden associated deaths (survivor treatment bias), 1 year landmark analysis was performed. Results: A total of 14,399 patients met inclusion criteria and 6,735 patients were eligible for landmark analysis. PTR was performed in 38.2% of the total cohort and 73.8% of those at landmark. Using multivariate Cox regression analysis, PTR was associated with a significant reduction in mortality (HR 0.39; 95% CI, 0.38-0.41). This effect persisted with PSW (HR 0.4; 95% CI, 0.38-0.43). However, IV analysis showed a much smaller effect, (RR 0.88; 95% CI, 0.83-0.93). While a smaller benefit was seen on landmark analysis using multivariate Cox regression (HR 0.6; 95% CI, 0.55-0.64) and PSW (HR 0.59; 95% CI, 0.54-0.64), IV analysis showed no improvement in survival with PTR (RR 0.97; 95% CI, 0.87-1.06). Stratification by chemotherapy did not alter the results. Conclusions: Among patients with stage IV colon cancer, PTR offered no survival benefit over systemic chemotherapy alone when the IV method was applied at the 1 year landmark. Subject to selection and survivor treatment bias, standard regression analysis may overestimate the benefit of PTR. Future study should focus on identifying patients most likely to benefit from PTR.

Foreign material erosion after laparoscopic Roux-en-Y gastric bypass: findings and treatment

BACKGROUND

Patients after laparoscopic Roux-en-Y gastric bypass (LRYGB) can have nonspecific, upper gastrointestinal (UGI) complaints. During postoperative endoscopy, we have noted the erosion of nondissolvable material, such as Peri-Strips or silk sutures, into the gastric pouch. This study reports the incidence and presentation of foreign material erosion into the gastric pouch after a LRYGB and the outcome after therapeutic endoscopy.

METHODS

From a prospective LRYGB database, postoperative endoscopies from February 2002 to June 2005 that found foreign material in the gastric pouch were reviewed. Presenting symptoms, time until endoscopy, and patient outcomes were evaluated. A therapeutic endoscopy was performed by using endo-shears and biopsy forceps to remove the foreign material.

RESULTS

A total of 23 patients underwent 29 therapeutic endoscopies. From February 2002 to November 2004, 208 LRYGB were performed using silk suture for the outer layer of the gastrojejunostomy, and 21 patients (10%) had silk suture found on endoscopy. Peri-Strips were used from February 2002 to December 2003 (n = 153) and 6 patients (4%) had erosions. Since converting to Vicryl suture and Seamguard, we have had 173 and 228 patients, respectively, without pouch erosion. The most common presenting symptom was abdominal pain (n = 15, 65%). Other symptoms included nausea (n = 13, 57%), vomiting (n = 12, 52%), dysphagia (n = 5, 22%), and melena (n = 3, 13%). Foreign material was found by a mean of 34 weeks. Of 29 therapeutic endoscopies, 20 resulted in resolution of symptoms (69%), 4 led to improvements (14%), and 5 had no effect (17%). There were no endoscopic complications and no anastomotic leaks.

CONCLUSIONS

Nonabsorbable material used during a LRYGB can migrate into the gastric pouch and cause UGI complaints. A therapeutic endoscopy will resolve most UGI symptoms. Using absorbable material in the creation of the gastric pouch and the gastrojejunostomy will avoid foreign material erosion.

Comparison of novel and existing methods for detection of linkage disequilibrium using parent-child trios in the GAW12 genetic isolate simulated data

A novel method for joint detection of association caused by linkage disequilibrium (LD) and estimation of both recombination fraction and linkage disequilibrium parameters was compared to several existing implementations of the transmission/disequilibrium test (TDT) and modifications of the TDT in the simulated genetic isolate data from Genetic Analysis Workshop 12. The first completely genotyped trio of affected child and parents was selected from each family in each replicate so that the TDT tests are valid tests of linkage and association, rather than being only valid as tests for linkage. In general, power to detect LD using the genome-wide scan markers was inadequate in the individual replicate samples, but the power was better when analyzing several SNP markers in candidate gene 1.

Carotid endarterectomy in a community hospital setting: a three-year experience

The need for all medical institutions that treat carotid artery occlusive disease to continuously monitor their surgical experience is quite evident. Nonetheless, a national survey in 1995 found that only 15% of physicians reported knowing the perioperative stroke rate at the hospitals where they perform or refer patients for carotid endarterectomy. Neurologic morbidity related to the performance of carotid endarterectomy has been continuously monitored at Howard County General Hospital for the past decade, but the true significance of this data could not be appreciated without a more comprehensive analysis of the clinical experience. The present study was undertaken with the intent of providing this information.

Neonatal outcome in severe preeclampsia at 24 to 36 weeks' gestation: does the HELLP (hemolysis, elevated liver enzymes, and low platelet count) syndrome matter?

OBJECTIVE

Our purpose was to compare neonatal outcome after preterm delivery of infants whose gestation was complicated by the HELLP (hemolysis, elevated liver enzymes, and low platelet count) syndrome, partial HELLP syndrome, or severe preeclampsia.

STUDY DESIGN

We reviewed the maternal and neonatal charts from 269 consecutive pregnancies complicated by the HELLP syndrome or severe preeclampsia managed at our perinatal center. The HELLP syndrome was defined by previously published laboratory criteria. Viable pregnancies were divided into 3 groups: HELLP syndrome, partial HELLP syndrome (at least 1, but not all 3, features of the HELLP syndrome), and severe preeclampsia (no features of the HELLP syndrome). Results were compared by means of chi2 analysis and Student t test where appropriate. Logistic regression was used to evaluate outcome variables at different gestational ages.

RESULTS

There were no significant differences in complications among the 3 groups at each gestational age. There was, as expected, a significant decrease in morbidity and mortality rates with advanced gestational age.

CONCLUSIONS

In severe preeclampsia, neonatal morbidity and death are related to gestational age rather than to the presence or absence of the HELLP syndrome. Whether expectant management is safe for women with the HELLP syndrome requires further study.

The clinical utility of serum uric acid measurements in hypertensive diseases of pregnancy

OBJECTIVE

Our purpose was to evaluate the clinical utility of serum uric acid measurements in the hypertensive diseases of pregnancy.

STUDY DESIGN

We performed a nested case-control study to assess the clinical utility of serum uric acid measurements in women with hypertensive diseases of pregnancy. We identified 344 women who had serum uric acid measurements at term and categorized them into five diagnostic groups according to definitions of hypertensive diseases in pregnancy published by the National Working Group on Hypertension in Pregnancy: transient hypertension of pregnancy (n = 69), preeclampsia (n = 130), chronic hypertension (n = 23), chronic hypertension with superimposed preeclampsia (n = 29), and normal (n = 93). We compared the mean uric acid concentration for each group with use of a one-way analysis of variance and Scheffe's post hoc test and calculated the sensitivities and specificities in diagnosing preeclampsia as well as the likelihood ratios for serum uric acid values of 5.5, 6.0, and 6.5 mg/dl. We also examined the correlation between serum uric acid levels and several clinical outcome measures in women with hypertensive diseases of pregnancy.

RESULTS

The mean serum uric acid values for women with preeclampsia (6.2 +/- 1.4 mg/dl) and transient hypertension (5.6 +/- 1.7 mg/dl) were significantly higher than those of controls (4.3 +/- 0.8 mg/dl, p < 0.05). The difference in mean serum uric acid values between women with chronic hypertension (4.9 +/- 1.0 mg/dl) and superimposed preeclampsia (5.8 +/- 1.4 mg/dl) were not statistically significant. The likelihood ratio of having preeclampsia with a serum uric acid value of 5.5 mg/dl was 1.41 in gestational hypertension of pregnancy and 2.5 in chronic hypertension. With use of a receiver-operator characteristic curve, we were unable to identify a serum uric acid value that could be used to differentiate various hypertensive diseases of pregnancy. There was a weak correlation between serum uric acid values and several clinical outcome measures of preeclampsia (r = 0.06 to 0.26).

CONCLUSION

Although mean serum uric acid values are elevated in women with preeclampsia, the clinical utility of serum uric acid values in differentiating various hypertensive diseases of pregnancy appears to be limited. In the setting of chronic hypertension, however, a serum uric acid level of > or = 5.5 mg/dl could identify women with an increased likelihood of having superimposed preeclampsia.

Do twins mature earlier than singletons? Results from a matched cohort study

OBJECTIVE

Our purpose was to determine whether, as a consequence of advanced maturity, preterm twin infants have a more favorable neonatal outcome than matched singleton infants.

STUDY DESIGN

A matched cohort study design was used. Two hundred twenty-four twin infants (112 sets) were matched for gestational age, race, gender, and mode of delivery with singleton infants who were delivered because of refractory preterm labor. Pregnancies with maternal medical disease including preeclampsia, premature rupture of membranes, twin-twin transfusion syndrome, and known fetal anomalies were excluded. Information was obtained by review of maternal and neonatal charts.

RESULTS

There was no difference in the incidence of neonatal death (5% vs 7%, p = 0.66), respiratory distress syndrome (38% vs 35%, p = 0.54), grades 3 and 4 intraventricular hemorrhage (5% vs 4%, p = 0.63), grades 2 and 3 necrotizing enterocolitis (4% vs 6%, p = 0.52), and 5-minute Apgar score < or = 6 (21% vs 21%, p = 1.00). Twins had a higher incidence of admission to the Special Care Unit (88% vs 72%, p < 0.001). Results were similar when analysis was limited to presenting twins, nonpresenting twins, and twins concordant with controls for antenatal glucocorticoid exposure.

CONCLUSION

Twin infants do not have accelerated maturation and improved neonatal outcome compared with matched singleton infants born at the same gestational age because of preterm labor.

Fetal plasma levels of cellular fibronectin as a measure of fetal endothelial involvement in preeclampsia

OBJECTIVE

To determine the degree of fetal endothelial involvement in preeclampsia by measuring fetal plasma concentrations of cellular fibronectin.

METHODS

In a prospective cohort study, fetal plasma was collected at delivery from the chorionic plate arteries and veins in a convenience sample of 28 pregnancies complicated by preeclampsia and in 28 normal pregnancies. Stored plasma was assayed for cellular fibronectin using a sensitive and specific enzyme immunoassay. On the basis of a desired power of 0.8, alpha of .05, and expected fetal plasma cellular fibronectin values of 4 +/- 2 micrograms/mL, 26 women were required in each group to detect a 40% difference between the groups. Results were compared using the unpaired Student t test, chi 2 analysis with Yates correction, and linear regression.

RESULTS

There was no statistically significant difference in fetal plasma concentrations of cellular fibronectin in women with preeclampsia compared with normal pregnant women, either in arteries (3.2 +/- 1.1 and 2.9 +/- 1.5 micrograms/mL; P = .33) or veins (3.3 +/- 1.5 and 2.8 +/- 1.6 micrograms/mL; P = .18). Plasma cellular fibronectin concentrations in fetal arteries correlated significantly with those in fetal veins (r = 0.45, P < .001), but not with those in maternal veins (r = 0.15, P = .27).

CONCLUSION

Fetal plasma cellular fibronectin concentrations are similar in preeclamptic and normal pregnancies. We found no evidence that factors responsible for maternal endothelial involvement in preeclampsia are operative in the fetal circulation.

The importance of urinary protein excretion during conservative management of severe preeclampsia

OBJECTIVES

We determined the natural course of urinary protein excretion during conservative management of severe preeclampsia and investigated whether changes in urinary protein excretion can predict maternal or perinatal outcome.

STUDY DESIGN

We reviewed the medical charts of 66 women with severe preeclampsia which was managed conservatively before 32 weeks of gestation and who had at least two 24-hour urinary protein determinations 4 or more days apart after admission.

RESULTS

Fifty-nine (89%) of 66 women had an increase in proteinuria during conservative management of severe preeclampsia. The median increase in protein excretion after admission was 660 mg/24 hours (range-4580 to 18,960 mg/24 hours). Patients were divided into two groups. The first group (n = 24) had an increase in 24-hour urinary protein excretion of > or = 2 gm; the second group (n = 42) had a 24-hour urinary protein excretion that decreased (n = 7) or increased by < 2 gm (n = 35). There were no cases of eclampsia or stillbirth in either group. The rate of HELLP (hemolysis, elevated liver enzyme levels, low platelet counts) syndrome, abruptio placentae, cesarean delivery because of fetal distress, 5-minute Apgar scores < or = 6, and the admission-to-delivery intervals were all similar in the two groups.

CONCLUSIONS

Proteinuria increases in most women with severe preeclampsia managed conservatively. No differences in maternal or fetal outcomes were found between pregnancies with marked increases in proteinuria and those with modest or no increases.

Dietary consumption and plasma concentrations of vitamin E in pregnancies complicated by preeclampsia

OBJECTIVE

Vitamin E, a potent antioxidant, has been suggested to play a role in preventing preeclampsia. Our aim was to determine whether consumption and plasma levels of vitamin E are lower in the preeclamptic than in normal women.

STUDY DESIGN

A case-control study design was used. We identified 48 women with preeclampsia (late-pregnancy hypertension, proteinuria, and hyperuricemia). Ninety normal women served as the control group. Vitamin E consumption was estimated by use of a previously validated dietary recall questionnaire administered by a single trained research nurse to 42 of the preeclamptic women and all 90 of the control women. Blood was drawn from all women and stored until assayed at -70 degrees C. Plasma vitamin E concentrations were determined by use of high-pressure liquid chromatography.

RESULTS

The mean dietary vitamin E consumption was similar for both the preeclamptic and control group (11.74 +/- 9.39 vs 11.34 +/- 7.51 mg/24 hr, p = 0.73). When the analysis also included estimations of vitamin E supplements, the total consumption was found to be higher in those who had preeclampsia than in controls (37.20 +/- 20.54 vs 22.3 +/- 27.24 mg/24 hr, p = 0.003). The mean plasma vitamin E concentration was significantly higher in preeclamptic than in control patients (1.41 +/- 0.39 vs 1.15 +/- 0.32 mg/dl, p < 0.001). Among the preeclamptic patients, those with severe disease associated with HELLP (hemolysis, elevated liver enzymes, and low platelets) syndrome (n = 11) had the highest plasma vitamin E concentrations.

CONCLUSIONS

We found no evidence that low vitamin E consumption is related to the development of preeclampsia. Higher plasma vitamin E concentrations in preeclamptic patients are speculated to represent a response to oxidative stress.

Plasma and placental calcitonin gene-related peptide in pregnancies complicated by severe preeclampsia

OBJECTIVE

Our purpose was to determine the concentration of calcitonin gene-related peptide, a potent vasodilator, in maternal plasma, fetal plasma, and placental tissue from pregnancies complicated by severe preeclampsia.

STUDY DESIGN

The following groups were studied: severe preeclampsia (group 1, n = 21), normal pregnancies matched for mode of delivery (group 2, n = 21), and nonpregnant women (group 3, n = 17). Maternal venous blood samples were drawn before labor, and fetal venous samples were drawn from the chorionic plate immediately after delivery. Calcitonin gene-related peptide was also quantified in placental tissue samples from 15 patients in group 1 and 15 patients in group 2. Calcitonin gene-related peptide was measured with a sensitive and specific radioimmunoassay.

RESULTS

No differences were found between maternal plasma calcitonin gene-related peptide concentrations in groups 1 and 2 (29.8 +/- 4.2 and 30.4 +/- 4.3 pmol/L, respectively). Both had levels similar to those in group 3 (28.5 +/- 5.4 pmol/L). Maternal plasma concentrations in the preeclamptic group were unchanged 3 days post partum (29.1 +/- 3.6 pmol/L). Fetal plasma calcitonin gene-related peptide concentrations were similar in groups 1 and 2 (30.2 +/- 3.9 and 32.2 +/- 8.8 pmol/L, respectively). A significant correlation was found between maternal and fetal calcitonin gene-related peptide concentrations (r = 0.43, p < 0.01). Like plasma levels, calcitonin gene-related peptide levels in the supernatants of placental extracts were not different in preeclamptic and normal pregnancies (108.0 +/- 70.4 and 100.9 +/- 56.1 fmol/gm, respectively).

CONCLUSION

On the basis of plasma and placental concentrations, calcitonin gene-related peptide does not seem to play an important role in the pathophysiologic mechanisms of preeclampsia.

Neonatal outcome after preterm delivery for preeclampsia

OBJECTIVE

Our purpose was to determine whether maternal preeclampsia per se has a beneficial effect on neonatal outcome after delivery before 35 weeks.

STUDY DESIGN

A matched cohort study design was used. Two hundred twenty-three infants of strictly defined preeclamptic women were matched for gestational age, race, gender, and mode of delivery with infants of normotensive women with preterm labor and delivery. Pregnancies with multiple gestation, premature rupture of membranes, known fetal anomalies, diabetes, or maternal medical disease were excluded. Information was obtained by review of maternal and neonatal charts. Paired categoric and continuous data were compared by McNemar's test and the Wilcoxon signed-rank test, respectively.

RESULTS

There was no difference in the incidence of neonatal death (4.5% vs 4.5%, p = 0.82), respiratory distress syndrome (22.0% vs 22.0%, p = 0.88), grades 3 and 4 intraventricular hemorrhage (2.2% vs 2.2%, p = 0.72), grades 2 and 3 necrotizing enterocolitis (5.8% vs 4.0%, p = 0.48), and culture-proved sepsis (9.0% vs 9.0%, p = 0.85). Results were similar when analysis was limited to infants born at < or = 32 weeks, infants born to mothers with severe preeclampsia, and infants with intrauterine growth restriction.

CONCLUSION

Maternal preeclampsia per se does not have a beneficial effect on the postnatal course of infants born at 24 to 35 weeks' gestation.

[Clinical evaluation of cefpodoxime proxetil on the treatment of bacterial infections]

122 patients with bacterial infections of respiratory tract, ear, nose, and throat, urinary tract and skin and soft tissue were treated with cefpodoxime proxetil. In the treatments of patients with clinical efficacy tates of cefpodoxime proxetil for infections in these four systems were 90.0%, 97.5%, 90.0% and 86.4%, respectively. The bacterial clearance rate of gram-positive bacterial was 96.9%, and that of gram-negative bacteria 96.4%. Adverse drug reaction rate was 18.9%.

Analysis of dystrophin in fast- and slow-twitch skeletal muscles from mdx and dy2J mice at different ages

Muscles from mdx, control, and dy2J/dy2J mice at different ages were analyzed for dystrophin in an attempt to relate the chronology of the protein expression with the final phenotypes in regenerated, normal, and dystrophic muscle, respectively. Immunostaining and gold staining of electrophoresis gels were carried out in the investigation. At 5, 25, and 219 days of age, control muscles exhibited dystrophin bands in both the fast-twitch extensor digitorum longus (EDL) and the slow-twitch soleus (SOL) muscles. Muscles from the mdx mice at comparable ages (8, 28, and 217 days) never exhibited bands for dystrophin, although titin, nebulin, myosin, and other protein bands were present at intensities comparable to those in control muscles. The dystrophin band was present in both the EDL and SOL from dy2J/dy2J dystrophic mice. As indicated by the present study, the dystrophin deficiency from mdx tissue is not transient. This suggests that dystrophin is not necessary for the success of mdx muscle regeneration.

Striatal homogenates from animals chronically treated with haloperidol stimulate dopamine and GABA uptake in cultures of rostral mesencephalic tegmentum

The effect of pharmacologic denervation of striatal tissue on the production of growth promoting factors was examined in a cell culture system. Relative to saline-treated controls, rats were rendered behaviorally hypersensitive to a subsequent apomorphine challenge by 2 months of chronic treatment with haloperidol. Four days following chronic treatment, the animals were killed and the striata and cerebella were homogenized in Hank's Balanced Salt solution. The supernatants of these crude homogenates were then added to E-13 rostral mesencephalic tegmentum cultures for 6 days. Within 24 h, the haloperidol-treated striatal supernatants induced an overt increase in culture growth relative to all other supernatants. After 6 days, cultures incubated with haloperidol-treated striatal supernatants exhibited a significant increase in dopamine and GABA uptake relative to cultures incubated with all other supernatants. This effect was observed in the presence and absence of glia. The relative degree of this increased uptake was dependent upon the amount of haloperidol-treated striatal supernatant added. Boiling the supernatant removed the growth promoting effect. These results suggest that pharmacologic denervation of striatal tissue leads to a "target-specific" increase in growth promoting activity that may play a role in the pharmacologic and behavioral effects of haloperidol.

Lithium transport in human fibroblasts: relationship to RBC lithium transport and psychiatric diagnoses

Cultured fibroblasts were prepared from six normal controls, five DSM-III manic patients, and six DSM-III schizophrenic patients. Lithium (Li+) uptake, 24-hour Li+ ratios, and steady-state membrane potential were measured in these cell lines. The uptake of 10 mM Li+ reached maximum at 2 hours, with an intracellular concentration of approximately 15 mM. No significant difference in uptake was found among subject groups. Twenty-four hour Li+ (ratio of intracellular/extracellular Li+) ratios were determined by incubating the cell lines for 24 hours in the presence of 2 mM Li+. No significant difference was observed among groups; nor was there any significant correlation between the fibroblast 24-hour ratios and 24-hour in vitro ratios determined in donor red cells. The relationship between membrane potential and the 24 hour Li+ ratio in fibroblasts was determined. The average potential in these cell lines was -56 mV and was not affected by Li+ treatment. No correlation between the Li+ ratio and membrane potential was found.

Immunological identification of a high molecular weight protein as a candidate for the product of the Duchenne muscular dystrophy gene

An oligopeptide was synthesized based on translation of the nucleotide sequence of the putative exon region of clone pERT87-25 from the gene for Duchenne muscular dystrophy. Immunization of rabbits with this oligopeptide induced the formation of antibodies directed against a protein present in human, rat, and rabbit skeletal muscle. This protein, which is missing in the skeletal muscle of two patients with Duchenne muscular dystrophy, has a molecular mass of approximately equal to 320-420 kDa and is clearly different from the putative Duchenne muscular dystrophy-related protein nebulin. The data suggest that this 320- to 420-kDa protein is produced by the Duchenne muscular dystrophy gene.

Respiratory burst facilitates the digestion of Escherichia coli killed by polymorphonuclear leukocytes

We examined factors that may limit degradation of bacterial protein of Escherichia coli S15 killed by polymorphonuclear leukocytes (PMN). Both human and rabbit PMN degraded up to 40% of [14C]amino acid-labeled protein of ingested and killed E. coli in 2 h as determined by loss of acid-precipitable radioactivity. In contrast, equally bactericidal broken-PMN preparations or isolated granules degraded only about 10% of bacterial protein regardless of pH. To determine whether activation of the respiratory burst contributes to digestion, we compared degradation by intact PMN in room air and under N2. Depletion of O2 by N2 flushing had no effect on the bactericidal activity of either human or rabbit PMN but reduced degradation by approximately 50%. Protein degradation during phagocytosis was also reduced in the presence of cyanide or azide, inhibitors of myeloperoxidase (MPO). PMN of two patients with chronic granulomatous disease ingested and killed E. coli S15 as well as did normal PMN but degraded bacterial protein as did normal PMN incubated under N2. The low degradative activity of PMN disrupted by sonication could be raised to nearly the level of intact PMN incubated in room air by preincubation of the PMN with 10(-7) M formyl-methionyl-leucyl-phenylalanine (fMLP) before sonication and by pretreatment of E. coli with MPO. Depletion of O2 or chloride during these preincubations with formyl-methionyl-leucyl-phenylalanine respectively, virtually abolished and markedly diminished stimulation of bacterial protein degradation. We conclude that enhanced MPO-mediated O2 metabolism of intact PMN plays a role in the digestion of killed E. coli.

Environmental modulation of lipopolysaccharide chain length alters the sensitivity of Escherichia coli to the neutrophil bactericidal/permeability-increasing protein

We have shown previously that the sensitivity of Escherichia coli to the neutrophil bactericidal/permeability-increasing protein (BPI) depends mainly on the polysaccharide chain length of outer membrane lipopolysaccharides (LPS) (J. Weiss, S. Beckerdite-Quagliata, and P. Elsbach, J. Clin. Invest. 65:619-628, 1980). Thus, rough strains of E. coli producing only short-chain LPS are more sensitive to BPI than smooth strains that produce LPS with varied chain lengths. We now show that changes in the bacterial growth environment can modify BPI sensitivity of smooth E. coli as much as 30-fold depending on the bacterial strain and the growth conditions examined. Changes in BPI sensitivity paralleled differences in binding affinity of E. coli for BPI and closely correlated with changes in the chain length of LPS produced under different growth conditions, as assessed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. No concomitent changes in either the number of LPS molecules per cell or the bacterial protein profile were detected. Rough strains showed little or no growth-dependent variation in BPI sensitivity, further indicating that subtle alterations in bacterial constituents other than LPS do not significantly affect bacterial sensitivity to BPI. Thus, the BPI sensitivity of E. coli can be modulated not only by the genotypic conversion of the LPS phenotype, but also by environmental effects on LPS-polysaccharide formation in wild-type strains.

Oxygen-independent intracellular and oxygen-dependent extracellular killing of Escherichia coli S15 by human polymorphonuclear leukocytes

Effective killing of bacteria by polymorphonuclear leukocytes (PMN) is generally assumed to require intracellular sequestration and, depending on the bacterial species, can be both O2-dependent or O2-independent. Killing of several strains of Salmonella typhimurium and Escherichia coli by rabbit PMN does not require O2 and is apparently due to a granule-associated bactericidal/permeability-increasing protein (BPI) present in rabbit and human PMN. In this study we examined the O2 dependence of the killing of E. coli (S15) by human PMN. Ingested and noningested E. coli were separated by centrifugation after incubation with PMN in room air or under N2. In the presence of heat-treated serum approximately 50% of E. coli (10 bacteria/PMN) were taken up by PMN and rapidly (5-15 min) killed both in room air and under N2. The remaining extracellular bacteria (approximately 50%) were killed during 30-60 min of incubation in room air but not under N2. When uptake of E. coli by PMN was increased to approximately 80% by the use of C6-depleted serum (retaining heat-labile opsonins), bacterial survival under N2 was reduced from 54 +/- 7.6% to 13 +/- 5.5%. PMN from a patient with chronic granulomatous disease killed PMN-associated but not extracellular E. coli. BPI was detected, by indirect immunofluorescence, on the surface of PMN-associated E. coli within 5 min of incubation of E. coli with PMN both in room air and under N2. In contrast, at no time was BPI detected on the surface of extracellular E. coli, indicating that the non-PMN-associated E. coli had not been previously ingested. Thus, killing of ingested E. coli S15 by human as well as rabbit PMN does not require O2 and appears to be BPI-mediated. However, when ingestion is limited, extracellular bacteria can also be killed but principally by O2-dependent mechanisms.

The role of intramembrane Ca2+ in the hydrolysis of the phospholipids of Escherichia coli by Ca2+-dependent phospholipases

Ca2+-dependent phospholipases A require Ca2+ concentrations in the millimolar range for optimal activity toward artificial substrates. Because Ca2+-dependent phospholipases A2 degrade the phospholipids of Escherichia coli, treated with the membrane-active antibiotic polymixin B equally well with and without added Ca2+ (Weiss, J., Beckerdite-Quagliata, S., and Elsbach, P. (1979) J. Biol. Chem. 254, 11010-11014), we have examined the possibility that intramembrane Ca2+ can provide the Ca2+ needed for phospholipase action. We studied the effect of Ca2+ depletion on the hydrolysis of the phospholipids of polymixin B-killed E. coli by 1) added pig pancreas phospholipase A2 in E. coli S17 (a phospholipase A-lacking mutant) and 2) endogenous Ca2+-dependent phospholipase A1 in the parent strain E. coli S15. Transfer of E. coli from nutrient broth (Ca2+ concentration approximately 3 X 10(-5) M) to Ca2+-depleted medium (Ca2+ concentration less than 10(-6)M) reduced polymixin B-induced hydrolysis by 50-75%, in parallel with a reduction of bacterial Ca2+ from 19.6 +/- 2.8 to 3.9 +/- 0.6 nmol (mean +/- standard error) per 3 X 10(10) bacteria. The bacterial Ca2+ content was repleted and the sensitivity of the bacterial phospholipids to hydrolysis by both exogenous phospholipase A2 (E. coli S17) and endogenous phospholipase A (E. coli S15) was restored by adding Ca2+ back to the suspensions. Complete restoration occurred at low Ca2+ levels in the reaction mixture (3 X 10(-5) - 10(-4) M) and required time, suggesting that hydrolysis was restored because bacterial Ca2+ stores were gradually replenished and not because extracellular Ca2+ concentrations were raised to levels that were still at least 10X lower than needed for optimal phospholipase A activity. This conclusion is supported by the finding that Ca2+ depletion or addition caused respectively decreased and increased release of lipopolysaccharides by EGTA (ethylene glycol bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid), suggesting that the bacterial Ca2+ pool bound to lipopolysaccharides in the outer membrane shrinks or expands depending on extracellular Ca2+ levels. Thus, the cationic membrane-disruptive polymixin B, thought to compete with Mg2+ and Ca2+ for the same anionic sites on lipopolysaccharides, may liberate the Ca2+ near where the phospholipids are exposed to phospholipase.

Killing of gram-negative bacteria by neutrophils: role of O2-independent system in intracellular killing and evidence of O2-dependent extracellular killing

For many strains of these two bacterial species, ingested bacteria are efficiently killed by O2-independent mechanisms. Intracellular killing depends not on 2de novo generation of toxic products of the respiratory burst but rather on intracellular delivery to pre-existing cytotoxic proteins. The principal O2- independent bactericidal system toward these bacteria appears to be BPI which rapidly binds to ingested bacteria and whose discrete action closely resembles the initial lesions produced by the intact neutrophil. In addition, at least for one strain of E. coli (S15), extracellular bacteria can be killed in an O2- dependent fashion.

"Bell-shaped ureter," a radiographic sign of antegrade intussusception

A unique case of a hitherto unreported antegrade intussusception of the ureter secondary to a lead pedunculated polypoid transitional cell tumor is presented. Radiological documentation and surgical verification are illustrated. An attempted explanation of the peculiar radiographic appearance proximal to and within the intussusception is given. The potential aid in preoperative recognition of such an entity is proposed.

The posterior median eyes of the dinopid spider Menneus

The posterior median (pm) eyes of the dinopid spider Menneus unifasciatus L. Koch are described and compared with the pm eyes of Dinopis, which are highly specialised for night vision. The lenses of Menneus have F-numbers of 0.72 compared to 0.58 in Dinopis, the distance between receptors is ca. 4.0 microns compared to 20-22 microns for Dinopis, and image quality is matched to receptor spacing. The lens of Menneus is simple, while that of Dinopis comprises two components of different refractive indices (Blest and Land 1977). Receptive segments of the pm eyes of Dinopis are hexagonal in transverse section and those of adjacent cells are tightly contiguous, allowing the possibility of both optical and electrical coupling (Blest 1978). Receptive segments of Menneus are separated from each other by glial processes containing little pigment, and each segment possesses two rhabdomeres on opposite faces of the cell. Rhabdomere volumes undergo a daily cycle similar to that described for Dinopis, but of relatively minor extent. It is shown that the pm eye of Dinopis could have evolved from that of Menneus by a simple series of transformations, and that a gain of two logarithmic units of sensitivity can be attributed to changes in optical design alone.