Growth phase-specific changes in the composition of E. coli transcription complexes.

In E. coli, a single oligomeric enzyme transcribes the genomic DNA, while multiple auxiliary proteins and regulatory RNA interact with the core RNA polymerase (RP) during different stages of the transcription cycle to influence its function. In this work, using fast protein isolation techniques combined with mass spectrometry (MS) and immuno-analyses, we studied growth phase-specific changes in the composition of E. coli transcription complexes. We show that RP isolated from actively growing cells is represented by prevalent double copy assemblies and single copy RP-RNA and RP-RNA-RapA complexes. We demonstrate that RpoD/σ70 obtained in fast purification protocols carries tightly associated RNA and show evidence pointing to a role of sigma-associated RNA in the formation of native RP-(RNA)-RpoD/σ70 (holoenzyme) complexes. We report that enzymes linked functionally to the metabolism of lipopolysaccharides co-purify with RP-RNA complexes and describe two classes of RP-associated molecules (phospholipids and putative phospholipid-rNT species). We hypothesize that these modifications could enable anchoring of RP-RNA and RNA in cell membranes. We also report that proteins loosely associated with ribosomes and degradosomes (S1, Hfq) co-purify with RP-RNA complexes isolated from actively growing cells - a result consistent with their proposed roles as adaptor-proteins. In contrast, GroEL, SecB, and SecA co-purified with RP obtained from cells harvested in early stationary phase. Our results demonstrate that fast, affinity chromatography-based isolation of large multi-protein assemblies in combination with MS can be used as a tool for analysis of their composition and the profiling of small protein-associated molecules (SPAM).

Validating the portal population of the United Kingdom Multiple Sclerosis Register.

The UK Multiple Sclerosis Register (UKMSR) is a large cohort study designed to capture 'real world' information about living with multiple sclerosis (MS) in the UK from diverse sources. The primary source of data is directly from people with Multiple Sclerosis (pwMS) captured by longitudinal questionnaires via an internet portal. This population's diagnosis of MS is self-reported and therefore unverified. The second data source is clinical data which is captured from MS Specialist Treatment centres across the UK. This includes a clinically confirmed diagnosis of MS (by Macdonald criteria) for consented patients. A proportion of the internet population have also been consented at their hospital making comparisons possible. This dataset is called the 'linked dataset'. The purpose of this paper is to examine the characteristics of the three datasets: the self-reported portal data, clinical data and linked data, in order to assess the validity of the self-reported portal data. The internet (n = 11,021) and clinical (n = 3,003) populations were studied for key shared characteristics. We found them to be closely matched for mean age at diagnosis (clinical = 37.39, portal = 39.28) and gender ratio (female %, portal = 73.1, clinical = 75.2). The Two Sample Kolmogorov-Smirnov test was for the continuous variables to examine is they were drawn from the same distribution. The null hypothesis was rejected only for age at diagnosis (D = 0.078, p < 0.01). The populations therefore, were drawn from different distributions, as there are more patients with relapsing disease in the clinical cohort. In all other analyses performed, the populations were shown to be drawn from the same distribution. Our analysis has shown that the UKMSR portal population is highly analogous to the entirely clinical (validated) population. This supports the validity of the self-reported diagnosis and therefore that the portal population can be utilised as a viable and valid cohort of people with Multiple Sclerosis for study.

Brain natriuretic peptide is not reno-protective during renal ischemia-reperfusion injury in the rat.

BACKGROUND: Acute kidney injury (AKI) occurs in 30% of patients undergoing complex cardiovascular surgery, and renal ischemia-reperfusion (I/R) injury is often a contributing factor. A recent meta-analysis observed that perioperative natriuretic peptide administration was associated with a reduction in AKI requiring dialysis in cardiovascular surgery patients. This study was designed to further clarify the potential reno-protective effect of brain natriuretic peptide (BNP) using an established rat model of renal I/R injury. METHODS: The study comprised three groups (n = 10 kidneys each): (1) control (no injury); (2) I/R injury (45 min of bilateral renal ischemia followed by 3 h of reperfusion); and (3) BNP (I/R injury plus rat-BNP pretreatment at 0.01 µg/kg/min). Glomerular filtration rate (GFR) and a biomarker of AKI, urinary neutrophil gelatinase-associated lipocalin (uNGAL), were measured at baseline and at 30 minute intervals post-ischemia. Groups were compared using two-way repeated measures analysis of variance (mean ± SD, significance P < 0.05). RESULTS: Baseline GFR measurements for control, I/R, and BNP groups were 1.07 ± 0.55, 0.88 ± 0.51, and 1.03 ± 0.59 mL/min (P = 0.90), respectively. Post-ischemia, GFR was significantly lower in I/R and BNP compared with controls at 30 min, 1.29 ± 0.97, 0.08 ± 0.04, and 0.06 ± 0.05 mL/min (P < 0.01), and remained lower through 3 h, 1.79 ± 0.44, 0.30 ± 0.17, and 0.32 ± 0.12 mL/min (P < 0.01). Comparing I/R to BNP groups, GFR did not differ significantly at any time point. There was no significant difference in uNGAL levels at 1 h (552 ± 358 versus 516 ± 259 ng/mL, P = 0.87) or 2 h (1073 ± 589 versus 989 ± 218 ng/mL, P = 0.79) between I/R and BNP. CONCLUSIONS: BNP does not reduce the renal injury biomarker, urinary NGAL, or preserve GFR in acute renal ischemia-reperfusion injury.

Early outcomes using the Florida sleeve repair for correction of aortic insufficiency due to root aneurysms.

BACKGROUND: The Florida sleeve procedure is a simplified valve-sparing technique for repair of functional type I aortic insufficiency associated with root aneurysms. Midterm outcomes are reported, including standard echocardiographic measurements. METHODS: The study included all patients undergoing the Florida sleeve procedure who had at least 2 years of postoperative echocardiographic follow-up. Data were acquired preoperatively and postoperatively at 1 week and 1, 2, and 3 years. Measurements analyzed included left ventricular end-diastolic diameter (LVEDD), left ventricular end-systolic diameter (LVESD), and degree of aortic insufficiency. RESULTS: Complete echocardiographic data for a mean 32 +/- 6.3 months after repair were available for 18 patients. Mean LVEDD decreased from 51.6 +/- 7.4 to 49.7 +/- 6.3 mm at 1 week (p = 0.05) and 47.1 +/- 6.3 mm at 1 year (p = 0.008), and remained unchanged at 47.2 +/- 6.6 and 47.1 +/- 5.0 mm at 2 and 3 years. Mean LVESD decreased from 35.2 +/- 7.6 to 32.9 +/- 7.0 mm at 1 week (p = 0.002) and 30.7 +/- 5.6 mm at 1 year (p < 0.001), and remained unchanged at 30.9 +/- 6.2 and 31.7 +/- 4.9 mm after 2 and 3 years. The mean grade of aortic insufficiency decreased from 2.61 +/- 0.78 to 1.39 +/- 0.85 mm at 1 week (p < 0.001) and remained 1.39 +/- 0.84 mm at 1 year. Aortic insufficiency increased to 1.72 +/- 0.89 (p = 0.03) at 2 years and decreased to 1.67 +/- 0.50 (p = 0.59, from 1 week postoperatively) at 3 years. CONCLUSIONS: The sustained reduction of left ventricular dimensions 3 years after operation suggests the Florida sleeve procedure is a durable valve repair. A minor increase in the degree of aortic insufficiency warrants close follow-up, but the absence of an increase of LVEDD supports continued use of the procedure in closely studied series.

A national survey of herbal preparation use by nurse-midwives for labor stimulation. Review of the literature and recommendations for practice.

To document the use of herbal preparations for cervical ripening, induction, and augmentation of labor by certified nurse-midwives (CNMs) and nurse-midwifery education programs, a national survey of 500 members of the American College of Nurse-Midwives was conducted. Forty eight nurse-midwifery education programs were also surveyed to determine whether they were formally or informally educating students in the use of herbal preparations for cervical ripening, induction, or augmentation of labor. The results of this study, a review of the literature, professional issues, and recommendations for clinical practice are presented in this article. Of 500 questionnaires mailed to ACNM members, 90 were returned from CNMs who used herbal preparations to stimulate labor and 82 were returned from CNMs who did not use herbal preparations to stimulate labor. Three questionnaires were excluded due to incomplete data or blank questionnaires. No significant differences were noted in relations to geographical region, midwifery education, or highest level of education between the CNM respondents who did and those who did not use alternative methods to stimulate labor. Of the CNMs who used herbal preparations to stimulate labor, 64% used blue cohosh, 45% used black cohosh, 63% used red raspberry leaf, 93% used castor oil, and 60% used evening primrose oil. CNMs who used herbal preparations to stimulate labor were younger (43 versus 45 years, P < .01) and more likely to deliver at home or in an in-hospital or out-of-hospital birthing center (P < .0006), than CNMs who never used herbal preparations to stimulate labor. The most cited reason for using herbal preparations to stimulate labor was that they are "natural," whereas the most common reason for not using herbal preparations was the lack of research or experience with the safety of these substances. Sixty-nine percent of CNMs who used herbal preparations to stimulate labor learned about using them from other CNMs, 4% from formal research publications, and none from their formal education programs. Although 78% of the CNMs who used herbal preparations to stimulate labor directly prescribed them and 70% indirectly suggested them to clients, only 22% had included them within their written practice protocols. Seventy-five percent of the CNMs who used herbal preparations to stimulate labor used them first or instead of pitocin. Twenty-one percent reported complications including precipitous labor, tetanic uterine contractions, nausea, and vomiting. Sixty-four percent of the nurse-midwifery education programs included instruction in the use of herbal preparations to stimulate labor in their formal curricula, and 92% included informal discussions on the use of herbal preparations. Evening primrose oil was the most common herbal preparation discussed in nurse-midwifery education programs. Castor oil was the most commonly used herbal preparation used by nurse-midwives in clinical practice.

Interdisciplinary teaching. A survey of CNM participation in medical education in the United States.

Nurse-midwives have participated informally in the education of medical students and residents for many years, yet little is known about their formal involvement in medical education. A two-part survey was conducted to investigate the extent and characteristics of nurse-midwifery participation in medical education in the United States. The initial questionnaire was sent to every department of obstetrics and gynecology chair listed in the directory of the Association of Professors of Gynecology and Obstetrics and addressed the use of certified nurse-midwives (CNMs) as educators within their respective departments. A subsequent questionnaire was distributed to CNMs participating in medical education and addressed their demographic characteristics, roles within the medical school faculty, and attitudes regarding work in medical education. More than one half (54%) of U.S. allopathic medical schools are formally using CNMs as educators, with the strongest involvement reported in the West and Northeast. Nearly as many CNM respondents are participating in the education of family medicine residents (57%) as in obstetrics and gynecology (59%). Most CNMs (93%) involved in medical education are also involved in nurse-midwifery education. Eighty percent of CNM respondents perceived congruency between educating student physicians and their philosophy of nurse-midwifery practice.

The role of home-made ice cream as a vehicle of Salmonella enteritidis phage type 4 infection from fresh shell eggs.

A family outbreak of Salmonella enteritidis PT4 infection is described in which home-made ice cream was identified as the vehicle of infection. The ice cream contained approximately 10(5) S. enteritidis PT4 organisms per gm and was probably contaminated by an infected shell egg containing between 10(5)-10(8) organisms. The continued relevance of the Chief Medical Officer's warning on the use of raw shell eggs is highlighted. Home-made ice cream using the same recipe as ice cream that had been incriminated as the cause of the family outbreak of S. enteritidis PT4 infection was used to study the growth of the organism that might have occurred in the 3-4 h it took to prepare the product. When the inoculum was in the stationary phase, as it would be from shell or other cross contamination, there was a lag phase of 3 h before growth occurred at room temperature. Even when actively multiplying organisms were introduced, as may be found in an infected egg, there was less than 3 log(10) increase in the salmonella count in 4 h at room temperature. It was, therefore, given the high S. enteritidis count, unlikely that the ice cream was cross-contaminated. By contrast, raspberry sorbet at pH 3.73 proved to be lethal to a large inoculum of S. enteritidis and may be a relatively safe raw egg containing product.

The effect of an antacid and food on the absorption of cimetidine and ranitidine.

The effect of varying doses of a liquid antacid preparation containing magnesium hydroxide, aluminum hydroxide and simethicone on the absorption of the H2-receptor antagonists, cimetidine and ranitidine, was determined in 2 groups of 11 volunteers; one group fasted and one group fed a standardized breakfast. The antacid alone caused a significant decrease in the AUC of cimetidine (24%). Similarly, concomitant antacid caused a 59% decrease in the AUC of ranitidine. There were no effects on any of the other pharmacokinetic parameters examined. The absorption of both drugs was similar in fasted and fed volunteers, but in the fed volunteers the antacid did not produce the decrease in AUC seen in the fasted volunteers. These data suggest that H2-receptor antagonists should not be taken at the same time as antacids.

Management of penetrating lung injuries in civilian practice.

Recent reports of military thoracic injuries have advocated early thoracotomy and aggressive management of pulmonary injuries with resection as opposed to the more conservative and traditional treatment with chest tube thoracostomy. A retrospective study was therefore performed to determine the incidence of thoracotomy and lung resection in civilian injuries and to evaluate the effectiveness of treatment of these injuries. Between 1973 and 1985, in a series of 1,168 patients, there were 384 gunshot wounds and 784 stab wounds to the thorax. Two hundred eighty-three patients with a gunshot wound (74%) and 602 with a stab wound (77%) were treated with chest tubes alone. Sixty-eight patients (6% of the total) required operative repair of pulmonary hilar or parenchymal injury. Pulmonary resection was necessary in only 18 patients (nine with a gunshot wound and nine with a stab wound), and 10 patients had repair of hilar injuries (nine with a gunshot wound and one with a stab wound). Of patients requiring pulmonary resection, nine required wedge or segmental resection, six required lobectomy, and three patients required pneumonectomy. Mortality for all thoracic injuries was 2.3%: for those treated with chest tube alone, 0.7%; for pulmonary hilar injuries, 30%; for pulmonary parenchymal injuries, 8.6%; and for injuries necessitating lung resection, 28%. Most civilian lung injuries can be treated by tube thoracostomy alone. Although relatively few patients with primary pulmonary injury require thoracotomy, those that do are at significant risk and may require lung resection to control bleeding or hemoptysis or to remove destroyed or devitalized lung tissue.

Standard biplane roentgenography is highly sensitive in documenting mediastinal masses.

The records of 30 patients with mediastinal masses were reviewed to evaluate the signs, symptoms, and preoperative tests that were most useful in diagnosing and localizing the masses. Sixteen (53%) of the tumors were benign, and 14 (47%) were malignant. Twenty patients were seen with symptoms. The most common symptoms suggesting malignancy were pain, weight loss, fever, and cough. Four of the 5 patients who were truly asymptomatic had benign lesions. All 4 patients with palpable adenopathy had malignant tumors. Posteroanterior and lateral chest roentgenograms detected the mediastinal mass in 29 (97%) of the 30 patients. All patients were operated on for tissue diagnosis or resection (13, median sternotomy; 8, right thoracotomy; 3, left thoracotomy; 2, low anterior cervical approach). Eight patients underwent mediastinoscopy, which was diagnostic in 6 and obviated the need for operation in 4. It was of particular value for patients with lymphoma, who can be managed without resection.

Studies on the mechanisms of action of activated charcoal on theophylline pharmacokinetics.

Oral administration of repeated doses of activated charcoal to volunteers and dogs significantly increased the systemic clearance of intravenously administered theophylline and decreased its elimination half-life. This effect is most likely to be due to theophylline entering the gut and being adsorbed onto the charcoal. The mechanism by which intravenously administered theophylline enters the gut has been examined. Its biliary excretion after intravenous administration to patients with T-tube biliary drainage accounted for 0.28% of the dose and a similarly small biliary excretion was found in dogs. In the latter total biliary diversion had no effect on the clearance or half-life of theophylline after intravenous administration. In two dogs the theophylline content of jejunal aspirate was comparable with that of simultaneously withdrawn venous plasma samples. These results suggest that the presence of charcoal in the gut represents a sink adsorbing theophylline entering the lumen by diffusion across the intestinal wall, and by this mechanism it increases clearance of the drug even after intravenous administration.

Anterolateral thoracotomy as an alternative to repeat median sternotomy for replacement of the mitral valve.

Median sternotomy is the most common approach for repeat cardiac surgery despite the potential complications of cardiac injury. Right anterolateral thoracotomy has been recommended as an alternative for patients undergoing mitral valve replacement, but data supporting one approach over the other do not exist. To compare these procedures, the records of 43 patients who had had a previous median sternotomy and who underwent mitral valve replacement were reviewed. No statistically significant differences between patients undergoing repeat median sternotomy (33 patients) and those undergoing right anterolateral thoracotomy (10 patients) were demonstrable when compared for age, gender, New York Heart Association Functional Class, other diseased valves, urgency of operation, indication for operation, type of valve removed, type of valve implanted, length of postoperative hospitalization, length of operation, days of ventilatory support, length of intensive care unit stay, and survival (90% for thoracotomy group; 76% for median sternotomy group; p, NS). Significant differences between the two groups, favoring right anterolateral thoracotomy, were apparent when comparisons were made for length of perfusion (means, 94.8 min, thoracotomy group; 121.4 min, sternotomy group; p = .03), incidence of reexploration (0%, thoracotomy group; 13%, sternotomy group; p = .001), and blood transfusion (means, 5.3 units, thoracotomy group; 11.4 units, sternotomy group; p = .003). Right anterolateral thoracotomy is an effective alternative to repeat median sternotomy for replacement of the mitral valve in patients who have had a previous median sternotomy.

Operative closure of patent ductus arteriosus in premature infants in the neonatal intensive care unit.

Fifty-two premature infants underwent hemoclip closure of patent ductus arteriosus in the neonatal intensive care unit after a brief trial of fluid restriction and diuretics. Indomethacin was used in only four patients. The median time from diagnosis to operation was 3 days. There were no deaths directly attributable to operation. Nine operative complications developed in nine patients (17 percent). There were no surgical infections. Complications related to prematurity resulted in 20 deaths (38 percent). Patent ductus arteriosus closure in the neonatal intensive care unit prevented the complications of hypothermia, inadvertent extubation, and interruption of vascular access and monitoring. Early operative closure in the neonatal intensive care unit is the treatment of choice in most premature infants with patent ductus arteriosus.

Management of blunt rupture of the heart.

Ten patients with blunt heart rupture arrived in our emergency center alive during an 11-year period ending in 1984. Ages ranged from 19 to 65 years (mean, 35), and seven patients were male. Six patients presented with tamponade, three with hemorrhagic shock, and one with combined symptoms. Associated injuries averaged 2.25 organ systems per patient. All but one patient had surgery within 90 minutes of arrival. All patients had primary closure of the defect without cardiopulmonary bypass, five patients had subxiphoid window followed by sternotomy, two had right thoracotomy, two underwent left thoracotomy, and one patient was subjected to immediate sternotomy. Seven patients survived. Three deaths were due to irreversible hemorrhagic shock, two secondary to heart injury, and one from an associated liver injury. Prompt pericardial window with subsequent median sternotomy was successful for patients presenting with tamponade and immediate thoracotomy for those bleeding into a pleural cavity.

Bronchopulmonary foregut malformations. The spectrum of anomalies.

Ventral anomalies of accessory pulmonary tissue have been classified as "bronchopulmonary foregut malformations." Between July 1, 1981, and May 31, 1985, 10 children with bronchopulmonary malformations have been cared for on the Pediatric Surgical Service at the University of Virginia. Six patients had bronchogenic cysts, one in an extrathoracic location and one associated with a pulmonary sequestration. Diagnosis was suspected in each case by plain chest radiographs and confirmed by computed tomography scans and ultrasound. Four patients had pulmonary sequestrations, two in association with diaphragmatic hernias. One patient had accessory pulmonary tissue, best classified as a tracheal lobe. Diagnosis in this patient was confirmed by bronchography. Nine patients underwent excision of the malformation without event. In one patient, a bronchogenic cyst was treated successfully by thoracoscopy. Review of the anatomy of these malformations leads to the conclusion that three embryologic events are cardinal in determining their ultimate form: (1) investment of the anomalous pulmonary tissue by the pulmonary artery; (2) the degree of involution of the original foregut communication; and (3) the stage of development leading to pleural investment.