[The place of emergency thoracotomy in trauma].
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Emergencies↗
Biomedical subjects
M Stein
Publications and source records attributed to M Stein.
Residue Glu-91 of Chlamydomonas reinhardtii ferredoxin is essential for electron transfer to ferredoxin-thioredoxin reductase.
The [2Fe-2S] soluble ferredoxin from Chlamydomonas reinhardtii was mutated by site directed mutagenesis, using PCR and the expression plasmid pET-Fd as a template. The recombinant mutated proteins were purified to homogeneity and tested in the activation of NADP-malate dehydrogenase, a light dependent reaction in which ferredoxin thioredoxin reductase (FTR) and thioredoxin are involved. The mutation of residue Glu-91 (E92 in spinach, E94 in Anabaena) alone, either to Gln (E91Q) or to Lys (E91K), was found to completely abolish the reaction of the enzyme light activation. On the other hand, the mutants (E92Q) or (E92K) were as efficient as the wild type ferredoxin in this reaction whereas the double mutants (E91Q/E92Q) or (E91K/E92K) had no activity. In addition, a triple mutant (D25A/E28Q/E29Q) was also found to be inactive for this redox dependent light activation. All these mutations had much weaker effects on the ferredoxin/ferredoxin NADP reductase interaction as measured by the cytochrome c reduction assay. These results indicate that there is a recognition site for FTR in the C terminus part of ferredoxin, but also that a core of negatively charged residues in the alpha1 helix of ferredoxin might be important in the general process of light activation.
Animals↗
Eye manifestations of congenital toxoplasmosis.
PURPOSE: To determine the natural history of treated and untreated congenital toxoplasmosis and impact of this infection on vision. METHODS: In this prospective, longitudinal study, 76 newborns were treated with pyrimethamine and sulfadiazine for approximately one year, and 18 individuals not treated during their first year of life entered the study after age 1 year (historical patients). RESULTS: Chorioretinal scars were the most common eye finding in all patients and were most common in the periphery (58% of treated and 82% of historical patients). Macular scars were present in 54% of the treated patients; 41% were bilateral. Macular scars were present in 76% of the historical patients; 23% were bilateral. Visual acuity in the presence of macular lesions ranged from 20/20 to 20/400. Of the patients followed up from the newborn period and treated, 29% had bilateral visual impairment, with visual acuity for the best eye of less than 20/40. Causes for this visual impairment in eyes with quiescent lesions included macular scars, dragging of the macula secondary to a peripheral lesion, retinal detachment, optic atrophy, cataract, amblyopia, and phthisis. There were recurrences in both treated (13%, 7/54) and previously untreated historical patients (44%, 8/18). The total, median, and range of years of follow-up during which recurrences were observed were, for treated patients, 189 years (total), five years (median) and three to ten years (range) and, for historical, untreated patients, 160 years (total), 11 years (median), and three to 24 years (range). New lesions occurred in previously normal retinas and also contiguous to older scars. Active lesions appeared to become quiescent within ten to 14 days after beginning pyrimethamine and sulfadiazine therapy. CONCLUSION: Many children with congenital toxoplasmosis have substantial retinal damage at birth and consequent loss of vision. Nonetheless, vision may be remarkably good in the presence of large macular scars. Active lesions become quiescent with treatment.
Adolescent↗
Reoperation. Planned and unplanned.
Reoperation is an integral part of the damage control sequence. Each type of reoperation represents an entirely different operative profile with different tactical considerations. This article discusses in detail the key decisions and techniques of planned and unplanned reoperation.
Abdomen↗
Interhospital patient transfer: a quality improvement indicator for prehospital triage in mass casualties.
The need for interhospital patient transfer after mass casualties may be a consequence of triage errors. Indications for interhospital patient transfer following seven suicidal bus bombings in Israel were reviewed to identify possible errors in triage at the scene. Medical records of victims arriving to hospitals were analyzed for age, injury description, injury Severity Score (ISS), and indication and destination of interhospital transfer. A total of 473 victims were involved, 74 of whom died at the scene (15.6%). Mean victim age was 29 +/- 16 (SD) years. Interhospital transfer was necessary for 29 patients. Indications for transfer included (1) mandatory lifesaving procedures on route to trauma center (n = 14), (2) underdiagnosis at the scene (n = 1), (3) insufficient local resources (n = 9), and (4) triage-related errors (n = 5). The ratio between interhospital transfer due to triage errors and the victim population who may need to be transferred is suggested as quality assurance (QA/QI) indicator for triage.
Adolescent↗
Structural and functional roles of a conserved proline residue in the alpha2 helix of Escherichia coli thioredoxin.
Proline 40 in Escherichia coli thioredoxin is located close to the redox active site (Cys32-Cys35) within the alpha2 helix. The conservation of this residue among most of the thioredoxins suggests that it could play an important role in the structure and/or function of this protein. We have substituted Pro40 for Ala by using site-directed mutagenesis and expressed the mutant P40A in E.coli. The effects of the mutation on the biophysical and biological properties of thioredoxin have been analyzed and compared with molecular dynamics simulations. Modeling predicted that the replacement of Pro40 by Ala induced a displacement of the active site which exposes Trp31 to the solvent and opens a cleft located between helices alpha2 and alpha3. The solvation free energy (SFE) calculation also indicated that P40A became more hydrophobic as W31 became more accessible. These predictions were totally in agreement with the experimental results. The mutant P40A exhibited chromatographic behavior and fluorescence properties very different from those of the wild-type (WT) protein, in relationship with the displacement of W31. The determination of the free energy of unfolding of P40A showed that the mutant was globally destabilized by 2.9 kcal/mol. However, the effect of the mutation on the transition curve was highly unusual as the midpoint of the unfolding transition increased, indicating that some local structures were actually stabilized by the mutation. Despite these structural modifications, neither the ability of the protein to reduce a chloroplastic enzyme nor its reactivity with the bacterial reductase decreased. The only functional difference was the higher stability of P40A in light activation of NADP-malate dehydrogenase under air, which suggests that the mutant was less rapidly re-oxidized than WT. Therefore, it can be concluded that Pro40 is not essential for maintaining the redox function of thioredoxin but rather is required for the stability of the protein.
Amino Acid Sequence↗
A rare event of megestrol acetate (Megace)-induced adrenal suppression in a breast cancer patient.
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Adrenal Glands↗
Abdominal injuries without hemoperitoneum: a potential limitation of focused abdominal sonography for trauma (FAST)
BACKGROUND: Focused abdominal sonography for trauma (FAST) relies on hemoperitoneum to identify patients with injury. Blunt trauma victims (BTVs) with abdominal injury, but without hemoperitoneum, on admission are at risk for missed injury. METHODS: Clinical, radiologic, and FAST data were collected prospectively on BTVs over a 12-month period. All patients with FAST-negative for hemoperitoneum were further analyzed. Examination findings and associated injuries were evaluated for association with abdominal lesions. RESULTS: Of 772 BTVs undergoing FAST, 52 (7%) had abdominal injury. Fifteen of 52 (29%) had no hemoperitoneum by admission computed tomographic scan, and all had FAST interpreted as negative. Four patients with splenic injury underwent laparotomy. Six other patients with splenic injury and five patients with hepatic injury were managed nonoperatively. Clinical risk factors significantly associated with abdominal injury in BTVs without hemoperitoneum include: abrasion, contusion, pain, or tenderness in the lower chest or upper abdomen; pulmonary contusion; lower rib fractures; hemo- or pneumothorax; hematuria; pelvic fracture; and thoracolumbar spine fracture. CONCLUSIONS: Up to 29% of abdominal injuries may be missed if BTVs are evaluated with admission FAST as the sole diagnostic tool. Consideration of examination findings and associated injuries should reduce the risk of missed abdominal injury in BTVs with negative FAST results.
Abdominal Injuries↗
Enteropathogenic Escherichia coli protein secretion is induced in response to conditions similar to those in the gastrointestinal tract.
The pathogenicity of enteropathogenic Escherichia coli (EPEC) is associated with the expression and secretion of specific bacterial factors. EspB is one such secreted protein which is required to trigger host signaling pathways resulting in effacement of microvilli and cytoskeletal rearrangements. These events presumably contribute to the ensuing diarrhea associated with EPEC infections. EPEC encounters several environmental changes and stimuli during its passage from the external environment into the host gastrointestinal tract. In this paper we show that the secretion of EspB is subject to environmental regulation, and maximal secretion occurs under conditions reminiscent of those in the gastrointestinal tract. Thus, secretion is maximal at 37 degrees C, pH 7, and physiological osmolarity. In addition, maximal secretion requires the presence of sodium bicarbonate and calcium and is stimulated by millimolar concentrations of Fe(NO3)3. The secretion of the four other EPEC-secreted proteins appears to be modulated in a manner similar to that of EspB. Our results also show that secretion is not dependent on CO2, as originally reported by Haigh et al. (FEMS Microbiol. Lett. 129: 63-67, 1995), but that CO2 more likely acts as a component of the medium buffering system, since CO2 dependence was abolished by the use of alternative buffers.
Ammonium Chloride↗
Characterization of two virulence proteins secreted by rabbit enteropathogenic Escherichia coli, EspA and EspB, whose maximal expression is sensitive to host body temperature.
Enteropathogenic Escherichia coli (EPEC) and rabbit EPEC (RDEC-1) cause unique histopathological features on intestinal mucosa, including attaching/effacing (A/E) lesions. Due to the human specificity of EPEC, RDEC-1 has been used as an animal model to study EPEC pathogenesis. At least two of the previously identified EPEC-secreted proteins, EspA and EspB, are required for triggering host epithelial signal transduction pathways, intimate adherence, and A/E lesions. However, the functions of these secreted proteins and their roles in pathogenesis have not been characterized. To investigate the function of EspA and EspB in RDEC-1, the espA and espB genes were cloned and their sequences were compared to that of EPEC O127. The EspA proteins showed high similarity (88.5% identity), while EspB was heterogeneous in internal regions (69.8% identity). However, RDEC-1 EspB was identical to that of enterohemorrhagic E. coli serotype O26. Mutations in RDEC-1 espA and espB revealed that the corresponding RDEC-1 gene products are essential for triggering of host signal transduction pathways and invasion into HeLa cells. Complementation with plasmids containing EPEC espA or/and espB genes into RDEC-1 mutant strains demonstrated that they were functionally interchangeable, although the EPEC proteins mediated higher levels of invasion. Furthermore, maximal expression of RDEC-1 and EPEC-secreted proteins occurred at their respective host body temperatures, which may contribute to the lack of EPEC infectivity in rabbits.
Amino Acid Sequence↗
Comparison of real-time virtual and fiberoptic bronchoscopy in patients with bronchial carcinoma: opportunities and limitations.
OBJECTIVE: Both helical CT and fiberoptic bronchoscopy are used in the staging of pulmonary tumors for therapeutic decision making. The improved resolution offered by helical CT has led to the clinical use of three-dimensional reconstruction techniques such as virtual bronchoscopy. We tested this new simulated endoscopic view of inner organ surfaces and compared it with corresponding fiberoptic examinations of the tracheobronchial system. SUBJECTS AND METHODS: Twenty patients with malignancies of the lung and mediastinum were examined with both virtual bronchoscopy and fiberoptic bronchoscopy. Both examinations were reviewed by radiologists and surgeons familiar with fiberoptic bronchoscopy. Virtual bronchoscopy was calculated and reconstructed from the cross-sectional images on a separate workstation. Stenoses and tumor infiltration were classified from the fiberoptic examination. These results were compared with the virtual bronchoscopy findings. RESULTS: Virtual bronchoscopy of diagnostic quality was achieved in 19 of 20 patients. High-grade stenoses were revealed equally well with virtual and fiberoptic techniques. Virtual bronchoscopy offered the advantage of being able to visualize areas beyond even high-grade stenoses. However, on virtual bronchoscopy discrete infiltration or extraluminal impression was not visible in five patients. In another patient, strong heart pulsation produced motion artifacts that prevented evaluation of the reconstruction. CONCLUSION: Virtual bronchoscopy represents a new noninvasive method for evaluating helical CT findings. In comparison with fiberoptic bronchoscopy, virtual bronchoscopy offers the advantage of being able to visualize areas beyond even high-grade stenoses. In addition to the limited view of fiberoptic bronchoscopy, extraluminal causes of lumen compressions can be analyzed in the cross-sectional images and evaluated together with the virtual representation. However, it was not possible to detect small infiltrations with virtual bronchoscopy. This new representation of helical CT data might be helpful for postoperative follow-up examinations, such as after stent implantation, and can be carried out without additional risk to the patient. Radiologists do need special fiberoptic bronchoscopy knowledge and experience with three-dimensional-reconstructions to differentiate between real stenoses and artificial stenoses that might be caused by pulsation artifacts.
Artifacts↗
A tale of two health care delivery systems.
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Acquired Immunodeficiency Syndrome↗
The trimodal death distribution of trauma victims: military experience from the Lebanon War.
INTRODUCTION: Mortality in war is traditionally divided into two categories: killed in action and died of wounds. Mortality in civilian trauma is generally divided into three categories: immediate death (50%), early death (30%), and late death (20%). Can we identify a trimodal death distribution among war victims? METHODS: We analyzed data for casualties in the Lebanon War from June 6 to September 20, 1982. During this period a total of 1,950 soldiers were injured; 351 (18%) of them died. Time of injury and time of death of the victims was determined from real-time recordings during the battle and from hospital files. RESULTS: Analyzing the time of death revealed that 329 of the soldiers (93.7%) died within the first hour after injury, 7 soldiers died 1 to 4 hours after injury (2%), and 15 soldiers died 24 hours to 75 days after injury (4.3%). The most common causes of death during the first hour after injury were central nervous system (CNS) injuries 31%, exsanguination 30%, incineration 21%, and combined CNS injury and exsanguination 10.9%. Exsanguination was the leading cause of death 1 to 4 hours after injury (86%). CNS injury was the most common cause of late death (60%). Only 1.1% of the soldiers who reached the hospital alive died of their wounds. CONCLUSIONS: A trimodal mortality distribution with different causes of death in each peak can be identified in the mortality pattern of Israeli soldiers during the Lebanon War. The relative height of the different peaks and the causes of death in the third peak are different from those found in civilian trauma. We believe that prompt medical treatment and expeditious evacuation from the battle zone led to a very low death rate among the wounded soldiers who had reached the hospital alive. The same factors may have increased the relative portion of CNS injuries as a cause of late death.
Cause of Death↗
Intravenous line diameter: is bigger really better?
OBJECTIVE: To determine whether the size of an intravenous catheter influences the cannulation success rate and procedure duration among military medics. METHODS: According to a prospective, randomized, controlled crossover study design, 114 military medic cadets were paired and inserted 14-gauge (14G) and 16G intravenous catheters into veins in the antecubital fossa. Success rate and procedure duration were determined. RESULTS: The overall success rate for 14G and 16G catheters was 80 and 86%, respectively. Average procedure duration was 33 +/- 14.7 and 35.2 +/- 14.9 seconds, respectively. No significant differences were found in either success rate or procedure duration between the examined catheter sizes. CONCLUSION: Successful intravenous cannulation was unaffected by catheter size. Therefore, 14G intravenous catheters are recommended for use by military medics on the battlefield.
Adult↗
The impact of advanced trauma life support course on graduates with a non-surgical medical background.
The aim of this study was to assess advanced trauma life support (ATLS) and combat trauma life support (CTLS) skills implementation among general practising physicians, its perceived utility in their routine daily practice as well as in their potential army combat assignments. One hundred and ten physicians, graduates of ATLS and CTLS courses, from the subspecialties of geriatrics, psychiatry and family medicine, were surveyed by telephone, to answer a specially designed questionnaire. The response rate was 82%. Professional distribution was: 6.6% geriatrics; 46.7% family physicians; and 46.7% psychaitrists. The number of trauma events treated by these physicians in their post-course practise was: geriatrics-three; family physicians-30; psychiatrists-18. We believe that a properly designed ATLS course, executed and applied to general practitioners, can be highly beneficial to trauma victims.
Adult↗
The accumulated experience of the Israeli Advanced Trauma Life Support program.
BACKGROUND: Between January 1990 and May 1995 one faculty in Israel taught Advanced Trauma Life Support (ATLS) courses to 3,700 physicians. Two types of courses were given to three subpopulations. We studied the influence of demographic variables on students' achievements in the course and compared students' achievements as a function of their course type. STUDY DESIGN: This study was conducted as a concurrent longitudinal study. RESULTS: Achievements of 3,700 students were analyzed. The precourse grade, type of course, and their interaction were found to have a significant effect on the postcourse grades. Physicians practicing surgical subspecialties, in general, did better, as did students educated in English-speaking countries. Students who took part in the Combat Trauma Life Support (CTLS) course, which included the entire ATLS course and additional lectures and exercises, also ended with better scores. CONCLUSIONS: Physician's country of origin and clinical subspecialty have a significant effect on the cognitive achievement in the ATLS course provided in Israel. An expanded ATLS course (CTLS), to include additional military trauma topics as well as additional skill station training, can improve the results of the postcourse grades.
Adult↗
Combat trauma life support training versus the original advanced trauma life support course: the impact of enhanced curriculum on final student scores.
BACKGROUND: Within a military framework, the trauma course student, a young medical officer, is trained to become a trauma team leader and the first provider of medical aid. By adding battlefield medicine-related subjects to the basic Advanced Trauma Life Support (ATLS) course, as well as exercises tailored to the distinctive demands of military medicine, we could develop a special teaching unit: Combat Trauma Life Support (CTLS). The curriculum is basically the complete unchanged ATLS course of the American College of Surgeons enriched with lectures and practicums to fill the gap between the essentially civilian emergency department character of the ATLS course and the military tasks of the medical officer. PURPOSE OF STUDY: To compare the cognitive knowledge achievements of trauma course participants in the Israel Defence Force Medical Corps and to delineate the impact of the course type on students' written test results. DESIGN: A retrospective comparison analysis of pre- and post-course written test scores of 2,614 physicians who had participated in the ATLS and CTLS courses in the Israel Defence Force School of Military Medicine between 1990 and 1993. RESULTS: The analysis indicated that students who undertook the CTLS course achieved statistically better results in written tests (87.9 +/- 8.7 vs. 79.6 +/- 11.4, R2 = 0.33). CONCLUSIONS: We conclude that the CTLS comprehensive curriculum provides an improved training basis for the complex task of army battlefield trauma care support.
Curriculum↗