A comparative cytogenetic study of the rice (Oryza sativa L.) autotetraploid restorers and hybrids.

We studied pollen fertility, seed set and cytogenetic characteristics of restorer lines and F1 hybrids of autotetraploid rice. T4002, T4063, T461A x T4002 and T461A x T4063 showed significantly higher pollen fertility and seed set than T4132 and T461A x T4132. Meiotic pairing configurations of T4002, T4063, T4132, T461A x T4002, T461A x T4063 and T461A x T4132 were 0.051 + 19.96II (9.89 rod + 10.07 ring) + 0.01III + + 2.00IV, 0.11I + 19.17II (8.90 rod + 10.37 ring) + 0.09III + 2.26IV + 0.01VI, 1.34I + 9.46II (4.50 rod + 4.96 ring) + 0.80III + 6.02IV + 0.09VI + 0.09VIII, 0.02I + 14.36II (6.44 rod + 7.91 ring) + 0.01III + 4.80IV + 0.01VIII, 0.06I + 17.67II (11.01 rod + 6.67 ring) + 0.06III + 3.10IV + 0.01VI and 1.11I + 11.31II (5.80 rod + 5.51 ring) + 0.41III + 5.63IV + 0.03VI + 0.03VIII, respectively. Configuration 16II + 4IV and 12II + 6IV occurred in the highest frequency among the autotetraploid restorers and hybrids. Meiotic chromosome behaviors were less abnormal in the tetraploids with high seed set than those with low seed set. The hybrids had fewer frequencies of bivalents, univalents, trivalents and multivalents than the restorers, but higher frequency of quatrivalents than the restorers at MI. The frequency of univalents at MI had the most impact on pollen fertility and seed set, i.e., pollen fertility decreased with the increase of univalents. The secondary impact factors were trivalents and multivalents, and bivalents and quatrivalents had no effect on pollen fertility and seed set. The correlative relationship between pollen fertility and cytogenetic behaviors could be utilized to improve seed set in autotetraploidy breeding.

Pulmonary endarterectomy for chronic thromboembolic obstruction: recent surgical experience.

Pulmonary thromboendarterectomy for chronic pulmonary emboli was performed on ten patients, ages 20 to 67 years, between July 1977 and June 1981. Five patients each were assigned to New York Heart Association functional classes III and IV. All patients had pulmonary hypertension and increased pulmonary vascular resistance. Obstruction beginning in the lobar arteries and involving more than 50% of the sequential arteries was present in all patients. Five patients had complete obstruction of a pulmonary artery. All patients had obstructive disease in both lungs. Pulmonary thromboendarterectomy was performed through central pulmonary arteriotomies and by use of deep hypothermia and circulatory arrest. Circulatory arrest was employed in one to four periods totaling up to 60 minutes. No neurologic deficit was observed. All patients developed reperfusion edema in the lungs. All patients had improvement in pulmonary hypertension and pulmonary vascular resistance. One patient died of lung failure in the late postoperative period. All survivors had improved lung function, with two functional classes in seven patients. Improvement in one equaled three functional classes and in one, by one functional class.

Blunt cardiac rupture. The Emanuel Trauma Center experience.

OBJECTIVE: To analyze the factors affecting outcome in patients with blunt cardiac rupture, including anatomical cardiac injury, associated injury, clinical presentation, age, mechanism of injury, diagnostic method, surgical intervention, and presence of vital signs in the field and on arrival. DESIGN: Retrospective review. SETTING: A community-based level I trauma center. PATIENTS: A consecutive series of 27 patients seen between 1984 and 1993. MAIN OUTCOME MEASURE: Survival with return to preinjury activity. RESULTS: Eleven patients (41%) survived resuscitation, surgery, and initial hospital care. Survivors had a lower mean Injury Severity Score (38) than nonsurvivors (62) (P < .05). Three (33%) of nine patients who arrived with no blood pressure or viable electrical heart rhythm survived. No patient survived rupture of two cardiac chambers. CONCLUSIONS: Patients with blunt cardiac rupture who present with cardiac arrest can survive. Nonsurvivors tend to have more associated injuries, as indicated by higher Injury Severity Scores. Our institution's overall survival rate of 41% (11/27) compares favorably with rates at other trauma centers.

Sonomicrometry: its application as a routine monitoring technique in cardiac surgery.

We utilized ultrasonic-dimension crystals in approximately 50 patients during a three-year period to evaluate clinical sonomicrometry as a routine monitoring tool in patients undergoing cardiac operations. Standard research piezoelectric pulse transit ultrasonic transducers were modified with a hooked attachment in a tethered configuration to facilitate accurate alignment and quick insertion for the measurement of myocardial segment length changes. These segment crystals were used both intraoperatively and postoperatively to evaluate the left ventricular pressure-geometry relationships and to serve as a continuous monitor of myocardial function. The left ventricular pressure-volume relationship was varied by temporarily reapproximating the pericardium (pericardial closure resulted in a 12% reduction in fractional shortening, a 5% decrease in end-diastolic segment length, and an 8% increase in pulmonary artery diastolic pressure). During both the intraoperative and postoperative periods, we found good correlation between thermodilution, stroke volume, and myocardial dimensions; no correlation was noted between pulmonary artery diastolic pressure and stroke volume. No bleeding or major complications resulted from the use of these sonomicrometry transducers. Our initial clinical experience with sonomicrometry seems to support its use as a potentially valuable monitoring tool.

Interhospital transport of the patient on extracorporeal cardiopulmonary support.

Portable extracorporeal cardiopulmonary support systems have enhanced the resuscitation and support of moribund patients outside of the operating room environment. The literature documents the successful application of emergency cardiopulmonary support within the hospital setting. Clinicians have reported the use of helicopter and ground ambulance to transport patients requiring intraaortic balloon counterpulsation and fixed-wing transport of neonates requiring extracorporeal membrane oxygenation. As medical transport capabilities extend the sphere of tertiary care to outlying medical facilities, there is a role for extracorporeal cardiopulmonary support in the initial stabilization and safe transport of critically ill patients, via air or ground ambulance. Potentially, the early application of life-sustaining technology can lower mortality and morbidity in patients with a survivable pathology. This is a report on the experience with the resuscitation and interhospital transport of patients on extracorporeal cardiopulmonary support.

Patterns of injury in helmeted and nonhelmeted motorcyclists.

In the present study, the incidence of severe brain injury was 600 percent higher for patients riding without a helmet and the incidence of all brain injuries was nearly twice as high in the nonhelmeted riders. All surviving patients with severe brain injury sustained residual long-term disability. The incidence of injury and death was much higher for motorcyclists than for occupants of automobiles involved in accidents. Riding a motorcycle is dangerous and riding without a helmet is fool-hardy. Helmets also protect the face, as facial fractures were twice as common in the nonhelmeted riders. There were no significant differences between nonhelmeted and helmeted motorcyclists in terms of overall injury as measured by an injury severity score of 16 or greater. Orthopedic injuries, in this study, were so common that orthopedic surgeons performed more major operations than all other surgical specialists combined. Depth of orthopedic coverage is essential to treat significant numbers of injured motorcyclists. Neurosurgeons are key members of a trauma care team. Helmet laws would help us utilize our limited neurosurgical capacity more effectively by reducing the incidence of brain injury. Medical professionals must educate the public regarding the societal and personal cost of unhelmeted motorcycle riding. Legislation mandating helmet usage for motorcycle riders must be sought.

Accuracy and relationship of mechanisms of injury, trauma score, and injury severity score in identifying major trauma.

The accuracy of mechanism of injury criteria and trauma scores as triage criteria for identifying major trauma patients has been determined from the experience at one trauma center treating 2,500 patients over a 2 year period. Death of the other occupant of the same vehicle as the patient and patient extrication taking longer than 20 minutes were determined to be sufficiently accurate triage criteria. Trauma scores of 14 or less were more accurate than trauma scores of 12 or less.

Extracorporeal cardiopulmonary life support with heparin-bonded circuitry in the resuscitation of massively injured trauma patients.

BACKGROUND: Patients who have massive but potentially survivable injuries frequently die from complications of hypovolemia, hypoxemia, hypothermia, metabolic acidosis, and coagulopathy. Emergency cardiopulmonary bypass has been unsuccessful in preventing such deaths because it involves systemic anticoagulation that exacerbates coagulopathy. PATIENTS AND METHODS: A simplified extracorporeal cardiopulmonary life support (ECLS) system was assembled consisting of a centrifugal pump head, heat exchanger, membranous oxygenator, percutaneous cannulas, and heparin-bonded circuitry. The entire system has heparin-bonded surfaces. Patients were resuscitated with the system after femoral vein-femoral artery cannulation. ECLS was used to resuscitate massively injured patients who were deteriorating despite maximal conventional therapy. RESULTS: While receiving maximal conventional therapy, 6 patients developed hypothermia, metabolic acidosis, and coagulopathy causing pulmonary hemorrhaging and hypoxemia from severe underlying lung injuries. ECLS with heparin-bonded circuitry provided cardiopulmonary support and rewarming while physicians addressed coagulopathies and surgical bleeding and assessed survivability. Three patients survived. CONCLUSIONS: ECLS with heparin-bonded circuitry offers supplemental capability in the resuscitation and cardiopulmonary support of selected massively injured patients while their primary injuries are being evaluated and treated.

Clinical indications for cervical spine radiographs in the traumatized patient.

During a 4 1/2 year period, 4,941 trauma patients were admitted to a hospital, and details of their injuries and treatment were entered in a computerized trauma registry. Using that database, patients with cervical spine injury were studied. Of the 4,941 patients, 1,823 (38 percent) had radiographs of the cervical spine. Ninety-four patients (5 percent) of these patients had injuries of the cervical spine or spinal cord. Sixty five of the 94 patients with cervical spine injury were alert. All had either neck pain or neck tenderness. We do not recommend screening cervical spine radiographs for the alert trauma patient without neck pain; however, we do recommend screening for all patients with decreased levels of consciousness and an injury that could have conceivably injured the cervical spine, for all patients with neurologic deficits compatible with a cervical origin, and for all patients with neck pain or tenderness. Lateral cervical spine radiographs were obtained in all injured patients. They demonstrated cervical spine injury in 70 patients (74 percent) and missed the injury in the remaining 24, which resulted in an unacceptable false-negative rate of 26 percent. We believe that all patients at risk for cervical spine injuries must have complete radiographic examinations of the cervical spine. Computerized axial tomography was the most useful modality to confirm a cervical spine injury in those patients whose lateral cervical spines appeared normal radiographically, especially in patients with associated head injury requiring computerized axial tomography of the brain. Computerized axial tomography diagnosed the injury in 14 of the 24 patients requiring study beyond initial screening. Also presented herein is a radiologic screening algorithm for cervical spine injuries in trauma patients.

Biliary stone removal: the interventional radiologist's role.

Despite the recent popularity of endoscopic techniques, the interventional radiologist retains an important role in the non-surgical management of biliary duct stones. In the cases where endoscopic sphincterotomy is difficult, the radiologist can be of great assistance to the endoscopist. When endoscopic stone removal is not feasible, the radiologist can treat patients percutaneously. When surgery is performed in patients with recurrent stone disease, the radiologist can maintain biliary toilet. The various approaches to biliary removal through non-surgical tracts are discussed.

Considerations for inter-hospital extracorporeal cardiopulmonary support resuscitation and transport.

The availability of commercial, pre-packaged extracorporeal cardiopulmonary support (ECPS) circuits, which are simplified for rapid set-up and priming, has made the intra-hospital resuscitation of moribund patients routine. The successful utilization of this technology in the emergent setting requires planning and the coordination of personnel familiar with the technology. Many issues must be addressed when a patient requiring life-sustaining support utilizing this technology at an outlying hospital, must be transported while on ECPS. After reducing the size and weight of the ECPS cart and obtaining Federal Aviation Administration approval for use during aeromedical transport, the Emanuel Hospital Mobile Surgical Transport Team (MSTT) was able to extend the use of emergency cardiopulmonary bypass to outlying medical facilities. The patients selected for transport, using ECPS, are a group of patients with a potentially survivable pathology unlikely to survive inter-hospital transport without such measures. This report describes our experience with inter-hospital transport of patients on ECPS with special emphasis on transport considerations.

Mobile surgical transport team.

The "golden hour" of trauma is based on the principle that severely injured patients are more likely to survive with rapid, appropriate resuscitation and treatment. An inequality exists between sophisticated urban trauma centers and rural/community hospitals in their efforts and abilities to treat severely injured patients. A level I trauma center developed a unique program in an attempt to equalize this inequality--a mobile surgical transport team (MSTT). This article explains the origin of the MSTT, how and why the MSTT is activated, and the roles and responsibility of MSTT members. To further explain the MSTT, two contrasting case studies on trauma patients are presented.

Operative stabilization of flail chest injuries: review of literature and fixation options.

BACKGROUND: Flail chest injuries cause significant morbidity, especially in multiply injured patients. Standard treatment is typically focused on the underlying lung injury and involves pain control and positive pressure ventilation. Several studies suggest improved short- and long-term outcomes following operative stabilization of the flail segments. Despite these studies, flail chest fixation remains a largely underutilized procedure. METHODS: This article reviews the relevant literature concerning flail chest fixation and describes the different implants and techniques available for fixation. Additionally, an illustrative case example is provided for description of the surgical approach. RESULTS: Two prospective randomized studies, five comparative studies, and a number of case series documented benefits of operative treatment of flail chest injuries, including a decreased in ventilation duration, ICU stay, rates of pneumonia, mortality, residual chest wall deformity, and total cost of care. Historically, rib fractures have been stabilized with external plates or intramedullary implants. The use of contemporary, anatomically contoured rib plates reduced the need for intraoperative plate bending. Intramedullary rib splints allowed less-invasive fixation of posterior fractures where access for plating was limited. CONCLUSION: Operative treatment can provide substantial benefits to patients with flail chest injuries and respiratory compromise requiring mechanical ventilation. The use of anatomically contoured rib plates and intramedullary splints greatly simplifies the procedure of flail chest fixation.

Biomechanical rationale and evaluation of an implant system for rib fracture fixation.

BACKGROUND: Biomechanical research directed at developing customized implant solutions for rib fracture fixation is essential to reduce the complexity and to increase the reliability of rib osteosynthesis. Without a simple and reliable implant solution, surgical stabilization of rib fractures will remain underutilized despite proven benefits for select indications. This article summarizes the research, development, and testing of a specialized and comprehensive implant solution for rib fracture fixation. METHODS: An implant system for rib fracture fixation was developed in three phases: first, research on rib biomechanics was conducted to better define the form and function of ribs. Second, research results were implemented to derive an implant system comprising anatomical plates and intramedullary rib splints. Third, the functionality of anatomic plates and rib splints was evaluated in a series of biomechanical tests. RESULTS: Geometric analysis of the rib surface yielded a set of anatomical rib plates that traced the rib surface over a distance of 13-15 cm without the need for plate contouring. Structurally, the flexible design of anatomic plates did not increase the native stiffness of ribs while restoring 77% of the native rib strength. Intramedullary rib splints with a rectangular cross-section provided 48% stronger fracture fixation than traditional intramedullary fixation with Kirschner wires. CONCLUSION: The anatomic plate set can simplify rib fracture fixation by minimizing the need for plate contouring. Intramedullary fixation with rib splints provides a less-invasive fixation alternative for posterior rib fracture, where access for plating is limited. The combination of anatomic plates and intramedullary splints provides a comprehensive system to manage the wide range of fractures encountered in flail chest injuries.