bluuebunny/crossref_metadata_2025 huggingface dataset:
Gastrointestinal Carcinoid Tumors: Long‐term Prognosis for Surgically Treated Patients
Authors: Söreide Jon Arne , van Heerden Jon A. , Thompson Geoffrey B. , Schleck Cathy , Ilstrup Duane M. , Churchward Marilyn
Published: August 2002

To evaluate long‐term survival of patients with gastrointestinal carcinoid tumors and to assess factors that may influence prognosis, 154 patients (49% females, 51% males), median age 62 years (range 12–84 years) treated at our institution during 1972–1982 have been followed long term. Tumor location included the foregut (7%), midgut (62%), and hindgut (30%). Ninety‐five percent of the patients underwent surgical or endoscopic excision of the primary tumor, with overall operative mortality and postoperative morbidity rates of 2.6% and 11%, respectively. At follow‐up, 60 patients (39%) were alive (median follow‐up 18 years; range 1–26 years). The main causes of death included carcinoid tumor burden (32%), unrelated causes (45%), other malignancy (19%), and unknown causes (4%). Observed overall 5‐ and 10‐year survivals were 69% and 53%, respectively. Survival was not related to gender or symptoms at presentation. However, age, embryologic origin, tumor size, depth of invasion, nodal status, and stage of disease proved to be of statistical significance (log‐rank). In a multivariate Cox' model, only older age (> 62 years) [P =0.001, odds ratio (OR) = 3.4) and embryologic origin (midgut versus foregut) (P = 0.045, OR = 0.45) provided independent prognostic power when death from any cause was taken as the end‐point. This study confirms that patient's age and the site of the primary tumor have prognostic significance. Carcinoid tumors are neuroendocrine tumors with a relatively good prognosis, and long‐term survival is possible despite advanced stages of disease.
Role of Malignancy and Preoperative Embolization in the Management of Carotid Body Tumors
Authors: Liapis Christos D. , Evangelidakis Emmanouil L. , Papavassiliou Vassilios G. , Kakisis John D. , Gougoulakis Alexandros G. , Polyzos Aristidis K. , Sechas Michael N. , Gogas John G.
Published: August 2002

The purpose of this retrospective study is to present our approach to the management of patients with carotid body tumors (CBTs), emphasizing the role of malignancy and preoperative embolization. Between 1975 and 1998 a series of 18 patients with CBTs were treated, and 16 of them underwent successful excision of the tumor. According to the Shamblin classification, six of the tumors were type I, six type II, and six type III. In three of these patients (two with type II tumors and one with type III) in whom preoperative embolization had been performed, mean intraoperative blood loss was 400 ml, whereas in the remaining 13 cases this loss was 700 ml. Two patients with intracranial tumor spread underwent only radiotherapy. Neither postoperative deaths nor strokes occurred. Temporary cranial nerve injury occurred in four cases (25%). Local lymph node invasion was found in two patients, establishing the diagnosis of malignancy. One of these patients developed distal metastases 3 years after the operation and was treated with radiotherapy and octreotide. Follow‐up ranging from 30 months to 23 years (mean 5 years) revealed no local recurrence except for the two patients who were treated with radiotherapy only. In conclusion, surgical excision remains the treatment of choice for CBTs and can be performed without major risks and with low morbidity and mortality. Preoperative embolization is helpful by diminishing intraoperative bleeding, and malignancy, though rare justifies early management.
Analysis of 100 Consecutive Hepatectomies: Risk Factors in Patients with Liver Cirrhosis or Obstructive Jaundice
Authors: Das Bidhan Chandra , Isaji Shuji , Kawarada Yoshifumi
Published: August 2002

We analyzed various pre‐, intra‐, and postoperative variables in 100 consecutive patients treated by hepatectomy for various malignant and benign liver diseases to identify patients at risk of developing postoperative complications. Patients were divided into three groups: those with normal liver (NL, n= 53); those with liver cirrhosis (LC, n= 32); and those with obstructive jaundice (OJ, n= 15). The overall postoperative morbidity and mortality rates were 14% and 4% (due to liver failure), respectively. In the LC group the combined presence of abnormal levels of serum hyaluronic acid (HA, > 200 ng/ml), indocyanine green retention rate at 15 minutes (ICGR15, > 15%), and hepatic uptake ratio of 99mTc‐galactosyl human serum albumin (GSA) at 15 minutes (LHL15, < 0.9) preoperatively was found to be a risk factor with a 100% morbidity rate. Operative blood loss of more than 1000 ml in LC patients was associated with high morbidity. In the OJ group preoperative parameters were almost normal after biliary drainage, but the extent of liver resection, blood loss > 2000 ml, and high serum interleukin‐6 12 hours after hepatectomy correlated with high postoperative morbidity. No morbidity or mortality was reported in the NL group, except in a single patient who received long‐term intraarterial chemotherapy preoperatively. Consequently, the extent of hepatectomy should be carefully determined according to the preoperative risk factors in LC patients; and in OJ patients hepatectomy, which tends to become extensive, should be carefully performed to minimize surgical stress because preoperative factors do not help predict outcome. Furthermore, the present study revealed that a serum HA level higher than 500 ng/ml on postoperative day 1 or day 7 (or both) was a useful marker for hepatic failure.
Subcuticular Skin Closure as a Standard Approach to Emergency Appendectomy in Children: Prospective Clinical Trial
Authors: Serour Francis , Efrati Yigal , Klin Baruch , Barr Joseph , Gorenstein Arkadi , Vinograd Itzhak
Published: August 2002

We evaluated the morbidity associated with primary closure by interrupted subcuticular absorbable sutures following emergency appendectomy. In a prospective clinical trial over a 12‐month period, 216 children who underwent emergency appendectomy had skin closure using subcuticular interrupted absorbable polyglactin 4‐0 sutures. Preoperative prophylactic antibiotics consisting of metronidazole alone or in combination with gentamicin were used in patients with suspected phlegmonous appendicitis; a combination of metronidazole, gentamicin, and ampicillin was used when perforation of the appendix was suspected. Postoperatively, in patients with phlegmonous appendicitis metronidazole was given for 24 hours, whereas in those with peritonitis the triple antibiotics were continued for 7 to 10 days. All patients were assessed for complications resulting from the technique of wound closure. No intraabdominal abscesses or serious complications were recorded. The overall incidence of wound infection was 1.8%. Among children with a perforated appendix the rate of superficial wound infection was 5.7%. There was no difference in the rate of wound infection between patients who received metronidazole alone or metronidazole plus gentamicin preoperatively. All the patients and their families were satisfied with the cosmetic results and with the fact that removal of skin sutures was unnecessary. We conclude that the use of prophylactic antibiotics permits standard skin closure by interrupted absorbable subcuticular suture.
Carcinoid Tumors: Development of Our Knowledge
Authors: Creutzfeldt Werner
Published: August 2002

Historically, carcinoids have long been known to be a morphologically distinct class of rare intestinal tumors that behave less aggressively than the more common intestinal adenocarcinomas. It was not until much later that their endocrine nature was recognized. Some authors restrict the term carcinoid to intestinal endocrine tumors, whereas others include a large variety of neuroendocrine tumors. In the WHO classification of 1980, carcinoids were defined as tumors of the diffuse neuroendocrine system that are either benign or neoplasms with a more favored prognosis than carcinomas. They are characterized by a typical growth pattern, silver affinity, and positive immunohistochemical reaction with neuron‐specific markers; and they can express different peptides and biogenic amines. Neuroendocrine tumors originating from endocrine glands (pituitary, thyroid, adrenals, pancreas) and highly malignant neuroendocrine carcinomas are excluded from the carcinoid group of neoplasms. For the natural history of carcinoid tumors several independent predictive parameters can be defined: size, site of origin, growth pattern, and hormone dependence. The number of neuropeptides and amines expressed by a carcinoid or the amount of biologically active neurohormones secreted are of no prognostic significance regarding malignant behavior. The carcinoid syndrome is a rare clinical entity that occurs with a prevalence of 1.6% for carcinoid tumors and almost only if liver metastases are present. The complex clinical symptoms are only partially explained by the secretion of serotonin and tachykinins.
Biologic Control of Injury and Inflammation: Much More than Too Little or Too Late
Authors: Guirao Xavier , Lowry Stephen F.
Published: August 2002

A generalized host inflammatory response is necessary to orchestrate the maintenance or recovery of tissue repair and immune competence following severe injury or infection. When excessive in initial magnitude or duration, however, these otherwise beneficial inflammatory processes may eventuate in deterioration rather than restoration of homeostasis. Although the adverse consequences of excessive inflammatory stimuli may be acutely evident, their influences are more often insidious. A complex cascade of endogenously derived proinflammatory mediators are currently hypothesized to be responsible for both the beneficial and the adverse sequelae of infection and injury. The cytokine proteins tumor necrosis factor and interleukin 1 have been most widely studied as potential targets for antagonist intervention in both experimental models and prospective clinical trials. Preclinical evidence supporting these approaches is briefly discussed herein, as are the results of clinical trials attempting to modulate cytokine influences in the presence of sepsis. The present discussion focuses on potential insights gained from these investigations and the evolving appreciation for the importance of cytokine counterregulatory mechanisms. Examples of potentially complex interactions between inflammatory cytokines and infection‐induced antagonist proteins or counterregulatory hormones are provided. It is hypothesized that a sustained imbalance among these proinflammatory and counterregulatory influences may be a critical determinant of outcome in patients with severe infection.
Low‐Molecular‐Weight Heparin versus Warfarin for Prevention of Recurrent Venous Thromboembolism: A Randomized Trial
Authors: Das S. K. , Cohen A. T. , Edmondson R. A. , Melissari E. , Kakkar V. V.
Published: August 2002

A group of 105 consecutive patients with venographically proved major acute deep vein thrombosis (DVT) were randomized in an open prospective study to evaluate the comparative efficacy and safety of a fixed dose of subcutaneous low‐molecular‐weight heparin (LMWH) and warfarin for the prevention of recurrent venous thromboembolism. Four patients developed venographically proved recurrent DVT during the 3 months of treatment: three in the LMWH group and one in the warfarin group. Nonfatal pulmonary embolism occurred in two patients in the LMWH group and in one in the warfarin group. Five of the 55 patients (10%) in the warfarin group and none of the 50 patients in the LMWH developed bleeding complications (two‐tailed Fisher exact test, p = 0.06). A preliminary assessment of the costs indicated that treatment with LMWH was less expensive by £900 per patient than warfarin. In conclusion, the fixed daily dose of LMWH and the adjusted dose of warfarin therapy were of similar efficacy in preventing recurrence of DVT. However, warfarin therapy, despite strict laboratory control, is associated with more frequent side effects and is expensive. Another study with a higher dose of LMWH is recommended.
Laparoscopic Approach to Pheochromocytoma: Hemodynamic Changes and Catecholamine Secretion
Authors: Fernández‐Cruz Laureano , Taurá Pilar , Sáenz Alejandro , Benarroch Guerson , Sabater Luis
Published: August 2002

This study compares the outcome of laparoscopic adrenalectomy (LpA) in 23 patients using CO2 insufflation with the outcome of this procedure in another 8 patients with pheochromocytoma (7 unilateral, 1 bilateral) using helium for pneumoperitoneum. The adrenal lesions in the first group included nonfunctional adenoma (n= 3), aldosterone adenoma (n= 11), Cushing's adenoma (n= 6), and Cushing's disease (n= 3). The latter patients were compared with a third group of 8 patients with pheochromocytoma undergoing conventional transabdominal adrenalectomy (CTA). With both procedures, intraoperative changes in plasma catecholamine levels were studied during pheochromocytoma removal and the changes correlated with intraoperative cardiovascular derangements. LpA was successfully performed in 95% of patients with adrenal lesions and in 100% of patients with pheochromocytoma. There was no significant difference in laparoscopic adrenalectomy for pheochromocytoma compared to that for other adrenal lesions in terms of operative time, blood loss, hospital stay, analgesic requirements, and return to normal activity. The outcome was less favorable in pheochromocytoma patients undergoing CTA. The largest increase of catecholamine levels in pheochromocytoma patients occurred during tumor manipulation with both LpA (17.4‐fold for epinephrine and 8.6‐fold for norepinephrine) and CTA (34.2‐fold for epinephrine and 13.7‐fold for norepinephrine), but cardiovascular instability was associated only with CTA. LpA may become the technique of choice for surgical removal of adrenal lesions and may also become the preferred method for removing pheochromocytoma.
Evaluation of Penetrating Injuries of the Neck: Prospective Study of 223 Patients
Authors: Demetriades D. , Theodorou D. , Cornwell E. , Berne T.V. , Asensio J. , Belzberg H. , Velmahos G. , Weaver F. , Yellin A.
Published: August 2002

The objective of this study was to assess the role of clinical examination, angiography, color flow Doppler imaging, and other diagnostic tests in identifying injuries to the vascular or aerodigestive structures in patients with penetrating injuries to the neck. A prospective study was made of patients with penetrating neck injuries. All patients had a careful physical examination according to a written protocol. Stable patients underwent routine four‐vessel angiography and color flow Doppler imaging. Esophagography and endoscopy were performed for proximity injuries. The sensitivity, specificity, and predictive values of physical examination, color flow Doppler studies, and other diagnostic tests were assessed during the evaluation of vascular and aerodigestive tract structures in the neck. Altogether 223 patients were entered in the study. After physical examination 176 patients underwent angiography and 99 of them underwent color flow Doppler imaging. Angiographic abnormalities were seen in 34 patients for an incidence of 19.3%, but only 14 (8.0%) required treatment. Color flow Doppler imaging was performed on 99 patients with a sensitivity of 91.7%, specificity 100%, positive predictive value (PPV) 100%, and negative predictive value (NPV) 99%. These values were all 100% when only injuries requiring treatment were considered. None of the 160 patients without clinical signs of vascular injury had serious vascular trauma requiring treatment (NPV 100%), although angiography in 127 showed 11 vascular lesions not requiring treatment. “Hard” signs on clinical examination (large expanding hematomas, severe active bleeding, shock not responding to fluids, diminished radial pulse, bruit) reliably predicted major vascular trauma requiring treatment. Among 34 of the 223 total patients (15.2%) admitted with “soft” signs, 8 had angiographically detected injuries, but only one required treatment. An esophagogram was performed on 98 patients because of proximity injuries (49 patients) or suspicious clinical signs (49 patients), and two of them showed esophageal perforations. None of the 167 patients without clinical signs of esophageal trauma had an esophageal injury requiring treatment. It was concluded that physical examination is reliable for identifying those patients with penetrating injuries of the neck who require vascular or esophageal diagnostic studies. Color flow Doppler imaging is a dependable alternative to angiography. An algorithm for the initial assessment of neck injuries is suggested.
Complications and Nonclosure Rates of Fasciotomy for Trauma and Related Risk Factors
Authors: Velmahos G.C. , Theodorou D. , Demetriades D. , Chan L. , Berne T.V. , Asensio J. , Cornwell E.E. , Belzberg H. , Stewart B.M.
Published: August 2002

The objective of this study was to identify risk factors for the development of complications and unsatisfactory skin closure following fasciotomy for trauma. Risk factors included in the study are prolonged time from injury to fasciotomy, type of fasciotomy, site of injury, and kind of underlying injury. The study was a retrospective analysis of 100 consecutive fasciotomies done for trauma over a period of 38 months (December 1991 to January 1995) in a “level I” trauma center at a university‐affiliated county teaching hospital. Ninety‐four patients were eligible for analysis, 29 of whom (31%) developed complications at the fasciotomy site. The risk was increased for lower extremity versus upper extremity (34.3% versus 20.8%), prophylactic versus therapeutic (42.0% versus 24.6%), late (>8 hours) versus early (37% versus 25%), and vascular versus musculoskeletal (38.8% versus 22.2%) trauma cases. The same risk factors negatively influenced the ability to close the skin primarily. The four subgroups defined by vascular/nonvascular injury and upper/lower extremity site had significantly different nonclosure rates (p= 0.043). The rate was highest among the vascular/lower extremity group (60.5%) and lowest among the nonvascular/upper extremity group (15.4%). We concluded that fasciotomies in lower extremities, the presence of underlying vascular injuries, fasciotomies performed prophylactically, and a time between the injury and fasciotomy of more than 8 hours are associated with an increased risk for local complications. The same factors are associated with an increased need for skin grafting the wound.
Evaluation of Enoxaparin Given before and after Operation to Prevent Venous Thromboembolism during Digestive Surgery: Play‐the‐Winner Designed Study
Authors: Bjerkeset Ottar , Larsen Stig , Reiertsen Ola
Published: August 2002

A total of 316 patients were included in a play‐the‐winner (PTW) designed study comparing the safety of enoxaprain started preoperatively versus postoperatively as prophylaxis against venous thromboembolism for digestive surgery. In a PTW‐designed study the treatment of any next patient depends on the outcome of the previous patient. If successful, the next patient receives the same treatment, if not, the comparative regimen is given. Excessive bleeding according to specified criteria, severe adverse reactions, clinically detected deep venous thrombosis (DVT), or pulmonary embolism (PE) were criteria for classification as “loser.” The PTW design allocates most patients to the superior treatment. The main variable in PTW studies is the number of consecutive patients receiving the same treatment. In this study 163 patients were allocated to postoperatively started and 153 to preoperatively started prophylaxis with enoxaparin. The frequency of “winners” was found to be 82.8% and 78.4% in the post‐ and preoperatively treated groups, respectively. No significant differences were found between the groups with regard to frequency of
“winners” or the number of consecutive patients before change of treatment. The percentile of survival distribution did not detect superiority of any group. Prophylaxis against postoperative venous thromboembolism for digestive surgery using enoxaparin can safely be started preoperatively.
Laparoscopic Splenectomy for Benign and Malignant Hematologic Diseases: 35 Consecutive Cases
Authors: Decker Georges , Millat Bertrand , Guillon Françoise , Atger Jérôme , Linon Michel
Published: August 2002

The feasibility and safety of laparoscopic splenectomy (LS) has been shown for a variety of diseases with small or moderately enlarged spleens. Immune thrombocytopenic purpura thus has become the typical indication for LS, although few data are available to demonstrate any superiority of the laparoscopic approach over conventional surgery for this indication. We retrospectively analyzed 35 cases of LS for benign (22 patients) or malignant (13 patients) hematologic disorders. LS was attempted irrespective of the volume of the spleen. The overall operative mortality rate was 2.9%, and complications occurred in 23% of all patients. The conversion rate was 9%, and accessory spleens were found in 17% of patients. Although the patients with malignant disease were significantly older, were higher operative risks (ASA score), had much larger spleens, and required longer operative times, more conversions to laparotomy, and more blood transfusions than patients with benign disease, their mortality and complication rates and the duration of their hospital stays were not significantly different from those with benign disease. They also compare favorably with the results of conventional surgery for the same indications. Patient selection, operative technique, and outcome of laparoscopic and conventional splenectomy are discussed with regard to the literature. Although the experience with LS for these indications is still limited, the reported results indicate that LS may be as beneficial for patients with malignant as for those with benign hematologic conditions.
Nutritional Status of Gastric Cancer Patients after Total Gastrectomy
Authors: Bae Jae‐Moon , Park Jong‐Wan , Yang Han‐Kwang , Kim Jin‐Pok
Published: August 2002

A number of causes of malnutrition after total gastrectomy have been proposed. The purpose of this study was to assess nutritional status and to determine the cause of malnutrition after total gastrectomy. We studied 20 gastric cancer patients who had undergone total gastrectomy and immmunochemotherapy and 6 normal controls. Nutritional status was assessed by dietary history, anthropometric methods, and serologic measurements. Malabsorption tests included the fecal fat excretion test, d‐xylose absorption test, glucose tolerance test, vitamin B12 absorption test using dual isotopes, bacterial culture of jejunal aspirates, and jejunal biopsy. Weight loss was compared to the preoperative status in all patients (average 15%: 59.0 ± 9.9 vs. 50.2 ± 7.8 kg, preoperatively vs. postoperatively). Average daily calorie intake was 1586.2 kcal, which is lower than the normal intake of Korean adults (1838 kcal). Malnutrition of skeletal and visceral protein was not found. There was, however, severe fat malnutrition and a deficit of body fat. Postoperatively the body mass index was considerably lower than that preoperatively (22.2 ± 0.4 vs. 18.9 ± 0.4 kg/m2; preoperatively vs. postoperatively). With malabsorption tests, the daily excreted amount of fecal fat was 28.6 ± 3.4 g (mean ± SD) in patients and 6.9 ± 0.2 g in controls. There was no significant malabsorption of carbohydrates. In 64.3% (9/14) of patients, vitamin B12 absorption was abnormal; and the serum concentration of vitamin B12, which was significantly related to malabsorption of this vitamin, was lower than normal in 73.7% (14/19). Bacterial overgrowth was not found, and there were no abnormal histologic findings in the jejunal mucosa. These results suggest that poor oral intake and fat malabsorption following total gastrectomy cause malnutrition and that fat malabsorption may be related to relative pancreatic insufficiency.
Acute Cholangitis and Pancreatitis Secondary to Common Duct Stones: Management Update
Authors: Raraty Michael G.T. , Finch Margaret , Neoptolemos John P.
Published: August 2002

Gallstones are found within the main bile duct (MBD) of 7% to 20% of patients undergoing cholecystectomy. MBD stones are the commonest cause of acute cholangitis and acute pancreatitis. Acute cholangitis is the result of infection superimposed on an obstructed biliary system and carries a high mortality rate if left untreated. The mainstay of treatment is a regimen of broad‐spectrum intravenous antibiotics followed by prompt decompression of the obstructed biliary tree. Decompression is best accomplished by the endoscopic route, although transhepatic approaches may also be employed. Gallstone pancreatitis may be associated with cholangitis but is also common as a separate entity. Initial treatment is supportive, although new agents designed to suppress the systemic inflammatory response are under development and have proved beneficial in clinical trials. Severe cases should be treated with systemic antibiotics and early removal of the obstructing stones by endoscopic retrograde cholangiopancreatography and endoscopic sphincterotomy. Prophylactic cholecystectomy is recommended to prevent further episodes of gallstone pancreatitis.
Helium and Carbon Dioxide Pneumoperitoneum in Patients with Pheochromocytoma Undergoing Laparoscopic Adrenalectomy
Authors: Fernández‐Cruz Laureano , Sáenz Alejandro , Taurá Pilar , Sabater Luis , Astudillo Emiliano , Fontanals Jaume
Published: August 2002

Insufflation with helium is used to prevent respiratory acidosis, hypercapnia, and cardiovascular instability associated with carbon dioxide (CO2) pneumoperitoneum. The aim of this prospective study was to compare CO2 with helium pneumoperitoneum with special reference to respiratory and hemodynamic changes at different times during the operation. Altogether 22 pheochromocytoma patients undergoing laparoscopic adrenalectomy (LpA) were included using CO2 in 11 patients (CO2LpA) and helium in 11 patients (HeLpA). The insufflation pressure was 12 mmHg. The two groups were comparable with regard to demographic data and preoperative management. CO2 and helium insufflation were associated with similar catecholamine increase. The most striking significant increase compared with the baseline was observed during tumor isolation: The mean plasma epinephrine (EPI) and norepinephrine (NE) levels increased 32.86‐fold and 25.92‐fold, respectively, in the CO2LpA patients and 27.43‐fold and 18.46‐fold, respectively, in the HeLpA patients. HeLpA did not result in significant hypercarbia or acidosis at any measured intraoperative point; this was without any alteration in minute ventilation to maintain these normal PaCO2, excess base (EB), and pH values. Significant increases of mean arterial pressure, pulmonary arterial pressure, pulmonary vascular resistance index, PaCO2, EB, and acidosis were seen in the CO2LpA patients at the time of tumor isolation and tumor removal compared with those in HeLpA patients. No patient required conversion to open surgery. There were no significant differences between CO2LpA and HeLpA regarding mean operative time (117.50 ± 93.68 vs. 106.87 ± 16.60 minutes), mean blood loss (168.54 ± 78.63 vs. 142.02 ± 109.26 ml), hospital stay (4 days), the need for analgesics, or mean time required to return to normal activity (12 days). There was one wound infection in the HeLpA group and one wound hematoma and one case of atelectasis in the CO2LpA group. Helium may be the agent of choice for abdominal insufflation in patients undergoing LpA for pheochromocytoma, eliminating the adverse hemodynamic and respiratory changes associated with CO2 insufflation.
Nitric Oxide Release from Coronary Vasculature before, during, and following Cardioplegic Arrest
Authors: Gohra Hidenori , Fujimura Yoshihiko , Hamano Kimikazu , Noda Hiroshi , Katoh Tomoe , Zempo Nobuya , Esato Kensuke , Ueda Toshiko , Sadamitsu Daikai , Maekawa Tsuyoshi
Published: August 2002

Nitric oxide (NO) is known as a vasodilatory molecule synthesized by vascular endothelium. The NO‐dependent vasodilatory response of coronary artery is impaired after ischemia and reperfusion. In the present study, the release of NO from coronary vasculature was evaluated before and during cardioplegic arrest and after reperfusion. Nine patients undergoing heart surgery were studied. Multidose crystalloid cardioplegics were used for myocardial protection. The coronary affluent and effluent were obtained simultaneously before cardioplegic arrest, at each cardioplegic administration, and after reperfusion; and the levels of nitrite and nitrate, the stable end‐products of NO, were measured. The NO release from the coronary vasculature was determined as the difference in the levels of nitrite and nitrate between the coronary effluent and affluent. The level of nitrite/nitrate release from coronary vasculature was 6.8 ± 3.7 μM before cardioplegic arrest. During cardioplegic arrest the nitrite/nitrate release decreased, reaching 1.3 ± 1.3 μM (p < 0.05, vs. before cardioplegic arrest) at the fourth administration of the cardioplegic. At 3 to 5 minutes after reperfusion, nitrite/nitrate release further decreased to 0.36 ± 0.34 μM (p < 0.05, vs. before cardioplegic arrest). During cardioplegic arrest the NO release decreased and reached significance at approximately 70 minutes of cardioplegic arrest compared to that before cardioplegic arrest. After reperfusion, NO release was further reduced, with statistical significance compared to that before cardioplegic arrest. Our data may indicate that cardioplegic arrest and reperfusion cause endothelial dysfunction.
Basic Physics and Imaging Characteristics of Ultrasound
Authors: Kossoff George
Published: August 2002

The imaging characteristics of diagnostic ultrasound (US) are determined by the ultrasonic properties of tissue. The velocity of propagation of US and the attenuation are the 2 most important parameters. These determine the frequency with which the tissues may be imaged, which in turn sets a fundamental limit on the axial and the lateral resolution. Ultrasonic imaging equipment is designed on the premise that the ultrasonic energy propagates through tissue in a straight line and that the ultrasonic beam is very narrow. In fact, the ultrasonic energy propagates through tissue as a beam of finite dimensions set by the physical dimensions of the transducer, the way it is constructed, and the way it is energized. Also, the velocity of propagation in different tissues varies and this can lead to deviation of the ultrasonic beam from the assumed direction of propagation. This breakdown in assumptions leads to the creation of artifacts that must be appreciated in the interpretation of ultrasonic images. For this reason skilled interpreters of ultrasonic images follow 3 golden rules: never make an interpretation on a single image; just because a feature is displayed do not consider that it is necessarily real; and just because a feature is not displayed do not consider that it is necessarily not there.
Sequential Metabolic Changes following Induction of Systemic Inflammatory Response in Patients with Severe Sepsis or Major Blunt Trauma
Authors: Plank Lindsay D. , Hill Graham L.
Published: August 2002

We have recently completed studies in critically ill patients with severe sepsis or major trauma that investigated sequential changes in the metabolic response following admission to the intensive care unit. Protein, water, and energy metabolism were measured using in vivo neutron activation analysis, tracer dilution, dual‐energy x‐ray absorptiometry, and indirect calorimetry. Over the 3‐week study period both groups of patients lost 13% of their total body protein. The severe sepsis patients retained twice the volume of fluid of those with major trauma, and the return to normal hydration in the sepsis group was correspondingly prolonged, especially for those in the elderly age group. In both groups of patients resting energy expenditure increased progressively over the first week to around 40% above normal and was still elevated 3 weeks from onset of illness. A twofold increase in total energy expenditure occurred in both groups of patients between the first and second weeks of critical care admission. The prolonged hypermetabolism throughout the study period was not reflected in the concentrations of circulating proinflammatory cytokines, which fell rapidly over the first week. The pattern of changes seen in plasma proinflammatory and antiinflammatory cytokine concentrations is similar for sepsis and trauma. The remarkably similar metabolic sequelae seen in critically ill patients following the onset of severe sepsis or major trauma may constitute a universal response to the induction of the systemic inflammatory response syndrome.
A Biomechanical Comparison of Headless Tapered Variable Pitch and AO Cortical Bone Screws for Fixation of a Simulated Lateral Condylar Fracture in Equine Third Metacarpal Bones
Authors: Galuppo Larry D. , Stover Susan M. , Jensen David G. , Willits Neil H.
Published: August 2002

Objective—To compare drilling, tapping, and screw‐insertion torque, force, and time for the 4.5‐mm AO and 6.5‐mm Acutrak Plus®(AP) bone screws, and to compare the mechanical shear strength and stiffness of a simulated complete lateral condylar fracture of the equine third metacarpal bone (MC3) stabilized with either an AO or AP screw.

Study Design—In vitro biomechanical assessment of screw‐insertion variables, and shear failure tests of a bone‐screw‐stabilized simulated lateral condylar fracture.

Sample Population—Eight pairs of cadaveric equine MC3s

Methods—Metacarpi were placed in a fixture and centered on a biaxial load cell in a materials‐testing system to measure torque, compressive force, and time for drilling, tapping, and screw insertion. Standardized simulated lateral condylar fractures were stabilized by either an AO or AP screw and tested in shear until failure. A pairedttest was used to assess differences between screws, with significance set atP< .05.

Results—Insertion and mechanical shear testing variables were comparable for AO and AP insertion equipment and screws.

Conclusion—The 6.5‐mm tapered AP screw can be inserted in equine third metacarpal condyles and is mechanically comparable with the 4.5‐mm AO screw for fixation of a simulated lateral condylar fracture.

Clinical Relevance—Considering the comparable mechanical behavior, the potential for less‐persistent soft‐tissue irritation with the headless design, and the ability to achieve interfragmentary compression by inserting the screw in one hole drilled perpendicular to the fracture plane, the 6.5‐mm tapered AP screw may be an attractive alternative for repair of incomplete lateral condylar fractures in horses.
The Mitochondrial Uncoupling Protein UCP1: A Gated Pore
Authors: Arechaga Ignacio , Ledesma Amalia , Rial Eduardo
Published: August 2002

The uncoupling protein UCP1 is a member of a superfamily of homologous proteins formed by the mitochondrial metabolite transporters. Although they act in vivo as carriers, under specific experimental conditions some of these transporters have been shown to behave as channels. This dual transport operation suggests that these carriers are likely to be formed by two differentiated functional and structural domains. The kinetic model termed “single binding center gated pore” is well suited to understand the behaviour of these carriers. It proposes that in the protein core there must exist a hydrophilic translocation pore whose access is controlled by gates. It is highly likely that the hydrophilic channel is formed by the transmembrane α‐helices and that loops contribute to the formation of the gates. UCP1 is regulated physiologically by fatty acids and purine nucleotides. Nucleotides maintain the proton conductance inhibited while fatty acids act as cytosolic second messengers of noradrenaline to active UCP1. Based on photoaffinity labeling and mutagenesis data, we propose a structural model for the localization of the binding site. The nucleotide enters through a gate in the cytosolic side and binds deep inside the protein. The three matrix loops contribute to the formation of a hydrophobic binding pocket that would accommodate the purine moiety. Three arginine residues (in helices II, IV, and VI) would interact with the phosphate groups. His214 and Glu190 have been involved in the pH regulation of the nucleotide binding but because they are on the cytosolic side of the protein, we propose that their state of protonation will determine the access of the nucleotide to the binding center.
Mitochondrial Contribution in the Progression of Cardiac Ischemic Injury
Authors: Lisa Fabio Di
Published: August 2002

The multifaceted relationship between mitochondria and the rest of the cell is reviewed in the context of myocardial ischemia. Paradoxically, mitochondria can exacerbate the ischemic damage, especially at the onset of reperfusion. Indeed, the recovery of oxidative phosphorylation in the presence of an excessive energy demand is likely to represent a crucial factor in the ensuing irreversible damage of cardiomyocytes. A major role in the progression towards cell death might be attributed to the opening of the permeability transition pore, which besides abolishing mitochondrial ATP production might amplify the damage by causing NAD + release. This damaging role is balanced by the contribution of mitochondria in self‐defense mechanisms operating in the ischemic cardiomyocytes. The mitochondrial ATP‐sensitive K + channel and a slight increase in the production of reactive oxygen species appear to mediate the attempt of the heart to maintain its viability under conditions of acute and chronic ischemia. The significance of the various processes is discussed along with the critical evaluation of both the difficulties in studying mitochondria in situ and the possible sources of errors or misinterpretations.
Oxygen Signal Transduction
Authors: Gilles‐Gonzalez Marie‐Alda
Published: August 2002

Although manifestations of O 2 adaptation have long been examined, only now are biochemical mechanisms of O 2 regulation beginning to be understood. This article comments on the current state of knowledge about proteins that function as direct sensors of molecular oxygen and makes predictions about as yet undiscovered sensors.
Predicting aggressive driving behavior: The role of macho personality, age, and power of car
Authors: Krahé Barbara , Fenske Ilka
Published: August 2002

A study is presented that explored the role of macho personality, age, and power of car as predictors of aggressive driving behavior. A total of 154 male motorists completed two subscales of the Hypermasculinity Inventory as a measure of macho personality and self‐reports of aggressive driving behavior based on the Driver Behaviour Questionnaire. They also provided information about their age, annual mileage, horsepower of their car, and features that had guided their choice of a car. A multiple regression analysis showed that each of the predictors was significantly related to aggressive driving: Younger motorists, those driving powerful cars, and those showing macho personality were significantly more likely to report driving aggression. Together, the three predictors accounted for 35.8% of the variance. In addition, macho men assigned greater importance to speed and sportiness of a car and less importance to safety aspects than nonmacho men. The findings are discussed with reference to individual and situational explanations of driving aggression. Aggr. Behav. 28:21–29, 2002. © 2002 Wiley‐Liss, Inc.
Conflict and postconflict behaviour in two lemur species with different social organizations (Eulemur fulvus and Eulemur macaco): A study on captive groups
Authors: Roeder Jean‐Jacques , Fornasieri Isabelle , Gosset Delphine
Published: August 2002

Although the brown lemur (Eulemur fulvus) and the black lemur (Eulemur macaco) share many life parameters and are genetically closed, they show considerable difference in social organization. Dominance relationships with no systematic effect of gender characterize the former, whereas the latter is based on female dominance. The present study was done on two captive groups of brown lemurs and one semi–free‐ranging group of black lemurs. To reveal links between the specific pattern of social organization and agonistic behaviors, agonistic interactions were analyzed for each species as for their context of occurrence, symmetry, initiation, and outcome. The effect of gender in the initiation of conflicts appeared as the only notable interspecific difference, aggression being mostly initiated by females in E. macaco and by males in E. fulvus. Conflict outcome was generally in favor of the initiator, regardless of gender in both species. The analysis of postconflict behaviors revealed conciliatory processes in the brown lemur, whereas reconciliation seemed to be absent in the black lemur, a characteristic shared with the ring‐tailed lemur (Lemur catta), another lemur species with female dominance. Aggr. Behav. 28:62–74, 2002. © 2002 Wiley‐Liss, Inc.
Journal writing in health education
Authors: Gillis Angela J.
Published: August 2002

The use of journals in university nursing education, as well as their role in continuing professional development for nurses and other health professionals working in clinical settings, are the focus of this chapter.
The politics of neglect: Adult learners in higher education
Authors: Sissel Peggy A. , Hansman Catherine A. , Kasworm Carol E.
Published: August 2002

We challenge the broader adult education community to examine how they are either accommodating or reproducing hegemonic campus policies toward adult learners, take action to resist these policies, and support the development of improved policies, procedures, programs, and practices aimed toward adult learners in higher education.
Political hotbeds: Professional organizations as policymakers
Authors: Cunningham Phyllis M.
Published: August 2002

This chapter explores the political hot spots within the American Association for Adult and Continuing Education that provide a backdrop for its focus, or lack thereof, on educational public policy.
Linguistic predictors of trauma pathology and physical health
Authors: Alvarez‐Conrad Jennifer , Zoellner Lori A. , Foa Edna B.
Published: August 2002

The present study examined how specific linguistic elements in trauma narratives were associated with post‐treatment psychopathology and physical symptoms. We analysed the narratives of 28 female assault victims being treated for chronic PTSD. During exposure therapy, participants were asked to recount their assault ‘as if it was happening now’. These trauma narratives were videotaped, transcribed, and analysed using a linguistic coding program. In particular, narratives containing words about death and dying were associated with worse post‐treatment functioning. This relationship could not be accounted for by assault‐related characteristics. The focus on death and dying in the trauma narrative may reflect the concept of mental defeat, suggesting a possible target for intervention in cognitive‐behavioural treatment of PTSD. Copyright © 2001 John Wiley & Sons, Ltd.
Variable structure robust state and parameter estimator
Authors: Poznyak Alex S. , Martínez Joel Correa
Published: August 2002

The problem of simultaneous robust state and parameters estimation for a class of SISO non‐linear systems under mixed uncertainties (unmodelled dynamics as well as observation noises) is addressed.

A non‐linear variable structure robust ‘observer–identifier’ is introduced to obtain the corresponding estimates. Lie derivative technique is used to obtain the observability conditions for the equivalent extended non‐linear system. It is shown that, in general, the extended system can lose the global observability property and a special procedure is needed to work well in this situation. The suggested adaptive observer has the non‐linear high‐gain observer structure with adjusted parameters that provides ‘a good’ upper bound for the identification error performance index. The van der Monde transformation is used to derive this bound which turns out to be tight. Three examples dealing with a simple pendulum, the Duffing equation and the van del Pol oscillator are considered to illustrate the effectiveness of the suggested approach. Copyright © 2001 John Wiley & Sons, Ltd.
Fuzzy decision support for the control of detergent production
Authors: Setnes Magne , Babuška Robert
Published: August 2002

This paper describes a fuzzy decision support system (DSS) for the control of a detergent production process. The application has been carried out at a real‐world, large‐scale industrial production plant in the Netherlands, where a large variety of powder‐based detergents for industrial users are produced in a spray drying process. The system consists of several fuzzy rule bases that model the control actions of experienced process operators in response to different quality deviations of the product. A hierarchical architecture of the fuzzy system is introduced to cope with the complexity. A fuzzy supervisor is used to deal with process constraints and to activate the applicable rule bases when control actions are needed. In this way, a system is obtained that enables the control of the process within stricter quality bounds than those applied by human operators alone. During in‐production evaluation, the average improvement in the quality parameters for all product classes was above 30 percent. Copyright © 2001 John Wiley & Sons, Ltd.
Physiology of hot flashes
Authors: Freedman Robert R.
Published: August 2002

Hot flashes are the most common symptom of the climacteric, although prevalence estimates are lower in some rural and non‐Western areas. The symptoms are characteristic of a heat‐dissipation response and consist of sweating on the face, neck, and chest, as well as peripheral vasodilation. Although hot flashes clearly accompany the estrogen withdrawal at menopause, estrogen alone is not responsible since levels do not differ between symptomatic and asymptomatic women. Until recently it was thought that hot flashes were triggered by a sudden, downward resetting of the hypothalamic setpoint, since there was no evidence of increased core body temperature. Evidence obtained using a rapidly responding ingested telemetry pill indicates that the thermoneutral zone, within which sweating, peripheral vasodilation, and shivering do not occur, is virtually nonexistent in symptomatic women but normal (about 0.4°C) in asymptomatic women. The results suggest that small temperature elevations preceding hot flashes acting within a reduced thermoneutral zone constitute the triggering mechanism. Central sympathetic activation is also elevated in symptomatic women which, in animal studies, reduces the thermoneutral zone. Clonidine reduces central sympathetic activation, widens the thermoneutral zone, and ameliorates hot flashes. Estrogen virtually eliminates hot flashes but its mechanism of action is not known. Am. J. Hum. Biol. 13:453–464, 2001. © 2001 Wiley‐Liss, Inc.