bluuebunny/crossref_metadata_2025 huggingface dataset:
Neurovascular microsurgery
Authors: Sundt Thoralf M.
Published: April 2005

The results and complications of neurovascular operations in one surgeon's experience during the era of the operating microscope are reviewed in the framework of the pathophysiology of the illness for which they were performed. Overall mortality rate was 5% and morbidity rate 11% in 405 patients with intracranial aneurysms. Morbidity and mortality varied according to preoperative neurological function, location and size of aneurysm, and number of days from last subarachnoid hemorrhage to surgery. Although a delay in operation improved the operative results, there were significant mortality and morbidity among patients awaiting surgery. There were immediate and delayed ischemic complications. In the former group (7% of cases), the cause was clearly attributable to surgical trauma, such as damage to perforating vessels and major vessel occlusion, which was related to size and location of the aneurysm and unrelated to the patient's neurological function or timing of surgery. Delayed ischcmic complications, minor and reversible in 10% of patients, severe in 5%, were related to preoperative neurological function and timing of surgery. These did not occur in any patients operated on for a mass effect from the aneurysm without a subarachnoid hemorrhage.

The overall combined major morbidity and mortality for carotid endarterectomy in 681 patients in whom the microscope was not used was 2%, but varied according to medical, neurological, and angiographically determined risk factors. Patients were seldom operated on for lesions that did not produce at least a 70–80% stenosis unless there was angiographie evidence of severe ulccration. All patients were monitored intraoperatively with cerebral blood flow measurements and a continuous electroencephalogram. Retinal artery pressure measurements were performed pre‐operatively and postoperatively. The relationship of these monitoring techniques to the pathophysiology of ischemic symptomatology is reviewed.

Preliminary evaluation of 149 extracranial to intracranial bypass procedures for occlusive disease of the carotid system, and of 22 procedures for occlusive disease in the vertebral‐basilar system indicates a patency rate of 95% and 90%, respectively. The effectiveness of these operations was related to the symptomatology for which they were performed. The overall combined morbidity and mortality was 5%, but varied according to preoperative neurological function.

There were 59 operations for cerebral arteriovenous malformations (AVM) (38 parenchymal, 1 death; 21 durai, 1 death). Low morbidity and mortality rates were achieved in parenchymal AVMs by not operating on large lesions or those with a thalamic component and, therefore, these results must be placed in that perspective. This conservative approach was justified by the current lack of information concerning the natural history of this illness. In contrast, virtually all durai AVMs were eventually operated on because of the progressive nature of this acquired illness.
Microscopic surgery in urology
Authors: Gil‐Vernet José M.
Published: April 2005

Although the use of microscopic surgery in the field of urology is recent and experience is limited, it is already playing an important role in operations on the genitourinary tract. During the past 10 years, we have used microsurgical techniques in 1,102 operations. This report presents a review of our experience. Extracorporeal microsurgery, or bench surgery, has been used for correcting disorders of the intrarenal excretory tract, for removing kidney tumors, for preserving the traumatized kidney, and for transplantation of kidneys with vascular irregularities. Microsurgical techniques have been very helpful in various operations on the urinary tract, including ureterotomy, pyeloureteral anastomosis, ureteroureteral anastomosis, and reestablishing urinary continuity of transplanted kidneys. Microscopic surgery has made substantial contributions to advances in treatment of disorders of the genital apparatus, such as infertility, chordee, plastic induration of the cavernous bodies, impotence, and ectopic testes.
Mechanism of action of “intracellular” renal preservation solutions
Authors: Green Colin J. , Pegg David E.
Published: April 2005

Brief perfusion with Collins' C4 solution is commonly employed for hypothermic storage of kidneys for short periods, but the mechanism of action has never been satisfactorily explained. In the studies described in this report, an attempt was made to discover the essential ingredients so that a more reproducible solution could be formulated. Rabbit kidneys were excised, infused with a number of test solutions, stored at 4°C, and then autografted into recipients in which a contralateral nephrectomy had been performed. Starting with a buffered balanced salt solution, it was found that increasing the osmolality with glucose produced a dramatic improvement in function, while replacing half of the chloride by sulfate produced a further small improvement. The other changes were either deleterious (increasing potassium or magnesium concentration) or had no effect (reducing ionic strength). It is concluded that the benefit conferred by these solutions during storage is unrelated to intracellular ionic composition but is due to the inclusion of impermeant solutes to raise total osmolality.
Choice of the most suitable oxygenator for long‐term pulmonary support
Authors: Birnbaum D. , Thom R. , Bücherl E. S.
Published: April 2005

Five different membrane oxygenators were tested in dogs for reliability, efficiency, and side effects. The Teflo‐Lung® was found to have the most effective gas exchange per membrane unit and acceptable reliability. Experience in clinical long‐term oxygenation, however, revealed passage of plasma fractions through the membrane. This caused increasing deterioration of the gas exchange and necessitated frequent replacement of the oxygenator. The Spiral‐Coil® oxygenator showed an effective oxygen exchange rate and good reliability, but like all silicone membranes, had limited CO2 exchange capacity. Only the Dua‐Lung® resulted in deterioration of the red blood cells. The Landé Oxygenator® needed pretreatment to rinse the sodium‐powdered membranes that impeded handling and entailed possible risks. Plasma hemoglobin was not studied because another parameter was introduced to measure subhemolytic trauma.
Studies on the structure and biological effects of pyrotoxins purified from burned skin
Authors: Schmidt Karlheinz , Schölmerich Jürgen , Kremer Bernd , Heller Wolfgang , Koslowski Leo
Published: April 2005

Murine skin was thermally injured under controlled conditions in a standard high temperature burn model. After high‐speed homogenization of the burned skin, a toxic fraction was isolated applying different purification procedures. It was demonstrated that high temperature burns produced chemical condensations and high molecular aggregates in the protein moiety of the skin. Plasma proteins were involved in these reactions. After the purification process, the high molecular aggregates were obtained not as pure proteins, but as lipid‐protein micelles. In the lipid moiety itself, thermal decomposition products were detectable. The biological effects of the purified lipid‐protein fraction were studied by aid of rat liver perfusions 5 days after intraperitoneal injection of the material measuring different biosynthetic activities of the isolated organ. Significantly reduced biosynthesis of urea and depressed gluconeogenesis were demonstrable. The biochemical results are paralleled by ultrastructural findings indicating that the lipid‐protein complex from burned skin causes mitochondrial vacuolization in liver cells of treated animals.
Curability of patients with invasive breast carcinoma based on a 30‐year study
Authors: Robbins Guy F. , Berg John
Published: April 2005

A 30‐year follow‐up study of 1458 women who were treated by standard radical mastectomy for potentially curable invasive breast cancer at Memorial Hospital, New York, showed 12.6% of the patients alive and free of cancer, 24% dead of other causes without breast cancer, 56.6% dead of breast cancer and 6.8% lost to follow‐up. Small primary lesions, negative axillary lymph nodes and histologic types of cancer other than infiltrating duct carcinoma were all associated wih higher survival rates. Patients with low grade cancers developed a second cancer in the remaining breast much more frequently than patients with infiltrating duct carcinoma. Of the 184 30‐year survivors, 34 had metastases to axillary lymph nodes at levels II and III at the time of operation. It is concluded that radical mastectomy is capable of controlling local disease and curing a substantial number of patients.
Urinary hydroxyproline in the management of breast cancer
Authors: Cuschieri A.
Published: April 2005

Turnover of collagen in the body, 50% of which occurs in bone, results in the excretion of substantial amounts of hydroxyproline in the urine. Urinary hydroxyproline excretion and, in particular, the hydroxyproline/creatine ratio increase in the presence of primary and secondary neoplasms of bone. There is a good correlation between elevated urinary hydroxyproline excretion and metastases to bone from breast cancer. Moreover, in “early” breast cancer without demonstrable metastases we have found a good correlation between elevated levels of hydroxyproline in urine and axillary lymph node metastases at operation, subsequent development of bone metastases, and survival. In patients with disseminated disease undergoing hormone manipulation therapy, we have observed that urinary hydroxyproline excretion correlates with the response to treatment. Measurement of urinary hydroxyproline excretion appears to be a useful tool in staging breast cancer and monitoring the activity of the disease.
Subclavicular biopsy as a guideline for the treatment of breast cancer
Authors: van Dongen Johannes A.
Published: April 2005

To better select patients with breast cancer for radical surgery, all operable patients at the Netherlands Cancer Institute are subjected to exploration of the medial apex of the axilla as the initial step in the mastectomy operation, and lymph nodes in the subclavicular fat pad are examined by frozen section. Patients with positive apex biopsies are treated by primary radiotherapy rather than by mastectomy, since the 10‐year survival rate of such patients who were treated by mastectomy in our previous series was only 5%. In about 1600 cases of operable breast cancer treated by our staff since 1956, the incidence of positive apex biopsy has been 16%. In 6% of the cases with a positive apex biopsy, the tumor was small and there were no suspicious lymph nodes on clinical examination. Survival rate and duration of survival of patients with a positive apex biopsy has been the same after treatment by primary irradiation as after treatment by radical mastectomy.
Cancer research campaign study of the management of “early” breast cancer
Authors: Greig Murray J. , MacIntyre John , Simpson John S. , McDonald Alexander M.
Published: April 2005

Between 1970 and 1975, 2268 patients with clinical stages I and II breast cancer were assigned by random sample to receive either simple mastectomy plus postoperative radiotherapy or simple mastectomy followed by a watch policy, with further treatment employed only for recurrent disease. After 5 years of follow‐up there is no evidence that postoperative radiotherapy increases the survival rate or decreases the incidence of distant metastases, although it is clearly advantageous in preventing local recurrence. Histological examination of the lymph nodes from the tail of the breast or pectoral region in 350 patients showed that postoperative radiotherapy did not influence survival, local recurrence or the occurrence of distant metastases in patients with negative nodes. However, in patients with positive nodes postoperative radiotherapy was associated with a decreased incidence of local recurrence, but a 10% increase in mortality rate during the first year after treatment.
Estrogen receptors in breast cancer
Authors: Jensen Elwood V. , Block George E. , Ferguson Donald J. , DeSombre Eugene R.
Published: April 2005

Of 1100 women whose primary and/or metastatic breast cancers have been analyzed for estrophilin, 30% are receptor‐rich and 70% receptor‐poor. On the basis of 134 treated patients, nearly two‐thirds of the receptor‐rich group can expect objective benefit from endocrine therapy, whereas few if any of the receptor‐poor patients will respond. Thus, estrophilin assay indicates the proper type of therapy for 85 to 90% of women with advanced breast cancer. Analysis of the primary tumor in the mastectomy specimen offers promise in predicting hormone dependency in metastases that appear up to 5 years later.
Screening for “early” breast cancer
Authors: Strax Philip
Published: April 2005

The only means available today to reduce the mortality from breast cancer is by detection of localized disease. So doing involves mass screening of apparently well women. For best results, both the clinician and the radiologist must be involved and develop expertise because early cancers are often detectable on palpation alone or on mammography alone. Cooperation of the clinician and the radiologist is needed to motivate women to receive as complete a breast examination as is available in their community. This should include, if possible, an interview for demographic data, palpation, mammography and thermography. New radiological methods are available which produce improved resolution, detail and contrast with radiation dosage reduced to 0.3 R or less per skin exposure. Indoctrination of women in breast self‐examination by the clinician or trained personnel, preferably at the time of breast palpation, is a vital step. The validity of this approach has been demonstrated by the mass screening programs of the Health Insurance Plan of Greater New York and the Guttman Institute.
The surgeon's problem with breast cancer screening programs
Authors: Snyder Ruth E.
Published: April 2005

Any decision to biopsy a breast on the basis of findings discovered in a screening program must carefully consider the expertise of the clinical examination, the technical quality of the mammograms, and the skill and experience of the radiologist reading them. A positive clinical examination with or without mammographic confirmation is indication for biopsy. However, the surgeon must sometimes be governed solely by the report of the radiologist. On the basis of competent mammographic interpretation, patients without clinical evidence of disease face at least a 25% chance of having cancer. The area of concern must be carefully localized preoperatively and the specimen radiographed, particularly if it contains calcifications. This requires a clear understanding of the problem and complete cooperation between the surgeon, the radiologist, and the pathologist.
Bile induced chronic gastric ulcer in swine
Authors: Rokkjaer Mogens , Søgaard Helmer , Kruse Aksel , Amdrup Erik
Published: April 2005

The role of bile in the pathogenesis of chronic gastric ulcer was studied in 10 grown‐up miniature pigs. After an observation period of 14–186 days, 4 pigs out of 5 with total diversion of bile into the stomach developed peptic ulcers in the glandular part of the stomach, whereas none of 5 sham operated pigs developed ulcers after an observation period of 150–196 days. This difference was significant (p<0.05). In all 5 pigs with bile diversion the pyloric gland area enlarged at the cost of the fundic gland area, whereas this was not the case in the 5 controls. This difference was also significant (p<0.01). There was no significant change in gastric emptying after the operations. It is concluded that bile can cause gastric ulcer in the pig.
A case report of hepatoblastoma treated by chemotherapy and hepatic lobectomy
Authors: Fegiz Gianfranco , Rosati Domenico , Tonelli Francesco , Donfrancesco Alberto
Published: April 2005

A hepatoblastoma in a 2‐year‐old child was considered unresectable at exploratory laparotomy because of diffuse liver involvement. The treatment of the patient with intravenous 5‐fluorouracil for 5 months resulted in a remarkable reduction in the size of the tumor so that it became resectable and was removed by right hepatic lobectomy. The child is alive and well 26 months after surgery. Several similar cases have been reported in which an unresectable hepatoblastoma was made resectable by chemotherapy, and operation was then followed by long‐term survival without recurrence.
Microvascular neurosurgical arterial bypass for cerebral ischemia: A decade of development
Authors: Mehdorn H. Maximilian , Hoffman William F. , Chater Norman L.
Published: April 2005

The microsurgical extracranial‐intracranial arterial bypass (EIAB) procedure, usually performed to anastomose the superficial temporal artery to a cortical branch of the middle cerebral artery, offers a therapeutic alternative in treating patients who present with symptoms of cerebral ischemia varying from transient ischemic attack (TIA) to stroke‐in‐evolution, and who have intracranial or otherwise inaccessible high cervical carotid lesions. Preoperative diagnostic steps include angiography, computer‐assisted tomography (CT) scan, and measurements of regional cerebral blood flow (rCBF).

A comparison of our series of 172 patients with series reported in the literature suggests that EIAB is more effective than medical therapy in preventing the development of permanent neurological deficit after a series of TIA and in treating cases of stroke‐in‐evolution. It also can prevent further deterioration in selected patients after stroke. An analysis of patients who had an unfavorable outcome suggests that bilateral EIAB should be performed in a greater number of patients who have generalized low‐perfusion syndrome; that low doses of heparin should be administered intraoperatively and postoperatively in patients who have high‐grade siphon stenosis; and that aspirin should be given to patients experiencing TIA after EIAB.
Effect of vasopressin on portal pressure during volume replacement after acute hemorrhage
Authors: Skivolocki William P. , Sirinek Kenneth R. , Pace William G.
Published: April 2005

This study evaluated both the isolated and combined effects of intravenous vasopressin and volume replacement on cardiac output and portal pressure in hypovolemic dogs. Following acute hemorrhage and sustained hypotension (60 mm Hg for 45 min), 20 anesthetized dogs received either: no treatment; intravenous vasopressin (20 units/30 min); Ringer's lactate (volume equal to shed blood/30 min); or intravenous vasopressin and Ringer's lactate. At 30 minutes after hypotension, cardiac output decreased 52% and portal pressure decreased 61% in control animals. Hypovolemia plus intravenous vasopressin resulted in significant reductions in cardiac output (41%) and portal pressure (62%) compared to baseline recordings, but not compared to control animals. Following hypovolemia and Ringer's lactate, cardiac output and portal pressure increased to prehemorrhage levels. With vasopressin and Ringer's lactate, portal pressure remained decreased (39%), while cardiac output returned to prehemorrhage levels. This study demonstrates that administration of intravenous vasopressin during hypovolemia does not cause an added reduction in cardiac output and does not prevent restoration of the normal cardiac output by volume replacement. Moreover, administration of vasopressin during volume replacement prevented a return of portal venous pressure to prehemorrhage levels.
Should hyperthyroidism be treated by surgery?
Authors: Heimann Peter
Published: April 2005

Although radioactive iodine has been shown to be an effective nonsurgical treatment for hyperthyroidism, surgery remains a major treatment methodology. Nodular goiters with hyperthyroidism, which are still common in Scandinavia and elsewhere in Europe, are most effectively treated with surgery. The carcinogenic effects of131I have not been fully determined; until a large‐ scale, long‐ term controlled study of patients treated with131I is performed to establish the role of radioactive iodine in the development of carcinoma, its complete worldwide use is not recommended. There is low postoperative recurrence, mortality and morbidity with surgery for hyperthyroidism as performed in Scandinavia.
Choice of preoperative treatment in hyperthyroidism
Authors: Heimann Peter
Published: April 2005

From our knowledge of thyroid pathophysiology and from morphological studies, preoperative treatment of hyperthyroidism should consist of:

A period of treatment to control hyperthyroidism by giving the patient antithyroid drugs (carbimazole) and, if necessary, propranolol.

An attempt to keep the patient euthyroid. It seems reasonable to add thyroxine to a relatively high dosage of carbimazole in order to be sure of both euthyroidism and a hormone‐free gland.

Inhibition of all stimulation of the gland by TSH in order to minimize the risk of bleeding. A bloodless operation guarantees the best anatomical dissection, which gives the best results with an absolute minimum of damage to the parathyroid glands or recurrent nerves.

This treatment fulfills the objectives of an ideal preoperative treatment of hyperthyroidism.
Indications for peritoneo‐jugular shunt for ascites
Authors: LeVeen Harry H. , Wapnick Simon , Guinto Roy , Kinney Michael
Published: April 2005

In the past, refractory ascites was considered to be the only indication for insertion of an ascites valve with a peritoneo‐jugular shunt. Such patients required a prolonged hospital stay prior to surgery and often succumbed to acute renal failure. In the present study, every patient entering with massive ascites was placed on a low‐salt diet for 2 weeks. Eleven patients did not respond in a 2‐week period and were placed on a regimen of continued medical therapy starting with aldactone. Although most of these patients lost weight, onehalf of them died within 6 months. Only 1 patient in the entire group survived more than a year.

Sodium clearance is a simple measurement which differentiates hepatorenal syndrome from acute tubular necrosis. The absence of natriuresis on diuretic therapy is an indication that surgery is required. Sodium and water retention are no longer problems in postshunt patients.

In the absence of contraindications, failure of a patient to lose weight on a salt‐restricted diet would appear to be a useful guide for the shunt operation.
The recognition and management of gastroesophageal reflux without hiatal hernia
Authors: Hiebert Clement A.
Published: April 2005

Since 1969, 40 additional patients with gastroesophageal reflux without demonstrable hiatal hernia have been identified, treated, and followed. Diagnosis is established from the clinical history of posturally aggravated symptoms plus the identification of a relaxed and incompetent lower esophageal sphincter on esophagoscopy. Esophageal pH studies and manometry may provide supporting evidence when necessary. Twenty‐five of the 31 patients treated by the Mark IV Belsey procedure had a good to excellent result when scored on the basis of durable relief from preoperative reflux symptoms, as well as the ability to swallow easily, belch, and, when necessary, vomit.
Mark IV repair of hiatal hernia by the transthoracic approach
Authors: Belsey Ronald
Published: April 2005

Following 10 years of clinical evaluation of various surgical techniques for control of gastroesophageal reflux, the Mark IV repair was developed and has now been used in over 2,000 patients. The operation is performed through a left posterolateral thoracotomy and entails extensive mobilization of the esophagus up to the aortic arch with preservation of the vagus nerves, and a 240 degree semi‐fundoplication between the stomach and esophagus. The lower esophagus and its sphincter are returned to the abdomen when possible, and the two halves of the right crus of the diaphragm are gently approximated to create a posterior buttress. When indicated, surgical treatment of associated upper abdominal disorders can be accomplished through the thoracic approach. A review of 892 patients who had undergone Mark IV repair during a 10‐year period showed that 84% had an excellent or good result with an 86% follow‐up rate. The over‐all recurrence rate was 11%, with indications that a significant number of failures were due to deviations from the standard Mark IV technique. Surgical treatment of recurrent hiatal hernia by the Mark IV technique is technically difficult. Of the 892 patients reviewed in 1972, the late results in 98 were classified as unsatisfactory. Of these, 45 required further surgical treatment which consisted of a second Mark IV repair, resection of the cardia and reconstruction, or gastric resection. The late results of reoperation were excellent or good in 75% of patients. Dilatable strictures may be treated by the Mark IV repair, but there is only a 50% chance of success. Undilatable strictures require resection followed by interposition of left colon or jejunum. Prevention of stricture by recognition and treatment of reflux esophagitis is the best management.
Indications and techniques for the use of heparin in the treatment of thromboembolism
Authors: Deykin Daniel
Published: April 2005

Heparin acts by binding to antithrombin, thereby potentiating its ability to destroy activated clotting factors. There are two distinct, mutually exclusive modes of heparin therapy. These are (a) full‐dose intravenous heparin for treatment of established venous thromboembolic disease, and (b) low‐dose subcutaneous heparin for prevention of venous thrombosis in patients at risk. Substantial evidence from prospective clinical trials indicates that heparin is the single most effective agent in both the prevention and treatment of venous thromboembolic disease. Although the administration of heparin necessarily increases the risk of bleeding, attention to details of treatment can minimize that risk. In the appropriate clinical setting, heparin is truly a lifesaving drug.
The aarhus county vagotomy trial
Authors: Amdrup Erik , Andersen Daniel , Høstrup Hans
Published: April 2005

Since June, 1972 a total of 830 patients have been consecutively operated on electively for proven duodenal, pyloric, or prepyloric ulcer. For various reasons 82 patients were excluded, while 748 were allocated at random to parietal cell vagotomy (PCV) or selective gastric vagotomy (SGV). A drainage (D) was added to PCV in 68 patients with gastric retention. In the SGV group, a secondary randomization between antrectomy (A) and drainage was performed when the peak acid output response to pentagastrin was 45 mEq/h or more. The patient material comprised 353 SGV + D, 54 SGV + A, 273 PCV, and 68 PCV + D. Five patients died postoperatively from cardiovascular disease (0.7%). Splenectomy was necessary in 4%, and 5 patients sustained an operative perforation of the esophagus or the cardia which was recognized at operation and successfully treated. Postoperative complications were evenly distributed, but were milder after PCV. Only 11% of patients with PCV were discharged from the hospital later than the 10th postoperative day, compared to 19% of patients after SGV + D. No patients had postoperative gastric retention after PCV, while 20 patients had retention after SGV + D, and in the following years vomiting was less frequent after PCV than after the other operations. A transitory dysphagia occurred in 9% of all patients and subsided in a couple of months. Dumping occurred significantly less frequently after PCV without D than after the other operations and was considerably milder. The addition of D to either PCV or SGV led to a similar incidence of dumping. It is concluded that it is unnecessary to add a drainage procedure to PCV and that PCV without D is followed by milder postoperative complications and a lower rate of sequelae than other operations for duodenal ulcer.
The role of staging laparotomy in combined modality therapy of Hodgkin's disease: A new treatment plan based on a 6‐year experience
Authors: Wilson Richard E. , Osteen Robert T. , Rosenthal David S. , Mauch Peter M. , Goodman Robert L.
Published: April 2005

From 1969 to 1974, staging laparotomy was performed on 187 consecutive patients with Hodgkin's disease. Laparotomy changed the type of therapy in 59 of 187 patients (32%). Major staging revisions were: IIA to IIIA, 20 patients; IIIA to IA, 6 patients; IIIA to IIA, 12 patients; IIB to IIIB, 14 patients; and IIIB to IIB, 4 patients. Of stage II patients, 32 of 101 (32%) became stage III and of stage III patients, 24 of 61 (39%) became stage I or II. Forty‐four patients with stage IIIA disease received 3,600–4,000 rad total nodal irradiation and their probability of relapse‐free survival at 5 years was 52%. No relapses occurred in 11 stage IIB patients given combination of mantle and periaortic irradiation plus MOPP. Only 3 of 19 stage IIIB patients treated with total nodal irradiation and MOPP relapsed. Stage IIB patients with combined therapy had a diseasefree survival of 100%, while stage IIIB patients had a relapse‐free survival of 77%. These striking results have led to a new treatment plan. Clinical stage IIA, pathological stage IIIA patients, and those with stage IIB disease now receive a combination of mantle and periaortic irradiation plus MOPP. Clinical stage IIIA, pathological stage IIIA patients, as well as those with stage IIIB disease, receive total nodal irradiation and MOPP. Surgical staging in this series has proved essential for effective and precise therapy.
A closed system surgical isolator for major elective abdominal operations
Authors: Joffe Stephen N. , Thomson William O. , McGavigan James , Trexler P. C.
Published: April 2005

This prospective unranclomized study examined the usefulness of a closed system disposable surgical isolator that provided a germ‐free environment for abdominal surgical procedures. In 30 patients who underwent clean and clean‐contaminated operations, only 1 patient (3.3%) developed a stitch abscess compared to an 11.2% incidence of major wound infection in 170 similar operations performed under conventional operating room conditions (p<0.05). The surgical isolator did not delay the operation, gave excellent visibility, and did not interfere with surgical access. The surgical isolator provided a sterile environment despite environmental contamination with a variety of organisms, especially penicillinase‐producingS. aureus, and deserves further assessment in high‐risk patients in general surgery including transplantation surgery.
Quiet-time Pc 5 pulsations in the Earth's magnetotail: IMP-8, ISEE-1 and ISEE-3 simultaneous observations
Authors: Sarafopoulos D. V. , Sarris E. T.
Published: April 2005

Abstract. Quasi-periodic Pc 5 pulsations have been reported inside and just outside the Earth's magnetotail during intervals of low geomagnetic activity. In order to further define their characteristics and spatial extent, we present three case studies of simultaneous magnetic field and plasma observations by IMP-8, ISEE-1 (and ISEE-2 in one case) in the Earth's magnetotail and ISEE-3 far upstream of the bow shock, during intervals in which the spacecraft were widely separated. In the first case study, similar pulsations are observed by IMP-8 at the dawn flank of the plasma sheet and by ISEE-1 near the plasma sheet boundary layer (PSBL) near midnight local time. In the second case study, simultaneous pulsations are observed by IMP-8 in the dusk magnetosheath and by ISEE-1 and 2 in the dawn plasma sheet. In the third case study, simultaneous pulsations are observed in the north plasma sheet boundary layer and the south plasma sheet. We conclude that the pulsations occur simultaneously throughout much of the nightside magnetosphere and the surrounding magnetosheath, i.e. that they have a global character. Some additional findings are the following: (a) the observed pulsations are mixed mode compressional and transverse, where the compressional character is more apparent in the close vicinity of the plane ZGSM=0; (b) the compressional pulsations of the magnetic field in the dusk magnetosheath show peaks that coincide (almost one-to-one) with similar peaks observed inside the dawn plasma sheet; (c) in the second case study the polarization sense of the magnetic field and the recurrent left-hand plasma vortices observed in the dawn plasma sheet are consistent with anti-sunward moving waves on the magneto-pause; (d) pulsation amplitudes are weaker in the PSBL(or lobe) as compared with those in the magneto-tail's flanks, suggesting a decay with distance from the magnetopause; (e) the thickness of the plasma sheet (under extremely quiet conditions) is estimated to be ~22 RE at an average location of (X, Y)GSM=(16, 17) RE, whereas at midnight local time the thickness is ~14 RE. The detected pulsations are probably due to the pressure variations (recorded by ISEE-3) in the solar wind, and/or the Kelvin Helmholtz instability in the low-latitude boundary layer or the magnetopause due to a strongly northward IMF.
Role of interchange instability in flux transfer event origin
Authors: Rezhenov B. V. , Maltsev Y. P.
Published: April 2005

Abstract. It is shown that the interaction of the interplanetary magnetic field (IMF), when it has southward component, with the geomagnetic field leads to the formation of an enhanced pressure layer (EPL) near the magnetopause. Currents flowing on the boundary between the EPL and the magnetosheath prevent the IMF from penetrating the magnetosphere. However, the outward boundary of the EPL is unstable. The interchange instability permanently destroys the EPL. Separate filaments of the EPL move away from the Earth. New colder plasma of the magnetosheath with a frozen magnetic field replaces the hotter EPL plasma, and the process of EPL formation and destruction repeats itself. The instability increment is calculated for various magnitudes of the azimuthal wave number, ky, and curvature radius of the magnetic field lines, Rc. The disturbances with R-1e≤ky≤4R-1e (where Re is the Earth's radius) and Rc≅Re are the most unstable. A possible result of the interchange instability of the EPL may be patchy reconnection, displayed as flux transfer events (FTEs) near the magnetopause.
Acoustic gravity wave growth and damping in convecting plasma
Authors: Robinson T. R.
Published: April 2005

Abstract. The propagation of acoustic gravity waves through steadily convecting plasma in the thermosphere has been analysed theoretically. The growth and damping rates of internal gravity waves due to the feedback effects of wave-modulated Joule heating and Laplace forcing have been calculated. It is found that large convection flow velocities lead to the growth of large-scale internal gravity waves, whilst small- and medium-scale waves are heavily damped, under similar conditions. It has also been shown that wave growth is favoured for waves travelling against the plasma flow direction. The effects of critical coupling when wave phase speeds match the plasma flow speed have also been investigated. The results of these calculations are discussed in the context of the atmospheric energy budget and thermosphere-ionosphere coupling.
A search for north-south asymmetry of interplanetary magnetic field and solar plasma
Authors: Sabbah I.
Published: April 2005

Abstract. An analysis of interplanetary magnetic field (IMF) and plasma data taken near 1 AU during solar activity cycle 21 reveals the following. 1. The yearly averaged spiral angle shows a solar cycle dependence. 2. The spiral angle north of the current sheet is 2.4° higher than south of it during both epochs of positive and negative polarities. 3. The included angle is 4.8° higher during the epoch of positive polarity than during the epoch of negative polarity. 4. The asymmetries in the number of away and toward IMF days are correlated with the asymmetries in solar activity. 5. The solar plasma north of the current sheet is hotter, faster and less dense than south of it during the epoch of negative polarity. 6. An asymmetry in the averaged filed magnitude is absent for solar cycle 21.
Extension of MF radar tidal measurements to E-region heights (95-125 km): Saskatoon (52°N, 107°W), Canada
Authors: Namboothiri S. P. , Manson A. H. , Meek C. E.
Published: April 2005

Abstract. Efforts have been made to extend the MF radar tidal profiles to E-region heights. The totally reflected MF radar echoes from E-region heights during daytime are known to be group-retarded and the corresponding wind and tidal data will have associated height discrepancies. The estimation of the E-region real heights (Namboothiri et al., 1993), and the elimination of the data for which the group retardation is significant, are selected as the basic criteria to extend the tidal profiles to 100-125 km. The analysis of the quiet (Ap<19) days of the winter and summer seasons of 1988/89 shows that the tidal propagation continues to higher altitudes with some changes in their pattern, e.g. longer wavelengths, compared to that in the lower altitudes. Comparison with the model profiles shows some resemblance and some disagreements. The reliability of the MF radar tidal measurements of E-region heights and the propagation of tides in this region have been discussed in the light of existing theories and other experimental observations. It is concluded that, based on the initial studies with UHF and MF systems and within the limits of the available theories, the information on tides presented here for the 100-125 km region using the MF radar observations is useful. Suggestions for future work in this direction are also given.
Chemistry in plumes of high-flying aircraft with H2 combustion engines: a modelling study
Authors: Weibring G. , Zellner R.
Published: April 2005

Abstract. Recent discussions on high-speed civil transport (HSCT) systems have renewed the interest in the chemistry of supersonic-aircraft plumes. The engines of these aircraft emit large concentrations of radicals like O, H, OH, and NO. In order to study the effect of these species on the composition of the atmosphere, the detailed chemistry of an expanding and cooling plume is examined for different expansion models. For a representative flight at 26 km the computed trace gas concentrations do not differ significantly for different models of the expansion behaviour. However, it is shown that the distributions predicted by all these models differ significantly from those adopted in conventional meso-scale and global models in which the plume chemistry is not treated in detail. This applies in particular to the reservoir species HONO and H2O2.
On the role of collective interactions in asymmetric ring current formation
Authors: Bespalov P. A. , Demekhov A. G. , Grafe A. , Trakhtengerts V. Yu.
Published: April 2005

Abstract. The contribution of resonant wave-particle interactions to the formation and decay of the magnetospheric ring current is analysed in the framework of a self-consistent set of equations which take into account azimuthal plasmasphere asymmetry. It is shown that the cyclotron interaction of westward drifting energetic protons with Alfven waves in the evening-side plasmaspheric bulge region leads to the formation of a ring current asymmetry located near 18:00 MLT. The time-scale of this asymmetry is determined by the proton drift time through the plasmaspheric bulge and is about 1 - 3 h. A symmetrical ring current decays mainly due to charge exchange processes. The theory is compared with known experimental data on ions and waves in the ring current and on low-latitude magnetic disturbances. New low-latitude magnetometer data on the magnetic storm of 24 - 26 July 1986 are also discussed. The model presented explains the observed localization of an asymmetrical ring current loop in the evening sector and the difference in relaxation time-scales of the asymmetry and the Dst index. It also explains measured wave turbulence levels in the evening-side plasmasphere and wave observation statistics.
Data processing algorithms used by NOAA's wind profiler demonstration network
Authors: Barth M. F. , Chadwick R. B. , van de Kamp D. W.
Published: April 2005

Abstract. The National Oceanic and Atmospheric Administration's (NOAA) Wind Profiler Demonstration Network consists of 32 wind profiling radars, based primarily in the central United States. The network is being used to determine the operational feasibility and characteristics of a possible future nationwide profiler network. Data processing is performed both at the individual profiler sites and at a central hub processing system. This paper documents the algorithms used at the profilers to produce profiles of the moments of the velocity spectrum every 6 minutes, as well as those used on the hub to produce quality-controlled hourly winds.
Experience from one year of operating a boundary-layer profiler in the center of a large city
Authors: Rogers R. R. , Cohn S. A. , Ecklund W. L. , Wilson J. S. , Carter D. A.
Published: April 2005

Abstract. Since May 1992 a small, 915-MHz profiler has been operated continuously in downtown Montreal. It is a five-beam system employing a microstrip array antenna, located atop a 14-story office building that houses several academic departments of McGill University. The data are used for research on precipitation physics and the clear-air reflectivity in addition to wind profiling. We are especially interested in situations in which the reflectivities of the clear air and the precipitation are comparable. This permits the study of interactions between the precipitation and the clear air, a new area of research made possible by wind profilers. On clear days in the summer, 30-min consensus winds can often be measured to an altitude of 3 km, but ground clutter in the antenna sidelobes interferes with measurements below 600 m. Rain when present often permits wind profiling down to 100 m and up to 6 km or higher. On cold winter days there are some periods when the reflectivity is too weak at all levels to permit wind estimation. Falling snow, however, provides readily detectable echoes and serves as a good tracer of the wind and so allows profiling over its full altitude extent. The best conditions for observing interactions between precipitation and the clear air are when light rain falls through a reflective layer associated with a frontal surface or inversion. Unexpectedly, flocks of migrating birds sometimes completely dominate the signal at night in the spring and fall seasons.
Artificial spacecraft in hybrid simulations of the quasi-parallel Earth's bow shock: analysis of time series versus spatial profiles and a separation strategy for Cluster
Authors: Giacalone J. , Schwartz S. J. , Burgess D.
Published: April 2005

Abstract. We construct artificial "software" spacecraft consisting of magnetometers and 3D thermal and energetic ion detectors. Four such spacecraft are "flown" through a 1D simulation of a quasi-parallel shock. We analyze the resulting time series from the spacecraft, and then use the more complete simulational information to evaluate our interpretations based on the limited times series information. The separation strategy used, with two closely spaced spacecraft pairs separated by a large distance, was helpful in the interpretation, since a variety of important processes operate over several different scale lengths. This work highlights the ability to draw inferences about spatially and temporally varying phenomena based on multiple-spacecraft time series data, and suggests that many spacecraft configurations which bear little resemblance to the classic Cluster tetrahedron may be necessary when multiple scale lengths are present.
An evaluation of two automated quality control methods designed for use with hourly wind profiler data
Authors: Miller P. A. , Barth M. F. , van de Kamp D. W. , Schlatter T. W. , Weber B. L. , Wuertz D. B. , Brewster K. A.
Published: April 2005

Abstract. The National Oceanic and Atmospheric Administration (NOAA) has completed the installation of a 30-site demonstration network of wind-profiling radars in the central United States. The network is being used to demonstrate and assess the utility of wind profiler technology in a quasi-operational environment, and to help define operational requirements for possible future national networks. This paper describes two automated quality control methods designed to remove erroneous winds from the hourly network data. Case study examples and statistical evaluation of the performance of each method are also presented.
Analysis and interpretation of VHF-radar data
Authors: Rüster R.
Published: April 2005

Abstract. Doppler measurements have been carried out during a variety of observational campaigns using the stationary and the mobile SOUSY-VHF-Radars. The general data reduction procedure is presented in some detail. Particular emphasis is placed upon possible problems arising from contaminated data and solutions are proposed. Some results from measurements at tropospheric and mesospheric heights are presented.
Field campaign for the comparison of SOUSY radar wind measurements with rawinsonde and model data
Authors: Steinhagen H. , Christoph A. , Czechowsky P. , Görsdorf U. , Gube-Lenhardt M. , Lippmann J. , Neisser J. , Rüster R. , Schmidt G. , Wergen W. , Yoe J. G.
Published: April 2005

Abstract. A field campaign was carried out from 26 October to 7 November 1992, using the SOUSY-VHF radar and a mobile rawinsonde system installed and operated nearby to produce vertical wind profiles. The purpose of this campaign was to compare the two types of wind measurements with one another and with results from forecast models. Numerical algorithms were developed and applied to the radar data in order to eliminate random errors, correct for velocity aliasing, and calculate the effective zenith angle of the off-vertical beams. Differences between wind profiler data and rawinsonde or model results depend not only upon the errors of the different systems, but also on temporal and spatial variations of the wind field. Therefore, methods for the comparison of radar and rawinsonde data were developed which take into consideration these variations. The practical potential of these methods is demonstrated by comparisons of rawinsonde and radar wind profiles. The comparison of radar data and model output shows excellent agreement in the direction and in the speed of the wind at virtually all altitudes. An evaluation of the quality of wind profiler measurements is possible using the estimation of variance and variability of wind components.