Direct Observation of Incoherent Cherenkov Diffraction Radiation in the Visible Range.

We report on the observation of incoherent Cherenkov radiation emitted by a 5.3 GeV positron beam circulating in the Cornell electron-positron storage ring as the beam passes in the close vicinity of the surface of a fused silica radiator (i.e., at a distance larger than 0.8 mm). The shape of the radiator was designed in order to send the Cherenkov photons towards the detector, consisting of a compact optical system equipped with an intensified camera. The optical system allows both the measurements of 2D images and angular distribution including polarization study. The corresponding light intensity has been measured as a function of the distance between the beam and the surface of the radiator and has shown a good agreement with theoretical predictions. For highly relativistic particles, a large amount of incoherent radiation is produced in a wide spectral range. A light yield of 0.8×10^{-3} photon per particle per turn has been measured at a wavelength of 600±10 nm in a 2 cm long radiator and for an impact parameter of 1 mm. This will find applications in accelerators as noninvasive beam diagnostics for both leptons and hadrons.

Experimental Observation of "Shadowing" in Optical Transition Radiation.

We report the observation of shadowing between two optical transition radiation (OTR) sources from a 205 MeV electron beam. The total optical intensity is measured as a function of the distance d between the sources, covering the range 0

Global trends, needs, issues.

Worldwide, Pharmaceutical Plant Management struggles with the competing priorities of lowering costs, rising customer expectations, more demanding government regulations, and the need to reduce cycle times especially in the introduction of new products. All of this takes place in an environment of global competition, regulatory harmonization, mergers and downsizing, and employee insecurity. Employees are expected to do more with less, work with more sophisticated equipment and processes, take more personal responsibility for quality and productivity, work in teams, etc. In summary, we are talking about CHANGE, the speed of which will accelerate in the years to come. This presentation will discuss how some pharmaceutical plants are addressing these challenges. Examples will be given in the areas of validation, process reengineering, risk analysis, role of the quality function and people. It is my contention that most of the global trends today are insufficient to meet the challenges that we face. I hope that this presentation will generate some ideas on what the global trends should be.

Validation and the human element.

Frequently the steps in the process which involve human intervention are the weak links in the process, the steps representing the highest risk. This is not due to lack of training or motivation of people, but to weaknesses in the design of the process and to the intrinsic error rate of manual operations. Quite often in validation work the human element is ignored while mechanical and technological aspects are studied in great detail. This article will include some examples about what we have learned about risk where human intervention is involved by using Failure Mode Effect Analysis (FMEA) and Process Reengineering methodologies. Furthermore, the implications for training and qualification of people in the validation context will be discussed.

Asymptomatic carotid artery stenosis and stroke in patients undergoing cardiopulmonary bypass.

PURPOSE: This study was undertaken to assess the natural history of carotid artery stenosis in patients undergoing cardiopulmonary bypass (CPB) at a Veterans Administration Medical Center. METHODS: Between January 1989 and August 1993, all patients undergoing CPB were offered preoperative carotid artery ultrasound screening as part of an investigative protocol. Patients were monitored in-hospital for the occurrence of perioperative neurologic deficit. RESULTS: A total of 582 patients underwent carotid artery ultrasound screening. Greater than 50% stenosis or occlusion of one or both internal carotid arteries was present in 130 patients (22%), with 80% or greater stenosis or occlusion of one or both arteries present in 70 patients (12%). In-hospital stroke or death occurred in 12 (2.1%) and 36 (6.2%) patients, respectively. Of the 12 strokes, five were global and seven were hemispheric in distribution. Of the five patients who had global events, none had evidence of carotid artery stenosis. However, of the seven patients who had hemispheric events, five had significant 50% or greater stenosis or occlusion of the internal carotid artery ipsilateral to the hemispheric stroke. Therefore the presence of carotid artery stenosis or occlusion was significantly associated with hemispheric stroke (no stenosis 0.34% vs stenosis 3.8%; p = 0.0072). Furthermore, the risk of hemispheric stroke in patients with unilateral 80% to 99% stenosis, bilateral 50% to 99% stenosis, or unilateral occlusion with contralateral 50% or greater stenosis was 5.3% (4 of 75). No strokes occurred in patients with unilateral 50% to 79% stenosis (n = 52). CONCLUSIONS: It is concluded that carotid atherosclerosis is a risk factor for hemispheric stroke in patients undergoing CPB.

Indications for internal stenting in intestinal obstruction.

Internal stenting (sutureless plication) for intestinal adhesions was performed operatively in 16 patients. Subsequent recurrent obstruction occurred in four patients. Other complications occurred in three patients and included retained tube, jejunostomy-site abscess, and intestinal fistulization. Four patients died for an in-hospital mortality of 25%. Internal stenting for adhesions should be used cautiously. Its use should probably be restricted to the setting of severe adhesive small bowel obstruction particularly when numerous enterotomies are incurred during the course of adhesiolysis.

[Comparative studies of the Osborne protein fraction of wheat varieties with different dough and baking properties]. / Vergleichende Untersuchungen an Osborne-Proteinfraktionen von Weizensorten mit unterschiedlichen Teig- und Backeigenschaften.

The proteins of flours from the wheat varieties Clement (CLE) and Disponent (DIS), which are characterized by substitution of the wheat chromosome 1B by the rye chromosome 1R (CLE) and by 1BL/1RS-translocation of chromosome segments (DIS), respectively, and which yield sticky doughs, were extracted by the Osborne procedure and compared with the good variety Kolibri (KOL). CLE and DIS delivered significantly higher amounts of water-soluble proteins (31.2 and 23.2% of the total protein) than KOL (15.5%). The proportions of ethanol-soluble proteins were approximately constant for the three varieties (31.5-33.9%) while the amounts of residual proteins after extraction with ethanol were significantly different (CLE, 16.8%; DIS, 21.6%; KOL, 26.4%). Water extracts as well as residues exhibited also marked differences in their amino acid compositions. Investigation of the water extract from DIS by gel permeation chromatography and by RP-HPLC showed the presence of prolamins: omega 1,2-gliadins and/or omega-secalins could be detected on the basis of amino acid composition and N-terminal amino acid sequence. In the case of good varieties such as KOL, these prolamins seem to remain partially in the residue of the ethanol extract under the conditions of the classical Osborne procedure, whereas they are found in the water extract in the case of such varieties as CLE and DIS. On the other hand, a modified Osborne procedure (salt/ethanol/acetic acid) delivered the prolamins, which correspond to 39-40% of the total protein, completely within the ethanol fraction in the case of all three varieties.(ABSTRACT TRUNCATED AT 250 WORDS)

Preoperative CT in symptomatic abdominal aortic aneurysms: accuracy and efficacy.

Of 80 patients who underwent operations for abdominal aortic aneurysm at the Gainesville Veterans Administration Medical Center, 23 had a preoperative CT scan. Twenty patients in this group were symptomatic. In determining the presence of rupture, there was only one false-negative examination and no false-positives for a sensitivity of 0.9 and a specificity of 1.0. Nine of the 20 symptomatic patients had a rupture confirmed at laparotomy, and these patients had a 22 per cent mortality. Unruptured symptomatic patients operated upon after an expeditious preparation (usually about 36 hr), including optimization of cardiac output and mechanical bowel cleansing, had a mortality of 30 per cent primarily for postoperative myocardial infarction and left ventricular failure. The high operative mortality previously reported for emergently repaired unruptured symptomatic abdominal aortic aneurysms (18%) was not diminished by limited preoperative preparation.

Metastatic squamous cell carcinoma from the esophagus occurring as small bowel obstruction.

Metastatic tumors of the small bowel from extra-abdominal sites are rare. The primary tumors that have been reported are malignant melanoma, breast cancer, bronchogenic carcinoma, embryonal myosarcoma, and seminoma. We have presented a case of small bowel obstruction due to metastasis from esophageal cancer.

Giant fibrovascular polyp of the esophagus.

An adult patient with a giant fibrovascular esophageal polyp, measuring 17 cm in length, is described in this report. The patient presented with dysphagia and intermittent partial regurgitation of a fleshy mass in the mouth, only after the polyp had attained giant proportions. The polyp appeared as a large polypoid filling defect on a barium swallow and the findings were confirmed at endoscopy. The stalk was attached just below the cricopharyngeus muscle, and the club-shaped polyp extended almost up to the gastroesophageal junction. Because of the vascularity of this large structure and the proximity of respiratory passages to the site of attachment of the stalk, surgical resection of the polyp was undertaken.

Sarcoma of the gastrointestinal tract: a review of 40 cases.

In a ten-year update of the Vanderbilt University Medical Center experience, cases of malignant lymphomas (20) and soft tissue sarcomas (20) of the gastrointestinal tract were reviewed. The stomach was the most common site (63%). The three most common presenting symptoms were abdominal pain, weight loss, and hemorrhage. The average duration of symptoms prior to seeking medical consultation was 14 months. The five-year survival was 50% for soft tissue sarcomas and 60% for malignant lymphomas. It is suggested that delay is establishing a diagnosis be a consideration in recommending adjuvant therapy.

An appraisal of en bloc resection of peripheral bronchogenic carcinoma involving the thoracic wall.

Thirty-two patients with peripheral bronchogenic neoplasms adherent to the chest wall underwent en bloc pulmonary and thoracic wall resections. Presenting symptoms were thoracic wall pain (75 percent), hemoptysis (12.5 percent), and cough with weight loss (12.5 percent). Patients were selected for surgical resection only after a search for metastatic disease, including mediastinoscopy, showed negative results. A standard posterolateral thoracotomy incision was used which did not require skeletal reconstruction or prosthetic material for closure. There were nine major postoperative complications (28.8 percent), principally respiratory, and one operative death (3.1 percent). The five-year actuarial survival was 35 percent. None of the patients with regional lymph node involvement or positive chest wall margins lived more than two years after surgery. Preoperative irradiation performed in 12 patients (37.5 percent) improved operability, but did not significantly alter survival. These results indicate that patients with peripheral bronchogenic carcinoma involving the thoracic wall may be successfully managed with en bloc pulmonary and chest wall resection, particularly if surgery is performed in the early stage of the disease.

Renovascular hypertension: anatomic and renal function changes during drug therapy.

Serial renal function studies were performed on 41 patients wtih renovascular hypertension (RVH) secondary to atherosclerotic renal artery disease who had been randomly selected for nonoperative management. In 19 patients, serum creatinine levels increased between 25% and 120%. The glomerular filtration rates dropped between 25% and 50% in 12 patients. Fourteen patients (37%) lost more than 10% of renal length. In four patients (12%), a significant stenosis progressed to total occlusion. Seventeen patients (41%) had deterioration of renal function or loss of renal size that led to operation. One patient required removal of a previously reconstructible kidney. Of the 17 patients with deterioration, 15 had acceptable blood pressure (BP) control during the period of nonoperative observation. Progressive deterioration of renal function in nonoperatively treated patients with atherosclerotic renal artery stenosis and RVH is common, and occurs even in the presence of BP control with drugs.

Prospective clinical trial of antibiotics for pulmonary resections.

One hundred and seventy-one patients undergoing pulmonary resection were included in a prospective randomized clinical study evaluating the efficacy of prophylactic antibiotics. Eight-three patients randomly chosen received no parenteral antibiotics and 88 received a short course of cephalothin intravenously. Topical antibiotics were used in the pleural cavity and would of all patients. There were no statistically significant differences between the two groups in terms of days of postoperative fever, number of postoperative septic complications and length of postoperative stay. However, when postoperative infectious complications developed in the antibiotic group, they were often secondary to gram-negative organisms resistant to cephalothin.

Intussusception of the excluded segment following jejuno-ileal bypass.

Intussusception of the defunctionalized intestinal segment following jejuno-ileal bypass for obesity has rarely been reported. Persistent crampy abdominal pain (often accompanied by nausea and vomiting) and normal radiologic evaluation are suggestive of this entity. The routine use of silver clips, although helpful in some instances, cannot exclude this diagnosis. A high index of suspicion and the use of sonography may prove that intussusception of the defunctionalized segment is more common than has been previously reported.

Selective nonoperative management of contained intrathoracic esophageal disruptions.

Eight patients with intrathoracic esophageal disruptions were managed nonoperatively and without pleural drainage. Criteria for nonoperative treatment included the following: disruption contained in the mediastinum or between the mediastinum and visceral lung pleura; drainage of the cavity back into the esophagus; minimal symptoms; and minimal signs of clinical sepsis. Cause of the esophageal perforation was pneumostatic dilatation (1 patient), vomiting (2), and a leak following esophageal operation (5). Antibiotics were administered intravenously to all patients; hyperalimentation was accomplished intravenously in 5, and nasogastric suction was used in only 1. The cavities contracted and the esophageal leaks sealed in all instances. Time before oral intake was resumed ranged from 7 to 38 days (average, 18 days). Days until discharge ranged from 15 to 52 days (average, 28 days).