Effort, safety, and findings of routine preoperative endoscopic evaluation of morbidly obese patients undergoing bariatric surgery.

BACKGROUND: Obesity is becoming an epidemic health problem and is associated with concomitant diseases, such as sleep apnea syndrome and gastroesophageal reflux disease (GERD). There is no standardized diagnostic workup for the upper gastrointestinal tract in obese patients; many patients have no upper gastrointestinal symptoms, and few data are available on safety of endoscopy in morbidly obese patients. METHODS: Sixty-nine consecutive diagnostic upper gastrointestinal endoscopies in morbidly obese patients (26 men, 43 women; mean age 43.4 +/- 10.9 years) were prospectively evaluated from January to December 2008 in an outpatient setting before bariatric procedures. Sedation was administered with propofol. Data on sedation, critical events, and examination times were recorded, as well as pathological findings. RESULTS: The patients' mean body mass index was 47.6 +/- 7.9 (range, 35.1-73.3) kg/m(2); 17.4% reported GERD symptoms. The mean duration of the endoscopy procedure (including sedation) was 20.3 +/- 9.3 (range, 5-50) min, and the whole procedure (including preparation and postprocessing) took 58.2 +/- 19 (range, 20-120) min. The mean propofol dosage was 380 +/- 150 (range, 80-900) mg. Two patients had critical events that required bronchoscopic intratracheal O(2) insufflation due to severe hypoxemia (<60% SaO: (2)). Nearly 80% of patients had pathological findings in the upper gastrointestinal tract. Only 20% reported upper gastrointestinal symptoms. Pathologic conditions were found in the esophagus in 23.2% of the patients, in the stomach in 78.2%, and in the duodenum in 11.6%. The prevalence of Helicobacter pylori infection was 8.7%. CONCLUSIONS: Upper gastrointestinal endoscopy can be performed safely. However, careful monitoring and anesthesiological support are required for patients with concomitant diseases and those receiving sedation. Because 80% of the patients with pathological findings were asymptomatic, every morbidly obese patient should undergo endoscopy before bariatric surgery because there may be findings that might change the surgical strategy.

Transient lower esophageal sphincter relaxation in morbid obesity.

BACKGROUND: There is strong evidence that morbid obesity is often accompanied by gastroesophageal reflux. Gastroesophageal reflux is caused predominantly by transient lower esophageal sphincter relaxations (TLESRs). Only few data are available about TLESRs in patients with stage III obesity (body mass index > 35). The aim of this study was to analyze the frequency and types of TLESRs in patients with morbid obesity in different physiological stages (postprandial: upright and recumband) compared to patients with normal weight gastroesophageal reflux disease (GERD) and diffuse esophagus spasm (DES). METHODS: In order to measure TLESRs in obese patients with and without GERD, three subgroups were prospectively performed: group I consisted of seven healthy controls, group II consisted of seven obese patients, group III consisted of seven non-obese patients with GERD, and in group IV, five patients were recruited with diffuse esophageal spasm. All participants underwent both conventional water-perfused stationary esophagus manometry and a 24-h ambulatory esophagus manometry, 24-h ambulatory pH monitoring, and esophago-gastroscopy. In order to measure the lower esophageal sphincter pressure (LESP) over a prolonged time under physiological conditions, a special solid-state sleeve catheter was used. Additionally, all patients were interviewed using a standardized questionnaire. RESULTS: Compared to normal subjects, patients with morbid obesity and patients with gastroesophageal reflux show a substantial increase of TLESRs in the postprandial phase. There was a tendency towards more TLESRs per hour in patients with DES than in healthy subjects, but the difference was not statistically significant. The types of TLESRs differed with the LESP. The majority of isolated TLESRs were complete and incomplete. Some of the isolated TLESRs were accompanied by contractions of the tubular esophagus. CONCLUSION: Morbid obesity is associated with gastroesophageal reflux. The frequency of TLESRs has significantly increased compared to healthy subjects and does not differ statistically from patients with GERD. Isolated TLESRs are mostly incomplete in patients with a hypotonic LES.

Dysfunction of the lower esophageal sphincter and dysmotility of the tubular esophagus in morbidly obese patients.

BACKGROUND: Morbid obesity is associated with gastroesophageal reflux (GERD). The aim of this prospective study was to determine esophageal motility in asymptomatic morbidly obese patients and compare it to non-obese individuals. METHODS: Forty-seven morbidly obese patients without GERD symptoms and 15 normal weight individuals were divided into four groups according to their body mass index (BMI; group I, <30 kg/m2; group II, 35-39.9 kg/m2; group III, 40-49.9 kg/m2; group IV, >or=50 kg/m2). Standard stationary water-perfused manometry was performed for the assessment of anatomy and function of the lower esophageal sphincter (LES). Twenty-four-hour ambulatory pH-metry and measurement of esophageal motility were performed with a microtransducer sleeve catheter. Data are given as mean+/-SD, and the results of groups II-IV were compared to the non-obese individuals from group I. RESULTS: Patients with morbid obesity had significantly lower LES pressures than non-obese individuals (I, 15.1+/-4.9; II-IV, 10.5+/-5.4, mmHg, p<0.05 vs. I) and showed an altered esophageal motility with respect to contraction frequency (I, 1.8+/-0.7/min; II-IV, 3.6+/-2.5/min; p<0.05 vs. I) and contraction amplitude (I, 38+/-12 mmHg; II-IV, 33+/-17 mmHg; p<0.05 vs. I). Furthermore, these patients had significantly higher DeMeester scores than non-obese individuals. Length and relaxation of the LES as well as propulsion velocity of the tubular esophagus did not differ. CONCLUSION: Patients with morbid obesity (=BMI>40 kg/m2) have a dysfunction of the LES and an altered esophageal motility, even when they are asymptomatic for GERD symptoms.

Selective dissemination and indexing of scientific information.

Selective dissemination of information to individuals provides a new and promising method for keeping abreast of current scientific information. Since SDI services are directed to the information needs of each individual, they are a significant step beyond grouporiented services and products, which require considerable expenditure of effort by each user as he sorts useful information from trash. However, SDI systems do require a high degree of precision in matching scientists against documents. They must operate more efficiently and economically than many current systems which occasionally provide a useful item of information to users. To meet these stringent requirements for quality, precision, efficiency, and economy, more research must be devoted to comparing and improving indexing methods, which are the basic component of all information storage and retrieval systems. It is incredible that so much money has been spent on the development and operation of scientific information systems before basic data on the comparative performance of various indexing methods have been gathered, analyzed, and confirmed by multiple investigators. The design of an effective information system would seem to require this type of basic knowledge, just as basic properties of alternative materials must be known before an engineer can design a building, bridge, or factory. Yet, except for the few studies mentioned in the previous section, research on indexing methods has been greatly neglected. Bourne's comment about studies of indexing languages is still an appropriate description of the situation: "In almost all the experimental reports, the investigator worked with an indexing language different than that of other experimenters. Consequently, no one has ever had his test results verified, or expanded, or made more precise by another experimenter" (47). Most existing information systems are based on keyword indexing, with concepts broken into isolated terms during input operations and recombined to synthesize the original concept during search and retrieval. Such systems tend to involve imprecise indexing, with a high level of "noise" in retrieved documents, difficult search strategy involving extensive post-coordination, and lengthy, complex computer manipulations. This situation reflects the fact that many producers of indexed data originally focused the design of their systems on the production of a published product with entries printed under short, concise index headings. Production of magnetic tapes as a by-product of the publication process, and their use for retrospective searching or for SDI services, was a much later development, almost an afterthought. Yet use of these tapes is growing so rapidly that it may be time to redesign the tape-producing systems, with ease of tape use for SDI services and retrospective searching as the primary consideration, and with publication of abstract and index bulletins or title listings relegated to secondary importance (49). The use of keywords to index documents creates a high degree of disorganization in information search and retrieval operations: Information is scattered under the many different terms that can be used to index different aspects of a concept. If the large-scale, comprehensive abstracting and indexing services were based on enumerative classifications with assignment of documents to logical hierarchical categories at the time of initial indexing, then many of the specialized information centers (50) and the 1300 abstracting and indexing services (3) would be unnecessary, and much of the reindexing and reprocessing of documents, the repackaging and reworking of abstracts and index data, and the resulting overlap and duplication characteristic of current information processing could be terminated. Partly because of the disorganization resulting from keyword indexing, the cost of a 5-year retrospective search of information on just one data base on magnetic tapes is a major investment (16). The effort and cost required to find a few items of useful information scattered among 1,285,000 abstracts indexed on 116 full reels of magnetic tape (11 million characters per reel) which will be needed for the 5-year Eighth Collective Index to Chemical Abstracts (1967-1971) (51) staggers the imagination. In contrast, when HICLASS systems based on enumerative hierarchical classifications are used, concepts that might be useful for later retrieval are identified and related items of information are grouped together during the indexing process. These enumerative classifications, with single-hit matching, make it possible to index and retrieve ideas as intact units and to perform simple sequential searches of the very small segment of a file that deals with a given topic (31). The experiments at both the Science Information Exchange and the National Cancer Institute, as described in this article, demonstrate that automated HICLASS systems are feasible and can operate at a very satisfactory level of performance. Although considerable effort may be required for the development and constant updating of detailed enumerative classifications, HICLASS categories may facilitate organization of data at the time of input, improve the precision of matching documents with users, and greatly simplify search logic and computer manipulations. If so, then output savings and performance would more than justify input costs, and the development and use of enumerative classifications would be a better solution to information problems than the current keyword-and-coordination approach. It is time to think beyond the ease of the single input step in information systems and to take a hard look at ways of easing retrieval problems for the multitude of information systems that process the indexed data (52). Indexing effort is expended only once, whereas search and retrieval effort is required by every user of a system. If information were better analyzed and organized during input operations, if more basic research were devoted to the effect of indexing methods on the performance of information systems, and if more emphasis were placed on the quality and usefulness of retrieved information, then the magnitude of problems related to the storage and retrieval of scientific information might be considerably reduced.

Ambulatory pH: monitoring with a wireless system.

BACKGROUND: Currently, pH monitoring is the gold standard for assessing esophageal acid exposure in patients with gastroesophageal reflux disease (GERD). The shortcomings of 24-h pH-monitoring wires led to the development of a 48-h, catheter-free pH measurement system using the telemetry technique with the BRAVO capsule. This prospective study aimed to compare conventional 24-h pH monitoring with the BRAVO catheter-free pH-monitoring system in patients with GERD, patients after antireflux surgery, and a healthy control group. METHODS: A sample of 133 participants were enrolled in the current trial and divided into three subgroups. Group 1 consisted of 10 healthy volunteers. Group 2 consisted of 123 patients with symptomatic gastroesophageal reflux and endoscopic signs of esophagitis. Group 3 consisted of 43 GERD patients (extracted from group 2) who underwent a laparoscopic 360 degree "floppy" Nissen fundoplication. All the patients underwent both conventional 24-h pH monitoring and BRAVO catheter-free pH monitoring. The data for both methods were recorded and compared in line with the different patient groups regarding their validity and reliability. Additionally, all the patients were interviewed with a standardized questionnaire concerning their subjective perception of the two different methods. RESULTS: Both the 24-h pH monitoring and the 48-h BRAVO catheter-free pH monitoring could be successfully performed for all the patients. During measurement, 122 of the patients (92%) continued working or performing daily activities. A significant difference could not be found regarding objective outcome between the two measurement methods in the three patient groups. The two methods showed comparable results in terms of data and measurement reliability. The validity also was comparable, with no significant differences within the groups. Concerning the patients' subjective estimation of the two methods, the patients reported reduced regular activities and a higher level of discomfort during measurement with the conventional 24-h pH-monitoring system (p < 0.001 and p< 0.0001, respectively). CONCLUSION: Both conventional 24-h pH monitoring and the 48-h catheter-free pH monitoring are valid and reliable recording devices for measuring esophageal acid exposure. However, from the patients' point of view, the BRAVO capsule affords less discomfort in the throat and allows more normal daily activities.

Epidemiology of cercospora leaf spot on sugar beet: modeling disease dynamics within and between individual plants.

ABSTRACT Disease dynamics of Cercospora leaf spot (CLS) of sugar beet was analyzed at two hierarchical scales: as vertical profiles within individual plants and in relation to disease on neighboring plants. The relative contribution of different leaf layers to increase in CLS was analyzed using a simple continuous-time model. The model was fitted to data from two field trials in the Netherlands: one in an area with a long history of CLS, the other in an area where CLS has only recently established; in each case these were unsprayed and twice-sprayed treatments. There were differences in the relative contribution of different leaf layers to disease increase on the target leaf layer according to the CLS history and whether the plants were sprayed or unsprayed. In both field trials, parameter estimates giving the relative contribution of the target leaf layer to disease increase at that leaf layer were higher than those for the lower leaf layer. On only a few occasions the contribution of an upper leaf layer to disease increase at the target leaf layer was significant. Thus, CLS increase at the target leaf layer was determined mainly by disease severity at that leaf layer and to a lesser extent by disease at the lower leaf layer. Our continuous-time model was also used to analyze CLS increase on an individual sugar beet plant in relation to its own and its neighbor's level of disease in field trials at five locations in the two CLS areas over two years. In all field trials, the contribution of the target plant itself to disease increase (auto-infection) was larger than that of its neighboring plants (allo-infection). The overall analysis in the two CLS areas also indicated a larger contribution of the target plant to its disease increase than of neighboring plants, and this pattern was also apparent in a pooled analysis across all sites. Thus, CLS increase on a sugar beet plant was mainly determined by the disease severity on that plant and to a lesser extent by its within-row neighboring plants.

Registry of experimental cancers of the National Cancer Institute.

This report describes the organization and functions of the Registry of Experimental Cancers and gives the chronology of events that led to its establishment. Currently 21,500 accessions have been coded; the vast majority are spontaneous and induced cancers, chiefly of rodents, and also a wide variety of nonneoplastic diseases. Accessions are accepted from contributors working in laboratories in this country and abroad. The material is available for study by responsible scientists, and a limited number of study sets is available for loan on request.

Soil suppressiveness to Rhizoctonia solani and microbial diversity.

Rhizoctonia solani anastomosis group 2-2IIIB causes damping-off, black root rot and crown rot in sugar beet (Beta vulgaris). Based on experiences of growers and field experiments, soils can become suppressive to R. solani. The fungus may be present in the soil, but the plant does not show symptoms. Understanding the mechanisms causing soil suppressiveness to R. solani is essential for the development of environmentally friendly control strategies of rhizoctonia root rot in sugar beet. A bioassay that discriminates soils in their level of disease suppressiveness was developed. Results of bioassays were in accordance with field observations. Preliminary results indicate an active role of microbial communities. Our research is focused on the disentanglement of biological mechanisms causing soil suppressiveness to R. solani in sugar beet. Therefore, we are handling a multidisciplinary approach through experimental fields, bioassays, several in vitro techniques and molecular techniques (PCR-DGGE).

Are the motility abnormalities of achalasia reversible? An experimental outflow obstruction in the feline model.

BACKGROUND: Experimental and clinical evidence suggests that the loss of esophageal body function in achalasia may be a result of the outflow obstruction of a nonrelaxing, hypertensive lower esophageal sphincter. The reversibility of such abnormalities has implications to the timing of therapeutic interventions. This study was designed to evaluate the evolution and reversibility of motility abnormalities resulting from esophageal outflow obstruction in cats. METHODS: Twenty adult cats were divided into 2 groups. Group 1 consisted of 4 cats that underwent laparotomy as a sham procedure. Group 2 consisted of 16 cats that underwent surgical placement of a loose Gore-tex expanded polytetrafluoroethylene (W. L. Gore, Elkton, Md) band calibrated to 110% of the circumference of the gastroesophageal junction. The band was removed from 4 randomly selected cats each at 1, 2, 4, and 6 weeks after placement. Esophageal manometry was performed before placement of the band, at weekly intervals after placement of the band, and after removal of the band. The resting pressure and percent relaxation of the lower esophageal sphincter (LES), in addition to amplitude, duration, and propagation of esophageal body contractions, were measured at each interval. Data are expressed as median and interquartile range and compared with use of the Mann-Whitney U test for independent samples. RESULTS: The LES resting pressure remained unchanged after placement of the band, but sphincter compliance was reduced, as manifested by a significant reduction in the percent of sphincter relaxation (98% prebanding, 65% postbanding, P < .05). The median amplitude of esophageal contraction decreased significantly after banding. By 6 weeks after banding the esophagus was markedly dilated and exhibited aperistaltic, low-amplitude esophageal motility typical of that seen in clinical achalasia. Importantly, removal of the bands resulted in a prompt return of both peristalsis and amplitude of contraction. CONCLUSIONS: Loss of compliance of the lower esophageal sphincter produces outflow obstruction with the resultant loss of esophageal contraction amplitude and peristaltic waveform typical of achalasia in humans. These abnormalities were reversible after relief of obstruction in the feline model and may indicate that early relief of outflow obstruction in clinical achalasia may preserve esophageal function in patients.

Benign cerebellar astrocytomas of childhood.

Benign cerebellar astrocytomas of childhood are potentially surgically curable lesions. Histologically, these neoplasms can be divided into pilocytic and diffuse astrocytomas. Whether there is a difference in the recurrence rate between these two tumor types after a surgical resection is not clear. In addition, the role of immediate postoperative imaging in predicting a recurrence has not been established. To answer these questions, we have reviewed the charts of 23 patients with benign cerebellar astrocytomas treated at Childrens Hospital of Los Angeles over a 10-year period (1977-1987). Of the 23 tumors, 15 were pilocytic and 8 were diffuse. All patients underwent an attempted gross total surgical removal of the tumor, and all patients had a postoperative computed tomographic (CT) scan with and without intravenously administered contrast material performed within 72 hours of the operation. Based on the postoperative CT scan, 12 patients had residual tumors. Seven of the subtotally resected tumors were pilocytic (7 of 15), and 5 were diffuse (5 of 8). Interestingly, the surgeon believed that a gross total resection had been obtained in 9 of these patients. There have been 4 recurrences in these 23 patients, with a mean follow-up of 4.9 years. All recurrences were in patients with subtotal resections. Of the 11 patients with a total resection of the tumor, 7 developed a small rim of enhancement on subsequent scans an average of 5 months after the operation.(ABSTRACT TRUNCATED AT 250 WORDS)

Application of photodynamic therapy to the treatment of atherosclerotic plaques.

Photodynamic therapy is a therapeutic modality long studies for its application to the treatment of malignant neoplasms. Recently, studies have suggested its potential use in the treatment of atherosclerosis. In this study, two atherosclerotic plaques were induced in the abdominal aortas of 35 rabbits. The animals then received Photofrin II (Quadralogic Technologies Inc., Pearl River, NY), a photosensitizer, at doses of 5 mg/kg and 2.5 mg/kg. After 48 hours, the plaques were irradiated by a fiberoptic connected to an argon ion laser. Fluency rates from 32 mW to 256 mW and energy doses from 1.6 to 60 joules were applied. Only one of the paired plaques was irradiated, the other remaining as a control. Four weeks after treatment, the vessels were assessed. Of 26 plaques treated with photodynamic therapy, 22 were no longer grossly visible, while the nine animals that received light irradiation but no Photofrin II all had visible plaque (P < 0.001). Studies of the vessel sections confirmed a reduction in intimal thickness from 0.74 +/- 0.15 mm in matched controls as compared with 0.51 +/- 0.13 mm in animals with treated plaques. There was a concomitant enlargement of the luminal diameter from 1.13 +/- 0.51 to 1.41 +/- 0.72. On the microscopic level, plaque reduction was most complete in the groups treated with 40 and 60 joules. Different fluency rates and drug dosages did not lead to differing outcomes. Our findings indicate that photodynamic therapy with dihematoporphyrin ether met our goal of reducing plaque size and may represent a means of treating atherosclerotic plaques.

Cytokine expression in radiation-induced delayed cerebral injury.

Radiation-induced delayed brain injury is a well-documented complication of both standard external beam radiation (teletherapy) and interstitial brachytherapy; however, the cause of this damage has not been determined. Cytokines and growth factors are important regulatory proteins controlling the growth and differentiation of normal and malignant glial cells, which have been implicated in the tissue response to radiation injury. Six snap-frozen brain biopsies showing radiation injury were obtained from four patients harboring malignant gliomas who underwent either postoperative external beam and/or stereotactic interstitial brachytherapy at standard dosages. The specimens showed variable amounts of gliosis, tissue necrosis, calcification, inflammation, and vascular proliferation and hyalinization. Frozen tissue sections were examined for the presence of infiltrating lymphocytes, macrophages, cytokines, and other immunoregulatory molecules by the use of a panel of specific monoclonal and polyclonal antibodies. All specimens showed diffuse T cell infiltration with both CD4+ and CD8+ cells. Infiltrating activated macrophages (CD11c+, HLA-DR+) were prominent in five of six cases. Tumor necrosis factor-alpha and interleukin-6 immunoreactivity was prominent in four of six cases and was predominately localized to macrophages. Transforming growth factor-beta astrocytic and macrophage immunoreactivity was present at moderate levels in all cases. This study suggests that in radiation necrosis, interleukin-1 alpha, tumor necrosis factor-alpha, and interleukin-6 are expressed, predominately by infiltrating macrophages.

Development of neurosurgery in southern California and the Los Angeles county/University of Southern California Medical Center.

The Los Angeles County General Hospital has played an integral role in the development of medicine and neurosurgery in Southern California. From its fledgling beginnings, the University of Southern California School of Medicine has been closely affiliated with the hospital, providing the predominant source of clinicians to care for and to utilize as a teaching resource the immense and varied patient population it serves.

Interactions of water-soluble porphyrins with hexadeoxyribonucleotides: resonance raman, UV-visible and 1H NMR studies.

The interactions of the water-soluble porphyrins M(TMpy-P4) [M = H2, Cu(II), Ni(II), and Co(III); TMpy-P4 = tetrakis(4-N-methylpyridyl)porphyrinato ion], with the hexadeoxyribonucleotides d(CGTACG)2, d(TACGTA)2, d(GCATGC)2, d(TGTGCA)2, and d(CTATAG)2 have been investigated by resonance Raman and/or UV-visible spectroscopy. The results indicate that all hexamers containing the 5'CG3' as well as the 5'GC3' site, and also the mismatched hexamer d(TGTGCA)2, are capable of intercalating the H2, Cu(II) and Ni(II) porphyrins. 1H nuclear magnetic resonance spectra of d(CGTACG)2 mixed with Cu(TMpy-P4) have provided further evidence for the intercalation. For the other cases, outside binding by localized electrostatic interaction is suggested. There is no evidence of groove binding to any of the hexamers. Possible reasons for different binding properties of long and short helices are discussed.

Temporary loss of intraoperative motor-evoked potential and permanent loss of somatosensory-evoked potentials associated with a postoperative sensory deficit.

We describe a case of the temporary loss of right popliteal fossa intraoperative neurogenic motor-evoked potential and the permanent loss of right median and ulnar somatosensory-evoked potentials (SSEPs) with retention of posterior tibial (SSEPs) during intramedullary spinal cord surgery in a 28-year-old man. Postoperatively, the patient had preserved motor function in all extremities and loss of proprioception, two-point discrimination, and vibration in his right upper extremity. The complementary and beneficial use of intraoperative monitoring of both motor-evoked potentials and SSEPs during spinal cord surgery is discussed.

Exploring Differential Interactions Between Rhizoctonia solani AG 2-t Isolates and Tulip Cultivars.

Experiments were conducted to explore differential interaction of Rhizoctonia solani AG 2-t isolates on tulip cultivars in soil artificially infested under different experimental conditions. Comparison of residual variances obtained by analysis of variance and by analysis of additive main effects and multiplicative interaction effects (AMMI) showed that open-air experiments should be used for interpretation of isolate by cultivar interaction. In open-air experiments, variability was lower than in greenhouse tests. In the biplot, derived after AMMI-analysis over isolates by years and by cultivars, isolates tended to occur in year clusters, indicating a differential effect of year on disease expression. Three isolates occurred in isolate clusters, thus accounting for a significant year by isolate by cultivar interaction. One cluster consisted of three isolates high in aggressiveness on all tested tulip cultivars, and another cluster consisted of three isolates low in aggressiveness. Greenhouse conditions and inoculum carrier significantly influenced quantitative differential interaction patterns. Isolates grown on oat kernels were more aggressive than those grown on autoclaved perlite particles soaked in liquid malt peptone. Differential interaction of AG 2-t isolates on tulip cultivars does occur, although it cannot yet be disentangled completely.