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.

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.

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.

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.

Development of a specific PCR assay for the detection of Rhizoctonia solani AG 1-IB using SCAR primers.

AIMS: The aim of this study was to develop a specific and sensitive identification method for Rhizoctonia solani AG 1-IB isolates based on phylogenetic relationships of R. solani AG-1 subgroups using rDNA-internal transcribed spacer (rDNA-ITS) sequence analysis. METHODS AND RESULTS: A neighbour-joining tree analysis of 40 rDNA-ITS sequences demonstrated that R. solani AG-1 isolates cluster separately in six subgroups IA, IB, IC, ID, IE and IF. A molecular marker was generated from a random amplified polymorphic DNA fragment (RAPD). After conversion into a sequence-characterized amplified region (SCAR), a specific primer set for identification of subgroup AG 1-IB was designed for use in a polymerase chain reaction (PCR). The primer pair amplified a single DNA product of 324 bp. CONCLUSIONS: R. solani AG-1 subgroups were discriminated by sequence analysis of the ITS region. The designed SCAR primer pair allowed an unequivocal and rapid detection of R. solani AG 1-IB in plant and soil samples. SIGNIFICANCE AND IMPACT OF THE STUDY: Sequence analysis of the rDNA-ITS region can be used for differentiation of subgroups within AG-1. The use of the developed SCAR primer set allowed a reliable and fast identification of R. solani AG 1-IB and provides a powerful tool for disease diagnosis.

The lower esophageal sphincter strength in patients with gastroesophageal reflux before and after laparoscopic Nissen fundoplication.

Lower esophageal sphincter pressure (LESP) and sphincter strength (LESS) were measured before and after short and floppy laparoscopic Nissen fundoplication (LNF) in 38 patients with severe gastro-esophageal reflux disease (GERD). These patients were compared with a control group of 23 healthy volunteers. GERD was assessed by stationary manometry, 24-h pH recordings and endoscopy. LESS was verified by motorized pull-back of an air-filled balloon catheter from the stomach into the esophagus. The catheter assembly was well tolerated by all study participants. LESP increased significantly after operation from 8 mmHg to 14 mmHg (75% of normal values; P < 0.0001), but compared to the control group, LESP (22 mmHg) decreased significantly (P < 0.002). In the control group and in patients with GERD, LESP and LESS showed excellent correlation (r = 0.97, r = 0.94, respectively). After LNF, LESS increased significantly from 0.6 to 1.6 N (P < 0.0001), about 166%. We conclude that the measurement of LESS is able to explain the discrepancy between satisfactory NF operation and the distinct increase of postoperative LESP. The evaluation of LESS is a helpful tool in assessing functional understanding of laparoscopic Nissen fundoplication with a short and floppy wrap.

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.

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).

Online personal medical records: are they reliable for acute/critical care?

OBJECTIVE: To provide an introduction to Internet-based Online Personal Medical Records (OPMRs), to assess their use and limitations in acute/critical care situations, and to identify potential improvements that could increase their usefulness. DESIGN: A review of publicly available Internet-based OPMRs conducted in April 2001. DATA SOURCES: Twenty-nine OPMR sites were identified in March 2000 using ten Internet search engines with the search term "Personal Medical Records." Through 2000 and 2001, an additional 37 sites were identified using lists obtained from trade journals and through the author's participation in standards-setting meetings. MEASUREMENTS: Each publicly available site was reviewed to assess suitability for acute/critical care situations using four measures developed by the author and for general use using eight measures developed in a standards-setting process described in the article. RESULTS: Of the 66 companies identified, only 16 still offer OPMRs that are available to the public on the Internet. None of these met all of the evaluation measures. Only 19% had rapid emergency access capabilities and only 63% provided medical summaries of the record. Security and confidentiality issues were well addressed in 94% of sites. Data portability was virtually nonexistent because all OPMRs lacked the ability to exchange data electronically with other OPMRs, and only two OPMRs permitted data transfer from physician electronic medical records. Controls over data accuracy were poor: 81% of sites allowed entry of dates for medical treatment before the patient's date of birth, and one site actually gave incorrect medical advice. OPMRs were periodically inaccessible because of programming deficiencies. Finally, approximately 40 sites ceased providing OPMRs in the past year, with the probable loss of patient information. CONCLUSIONS: Most OPMRs are not ready for use in acute/critical care situations. Many are just electronic versions of the paper-based health record notebooks that patients have used for years. They have, however, great promise and, with further development, could form the basis of a new medical record system that could contribute to improving the quality of medical care.

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.

Four-channel sleeve catheter for prolonged measurement of lower esophageal sphincter pressure.

A sleeve catheter capable of monitoring the lower esophageal sphincter (LES) pressure in four quadrants at right angels has been developed. The present study used this four-quadrant sleeve catheter to assess radial asymmetry in LES in the supine, prone, and upright positions. The results in 37 normal subjects were compared with those of a conventional side-hole catheter and a Dent sleeve catheter. In vitro studies showed that the response rate of each radially oriented sleeve is comparable to the Dent sleeve. Mean pressures were not significantly different between the three different types of catheter. The four-quadrant sleeve catheter consistently detected a higher LES pressure in the left posterior position, regardless of body position. The four quadrant sleeve catheter can be used to record LES pressure from four different quadrants of the LES for prolonged periods.

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.

Lower esophageal sphincter measurement in four different quadrants in normals and patients with achalasia.

In order to determine the endoluminal pressure force distribution, the pressure in the lower esophageal sphincter (LES) and esophageal body was recorded in healthy volunteers and patients with achalasia, using a new waterperfused circular four-channel-sleeve (FCS) manometry catheter. The median lower esophageal sphincter pressure (LESP) and interquartile range in healthy control subjects (group 1) was significantly higher in the left lateral quadrant: 37 (28-43) mmHg (channel III) (P < 0.001), in comparison to the right lateral: 24 (20-25) mmHg (channel I), anterior: 22 (18-30) mmHg (channel II), and posterior quadrant: 24 (22-28) mmHg (channel IV). The median LESP in achalasic patients (group 2) was significantly increased in channel I: 31 (27-36) mmHg, channel II: 35 (28-39) mmHg, and in channel IV: 29 (26-237) mmHg (P < 0.001) when compared to controls. The detected pressure of the left lateral quadrant of the LES was not found to be significantly different from controls: 38 (29-39) mmHg. The median contraction amplitude of healthy subjects was significantly higher when compared with achalasic patients (P < 0.001). In patients with achalasia (group 2) the median contraction amplitude of the proximal esophagus was significantly higher than the distal contraction amplitude. In contrast, healthy volunteers showed a reverse relationship. No asymmetric pressure force was detected with the FCS in the proximal or distal esophageal body in either group. In conclusion, the abolition of the normal manometric LES asymmetry in patients with achalasia might indicate regional variations of muscle functions in the high pressure zone of the gastroesophageal junction (GEJ).

[Achalasia: botulinus toxin, interventional balloon dilatation, myotomy?]. / Achalasie: Botulinustoxin--Ballon-laparoskopische Myotomie?

67 patients with achalasia were treated either medically, endoscopically or surgically from 1987 to 1997 in the Department of Surgery of the University of Tübingen. 27/67 (40%) of the patients, who were pneumatically dilatated, had a very successful therapy within the first year after dilatations. 12/67 (17%) of the patients had good results with a dysphagia score less than 1 after dilatations within the first year. The perforation rate of interventionally treated patients was 1.4% without any surgical procedure. Open myotomy according to Heller was performed in 28 of 67 patients (41%); after 1993 a laparoscopic procedure was performed in all patients. The average hospitalization for MIC was 5.4 days. The manometric control investigations showed a decrease of the basal LES pressure from preoperative values. When evaluated manometrically 87% showed good results in the follow up time of at least 24 months. 14% of those who underwent surgery had to be endoscopically dilatated after surgery.

[Differential achalasia therapy]. / Differentialtherapie der Achalasie.

The early relief of esophageal outflow obstruction in patient with achalasia diminishes complaints and avoids deterioration as a result of this disease. The pneumatic myotomy of the lower esophageal sphincter is the initial therapeutic concept. After two unsuccessful dilations, the laparoscopic myotomy with semifundoplication shows the best long-term results in the treatment of achalasia with fewer complications.

Strongyloidiasis. The protean parasitic infection.

To turn a well-known phrase regarding history, those who forget to diagnose strongyloidiasis will be condemned to rediscover it. The often protean manifestations of this disease cannot be emphasized enough. The parasite's unique life cycle enables it to live for decades in an unsuspecting host, presenting with symptomatic disease only occasionally. Making a definitive diagnosis may be difficult and requires persistence. A good history should reveal whether a patient belongs to a high-risk group. The physician should strongly suspect the diagnosis when nonspecific cutaneous, pulmonary, and gastrointestinal symptoms coexist. Unexplained enteric bacteremia or meningitis may be important clues to diagnosing disseminated disease, which carries a high mortality rate. Therapy is available, and advances are being made to make it more tolerable. Follow-up for eradication is laborious yet essential: In patients at high risk for disseminated disease, invasive procedures may be warranted to prove eradication. Incomplete therapy puts the patient at further risk for significant complications in the future.

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.

Efficacy dose determination study of tilmicosin phosphate in feed for control of pneumonia caused by Actinobacillus pleuropneumoniae in swine.

OBJECTIVE: To determine the effective dosage of tilmicosin phosphate when fed to pigs for the control of pneumonia attributable to Actinobacillus pleuropneumoniae. DESIGN: Randomized complete block design, with initial weight as the blocking factor. ANIMALS: Seeder pigs were used to infect clinically normal male and female pigs weighing between 13.6 and 36.3 kg at each of 4 trials. PROCEDURE: Five doses of tilmicosin phosphate (0, 100, 200, 300, and 400 micrograms/g) were fed to pigs for 21 days. Pigs received experimental feeds 7 days before the seeder pigs were placed into pens. Feeding continued for an additional 14 days, with seeder pigs removed 3 to 8 days after placement. All pigs were euthanatized and necropsied, with lung bacterial flora and percentages of pneumonic involvement determined. RESULTS: Improvement in clinical impression score, daily rectal temperature, and weight gain were seen for all doses of tilmicosin, compared with controls. For the same variables, tilmicosin administered at 200 to 400 micrograms/g resulted in improvements over the 100 micrograms/g dose. CONCLUSIONS: Data indicate that tilmicosin phosphate fed to pigs at 200 to 400 micrograms/g is effective in controlling and preventing A pleuropneumoniae-induced pneumonia, when administered in feed for 21 days.

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.

Biomaterials with permanent hydrophilic surfaces and low protein adsorption properties.

Low protein adsorbing polymer films have been prepared with which to fabricate intravenous containers, designed for compatibility with low concentrations of protein drugs. The material is economically manufactured utilizing physical melt blending of water-soluble surface-modifying polymers (PEO, PEOX, PVA, and PNVP) with a base polymer (EVA, PP, PETG, PMMA, SB, and nylon). Permanency of the hydrophilic surfaces so generated was confirmed by surface contact angle experiments and total organic carbon leachables analysis of the aqueous contacting solutions. Binding of IgG, albumin and insulin was studied. A sixfold reduction of protein adsorption was obtained by adding 5% PVA13K to EVA, for IgG at a bulk concentration of 2.5 ppm. Surface bound protein measured by micro-BCA colorimetry, agreed with the solution protein lost, as determined by the Fluoraldehyde procedure. Imaging of the protein exposed plastic surfaces by silver enhanced protein conjugated gold staining agreed with the quantitative assay determinations.