Activities of Pu and Am isotopes and isotopic ratios in a soil contaminated by weapons-grade plutonium.

An accident and fire at the former McGuire Air Force Base and Boeing Michigan Aeronautical Research Center (BOMARC) site in New Jersey resulted in dispersion of weapons-grade plutonium in particulate form to the local environment. Soil samples collected at the BOMARC site were measured for their activities and isotopic ratios of Pu and Am isotopes by radioanalytical techniques. The activities of the Pu and Am isotopes in the BOMARC soil were markedly higher than fallout levels, and they decreased nearly exponentially with increasing particle size of the soil. The measured (241)Am activity was compared to calculated values based on decay of (241)Pu. The activity ratios of (238)Pu/(239,240)Pu, (241)Pu/(239,240)Pu, and (241)Am/(239,240)Pu observed in the BOMARC soil were much lower than those attributed to nuclear reprocessing plants and Chernobyl fallout. From the activity ratios of (241)Pu/(239,240)Pu and (241)Am/(239,240)Pu, the origin of the Pu isotopes was identified as weapons-grade and the time since production of the material was estimated. Furthermore, the atomic ratio of (240)Pu/(239)Pu in the BOMARC soil was remarkably lower than the fallout value influenced by nuclear weapons testing and the Chernobyl accident. The atomic ratio of (240)Pu/(239)Pu was very close to the value of the weapons-grade Pu detected from the Thule accident in Greenland. This work demonstrates the utility of radioanalytical measurements and decay calculations for defining characteristics of the source term and discriminating multiple processes that contribute to a source. Such an approach would also be needed to respond to a terrorist event involving an improvised nuclear device or radiological dispersal device.

Flow-through sequential extraction approach developed from a batch extraction method.

Sequential extractions of contaminants from a soil or sediment have been shown to be cost-effective contaminated site assessment tools that provide information on contaminant partitioning within an environmental matrix. Such information is necessary for defining remediation alternatives and mitigation strategies. The typical sequential extraction approach involves a batch method, and known limitations include the possibility of contaminant readsorption to the remaining soil or sediment In this work, a flow-through reactor was constructed and tested for application in a sequential extraction scheme. The sequential extraction scheme used was one developed for actinide-contaminated materials. The flow-through approach gave partitioning results that were similar to the batch method for uranium. We also monitored the extraction of stable Ca, K, Fe, Al, Zr, and Sc and obtained partitioning results generally similar to those observed with the batch extraction, except for Ca. Our results indicate readsorption of Ca when using a batch approach is small but significant and is eliminated with our new flow-through method. A limitation of the flow-through method is the possibility of underextraction of certain phases and higher analytical uncertainties. These uncertainties are more difficult to minimize, as compared to the uncertainty obtained with a batch approach.

Chromatographic separation and characterization of hydrolyzed Cr(III) species.

Both macroscale and microscale methods to separate hydrolyzed Cr(III) species from acidic to near-neutral pH solutions have been developed. The macroscale approach is based on ion exchange, and involves separating monomeric, dimeric, trimeric, tetrameric, and higher order Cr(III) oligomers from such solutions using a gradient elution with increasing cationic charge. With this approach, the concentration of a given fraction can be maximized, and complete resolution between these species can be achieved. In addition, complete recovery of Cr(III) from the column is achievable. For the microscale approach, capillary electrophoresis with indirect detection is used to isolate and uniquely identify the same smaller oligomers and a fraction of larger Cr(III) species that are not uniquely identified. Capillary electrophoresis also provides indirect structural information for the Cr(III) trimer, suggesting that it exists in a triangular configuration rather than as a linear species. These methods are described in detail, and possible applications are discussed.

Squamous mucosal alterations in esophagectomy specimens from patients with end-stage achalasia.

Achalasia is an esophageal motor disorder in which the primary morphologic changes are found in the myenteric plexus. However, a number of secondary alterations are characteristically found in esophagectomy specimens, including the mucosa. In addition, these patients are at increased risk of developing esophageal squamous cell carcinoma. We studied the squamous mucosal alterations in 35 esophagectomy specimens from patients with end-stage achalasia and compared them with those found in the squamous mucosa near the esophagogastric junction from pediatric autopsies (

Plutonium partitioning to colloidal and particulate matter in an acidic, sandy sediment: implications for remediation alternatives and plutonium migration.

Plutonium partitioning within a bulk, freshwater sediment and to specific size fractions of the sediment was determined. Fission track analysis was used to observe the spatial heterogeneity of fissile isotopes of Pu and U in the sediment. For the bulk sediment, a six-step sequential extraction scheme was used to elucidate Pu partitioning. Although no direct Pu speciation is obtained from our sequential extraction scheme, this study demonstrates that the partitioning information obtained is more useful for evaluating ex-situ remediation treatments than information obtained from complete digestion and analysis of the bulk sediment. The majority of 238Pu and 239 + 240Pu appear to be partitioned in the oxidizable fraction, suggesting that Pu is primarily associated with organic matter in the bulk sediment or may exist as a discrete, oxidizable phase. By varying filter pore size used to separate the sequential extraction leachate solution from the remaining solid phase, a fraction of 238Pu associated with colloidal material was observed, and chemical evidence suggests that this colloidal material is relatively refractory. Pu partitioning to various size fractions of the bulk sediment was also compared to the percent organic carbon present in those size fractions. Interestingly, little correlation was observed between the percentage of organic carbon and concentrations of Pu isotopes in the various size fractions, although differences were observed in the distributions of 238Pu versus 239 + 240Pu in the size fractions. These results suggest that other sediment phases may also be important for Pu partitioning. Our observations are described in the context of feasibility of various remediation options.

Breast biopsy avoidance: the value of normal mammograms and normal sonograms in the setting of a palpable lump.

PURPOSE: To review the authors' experience with patients who presented with breast lumps and had normal mammograms and normal sonograms. MATERIALS AND METHODS: The findings from 600 lumps in 486 women with no focal ultrasonographic (US) mass or mammographic finding in the area of clinical concern were retrospectively studied. Evaluated parameters included the individual reporting the lump, qualitative descriptors for the physical finding, mammographic density, US characteristics in the area of concern, whether there was a change in imaging and/or physical examination results, and whether there were diagnostic biopsy findings at follow-up. The study group included 540 lumps in 435 women who had a minimum mammographic and clinical follow-up of 2 years, as well as 60 additional lumps in 51 patients who underwent biopsy. RESULTS: No patient in the nonbiopsy group developed carcinoma at the initial site of concern during a mean mammographic and clinical follow-up period of 43 months, and all biopsy specimens were benign (negative predictive value, 100%). CONCLUSION: Results of this retrospective study suggest that breast biopsy may be avoided in women with palpable abnormalities when both US and mammography depict normal tissue at the lump site.

Phase II trial of neoadjuvant estramustine and etoposide plus radical prostatectomy for locally advanced prostate cancer.

OBJECTIVES: To report the results of a Phase II trial of neoadjuvant estramustine and etoposide before radical prostatectomy in patients with locally advanced disease. METHODS: Treatment consisted of three cycles of estramustine (10 mg/kg/day) and etoposide (50 mg/m(2)/day) orally on days 1 through 21, repeated every 28 days, followed by radical prostatectomy. The eligibility criteria included locally advanced prostate cancer (clinical Stage T2b/c or T3, prostate-specific antigen [PSA] level of 15 ng/mL or greater, or Gleason score of 8 or higher) without evidence of metastatic disease. The median PSA level was 14 ng/mL (range 5.3 to 50), the median Gleason score was 7 (range 6 to 9), and 44% had Stage T2b/c or T3 disease. The primary endpoint was feasibility of neoadjuvant therapy and radical prostatectomy, including drug and surgery-related toxicities. Secondary endpoints included the pre-prostatectomy PSA level, local response, pathologic outcomes, and time to PSA failure. RESULTS: Eighteen patients were entered and completed all three cycles of therapy, and 16 (89%) underwent radical prostatectomy. A local response occurred in 15 (94%) of 16 patients with palpable tumors, and the serum PSA reached undetectable levels after therapy and before radical prostatectomy in 9 patients (50%). Five patients (28%) experienced grade 3 toxicity (two with deep venous thrombosis, two with neutropenia, and one with diarrhea) and one (6%) experienced grade 4 toxicity (pulmonary embolus) before surgery. The median operative time was 125 minutes, the mean blood loss was 665 mL, and the mean length of stay was 2.5 nights. Five minor surgical complications occurred in 4 patients. The pathologic analysis demonstrated residual carcinoma with squamous metaplasia and androgen deprivation effect in all patients. Five patients (31%) had organ-confined disease and 9 patients (56%) had specimen-confined disease. All patients achieved an undetectable PSA level postoperatively and at a median follow-up of 14 months (range 5 to 20) and without additional therapy, all 14 patients with negative lymph nodes were disease free. CONCLUSIONS: This trial confirms the feasibility of radical prostatectomy with acceptable surgical morbidity after neoadjuvant therapy with estramustine and etoposide in patients with locally advanced prostate cancer. However, this regimen is associated with estramustine-induced thromboembolic toxicity. The results of the pathologic analysis suggest a higher than expected rate of organ-confined and specimen-confined disease, but little histologic evidence of antitumor effect beyond that associated with androgen deprivation. Additional study of this paradigm with other drug regimens is warranted.

Transcostovertebral approach for thoracic disc herniations.

OBJECT: The authors describe a new posterolateral transcostovertebral approach for the removal of herniated thoracic discs. METHODS: From January 1994 to January 2000, 28 thoracic discs in 22 patients were excised via a new transcostovertebral surgical approach. Seventeen patients (77%) presented with axial pain, 14 (64%) with radicular pain, 13 (59%) with myelopathy, eight (36%) with sensory loss, and 10 (45%) with genitourinary (GU) symptoms such as urinary hesitancy or incontinence. The affected discs were approached using a midline incision to gain access of the costovertebral junction. The surgical corridor was posterolateral; the costovertebral joint and lateral edge of the vertebral endplates were drilled to expose the lateral annulus. The ribs were preserved, obviating the need for insertion of a chest tube postoperatively. The average operating time per level was 200.5 minutes (range 90-360 minutes). The average blood loss was 231 ml (50-750 ml). The average length of stay was 3.8 days. Most patients were discharged home on postoperative Day 2 or 3. No patients were worse postoperatively. Improvement was demonstrated in 13 (76%) of 17 patients with axial pain, 11 (79%) of 14 patients with radicular pain, 11 (85%) of 13 patients with myelopathy, seven (88%) of eight patients with sensory loss, and six (60%) of 10 patients with GU symptoms. CONCLUSIONS: This procedure is well suited for any thoracic disc level and offers several advantages over the traditional costotransversectomy or transthoracic approaches: shorter operating time, less blood loss, less extensive soft-tissue and bone dissection, reduced postoperative pain, and shorter hospital stays.

The nature of the myenteric infiltrate in achalasia: an immunohistochemical analysis.

Achalasia is an esophageal motor disorder characterized by abnormal relaxation of the lower esophageal sphincter and absence of progressive peristalsis in the esophageal body. Previous studies evaluating esophagomyotomy and esophageal resection specimens have shown the presence of myenteric inflammation to be a consistent and early pathologic change in patients with achalasia. Thus, the goal of this study was to determine the immunohistochemical characteristics of the inflammatory infiltrate within the myenteric plexus in patients with clinically early and end-stage achalasia. Using formalin-fixed tissue, we analyzed the immunohistochemical features of the myenteric lymphocytes using antibodies that recognize B cells (CD20), T cells (CD3), T cell subsets (CD8), and the activation state of T cell subpopulations (TIA-1 and granzyme B) in nine patients with clinically early achalasia who underwent esophagomyotomy and 13 patients with clinically endstage achalasia who underwent esophageal resection. The myenteric infiltrate in all nine esophagomyotomy specimens was composed predominantly of T cells (CD3-positive), the majority of which also stained for CD8. In five of nine specimens, the majority of CD8-positive cells stained for TIA-1. In the esophageal resection specimens, the myenteric infiltrate was composed predominantly of CD3-positive T cells in seven of 13 cases. In three cases, there was a predominance of CD20-positive B cells, and in the remaining three cases there were relatively equal numbers of T and B cells. In eight of 13 cases, the majority of T cells stained for CD8. TIA-1 immunoreactivity was found in the majority of CD8-positive cells in nine of 13 cases. In all esophagomyotomy and esophageal resection specimens studied, rare granzyme B-positive cells were detected. In conclusion, the majority of myenteric inflammatory cells in patients with achalasia are CD3-positive T cells, most of which are also CD8-positive, although the relative percentage of such cells appears to decrease with disease progression. Furthermore, many of the CD3-positive/CD8-positive myenteric lymphocytes also express TIA-1, suggesting they are resting or activated cytotoxic T cells. The immunohistochemical demonstration of granzyme B in a subpopulation of these cells supports the contention that achalasia is an immune-mediated disease, although the inciting antigen remains an enigma.

Intracanalicular meningioma.

Intracanalicular meningiomas are extremely rare and difficult to differentiate from intracanalicular vestibular schwannomas. We report an unusual case of a posterior fossa meningioma in the proximal internal auditory canal that was originally diagnosed as a vestibular schwannoma due to its appearance on magnetic resonance imaging. However, closer inspection of the preoperative neuroimages revealed features inconsistent with vestibular schwannoma that suggested the possibility of other less common lesions.

Confirmation of gentamicin and neomycin in milk by weak cation-exchange extraction and electrospray ionization/ion trap tandem mass spectrometry.

A new procedure for the confirmation of two aminoglycoside antibiotics in milk was developed and validated. This work is among the early applications of ion trap mass spectrometry for regulatory methodology, and it incorporates a novel weak cation-exchange extraction. The procedure was validated for the confirmation of both gentamicin and neomycin at 30 ng ml(-1) and above. Milk is first treated with acid and centrifuged. The supernate, excluding the fat layer, is buffered with sodium citrate to neutral pH. The extract is applied to a weak cation-exchange solid-phase extraction column. Aminoglycosides are eluted with acidified methanol. Following separation by ion-pair liquid chromatography, analytes are ionized with an electrospray interface. Protonated molecular ions are selectively stored in an ion trap mass spectrometer, then collisionally dissociated to yield unique product ion spectra. Confirmation is based on matching spectral responses between samples and comparison standards consisting of a bona fide standard spiked into control extracts. Method performance was demonstrated with replicate samples of control milk, fortified milk, and milk containing incurred residues of each compound.

Preoperative Multidimensional Affect and Pain Survey (MAPS) scores predict postcolectomy analgesia requirement.

OBJECTIVES: One aim of this study was to evaluate the relation of scores on the Multidimensional Affect and Pain Survey (MAPS) that was administered before surgery to postoperative morphine consumption and patient-controlled analgesia. A second aim of the study was to compare the ability of MAPS administered postsurgery with the commonly used Numerical Pain Rating Scale to predict patient-controlled analgesia behavior. DESIGN: The MAPS questionnaire measures pain, suffering, and well-being. It was administered to patients 1 day before and 1 day after left hemicolectomy for colon cancer. The relations of the two scores to postoperative pain control were determined. PATIENTS: Thirty-four patients in the surgical ward of a general hospital admitted for colorectal cancer surgery participated in this study. RESULTS: High preoperative MAPS scores on sensory and emotional words predicted postoperative morphine dosage, dose presses, and lockout presses. Greater morphine consumption was correlated positively with high presurgery MAPS scores in four of the eight "Suffering" subclusters (Depressed Mood, Anger, Anxiety, and Fear). High presurgery MAPS scores in 13 of the 17 "Sensory Qualities" subclusters (e.g., Bothersome, Intense Pain, Pain Extent, Incisive Pressure, Traction/Abrasion) were correlated positively with lockout presses. Neither the postsurgery MAPS nor the postsurgery Numerical Pain Rating Scale predicted patient-controlled analgesia behavior. CONCLUSION: The emotional states and attitudes of the patients toward pain before surgery are important factors in determining patient-controlled analgesia pressing behavior and postoperative demand for analgesics.

Esophagectomy with gastric reconstruction for achalasia.

PURPOSE: Achalasia is a degenerative esophageal disorder that may result in esophageal failure necessitating resection for restoration of gastrointestinal function. This study evaluates a protocol of esophageal resection and gastric reconstruction for end-stage achalasia. METHODS: Hospital records, radiographic studies, and resection specimens of patients undergoing esophagectomy and gastric reconstruction were reviewed. Patient outcome was defined by an evaluation of symptoms (early satiety, dysphagia, regurgitation, and reflux), dietary restrictions, and ability to maintain or gain weight. Preoperative, operative, and postoperative variables and pathologic features in the resection specimens were analyzed to determine predictors of outcome. RESULTS: In a 10-year period, 32 patients underwent esophagectomy with gastric reconstruction for achalasia; 30 (94%) underwent elective surgery and 2 (6%), emergency surgery. No postoperative deaths occurred. Of 29 patients completing telephone interviews, 24 (83%) had no or mild dysphagia; 21 (72%), no or mild regurgitation; 20 (69%), no or mild reflux; and 19 (66%), no or mild early satiety. Twenty-four (83%) patients had no or minimal dietary restrictions; 26 (90%) had no or minimal social dietary restrictions. Postoperative weight was not different from preoperative weight. Of 30 patients, 26 (87%) felt better after esophagectomy and 25 (83%) would have the operation again. There were few predictors of outcome. Younger patients were more likely to have dysphagia ( P =.03). CONCLUSIONS: Esophagectomy with gastric reconstruction relieves preoperative dysphasia and regurgitation in the majority of patients. Dietary function and weight maintenance are excellent, attesting to the durability of the procedure in patients with end-stage achalasia.

Manometric study of the voluntary inhibition action in normal volunteers.

PURPOSE: A voluntary inhibition action whereby a voluntary squeeze of the external sphincter causes reflex relaxation of the rectum has been previously proposed but not proven. Such a reflex would enable the subject to defer defecation to a socially acceptable time. The purpose of this study was to determine whether or not such a reflex exists. METHODS: We measured rectal compliance with and without a voluntary squeeze using a specially designed balloon catheter in nine subjects. RESULTS: When corrected for increased intra-abdominal pressure caused by inadvertent Valsalva's maneuver during voluntary squeezing, there was a significant increase in rectal compliance during voluntary contraction of the external sphincter (P < 0.01). CONCLUSION: This lends support to the proposed existence of the voluntary inhibition action.

Open label study of long-term effectiveness of cisapride in patients with idiopathic gastroparesis.

Cisapride induces acetylcholine release in cells of the myenteric plexus, thus promoting gastrointestinal motility. We studied the effects of cisapride on 11 patients with idiopathic gastroparesis. All had negative gastrointestinal endoscopy, normal glucose, and took no drugs capable of influencing motility. Most (9/11) were prior metoclopramide treatment failures. Patients' symptoms were scored (0-60) for pain, satiety, bloating, nausea, vomiting, and heartburn. All underwent a solid gastric emptying study using a Technetium-99-labeled egg meal and received placebo prior to cisapride. There were 10 females and one male with a mean (+/- SE) age of 37.8 +/- 2.6 years. Disease duration was 7.9 +/- 2.8 years. The dose of cisapride was 30-60 mg/day and the duration of therapy was 12.6 +/- 2.6 months (range 2.5-25 months). The symptom score improved on cisapride from 30.9 +/- 3.6 to 14.4 +/- 2.7 (P < 0.002 signed rank test). Emptying half-time improved from 113 +/- 4 min to 94 +/- 6 min, and 46.9 +/- 2.4% food remaining at 120 min decreased to 35.5 +/- 3.6% (both P < 0.05). Emptying half-time in normals was 68 +/- 5 min with 16.9 +/- 2.9% remaining at 120 min. Nine of 11 patients gained weight, with a mean increase of 6.7 +/- 1.6 lb (range 2-12 lb). We conclude that cisapride significantly reduces gastrointestinal symptoms and promotes weight gain in patients with idiopathic gastroparesis and is associated with improvement in solid gastric emptying. The drug is useful in patients who previously failed metoclopramide.

A comparison of lipoprotein secretion, bile production and hepatic morphology in isolated rat livers perfused with a perfluorocarbon emulsion or rat erythrocytes.

Isolated rat livers were perfused with an oxygenated perfluorocarbon emulsion, FC-43 emulsion for 1 to 4 hr. FC-43 emulsion contained 20% FC-43 (wt/vol) perfluorotributylamine (the fluorocarbon component for the transport of oxygen and carbon dioxide) emulsified with 2.56% Pluronic F-68 (a nonionic surfactant) in Krebs-Ringer bicarbonate buffer. FC-43 emulsion also contained 3% hydroxyethyl starch as an oncotic agent and 1.8 mg/ml glucose. The viability (oxygen consumption), bile secretion, structural integrity and secretion of nascent lipoproteins by FC-43-perfused rat livers was compared with livers perfused with Krebs-Henseleit bicarbonate buffer that contained rat erythrocytes (25% hematocrit) and 1.5 mg/ml glucose (red blood cell medium). Oxygen consumption was somewhat higher in livers perfused with FC-43 emulsion. Bile secretion of livers perfused with FC-43 emulsion for 4 hr was reduced significantly to 40% of that by red blood cell medium. The structural integrity of livers perfused with FC-43 emulsion varied from normal to marked cellular damage. Light-microscopical examination of rat livers perfused with FC-43 emulsion showed ballooning of sinusoids, presence of vacuoles in sinusoidal lining cells in some hepatocytes and detachment of endothelium in sinusoids. The number of vacuoles progressively increased in longer perfusions. Electron-microscopical studies showed the presence of small (60 to 100 nm) vesicles of varying electron density, presumably fluorocarbon particles inside the vacuoles in sinusoidal lining cells (Kupffer and endothelial) and hepatocytes. After 4 hr of perfusion with FC-43 emulsion, most of the sinusoidal endothelia were denuded, and the microvilli of the hepatocytes all but disappeared. In contrast, the ultrastructure of rat livers perfused with red blood cell medium for 4 hr was unaltered. The accumulation of nascent lipoproteins in perfusates of FC-43-perfused livers was markedly reduced, and no normal very-low-density lipoprotein, low-density lipoprotein or high-density lipoprotein were isolated. Chemical analysis showed the presence of Pluronic F-68 in all lipoprotein fractions. Our data strongly suggest that, during recirculating liver perfusions with FC-43 emulsion (between 1 and 4 hr), the nonionic surfactant detergent Pluronic F-68 dissociated from the emulsion and markedly affected hepatic structure, lipoprotein secretion and the composition of lipoproteins isolated from perfusate. Therefore FC-43 emulsion is not a suitable liver-perfusion medium for studies of lipoprotein metabolism.

Triolein-phosphatidylcholine-cholesterol emulsions as substrates for lipoprotein and hepatic lipases.

Lipolysis of emulsified glycerol tri[9,10-3H]oleate by lipoprotein lipase purified from bovine milk (E.C.3.1.1.34) and by hepatic lipase purified from rat liver perfusate was studied as a function of the phosphatidylcholine molecular species and the cholesterol content of the emulsions. Overall, the activities of the two enzymes were similar on a molar basis. Lipoprotein lipase initial lipolysis rates also were comparable for emulsions made with egg phosphatidylcholine or with saturated (dimyristoyl, dipalmitoyl and distearoyl) phosphatidylcholines when cholesterol was low. Increasing the cholesterol content of the emulsion from 2-3 mole percent to 7-14 mole percent reduced triolein lipolysis by lipoprotein lipase in emulsions made with saturated phosphatidylcholines. Rat hepatic lipase was more sensitive to increased cholesterol in emulsions made with saturated phosphatidylcholines than was lipoprotein lipase. The ability to maintain triolein lipolysis during longer incubations differed strikingly among the emulsions and for the two enzymes. Lymph chylomicrons were better substrates for both enzymes than any of the emulsions.