A new method for determining gastric acid output using a wireless pH-sensing capsule.

BACKGROUND: Gastro-oesophageal reflux disease (GERD) and gastric acid hypersecretion respond well to suppression of gastric acid secretion. However, clinical management and research in diseases of acid secretion have been hindered by the lack of a non-invasive, accurate and reproducible tool to measure gastric acid output (GAO). Thus, symptoms or, in refractory cases, invasive testing may guide acid suppression therapy. AIM: To present and validate a novel, non-invasive method of GAO analysis in healthy subjects using a wireless pH sensor, SmartPill (SP) (SmartPill Corporation, Buffalo, NY, USA). METHODS: Twenty healthy subjects underwent conventional GAO studies with a nasogastric tube. Variables impacting liquid meal-stimulated GAO analysis were assessed by modelling and in vitro verification. Buffering capacity of Ensure Plus was empirically determined. SP GAO was calculated using the rate of acidification of the Ensure Plus meal. Gastric emptying scintigraphy and GAO studies with radiolabelled Ensure Plus and SP assessed emptying time, acidification rate and mixing. Twelve subjects had a second SP GAO study to assess reproducibility. RESULTS: Meal-stimulated SP GAO analysis was dependent on acid secretion rate and meal-buffering capacity, but not on gastric emptying time. On repeated studies, SP GAO strongly correlated with conventional basal acid output (BAO) (r = 0.51, P = 0.02), maximal acid output (MAO) (r = 0.72, P = 0.0004) and peak acid output (PAO) (r = 0.60, P = 0.006). The SP sampled the stomach well during meal acidification. CONCLUSIONS: SP GAO analysis is a non-invasive, accurate and reproducible method for the quantitative measurement of GAO in healthy subjects. SP GAO analysis could facilitate research and clinical management of GERD and other disorders of gastric acid secretion.

Noise reduction in oncology FDG PET images by iterative reconstruction: a quantitative assessment.

UNLABELLED: Tumor detection depends on the contrast between tumor activity and background activity and on the image noise in these 2 regions. The lower the image noise, the easier the tumor detection. Tumor activity contrast is determined by physiology. Noise, however, is affected by many factors, including the choice of reconstruction algorithm. Previous simulation and phantom measurements indicated that the ordered-subset expectation maximization (OSEM) algorithm may produce less noisy images than does the usual filtered backprojection (FBP) method, at equivalent resolution. To see if this prediction would hold in actual clinical situations, we quantified noise in clinical images reconstructed with both OSEM and FBP. METHODS: Three patients (2 with colon cancer, 1 with breast cancer) were imaged with FDG PET using a "gated replicate" technique that permitted accurate measurement of noise at each pixel. Each static image was acquired as a gated image sequence, using a pulse generator with a 1-s period, yielding 40 replicate images over the 10- to 15-min imaging time. The images were or were not precorrected for attenuation and were reconstructed with both FBP and OSEM at comparable resolution. From these data, images of pixel mean, SD, and signal-to-noise ratio (S/N) could be produced, reflecting only noise caused by the statistical fluctuations in the emission process. RESULTS: Noise did not vary greatly over each FBP image, even when image intensity varied greatly from one region to the next, causing S/N to be worse in low-activity regions than in high-activity regions. In contrast, OSEM had high noise in hot regions and low noise in cold regions. OSEM had a much better S/N than did FBP in cold regions of the image, such as the lungs (in the attenuation-corrected images), where improvements in S/N averaged 160%. Improvements with OSEM were less dramatic in hotter areas such as the liver (averaging 25% improvement in the attenuation-corrected images). In very hot tumors, FBP actually produced higher S/Ns than did OSEM. CONCLUSION: We conclude that OSEM reconstruction can significantly reduce image noise, especially in relatively low-count regions. OSEM reconstruction failed to improve S/N in very hot tumors, in which S/N may already be adequate for tumor detection.

Alendronate does not interfere with 99mTc-methylene diphosphonate bone scanning.

UNLABELLED: Several studies have found that administration of etidronate results in competitive interference with 99mTc-labeled bone scanning reagents. In contrast, in other studies this problem was not encountered with other bisphosphonates. METHODS: We prospectively studied 9 patients with hormone-refractory prostate cancer. 99mTc-methylene diphosphonate (MDP) bone scanning was performed before they received alendronate, and scanning was repeated a mean of 16.6 d afterward, when the patients had been receiving 40 mg alendronate daily for a mean of 6 d. In addition, 7 patients who underwent delayed scanning when they had been receiving alendronate for a mean of 111 d were also restudied. Quantitative whole-body bone scanning was performed, and radioactivity deposited in the bone metastasis was determined using region-of-interest analysis. RESULTS: A <6% increase in whole-body retention of 99mTc-MDP was seen on the initial postalendronate scan compared with the baseline scan. No significant differences in activity were seen in the bone lesion evaluated on the baseline and initial postalendronate studies. The delayed postalendronate scan generally showed similar or higher tracer accumulation compared with the baseline scan. CONCLUSION: Alendronate did not competitively inhibit uptake of 99mTc-MDP in the skeleton or tumor metastasis. Use of alendronate before bone scanning is unlikely to result in decreased detection of lesions or falsely decreased 99mTc-MDP activity at metastatic bone tumor sites.

A prospective study of 2-[18F] fluoro-2-deoxy-D-glucose/positron emission tomography scan, 99mTc-labeled arcitumomab (CEA-scan), and blind second-look laparotomy for detecting colon cancer recurrence in patients with increasing carcinoembryonic antigen levels.

BACKGROUND: An increasing carcinoembryonic antigen (CEA) level in the absence of disease on imaging studies can present a diagnostic challenge. We evaluated 2-[18F] fluoro-2-deoxy-D-glucose and positron emission tomography (FDG-PET) scan and CEA scan before second-look laparotomy as a means of localizing recurrent colorectal cancer. METHODS: Patients underwent computed tomography scan, bone scan, colonoscopy, and magnetic resonance imaging, and those without evidence of disease or resectable disease in the abdomen had FDG-PET and CEA scans. At second-look laparotomy, a surgeon blinded to the results of the FDG-PET and CEA scans performed an exploration and mapped findings. A second surgeon, with knowledge of the FDG-PET and CEA scans, then explored the patient; all lesions were biopsied or resected for pathology. RESULTS: In 28 patients explored, disease was found at operation in 26 (94%). Ten had unresectable disease. FDG-PET scans predicted unresectable disease in 90% of patients. CEA scans failed to predict unresectable disease in any patient. In 16 patients found to have resectable disease or disease that could be treated with regional therapy, FDG-PET scan predicted this in 81% and CEA scan in 13%. CONCLUSIONS: FDG-PET scan can predict those patients who would likely benefit from a laparotomy. If the FDG-PET scan indicates resectable disease, laparotomy can be considered. However, if the findings predict unresectable disease or the absence of disease, the patient should pursue systemic therapy or continued observation.

Parametric images of blood flow in oncology PET studies using [15O]water.

UNLABELLED: PET was used to measure tumor blood flow, which is potentially valuable for diagnosis and assessing the effects of therapy. To help visualize regional differences in blood flow and to improve the accuracy of region-of-interest placement, a parametric imaging approach was developed and compared with the standard region-of-interest method. METHODS: Five patients with renal cell metastases in the thorax were studied using [15O]water and dynamic PET. To assess the reproducibility of the blood flow measurements, multiple water studies were performed on each patient. Model fitting was done on a pixel-by-pixel basis using several different formulations of the standard single-compartment model. RESULTS: The tumors studied spanned a wide range of blood flows, varying from 0.4 to 4.2 mL/min/g. These values were generally high compared with those of most other tissues, which meant that the tumors could be readily identified in parametric images of flow. The different model formulations produced images with different characteristics, and no model was entirely valid throughout the field of view. Although tumor blood flow measured from the parametric images was largely unbiased with respect to a standard regional method, large errors were observed with certain models in regions of low flow. The most robust model throughout the field of view had only 1 free parameter and, compared with a regional method, gave rise to a flow bias of 0.3%+/-3.1% for tumor and 16%+/-11% for low-flow soft tissue (muscle plus fat). With this model, tumor blood flow was measured with an SD of 7.6%+/-4.0%. CONCLUSION: Parametric imaging provides a convenient way of visualizing regional changes in blood flow, which may be valuable in studies of tumor blood flow.

Imaging and phase I study of 111In- and 90Y-labeled anti-LewisY monoclonal antibody B3.

B3 is a murine monoclonal antibody (mAb) that recognizes a LewisY carbohydrate antigen present on the surface of many carcinomas. An imaging and Phase I trial was performed to study the ability of 111In-mAb B3 to image known metastasis and determine the maximum tolerated dose (MTD), dose-limiting toxicity (DLT), kinetics, and biodistribution of 90Y-mAb B3. Patients (n = 26) with advanced epithelial tumors that express the LewisY antigen were entered. All patients received 5 mCi of 111In-mAb B3 for imaging. 90Y-mAb B3 doses were escalated from 5 to 25 mCi in 5-mCi increments. 111In-mAb B3 and 90Y-mAb B3 were coadministered over a 1-h infusion. Definite tumor imaging was observed in 20 of 26 patients. Sites imaged included lung, liver, bone, and soft tissues. The MTD of 90Y-mAb B3 was determined to be 20 mCi. The DLTs were neutropenia and thrombocytopenia. Tumor doses ranged from 7.7 to 65.1 rad/mCi. 111In- and 90Y-mAb B3 serum pharmacokinetics (n = 23) were found to be similar. The amount of B3 administered (5, 10, and 50 mg) did not alter the pharmacokinetics. Bone marrow biopsies (n = 23) showed 0.0038+/-0.0016% of injected dose/gram for 111In-mAb B3 compared to 0.0046+/-0.0017% of injected dose/gram for 90Y-mAb B3 (P = 0.009). When given to patients with carcinomas that express the LewisY antigen, 111In-mAb B3 demonstrated good tumor localization. The MTD of 90Y-mAb B3 is 20 mCi, with myelosuppression as the DLT. Higher doses of radioactivity need to be delivered to achieve an antitumor effect. Humanized mAb B3 is being developed for evaluation in radioimmunotherapy. A clinical trial to explore the use of higher doses of 90Y-mAb B3 with autologous stem cell support is planned.

8:45-9:00. Using PET 18F-FDG, 11CO, and 15O-water for Monitoring Prostate Cancer During a Phase II Anti-angiogenic Drug Trial with Thalidomide.

Assessing prostate metastases is difficult with conventional radiographic modalities as few patients have soft tissue involvement and most have only bone lesions. Even with FDG PET, problems due to decreased avidity compared to other tumor types can occur. We assessed PET's ability to monitor changes in such tumors during an anti-angiogenic therapy. We measured changes in tumor blood flow (15O), blood volume (11CO), 18F-FDG uptake and "metabolic volume" before and during thalidomide treatment, to see if these changes correlated with changes in PSA values.Six patients with androgen-independent prostate cancer were imaged with 18F-FDG, 11CO, and 15O water before and during (mean interval 63 days, range 55-76 days) thalidomide therapy (200-1200mg/day). Lesions were visually identified on FDG images (9 bone, 5 soft tissue lesions). VOI's were generated by 3D region growing, with a 50% maximum pixel threshold. These VOI's were registered with, and applied to, the 11CO and water studies. Correlations with PSA values were done using the Spearman rank test.The change in maximum (r = 0.77, p = 0.06) and mean FDG value (r = 0.83, p = 0.03), functional FDG volume (r = 0.66, p = 0.14), and 11-CO blood volume (r = 0.77, p = 0.06) all correlated with the change in PSA. Changes in blood flow values were smaller than the variance of the method for repeated measures, likely due to low flow values in bone.Changes in blood volume measured by 11CO, and the mean and peak activity and functional volume measured by 18F-FDG, correlate with changes in PSA and may be useful in monitoring anti-angiogenic therapy in prostate cancer.

Aminosyn II effectively blocks renal uptake of 18F-labeled anti-tac disulfide-stabilized Fv.

Because intact IgG has limitations as a tumor-imaging agent, radiolabeled Fv fragments are being evaluated. Due to the high renal accumulation of Fv fragments, methods to block renal uptake are being sought. This study evaluated how well Aminosyn II, a Food and Drug Administration-approved 15% amino acid solution, would block the renal accumulation of 18F anti-Tac disulfide-stabilized Fv (dsFv) fragments (small fragments with high renal uptake). The anti-Tac dsFv is directed against the alpha subunit of the interleukin 2 receptor. It was labeled at specific activities of 1.1-2.7 mCi/mg using N-succinimidyl 4-[18F]fluoromethyl benzoate. Four adult baboons were injected i.v. with 0.7-1.9 mCi and 150 microg of dsFv. Each baboon was preinjected with Aminosyn II i.v. and, on a separate occasion, with a control solution. Thirty min before injection of 18F-labeled anti-Tac dsFv, a bolus of either solution was given, followed by a constant infusion of 13.3 ml/kg/h. Quantitative positron emission tomography imaging was performed. The amino acid levels in serum were measured serially. The baseline levels of lysine (and other amino acids) in plasma were not significantly different in either the Aminosyn II or control infusion group and did not change during the control infusion. In the Aminosyn II group, lysine levels in plasma 5 min before anti-Tac dsFv infusion were 5-15 times higher than the baseline value and continued to rise during the infusion. The areas under the curve in blood of the 18F-labeled anti-Tac dsFv, from time of injection to end of imaging, expressed as percentage injected dose (%ID), were 28.94 +/- 4.05%ID x h/liter (mean +/- SD) for the control group and 32.09 +/- 11.15%ID x h/liter for the Aminosyn II group (P = 0.54). The peak concentration of 18F-labeled anti-Tac dsFv in the kidney of the controls was 24.53 +/- 4.34%ID; the value in the Aminosyn II group was 5.39 +/- 1.89%ID, representing a mean decrease of 78.5%. The times to reach 90% of the peak levels of 18F in the kidney were 5.6 +/- 3.0 min for the Aminosyn II group and 33.8 +/- 4.8 min for the control group. The amounts excreted in urine by 90 min were 47.7 +/- 8.55%ID and 78.5 +/- 12.8%ID (P = 0.01) for the controls and Aminosyn II group, respectively. In conclusion, Aminosyn II effectively blocks the renal accumulation of 18F-labeled anti-Tac dsFv. Use of Aminosyn II should allow much higher tracer administration for the same radiation exposure to the target organ (kidney).

For better or worse: the case of marital rape.

The small amount of literature on marital rape compared to the rather large amount of literature on stranger rape suggests that the former is viewed as a less serious crime. This conclusion is supported, in part, by the way marital rape is minimized by the law. This paper is a review of the existing literature on marital rape. It combines the material on the history of marital rape, the legal issues involved with marital rape, when marital rape is likely to occur, the effects of marital rape, and societal views of the marital rape victim in a single comprehensive paper. The intent is to provide a synthesized examination of marital rape, as well as to encourage research on marital rape. It is concluded that marital rape is a pressing problem that tends to be minimized by society and researchers need to devote greater attention to marital rape issues.

Images of gays and lesbians in sexuality and health textbooks.

Photographs have become a major form of illustration in college level health and sexuality textbooks and may be more memorable than the text itself. Unlike other forms of illustration, photographs are often viewed as objective and unable to "lie." Photographs of individuals from nondominant groups, in addition to being seen as objective representations of reality, are often seen as representing the group to which they belong. To study the representation of nondominant groups in textbooks, it is, therefore, as important to analyze the photographs as the text itself. This paper examines photographs of gay men and lesbians in 14 health and 16 human sexuality college level textbooks. The photographs of individuals present an inaccurate portrait of lesbians and gay men as white, young, and physically-abled. Individual and large group photographs of activism (31% of the total photographs of gay men and lesbians) were positive images that emphasized issues of civil rights. The paper discusses various interpretations of the photographs of gay men and lesbians, subtle homophobia or heterosexism in the texts, and progress that has been made.

An instrument for measuring cancer patients' preferences for support groups.

The purpose of this study was to develop a valid and reliable instrument to assess cancer patients' preferences for all types of social support and organizational features of cancer support groups. The content of the instrument was the result of a detailed analysis of four resources: (1) literature relating to cancer support group interventions, (2) program materials from existing groups, (3) interviews with individuals who developed or directed groups, and (4) interviews with patients who have participated in cancer support groups. A jury of six experts was used to establish content validity of the instrument. The reliability of the instrument was examined by measuring a sample of 258 cancer patients. The reliability coefficients of the instrument were all above .80, except for two types of social support (instrumental and informational-educational), which were .72 and .78, respectively. It was concluded that the instrument produces valid and reliable measurements of cancer patients' preferences for cancer support groups.

School sexual abuse prevention: unintended consequences and dilemmas.

In view of the recent proliferation of school sexual abuse prevention programs and materials, this article critically examines current assumptions about the role of elementary school personnel in prevention and possible unintended consequences of such assumptions. These unintended consequences include emphasizing a simple solution to a complex social problem and contributing to victim blaming. Some dilemmas that arise for classroom teachers around predeveloped curricular materials and mandatory reporting are also explored. Teacher use of predeveloped materials may mean a diminishing of wider teaching skills and reduction of complex concepts to brief, noncontroversial interventions that may serve to mystify sexuality and unduly frighten students. Mandatory reporting, as it is frequently presented to teachers, can create further dilemmas by obscuring the ethical decisions inherent in the process, assuming consistently positive outcomes after reporting, and neglecting the context in which teachers work. The authors suggest that educators should be aware of these possible unintended consequences and dilemmas in order to maintain a broad perspective on child sexual abuse and to focus their efforts more effectively within a larger network addressing the problem.

Nursing and men's health. Some critical considerations.

This article addresses issues concerning the relationships among nursing, a nascent "men's health" movement, and the established "women's health" movement. Suggestions are made in regard to the potential positive contributions of a men's health movement that recognizes masculinity as a social reality while aiding men with health problems from a holistic nursing perspective.

Agglutination of Erwinia stewartii Strains with a Corn Agglutinin: Correlation with Extracellular Polysaccharide Production and Pathogenicity.

A bacterial agglutinin was extracted from ground corn (WI hybrid 64A x W117) seed with phosphate-buffered saline (pH 6.0) and precipitated with (NH(4))(2)SO(4) at 70% saturation. The activities of this agglutinin against 22 strains of Erwinia stewartii (agent of bacterial wilt of corn) that varied in virulence were determined. Specific agglutination (agglutination titer per milligram of protein per milliliter) values were correlated negatively with virulence ratings. Strains with high specific agglutination values (15 or higher) were avirulent or weakly virulent; strains with low specific agglutination values (10 or lower) were highly virulent, with two exceptions. Avirulent strains produced butyrous colonies and released only small amounts of extracellular polysaccharide (EPS) into the medium, and the cells lacked capsules; virulent strains produced fluidal colonies and released large amounts of EPS, and the cells were capsulated. There was a strong correlation between the amount of EPS produced by each strain (as determined by increase in viscosity of the medium) and the specific agglutination value; in contrast, lipopolysaccharide compositions were similar in all strains. When cells of six fluidal strains were washed by repeatedly centrifuging and resuspending them in buffer, they were agglutinated more strongly by corn agglutinin than were unwashed cells. When avirulent cells were washed, their specific agglutination values did not increase significantly. Eight EPS-deficient mutants of E. stewartii, selected for resistance to the capsule-dependent bacteriophage K9, had lower virulence but higher specific agglutination than did their corresponding wild-type parents. Production of EPS appears to be essential for virulence; EPS may prevent agglutination of bacteria in the host, thus allowing their multiplication.

Lipopolysaccharide Composition of the Wilt Pathogen, Pseudomonas solanacearum: CORRELATION WITH THE HYPERSENSITIVE RESPONSE IN TOBACCO.

In the induction of the hypersensitive response (HR) in tobacco by Pseudomonas solanacearum, the recognition between host and pathogen is thought to involve an interaction between plant lectins and bacterial lipopolysaccharide (LPS). The LPS of a series of strains of P. solanacearum were examined to determine if there are structural differences that might account for the ability or inability of these strains to induce the hypersensitive response. Analysis of the components of LPS by gas chromatography indicates a clear difference in sugar composition between the HR-inducing and non-HR-inducing strains, especially in terms of the percentage of glucose, xylose and rhamnose. Sodium dodecyl sulfate polyacrylamide gel electrophoresis shows there are two distinct kinds of LPS, differing greatly in size, which correspond to rough and smooth LPS in other systems. In addition, a phage, CH154, was isolated which lyses non-HR-inducing bacteria and which is inactivated by LPS from these bacterial strains. Therefore, differences in LPS structure correlate strongly with host recognition of Pseudomonas solanacearum.

Role of bacterial lipopolysaccharide in attachment of agrobacterium to moss.

Gametophore induction in moss by Agrobacterium tumefaciens was inhibited by addition of lipopolysaccharide (LPS) from A. tumefaciens. The LPS did not affect bacterial viability or appear to bind to bacterial cells. LPS from nonbinding Agrobacterium radiobacter was not effective in reducing gametophore formation. A. tumefaciens LPS, if added 24 hours after addition of viable bacterial cells, had no effect in reducing gametophore formation. The polysaccharide portion of the LPS was identified as the binding component necessary for attachment of agrobacteria for induction of gametophores in moss and tumors in higher plants.

Tumor induction by agrobacterium involves attachment of the bacterium to a site on the host plant cell wall.

Cell wall preparations from primary bean leaves were found to inhibit tumor initiation by Agrobacterium tumefaciens strain B6 when inoculated with the bacteria on bean leaves. Membrane fractions from these same leaves were noninhibitory. The cell walls were effective when applied prior to or with bacteria, but application of cell walls about 15 minutes after bacteria did not affect the number of tumors initiated. Much of the inhibitory activity of the plant cell walls was eliminated by pretreatment with dead site-attaching bacteria or with lipopolysaccharide from these bacteria. Cells and lipopolysaccharide from non-site-attaching agrobacteria had no effect on the activity of the plant cell walls. About 30% inhibition of tumor initiation was obtained with plant cell walls at 50 mug/ml dry weight, and at 10 mg/ml dry weight about 70% inhibition was typical. Both early and late appearing tumors were affected by the cell walls, indicating that they do not exclusively affect tumors arising from either small or large wounds. These data show that plant cell walls but not membranes contain surfaces to which A. tumefaciens adheres and these exhibit the specificity typical of the host site to which virulent agrobacteria must attach to induce tumors. It is concluded that some portion of wound-exposed plant cell wall constitutes the host adherence site in Agrobacterium infections.

Role of Agrobacterium cell envelope lipopolysaccharide in infection site attachment.

Lipopolysaccharide (LPS) isolated from Agrobacterium tumefaciens inhibited tumor induction by virulent bacteria. LPS from site-binding strains was not effective if added to the plant wound shortly after the bacteria, and LPS from avirulent, non-site-binding strains of Agrobacterium was not inhibitory regardless of the order of addition. However, LPS and whole cells of avirulent strains NT1 and IIBNV6, which lack of Agrobacterim virulence plasmid, were inhibitory. Chromosomal deoxyribonucleic acid thus determines specificity of this essential component of the Agrobacterium infection process.