Providing Reliable Prognosis to Patients with Gastric Cancer in the Era of Neoadjuvant Therapies: Comparison of AJCC Staging Schemata

Purpose

Patients with gastric cancer who receive neoadjuvant therapy are staged before treatment (cStage) and after treatment (ypStage). We aimed to compare the prognostic reliability of cStage and ypStage, alone and in combination.

Materials and Methods

Data for all patients who received neoadjuvant therapy followed by surgery for gastric adenocarcinoma from 2004 to 2015 were extracted from the National Cancer Database. Kaplan-Meier (KM)curves were used to model overall survival based on cStage alone, ypStage alone, cStage stratified by ypStage, and ypStage stratified by cStage. P-values were generated to summarize the differences in KM curves. The discriminatory power of survival prediction was examined using Harrell's C-statistics.

Results

We included 8,977 patients in the analysis. As expected, increasing cStage and ypStage were associated with worse survival. The discriminatory prognostic power provided by cStage was poor (C-statistic 0.548), while that provided by ypStage was moderate (C-statistic 0.634). Within each cStage, the addition of ypStage information significantly altered the prognosis (P<0.0001 within cStages I–IV). However, for each ypStage, the addition of cStage information generally did not alter the prognosis (P=0.2874, 0.027, 0.061, 0.049, and 0.007 within ypStages 0–IV, respectively). The discriminatory prognostic power provided by the combination of cStage and ypStage was similar to that of ypStage alone (C-statistic 0.636 vs. 0.634).

Conclusions

The cStage is unreliable for prognosis, and ypStage is moderately reliable. Combining cStage and ypStage does not improve the discriminatory prognostic power provided by ypStage alone. A ypStage-based prognosis is minimally affected by the initial cStage.

Abstract A105: Racial disparities in reasons for not receiving surgery for gastrointestinal cancer

Introduction: Differences in rates of surgery performed for gastrointestinal (GI) cancers contribute to racial disparities in cancer mortality. The National Cancer Database (NCDB) contains data obtained from Commission on Cancer-accredited hospital cancer registries and collects reasons for nonreceipt of surgery as a registry item. This study aims to examine whether racial disparities exist in this provided reason for not receiving surgery.

Methods: The NCDB was used to obtain data for patients diagnosed with gastric, pancreatic, and colorectal cancer in years 2004-2015. Analysis was limited to patients who were Black or White, and cancers stages 1-3. Unadjusted and adjusted differences between Black and White patients were examined for all variables in the model. Variables included demographics, receipt of surgery, reason for not having surgery, tumor stage and characteristics, and hospital factors. Reasons for patients' not receiving surgery were evaluated with Generalized Linear Modeling regression to see if certain responses, such as “contraindicated due to patient risk factors,”, “not part of the planned first course treatment,” and “refused by the patient” were more frequently assigned to Black compared to White patients.

Results: 540,205 patients with stage 1-3 gastrointestinal cancer were included in the study. 43% of the cohort had colon cancer, 24% rectal cancer, 11% gastric cancer, and 22% pancreatic cancer. For stage 1-3 disease, the raw operative rate for Black patients was 0.3%, 6.6%, 2.0%, and 6.7% lower than in White patients for stomach, pancreas, colon, and rectum cancers, respectively. These gaps widened when adjusted for age, comorbidities, and stage. On multivariate regression, Black patients were more likely to be recorded as being denied surgery due to patient risk factors even after controlling for age, stage, comorbidities, tumor characteristics, demographics, and hospital factors: OR 1.03 (95% CI 0.91-1.16), 1.25 (1.18-1.33), 1.43 (1.22-1.66), 1.63 (1.41-1.88) for stomach, pancreas, colon, and rectum cancer, respectively. Similarly, Black patients were more likely to reportedly not receive surgery due to surgery “not being the first course of treatment”: OR 0.99 (0.93-1.05), 1.14 (1.09-1.19), 1.30 (1.21-1.39), 1.33 (1.26-1.41). These two factors explain more than 80% of the difference in operative rates. Lastly, Black patients were disproportionately more likely to be recorded as having refused surgery: OR 1.84 (1.61-2.12), 1.07 (0.96-1.19), 1.59 (1.45-1.75), 1.81 (1.61-2.02).

Conclusion: Compared to White patients, Black patients are more likely to be described as not receiving surgery due to patient risk factors, surgery not being part of their first course of treatment, and their having refused surgery. Further studies are needed to evaluate whether the differences in operative rates are attributable to factors not captured in cancer registries, such as frailty and lack of social support.

Citation Format: John Bliton, Michael Parides, John McAuliffe, Peter Muscarella, Haejin In. Racial disparities in reasons for not receiving surgery for gastrointestinal cancer [abstract]. In: Proceedings of the Eleventh AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2018 Nov 2-5; New Orleans, LA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl):Abstract nr A105.

Abstract D105: Differences in receipt of surgery contribute to survival disparities in esophageal and gastric cancers

Introduction: Mortality disparities for gastrointestinal cancers are well described. Differences in rates of surgery across race and ethnicity may contribute to this phenomenon. In order to evaluate this, we assessed the extent to which the mortality disparity among racial/ethnic groups for gastrointestinal cancers are due to differences in operative rates. Methods: Data for patients with stage I-III esophageal and gastric cancer diagnoses between 2004-2015 were obtained from National Cancer Database. Cancers were categorized in 3 groups: mid-esophageal (ME) cancers, distal third of esophagus and cardia gastric cancers (DEC), and non-cardia gastric (NCG) cancers. Variables included demographics, receipt of surgery, tumor stage and characteristics, and hospital factors. The racial disparity in survival was measured as the hazard ratio (HR) for Black, Latinx, and Asian/Pacific Islander patients compared to White patients. A mediation analysis was performed to quantify the contribution of variables to the observed disparity between minority and White patients. The magnitude of the contributions was estimated using two methods: the change in HR with (1) the addition of each variable of interest to a model only adjusted by age and year, and (2) the removal of each variable from a multivariate model that included all variables. Factors associated with undergoing surgery were also examined using a logistic regression model. Results: A total of 124,862 patients were included (20,852 with ME, 74,427 with DEC, and 29,583 with NCG). Black patients were more likely to be from lower-income and urban areas and had lower operative rates in all cancers. The observed HRs for Black patients compared to White patients were 1.42 (95% CI 1.36-1.49) for ME, 1.36 (1.31-1.43) for DEC and 1.01 (0.97-1.05 – no observed disparity) for NCG tumors, adjusting for age and year of diagnosis. Only Black race/ethnicity was associated with a mortality disadvantage compared to White patients. Without adjustment for any additional variables, receipt of surgery accounted for more than half of the observed survival disparity for tumors of the esophagus and cardia (ΔHRs for ME: 0.27, DECS: 0.25 and NCG: 0.07). After adjustment for tumor, patient and hospital factors, receipt of surgery remained the single strongest contributor to the Black/White disparity in survival for all cancers (ΔHRs for ME: 0.070, DEC: 0.091 and NCG: 0.07). On logistic regression, Black patients were less likely to have received surgery after adjusting for other variables compared to White patients (ME aOR: 0.41 (0.37-0.46), DECS aOR: 0.42 (0.39-0.46), and NCG aOR: 0.79 (0.73-0.86)). Conclusions: Observed survival disparities in upper GI cancers may be due to fewer surgeries being performed for Black patients. Addressing differences in receipt of surgery for stage I through III esophageal and proximal stomach cancer has potential to mitigate cancer mortality disparities.

Citation Format: John Bliton, Peter Muscarella, Michael Parides, Katia Papalezova, John McAuliffe, Haejin In. Differences in receipt of surgery contribute to survival disparities in esophageal and gastric cancers [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr D105.

Abstract A104: Racial disparities in receipt of cancer surgery contribute to worse outcomes for patients with gastrointestinal cancers

Introduction: Mortality disparities exist in gastrointestinal (GI) cancers among racial/ethnic groups. One potential contributor to this disparity is a gap in who receives surgery. We aim to examine how much of the mortality disparity among racial/ethnic groups for GI cancers is explained by differences in operative rates.

Methods: The National Cancer Database was used to obtain data from patients diagnosed with gastric, pancreatic, and colorectal cancer in 2004-2015. Descriptive statistics were used to compare raw differences for variables among races. Variables included demographics, receipt of surgery, tumor stage and characteristics, and hospital factors. The racial disparity in survival was measured as the hazard ratio (HR) for each minority compared to White patients, controlling for age and year in Cox regression. The contributions of the variables, including surgical resection, to the racial disparities were estimated by measuring how inclusion of each of these variables affected the HRs of minorities compared to White patients. The magnitudes of the contributions to the HRs were estimated using two methods: (1) the addition of each variable to the age- and year-controlled model, and (2) the serial removal of each variable from a multivariate model that included all variables. The main analysis was performed excluding patients with unknown stage or disseminated cancer.

Results: 1.47 million patients with GI cancer were included in the study: 52% colon, 11% gastric, 21% pancreatic, and 16% rectal. Black patients were more likely to be from lower-income areas, from urban areas, and had lower operative rates in all cancers except gastric cancer. On Cox regression of stage 1-3 disease controlling for age and year of diagnosis, the HRs for Black patients compared to White patients were 1.01 (95% CI 0.97- 1.03), 1.11 (1.09-1.13), 1.22 (1.19-1.24), and 1.28 (1.24-1.32) for stomach, pancreas, colon, and rectum tumors, respectively. Based on the multivariate regression, the factors with the greatest influence on the survival disparity were zip income quartile and receipt of surgery. Receipt of surgery independently accounted for 29%, 11%, and 19% of the survival disadvantage observed in Black compared to White patients for pancreas, colon, and rectum cancer. Zip income quartile accounted for 16%, 18%, and 17%, excluding interactions. In contrast, no gap in operative rates or overall survival was observed for stomach cancer. The significance of surgery to outcomes was most pronounced for pancreatic cancer, where adding receipt of surgery to the age- and year-controlled model reduced the HR from 1.11 to 0.99; for colon and rectal cancer the HR changed from 1.22 to 1.15 and from 1.28 to 1.17.

Conclusion: Part of the observed cancer disparities for Black patients may be due to fewer surgeries being performed for Black patients. Correcting the disparities on the receipt of surgery for stage I through III GI cancer would likely have a large impact on mortality disparities.

Citation Format: John Bliton, Michael Parides, John McAuliffe, Peter Muscarella, Haejin In. Racial disparities in receipt of cancer surgery contribute to worse outcomes for patients with gastrointestinal cancers [abstract]. In: Proceedings of the Eleventh AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2018 Nov 2-5; New Orleans, LA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl):Abstract nr A104.

Upper airway morphology in Down Syndrome patients under dexmedetomidine sedation

BACKGROUND AND OBJECTIVES

Children with Down Syndrome are vulnerable to significant upper airway obstruction due to relative macroglossia and dynamic airway collapse. The objective of this study was to compare the upper airway dimensions of children with Down Syndrome and obstructive sleep apnea with normal airway under dexmedetomidine sedation.

METHODS

IRB approval was obtained. In this retrospective study, clinically indicated dynamic sagittal midline magnetic resonance images of the upper airway were obtained under low (1mcg/kg/h) and high (3mcg/kg/h) dose dexmedetomidine. Airway anteroposterior diameters and sectional areas were measured as minimum and maximum dimensions by two independent observers at soft palate (nasopharyngeal airway) and at base of the tongue (retroglossal airway).

RESULTS AND CONCLUSIONS

Minimum anteroposterior diameter and minimum sectional area at nasopharynx and retroglossal airway were significantly reduced in Down Syndrome compared to normal airway at both low and high dose dexmedetomidine. However, there were no significant differences between low and high dose dexmedetomidine in both Down Syndrome and normal airway. The mean apnea hypopnea index in Down Syndrome was 16±11. Under dexmedetomidine sedation, children with Down Syndrome and obstructive sleep apnea when compared to normal airway children show significant reductions in airway dimensions most pronounced at the narrowest points in the nasopharyngeal and retroglossal airways.

Novel associations between FAAH genetic variants and postoperative central opioid-related adverse effects

Opioid effects are potentiated by cannabinoid agonists including anandamide, an endocannabinoid. Inter-individual variability in responses to opioids is a major clinical problem. Multiple deaths and anoxic brain injuries occur every year because of opioid-induced respiratory depression (RD) in surgical patients and drug abusers of opioids and cannabinoids. This study aimed to determine specific associations between genetic variants of fatty acid amide hydrolase (FAAH) and postoperative central opioid adverse effects in children undergoing tonsillectomy. This is a prospective genotype-blinded observational study in which 259 healthy children between 6 and 15 years of age who received standard perioperative care with a standard anesthetic and an intraoperative dose of morphine were enrolled. Associations between frequent polymorphisms of FAAH and central postoperative opioid adverse effects including, RD, postoperative nausea and vomiting (PONV) and prolonged stay in Post Anesthesia Recovery Room (postoperative anesthesia care unit, PACU) due to RD and PONV were analyzed. Five specific FAAH single nucleotide polymorphisms (SNPs) had significant associations with more than twofold increased risk for refractory PONV (adjusted P<0.0018), and nominal associations (P<0.05) with RD and prolonged PACU stay in white children undergoing tonsillectomy. The FAAH SNP, rs324420, is a missense mutation with altered FAAH function and it is linked with other FAAH SNPs associated with PONV and RD in our cohort; association between PONV and rs324420 was confirmed in our extended cohort with additional 66 white children. Specific FAAH polymorphisms are associated with refractory PONV, opioid-related RD, and prolonged PACU stay due to opioid adverse effects in white children undergoing tonsillectomy.

Trigger finger: assessment of surgeon and patient preferences and priorities for decision making

PURPOSE

To test the null hypothesis that there are no differences in the priorities and preferences of patients with idiopathic trigger finger (TF) and hand surgeons.

METHODS

One hundred five hand surgeons of the Science of Variation Group and 84 patients with TF completed a survey about their priorities and preferences in decision making regarding the management of TF. The questionnaire was structured according the Ottawa Decision Support Framework for the development of a decision aid.

RESULTS

Patients desired orthotics more and surgery less than physicians. Patients and physicians disagreed on the main advantage of several treatment options for TFs and on disadvantages of the treatment options. Patients preferred to decide for themselves after receiving advice, whereas physicians preferred a shared decision. Patients preferred booklets, and physicians opted for Internet and video decision aids.

CONCLUSIONS

Comparing patients and hand surgeons, there were some differences in treatment preferences and perceived advantages and disadvantages regarding idiopathic TF-differences that might be addressed by a decision aid.

CLINICAL RELEVANCE

Information that helps inform patients of their options based on current best evidence might help them understand their own preferences and values, reduce decisional conflict, limit surgeon-to-surgeon variations, and improve health.

Carpal tunnel syndrome: assessment of surgeon and patient preferences and priorities for decision-making

PURPOSE

This study tested the null hypothesis that there are no differences between the preferences of hand surgeons and those patients with carpal tunnel syndrome (CTS) facing decisions about management of CTS (ie, the preferred content of a decision aid).

METHODS

One hundred three hand surgeons of the Science of Variation Group and 79 patients with CTS completed a survey about their priorities and preferences in decision making regarding the management of CTS. The questionnaire was structured according the Ottawa Decision Support Framework for the development of a decision aid.

RESULTS

Important areas on which patient and hand surgeon interests differed included a preference for nonpainful, nonoperative treatment and confirmation of the diagnosis with electrodiagnostic testing. For patients, the main disadvantage of nonoperative treatment was that it was likely to be only palliative and temporary. Patients preferred, on average, to take the lead in decision making, whereas physicians preferred shared decision making. Patients and physicians agreed on the value of support from family and other physicians in the decision-making process.

CONCLUSIONS

There were some differences between patient and surgeon priorities and preferences regarding decision making for CTS, particularly the risks and benefits of diagnostic and therapeutic procedures.

CLINICAL RELEVANCE

Information that helps inform patients of their options based on current best evidence might help patients understand their own preferences and values, reduce decisional conflict, limit surgeon-to-surgeon variations, and improve health.

Race and unequal burden of perioperative pain and opioid related adverse effects in children

BACKGROUND

Interindividual variability in pain perception and analgesic response is a major problem in perioperative practice. Adult studies suggest pain management is influenced by patient's race. The objective of this study is to evaluate the influence of race on perioperative pain treatment in children.

METHODS

Prospective observational study evaluating effect of race on analgesia and opioid related adverse effects after tonsillectomy in African American and Caucasian children. A sample of 194 healthy children between 6 and 15 years of age were included. Race was self-identified by parents. All participants received standard perioperative care with a standard anesthetic and an intraoperative dose of morphine. Analgesia outcomes included maximum postoperative pain scores, postoperative opioid requirement, and analgesic interventions. Safety outcomes included incidences of opioid related adverse effects.

RESULTS

African American children experienced significantly more postoperative pain than Caucasian children as measured by postoperative opioid requirement (P = .0011), maximum postoperative pain scores (P < .0001), and analgesic interventions (P < .0001) in the recovery room. Although Caucasian children received relatively less opioids perioperatively, they had significantly higher opioid related adverse effects (P = .039). African American children with obstructive sleep apnea were more likely to have prolonged post anesthesia recovery unit stay due to inadequate pain control.

CONCLUSIONS

After similar uses of intraoperative morphine for tonsillectomy, there was an unequal burden of increased pain in African American children and increased opioid adverse effects in Caucasian children in the recovery room. Though Caucasian children received relatively less opioids perioperatively, they had higher incidences of opioid related adverse effects than African American children.

The Alzheimer's Association external quality control program for cerebrospinal fluid biomarkers

BACKGROUND

The cerebrospinal fluid (CSF) biomarkers amyloid β (Aβ)-42, total-tau (T-tau), and phosphorylated-tau (P-tau) demonstrate good diagnostic accuracy for Alzheimer's disease (AD). However, there are large variations in biomarker measurements between studies, and between and within laboratories. The Alzheimer's Association has initiated a global quality control program to estimate and monitor variability of measurements, quantify batch-to-batch assay variations, and identify sources of variability. In this article, we present the results from the first two rounds of the program.

METHODS

The program is open for laboratories using commercially available kits for Aβ, T-tau, or P-tau. CSF samples (aliquots of pooled CSF) are sent for analysis several times a year from the Clinical Neurochemistry Laboratory at the Mölndal campus of the University of Gothenburg, Sweden. Each round consists of three quality control samples.

RESULTS

Forty laboratories participated. Twenty-six used INNOTEST enzyme-linked immunosorbent assay kits, 14 used Luminex xMAP with the INNO-BIA AlzBio3 kit (both measure Aβ-(1-42), P-tau(181P), and T-tau), and 5 used Meso Scale Discovery with the Aβ triplex (AβN-42, AβN-40, and AβN-38) or T-tau kits. The total coefficients of variation between the laboratories were 13% to 36%. Five laboratories analyzed the samples six times on different occasions. Within-laboratory precisions differed considerably between biomarkers within individual laboratories.

CONCLUSIONS

Measurements of CSF AD biomarkers show large between-laboratory variability, likely caused by factors related to analytical procedures and the analytical kits. Standardization of laboratory procedures and efforts by kit vendors to increase kit performance might lower variability, and will likely increase the usefulness of CSF AD biomarkers.

Oral contrast for abdominal computed tomography in children: the effects on gastric fluid volume

BACKGROUND

Oral enteric contrast medium (ECM) is frequently administered to achieve visualization of the gastrointestinal tract during abdominal evaluation with computed tomography (CT). Administering oral ECM less than 2 hours before sedation/anesthesia violates the nothing-by-mouth guidelines and in theory may increase the risk of aspiration pneumonia. In this study we measured the residual gastric fluid when using a protocol in which ECM is administered up to 1 hour before anesthesia/sedation. We hypothesized that patients receiving ECM 1 hour before anesthesia/sedation would have residual gastric fluid volume (GFV) >0.4 mL/kg.

METHODS

Anesthesia and radiology reports, CT images, and department incident reports were reviewed between January 2005 and June 2009 for all patients who required sedation/anesthesia for abdominal CT. For each patient, the volume of contrast or stomach fluid was calculated using a region of interest outlining the stomach portion containing high-attenuation fluid and low-attenuation of other gastric contents. Information obtained from anesthesia/sedation reports included demographic characteristics, presenting pathology, drugs used for anesthesia/sedation induction and maintenance, airway interventions, method for securing endotracheal tube, and complications related to ECM administration, including oxygen desaturation, vomiting, coughing, bronchospasm, laryngospasm, and aspiration.

RESULTS

We identified 365 patients (mean age = 32 months; range = 0.66 to 211.10 months) who received oral/IV contrast material before anesthesia/sedation for abdominal CT and 47 patients (mean age = 52 months; range = 0.63 to 215.84 months) who received only IV contrast material and followed the traditional fast. For those who received oral contrast, the mean contrast volume administered was 18.10 mL/kg (range = 1.5 to 82.76 mL/kg). The median GVF 1 hour after completing the oral contrast was significantly higher than that in patients who received only IV contrast (0.38 mL/kg vs. 0.15 mL/kg, P = 0.0049). GFV exceeded 0.4 mL/kg in 189 patients (178 of 365 [49%] in the oral contrast group vs. 11 of 47 [23%] in the IV contrast group) (χ(2) = 10.7874, P = 0.0010). Among those who received oral contrast, 207 patients had general anesthesia and 158 patients had deep sedation. Two cases of vomiting were reported in the general anesthesia group with no evidence of pulmonary aspiration identified.

CONCLUSION

For children receiving an abdominal CT, the residual GFV exceeded 0.4 mL/kg in 49% (178/365) of those who received oral ECM up to 1 hour before anesthesia/sedation in comparison with 23% (11/47) of those who received IV-only contrast.

Effect of increasing depth of dexmedetomidine anesthesia on upper airway morphology in children

OBJECTIVE

This prospective study examines the dose-response effects of dexmedetomidine on upper airway morphology in children with no obstructive sleep apnea (OSA).

AIM

To determine the effect of increasing doses of dexmedetomidine on static and dynamic magnetic resonance (MR) images of the upper airway in spontaneously breathing children with no OSA.

BACKGROUND

General anesthetics and sedatives attenuate upper airway muscle activity, rendering the airway vulnerable to obstruction. Dose-response effects of dexmedetomidine on upper airway of children are not known. We prospectively examined the dose-response effects of dexmedetomidine on upper airway morphology in children.

METHODS/MATERIALS

Increasing doses of dexmedetomidine was administered to 23 children scheduled for MR imaging of the brain while breathing spontaneously via the native airway. Static axial and dynamic sagittal midline MR ciné images of the upper airway were obtained during low (1 mcg.kg(-1).h(-1)) and high (3 mcg.kg(-1).h(-1)) doses of dexmedetomidine. The airway anteroposterior diameter, transverse diameter, and cross-sectional areas were measured manually by two independent observers. Static airway measurements were taken at the level of the nasopharyngeal airway (sagittal images) and retroglossal airway (RGA) (sagittal and axial images). Dynamic change in cross-sectional area of airway between inspiration and expiration was considered a measure of airway collapsibility.

RESULTS

Static axial measurements of RGA did not change with increasing dose of dexmedetomidine. Most sagittal airway dimensions demonstrated clinically modest, although statistically significant, reductions with high dose compared to low dose dexmedetomidine. Although, the dynamic changes in nasopharyngeal and retroglossal area with respiration were marginally greater for high dose than for low dose dexmedetomidine, no subject exhibited any clinical evidence of airway obstruction.

CONCLUSION

Upper airway changes associated with increasing doses of dexmedetomidine in children with no OSA are small in magnitude and do not appear to be associated with clinical signs of airway obstruction. Even though these changes are small, all precautions to manage airway obstruction should be taken when dexmedetomidine is used for sedation.

The effects of onsets and offsets on visual attention

Two experiments are presented which examine the effect of onset and offset cues on early occurring attentional cueing effects and later occurring inhibition of return (IOR). The first experiment compared the effects of single onset cues, single offset cues, and simultaneous onset and offset cues (at opposite locations) at a 100-ms stimulus-onset-asynchrony (SOA) and IOR at a 900-ms SOA. Whereas the first experiment examined these conditions with choice localization keypress responses, the second experiment used simple detection keypress responses. Both experiments found that onset and offset cues presented in isolation produce early facilitation and late IOR. When onset and offset cues were simultaneously presented, facilitation but not IOR was found with localization responses, while neither facilitation or IOR was found with detection responses. Overall, these findings suggest that offset cues can be treated in the same manner as onset cues by the attentional system, although the onset cues may have priority in orienting attention when targets must be localized in space.

Examining location-based and object-based components of inhibition of return in static displays

Tipper and Colleagues (e.g., Jordan & Tipper, 1998; Tipper, Driver, & Weaver, 1991; Tipper, Weaver, Jerreat, & Burak, 1994) have provided support for inhibition of return (IOR) being composed of a location-based and an object-based component. They were able to separate out the effects of location-based and object-based IOR by using complex displays and displays that involved moving the cued object. The present study was designed to further examine the object- and location-based components of IOR in static displays. Three experiments were conducted that looked at the presence or absence of placeholder boxes on IOR. The first experiment was designed to replicate the results of Jordan and Tipper by presenting both objects and no-objects in the same display. In the second experiment, trials were blocked, and in the third experiment trials were presented in a random order. Overall, the results are inconsistent with the notion that independent object-based and location-based IOR components combine to produce the overall IOR effect and that additive effects are realized due to the context in which the trials are presented. We propose that a single inhibitory mechanism can account for the data.

Molecular cloning and expression of a novel human beta-Gal-3-O-sulfotransferase that acts preferentially on N-acetyllactosamine in N- and O-glycans

A novel cDNA-encoding galactose 3-O-sulfotransferase was cloned by screening the expressed sequence tag data base using the previously cloned cDNA encoding a galactosyl ceramide 3-O-sulfotransferase, which we term Gal3ST-1. The newly isolated cDNA encodes a novel 3-O-sulfotransferase, termed Gal3ST-3, that acts exclusively on N-acetyllactosamine present in N-glycans and core2-branched O-glycans. These conclusions were confirmed by analyzing CD43 chimeric proteins in Chinese hamster ovary cells expressing core2 beta1,6-N-acetylglucosaminyltransferase. The acceptor specificity of Gal3ST-3 contrasts with that of the recently cloned galactose 3-O-sulfotransferase (Honke, K., Tsuda, M., Koyota, S., Wada, Y., Iida-Tanaka, N., Ishizuka, I., Nakayama, J., and Taniguchi, N. (2001) J. Biol. Chem. 276, 267-274), which we term Gal3ST-2 in the present study because the latter enzyme can also act on core1 O-glycan and type 1 oligosaccharides, Galbeta1-->3GlcNAc. Moreover, Gal3ST-3 but not Gal3ST-2 can act on Galbeta1-->4(sulfo-->6)GlcNAc, indicating that disulfated sulfo-->3Galbeta1-->4(sulfo-->6) GlcNAc-->R may be formed by Gal3ST-3 in combination with GlcNAc 6-O-sulfotransferase. Although both Gal3ST-2 and Gal3ST-3 do not act on galactosyl ceramide, Gal3ST-3 is only moderately more homologous to Gal3ST-2 (40.1%) than to Gal3ST-1 (38.0%) at the amino acid level. Northern blot analysis demonstrated that transcripts for Gal3ST-3 are predominantly expressed in the brain, kidney, and thyroid where the presence of 3'-sulfation of N-acetyllactosamine has been reported. These results indicate that the newly cloned Gal3ST-3 plays a critical role in 3'-sulfation of N-acetyllactosamine in both O- and N-glycans.

Human corneal GlcNac 6-O-sulfotransferase and mouse intestinal GlcNac 6-O-sulfotransferase both produce keratan sulfate

Human corneal N-acetylglucosamine 6-O-sulfotransferase (hCGn6ST) has been identified by the positional candidate approach as the gene responsible for macular corneal dystrophy (MCD). Because of its high homology to carbohydrate sulfotransferases and the presence of mutations of this gene in MCD patients who lack sulfated keratan sulfate in the cornea and serum, hCGn6ST protein is thought to be a sulfotransferase that catalyzes sulfation of GlcNAc in keratan sulfate. In this report, we analyzed the enzymatic activity of hCGn6ST by expressing it in cultured cells. A lysate prepared from HeLa cells transfected with an intact form of hCGn6ST cDNA or culture medium from cells transfected with a secreted form of hCGn6ST cDNA showed an activity of transferring sulfate to C-6 of GlcNAc of synthetic oligosaccharide substrates in vitro. When hCGn6ST was expressed together with human keratan sulfate Gal-6-sulfotransferase (hKSG6ST), HeLa cells produced highly sulfated carbohydrate detected by an anti-keratan sulfate antibody 5D4. These results indicate that hCGn6ST transfers sulfate to C-6 of GlcNAc in keratan sulfate. Amino acid substitutions in hCGn6ST identical to changes resulting from missense mutations found in MCD patients abolished enzymatic activity. Moreover, mouse intestinal GlcNAc 6-O-sulfotransferase had the same activity as hCGn6ST. This observation suggests that mouse intestinal GlcNAc 6-O-sulfotransferase is the orthologue of hCGn6ST and functions as a sulfotransferase to produce keratan sulfate in the cornea.

Differential biosynthesis of polysialic acid on neural cell adhesion molecule (NCAM) and oligosaccharide acceptors by three distinct alpha 2,8-sialyltransferases, ST8Sia IV (PST), ST8Sia II (STX), and ST8Sia III

Polysialylated neural cell adhesion molecule (NCAM) is thought to play a critical role in neural development. Polysialylation of NCAM was shown to be achieved by two alpha2,8-polysialyltransferases, ST8Sia IV (PST) and ST8Sia II (STX), which are moderately related to another alpha2,8-sialyltransferase, ST8Sia III. Here we describe that all three alpha2,8-sialyltransferases can utilize oligosaccharides as acceptors but differ in the efficiency of adding polysialic acid on NCAM. First, we found that ST8Sia III can form polysialic acid on the enzyme itself (autopolysialylation) but not on NCAM. These discoveries prompted us to determine if ST8Sia IV and ST8Sia II share the property of ST8Sia III in utilizing low molecular weight oligosaccharides as acceptors. By using a newly established method, we found that ST8Sia IV, ST8Sia II, and ST8Sia III all add oligosialic and polysialic acid on various sialylated N-acetyllactosaminyl oligosaccharides, including NCAM N-glycans, fetuin N-glycans, synthetic sialylated N-acetyllactosamines, and on alpha(2)-HS-glycoprotein. Our results also showed that monosialyl and disialyl N-acetyllactosamines can serve equally as an acceptor, suggesting that no initial addition of alpha2,8-sialic acid is necessary for the action of polysialyltransferases. Polysialylation of NCAM by ST8Sia IV and ST8Sia II is much more efficient than polysialylation of N-glycans isolated from NCAM. Moreover, ST8Sia IV and ST8Sia II catalyze polysialylation of NCAM much more efficiently than ST8Sia III. These results suggest that no specific acceptor recognition is involved in polysialylation of low molecular weight sialylated oligosaccharides, whereas the enzymes exhibit pronounced acceptor specificities if glycoproteins are used as acceptors.

Poly-N-acetyllactosamine extension in N-glycans and core 2- and core 4-branched O-glycans is differentially controlled by i-extension enzyme and different members of the beta 1,4-galactosyltransferase gene family

Poly-N-acetyllactosamines are attached to N-glycans, O-glycans, and glycolipids and serve as underlying glycans that provide functional oligosaccharides such as sialyl Lewis(X). Poly-N-acetyllactosaminyl repeats are synthesized by the alternate addition of beta1,3-linked GlcNAc and beta1,4-linked Gal by i-extension enzyme (iGnT) and a member of the beta1,4-galactosyltransferase (beta4Gal-T) gene family. In the present study, we first found that poly-N-acetyllactosamines in N-glycans are most efficiently synthesized by beta4Gal-TI and iGnT. We also found that iGnT acts less efficiently on acceptors containing increasing numbers of N-acetyllactosamine repeats, in contrast to beta4Gal-TI, which exhibits no significant change. In O-glycan biosynthesis, N-acetyllactosamine extension of core 4 branches was found to be synthesized most efficiently by iGnT and beta4Gal-TI, in contrast to core 2 branch synthesis, which requires iGnT and beta4Gal-TIV. Poly-N-acetyllactosamine extension of core 4 branches is, however, less efficient than that of N-glycans or core 2 branches. Such inefficiency is apparently due to competition between a donor substrate and acceptor in both galactosylation and N-acetylglucosaminylation, since a core 4-branched acceptor contains both Gal and GlcNAc terminals. These results, taken together, indicate that poly-N-acetyllactosamine synthesis in N-glycans and core 2- and core 4-branched O-glycans is achieved by iGnT and distinct members of the beta4Gal-T gene family. The results also exemplify intricate interactions between acceptors and specific glycosyltransferases, which play important roles in how poly-N-acetyllactosamines are synthesized in different acceptor molecules.

Continuous epidural butorphanol relieves pruritus associated with epidural morphine infusions in children

We examined the efficacy of epidural butorphanol to either prevent or relieve pruritus associated with epidural morphine infusion in children. Forty-six children were randomized to receive either epidural morphine (M) or epidural M with butorphanol (B) for postoperative analgesia. They received bupivacaine and either M 50 microg.kg-1 or the same dose of M plus B 10 microg.kg-1. Following surgery, a continuous infusion of 0.1% bupivacaine with either M 20 microg.ml-1 or M 20 microg.ml-1 + B 4 microg.ml-1 was given at a rate of 0.3 ml.kg-1.h-1. Pain scores and pruritus scores were recorded every 4 h during epidural infusion. Subjects with a pruritus score=2 received diphenhydramine 0.5 mg.kg-1 i.v. and were switched to an alternate epidural infusion; subjects receiving M (group M) were switched to M+B while subjects receiving M+B (group B) were switched to hydromorphone (H) 4 microg.ml-1. There was no difference in the initial incidence of pruritus (group M 11/18; group B 13/28). No subject in group M required a second change of epidural infusion because of continued pruritus after being switched to M+B; five of 13 subjects in group B continued to experience pruritus after being switched to H and required a second change of epidural infusion or an alternate analgesic modality (P=0.038). The median pruritus score in the first 24 h after changing epidural infusions was 0 in subjects in group MDelta (changed from M to M+B) and 1 in subjects in group BDelta (changed from M+B to H; P=0.012). While the median sedation score in the first 24 h was 1 in both groups, there was a greater incidence of sedation scores of 2 in group B than group M (28% vs 12.3%; P=0.021). B 10 microg.kg-1 was not effective in preventing pruritus associated with bolus epidural administration of M 50 microg.kg-1 in children. B 1.2 microg.kg-1. h-1 was effective in relieving pruritus associated with continuous epidural infusion of M 6 microg.kg-1.h-1.

Poly-N-acetyllactosamine synthesis in branched N-glycans is controlled by complemental branch specificity of I-extension enzyme and beta1,4-galactosyltransferase I

Poly-N-acetyllactosamine is a unique carbohydrate that can carry various functional oligosaccharides, such as sialyl Lewis X. It has been shown that the amount of poly-N-acetyllactosamine is increased in N-glycans, when they contain Galbeta1-->4GlcNAcbeta1-->6(Galbeta1-->4GlcNAcbeta1 -->2)Manalpha1-->6 branched structure. To determine how this increased synthesis of poly-N-acetyllactosamines takes place, the branched acceptor was incubated with a mixture of i-extension enzyme (iGnT) and beta1, 4galactosyltransferase I (beta4Gal-TI). First, N-acetyllactosamine repeats were more readily added to the branched acceptor than the summation of poly-N-acetyllactosamines formed individually on each unbranched acceptor. Surprisingly, poly-N-acetyllactosamine was more efficiently formed on Galbeta1-->4GlcNAcbeta1-->2Manalpha-->R side chain than in Galbeta1-->4GlcNAcbeta1-->6Manalpha-->R, due to preferential action of iGnT on Galbeta1-->4GlcNAcbeta1-->2Manalpha-->R side chain. On the other hand, galactosylation was much more efficient on beta1,6-linked GlcNAc than beta1,2-linked GlcNAc, preferentially forming Galbeta1-->4GlcNAcbeta1-->6(GlcNAcbeta1-->2)Manalph a1-->6Manbeta -->R. Starting with this preformed acceptor, N-acetyllactosamine repeats were added almost equally to Galbeta1-->4GlcNAcbeta1-->6Manalpha-->R and Galbeta1-->4GlcNAcbeta1-->2Manalpha-->R side chains. Taken together, these results indicate that the complemental branch specificity of iGnT and beta4Gal-TI leads to efficient and equal addition of N-acetyllactosamine repeats on both side chains of GlcNAcbeta1-->6(GlcNAcbeta1-->2)Manalpha1-->6Manbet a-->R structure, which is consistent with the structures found in nature. The results also suggest that the addition of Galbeta1-->4GlcNAcbeta1-->6 side chain on Galbeta1-->4GlcNAcbeta1-->2Man-->R side chain converts the acceptor to one that is much more favorable for iGnT and beta4Gal-TI.

Examining the effect of practice on inhibition of return in static displays

In a recent article, Weaver, Lupiáñez, and Watson (1998) reported that both object-based and location-based inhibition of return effects were reduced with practice. The present study was conducted to (1) replicate the reduction of inhibition of return with practice in single-session experiments with a variety of displays and responses and (2) to examine the notion that the reduction was, at least partly, due to habituation. However, no evidence for practice-related changes in the size of the inhibitory effect were found over a series of different inhibition of return experiments using static displays (using various numbers of target locations, types of keypress responses, and number of trials). Overall, the results suggest that inhibition of return is a robust phenomenon and may not, with static displays, be especially sensitive to practice effects.

Regulation of I-branched poly-N-acetyllactosamine synthesis. Concerted actions by I-extension enzyme, I-branching enzyme, and beta1,4-galactosyltransferase I

I-branched poly-N-acetyllactosamine is a unique carbohydrate composed of N-acetyllactosamine branches attached to linear poly-N-acetyllactosamine, which is synthesized by I-branching beta1, 6-N-acetylglucosaminyltransferase. I-branched poly-N-acetyllactosamine can carry bivalent functional oligosaccharides such as sialyl Lewisx, which provide much better carbohydrate ligands than monovalent functional oligosaccharides. In the present study, we first demonstrate that I-branching beta1, 6-N-acetylglucosaminyltransferase cloned from human PA-1 embryonic carcinoma cells transfers beta1,6-linked GlcNAc preferentially to galactosyl residues of N-acetyllactosamine close to nonreducing terminals. We then demonstrate that among various beta1, 4-galactosyltransferases (beta4Gal-Ts), beta4Gal-TI is most efficient in adding a galactose to linear and branched poly-N-acetyllactosamines. When a beta1,6-GlcNAc branched poly-N-acetyllactosamine was incubated with a mixture of beta4Gal-TI and i-extension beta1,3-N-acetylglucosaminyltransferase, the major product was the oligosaccharide with one N-acetyllactosamine extension on the linear Galbeta1-->4GlcNAcbeta1-->3 side chain. Only a minor product contained galactosylated I-branch without N-acetyllactosamine extension. This finding was explained by the fact that beta4Gal-TI adds a galactose poorly to beta1,6-GlcNAc attached to linear poly-N-acetyllactosamines, while beta1, 3-N-acetylglucosaminyltransferase and beta4Gal-TI efficiently add N-acetyllactosamine to linear poly-N-acetyllactosamines. Together, these results strongly suggest that galactosylation of I-branch is a rate-limiting step in I-branched poly-N-acetyllactosamine synthesis, allowing poly-N-acetyllactosamine extension mostly along the linear poly-N-acetyllactosamine side chain. These findings are entirely consistent with previous findings that poly-N-acetyllactosamines in human erythrocytes, PA-1 embryonic carcinoma cells, and rabbit erythrocytes contain multiple, short I-branches.

Synthesis of poly-N-acetyllactosamine in core 2 branched O-glycans. The requirement of novel beta-1,4-galactosyltransferase IV and beta-1,3-n-acetylglucosaminyltransferase

Poly-N-acetyllactosamine is a unique carbohydrate composed of N-acetyllactosamine repeats and provides the backbone structure for additional modifications such as sialyl Lex. Poly-N-acetyllactosamines in mucin-type O-glycans can be formed in core 2 branched oligosaccharides, which are synthesized by core 2 beta-1,6-N-acetylglucosaminyltransferase. Using a beta-1, 4-galactosyltransferase (beta4Gal-TI) present in milk and the recently cloned beta-1,3-N-acetylglucosaminyltransferase, the formation of poly-N-acetyllactosamine was found to be extremely inefficient starting from a core 2 branched oligosaccharide, GlcNAcbeta1-->6(Galbeta1-->3)GalNAcalpha-->R. Since the majority of synthesized oligosaccharides contained N-acetylglucosamine at the nonreducing ends, galactosylation was judged to be inefficient, prompting us to test novel members of the beta4Gal-T gene family for this synthesis. Using various synthetic acceptors and recombinant beta4Gal-Ts, beta4Gal-TIV was found to be most efficient in the addition of a single galactose residue to GlcNAcbeta1-->6(Galbeta1-->3)GalNAcalpha-->R. Moreover, beta4Gal-TIV, together with beta-1,3-N-acetylglucosaminyltransferase, was capable of synthesizing poly-N-acetyllactosamine in core 2 branched oligosaccharides. On the other hand, beta4Gal-TI was found to be most efficient for poly-N-acetyllactosamine synthesis in N-glycans. In contrast to beta4Gal-TI, the efficiency of beta4Gal-TIV decreased dramatically as the acceptors contained more N-acetyllactosamine repeats, consistent with the fact that core 2 branched O-glycans contain fewer and shorter poly-N-acetyllactosamines than N-glycans in many cells. These results, as a whole, indicate that beta4Gal-TIV is responsible for poly-N-acetyllactosamine synthesis in core 2 branched O-glycans.

Quality assurance of a diarrhoea control programme in northeastern Brazil

In this study quality assurance methods were used in an evaluation of a programme for Control of Diarrhoeal Diseases (CDD) in northeastern Brazil. Seventy-eight randomly selected public primary care facilities in four states were assessed by trained surveyors. Problems observed in the facilities were lack of information on target population and coverage, lack of equipment to permit rehydration in the premises, and frequent unavailability of trained professionals. Health workers showed deficiencies in history taking, physical examination and knowledge on diarrhoea management. Many caretakers had difficulties in recalling information given to them in the health facilities. Eighty-four percent of the cases were treated with oral rehydration, but 90% were sent home immediately and not kept in the facilities to practice rehydration under guidance as recommended by the national CDD programme. An overuse of the medical treatment was observed. More than two-thirds of health professionals gave wrong indications for use of antibiotics. The study showed that oral rehydration therapy is well established in the government health services in the region but that the CDD programme needs to take early action to correct deficiencies in logistics, case management and health education.

AIDS in the hand patient: the team approach

Hand surgeons and therapists were faced with a new clinical entity in the 1980s with the emergence of hand and upper extremity infections in patients with AIDS and HIV disease. This entity has become a worldwide epidemic of vast proportions and has proven to be one of the major health concerns of the 1990s. It seems likely that treatment of patients with this devastating disease for hand infections or more routine upper extremity problems will become routine in the future. The reality of surgical treatment and hands-on rehabilitative therapy for patients with a life-threatening infectious disease has been a concern voiced publicly by very few health care professionals, yet discussed quietly among colleagues quite frequently. Our aim must be to provide the highest quality of health care to this group of hand patients, just as we do for all other patients, while at the same time providing the safest possible environment for all members of the health care team. It appears that there is a higher incidence of HIV infection among hand patients than is noted in the general public; therefore, the hand surgeon and medical team should pay particular attention to the rapidly advancing front of new information available regarding care for this challenging group of patients. Hand surgeons and therapists are entering the 1990s armed with a wealth of new and valuable information about HIV disease that has been produced by intensive basic science research and clinical observations accumulated over the last 10 years. The fears generated by the initial misinformation and lack of information concerning modes of transmission of HIV have generally been supplanted by a more rational approach to patient care, fostered by the more accurate scientific information currently becoming available. Unfortunately, the rational approach to the HIV-related political and socioeconomic issues has not yet overtaken the discrimination and stereotyping of the populace stricken with HIV disease. It remains the responsibility of the medical community to continue research efforts aimed at delineating the clinical deficiencies manifested by these patients and determining their effects on treatment regimens for both the unique and commonplace medical and orthopedic problems noted in this patient population.

Management of childhood diarrhoea at the household level: a population-based survey in north-east Brazil

The management of childhood diarrhoea at the household level was studied in a population-based survey in four states in north-east Brazil. Of a representative sample of 6524 children under 5 years of age, 982 (15.1%) had diarrhoea on the day of the interview or had had diarrhoea at some time during the previous 15 days. A total of 66% of the children were not taken for treatment, while government health services were used by 14%, private doctors by 1%, and traditional healers (rezadeiras) by 24%. Oral rehydration therapy was given to 24.3% of the children as follows: solutions of oral rehydration salts (ORS) were received by 6.8%, salt-and-sugar solutions by 14.7%, and solutions of commercial ORS brands by 4.3%. Although 95% of the caretakers knew about rehydration solutions, only 18% prepared them correctly, the most common error being the use of insufficient water. Of the rehydration solutions used, 39% had a sodium concentration that was potentially dangerous (greater than 120 mmol/l), and 8% had a sodium concentration that was very low. Of those solutions prepared using ORS, 38% had too high a sodium concentration, while 14% of the salt-and-sugar solutions prepared using either the "scoop-and-pinch" approach or a plastic spoon were too concentrated. However, potentially the most dangerous were the salt-and-sugar solutions prepared using nonstandard recipes. More than half of these had an unacceptably high sodium concentration or osmolarity.

Velocity of the creatine kinase reaction in the neonatal rabbit heart: role of mitochondrial creatine kinase

To examine the role of changes in the distribution of the creatine kinase (CK) isoenzymes [BB, MB, MM, and mitochondrial CK (mito-CK)] on the creatine kinase reaction velocity in the intact heart, we measured the creatine kinase reaction velocity and substrate concentrations in hearts from neonatal rabbits at different stages of development. Between 3 and 18 days postpartum, total creatine kinase activity did not change, but the isoenzyme distribution and total creatine content changed. Hearts containing 0, 4, or 9% mito-CK activity were studied at three levels of cardiac performance: KCl arrest and Langendorff and isovolumic beating. The creatine kinase reaction velocity in the direction of MgATP production was measured with 31P magnetization transfer under steady-state conditions. Substrate concentrations were measured with 31P NMR (ATP and creatine phosphate) and conventional biochemical analysis (creatine) or estimated (ADP) by assuming creatine kinase equilibrium. The rate of ATP synthesis by oxidative phosphorylation was estimated with oxygen consumption measurements. These results define three relationships. First, the creatine kinase reaction velocity increased as mito-CK activity increased, suggesting that isoenzyme localization can alter reaction velocity. Second, the reaction velocity increased as the rate of ATP synthesis increased. Third, as predicted by the rate equation, reaction velocity increased with the 3-fold increase in creatine and creatine phosphate contents that occurred during development.

Group B streptococcal sepsis with osteomyelitis and arthritis. Its occurrence with acute heart failure

In a 20-day-old female infant, bacteremia, osteomyelitis, and pyogenic arthritis developed due to infection with group B streptococcus, type Ic. She had an unusual clinical presentation with overwhelming sepsis and acute congestive heart failure.