30-day Delay Research Articles

Association between Charlson-Deyo Score and delay to colonoscopy in veterans subsequently diagnosed with colorectal cancer.

288 Background: Colorectal cancer (CRC) is the second most common cause of cancer deaths in the United States and expected to cause 51,020 deaths in 2019. Early detection with yearly fecal occult blood test (FOBT) has been proven to decrease CRC mortality. A 30-day delay from positive FOBT to colonoscopy is associated with increased risk of CRC. The Veterans Affairs Health System (VAHS) treats approximately 11% of CRCs in the United States. The effects of an aging population, physician shortage, and increased military personnel entering the VAHS may increase demands on VAHS resources. The primary aim of this study was to determine risk factors that caused delay to colonoscopy. Methods: We retrospectively reviewed records of 600 patients referred for colonoscopy from January 1999 to January 2009, who were subsequently diagnosed with CRC. Patients with a prior CRC diagnosis were excluded. The final study cohort consisted of 530 patients. We analyzed the relationship between 10 variables and delay in time from initial consultation to colonoscopy. Variables consisted of age, sex, race, ethnicity, CRC location, marital status, history of mental health diagnosis, tobacco use, substance abuse, Charlson/Deyo (C/D) score and season of referral for colonoscopy. A delay in time was defined as 30 days or greater. Logistic regression analysis adjusted for age, race, CRC location and C/D score. Results: A total of 87.17% of patients experienced a delay in time from initial consultation to colonoscopy. When analyzed with a predictive variable of delay to colonoscopy, C/D score of ≥ 2 versus 0, was associated with higher odds of delay in time to colonoscopy (OR = 2.18, p = 0.02). African American race and Hispanic ethnicity was associated with a higher odds of delay in time to colonoscopy, but was not statistically significant (OR = 1.47, p = 0.47, OR = 1.37, p = 0.48). Conclusions: Patients with a C/D score ≥ 2 were 218% more likely to have delay in time from initial consult to colonoscopy, resulting in a delayed CRC diagnosis. C/D score may be used to determine which patients should have more frequent reminders to schedule their colonoscopy to prevent delays in care. Randomized and prospective studies will need to be performed.

Vertebral Osteomyelitis: A Comparison of Associated Outcomes in Early Versus Delayed Surgical Treatment.

The recommended timing of surgical intervention for vertebral osteomyelitis (VO) is controversial; however, most studies are not sufficiently powered. Our goal was to investigate the associated effects of delaying surgery in VO patients on in-hospital complications, neurologic deficits, and mortality. Retrospective review of the National Inpatient Sample. Patients who underwent surgery for VO from 1998 to 2013 were identified using codes from the International Classification of Disease, Ninth Revision, Clinical Modification. Patients were stratified into groups based on incremental delay of surgery: 0-day delay (same-day surgery), 1-day delay, 2-day delay, 3- to 6-day delay, 7- to 14-day delay, and 14- to 30-day delay. Univariate analysis compared demographics and outcomes between groups. Multivariate logistic regression models calculated independent predictors of any complication, mortality, and neurologic deficits. A 0-day delay was the reference group. A total of 34 465 patients were identified. Delayed groups were older (same day: 53.5 vs. 7-14-day delay: 61.1) and had a higher Deyo-Charlson score (same day: 0.4901 vs. 14-30-day delay: 1.66), length of stay (same day: 4.2 vs. 14-30-day delay: 34.04 days), and total charges (same day: $63,390.78 vs. 14-30-day delay: $245,752.4), all P < .001. Delayed groups had higher surgical combined-approach rates (same day: 9.1% vs. 14-30-day delay: 31.5%) and lower anterior-approach rates (same day: 42.4% vs. 14-30-day delay: 24.2%). Delayed groups had increased mortality and complication rates. Regressions showed delayed groups as the strongest independent indicators of any complication (14-30-day delay: odds ratio [OR] 3.384), mortality (14-30-day delay: OR 10.658), and neurologic deficits (14-30-day delay: OR 3.464), all P < .001. VO patients who operate within 24 hours of admission are more likely to have desirable outcomes. Patients with delayed surgery had a significantly increased risk of developing any complication, mortality, and discharging with neurologic deficits. III. Medically fit patients may benefit from earlier surgical management in order to reduce risk of postoperative complications, improve outcomes, and reduce overall hospital costs.

Improved Treatment Outcomes With Bedaquiline When Substituted for Second-line Injectable Agents in Multidrug-resistant Tuberculosis: A Retrospective Cohort Study.

Bedaquiline is used as a substitute for second-line injectable (SLI) intolerance in the treatment of multidrug-resistant (MDR) tuberculosis, but the efficacy and safety of this strategy is unknown. In this retrospective cohort study adults receiving bedaquiline substitution for MDR tuberculosis therapy, plus a matched control group who did not receive bedaquiline, were identified from the electronic tuberculosis register in the Western Cape Province, South Africa. The primary outcome measure was the proportion of patients with death, loss to follow-up, or failure to achieve sustained culture conversion at 12 months of treatment. Data from 162 patients who received bedaquiline substitution and 168 controls were analyzed; 70.6% were infected with human immunodeficiency virus. Unfavorable outcomes occurred in 35 of 146 (23.9%) patients in the bedaquiline group versus 51 of 141 (36.2%) in the control group (relative risk, 0.66; 95% confidence interval, .46 -.95). The number of patients with culture reversion was lower in those receiving bedaquiline (1 patient; 0.8%) than in controls (12 patients; 10.3%; P = .001). Delayed initiation of bedaquiline was independently associated with failure to achieve sustained culture conversion (adjusted odds ratio for every 30-day delay, 1.5; 95% confidence interval, 1.1-1.9). Mortality rates were similar at 12 months (11 deaths in each group; P = .97). Substituting bedaquiline for SLIs in MDR tuberculosis treatment resulted in improved outcomes at 12 months compared with patients who continued taking SLIs, supporting the use of bedaquiline for MDR tuberculosis treatment in programmatic settings.

Field study of charitable giving reveals that reciprocity decays over time

We examine how reciprocity changes over time by studying a large quasiexperiment in the field. Specifically, we analyze administrative data from a university hospital system. The data include information about over 18,000 donation requests made by the hospital system via mail to a set of its former patients in the 4 months after their first hospital visit. We exploit quasiexperimental variation in the timing of solicitation mailings relative to patient hospital visits and find that an extra 30-day delay between the provision of medical care and a donation solicitation decreases the likelihood of a donation by 30%. Our findings have important implications for models of economic behavior, which currently fail to incorporate reciprocity's sensitivity to time. The fact that reciprocal behavior decays rapidly as time passes also suggests the importance of capitalizing quickly on opportunities to benefit from a quid pro quo.

An Update on the Appropriate Role for Hyperbaric Oxygen: Indications and Evidence.

Background:Among advanced therapeutic interventions for wounds, hyperbaric oxygen therapy (HBOT) has the unique ability to ameliorate tissue hypoxia, reduce pathologic inflammation, and mitigate ischemia reperfusion injury. Most of the conditions for which it is utilized have few successful alternative treatments, and the morbidity and mortality associated with treatment failure are significant. Data on the efficacy and effectiveness of HBOT were reviewed, comparative effectiveness research of HBOT was explained, and a new paradigm for the appropriate use of HBOT was described.Methods:Systematic reviews and randomized controlled trials that have evaluated HBOT were reviewed.Results:Although numerous small randomized controlled trials provide compelling support for HBOT, the physics of the hyperbaric environment create significant barriers to trial design. The electronic health record infrastructure created to satisfy mandatory quality and registry reporting requirements as part of healthcare reform can be harnessed to facilitate the acquisition of real world data for HBOT comparative effectiveness studies and clinical decision support.Conclusions:Predictive models can identify patients unlikely to heal spontaneously and most likely to benefit from HBOT. Although electronic health records can automate the calculation of predictive models making them available at the point of care, using them in clinical decision making is complicated. It is not clear whether stakeholders will support the allocation of healthcare resources using mathematical models, but the current patient selection process mandates a 30-day delay for all patients who might benefit and allows treatment for at least some patients who cannot benefit.

Real-World Assessment of Interventional Treatment Timing and Outcomes for Varicose Veins: A Retrospective Claims Analysis

PurposeTo evaluate the impact of delaying interventional treatment on varicose vein disease progression, complications, and health care costs in a real-world setting. Materials and MethodsThis was a retrospective analysis of adults diagnosed with varicose veins between January 2008 and June 2010. Patients were followed for 2 years after diagnosis and categorized into three cohorts based on the timing of interventional therapy: early (≤ 2mo), intermediate (> 2mo but ≤ 6mo), and late (> 6 mo). Disease progression and all-cause health care costs were evaluated. ResultsA total of 44,206 patients were included, with 43% classified as receiving early interventional therapy, 33% as intermediate, and 24% as late. Early interventional treatment was associated with lower disease progression rates (29.2%) compared with intermediate (42.5%; P < .0001) and late treatment (52.2%; P < .0001). Also, early interventional treatment was associated with lower costs ($17,564) than intermediate ($17,923; P > .05) and late treatment ($18,399; P < .05). Each 30-day delay in treatment initiation was associated with a 7% higher risk of disease progression (P < .0001) and a 1% increase in costs (P < .0001). ConclusionsFindings suggest that early initiation of interventional varicose vein treatment was significantly associated with a decreased risk of disease progression and costs.

The impact of late budgets on state government borrowing costs

We analyze how a key component of fiscal governance, the ability of governments to pass a budget on time, affects government bond yield spreads. Based on a sample of 36 US states from 1988 to 1997, and using an original data set on budget enactment dates, we estimate that a 30day budget delay has a cumulative impact that is equivalent to a one-time increase in the yield spread of around 10 basis points. States with sufficient liquidity incur no costs from late budgets, while unified governments face large penalties from not finishing a budget on time.

Language Barriers, Location of Care, and Delays in Follow-up of Abnormal Mammograms

Breast cancer is frequently diagnosed after an abnormal mammography result. Language barriers can complicate communication of those results. We evaluated the association of non-English language with delay in follow-up. Retrospective cohort study of women at 3 mammography facilities participating in the San Francisco Mammography Registry with an abnormal mammogram result from 1997 to 2008. We measured median time from report of abnormal result to first follow-up test. Of 13,014 women with 16,109 abnormal mammograms, 4027 (31%) had a non-English patient language. Clinical facilities differed in proportion of non-English speakers and in time to first follow-up test: facility A (38%; 25 d), facility B (18%; 14 d), and facility C (51%; 41 d). Most mammography examinations (67%) had breast imaging and reporting data system 0 (incomplete) assessment, requiring radiographic follow-up. At 30 days of follow-up, 67% of all English speakers with incomplete assessments had a follow-up examination compared with 50% of all non-English speakers (P<0.0001). The facility with the least delay and the lowest proportion of non-English speakers, had the biggest difference by language; compared with English speakers and adjusting for education, non-English speakers had twice the odds ratio of >30-day delay in follow-up (odds ratio=2.3; 95% confidence interval, 1.4-3.9). There are considerable differences among facilities in delays in diagnostic follow-up of abnormal mammography results. More attention must be paid to understanding mammography facility factors, such as wait time to schedule diagnostic mammography and radiology workload, to improve rates of timely follow-up, particularly for those facilities disproportionately serving vulnerable non-English speaking patients.

Hepatic proliferation after partial liver irradiation in Sprague–Dawley rats

The liver has powerful capability to proliferate in response to various injuries, but little is known as to liver proliferation after irradiation (IR) injury. This study investigated whether liver proliferation could be stimulated in low-dose irradiated liver by partial liver IR injury with high dose radiation. Sprague-Dawley rats were irradiated by 6-MV X-ray with single dose of 25Gy to the right-half liver, while the left-half liver was shielded (0.7Gy) or irradiated with single doses of 3.2, 5.6, and 8.0Gy, respectively. Hepatic proliferation in the shielded and low-dose irradiated left-half liver was evaluated by serum hepatic growth factor (HGF), proliferating cell nuclei antigen (PCNA), liver proliferation index (PI), hepatocyte mitosis index (MI). The observation time was 0day (before IR), 30, 60, 90, and 120days after IR. Our results showed that serum HGF and hepatocyte HGF mRNA increased after IR with HGF mRNA peak on day 30 in the shielded and low-dose irradiated left-half livers, and their values increased as the dose increased to the left-half liver. Liver PI and PCNA mRNA peaked on day 60 with stronger expressions in higher doses-irradiated livers. MI increased after IR, with the peak noted on day 60 in the shielded and on day 90 in the low-dose irradiated left-half livers. There was a 30day delay between MI peaks in the shielded and low-dose irradiated livers. In conclusion, 25Gy partial liver IR injury could stimulate the shielded liver and low-dose irradiated liver to proliferate. In the livers receiving a dose range of 3.2-8.0Gy, the proliferation was stronger in higher doses-irradiated liver than the low-dose irradiated. However, IR delayed hepatocyte mitosis.

Model Predicts That 70% Vaccination Coverage Could Curb Pandemic

Vaccination of 70% of the U.S. population could mitigate a severe epidemic of the pandemic influenza A(H1N1) virus, according to data from simulation models and analyses of existing studies. The research was published in the online edition of the journal Science.Researchers at the Fred Hutchinson Cancer Research Center in Seattle devised models for two scenarios: prevaccination of all age and risk groups before the pandemic influenza A(H1N1) virus becomes widespread in the United States, and phased vaccination (either universal or starting with children) over time as the epidemic progresses. Phased vaccination starts either at the beginning of the spread of disease or after a 30-day delay.All the vaccination strategies studied that involved a 70% coverage rate could have a significant mitigating effect on an H1N1 epidemic, the researchers said. “Clearly, combining vaccination with other mitigation measures, such as social distancing and targeted use of antiviral agents, could be quite effective,” wrote the team led by Yang Yang, PhD.The models in the study suggested that, with a 30-day delay after the spread of infection begins, a phased vaccination strategy starting with 70% of children aged 6 months to 18 years would mitigate an epidemic, as would a phased strategy that didn't prioritize children and didn't wait until 30 days into the spread of disease. But the models suggested that a universal strategy with a 30-day delay would be less effective, the researchers noted.Without knowledge of how well matched an H1N1 vaccine is to the virus, the researchers evaluated vaccination strategies involving both heterologous and homologous vaccines. A universal prevaccination protocol with a homologous vaccine and 70% vaccination coverage would significantly mitigate an epidemic. A 50% vaccine coverage rate would mitigate an epidemic spread to levels similar to that of a relatively mild seasonal flu epidemic. But a 30% rate of coverage would not be effective, the researchers stated.More research is needed to examine the logistics of vaccination with a limited vaccine supply, the researchers said. Vaccination of 70% of the U.S. population could mitigate a severe epidemic of the pandemic influenza A(H1N1) virus, according to data from simulation models and analyses of existing studies. The research was published in the online edition of the journal Science. Researchers at the Fred Hutchinson Cancer Research Center in Seattle devised models for two scenarios: prevaccination of all age and risk groups before the pandemic influenza A(H1N1) virus becomes widespread in the United States, and phased vaccination (either universal or starting with children) over time as the epidemic progresses. Phased vaccination starts either at the beginning of the spread of disease or after a 30-day delay. All the vaccination strategies studied that involved a 70% coverage rate could have a significant mitigating effect on an H1N1 epidemic, the researchers said. “Clearly, combining vaccination with other mitigation measures, such as social distancing and targeted use of antiviral agents, could be quite effective,” wrote the team led by Yang Yang, PhD. The models in the study suggested that, with a 30-day delay after the spread of infection begins, a phased vaccination strategy starting with 70% of children aged 6 months to 18 years would mitigate an epidemic, as would a phased strategy that didn't prioritize children and didn't wait until 30 days into the spread of disease. But the models suggested that a universal strategy with a 30-day delay would be less effective, the researchers noted. Without knowledge of how well matched an H1N1 vaccine is to the virus, the researchers evaluated vaccination strategies involving both heterologous and homologous vaccines. A universal prevaccination protocol with a homologous vaccine and 70% vaccination coverage would significantly mitigate an epidemic. A 50% vaccine coverage rate would mitigate an epidemic spread to levels similar to that of a relatively mild seasonal flu epidemic. But a 30% rate of coverage would not be effective, the researchers stated. More research is needed to examine the logistics of vaccination with a limited vaccine supply, the researchers said.

Impact of delaying 5-alpha reductase inhibitor therapy in men on alpha-blocker therapy to treat BPH: assessment of acute urinary retention and prostate-related surgery

Objective:Pharmacologic treatment of lower urinary tract symptoms from benign prostatic hyperplasia (BPH) commonly includes α-blockers (ABs) and 5α-reductase inhibitors (5ARIs). Many clinicians use ABs for rapid symptom control and 5ARIs to modify long-term disease progression. The purpose of this study was to assess the clinical impact of delayed 5ARI therapy in patients treated with AB for lower urinary tract symptoms.Research design and methods:Using two nationally representative databases, two retrospective analyses were conducted including patients aged ≥50 years treated for BPH between 2000 and 2007. Clinical outcomes for those using add-on 5ARI therapy early (within 30 days of initiating AB) and late (>30 days after initiating AB) were compared. Likelihood of clinical progression, defined as the presence of acute urinary retention (AUR) and prostate surgery, was assessed over 1 year after AB initiation, and modeled as a function of the treatment cohorts and the following baseline covariates: AUR, BPH stage, Charlson Comorbidity Index, age, and number of unique diagnosis codes, unique non-BPH-related classes of prescriptions filled, and specialty care.Results:Of 6896 men included in the analyses, approximately 60% initiated 5ARI therapy within 30 days of AB therapy (the early cohort). Patients in the early cohort were less likely to have clinical progression. Each 30-day delay in starting 5ARIs resulted in an increased likelihood of overall clinical progression (average 21.1%), AUR (average 18.6%), and prostate-related surgery (average 26.7%).Conclusions:These results suggest that delaying 5ARI therapy in men with BPH increases the risk of AUR and prostate surgery.Limitations:Confounding factors, such as symptom severity and prostate volume, may have influenced the findings of the study.

Predictors of delayed return to work after back injury: A case–control analysis of union carpenters in Washington State

Union administrative records identified 20,642 union carpenters who worked in Washington State from 1989 to 2003. The Department of Labor and Industries provided records of workers' compensation claims and associated medical care. Work-related back claims (n = 4,241) were identified by ANSI codes (back, trunk, or neck/back) or ICD-9 codes relevant to medical care consistent with a back injury. Cases (n = 738) were defined as back injury claims with >90 days of paid lost time; controls (n = 699) resulted in return to work within 30 days. Logistic regression models estimated odds ratios and 95% confidence intervals (OR, 95% CI) of delayed return to work (DRTW). Thirty percent of case claims and 8% of control claims were identified by an ICD-9 code. DRTW after back injury was associated with being female (2.7, 95% CI: 1.3-5.5), age 30-44 (1.2, 95% CI: 0.9-1.7) and age over 45 (1.6, 95% CI: 1.1-2.3), four or more years union experience (1.4, 95% CI: 1.1-1.8), previous paid time loss back claim (1.8, 95% CI: 1.3-2.5), and >or=30-day delay to medical care (3.6, 95% CI: 2.1, 6.1). Evidence of more acute trauma was also associated with DRTW. Use of ICD-9 codes identified claims with multiple injuries that would otherwise not be captured by ANSI codes alone. Though carpenters of younger age and inexperience were at increased risk for a paid lost time back injury claim, older carpenters and more experienced workers, once injured, were more likely to have DRTW as were those who experienced acute events.

Effective Treatment of Established Human Breast Tumor Xenografts in Immunodeficient Mice with a Single Dose of the α-Emitting Radioisotope Astatine-211 Conjugated to Anti-HER2/neu Diabodies

Successful radioimmunotherapy strategies depend on selecting radioisotopes with physical properties complementary to the biological properties of the targeting vehicle. Small, engineered antitumor antibody fragments are capable of rapid, highly specific tumor targeting in immunodeficient mouse models. We hypothesized that the C6.5 diabody, a noncovalent anti-HER2 single-chain Fv dimer, would be an ideal radioisotope carrier for the radioimmunotherapy of established tumors using the short-lived alpha-emitting radioisotope (211)At. Immunodeficient nude mice bearing established HER2/neu-positive MDA-MB-361/DYT2 tumors treated with N-succinimidyl N-(4-[(211)At]astatophenethyl)succinamate ((211)At-SAPS)-C6.5 diabody. Additional cohorts of mice were treated with (211)At-SAPS T84.66 diabody targeting the carcinoembryonic antigen or (211)At-SAPS on a diabody specific for the Müllerian inhibiting substance type II receptor, which is minimally expressed on this tumor cell line. A single i.v. injection of (211)At-SAPS C6.5 diabody led to a 30-day delay in tumor growth when a 20 muCi dose was administered and a 57-day delay in tumor growth (60% tumor-free after 1 year) when a 45 muCi dose was used. Treatment of mice bearing the same tumors with (211)At-SAPS T84.66 diabody at the same doses led to a delay in tumor growth, but no complete responses, likely due to substantially lower expression of this antigen on the MDA-MB-361/DYT2 tumors. In contrast, a dose of 20 muCi of (211)At-SAPS on the anti-Müllerian-inhibiting substance type II receptor diabody did not affect tumor growth rate, demonstrating specificity of the therapeutic effect. These findings indicate that diabody molecules can be effective agents for targeted radioimmunotherapy of solid tumors using powerful, short-lived alpha-emitting radioisotopes.

Assessing risks of climate variability and climate change for Indonesian rice agriculture

El Niño events typically lead to delayed rainfall and decreased rice planting in Indonesia's main rice-growing regions, thus prolonging the hungry season and increasing the risk of annual rice deficits. Here we use a risk assessment framework to examine the potential impact of El Niño events and natural variability on rice agriculture in 2050 under conditions of climate change, with a focus on two main rice-producing areas: Java and Bali. We select a 30-day delay in monsoon onset as a threshold beyond which significant impact on the country's rice economy is likely to occur. To project the future probability of monsoon delay and changes in the annual cycle of rainfall, we use output from the Intergovernmental Panel on Climate Change AR4 suite of climate models, forced by increasing greenhouse gases, and scale it to the regional level by using empirical downscaling models. Our results reveal a marked increase in the probability of a 30-day delay in monsoon onset in 2050, as a result of changes in the mean climate, from 9-18% today (depending on the region) to 30-40% at the upper tail of the distribution. Predictions of the annual cycle of precipitation suggest an increase in precipitation later in the crop year (April-June) of approximately 10% but a substantial decrease (up to 75% at the tail) in precipitation later in the dry season (July-September). These results indicate a need for adaptation strategies in Indonesian rice agriculture, including increased investments in water storage, drought-tolerant crops, crop diversification, and early warning systems.

Effect of surgical delay on early mortality in patients with femoral neck fracture

The aim of this study was to investigate the relationship between the delay between surgical treatment and mortality occurring within 30 days post-injury in patients aged 60 or older with femoral neck fracture. Data derive from the nationwide database of the National Health Insurance Fund Administration. Logistic regression analysis was performed to analyse the relationship between 30-day mortality and surgical delay in four groups of patients operated on within 12 h, between 12-24 h, 24-48 h or over 48 h post-injury. There were 3,777 patients involved in the study. Mortality rates in the four groups were 7.7%, 10.5%, 10.5% and 9.4%, respectively. Univariate logistic regression analysis revealed a statistically significant increase in the mortality risk in the 12-24-h treatment group compared to the group treated within 12 h (odds ratio, OR(12-24h)=1.413, confidence interval, CI(12-24h): 1.032-1.935; p=0.031). According to multiple regression analysis, all three groups (12-24 h, 24-48 h and over 48 h) showed a trend to increased mortality risks, but this was not statistically significant (OR(12-24h)=1.301, CI(12-24h): 0.945-1.791, p=0.106; OR(24-48 h)=1.384, CI(24-48 h): 0.932-2.056, p=0.108; OR(>48 h)=1.246, CI(>48 h): 0.950-1.635, p=0.113). We can conclude that sex, age and accompanying diseases significantly influenced early mortality, while early post-operative complications did not have a significant impact on the mortality risks.

Association of Food Quality and Locations by Cattle

Twelve yearling steers were observed in an 8-arm radial maze to determine the strength of the association between food quality and spatial locations following a 0- or 30-day delay. The study was conducted using 3 qualities of feed, low (straw), medium (alfalfa pellets), and high (grain). During phase 1, all 8 arms contained dehydrated alfalfa pellets. In phase 2, steers were fed either grain or wheat straw, in 2 arms (key arms). The remaining 6 arms contained alfalfa pellets. Six steers received straw in key arms, and 6 received grain. Key arms varied among steers and were selected so a change in arm selection patterns between phases would clearly be associated with corresponding changes in food quality. Straw was placed in arms that steers selected first during phase 1, and grain was placed in arms that were selected last in phase 1. Phase 3 began after a 0- or 30-day delay following phase 2. In this phase, all arms contained alfalfa. Steers rarely reentered a previously entered arm indicating an accurate spatial memory for food location. The sequence of arm selections in phase 2 changed (P 0.05) the selection patterns of steers that had grain in key arms, but did appear to affect the number and sequence of arm entries for steers receiving low quality food in key arms during phase 2. With no delay, steers that received straw in phase 2 did not enter key arms on the first day of phase 3, but after 30 days animals entered and consumed food in key arms. Steers with no delay entered key arms fewer (P = 0.03) times during phase 3 than steers that began 30 days later. This suggests that strength of the association between food quality and spatial locations can decline over time.

Acute biliary pancreatitis. The roles of laparoscopic cholecystectomy and endoscopic retrograde cholangiopancreatography.

Since January 1990, we have treated 113 patients for gallstone pancreatitis; 59 with laparoscopic cholecystectomy (LC), 50 with open cholecystectomy, and 4 with ERCP/sphincterotomy only. In the LC group, 47 had LC during the index admission and 12 underwent delayed LC. Fifty patients had open cholecystectomy, 47 during the index admission. ERCPs were performed in 43 of the 113 patients; CBD stones were identified in 19/43 (44%) and removed endoscopically in 18 (95%). The ERCP complication rate was 6.5%. In total, CBD stones were identified in 29/113 patients (26%). Patients who had imaging of the CBD within the first 4 days from onset of symptoms were more likely to have stones identified than were those patients who were studied after 5 days. Recurrent pancreatitis occurred in in five of 11 patients (45%) who had a > or = 30-day delay to definitive treatment. We conclude that LC can be safely performed in most patients during the index admission for gallstone pancreatitis. This policy should reduce the 30-50% risk of recurrent pancreatitis associated with a delayed operation. ERCP is a helpful adjunct for CBD stones.

The recency effect in pigeons’ long-term memory

Four experiments are reported in which pigeons first learned one wavelength discrimination (green S+, yellow S−) and then the reversal; finally, after various delays, they were tested for wavelength generalization in extinction. In Experiment 1, the two problems were learned in different contexts; testing in Context 1 produced maximal responding to green in only half of the subjects, even when testing was delayed 30 days. In Experiment 2, testing of the subjects repeatedly in both contexts showed good control by each context after a 30-day delay. In Experiment 3, both problems were learned in the same context, and all gradients showed recency, peaking at yellow, even after 30 days. In Experiment 4, the subjects learned a series of reversals in the same context, terminating in yellow, S+, green, S−, and their gradients peaked at yellow, even after a 30-day delay. In Experiments 3 and 4, the gradients became flatter with increasing delays, and they were flatter in Experiment 4 (after three reversals) than in Experiment 3 (after one reversal). The location of the peak was not affected by delay, but only by testing in a context that had been uniquely associated with Problem 1 (Experiments 1 and 2). It is proposed that the location of gradient peaks indicates what is being remembered, whereas the slope of the obtained gradients indicates how well the target memory has been retrieved.

Persistence of Cotton (Gossypium hirsutum) Herbicides and Injury to Replacement Soybeans (Glycine max) after Stand Failure

Soybeans [Glycine max(L.) Merr.] are often the replacement crop when cotton (Gossypium hirsutumL.) is abandoned because of stand failure in the southern United States. Injury from cotton herbicides may be reduced if the soybean planting is delayed more than 4 weeks after cotton planting or if the original herbicide-treated area is fully tilled and a new seedbed formed. Planting delay intervals were compared with five cotton preemergence herbicides on Calloway silt loam at one location. Seedbed-preparation methods were included in a similar experiment at two locations on Sharkey silty clay. Herbicides compared were fluometuron [1,1-dimethyl-3-(α,α,α-trifluoro-m-tolyl)urea], norflurazon [4-chloro-5-(methylamino)-2-(α,α,α-trifluoro-m-tolyl)-3(2H)-pyridazinone], cyanazine {2-[[4-chloro-6-(ethylamino)-s-triazin-2-yl] amino]-2-methylpropionitrile}, perfluidone {1,1,1-trifluoro-N-[2-methyl-4-phenylsulfonyl)phenyl] methanesulfonamide}, fluridone {1-methyl-3-phenyl-5-[3-(trifluoromethyl)phenyl]-4(1H)-pyridinone}, and diuron [3-(3,4-dichlorophenyl)-1,1-dimethylurea]. Seedbeds compared were no-till and conventional (fully tilled). Soybean planting delays after cotton planting were 20, 29, and 56 days (first year), and 15 and 29 or 15 and 30 days (second year). We found in the 2-yr studies that fluridone severely damaged soybeans both years. Fluometuron and diuron also caused damage the second year when we experienced wet, cool conditions in the spring. Most injury occurred on the clay, with yield reductions occurring even after the 30-day delay. Norflurazon was most injurious at this location. The no-tillage planting method resulted in the least herbicide injury on the silt loam and the conventional tillage method was better on the clay. Detailed studies with fluometuron under incubation conditions showed that degradation was inhibited most by low temperatures and high soil moisture.