Evaluating phytochemical and microbial contributions to atrazine degradation

The inclusion of warm-season grasses, such as switchgrass (Panicum virgatum) and eastern gamagrass (EG) (Tripsacum dactyloides), in vegetated buffer strips has been shown to mitigate herbicide contamination in runoff and increase herbicide degradation in soil. The mode of action by which buffer strip rhizospheres enhance herbicide degradation remains unclear, but microorganisms and phytochemicals are believed to facilitate degradation processes. The objectives of this study were to: 1) screen root extracts from seven switchgrass cultivars for the ability to degrade the herbicide atrazine (ATZ) in solution; 2) determine sorption coefficients (K_d) of the ATZ-degrading phytochemical 2-β-D-glucopyranosyloxy-4-hydroxy-1,4-benzoxazin-3-one (DBG) to soil and Ca-montmorillonite, and investigate if DBG or ATZ sorption alters degradation processes; and 3) quantify ATZ degradation rates and soil microbial response to ATZ application in mesocosms containing soil and select warm-season grasses. Phytochemicals extracted from the roots of switchgrass cultivars degraded 44-85% of ATZ in 16-h laboratory assays, demonstrating that some switchgrass cultivars could rapidly degrade ATZ under laboratory conditions. However, attempts to isolate ATZ-degrading phytochemicals from plant roots were unsuccessful. Sorption studies revealed that DBG was strongly sorbed to soil (K_d = 87.2 L kg^-1) and Ca-montmorillonite (K_d = 31.7 L kg^-1), and DBG driven hydrolysis of ATZ was entirely inhibited when either ATZ or DBG were sorbed to Ca-montmorillonite. Atrazine degradation rates in mesocosm soils were rapid (t_0.5 = 8.2-11.2 d), but not significantly different between soils collected from the two switchgrass cultivar mesocosms, the eastern gamagrass cultivar mesocosm, and the unvegetated mesocosm (control). Significant changes in three phospholipid fatty acid biomarkers were observed among the treatments. These changes indicated that different ATZ-degrading microbial consortia resulted in equivalent ATZ degradation rates between treatments. Results demonstrated that soil microbial response was the dominant mechanism controlling ATZ degradation in the soil studied, rather than root phytochemicals.

Entry of Graduates of US Pathology Residency Programs Into the Workforce: Cohort Data Between 2008 and 2016 Remain Positive and Stable

The pathologist workforce in the United States is a topic of interest to the health-care community as a whole and to institutions responsible for the training of new pathologists in particular. Although a pathologist shortage has been projected, there has been a pervasive belief by medical students and their advisors that there are “no jobs in pathology.” In 2013 and again in 2017, the Program Directors Section of the Association of Pathology Chairs conducted surveys asking pathology residency directors to report the employment status of each of their residents graduating in the previous 5 years. The 2013 Program Directors Section survey indicated that 92% of those graduating in 2010 had obtained employment within 3 years, and 94% of residents graduating in 2008 obtained employment within 5 years. The 2017 survey indicated that 96% of those graduating in 2014 had obtained employment in 3 years, and 97% of residents graduating in 2012 obtained positions within 5 years. These findings are consistent with residents doing 1 or 2 years of fellowship before obtaining employment. Stratification of the data by regions of the country or by the size of the residency programs does not show large differences. The data also indicate a high percentage of employment for graduates of pathology residency programs and a stable job market over the years covered by the surveys.

Gender Parity in Gainful Employment and Other Gender Trends in the Job Market for Recent Pathology Graduates

Context.—

Gender-based barriers to equal salary, career advancement, and leadership still exist in medicine. Herein we provide the first report of data comparing the experiences of men and women seeking their first nonfellowship position in pathology.

Objective.—

To identify gender trends regarding pathologists taking their first job after training and the relationship to various demographic factors, job search satisfaction, and outcome.

Design.—

Aggregate data from the College of American Pathologists Graduate Medical Education Committee Job Market surveys (2015–2018) were analyzed across multiple domains including residency focus, number and subspecialty of fellowships completed, and extent to which expectations were met in regard to work duties, geographic preference, benefits, and salary. These data were examined in the context of assessing gender-based differences.

Results.—

Comparable results were identified in all measured outcomes according to gender. There were no differences between gender and medical school type, relocation, residency training focus, number of fellowships completed, overall satisfaction with position accepted, salary, or extent to which the position met expectations. Similarly, there were also no discrepancies between gender and the geographic region in which positions were accepted, practice setting, practice subspecialty, partnership track, length of job search, or difficulty finding a position.

Conclusions.—

Analysis from 4 years of job market survey data shows equivalent results between men and women looking for their first nonfellowship position in pathology. There were no significant differences with regard to difficulty finding a position, overall satisfaction with the position accepted, salary, benefits, or access to partnership track.

The Increasing Incidence of Remote Metastasis: A Case Report of Metastatic Hepatocellular Carcinoma to the Rectosigmoid

As the fifth most common malignancy worldwide, survival rates of hepatocellular carcinoma (HCC) have only slightly improved over the years due to early-stage detection. HCC is well known to metastasize to the lung, lymph nodes, and musculoskeletal regions; however, only 0.5% to 6% of HCCs metastasize to the gastrointestinal tract. In the case described here, a CT scan and subsequent colonoscopy of a 51-year-old Asian male with a history of hepatitis B and HCC revealed a mass lesion of metastatic HCC 12 cm from the anal verge. Because metastatic HCC to the lower gastrointestinal tract has only recently been reported, it is speculated that the prolonged survival of patients is also increasing the incidence of extrahepatic metastasis, giving the disease greater opportunity to spread to more distant regions of the body. This case may be the farthest metastasis within the gastrointestinal tract to date.

Development of Professionalism in Graduate Medical Education: A Case-Based Educational Approach From the College of American Pathologists' Graduate Medical Education Committee

Professionalism and physician well-being are important topics in academic medicine. Lapses in professional judgment may lead to disciplinary action and put patient's health at risk. Within medical education, students and trainees are exposed to professionalism in the institution's formal curriculum and hidden curriculum. Development of professionalism starts early in medical school. Trainees entering graduate medical education already have developed professional behavior. As a learned behavior, development of professional behavior is modifiable. In addition to role modeling by faculty, other modalities are needed. Use of case vignettes based on real-life issues encountered in trainee and faculty behavior can serve as a basis for continued development of professionalism in trainees. Based on the experience of program directors and pathology educators, case vignettes were developed in the domains of service, research, and education and subdivided into the areas of duty, integrity, and respect. General and specific questions pertaining to each case were generated to reinforce model behavior and overcome professionalism issues encountered in the hidden curriculum. To address physician burnout, cases were generated to provide trainees with the skills to deal with burnout and promote well-being.

The Recent Pathology Residency Graduate Job Search Experience: A Synthesis of 5 Years of College of American Pathologists Job Market Surveys

CONTEXT

- Pathology residents and fellows tailor their training and job search strategies to an actively evolving specialty in the setting of scientific and technical advances and simultaneous changes in health care economics.

OBJECTIVE

- To assess the experience and outcome of the job search process of pathologists searching for their first non-fellowship position.

DESIGN

- The College of American Pathologists (CAP) Graduate Medical Education Committee has during the past 5 years sent an annual job search survey each June to CAP junior members and fellows in practice 3 years or less who have actively searched for a non-fellowship position.

RESULTS

- Job market indicators including job interviews, job offers, positions accepted, and job satisfaction have remained stable during the 5 years of the survey. Most survey respondents who had applied for at least 1 position had accepted a position at the time of the survey, and most applicants who had accepted a position were satisfied or very satisfied. However, most attested that finding a non-fellowship position was difficult. Despite a perceived push toward subspecialization in surgical pathology, the reported number of fellowships completed was stable. Respondent demographics were not associated with job search success with 1 significant exception: international medical school graduate respondents reported greater perceived difficulty in finding a position, and indeed, fewer reported having accepted a position.

CONCLUSIONS

- Pathology residents and fellows seeking their first position have faced a relatively stable job market during the last 5 years, with most accepting positions with which they were satisfied.

Entrustable Professional Activities for Pathology: Recommendations From the College of American Pathologists Graduate Medical Education Committee

Competency-based medical education has evolved over the past decades to include the Accreditation Council for Graduate Medical Education Accreditation System of resident evaluation based on the Milestones project. Entrustable professional activities represent another means to determine learner proficiency and evaluate educational outcomes in the workplace and training environment. The objective of this project was to develop entrustable professional activities for pathology graduate medical education encompassing primary anatomic and clinical pathology residency training. The Graduate Medical Education Committee of the College of American Pathologists met over the course of 2 years to identify and define entrustable professional activities for pathology graduate medical education. Nineteen entrustable professional activities were developed, including 7 for anatomic pathology, 4 for clinical pathology, and 8 that apply to both disciplines with 5 of these concerning laboratory management. The content defined for each entrustable professional activity includes the entrustable professional activity title, a description of the knowledge and skills required for competent performance, mapping to relevant Accreditation Council for Graduate Medical Education Milestone subcompetencies, and general assessment methods. Many critical activities that define the practice of pathology fit well within the entrustable professional activity model. The entrustable professional activities outlined by the Graduate Medical Education Committee are meant to provide an initial framework for the development of entrustable professional activity–related assessment and curricular tools for pathology residency training.

Benzoxazinone-Mediated Triazine Degradation: A Proposed Reaction Mechanism

The role of benzoxazinones (Bx, 2-hydroxy-2H-1,4-benzoxazin-3(4H)-one) in triazine resistance in plants has been studied for over half a century. In this research, fundamental parameters of the reaction between DIBOA-Glc (2-β-d-glucopyranosyloxy-4-hydroxy-1,4-benzoxazin-3-one) and atrazine (ATR, 6-chloro-N-ethyl-N'-(1-methylethyl)-1,3,5-triazine-2,4-diamine) were examined. Through a series of experiments employing a variety of chromatographic and spectroscopic techniques, the DIBOA-Glc/ATR reaction was characterized in terms of reactant and product kinetics, stoichiometry, identification of a reaction intermediate, and reaction products formed. Results of these experiments demonstrated that the reaction mechanism proceeds via nucleophilic attack of the hydroxamic acid moiety of DIBOA-Glc at the C-2 position of the triazine ring to form hydroxyatrazine (HA, 2-hydroxy-4-ethylamino-6-isopropylamino-s-triazine), with associated degradation of DIBOA-Glc. Degradation of reactants followed first-order kinetics with a noncatalytic role of DIBOA-Glc. A reaction intermediate was identified as a DIBOA-Glc-HA conjugate, indicating a 1:1 DIBOA-Glc:ATR stoichiometry. Reaction products included HA and Cl(-), but definitive identification of DIBOA-Glc reaction product(s) was not attained. With these reaction parameters elucidated, DIBOA-Glc can be evaluated in terms of its potential for a myriad of applications, including its use to address the problem of widespread ATR contamination of soil and water resources.

Cortical oxygenation suggests increased effort during cognitive inhibition in ecstasy polydrug users

BACKGROUND

It is understood that 3,4-methylenedioxymethamphetamine (ecstasy) causes serotonin dysfunction and deficits in executive functioning. When investigating executive function, functional neuroimaging allows the physiological changes underlying these deficits to be investigated. The present study investigated behavioural and brain indices of inhibition in ecstasy-polydrug users.

METHODS

Twenty ecstasy-polydrug users and 20 drug-naïve participants completed an inhibitory control task (Random Letter Generation (RLG)) while prefrontal haemodynamic response was assessed using functional near infrared spectroscopy (fNIRS).

RESULTS

There were no group differences on background measures including sleep quality and mood state. There were also no behavioural differences between the two groups. However, ecstasy-polydrug users displayed significant increases in oxygenated haemoglobin (oxy-Hb) from baseline compared to controls at several voxels relating to areas of the inferior right medial prefrontal cortex, as well the right and left dorsolateral prefrontal cortex. Regression analysis revealed that recency of ecstasy use was a significant predictor of oxy-Hb increase at two voxels over the right hemisphere after controlling for alcohol and cannabis use indices.

CONCLUSION

Ecstasy-polydrug users show increased neuronal activation in the prefrontal cortex compared to non-users. This is taken to be compensatory activation/recruitment of additional resources to attain similar performance levels on the task, which may be reversible with prolonged abstinence.

Differences in prefrontal blood oxygenation during an acute multitasking stressor in ecstasy polydrug users

BACKGROUND

Cognitive deficits are well documented in ecstasy (3,4-methylenedioxymethamphetamine; MDMA) users, with such deficits being taken as evidence of dysregulation of the serotonin (5-hydroxytryptamine; 5-HT) system. More recently neuroimaging has been used to corroborate these deficits. The present study aimed to assess multitasking performance in ecstasy polydrug users, polydrug users and drug-naive individuals. It was predicted that ecstasy polydrug users would perform worse than non-users on the behavioural measure and this would be supported by differences in cortical blood oxygenation.

METHOD

In the study, 20 ecstasy-polydrug users, 17 polydrug users and 19 drug-naive individuals took part. On day 1, drug use history was taken and questionnaire measures were completed. On day 2, participants completed a 20-min multitasking stressor while brain blood oxygenation was measured using functional near infrared spectroscopy (fNIRS).

RESULTS

There were no significant differences between the three groups on the subscales of the multitasking stressor. In addition, there were no significant differences on self-report measures of perceived workload (NASA Task Load Index). In terms of mood, ecstasy users were significantly less calm and less relaxed compared with drug-naive controls. There were also significant differences at three voxels on the fNIRS, indicating decreased blood oxygenation in ecstasy users compared with drug-naive controls at voxel 2 (left dorsolateral prefrontal cortex), voxel 14 and voxel 16 (right dorsolateral prefrontal cortex), and compared with polydrug controls at V14.

CONCLUSIONS

The results of the present study provide support for changes in brain activation during performance of demanding tasks in ecstasy polydrug users, which could be related to cerebral vasoconstriction.

Lymphocytic gastritis is not associated with active Helicobacter pylori infection

BACKGROUND

Lymphocytic gastritis (LG), characterized by marked intra-epithelial lymphocytosis in the gastric mucosa, has been frequently associated with both celiac disease (CD) and H. pylori gastritis. The aim of this study was to review and correlate the morphology of LG with the presence of CD and H. pylori.

MATERIALS AND METHODS

Gastric biopsies diagnosed with LG from 1/1/2006 to 8/1/2013 at our institution and corresponding small bowel biopsies, when available, were reviewed for verification of the diagnosis and to assess for the presence of H. pylori and CD. Immunohistochemical (IHC) staining for H. pylori was performed on all gastric biopsies. Demographic, clinical, and laboratory data were obtained from the medical record.

RESULTS

Fifty-four of the 56 cases that met inclusion criteria demonstrated significant intra-epithelial lymphocytosis as the predominant histologic abnormality; however, none were associated with H. pylori infection by IHC staining. Two cases that also showed a prominent intra-epithelial and lamina propria neutrophilic infiltrate were both positive for H. pylori and were excluded from further study. Of the 36 small bowel biopsies available, 19 (53%) showed changes in CD.

CONCLUSIONS

LG is not a distinct clinicopathologic entity, but a morphologic pattern of gastric injury that can be secondary to a variety of underlying etiologies. When restricted to cases with lymphocytosis alone, LG is strongly associated with CD and not with active H. pylori infection. However, cases that also show significant neutrophilic infiltrate should be regarded as "active chronic gastritis" and are often associated with H. pylori infection. A morphologic diagnosis of LG should prompt clinical and serologic workup to exclude underlying CD.

Evaluation of skeletal tissue repair, part 2: enhancement of skeletal tissue repair through dual-growth-factor-releasing hydrogels within an ex vivo chick femur defect model

There is an unmet need for improved, effective tissue engineering strategies to replace or repair bone damaged through disease or injury. Recent research has focused on developing biomaterial scaffolds capable of spatially and temporally releasing combinations of bioactive growth factors, rather than individual molecules, to recapitulate repair pathways present in vivo. We have developed an ex vivo embryonic chick femur critical size defect model and applied the model in the study of novel extracellular matrix (ECM) hydrogel scaffolds containing spatio-temporal combinatorial growth factor-releasing microparticles and skeletal stem cells for bone regeneration. Alginate/bovine bone ECM (bECM) hydrogels combined with poly(d,l-lactic-co-glycolic acid) (PDLLGA)/triblock copolymer (10-30% PDLLGA-PEG-PLDLGA) microparticles releasing dual combinations of vascular endothelial growth factor (VEGF), chondrogenic transforming growth factor beta 3 (TGF-β3) and the bone morphogenetic protein BMP2, with human adult Stro-1+bone marrow stromal cells (HBMSCs), were placed into 2mm central segmental defects in embryonic day 11 chick femurs and organotypically cultured. Hydrogels loaded with VEGF combinations induced host cell migration and type I collagen deposition. Combinations of TGF-β3/BMP2, particularly with Stro-1+HBMSCs, induced significant formation of structured bone matrix, evidenced by increased Sirius red-stained matrix together with collagen expression demonstrating birefringent alignment within hydrogels. This study demonstrates the successful use of the chick femur organotypic culture system as a high-throughput test model for scaffold/cell/growth factor therapies in regenerative medicine. Temporal release of dual growth factors, combined with enriched Stro-1+HBMSCs, improved the formation of a highly structured bone matrix compared to single release modalities. These studies highlight the potential of a unique alginate/bECM hydrogel dual growth factor release platform for bone repair.

The increasing incidence of remote metastasis: a case report of metastatic hepatocellular carcinoma to the rectosigmoid

As the fifth most common malignancy worldwide, survival rates of hepatocellular carcinoma (HCC) have only slightly improved over the years due to early-stage detection. HCC is well known to metastasize to the lung, lymph nodes, and musculoskeletal regions; however, only 0.5% to 6% of HCCs metastasize to the gastrointestinal tract. In the case described here, a CT scan and subsequent colonoscopy of a 51-year-old Asian male with a history of hepatitis B and HCC revealed a mass lesion of metastatic HCC 12 cm from the anal verge. Because metastatic HCC to the lower gastrointestinal tract has only recently been reported, it is speculated that the prolonged survival of patients is also increasing the incidence of extrahepatic metastasis, giving the disease greater opportunity to spread to more distant regions of the body. This case may be the farthest metastasis within the gastrointestinal tract to date.

Propofol infusion syndrome or not? A case report

BACKGROUND

Propofol is commonly used and well tolerated for induction of general anesthesia and is also used as a sedative in the intensive care unit. However, in rare cases, the agent may cause a fatal condition known as propofol infusion syndrome (PRIS).

CASE REPORT

We present a case of PRIS that could have been fatal in a previously healthy male patient with multiple gunshot wounds.

CONCLUSION

Because patients typically exhibit other potentially fatal comorbidities, PRIS is always a diagnosis of exclusion. The true incidence of PRIS remains unknown, and more objective criteria for its diagnosis need to be established.

Electrophysiological indices of response inhibition in human polydrug users

Previous research in ecstasy users suggests impairment of various executive functions. In general, the executive function of response inhibition appears unaffected by ecstasy use. Nonetheless, it remains a possibility that cognitive tasks alone are not sensitive enough to pick up subtle changes in function. The current study sought to investigate behavioural measures of response inhibition and their electrophysiological correlates in drug users. Twenty ecstasy polydrug users, 20 non-ecstasy polydrug users and 20 drug naïve controls were recruited. Participants completed questionnaires about their background drug use, sleep quality, fluid intelligence and mood state. Each individual also completed a Go/NoGo response inhibition task whilst electroencephalography (EEG) measures were recorded. Analysis of variance (ANOVA) revealed that there were no between-group differences on the behavioural measure of response inhibition. Multivariate analysis of variance (MANOVA) revealed no main effect of group across midline electrodes for the P3, N2 and P2 components. Univariate ANOVA revealed significant between-group differences in the P2 component with the ecstasy user group having a significantly higher mean amplitude than drug naïve controls at two midline frontal electrodes: at Fz and significantly higher mean amplitude than both control groups at FCz. The present study provides evidence of atypical early processing in ecstasy users that is suggestive of compensatory mechanisms ameliorating any behavioural differences.

Incidence of diagnostic change in colorectal polyp specimens after deeper sectioning at 2 different laboratories staffed by the same pathologists

OBJECTIVES

To calculate the incidence of nondiagnostic (ND) colorectal (CR) polyp cases in which deeper tissue sectioning rendered new diagnostic information--particularly adenomas--in 2 laboratories staffed by the same pathologists.

METHODS

After initial diagnosis, 100 ND CR polyps from each laboratory were reexamined with 3 deeper levels to establish rates of diagnostic conversion based on biopsy specimen location and original observation(s).

RESULTS

Deeper sectioning rendered new diagnostic information in 43 (21.5%) of 200 biopsy specimens and specifically adenomas in 16 (8.0%) of 200 biopsy specimens.

CONCLUSIONS

These results support routine ordering of deeper levels on ND CR polyps to improve adenoma detection rates, especially those cases without any histologic abnormality. If another biopsy in the same case already is adenomatous, examination of deeper levels may not be necessary, as it may not have any significant effect on the clinical management of the patient.

ERP evidence suggests executive dysfunction in ecstasy polydrug users

BACKGROUND

Deficits in executive functions such as access to semantic/long-term memory have been shown in ecstasy users in previous research. Equally, there have been many reports of equivocal findings in this area. The current study sought to further investigate behavioural and electro-physiological measures of this executive function in ecstasy users.

METHOD

Twenty ecstasy-polydrug users, 20 non-ecstasy-polydrug users and 20 drug-naïve controls were recruited. Participants completed background questionnaires about their drug use, sleep quality, fluid intelligence and mood state. Each individual also completed a semantic retrieval task whilst 64 channel Electroencephalography (EEG) measures were recorded.

RESULTS

Analysis of Variance (ANOVA) revealed no between-group differences in behavioural performance on the task. Mixed ANOVA on event-related potential (ERP) components P2, N2 and P3 revealed significant between-group differences in the N2 component. Subsequent exploratory univariate ANOVAs on the N2 component revealed marginally significant between-group differences, generally showing greater negativity at occipito-parietal electrodes in ecstasy users compared to drug-naïve controls. Despite absence of behavioural differences, differences in N2 magnitude are evidence of abnormal executive functioning in ecstasy-polydrug users.

Mobility histories of 7th-9th century AD people buried at early medieval Bamburgh, Northumberland, England

Early Medieval England is described historically as a time when people migrated from the Continent to English shores. This study tests the hypothesis that those buried in the Bowl Hole cemetery, Bamburgh, Northumberland were nonlocally born, because of its royal status. Ninety-one male and female adult, and nonadult, skeletons were studied. Isotope ratios of strontium ((87) Sr/(86) Sr) and oxygen (δ(18) O) were generated for 78 individuals (28 females, 27 males, five "adults," 18 nonadults). The mean Sr value for human enamel was 0.71044, standard deviation (sd) 0.001, and the mean O (δw) value is -5.9‰, sd 1.6‰. Additionally, animal tooth enamel (mean Sr value 0.710587, sd 0.001; mean O value -6.5‰, sd 1.5‰), local soil (mean Sr value 0.709184, sd 0.0006), snail shells (mean Sr value 0.708888, sd 0.0001), and soil samples from a 5 km transect heading inland (mean Sr value 0.709121, sd 0.0003), were analyzed for an indication of the isotopic composition of bioavailable Sr in the modern environment and to assess the impact of sea-spray; water samples from a well, local rivers, and standing water were analyzed for local δ(18) O values (mean O value -6.4‰, relative to VSMOW, sd 2.8‰). Over 50% of those buried at Bamburgh were nonlocal. All ages and both sexes produced "nonlocal" signatures; some suggested childhood origins in Scandinavia, the southern Mediterranean or North Africa. Stature and other indicators of health status indicated differences in quality of life between local and migrant groups. These differences did not extend to burial practices.

Esophageal lichen planus: A case report and review of the literature

Esophageal involvement by lichen planus (ELP), previously thought to be quite rare, is a disease much more common in women and frequently the initial manifestation of mucocutaneous lichen planus (LP). Considering that the symptoms of ELP do not present in a predictable manner, ELP is perhaps more under-recognized than rare. To date, four cases of squamous cell carcinoma in association with ELP have been reported, suggesting that timely and accurate diagnosis of ELP is of importance for appropriate follow-up. In this case report, a 69-year-old female presented with dysphagia and odynophagia. She reported a history of oral LP but had no active oral or skin lesions. Endoscopic examination revealed severe strictures and web-like areas in the esophagus. Histologic examination demonstrated extensive denudation of the squamous epithelium, scattered intraepithelial lymphocytes, rare eosinophils and dyskeratotic cells. Direct immunofluorescence showed rare cytoid bodies and was used to exclude other primary immunobullous disorders. By using clinical, endoscopic, and histologic data, a broad list of differential diagnoses can be narrowed, and the accurate diagnosis of ELP can be made, which is essential for proper treatment and subsequent follow-up.

Isotopic tracing of the impact of mobility on infectious disease: The origin of people with treponematosis buried in hull, England, in the late medieval period

Treponematosis has been one of the most studied and debated infectious diseases in paleopathology, particularly from the standpoint of its origin, evolution, and transmission. This study links evidence for treponematosis in skeletons from the 14th-16th century AD cemetery of the Augustinian friary of Hull Magistrates Court, England, with data from stable isotope analysis to test the hypothesis that the people with treponemal disease buried at this site were not locally born and raised. The objective is to explore the potential of using stable isotope data to track the place of origin and extent of mobility of individuals with an infectious disease. Dental enamel samples of 12 skeletons were selected for strontium ((87) Sr/(86) Sr ratio) and oxygen (δ(18) O) stable isotope analysis based on the presence (six - diseased) or absence (six - controls) of bone changes associated with treponemal disease. The oxygen isotope ratios of all but three individuals (1047, 1121, 823) overlapped at two standard deviations with the inferred local precipitation range, and only one individual (1216) had a strontium isotope ratio outside the regional range. Two of the four had probable/possible treponemal bone changes. Those with treponemal bone changes were not demonstrably more likely to be migrants than those without such lesions. However, because of extensive documentary evidence for trade with the Baltic Sea area, and for merchants from towns such as Stralsund, Danzig and Elbing being in Hull, it is very plausible that the four migrants came from the Baltic area or even southern Sweden.

The effect of inspired gas density on pulmonary artery transmural pressure and exercise induced pulmonary haemorrhage

REASONS FOR PERFORMING STUDY

Pulmonary capillary stress failure, largely as a result of high pulmonary vascular pressures, has been implicated in the aetiology of EIPH. However, the role of the respiratory system in determining the magnitude of EIPH has received little attention.

HYPOTHESIS

Horses breathing a gas of greater density than air will exhibit greater transmural pulmonary arterial pressures (TPAP) and more severe EIPH, and horses breathing a gas of lower density than air will exhibit lower TPAP and less severe EIPH, both compared with horses breathing air.

METHODS

Following a warm-up, 8 Thoroughbred horses were exercised for 1 min at 10, 11 and 12 m/sec (5 degrees incline) breathing air or 21% oxygen/79% helium or 21% oxygen/79% argon in a randomised order. Heart rate, respiratory rate, pulmonary arterial pressure and oesophageal pressure were measured during exercise. Bronchoalveolar lavage fluid (BALF) was collected from the dorsocaudal regions of the left and right lungs 40 min post exercise and red blood cell (RBC) counts were performed.

RESULTS

The exercise tests induced mild EIPH. Maximum changes in oesophageal pressure were lower on helium-oxygen compared to argon-oxygen (P<0.001). TPAP and median RBC counts did not differ between gas mixtures. BALF RBC counts from the left lung correlated with counts from the right lung (P<0.0001). However BALF RBC counts from the left lung were higher than those from the right lung (P = 0.004).

CONCLUSION

As alterations in pulmonary arterial and oesophageal pressure caused by changes in inspired gas density were of similar magnitude, TPAP remained unchanged and there was no significant effect on EIPH severity.

POTENTIAL RELEVANCE

Manipulations that decrease swings in intrapleural pressure may only decrease the degree of EIPH in horses severely affected by the condition.

Influence of toxic endophyte-infected fescue on sperm characteristics and endocrine factors of yearling Brahman-influenced bulls

Sixteen (mean age = 1.1 +/- 0.1 yr; mean BW = 478 +/- 34 kg) Brahman-influenced bulls were used to determine the influence of fescue type on sperm characteristics and serum concentrations of prolactin, cortisol, and testosterone. Bulls were blocked by BW, scrotal circumference (SC), and pregrazing sperm characteristics and randomly assigned to graze toxic endophyte-infected (EI; 4 bulls/pasture; 2 pastures) or novel endophyte-infected (NE; 4 bulls/pasture; 2 pastures) tall fescue for 121 d. Semen was collected by electroejaculation, and SC was measured and blood samples collected monthly. Sperm were evaluated for motility and morphology with an integrated visual optical system. Overall mean concentration of prolactin was decreased more (P < 0.01) in EI bulls than NE bulls from May to August. Scrotal circumference was not affected by fescue type (P = 0.58); overall SC averaged 36.7 +/- 2.3 cm. Percentage of live sperm was not different (P = 0.24) between NE bulls (80%) than EI bulls (67%) in July and August. Bulls grazing NE fescue had more (P < 0.06) motile sperm than EI bulls in July and August. Percentages of progressive (57 vs. 38%, NE and EI, respectively; P < 0.06) and rapid (67 vs. 46%, NE and EI, respectively; P = 0.04) sperm were greater from bulls grazing NE than EI bulls in July and August. Average velocity of the smoothed sperm path and progressive velocity in a straight line from the beginning to the end of the sperm track were slower (P < 0.09) in EI bulls than NE bulls and were slower (P = 0.04) in August compared with July. Mean width of head oscillation as the sperm swims was less (P < 0.06) in August than July. Concentrations of cortisol and testosterone were not (P > 0.10) influenced by fescue type. Semen from bulls grazing EI had reduced motility and morphology than bulls grazing NE. Detrimental effects of toxic fescue may not be mediated by cortisol, testosterone, or both. Semen quality of bulls grazing toxic EI tall fescue was decreased with increased maximum ambient temperatures.

Allocating forage to fall-calving cow-calf pairs strip-grazing stockpiled tall fescue

In a 2-yr study, we evaluated the effect of different forage allocations on the performance of lactating beef cows and their calves grazing stockpiled tall fescue. Allocations of stockpiled tall fescue at 2.25, 3.00, 3.75, and 4.50% of cow-calf pair BW/d were set as experimental treatments. Conventional hay-feeding was also evaluated as a comparison to grazing stockpiled tall fescue. The experiment had a randomized complete block design with 3 replications and was divided into 3 phases each year. From early December to late February (phase 1) of each year, cows and calves grazed stockpiled tall fescue or were fed hay in the treatments described above. Immediately after phase 1, cows and calves were commingled and managed as a single group until weaning in April (phase 2) so that residual effects could be documented. Residual effects on cows were measured after the calves were weaned in April until mid-July (phase 3). During phase 1 of both years, apparent DMI of cow-calf pairs allocated stockpiled tall fescue at 4.50% of BW/d was 31% greater (P < 0.01) than those allocated 2.25% of BW/d. As allocation of stockpiled tall fescue increased from 2.25 to 4.50% of cow-calf BW/d, pasture utilization fell (P < 0.01) from 84 +/- 7% to 59 +/- 7%. During phase 1 of both years, cow BW losses increased linearly (P < 0.02) as forage allocations decreased, although the losses in yr 1 were almost double (P < 0.01) those in yr 2. During phases 2 and 3, few differences were noted across treatment groups, such that by the end of phase 3, cow BW in all treatments did not differ either year (P > 0.40). Calf ADG in phase 1 increased linearly (P < 0.01) with forage allocation (y = 0.063x + 0.513; R(2) = 0.91). However, calf gain per hectare decreased linearly (P < 0.01) as stockpiled tall fescue allocations increased (y = -26.5x + 212; R(2) = 0.97) such that gain per hectare for cow-calf pairs allocated stockpiled tall fescue at 4.50% BW/d was nearly 40% less (P < 0.01) than for those allocated 2.25% of BW/d. Allocating cow-calf pairs stockpiled tall fescue at 2.25% of BW/d likely optimizes its use; because cow body condition is easily regained in the subsequent spring and summer months, less forage is used during winter, and calf gain per hectare is maximized.

Fatty acid profiling of soybean cotyledons by near-infrared spectroscopy

Genetically improved soybean grain often contains altered fatty acid profiles. Such alterations can have deleterious effects on seed germination and seedling development, making it necessary to monitor fatty acid profiles in follow-up physiological studies. The objective of this research was to quantify the five fatty acids in soybean (Glycine max) cotyledons using near-infrared (NIR) spectroscopy. Soybean cotyledon samples were dried, ground, and scanned with visible and NIR radiation from 400 to 2500 nm, and reflectance was recorded. Samples were also analyzed by gas chromatography (GC) for palmitic, stearic, oleic, linoleic, and linolenic acids and total oil; GC data, expressed as actual concentration and proportion of total oil, were regressed against spectral data to develop calibration equations. Equation statistics indicated that four of the five fatty acids could be predicted accurately by NIR spectroscopy; the fifth fatty acid could be determined by subtraction. Principal component analysis revealed that most of the spectral variation in this population was due to chlorophyll absorbance in the visible region. Therefore, the spectra were trimmed to include the NIR region only (1100-2500 nm), and a second set of equations was developed. Equations based exclusively on NIR spectra had equal or greater precision than equations based on visible and NIR spectra. Principal component analysis and partial least squares analysis revealed that even after trimming, at least 90% of the spectral variation was unrelated to fatty acid, though variation from fatty acid was identified in the second and third principal components. This research provides an NIR method for complete fatty acid profiling of soybean cotyledons. Equations were achieved with NIR spectra only, so spectrophotometers that analyze both the visible and NIR regions are not needed for this analysis. In addition, equations were possible with a 250 mg sample, which is one-tenth the normal sample size for this analysis.

Immunohistochemical expression of beta-catenin in solitary fibrous tumors

CONTEXT

Immunohistochemical staining for beta-catenin may be used as an indicator of the integrity of the Wnt signaling and beta-catenin degradation pathways. Among mesenchymal tumors, aberrant nuclear localization of beta-catenin is seen in desmoid-type fibromatoses but has not been described for solitary fibrous tumors that may mimic the former lesions, especially in small biopsy samples.

OBJECTIVE

To study the immunohistochemical expression of beta-catenin in solitary fibrous tumors.

DESIGN

We performed immunohistochemical staining for beta-catenin in 12 solitary fibrous tumors, one of which showed histologic features of malignancy.

RESULTS

All the tumors showed strong and diffuse reactivity for beta-catenin. Four tumors (33%) showed nuclear staining for beta-catenin, whereas the remaining tumors showed either a membranous or mixed membranous and cytoplasmic pattern of staining. The only histologically malignant tumor of the group showed a mixed membranous and cytoplasmic pattern of staining for beta-catenin.

CONCLUSIONS

Immunohistochemical staining for beta-catenin in solitary fibrous tumors does not show a consistent pattern, which may be due to differences in tumorigenesis. Larger studies with clinical follow-up are required for estimating the impact of the variable staining pattern on clinical behavior of these tumors.

Antioxidant and inflammatory responses of healthy horses and horses affected by recurrent airway obstruction to inhaled ozone

REASONS FOR PERFORMING STUDY

Inhaled ozone can induce oxidative injury and airway inflammation. Horses affected by recurrent airway obstruction (RAO) have a decreased pulmonary antioxidant capacity, which may render them more susceptible to oxidative challenge. It is currently unknown whether RAO-affected horses are more susceptible to oxidative stress than those unaffected by RAO.

OBJECTIVES

To determine whether ozone exposure induces greater oxidative stress and airway inflammation in RAO-affected horses in remission than in healthy horses.

METHODS

Seven healthy control horses and 7 RAO-affected horses were exposed to 0.8 ppm ozone for 2 h at rest.

RESULTS

At baseline, bronchoalveolar lavage fluid (BALF) ascorbic acid concentrations were lower in RAO-affected horses than healthy controls. Ozone appeared to preferentially oxidise glutathione rather than ascorbic acid 6 h after exposure. Individual healthy and RAO-affected horses demonstrated oxidation of BALF glutathione after ozone exposure. Overall, RAO-affected horses did not demonstrate increased oxidative stress following ozone exposure, compared with healthy horses. Ozone did not induce significant airway inflammation in either group.

CONCLUSIONS

RAO-affected horses in remission are not more sensitive to ozone despite a decreased pulmonary antioxidant capacity. Sensitivity to ozone appears to be independent of initial pulmonary antioxidant status.

POTENTIAL RELEVANCE

Horses with high susceptibility to oxidative stress may benefit from antioxidant supplementation.

Intraoperative cytologic diagnosis of breast sentinel lymph nodes in the routine, nonacademic setting: a highly specific test with limited sensitivity

Intraoperative determination of metastatic breast carcinoma in sentinel lymph nodes (SLNs) by cytologic methods has been proposed as highly specific and sensitive. Much of these data are derived from academic institutes with highly trained personnel and without axillary dissection occurring as a direct result of the intraoperative interpretation. This prospective study was undertaken to assess the sensitivity and specificity of cytology in the routine, private-practice, intraoperative setting. A total of 207 SLNs from 96 breast carcinoma patients were evaluated by intraoperative cytologic preparations by general surgical pathologists; positive results led to axillary lymphadenectomy. Ten nodes were positive by intraoperative cytology (IC). Permanent section analysis confirmed the presence of carcinoma in the IC-positive cases and documented carcinoma in 19 of the IC-negative cases. IC sensitivity and specificity were 34% and 100%, respectively. False-negative IC interpretations occurred in nodes with occult micrometastases (12 of 19 nodes) and lobular carcinoma (6 of 19 nodes). Only one of eight grossly positive sentinel nodes resulted in a false-negative IC. While near-perfect specificity and high sensitivity can be achieved with grossly positive sentinel nodes by IC, sensitivity is quite low in cases with micrometastatic and lobular carcinoma.

Growth rate and physiology of steers grazing tall fescue inoculated with novel endophytes

Cattle grazing tall fescue (Festuca arundinacea Schreb.) often develop fescue toxicosis. This condition is thought to be caused by ergot alkaloids produced by the endophyte Neotyphodium coenophialum. Endophytes from wild tall fescue plants, which do not produce ergot alkaloids, were transferred into the endophyte-free tall fescue germplasm, HiMag. The novel associations also lacked the ability to produce ergot alkaloids. Our objective was to determine whether cattle grazing these novel endophyte associations showed signs of fescue toxicosis. At the Fayetteville, Arkansas location, tester steers (n = 72) were assigned to one of four pasture treatments: endophyte-free HiMag tall fescue (HiMag-); 'Kentucky-31' tall fescue infected with its native, toxic endophyte (KY+); and two novel endophyte-infected tall fescue associations, HiMag4 and HiMag9. At the Mount Vernon, Missouri location, steers (n = 54) were used to test three of the four cultivars (HiMag9 was not tested). Ergot alkaloid concentrations in the forage of HiMag4 and HiMag9 were low or undetectable. Respiration rate, rectal temperature, ADG, and hair scores were measured during the grazing period. Blood was collected via jugular venipuncture and used for prolactin, aspartate aminotransferase, alkaline phosphatase (ALP), lactate dehydrogenase (LDH), cholesterol, triglyceride, and creatinine analysis. Weight gains by steers grazing HiMag4 and HiMag9 did not differ from those of steers grazing HiMag-, but were greater than gains (P < 0.05) by steers on the KY+ treatment. Steers grazing KY+ had higher (P < 0.05) respiration rates, rectal temperatures, and hair scores than did steers grazing novel endophyte and HiMag- pastures. Prolactin, ALP, cholesterol, LDH, and triglycerides all were suppressed (P < 0.05) in steers grazing KY+ compared with steers grazing novel endophyte and HiMag- pastures. Steers grazing the novel endophyte tall fescues did not suffer from the decreased weight gains and toxicities associated with fescue toxicosis, resulting in enhanced animal production.

Interpretive disparity among pathologists in breast sentinel lymph node evaluation

BACKGROUND

Immunohistochemical staining on breast sentinel lymph nodes (SLN) is controversial.

METHODS

Twenty-five SLN cases were reviewed by 10 pathologists (three academic, seven private) including 5 negative by both hematoxylin and eosin (H&E) and immunohistochemistry, 11 micrometastases (<2 mm) negative by H&E but positive by immunohistochemistry, and 8 micrometastases and 1 macrometastasis (>2 mm) positive for both H&E and immunohistochemistry. Answers included "positive," "negative," and "indeterminate" for each slide.

RESULTS

The mean number of incorrect responses was 6.6 for immunohistochemistry and 5 for H&E. Twelve percent of cases were correct by all 10 pathologists; 80% of positive IHC cases had at least one pathologist score it incorrectly. As tumor cells decrease in number, incorrect responses increase. When tumor cells numbered less than 10, more than 30% of pathologists answered incorrectly.

CONCLUSIONS

As tumor cells decrease in number pathologists' ability to recognize them decreases. We propose adding "indeterminate" to "positive" and "negative" when tumor cells number less than 10.

Asymmetric cardiac hypertrophy at autopsy in patients who received FK506 (tacrolimus) or cyclosporine A after liver transplant

BACKGROUND

Cardiotoxicity has been described in a group of pediatric patients receiving FK506 as a part of immunosuppression for orthotopic liver transplantation (OLT). Information regarding the cardiac pathology related to this agent is limited.

METHODS

Among the first 975 liver transplants at our institution (1985-1995), autopsy hearts were available for 19 patients (14 adults and 5 children) who received FK506 for a minimum of 1 week prior to death. Patients with excessive alcohol use, significant coronary artery disease, valvular disease, diabetes mellitus, or pretransplant hypertension were excluded from analysis. We compared heart weight (HW), heart weight-to-body weight ratio (HW/BW), ventricular septal (VS) thickness with left ventricular (LV) thickness ratio (VS/LV), and cardiac histologic findings of 12 OLT patients (7 adults, 5 children) who received FK506 with a group of 75 OLT patients (48 adults, 27 children) who received Cyclosporine (CsA) and 20 (10 adults, 10 children) age-comparable control patients without OLT.

RESULTS

All FK506 and CsA children and adults had cardiomegaly by HW, HW/BW (P(FK506 peds) <0.024, P(CsA peds)<0.028, P(FK506 adults) <0.017, P(CsA adults)<0.006) and increased VS/LV ratio 1.25(FK506) (P <0.006) and 1.23(CsA) (P <0.006)(pediatric) and 1.09(FK506) (P <0.0122) and 1.21(CsA) (P <0.0009)(adults), compared with control.

CONCLUSION

Cardiomegaly by HW, HW/BW, and histology was uniformly present in both FK506 and CsA adult and pediatric OLT patients at autopsy. A relatively greater VS hypertrophy than LV was present in both transplant groups. We found no gross or histologic cardiac finding that separated these FK506 from CsA OLT patients at autopsy.

Use of a rat model to evaluate tall fescue seed infected with introduced strains of Neotyphodium coenophialum

Experimental cultivars of the pasture grass tall fescue are infected with unique strains of the fungal endophyte Neotyphodium coenophialum, which produce low concentrations of ergot alkaloids. A rat model was evaluated as a tool for rapid, initial screening of experimental cultivars considered to be nontoxic. Rats were fed diets that included seed from experimental cultivars of tall fescue with introduced strains of N. coenophialum and a toxic control diet containing seed of the cultivar Kentucky 31 (KY31), with its endemic strain of N. coenophialum. Rats were preconditioned to a nontoxic diet and then fed treatment diets for 13 days with 5 days at thermoneutrality (21 degrees C) followed by 8 days under heat stress (31 degrees C). For most of the 13-day treatment period, rats fed KY31 exhibited depressed daily intake compared to those fed diets of cultivars with introduced endophytes (P < 0.05). In addition, rats fed KY31 exhibited significantly less weight than rats on other diets after heat treatment was imposed. For all initial trials and repeated trials, total intake and total gain calculated at the end of each trial were the most consistent indicators of toxicity.

Heart size estimated by echocardiography correlates with maximal oxygen uptake

Maximum oxygen uptake also appears to correlate to athletic performance in horses. In the Thoroughbred industry, there has long been an empirical theory that heart size is related to athletic performance, despite a lack of scientific evidence supporting this assertion. To investigate the relationship between peak oxygen consumption (VO2max) and cardiac size measured by echocardiography, guided M-mode and 2-dimensional echocardiography were performed in 17 conditioned Thoroughbreds with a range of VO2max from 126 to 217 ml/min/kg STPD (mean +/- s.d. 158 +/- 28 m/min/kg). Horses were age 2-10 years and weighed 430-510 kg. Echocardiography was performed using a Vingmed System V echocardiograph with a 2.25 MHz phased array ultrasound transducer. All images were obtained from the right hemithorax using a short axis view of the left ventricle (LV) at the level of the chordae tendinae. All horses were free from significant regurgitation at the aortic or mitral valves. Maximal oxygen uptake was measured during a standardised incremental treadmill exercise test to fatigue. Maximal oxygen uptake was correlated significantly with LVIDd (r = 0.71; P = 0.001), MWT (r = 0.72; P = 0.001), LV mass (r = 0.78; P = 0.0002) and LV short-axis area (r = 0.69; P = 0.003). When indices of heart size were indexed to bodyweight, the correlation between VO2max and indices of heart size were LVIDd (r = 0.57; P = 0.01), MWT (r = 0.44; P = 0.07), LV mass (r = 0.78; P = 0.0002) and LV short-axis area (r = 0.69; P = 0.003). The current study suggests there is a strong relationship between VO2max and measurements of left ventricular size in Thoroughbred horses when individuals with a range of VO2max are compared.

Antioxidant supplementation and pulmonary function at rest and exercise

Antioxidants have been implicated in the reduction and prevention of oxidative stress during exercise. We hypothesised that a dietary supplement containing a mixture of natural antioxidants together with vitamins E, C and selenium, given for 4 weeks, would increase the systemic and pulmonary antioxidant capacity leading to a reduction in markers of oxidative damage and an improvement in pulmonary function during exercise. In 6 healthy horses studied, the antioxidant supplement significantly increased plasma concentrations of ascorbic acid (from mean +/- s.d. 16 +/- 7 to 23 +/- 4 micromol/l; P = 0.007) and alpha-tocopherol (from 10 +/- 3 to 14 +/- 3 micromol/l; P = 0.02) and increased the bronchoalveolar lavage pulmonary epithelial lining fluid (ELF) concentration of ascorbic acid compared to a placebo, but not significantly (2.0 +/- 0.9 mmol/l and 1.2 +/- 0.9 mmol/l, respectively; P>0.05). Alpha-tocopherol was not detected in ELF either before or after supplementation or exercise. The mean concentration of malondialdehyde (MDA) in ELF was lower following antioxidant supplementation compared to placebo and control periods, but not significantly. An intermittent exercise test consisting of 2 min at 70, 80 and 90% of the horses' individual maximum oxygen uptake, failed to induce significant systemic or pulmonary oxidative stress (based on the glutathione redox ratio (GRR) and the ascorbic acid redox ratio (ARR)) and lipid peroxidation (based on the concentration of thiobarbituric acid reactive substances in plasma and MDA in ELF) either for placebo or antioxidant treatments. There was a strong correlation between GRR and ARR in the pulmonary epithelial lining fluid (r = 0.89; P<0.0001). In healthy horses on a diet containing adequate levels of antioxidants, additional antioxidant supplementation has no apparent beneficial or detrimental effect on pulmonary function during moderate intensity exercise. The importance of antioxidant supplementation may only become apparent if the diet is deficient in antioxidants, if exercise intensity is higher or more prolonged, or if disease or additional stresses are present.

Pooled library tissue tags for EST-based gene discovery

MOTIVATION

In gene discovery projects based on EST sequencing, effective post-sequencing identification methods are important in determining tissue sources of ESTs within pooled cDNA libraries. In the past, such identification efforts have been characterized by higher than necessary failure rates due to the presence of errors within the subsequence containing the oligo tag intended to define the tissue source for each EST.

RESULTS

A large-scale EST-based gene discovery program at The University of Iowa has led to the creation of a unique software method named UITagCreator usable in the creation of large sets of synthetic tissue identification tags. The identification tags provide error detection and correction capability and, in conjunction with automated annotation software, result in a substantial improvement in the accurate identification of the tissue source in the presence of sequencing and base-calling errors. These identification rates are favorable, relative to past paradigms.

AVAILABILITY

The UITagCreator source code and installation instructions, along with detection software usable in concert with created tag sets, is freely available at http://genome.uiowa.edu/pubsoft/software.html

CONTACT

tomc@eng.uiowa.edu

Performance of steers grazing rhizomatous and nonrhizomatous birdsfoot trefoil in pure stands and in tall fescue mixtures

This study investigated the performance of steers grazing rhizomatous birdsfoot trefoil (Lotus corniculatus L.) (RBFT) compared to nonrhizomatous birdsfoot trefoil (BFT) in pure stands or when interseeded with endophyte-free tall fescue (Festuca arundinacea Schreb.; TF). Five forage treatments of RBFT, BFT, TF, RBFT+TF, and BFT+TF (four replicate paddocks per treatment) were continuously stocked in spring and fall of 1998 and spring of 1999. Grazing for individual treatments was terminated when pasture mass fell below 900 kg/ha. Average daily gain was greatest (P < 0.10) in pure stands of BFT and RBFT, but total forage production, and thus grazing days, for these treatments was low. Average daily gain for steers grazing BFT+TF and RBFT+TF treatments was not different from (spring and fall 1998) or greater (P < 0.10) (spring 1999) than that for TF. Total forage production of BFT+TF and RBFT+TF was greater (P < 0.10) than that of TF in spring 1998. In fall 1998, BFT+TF produced more (P < 0.10) total forage than either RBFT+TF or TF, and in spring 1999, RBFT+TF had less (P < 0.10) total forage than TF or BFT+TF. Total steer days on mixed pastures were greater (P < 0.10) than that for TF in spring and fall 1998 but not different from those for TF in spring 1999. In all three trials total weight gain/hectare was greater (P < 0.10) for RBFT+TF and BFT+TF than for TF. The RBFT+TF and BFT +TF had greater (P < 0.05) CP than TF in spring and fall 1998 and less (P < 0.05) NDF and ADF in fall 1998. We concluded that either RBFT or BFT could be interseeded with tall fescue to enhance ADG and total steer days.

Mycolic acids and ancient DNA confirm an osteological diagnosis of tuberculosis

SETTING

The underlying trends in the past epidemiology of tuberculosis (TB) are obscure, requiring recourse to the archaeological record. It would therefore be of value to develop methods for reliable TB diagnosis in ancient populations.

OBJECTIVE

To test the capability of two biomarkers, Mycobacterium tuberculosis complex mycolic acids and a DNA target (IS6110), for confirming an osteological diagnosis of TB in medieval individuals, based on the presence of Pott's disease and/or rib lesions.

DESIGN

Osteological examination of three archaeological individuals (Medieval: approximately 1000 years old) revealed a Pott's disease case, one with no changes consistent with TB and one with rib lesions. Rib samples from these individuals were examined for the presence of Mycobacterium tuberculosis complex mycolic acids and mycobacterial DNA.

RESULTS

Mycobacterium tuberculosis complex mycolic acids and the DNA target were detected in the Pott's disease case, whilst mycolic acids (insufficient for confirmation) alone were detected in the rib lesion case.

CONCLUSIONS

Biomarkers provide a sensitive tool to detect ancient TB. Mycobacterium tuberculosis DNA is not distributed homogeneously, making multiple sampling essential. Mycolic acids seem more reliable for ancient TB diagnosis than IS6110. The demonstrated stability of mycolic acids show that they may be of value in tracing the palaeoepidemiology of tuberculosis back into antiquity.

An evaluation of methods for calculating mean sediment quality guideline quotients as indicators of contamination and acute toxicity to amphipods by chemical mixtures

Mean sediment quality guideline quotients (mean SQGQs) were developed to represent the presence of chemical mixtures in sediments and are derived by normalizing a suite of chemicals to their respective numerical sediment quality guidelines (SQGs). Mean SQGQs incorporate the number of SQGs exceeded and the degree to which they are exceeded and are used for comparison with observed biological effects in the laboratory or field. The current research makes it clear, however, that the number and type of SQGs used in the derivation of these mean quotients can influence the ability of mean SQGQ values to correctly predict acute toxicity to marine amphipods in laboratory toxicity tests. To determine the optimal predictive ability of mean SQGQs, a total of 18 different chemical combinations were developed and compared. The ability of each set of mean SQGQs to correctly predict the presence and absence of acute toxicity to amphipods was determined using three independent databases (n = 605, 2753, 226). Calculated mean SQGQ values for all chemical combinations ranged from 0.002 to 100. The mean SQGQ that was most predictive of acute toxicity to amphipods is calculated as SQGQ1 = ((sigma ([cadmium]/4.21 )([copper]/270)([lead]/ 12.18)([silver]/1.77)([zinc]/ 410)([total chlordane]/6)([dieldrin]/8)([total PAHoc]/1,800)([total PCB]/400))/9). Both the incidence and magnitude of acute toxicity to amphipods increased with increasing SQGQI values. To provide better comparability between regions and national surveys, SQGQ1 is recommended to serve as the standard method for combination of chemicals and respective SQGs when calculating mean SQGQs.

A picture of tuberculosis in young Portuguese people in the early 20th century: a multidisciplinary study of the skeletal and historical evidence

The aim of this study was to examine the evidence, and consider the differential diagnosis, for tuberculosis (TB) in juvenile individuals from early 20th century documented skeletons. There are 66 male and female juvenile individuals in the Coimbra Identified Skeletal Collection (CISC) with an age at death ranging from 7-21 years. The individuals died between 1904-1936 in different areas of Coimbra, Portugal. Eighteen of these individuals died from TB affecting different parts of the body. Thirteen (72.2%) showed skeletal lesions that may be related to this infection. Of the 48 individuals with a non-tuberculous cause of death, only 2 (4.2%) had skeletal changes that could be attributed to TB. The distribution of skeletal manifestations caused by the types of TB under study, based on macroscopic and radiological findings, is described and discussed. In addition, the medical records from 6 tuberculous individuals who died in Coimbra University Hospital (CUH) were analysed, and the information, including their diet and access to treatment, is presented. This work, based on data arising before antibiotics became available for treatment, can contribute to the future diagnosis of TB in non-documented skeletal material, and will facilitate a more reliable diagnosis of TB in juvenile individuals.

Sediment quality in Los Angeles Harbor, USA: a triad assessment

Sediment quality in the Los Angeles and Long Beach Harbor area of southern California, USA, was assessed from 1992 to 1997 as part of the California State Water Resources Control Board's Bay Protection and Toxic Cleanup Program and the National Oceanic and Atmospheric Administration's National Status and Trends Program. The assessment strategy relied on application of various components of the sediment quality triad, combined with bioaccumulation measures, in a weight-of-evidence approach to sediment quality investigations. Results of bulk-phase chemical measurements, solid-phase amphipod toxicity tests, pore-water toxicity tests with invertebrate embryos, benthic community analyses (presented as a relative benthic index), and bioaccumulation measures indicated that inner harbor areas of this system are polluted by high concentrations of a mixture of sediment-associated contaminants and that this pollution is highly correlated with toxicity in laboratory experiments and degradation of benthic community structure. While 29% of sediment samples from this system were toxic to amphipods (Rhepoxynius abronius or Eohaustorius estuarius), 79% were toxic to abalone embryos (Haliotis rufescens) exposed to 100% pore-water concentrations. Statistical analyses indicated that amphipod survival in laboratory toxicity tests was significantly correlated with the number of crustacean species and the total number of species measured in the benthos at these stations. Triad measures were incorporated into a decision matrix designed to classify stations based on degree of sediment pollution, toxicity, benthic community degradation, and, where applicable, tissue concentrations in laboratory-exposed bivalves and feral fish.

Real-time RT-PCR fluorescent detection of tomato spotted wilt virus

A real-time reverse transcription-polymerase chain reaction assay based on TaqMan chemistry was developed for the detection and quantification of tomato spotted wilt virus (TSWV). This method enabled sensitive, reproducible and specific detection of TSWV in 'leaf soak' and total RNA extracts from infected plants. TaqMan reliably detected TSWV in as little as 500 fg total RNA. The assay was 10-fold more sensitive than visualisation of ethidium bromide-stained bands following agarose gel electrophoresis. TSWV isolates from various crops and locations were detected with a cycle threshold of 20-26 in 1 ng total RNA extracted from fresh or freeze-dried leaves. A dilution series of in vitro transcripts from a cloned 628 base pair fragment of TSWV S RNA served as standard for quantification of viral template in infected leaf samples. The TaqMan assay detected reproducibly 1000 molecules of the target transcript.

Ogilvie's syndrome after cesarean delivery

Ogilvie's syndrome is a rare postsurgical complication that can be associated with cesarean delivery. It is characterized by massive dilation of the colon, much like that which occurs with an obstruction but in the absence of a mechanical obstruction. Early detection and intervention are necessary to avoid serious morbidity and/or mortality. Conservative treatment is effective in many cases, but surgical intervention may be required. Nursing assessment of the gastrointestinal system in the postsurgical patient is reviewed using a case report of a patient who developed Ogilvie's syndrome after a cesarean delivery.

Synthesis and biological activity of peptidyl aldehyde urokinase inhibitors

Solid- and solution-phase synthesis of peptidomimetic inhibitors of urokinase-type plasminogen activator based on the sequence dSerAlaArg-al are described. The biological activities of these unique inhibitors are reported herein. Carbonate prodrugs were prepared and tested as potential drug delivery systems.

Respiratory responses of mature horses to intravenous lobeline bolus

The respiratory stimulant lobeline has been used in equine clinical practice to increase inspiratory and expiratory airflow rates at rest in order to facilitate investigation of both lower and upper airway function. Some of the responses to lobeline in the pony have been reported, but the detailed time course, effect of dose, possible side effects and reproducibility associated with lobeline administration have not been described in the horse. Respiratory airflow rates and oesophageal pressure were measured with a Fleisch No. 5 pneumotachometer and lightweight facemask and a microtip pressure transducer catheter, respectively. The output of the Fleisch pneumotachometer was calibrated for flow rates up to +/- 70 l/s. Seven mature horses with no clinical signs of respiratory disease were studied. Investigations were conducted to determine: (1) the responses to different doses of lobeline (0.15, 0.20, 0.25 and 0.30 mg/kg bwt) as a rapid i.v. bolus (6 horses); (2) arterial blood gases during and after lobeline administration (0.20 mg/kg bwt; 3 horses); and (3) the reproducibility of lobeline-stimulated hyperpnoea (5 horses; 2 doses of 0.20 mg/kg bwt lobeline, 15 min apart). All horses tolerated the lobeline-stimulated hyperpnoea well, although one always coughed or snorted at the onset. Mild tremor was noted following the highest dose in several horses. Apnoea of approximately 40 s was common after the hyperpnoea. Both tidal volume (VT) and frequency (fR) increased with lobeline dose. During peak hyperpnoea at a dose of 0.30 mg/kg bwt, peak inspired flow rate (PIF), peak expired flow rate (PEF) and minute ventilation (VE) were mean +/- s.e. 41+/-5 l/s, 61+/-10 l/s and 920+/-99 l/min, respectively. The hyperpnoea also caused marked changes in arterial PaO2, PaCO2 and pHa at 90 s after lobeline (0.20 mg/kg bwt) administration (mean +/- s.e. 146.0+/-6.9 mmHg, 20.6+/-0.8 mmHg and 7.707+/-0.020, respectively) compared to at rest (mean +/- s.e. 104.0+/-4.0 mmHg, 50.6+/-2.8 mmHg and 7.432+/-0.012). Dynamic lung compliance (Cdyn) was unaltered by lobeline administration. The lobeline-induced hyperpnoea was highly reproducible, with no significant difference in any of the parameters during 2 stimulations 15 min apart. Lobeline induced highly reproducible responses without any apparent adverse effects and may be useful in the investigation of pulmonary function in healthy horses and those with airway disease.

Comparison of the performance of linear resistance and ultrasonic pneumotachometers at rest and during lobeline-induced hyperpnoea

The performance of a Fleisch No. 5 pneumotachometer (F), and two commercial ultrasonic pneumotachometers, the BRDL (B) and the Spiroson (S) systems were compared in respect to their use for determination of ventilatory parameters at rest and during lobeline-induced hyperpnoea. Five clinically healthy Thoroughbred horses were tested with the three pneumotachometers in random order. Respiratory airflow, respired gas concentrations, oesophageal pressures, pressures within the mask systems and arterial blood gases were determined before and during lobeline-induced hyperpnoea. Because measured peak expiratory airflow rates exceeded the stated linear range of the Fleisch pneumotachometer ( approximately +/- 25 l s(-1)) differential pressure-flow curves were determined in vitro over the range of flows recorded in vivo. Expired flows greater than the linear range were corrected according to the derived regression equation. No differences in any of the measured variables among the three systems were present at rest. At peak ventilation of lobeline-induced hyperpnoea mask pressures [Delta P(mask)(mean (SEM)): F: 9.6 (2.8) cm H(2)O, B: 0.8 (0.4) cm H(2)O, S: 1.4 (0.8) cm H(2)O] and end tidal carbon dioxide [ ET CO(2)(mean (SEM)): F: 2. 6 (0.1)%, B: 2.1 (0.2)%, S: 2.1 (0.1)%] were significantly higher in system F. Despite a tendency for respiratory frequency and peak inspired and expired flows, to be lower with system F, no significant differences in the measurements of ventilatory mechanics were detected. In conclusion, the ultrasonic flowmeters pose significantly lower resistive loads onto the respiratory system during ventilation above resting levels than Fleisch No 5 pneumotachometers. However, at the flowrates achieved during lobeline-induced hyperpnoea an in vitro calibration of the differential pressure-flow relationship allows correction for expiratory alinearity in system F. In addition, the performance of the Spiroson flowmeter is accurate in determining ventilatory mechanics at rest and during lobeline-induced hyperpnoea.

Is infection control in residential homes neglected?

We investigated the potential for cross infection during the cleaning of commodes in residential homes in one health authority in order to investigate why residential institutions are the commonest setting for outbreaks of infectious intestinal disease. Most homes used commodes, but half lacked a designated sluice area for cleaning them after use and in half soiled commodes were cleaned in bathroom or toilet washbasins, baths, showers, or toilet pans, creating a risk of cross infection.

Task and socioemotional behaviors of physicians: a test of reciprocity and social interaction theories in analogue physician-patient encounters

The purpose of the present study is to assess social interaction and reciprocity theories as explanations for patient responses to a physician in a medical consultation. Social interaction theory predicts that patients mostly recognize and react to socioemotional behavior of their physicians due to a lack of understanding of physician task behaviors or a preoccupation with anxiety. Reciprocity theory predicts that patients recognize socioemotional and task behaviors of their physicians, and they respond to these behaviors in thematically similar ways. We examined these hypotheses by having subjects view one of four videotapes which varied in physician task behavior (thorough or minimum levels of explanation of etiology, symptoms, and treatment) and physician socioemotional behavior (high or low levels of concern and affection displayed verbally and non-verbally). Results supported the general proposition of social interaction theory in that high levels of socioemotional behavior of the physician increased measures of patient self-disclosure, trust, satisfaction, and likelihood of recommending the physician. Physician task behavior had no effect on patient response to the physician, a finding inconsistent with reciprocity theory.

Rib lesions and tuberculosis: the palaeopathological evidence

SETTING

Tuberculosis diagnosis in past populations relies on lesions in the spine and major weight bearing joints of the body. Bone formation on visceral surfaces of ribs has also been suggested to be the result of chronic pulmonary disease.

OBJECTIVE

To test whether these lesions are the result of pulmonary infection (most likely tuberculosis), by reviewing past work, and to discuss whether these lesions could be considered another diagnostic criterion for pulmonary tuberculosis.

DESIGN

A review of the literature on new bone formation on ribs, and consideration of further evidence from archaeological skeletal material from the UK.

RESULTS

Results from modern studies suggest that bone formation on ribs is often the result of pulmonary tuberculosis, that lesions are relatively common in archaeological skeletal material, and that some skeletons have rib lesions plus pathognomonic changes of tuberculosis.

CONCLUSION

Evidence suggests that new bone formation on visceral surfaces of ribs should be considered a possible indicator of tuberculosis. If accepted, historical evidence, when correlated with rib data, produces closer approximations to the frequency of the disease in the past. This study indicates the importance of palaeopathology in identifying sometimes subtle lesions that may not be noted by clinicians because of their non-visibility on radiographs.