The Characterization of Violent Deaths Among Asian and Pacific Islander Americans

INTRODUCTION

Health disparities in the Asian and Pacific Islander Americans (APIAs) community have not been well described, unlike non-Hispanic Black and Hispanic communities. However, there has been a rise in violence against the APIA community. This study explores and characterizes violent death by incident (e.g., homicide, suicide), weapon (e.g., firearm, strangulation), and location types among APIAs as they compare with other racial or ethnic groups.

METHODS

We used the National Violent Death Reporting System from 2003 to 2018 to characterize violent deaths among APIA and compared them to all other races. We compared these racial categories in two ways. First, we compared all races as a categorical variable that included six non-Hispanic racial categories including "Other or unspecified" and "two or more races. We then created a binary variable of APIA versus All Other Races for analysis. We explored the incident type of death, substance abuse disorders, mental health history, and gang involvement among other variables. We used Chi-square tests for categorical variables and Mann-Whitney U-tests for continuous variables.

RESULTS

Overall, APIAs had a unique pattern of violent death. APIAs were more likely to commit suicide (71.74%-62.21%, P<0.001) and less likely to die of homicide than other races (17.56%-24.31%, P<0.001). In the cases of homicide, APIAs were more likely to have their deaths precipitated by another crime (40.87% versus 27.87%, P < 0.001). APIAs were more than twice as likely to die of strangulation than other races (39.93%-18.06%, P<0.001). Conversely, APIAs were less likely to die by firearm than other races (29.69-51.51, P<0.001).

CONCLUSIONS

APIAs have a unique pattern of violence based on analysis of data from the National Violent Death Reporting System. Our data reveal a significant difference in the incident, weapon and location type as compared to Americans of other races, which begs further inquiry into the patterns of change in time and factors that contribute to inter-racial differences in death patterns.

Analyzing the Impact of the COVID-19 Pandemic on Initial Oncologic Presentation and Treatment of Non-Small Cell Lung Cancer in the United States

BACKGROUND

Significantly lower rates of NSCLC screening, healthcare avoidance, and changes to oncologic recommendations were some consequences of the medical environment during the COVID-19 pandemic. We sought to determine how the healthcare environment during the COVID-19 pandemic affected the oncologic treatment of patients diagnosed with non-small cell lung cancer (NSCLC).

METHODS

This was a retrospective cohort study evaluating patients with NSCLC in the National Cancer Database (2019-2020). Patients were divided into pre-pandemic (2019) and pandemic (2020) cohorts. Patient, oncologic, and treatment variables were compared. Multivariable logistic regression was performed to control for the impact of demographic characteristics on oncologic variables and the impact of oncologic variables on treatment variables.

RESULTS

There were 250,791 patients included: 114,533 patients (45.7%) were in the pandemic cohort. There were 15% fewer new NSCLC diagnoses during the pandemic. Patients diagnosed during the pandemic had more advanced clinical TNM stage on presentation (p<0.0001) and were more likely to have tumors in overlapping lobes or in a main bronchus (p=0.0002). They were less likely to receive cancer treatment (p<0.0001), to undergo primary resection (p<0.0001), and more likely to receive adjuvant systemic therapy (p=0.004), and a combination of palliative treatment regimens (p<0.0001). After risk-adjustment, these differences remained statistically significant (p-values<0.05).

CONCLUSION

The COVID-19 pandemic was associated with increased clinical stage at presentation for patients with NSCLC, which impacted subsequent treatment strategies. However, treatment differed minimally when controlling for cancer stage. Future studies will examine the impact of these differences on overall and cancer-free survival.

Prioritizing rapid COVID-19 testing in emergency general surgery patients decreases burden of inpatient hospital admission

Objectives

The COVID-19 pandemic has changed delivery of emergency general surgery (EGS) and contributed to widespread bed shortages. At our institution, rapid testing is not routinely approved for EGS patients. We examined common EGS conditions (appendicitis and acute cholecystitis), hypothesizing that necessity of testing for COVID-19 significantly delayed operative intervention.

Methods

We performed a prepost study to examine a 2-month timeframe, or historical control, prior to COVID-19 testing (January 1, 2020-March 1, 2020) as well as a 2-month timeframe during the COVID-19 era (January 1, 2021-March 1, 2021). We chose conditions that are frequently treated surgically as outpatient or observation status. We examined time for COVID-19 test to result, and associated time to operative intervention (operating room (OR)) and need for admission.

Results

Median time to COVID-19 test results was 7.4 hours (IQR 5.8-13.1). For appendectomy, time to surgical consultation or case request did not differ between cohorts. Time to OR after case request was significantly longer (12.5 vs 1.9 hours, p<0.001) and patients more frequently required admission prior to operative intervention if receiving treatment in the COVID-19 timeframe. Similarly, for cholecystectomy there were no differences in time to surgical consultation or case request, but time to OR after case request was longer in the COVID-19 era (21.1 vs 9.0 hours, p<0.001).

Conclusion

While COVID-19 positivity rates have declined, the purpose of this study was to reflect on one element of our hospital system's response to the COVID-19 pandemic. Based on our institutional experience, waiting for COVID-19 test results directly impacts time to surgery, as well as the need for admission for a historically outpatient procedure. In the future, if the healthcare system is asked to respond to another pandemic or similar situation, expediting time to OR to eliminate unnecessary time in the hospital and non-critical admissions should be paramount.

Level of evidence

Level III, prognostic/epidemiological.

Tick-tock: Prehospital intubation is associated with longer field time without any survival benefit

BACKGROUND

Prehospital endotracheal intubation is a debated topic, and few studies have found it beneficial after trauma. A growing body of evidence suggests that prehospital endotracheal intubation is associated with increased morbidity and mortality. Our study was designed to compare patients with attempted prehospital endotracheal intubation to those intubated promptly upon emergency department arrival.

METHODS

A retrospective review of a single-center trauma research data repository was utilized. Inclusion criteria included age ≥15 years, transport from the scene by ground ambulance, and undergoing prehospital endotracheal intubation attempts or intubation within 10 minutes of emergency department arrival without prior prehospital endotracheal intubation attempt. Propensity score matching was used to minimize differences in baseline characteristics between groups. Standard mean differences are also presented for pre- and post-matching datasets to evaluate for covariate balance.

RESULTS

In total, 208 patients met the inclusion criteria. Of these, 95 patients (46%) underwent prehospital endotracheal intubation, which was successful in 47% of cases. A control group of 113 patients (54%) were intubated within 10 minutes of emergency department arrival. We performed propensity score matching between cohorts based on observed differences after univariate analysis and used standard mean differences to estimate covariate balance. After propensity score matching, patients who underwent prehospital endotracheal intubation experienced a longer time on scene as compared with those intubated in the emergency department (9 minutes [interquartile range 6-12] vs 6 minutes [interquartile range 5-9], P < .01) without difference in overall mortality (67% vs 65%, P = 1.00). Rapid sequence intubation was not used in the field; however, it was used for 58% of patients intubated within 10 minutes of emergency department arrival. After matched analysis, patients with a failed prehospital intubation attempt were equally likely to receive rapid sequence intubation during re-intubation in the emergency department as compared with those undergoing a first attempt (n = 13/28, 46% vs n = 28/63, 44%, P = 1.00, standard mean differences 0.04). Among patients with prehospital arrest (n = 98), prehospital endotracheal intubation was associated with shorter time to death (8 minutes [interquartile range 3-17] vs 14 minutes [interquartile range 8-45], P = .008) and longer total transport time (23 minutes [interquartile range 19-31] vs 19 minutes [interquartile range 16-24], P = .006), but there was no difference in observed mortality (n = 29/31, 94% vs n = 30/31, 97%, P = 1.00, standard mean differences = 0.15) after propensity score matching.

CONCLUSION

Prehospital providers should prioritize expeditious transport over attempting prehospital endotracheal intubation, as prehospital endotracheal intubation is inconsistently successful, may delay definitive care, and appears to have no survival benefit.

Emergency thoracic surgery patients have worse risk-adjusted outcomes than non-emergency patients

BACKGROUND

Outcomes for patients undergoing emergency thoracic operations have not been well described. This study was designed to compare postoperative outcomes among patients undergoing emergency versus nonemergency thoracic operations.

METHODS

We retrospectively analyzed the American College of Surgeons National Surgical Quality Improvement Program database (2005-2018). We identified patients who underwent emergency thoracic operations using current procedural technology codes. Patients were then sorted into 1 of 4 cohorts: lung and chest wall, hiatal hernia, esophagus, and pericardium. Emergency versus nonemergency outcomes were compared. Univariate logistic regression was performed with "emergency status" as the independent variable and 30-day postoperative outcomes as the dependent variables. Multiple logistic regression models were performed to control for preoperative factors.

RESULTS

Of 90,398 thoracic operations analyzed, 4,044 (4.5%) were emergency. Common emergency operations were pericardial window (n = 580, 10.2%), laparoscopic hiatal hernia repair (n = 366, 8.9%), thoracoscopic partial lung decortication (n = 334, 8.1%), thoracoscopic wedge resection (n = 301, 7.3%), thoracoscopic total lung decortication (n = 256, 6.2%), and open repair of hiatal hernia without mesh (n = 254, 6.2%). In all 4 cohorts, 30-day postoperative complications occurred more frequently after emergency surgery. After controlling for patient characteristics, 8 complications were more frequent after emergency lung and chest wall surgery, 5 complications were more frequent after emergency hiatal hernia surgery, and 3 complications were more frequent after emergency pericardium surgery. Risk-adjusted complications were not different after emergency esophageal surgery.

CONCLUSION

Patients undergoing emergency thoracic operations have worse risk-adjusted outcomes than those undergoing nonemergency thoracic operations. Subset analysis is needed to determine what factors contribute to increased adverse outcomes in specific patient populations.

De-implementation of Axillary Dissection in Women Undergoing Mastectomy for Breast Cancer

BACKGROUND

Completion axillary lymph node dissection (cALND) was standard treatment for breast cancer with positive sentinel lymph nodes (SLNs) until 2011, when data from the Z11 and AMAROS trials challenged its survival benefit in early stage breast cancer. We assessed the contribution of patient, tumor, and facility factors on cALND use in patients undergoing mastectomy and SLN biopsy.

PATIENTS AND METHODS

Using the National Cancer Database, patients diagnosed from 2012 to 2017 who underwent upfront mastectomy and SLN biopsy with at least one positive SLN were included. A multivariable mixed effects logistic regression model was used to determine the effect of patient, tumor, and facility variables on cALND use. Reference effect measures (REM) were used to compare the contribution of general contextual effects (GCE) to variation in cALND use.

RESULTS

From 2012 to 2017, the overall use of cALND decreased from 81.3% to 68.0%. Overall, younger patients, larger tumors, higher grade tumors, and tumors with lymphovascular invasion were more likely to undergo cALND. Facility variables, including higher surgical volume and facility location in the Midwest, were associated with increased use of cALND. However, REM results showed that the contribution of GCE to the variation in cALND use exceeded that of the measured patient, tumor, facility, and time variables.

CONCLUSIONS

There was a decrease in cALND use during the study period. However, cALND was frequently performed in women after mastectomy found to have a positive SLN. There is high variability in cALND use, mainly driven by interfacility practice variation rather than specific high-risk patient and/or tumor characteristics.

Exposure to brominated and organophosphate ester flame retardants in U.S. childcare environments: Effect of removal of flame-retarded nap mats on indoor levels

We assessed exposure to 39 brominated and 16 organophosphate ester flame retardants (FRs) from both dust and indoor air at seven childcare centres in Seattle, USA, and investigated the importance of nap mats as a source of these chemicals. Many childcare centres serving young children use polyurethane foam mats for the children's naptime. Until recently, the vast majority of these mats sold in the United States contained flame-retarded polyurethane foam to meet California Technical Bulletin 117 (TB117) requirements. With the 2013 update of TB117, allowing manufacturers to meet flammability standards without adding FRs to filling materials, FR-free nap mats have become widely available. We conducted an intervention study by actively switching out FR-treated nap mats with FR-free nap mats and measuring FR levels in indoor air and dust before and after the switch-out. The predominant FRs found in dust and indoor air were 2-ethylhexyl tetrabromobenzoate (EHTBB) and tris(1-chloro-2-propyl) phosphate (TCIPP), respectively. Nap mat samples analysed from four of the six centres contained a Firemaster^® mixture, while one mat was predominantly treated with tris(1,3-dichloroisopropyl) phosphate (TDCIPP) and the other contained no detectable target FRs. After replacement, there was a significant decrease (p = 0.03-0.09) in median dust concentrations for bis(2-ethylhexyl) tetrabromophthalate (BEHTBP), EHTBB, tris(4-butylphenyl) phosphate (TBPP), and TDCIPP with reductions of 90%, 79%, 65%, and 42%, respectively. These findings suggest that the nap mats were an important source of these FRs to dust in the investigated childcare environments and that a campaign of swapping out flame-retarded mats for FR-free ones would reduce exposure to these chemicals. While calculated exposure estimates to the investigated FRs via inhalation, dust ingestion, and dermal absorption were below established reference dose values, they are likely underestimated when considering the toddlers' direct contact to the mats and personal cloud effects.

Demographic and dietary risk factors in relation to urinary metabolites of organophosphate flame retardants in toddlers

Organophosphate flame retardants (OPFRs), including Tris (1,3-dichloro-isopropyl) phosphate (TDCPP), triphenyl phosphate (TPP), and isopropylated triphenyl phosphate (ITP), are increasingly used in consumer products because of the recent phase out of polybrominated diphenyl ether (PBDE) flame retardants. OPFRs have been widely detected in adults and have been linked to reproductive and endocrine changes in adult males. Carcinogenicity and damage to immunologic, neurologic and developmental systems have been observed in human cell lines. Young children are especially vulnerable to OPFR exposure, but little is known about exposure levels or exposure risk factors in this population. We examined parent-reported demographic and dietary survey data in relation to OPFR urinary metabolite concentrations in 15- to 18-month old toddlers (n = 41). OPFR metabolites were detected in 100% of subjects. The metabolite of TPP, diphenyl phosphate (DPP) was detected most commonly (100%), with TDCPP metabolite, bis(1,3-dichloro-2-propyl) phosphate (BDCPP), detected in 85-95% of samples, and ITP metabolite, monoisopropylphenyl phenyl phosphate (ip-DPP), detected in 81% of samples (n = 21). Toddlers of mothers earning <$10,000 annually had geometric mean DPP concentrations 66% higher (p = 0.05) than toddlers of mothers earning >$10,000/year (7.8 ng/mL, 95% CI 5.03, 12.11 and 4.69 ng/mL, 95% CI 3.65-6.04, respectively). While no dietary factors were significantly associated with OPFR metabolite concentrations, results suggested meat and fish consumption may be associated with higher DPP and BDCPP levels while increased dairy and fresh food consumption may be associated with lower DPP, BDCPP, and ip-DPP levels. Research with larger sample sizes and more detailed dietary data is required to confirm these preliminary findings.

Malaria transmission potential could be reduced with current and future climate change

Several studies suggest the potential for climate change to increase malaria incidence in cooler, marginal transmission environments. However, the effect of increasing temperature in warmer regions where conditions currently support endemic transmission has received less attention. We investigate how increases in temperature from optimal conditions (27 °C to 30 °C and 33 °C) interact with realistic diurnal temperature ranges (DTR: ± 0 °C, 3 °C, and 4.5 °C) to affect the ability of key vector species from Africa and Asia (Anopheles gambiae and An. stephensi) to transmit the human malaria parasite, Plasmodium falciparum. The effects of increasing temperature and DTR on parasite prevalence, parasite intensity, and mosquito mortality decreased overall vectorial capacity for both mosquito species. Increases of 3 °C from 27 °C reduced vectorial capacity by 51–89% depending on species and DTR, with increases in DTR alone potentially halving transmission. At 33 °C, transmission potential was further reduced for An. stephensi and blocked completely in An. gambiae. These results suggest that small shifts in temperature could play a substantial role in malaria transmission dynamics, yet few empirical or modeling studies consider such effects. They further suggest that rather than increase risk, current and future warming could reduce transmission potential in existing high transmission settings.

Phase I study of PF-03446962, a fully human monoclonal antibody against activin receptor-like kinase-1, in patients with hepatocellular carcinoma

BACKGROUND

This expansion cohort of a multicenter, dose-escalation, phase I study (NCT00557856) evaluated safety, tolerability, antitumor activity, pharmacokinetics, and pharmacodynamic effects of the anti-activin receptor-like kinase-1 (ALK-1) monoclonal antibody PF-03446962 in advanced hepatocellular carcinoma (HCC).

PATIENTS AND METHODS

Patients with HCC and disease progression after prior antiangiogenic therapy or intolerance to treatment received PF-03446962 7 mg/kg intravenously biweekly, as recommended in the dose-escalation part of the study.

RESULTS

Twenty-four patients received PF-03446962. The most frequent treatment-related adverse events (AEs) were thrombocytopenia (33.3%), asthenia (29.2), and chills (16.7%). Two patients experienced treatment-related telangiectasia, suggesting an in vivo knockout of ALK-1 function through ALK-1 pathway inhibition. Overall, treatment-related grade 3-4 AEs were reported in eight patients (33.3%). Treatment-related grade 3-4 thrombocytopenia was noted in four patients. No complete or partial responses were reported. Twelve (50%) patients achieved stable disease, which lasted ≥12 weeks in seven (29.2%) patients. The median time to progression was 3 months. Biomarker analyses showed higher mean tumor expression of c-tumor mesenchymal-epithelial transition factor and higher mean serum levels of bone morphogenetic protein-9 in patients with disease control (DC) for ≥12 weeks versus patients with disease progression. Conversely, lower mean serum transforming growth factor-β and vascular endothelial growth factor receptor-3 levels were detected in patients with DC versus patients with progression.

CONCLUSIONS

The observed safety, tolerability, pharmacokinetic profile, and clinical activity support further evaluation of PF-03446962 in patients with HCC and other solid malignancies, as single agent or in combination with other antiangiogenic, chemotherapeutic, or immunotherapeutic agents.

TRIAL REGISTRATION NUMBER

NCT00557856.

Biocontrol-risky but necessary?

There is currently much debate concerning the risks of biological control and the potential harmful effects of nonindigenous species introduced for controlling exotic pests. Biocontrol advocates generally appear reluctant to accept the possibility that there could be side-effects associated with biocontrol, often refuting evidence of harmful effects and suggesting that current practices are sufficient to minimize any risks. The biocontrol critics, on the other hand, although eager to provide evidence to the contrary, appear reluctant to propose any detailed, constructive criticisms or workable solutions. Here, we attempt to put these arguments into context, and suggest some directions for future research that might help to resolve some of the problems.

Efficacy of bevacizumab plus erlotinib for advanced hepatocellular carcinoma and predictors of outcome: final results of a phase II trial

OBJECTIVE

A phase II study was performed to evaluate the efficacy and tolerability of bevacizumab and erlotinib in advanced hepatocellular carcinoma (HCC) patients, and to investigate clinical and molecular predictors of outcome.

METHODS

59 patients with advanced HCC received 10 mg/kg i.v. of bevacizumab every 14 days and 150 mg p.o. of erlotinib daily. The primary endpoint was progression-free survival (PFS) at 16 weeks. Clinical characteristics and plasma biomarkers expression levels were analyzed.

RESULTS

PFS at 16 weeks was 64% (95% CI 51-76): 14 patients achieved partial response (24%), 33 had stable disease (56%), 6 progressed (10%), and 6 were not evaluable (10%). Median overall survival was 13.7 months (95% CI 9.6-19.7), and median PFS was 7.2 months (95% CI 5.6-8.3). Grade 3-4 adverse events included fatigue (30%), diarrhea (17%), hypertension (14%), elevated transaminases (12%), and gastrointestinal hemorrhage (10%). High plasma angiopoietin-2, epidermal growth factor receptor, and endothelin-1, and lack of acneiform rash were associated with poor outcome.

CONCLUSIONS

The combination of bevacizumab with erlotinib achieved encouraging results in patients with advanced HCC. Current correlatives may help to guide future HCC studies.

Refuge theory and biological control

An important question in ecology is the extent to which populations and communities are governed by general rules. Recent developments in population dynamics theory have shown that hosts' refuges from their insect parasitoids predict parasitoid community richness patterns. Here, the refuge theory is extended to biological control, in which parasitoids are imported for the control of insect pests. Theory predicts, and data confirm, that the success of biological control is inversely related to the proportion of insects protected from parasitoid attack. Refuges therefore provide a general mechanism for interpreting ecological patterns at both the community level (their species diversity) and population level (their dynamics).

A splice site single nucleotide polymorphism of the fatty acid binding protein 4 gene appears to be associated with intramuscular fat deposition in longissimus muscle in Australian cattle

Fatty acid binding protein 4 (FABP4) is a candidate gene affecting fatness traits of mammals. However, its association with fatness traits in cattle and other livestock species is not consistent from one study to another. Here, we sequenced the coding sequence of FABP4 looking for non-synonymous variants. We identified a splice site mutation between the third exon and the third intron of bovine FABP4. We genotyped this SNP, FABP4:g.2502C>G, in 1409 cattle with intramuscular fat measurements from seven breeds. The average allele frequency of the C allele was 0.66 with a range of 0.45 to 0.85. A regression on the number of G alleles shows a statistically significant effect of alpha = 0.11, P = 0.044. This appears to confirm an association between IMF and variation at FABP4, with an effect of 0.3% of the variation in our sample when using this SNP.

An age-structured model to evaluate the potential of novel malaria-control interventions: a case study of fungal biopesticide sprays

It has recently been proposed that mosquito vectors of human diseases, particularly malaria, may be controlled by spraying with fungal biopesticides that increase the rate of adult mortality. Though fungal pathogens do not cause instantaneous mortality, they can kill mosquitoes before they are old enough to transmit disease. A model is developed (i) to explore the potential for fungal entomopathogens to reduce significantly infectious mosquito populations, (ii) to assess the relative value of the many different fungal strains that might be used, and (iii) to help guide the tactical design of vector-control programmes. The model follows the dynamics of different classes of adult mosquitoes with the risk of mortality due to the fungus being assumed to be a function of time since infection (modelled using the Weibull distribution). It is shown that substantial reductions in mosquito numbers are feasible for realistic assumptions about mosquito, fungus and malaria biology and moderate to low daily fungal infection probability. The choice of optimal fungal strain and spraying regime is shown to depend on local mosquito and malaria biology. Fungal pathogens may also influence the ability of mosquitoes to transmit malaria and such effects are shown to further reduce vectorial capacity.

A phase II study of UFT with leucovorin administered as a twice daily schedule in the treatment of patients with metastatic colorectal cancer

Prolonged infusions have been shown to be safer and potentially more effective than bolus regimens of 5-fluorouracil (5-FU) as treatment for metastatic colorectal cancer (mCRC). However, infusional 5-FU requires central venous access and costly infusion pumps. Oral fluoropyrimidines enable longer exposures to 5-FU with increased convenience. Tegafur–uracil (UFT) with leucovorin (LV) given thrice daily has improved safety plus comparable survival and response rates to bolus 5-FU/LV. We conducted a phase II clinical study in 98 patients with mCRC to evaluate if UFT with LV given twice daily provided comparable time to progression (TTP), efficacy and tolerability to that reported for thrice daily in two phase III clinical studies. Secondary objectives included overall response rate (ORR) and overall survival (OS). Median TTP was 3.8 months, when compared with 3.5 months for thrice daily. The ORR (11%) and median OS (12.8 months) with twice daily administration were similar to that of thrice daily administration (12% and 12.4 months). The incidence of grade 3/4 treatment-related diarrhoea was 30% on the twice daily and 21% on the thrice daily schedule. These results suggest that twice daily administration has similar efficacy and tolerability to thrice daily administration and is an acceptable alternative for patients who would benefit from UFT with LV therapy.

Cyanide poisoning in cattle from Dysphania glomulifera (red crumbweed): using the internet for rapid plant identification and diagnostic advice

A 300-strong Angus-Brahman cattle herd near Springsure, central Queensland, was being fed Acacia shirleyi (lancewood) browse during drought and crossed a 5-hectare, previously burnt area with an almost pure growth of Dysphania glomulifera subspecies glomulifera (red crumbweed) on their way to drinking water. Forty cows died of cyanide poisoning over 2 days before further access to the plant was prevented. A digital image of a plant specimen made on a flat-bed scanner and transmitted by email was used to identify D glomulifera. Specific advice on the plant's poisonous properties and management of the case was then provided by email within 2 hours of an initial telephone call by the field veterinarian to the laboratory some 600 km away. The conventional method using physical transport of a pressed dried plant specimen to confirm the identification took 5 days. D glomulifera was identified in the rumen of one of two cows necropsied. The cyanogenic potential of D glomulifera measured 4 days after collection from the site of cattle deaths was 18,600 mg HCN/kg in dry matter. The lethal dose of D glomulifera for a 420 kg cow was estimated as 150 to 190 g wet weight. The plant also contained 4.8% KNO3 equivalent in dry matter, but nitrate-nitrite poisoning was not involved in the deaths.

Self-assembling layers created by membrane proteins on gold

Membrane systems are based on several types of organization. First, amphiphilic lipids are able to create monolayer and bilayer structures which may be flat, vesicular or micellar. Into these structures membrane proteins can be inserted which use the membrane to provide signals for lateral and orientational organization. Furthermore, the proteins are the product of highly specific self-assembly otherwise known as folding, which mostly places individual atoms at precise places in three dimensions. These structures all have dimensions in the nanoscale, except for the size of membrane planes which may extend for millimetres in large liposomes or centimetres on planar surfaces such as monolayers at the air/water interface. Membrane systems can be assembled on to surfaces to create supported bilayers and these have uses in biosensors and in electrical measurements using modified ion channels. The supported systems also allow for measurements using spectroscopy, surface plasmon resonance and atomic force microscopy. By combining the roles of lipids and proteins, highly ordered and specific structures can be self-assembled in aqueous solution at the nanoscale.

Epistasis between calpain 1 and its inhibitor calpastatin within breeds of cattle

The calpain gene family and its inhibitors have diverse effects, many related to protein turnover, which appear to affect a range of phenotypes such as diabetes, exercise-induced muscle injury, and pathological events associated with degenerative neural diseases in humans, fertility, longevity, and postmortem effects on meat tenderness in livestock species. The calpains are inhibited by calpastatin, which binds directly to calpain. Here we report the direct measurement of epistatic interactions of causative mutations for quantitative trait loci (QTL) at calpain 1 (CAPN1), located on chromosome 29, with causative mutations for QTL variation at calpastatin (CAST), located on chromosome 7, in cattle. First we identified potential causative mutations at CAST and then genotyped these along with putative causative mutations at CAPN1 in >1500 cattle of seven breeds. The maximum allele substitution effect on the phenotype of the CAPN1:c.947G>C single nucleotide polymorphism (SNP) was 0.14 sigma(p) (P = 0.0003) and of the CAST:c.155C>T SNP was also 0.14 sigma(p) (P = 0.0011) when measured across breeds. We found significant epistasis between SNPs at CAPN1 and CAST in both taurine and zebu derived breeds. There were more additive x dominance components of epistasis than additive x additive and dominance x dominance components combined. A minority of breed comparisons did not show epistasis, suggesting that genetic variation at other genes may influence the degree of epistasis found in this system.

A validated whole-genome association study of efficient food conversion in cattle

The genetic factors that contribute to efficient food conversion are largely unknown. Several physiological systems are likely to be important, including basal metabolic rate, the generation of ATP, the regulation of growth and development, and the homeostatic control of body mass. Using whole-genome association, we found that DNA variants in or near proteins contributing to the background use of energy of the cell were 10 times as common as those affecting appetite and body-mass homeostasis. In addition, there was a genic contribution from the extracellular matrix and tissue structure, suggesting a trade-off between efficiency and tissue construction. Nevertheless, the largest group consisted of those involved in gene regulation or control of the phenotype. We found that the distribution of micro-RNA motifs was significantly different for the genetic variants associated with residual feed intake than for the genetic variants in total, although the distribution of promoter sequence motifs was not different. This suggests that certain subsets of micro-RNA are more important for the regulation of this trait. Successful validation depended on the sign of the allelic association in different populations rather than on the strength of the initial association or its size of effect.

The effect of genetic variation of the retinoic acid receptor-related orphan receptor C gene on fatness in cattle

Genotypes at the retinoic acid receptor-related orphan receptor C (RORC) gene were associated with fatness in 1750 cattle. Ten SNPs were genotyped in RORC and the adjacent gene leucine-rich repeat neuronal 6D (LRRN6D) to map the QTL, 7 of which are in a 4.2-kb sequence around the ligand-binding domain of the RORC gene. Of the 29 inferred haplotypes for these SNPs, 2 have a combined frequency of 54.6% while the top 5 haplotypes have a combined frequency of 85.3%. The average D' value of linkage disequilibrium was 0.92 although the average r2 was a low 0.18. The RORC:g.3290T>G SNP had the strongest association with marbling. The inferred haplotypes were significantly associated with marbling and the difference between the most divergent haplotypes was 0.35 sigma(p) of marbling and 0.28 sigma(p) of rump fat, explaining the previously reported QTL effect. cDNA for RORC were sequenced and 2 new alternative transcripts were found. Fetal tissue shows 40 times greater transcription of RORC than adult tissue. The highest expression in fetal tissue was found in liver and kidney, but in adults the longissimus muscle had the greatest expression of the tissues tested.

The growth hormone 1 GH1:c.457C>G mutation is associated with intramuscular and rump fat distribution in a large sample of Australian feedlot cattle

The GH1:c.457C>G exon 5 missense mutation in the bovine growth hormone 1 (GH1) gene that causes the replacement of leucine (L) with valine (V) was investigated in 1027 cattle with primarily Angus and Shorthorn breeding from Australian feedlots. The allele frequency of the GH1:c.457C allele was 0.77 in Angus and 0.76 in Shorthorn. The GH1:c.457C allele was associated with lower marbling (P = 0.0472), and the average effect of allele substitution was -0.22 of a phenotypic standard deviation. This allele was also associated with slightly higher rump fat (P = 0.0541) and the average effect of allele substitution was 0.11 SD. Marbling and rump fat were not strongly correlated (r = 0.097, P < 0.01) in this data set. This mutation had no significant effect on eye muscle area or hot dressed carcass weight (P > 0.1). Given these relationships, the differences between GH1 alleles could be the result of differential deposition of fat in fat depots.

Calcification in the planula and polyp of the hydroidHydractinia symbiolongicarpus(Cnidaria, Hydrozoa)

This study examines calcification in planulae and polyps of the hydroid Hydractinia symbiolongicarpus. We observed that established colonies produce a crystalline mat on their substratum and that crystals visible by polarized light microscopy occur in the vacuoles of the gastrodermal cells of both polyps and planulae. The crystalline mat was found by infrared spectroscopy to contain calcium carbonate in the form of aragonite. The composition of the vacuolar crystals and the cellular mechanisms for manufacturing them were explored by alteration of calcium levels in the environment and by the use of pharmacological agents (acetazolamide, caffeine, DIDS, diltiazem, nifedipine, procaine, Ruthenium Red, ryanodine and verapamil) that affect cellular uptake and transport of calcium and bicarbonate. The results indicated that the crystals in the vacuoles contained calcium carbonate. The gastrodermal cells are hypothesized to serve as a physiological sink for excess calcium that enters the organism during motility, secretion and metamorphosis of the planula, and to create a crystalline substratum for the colony of polyps.

Effects of temperature and relative humidity on sporulation of Metarhizium anisopliae var. acridum in mycosed cadavers of Schistocerca gregaria

The effects of relative humidity (RH) and temperature on the sporulation of Metarhizium anisopliae var. acridum on mycosed cadavers of desert locust, Schistocerca gregaria, were assessed in the laboratory. Quantitative assessments of conidial production over 10 days under constant conditions showed that sporulation was optimized at RH > 96% and at temperatures between 20 and 30 degrees C. Under both these conditions >10(9) conidia/cadaver were produced. At 25 degrees C, conidial yield was maximized under conditions in which cadavers remained in contact with damp substrate. Relatively little sporulation occurred at 15 degrees C (< 3 x 10(7) conidia/cadaver) and 40 degrees C (< 4 x 10(6) conidia/cadaver) and no sporulation occurred at 10 or 45 degrees C. Following incubation, conidial yield was closely related to the water content of locust cadavers. In separate tests, locust cadavers were incubated for 10 days under diurnally fluctuating temperature and RH that comprised favorable (25 degrees C/100% RH) alternating with unfavorable (40 degrees C/80% RH) conditions for sporulation. In this case, fewer conidia were produced compared with cadavers that were incubated under the favorable conditions for an equal period cumulatively but were not periodically exposed to unfavorable conditions. However, this reduced sporulation observed with the fluctuating condition was not observed when cadavers were similarly incubated under favorable/unfavorable conditions of temperature but were not periodically exposed to the low RH condition. This result implies that sporulation is a dynamic process, dependent not only on periodic exposure to favorable RH but also on the interrelation of this with low RH. Associated tests and the monitoring of changes in cadaver weights imply that the mechanism driving the reduced sporulation under fluctuating RH is the net water balance of cadavers, i.e. the cumulative ability of the fungus/cadaver to adsorb water necessary for sporulation at high RH is restricted by water loss associated with intermittent exposure to a low RH. The duration of daily exposure to high humidity appears to be a crucial constraint to the recycling ability of M. anisopliae var. acridum.

Adult survival, maturation, and reproduction of the desert locust Schistocerca gregaria infected with the fungus Metarhizium anisopliae var acridum

Studies were conducted with two different doses of Metarhizium anisopliae var acridum to examine the effects on survival and reproductive potential of adult Schistocerca gregaria under conditions that either limited thermoregulation or enabled optimal thermoregulation. Adult S. gregaria infected with the fungal pathogen showed either a rapid and high mortality at relatively constant temperatures or a much reduced mortality and lengthened survival time when allowed to thermoregulate. Mortality rate varied from >90% after 10 days under constant temperature conditions to 66% after 70 days under optimal thermoregulatory conditions. Effects of infection on maturation and reproduction depended on the age of the adults at the time of inoculation, the nighttime temperature regime, the fungal dose, and the length of time of the monitoring period. No difference in reproductive behaviors in treated and control insects were found in one experiment that utilized older adults and was conducted over 25 days. In a second experiment with newly fledged locusts, differences in maturation rates and total reproductive output were observed due to infection. The results from these experiments are discussed in terms of the potential of M. anisopliae var acridum to alter the balance of insect endocrine systems and the importance of the assessment of behavioral changes and their impact on microbial control agents in the long term.

A database model for integrating and facilitating collaborative ethnomedicinal research

A model for a database system that provides a standardized environment for submission, storage, and retrieval of ethnomedicinal data was developed. The model is based on object oriented database technology, and is suitable for not only storing data, digital images, sound and video, but also for modeling domain knowledge associated with plant-based medicinal preparations utilized in systems of traditional medicine. The model incorporates both linguistic and semantic elements. Terms in natural language are mapped to database objects that represent knowledge in various ethnomedicinal domains. The distributed object infrastructure permits integration with other authoritative taxonomic databases and includes an interface capable of supporting existing and emerging standards of data. The model provides a foundation for a globally current dynamic data resource that encourages comparative ethnomedicinal research through direct contributions by members of the research community. Examples of integrated domain models are presented incorporating medical terminology, plant systematics, ecology, and pharmacology.

Ecological approaches and the development of "truly integrated" pest management

Recent predictions of growth in human populations and food supply suggest that there will be a need to substantially increase food production in the near future. One possible approach to meeting this demand, at least in part, is the control of pests and diseases, which currently cause a 30-40% loss in available crop production. In recent years, strategies for controlling pests and diseases have tended to focus on short-term, single-technology interventions, particularly chemical pesticides. This model frequently applies even where so-called integrated pest management strategies are used because in reality, these often are dominated by single technologies (e.g., biocontrol, host plant resistance, or biopesticides) that are used as replacements for chemicals. Very little attention is given to the interaction or compatibility of the different technologies used. Unfortunately, evidence suggests that such approaches rarely yield satisfactory results and are unlikely to provide sustainable pest control solutions for the future. Drawing on two case histories, this paper demonstrates that by increasing our basic understanding of how individual pest control technologies act and interact, new opportunities for improving pest control can be revealed. This approach stresses the need to break away from the existing single-technology, pesticide-dominated paradigm and to adopt a more ecological approach built around a fundamental understanding of population biology at the local farm level and the true integration of renewable technologies such as host plant resistance and natural biological control, which are available to even the most resource-poor farmers.

Characterization of the mouse Ron/Stk receptor tyrosine kinase gene

In an effort to understand the mechanisms governing the regulation of the mouse Ron receptor gene, a mouse genomic library was screened and overlapping clones coding for the Ron gene and flanking DNA were identified. Continuous DNA sequence was obtained for approximately 16.4 kilobases. The gene, from the initiator methionine to the polyadenylation site, is contained within 13 244 basepairs and contains 19 exons. Primer extension analyses were performed to determine the transcription start site of the mouse Ron transcript. Multiple transcription start sites were found which also appear to be used in transfected reporter constructs containing Ron 5' flanking DNA. To determine the location of sites which may be critical for the function of the Ron gene promoter, a series of chimeric genes containing serial deletions of the Ron gene promoter fused to the coding sequences for the chloramphenicol acetyl-transferase gene were constructed. Transient transfection analyses of these hybrid genes into various cell lines demonstrated that two regions of the Ron gene promoter, encompassing nucleotides -585 to -465 and from -465 to -285, are important for expression of this transcript in CMT-93 cells. Further analysis of the Ron promoter utilizing gel mobility shift analyses suggests that regions encompassing nucleotides -585 to - 508 and nucleotides -375 to -285 appear to bind specific proteins which may be involved in the negative and positive regulation, respectively, of the mouse Ron gene.

Vaccination against Babesia bovis: T cells from protected and unprotected animals show different cytokine profiles

Vaccination of cattle against the haemoprotozoan parasite, Babesia bovis, with the recombinant antigen 11C5 resulted in 9 of 15 cattle being protected against challenge infection. The cellular immune responses of protected and unprotected cattle were compared in order to identify differences in response. No differences were observed in the pattern of change in various blood leukocyte populations throughout challenge infection. FACScan analysis revealed an increase in the proportion of cells bearing the CD2 marker in both protected and unprotected cattle over the course of infection. There were no observable differences in the frequency of various cell-surface markers between the unprotected and protected cattle. During the period of patent parasitaemia, in vitro cultures of peripheral blood mononuclear cells (PBMC) from protected cattle produced significantly more TNF-alpha (P < 0.05) than cultures from unprotected cattle. TNF-alpha concentrations remained at pre-challenge levels until day 10, when levels in the unvaccinated control and vaccinated/unprotected animals dropped. By peak parasitaemia, TNF-alpha production in vitro was significantly greater (P < 0.05) in cultures of PBMCs from protected cattle. Interferon production showed an initial peak at day 5 in all cattle, followed by a decrease and a second peak at days 10-13 in protected cattle only, which coincided with resolution of the infection.

Regulation of duodenal specific expression of the human adenosine deaminase gene

Formation of the mammalian gastrointestinal tract is an ordered process of development and differentiation. Yet, the adult small intestine also retains the plasticity to respond to cues both internal and environmental to modulate intestinal function. The components that regulate this development, differentiation, and modulation at the molecular level are only now being elucidated. We have used the human adenosine deaminase (ADA) gene as a model to identify potential cis-regulatory components involved in these processes within the small intestine. In mammals, high levels of ADA in the small intestine are limited specifically to the differentiated enterocytes within the duodenal region. These studies describe the identification of a region of the human ADA gene, completely distinct from the previously identified T-cell enhancer, which is capable of directing the human intestinal expression pattern in the intestine of transgenic mice. The reporter gene expression pattern observed in these transgenic mice is identical to the endogenous gene along both the cephalocaudal and crypt/villus axis of development. Timing of this transgene activation, however, varies from that of the endogenous mouse gene in that the transgene is activated approximately 2 weeks earlier in development. Even so, this precocious activation is also limited to the epithelium of the developing villi strictly within the duodenal region of the small intestine.

An enhancer LEF-1/TCF-1 site is essential for insertion site-independent transgene expression in thymus

Transcriptional activation of eukaryotic genes involves assembly of specific multiprotein complexes on the promoters and enhancers of the genes. Recently, it has been proposed that the role of some of the proteins in the complex may be architectural, involving DNA bending, orchestration of protein-protein interaction and modulation of nucleosome structure. This role has been proposed for the HMG proteins LEF-1 and TCF-1. We examined the role of a LEF-1/TCF-1 binding site in the human adenosine deaminase (ADA) thymic enhancer. Mutational analysis demonstrated that a functional LEF-1/TCF-1 binding site is not required for enhancer-mediated transcriptional activation in transient transfection studies, but is essential for enhancer function in the in vivo chromatin context of transgenic mice. Mutation of the LEF-1/TCF-1 site destroyed the ability of the ADA enhancer/locus control region to specify high level, insertion site-independent transgene expression in thymus. DNase I and DpnII accessibility experiments indicated dramatic changes in the chromatin organization of the ADA enhancer in transgenic mice with a mutated LEF-1/TCF-1 site. This supports the hypothesis that factors binding the LEF-1/TCF-1 site play an architectural role during the in vivo activation of the ADA enhancer, possibly involving chromatin modification.

Chemoreceptors expressed in taste, olfactory and male reproductive tissues

We have identified three genes encoding previously uncharacterized chemoreceptors expressed in rat sensory and reproductive tissues using a reverse transcriptase polymerase chain reaction strategy. Degenerate oligonucleotides designed from conserved sequences in the rat olfactory receptor gene family were used to amplify candidate receptor gene products expressed in taste tissue. Sequence analysis of three distinct clonal isolates revealed that the gene products from taste bud were 30-75% identical to previously identified olfactory receptor genes. The genomic coding sequences predicted protein structures with seven membrane spanning regions that have strong conservation relative to other members of the G-protein-coupled olfactory receptor gene family. Transcripts for each of the three gene products were detected exclusively in taste, olfactory and male reproductive tissue. Sequence analysis of the polymerase chain reaction products confirmed that identical transcripts were expressed in all three tissues. These findings are the first demonstration that identical olfactory receptor-like gene are expressed in three distinct tissues.

Space, time and persistence of virulent pathogens

Epidemiological theory predicts that pathogens of high virulence should not become endemic. We show, using an empirically based lattice map model, that a pathogen that is too virulent to persist if its host population is spatially well mixed, can persist if the host population is spatially distributed, because of internally generated complex spatial dynamics, provided that the area occupied by the host population is sufficiently large. The dynamics are not an artefact of spatial or temporal discretization. The results uncover a mechanism for the persistence of virulent pathogens, suggesting a means by which pathogens of high virulence could achieve sustained as well as short-term biological pest control.

The Role of Shell Granules and Accessory Cells in Eggshell Formation in Convoluta pulchra (Turbellaria, Acoela)

Most turbellarian embryos are surrounded by a sclerotinized eggshell originating from polyphenol-containing eggshell-forming granules (EFGs). Although embryos of the acoel Convoluta pulchra are surrounded by a shell, it is not sclerotinized. Therefore, in the absence of polyphenols as a marker for EFGs, it was not clear which, if any, of the granules of the oocyte function in eggshell synthesis. In this study, electron-opaque, elliptical granules with a characteristic frothy component and a diameter of 480 nm were identified in the oocyte as EFGs by their participation in eggshell formation. In addition, it was shown that accessory cells to the oocyte initiate synthesis of the shell by producing a thin, granular, electron-opaque primary shell, against which the contents of the EFGs are released by exocytosis. Morphological components of the shell and stages of its synthesis are described. A second type of membrane-bound granule and the lipid droplets that occur in the ooplasm were found not to be involved in eggshell formation and are probable sources of nutrients for the developing embryo. Possible implications of the findings for taxonomy and phylogeny are discussed.

Determinants of intact parathyroid hormone and free 1,25-dihydroxyvitamin D levels in mild and moderate renal failure

Parameters of calcium and phosphate metabolism were measured in 27 patients with mild renal failure [glomerular filtration rate (GFR) 40-90 ml/min], 12 patients with moderate renal failure (GFR 20-39 ml/min) and in 12 healthy subjects. GFR was determined by technetium-99m diethylenetriamine penta-acetic acid clearance. Intact parathyroid hormone (PTH) was measured by a sensitive immunochemiluminometric assay and somatomedin-C was determined by radioimmunoassay. Both 1,25-dihydroxyvitamin D [1,25(OH)2D] and vitamin-D-binding protein were measured allowing calculation of the free 1,25(OH)2D index. By linear regression and multivariate analysis, PTH was negatively and independently correlated with GFR, plasma bicarbonate and 25-hydroxyvitamin D [25(OH)D] while free 1,25(OH)2D was positively correlated with GFR. Increased PTH secretion and reductions in 1,25(OH)2D were present in mild renal failure patients before any changes in plasma calcium, phosphate and bicarbonate were noted. Plasma alkaline phosphatase was significantly higher in mild chronic renal failure patients compared to normal subjects, possibly indicating early effects of the secondary hyperparathyroidism on the skeleton. Somatomedin-C did not correlate with the free 1,25(OH)2D index or a measure of 1,25(OH)2D production. It is concluded that the secondary hyperparathyroidism which occurs very early in the onset of chronic renal failure may be due to a reduction in the circulating concentration of 1,25(OH)2D consequent upon the renal failure. Low plasma bicarbonate and 25(OH)D also appear to be determinants of a raised PTH concentration. The compensatory increase in PTH presumably maintains extracellular calcium and phosphate levels constant but with possible deleterious effects on the skeleton.

Production of extracellular enzymes and cytotoxicity by Vibrio vulnificus

Thirty-three strains of Vibrio vulnificus of clinical and environmental origin were examined for production of 12 extracellular enzymes of potential importance to the virulence of this bacterium. Strains of Vibrio vulnificus were consistent in their production of protease, mucinase, lipase, chondroitinase, hyaluronidase, DNase, sulfatase, and hemolysin. No differences between clinical and environmental isolates were noted. Although none of the enzymes appeared to correlate with the ability of these strains to produce lethality in mice, the production of hemolysin and of a protease with activity against native serum albumin may be significant in the pathogenesis of the potentially fatal infections produced by this organism. The production of several of these exoenzymes also appeared to correlate with pathogenicity in the seven other Vibrio species examined. Culture filtrates of all virulent strains of Vibrio vulnificus were cytotoxic for Chinese hamster ovary cells, whereas those of the strains of Vibrio parahaemolyticus and Vibrio alginolyticus examined lacked this activity.

Bleomycin-induced cutaneous toxicity in the rat: analysis of histopathology and ultrastructure compared with progressive systemic sclerosis (scleroderma)

Rats injected with bleomycin over a 58-week period developed weight loss, alopecia, hyperpigmentation, skin thickening and skin tautness when compared with saline-injected control animals. The only significant abnormality in laboratory blood tests was an increased sedimentation rate in the bleomycin-treated rats compared with controls. Histological examination of dorsal skin showed atrophied sebaceous glands and increased collagen fibres, with diameters ranging from 37.5 to 75 nm as compared with 72.5 to 100 nm in control animals. Chronic bleomycin exposure produces clinical, histological and ultrastructural skin changes similar to those found in human progressive systemic sclerosis (scleroderma).

A comparison of procedures for the isolation of adrenocorticotrophin from human pituitary glands

Two methods for the purification of corticotrophin from human pituitary glands have been assessed by two radioimmunoassays directed towards the C-terminal and N-terminal parts of the molecule, and by bioassay. One procedure, applied to small amounts of tissue, employs acid acetone extraction, oxycellulose adsorption and chromatography on CM-cellulose (CM-23). It is suitable for the small-scale purification of corticotrophin from pituitary glands but the losses associated with extracting low concentrations of hormone suggest that it would be inadequate for application to extrapituitary tissues and tumours. The starting material for the second procedure was a side fraction derived from the large scale extraction of protein hormones from whole pituitary glands. The purification employs oxycellulose adsorption, gel filtration on Sephadex G-50 and chromatography on CM-cellulose (CM-32). It yields sufficient highly potent corticotrophin for use as radioimmunoassay standard while conserving other scarce human pituitary hormones.

The "9+1" pattern of microtubules in spermatozoa of Mesostoma (Platyhelminthes, Turbellaria)

The living spermatozoa of the flatworm Mesostoma georgianum have a sperm body about 100 mu long and 0.5 mu wide, and two motile free flagella, ca. 200 mu long. In sections examined with the electron microscope, these flagella have the usual nine pairs of peripheral doublet microtubules and have a single central core unit which is connected to the A members of the doublets by spokelike structures. There are also short connections between the doublets and the flagellar membrane. In material negatively stained with phosphotungstic acid, the doublet microtubules seem to have very different elastic properties than the core; they tend to fall on the copper grids in coils of rather uniform diameter (2-4 mu), while the core is much more rigid and is often found extending alone, along a relatively straight course, for very long distances (up to 73 mu). After negative staining, the core has a striking appearance with a dense center around which are wound two hollow structures in a double helix of 45 degrees pitch. The center-to-center distance of each gyre is approximately 650 A, and the hollow structures are ca. 180 A in diameter.