Medicine in motion: Opportunities, challenges and data analytics-based solutions for traditional medicine integration into western medical practice

ETHNOPHARMACOLOGICAL RELEVANCE

Traditional pharmacopeias have been developed by multiple cultures and evaluated for efficacy and safety through both historical/empirical iteration and more recently through controlled studies using Western scientific paradigms and an increasing emphasis on data science methodologies for network pharmacology. Traditional medicines represent likely sources of relatively inexpensive drugs for symptomatic management as well as potential libraries of new therapeutic approaches. Leveraging this potential requires hard evidence for efficacy that separates science from pseudoscience.

MATERIALS AND METHODS

We performed a review of non-Western medical systems and developed case studies that illustrate the epistemological and practical translative barriers that hamper their transition to integration with Western approaches. We developed a new data analytics approach, in silico convergence analysis, to deconvolve modes of action, and potentially predict desirable components of TM-derived formulations based on computational consensus analysis across cultures and medical systems.

RESULTS

Abstraction, simplification and altered dose and delivery modalities were identified as factors that influence actual and perceived efficacy once a medicine is moved from a non-Western to Western setting. Case studies on these factors highlighted issues with translation between non-Western and Western epistemologies, including those where epistemological and medicinal systems drive markets that can be epicenters for zoonoses such as the novel Coronavirus. The proposed novel data science approach demonstrated the ability to identify and predict desirable medicinal components for a test indication, pain.

CONCLUSIONS

Relegation of traditional therapies to the relatively unregulated nutraceutical industry may lead healthcare providers and patients to underestimate the therapeutic potential of these medicines. We suggest three areas of emphasis for this field: First, vertical integration and embedding of traditional medicines into healthcare systems would subject them to appropriate regulation and evidence-based practice, as viable integrative implementation mode. Second, we offer a new Bradford-Hill-like framework for setting research priorities and evaluating efficacy, with the goal of rescuing potentially valuable therapies from the nutraceutical market and discrediting those that are pseudoscience. Third, data analytics pipelines offer new capacity to generate new types of TMS-inspired medicines that are rationally-designed based on integrated knowledge across cultures, and also provide an evaluative framework against which to test claims of fidelity and efficacy to TMS made for nutraceuticals.

REVIEW: Assessing North Atlantic right whale health: threats, and development of tools critical for conservation of the species

Whaling has decimated North Atlantic right whales Eubalaena glacialis (NARW) since the 11th century and southern right whales E. australis (SRW) since the 19th century. Today, NARWs are Critically Endangered and decreasing, whereas SRWs are recovering. We review NARW health assessment literature, NARW Consortium databases, and efforts and limitations to monitor individual and species health, survival, and fecundity. Photographs are used to track individual movement and external signs of health such as evidence of vessel and entanglement trauma. Post-mortem examinations establish cause of death and determine organ pathology. Photogrammetry is used to assess growth rates and body condition. Samples of blow, skin, blubber, baleen and feces quantify hormones that provide information on stress, reproduction, and nutrition, identify microbiome changes, and assess evidence of infection. We also discuss models of the population consequences of multiple stressors, including the connection between human activities (e.g. entanglement) and health. Lethal and sublethal vessel and entanglement trauma have been identified as major threats to the species. There is a clear and immediate need for expanding trauma reduction measures. Beyond these major concerns, further study is needed to evaluate the impact of other stressors, such as pathogens, microbiome changes, and algal and industrial toxins, on NARW reproductive success and health. Current and new health assessment tools should be developed and used to monitor the effectiveness of management measures and will help determine whether they are sufficient for a substantive species recovery.

Evaluating exposure of northern fur seals, Callorhinus ursinus, to microplastic pollution through fecal analysis

Environmental microplastics are widely documented in marine life and bioaccumulation may present risks to marine predators. Investigations of microplastics in marine mammals are increasing, though none have examined animals routinely consumed by humans. Here, we investigate microplastic exposure in the northern fur seal (Callorhinus ursinus), a species consumed by humans, using fecal material. We examined 44 feces (scat) at sites encompassing the seals' eastern Pacific range. Multiple contamination control measures were implemented, including field and laboratory controls. Fragments were the most common microplastic recovered, in 55% (24/44) of scat and no controls (range 1 to 86 fragments/scat, mean 16.6, sd 19.1). Microplastic fibers were recovered from 41% of scats (18/44), though some controls contained fibers confounding fiber results. Fecal analysis documented northern fur seal exposure to microplastics throughout their eastern Pacific range.

Model recommendations meet management reality: implementation and evaluation of a network-informed vaccination effort for endangered Hawaiian monk seals

Where disease threatens endangered wildlife populations, substantial resources are required for management actions such as vaccination. While network models provide a promising tool for identifying key spreaders and prioritizing efforts to maximize efficiency, population-scale vaccination remains rare, providing few opportunities to evaluate performance of model-informed strategies under realistic scenarios. Because the endangered Hawaiian monk seal could be heavily impacted by disease threats such as morbillivirus, we implemented a prophylactic vaccination programme. We used contact networks to prioritize vaccinating animals with high contact rates. We used dynamic network models to simulate morbillivirus outbreaks under real and idealized vaccination scenarios. We then evaluated the efficacy of model recommendations in this real-world vaccination project. We found that deviating from the model recommendations decreased the efficiency; requiring 44% more vaccinations to achieve a given decrease in outbreak size. However, we gained protection more quickly by vaccinating available animals rather than waiting to encounter priority seals. This work demonstrates the value of network models, but also makes trade-offs clear. If vaccines were limited but time was ample, vaccinating only priority animals would maximize herd protection. However, where time is the limiting factor, vaccinating additional lower-priority animals could more quickly protect the population.

Differential regulation of calcium signalling pathways by components of Piper methysticum ('Awa)

Kava is a soporific, anxiolytic and relaxant in widespread ritual and recreational use throughout the Pacific. Traditional uses of kava by indigenous Pacific Island peoples reflect a complex pharmacopeia, centered on GABA-ergic effects of the well-characterized kavalactones. However, peripheral effects of kava suggest active components other than the CNS-targeted kavalactones. We have previously shown that immunocytes exhibit calcium mobilization in response to traditionally prepared kava extracts, and that the kavalactones do not induce these calcium responses. Here, we characterize the complex calcium-mobilizing activity of traditionally prepared and partially HPLC-purified kava extracts, noting induction of both calcium entry and store release pathways. Kava components activate intracellular store depletion of thapsigargin-sensitive and -insensitive stores that are coupled to the calcium release activated (CRAC) current, and cause calcium entry through non-store-operated pathways. Together with the pepper-like potency reported by kava users, these studies lead us to hypothesize that kava extracts contain one or more ligands for the transient receptor potential (TRP) family of ion channels. Indeed, TRP-like conductances are observed in kava-treated cells under patch clamp. Thus TRP-mediated cellular effects may be responsible for some of the reported pharmacology of kava.

Phocine distemper virus: current knowledge and future directions

Phocine distemper virus (PDV) was first recognized in 1988 following a massive epidemic in harbor and grey seals in north-western Europe. Since then, the epidemiology of infection in North Atlantic and Arctic pinnipeds has been investigated. In the western North Atlantic endemic infection in harp and grey seals predates the European epidemic, with relatively small, localized mortality events occurring primarily in harbor seals. By contrast, PDV seems not to have become established in European harbor seals following the 1988 epidemic and a second event of similar magnitude and extent occurred in 2002. PDV is a distinct species within the Morbillivirus genus with minor sequence variation between outbreaks over time. There is now mounting evidence of PDV-like viruses in the North Pacific/Western Arctic with serological and molecular evidence of infection in pinnipeds and sea otters. However, despite the absence of associated mortality in the region, there is concern that the virus may infect the large Pacific harbor seal and northern elephant seal populations or the endangered Hawaiian monk seals. Here, we review the current state of knowledge on PDV with particular focus on developments in diagnostics, pathogenesis, immune response, vaccine development, phylogenetics and modeling over the past 20 years.

Evidence of localized resource depletion following a natural colonization event by a large marine predator

For central place foragers, forming colonies can lead to extensive competition for prey around breeding areas and a zone of local prey depletion. As populations grow, this area of reduced prey can expand impacting foraging success and forcing animals to alter foraging behaviour. Here, we examine a population of marine predators, the northern fur seal (Callorhinus ursinus), which colonized a recently formed volcanic island, and assess changes in foraging behaviour associated with increasing population density. Specifically, we measured pup production and adult foraging behaviour over a 15-year period, during which the population increased 4-fold. Using measures of at-sea movements and dive behaviour, we found clear evidence that as the population expanded, animals were required to allot increasing effort to obtain resources. These changes in behaviour included longer duration foraging trips, farther distances travelled, a larger foraging range surrounding the island and deeper maximum dives. Our results suggest that as the northern fur seal population increased, local prey resources were depleted as a result of increased intraspecific competition. In addition, the recent slowing of population growth indicates that this population may be approaching carrying capacity just 31 years after a natural colonization event. Our study offers insight into the dynamics of population growth and impacts of increasing population density on a large marine predator. Such data could be vital for understanding future population fluctuations that occur in response to the dynamic environment, as natural and anthropogenic factors continue to modify marine habitats.

The psychological wellbeing of patients following excision of a pilonidal sinus

OBJECTIVE

To explore the effects of a pilonidal sinus wound on patients' psychological wellbeing.

METHOD

An interpretive descriptive approach, using the Model of Living conceptual framework, guided data collection and analysis. The Model of Living was chosen to elicit information on how a pilonidal sinus wound affected activities of living. Participants were recruited from a database of a community nursing service, using purposive sampling, until data saturation was evident. Semi-structured interviews were used to collect the data. Data were examined for frequent patterns, which were organised into themes.

RESULTS

Seven males and four females with ages ranging 17-39 years were selected through purposive sampling. Five participants reported that their wound affected their psychological wellbeing. Three themes and eight sub themes were identified from the data: adaption, perception and control. Depression and stress were associated with pain, physical inactivity, body weight changes and delayed wound healing.

CONCLUSION

A pilonidal sinus wound can affect the psychological wellbeing of patients through pain,physical inactivity, changed body weight and delayed wound healing. Pre-existing conditions could also be exacerbated by the wound.

Range-wide genetic connectivity of the Hawaiian monk seal and implications for translocation

The Hawaiian monk seal (Monachus schauinslandi) is one of the most critically endangered marine mammals. Less than 1200 individuals remain, and the species is declining at a rate of approximately 4% per year as a result of juvenile starvation, shark predation, and entanglement in marine debris. Some of these problems may be alleviated by translocation; however, if island breeding aggregates are effectively isolated subpopulations, moving individuals may disrupt local adaptations. In these circumstances, managers must balance the pragmatic need of increasing survival with theoretical concerns about genetic viability. To assess range-wide population structure of the Hawaiian monk seal, we examined an unprecedented, near-complete genetic inventory of the species (n =1897 seals, sampled over 14 years) at 18 microsatellite loci. Genetic variation was not spatially partitioned ((w) =-0.03, p = 1.0), and a Bayesian clustering method provided evidence of one panmictic population (K =1). Pairwise F(ST) comparisons (among 7 island aggregates over 14 annual cohorts) did not reveal temporally stable, spatial reproductive isolation. Our results coupled with long-term tag-resight data confirm seal movement and gene flow throughout the Hawaiian Archipelago. Thus, human-mediated translocation of seals among locations is not likely to result in genetic incompatibilities.

Extremely low genetic diversity in the endangered Hawaiian monk seal (Monachus schauinslandi)

Hunted to near extinction in the late 19th century, the endangered and endemic Hawaiian monk seal (Monachus schauinslandi) exhibits low variation at all molecular markers tested to date. Here we confirm extreme paucity of genetic diversity, finding polymorphisms at only 8 of 154 microsatellite loci tested (143 novel species-specific loci, 10 loci from Antarctic seals, and 1 previously characterized locus). This screening revealed unprecedentedly low levels of allelic diversity and heterozygosity (A = 1.1, H(e) = 0.026). Subsequent analyses of 2409 Hawaiian monk seals at the 8 polymorphic loci provide evidence for a bottleneck (P = 0.002), but simulations indicate low genetic diversity (H(e) < 0.09) prior to recorded human influence. There is little indication of contemporary inbreeding (F(IS) = 0.018) or population structure (K = 1 population). Minimal genetic variation did not prevent partial recovery by the late 1950s and may not be driving the current population decline to approximately 1200 seals. Nonetheless, genotyping nearly every individual living during the past 25 years sets a new benchmark for low genetic diversity in an endangered species.

Temporal and spatial variation in age-specific survival rates of a long-lived mammal, the Hawaiian monk seal

Estimates of variability in pinniped survival rates are generally based on observations at single sites, so it is not certain whether observed rates represent the whole population. Here, we provide a comprehensive analysis of spatio-temporal variation in age-specific survival rates for endangered Hawaiian monk seals (Monachus schauinslandi) based on capture-recapture analyses of more than 85% of the pups weaned in this population over the last two decades. Uniquely, these data have been collected from six subpopulations, encompassing all major breeding sites across its 1800 km long core range. Analyses of individual subpopulations revealed similar patterns in age-specific survival, characterized by the relatively low survival rates from weaning to 2 years of age, intermediate rates to 4 years of age, and then by relatively high 'mature' survival rates until 17 years of age, after which a senescent decline was observed. Juvenile, subadult and adult survival rates all varied significantly over time. Trends in survival among subpopulations were coherent with their relative geographical positions, suggesting regional structuring and connectedness within the archipelago. Survival rates for different age classes tended to be positively correlated, suggesting that similar factors may influence the survival for seals of all ages.

Separation of foraging habitat among breeding sites of a colonial marine predator, the northern fur seal (Callorhinus ursinus)

This study examines whether lactating northern fur seals (Callorhinus ursinus) from different breeding sites on the Pribilof Islands in the eastern Bering Sea forage in separate areas. Satellite transmitters were attached to 97 northern fur seal females from nine breeding areas for 119 complete foraging trips during the 1995 and 1996 breeding seasons. Females from St. Paul and St. George islands tended to travel in different directions relative to their breeding site in both years of the study. St. Paul Island females dispersed in all directions except to the southeast, where St. George Island females foraged. Habitat separation was also observed among breeding areas on northeastern and southwestern St. Paul Island and to a lesser degree on northern and southern St. George Island. Although foraging direction led to geographical separation among sites, the maximum distance traveled and the duration of foraging trips did not differ significantly among islands in either year. The results of this study document that lactating fur seals from the same site share a common foraging area and that females from different breeding sites tend to forage in separate areas and hydrographic domains.

Nuclear DNA identification of migrating bull trout captured at the Puget Sound Energy diversion dam on the White River, Washington State

Bull trout (Salvelinus confluentus) is a char listed as threatened under the United States Endangered Species Act throughout its range in the coterminous United States. Substantial morphological similarities between bull trout and Dolly Varden (S. malma) make field identification difficult. This has resulted in an incomplete understanding of their distribution and abundance in Washington State where these two species occur sympatrically. We used three diagnostic nuclear loci to determine the species of char collected at a trap on the White River in southern Puget Sound (Washington State, USA). Each of the 104 samples revealed the expected bull trout genotype at all three loci. This work presents three principle results: (i) the presence of a migratory bull trout population in southern Puget Sound; (ii) no evidence of migratory Dolly Varden over 3 years; and (iii) no evidence of hybridization was detected. These results also demonstrate how molecular markers can provide information essential to the conservation and management of these species.

Feeding of the 232Th levels from the decay of 236U

Population of the 6+ 332 keV level in 232Th from the decay of 236U was observed for the first time. The 49, 112, and 171 keV gamma-ray energies and relative intensities from the decay of 236U were measured.

Milk intake and energy expenditure of free-ranging northern fur seal, Callorhinus ursinus, pups

Milk ingested by mammalian offspring, coupled with offspring's utilization of this energetic investment, influences survival and growth. A number of studies have examined milk intake in otariids, but few have examined milk intake over the entire lactation period, and none has independently measured energy expenditure concurrent with milk intake. We concurrently examined milk intake, field metabolic rate (FMR), and body composition of 41 pups over the entire lactation interval in 1995 and 1996 on St. Paul Island, Alaska. One hundred two metabolic measurements were obtained with isotope dilution methods. Mean milk intake did not differ annually but increased with age and mass, ranging from 3,400+/-239 to 6,780+/-449 (+/-SE) mL per suckling bout. Milk energy consumption did not vary with age on a mass-specific basis. No differences were detected in milk volume consumed by male and female pups, either absolutely or on a mass-specific basis. Mass-specific FMR peaked during molting, was lowest postmolt, and did not vary by sex. Pups in 1995 had lower FMR than pups in 1996 and were also fatter. Mean milk energy utilized for maintenance metabolism decreased over time from 77% to 43% in 1995 and remained at 71% in 1996. Pup body mass was negatively correlated with the percentage of total body water and positively correlated with the percentage of total body lipid (TBL). Pups increased the percentage of TBL from 16% to 37%. Northern fur seal pups increased energy intake over lactation, while concurrent changes in body composition and pelage condition resulted in mass-specific metabolic savings after the molt.

Imaging of the internal carotid artery: the dilemma of total versus near total occlusion

PURPOSE

To evaluate ultrasonography (US) and magnetic resonance (MR) angiography in the differentiation between occlusion and near occlusion of internal carotid artery (ICA).

MATERIALS AND METHODS

Consecutive patients with occlusion or near occlusion of ICA at catheter angiography and who underwent MR angiography and US were included. MR angiography and US were compared with catheter angiography, the standard, for the ability to help distinguish occlusion from near occlusion. Noninvasive examinations were evaluated for the ability to classify near occlusions as having severe focal stenosis with distal luminal collapse versus diffuse nonfocal disease. The 95% CIs were calculated.

RESULTS

In 55 of 274 patients with 548 ICAs, catheter angiography depicted 37 total occlusions and 21 near occlusions. US depicted all total occlusions; MR angiography depicted 34 (92%) (95% CI: 0.78, 0.98). US depicted 18 (86%) of 21 (95% CI: 0.64, 0.97) near occlusions; MR angiography depicted all (100%). Of 18 vessels that were determined to be patent at US, 17 (94%) (95% CI: 0.73, 0.99) were classified as having focal stenosis or diffuse disease. Because flow gaps were identified in vessels with focal and diffuse disease, MR angiography was not effective in helping to differentiate these lesions.

CONCLUSION

Assuming US is the initial imaging examination, when occlusion is diagnosed, MR angiography can depict it. If occlusion is confirmed, no further imaging is necessary. US performed well in helping to differentiate vessels with focal severe stenosis from those with diffuse disease. MR angiography added little in this group. Catheter angiography remains beneficial for vessels with diffuse nonfocal narrowing.

Combined carotid endarterectomy and coronary bypass: a decade experience at UCLA

PURPOSE

The purpose of this review was to determine outcomes for combined carotid endarterectomy (CEA) and coronary revascularization (CABG) in patients with asymptomatic carotid stenosis.

METHODS

We reviewed the medical records of consecutive combined procedures (CEA and CABG), performed at UCLA Medical Center from October, 1989 to January, 1999.

FINDINGS

There were 43 patients, 27 men and 16 women, with a mean age of 71 yr (range 51-87). Thirty-four patients 79% (34/43) had asymptomatic carotid stenosis. Stroke occurred in three patients (3/43 = 6.9%). Stroke ipsilateral to the CEA occurred in two patients: one asymptomatic (1/34 = 2.9%) and one symptomatic (1/9 = 11.1%).

CONCLUSIONS

The majority of patients undergoing combined CEA/CABG have asymptomatic carotid stenosis identified in preparation for elective CABG. The asymptomatic carotid subset stroke rate of 2.9% resulting from a combined CEA/CABG is higher than our reported rate for CEA performed alone. In patients with asymptomatic carotid stenosis, the combined procedure should be selectively performed.

Carotid endarterectomy with normal findings from a completion study: Is there need for early duplex scan?

OBJECTIVE

The objective of this study was to determine the value of early (< 6 months) duplex scanning after carotid endarterectomy (CEA) with an intraoperative completion study with normal results. Attention was paid to restenosis rates and reoperation for recurrent stenosis within the first 6 months.

METHODS

A retrospective review was performed on 380 CEAs (338 patients) with intraoperative completion studies and duplex surveillance within the first 6 months. Results of completion studies, restenosis rates, and recurrent symptoms were evaluated for each operation. Studies were performed from 0 to 200 days postoperatively (median, 28).

RESULTS

Intraoperative completion studies included 333 angiograms, 26 duplex scans, and 21 angiograms with duplex scans. Of the 380 intraoperative completion studies, 28 (7.5%) had abnormal findings, including 14 abnormal internal carotid arteries (ICAs). Twenty-four procedures were revised, and the findings of all repeat completion studies were normal. Of the initial completion studies, in four cases, abnormalities (3 ICAs) were insignificant and did not warrant further intervention. Follow-up ICA duplex scans had normal results after 364 (95.8%) CEAs. There were 14 mild recurrent ICA stenoses and two moderate recurrent ICA stenoses; neither had abnormal findings from the completion study. There were no severe recurrent ICA stenoses. External carotid artery (ECA) recurrent stenosis included 7 mild, 15 moderate, and 9 severe restenoses.

CONCLUSIONS

Only 0.5% of CEAs developed moderate restenosis. No procedures had severe recurrent stenosis on duplex scan within the first 6 months, and none required intervention. Duplex surveillance in the first 6 months is relatively unproductive, providing that there were normal results from an intraoperative completion study for each patient. Routine surveillance can be started at 1 year.

Penetrating ulceration of the infrarenal aorta: case reports of an embolic and an asymptomatic lesion

Penetrating aortic ulceration is uncommon in the infrarenal aorta. We describe a patient with a penetrating infrarenal aortic ulcer manifesting as blue toe syndrome, and a second patient with a similar lesion identified as an incidental finding. These two patients were treated for penetrating infrarenal aortic ulceration within the past 9 months at two university-affiliated hospitals, a regional Veterans Administration Medical Center, and a County Medical Center. Both lesions demonstrated aneurysm changes with varying degrees of mural thrombus. The lesion filled with fresh thrombus proved labile, with embolization manifesting as blue toe syndrome. We support the aggressive treatment of aneurysmal penetrating aortic ulcer with aortic graft replacement to eliminate the potential for distal embolization and to obviate the risk of rupture and death.

Cardiac morbidity and mortality following carotid endarterectomy: the importance of diabetes and multiple Eagle risk factors

The objectives of this study were to (1) determine cardiac morbidity and mortality in patients undergoing carotid endarterectomy (CEA) and (2) to determine whether any Eagle risk factors and/or the indication for CEA are associated with a higher risk of an adverse cardiac event. The records of 123 male patients who underwent CEA were retrospectively reviewed. The Eagle risk factors for adverse cardiac events, indications for CEA, and adverse cardiac events were recorded and analyzed. In males undergoing CEA, the presence of diabetes or multiple Eagle risk factors significantly increases the risk of an adverse postoperative cardiac event. There is no difference in cardiac event rate between symptomatic and asymptomatic CEA. Thus, asymptomatic CEA should be approached with caution in these higher cardiac risk patients.

Dipyridamole-thallium/sestamibi before vascular surgery: a prospective blinded study in moderate-risk patients

PURPOSE

This study assessed in a prospective, blinded fashion whether a reversible defect on dipyridamole-thallium (DTHAL)/sestamibi (DMIBI) can predict adverse cardiac events after elective vascular surgery in patients with one or more clinical risk factors.

METHODS

Consecutive patients with one or more clinical risk factors underwent a preoperative blinded DTHAL/DMIBI. Patients with recent congestive heart failure (CHF) or myocardial infarction (MI) or severe or unstable angina were excluded.

RESULTS

Eighty patients (78% men; mean age, 65 years) completed the study. Diabetes mellitus was the most frequent clinical risk factor (73%), followed by age older than 70 years (41%), angina (29%), Q wave on electrocardiogram (26%), history of CHF (7%), and ventricular ectopy (3%). The results of DTHAL/DMIBI were normal in 36 patients (45%); a reversible plus or minus fixed defect was demonstrated in 28 patients (36%), and a fixed defect alone was demonstrated in 15 patients (19%). Nine adverse cardiac events (11%) occurred, including three cases of CHF, and one case each of unstable angina, Q wave MI, non-Q wave MI, and cardiac arrest (successfully resuscitated). Two cardiac deaths occurred (2% overall mortality), one after a Q wave MI and one after CHF and a non-Q wave MI. The cardiac event rate was 14% for reversible defect and 9.8% without reversible defect (P =.71). The cardiac event rate was 12.5% (one of eight cases) for two or more reversible defects, versus 11.1% (eight of 72 cases) for fewer than two reversible defects (P = 1.0). The sensitivity rate of two or more areas of redistribution was 11% (95% CI, 0.3%-48%), the specificity rate was 90%, and the positive and negative predictive values were 12.5% and 89%, respectively.

CONCLUSION

Our study demonstrated no association between reversible defects on DTHAL/DMIBI and adverse cardiac events in moderate-risk patients undergoing elective vascular surgery.

The ontogeny of metabolic rate and thermoregulatory capabilities of northern fur seal, Callorhinus ursinus, pups in air and water

Young pinnipeds, born on land, must eventually enter the water to feed independently. The aim of this study was to examine developmental factors that might influence this transition. The ontogeny of metabolic rate and thermoregulation in northern fur seal, Callorhinus ursinus, pups was investigated at two developmental stages in air and water using open-circuit respirometry. Mean in-air resting metabolic rate (RMR) increased significantly from 113+/−5 ml O(2)min(−)(1) (N=18) pre-molt to 160+/−4 ml O(2)min(−)(1) (N=16; means +/− s.e.m.) post-molt. In-water, whole-body metabolic rates did not differ pre- and post-molt and were 2.6 and 1.6 times in-air RMRs respectively. Mass-specific metabolic rates of pre-molt pups in water were 2.8 times in-air rates. Mean mass-specific metabolic rates of post-molt pups at 20 degrees C in water and air did not differ (16.1+/−1.7 ml O(2)min(−)(1)kg(−)(1); N=10). In-air mass-specific metabolic rates of post-molt pups were significantly lower than in-water rates at 5 degrees C (18.2+/−1.1 ml O(2)min(−)(1)kg(−)(1); N=10) and 10 degrees C (19.4+/−1.7 ml O(2)min(−)(1)kg(−)(1); N=10; means +/− s.e.m.). Northern fur seal pups have metabolic rates comparable with those of terrestrial mammalian young of similar body size. Thermal conductance was independent of air temperature, but increased with water temperature. In-water thermal conductance of pre-molt pups was approximately twice that of post-molt pups. In-water pre-molt pups matched the energy expenditure of larger post-molt pups while still failing to maintain body temperature. Pre-molt pups experience greater relative costs when entering the water regardless of temperature than do larger post-molt pups. This study demonstrates that the development of thermoregulatory capabilities plays a significant role in determining when northern fur seal pups enter the water.

Acquisition, extinction, and reinstatement of Pavlovian fear conditioning: the roles of the NMDA receptor and nitric oxide

The acquisition and extinction of Pavlovian conditioned fear have been shown to be mediated by the N-methyl-D-aspartate (NMDA) glutamate receptor. This study found that the NMDA antagonist (+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclo-hepten-5,10-imine maleate (MK-801) blocked the reinstatement of Pavlovian conditioned fear in rats. The role of nitric oxide (NO) in the acquisition and extinction of Pavlovian fear conditioning was also examined. L-NAME, an NO synthase inhibitor, failed to block the acquisition or extinction of Pavlovian fear conditioning. The results are discussed in the context of hierarchical associations and the array of NMDA and calcium mediated mechanisms of synaptic strengthening.

Ontogeny of swimming and diving in northern fur seal (Callorhinus ursinus) pups

Time spent in the water and diving behavior of northern fur seal (Callorhinus ursinus) pups were monitored between birth and weaning at St. Paul Island, Alaska. The median age when pups began swimming was 26 days, but prior to 40 days of age they spent virtually all their time on shore and only rarely took brief (15-20 min) swims. Pups began spending substantial time in the water at approximately 40-50 days of age, coinciding both with the early growth of insulating underfur and a seasonal peak in sea surface temperature. This suggests that pups had earlier been constrained to remain on shore by their undeveloped thermoregulatory capabilities. Time in the water increased up to approximately 100 days of age, when molted pups spent about 35% of their time in the water and swim bouts were several hours in duration. Moreover, the presence of a pup's mother on shore, photoperiod, and precipitation also influenced the amount of time pups spent in the water. Pups (mean age = 100 days) dove to very shallow depths (mean = 3 m) for short durations (mean = 11 s). Because pups did not gain mass unless suckled by their mothers, it is unlikely that they fed extensively while diving prior to migration. The pattern of development of swimming and diving in northern fur seals is intermediate between typical phocid and otariid patterns, as is the maternal strategy.

Ability to use duplex US to quantify internal carotid arterial stenoses: fact or fiction?

PURPOSE

To determine if duplex ultrasonography (US) can help predict the degree of internal carotid arterial (ICA) stenosis.

MATERIALS AND METHODS

ICA peak systolic velocity (PSV) and the ratio of the PSV in the ICA to that in the ipsilateral common carotid artery (VICA/VCCA) were compared with the degree of arteriographically measured stenosis. ICAs were arteriographically subgrouped at 10% incremental levels of stenosis and broader ranges. Mean PSV, VICA/VCCA, and SDs were calculated for each category. Histograms showing the numbers of stenotic ICAs in subgroups and for vessels with stenoses of greater than or equal to or less than 70% narrowing were constructed. The number of vessels correctly subgrouped with typical Doppler US thresholds was calculated.

RESULTS

Mean PSV and VICA/VCCA increased with stenosis level (P < .01); SDs were wide. Histograms showed Doppler US values in the central groups across all disease levels. Histograms differentiating at least or less than 70% stenosis showed minimal overlap. PSV and VICA/VCCA helped classify, respectively, 185 and 181 of 204 vessels with stenoses of less than 50%, 15 and 21 of 46 vessels with stenoses of 50%-69%, and 73 and 67 of 84 vessels with stenoses of 70% or greater. When classifying stenoses as 69% or less or 70% or more, PSV and VICA/VCCA were correct in 90.6% and 90.3% of vessels.

CONCLUSION

Doppler US is excellent for classifying stenoses as above or below a single degree of severity but does not function well in stenosis subclassification.

The hormonal coordination of behavior and physiology at adult ecdysis in Drosophila melanogaster

In insects, ecdysis is thought to be controlled by the interaction between peptide hormones; in particular between ecdysis-triggering hormone (ETH) from the periphery and eclosion hormone (EH) and crustacean cardioactive peptide (CCAP) from the central nervous system. We examined the behavioral and physiological functions of the first two of these peptides in Drosophila melanogaster using wild-type flies and knockout flies that lacked EH neurons. We used ETH from Manduca sexta (MasETH) to induce premature ecdysis and compared the responses of the two types of flies. The final release of EH normally occurs approximately 40 min before ecdysis. It is correlated with cyclic guanosine monophosphate (cGMP) production in selected neurons and tracheae, by an elevation in the heart rate and by the filling of the new tracheae with air. Injection of developing flies with MasETH causes all these events to occur prematurely. In EH cell knockouts, none of these changes occurs in response to MasETH, and these flies show a permanent failure in tracheal filling. This failure can be overcome in the knockouts by injecting them with membrane-permeant analogs of cGMP, the second messenger for EH. The basis for the 40 min delay between EH release and the onset of ecdysis was examined by decapitating flies at various times relative to EH release. In flies that had already released EH, decapitation was always followed within 1 min by the start of ecdysis. Immediate ecdysis was never observed when the EH cell knockout flies were decapitated. We propose that EH activates both ventral central nervous system elements necessary for ecdysis (possibly the CCAP cells) and descending inhibitory neurons from the head. This descending inhibition establishes a delay in the onset of ecdysis that allows the completion of EH-activated physiological processes such as tracheal filling. A waning in the inhibition eventually allows ecdysis to begin 30–40 min later.

Challenge differentially affects cytokine production and metabolic status of growing and finishing swine

Growing (35 kg body weight) and finishing (85 kg body weight) swine challenged with endotoxin (Escherichia coli O55:B5) at a dose of either 2 or 20 microg/kg produced tumor necrosis factor (TNF)alpha in a dose-response relationship as measured by bioassay. Peak TNFalpha plasma levels were observed 1-2 hr post-challenge, returning to basal values 4 hr post-challenge. However, both an enzyme-linked immunosorbent assay specific for swine TNFalpha and total human TNFalpha demonstrated no dose-response relationship; peak plasma levels of immunoreactive TNFalpha were also observed 1-2 hr post-challenge. Maximal plasma interleukin-6 levels occurred 1-2 hr post-challenge and remained elevated through 8 hr post-challenge; there was no effect of lipopolysaccharide dose or metabolic status. Although the metabolic status of the animals also affected glucose levels, with growing animals exhibiting greater sensitivity compared with finishing animals, endotoxin-induced decreases in blood glucose levels were primarily dose-dependent. In contrast, changes in plasma urea nitrogen and free fatty acid (FFA) levels were strictly related to the metabolic status. Urea nitrogen levels were unchanged in growing swine, whereas they were increased in finishing swine and remained elevated 24 hr post-challenge. FFA levels in growing and finishing swine increased 3-6 hr post-challenge. FFA levels returned to basal values for finishing swine 24 hr post challenge, but in growing swine remained elevated 24 hr post-challenge. Plasma aspartate transaminase levels were increased through 24 hr post-challenge; animals given a dose of 20 microg/kg exhibited the greatest increase. Similarly, swine challenged with a dose of 20 microg/kg also exhibited the greatest increase in levels of conjugated bilirubin; there was no effect on unconjugated (free) bilirubin. These results demonstrate that endotoxin challenge of swine result in a pattern of changes that are dependent on both the dose of endotoxin used and the metabolic status of the animal examined.

Can prism adaptation for acquired esotropia be accomplished in a shorter time frame?

PURPOSE

Results of the Prism Adaptation Study (PAS) indicated that surgical success rates were highest when augmented surgery was performed for the increased angle of deviation in the prism adaptation responders who underwent surgery for the prism-determined angle of esotropia. The purpose of this study was to see if the prism adaptation response process could be performed in a shorter time span than dictated in the PAS protocol (minimum, 4-7 days).

METHODS

After the prescription of appropriate spectacles, patients with acquired stable esotropia were prism adapted and then reexamined and readapted if necessary at 24 hours and 4 to 7 days. The 4- to 7-day visit was the determining visit in the PAS. The question in this study was whether the 24-hour visit would provide the same end point and allow adaptation in a shorter period of time. In addition, a motor end point was used in this study, whereas in the PAS, the end point was both motor and sensory.

RESULTS

Thirty-two patients met the entry criteria. Nineteen of the 32 patients built up their entry angle during the prism adaptation process. Thirty of the 32 patients who left the office stable at the 24-hour visit remained stable at the 4- to 7-day visit.

CONCLUSION

If the 4- to 7-day visit is used as the "gold" standard, 94% of the patients in this study would not have benefited from a longer (beyond 24 hours) wear time of prisms. With the use of motor stability, prism adaptation can be carried out in a reproducible and timely fashion.

Doppler sonographic parameters for detection of carotid stenosis: is there an optimum method for their selection?

OBJECTIVE

A wide range of Doppler threshold values for carotid stenosis is found in the literature. We undertook this study to compare methods of derivation and to determine if an optimum strategy of threshold selection exists for a high-risk population.

MATERIALS AND METHODS

From the sonograms of all patent internal carotid arteries, peak systolic velocity in the internal carotid artery (ICA(PSV)) and the ratio of peak systolic velocity in the internal carotid artery to that of the common carotid artery (ICA(PSV)/ CCA(PSV)) were compared with the percentage of angiographically determined stenosis. Receiver operating characteristic curves were generated for levels of stenosis > or =60% and > or =70%. Doppler thresholds were chosen on the basis of maximum accuracy and on the basis of > or =90% sensitivity and specificity. Patients were then segregated into symptomatic and asymptomatic cohorts, and the above process was repeated. An effectiveness analysis was also conducted using various Doppler thresholds. Thresholds derived using these three methods were compared and optimal values chosen. RESULTS. Of 333 carotid arteries that fit inclusion criteria, 132 were found in asymptomatic patients and 201 in symptomatic patients. Maximum accuracy, > or =90% sensitivity and specificity, and effectiveness analysis each produced different ranges of thresholds. We chose final thresholds that maintained patient outcome profiles. For asymptomatic patients at the > or =60% stenosis level, thresholds were ICA(PSV) = 200 cm/sec and ICA(PSV)/CCA(PSV) = 3.0. For symptomatic patients with stenosis > or =70%, thresholds were ICA(PSV) = 175 cm/sec and ICA(PSV)/CCA(PSV) = 2.5.

CONCLUSION

Considerable latitude exists in the choice of carotid Doppler thresholds. We propose a rational strategy for threshold selection based on a combination of three commonly used methods. Our observations indicate that it appears advisable to consider symptomatic and asymptomatic patients separately and to apply appropriately derived thresholds.

Cardiac morbidity and operative mortality following lower-extremity amputation: the significance of multiple Eagle criteria

The ability of the Eagle criteria (age >70 years, angina, diabetes, Q wave on EKG, history of congestive heart failure) to predict adverse cardiac events following major vascular surgery has previously been demonstrated. However, the utility of these criteria for lower-extremity amputation is not well established. To determine the value of the Eagle criteria for predicting cardiac morbidity and operative mortality following major lower-extremity amputation, we reviewed 214 consecutive procedures performed at two institutions over a 3-year period. Mean age was 62.7 years and 85% of the patients were male. Diabetes was the most frequent Eagle criterion (74%). The mean number of Eagle criteria was 1.6. Fifty-six percent of the amputations were below the knee, 24% were above the knee, and 20% were guillotine. On multivariate regression analysis, the presence of two or more Eagle criteria (16% vs. 4%, p = 0.04) and decompensated heart failure (39% vs. 7%, p = 0.003) were predictive of adverse cardiac events. The only predictor of postoperative mortality was the presence of two or more Eagle criteria (15% vs. 4%, p = 0.004). Our evaluation of the results of this study led us to conclude that patients requiring major lower-extremity amputation for major vascular disease who have multiple Eagle criteria or decompensated congestive heart failure are at high risk for adverse cardiac events and postoperative death. These findings should be used to guide perioperative cardiac evaluation and therapy.

Agreement between grating acuity at age 1 year and Snellen acuity at age 5.5 years in the preterm child. Cryotherapy for Retinopathy of Prematurity Cooperative Group

PURPOSE

To examine the relation between grating acuity at age 1 year and Snellen acuity and grating acuity at 5.5 years, in preterm children with birth weights less than 1251 g.

METHODS

Subjects were participants in the multicenter study of Cryotherapy for Retinopathy of Prematurity. The Teller acuity card (TAC; Vistech Consultants, Dayton, OH) procedure was used to measure monocular grating acuity in children at ages 1 and 5.5 years. Early-treatment diabetic retinopathy study (ETDRS) charts were used to measure the childrens' monocular recognition (Snellen) acuity at age 5.5 years. Data are presented for 575 eyes with measurable TAC grating acuity at 1 year and 111 eyes that had no measurable acuity at 1 year.

RESULTS

Among eyes with normal acuity at 1 year, 86.8% showed normal Snellen acuity, and 94.3% showed normal grating acuity at 5.5 years. Among eyes that were blind (i.e., had no measurable TAC grating acuity) at 1 year, 96.8% showed no quantifiable Snellen acuity, and 89.2% showed no quantifiable grating acuity at 5.5 years. Only 2.4% of eyes had acuity in the range between normal and blind at 1 year (i.e., measurable grating acuity <1.6 cyc/deg); thus, the predictive value of acuity scores in this range could not be determined. Correlation analysis indicated that the relative position within the normal range of an eye's grating acuity score at 1 year was not predictive of the relative position within the normal range of that eye's acuity score at 5.5 years.

CONCLUSIONS

Among a large population of low-birth-weight infants, eyes with normal grating acuity at age 1 year generally showed normal Snellen and grating acuity at age 5.5 years, and eyes that had no quantifiable acuity at 1 year remained blind at 5.5 years. Relative position of an eye's acuity score within the normal range was not predictive of the relative position of that eye's later acuity score.

Pharyngeal flap necrosis as a cause of airway obstruction during induction of anesthesia

Anesthesiologists should approach the airway carefully in the patient with a diagnosis of head and neck carcinoma, particularly if the patient has had previous surgery and reconstruction. Patients with head and neck carcinoma may be difficult intubations due to altered anatomy from the tumor or fibrotic changes because of radiation therapy. Our patient had had pharyngectomy and reconstruction with a pectoralis major skin flap. The patient returned to the operating suite for wide-excision pharyngectomy and had acute airway obstruction after induction of general anesthesia. The pectoralis flap had necrosed, pulling away from the pharyngeal wall and obstructing the patient's glottic opening.

Strabismus in premature infants in the first year of life. Cryotherapy for Retinopathy of Prematurity Cooperative Group

OBJECTIVES

To present the 3- and 12-month strabismus data from 3030 premature infants with birth weights less than 1251 g enrolled in the Multicenter Trial of Cryotherapy for Retinopathy of Prematurity.

DESIGN

Data from the 3- and 12-month examinations conducted at 23 regional study centers were tabulated for all infants. The main outcome measure, ocular motility, was compared with baseline demographic variables and retinopathy of prematurity severity for the worse eye. Findings at 3 months were compared with the incidence of strabismus at 12 months.

RESULTS

At 3 months, 200 (6.6%) of the 3030 infants were strabismic. In the 2449 infants examined at both time points, 289 (11.8%) were found to have strabismus at 12 months. Retinopathy of prematurity was significant for strabismus at both 3 and 12 months (P<.001). The presence of strabismus at 3 months was found to be a highly significant predictor of strabismus at 12 months. Anisometropia, abnormal fixation, and unfavorable retinal structure also were significant predictors of strabismus at 1 year. The total prevalence of strabismus in the first year of life was 14.7%.

CONCLUSION

The presence of acute-phase retinopathy of prematurity places the premature infant at increased risk for strabismus.

Disruption of a behavioral sequence by targeted death of peptidergic neurons in Drosophila

The neuropeptide eclosion hormone (EH) is a key regulator of insect ecdysis. We tested the role of the two EH-producing neurons in Drosophila by using an EH cell-specific enhancer to activate cell death genes reaper and head involution defective to ablate the EH cells. In the EH cell knockout flies, larval and adult ecdyses were disrupted, yet a third of the knockouts emerged as adults, demonstrating that EH has a significant but nonessential role in ecdysis. The EH cell knockouts had discrete behavioral deficits, including slow, uncoordinated eclosion and an insensitivity to ecdysis-triggering hormone. The knockouts lacked the lights-on eclosion response despite having a normal circadian eclosion rhythm. This study represents a novel approach to the dissection of neuropeptide regulation of a complex behavioral program.

Recommended standards for reports dealing with lower extremity ischemia: revised version

Recommended standards for analyzing and reporting on lower extremity ischemia were first published by the Journal of Vascular Surgery in 1986 after approval by the Joint Council of The Society for Vascular Surgery and the North American Chapter of the International Society for Cardiovascular Surgery. Many of these standards have been accepted and are used in the current literature on peripheral arterial occlusive disease. With the passage of time, some oversights, aspects that require clarification, and better modifications have been recognized. This report attempts to correct these shortcomings while reinforcing those recommendations that have proven satisfactory. Explanatory comments are added to facilitate understanding and application. This version is intended to replace the original version.

Asymptomatic carotid artery stenosis screening in patients with lower extremity atherosclerosis: a prospective study

Eighty-nine male veterans presenting to a vascular surgery clinic with symptomatic lower extremity atherosclerosis were prospectively screened by duplex scan for asymptomatic carotid artery stenosis (CAS). Their chief complaint was: claudication (90%), rest pain (6%), and ischemic ulcer or gangrene (4%). The mean ankle-brachial index (ABI) was 0.77. Twenty-five CAS > 50% were detected in 18 (20%) patients. Twelve CAS > 75% were detected in 11 (12%) patients. There was no difference between patients with and without CAS > 50% with regards to mean ABI, history of angina, diabetes, hypertension, prior coronary artery bypass, or history of smoking. Carotid bruit was associated with ipsilateral CAS > 50% [p < 0.0001, sensitivity (52%), specificity (88%), positive predictive value (41%), negative predictive value (92%)]. As a result of the screening, eight elective carotid endarterectomies have been performed to date in six (7%) patients with one transient twelfth cranial nerve paresis as the only postoperative complication. We conclude that: (1) male patients presenting with symptomatic lower extremity atherosclerosis have a 20% prevalence of asymptomatic CAS > 50%, (2) there is no correlation between the degree of lower extremity ischemia and CAS > 50%, (3) carotid bruit is significantly associated with CAS > 50%, but has a low sensitivity, and (4) routine CAS screening should be considered for all male patients with symptomatic lower extremity atherosclerosis regardless of whether a bruit is present.

Retinal examinations in infants after extracorporeal membrane oxygenation

BACKGROUND

Ophthalmic examinations performed in infants undergoing extracorporeal membrane oxygenation (ECMO) are recommended because ocular abnormalities have been known to occur after this procedure.

METHODS

We reviewed medical records of infants treated with ECMO was subsequently underwent routine ophthalmic examination prior to or immediately after hospital discharge. Examinations were performed in a fashion similar to that for retinopathy of prematurity screening.

RESULTS

Eye examinations were recorded for 171 patients (342 eyes). Fundus examination was normal in 302 eyes (88%). Abnormal retinovascular findings such as venous dilation or intraretinal hemorrhages, when present, were not considered vision threatening and required no treatment.

CONCLUSION

Clinically important retinal findings were not identified in our patients undergoing postECMO screening. Routine dilated fundus examination is probably not cost effective and places additional and potentially unnecessary stress on these infants.

Phenomenography: an alternative approach to researching the clinical decision-making of nurses

In this paper, the limitations associated with current research approaches to the study of clinical decision-making are discussed. Research examining the clinical decision-making of nurses and doctors, and associated work in information procession, is reviewed. It is concluded that although the research is valuable in furthering the understanding of clinical decision-making, there are limitations associated with the current research approaches. The limitations are primarily related to the research approaches employed and the concentration on experienced nurses. The research fails to examine the development of clinical decision-making ability and the learning that occurs in practice. Phenomenography is proposed as an alternative approach. The aim of phenomenography is to describe an individual's perception of a phenomenon. Phenomenography is relevant to the study of clinical decision-making as it is concerned with variation in experience. When applied to the study of new graduate nurses, phenomenography can provide valuable information in relation to individual differences in learning that arise from experience, what factors influence learning and how they affect clinical decision-making ability.

Strategies for teaching clinical decision-making

Nursing today requires clinicians who are autonomous decision-makers. It is therefore essential that nurses develop effective problem-solving and decision-making skills. The authors have found, both in practice and in searches of the literature, that registered nurses (RNs) appear to lack the skills necessary to make effective decisions. RNs demonstrate a propensity to stereotype, to be influenced by cultural bias and a desire to make rapid decisions. The literature abounds with research into and discussion on clinical decision-making. It fails however, to specify the skills required and to delineate the educational strategies that may be employed to improve the process of making decisions. An educational program developed by the authors indicates that it is possible to facilitate the development of cognitive skills in clinical decision-making. This paper explores views expressed in the literature, as well as examining the skills developed within the program that have been found to enhance decision-making. Finally, educational strategies designed to improve these skills are discussed.