Socially vulnerable patients are more likely to fail outpatient management of symptomatic cholelithiasis

BACKGROUND

Symptomatic cholelithiasis is a common surgical problem, with many patients requiring multiple gallstone-related emergency department (ED) visits before cholecystectomy. The Social Vulnerability Index (SVI) identifies vulnerable patient populations. This study aimed to assess the association between social vulnerability and outpatient management of symptomatic cholelithiasis.

METHODS

Patients with symptomatic cholelithiasis-related ED visits were identified within our health system from 2016 to 2022. Clinical outcomes data were merged with SVI census track data, which consist of 4 SVI subthemes (socioeconomic status, household characteristics, racial and ethnic minority status, and housing type and transportation). Multivariate analysis was used for statistical analysis.

RESULTS

A total of 47,292 patients presented to the ED with symptomatic cholelithiasis, of which 6103 patients (13.3 %) resided in vulnerable census tract regions. Of these patients, 13,795 (29.2 %) underwent immediate cholecystectomy with a mean time to surgery of 35.1 h, 8250 (17.4 %) underwent elective cholecystectomy at a mean of 40.6 days from the initial ED visit, and 2924 (6.2 %) failed outpatient management and returned 1.26 times (range, 1-11) to the ED with recurrent biliary-related pain. Multivariate analysis found social vulnerability subthemes of socioeconomic status (odds ratio [OR], 1.29; 95 % CI, 1.09-1.52) and racial and ethnic minority status (OR, 2.41; 95 % CI, 2.05-2.83) to be associated with failure of outpatient management of symptomatic cholelithiasis.

CONCLUSION

Socially vulnerable patients are more likely to return to the ED with symptomatic cholelithiasis. Policies to support this vulnerable population in the outpatient setting with timely follow-up and elective cholecystectomy can help reduce delays in care and overutilization of ED resources.

Virtually delivered Mindfulness-Oriented Recovery Enhancement (MORE) reduces daily pain intensity in patients with lumbosacral radiculopathy: a randomized controlled trial

Introduction

Lumbosacral radiculopathy (LR), also known as sciatica, is a common type of radiating neurologic pain involving burning, tingling, and numbness in the lower extremities. It has an estimated lifetime prevalence as high as 43%.

Objectives

The objective of this randomized controlled trial was to evaluate the impact of virtually delivered Mindfulness-Oriented Recovery Enhancement (MORE) on patients with LR during the COVID-19 pandemic.

Methods

Potentially eligible patients were identified using electronic health record queries and phone screenings. Participants were then randomized to MORE or treatment-as-usual (TAU) for 8 weeks, with pain intensity assessed daily. At baseline and follow-up visits, participants completed questionnaires assessing the primary outcome, disability, as well as quality of life, depression, mindful reinterpretation of pain, and trait mindfulness.

Results

In our study, patients undergoing virtual delivery of MORE had greater improvements in daily pain intensity (P = 0.002) but not in disability (P = 0.09), depression (P = 0.26), or quality of life (P = 0.99 and P = 0.89, SF-12 physical and mental component scores, respectively), relative to TAU patients. In addition, patients in MORE experienced significantly greater increases in mindful reinterpretation of pain (P = 0.029) and trait mindfulness (P = 0.035).

Conclusion

Among patients with lumbar radiculopathy, MORE significantly reduced daily pain intensity but did not decrease disability or depression symptoms. Given the long duration of symptoms in our sample, we hypothesize the discrepancy between changes in daily pain intensity and disability is due to fear avoidance behaviors common in patients with chronic pain. As the first trial of a mindfulness intervention in patients with LR, these findings should inform future integrative approaches to LR treatment, particularly when considering the increasing use of virtual interventions throughout the COVID-19 pandemic.

Integrative medicine for hypermobility spectrum disorders (HSD) and Ehlers-Danlos syndromes (EDS): a feasibility study

PURPOSE

Hypermobility spectrum disorders (HSD) and Ehlers-Danlos syndromes (EDS) are multisystem conditions marked by dysfunctional connective tissue. This feasibility study evaluated a 9-week integrative medicine program in this population.

METHODS

Using a single-arm study design, adults with HSD or EDS were given recommendations for an anti-inflammatory Mediterranean diet and self-management with additional behavioral and psychosocial support. Preliminary data on feasibility based on recruitment and retention, adherence to the diet, mobile app tracking, changes to perceived well-being via health outcomes, and satisfaction with care were obtained.

RESULTS

Thirteen participants were enrolled within a 4-month timeframe. Eight participants completed the study. Three participants met dietary tracking requirement in at least 4 of 8 intervention weeks and met the macronutrient requirements in at least half of the weeks tracked. No decreases in VAS pain scores after 5 and 9 weeks were noted; however, 62.5% (n = 5) of participants had decreased pain at 9 weeks, compared to baseline. There were significant improvements (p<.05) in six of twelve measurements of satisfaction with care at the end of the intervention.

CONCLUSION

This study provides a foundation for future research on patient experience and introduces a novel treatment paradigm focused on nutrition and self-management.

Trial Registration: National Institutes of Health clinicaltrials.gov; identifier: NCT04734041.

IMPLICATIONS FOR REHABILITATION

Lifestyle and dietary interventions are relatively safe and well tolerated in the hypermobility spectrum disorder (HSD) and Ehlers-Danlos disorder (EDS) population.Participants in our 9-week integrative medicine program actively engaged in self-management of their condition and showed promising adherence to dietary and tracking requirements.Effective treatment of the intricacies and dynamics of these highly variable and clinically heterogeneous disorders may require a network of healthcare providers, integrative healthcare, as well as behavioral and psychosocial support.Dietary tracking through mobile apps might help promote self-efficacy and adherence to dietary changes.Symptom tracking might be an effective way for patients to track changes to their health and could provide valuable information for health professionals engaged in managing the disorders.

Long Term Outcomes of Radiation (RT)-Monotherapy vs. Combined RT + Endocrine Therapy (RT+ET) in Low-Risk Early-Stage Breast Cancer Patients 70 Years or Older after Breast-Conserving Surgery (BCS)

PURPOSE/OBJECTIVE(S)

Combined Radiation and Endocrine Therapy (RT+ET) and ET Monotherapy are acceptable adjuvant strategies based on randomized trial data. Less is known about RT Monotherapy as a form of treatment de-escalation. Radiation delivery has become safer and more convenient. This study compares long-term outcomes in patients who opted for RT-Monotherapy versus combined RT+ET.

MATERIALS/METHODS

This retrospective study included female patients from Swedish Cancer Institute breast cancer registry (Seattle, WA), aged ≥70 years with estrogen receptor-positive (ER+)/human epidermal growth factor receptor 2-negative (HER2-) T1N0 breast cancer treated with BCS between 1995 and 2015. Patients with positive surgical margins, multifocality, histologic grade 3 and LVI were excluded. Patients were classified into 4 groups: (1) RT+ET (reference); (2) RT Monotherapy; (3) ET Monotherapy; and (4) neither RT nor ET (NT). Choice of therapy was determined by the treating physician and the patient. The primary endpoints were local recurrence (LR), distant metastasis (DM), disease specific survival (DSS), overall survival (OS), and second breast cancer events (SBCEs). Competing risk models were used to estimate cumulative incidence at varying lengths of follow-up and sub distribution hazard ratios (HR) between treatment groups. Significance was set at P ≤ .05.

RESULTS

We analyzed 496 patients with a median age of 76 years and median follow-up of 9.6 years. 62% (N = 307) of patients received combined RT+ET, 30% (N = 148) RT Monotherapy, 4% (N = 20) ET alone and 4% (N = 21) no therapy, NT group. Only the RT monotherapy and combined RT+ET groups were large enough for a meaningful statistical analysis. RT monotherapy conferred non-inferior disease control compared to combined RT+ET. Recurrence events were extremely low. Incidence of SBCEs was not significantly different between treatments.

CONCLUSION

For this favorable patient population, RT monotherapy was associated with equivalent long-term outcomes compared to combined RT+ET therapy. Recurrence rates stayed extremely low with long-term FU. RT monotherapy may be a reasonable de-escalation option for this older low risk patient population. Further prospective trials are needed to help refine treatment strategies that allow for more choices in treatment de-escalation.

Patient experience of chronic illness care and complementary integrative health use: a cross-sectional study of patients with hypermobility spectrum disorders (HSD) and Ehlers-Danlos syndromes (EDS)

PURPOSE

Hypermobility spectrum disorders (HSD) and Ehlers-Danlos syndromes (EDS) are frequently underdiagnosed, contributing to patient dissatisfaction in the healthcare system. This study evaluated the health service utilization, care, and subjective experiences of living with chronic illness among adults with HSD and EDS in the United States and Canada.

METHODS

This was an anonymous, web-based, cross-sectional healthcare survey. The survey obtained basic demographic information, the Patient Assessment of Chronic Illness Care (PACIC+), as well as responses to questions on the use of healthcare and integrative medicine.

RESULTS

A total of 353 surveys were received. The most common complementary therapies used were physical therapy (82%), massage (68%), yoga (58%), chiropractic (48%), and meditation (43%). Mean (SD) summary PACIC and PACIC 5 As scores were 2.16 (0.77) and 2.25 (0.83), respectively. Across all PACIC domains, mean scores of individuals whose typical doctor visit was 30 min or at least an hour were significantly higher than those of individuals who indicated typical visits of 15 min (all p < 0.0001 by one-way ANOVA). There was widespread agreement on the importance of patient-provider relationship and trust, physicians' understanding of the individual's complete medical history, and prioritization of physical and emotional safety (>95% agree or strongly agree to each).

CONCLUSION

Individuals with HSD or EDS report low satisfaction with chronic illness care and commonly seek out complementary and self-administered therapies, likely in an attempt to manage symptoms. Respondents reported a desire for greater time and attention from physicians. Results from this study could educate the healthcare community to improve support mechanisms for HSD and EDS populations.IMPLICATIONS FOR REHABILITATIONPatients with hypermobility spectrum disorders (HSD) or Ehlers-Danlos syndromes (EDS) express a desire for patient-centered care and peer support from other individuals with HSD or EDS.Individuals with HSD or EDS have typically seen multiple doctors for their condition and their satisfaction with chronic care, as measured by the Patient Assessment of Chronic Illness Care (PACIC+), is low.The use of various complementary and integrative health treatments, as well as specialized diets, is common in this population, and might be beneficial for symptom management.Healthcare delivery for HSD and EDS may require a multidisciplinary healthcare team, as complementary and self-care modalities are typically used in addition to physical therapy, pain medication, and other conventional care.

Characterization of Lymph Node Tumor Burden in Node-Positive Prostate Cancer Patients after Robotic-Assisted Radical Prostatectomy with Extended Pelvic Lymph Node Dissection

BACKGROUND

Prostate cancer (PCa) nodal staging does not account for lymph node (LN) tumor burden. The LN anatomical compartment involved with the tumor or the quantified extent of extranodal extension (ENE) have not yet been studied in relation to biochemical recurrence-free survival (BRFS).

METHODS

Histopathological slides of 66 pN1 PCa patients who underwent extended pelvic lymph node dissection were reviewed. We recorded metrics to quantify LN tumor burden. We also characterized the LN anatomical compartments involved and quantified the extent of ENE.

RESULTS

The median follow-up time was 38 months. The median number of total LNs obtained per patient was 30 (IQR 23-37). In the risk-adjusted cox regression model, the following variables were associated with BRFS: mean size of the largest LN deposit per patient (log2: adjusted hazard ratio (aHR) = 1.91, p < 0.001), the mean total span of all LN deposits per patient (2.07, p < 0.001), and the mean percent surface area of the LN involved with the tumor (1.58, p < 0.001). There was no significant BRFS association for the LN anatomical compartment or the quantified extent of ENE.

CONCLUSION

LN tumor burden is associated with BRFS. The LN anatomical compartments and the quantified extent of ENE did not show significant association with BRFS.

Protocol for mindfulness-oriented recovery enhancement (MORE) in the management of lumbosacral radiculopathy/radiculitis symptoms: A randomized controlled trial

Introduction

Lumbosacral radiculopathy/radiculitis (LR) or "sciatica" is a commonly intractable sequelae of chronic low back pain (LBP), and challenges in the treatment of LR indicate that persistent pain may have both mechanical and neuropathic origins. Mindfulness-based interventions have been demonstrated to be effective tools in mitigating self-reported pain in LBP patients. This paper describes the protocol for a randomized controlled trial (RCT) evaluating the effects of the specific mindfulness-based intervention Mindfulness-Oriented Recovery Enhancement (MORE) on LR symptoms and sequelae, including mental health and physical function.

Methods

Participants recruited from the Portland, OR area are screened before completing a baseline visit that includes a series of self-report questionnaires and surface electromyography (sEMG) of the lower extremity. Upon enrollment, participants are randomly assigned to the MORE (experimental) group or treatment as usual (control) group for 8 weeks. Self-reported assessments and sEMG studies are repeated after the intervention is complete for pre/post-intervention comparisons. The outcome measures evaluate self-reported pain, physical function, quality of life, depression symptoms, trait mindfulness, and reinterpretation of pain, with surface electromyography (sEMG) findings evaluating objective physical function in patients with LR. To our knowledge, this is the first trial to date using an objective measure, sEMG, to evaluate the effects of a mindfulness-based intervention on LR symptoms.

Hypotheses

We hypothesize that MORE will be effective in improving self-reported pain, physical function, quality of life, depression symptoms, mindfulness, and reinterpretation of pain scores after 8 weeks of mindfulness training as compared to treatment as usual. Additionally, we hypothesize that individuals in the MORE group with abnormal sEMG findings at baseline will have improved sEMG findings at their 8-week follow-up visit.

Inflammatory Bowel Disease and Neutrophil-Lymphocyte Ratio: A Systematic Scoping Review

Neutrophil–lymphocyte ratio (NLR) is a biomarker of the systemic inflammatory response. The objective of this systematic scoping review was to examine the literature on NLR and inflammatory bowel disease (IBD). PubMed, Embase, Cochrane CENTRAL, CINAHL, ClinicalTrials.gov, Cochrane Specialized Register, DOAJ, PDQT, Biosis Citation Index, Scopus, and Web of Science were systematically searched. A total of 2621 citations yielding 62 primary studies were synthesized under four categories: distinguishing patients with IBD from controls, disease activity differentiation, clinical outcome prediction, and association of NLR with other IBD biomarkers. Thirty-eight studies employed receiver operating characteristic (ROC) curve analysis to generate optimal NLR cutpoints for applications including disease activity differentiation and prediction of response to treatment. Among the most promising findings, NLR may have utility for clinical and endoscopic disease activity differentiation and prediction of loss of response to infliximab (IFX). Overall findings suggest NLR may be a promising IBD biomarker. Assessment of NLR is non-invasive, low cost, and widely accessible given NLR is easily calculated from blood count data routinely and serially monitored in patients with IBD. Further research is justified to elucidate how evaluation of NLR in research and clinical practice would directly impact the quality and cost of care for patients living with IBD.

Xanthohumol microbiome and signature in healthy adults (the XMaS trial): a phase I triple-masked, placebo-controlled clinical trial

BACKGROUND

Natural products may provide a source for the discovery and development of adjunctive pharmacological interventions to modulate the inflammatory pathways contributing to chronic disease. Xanthohumol, a flavonoid from the hops plant (Humulus lupulus), has antioxidant and anti-inflammatory properties and may act as a prebiotic to the intestinal microbiota. Xanthohumol is not currently approved as a drug by the US Food and Drug Administration (FDA), but is available as a dietary supplement and ingredient in medical foods. To formally test the safety of xanthohumol, a phase I clinical trial ("XMaS") was designed and approved under an Investigational New Drug application to the US FDA. The main objective is to examine the clinical safety and subjective tolerability of xanthohumol in healthy adults compared to placebo. Additional aims are to monitor biomarkers related to inflammation, gut permeability, bile acid metabolism, routes, and in vivo products of xanthohumol metabolism, and to evaluate xanthohumol's impact on gut microbial composition.

METHODS

The safety and tolerability of xanthohumol in healthy adults will be evaluated in a triple-masked, randomized, placebo-controlled trial. Participants will be randomized to either 24 mg/day of xanthohumol or placebo for 8 weeks. Blood cell counts, hepatic and renal function tests, electrolytes, and self-reported health-related quality of life measures will be collected every 2 weeks. Participants will be queried for adverse events throughout the trial. Xanthohumol metabolites in blood, urine, and stool will be measured. Biomarkers to be evaluated include plasma tumor necrosis factor-alpha, various interleukins, soluble CD14, lipopolysaccharide-binding protein, fecal calprotectin, and bile acids to assess impact on inflammatory and gut permeability-related mechanisms in vivo. Stool samples will be analyzed to determine effects on the gut microbiome.

DISCUSSION

This phase I clinical trial of xanthohumol will assess safety and tolerability in healthy adults, collect extensive biomarker data for assessment of potential mechanism(s), and provide comparison data necessary for future phase II trials in chronic disease(s). The design and robustness of the planned safety and mechanistic evaluations planned provide a model for drug discovery pursuits from natural products.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03735420 . Registered on November 8, 2018.

Effect of a Nutrition Support Formula in Adults With Inflammatory Bowel Disease: A Pilot Study

Background

Due to the high prevalence of nutrient deficiencies in patients with inflammatory bowel disease (IBD), routine monitoring of nutrient status and supplementation are recommended.

Objective

This preliminary study was implemented to prospectively identify potential effects of a nutrition support formula on blood nutrient parameters in adults with IBD.

Methods

Ten adults with Crohn’s disease or ulcerative colitis were recruited from the Portland, Oregon, metropolitan area into a single-arm, open-label pilot study. Participants consumed a nutrition support beverage twice daily for 12 weeks. The formula contained a mixture of micronutrients (including methylated forms of folate and vitamin B12), macronutrients, and phytonutrients (including curcumin, xanthohumol, ginger compounds, and quercetin). Primary measures were the following parameters: folate, vitamin B12, red blood cell (RBC) count, hemoglobin, hematocrit, electrolytes, and albumin. Exploratory measures included a food frequency questionnaire, circulating blood cell counts, and inflammatory markers.

Results

Nine participants completed the study and one withdrew. Adherence was 98%. Serum folate increased 48.7% (P = .029), serum vitamin B12 increased 17.4% but did not reach statistical significance (P = .053), and red cell distribution width (RDW) decreased 9.2% (P = .012) over the 12-week study period. There were minimal shifts in total white blood cell (WBC) counts (−1.0%, P = .845), but percent neutrophils decreased 10.4% (P = .042) and absolute lymphocyte count increased 18.6% (P = .048). RBC count, hemoglobin, hematocrit, electrolytes, albumin, and inflammatory markers did not change significantly. Post hoc analysis demonstrated that neutrophil–lymphocyte ratio (NLR) decreased 18.4% (not significant, P = .061).

Conclusion

Serum folate and RDW improved in adults with IBD after 12 weeks. Modulation of leukocyte subtypes was also observed, including a decrease in neutrophils and an increase in lymphocytes, with no change in total WBC count. A randomized, controlled study to further examine effects of the nutrition support formula will be initiated to follow up on this promising, but preliminary investigation.

Impact of a Short-Term Naturopathic Whole-Foods-Based Nutrition Education Intervention on Dietary Behavior and Diabetes Risk Markers: A Pilot Study

OBJECTIVE

To assess the feasibility of measuring the health impacts of a 12-week naturopathic whole foods nutrition education course among adults with or at risk for prediabetes.

DESIGN

A pilot nonrandomized pre-post intervention design investigated physiological changes associated with participation in a 12-week structured naturopathic nutrition education course. Follow-up measures were assessed at 6 and 12 months from baseline.

SETTINGS/LOCATION

Three community-based kitchens in Oregon.

SUBJECTS

Forty-five adults with or at risk for prediabetes.

INTERVENTION

Twelve weekly 90-min workshops emphasizing the health benefits of a naturopathic whole foods diet and including collective meal preparation and communal dining.

OUTCOME MEASURES

Changes in biomarkers of diabetes and cardiovascular disease risk, including high-sensitivity C-reactive protein (hs-CRP), hemoglobin A1c, insulin, and lipids, and changes in dietary behaviors at baseline, postintervention (12 weeks), and 6- and 12-month follow-up. Changes in biomarkers and food consumption patterns were assessed using linear mixed models with random intercept, including data from all participants who completed the end-of-intervention assessment.

RESULTS

Pre-post intervention results for 45 participants showed decreases in blood glucose and hs-CRP. Food frequency questionnaire data showed decreases in daily servings of grain, dairy, and fat postintervention. Decreases in blood glucose, hs-CRP, triglycerides, cholesterol, low-density lipoprotein, very-low-density lipoprotein, and HbA1c from baseline were observed at 12-month follow-up. Both insulin and high-density lipoprotein were decreased from baseline and 12-week levels at the 6-month follow-up but increased from all earlier levels at 12 months (all p < 0.0001). Daily servings of meat, dairy, and fat remained decreased at 6-month follow-up. Reduced grain consumption observed at 12-week and at 6-month follow-up was not sustained, and increased at 12 months, although still decreased from baseline.

CONCLUSIONS

Results suggest that this naturopathic nutrition education series may promote dietary behavior change with associated changes in clinical biomarkers. Larger controlled studies are needed to confirm these results.

Symmetries of a generic utricular projection: neural connectivity and the distribution of utricular information

Sensory contribution to perception and action depends on both sensory receptors and the organization of pathways (or projections) reaching the central nervous system. Unlike the semicircular canals that are divided into three discrete sensitivity directions, the utricle has a relatively complicated anatomical structure, including sensitivity directions over essentially 360° of a curved, two-dimensional disk. The utricle is not flat, and we do not assume it to be. Directional sensitivity of individual utricular afferents decreases in a cosine-like fashion from peak excitation for movement in one direction to a null or near null response for a movement in an orthogonal direction. Directional sensitivity varies slowly between neighboring cells except within the striolar region that separates the medial from the lateral zone, where the directional selectivity abruptly reverses along the reversal line. Utricular primary afferent pathways reach the vestibular nuclei and cerebellum and, in many cases, converge on target cells with semicircular canal primary afferents and afference from other sources. Mathematically, some canal pathways are known to be characterized by symmetry groups related to physical space. These groups structure rotational information and movement. They divide the target neural center into distinct populations according to the innervation patterns they receive. Like canal pathways, utricular pathways combine symmetries from the utricle with those from target neural centers. This study presents a generic set of transformations drawn from the known structure of the utricle and therefore likely to be found in utricular pathways, but not exhaustive of utricular pathway symmetries. This generic set of transformations forms a 32-element group that is a semi-direct product of two simple abelian groups. Subgroups of the group include order-four elements corresponding to discrete rotations. Evaluation of subgroups allows us to functionally identify the spatial implications of otolith and canal symmetries regarding action and perception. Our results are discussed in relation to observed utricular pathways, including those convergent with canal pathways. Oculomotor and other sensorimotor systems are organized according to canal planes. However, the utricle is evolutionarily prior to the canals and may provide a more fundamental spatial framework for canal pathways as well as for movement. The fullest purely otolithic pathway is likely that which reaches the lumbar spine via Deiters' cells in the lateral vestibular nucleus. It will be of great interest to see whether symmetries predicted from the utricle are identified within this pathway.

Proinflammatory cytokines and DHEA-S in women with fibromyalgia: impact of psychological distress and menopausal status

Though fibromyalgia is not traditionally considered an inflammatory disorder, evidence for elevated inflammatory processes has been noted in this disorder in multiple studies. Support for inflammatory markers in fibromyalgia has been somewhat equivocal to date, potentially due to inattention to salient patient characteristics that may affect inflammation, such as psychiatric distress and aging milestones like menopause. The current study examined the relationships between proinflammatory cytokines and hormone levels, pain intensity, and psychological distress in a sample of 34 premenopausal and postmenopausal women with fibromyalgia. Our results indicated significant relationships between interleukin-8 and ratings of pain catastrophizing (r=0.555, P<0.05), pain anxiety (r=0.559, P<0.05), and depression (r=0.551, P<0.05) for postmenopausal women but not premenopausal women (r,0.20 in all cases). Consistent with previous studies, ratios of interleukin-6 to interleukin-10 were significantly lower in individuals with greater levels of depressive symptoms (r=−0.239, P<0.05). Contrary to previous research, however, dehydroepiandrosterone sulfate did not correlate with pain intensity or psychological or biological variables. The results of the current study highlight the importance of psychological functioning and milestones of aging in the examination of inflammatory processes in fibromyalgia.

Naturopathic practice at north american academic institutions: description of 300,483 visits and comparison to conventional primary care

This study collected patient visit data to explore similarities and differences between conventional and naturopathic primary care (PC). Administrative data from practice management software systems from the main teaching clinics of four of the eight accredited North American naturopathic academic institutions were abstracted into an integrated database containing five years (2006-2010) of visit, patient, laboratory, and prescribing data. Descriptive analyses of healthcare services were compared to the National Ambulatory Medical Care Survey (NAMCS). Over the five-year period, 300,483 patient visits to naturopathic doctors occurred at clinics, excluding visits at clinics operated by the schools in community settings. Patients were 69% female; mean age was 39 (SE 0.09). Older adults (>65) comprised 9% of the population and children (<16) comprised 8%. Comparing academic naturopathic clinics to national conventional PC (NAMCS), we found more patients paid out of pocket at naturopathic clinics (50 vs. 4%) and naturopathic clinics more frequently offered discounted care (26 vs. 0.3%). There was a 44% overlap in the most frequent 25 diagnoses for PC at conventional community clinics. Overall, these data suggest substantial similarities in care offered by academic naturopathic clinics, at which most Naturopathic Doctor (ND) students are trained, and by conventional PC practices.

Perceptual centering of body segment orientation

It has been shown experimentally that under certain combinations of sensory stimuli, human subjects can perceive one of several distinct illusions about their overall orientation in or movement through space. In at least some cases, the structure of such multistable illusory perceptions of orientation can be efficiently described by perceptual transformations that act on a current orientation estimate to yield an updated perceptual construct. Repeated application of identified generating transformations yields a limited set of predicted illusions for a given sensory environment. This approach is especially valuable for perceptual data that exhibits discretely differing classes of illusions between subjects or trials. In a previous study, application of a semigroup of perceptual centering transformations has succeeded in reproducing and simplifying data from an experiment in which subjects experiencing visual vection reported a range of illusions about the orientations of their gaze, head, and torso to gravity. After reviewing previously obtained results on perceptual centering, this article generalizes the approach, presenting the mathematics required to characterize perceptual transformations. The developed framework should be widely applicable in the understanding of perceptual illusions, particularly when these are guided by alignment with preferred constructs. Secondly, the article reveals the nontrivial mathematical process of perceptual semigroup formation and evaluation, deducing the complete description of the semigroup constructed in the previous study. Perceptual centering transformations identified in terrestrial experiments may predict illusions to be expected in spacefiight. For example, our results indicate that under certain conditions, many astronauts will misperceive a visual rotation axis to be centered in front of the head or even the torso.

Motion parallax contribution to perception of self-motion and depth

The object of this study is to mathematically specify important characteristics of visual flow during translation of the eye for the perception of depth and self-motion. We address various strategies by which the central nervous system may estimate self-motion and depth from motion parallax, using equations for the visual velocity field generated by translation of the eye through space. Our results focus on information provided by the movement and deformation of three-dimensional objects and on local flow behavior around a fixated point. All of these issues are addressed mathematically in terms of definite equations for the optic flow. This formal characterization of the visual information presented to the observer is then considered in parallel with other sensory cues to self-motion in order to see how these contribute to the effective use of visual motion parallax, and how parallactic flow can, conversely, contribute to the sense of self-motion. This article will focus on a central case, for understanding of motion parallax in spacious real-world environments, of monocular visual cues observable during pure horizontal translation of the eye through a stationary environment. We suggest that the global optokinetic stimulus associated with visual motion parallax must converge in significant fashion with vestibular and proprioceptive pathways that carry signals related to self-motion. Suggestions of experiments to test some of the predictions of this study are made.

Spatial symmetries in vestibular projections to the uvula-nodulus

The discharge of secondary vestibular neurons relays the activity of the vestibular endorgans, occasioned by movements in three-dimensional physical space. At a slightly higher level of analysis, the discharge of each secondary vestibular neuron participates in a multifiber projection or pathway from primary afferents via the secondary neurons to another neuronal population. The logical organization of this projection determines whether characteristics of physical space are retained or lost. The logical structure of physical space is standardly expressed in terms of the mathematics of group theory. The logical organization of a projection can be compared to that of physical space by evaluating its symmetry group. The direct projection from the semicircular canal nerves via the vestibular nuclei to neck motor neurons has a full three-dimensional symmetry group, allowing it to maintain a three-dimensional coordinate frame. However, a projection may embed only a subgroup of the symmetry group of physical space, which incompletely mirrors the properties of physical space. The major visual and vestibular projections in the rabbit via the inferior olive to the uvula-nodulus carry three degrees of freedom-rotations about one vertical and two horizontal axes-but do not have full three dimensional symmetry. Instead, the vestibulo-olivo-nodular projection has symmetries corresponding to a product of two-dimensional vestibular and one-dimensional optokinetic spaces. This combination of projection symmetries provides the foundation for distinguishing horizontal from vertical rotations within a three dimensional space. In this study, we evaluate the symmetry group given by the physiological organization of the vestibulo-olivo-nodular projection. Although it acts on the same sets of elements and mirrors the rotations that occur in physical space, the physiological transformation group is distinct from the spatial group. We identify symmetries as products of physiological and spatial transformations. The symmetry group shapes the information the projection conveys to the uvula-nodulus; this shaping may depend on a physiological choice of generators, in the same way that function depends on the physiological choice of coordinates. We discuss the implications of the symmetry group for uvula-nodulus function, evolution, and functions of the vestibular system in general.

Perceptual centering of body segment orientation

It has been shown experimentally that under certain combinations of sensory stimuli, human subjects can perceive one of several distinct illusions about their overall orientation in or movement through space. In at least some cases, the structure of such multistable illusory perceptions of orientation can be efficiently described by perceptual transformations that act on a current orientation estimate to yield an updated perceptual construct. Repeated application of identified generating transformations yields a limited set of predicted illusions for a given sensory environment. This approach is especially valuable for perceptual data that exhibits discretely differing classes of illusions between subjects or trials. In a previous study, application of a semigroup of perceptual centering transformations has succeeded in reproducing and simplifying data from an experiment in which subjects experiencing visual vection reported a range of illusions about the orientations of their gaze, head, and torso to gravity. After reviewing previously obtained results on perceptual centering, this article generalizes the approach, presenting the mathematics required to characterize perceptual transformations. The developed framework should be widely applicable in the understanding of perceptual illusions, particularly when these are guided by alignment with preferred constructs. Secondly, the article reveals the nontrivial mathematical process of perceptual semigroup formation and evaluation, deducing the complete description of the semigroup constructed in the previous study. Perceptual centering transformations identified in terrestrial experiments may predict illusions to be expected in spaceflight. For example, our results indicate that under certain conditions, many astronauts will misperceive a visual rotation axis to be centered in front of the head or even the torso.

Cognitive-vestibular interactions: A review of patient difficulties and possible mechanisms

Cognitive deficits such as poor concentration and short-term memory loss are known by clinicians to occur frequently among patients with vestibular abnormalities. Although direct scientific study of such deficits has been limited, several types of investigations do lend weight to the existence of vestibular-cognitive effects. In this article we review a wide range of studies indicating a vestibular influence on the ability to perform certain cognitive functions. In addition to tests of vestibular patient abilities, these studies include dual-task studies of cognitive and balance functions, studies of vestibular contribution to spatial perception and memory, and works demonstrating a vestibular influence on oculomotor and motor coordination abilities that are involved in the performance of everyday cognitive tasks. A growing literature on the physiology of the vestibular system has demonstrated the existence of projections from the vestibular nuclei to the cerebral cortex. The goals of this review are to both raise awareness of the cognitive effects of vestibular disease and to focus scientific attention on aspects of cognitive-vestibular interactions indicated by a wide range of results in the literature.

Variables contributing to the coordination of rapid eye/head gaze shifts

In this article results of several published studies are synthesized in order to address the neural system for the determination of eye and head movement amplitudes of horizontal eye/head gaze shifts with arbitrary initial head and eye positions. Target position, initial head position, and initial eye position span the space of physical parameters for a planned eye/head gaze saccade. The principal result is that a functional mechanism for determining the amplitudes of the component eye and head movements must use the entire space of variables. Moreover, it is shown that amplitudes cannot be determined additively by summing contributions from single variables. Many earlier models calculate amplitudes as a function of one or two variables and/or restrict consideration to best-fit linear formulae. Our analysis systematically eliminates such models as candidates for a system that can generate appropriate movements for all possible initial conditions. The results of this study are stated in terms of properties of the response system. Certain axiom sets for the intrinsic organization of the response system obey these properties. We briefly provide one example of such an axiomatic model. The results presented in this article help to characterize the actual neural system for the control of rapid eye/head gaze shifts by showing that, in order to account for behavioral data, certain physical quantities must be represented in and used by the neural system. Our theoretical analysis generates predictions and identifies gaps in the data. We suggest needed experiments.

Perceptual centering effects in body orientation

This study mathematically characterizes the results of DiZio and Lackner (Percept Psychphys 39(1): 39-46) on the perception of self-orientation during circular vection induced by an optokinetic stimulus. Using the hypothesis of perceptual centering, it is shown that five basic centering transformations can logically account for the full range of illusions reported by the subjects. All five of these transformations center the perceived orientations of body components, the rotating disk, and gravity : two align the perceived visual and inertial rotation axes, one centers the perceived axis of visual rotation in front of the head, and two straighten the perceived neck angle. These transformations generate a mathematical semigroup. Application of the semigroup to an actual stimulus condition generates an orbit of predicted illusions. The semigroup analysis of perceptual centering predicts all of the illusions observed in the experiments of DiZio and Lackner (Percept Psychphys 39(1): 39-46). Moreover, the structure of perceptual centering (1) provides a logical explanation for the occurrence of those misperceptions; and (2) predicts the complete set of perceptions that are expected to occur in a larger sample. In addition, our analysis predicts illusions in experimental conditions not yet investigated.

Cognitive-vestibular interactions: a review of patient difficulties and possible mechanisms

Cognitive deficits such as poor concentration and short-term memory loss are known by clinicians to occur frequently among patients with vestibular abnormalities. Although direct scientific study of such deficits has been limited, several types of investigations do lend weight to the existence of vestibular-cognitive effects. In this article we review a wide range of studies indicating a vestibular influence on the ability to perform certain cognitive functions. In addition to tests of vestibular patient abilities, these studies include dual-task studies of cognitive and balance functions, studies of vestibular contribution to spatial perception and memory, and works demonstrating a vestibular influence on oculomotor and motor coordination abilities that are involved in the performance of everyday cognitive tasks. A growing literature on the physiology of the vestibular system has demonstrated the existence of projections from the vestibular nuclei to the cerebral cortex. The goals of this review are to both raise awareness of the cognitive effects of vestibular disease and to focus scientific attention on aspects of cognitive-vestibular interactions indicated by a wide range of results in the literature.

Calcium and oxalic acid kinetics differ in rats

Small molecular weight calcium salts, if absorbed intact, could provide a nutritional source of calcium in subjects with impaired absorption of calcium by the saturable pathway. An understanding of the mechanism of absorption of calcium oxalate (as a representative salt) may be important nutritionally and therapeutically. The aim of the present study was to develop models to study absorption, distribution and retention of calcium and oxalate in rats as a basis for studying calcium oxalate absorption. Labeled compounds (45Ca and [14C]-oxalic acid) were administered to separate groups of rats orally (n = 8-11) or intravenously (n = 3-5) and blood was sampled for up to 240 min. Data were analyzed using SAAM/CONSAM. Calcium kinetics were fitted by a model with three compartments in the body and one absorption pathway from the intestine. By contrast, oxalic acid kinetics were fitted by two pools in the body and two absorption pathways from the intestine. Calcium and oxalic acid, therefore, demonstrate different absorption and distribution kinetics in rats.

Absorption of calcium oxalate does not require dissociation in rats

Calcium absorption is thought to occur only if calcium is in a soluble or dissociated form, although experimental evidence is lacking. The intestinal absorption of calcium oxalate, a small, neutral and virtually insoluble calcium salt, was elucidated in the whole body of awake rats. Suspensions of 45Ca ascorbate, 14C-oxalic acid and doubly labeled 45Ca-[14C]-oxalate were given by gavage to separate groups of rats. Following dosing, blood samples were drawn for up to 240 min through a previously inserted intravenous catheter. Serum was assayed for radioactive tracers, and data were then plotted as fraction of dose over time. Calcium absorption was 15% [with a loading of 0.3 mmol (15 mg) calcium], oxalic acid absorption was 22% and Ca-oxalate absorption was <2%. Appearance of 45Ca from calcium ascorbate and 14C from oxalic acid differed, whereas 45Ca and 14C from doubly labeled Ca-oxalate had identical serum appearance profiles. Therefore, we conclude that calcium oxalate was absorbed intact. Addition of excess, unlabeled calcium to the doubly-labeled calcium oxalate did not alter the relationship of the serum level of the two tracers, confirming absorption of calcium oxalate as the intact salt. Thus, calcium bound as a small, neutral, calcium salt such as calcium oxalate does not have to be dissociated prior to absorption. Possibly other small compounds would be similarly absorbed. These results alter our current understanding of calcium bioavailability from foods and therapeutic agents.