Chemical recovery and browning of Nova Scotia surface waters in response to declining acid deposition

Declining emissions of sulfur and nitrogen have curtailed acid deposition across large areas of North America and Europe. This has allowed many lakes to recover from acidification, with decreases in sulfate, increases in pH, and increases in alkalinity. But reduced acid deposition has not always coincided with chemical lake recovery. Surface waters in Nova Scotia did not exhibit clear evidence of recovery as recently as 2007, due in part to increasing organic acidity and slow replenishment of base cations. In an updated assessment with data collected as recently as 2019, we analyze water chemistry representing 81 lakes and rivers and two precipitation monitoring stations over up to 41 years. We find that Nova Scotia surface waters are now exhibiting signs of chemical recovery. We estimated the linear decrease in precipitation sulfate and nitrate yield at up to 0.31 and 0.18 kg ha^-1 year^-2, respectively, and the linear increase in precipitation pH at up to 0.014 year^-1. Sulfate decreased in 60 of 62 lakes and 14 of 17 rivers (-0.0051 to -0.23 mg L^-1 year^-1), while pH increased in 55 of 64 lakes and 11 of 17 rivers (0.0015-0.072 year^-1). Apparent colour increased in 54 of 62 lakes and 13 of 17 rivers (0.0026-3.9 Pt-Co year^-1). We identified increasing aluminum trends in 46 of 61 lakes, and we show using size-exclusion chromatography that binding to organic and iron-based colloids may help to explain these trends. To the extent that increases in apparent colour are explained by chromophoric dissolved organic matter (DOM), they imply greater binding capacity for metals in surface waters, and greater capacity for DOM to stabilize metal (oxyhydr)oxide colloids.

What liver transplant outcomes can be expected in the uninsured who become insured via the Affordable Care Act?

Our study objective is to measure the survival impact of insurance status following liver transplantation in a cohort of uninsured "charity care" patients. These patients are analogous to the population who will gain insurance via the Affordable Care Act. We hypothesize there will be reduced survival in charity care compared to other insurance strata. We conducted a retrospective study of 898 liver transplants from 2000 to 2010. Insurance cohorts were classified as private (n = 640), public (n = 233) and charity care (n = 23). The 1, 3 and 5-year survival was 92%, 88% and 83% in private insurance, 89%, 80% and 73% in public insurance and 83%, 72% and 51% in charity care. Compared to private insurance, multivariable regression analyses demonstrated charity care (HR 3.11, CI 1.41-6.86) and public insurance (HR 1.58, CI 1.06-2.34) had a higher 5-year mortality hazard ratio. In contrast, other measures of socioeconomic status were not significantly associated with increased mortality. The charity care cohort demonstrated the highest incidence of acute rejection and missed clinic appointments. These data suggest factors other than demographic and socioeconomic may be associated with increased mortality. Further investigations are necessary to determine causative predictors of increased mortality in liver transplant patients without private insurance.

The functional mu opioid receptor (OPRM1) Asn40Asp variant predicts short-term response to nicotine replacement therapy in a clinical trial

To determine whether the functional mu-opioid receptor (OPRM1) Asn40Asp variant predicts the comparative efficacy of different forms of NRT, we conducted a clinical trial of transdermal nicotine (TN) vs nicotine nasal spray (NS) in 320 smokers of European ancestry. Smokers carrying the OPRM1 Asp40 variant (n=82) were significantly more likely than those homozygous for the Asn40 variant (n=238) to be abstinent at the end of treatment, and reported less mood disturbance and weight gain. The genotype effect on treatment outcome was most pronounced among smokers receiving TN, particularly during the 21 mg dose phase. Smokers who carry the OPRM1 Asp40 variant are likely to have a favorable response to TN and may benefit from extended therapy with the 21 mg dose.

Chronic obstructive pulmonary disease stage and 6-minute walk outcome

PURPOSE

Although physicians generally reserve pulmonary rehabilitation (PR) referral for patients in later stages of chronic obstructive pulmonary disease (COPD), there is no evidence to suggest that PR programs are more effective for these persons than for those in earlier stages of the disease. This study examined the relationship between 6-minute walk change and COPD stage in patients completing PR.

METHODS

The sample consisted of 76 patients who enrolled in the University of Alabama at Birmingham's Cardiopulmonary Rehabilitation Program with a primary diagnosis of COPD between January 1996 and June 2000. Data was collected on 6-minute walk upon entry into the program and upon program completion. Patients were stratified according to COPD stage using the American Thoracic Society staging system.

RESULTS

There were significant differences among the three stages with regard to initial and ending 6-minute walk distances such that persons in later stages of the disease have shorter initial and ending 6-minute walk distances. However, all three stages show significant improvements in the 6-minute walk after PR. There were no significant differences in the median change among groups indicating that the median change was not better (or worse) for patients in any particular COPD stage.

CONCLUSIONS

This study suggests that PR is equally effective in increasing physical performance for all patients regardless of COPD stage. This type of information can be used to support the recommendation of PR for patients early in the disease process.

Chemotherapy for human immunodeficiency virus-associated non-Hodgkin's lymphoma in combination with highly active antiretroviral therapy

PURPOSE

This study investigated the efficacy, toxicity, and pharmacokinetic interactions resulting from simultaneous combination chemotherapy and highly active antiretroviral therapy (HAART) for patients with human immunodeficiency virus (HIV)-associated non-Hodgkin's lymphoma (NHL). In addition, the effects on viral load, CD4 counts, and opportunistic infections were examined with the use of combination chemotherapy combined with HAART.

PATIENTS AND METHODS

Sixty-five patients with previously untreated and measurable disease at any stage of HIV-associated NHL of intermediate or high grade were entered onto this study at 17 different centers. The first 40 patients entered onto the study received reduced doses of cyclophosphamide and doxorubicin, combined with vincristine and prednisone (modified CHOP [mCHOP]), whereas the subsequent 25 patients entered onto the study received full doses of CHOP combined with granulocyte colony-stimulating factor (G-CSF). All patients also received stavudine, lamivudine, and indinavir.

RESULTS

The complete response rates were 30% and 48% among patients who received mCHOP and full-dose CHOP combined with HAART, respectively. Grade 3 or 4 neutropenia occurred in 25% of patients receiving mCHOP and 12% of those receiving full-dose CHOP combined with G-CSF (25% v 12%). There were similar numbers of patients with grade 3 or 4 hyperbilirubinemia (12% and 17%), constipation and abdominal pain (18% and 17%), and transaminase elevation (48% and 52%) on the modified and full-dose arms of the study, respectively. Doxorubicin clearance and indinavir concentration curves were similar among patients on this study and historical controls, whereas cyclophosphamide clearance was 1.5-fold reduced as compared with control values. Human immunodeficiency virus (HIV) load declined from a median baseline value of 29,000 copies/mL to a median minimum value on therapy of 500 copies/mL.

CONCLUSION

Either modified-dose or full-dose CHOP chemotherapy for HIV-NHL, delivered with HAART, is effective and tolerable.

Are pediatric emergency medicine training programs adequately preparing graduates for involvement in EMS?

OBJECTIVE

To examine the level of involvement in pre-hospital care for children by faculty and fellows of teaching hospitals with a Pediatric Emergency Medicine (PEM) fellowship. In addition, we hypothesized that a divisional faculty member's involvement as principal investigator (PI) on an EMSC grant would not impact divisional involvement in on or off-line medical direction.

DESIGN

Cross-sectional national survey.

PARTICIPANTS

PEM fellowship directors.

INTERVENTIONS

Self-administered questionnaire.

STATISTICS

Descriptive and Chi-square analysis to study null hypothesis.

RESULTS

The response rate to the survey was 62% (53/85). Of the programs responding, 53 % provided on-line pediatric medical direction for pre-hospital providers, 77% were involved with paramedic education other than PALS, and 58% of systems had pediatric specific protocols. In 87 % of the programs, a designated faculty member functioned as an EMSC liaison. A division faculty member was or had been the PI on an EMSC grant in 18 programs (34%). There was no significant difference in the provision of on or off-line medical direction comparing programs with or without involvement in an EMSC grant. Only 34% of the responding program directors felt that the current level of exposure to EMS was adequate for PEM fellow training.

CONCLUSIONS

The current level of involvement in EMS of PEM faculty and fellows has significant room for improvement. It does not appear that grant support translates into increased local involvement in EMS. Current PEM fellowship curriculum guidelines for training in EMS are not being met by the majority of responding training programs.

A prospective trial of telepathology for intraoperative consultation (frozen sections)

Telepathology is a maturing technology that, for a variety of reasons, has not been widely deployed. In addition, clinical validation is relatively modest compared with accepted telemedicine applications such as teleradiology. A prototype telepathology system (Tele-Path(sm)) featuring high-resolution images selected from a remote microscope site has been developed at the University of Alabama at Birmingham (UAB). To validate the diagnostic efficacy of the system, a prospective study was undertaken of parallel diagnoses by conventional microscopy and telepathology with a remotely operated microscope. Slides from 99 intraoperative consultations from 29 tissue/ organ sites in the University of Alabama Hospitals by 9 academic pathologists were used in the study. Each microscopic and telepathology diagnosis was compared with the final diagnosis rendered by a referee pathologist. Diagnoses were classified as correct, false positive, or false negative or classification error. Of the 99 frozen sections evaluated, 3 cases were deferred. Of the remaining 96 cases, 2 received incorrect diagnoses in both the microscopic and telepathology arms of the study. Three errors occurred only in the telepathology arm. There was 1 false-positive diagnosis, 1 false-negative diagnosis, and 1 classification error. Statistical analysis indicated no significant difference between telepathology and conventional microscopy. Qualitative data indicated that the pathologists were generally satisfied with the performance of the system. Telepathology using this system paradigm is sufficiently accurate for real time utilization in a complex surgical environment. Telepathology therefore may be an effective model to support the surgical services of hospitals lacking full-time pathology coverage, resulting in full-time access to anatomic pathology services.

Hu antigen specificities of ANNA-I autoantibodies in paraneoplastic neurological disease

Despite a broad clinical spectrum, paraneoplastic enecephalomyelitis/sensory neuronopathy (PEM/SSN) is characterized by the presence of a common autoantibody, referred to as anti-Hu or type I anti-neuronal nuclear antibody (ANNA-1). The target of these antibodies is a family of four Hu antigens: three (Hel-N1, HuC, HuD) are neural-specific, while the fourth (HuR) is ubiquitous. Here, we have analysed by enzyme-linked immunosorbent assay (ELISA) the immunoreactivity of all four Hu antigens in serum from 75 patients with ANNA-1 autoantibodies and looked for clinical correlations. IgG in all the patients' sera bound to each of the four antigens, and the titers correlated with those of the ANNA-I immunofluorescence assay. Median titers for the neural-specific antigens (range: 56, 892-90,051) were significantly higher than for HuR (36,799). Patients with gastrointestinal dysmotility or subacute sensory neuronopathy had the highest median titers to all four antigens, while patients with sensorineural deafness had the lowest titers. The results indicate a heterogeneous immune response to individual Hu antigens in patients with PEM/SSN, and that the titers to these antigens as a group, rather than individually, correlate with clinical profile. Furthermore, these results suggest that ELISA analysis of a single neural-specific Hu antigen is sufficient for serological screening in PEM/SSN.

A comparison of carotid angioplasty with stenting versus endarterectomy with regional anesthesia

INTRODUCTION

Percutaneous transluminal angioplasty with stenting (PTAS) has been considered a potential alternative to carotid endarterectomy (CEA) for stroke prevention. Interventionalists have suggested that PTAS carries less anesthetic risk than CEA. The treatment of carotid stenosis with local or regional anesthesia (LRA) allows direct intraprocedural neurologic evaluation and avoids the potential risks of general anesthesia.

METHODS

We retrospectively analyzed the clinical charts of 377 patients who underwent 414 procedures for the elective treatment of carotid stenosis in 433 cerebral hemispheres with LRA between August 1994 and May 1997. Group I (312 hemispheres) underwent PTAS, and group II (121 hemispheres) underwent CEA.

RESULTS

The indications for treatment included the following: asymptomatic severe stenosis (n = 272; 62.8%), transient ischemic attack (TIA; n = 100; 23.1%), and prior stroke (n = 61; 14.1%). The early neurologic results for the patients in group I (n = 268) included 11 TIAs (4.1%), 23 strokes (8.6%), and 3 deaths (1.1%). The early neurologic results for the patients in group II (n = 109) included 2 TIAs (1.8%), one stroke (0.9%), and no deaths. The total stroke and death rates were 9.7% for the patients in group I and 0.9% for the patients in group II (P = .0015). The cardiopulmonary events that led to additional monitoring were evident after 96 procedures in group I (32.8%) and 21 procedures in group II (17.4%; P = .002).

CONCLUSION

PTAS carries a higher neurologic risk and requires more monitoring than CEA in the treatment of patients with carotid artery stenosis with LRA. The proposed benefit for the use of PTAS to avoid general anesthesia cannot be justified when compared with CEA performed with LRA.

Retinal venous oxygen saturation correlates with blood volume

OBJECTIVES

To evaluate the sensitivity of retinal venous O2 saturation (SrvO2) for early blood loss and reinfusion. A secondary objective was to measure the correlation between SrvO2 and mixed venous O2 saturation (SvO2) during blood loss and reinfusion.

METHODS

Seven anesthetized swine were bled at 0.8 mL/kg/min to 16 mL/kg. Shed blood was re-infused at the same rate and the swine were allowed to equilibrate. After equilibration, repeat hemorrhages were performed at 1.6 mL/kg/min and 2.4 mL/kg/min. SrvO2 was measured using an eye oximeter (EOX) and SvO2 was measured using a fiber-optic catheter.

RESULTS

During blood loss, SrvO2 correlated with blood removed (r = -0.88, -0.97, -0.96) and SvO2 (r = 0.87, 0.98, 0.92). During reinfusion, SrvO2 correlated with blood re-infused (r = 0.63, 0.76, 0.82) and SvO2 (r = 0.80, 0.93, 0.96). SrvO2 decreased 1.22 +/- 0.60%/mL/kg of blood removed. The rate of decrease in SrvO2 per minute (deltaSrvO2) when blood was removed at 2.4 mL/kg/min was significantly greater than deltaSrvO2 when blood was removed at 0.8 mL/kg/min (p < 0.007). The rates of change in blood pressure (BP) and pulse were not significantly different at any rate of blood removal.

CONCLUSIONS

In this model, retinal venous O2 saturation correlated with blood volume and central venous O2 saturation. Unlike the rate of change in BP and heart rate, deltaSrvO2 values were significantly different at different rates of blood removal. Use of an EOX to monitor for blood loss, estimate the rate of hemorrhage, and evaluate the response to therapy during resuscitation warrants further study.

A cost comparison of balloon angioplasty and stenting versus endarterectomy for the treatment of carotid artery stenosis

PURPOSE

Percutaneous transluminal angioplasty with stenting (PTAS) of the carotid artery has been advocated as an alternative treatment for high-grade stenosis. Rationale for this approach includes less morbidity, shorter recovery, and lower cost when compared with carotid endarterectomy (CEA).

METHODS

The clinical results and hospital charges of patients who underwent elective treatment for carotid stenosis were reviewed. During a concurrent 14-month period, 218 patients were admitted 229 times for 234 procedures for the treatment of 239 carotid bifurcation stenoses, 109 by PTAS and 130 by CEA. Hospital charges were reviewed for each hospitalization and were categorized according to radiology, operating room, cardiac catheterization laboratory, and all other hospital charges.

RESULTS

The combined incidence of postprocedure strokes and deaths were: PTAS, eight strokes (7.7%) and one death (0.9%); CEA, two strokes (1.5%) and two deaths (1.5%). Total hospital charges per admission for the two groups were $30,140 for PTAS and $21,670 for CEA. The average postprocedure length of stay for PTAS was 2.9 days (median, 2 days) and for CEA was 3.1 days (median, 3 days). Cardiac catheterization laboratory charges for the PTAS group were $12,968, whereas the operating room charges for the CEA group were $4263. When hospitalizations that were extended by complications were excluded, the average total charges for the PTAS group (n = 84) dropped to $24,848 (mean length of stay, 1.9 days) and for the CEA group (n = 111) to $19,247 (mean length of stay, 2.6 days).

CONCLUSIONS

After evaluating hospital charges, PTAS for the treatment of carotid stenosis cannot currently be justified on the basis of reduced costs alone. With future cost-containing measures, total hospital charges can be reduced in both groups.

Nutritional status of urban homebound older adults

The purposes of this study were to assess comprehensively the nutritional status of frail older adults living in an urban area and to identify factors associated with nutritional insufficiency. Subjects were 49 adults aged > or = 65 y followed by the Jefferson County Home Health Department. Twenty-nine percent of the women and 63% of the men had a body mass index (BMI; in kg/m2) < 24. Nineteen percent had serum albumin concentrations < 35 g/L (3.5 g/dL). More than one-half of the subjects reported symptoms of oral health problems. The key dependent variables were serum albumin concentration and BMI. In univariate analyses, a lower BMI correlated with oral symptoms, male sex, increased age, and less education. Lower serum albumin concentrations were associated with advanced age, increased dependence in Activities of Daily Living (ADL), oral symptoms, and presence of a caregiver. A stepwise multiple-regression model for BMI and serum albumin showed that predictors of low BMI were increased age, less education, difficulty in chewing, and absence of dentures. Variables in the model for lower serum albumin concentrations were sex, increased age, increased dependence in ADLs, and wearing of dentures. In a secondary analysis that controlled for age, education level, functional status, and sex, oral symptoms remained associated with lower BMI but not with lower serum albumin concentrations. This study found a high prevalence of undernutrition in urban homebound older adults and suggests that oral health disability may affect nutritional status in this population.