The 2-year costs and effects of a public health nursing case management intervention on mood-disordered single parents on social assistance

Rationale, aims and objectives This randomized controlled trial was designed to evaluate the 2‐year costs and effects of a proactive, public health nursing case management approach compared with a self‐directed approach for 129 single parents (98% were mothers) on social assistance in a Canadian setting. A total of 43% of these parents had a major depressive disorder and 38% had two or three other health conditions at baseline. Methods Study participants were recruited over a 12 month period and randomized into two groups: one receiving proactive public health nursing and one which did not. Results At 2 years, 69 single parents with 123 children receiving proactive public health nursing (compared with 60 parents with 91 children who did not receive public health nursing services) showed a slightly greater reduction in dysthymia and slightly higher social adjustment. There was no difference between the public health and control groups in total per parent annual cost of health and support services. However, costs were averted due to a 12% difference in non‐use of social assistance in the previous 12 months for parents in the public health nursing group. This translates into an annual cost saving of $240 000 (Canadian) of costs averted within 1 year for every 100 parents. Conclusions In the context of a system of national health and social insurance, this study supports the fact that it is no more costly to proactively service this population of parents on social assistance.     

A prospective evaluation of the Charlson Comorbidity Index for use in long-term care patients

OBJECTIVES: Because of the high prevalence of coexisting medical conditions in frail older adults, clinical investigators often need to adjust for comorbidity when assessing the effect of long-term care (LTC) on patient outcomes.This study examined the prognostic value of the Charlson Comorbidity Index (CCI) in predicting 3-year mortality and functional decline in the LTC setting and compared its prognostic value to that of two data-derived comorbidity indices. DESIGN: Longitudinal cohort study. SETTING: Eighty-eight residential care facilities from Quebec, Canada. PARTICIPANTS: Two hundred ninety-one dependent older adults aged 65 and older. MEASUREMENTS: Subjects' functional abilities were assessed at baseline and 3 years later with the revised version of the Functional Autonomy Measurement System(SMAF). Comorbidity data and the exact date of death for those who had died were collected retrospectively from the subjects' medical files. Subjects were classified as functional decliners if they died or gained 5 points or more on the SMAF between the two assessments. RESULTS: Multivariate Cox and logistic regressions were used to derive two new comorbidity indices, one for predicting mortality and the other for identifying functional decliners. Although the CCI performed well in predicting these two outcomes, its performance was generally inferior to that of the two newly proposed indices. CONCLUSIONS: Findings suggest that the CCI can be improved upon when used to measure comorbidity in LTC patients.     

Aging-related changes in release of growth hormone and luteinizing hormone in female rhesus monkeys

A decline in somatic function with aging in women is associated with a decrease in GH release and a loss of estrogen after menopause. As an initial step to establish a monkey model for the neuroendocrine mechanisms underlying somatopause and menopause, we have conducted three experiments in unrestrained aged (approximately 25.7-yr-old) and young (approximately 5.4-yr-old) female rhesus monkeys. GH release was pulsatile, and mean GH release and pulse amplitude were significantly lower in aged monkeys than in young monkeys. Injection of GHRH alone, GH-releasing peptide-2 alone, or the combination of both induced an increase in GH release in both age groups. The mean LH level, pulse amplitude, and baseline LH levels were significantly higher in aged animals than in young animals. Both estrogen and IGF-I levels were lower in aged than young monkeys. These results suggest that in female rhesus monkeys 1) there is a clear decline in circulating GH and IGF-I levels with aging; 2) GHRH and GH-releasing peptide-2 stimulate GH release synergistically; and 3) circulating LH levels increase as estrogen decreases with aging. These results indicate that the rhesus monkey is an excellent model for studies of the neuroendocrine mechanisms of aging.     

Laboratory calibration and validation of the Biotrainer and Actitrac activity monitors

PURPOSE: The Biotrainer and Actitrac activity monitors (IM Systems) offer potential research advantages over existing accelerometry-based activity monitors, but they have not been tested under controlled conditions. The purpose of this study was to develop and test laboratory-based prediction equations for both monitors to estimate energy expenditure (EE) for walking/running movements. METHODS: Participants in the study wore a Biotrainer and Actitrac monitor on both hips and completed three paced bouts on the treadmill (3, 4, and 6 mph for 6 min each). Metabolic data collected using an indirect calorimetry system were used as the criterion measure. Multiple regression techniques were performed to develop prediction equations, and these equations were then applied to data from a separate sample for cross-validation purposes. Reliability was also examined. RESULTS: The correlations between the raw counts from each monitor and the measured metabolic variables ranged from r = 0.74-0.88 for the Biotrainer and from r = 0.81-0.91 for the Actitrac. The equations predicting EE (kcal x min-1) from counts yielded strong validation results for both the Biotrainer (R2 = 0.88, SEE = 1.47) and the Actitrac (R2 = 0.91, SEE = 1.24). When used on the cross-validation sample, the correlations between measured and predicted EE were r = 0.93 (Biotrainer) and r = 0.94 (Actitrac). Intraclass reliability coefficients computed between the left and right monitors ranged from 0.60 to 0.71 (Biotrainer) and 0.80 to 0.87 (Actitrac). When the equation developed from one side was applied to data from the monitor on the other side, there were no significant differences in predicted and measured EE for most comparisons. CONCLUSION: The results support the validity of Biotrainer and Actitrac monitors for estimating energy expenditure under controlled conditions.     

Improving cardiopulmonary bypass: heparin-coated circuits

Heparin-coated circuits have been repeatedly proven to reduce the inflammatory response and foreign surface activation triggered upon initiation of cardiopulmonary bypass (CPB). In recent years, increasing numbers of studies are proving significant reductions in postoperative blood loss and transfusion requirements and improvements in clinical outcomes as a result of heparin-coated circuits. These results are promising steps in our efforts to improve CPB, as our patient population gets older and more complicated.     

Safety of gadolinium contrast angiography in patients with chronic renal insufficiency

OBJECTIVE: To prevent iodinated contrast medium-induced nephrotoxicity, gadolinium has been used increasingly for magnetic resonance angiography (MRA) or conventional digital subtraction angiography (DSA) to visualize arterial anatomy in patients undergoing vascular surgery who are considered at high risk because of chronic renal insufficiency. We assessed the safety of gadolinium-based contrast medium as a substitute for iodinated contrast medium-enhanced examinations. We determined the incidence of gadolinium-induced nephrotoxicity in a clinical setting and searched for contributing risk factors.Patients and methods In a single-center retrospective study from December 1999 to January 2001, 218 inpatients underwent MRA and 42 inpatients underwent DSA, with gadolinium as the sole contrast agent. Patient comorbid conditions, indications for vascular imaging, contrast dose, urine output, baseline and post-procedure serum creatinine concentration (SCr), and outcome were recorded for all patients in whom gadolinium-induced renal failure developed. RESULTS: Of 260 patients who received gadolinium-based contrast agents, at a dose of 0.25 mmol/kg or more, 195 patients (75%) had pre-test baseline chronic renal insufficiency. In 7 of 195 patients (3.5%) acute renal failure developed after gadolinium-based contrast medium administration, for MRA (n = 153) in 3 patients (1.9%) and DSA (n = 42) in 4 patients (9.5%). Average baseline SCr in the 195 patients with chronic renal insufficiency was 38.2 +/- 1.6 mL/min/1.73 m(2), and in the 7 patients in whom acute renal failure developed, baseline SCr was 32.5 +/- 7.8 mL/min/1.73 m(2) (P =.33). Respective intravenous and intra-arterial gadolinium doses in these 7 patients ranged from 0.31 to 0.41 mmol/kg for MRA and 0.27 to 0.42 mmol/kg for DSA. Acute renal failure did not develop in any of 65 patients with normal baseline SCr. CONCLUSION: Despite reports of negligible nephrotoxicity, rarely gadolinium-based contrast agents can cause acute renal failure in patients with underlying chronic renal insufficiency. Estimation of creatinine clearance alone does not enable prediction of which patients are likely to have acute renal failure. Patients at high-risk should be identified, and prophylactic measures should be taken to reduce the risk for nephrotoxicity.     

Drug interaction potential of soy extract and Panax ginseng

To determine if soy extract or Panax ginseng increases the urinary excretion of the 6-beta-hydroxycortisol/cortisol ratio as a marker of cytochrome P450 (CYP) 3A enzyme induction, subjects received a soy extract containing 50 mg isoflavones twice daily (n = 20) or Panax ginseng 100 mg standardized to 4% ginsenosides twice daily (n = 20) for 14 days. Neither Panax ginseng nor soy extract significantly altered the urinary 6-beta-OH-cortisol/cortisol ratio, suggesting that unlike St. John's wort, they are not CYP3A inducers. Studies in vitro using human liver microsomes were performed to determine the effect of soy extract on probe substrates of CYP and UDP glucuronosyltransferase (UGT). Unhydrolyzed soy extract produced very little inhibition of CYP1A2, CYP2A6, and CYP2D6 and a trend of activation of CYP3A4. Hydrolyzed soy extract showed inhibition of all of the CYPs tested, particularly CYP2C9 and CYP3A4. UGT2B15 was the only UGT significantly inhibited. Even though both soy extract and ginseng have been shown to activate CYP3A4 in vitro, there is a lack of an in vitro correlation with the in vivo effects.     

Priming characteristics of peptide mimotopes of carbohydrate antigens

Immunization with peptide mimetics of carbohydrate antigens can induce functional carbohydrate-reactive antibodies. Here, we examine the immune characteristics of alternative approaches in prime and boost strategies using glycosylated HIV-1 envelope protein and model tumor associated carbohydrate antigens. Our results indicate that peptide mimotopes either in a DNA or carrier-conjugated format can induce comparable levels of IgM and IgG. Carbohydrate boosting of peptide-primed animals does not affect end-point titer, however, boosting mediates a stable long lasting carbohydrate reactive IgM response, not achievable by carbohydrate immunization alone. Boosting with carbohydrate in animals primed with DNA- or peptide-conjugate, facilitates the induction of detectable IgG with a dominant IgG2a isotype. Immunization with HIV-1 envelope glycoprotein of peptide-primed animals induces different IgG isotype profiles with a dominant IgG1 antibody. We observed that HIV-1 envelope glycoprotein immunization of peptide primed mice induces a cross-reactive cellular response, as detected by cytokine secretion, which lends to IFN-gamma production upon splenocyte stimulation and CTL activity against recombinant vaccinia virus infected cells after in vitro stimulation. DNA immunization with mimotope, inclusion of a T-cell epitope from the HIV-1 envelope protein in the expression cassette and co-administration with IL-12 or GM-CSF encoding plasmids activate a cellular response to the HIV-1 envelope protein.     

Effect of culture water hardness on the sensitivity of Ceriodaphnia dubia to copper toxicity

We examined whether the sensitivity of Ceriodaphnia dubia to copper toxicity was influenced by the hardness of the water in which they were reared or in which they were exposed. Organisms cultured in very hard water were 1.5-fold less sensitive to copper than those in moderately hard water. However, the hardness of the exposure water had a greater (2.5-fold) effect on copper median effective concentration (EC50s).