Using food fortification to improve vitamin D bioaccessibility and intakes.

Vitamin D intakes and status are low in many countries due to seasonal UVB exposure variation and the fact that few foods are naturally vitamin D rich. Data modelling studies show that vitamin D intakes increase with food fortification, and countries with mandatory fortification policies have higher vitamin D intakes and status compared to countries without. While many foods can be vitamin D fortified, vitamin D bioavailability differs depending on fortification methods, food structure and composition. Randomised controlled trials (RCT) report that vitamin D2 bioavailability varies between foods, whereas vitamin D3 is bioavailable from many foods. In vitro studies suggest that altering the lipid composition of fortified foods increases vitamin D3 absorption. Olive oil increased vitamin D3 absorption during in vitro digestion compared to other dietary oils. Additionally, when vitamin D3 was incorporated into micelles formed from in vitro digestion of olive oil, more vitamin D3 was absorbed compared to other dietary oils. However, in a human postprandial study, a preformed vitamin D3 micelle dairy drink did not increase vitamin D3 absorption, and a vitamin D3 olive dairy drink increased vitamin D3 absorption in vitamin D insufficient participants only. Action is urgently needed to improve vitamin D intakes and status worldwide. Food fortification improves vitamin D intakes; however, fortification strategies unique to each country are needed. This review will synthesise the literature describing data modelling and intervention trials that assess the safety and efficacy of vitamin D fortification strategies, and those manipulating food composition to alter vitamin D bioavailability from fortified foods. Additionally, RCT examining the impact of vitamin D fortification strategies on vitamin D intakes and status over time are reviewed.

Exercise as a therapeutic intervention for motor and non-motor symptoms in Parkinson's disease: Evidence from rodent models.

Parkinson's disease (PD) is characterised by degeneration of dopaminergic neurons of the nigrostriatal pathway, which leads to the cardinal motor symptoms of the disease - tremor, rigidity and postural instability. A number of non-motor symptoms are also associated with PD, including cognitive impairment, mood disturbances and dysfunction of gastrointestinal and autonomic systems. Current therapies provide symptomatic relief but do not halt the disease process, so there is an urgent need for preventative strategies. Lifestyle interventions such as aerobic exercise have shown potential to lower the risk of developing PD and to alleviate both motor and non-motor symptoms. However, there is a lack of large-scale randomised clinical trials that have employed exercise in PD patients. This review will focus on the evidence from studies on rodent models of PD, for employing exercise as an intervention for both motor and non-motor symptoms.

Neuroprotective effects of novel phosphatidylglycerol-based phospholipids in the 6-hydroxydopamine model of Parkinson's disease.

Administration of VP025 (Vasogen Inc.), a novel drug formulation based on phospholipid nanoparticles incorporating phosphatidylglycerol, has previously been shown to have a neuroprotective effect in the brain. We examined the effect of VP025 in a rat model of Parkinson's disease, the 6-hydroxydopamine (6-OHDA) lesion of the medial forebrain bundle. VP025 or phosphate-buffered saline (PBS) was administered to rats 14 days, 13 days and 1 day before the unilateral 6-OHDA lesion. Functional integrity of nigrostriatal dopaminergic neurons was assessed 7 and 21 days later by amphetamine-induced rotational testing and we observed that rotational counts were significantly less in rats that were pretreated with VP025 compared with PBS-pretreated 6-OHDA-lesioned rats. Neurochemical analysis at 10 and 28 days after lesion revealed that VP025 protected against a 6-OHDA-induced decrease in concentrations of striatal dopamine and its metabolites. Immunocytochemical studies of the ipsilateral substantia nigra showed that VP025 significantly inhibited 6-OHDA-induced loss of dopaminergic neurons. We also observed that increases in immunostaining for activated microglia and for activated p38 in dopaminergic neurons of 6-OHDA-lesioned rats were prevented by VP025. This study shows that VP025 has significant protective effects on the 6-OHDA-lesioned nigrostriatal pathway and may therefore have potential for the treatment of Parkinson's disease.

Immune activation by a sterile aqueous extract of Cordyceps sinensis: mechanism of action.

Cordyceps sinensis is a fungus that has been used for over 2,000 years in China as a treatment for a variety of conditions including infectious diseases. The available evidence suggests a hypothesis that any efficacy of C. sinensis as an anti-infective therapeutic would be related to a role as an activator of innate immune responses. The objectives of this study were first to investigate the ability of C. sinensis to activate pro-inflammatory responses in macrophages in vitro and induce protective responses against intracellular pathogens in vivo, and second to characterize a method of action. We found that C. sinensis activates murine macrophages to produce a variety of pro-inflammatory cytokines. IFN-gamma synergizes with C. sinensis to amplify this response. Bacterial endotoxin contamination was ruled out as a potential artefact. The evidence presented in this study supports a hypothesis that C. sinensis activates macrophages by engaging Toll-like receptors and inducing mitogen-activated protein kinase (MAPK) pathways characteristic of inflammatory stimuli.

Progenitor-cell mobilization after low-dose cyclophosphamide and granulocyte colony-stimulating factor: an analysis of progenitor-cell quantity and quality and factors predicting for these parameters in 101 pretreated patients with malignant lymphoma.

PURPOSE: To define parameters that predict for rapid engraftment after peripheral-blood stem-cell (PBSC) transplantation, progenitor thresholds, the proportion of patients who achieve these thresholds with a standardized mobilization regimen, and the factors that predict for mobilization efficiency. PATIENTS AND METHODS: One hundred and one patients with pretreated lymphoma were mobilized with cyclophosphamide 1.5 g/m2 and granulocyte colony-stimulating factor (G-CSF), with the first apheresis performed when the recovery WBC count was > or = 5.0 x 10(9)/L. The relationship between the number of progenitor cells collected and patient age, sex, diagnosis, prior radiotherapy, and time since last chemotherapy was determined by multivariate analysis. The relationship between these factors, progenitor numbers returned, post-PBSC G-CSF, and hematologic recovery was performed in 81 patients following chemotherapy with carmustine (BCNU), etoposide, cytarabine, and melphalan (BEAM protocol). RESULTS: No BEAM recipients had delayed neutrophil recovery beyond 28 days. Delayed platelet recovery occurred in 7.4% and minimum and optimum thresholds of 1 x 10(6) and 3.5 x 10(6) CD34+ cells/kg and 1 x 10(5) and 3.5 x 10(5) granulocyte-macrophage colony-forming cells (GM-CFC)/kg were established. Hematologic recovery was adversely affected by prior treatment with mini-BEAM, and neutrophil recovery was accelerated by post-PBSC G-CSF. The minimum GM-CFC threshold was achieved with a single apheresis in 83% of patients and in 90% with two aphereses. The optimal threshold was achieved with two leukaphereses in 69% of patients. Prior radiotherapy adversely affected mobilization. CONCLUSION: Hematopoietic recovery following PBSC is dependent on progenitor-cell number infused and affect of previous chemotherapy on progenitor quality. Progenitor-cell mobilization is adversely affected by prior radiotherapy. The minimum threshold of GM-CFC required is achieved in most patients with a single apheresis, but an optimal collection usually requires at least two harvests.

Back-up bone marrow is frequently ineffective in patients with poor peripheral-blood stem-cell mobilization.

PURPOSE: To assess hematologic recovery and procedure-related mortality in patients who received high-dose therapy with stem-cell support, in whom the peripheral-blood stem-cell (PBSC) collection fails (CD34+ cells < 1 x 10(6)/kg). The predictive value of granulocyte-monocyte colony-forming cell (GM-CFC) measurements and the value of bone marrow obtained after PBSC collection failure was assessed. PATIENTS AND METHODS: The study group comprised 324 consecutive patients mobilized with granulocyte colony-stimulating factor (G-CSF) and cyclophosphamide (273 patients), G-CSF with other chemotherapy (37 patients), and G-CSF alone (14 patients). Between one and four aphereses were performed. RESULTS: In 51 of 324 patients, there was failure to obtain 1 x 10(6)/kg CD34+ cells. Twenty-three patients had greater than 1 x 10(5)/kg GM-CFC; 22 patients proceeded to high-dose therapy. Neutrophil recovery occurred within 21 days, but platelet independence was delayed (> 28 days) in eight patients. Of 28 patients with less than 1 x 10(5)/kg GM-CFC, six received high-dose therapy with PBSC alone and five had delayed engraftment. Twelve patients with less than 1 x 10(5)/kg GM-CFC received high-dose therapy supported by bone marrow collected after PBSC collection failure. Eleven patients were assessable for engraftment; four patients had slow (> 21 days) or delayed (> 28 days) neutrophil recovery and eight patients had delayed platelet recovery. In the group of patients who received less than 1 x 10(5)/kg GM-CFC, there were five procedure-related deaths. CONCLUSION: This study shows that delayed hematologic recovery is frequent if less than 1 x 10(6)/kg CD34+ cells are infused after high-dose therapy, particularly with GM-CFC less than 1 x 10(5)/kg. The procedure-related mortality in this latter group is high. In most patients whose PBSC collection contains less than 1 x 10(5)/kg GM-CFC, the use of bone marrow cells does not improve engraftment, which suggests that poor PBSC mobilization usually indicates poor marrow function.

Heparin-binding epidermal growth factor-like growth factor: a component in chromaffin granules which promotes the survival of nigrostriatal dopaminergic neurones in vitro and in vivo.

Chromaffin cells can restore function to the damaged nigrostriatal dopaminergic system in animal models of Parkinson's disease. It has been reported that a protein which is released from chromaffin granules can promote the survival of dopaminergic neurones in vitro and protect them against N-methylpyridinium ion toxicity. This neurotrophic effect has been found to be mediated by astroglial cells and blocked by inhibitors of the epidermal growth factor (EGF) receptor signal transduction pathway. Here we report the identification of bovine heparin-binding EGF-like growth factor (HB-EGF) in chromaffin granules and the cloning of the respective cDNA from bovine-derived adrenal gland. Protein extracts from bovine chromaffin granules were found to promote the survival of embryonic dopaminergic neurones in culture, to the same extent as recombinant human HB-EGF. Furthermore, the neurotrophic action of the chromaffin granule extract could be abolished by antiserum to recombinant human HB-EGF. We also show that intracerebral injection of recombinant human HB-EGF protected the nigrostriatal dopaminergic system in an in vivo adult rat model of Parkinson's disease. Intracerebral administration of this protein at the same time as a 6-hydroxydopamine lesion of the medial forebrain bundle was found to spare dopamine levels in the striatum and tyrosine hydroxylase-immunopositive neurones in the midbrain. This study has found that the main component in chromaffin granules responsible for their neurotrophic effect on dopaminergic neurones is HB-EGF. Furthermore, HB-EGF has significant protective effects on nigrostriatal dopaminergic neurones in vivo, making it a potential candidate for use in the treatment of Parkinson's disease.

A third generation immunoassay for tumor necrosis factor alpha.

Tumor necrosis factor alpha (TNF alpha) is a polypeptide cytokine produced primarily by monocytes and macrophages. It is involved in a wide variety of immune reactions. Measurement of TNF alpha originally depended upon bioassays that are of varying reliability and reproducibility. Early immunoassays for TNF alpha required handling of radioisotopes and costly disposal of radioactive waste. Subsequent use of enzymes as reporter molecules in enzyme immunoassay (EIA) has eliminated the burden of radioisotope handling and its associated costs. However, EIA has presented new challenges. Use of thimerosal as a preservative in EIAs may require high disposal costs due to its mercury content. In addition, many EIAs lack the sensitivity achievable in radioimmunoassay (RIA). We have developed a simple microplate enzyme-linked immunosorbent assay (ELISA) for the detection of TNF alpha in serum, plasma and culture supernatants. Our high affinity capture antibody has enabled us to achieve a sensitivity of 1.5 pg/mL. The assay is calibrated to the World Health Organization (W.H.O.) first international standard for TNF alpha (87/650) and exhibits excellent precision and reproducibility. Tetramethylbenzidine is used to generate the colored end product of the reaction, and thimerosal has been removed from all components.

The influence of different stages of pregnancy on group B streptococcal infection in mice.

Eight-day pregnant mice were found to be more resistant to the lethal effects of group B streptococci than those which were 17 days pregnant. From studies on the multiplication of the organisms in vivo it is suggested that the apparent enhancement of the infection in the 17-day pregnant animals is due to the lethal effects of the greater number of streptococci found in their tissues.

Peripheral blood stem cell support does not accelerate haemopoietic recovery from miniBEAM chemotherapy.

Intermediate-dose salvage therapy is frequently given for relapsed and resistant lymphomas and is usually intensely myelosuppressive. In an attempt to reduce the haematological toxicity of miniBEAM, one of the commonly used salvage regimens, peripheral blood stem cell (PBSC) support was given to 21 consecutive patients who received miniBEAM chemotherapy. The outcome was compared with a non-randomised control group of consecutive patients who were similar to the supported group apart from the fact that it was not possible to collect PBSC before miniBEAM therapy. Apart from a small, marginally significant difference between the supported and unsupported groups in the number of days for which intravenous antibiotics were required, there were no other differences between the two groups in supportive care required and times to haematological recovery. In conclusion, PBSC support does not accelerate haematological recovery from miniBEAM therapy.

Evaluation of clinical scale CD34+ cell purification: experience of 71 immunoaffinity column procedures.

Seventy-one mobilised PBSC collections were subject to CD34+ cell purification using the CEPRATE SC stem cell concentration system. The overall median purity of CD34+ cells was 69% (6-93%). CD34+ cell, and GM-CFC recoveries were 52% (8-107%) and 36% (3-118%). Purity was logarithmically related to the input percentage of CD34+ cells and starting requirements were established of 1% CD34 cell content for optimal purity and a minimum of 2 x 10(6)/kg CD34+ cells to ensure recovery of our minimum engraftment threshold of 1 x 10(6)/kg CD34+ cells. Reduction of the washing steps reduced non-specific cell losses and shortened the procedure but did not affect progenitor cell recovery. Purified CD34+ cells were reinfused following high-dose therapy in 35 patients. The median time to neutrophil recovery of 0.5 x 10(9)/l was 12 (10-23) days and to the attainment of platelet independence was 13 (7-100) days. The risks of delayed platelet recovery were related to the CD34+ cell dose infused and were identical to the risks when non-purified PBSC collections were used. In conclusion, purification of CD34+ cells using the CEPRATE device is reliable and the purified product results in prompt engraftment. The cell losses that occur do however restrict its use in many patients.

Cortical induction of c-fos by intrastriatal endothelin-1 is mediated via NMDA receptors.

Endothelin (ET) is a potent vasoconstrictor which has also been proposed to act as a neuromodulator. We have investigated the action of ET-1 on neurones in vivo, using c-fos as a marker of neuronal activation. Intrastriatal injection of ET-1 caused seizures and barrel rolling which were prevented by pretreatment with the N-methyl-D-aspartate (NMDA) receptor antagonist MK-801 and attenuated by the nitric-oxide synthase inhibitor N omega-nitro-L-arginine (L-NNA). In association with these behaviours, a dramatic increase in c-fos mRNA expression was seen in the cerebral cortex. This increase was blocked by both MK-801 and L-NNA. We suggest that ET-1 modulates the activity of cortical afferents to the striatum, and causes seizures via an NMDA receptor-dependent mechanism.

Campylobacters and impaired fetal development in mice.

Intravenous injection of eight human strains of Campylobacter fetus ss fetus and Campylobacter jejuni into mice at various stages of pregnancy demonstrated significant strain differences in ability to affect implantation of the fertilised ovum and to cause resorption of the mouse fetus. Implantation was significantly impaired when C. fetus ss fetus was injected intravenously on day 2 of pregnancy, but no effect was observed in mice receiving C. jejuni. On day 6 of pregnancy, before the development of placental circulation, both C. fetus ss fetus and C. jejuni impaired fetal growth; one strain of C. jejuni had a greater effect than others of the same species. In animals inoculated on day 13 of pregnancy, after the development of placental circulation, six of the eight campylobacter strains caused resorption of the mouse embryos. A similar effect on the embryos was observed after injection of heat-killed organisms, and endotoxin-like substances may have been responsible. It is also suggested that factors other than endotoxin-like substances have a deleterious effect on embryonic growth.

Variations in the virulence, for pregnant guinea pigs, of campylobacters isolated from man.

Pregnant guinea pigs were used to compare the virulence of four human isolates of Campylobacter fetus ss. fetus and four of C. jejuni on the basis of their ability to cause abortion and bacteraemia. Of the four strains of C. fetus ss. fetus two produced abortion readily after intramuscular injection. The four C. jejuni isolates were, however, of comparatively low virulence and no differences between them were demonstrated. Some of the isolates differed in their ability to survive in vitro in human and guinea-pig serum. It is suggested that campylobacters vary in their virulence for man and that this may influence the outcome of infections. Guinea pigs may prove useful in studying the pathogenesis of systemic campylobacter infections.

The effect of campylobacter lipopolysaccharide on fetal development in the mouse.

Purified lipopolysaccharide (LPS) obtained from isolates of Campylobacter fetus ss. fetus and Campylobacter jejuni impaired fetal development when administered to mice on day 13 of pregnancy. Strikingly more fetal resorption was produced by C. jejuni LPS than by similar amounts of C. fetus ss. fetus LPS. Three of the four Campylobacter strains examined produced LPS that had no effect on maternal health, but LPS from one C. jejuni strain killed all of the mice to which it was administered.

Neuroprotective effects of growth/differentiation factor 5 depend on the site of administration.

Growth/differentiation factor 5 (GDF5) is a neurotrophin which protects the rat nigrostriatal dopaminergic pathway from 6-hydroxydopamine-induced damage. Here we used amphetamine-induced rotational testing, high-performance liquid chromatography and immunocytochemistry to investigate the minimum effective dose of GDF5. We also compared the effectiveness of injecting GDF5 into either the substantia nigra pars compacta (SNpc), the lateral ventricle (LV) or the striatum (or combinations of these sites).

Growth/differentiation factor 5 protects nigrostriatal dopaminergic neurones in a rat model of Parkinson's disease.

Growth/differentiation factor 5 (GDF5), a novel member of the transforming growth factor beta superfamily, promotes the survival of dopaminergic neurones in vitro. We present here the first evidence for a neuroprotective action of GDF5 in vivo. We investigated the effects of intracerebral administration of GDF5 on a rat model of Parkinson's disease. GDF5 was administered just above the substantia nigra and into the lateral ventricle immediately before ipsilateral injection of 6-hydroxydopamine into the medial forebrain bundle. GDF5 prevented the development of amphetamine-induced rotations and preserved the integrity of striatal dopaminergic nerve terminals, as measured by positron emission tomography. Post-mortem studies showed that GDF5 spared dopamine levels in the striatum and tyrosine hydroxylase positive neurones in the midbrain. This study suggests that GDF5 has potential for the treatment of Parkinson's disease.

The effect of medical education on primary care orientation: results of two national surveys of students' and residents' perspectives.

PURPOSE: To examine changes among a nationally representative sample of students and residents in their orientations toward primary care as reflected in their attitudes toward the psychosocial and technical aspects of medicine and their perceptions of the academic environment for primary care. METHOD: Confidential telephone interviews of stratified national probability samples of first- and fourth-year medical students and residents were conducted in 1994 and 1997. The 1997 survey included 219 students and 241 residents who had also been interviewed in 1994. Participants were asked about their attitudes toward addressing psychosocial issues in medicine and their perceptions of faculty and peer attitudes toward primary care. Responses were compared over time and across groups. RESULTS: Between the first and fourth years of medical school, there was a decline over time in students' reported orientations to socioemotional aspects of patient care (61.6% versus 42.7%, p =.001) and their perceptions that working with psychosocial issues of patients made primary care more attractive (56.3% versus 43.5%, p =.01). This pattern continued for 1997 residents (PGY-3), who were even less likely to say that addressing psychosocial issues made primary care more attractive (26.9%). For fourth-year students in 1994 who became PGY-3 residents in 1997, there was an increased perception that non-primary-care house officers and specialty faculty had positive attitudes toward primary care (20.8% versus 33.0%, p =.005; 28.3% versus 45.7%, p <.0001; respectively). CONCLUSIONS: Between 1994 and 1997 students and residents perceived a positive shift in the attitudes of peers and faculty toward primary care. During the course of their education and training, however, the students experienced an erosion of their orientations to primary care as they progressed through medical school into residency.

Incidence of coagulase positive Staphylococcus on beef carcasses in three Australian abattoirs.

The contamination of beef carcasses with coagulase-positive staphylococci (CPS) was studied at three beef abattoirs (A, B and C). The incidence and the number of CPS were determined on cattle hides immediately after slaughter and on three carcass sites (brisket, flank and round) at different points during processing along the slaughter line. The incidence of CPS on cattle hides ranged from 20 to 68.6%. At abattoir A, 6.5% of the carcasses sampled before evisceration were contaminated with CPS, compared to 40% of the carcasses after evisceration. The incidence on carcasses changed little during further processing; however, after chilling for 72 h, the incidence increased to 83%. After evisceration, the brisket and flank areas were more often contaminated than the round. A similar pattern of contamination was observed at abattoir B. At abattoir C, 26.7% of the samples collected before evisceration were contaminated and this fell to 16.7% after evisceration. After chilling for 72 h, the incidence of carcass contamination with CPS increased to 46.7%. The average number of CPS on contaminated carcasses prior to and after overnight chilling was less than 50 colony-forming units (cfu)/cm2 and, after weekend chilling, increased to 64 and 112 cfu/cm2 in abattoirs A and B, respectively. Of the isolates tested, 71.4% produced staphylococcal enterotoxin and 21% could not be classified phenotypically. The hands of workers and environmental sites associated with the evisceration process were examined for CPS at abattoir A. Hands were heavily contaminated and were the likely source of CPS contamination at this abattoir.

Attitudes about end-of-life care: a national cross-sectional study.

BACKGROUND: Major concerns have been expressed about the preparation of physicians to provide end-of-life care. Little is known about how well academic health centers prepare students and residents to care for patients at the end-of-life and about the values about end-of-life care transmitted by faculty. METHODS: In 1997, we conducted a telephone survey of a nationally representative sample of first-year medical students (n = 287), fourth-year medical students (n = 173), residents (n = 473), clinical faculty (n = 728), internal medicine residency training directors (n = 143), department chairs (n = 186), and medical school deans (n = 101) within U.S. academic health centers (response rate = 80.2%). RESULTS: U.S. medical students, residents and faculty evaluate themselves as inadequately prepared to provide end-of-life care. Academic health center constituents perceive that providing care at the end of life requires medium to high levels of expertise. Academic health center constituents are divided about whether responsibility for providing care at the end of life rests with generalists or with specialists and view managed care as nearly equivalent to the fee-for-service sector in its capacity to provide excellent end-of-life care. CONCLUSIONS: Academic leaders and faculty, as well as their students, lack confidence in their own skills in providing end-of-life care. They also question the ability of the current and evolving health care delivery system to provide excellent end-of-life care.