Microsporidia: emerging ocular pathogens

Microsporidia are eukaryotic, spore forming obligate intracellular parasites, first recognized over 100 years ago. Microsporidia are becoming increasingly recognized as infectious pathogens causing intestinal, ocular, sinus, pulmonary, muscular and renal diseases, in both immunocompetent and immunosuppressed patients. Ocular microsporidiosis, though uncommon, could be isolated or part of systemic infections. It occurs mainly in two forms: keratoconjunctivitis form, mostly seen in immunocompromised individuals; stromal keratitis form seen in immunocompetent individuals. Recent reports indicate increasing number of cases of ocular microsporidiosis in immunocompetent individuals. The ocular cases present as superficial keratitis in AIDS patients, and these differ in presentation and clinical course from the cases seen in immunocompetent individuals which mainly appear to be as deep stromal keratitis. For most patients with infectious diseases, microbiological isolation and identification techniques offer the most rapid and specific determination of the etiologic agent, however this does not hold true for microsporidia, which are obligate intracellular parasites requiring cell culture systems for growth. Therefore, the diagnosis of microsporidiosis currently depends on morphological demonstration of the organisms themselves, either in scrapings or tissues. Although the diagnosis of microsporidiosis and identification of microsporidia by light microscopy have greatly improved during the last few years, species differentiation by these techniques is usually impossible and electron microscopy may be necessary. Immuno fluorescent-staining techniques have been developed for species differentiation of microsporidia, but the antibodies used in these procedures are available only at research laboratories at present. During the last 10 years, molecular techniques have been developed for the detection and species differentiation of microsporidia.

Pancam multispectral imaging results from the Opportunity Rover at Meridiani Planum

Panoramic Camera (Pancam) images from Meridiani Planum reveal a low-albedo, generally flat, and relatively rock-free surface. Within and around impact craters and fractures, laminated outcrop rocks with higher albedo are observed. Fine-grained materials include dark sand, bright ferric iron-rich dust, angular rock clasts, and millimeter-size spheroidal granules that are eroding out of the laminated rocks. Spectra of sand, clasts, and one dark plains rock are consistent with mafic silicates such as pyroxene and olivine. Spectra of both the spherules and the laminated outcrop materials indicate the presence of crystalline ferric oxides or oxyhydroxides. Atmospheric observations show a steady decline in dust opacity during the mission. Astronomical observations captured solar transits by Phobos and Deimos and time-lapse observations of sunsets.

Pancam multispectral imaging results from the Spirit Rover at Gusev Crater

Panoramic Camera images at Gusev crater reveal a rock-strewn surface interspersed with high- to moderate-albedo fine-grained deposits occurring in part as drifts or in small circular swales or hollows. Optically thick coatings of fine-grained ferric iron-rich dust dominate most bright soil and rock surfaces. Spectra of some darker rock surfaces and rock regions exposed by brushing or grinding show near-infrared spectral signatures consistent with the presence of mafic silicates such as pyroxene or olivine. Atmospheric observations show a steady decline in dust opacity during the mission, and astronomical observations captured solar transits by the martian moons, Phobos and Deimos, as well as a view of Earth from the martian surface.

Pancam multispectral imaging results from the Spirit Rover at Gusev Crater

Panoramic Camera images at Gusev crater reveal a rock-strewn surface interspersed with high- to moderate-albedo fine-grained deposits occurring in part as drifts or in small circular swales or hollows. Optically thick coatings of fine-grained ferric iron-rich dust dominate most bright soil and rock surfaces. Spectra of some darker rock surfaces and rock regions exposed by brushing or grinding show near-infrared spectral signatures consistent with the presence of mafic silicates such as pyroxene or olivine. Atmospheric observations show a steady decline in dust opacity during the mission, and astronomical observations captured solar transits by the martian moons, Phobos and Deimos, as well as a view of Earth from the martian surface.

Complete genomic sequence of Pepper vein banding virus (PVBV): a distinct member of the genus Potyvirus

The complete genomic sequence of Pepper vein banding virus (PVBV), a potyvirus infecting chilli and other solanaceous plants in south India, was determined and compared with those of other potyviruses. The viral genome contained 9711 nucleotides, excluding the poly-A tail. The length of the 5'- and 3'-untranslated regions (UTR) were 163 and 281 nucleotides respectively. As for other potyviruses, the PVBV genome has a single open reading frame (ORF) starting at nucleotide 164 and ending at nt 9430, which encodes a polyprotein of 3088 amino acid residues. There are nine putative conserved cleavage sites within the polyprotein, which can result in ten functionally distinct protein products. Phylogenetic analysis of the potyviral polyprotein sequences showed that PVBV is a distinct species of this genus.

Effects of neurotransmitters on the chemokinesis and chemotaxis of MDA-MB-468 human breast carcinoma cells

Most patients suffering from breast carcinoma do not die due to the primary tumor but from the development of metastases. Active migration of cancer cells is a prerequisite for development of these metastases. We used time-lapse videomicroscopy and computer-assisted cell tracking of MDA-MB-468 human breast carcinoma cells, which were incorporated into a three-dimensional collagen matrix, in order to analyze the migratory activity of these cells in response to different neurotransmitters. Our results show that met-enkephalin, substance P, bombesin, dopamine, and norepinephrine have a stimulatory effect on the migration of the breast cancer cells; moreover, these cells show positive chemotaxis towards norepinephrine as was analyzed by the directionality and persistence on a single-cell basis. Gamma-aminobutyric acid (GABA) however has an inhibitory effect. Endorphin and leu-enkephalin, as well as histamin and acetylcholine, had no influence on the migratory activity of the cells. In summary, we provide evidence for a strong regulatory involvement of neurotransmitters in the regulation of breast cancer cell migration, which might provide the basis for the use of the pharmacological agonists and antagonists for the chemopreventive inhibition of metastasis development.

Effects of fruits and vegetables on levels of vitamins E and C in the brain and their association with cognitive performance

Demographic trends, together with improvements in general health and life expectancy, will greatly change the population structures of most industrialized and developing countries during the next 50 years. By 2050, approximately 30% of people in industrialized countries will be 65 years old or older. Aging is associated with increased risk for neurodegenerative disorders, which can cause significant cognitive and physical impairment and shortened lifespan, thereby causing a burden to society. Diets rich in fruits and vegetables have been shown to improve human well-being and to significantly delay the development of pathologic processes, including neurodegenerative disorders. Foods are important sources of micronutrients, including vitamins E and C, which play crucial roles in optimal cell function. Vitamin E is an important component of biologic membranes, and vitamin C acts as a cosubstrate for several enzymes. Both E and C are involved in the antioxidant defense of cells and actively contribute to the redox status of the cell. The levels of vitamins E and C provided by diet vary significantly. Vegetable oils, nuts and seeds are the main dietary sources of vitamin E, whereas fruits and vegetable are the primary sources of vitamin C. Human trials of varying doses of vitamins E and C, including low, supplemental, and pharmacologic, have found that these nutrients may improve immunity, vascular function, and brain performance. An optimal intake of these nutrients has been associated with decreased risk of developing cognitive impairments associated with aging. This paper will review the scientific literature on the sources, tissue levels and roles of vitamins E and C in cognitive performance and pathologic processes of the central nervous system in the elderly.

Dental caries prevalence and experience among the group of institutionalized hearing impaired individuals in Pondicherry--a descriptive study

A descriptive study was conducted among a group of hearing-impaired individuals in Pondicherry to assess the dental caries prevalence and experience. A total 114 individuals were examined. The data was collected by direct clinical examination using appropriate indices and findings were recorded on the proforma sheets. The data were statistically processed and the results were obtained. Prevalence of dental caries in terms of DMFT is 42.98% and dft is 45%. Mean dft +/- s.d is 1.2 +/- 1.38 and Mean DMFT +/- s.d is 1.0 +/- 1.42. It was concluded that in both permanent and deciduous dentition and the females have high caries prevalence.

"Anti-intellectualism" and genetics

The 2001 claim by Eigenberger and Sealander that "anti-intellectualism" has an important genetic component is discussed in reference to a rejoinder by Howley.

Open access follow-up for lung cancer: patient and staff satisfaction

The majority of patients with lung cancer have incurable disease from presentation and a survival measured in months. Treatments offered to these patients are aimed at the palliation of symptoms with either radiotherapy or chemotherapy, or with supportive measures. It has been traditional to offer regular outpatient follow-up after initial palliative treatment. Further treatment options, which may be limited, are usually reserved for the recurrence of troublesome symptoms. A pilot 'open access' lung cancer clinic has been set up. Rather than have regular follow-up at the hospital, patients who have completed initial palliative treatments are discharged to the community with follow-up by their general practitioner and Macmillan nurse. Review at the open access clinic can be arranged at short notice if requested by the patient, carers, general practitioner or Macmillan nurse. The outcomes and level of satisfaction of patients, their relatives and staff to this method of follow-up were found to be positive. Open access follow-up may be useful for many patients after the completion of initial palliative treatment.

Increased mortality in women with cataract: a population based follow up of the North London Eye Study

BACKGROUND/AIMS

In diabetics, cataract is associated with higher risk of death. In non-diabetics the data are conflicting, but some indicate an association between one type of cataract (nuclear) and increased mortality. The aim of this study was to estimate and compare age and sex specific mortality for elderly people with and without cataract in a population based cohort.

METHODS

A random sample drawn from a defined population of elderly people (age 65 and older) registered with 17 general practice groups in north London formed the study cohort and were followed up for 4 years. The age and sex specific mortality from various causes was estimated and compared in those with and without cataract.

RESULTS

In non-diabetics (n=1318), cataract (lens opacity at baseline) was significantly associated with higher mortality in women. The age standardised death rate per 1000 was 39.8 and 24.8 in women with and without cataract, respectively (age adjusted hazard ratio 1.7, confidence limits 1.1 to 2.7, p=0.032). This was not the case in non-diabetic men (hazard ratio 0.9, confidence limits 0.6 to 1.5, p=0.782). The excess mortality in women with cataract was consistent for cardiovascular, respiratory, and other non-cancer causes of death. There was no association between cataract and mortality from cancer.

CONCLUSIONS

This study has shown, for the first time, that cataract is associated with higher mortality in women but not in men, among the non-diabetic population. This sex effect suggests that women may be exposed to risk factors that increase both the risk of cataract and mortality, and that men may have little or no exposure to these "sex specific" factors. Possible risk factors that warrant further investigation may be those associated with some pregnancy and childbearing experience.

Doxorubicin-induced apoptosis is associated with increased transcription of endothelial nitric-oxide synthase. Effect of antiapoptotic antioxidants and calcium

The clinical efficacy of the antitumor antibiotic drug doxorubicin (DOX) is severely limited by its dose-limiting cardiotoxicity in cancer patients. DOX-induced generation of reactive oxygen species was proposed to be a major mechanism of its cardiotoxicity. Previously, we showed that DOX undergoes a reductive activation at the reductase domain of endothelial nitric-oxide synthase (eNOS) forming the semiquinone and superoxide (Vásquez-Vivar, J., Martasek, P., Hogg, N., Masters, B. S. S., Pritchard, K. A., Jr., and Kalyanaraman, B. (1997) Biochemistry 36, 11293-11297). In this report, we provide evidence for DOX-induced increase in eNOS transcription and protein expression in bovine aortic endothelial cells (BAEC). We propose that DOX-induced hydrogen peroxide formation is responsible for the increased transcription of eNOS. BAEC treated with antisense eNOS oligonucleotide inhibits DOX-induced endothelial apoptosis. Treatment with antioxidants restored the levels of antiapoptotic proteins (Hsp70 and Bcl-2) in DOX-treated BAEC. DOX-induced intracellular oxidative stress, as measured by oxidation of dichlorodihydrofluorescein diacetate to dichlorofluorescein and hydroethidium to ethidium, was inhibited by antisense eNOS oligonucleotide and antioxidant treatment. Furthermore, antiapoptotic antioxidants (e.g. FeTBAP, ebselen, and alpha-phenyl-tert-butyl nitrone) inhibited DOX-induced eNOS transcription. We conclude that DOX-induced apoptosis is linked to the redox activation of DOX by eNOS.

Inhibition of LOX-1 by statins may relate to upregulation of eNOS

LOX-1, a receptor for oxidized low-density lipoprotein (ox-LDL), plays a critical role in endothelial dysfunction and atherosclerosis; both of these conditions are associated with diminished expression of constitutive endothelial nitric oxide synthase (eNOS). Recent studies show that HMG CoA reductase inhibitors (statins) exert cardioprotective effect. We examined the role of LOX-1 in eNOS expression and modulation of this relationship by two different statins, simvastatin and atorvastatin in human coronary artery endothelial cells (HCAECs). Ox-LDL (40 microg/ml) upregulated the expression of LOX-1; simultaneously, there was a reduction in eNOS expression. Pretreatment of HCAECs with simvastatin or atorvastatin (1 and 10 microM) reduced ox-LDL-induced upregulation of LOX-1 and downregulation of eNOS (both P < 0.05). High concentration of statins (10 microM) was more potent than the low concentration (1 microM) (P < 0.05). Both statins also attenuated ox-LDL-mediated activation of MAP kinase. These observations indicate that statins attenuate the effect of ox-LDL on eNOS expression. Inhibitory effect on LOX-1 and subsequently MAP kinase activity provides a potential mechanism of beneficial effects of statins beyond lowering cholesterol.

Clinical practice guidelines in the nursing home

Clinical practice guidelines are an important tool for improving quality of care. This study determined whether and how guidelines are being used in nursing homes. We surveyed staff at 36 Department of Veterans Affairs (VA) nursing homes. Employees were asked whether they were familiar with guidelines as well as whether 5 specific guidelines had been read, were available, and had been adopted. Among 1065 respondents (60% of those surveyed), 79% reported familiarity with guidelines. The proportion of staff at a facility reporting adoption was generally less than 50%. Those nursing homes in which a high percentage of the staff reported adoption of one guideline were more likely to have adopted other guidelines. However, staff were not more likely to report adoption of a specific guideline when the nurse manager stated that it was adopted. We conclude that staff at VA nursing homes are familiar with guidelines. Guideline adoption at individual nursing homes, however, is not a systematic process involving the entire staff.