727 research outputs found

    Control of cytosolic free calcium in rat and chicken osteoclasts. The role of extracellular calcium and calcitonin.

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    Single cell [Ca2+], studies were performed in chicken and rat osteoclasts loaded with fura-2 and exposed to a variety of treatments. Under resting conditions, basal [Ca2+]i, was 79.2 +/- 47.3 and 84.3 +/- 65.7 nM (averages +/- S.D.; n = 141 and 126) in the osteoclasts of the two species, respectively. Basal [Ca2+]i was stable in all rat and in approximately 80% of chicken osteoclasts. In the remaining 20%, spontaneous, irregular [Ca2+], fluctuations were observed (amplitude range: 50-200 nm over basal values). Increase of [Ca2+]o over the concentration of the Krebs-Ringer incubation medium (2 mM) induced rises of [Ca2+] in almost all cells investigated. [Ca2+] rises were already appreciable with 0.5 mM [Ca2+]o additions and reached high values with 4 mM additions: 390 +/- 113 and 364 +/- 214 nM [Ca2+], in rat and chicken osteoclasts, respectively (n = 122 and 101). Qualitatively, the responses to [Ca2+]o additions consisted of discrete [Ca2+]i transients, biphasic (an initial spike followed by a plateau), or monophasic (either the spike or the plateau). In a few chicken osteoclasts, the [Ca2+]i increase occurring after [Ca2+]o addition consisted of multiple, irregular fluctuations, similar to those observed in 20% of these cells under resting conditions. In individual osteoclasts subsequently exposed to multiple [Ca2+]o increase pulses, the type of the [Ca2+]i transient (mono- or biphasic) was maintained, and the size was dependent on the magnitude of the [Ca2+]o additions. Effects similar to those of [Ca2+]o were induced by the addition of Cd2+ or Ba2+ (but not La3+ or Mg2+) into the medium. The Cd2+ effect was maintained in part even in a Ca2+-free medium. Of various hormones and factors, parathormone, 1,25-dihydroxyvitamin D3, and prostaglandin E2 were inactive. In contrast, calcitonin was active in rat osteoclasts (which express numerous receptors). [Ca2+]i increases were small (19 +/- 17.9 nM; n = 21) when the hormone was administered alone; they were synergistic (severalfold potentiation) when the hormone was administered before or after [Ca2+]o. The [Ca2+]i effects of calcitonin were mimicked by 8Br-cAMP (31 +/- 26 nM; n = 12) when the nucleotide was administered alone; marked synergism when it was administered in combination with [Ca2+]o. This paper demonstrates for the first time that changes of [Ca2+]i are induced in osteoclasts by treatments with [Ca2+]o and calcitonin and can therefore be involved in intracellular mediation of the physiological effects of these two extracellular signals

    Uji Daya Hambat Ekstrak Etanol Daun Srikaya (Annona Squamosa) Terhadap Pertumbuhan Bakteri Escherichia Coli Dan Staphylococcus Aureus

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    : Srikaya leaf contains terpenoid, polyphenol, alkaloid, and flavonoid that can potentially be an antibacterial. This study was aimed to obtain the potency of srikaya leaf extract against Staphylococcus aureus (ATCC25923) and Escherichia coli (ATCC11229). This was an experimental laboratory study using the Kirby-Bauer modified well diffusion technique in the Phytochemistry and Microbiology Laboratory of MIPA Faculty at Sam Ratulangi University. Srikaya leaf extract was obtained by using ethanol maceration technique. The concentrations of the extract were as follows: 50%, 25%, and 12.5%. Ciprofloxacin was used as the positive control while CMC as the negative one. The results showed that CMC did not have any inhibition zone around the well. Ciprofloxacin showed the largest mean diameters of inhibition zones: 35.78 mm against E.coli and 36.55 mm against S.aureus. The mean diameters of inhibition zones of Srikaya leaf extract 50% were 9.13 mm against E.coli and 13.78 mm against S.aureus. The mean diameters of inhibition zones of Srikaya leaf extract 25% were 7.8 mm against E.coli and 13.55 mm agaisnt S.aureus. Meanwhile, the mean diameters of inhibition zones of srikaya leaf extract 12.5% were 7.05 mm against E.coli and 11.31mm agaimst S.aureus. Conclusion: Srikaya leaf extract could potentially inhibit the growth of S.aureus and E.coli. The srikaya leaf extract could inhibit S.aureus more effectively than E.coli

    The Evaluation of Metals and Other Substances Released into Coal Mine Accrual Waters on the Wasatch Plateau Coal Field, Utah

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    Six sites on the Wasatch Plateau were chosen representing subsurface coal mines which were discharging or collecting accrual water on this coal field. Water samples were collected monthly at these sites for a period of 1 year (May 1981 to April 1982). Samples were taken before and after each mine\u27s treatment system. Water sampels were analyzed for major anions and cations, trace metals, physical properaties, nutrients, total organic carbon, oil and grease, trihalomethanes, and algal assay. Predictions were made as to the possible effects these coal mine accrual waters would have when used for drinking water, irrigation water, stock and wildlife watering, and as discharges into freshwater aquatic ecosystems. Compliance of the mine water discharges with NPDES regulations was also noted. Crushed coal samples were obtained from each of the six mine sites and evaluated with regard to their leaching characteristics in laboratory upflow leaching columns using an aqueous leaching medium characteristic of the area\u27s water supplies. Leachate samples were anlyzed for major anions and cations, trace metals, physical properaties, and total organic carbon. laboratory leaching characteristics were compared to the chemical nature of the actual mine water discharges. Mine water discharges were not found to be acidic in nature, the values for most parameters monitored during the field and laboratory portions of the study fell below the toxicity criteria for uses mentioned above, and were generally in compliance with NPDES regulations. Boron was present in the mine waters, but at levels which would be predicted to cause only minor or no damage to the most sensitive crops. The drinking water limit and the freshwater aquatic life bioaccumulation criterion for mercury were exceeded on several occasions in the coal mine accrual waters sampled. A comprehensive study of fish tissue samples and water samples taken from bodies of water near coal mines is recommended. Total suspended solids (TSS) and oil and grease were among the most frequently violated parameters with regard to NPDES regulations. Further studies are recommended with regard to the effects of these substances on stream biota, their sources and their rate in aquatic ecosystems. Coal leaching trends in the laboratory column experiments pralleled many of the trends observed in the field data collected. Trends for pH, aluminum, arsenic, beryllium, cadmium, chromium, cobalt, copper, iron, lead, molybdenum, nickel, silver, zinc, boron, lithium, strontium, alkalinity, chloride, cluoride, potassium, sodium, and silica were generally consistent when these comparisons were made. Values for water hardness parameters were observed to be specific to the mine site involved and not always comparable to laboratory leachate column data. Generalizations with respect to leaching trends and origins of chemical substances in coal mine accrual waters must be made with caution due to the great potential variability in coal samples and the complexity of leaching phenomena

    Uveitis causes according to immune status of patients

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    Purpose: The advances in medicine have led to an increased number of people living with some form of immunodeficiency. Most ocular infections in immunocompromised patients may lead to irreversible blindness. We identify the causes of uveitis in immunocompetent and immunocompromised patients. Methods: A retrospective cohort study of 1354 consecutive patients. All patients underwent a standard work-up for uveitis. Results: An immunocompromised state was identified in 171/1354 patients (13%), of whom 40 had Human immunodeficiency virus (HIV) infection, 52 received immunosuppressive medications, 28 had concurrent malignant disorder and 20 had other causes for their immunosuppression. In addition, 93/1354 patients (7%) had diabetes mellitus (DM). The prevalence of intraocular infections was much higher in immunocompromised patients than in immunocompetent patients and DM (p < 0.001). Causes of uveitis differed between the diverse immunocompromised groups. The non-HIV immunocompromised patients showed primarily intraocular herpes simplex and varicella zoster virus infections, whilst HIV-positive patients exhibited frequently cytomegalovirus (CMV) retinitis and syphilis. Patients with generalized malignancies were characterized by a lower prevalence of infections and higher prevalence of sarcoidosis. Patients with DM typically showed sarcoidosis and bacterial intraocular infections. The percentage of undetermined uveitis diagnoses was markedly lower in immunosuppressed patients (p < 0.001). Conclusion: In immunocompromised patients with uveitis, infections were diagnosed in 46% of cases in contrast to 12% in the immunocompetent patients. The causes of uveitis differed among the various types of immunosuppression. Immunocompromised patients with uveitis require a rapid assessment for the

    Olig2-Regulated Lineage-Restricted Pathway Controls Replication Competence in Neural Stem Cells and Malignant Glioma

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    Recent studies have identified stem cells in brain cancer. However, their relationship to normal CNS progenitors, including dependence on common lineage-restricted pathways, is unclear. We observe expression of the CNS-restricted transcription factor, OLIG2, in human glioma stem and progenitor cells reminiscent of type C transit-amplifying cells in germinal zones of the adult brain. Olig2 function is required for proliferation of neural progenitors and for glioma formation in a genetically relevant murine model. Moreover, we show p21^(WAF1/CIP1), a tumor suppressor and inhibitor of stem cell proliferation, is directly repressed by OLIG2 in neural progenitors and gliomas. Our findings identify an Olig2-regulated lineage-restricted pathway critical for proliferation of normal and tumorigenic CNS stem cells

    Differences in clinical presentation of primary open-angle glaucoma between African and European populations

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    PURPOSE: Primary open‐angle glaucoma (POAG) has been reported to occur more frequently in Africans, and to follow a more severe course compared to Europeans. We aimed to describe characteristics of POAG presentation and treatment across three ethnic groups from Africa and one from Europe. METHODS: We ascertained 151 POAG patients from South African Coloured (SAC) and 94 South African Black (SAB) ethnicity from a university hospital in South Africa. In Tanzania, 310 patients were recruited from a university hospital and a referral hospital. In the Netherlands, 241 patients of European ancestry were included. All patients were over 35 years old and had undergone an extensive ophthalmic examination. Patients were diagnosed according to the ISGEO criteria. A biogeographic ancestry analysis was performed to estimate the proportion of genetic African ancestry (GAA). RESULTS: The biogeographic ancestry analysis showed that the median proportion of GAA was 97.6% in Tanzanian, 100% in SAB, 34.2% in SAC and 1.5% in Dutch participants. Clinical characteristics at presentation for Tanzanians, SAB, SAC and Dutch participants, respectively: mean age: 63, 57, 66, 70 years (p < 0.001); visual acuity in the worse eye: 1.78, 1.78, 0.3, 0.3 LogMAR (p < 0.001); maximum intraocular pressure of both eyes: 36, 34, 29, 29 mmHg (p (anova)  < 0.001); maximum vertical cup to disc ratio (VCDR) of both eyes: 0.90, 0.90, 0.84, 0.83 (p < 0.001); mean central corneal thickness: 506, 487, 511, 528 μm (p < 0.001). Fourteen percent of Tanzanian patients presented with blindness (<3/60 Snellen) in the better eye in contrast to only 1% in the Dutch. CONCLUSION: In this multi‐ethnic comparative study, Sub‐Saharan Africans present at a younger age with lower visual acuity, higher IOP, larger VCDR, than SAC and Dutch participants. This indicates the more progressive and destructive course in Sub‐Saharan Africans
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