A Study of the Role of Small Ethnic Retail Grocery Stores in Urban Renewal in a Social Housing Project, Toronto, Canada.

Urban renewal often drives away the original residents, replacing them with higher income residents who can afford the new spaces, leading to gentrification. Urban renewal that takes place over many years can create uncertainties for retailers and residents, exacerbating the gentrification process. This qualitative study explored how the urban renewal process in a multi-cultural social housing neighborhood in Toronto (Regent Park) affected the small ethnic retail grocery stores (SERGS) that supplied ethnic foods and items to the ethnic populations living there. Interviews were conducted with ten SERGS store owners/managers and 16 ethnic residents who lived in Regent Park before renewal and were displaced, or who were displaced and returned. The SERGS stated that they provided culturally familiar items and offered a social credit scheme that recognized existing social relationships and allowed low-income residents to afford food and other amenities in a dignified manner and pay later, without penalty or interest. At the same time, the SERGS were unsupported during the renewal, were excluded from the civic planning processes, could not compete for space in the new buildings, and experienced declining sales and loss of business. The residents stated that the SERGS were trusted, provided a valued cultural social spaces for ethnic identity formation, and ethnic food security but they faced many uncertainties about the role of SERGS in a renewed neighborhood. Based on this study, it is recommended that ethnic retailers be recognized for the role they play in formulating ethnic identities and food security in mixed-use mixed-income communities and that they be included in planning processes during urban renewal. Such recognition may enable more former residents to return and lessen the gentrification.

An unexpectedly rapid decline in the X-ray afterglow emission of long gamma-ray bursts.

'Long' gamma-ray bursts (GRBs) are commonly accepted to originate in the explosion of particularly massive stars, which give rise to highly relativistic jets. Inhomogeneities in the expanding flow result in internal shock waves that are believed to produce the gamma-rays we see. As the jet travels further outward into the surrounding circumstellar medium, 'external' shocks create the afterglow emission seen in the X-ray, optical and radio bands. Here we report observations of the early phases of the X-ray emission of five GRBs. Their X-ray light curves are characterised by a surprisingly rapid fall-off for the first few hundred seconds, followed by a less rapid decline lasting several hours. This steep decline, together with detailed spectral properties of two particular bursts, shows that violent shock interactions take place in the early jet outflows.

Under-the-Mango-Tree: a theatre-based male EMTCT engagement intervention in post-conflict northern Uganda.

Male involvement in human immunodeficiency virus (HIV) care cascades is identified as a critical prerequisite for the successful elimination of mother-to-child transfer of HIV. Scant evidence exists on efficacious culturally appropriate and male-inclusive elimination of mother-to-child transfer interventions. This reflection-in-action paper highlights field notes and observations of the development of Under-the- Mango-Tree, a theatre-based male-inclusive intervention pilot tested in northern Uganda. The intervention included: (a) traditional drama, dances and songs and (b) expert testimonies and group dialogue. Observations in this pilot showed that a theatre-based intervention was suitable for social persuasion; role modelling and moderating mastery of experience through effectively combining simple songs, dances and drama; testimonies of successful adherence by expert clients; and through reflective group discussions. These observations have implications for male-inclusive elimination of mother-to-child transfer intervention development.

The Notch pathway mediates expansion of a progenitor pool and neuronal differentiation in adult neural progenitor cells after stroke.

Molecular mechanisms by which stroke increases neurogenesis have not been fully investigated. Using neural progenitor cells isolated from the subventricular zone (SVZ) of the adult rat subjected to focal cerebral ischemia, we investigated the Notch pathway in regulating proliferation and differentiation of adult neural progenitor cells after stroke. During proliferation of neural progenitor cells, ischemic neural progenitor cells exhibited substantially increased levels of Notch, Notch intracellular domain (NICD), and hairy enhancer of split (Hes) 1, which was associated with a significant increase of proliferating cells. Blockage of the Notch pathway by short interfering ribonucleic acid (siRNA) against Notch or a gamma secretase inhibitor significantly reduced Notch, NICD and Hes1 expression and cell proliferation induced by stroke. During differentiation of neural progenitor cells, Notch and Hes1 expression was downregulated in ischemic neural progenitor cells, which was coincident with a significant increase of neuronal population. Inhibition of the Notch pathway with a gamma secretase inhibitor further substantially increased neurons, but did not alter astrocyte population in ischemic neural progenitor cells. These data suggest that the Notch signaling pathway mediates adult SVZ neural progenitor cell proliferation and differentiation after stroke.

Percutaneous transluminal coronary angioplasty in women compared with men.

OBJECTIVES: This study compares in-hospital and long-term outcome after angioplasty in women and men. BACKGROUND: The recognition that coronary artery disease is the most common cause of death in women has increased interest in outcome studies of coronary artery disease in women. METHODS: Patients who had previous coronary revascularization and those who underwent angioplasty in the setting of acute myocardial infarction were excluded. Angioplasty was performed with standard methods. Clinical data were retrieved from a clinical data base and analyzed with standard statistical methods. RESULTS: There were 2,845 women and 7,940 men. The women were older (62 +/- 11 vs. 57 +/- 10 years) and had more hypertension (54.5% vs. 40.1%), diabetes (19.3% vs. 11.7%), grade III to IV angina (71.5% vs. 58.4%) and congestive failure (4.3% vs. 2.1%) than men (all p < 0.0001). More men had a previous myocardial infarction (35.4% vs. 31.0%) and were taller and weighed more (all p < 0.0001). The men had lower ejection fractions and more multivessel disease (31.0% vs. 25.2%) (both p < 0.0001). In women there was a trend toward more Q wave myocardial infarctions (1.1% vs. 0.75%, p = 0.10), and hospital mortality was higher (0.7% vs. 0.1%, p < 0.0001). Angina at follow-up was more common in women 40.2% vs. 26.7%, p < 0.0001). The multivariate correlates of in-hospital death were short stature, reduced ejection fraction and multivessel disease, with trends for older age and female gender. Five-year survival was 95% in men and 92% in women (p = 0.0002). However, female gender was not a multivariate correlate of long-term survival and was accounted for by other characteristics, primarily age. The multivariate correlates of long-term survival were older age, congestive failure, reduced ejection fraction, multivessel disease, diabetes, hypertension and a trend for severe angina. No difference between women and men was noted in long-term freedom from myocardial infarction. There were more additional procedures in men than in women. CONCLUSIONS: Despite higher in-hospital mortality, long-term mortality and clinical outcome were similar in both genders when age and body habitus were accounted for.

Contemporary reperfusion therapy for cardiogenic shock: the GUSTO-I trial experience. The GUSTO-I Investigators. Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries.

OBJECTIVES: This study sought to examine the incidence, temporal profile and clinical implications of shock in a large trial of thrombolytic therapy for acute myocardial infarction. BACKGROUND: Despite advances in the treatment of acute ischemic syndromes, cardiogenic shock remains associated with significant morbidity and mortality. METHODS: Patients who presented within 6 h of symptom onset were randomized to four treatment strategies: 1) streptokinase plus subcutaneous heparin; 2) streptokinase plus intravenous heparin; 3) accelerated recombinant tissue-type plasminogen activator (rt-PA) plus intravenous heparin; or 4) streptokinase and rt-PA plus intravenous heparin. The primary end point was 30-day all-cause mortality. RESULTS: Shock occurred in 2,972 patients (7.2%): 315 (11%) had shock on arrival, and 2,657 (89%) developed shock after hospital admission. Reinfarction occurred in 11% of patients who developed shock compared with 3% of patients without shock. The mortality rate was significantly higher in patients who presented with (57%) or developed (55%) shock than in those without shock (3%) (p < 0.001). Shock developed significantly less frequently in patients receiving rt-PA. There were fewer deaths in patients who presented with shock and were treated with streptokinase plus intravenous heparin or who developed shock and were treated with streptokinase plus subcutaneous heparin. Patients who developed shock had a significantly lower 30-day mortality rate if angioplasty was performed. CONCLUSIONS: Because cardiogenic shock occurred most often after admission and with recurrent ischemia and reinfarction, recognizing signs of incipient shock may improve outcome. Fewer patients treated with rt-PA developed shock, yet those developing shock had the same high mortality rate as those presenting with shock, regardless of treatment. Only angioplasty was associated with a significantly lower mortality rate.

Outcome of coronary bypass surgery versus coronary angioplasty in diabetic patients with multivessel coronary artery disease.

OBJECTIVES: This study sought to compare the outcome of percutaneous transluminal coronary angioplasty (PTCA) (n = 834) and coronary artery bypass graft surgery (CABG) (n = 1805) in diabetic patients with multivessel coronary disease from an observational database. BACKGROUND: There is concern about selection of revascularization in diabetic patients with multivessel coronary artery disease. METHODS: Data were collected prospectively and entered into a computerized database. Follow-up was by letter or telephone or additional events resulting in readmission. RESULTS: After CABG there were more in-hospital deaths (0.36% vs. 4.99%, p < 0.0001) and a trend toward more Q wave myocardial infarctions than after PTCA. Five- and 10-year survival rates were 78% and 45% after PTCA and 76% and 48% after CABG, respectively (p = 0.47). At 5 and 10 years, insulin-requiring patients had lower survival rates of 72% and 31% after PTCA and 70% and 48% after CABG, respectively (p = 0.54). Multivariate correlates of long-term mortality were older age, low left ventricular ejection fraction, heart failure and hypertension. In the total group, insulin requirement was a correlate of long-term mortality. For the total group, choice of therapy had a multivariate hazard ratio close to 1. In the insulin-requiring subgroup, the multivariate hazard ratio was 1.35 (95% confidence interval 1.01 to 1.79) for PTCA versus CABG. Corrected for baseline differences, 5- and 10-year survival rates were 68% and 36% after PTCA and 75% and 47% after CABG, respectively, in the insulin-requiring subgroup. Nonfatal events were more common after PTCA, especially additional revascularization. CONCLUSIONS: This study reveals a high incidence of events in diabetic patients and raises further questions about angioplasty in insulin-requiring diabetic patients with multivessel disease.

A multicenter, randomized, placebo-controlled trial of a new form of intravenous recombinant tissue-type plasminogen activator (activase) in acute myocardial infarction.

A new, predominantly single chain preparation of recombinant tissue-type plasminogen activator was evaluated to determine coronary thrombolytic efficacy in 100 patients with acute myocardial infarction. At 3.6 +/- 1.2 hours (mean +/- SD) from symptom onset, patients received either intravenous tissue plasminogen activator (1.25 mg/kg body weight over 3 hours) or placebo on a 3:1 randomized, double-blind basis. Coronary angiography, performed 68 +/- 13 minutes after initiation of the study drug infusion, demonstrated patency of the infarct-related artery in 40 (57%) of 70 patients in the tissue plasminogen activator group compared with 3 (13%) of 23 patients in the placebo group (p less than 0.001). Patients in the placebo group were then eligible to receive intracoronary streptokinase. At 90 minutes the patency was observed in 49 (69%) of 71 tissue plasminogen activator patients compared with 5 (24%) of 21 placebo patients (p less than 0.001). At 120 minutes patency was observed in 59 (79%) of 75 patients of the tissue plasminogen activator group and in 10 (40%) of 25 in the intracoronary streptokinase/placebo group. A nadir value of less than 100 mg/dl fibrinogen occurred in 8 (11%) of 73 patients receiving tissue plasminogen activator versus 8 (40%) of 20 patients treated with intracoronary streptokinase (p = 0.002). Moderate or severe bleeding episodes occurred in 39% of patients treated with tissue plasminogen activator compared with 32% of patients who received placebo/intracoronary streptokinase (p = NS). Thus, this tissue plasminogen activator preparation achieves a high rate of recanalization and, at the doses employed, exhibits increased fibrinogen sparing compared with intracoronary streptokinase.

Anistreplase versus alteplase in acute myocardial infarction: comparative effects on left ventricular function, morbidity and 1-day coronary artery patency. The TEAM-3 Investigators.

OBJECTIVES: This double-blind, randomized, multicenter trial was designed to compare the effects of treatment with anistreplase (APSAC) and alteplase (rt-PA) on convalescent left ventricular function, morbidity and coronary artery patency at 1 day in patients with acute myocardial infarction. BACKGROUND: Anistreplase (APSAC) is a new, easily administered thrombolytic agent recently approved for treatment of acute myocardial infarction. Alteplase (rt-PA) is a rapidly acting, relatively fibrin-specific thrombolytic agent that is currently the most widely used agent in the United States. METHODS: Study entry requirements were age less than or equal to 75 years, symptom duration less than or equal to 4 h, ST segment elevation and no contraindications. The two study drugs, APSAC, 30 U/2 to 5 min, and rt-PA, 100 mg/3 h, were each given with aspirin (160 mg/day) and intravenous heparin. Prespecified end points were convalescent left ventricular function (rest/exercise), clinical morbidity and coronary artery patency at 1 day. A total of 325 patients were entered, stratified into groups with anterior (37%) or inferior or other (63%) acute myocardial infarction, randomized to receive APSAC or rt-PA and followed up for 1 month. RESULTS: At entry, patient characteristics in the two groups were balanced. Convalescent ejection fraction at the predischarge study averaged 51.3% in the APSAC group and 54.2% in the rt-PA group (p less than 0.05); at 1 month, ejection fraction averaged 50.2% versus 54.8%, respectively (p less than 0.01). In contrast, ejection fraction showed similar augmentation with exercise at 1 month after APSAC (+4.3% points) and rt-PA (+4.6% points), and exercise times were comparable. Coronary artery patency at 1 day was high and similar in both groups (APSAC 89%, rt-PA 86%). Mortality (APSAC 6.2%, rt-PA 7.9%) and the incidence of other serious clinical events, including stroke, ventricular tachycardia, ventricular fibrillation, heart failure within 1 month, recurrent ischemia and reinfarction were comparable in the two groups; and mechanical interventions were applied with equal frequency. A combined clinical morbidity index was determined and showed a comparable overall outcome for the two treatments. CONCLUSIONS: Convalescent rest ejection fraction was high after both therapies but higher after rt-PA; other clinical outcomes, including exercise function, morbidity index, and 1-day coronary artery patency, were favorable and comparable after APSAC and rt-PA.

Crystallization of a Fe,Zn superoxide dismutase from the archaebacterium Thermoplasma acidophilium.

The novel Fe,Zn superoxide dismutase from the archaebacterium Thermoplasma acidophilium has been crystallized in space groups P1, P2(1) and P2(1)2(1)2, with 2,4 and 1/2 of an 84,000 Mr tetramer, respectively, estimated to be in the asymmetric unit of the unit cell. The orthorhombic crystals, which have unit cell dimensions a = 84.2 A, b = 72.7 A, c = 67.8 A, diffract X-rays to at least 2.0 A and are suitable for a determination of the three-dimensional structure of the Fe,Zn superoxide dismutase.

Key innovation or adaptive change? A test of leaf traits using Triodiinae in Australia.

The evolution of novel traits ("key innovations") allows some lineages to move into new environments or adapt to changing climates, whereas other lineages may track suitable habitat or go extinct. We test whether, and how, trait shifts are linked to environmental change using Triodiinae, C4 grasses that form the dominant understory over about 30% of Australia. Using phylogenetic and relaxed molecular clock estimates, we assess the Australian biogeographic origins of Triodiinae and reconstruct the evolution of stomatal and vascular bundle positioning. Triodiinae diversified from the mid-Miocene, coincident with the aridification of Australia. Subsequent niche shifts have been mostly from the Eremaean biome to the savannah, coincident with the expansion of the latter. Biome shifts are correlated with changes in leaf anatomy and radiations within Triodiinae are largely regional. Symplectrodia and Monodia are nested within Triodia. Rather than enabling biome shifts, convergent changes in leaf anatomy have probably occurred after taxa moved into the savannah biome-they are likely to have been subsequent adaptions rather than key innovations. Our study highlights the importance of testing the timing and origin of traits assumed to be phenotypic innovations that enabled ecological shifts.

Inhibition of mediator release in systemic mastocytosis is associated with reversal of bone changes.

A 59-year-old male presented with systemic mastocytosis with extensive skeletal involvement resulting in vertebral compression fractures and bone pain. Histomorphometric analysis of bone revealed increased mast cells, elevated static parameters of bone resorption, and low bone formation. Serum calcium, phosphorus, and alkaline phosphatase were normal; however, serum 1,25-dihydroxyvitamin D3 and osteocalcin levels were low. Histamine levels in plasma and urine were elevated. Following therapy with ketotifen, the patient had resolution of bone pain along with decreased flushing and pruritus. Elevated plasma and urine histamine levels normalized, as did 1,25-dihydroxyvitamin D3 and osteocalcin levels. Indices of low bone formation improved on therapy. Eroded surfaces improved but remained elevated. This case is the first demonstration that bone symptoms and histomorphometric change in systemic mastocytosis are reversed with inhibition of mast cell degranulation. The role of mast cells and their products in bone metabolism is poorly understood, but the therapy of bone disease in systemic mastocytosis should include inhibition of the release of mast cell products along with the use of histamine antagonist.

Dissection of the molecular mechanism of action of GW5638, a novel estrogen receptor ligand, provides insights into the role of estrogen receptor in bone.

The estrogen receptor (ER) mixed agonists tamoxifen and raloxifene have been shown to protect against bone loss in ovariectomized rats. However, the mechanism by which these compounds manifest their activity in bone is unknown. We have used a series of in vitro screens to select for compounds that are mechanistically distinct from tamoxifen and raloxifene in an effort to define the properties of an ER modulator required for bone protection. Using this approach, we identified a novel high affinity ER antagonist, GW5638, which when assayed in vitro functions as an ER antagonist, inhibiting the agonist activity of estrogen, tamoxifen, and raloxifene and reversing the "inverse agonist" activity of the pure antiestrogen ICI182,780. Thus, GW5638 appears to function as an antagonist in these in vitro systems, although in a manner distinct from other known ER modulators. Predictably, therefore, GW5638 alone displays minimal uterotropic activity in ovariectomized rats, but will inhibit the agonist activity of estradiol in this environment. Unexpectedly, however, this compound functions as a full ER agonist in bone and the cardiovascular system. These data suggest that the mechanism by which ER operates in different cells is not identical, and that classical agonist activity is not required for the bone protective activity of ER modulators.

Extension of the therapeutic window for recombinant tissue plasminogen activator with argatroban in a rat model of embolic stroke.

BACKGROUND AND PURPOSE: Argatroban, a specific thrombin inhibitor, has been shown to reduce ischemic lesion size after focal cerebral ischemia in rats. In addition, recombinant tissue plasminogen activator (rtPA) has been shown to reduce ischemic lesion size in both rats and humans if given within 3 hours of symptom onset. We tested the hypothesis that the administration of argatroban with rtPA could extend the treatment window of stroke to 4 hours without increasing gross cerebral hemorrhage rates or reducing efficacy. METHODS: Male Wistar rats were subjected to middle cerebral artery (MCA) occlusion by a single fibrin-rich clot. After embolization, rats were administered argatroban at the following dose levels: 2.08, 6.25, and 18.75 microgram . kg(-1). min(-1). In a second experiment, rats received argatroban (6.25 microgram . kg(-1). min(-1)) or argatroban in combination with rtPA 4 hours after MCA occlusion. Tissue sections were then analyzed for lesion volume, gross hemorrhage and fibrin deposition. RESULTS: The 6.25 microgram. kg(-1). min(-1) dose demonstrated a significant reduction (P<0.05) in lesion volume after 48 hours (27.2+/-6.3%) compared with controls (35.3+/-3.7%). A significant reduction (P<0.05) in lesion volume was observed in the argatroban-plus-rtPA group (17.1+/-10.4%) compared with controls (35.3+/-3.7%). No increase in hemorrhagic transformation was observed. Fibrin deposition in the ipsilateral cortical microvasculature was significantly decreased in the 4-hour combination argatroban-plus-rtPA group compared with the controls (P<0.05). CONCLUSIONS: This study demonstrates that the combination of argatroban and rtPA extends the window of opportunity for treatment of stroke to 4 hours without increasing hemorrhagic transformation.

MR spectroscopy study of dichloroacetate treatment after ischemic stroke.

In a double-blind, placebo-controlled study, we used 1H MR spectroscopy to assess the effect of a single infusion of sodium dichloroacetate on lesion lactate 1 to 5 days after ischemic stroke. Apparent trends toward a reduction in lactate/N-acetyl compound ratios were seen at the higher drug doses employed, and in patients treated in the first 2 days following infarction. Use of spectroscopic measures as endpoints is feasible in acute stroke clinical trials.

Matrix vesicle calcification of ectopically induced osteoid tissue in 1-hydroxethylidene-1,1-bisphosphonate (HEBP)-treated mice.

The effects of 1 hydroxethylidene-1, 1-bisphosphonate (HEBP) on the mineralization of osteoid induced ectopically by a murine, osteosarcoma-derived, bone-inducing substance was examined at the ultrastructural level. Samples of Dunn osteosarcoma were chemically processed, lyophilized into pellets of uniform dimensions and protein content, and implanted into the back muscles of male, 4 week old, ddY mice. In control animals injected intraperitoneally (i.p.) with saline each day for 30 days, the pellets exhibited ectopic cartilage and bone formation in a sequential manner consistent with endochondral ossification. Daily administration of HEBP (30 mg/kg i.p. per day) to animals over the same period produced wide anastomosing strands of osteoid and haematopoietic marrow in the pellets. Electron microscopical examination revealed a tightly packed organization of collagen fibrils with many membrane bounded organelles or matrix vesicles (0.05-0.3 micron diameter) dispersed throughout this nonmineralized matrix. After withdrawal of HEBP, mineralization proceeded initially within matrix vesicles and secondarily by involvement of the surrounding collagen fibrils. In pellets retrieved at 30 days after HEBP withdrawal, most of the matrix had been mineralized and remodeled to reveal thin bony trabeculae and an overall histologic appearance similar to that seen in the control pellets. This model of ectopic bone formation permits clear visualization of the sequence of mineral nucleating events in osteoid in the absence of an established mineralizing front. The results add further support to the hypothesis that matrix vesicles are directly responsible for the initiation of mineralization in bone.

Development and cross-reactive properties of monoclonal antibodies to bovine matrix vesicle alkaline phosphatase.

Alkaline phosphatase (ALPase), concentrated in the membranes of matrix vesicles, is believed to play a role in initial calcification. To further purify, characterize, and identify this enzyme in tissue, a monoclonal antibody was developed against the ALPase of isolated fetal calf matrix vesicles. Splenic lymphocytes derived from mice immunized with Sepharose 6B-purified fetal calf matrix vesicle ALPase were fused with mouse plasmacytoma cells (line X63-Ag-8.653) using standard hybridoma technology. Hyperimmune sera and hybridoma culture supernatants were screened for the presence of specific antibody using a newly developed double-immunosorbent assay in which putative antibody is added to microtiter plate wells precoated with affinity-purified rabbit antimouse immunoglobulin. After incubation and washing, partially purified fetal calf matrix vesicle ALPase is added to each well. The enzyme adheres only to wells that contain specific anti-ALPase antibody. These wells are identified by adding the enzyme substrate p-nitrophenyl phosphate and reading the wells in a plate-reading spectrophotometer at 405 nm. A hybridoma-producing specific antibody was subsequently cloned and grown as ascities-producing tumors in pristane-primed mice. Ouchterlony analysis indicated that the cell line secretes an immunoglobulin of IgG1 class. This antibody reacts specifically with ALPase derived from calf matrix vesicles and cross-reacts with ALPase of bovine kidney, liver, and placental origin and human bone but does not cross-react with bovine intestinal ALPase or ALPase derived from matrix vesicles isolated from rachitic rat growth plate cartilage.

Enzyme cytochemical localization of alkaline phosphatase in cultures of chondrocytes derived from normal and rachitic rats.

Epiphyseal growth plate cartilages were removed from rats which had been maintained on normal laboratory chow or a rachitogenic diet. Chondrocytes were released from the growth plates by collagenase digestion and cultured in tissue chamber slides. After 7, 10 and 12 days of culture, the chondrocytes were removed as intact multilayers and processed for electron microscopical enzyme cytochemical studies. Alkaline phosphatase activity in the cultures was visualized by means of a cerium based capture method. Electron-dense cerium phosphate deposits were localized on the membrane of matrix vesicles and plasma membranes of chondrocytes derived from normal and rachitic animals. The appearance of first crystals within matrix vesicles was characterized by a concomitant decrease in alkaline phosphatase activity in the membrane of these structures. Calcification was initiated at approximately the same time in cultures of chondrocytes derived from normal or rachitic animals. The results suggest that rickets has no serious effects on the capacity of chondrocytes to support matrix calcification in vitro. Additionally, the evidence indicates that alkaline phosphatase-positive matrix vesicles play a significant role in the initiation of this process.

Fluorescent microtiter screening assay for immunocytochemically reactive antibodies.

We have developed a rapid in situ screening procedure that enables prescreening of hundreds of hybridomas in a 96-well format. The procedure involves fluorescence immunostaining of cells cultured in 96-well plates and the use of a fluorescence plate reader to detect reactive antibodies. Positive immunostaining in individual well, as denoted by elevated readings, is then confirmed by fluorescence microscopy. Using the method described here, we have successfully identified monoclonal antibodies that are specific to the nuclear receptor, peroxisome proliferator-activated receptor gamma (PPAR gamma). This assay is readily applicable for screening hybridomas raised against cell surface or intracellular antigens to aid in the initial identification of antibodies reactive in immunocytochemical procedures.

The use of the potassium pyroantimonate-osmium method as a means of identifying and localizing calcium at the ultrastructural level in the cells of calcifying systems.

Potassium pyroantimonate-osmium has been used to localize calcium as an electron dense precipitate in the odontoblast, ameloblast and early hypertrophic chondrocytes of the mandibular condylar growth cartilage. The precipitate exhibited a specific association with various cell organelles. The presence of calcium in the precipitates was confirmed using energy dispersive analysis by x-rays. It is suggested that this K-pyroantimonate method provides an accurate technique for the investigation of the subcellular localization of calcium in calcifying systems.