A convenient way to estimate the number of viable cells growing in microtitre tray wells is to use a colorimetric assay and an automatic microplate scanning spectrophotometer. One such assay, ...developed by Mosmann, depends on the reduction by living cells of tetrazolium salt, MTT, to form a blue formazan product. However the original technique has several technical limitations, namely a less than optimal sensitivity, a variable background due to protein precipitation on adding an organic solvent to dissolve the blue formazan product, and a low solubility of the product. These problems have been overcome by the following modifications: avoidance of serum in the incubation medium, thus overcoming precipitation problems in the organic solvent; avoidance of phenol red in the incubation medium, thus avoiding the use of acid in the final solvent which altered the spectral properties of the formazan; elimination of the medium containing MTT after the reaction and subsequent use of pure propanol or ethanol to rapidly solubilize the formazan; use of a higher concentration of MTT; use of half-area microtitre trays to increase the spectrophotometer readings from a given amount of formazan; use of a more judicious reference wavelength in a dual wavelength spectrophotometer. With these modifications the reliability and sensitivity of the test have been increased to the point where it can in many cases replace the 3Hthymidine uptake assay to measure cell proliferation or survival in growth factor or cytotoxicity assays. Examples of its use in IL-2 assays are given.
Total internal reflection microscopy (TIRM) was applied to measure depletion forces between a charged colloidal sphere and a charged solid wall induced by dextran, a nonionic nonadsorbing ...polydisperse polysaccharide. The polymer size polydispersity is shown to greatly influence the depletion potential. Using the theory for the depletion interaction due to ideal polydisperse polymer chains, we could accurately describe the experimental data with a single adjustable parameter.
Basal cell carcinoma (BCC) is the most common form of skin cancer worldwide. Although most BCCs can be treated by relatively simple surgical or nonsurgical methods, some patients with BCC may ...eventually develop advanced disease which can either be locally destructive or even include metastatic spread. The present review summarizes the current literature on the treatment of both early and advanced BCC with a focus on the hedgehog inhibitor vismodegib which has become an integral part of the management of patients with advanced BCC since its regulatory approval in 2012.
The cardiocytes of mammalian cardiac atria contain granules very similar to those in endocrine cells. The number of these atrial granules is related directly to salt loading and blood volume. ...Furthermore, crude extracts of rat atria and granule preparations have powerful natriuretic and diuretic effects. These effects are mediated by peptides identified previously as atrial natriuretic factor (ANF). The peptides are derived from a common precursor, whose structure has been elucidated recently. Although there is indirect evidence from morphological studies that at least some of these peptides may be released into the blood and function as hormones, their presence in the blood has not yet been demonstrated. Here we describe a sensitive and specific radioimmunoassay for ANF and its stimulation on volume loading.
Atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) are cardiac hormones that serve to unload the heart through their effects on the kidney and vasculature. Whether the heart itself ...represents a site of action for these peptides is currently the subject of debate. Although functional studies indicate that ANP has some effects on isolated myocytes, several studies have been unable to detect binding of the hormone to these cells. The present study demonstrates that the genes for all three natriuretic peptide receptor (NPR) subtypes, NPR-A, NPR-B, and NPR-C, are expressed in the rat heart. For microlocalization of the receptor mRNAs in myocytes and nonmyocytic cells, a combination of cell isolation and reverse transcription-polymerase chain reaction (RT-PCR) was used. Cardiac myocytes were isolated by enzymatic dissociation of rat ventricular tissue, purified by density gradient centrifugation, and collected as single cells under microscopic control. Analysis by RT-PCR revealed the presence of transcripts for NPR-A as well as NPR-B and NPR-C. However, cGMP generation in purified myocytes was stimulated only by ANP and BNP, which specifically bind to NPR-A, whereas C-type natriuretic peptide (CNP, an NPR-B agonist) was ineffective. Therefore, rat ventricular myocytes appear to produce predominantly NPR-A. The expression of NPR-B may be low or even absent. The mRNAs for all three NPRs were also found in cultures of fibroblasts from the rat heart. In contrast to the myocytes, large increases in cGMP were observed in response not only to ANP but also to CNP. Cardiac fibroblasts may therefore synthesize functionally relevant amounts of both NPR-A and NPR-B. The expression of NPR-C in these cells is suggested by binding studies demonstrating that more than 70% of the maximum binding of sup 125 IANP can be displaced by the NPR-C agonist C-ANP 4-23. These observations may help to resolve whether the heart muscle cells themselves are targets for natriuretic peptides. The finding that in addition to myocytes, cardiac fibroblasts are capable of expressing the NPR genes raises the interesting possibility that natriuretic peptides are involved in the structural remodeling of the heart.(Circ Res. 1995;77:750-758.)
OBJECTIVES
To test the feasibility of objective and automated evaluation of echocardiographic stress tests, we studied the ability of segmental analysis of color kinesis (CK) images to detect ...dobutamine-induced wall motion abnormalities and compared this technique with inexperienced reviewers of conventional gray-scale images.
BACKGROUND
Conventional interpretation of stress echocardiographic studies is subjective and experience dependent.
METHODS
CK images were obtained in 89 of 104 consecutive patients undergoing clinical dobutamine stress studies and were analyzed using custom software to calculate regional fractional area change in 22 segments in four standard views. Each patient’s data obtained at rest was used as a control for automated detection of dobutamine-induced wall motion abnormalities. Independently, studies were reviewed without CK overlays by two inexperienced readers who classified each segment’s response to dobutamine. A consensus reading of two experienced reviewers was used as the gold standard for comparisons. In a subgroup of 16 patients, these consensus readings and CK detection of wall motion abnormalities were compared with coronary angiography.
RESULTS
The consensus reading detected ischemic response to dobutamine in 43 of 1958 segments in 23 of 89 patients. Automated detection of stress-induced wall motion abnormalities correlated more closely with the standard technique than the inexperienced reviewers (sensitivity 0.76 vs. 0.55, specificity 0.98 vs. 0.94 and accuracy 0.97 vs. 0.92). When compared with coronary angiography in a subgroup of patients, analysis of CK images differentiated between normal and abnormal wall motion more accurately than expert readers of gray-scale images (accuracy of 0.93 vs. 0.82).
CONCLUSIONS
Analysis of CK images allows fast, objective and automated evaluation of regional wall motion, sensitive enough for clinical dobutamine stress data and more accurate than inexperienced readers. This method may result in a valuable adjunct to conventional visual interpretation of dobutamine stress echocardiography.
Coral species throughout the world are facing severe environmental pressures. Because of this, we began cryobiological studies on the sperm of the mushroom coral,
Fungia scutaria. We determined that
...F. scutaria sperm had a mean length of 56
μm and head diameter of 2.5
μm, and a mean spontaneous ice nucleation temperature of −37.2
±
1.7
°C. When the sperm were exposed to the cryoprotectant glycerol for 5 or 20
min (at 10% v/v), no fertilized larvae were produced. However, when sperm were exposed for 20
min to propylene glycol (10% v/v), fertilizations were produced at the same rate as untreated control eggs and sperm (
P
>
0.05), but slightly less for dimethyl sulfoxide (10% v/v) (
P
<
0.05). Regardless, dimethyl sulfoxide caused less osmotic damage to the sperm membrane than did propylene glycol. Therefore, we used the dimethyl sulfoxide (10% v/v) to develop cryopreservation protocols that yielded good post-thaw morphology and motility (>95%) for coral sperm.
Presents an obituary for Dieter Ferring who passed away unexpectedl in The Netherlands on August 3, 2017. Dieter Ferring eagerly served as a Founder and Associate Editor for GeroPsych: The Journal of ...Gerontopsychology and Geriatric Psychiatry for nearly an entire decade. His impact on and importance to this journal will continue to be noticed for a long time. Dieter Ferring was an enthusiastic, beloved, and much admired teacher, leader, and researcher at the University of Luxembourg, where he also served as a founder and head of a research unit and as course director. Geropsychology and Lifespan Science has lost an outstanding leader, who will be remembered as a passionate scientist, inspiring mentor, reliable partner, prudent advisor, and a warm-hearted colleague and friend to many. (PsycInfo Database Record (c) 2022 APA, all rights reserved)
This study documents early out-of-season induced spawning of channel catfish Ictalurus punctatus. During the early spring (February-April) of 1999, 2000 and 2001, ponds containing (1) male and female ...channel catfish (mixed-sex ponds) or (2) male channel and blue catfish I. furcatus only, or female channel catfish only (single-sex ponds) were heated to 24-30°C to encourage gonadal maturation and spawning. Unheated ponds were stocked with males and females and were monitored during the duration of heating. When natural spawning occurred in the heated ponds, the fish were captured by seining and unspawned females were injected with 100 μg kg⁻¹ of synthetic leutenizing hormone-releasing hormone. Injected females were either paired with males or held in communal all-female groups, and monitored for ovulation. Eggs were collected and fertilized with sperm of channel catfish or blue catfish. Females paired with males were induced to spawn 44 days (mixed-sex ponds) and 50 days (single-sex ponds) before natural spawning occurred in unheated ponds. Spawning latency (the time between injection and ovulation) and the percentage of neurulated embryos from eggs fertilized using channel catfish sperm was not different between spawning before the natural season (P=0.68) and during the natural season in fish from mixed-sex ponds (P=0.57). Females held in all-female groups produced eggs 34 days before the onset of spawning in unheated ponds. Spawning latency was not different between spawns before and during the natural season (P=0.16), and the percentages of neurulated embryos from eggs fertilized with channel catfish sperm (P=0.76) or blue catfish sperm (P=0.77) before or during the natural season were not different. This study demonstrates the feasibility of conditioning of channel catfish females for early out-of-season induced spawning in the laboratory.
The alpha decay of
210Po is a dangerous background to rare event searches. Here, we describe observations related to this alpha decay in the Cryogenic Rare Event Search with Superconducting ...Thermometers (CRESST). We find that lead nuclei show a scintillation light yield in our
CaWO
4
crystals of
0.0142
±
0.0013
relative to electrons of the same energy. We describe a way to discriminate this source of nuclear recoil background by means of a scintillating foil, and demonstrate its effectiveness. This leads to an observable difference in the pulse shape of the light detector, which can be used to tag these events. Differences in pulse shape of the phonon detector between lead and electron recoils are also extracted, opening the window to future additional background suppression techniques based on pulse shape discrimination in such experiments.
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