Multiple mechanisms for hereditary sideroblastic anemia.

Hereditary sideroblastic anemia (HSA) is a heterogeneous group of inherited anemic disorders which is characterized by the presence of ringed sideroblasts in the bone marrow, microcytic hypochromic anemia and typically its X-linked inheritance in patients. It has been shown that a deficiency of the erythroid-specific delta-aminolevulinate synthase (ALAS-E) activity is responsible for pyridoxine-responsive HSA in many patients, however, the pathogenesis of other types of HSA remains still unknown. In this article, recent evidence suggesting multiple causes for HSA is summarized and discussed.     

Polyamines of carbon monoxide-utilizing bacteria, Pseudomonas thermocarboxydovorans and Pseudomonas carboxydohydrogena

A slightly thermophilic, CO-utilizing pseudomonad, Pseudomonas thermocarboxydovorans grown under both autotrophic and heterotrophic growth conditions was found to contain 2-hydroxyspermidine and 2-hydroxyputrescine in addition to putrescine, diaminopropane and spermidine. A mesophilic CO — utilzing hydrogen bacterium, Pseudomonas carboxydohydrogena contained putrescine and homospermidine under both autotrophic and heterotrophic growth conditions. Although these two carboxydobacteria are classified to the same genus Pseudomonas , the difference in their polyamine distribution patterns suggests that they may belong to different subclasses of Proteobacteria .     

A new species ofRoumegueriella

A new species ofRoumegueriella (Ascomycetes; Hypocreales),R. pulchella, is described and illustrated. This fungus is characterized by its rapid growth on Czapek-yeast extract and YpSs agars at 37°C, bright yellow non-ostiolate ascomata, translucent membranaceous peridium, broadly clavate asci, and hyaline one-celled subglobose-ovoid ascospores ornamented with prominent spines. The holotype was isolated from soil in a sugarcane field in Okinawa, Japan.     

Lipid content of human platelets quantitated by thin-layer chromatography in combination with flame ionization detection

The lipid contents of human platelets from twenty-one healthy adults were analysed using thin-layer chromatography in combination with flame ionization detection.The weight per cent of neutral lipids in human platelets was 14.6%, which consisted mainly of free cholesterol, that of phosphatidylethanolamine 24.9%, phosphatidylserine plus phosphatidylinositol 6.8%, phosphatidylcholine 35.2% and sphingomyelin 18.6%. Free cholesterol in 10⁸ platelets was estimated as 7 μg and phospholipids as 46 μg from calibration standards. The reproducibility was satisfactory and the procedure could be performed quickly and simply.     

The Association of Elastin Gene Variants with Two Angiographic Subtypes of Polypoidal Choroidal Vasculopathy

Objective

To compare the association of elastin (ELN) gene variants between two different angiographic phenotypes of polypoidal choroidal vasculopathy (PCV).

Methods

We included 411 treatment-naïve PCV patients and 350 controls in the present study. PCV was classified into two phenotypes (152 Type 1 and 259 Type 2) according to the presence or absence of feeding vessels found in indocyanine-green angiography. Single nucleotide polymorphisms (SNPs) in the ELN region including rs868005, rs884843, rs2301995, rs13239907 and rs2856728 were genotyped using TaqMan Genotyping Assays.

Results

In the allelic association analyses, rs868005 showed the strongest association with Type 2 PCV (allelic odds ratio 1.56; p = 7.4x10^-6), while no SNP was significantly associated with Type 1 PCV. Genotype association analyses revealed the significant association of rs868005 with Type 2 PCV in log additive model and predominant model (odds ratio 1.75; p = 1.5x10^-6 and odds ratio 1.60; p = 0.0044, respectively), but not with Type 1 PCV. These findings were further corroborated by another control group in the literature.

Conclusions

There may be significantly different associations in genetic variants of elastin between two angiographic phenotypes of PCV.     

Scan-Free Absorbance Spectral Imaging A(x,y, λ) of Single Live Algal Cells for Quantifying Absorbance of Cell Suspensions

Label-free, non-invasive, rapid absorbance spectral imaging A(x,y,λ) microscopy of single live cells at 1.2 μm × 1.2 μm resolution with an NA = 0.85 objective was developed and applied to unicellular green algae Chlamydomonas reinhardtii. By introducing the fiber assembly to rearrange a two-dimensional image to the one-dimensional array to fit the slit of an imaging spectrograph equipped with a CCD detector, scan-free acquisition of three-dimensional information of A(x,y,λ) was realized. The space-resolved absorbance spectra of the eyespot, an orange organelle about 1 μm, were extracted from the green-color background in a chlorophyll-rich single live cell absorbance image. Characteristic absorbance change in the cell suspension after hydrogen photoproduction in C. reinhardtii was investigated to find a single 715-nm absorption peak was locally distributed within single cells. The formula to calculate the absorbance of cell suspensions from that of single cells was presented to obtain a quantitative, parameter-free agreement with the experiment. It is quantitatively shown that the average number of chlorophylls per cell is significantly underestimated when it is evaluated from the absorbance of the cell suspensions due to the package effect.     

Shortening of subjective visual intervals followed by repetitive stimulation

Our previous research demonstrated that repetitive tone stimulation shortened the perceived duration of the preceding auditory time interval. In this study, we examined whether repetitive visual stimulation influences the perception of preceding visual time intervals. Results showed that a time interval followed by a high-frequency visual flicker was perceived as shorter than that followed by a low-frequency visual flicker. The perceived duration decreased as the frequency of the visual flicker increased. The visual flicker presented in one hemifield shortened the apparent time interval in the other hemifield. A final experiment showed that repetitive tone stimulation also shortened the perceived duration of preceding visual time intervals. We concluded that visual flicker shortened the perceived duration of preceding visual time intervals in the same way as repetitive auditory stimulation shortened the subjective duration of preceding tones.