Substitution Reaction on the Indole Ring of ( – )-Indolactam V,the Fundamental Structure of Teleocidins

We isolated a temperature-sensitive mutant which did not exhibit derepression of acid phosphatase and invertase at the restrictive temperature. The mutation was mapped in the cryl gene, the structural gene for the catalytic subunit of adenylate cyclase. On electron microscopic observation of the mutant cells at the restrictive temperature, it was observed that they accumulated carbohydrate particles in the cytoplasm. Isolated particles had a rosette-like structure of 40 to 60 nm in diameter, and were identified as glycogen. After 2 hr incubation at the restrictive temperature, glycogen particles occupied most of the cytoplasmic space and the vacuoles were observed to be fragmented.     

Absence of Heterozygosity Due to Template Switching during Replicative Rearrangements

We investigated complex genomic rearrangements (CGRs) consisting of triplication copy-number variants (CNVs) that were accompanied by extended regions of copy-number-neutral absence of heterozygosity (AOH) in subjects with multiple congenital abnormalities. Molecular analyses provided observational evidence that in humans, post-zygotically generated CGRs can lead to regional uniparental disomy (UPD) due to template switches between homologs versus sister chromatids by using microhomology to prime DNA replication—a prediction of the replicative repair model, MMBIR. Our findings suggest that replication-based mechanisms might underlie the formation of diverse types of genomic alterations (CGRs and AOH) implicated in constitutional disorders.     

Serum Procalcitonin Level and SOFA Score at Discharge from the Intensive Care Unit Predict Post-Intensive Care Unit Mortality: A Prospective Study

Purpose

The final decision for discharge from the intensive care unit (ICU) is uncertain because it is made according to various patient parameters; however, it should be made on an objective evaluation. Previous reports have been inconsistent and unreliable in predicting post-ICU mortality. To identify predictive factors associated with post-ICU mortality, we analyzed physiological and laboratory data at ICU discharge.

Methods

Patients admitted to our ICU between September 2012 and August 2013 and staying for critical care>2 days were included. Sequential Organ Failure Assessment (SOFA) score; systemic inflammatory response syndrome score; white blood cell count; and serum C reactive protein, procalcitonin (PCT), interleukin-6 (IL-6), lactate, albumin, and hemoglobin levels were recorded. The primary end point was 90-day mortality after ICU discharge. Two hundred eighteen patients were enrolled (195 survivors, 23 non-survivors).

Results

Non-survivors presented a higher SOFA score and serum PCT, and IL-6 levels, as well as lower serum albumin and hemoglobin levels. Serum PCT, albumin, and SOFA score were associated with 90-day mortality in multiple logistic regression analysis. Hosmer-Lemeshow test showed chi-square value of 6.96, and P value of 0.54. The area under the curve (95% confidence interval) was 0.830 (0.771–0.890) for PCT, 0.688 (0.566–0.810) for albumin, 0.861 (0.796–0.927) for SOFA score, and increased to 0.913 (0.858–0.969) when these were combined. Serum PCT level at 0.57 ng/mL, serum albumin at 2.5 g/dL and SOFA score at 5.5 predict 90-day mortality, and high PCT, low albumin and high SOFA groups had significantly higher mortality. Serum PCT and SOFA score were significantly associated with survival days after ICU discharge in Cox regression analysis.

Conclusions

Serum PCT level and SOFA score at ICU discharge predict post-ICU mortality and survival days after ICU discharge. The combination of these two and albumin level might enable accurate prediction.     

Dysregulated Gene Expression in the Primary Osteoblasts and Osteocytes Isolated from Hypophosphatemic Hyp Mice

Osteocytes express multiple genes involved in mineral metabolism including PHEX, FGF23, DMP1 and FAM20C. In Hyp mice, a murine model for X-linked hypophosphatemia (XLH), Phex deficiency results in the overproduction of FGF23 in osteocytes, which leads to hypophosphatemia and impaired vitamin D metabolism. In this study, to further clarify the abnormality in osteocytes of Hyp mice, we obtained detailed gene expression profiles in osteoblasts and osteocytes isolated from the long bones of 20-week-old Hyp mice and wild-type (WT) control mice. The expression of Fgf23, Dmp1, and Fam20c was higher in osteocytic cells than in osteoblastic cells in both genotypes, and was up-regulated in Hyp cells. Interestingly, the up-regulation of these genes in Hyp bones began before birth. On the other hand, the expression of Slc20a1 encoding the sodium/phosphate (Na⁺/Pi) co-transporter Pit1 was increased in osteoblasts and osteocytes from adult Hyp mice, but not in Hyp fetal bones. The direct effects of extracellular Pi and 1,25-dihydroxyvitamin D₃ [1,25(OH)₂D₃] on isolated osteoblastic and osteocytic cells were also investigated. Twenty-four-hour treatment with 10⁻⁸ M 1,25(OH)₂D₃ increased the expression of Fgf23 in WT osteoblastic cells but not in osteocytic cells. Dmp1 expression in osteocytic cells was increased due to the 24-hour treatment with 10 mM Pi and was suppressed by 10⁻⁸ M 1,25(OH)₂D₃ in WT osteocytic cells. We also found the up-regulation of the genes for FGF1, FGF2, their receptors, and Egr-1 which is a target of FGF signaling, in Hyp osteocytic cells, suggesting the activation of FGF/FGFR signaling. These results implicate the complex gene dysregulation in osteoblasts and osteocytes of Hyp mice, which might contribute to the pathogenesis.     

Crucial role in light signal transduction for the conserved Met93 of the BLUF protein PixD/Slr1694

PixD/Slr1694 from the cyanobacterium Synechocystis sp. PCC6803 is a member of a new class of flavin-containing blue-light sensory proteins containing a BLUF (blue light using flavin) domain. The photocycle reaction mechanism of BLUF is unique because only small structural changes of a bound chromophore are accompanied by a few hydrogen bond rearrangements in the chromophore-binding site. Here, we show that in PixD, Met93, the residue conserved in all BLUF domains, is crucial for light-dependent signal transduction. Specifically, the light-insensitive M93A mutant of PixD revealed biochemical and physiological activities compatible with those of the light-adapted wild-type PixD. However, the W91A mutant of PixD retained light sensitivity and biological function, although the corresponding mutant of another BLUF protein, AppA, has been reported to be locked in the light signaling state. These observations suggest that the pathway through which the light signal is transformed into apoprotein structural changes has been modified in BLUF proteins for their respective functions.     

Effects of Calmodulin on Ca2+-Dependent Cl--Sensitive Anion Channels in the Chara Plasmalemma: a Patch-Clamp Study

The effects of calmodulin (from spinach) on the Ca²⁺-dependentCl^--sensitive anion channel in the Chara plasmalemma (Okiharaet al. 1991) were studied by the inside-out patch-clamp technique.The current of Cl^- ions, which flowed through the channel at1.0 µM Ca²⁺, tended to decrease irregularly with time.This tendency toward a decrease in the current was no longerapparent after application of calmodulin for some time. Theactivity of the channel was restored to a small extent or tendedto increase during the early stages of application of calmodulin.Such a transient action of calmodulin on the channel activitywas evident, at voltages more negative than –100 mV. (Received August 20, 1992; Accepted October 19, 1992)     

Thermal Analysis of Membrane Lipids from the Blue-Green Algae Anacystis nidulans and Anabaena variabilis

Differential scanning calorimetry was used on aqueous dispersionsof lipids extracted from the blue-green algae Anacystis nidulansand Anabaena variabilis. The reversible curves, exothermic oncooling and endothermic on heating, indicated that thermotrophicphase transition of the membrane lipids took place over a widerange of temperatures. These results suggest that the lipidsof the thylakoid membranes in these algae were in the liquidcrystalline state at the growth temperature, entered the phaseseparation state at about room temperature and went into thegel state below the freezing point. The temperature for theonset of phase separation was dependent on both the growth temperatureand the growth stage of the culture. ³Present address: Solar Energy Research Group, Institute ofPhysical and Chemical Research (RIKEN), Wako-shi, Saitama 351,Japan. (Received December 20, 1982; Accepted March 24, 1983)     

White-spotting mutations affect the regenerative differentiation of testicular germ cells: demonstration by experimental cryptorchidism and its surgical reversal.

The effect of white-spotting (W) mutations on differentiation of testicular germ cells was investigated by using experimental cryptorchidism and its surgical reversal. All mutant mice used in this study (Wv/+, Wsh/+, Wf/+ and Wf/Wf) showed normal fertility and well-ordered spermatogenesis, as in congenic +/+ mice. In the cryptorchid testis, which contains only type A spermatogonia as germ cells, the number and the proliferative activity of type A spermatogonia in mutant mice were comparable to +/+ mice. On the other hand, surgical reversal of the cryptorchid testis in mutants resulted in impaired regenerative differentiation of germ cells. Although complete recovery of spermatogenesis was observed in +/+ mice, testicular weight in Wsh/+, Wf/+ and Wf/Wf mice recovered to approximately 60-70% of intact levels, and some portions of seminiferous epithelium showed incomplete spermatogenesis. In Wv/+ mice, however, ability to recover the weight was completely lost, and only type A spermatogonia existed as germ cells in seminiferous tubules 3 mo after surgical reversal. These results suggest that W mutation affects the differentiation through type A spermatogonia to type B spermatogonia, indicating the functional significance of W (c-kit) in early spermatogenesis.