A model describing chemical interference caused by decomposing residues at different densities of growing plants

In literature, the biological response of plants to phytochemicals has been modelled and then used to simulate phytotoxicity caused by plant residues during decomposition. According to the resulting residue allelopathy model, stimulation dominates in the beginning of the residue decomposition process for a short while. Thereafter, severe inhibition is predicted to occur rapidly, until stimulation gradually re-emerges at the later stages of residue decomposition. Also in literature, direct chemical interference has been shown to be density-dependent; with increasing target plant density, the effects of phytochemicals are diluted. As a result, inhibition is the most probable outcome in density-dependent phytochemical interactions at low target plant densities, but phytotoxic effects often become stimulatory as target plant density increases. In this paper, these models that have been reported in literature are combined. While the original residue allelopathy model predicts inhibitory effects in most cases, the new density-dependent extension of the residue allelopathy model predicts that the density of target plants determines whether or not inhibition occurs. According to the new model, the intensity of inhibition decreases and the final stimulatory period begins earlier if target plant density increases. Therefore, combining the effects of density-dependency to the residue allelopathy model enhances our understanding of chemical interference. In addition, the new model may partially explain why several field studies have not observed chemically driven inhibitory effects similar to those observed in laboratory experiments.     

Iron Deficiency Without Anemia Is Associated with Anger and Fatigue in Young Japanese Women

Iron deficiency without anemia (IDNA), the most prevalent nutritional deficiency worldwide, affects young women of reproductive age. This study aimed to elucidate the relationship between IDNA and mental and somatic symptoms including anger and fatigue using the Japanese version of the Cornell Medical Index Health Questionnaire (CMI–J). Data regarding demographic characteristics, anthropometry, hematological, and biochemical indices of the iron status, frequencies of selected food intakes assessed by self-administered food frequency questionnaires (FFQs), frequencies of nonspecific symptoms, and grades of neurotic tendencies assessed by CMI–J were collected from 76 young women aged 18–22 years living in the metropolitan area of Tokyo, Japan. The subjects were classified as having IDNA (hemoglobin (Hb)?≥?12 g/dL and serum ferritin?<?20 ng/mL; n?=?29), having iron deficiency anemia (IDA) (Hb?<?12 g/dL and serum ferritin?<?20 ng/mL; n?=?10), or having a normal iron status (Hb?≥?12 g/dL and serum ferritin?≥?20 ng/mL; n?=?36). One subject was excluded from the analyses because of Hb?<?12 g/dL and serum ferritin?≥?20 ng/mL. Fisher’s protected least significant difference and the Dwass–Steel–Chritchlow–Fligner multiple comparison tests were used to compare the data of the three groups. P values <0.05 were considered significant. Sections M–R (mental complaints) were significantly higher in the IDNA subjects than in the normal subjects. No significant difference in CMI scores was found between the normal and IDA subjects. Sections I (fatigability), Q (anger), and R (tension) were significantly higher in the IDNA subjects than in the normal subjects, regardless of no significant differences between the normal and IDA subjects in those sections. Young women with IDNA demonstrated a significantly higher proportion of neurotic tendencies (grades II–IV). The intake frequency score of canned or bottled green tea fortified with vitamin C was significantly higher in the IDNA subjects than the IDA subjects. The findings suggest that IDNA may be a risk factor for anger, fatigue, and tension in women of childbearing age.     

Leucine aminopeptidase during meiotic development.

We found a leucine aminopeptidase (LAP; EC 3.4.11.1) to be abundant in meiotic prophase tissue of a basidiomycete, Coprinus cinereus. After direct purification of the aminopeptidase component from meiocytes, we cloned the gene by degenerate PCR using partial amino-acid sequences of the purified enzyme and 5' and 3' RACE. It was homologous to the eukaryotic leucine aminopeptidase gene. The recombinant protein possesses the characteristic activities of a Coprinus leucine aminopeptidase (CoLAP) with a molecular mass of 52.4 kDa, and forms a homohexamer. Northern blot and spatial distribution analysis by immunohistochemical staining indicated CoLAP to be abundant in meiotic prophase cells and the supporting cells around meiocytes, but scarce in mycelium cells. Interestingly, from zygotene to pachytene, CoLAP was mostly present in supporting cells around meiocytes, but from diplotene onwards, it was plentiful in meiocytes themselves, suggesting that its expression is required to control some of the biochemical events at meiotic prophase. Moreover, the strong expression of CoLAP mRNA immediately after treatment with methyl methanesulfonate in mycelium implies that CoLAP has a role in somatic DNA repair.     

Genome-wide CRISPR-Cas9 knockout library screening identified PTPMT1 in cardiolipin synthesis is crucial to survival in hypoxia in liver cancer

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Differences in coordination states of substituted tyrosine residues and quaternary structures among hemoglobin M probed by resonance Raman spectroscopy

Among the four types of hemoglobin (Hb) M with a substitution of a tyrosine (Tyr) for either the proximal (F8) or distal (E7) histidine in the α or β subunits, only Hb M Saskatoon (βE7Tyr) assumes a hexacoordinate structure and its abnormal subunits can be reduced readily by methemoglobin (metHb) reductase. This is distinct from the other three M Hbs. To gain new insight into the cause of the difference, we examined the ionization states of E7 and F8 Tyrs by UV resonance Raman (RR) spectroscopy and Fe–O(Tyr) bonding by visible RR spectroscopy. Hb M Iwate (αF8Tyr), Hb M Boston (αE7Tyr), and Hb M Hyde Park (βF8Tyr) exhibited two extra UV RR bands at 1,603 cm⁻¹ (Y8a′) and 1,167 cm⁻¹ (Y9a′) arising from deprotonated (ionized) Tyr, but Hb M Saskatoon displayed the UV RR bands of protonated (unionized) Tyr at 1,620 and 1,175 cm⁻¹ in addition to those of deprotonated Tyr. Evidence for the bonding of both ionization states of Tyr to the heme in Hb M Saskatoon was provided by visible RR spectroscopy. These results indicate that βE7Tyr of Hb M Saskatoon is in equilibrium between protonated and deprotonated forms, which is responsible for facile reducibility. Comparison of the UV RR spectral features of metHb M with that of metHb A has revealed that metHb M Saskatoon and metHb M Hyde Park are in the R (relaxed) structure, similar to that of metHb A, whereas metHb M Iwate, metHb M Boston and metHb M Milwaukee are in the T (tense) quaternary structure.     

PRRX1 promotes malignant properties in human osteosarcoma

Paired related homeobox 1 (PRRX1) is a marker of limb bud mesenchymal cells, and deficiency of p53 or Rb in Prrx1-positive cells induces osteosarcoma in several mouse models. However, the regulatory roles of PRRX1 in human osteosarcoma have not been defined. In this study, we performed PRRX1 immunostaining on 35 human osteosarcoma specimens to assess the correlation between PRRX1 level and overall survival. In patients with osteosarcoma, the expression level of PRRX1 positively correlated with poor prognosis or the ratio of lung metastasis. Additionally, we found PRRX1 expression on in 143B cells, a human osteosarcoma line with a high metastatic capacity. Downregulation of PRRX1 not only suppressed proliferation and invasion but also increased the sensitivity to cisplatin and doxorubicin. When 143B cells were subcutaneously transplanted into nude mice, PRRX1 knockdown decreased tumor sizes and rates of lung metastasis. Interestingly, forskolin, a chemical compound identified by Connectivity Map analysis using RNA expression signatures during PRRX1 knockdown, decreased tumor proliferation and cell migration to the same degree as PRRX1 knockdown. These results demonstrate that PRRX1 promotes tumor malignancy in human osteosarcoma.     

Formation of a complex between yeast L-lactate dehydrogenase (cytochrome b2) and cytochrome c. Ultracentrifugal and gel chromatographic analyses.

Yeast L-lactate dehydrogenase formed a stable complex with cytochrome c in weakly alkaline solution of low ionic strength. The binding ratio of cytochrome c to the enzyme depended on whether free cytochrome c was present: In the presence of a micromolar concentration of cytochrome c the enzyme formed a complex with about two molecules of cytochrome c, whereas the enzyme was in a 1:1 molecular complex after removal of free cytochrome c. This suggests that the binding of one molecule of cytochrome c changes the affinity of the other binding site on the enzyme for cytochrome c. The enzyme consists of four presumably identical subunits, each containing a binding site for cytochrome c. Thus, present data confirm the concept of negative cooperativity between the subunits of the enzyme molecule in their interaction with cytochrome c.