Inheritance of H3K9 methylation regulates genome architecture in Drosophila early embryos.

Constitutive heterochromatin is essential for transcriptional silencing and genome integrity. The establishment of constitutive heterochromatin in early embryos and its role in early fruitfly development are unknown. Lysine 9 trimethylation of histone H3 (H3K9me3) and recruitment of its epigenetic reader, heterochromatin protein 1a (HP1a), are hallmarks of constitutive heterochromatin.

A novel HLA allele, HLA-A*03:420, identified by next-generation sequencing.

HLA-A*03:420 differs from HLA-A*03:01:01:01 by a single nucleotide in exon 1, codon -22.

The novel HLA-DQB1*06 null allele, HLA-DQB1*06:423N, identified in a volunteer blood donor.

A single nucleotide exchange in exon 2 at position 370 (C ->T) generates a preterminal STOP encoding a C-terminally truncated protein.

Germ line-inherited H3K27me3 restricts enhancer function during maternal-to-zygotic transition.

Gametes carry parental genetic material to the next generation. Stress-induced epigenetic changes in the germ line can be inherited and can have a profound impact on offspring development. However, the molecular mechanisms and consequences of transgenerational epigenetic inheritance are poorly understood.

Plasma membrane phosphoinositide balance regulates cell shape during Drosophila embryo morphogenesis.

Remodeling of cell shape during morphogenesis is driven by the coordinated expansion and contraction of specific plasma membrane domains. Loss of this coordination results in abnormal cell shape and embryonic lethality. Here, we show that plasma membrane lipid composition plays a key role in coordinating plasma membrane contraction during expansion.

Tubular endocytosis drives remodelling of the apical surface during epithelial morphogenesis in Drosophila.

During morphogenesis, remodelling of cell shape requires the expansion or contraction of plasma membrane domains. Here we identify a mechanism underlying the restructuring of the apical surface during epithelial morphogenesis in Drosophila. We show that the retraction of villous protrusions and subsequent apical plasma membrane flattening is an endocytosis-driven morphogenetic process.

Chemical interactions between an active pharmaceutical ingredient and its counterion in a tromethamine salt under forced degradation conditions.

In this study, the tromethamine salt of an active pharmaceutical ingredient containing both a carboxylic acid and ethyl ester functionality was subjected to forced degradation conditions. Based on HPLC-MS analysis, it was found that tromethamine formed both amide and ester type condensation products with the API, with amide formation predominating over ester formation. Addition of tromethamine at the carboxylic acid group of the API was favored over addition at the ethyl ester group.

Correlations between conformational isomerism and chromatographic diastereoselectivity of bis amino amide s-triazine derivatives.

NMR spectroscopy was used to probe the conformational behavior of diastereomeric s-triazine derivatives containing two chiral amino amide substituents, in order to shed light onto the mechanism of chromatographic diastereoselectivity. Utilizing the amino hydrogen signals in the proton NMR spectrum, the population of the conformations caused by rotation about the bond between the amino nitrogen and aromatic carbon atoms could be observed. The population distribution between the three possible conformations was similar but not identical between the two diastereomers, with similar trends being observed for both bis alanine amide and bis valine amide derivatives.

Possible factors influencing the separation mechanism of diastereomeric amino acid derivatives obtained from s-triazine type reagents.

Diastereomeric derivatives prepared from an amino acid and an amino amide using trichloro s-triazine as a coupling platform are known to produce good chromatographic diastereoselectivity for many amino acid analytes. The chromatographic diastereoselectivity of these derivatives is difficult to rationalize based on the possibility of four possible conformational isomers, which can interconvert by rotation about the C-N bonds between the amino substituents and the triazine ring. The observed diastereoselectivity implicates an unobvious but significant driving force which causes one of several conformations to be favored over the others.

Feasibility of using gravimetry to measure excess adsorption effects of a binary solvent system in a reversed-phase high-performance liquid chromatography column.

A modified method for weighing HPLC columns filled with solvent is described. The method prevents the loss of traces of solvent from within the threads of the column. The method was tested by obtaining the weights of a C18 column filled with 10 different organic solvents, showing a standard deviation on the order of 0.

Water-immiscible solvents as diluents in reversed-phase liquid chromatography.

It has recently been shown that the use of strong organic solvents as diluent is possible in RPLC, provided that the solvent used as diluent is retained more strongly by the column than the analytes in the sample. In this study, the phenomenon was further studied experimentally using several water-immiscible solvents (ethyl acetate, isopropyl acetate, and methyl isobutyl ketone) and several model analyte compounds. In all cases, analyte peak distortion was minimal provided the analyte eluted earlier than the diluting solvent, in contrast to substantial broadening and distortion when the analyte eluted after the diluting solvent.

Evaluating the surface charge of C18 stationary phases.

The surface charge of four C18 stationary phases was investigated by measuring the flow induced streaming potential, a well known electrokinetic property of charged surfaces. Three of the stationary phases (Symmetry, Gemini, and Xterra-MS) had significantly positive streaming potentials at both pH 3 and 4.5.

Investigation of anion retention and cation exclusion effects for several C18 stationary phases.

When mobile-phase salt content is increased, cationic analytes often show increased retention. This effect is generally attributed to chaotropic or ion pairing effects. However, a cation exclusion mechanism could explain the same effects.

Using strong injection solvents with 100% aqueous mobile phase in RP-LC.

When samples are dissolved for HPLC analysis, organic solvents are often used to enhance the solubility of the sample components. However, when the diluent becomes significantly stronger than the mobile phase, peak shape distortions may develop during injection. This is a serious problem for weakly retained analytes under 100% aqueous mobile phase conditions.

Tumor suppressor properties of the ESCRT-II complex component Vps25 in Drosophila.

We have found that the Drosophila gene vps25 possesses several properties of a tumor suppressor. First, vps25 mutant cells activate Notch and Dpp receptor signaling, inducing ectopic organizers in developing eyes and limbs and consequent overproliferation of both mutant and nearby wild-type cells. Second, as the mutant cells proliferate, they lose their epithelial organization and undergo apoptosis.

Elucidation of an archaeal replication protein network to generate enhanced PCR enzymes.

Thermostable DNA polymerases are an important tool in molecular biology. To exploit the archaeal repertoire of proteins involved in DNA replication for use in PCR, we elucidated the network of proteins implicated in this process in Archaeoglobus fulgidus. To this end, we performed extensive yeast two-hybrid screens using putative archaeal replication factors as starting points.

[Relaxin in amniotic fluid and serum of pregnant patients].

Relaxin was measured in serum and amniotic fluid of 136 pregnant women between the 12th and 38th gestational week by means of a new human relaxin-RIA. The pregnancies consisted of 111 pathology-free single fetuses, 10 with rhesus incompatibility, 7 with chromosomal aberration and 8 with sonographic diagnosed abnormalities. Relaxin could be detected in all samples tested the levels being ten times lower in amniotic fluid compared to serum.

Induction of light hydrocarbon nephropathy by p-dichlorobenzene.

In order to clarify the etiology of a dose-related increase in the incidence of tubular cell adenocarcinomas of the kidney in male rats, the nephrotoxicity of p-dichlorobenzene (p-DCB) was investigated in a subchronic study. Groups of ten male and ten female Fischer 344 rats were dosed by gavage with 0 (controls), 75, 150, 300 or 600 mg p-DCB/kg/day in corn oil. Half of the animals were sacrificed after 4 weeks and the remainder after 13 weeks.

Spontaneous tumors of 2000 Wistar TNO/W.70 rats in two-year carcinogenicity studies.

Eleven two-year toxicity/carcinogenicity experiments in control Wistar TNO/W.70 rats were started between 1973 and 1976. Tumors occurring were compiled on the basis of histopathological reports.

Epoxidation of 1,3-butadiene in liver and lung tissue of mouse, rat, monkey and man.

When 1,3-butadiene is incubated with liver postmitochondrial fractions from mouse, rat, monkey or man and a NADPH-regenerating system the formation rate of butadiene monoxide is different in the four species. With the exception of rhesus monkey the amount of epoxide is proportional to the monooxygenase activity. The sequence of epoxide formation is B6C3F1-mouse, Sprague Dawley rat, man, rhesus monkey.

Species differences in the formation of butadiene monoxide from 1,3-butadiene.

When 1,3-butadiene is incubated with liver postmitochondrial fractions from mouse, rat, monkey or man and a NADPH-regenerating system, the formation rate of butadiene monoxide is different in the four species. With the exception of the rhesus monkey, the amount of epoxide is proportional to the monooxygenase activity. The sequence of epoxide formation is B6C3F1 mouse, Sprague Dawley rat, man, rhesus monkey.