Evidence for endogenous retroviruses in human chemokine receptor gene introns: possible evolutionary inferences and biological roles.

The human chemokine receptor (CKR) genes CCR2, CCR6, CCR7, CCR9, CCR10, CXCR4, and CXCR5 harbor one or two introns. CCR7, CCR9, CCR10, and CXCR5 introns, (but not CCR2, CCR6, and CXCR4 introns) encompass retrovirus-like inserts with the characteristics of SINEs (short interspersed nuclear elements) up to 300 nucleotides (nt) long. Other characteristic elements of the retroviral genome, such as long terminal repeats and gag, pol, and env genes, are lacking.

An analysis of the human and mouse CXCR5 gene introns.

Both mouse and human chemokine receptor CXC motif 5 (CXCR5) genes exhibit one single intron interrupting the coding sequence. The mouse intron is 12053 nucleotides (nt) long; the human intron is 9603 nt long. Sections of the mouse intron significantly align plus/plus with sections of the human intron; the aligned segments are in the same order in mouse as in man and overall cover 13% of the mouse sequence and 17% of the human sequence.

Viral sequence integration into introns of chemokine receptor genes.

Viral DNA sequences are able to integrate into the non-coding DNA sections of the genome of human cells which have been infected, either spontaneously or experimentally. We have made a data-base search for integration events of non-endogenous viruses into the introns of chemokine receptor sequences. A BLAST search of all viral DNA sequences, using the intronic sequences as "Query," returned several significant alignments.

Differential conservation of nucleotides and conservation/mutation correlations between nucleotides, with special reference to CXC 1 and 4 and FP receptors involved in immune regulation.

Random mutations of the first nucleotide of a coding triplet alter the hydropathic character of 27 % of the hydrophobic amino acids and of 23 % of the hydrophilic amino acids, while random mutations of the second nucleotide alter the hydropathic character of 82 % of the hydrophobic amino acids and of 47 % of the hydrophilic amino acids. In cases of a change of the hydropathic character, a second random mutation in the previously unmutated first or second nucleotide causes reversion to the original character of an additional 11 % of the originally hydrophobic-coding triplets and an additional 14 % of the originally hydrophilic-coding triplets (on average). Thus, a selection oriented towards the preservation of the hydropathic character of amino acids may be expected to eventually result in a higher conservation of the second nucleotide (as compared to the first).

Mutation, selection and the amino acid hydropathic character: a study on receptor genes involved in immune and non-immune functions.

In some mRNA sequences, namely those of formyl peptide receptors and chemokine CXC receptors 4, it has been observed that the second nucleotide (nt) of the coding triplets is significantly more highly conserved than the first nt and the correlation between the conservation indexes of the first two nt is positive and significantly higher than the "basic" correlation usually found between adjacent nt. A theoretical analysis demonstrated that random mutations in the first nt preserve hydrophobicity in 73 % of triplets coding for hydrophobic amino acids (aa) and hydrophilicity in 77 % of triplets coding for hydrophilic aa, while random mutations in the second nt preserve hydrophobicity in 18 % of triplets coding for hydrophobic aa and hydrophilicity in 53 % of triplets coding for hydrophilic aa. When the triplets which had changed their hydropathic aa coding character underwent a second random mutation in the previously unmutated first or second nt, an additional 11 % of the originally hydrophobic-coding triplets reverted to hydrophobicity and an additional 14 % of the originally hydrophilic-coding triplets reverted to hydrophilicity.

Mutation patterns in the chemokine CXC receptor 4 gene subfamily.

Six representative CXCR4 mRNAs of fish, amphibia, birds, and mammals were selected to study the pattern of conservation/mutation of the individual nt of the coding sequences. According to an arbitrary conservation index ranging from 1 to 6, the indexes of conservation were: 5.04 for the first nt of coding triplets; 5.

The HIV-1 Rev binding family of proteins: the dog proteins as a study model.

Various proteins that are required for the building of new complete human immunodeficiency type 1 virions (HIV-1) are coded by unspliced or partly spliced virus-derived mRNAs. HIV-1 has developed special strategies for moving these mRNAs to the cytoplasm to be translated. In the nucleus of the infected cell the virus-derived protein Regulator of expression of viral proteins (Rev) can bind both the viral intron-containing mRNAs and the cellular co-factor HIV-1 Rev binding protein (HRB) and this complex may be shuttled through the nuclear pores.

CD14 major role during lipopolysaccharide-induced inflammation in chick embryo cardiomyocytes.

CD14 is a surface differentiation antigen that functions as a receptor for bacterial lipopolysaccharide. The cellular signaling events that lead to lipopolysaccharide-induced production of inflammatory mediators are the primary cause of myocardial dysfunction observed in sepsis. Here, we evaluated the role of CD14 in chick embryo cardiomyocytes stimulated with lipopolysaccharide.

Caspase-dependent apoptosis of the HCT-8 epithelial cell line induced by the parasite Giardia intestinalis.

Giardia intestinalis is a flagellated protozoan which causes enteric disease worldwide. Giardia trophozoites infect epithelial cells of the proximal small intestine and can cause acute or chronic diarrhea. The mechanism of epithelial injury in giardiasis remains unknown.

Laparoscopic treatment gastric cancer with advanced techniques: technical notes and follow-up.

The aim of the study was to describe the development of a wholly laparoscopic total gastrectomy technique for gastric cancer. On the strength of their experience in traditional gastric surgery (about 120 operations for gastric cancer performed over the past 4 years) the authors have performed minimally invasive surgery with conviction also in the oncological field. They have also performed total gastrectomy with D2 lymphadenectomy for gastric cancer (December 2000), which is identical to that of open surgery.

Decrease in resting calcium and calcium entry associated with slow-to-fast transition in unloaded rat soleus muscle.

Using fura-2 and the manganese quenching technique, we show here that sarcolemmal permeability to cations (SP-Ca) of slow-twitch muscles is greater than that of fast-twitch ones. This appears to be related to a higher expression and/or activity of stretch-activated channels, whereas leak channel activities are similar. During hindlimb suspension (HU), we found highly correlated decreases in SPCa and resting calcium of soleus muscle toward values of extensor digitorum longus (EDL) muscle.