High protein flexibility and reduced hydration water dynamics are key pressure adaptive strategies in prokaryotes.

Water and protein dynamics on a nanometer scale were measured by quasi-elastic neutron scattering in the piezophile archaeon Thermococcus barophilus and the closely related pressure-sensitive Thermococcus kodakarensis, at 0.1 and 40 MPa. We show that cells of the pressure sensitive organism exhibit higher intrinsic stability. Both the hydration water dynamics and the fast protein and lipid dynamics are reduced under pressure. In contrast, the proteome of T. barophilus is more pressure sensitive than that of T. kodakarensis. The diffusion coefficient of hydration water is reduced, while the fast protein and lipid dynamics are slightly enhanced with increasing pressure. These findings show that the coupling between hydration water and cellular constituents might not be simply a master-slave relationship. We propose that the high flexibility of the T. barophilus proteome associated with reduced hydration water may be the keys to the molecular adaptation of the cells to high hydrostatic pressure.

Identification of acquired copy number alterations and uniparental disomies in cytogenetically normal acute myeloid leukemia using high-resolution single-nucleotide polymorphism analysis.

Recent advances in genome-wide single-nucleotide polymorphism (SNP) analyses have revealed previously unrecognized microdeletions and uniparental disomy (UPD) in a broad spectrum of human cancers. As acute myeloid leukemia (AML) represents a genetically heterogeneous disease, this technology might prove helpful, especially for cytogenetically normal AML (CN-AML) cases. Thus, we performed high-resolution SNP analyses in 157 adult cases of CN-AML. Regions of acquired UPDs were identified in 12% of cases and in the most frequently affected chromosomes, 6p, 11p and 13q. Notably, acquired UPD was invariably associated with mutations in nucleophosmin 1 (NPM1) or CCAAT/enhancer binding protein-alpha (CEBPA) that impair hematopoietic differentiation (P=0.008), suggesting that UPDs may preferentially target genes that are essential for proliferation and survival of hematopoietic progenitors. Acquired copy number alterations (CNAs) were detected in 49% of cases with losses found in two or more cases affecting, for example, chromosome bands 3p13-p14.1 and 12p13. Furthermore, we identified two cases with a cryptic t(6;11) as well as several non-recurrent aberrations pointing to leukemia-relevant regions. With regard to clinical outcome, there seemed to be an association between UPD 11p and UPD 13q cases with overall survival. These data show the potential of high-resolution SNP analysis for identifying genomic regions of potential pathogenic and clinical relevance in AML.

An inhibitor of ornithine decarboxylase antagonizes superoxide generation by primed human polymorphonuclear leukocytes.

Tumor necrosis factor-alpha (TNF-alpha) induces a rapid increase in polymorphonuclear leukocyte (PMN) polyamine content which appears to be required for optimal priming of the respiratory burst. The objective of the present study was to determine whether inhibition of polyamine biosynthesis modifies PMN responses to lipopolysaccharide (LPS), granulocyte-macrophage colony-stimulating factor (GM-CSF), or granulocyte colony-stimulating factor (G-CSF). Treatment with alpha-difluoromethylornithine (DFMO), a selective inhibitor of the rate-limiting biosynthetic enzyme ornithine decarboxylase, produced dose-dependent inhibition of the respiratory burst in PMNs that were primed by these agents and subsequently activated by formyl-Met-Leu-Phe (fMLP). However, DFMO did not significantly inhibit fMLP-stimulated superoxide generation or alter the induction of PMN adhesion and interleukin-1 beta (IL-1 beta) mRNA expression by LPS or GM-CSF. Antagonism of priming by DFMO correlated with a dose-dependent attenuation of fMLP-induced intracellular Ca2+ mobilization (r > or = 0.96). Since Ca2+ plays an important role in modulating the respiratory burst in primed PMNs, this could, in part, account for the selective effects of DFMO.

Regulation of ciprofloxacin uptake in human promyelocytic leukemia cells and polymorphonuclear leukocytes.

Polymorphonuclear leukocytes (PMNs) actively internalize ciprofloxacin, a capability that can enhance killing of intracellular bacteria and facilitate delivery of the antimicrobial agent to infection sites by migrating PMNs. In this study we investigated mechanisms for up-regulation of this process. Activation with N-formyl-methionyl-leucyl-phenylalanine (fMLP; 100 nM) enhanced PMN ciprofloxacin uptake by 50% (P < 0.05). Phorbol myristate acetate (PMA; > or = 10 nM) enhanced uptake by at least 36-fold, mainly by stimulating an increase in the Vmax of the ciprofloxacin transporter. This effect of PMA was inhibited by antagonists of protein kinase C (H7 and chelerythrine) and the mitogen-activated protein kinase cascade downstream (PD 098059). Under resting and PMA-activated conditions, ciprofloxacin uptake by immature human promyelocytic leukemia (HL-60) cells was much lower than in PMNs. However, when HL-60 cells were induced to mature into PMN-like cells, their ciprofloxacin uptake activity increased markedly. These findings implicate a role for protein kinase C in up-regulation of the ciprofloxacin transporter and suggest that myeloid cells acquire an enhanced ability to take up ciprofloxacin as they mature to end-stage PMNs.

pH changes observed in the inflamed gingival crevice modulate human polymorphonuclear leukocyte activation in vitro.

Previous studies have noted a positive correlation between gingival inflammation and crevicular pH, which reportedly varies from 6.5 to 8.5. In the present study, we characterized the manner in which deviation from the "physiological" pH of blood (7.2) influences activation of chemotaxis, phagocytosis, superoxide generation, and degranulation by human polymorphonuclear leukocytes (PMNs). Purified PMNs were suspended in HEPES-buffered balanced salts solutions adjusted to pH 6.7, 7.2, 7.7, or 8.2. In a modified Boyden chamber, the chemotactic response to fMet-Leu-Phe was maximal at pH 7.2. In comparison, chemotaxis was significantly depressed at pH 7.7 and pH 8.2 (P < 0.05), but was not significantly different at pH 6.7. Activation of the respiratory burst by fMet-Leu-Phe was optimal at pH 7.2, but was significantly depressed at pH 6.7 and 8.2 (P < 0.05). pH had little effect on N-acetyl-beta-glucosaminidase release from primary granules. However, lactoferrin release from the secondary granules of fMet-Leu-Phe-activated PMNs was significantly lower at pH 7.2 than at pH 6.7 or 8.2 (P < 0.05). Moreover, phagocytosis of opsonized bacteria was significantly lower at pH 7.2 than at pH 7.7. In addition to these effects on functional activation, extracellular pH influenced the magnitude of intracellular Ca2+ mobilization. Peak fMet-Leu-Phe-induced Ca2+ levels were significantly higher at pH 8.2 than at pH 7.2 (P < 0.01). These findings suggest that the pH of the periodontal environment can selectively influence PMN activation, thereby altering the balance between bacteria and the host response.

Polyamines found in gingival fluid inhibit chemotaxis by human polymorphonuclear leukocytes in vitro.

Putrescine and spermidine occur at concentrations approaching 1 mM in gingival fluid at diseased periodontal sites. Previous work demonstrates that these polyamines potentiate Ca2+ signaling in polymorphonuclear leukocytes (PMNs), resulting in enhanced degranulation and superoxide generation. The present study extends this work by characterizing the effects of polyamines on PMN chemotaxis and phagocytosis, in which Ca2+ signaling plays a less defined regulatory role. Putrescine (1 mM) and spermidine (0.1 to 0.5 mM) significantly inhibited chemotaxis to fMet-Leu-Phe and C5a (P < 0.05). This inhibition was not strongly related to any effect polyamines have on PMN adhesion, actin polymerization, or formyl peptide receptor expression. Neither putrescine nor spermidine had a significant impact on phagocytosis of opsonized bacteria by PMNs. Thus, at concentrations similar to those found in gingival fluid, polyamines could potentially inhibit recruitment of PMNs to diseased pockets without impairing their ability to engulf invading bacteria.

An inhibitor of polyamine biosynthesis impairs human polymorphonuclear leukocyte priming by tumor necrosis factor alpha.

TNF primes polymorphonuclear leukocytes (PMNs) for enhanced oxidative and secretory activity and directly induces adhesion and IL-1 beta expression. Previous reports suggest that polyamine biosynthesis by ornithine decarboxylase (ODC) has an essential role in macrophage activation by TNF. In the current study, TNF induced rapid increases in the putrescine and spermine content of PMNs. Difluoromethylornithine (DFMO), a selective inhibitor of ODC, inhibited these increases and blunted the enhancement of superoxide generation and secondary granule release associated with priming by TNF. DFMO did not affect the expression of TNF receptors or block receptor-independent activation of the respiratory burst by phorbol esters. Moreover, DFMO did not antagonize induction of adhesion or IL-1 beta mRNA expression by TNF. Thus, polyamine biosynthesis plays an important role in priming by TNF, but is not involved in all PMN responses to this cytokine. This suggests that ODC is a potential target for selective chemotherapeutic modulation of the inflammatory response.

[Dysgeusias]. / Disgeusias.

This is a review of multiple pathologic conditions associated with altered taste perception and identification. We stated the steps and the molecular basis of this sense. This paper includes two cases that exemplify two distinct types of dysgeusia; case, 1 a 48 year old man who had clinical manifestations of hypogeusia and dysgeusia for one year, probably secondary to air pollutants. Case 2, a 37 year old man who worked in the same factory and also had dysgeusia; we concluded that it was secondary to thermal and chemical agression of the oropharynx; his plasma and urinary levels of zinc were normal. Many medications and contaminants of air and water are related with changes in serum and urine levels of zinc, which is a determinant at several levels for the correct integration of the taste system. Namely it is important for synthesis of the metalloprotein, gustin, a parotid gland protein secreted into saliva, which in turns is very important to make union of the sapid substance (SS) with its receptor in the surface of the gustatory epithelium a the taste buds. Zinc is also related with neurotransmission of the electrical stimulus generated in the bud cell and ending in the central nervous system. There is an acute zinc loss syndrome, seen in patients treated with histidine, which simulates the steps in which taste sensation is integrated. A clinical approach for diagnosis of hypogeusic or dysgeusic patients must include a careful evaluation of the diat elements, an assesment of hereditary disorders, the type of work and contact with pollutants known to be related with dysgeusia. A special care regarding physical examination must be considered in particular a meticulous review of the oropharynx in order to diagnose inflammatory, neoplastic or neurological disorders. The levels of perception an identification of flavors: sweet, bitter, sour and salt, must be determined using the forced scale triple choice technic. Serum and urinary levels of zinc should be determined in each patient using a flameless atomic absorption spectrophotometer. A quantification of the activity of leucocyte alkaline phosphatase, a zinc metalloenzyme, is a useful aid, liver function tests. 13 and 14 determinations and serum protein electrophoresis are mandatory because many pathologic states of these organ systems are known to be related with disorders of taste. We wish to remark the important function of zinc in the taste system, the role of essential trace elements is receiving increased atention and these alterations are good examples of their clinical importance.

[Hepatic changes caused by contraceptive steroids]. / Alteraciones hepáticas producidas por esteroides anticonceptivos.

The number and type of contraceptive side effects is constantly increasing. Several abnormalities have been observed regarding liver function, these include: Jaundice, cholestasis, hepatitis, changes in the rate synthesis of many serum proteins and coagulation factors. One of the most dangerous complications in the liver is the risk to develop hepatic adenoma which has been reported in 250 cases. An even more dangerous complication is the development of liver cancer of several histological types which so far has been observed in 21 patients. Women receiving contraceptive steroids should be alert regarding their potential hazards and the physician must be informed of such risks and observe special control care in these patients.

PIP: Major known hepatic side effects from treatment with oral contraceptives (OCs) are cholestasis, jaundice, and changes in the synthesis of liver proteins. Cases of hepatic adenomas seem to be on the increase, and so are cases of malignant liver tumors. Hepatic tumors can spontaneously rupture causing death. Women on OCs should not only be kept under surveillance, but be informed of the potential dangers of treatment with OCs.