Trends in childbearing and stillbirth risk: heterogeneity among Italian regions

In Italy, as in all Western countries, the almost monotonic decline in fertility observed since the 1960s has been paralleled until the beginning of the 1980s by a decrease in maternal age at delivery. Since then, age at marriage and at childbearing has been increasing and marital fertility has continued to decrease. By 1994 Italy showed extreme values of low total fertility rate (1.22) and of high mean maternal age at delivery (29.7). For the period between 1960 and 1994 we identified five U-shaped patterns in maternal age at delivery corresponding to five geographical areas, which differ socioeconomically and culturally. Since it is well known that an increase in the maternal age is accompanied by an increase in the risk of unfavorable pregnancy outcome, we estimated the stillbirth risk run by older (> or =35 years) mothers who delivered in 1994, with respect to their younger counterparts. The differences between the areas are reflected in the higher risk in southern compared to northern Italy: the maximum value occurred in Sicily (odds ratio 2.02, 95% confidence interval, 1.51-2.70) and the minimum value, even lower than in the north but not statistically significant, was found in Sardinia (odds ratio 1.25, 95% confidence interval, 0.81-1.91), known to be characterized by peculiar cultural and biological features.     

Helix induction potential of N-terminal α-methyl, α-amino acids

Summary A series of longer analogues of the C-peptide of RNAse A has been synthesized with the aim of assessing the helix induction potential in water of α-methyl, α-amino acids at the N-terminus of the chain. The circular dichroism data indicate that one isovaline residue is effective in increasing the helix content of the 13-residue peptide by about 7%.     

Spectral Properties of Single Gold Nanoparticles in Close Proximity to Biological Fluorophores Excited by 2-Photon Excitation

Metallic nanoparticles (NPs) are able to modify the excitation and emission rates (plasmonic enhancement) of fluorescent molecules in their close proximity. In this work, we measured the emission spectra of 20 nm Gold Nanoparticles (AuNPs) fixed on a glass surface submerged in a solution of different fluorophores using a spectral camera and 2-photon excitation. While on the glass surface, we observed the presence in the emission at least 3 components: i) second harmonic signal (SHG), ii) a broad emission from AuNPS and iii) fluorescence arising from fluorophores nearby. When on the glass surface, we found that the 3 spectral components have different relative intensities when the incident direction of linear polarization was changed indicating different physical origins for these components. Then we measured by fluctuation correlation spectroscopy (FCS) the scattering and fluorescence signal of the particles alone and in a solution of 100 nM EGFP using the spectral camera or measuring the scattering and fluorescence from the particles. We observed occasional fluorescence bursts when in the suspension we added fluorescent proteins. The spectrum of these burst was devoid of the SHG and of the broad emission in contrast to the signal collected from the gold nanoparticles on the glass surface. Instead we found that the spectrum during the burst corresponded closely to the spectrum of the fluorescent protein. An additional control was obtained by measuring the cross-correlation between the reflection from the particles and the fluorescence arising from EGFP both excited at 488 nm. We found a very weak cross-correlation between the AuNPs and the fluorescence confirming that the burst originate from a few particles with a fluorescence signal.     

Apples increase nitric oxide production by human saliva at the acidic pH of the stomach: a new biological function for polyphenols with a catechol group?

Dietary inorganic nitrate is secreted in saliva and reduced to nitrite by bacterial flora. At the acidic pH of the stomach nitrite is present as nitrous acid in equilibrium with nitric oxide (*NO), and other nitrogen oxides with nitrating and nitrosating activity. *NO in the stomach exerts several beneficial effects, but nitrosating/nitrating species have been implicated as a possible cause of epithelial neoplasia at the gastroesophageal junction. We investigated the effects of apple extracts on *NO release by human saliva at pH 2. A water extract obtained from apple homogenate increased *NO release caused by acidification of saliva. Data show that polyphenols were responsible for this activity, with chlorogenic acid and (+)-catechin the most active and concentrated species. However, ferulic acid, a hydroxycinnamic acid with only one aromatic hydroxyl group, did not increase *NO release. Fructose, the most representative sugar in apples, was also inactive. Interestingly, ascorbic acid in saliva induced a SCN(-)-enhanced burst of *NO but, unlike apple, the release was transient. The simultaneous addition of ascorbic acid and apple extract caused a burst of *NO followed by the increased steady-state level characteristic of saliva containing apple extract. Chlorogenic acid and (+)-catechin, but not ferulic acid, formed o-semiquinone radicals and nitrated polyphenols, suggesting the scavenging of *NO(2) by o-semiquinones. Our results propose that some apple polyphenols not only inhibit nitrosation/nitration but also promote *NO bio-availabilty at the gastric level, a previously unappreciated function.     

Microporosity of the substratum regulates differentiation of MDCK cells in vitro

Summary We have analyzed the ability of the physical substratum to modulate both the ultrastructural and protein synthetic characteristics of the Madin-Darby canine kidney (MDCK) renal cell line. When MDCK cells were seeded on Millipore Millicell CM microporous membrane cell culture inserts they demonstrated a more columnar organization with an increase in cell density sixfold greater than the same cells seeded on conventional plastic substrata. After 1 wk postseeding on the microporous membrane a partial basal lamina was noted, with a contiguous basement membrane being apparent after 2 wk. One-dimensional sodium dodecyl sulfate gel electrophoresis was used to analyze detergent-solubilized proteins from MDCK cells maintained on plastic substrata vs. microporous membranes. When proteins were pulse-labeled with [³⁵S]methionine, a 55 kDa protein was evident in the cytosolic extract of cells grown on collagen, laminin, and nontreated plastic substrata; but this labeled protein was not evident in similar extracts from cells grown on collagen and laminin-coated microporous membranes. To test if the polarized, basement-membrane secreting phenotype of the MDCK cells could be generated on a microporous membrane without pretreatment with any extracellular matrix (ECM) components, cells were seeded on the Millipore Millicell HA (cellulosic) microporous membrane. This type of substrata does not need a coating of ECM components for cell attachment. A partial basement membrane was formed below cells where the basal surface of the cell was planar, but not in areas where the cell formed large cytoplasmic extensions into the filter. This led us to the conclusion that the microporous nature of the substrata can dictate both ultrastructural and protein synthetic activities of MDCK cells. Furthermore, we suggest that both the planar nature of the basal surface and the microporosity of the substrate are corequisites for the deposition of the basement membrane.     

Sleep characteristics of persons with chronic fatigue syndrome and non-fatigued controls: results from a population-based study

Background  

The etiology and pathophysiology of chronic fatigue syndrome (CFS) remain inchoate. Attempts to elucidate the pathophysiology must consider sleep physiology, as unrefreshing sleep is the most commonly reported of the 8 case-defining symptoms of CFS. Although published studies have consistently reported inefficient sleep and documented a variable occurrence of previously undiagnosed primary sleep disorders, they have not identified characteristic disturbances in sleep architecture or a distinctive pattern of polysomnographic abnormalities associated with CFS.     

Morphometry and sexual dimorphism of the coastal spotted dolphin, Stenella attenuata graffmani, from Bahía de Banderas, Mexico

External measurements and size differences between the sexes were examined in the coastal spotted dolphin, Stenella attenuata graffmani , in Bahía de Banderas, on the Mexican Pacific coast. The dolphins were collected by local fishermen and 29 external characteristics were measured by members of the Marine Mammals Laboratory, University of Mexico. The length of each characteristic with respect to total length was analysed through adjustment of the data to a power equation. A stepwise discriminant analysis was applied to the absolute values and to those expressed as proportions to analyse the differences between the sexes. Results indicate that growth in these dolphins is generally negatively allometric, and most of the characteristics measured were, in both absolute and proportional terms, greater in male dolphins than in female dolphins. As found in many species of odontocetes, the discriminant analysis showed that the main differences between the sexes for this coastal subspecies include the relative positions of the umbilicus, the genital aperture and the anus. The morphometric data provided by this study, corresponding to 29 specimens of S. a. graffmani collected in a restricted locality of the Mexican Pacific coast, are particularly interesting to studies documenting latitudinal morphological differences in the coastal spotted dolphin.