Spring and Fall recrudescence in Podarcis siculus ovaries: A role for progesterone.

In the lacertid Podarcis siculus the reproductive cycle is typically biphasic, with alternate recrudescence (Spring and Fall) and resting (Summer and Winter) phases. This study aimed to shed some light on the role exerted by progesterone during the two recrudescence periods; to this purpose, exogenous progesterone was administered intraperitoneally and the effects on oogonial proliferation, oocyte recruitment, and follicle cells apoptosis were determined. The presence and distribution of progesterone receptors was also investigated by immunohistochemistry and western blotting. Results indicate that progesterone would play different roles and follow different route of action in the two recrudescence periods thus confirming the complexity of the mechanisms controlling oogenesis in this species of vertebrate.

High density terahertz frequency comb produced by coherent synchrotron radiation.

Frequency combs have enabled significant progress in frequency metrology and high-resolution spectroscopy extending the achievable resolution while increasing the signal-to-noise ratio. In its coherent mode, synchrotron radiation is accepted to provide an intense terahertz continuum covering a wide spectral range from about 0.1 to 1 THz. Using a dedicated heterodyne receiver, we reveal the purely discrete nature of this emission. A phase relationship between the light pulses leads to a powerful frequency comb spanning over one decade in frequency. The comb has a mode spacing of 846 kHz, a linewidth of about 200 Hz, a fractional precision of about 2 × 10(-10) and no frequency offset. The unprecedented potential of the comb for high-resolution spectroscopy is demonstrated by the accurate determination of pure rotation transitions of acetonitrile.

Differential DMRT1 expression in the gonads of Podarcis sicula (Reptilia: Lacertidae).

DMRT genes encode a large family of transcription factors which share an unusual cysteine-rich DNA-binding motif, the DM domain. DM family members have been studied in the context of sexual development; in particular, the DMRT1 gene appeared to be the one most directly involved in sex determination, but its activity is largely unexplored and possible downstream targets of this factor have yet to be identified. DMRT1 of the lacertid lizard Podarcis sicula (PsDMRT1) was isolated as a model to study differential gene expression during the seasonal reproductive cycle of an ectothermal species. The adult testis of P. sicula exhibits full activity in spring, complete regression in summer and a slow autumnal recrudescence without spermiation. We cloned a 591-bp partial ORF of the PsDMRT1 fragment, whose putative amino acid sequence contains the conserved DM domain. Northern blot analysis of mRNA from different tissues of P. sicula individuals captured in spring demonstrated DMRT1 transcripts only in testis. Semi-quantitative RT-PCR and in situ hybridization experiments showed peak PsDMRT1 expression in spring, lower expression in autumn and no expression during the period of gonad regression. A possible correlation between androgen level variations and PsDMRT1 transcripts is hypothesized and discussed. Finally, data showed that PsDMRT1 is expressed only in spermatogenic cells, before the second meiotic division, suggesting that its role is confined to the proliferation and maintenance of spermatogonia and spermatocytes.

Oogenesis at subzero temperatures: a comparative study of the oocyte morphology in nine species of Notothenioids.

Oogenesis was examined in nine species of Antarctic fish to verify the existence of morphological peculiarities. The analyses were carried out on specimens belonging to three different families of Notothenioids (Nototheniidae, Channichthyidae and Bathydraconidae), all captured in the Ross Sea, in front of the Italian Station of Terra Nova Bay. Following dissection, the ovaries were processed and examined at the light and electron microscopes to determine the oocyte gross and fine morphology. The attention, in particular, was focused on the presence of cytoplasmic round bodies and on the organization of the cortical alveoli and the vitelline envelope. Results reveal significant specie-specific differences that could be partly correlated to the phylogenetic radiation but not to the peculiar environmental conditions being essentially comparable to those observed among temperate species.

The otoliths of the antarctic teleost Trematomus bernacchii: scanning electron microscopy and X-ray diffraction studies.

The authors studied the otoliths of the Nototheniid Trematomus bernacchii with scanning electron microscopy and X-ray diffraction analysis. Results obtained reveal that three otoliths are present: a large sagitta, a lapillus and a fragile asteriscus. Their sensorial faces appear finely decorated as shown by scanning electron microscopy (SEM). The sagitta and the lapillus are aragonitic while the asteriscus is vateritic, as demonstrated by X-ray diffraction.

Silent celiac disease in patients with childhood localization-related epilepsies.

PURPOSE: To evaluate how many patients with a clinical picture of idiopathic childhood localization-related epilepsies may also have silent celiac disease (CD). This will help determine whether investigation for CD should be restricted to those patients with childhood partial epilepsy with occipital paroxysms (CPEO) or should be extended to all patients with childhood partial epilepsy (CPE) regardless of seizure type and electroencephalographic (EEG) paroxysms. METHODS: The study group consisted of 72 patients (31 girls and 41 boys; mean age, 12.6 +/- 4.28 years; age at onset, 6.4 +/- 3.7 years) who were observed consecutively over a 5-year period and who received an initial diagnosis of idiopathic CPE. A diagnosis of CD was confirmed by using enzyme-linked immunosorbent assay (ELISA) to assess the presence of antigliadin antibodies and the immunofluorescent undirected test to assess the presence of antiendomysium antibodies. RESULTS: Twenty-five patients had CPEO, whereas the remaining 47 had CPE with centrotemporal spikes (CPEC). None of the patients with CPEC had positive antibody tests. Of the 25 patients with CPEO, two (8%) had antiendomysium immunoglobulin (Ig) A antibodies. In both of these patients, the jejunal biopsy showed atrophy of the villi and hyperplasia of the crypts, consistent with a diagnosis of CD. Brain computed tomography (CT) was normal in one of these patients and revealed occipital corticosubcortical calcifications in the other. CONCLUSIONS: Our study indicates that CD screening should be performed routinely only in patients with CPEO.

Storage in the yolk platelets of low MW DNA produced by the regressing follicle cells.

The present work was carried out to clarify the nature and origin of the yolk DNA present in vitellogenic oocytes of the lizard Podarcis sicula. Morphological and biochemical evidences indicate that it has an intrafollicular origin, from the apoptotic bodies resulting from follicle cells regression at the end of previtellogenesis. This conclusion is reinforced by the observation that the oocyte membrane, in in vitro experiments, is unpermeable to exogenous DNA. Biochemical evidences reveal that the yolk DNA has a low (200bp) molecular weight and this suggests that it is produced by the endonucleases typically involved in apoptotic DNA laddering. Indeed, immunocytochemical analyses demonstrate that follicle cells contain significant amounts of DNAse I. In immunoblots, carried out during different periods of the ovarian cycle, the enzyme shows a MW of about 33, 66 or 100 kDa thus indicating that its activity in the follicle of Podarcis is modulated by dimerization and/or binding to regulatory factors. Mol. Reprod. Dev. 59: 422-430, 2001.

Root-dentin sensitivity following non-surgical periodontal treatment.

BACKGROUND, AIMS: Little clinical data exist on the incidence and severity by which root dentin sensitivity (RDS) results from periodontal therapy. The aim of the present clinical trial was to study the degree to which a sample of patients requiring non-surgical periodontal treatment develops RDS. MATERIAL AND METHODS: Alterations in RDS was followed in 35 patients (29-65 years of age) requiring non-surgical treatment for moderate to advanced periodontal disease. Inclusion criteria for participation were need for periodontal treatment in at least 2 quadrants comprising a minimum of 4 teeth with vital pulps, no open caries lesions, no dental treatment in the last 3 months and no ongoing treatment for RDS. Baseline and follow-up recordings included responses of teeth to pain stimuli (directed compressed air) at buccal surfaces as graded by the patient on a 10-cm visual analogue scale (VAS). Periodontal therapy consisted of oral hygiene instruction (OH) followed by supra- and subgingival scaling/root planing by hand and ultrasonic instrumentation of one quadrant per each of the subsequent weeks. Thus, follow-up data included pain assessment after 1-3 weeks of OH alone, and 1-4 weeks post-instrumentation. RESULTS: There was a statistically significant reduction in mean VAS scoring over time in quadrants where only meticulous plaque control had been maintained, while VAS mean values increased significantly after instrumentation (p<0.001). Also the % of subjects reporting higher mean VAS values increased after instrumentation. Changes in mean VAS scores were generally moderate and only 9 patients gave an increase on VAS of >2 cm for 3 or more teeth. A statistically significantly higher increase of RDS was observed for initially sensitive teeth (VAS>0) than for teeth not responding at baseline (p<0.001). Although a reduction in the intensity of RDS could be noticed during the later phase of the 4-week follow-up period after scaling and root planing, the percentage of sensitive teeth remained unchanged. CONCLUSION: The data confirm that meticulous plaque control will diminish RDS problems and that scaling and root planing procedures in periodontal therapy result in an increase of teeth that respond to painful stimuli. However, pain experiences in general appeared minor and only a few teeth in a few patients developed highly sensitive root surfaces following instrumentation.

New site of temporary storage of rRNA in O. mykiss previtellogenic oocytes.

This article describes a new organelle found in the cytoplasm of the growth stage fish oocytes. In particular, we describe its organization at the morphological level and investigate its composition by different cytochemical and immunocytochemical approaches with both light and electron microscope. The conclusion is that the body is a peculiar protein scaffold functioning as a temporary trap for the storage of rRNA in the mid to late growth stage oocytes. Its presence would be related to the reorganization of the mass of amplified rDNA in micronucleoli and to the consequent temporary stop in the rRNA synthesis.

Interferon-gamma (IFN-gamma) and prostaglandin E2 (PGE2) regulate differently IL-12 production in human intestinal lamina propria mononuclear cells (LPMC).

IL-12 modulates Th1 immune response during chronic colitis. Mechanisms regulating IL-12 synthesis in human intestine are poorly understood. The aim of this study was to investigate the effect of IFN-gamma and PGE2 on lipopolysaccharide (LPS)-stimulated LPMC IL-12 production. Normal LPMC cultures were run in the presence or absence of IFN-gamma and/or PGE2 before LPS stimulation. To examine the role of endogenous PGE2 on LPS-stimulated IL-12 release, LPMC cultures were added of indomethacin before LPS stimulation. IL-12, IL-10 and IL-8 were measured by ELISA. No IL-12 was detected in either unstimulated or LPS-stimulated LPMC cultures. In contrast, LPMC released IL-8 (650 +/- 125 pg/ml) and IL-10 (75 +/- 25 pg/ml) in response to LPS. Treatment of LPMC with IFN-gamma facilitated LPS-stimulated IL-12, whereas it completely abrogated IL-10 production. IL-12 release by LPMC stimulated with IFN-gamma and LPS was significantly inhibited by exogenous IL-10. The addition of PGE2 to IFN-gamma-treated LPMC cultures inhibited in a dose-dependent manner LPS-induced IL-12 secretion. Furthermore, IL-12 was detectable (85 +/- 25 pg/ml) in the supernatants of LPMC cultures treated with indomethacin and LPS. In contrast to the effect on IL-12, PGE2 significantly augmented LPS-stimulated LPMC IL-10 production. However, the inhibition of IL-12 by PGE2 was only partially reversed by anti-IL-10. In a simplified model of LPS tolerance, we finally showed that monocyte-derived macrophages exhibited reduced IL-12 production after repeat LPS stimulation. In these cell cultures, indomethacin abrogated the induction of LPS desensitization. IFN-gamma and PGE2 modulate differently the LPMC responsiveness to LPS in terms of IL-12 synthesis.

Structural and functional modifications of the nucleolus during previtellogenic oocyte growth in the lizard Podarcis sicula.

In the present study we analyse the nature and the functional significance of the spherical and fibrillo-granular structures appearing in the oocyte nucleus of the lizard Podarcis sicula, following the disappearance of the typical nucleolus. By LM and TEM approaches, we demonstrate that the fibrillo-granuli, containing DNA, RNA and nucleolar proteins, are micronucleoli transcriptionally active and that their DNA is probably derived from nucleolar fragmentation. By contrast, we could not explain the origin and role of the so-called spherical bodies, appearing earlier in oocyte growth; these, in fact, do not contain nucleic acids or nucleolar proteins and do not incorporate uridine. Different possible explanations of their significance are discussed.

How the ovarian follicle of Podarcis sicula recycles the DNA of its nurse, regressing follicle cells.

In Podarcis sicula specialized follicle cells send reserve materials to the previtellogenic oocyte via intercellular bridges. Immediately before the onset of vitellogenesis this transferring becomes particularly massive so that the cell volume significantly reduces, meanwhile in the nucleus the morphological alterations typical of apoptosis appear. To clarify why these follicle cells are not simply fully resorbed by the oocyte and to determine whether their DNA is discarded or recycled, we carried out a series of morphological and biochemical investigations. The finding that large macromolecular scaffolds are formed and that these are able to retain the DNA until it is extensively cut by two different endonucleases suggests that regression of the follicle cells is programmed and that the fate of their DNA is strictly controlled. Following its genetical neutralization via fragmentation, the DNA is apparently recycled by being transferred into the oocyte via the intercellular bridges, that, in fact, remain open until the very late stages of cell regression. The small DNA fragments reaching the oocyte cytoplasm would not interfere with meiosis completion but could significantly contribute to the stock of reserve materials to the advantage of the growing oocyte and/or developing embryo.

Gingival recessions and noncarious cervical lesions: a soft and hard tissue challenge.

Gingival recessions and noncarious cervical lesions are frequent and closely related defects which can be successfully treated by mucogingival surgery and restorative therapy techniques either used alone or in combination depending on the defect characteristics. Proper treatment planning is guided by careful clinical diagnosis. A selection of treatment modalities are presented and useful hints proposed: the long term success is always strictly bound to the identification and elimination of the etiologic factors, to a correct treatment and a meticulous maintenance program.

Representation of verbal pain descriptors on a visual analogue scale by dental patients and dental students.

Verbal rating scales (VRS), composed of ranked pain descriptors, are often employed in pain research. Factors that may influence the subjective pain intensity values, however, are not well established. In this study, 5 common pain descriptor adjectives were represented on a visual analogue scale (VAS) by a group of 80 dental students, by a group of 48 patients undergoing periodontal therapy, and by a group of 31 dental phobic patients. It was thought that each group of individuals on conducting the test represented a different degree of apprehension, ranging from a relaxed to a very tense status. There were differences in the interpretation of the pain descriptors between groups. Furthermore, age seemed to influence the interpretation of the pain descriptors. No correlation was found with gender. The descriptors did not divide the analogue scale into equal segments. 71% of all subjects gave the adjective "mild" a lower pain intensity representation than the adjective "weak", while the order was reversed among remaining subjects. Findings cast doubt on the reliability of VRS and the data handling methods commonly adopted in clinical pain research.

Indirect composite restorations in the anterior region: a predictable technique for complex cases.

The indirect composite inlay technique demonstrates excellent aesthetic results in the posterior regions, achieved by reproducing the shape, color, and contour of the natural tooth on a cast model rather than using the free-hand composite restorative modality. The utilization of the indirect technique can be adapted for the anterior regions as well, and it offers a valid treatment alternative that is predictable with optimal restorative results. The evaluation, planning, and accuracy of implementation of the various phases of this methodology allow a more precise achievement of the result; any potential error in the restoration can be corrected prior to final cementation. This technique increases the quality of composite restorations that have always been considered unpredictable and extensively dependent upon the skills of the operator. The learning objective of this article is to familiarize the reader with the clinical and laboratory phases of this indirect treatment modality of the anterior dentition.