The contribution of a pollinating seed predator to selection on Silene latifolia females

Interactions, antagonistic or mutualistic, can exert selection on plant traits. We explored the role of Hadena bicruris, a pollinating seed predator, as a selective agent on its host, the dioecious plant Silene latifolia. We exposed females from artificial-selection lines (many, small flowers (SF) vs. few, large flowers (LF)) to this moth. Infestation did not differ significantly between lines, but the odds of attacked fruits aborting were higher in SF females. We partitioned selection between that caused by moth attack and that resulting from all other factors. In both lines, selection via moth attack for fewer, smaller flowers contrasted with selection via other factors for more flowers. In LF females, selection via the two components was strongest and selection via moth attack also favoured increased fruit abortion. This suggests that the moths act as more of a selective force on flower size and number via their predating than their pollinating role.

Fine-scale spatial genetic structure and gene dispersal in Silene latifolia

Plants are sessile organisms, often characterized by limited dispersal. Seeds and pollen are the critical stages for gene flow. Here we investigate spatial genetic structure, gene dispersal and the relative contribution of pollen vs seed in the movement of genes in a stable metapopulation of the white campion Silene latifolia within its native range. This short-lived perennial plant is dioecious, has gravity-dispersed seeds and moth-mediated pollination. Direct measures of pollen dispersal suggested that large populations receive more pollen than small isolated populations and that most gene flow occurs within tens of meters. However, these studies were performed in the newly colonized range (North America) where the specialist pollinator is absent. In the native range (Europe), gene dispersal could fall on a different spatial scale. We genotyped 258 individuals from large and small (15) subpopulations along a 60 km, elongated metapopulation in Europe using six highly variable microsatellite markers, two X-linked and four autosomal. We found substantial genetic differentiation among subpopulations (global F(ST)=0.11) and a general pattern of isolation by distance over the whole sampled area. Spatial autocorrelation revealed high relatedness among neighboring individuals over hundreds of meters. Estimates of gene dispersal revealed gene flow at the scale of tens of meters (5-30 m), similar to the newly colonized range. Contrary to expectations, estimates of dispersal based on X and autosomal markers showed very similar ranges, suggesting similar levels of pollen and seed dispersal. This may be explained by stochastic events of extensive seed dispersal in this area and limited pollen dispersal.

Silene as a model system in ecology and evolution

The genus Silene, studied by Darwin, Mendel and other early scientists, is re-emerging as a system for studying interrelated questions in ecology, evolution and developmental biology. These questions include sex chromosome evolution, epigenetic control of sex expression, genomic conflict and speciation. Its well-studied interactions with the pathogen Microbotryum has made Silene a model for the evolution and dynamics of disease in natural systems, and its interactions with herbivores have increased our understanding of multi-trophic ecological processes and the evolution of invasiveness. Molecular tools are now providing new approaches to many of these classical yet unresolved problems, and new progress is being made through combining phylogenetic, genomic and molecular evolutionary studies with ecological and phenotypic data.

Evidence for inbreeding depression and post-pollination selection against inbreeding in the dioecious plant Silene latifolia

In many species, inbred individuals have reduced fitness. In plants with limited pollen and seed dispersal, post-pollination selection may reduce biparental inbreeding, but knowledge on the prevalence and importance of pollen competition or post-pollination selection after non-self pollination is scarce. We tested whether post-pollination selection favours less related pollen donors and reduces inbreeding in the dioecious plant Silene latifolia. We crossed 20 plants with pollen from a sibling and an unrelated male, and with a mix of both. We found significant inbreeding depression on vegetative growth, age at first flowering and total fitness (22% in males and 14% in females). In mixed pollinations, the unrelated male sired on average 57% of the offspring. The greater the paternity share of the unrelated sire, the larger the difference in relatedness of the two males to the female. The effect of genetic similarity on paternity is consistent with predictions for post-pollination selection, although paternity, at least in some crosses, may be affected by additional factors. Our data show that in plant systems with inbreeding depression, such as S. latifolia, pollen or embryo selection after multiple-donor pollination may indeed reduce inbreeding.

Should food-deceptive species flower before or after rewarding species? An experimental test of pollinator visitation behaviour under contrasting phenologies

Many plant species reward their pollinators, whereas some species, particularly among orchids, do not. Similarity of floral cues between co-flowering species influences how rapidly pollinators learn to avoid deceptive plants. This learning process, which affects the reproductive success of deceptive plants, may additionally depend on relative timing of flowering of sympatric rewarding and deceptive species. We tested the combined effects of corolla colour similarity and flowering order of rewarding and deceptive artificial inflorescences on visitation by naïve bumblebees. When deceptive inflorescences were offered after rewarding inflorescences, bumblebees visited them four times more often if both species were similar compared with when they were dissimilar. Pollinator visitation rate to deceptive inflorescences offered before rewarding inflorescences was intermediate and independent of similarity. Thus, early-flowering deceptive species avoid the costs of dissimilarity with rewarding species. This mechanism may favour adaptive evolution of flowering phenology in deceptive species and explain why temperate deceptive orchids usually flower earlier than rewarding ones.

Effect of Helicobacter pylori infection and acid blockade by lansoprazole on clarithromycin bioavailability

The effect of proton pump inhibitors and Helicobacter pylori infection on the bioavailability of antibiotics is poorly understood. We determined the effects of 5-day oral administration of 60 mg lansoprazole on the bioavailability of clarithromycin in individuals with and without H. pylori infection. Thirteen H. pylori-infected and 10 non-infected healthy volunteers were enrolled in a study with an open-randomized two-period crossover design and a 21-day washout period between phases. Plasma concentrations of clarithromycin in subjects with and without lansoprazole pre-treatment were measured by liquid chromatography coupled to a tandem mass spectrometer. Clarithromycin Cmax and AUC0-10 h were significantly reduced after lansoprazole administration. In addition, lansoprazole treatment of the H. pylori-positive group resulted in a statistically significant greater reduction in Cmax (40 vs 15%) and AUC0-10 h (30 vs 10%) compared to lansoprazole-treated H. pylori-negative subjects. Thus, treatment with lansoprazole for 5 days reduced bioavailability of clarithromycin, irrespective of H. pylori status. This reduction, however, was even more pronounced in H. pylori-infected individuals.

Within/between population crosses reveal genetic basis for siring success in Silene latifolia (Caryophyllaceae)

Divergence at reproductive traits can generate barriers among populations, and may result from several mechanisms, including drift, local selection and co-adaptation between the sexes. Intersexual co-adaptation can arise through sexually antagonistic co-evolution, a timely hypothesis addressed in animals but, to our knowledge, not yet in flowering plants. We investigated whether male and female population of origin affected pollen competition success, offspring fitness and sex ratio in crosses within/between six genetically differentiated populations of the white campion, Silene latifolia. Each female was crossed with pollen from one focus male from the same population, and pollen from two focus males from two distinct populations, both as single-donor and two-donor crosses against a fixed tester male with a 2-h interpollination interval (n = 288 crosses). We analysed paternity with microsatellite DNA. Male populations of origin significantly differed for siring success and in vitro pollen germination rates. In vitro pollen germination rate was heritable. Siring success also depended on sex ratio in the female family of origin, but only in between-population crosses. In some female populations, two-donor crosses produced less female-biased sex ratios compared with single-donor crosses, yet in other female populations the reverse was true. Offspring sex ratio varied with donor number, depending on the female population. Within/between population crosses did not differ significantly in seed set or offspring fitness, nor were siring success and offspring fitness significantly correlated. Altogether this suggests reproductive divergence for traits affecting pollen competition in S. latifolia.

Determination of memantine in human plasma by liquid chromatography–electrospray tandem mass spectrometry: Application to a bioequivalence study

A simple, sensitive and specific liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the quantification of memantine (I) in human plasma is presented. Sample preparation consisted of the addition of amantadine (II) as internal standard (IS), liquid-liquid extraction in basic conditions using a mixture of diethyl ether-chloroform (7:3, v/v) as extracting solvent, followed by centrifugation, solvent evaporation and sample reconstitution in methanol. Both I and II (internal standard) were analyzed using a C18 column and a mobile phase composed of methanol-water-formic acid (80:20:0.1, v/v/v). Eluted compounds were monitored using positive mode electrospray (ES) tandem mass spectrometry. The analyses were carried out by selected reaction monitoring (SRM) using the parent to daughter combinations of m/z 180>163 (memantine) and m/z 152>135 (amantadine). The peak areas from the analyte and IS were used for quantification of I. The achieved limit of quantification (LOQ) was 0.1 ng/mL; the assay exhibited a linear dynamic range of 0.1-50.0 ng/mL with a determination coefficient (r2) of at least 0.98. Validation results on linearity, specificity, accuracy, precision and stability, as well as on application to the analysis of samples taken up to 320 h after oral administration of 20mg (two 10mg capsules) of I in healthy volunteers demonstrated the applicability to bioequivalence studies.

Validated method for determination of bromopride in human plasma by liquid chromatography--electrospray tandem mass spectrometry: application to the bioequivalence study

A simple, sensitive and specific liquid chromatography-tandem mass spectrometry method for the quantification of bromopride I in human plasma is presented. Sample preparation consisted of the addition of procainamide II as the internal standard, liquid-liquid extraction in alkaline conditions using hexane-ethyl acetate (1 : 1, v/v) as the extracting solvent, followed by centrifugation, evaporation of the solvent and sample reconstitution in acetonitrile. Both I and II (internal standard, IS) were analyzed using a C18 column and the mobile-phase acetonitrile-water (formic acid 0.1%). The eluted compounds were monitored using electrospray tandem mass spectrometry. The analyses were carried out by multiple reaction monitoring (MRM) using the parent-to-daughter combinations of m/z 344.20 > 271.00 and m/z 236.30 > 163.10. The areas of peaks from analyte and IS were used for quantification of I. The achieved limit of quantification was 1.0 ng/ml and the assay exhibited a linear dynamic range of 1-100.0 ng/ml and gave a correlation coefficient (r) of 0.995 or better. Validation results on linearity, specificity, accuracy, precision and stability, as well as application to the analysis of samples taken up to 24 h after oral administration of 10 mg of I in healthy volunteers demonstrated the applicability to bioequivalence studies.

Validation of a selective method for determination of paroxetine in human plasma by LC-MS/MS

PURPOSE

A sensitive, robust, and selective liquid chromatographic-tandem mass spectrometric method (LC-MS/MS) was developed and validated for paroxetine quantification in human EDTA plasma.

METHODS

Sample preparation was based on liquid-liquid extraction using a mixture of ethyl acetate/hexane (50/50; v/v) to extract the drug and internal standard from plasma. Chromatography was performed on a C-18 analytical column and the retention times were 1.6 and 1.7 for paroxetine and fluoxetine (IS), respectively. The ionization was optimized using ESI(+) and selectivity was achieved by tandem mass spectrometric analysis using MRM functions, 330.0 --> 70.0 and 310 --> 43.9 for paroxetine and fluoxetine.

RESULTS

Analytical curve ranged from 0.2 to 20.0 ng/mL. Inter-day precision and accuracy of the quality control (QC) samples were < 15% relative standard deviation (RSD). Analyte stability during sampling processing and storage were established.

CONCLUSION

Validation results on linearity, specificity, accuracy, precision as well as application to the analysis of samples taken up to 120 h after oral administration of 20 mg of paroxetine in 28 healthy volunteers were found to be of good performance in bioequivalence study.

Substituted tetraazaacenaphthylenes as potent CRF1 receptor antagonists for the treatment of depression and anxiety

Two isomers of the hexahydro-tetraazaacenaphthylene templates (1 and 2) are presented as novel, potent, and selective corticotropin releasing factor-1 (CRF1) receptor antagonists. In this paper, we report the affinity and SAR of a series of compounds, as well as pharmacokinetic characterization of a chosen set. The anxiolitic activity of a selected example (2ba) in the rat pup vocalization model is also presented.

Development and validation of a selective and robust LC-MS/MS method for quantifying amlodipine in human plasma

A liquid chromatographic-tandem mass spectrometric method (LC-MS/MS) for quantifying amlodipine in human plasma was developed and validated. Sample preparation was based on liquid-liquid extraction using NaOH and a mixture of ethyl acetate/hexane (80/20; v/v). Chromatography was performed on a C-18 analytical column and the retention times were 1.9 and 3.0 min for amlodipine and nimodipine (internal standard), respectively. The ionization was optimized using ESI(+) and enhanced selectivity was achieved using tandem mass spectrometric analysis via two MRM functions, 409 --> 238 and 418 --> 343 for amlodipine and nimodipine. The calibration curve ranged from 0.2 to 20.0 ng/mL. The inter-day precision and accuracy and the relative standard deviation (RSD) were <15%. The analyte was shown to be stable over the time-scale of the whole procedure. The robustness of the method was demonstrated by the good reproducibility of the results obtained during the analysis of clinical samples.

Evolutionary ecology of the prezygotic stage

The life cycles of sexually reproducing animals and flowering plants begin with male and female gametes and their fusion to form a zygote. Selection at this earliest stage is crucial for offspring quality and raises similar evolutionary issues, yet zoology and botany use dissimilar approaches. There are striking parallels in the role of prezygotic competition for sexual selection on males, cryptic female choice, sexual conflict, and against selfish genetic elements and genetic incompatibility. In both groups, understanding the evolution of sex-specific and reproductive traits will require an appreciation of the effects of prezygotic competition on fitness.

Expression of vascular endothelial growth factor in human dysfunctional temporomandibular joint discs

A high density of blood vessels is found in specimens of temporomandibular joint (TMJ) disc at any stage of internal derangement of the joint, but the factors responsible for angiogenesis in the disc have not been described. The purpose here was to investigate, in human TMJ discs, the expression of vascular endothelial growth factor (VEGF), a multifunctional cytokine that contributes to angiogenesis. Specimens, free of significant morphological alterations and with varying degrees of disc tissue degeneration/regeneration, were studied by immunohistochemistry for VEGF in order to correlate immunohistochemical with histopathological findings. In normal discs and discs with minor pathological changes, fibroblast-like cells, fibrochondrocytes and chondrocyte-like cells were either not or only weakly immunostained by VEGF antibody. In disc specimens from internal derangement of the TMJ with significant tissue degeneration/regeneration, VEGF was consistently expressed. In these specimens, immunoreaction products for VEGF were observed both in the disc and in the endothelial cells of newly formed vessels. This VEGF immunolocalization is consistent with the stimulation of angiogenesis and the morphogenesis and differentiation of chondrocytes. Therefore VEGF expression by disc chondrocyte-like cells might reflect the action of the cytokine as an inducer of angiogenesis and as an autocrine signal for cells of the chondrogenic lineage.

Amoxicillin and ampicillin are not transferred to gastric juice irrespective of Helicobacter pylori status or acid blockade by omeprazole

BACKGROUND

The effects of proton pump inhibitors and Helicobacter pylori infection on the distribution of drugs used for the eradication of the bacteria are poorly understood.

AIM

The aim of this study was to investigate the effects of a 7-day administration of 20 mg of omeprazole on the pharmacokinetics of amoxicillin and ampicillin in the plasma, saliva and gastric juice of individuals with and without H. pylori infection.

METHODS

Fifty-four healthy volunteers without endoscopic lesions were enrolled. Twenty-six volunteers were included in the amoxicillin study and 28 individuals in the ampicillin study. Each study had an open randomized two-period crossover design and a 21-day washout period between phases. Plasma, saliva and gastric juice concentrations of amoxicillin and ampicillin in subjects with and without omeprazole pre-treatment were measured by reversed-phase HPLC using UV detection.

RESULTS

Neither pre-treatment with omeprazole nor H. pylori infection interfered with the plasma bioavailability of amoxicillin or ampicillin, as assessed by the AUC0-2 h. Neither ampicillin nor amoxicillin were detected in saliva or gastric juice in any study phase.

CONCLUSION

Short-term treatment with omeprazole does not interfere with the pharmacokinetics of amoxicillin or ampicillin. Our results also exclude the presence of a transfer mechanism for amoxicillin or ampicillin from the plasma to the gastric lumen.

Immunolocalization of vimentin and alpha-smooth muscle actin in dysfunctional human temporomandibular joint disc samples

The expression of vimentin and alpha-smooth muscle (alpha-SM) actin was examined in 10 human temporomandibular joint (TMJ) disc samples, with internal derangement and in two control specimens, in order to evaluate the phenotypic characteristics of TMJ disc cells in relationship to histological findings. This was accomplished by means of monoclonal antibodies specific for vimentin and alpha-SM actin and immunocytochemical technique. The study, revealed that every disc cell constantly expressed vimentin. Scattered alpha-SM actin positive cells could be appreciated in normal TMJ discs and tissues with minor pathological findings. In TMJ discs with severe alterations, i.e. tears and clefts, almost fibroblast-like cells, fibrochondrocytes and chondrocyte-like cells were strongly immunolabelled by anti-alpha-SM actin antibody. According to these findings it can be assumed that vimentin is expressed by all disc cell populations and it appears not to be influenced by any disease condition of the disc; on the other hand the up-regulation alpha-SM actin immunolabelling seems to be correlated to histopathological findings of tears and clefts. Cells, with a contractile phenotype, close to such defects, could be involved in disc tissue contraction and repair. The plasticity of disc cell populations which evolve towards a different phenotype when subjected to action of macro- and micro-environmental factors is also supported.

Sperm survival in the female reproductive tract in the fly Scathophaga stercoraria (L.)

While sperm competition risk favours males transferring many sperm to secure fertilizations, females of a variety of species actively reduce sperm numbers reaching their reproductive tract, e.g. by extrusion or killing. Potential benefits of spermicide to females include nutritional gains, influence over sperm storage and paternity, and the elimination of sperm bearing somatic mutations that would lower zygote fitness.We investigated changes in sperm viability after in vivo and in vitro exposure to the female tract in the polyandrous fly, Scathophaga stercoraria. Sperm viability was significantly lower in the females' spermathecae immediately after mating than in the experimental males' testes. Males also varied significantly in the proportion of live sperm found in storage in vivo. However, the exact mechanism of sperm degradation remains to be clarified. In vitro exposure to extracts of the female reproductive tract, including female accessory glands, failed to significantly lower sperm viability compared to controls. These results are consistent either with postcopulatory sperm mortality in vivo depending entirely on the male (with individual differences in sperm viability, motility or longevity) or with postcopulatory sperm mortality being subtly affected by female effects which were not detected by the in vitro experimental conditions. Importantly, we found no evidence in support of the hypothesis that female accessory glands contribute to sexual conflict via spermicide. Therefore, female muscular control remains to date the only ascertained mechanism of female influence on sperm storage in this species.

Myositis ossificans traumatica of the temporal muscle: a case report

Myositis ossificans traumatica (MOT) is a pathological condition characterized by extraskeletal formation of bony tissue, induced by violent or repeated trauma. Reports of this pathology occurring in the region of the head and neck are rare, and even more so in the muscles of mastication. We present the case of patient with MOT of the temporal muscle, the etiology of which seems to be related to traumatic manipulations during dental treatment. A review of the literature is presented and the surgical approach, which resolved this case is discussed.

Histochemical study of the elastic fibers in pathologic human temporomandibular joint discs

PURPOSE

This study investigated histochemically the elastic fibers in human temporomandibular joint (TMJ) discs with varying degrees of tissue degeneration/regeneration to determine whether there are differences that correlate with the histologic findings.

MATERIALS AND METHODS

Ten diseased human TMJ discs and 2 control specimens were studied histochemically by staining with Weigert's resorcin-fuchsin after oxidation with peracetic acid. This technique selectively stains elastic, elaunin, (pre-elastic), and oxytalan fibers.

RESULTS

In TMJ discs with an abnormal collagen fiber arrangement, an increased number of oxytalan fibers could be observed, contrary to discs with scar-like tissue transformation in which oxytalan fibers were decreased in number. In discs showing tears and clefts, the oxytalan fibers run perpendicular to the defects, whereas elaunin and elastic fibers were mainly circumferentially arranged. In discs with chondroid metaplasia, elastic, elaunin, and oxytalan fibers were extensively detected.

CONCLUSIONS

It is hypothesized that the elastic, elaunin, and oxytalan fibers found in severely damaged discs appear to ensure biomechanical compliance by reinforcing regions devoid of collagen bundles and thus function as shock absorbers of stretch and compression.

Lipoxin A(4) and aspirin-triggered 15-epi-lipoxin A(4) antagonize TNF-alpha-stimulated neutrophil-enterocyte interactions in vitro and attenuate TNF-alpha-induced chemokine release and colonocyte apoptosis in human intestinal mucosa ex vivo

Lipoxins (LXs) are lipoxygenase-derived eicosanoids and putative endogenous braking signals for inflammation in the gastrointestinal tract and other organs. Aspirin triggers the production of 15-epimers during cell-cell interaction in a cytokine-primed milieu, and aspirin-triggered 15-epi-5(S),6(R),15(S)-trihydroxy-7,9,13-trans-11-cis-eicosatetraenoic acid (15-epi-LXA(4)) may contribute to the bioactivity profile of this prototype nonsteroidal anti-inflammatory drug in vivo. We determined the effect of LXA(4), 15-(R/S)-methyl-11,12-dehydro-LXA(4) methyl ester (15-(R/S)-methyl-LXA(4)), and stable analogs of LXA(4) on TNF-alpha-stimulated neutrophil-enterocyte interaction in vitro and TNF-alpha-stimulated chemokine release, changes in mucosal architecture, and enterocyte apoptosis in cytokine-activated intact human colonic mucosa ex vivo. LXA(4), 15-(R/S)-epi-LXA(4), and 16-phenoxy-11,12-dehydro-17,18,19,20-tetranor-LXA(4) methyl ester (16-phenoxy-LXA(4)) inhibited TNF-alpha-stimulated neutrophil adherence to epithelial monolayers at nanomolar concentrations. In parallel experiments involving human colonic mucosa ex vivo, LXA(4)potently attenuated TNF-alpha-stimulated release of the C-X-C chemokine IL-8, and the C-C chemokines monocyte-chemoattractant protein-1 (MCP-1) and RANTES. Exposure of strips of normal human colonic mucosa to TNF-alpha induced disruption of mucosa architecture and enhanced colonocyte apoptosis via a caspase-3-independent mechanism. Prior exposure of the mucosa strips to 15-(R/S)-methyl-LXA(4) attenuated TNF-alpha-stimulated colonocyte apoptosis and protected the mucosa against TNF-alpha-induced mucosal damage. In aggregate, our data demonstrate that lipoxins and aspirin-triggered 15-epi-LXA(4) are potent antagonists of TNF-alpha-mediated neutrophil-enterocyte interactions in vitro, attenuate TNF-alpha-triggered chemokine release and colonocyte apoptosis, and are protective against TNF-alpha-induced morphological disruption in human colonic strips ex vivo. Our observations further expand the anti-inflammatory profile of these lipoxygenase-derived eicosanoids and suggest new therapeutic approaches for the treatment of inflammatory bowel disease.

Octreotide 24-h prophylaxis in patients at high risk for post-ERCP pancreatitis: results of a multicenter, randomized, controlled trial

BACKGROUND

Pharmacological prophylaxis of post-ERCP pancreatitis is costly and not useful in most non-selected patients, in whom the incidence of pancreatitis is 5% or less. However, it could be useful and probably cost-effective, in patients at high risk for this complication, where the post-procedure pancreatitis rate is 10% and more.

AIM

To assess the efficacy of octreotide in reducing the incidence and severity of post-ERCP pancreatitis and procedure-related hospital stay, in subjects with known patient-related risk factors.

METHODS

A total of 120 patients were randomly allocated to receive octreotide or not, in a multicentre, randomized, controlled trial. The drug was given subcutaneously, 200 microg t.d.s., starting 24 h before the ERCP procedure, in patients with either sphincter of Oddi dysfunction, or a history of relapsing pancreatitis or post-ERCP pancreatitis, or who were aged under 35 years, or who had a small common bile duct diameter (< 8 mm).

RESULTS

A total of 114 patients (58 in the octreotide group and 56 in the control group) completed the trial. Post-procedure pancreatitis occurred in seven octreotide-treated patients (12.0%) and eight controls (14.3%). The two groups showed no significant differences in the incidence or severity of pancreatitis. Twenty-four hours after the procedure, severe hyperamylasemia (more than five times the upper normal limit) without pancreatic-like pain was recorded in three octreotide-treated patients (5.2%) and six controls (10.7%), the difference being not significant.

CONCLUSION

Twenty-four-hour prophylaxis with octreotide proved ineffective in preventing post-ERCP pancreatitis and in avoiding 24-h severe hyperamylasemia in high-risk patients.

CD44 standard form (CD44H) expression and distribution in dysfunctional human temporomandibular joint discs

The expression pattern of the cell adhesion molecule CD44 standard form (CD44H) in dysfunctional human temporomandibular joint (TMJ) discs was studied immunohistochemically and compared with normal disc pattern in order to evaluate the expression of this adhesion molecule and correlate it to histopathological changes. Immunohistochemistry with anti-CD44H antibodies was performed on paraffin sections of pathological and normal discs. In normal TMJ discs, a moderate immunolabelling with anti-CD44H antibodies was detectable in fibroblastlike cells, in the few fibrochondrocytes and in chondrocytelike cells. In dysfunctional discs, the staining pattern and intensity varied according to the histopathological findings of the specimens. The TMJ discs showing abnormal collagen arrangement or fragmentation of collagen fibres presented overall the same immunolabelling pattern of normal discs. In the discs showing areas of fibrocartilaginous metaplasia, CD44H expression was upregulated in fibrochondrocytes and fibroblastlike cells, especially around the chondroid tissue. Overall, these results suggest that CD44H mediates the binding of some ECM proteins in TMJ disc cells. The up-regulation of CD44H observed in some dysfunctional TMJ discs seems to indicate a prevention of apoptosis in fibroblastlike cells and an important role in phenotypical change of fibrochondrocytes into chondroblastlike cells, enabling the aggregation of chondroid tissue pericellular matrix components.

Cellular S-100 protein immunostaining in human dysfunctional temporomandibular joint discs

S-100 protein was detected immunohistochemically in diseased human temporomandibular joint discs with different degrees of pathology, and the findings compared with those of normal discs. In normal discs, large nerve trunks in the posterior ligament were strongly stained by anti-S-100 antiserum; the very few chondrocyte-like cells sometimes showed faint staining, while no staining was observed in any fibrochondrocyte-like or fibroblast-like cell. In dysfunctional discs, S-100 protein immunostaining seemed to correlate with structural pathological findings. The discs showing an abnormal collagen arrangement or fragmentation of collagen fibres presented overall the same immunolabelling pattern as normal discs. In discs with fibrocartilaginous metaplasia and dystrophic cartilage formation, fibrochondrocyte cells showed a very strong immunoreaction for S-100 protein and fibroblast-like cells in some instances were also positive. These findings suggest that S-100 upregulation in disc cells can be considered an attempt at tissue repair by chondroid metaplasia following an injury in that it enables fibroblast-like cells and fibrochondrocytes to acquire a chondrogenic phenotype.

Female-mediated differential sperm storage in a fly with complex spermathecae, Scatophaga stercoraria

Multiple spermathecae potentially allow selective sperm use, provided that sperm from rival males are stored differentially, that is, in different proportions across storage compartments. In the yellow dung fly, Scatophaga stercoraria, females have three spermathecae arranged as a doublet and singlet. To test whether females store the sperm of rival males actively and differentially, we mated fixed male pairs to three females. After copulation, females were (1) dissected immediately before they could start laying a clutch of eggs, (2) left awake for 30 min but prevented from oviposition, or (3) anaesthetized with carbon dioxide for 30 min to interfere with the muscular control presumably required for sperm transport from the site of insemination to the spermathecae. For each female, we estimated the proportion of the second male's sperm stored in her spermathecae (S(2)value), using sperm length as a male marker. After copulation, the S(2)values in the singlet and doublet spermathecae differed significantly, indicating differential sperm storage during copulation. Postcopulatory treatment affected differential sperm storage significantly. Females dissected immediately had lower S(2)values in the doublet than in the singlet spermatheca, while females left awake showed the reverse pattern for the same two males. This reversal did not occur when females were treated with carbon dioxide. The results indicate differential storage of sperm from different males during copulation and that female muscular activity can affect storage and separation of competing ejaculates beyond copulation. Copyright 2000 The Association for the Study of Animal Behaviour.

Immunolocalization of gelatinase-A (matrix metalloproteinase-2) in damaged human temporomandibular joint discs

The fibrous tissue of the articular disc of the dysfunctional temporomandibular joint undergoes deep and variable structural modifications. Here the concurrence of morphological changes and the expression of matrix metalloproteinase-2 (MMP-2) in damaged discs from individuals suffering joint dysfunction was investigated. Microscopic, ultrastructural and immunocytochemical investigations were made on variously damaged articular discs and on one control sample. Disaggregation of collagen fibres, an increase in cellular components and calcification of large areas of tissue were observed in the damaged discs. These modifications were accompanied by a positive immunoreaction pattern for MMP-2. Fibroblast-, chondroblast- and osteoblast-like cells displayed a positive cytoplasmic reaction. In samples displaying evidence of synovial hyperplasia, some cells of the synovial protrusions were MMP-2 immunoreactive. No MMP-2 staining was observed in the control sample. These findings demonstrate that structural modifications of the articular disc could be specific responses to changes in the function of the temporomandibular joint. Variations in extrinsic stimuli may activate intrinsic factors, such as MMPs, that induce structural modifications in the discal tissue.

Effect of queen phenotype and social environment on early queen mortality in incipient colonies of the fire ant, Solenopsis invicta

In many ant species, including the fire ant Solenopsis invicta, queens can found their colonies alone or in associations of two or more. Colonies founded by associations produce a larger worker brood, have higher survival and mature earlier than colonies founded by solitary queens. However, cofoundresses almost invariably fight after the eclosion of the first workers. As a result, only one queen survives and monopolizes the colony's future reproductive output. Queen mortality also occurs before worker eclosion, but neither the causes (e.g. starvation, conflict), nor the factors (e.g. social environment) potentially affecting its occurrence, have been investigated. We analysed the effect of social environment and queen body mass on early mortality by keeping queens (1) solitarily, (2) within associations of four queens of the same initial mass, and (3) within associations of four queens of random initial mass. Mortality was higher for queens within associations than for solitary queens. Within associations of equally heavy queens, mortality significantly increased with the queens' body mass. In contrast, mortality of solitary queens did not significantly depend on body mass. Early mortality was significantly more frequent in associations of queens of random initial mass than in associations of equally heavy queens. Altogether these results demonstrate that queen phenotype differentially affects early queen mortality depending on the social environment, and suggest that reproductive competition rather than starvation is the main cause of mortality in multiple-queen associations. Copyright 1999 The Association for the Study of Animal Behaviour.

Intramuscular beta interferon for chronic hepatitis C: is it worth trying?

BACKGROUND AND AIMS

The intramuscular use of beta interferon has been tested in the treatment of chronic hepatitis C, but it did not prove effective when the schedule was 3 million units three times a week for six months. Since the lack of effectiveness of this treatment might be due to the low bioavailability of beta interferon when administered intramuscularly, we tested a higher dosage of the drug: 6 million units three times a week for twelve months.

PATIENTS AND METHODS

Ninety-two patients were randomized to receive, intramuscularly, either 3 or 6 million units of natural human fibroblast beta interferon three times a week for 12 months.

RESULTS

The short-term biochemical response was significantly more frequent in the group of patients who received the higher dosage of beta interferon: 21% vs 4.5% (p < 0.05). Nevertheless, a sustained biochemical response was obtained in only one patient (2%), who received the higher dosage of beta interferon.

CONCLUSIONS

Since the better short-term response rate was obtained with the higher dosage of beta interferon, a further increase in the dosage might improve the short-term and, possibly, the long-term response to treatment. However, due to the high cost of beta interferon, this high-dose schedule would probably not be cost-effective in the treatment of chronic hepatitis C.

Presence of calcified tissue in the human temporomandibular joint disc

Large calcified areas were observed in the articular discs of the temporomandibular joint from five patients suffering from articular dysfunctions. The calcified regions were always located inside the fibrous tissue of the discs. They had a woven bone-like morphological pattern and consisted of a compact mineralized tissue containing cells in irregular lacunae. In all the samples the calcified tissue was completely surrounded by a mineralizing border rich in cells and variously arranged collagen fibrils. Energy-dispersive spectrometry showed that mineralized regions contained large amounts of Ca and P. X-ray powder diffraction identified the crystals in these areas as hydroxyapatite.

Synovia hyperplasia and calcification in the human TMJ disk: a clinical, surgical, and histologic study

The aim of the study was to investigate the morphologic modifications occurring in the synovial tissue after severe derangement of the articular structures with dislocation or perforation of the disks. Light microscopic, ultrastructural, and immunocytochemical investigations were performed on 10 disks. Arthroscopic examinations had documented adhesions between the diskal surfaces and the glenoid eminence or the condylar head in all the selected cases. Histologic examination showed a remarkable hyperplasia of the synovial tissue with the formation of prominent protrusions. An evident increase of type B (fibroblast-like) cells and the presence of cells with the ultrastructural and immunocytochemical characteristics of myofibroblasts were observed. Foci of mineral precipitates and large deposits of calcified tissue were present in the synovial villi in three samples. Our observations suggest that functional failure and morphologic lesions of the synovia may be caused by arthropathy.

The articular disc surface in different functional conditions of the human temporo-mandibular joint

The peripheral discal tissue and the surface covering layer have been studied in normal and in variously damaged human temporo-mandibular joint discs. In the normal disc the tissue consisted of dense bundles of fibers and rare fibrocytes. The surface of the disc was covered by a regular basophilic and electron-dense layer. These morphological characteristics persisted also in some pathological discs in which fibrous derangements had already occurred in the deep parts. In very deformed and damaged discs associated with serious functional anomalies, the superficial discal tissue consisted of rare fibers dispersed in a loose ground substance and of an increased number of cells. The superficial coating was formed by an irregular dense lamina and aggregates of various materials containing cellular debris, vesicles, filaments and amorphous components. These deposits are probably due to degeneration processes of discal tissue. This investigation suggests that the superficial discal tissue and the covering layer are together involved in maintaining the functional properties of the articular surfaces. Their structural modification in severe functional anomalies leads to failure in the maintenance of nonadherence conditions and to deterioration of the functional defect.

Interictal mood and personality disorders in temporal lobe epilepsy and juvenile myoclonic epilepsy

BACKGROUND

Mood disorders have been described as the commonest psychiatric disorders in patients with temporal lobe epilepsy. Secondary depression in temporal lobe epilepsy could be interpreted either as an adjustment reaction to a chronic disease or as a limbic dysfunction. To clarify this issue, a controlled study of psychiatric disorders was conducted in different forms of epileptic and non-epileptic chronic conditions.

METHODS

Twenty outpatients with temporal lobe epilepsy, 18 outpatients with juvenile myoclonic epilepsy--a primary generalised seizure disorder--20 matched type I diabetic patients, and 20 matched normal controls were assessed by a structured interview (SADS) and by self rating scales (Beck depression inventory (BDI) and the state and trait anxiety scales STAIX1 and STAIX2).

RESULTS

Sixteen (80%) patients with temporal lobe epilepsy fulfilled the criteria for a psychiatric diagnosis at the SADS interview with a significantly higher frequency than patients with juvenile myoclonic epilepsy (22%) and diabetic patients (10%) (P < 0.0001). The most frequent disorder in temporal lobe epilepsy was a mood disorder: 11 (55%) patients with temporal lobe epilepsy had depression compared with three patients with juvenile myoclonic epilepsy and two diabetic patients (P < 0.001). Eight patients with temporal lobe epilepsy with an affective disorder also had a comorbid personality or anxiety disorder. Patients with temporal lobe epilepsy scored significantly higher on BDI, STAIX1, and STAIX2 than the three control groups (P < 0.001, P < 0.01, P < 0.001).

CONCLUSIONS

Patients with temporal lobe epilepsy have a higher incidence of affective and personality disorders, often in comorbidity, than patients with juvenile myoclonic epilepsy and diabetic patients suggesting that these psychiatric disorders are not an adjustment reaction to a chronic disease but rather reflect a limbic dysfunction.

Conversion of recent onset atrial fibrillation with single loading oral dose of propafenone: is in-hospital admission absolutely necessary?

A population of 283 patients with recent onset (< 72 hours) AF, without heart failure, who received a single 450- or 600-mg oral dose of propafenone, or digoxin 1 mg, or placebo for conversion to sinus rhythm (SR), was studied to determine whether a routine admission to the hospital for drug administration is justified. Previous bradyarrhythmias or sick sinus syndrome (SSS), and concomitant use of antiarrhythmic drugs were exclusion criteria. None of the 283 patients studied experienced VT or VF and none of them needed implantation of a temporary pacemaker. Periods of atrial tachyarrhythmias with regularization of atrial waves and 1:1 AV conduction were observed in only two cases, both receiving placebo. No predictor of proarrhythmia was found among the clinical variables considered (age, etiology, arrhythmia duration, atrial dimension, and blood potassium). No serious hemodynamic adverse effects were noted in either group. The rates of conversion to SR after 4 hours were: 80 (57%) of 141 patients who received propafenone and 35 (25%) of 142 patients who received digoxin or placebo (P < 0.001). Acute oral treatment with propafenone is simple and effective for the conversion of recent onset AF to SR in patients without clinical signs of heart failure. The routine admission of these patients to the hospital is not necessary. Home-based administration of oral propafenone to a selected group of patients could significantly increase the cost effectiveness of this treatment.

Endoarticular loose bodies and calcifications of the disk of the temporomandibular joint: morphological features and chemical composition

We studied articular disks and endoarticular loose bodies taken from patients suffering from different types of temporomandibular joint (TMJ) pathology. The scanning electron microscopy (SEM) analysis of the disks and the endoarticular loose bodies was followed by a chemical-compositional analysis using an energy dispersive spectrometer (EDS) and by characterization of the crystalline phases by X-ray powder diffraction (XRD). The articular disks were composed of a central radiopaque area lacking any evident structural features, surrounded by compact bundles of collagen fibers. EDS and XRD analyses showed that endodiscal radio-opaque areas were hydroxyapatite. By SEM, we observed a fibrous network only in circumscribed areas of the endoarticular loose bodies. The chemical-compositional analysis showed that the loose bodies were composed of calcite (CaCO3). The results of this investigation, along with the clinical history of the patients, allow us to formulate some hypotheses regarding the etiopathogenesis of these structural anomalies. The endodiscal calcifications could be the result of a chronic inflammatory process that produces displastic alterations of the articular disk. Moreover, an acute inflammatory process with modifications in the mechanisms of the synovial fluid turnover seems to be the event that leads to the formation of endoarticular loose bodies.

A microscopic and immunocytochemical study of structural changes in dysfunctional human temporomandibular joint discs

The central part of 12 articular discs from patients with serious alterations in function of the temporomandibular joint were investigated. The control discs were removed at autopsy from individuals who did not have any such functional defects. The anomalous discs had an increased cellular component; fibrocytes, fibroblasts, numerous myofibroblasts and, less frequently, smooth muscle cells and mast cells were present. The myofibroblasts, which had numerous bundles of thin filaments in the cytoplasm, were positive to the immunocytochemical reaction with antibody to alpha-smooth muscle actin. In one disc only a large part had changed into a mostly fatty tissue. In the majority of the altered discs, the part examined, which usually is neither vascularized nor innervated, was characterized by the presence of numerous blood vessels. Besides the capillary network several larger vessels were present. In one disc, several myelinated and unmyelinated fibres, isolated or in nerve bundles, were also seen. These observations show that the disc fibrous tissue may undergo deep structural modifications that appear to indicate not only a capacity for repair but also an ability to adapt to new functional conditions.

Collagen fiber arrangement in temporo-mandibular joint (TMJ) disks from human subjects with functional diseases. Scanning electron microscopy investigations

Twelve articular disks from patients with temporo-mandibular joint (TMJ) arthropathy were studied and compared with two normal disks. Scanning electron microscopy (SEM) examination of the surfaces and of longitudinal and cross-sections of the disks allowed the observation of the arrangement of the collagen fiber component in different parts of the disk. The superficial part of the articular disks appears to be formed by rather compact fibers. The internal portion is usually formed by bundles of collagen fibers in sheets, alternating with isolated fibers arranged in a parallel or irregular way. In some samples, blood vessels were observed. Our investigations suggested that the appearance of vascularization is the first remarkable histological change that can be observed in functionally abnormal articular disks.

Detection and determination of selenoproteins by nuclear techniques

Microbeam X-ray spectrometry, energy-dispersive X-ray fluorescence analysis, and neutron activation analysis were evaluated for the detection of selenium contained in the selenoprotein glutathione peroxidase. The glutathione peroxidase had been previously separated using polyacrylamide gel electrophoresis. The use of Bragg-reflected polarized X-ray beams was employed in the X-ray fluorescence measurements to minimize the problem of scatter owing to the gel matrix. Current detection limits of selenium in a gel matrix are 2.1 ng in the bench-top microbeam X-ray system and 30-60 ng using XRF with polarized beams. Neutron activation analysis was used for quality-control measurements, with a detection limit here of < 0.08 ng. The work has in principle established the feasibility of such an approach.

[Dynamic magnetic resonance of the temporomandibular joint. Observations and findings]

Condylar movements can be executed only if the TMJ morphology can satisfy functional needs of the masticatory apparatus. Articular components have to be in good relation with dento-skeletal functional anatomy: if this does not occur, mandibular dynamics may establish some functional stresses on the condylar head and the articular eminence. These overloaded structures and particularly their functional surfaces react to this situation to be remodelling and deformation of the articular cavity. In our work we have used a new method to analyse condylar dynamics using MRI. The reconstruction of mandibular movements, using this instrumentation, permits to make some useful observations on the functional capability of TMJ to adjust itself to different maxillofacial morphologies and, consequently, how this joint can fall in a dysfunctional and pathological condition.

Psychiatric diagnoses in ulcerative colitis. A controlled study

Fifty patients with UC and 50 matched controls with urolithiasis were interviewed with the SADS (lifetime version) and completed the SCL-90. According to information given during the SADS, there was a history of psychiatric disturbance in 11 UC patients (22%) and 8 controls (16%). At the time of the interview a psychiatric disturbance was present in 31 UC patients (62%) and four controls (8%), the most frequent diagnoses in the former being minor depression and generalised anxiety disorder. Patients with UC scored significantly higher than the controls on all the different SCL-90 subscales.

[Computerized occlusal verification in denture frames]

Partial removable prosthesis must foresee masticatory force distribution on all dental arch, with occlusal contacts uniformly distributed on natural and artificial teeth. These dental contacts must have the same intensity and they must happen in the same time, rispetting the gnathology laws. In this work it is investigated the possible utilization in partial removable prosthesis of T-Scan.