Trend and seasonality in hospitalizations for pulmonary embolism: a time-series analysis

BACKGROUND

The existence of seasonal variability in patients with acute pulmonary embolism (PE) has been debated for years, with contradictory results. The aim of this study was to identify the trend and possible existence of a seasonal pattern in hospitalizations for PE in Spain.

METHODS

We analyzed the hospital discharge database of the Spanish National Health System from 2001 to 2010. Patients aged > 14 years diagnosed with PE were selected and a time series was constructed considering mean daily admissions for PE by month. The trend and seasonality factor of the series were determined using time-series analysis, and time-series modeling was used for analysis. Exponential smoothing models and the autoregressive integrated moving average test were used to generate a predictive model.

RESULTS

From 2001 to 2010, there were 162,032 diagnoses of PE (5.07 per 1000 hospitalizations). In 105,168 cases, PE was the reason for admission. The PE diagnosis rate ranged from 4.14 per 1000 in 2001 to 6.56 per 1000 in 2010; and hospital admissions due to PE ranged from 2.67 to 4.28 per 1000 hospital discharges. Time-series analysis showed a linear increase in the incidence and a significant seasonal pattern with 17% more admissions in February and 12% fewer in June-July with respect to the central tendency (difference from February to June, 29%).

CONCLUSIONS

The incidence of hospitalizations for PE showed a linear increase and a seasonal pattern, with the highest number of admissions in winter and the lowest number in summer.

[Medial versus lateral plating in distal tibial fractures: a prospective study of 40 fractures]

OBJECTIVE

Tibial plafond fractures are one of the most challenging injuries in orthopaedic surgery. Their results could be improved by following the new guidelines for the management, and modern plating techniques. The results and complication rate between anteromedial and anterolateral approach for open reduction and internal fixation of these fractures were compared.

MATERIAL AND METHODS

A study was conducted on 40 patients treated by open reduction an internal fixation between 2007 and 2008. The surgical approach was selected by the surgeon in charge, depending on fracture pattern and skin situation. Patients were evaluated clinically and radiographically by an independent orthopaedic surgeon, not involved in the surgical procedure, using clinical (American Orthopaedic Foot and Ankle Society score) and radiological criteria at a minimum of two years. The appearance of complications after both approaches was recorded.

RESULTS

Forty patients were included. The mean age was 53 years, with 24 males and 16 females. Seventeen of the injuries were of high energy, and there were 8 open fractures (3 of type i, 4 type ii and one type iii), and 12 of the closed injuries were grade ii or iii in the Tscherne classification. Six patients (15%) had associated injuries. At final follow-up there were 33 (82%) excellent or good results. No statistical differences were found between either surgical approach regarding time to bone union, rate of delayed union and infection rate. Three plates of the anteromedial group and none of the anterolateral group needed to be removed.

CONCLUSION

Open reduction and internal fixation of distal tibia fractures produced reliable results, with no statistical differences found between anteromedial and anterolateral surgical approaches. Clinical and radiological results and complication rate were mainly related to the fracture type.

Neuromedin s as novel putative regulator of luteinizing hormone secretion

Neuromedin S (NMS), a 36 amino acid peptide structurally related to neuromedin U, was recently identified in rat brain as ligand for the G protein-coupled receptor FM4/TGR-1, also termed neuromedin U receptor type-2 (NMU2R). Central expression of NMS appears restricted to the suprachiasmatic nucleus, and NMS has been involved in the regulation of dark-light rhythms and suppression of food intake. Reproduction is known to be tightly regulated by metabolic and photoperiodic cues. Yet the potential contribution of NMS to the control of reproductive axis remains unexplored. We report herein analyses of hypothalamic expression of NMS and NMU2R genes, as well as LH responses to NMS, in different developmental and functional states of the female rat. Expression of NMS and NMU2R genes was detected at the hypothalamus along postnatal development, with significant fluctuations of their relative levels (maximum at prepubertal stage and adulthood). In adult females, hypothalamic expression of NMS (which was confined to suprachiasmatic nucleus) and NMU2R significantly varied during the estrous cycle (maximum at proestrus) and was lowered after ovariectomy and enhanced after progesterone supplementation. Central administration of NMS evoked modest LH secretory responses in pubertal and cyclic females at diestrus, whereas exaggerated LH secretory bursts were elicited by NMS at estrus and after short-term fasting. Conversely, NMS significantly decreased elevated LH concentrations of ovariectomized rats. In summary, we provide herein novel evidence for the ability of NMS to modulate LH secretion in the female rat. Moreover, hypothalamic expression of NMS and NMU2R genes appeared dependent on the functional state of the female reproductive axis. Our data are the first to disclose the potential implication of NMS in the regulation of gonadotropic axis, a function that may contribute to the integration of circadian rhythms, energy balance, and reproduction.

Novel signals for the integration of energy balance and reproduction

Although the close link between body weight and fertility has been known for eons, only recently have the peripheral signals and neuroendocrine networks responsible for such a phenomenon begun to be identified. A key event in this field was the cloning of the adipocyte-derived hormone leptin, which has been demonstrated as a pivotal regulator for the integration of energy homeostasis and reproduction. In addition, other metabolic hormones, such as insulin, contribute to this physiological integration. Moreover, compelling experimental evidence implicates hormonal products of the gastrointestinal tract as adjuncts in the complex coordination and regulation of body weight and reproduction. Here, we review recent studies evaluating the reproductive effects and sites of action of ghrelin and PYY3-36, two hormonal signals of gastrointestinal origin involved in the control food intake and energy balance. In addition, we summarize the potential contribution of kisspeptin, the recently characterized gatekeeper of the GnRH system encoded by Kiss1 gene, to integrating reproductive function and energy status. Evidence suggests that besides having direct gonadal effects, ghrelin may participate in the regulation of gonadotropin secretion and it may influence the timing of puberty. Likewise, PYY3-36 modulates GnRH and gonadotropin release. In addition, the hypothalamic KiSS-1 system is sensitive to nutritional status, and its diminished expression during states of negative energy balance might contribute to the suppression of reproductive function in such conditions. We propose that the peripheral hormones, ghrelin and PYY3-36, and the central neuropeptide, kisspeptin, are 'novel' players in the neuroendocrine networks that integrate energy balance and reproduction.

Effects of polypeptide YY(3-36) upon luteinizing hormone-releasing hormone and gonadotropin secretion in prepubertal rats: in vivo and in vitro studies

Polypeptide YY(3-36) (PYY(3-36)) is a gastrointestinal secreted molecule, agonist of neuropeptide Y (NPY) receptor subtypes Y2 and Y5, recently involved in the control of food intake. Notably, several factors with key roles in energy homeostasis conduct pleiotropic effects upon the reproductive axis. However, whether PYY(3-36) is provided with similar biological actions remains so far largely unexplored. To address this issue, expression analyses of neuropeptide Y receptor Y2 and Y5 genes were conducted at the pituitary and the hypothalamus, and functional studies testing the effects of PYY(3-36) in vivo and in vitro were implemented, using the prepubertal rat as a model. Expression of the genes encoding Y2 and Y5 receptors was demonstrated, albeit at low levels, in whole hypothalamic and pituitary samples, and challenge of pituitary tissue with increasing doses of PYY(3-36) elicited LH and FSH secretion in male and female rats, a response that was persistently observed in the absence of extracellular calcium. Moreover, 10(-6) m PYY(3-36) enhanced LH and FSH responsiveness to LHRH in vitro. In contrast, systemic ip administration of PYY(3-36) over a range of doses (3, 10, and 30 microg/kg) failed to significantly modify serum LH levels in males and females, whereas central (intracerebroventricular) injection of 3 nmol PYY(3-36) inhibited LH secretion in vivo, and 10(-6) m PYY(3-36) decreased LHRH release by hypothalamic fragments in vitro in male but not in female rats. Overall, our data document the complex mode of action of the gut-derived anorexigenic signal PYY(3-36) at the hypothalamic-pituitary unit in the control of gonadotropin secretion and evidence that, as is the case for other peripheral factors with key roles in energy balance (as leptin and ghrelin), PYY(3-36) might play a role in the neuroendocrine modulation of the reproductive axis.

Effects of peptide YY(3-36) on PRL secretion: pituitary and extra-pituitary actions in the rat

Polypeptide YY(3-36) (PYY(3-36)) is a gastrointestinal secreted molecule, agonist of neuropeptide Y (NPY) receptor subtypes Y2 and Y5, that has been recently involved as anorexigenic signal in the network controlling food intake. Notably, several factors primarily involved in food intake control and energy homeostasis (as leptin, orexins, ghrelin and NPY) have been linked also to the regulation of anterior pituitary hormone secretion and carry out pleiotropic effects upon the reproductive axis. However, whether similar actions are conducted by PYY(3-36) remains so far largely unexplored. Present studies were undertaken to analyze the potential effects of PYY(3-36) in the control of prolactin (PRL) secretion in the rat. To this end, responses to PYY(3-36) in terms of PRL secretion were monitored in vitro, after pituitary exposure to 10(-8) to 10(-6) M concentrations, and in vivo, after i.p. administration of different doses of PYY(3-36) (3, 10 and 30 microg/kg) to prepubertal male and female rats. In addition, the in vivo effects of PYY(3-36) were tested after central (i.c.v.) administration of 3 nmol of the peptide to prepubertal rats, and in hyperprolactinaemic aged females. PYY(3-36) stimulated, in a dose-dependent manner, in vitro PRL secretion by pituitaries from prepubertal male and female rats. In contrast, systemic administration of PYY(3-36) failed to modify serum PRL levels, whereas central infusion of PYY(3-36) significantly inhibited PRL secretion in prepubertal rats. Finally, PRL secretion was stimulated in aged hyperprolactinaemic female rats by systemic administration of PYY(3-36). In conclusion, the anorexigenic peptide PYY(3-36) may participate in the control of PRL secretion in the prepubertal rat, acting at pituitary (stimulatory effect) and extra-pituitary (likely inhibitory action at the hypothalamus) sites of the lactotrope axis. Moreover, net actions of PYY(3-36) on PRL secretion may depend on the age and prevailing PRL levels.

The use of immobilised glycosyltransferases in the synthesis of sialyloligosaccharides

The CMP-sialic acids, cytidine 5'-(5-acetamido-3,5-dideoxy-beta-D-glycero-D-galacto-2-nonulopyranosy lonic acid monophosphate) (1) and cytidine 5'-(5-acetamido-9-O-acetyl-3,5-dideoxy-beta-D-glycero-D-galacto-2- nonulopyranosylonic acid monophosphate) (2) were prepared from CMP, phosphoenolpyruvate, N-acetylneuraminic acid or its 9-acetate, and a catalytic amount of ATP in the presence of immobilised pyruvate kinase, nucleoside monophosphate kinase, inorganic pyrophosphatase, and CMP-sialic acid synthetase. CMP-NeuAc (1) was used as a donor of N-acetylneuraminic acid in the reaction catalysed by immobilised porcine liver beta-D-Galp-(1----4)-alpha-D-GlcpNAc-(2----6)-sialyltransferase, alpha-D-Neup5Ac-(2----6)-beta-D-Galp-(1----4)-beta-D-GlcpNAc-(1--- -2)-alpha-D- Man-OMe (5) was obtained on a 0.1-mmol scale by enzymic sialylation of beta-D-Galp-(1----4)-beta-D-GlcpNAc-(1----2)-alpha-D-Man-OMe (4), prepared by enzymic galactosylation of beta-D-GlcpNAc-(1----2)-alpha-D-Man-OMe (3). Likewise, using 2, alpha-D-Neup-5,9Ac2-(2----6)-beta-D-Galp-(1----4)-D-GlcpNAc (7) was obtained from N-acetyl-lactosamine (6).