Human oocyte maturation is dependent on LH-stimulated accumulation of the epidermal growth factor-like growth factor, amphiregulin

BACKGROUND

The LH surge promotes ovulation via activation of multiple signaling networks in the ovarian follicle. Studies in animal models have shown the importance of LH-induced activation of the epidermal growth factor (EGF)signaling network in critical peri-ovulatory events. We investigated the biological significance of regulatory mechanisms mediated by EGF-like growth factors during LH stimulation in humans.

METHODS

We characterized the EGF signaling network in mature human ovarian follicles using in vivo and in vitro approaches. Amphiregulin (AREG) levels were measured in 119 follicular fluid (FF) samples from IVF/ICSI patients. Biological activity of human FF was assessed using in vitro oocyte maturation, cumulus expansion and cell mitogenic assays.

RESULTS

AREG is the most abundant EGF-like growth factor accumulating in the FF of mature follicles of hCG-stimulated patients. No AREG was detected before the LH surge or before hCG stimulation of granulosa cells in vitro, demonstrating that the accumulation of AREG requires gonadotrophin stimulation. Epiregulin and betacellulin mRNA were detected in both human mural and cumulus granulosa cells, although at significantly lower levels than AREG. FF from stimulated follicles causes cumulus expansion and oocyte maturation in a reconstitution assay. Immunodepletion of AREG abolishes the ability of FF to stimulate expansion (P < 0.0001) and oocyte maturation (P < 0.05), confirming the biological activity of AREG. Conversely, mitogenic activity of FF remained after depletion of AREG, indicating that other mitogens accumulate in FF. FF from follicles yielding an immature germinal vesicle oocyte or from an oocyte that develops into an aberrant embryo contains lower AREG levels than that from follicles yielding a healthy oocyte (P = 0.008).

CONCLUSIONS

EGF-like growth factors play a role in critical peri-ovulatory events in humans, and AREG accumulation is a useful marker of gonadotrophin stimulation and oocyte competence.

On the approximation of stochastic processes by approximate identity neural networks

The ability of a neural network to learn from experience can be viewed as closely related to its approximating properties. By assuming that environment is essentially stochastic it follows that neural networks should be able to approximate stochastic processes. The aim of this paper is to show that some classes of artificial neural networks exist such that they are capable of providing the approximation, in the mean square sense, of prescribed stochastic processes with arbitrary accuracy. The networks so defined constitute a new model for neural processing and extend previous results concerning approximating capabilities of artificial neural networks.

'Desperate house genes': the dramatic example of hypoxia

BACKGROUND

Microenvironmental conditions in normal or tumour tissues and cell lines may interfere on further biological analysis. To evaluate transcript variations carefully, it is common to use stable housekeeping genes (HKG) to normalise quantitative microarrays or real-time polymerase chain reaction results. However, recent studies argue that HKG fluctuate according to tissues and treatments. So, as an example of HKG variation under an array of conditions that are common in the cancer field, we evaluate whether hypoxia could have an impact on HKG expression.

METHODS

Expression of 10 commonly used HKG was measured on four cell lines treated with four oxygen concentrations (from 1 to 20%).

RESULTS

Large variations of HKG transcripts were observed in hypoxic conditions and differ along with the cell line and the oxygen concentration. To elect the most stable HKG, we compared the three statistical means based either on PCR cycle threshold coefficient of variation calculation or two specifically dedicated software. Nevertheless, the best HKG dramatically differs according to the statistical method used. Moreover, using, as a reference, absolute quantification of a target gene (here the proteinase activating receptor gene 1 (PAR1) gene), we show that the conclusions raised about PAR1 variation in hypoxia can totally diverge according to the selected HKG used for normalisation.

CONCLUSION

The choice of a valid HKG will determine the relevance of the results that will be further interpreted, and so it should be seriously considered. The results of our study confirm unambiguously that HKG variations must be precisely and systematically determined before any experiment for each situation, to obtain reliable normalised results in the experimental setting that has been designed. Indeed, such assay design, functional for all in vitro systems, should be carefully evaluated before any extension to other experimental models including in vivo ones.

Combination Treatment with Etanercept and an Intensive SPA Rehabilitation Program in Active Ankylosing Spondylitis

The aim of this study is to determine the effects of a combination treatment with etanercept and spa rehabilitation versus etanercept alone on function, disability and quality of life in a group of patients with active ankylosing spondylitis (AS). Sixty patients with AS underwent etanercept as suggested by ASAS/EULAR recommendations. As the clinical and laboratory conditions improved, 30 patients accepted the proposal of coupling the medical therapy with a 7-day rehabilitation program in a thermal baths centre; the remaining 30 subjects continued to take the biologic agent alone. The comparisons between the 2 groups were made after 3 and 6 months. The primary outcome was an improvement in BASFI. The secondary outcome was an improvement in the visual analogic scale of EuroQol (EQ-5Dvas). After 6 months a statistically significant improvement in BASFI (p < 0.05) and EQ-5DVAS (p < 0.05) scores was observed in both groups. The mean change in EQ-5DVAS value showed a statistically significant difference in favour of the combination therapy group versus the monotherapy group (22 vs 32, p < 0.05). A therapeutic regimen combining etanercept with an intensive rehabilitation program contributes to disability reduction and ameliorates quality of life for AS patients.

Accessory renal artery stenosis and hypertension: are these correlated? Evaluation using multidetector-row computed tomographic angiography

BACKGROUND

Renal artery stenosis may produce hypertension, and this condition is referred to as renovascular hypertension (RVH).

PURPOSE

To evaluate, by using multidetector-row spiral computed tomographic angiography (MDCTA), whether a relationship between accessory renal artery stenosis and hypertension may be hypothesized.

MATERIAL AND METHODS

214 patients (142 males, 72 females; mean age 66 years) who had previously undergone an MDCTA to study the abdominal vasculature were retrospectively studied. Patients with renal artery stenosis (RAS) were excluded from this analysis. The patients were studied by means of a four-detector-row CT, and scans were obtained after intravenous bolus administration of 110-140 ml of a nonionic contrast material with a 3-6 ml/s flow rate. As a second step, by means of statistical analysis, hypertension data were compared with findings of accessory artery stenosis. Two radiologists first independently reviewed the MDCTA images and then, in case of disagreement, in consensus. Interobserver agreement was calculated for all measurements.

RESULTS

The overall number of detected accessory renal arteries was 74 in 56 of the 214 patients. Accessory renal artery stenosis was detected in 21 of the 56 patients. There was a difference in the prevalence of hypertension between patients with (n = 21) and without (n = 35) accessory renal artery stenosis (P = 0.0187). Interobserver agreement was good (kappa value 0.733).

CONCLUSION

Any statistical association between the presence of accessory renal artery stenosis and hypertension could not be disclosed. However, accessory renal artery stenosis, detected by MDCTA, is an important pathological sign that the radiologist has to assess in the light of its possible association with hypertension.

Neuropsychiatric symptoms in amnestic and nonamnestic mild cognitive impairment

BACKGROUND

The information regarding neuropsychiatric symptoms in the subtypes of mild cognitive impairment (MCI) is inadequate.

OBJECTIVE

To describe the behavioral neuropsychiatric symptoms of MCI in two subgroups of MCI patients with different neuropsychological characteristics.

METHODS

MCI patients are classified as amnestic (aMCI) if they have a prominent memory impairment, either alone or with other cognitive impairments (multiple domains with amnesia), or nonamnestic (naMCI) if a single nonmemory domain is impaired alone or in combination with other nonmemory deficits (multiple domains without amnesia). The Neuropsychiatric Inventory (NPI) was administrated to detect behavioral and psychological disturbances observed by the caregiver.

RESULTS

120 subjects were analyzed: 94 were classified as aMCI and 26 as naMCI. Subjects with aMCI were more compromised than those with naMCI on global cognitive functions. About 85% of MCI patients had some neuropsychiatric symptoms evaluated with the NPI and the most prevalent symptom was depression, followed by anxiety. A significantly higher prevalence of hallucinations and sleep disorders has been observed in the naMCI group in comparison with the aMCI group.

CONCLUSION

Neuropsychiatric symptoms occur in the majority of persons with MCI and may be the earliest manifestation of different diseases, each one associated with different clinical profiles at the stage of MCI.

Pro-apoptotic activity of cyclopentenone in cancer cells

Studies on cyclopentenone prostaglandins (CPPGs), clavulones and other cyclopentenones have shown that these compounds have a significant anticancer activity mediated by their cyclopentenone (CP) chemical moiety. In this study the cytotoxicity against cancer cells of the model compound cyclopent-2-en-1-one (2CP) was investigated. Being a highly water soluble small molecule, 2CP could be an ideal candidate to overcome pharmacological issues related to drug delivery and penetration. Its cytotoxic activity was tested on various melanoma and lung cancer cells. Interestingly, 2CP was both cytotoxic and pro-apoptotic, more pronounced on melanoma cells, at concentrations in the sub-micromolar range. On melanoma cells its mechanism of action was mediated by the mitochondria and the activation of caspase 3.

Transient focal lesion in the splenium of the corpus callosum: MR imaging with an attempt to clinical-physiopathological explanation and review of the literature

PURPOSE

This article discusses the possible pathophysiological conditions responsible for magnetic resonance imaging (MRI) finding of transient focal lesions in the splenium of the corpus callosum on the basis of our experience and a review of the literature.

MATERIALS AND METHODS

In six patients undergoing computed tomography (CT) and MRI examinations, focal nonhemorrhagic lesions of the splenium of the corpus callosum were incidentally discovered. Patients had been referred for suspected encephalitis (n=2), dural sinus thrombosis (n=1) and multiple sclerosis (n=3). MRI examinations were repeated after 4, 8 and 12 weeks and in two cases also after 6 and 9 months. MRI and medical records were retrospectively reviewed with respect to patients' clinical history, medication and laboratory findings to define lesion aetiology.

RESULTS

In all patients, the lesions were isolated, reversible and with no contrast enhancement. In four patients, the lesion disappeared after complete remission of the underlying disease, whereas in two patients, they persisted for 6 and 9 months, respectively.

CONCLUSIONS

To our knowledge and according to previous reports, the fact that these lesions are detected in a relatively large number of conditions with heterogeneous etiopathogenetic factors leads to the hypothesis that a common underlying pathophysiological mechanism that, considering signal characteristic, reversibility and white matter location, could be represented by vasogenic oedema.

[Malformations of the anterior chest wall]

INTRODUCTION

Pectus excavatum or funnel chest is the most common anterior chest wall deformity seen in children and adults. The sternal depression appears to be caused by overgrowth of the costal cartilages, also the cause of the less common deformities: pectus carinatum (pigeon breast) and pectus arcuatum.

BACKGROUND

Usually the overgrowth involves the third to seventh costal cartilages but it can be more or less extensive. The cardiopulmonary functional consequences are insignificant in the protrusional deformities and inconsistent in pectus excavatum and the indications for surgery are mainly cosmetic.

VIEWPOINT AND CONCLUSIONS

The procedural modalities are guided by morphological study of the CT scan. We describe a surgical technique that comprise subperichondrial excision of all deformed costal cartilages followed by transverse sternotomy to correct the sternal deformity, anteriorly in the case of pectus excavatum and posteriorly for pectus carinatum and arcuatum. As the perichondrial sheaths are totally preserved they are sutured in continuous layers to give a shortening effect. In the case of pectus excavatum the sternum is then secured anteriorly for about 6 months by a retrosternal metallic strut in an overcorrected position. The partially resected seventh cartilages are then sutured to the xiphoid. Other surgical techniques are described, including modified Ravitch's procedure, modelling osteochondroplasty, prosthetic reconstruction and Nuss's procedure. Results of the more important series are reported and discussed.