Cuf2 Is a Novel Meiosis-Specific Regulatory Factor of Meiosis Maturation

Meiosis is the specialized form of the cell cycle by which diploid cells produce the haploid gametes required for sexual reproduction. Initiation and progression through meiosis requires that the expression of the meiotic genes is precisely controlled so as to provide the correct gene products at the correct times. During meiosis, four temporal gene clusters are either induced or repressed by a cascade of transcription factors

Evidence for induction of hepatic microsomal cytochrome P-450 by cimetidine: binding and kinetic studies

The interaction of cimetidine with liver microsomes has been examined by spectral and equilibrium partition studies. First, difference spectroscopy has been used to evaluate the proportion of cytochrome P-450 in rat liver microsomes that exhibits an affinity for cimetidine in the pharmacologically relevant, low micromolar range of drug concentration. The value of 0.45 so obtained has confirmed that a substantial proportion of rat liver cytochrome P-450 has a high binding affinity for this drug. Second, a study of the binding of cimetidine to human liver microsomes by difference spectroscopy and partition equilibrium has detected a similar interaction, thus providing direct support for the postulate that the clinically observed impairment of oxidative drug metabolism may be due in part to inhibition of cytochrome P-450 monooxygenase by cimetidine. Hepatic microsomes from cimetidine-pretreated rats have been shown to exhibit elevated cytochrome P-450 specific content but a decreased proportion of sites with high affinity for the drug; this finding has been shown not to be the consequence of cimetidine-mediated, time-dependent, irreversible monooxygenase inhibition. Although cimetidine pretreatment caused enhanced specific activity of 7-ethoxyresorufin O-dealkylation, the specific activities for O-dealkylation of 7-ethoxycoumarin and 4-nitroanisole were decreased, as were those for the N-dealkylation of morphine, ethylmorphine, aminopyrine, and dimethylnitrosamine. Since cimetidine pretreatment was shown to cause no change in the Michaelis constants for oxidation of morphine or 7-ethoxyresorufin, it is argued that these results provide strong presumptive evidence for changes in the relative abundance of isoenzymes catalyzing these various oxidations. Thus, a dual role of cimetidine, acting both as inhibitor and inducer of the cytochrome P-450 system, is proposed to account for the impaired oxidative metabolism of some drugs that occurs during coadministration with this H2-receptor antagonist

Statistiche culturali. Anni 1999-2000

Consiglio Nazionale delle Ricerche - Biblioteca Centrale - P.le Aldo Moro, 7 , Rome / CNR - Consiglio Nazionale delle RichercheSIGLEITItal

Sheep calcaneal tendon repair subsequent to amniotic derived stem cell allotransplantation.

This preclinical study was performed to evaluate the regenerative 7capacities of vitro-expanded amniotic fluid stem cells (AFSCs) allotransplanted 8within experimentally induced lesions in ovine calcaneal tendons. Explanted 9samples were evaluated for tendon architecture, collagen composition, AFSC 10retrieval, cell proliferation, blood vessel organization, and leukocyte infiltration. 11Tendon healing and viable AFSCs were observed within the lesion site 30 days after 12transplantation. AFSCs differentiated into collagen-producing cells, stimulated 13collagen type I deposition and fiber alignment, and exerted positive effects on 14angiogenesis and inflammatory reactions. Thus, as AFSCs markedly improved 15tendon healing, they may be used to develop innovative therapies.[...

Relationship between the strain measures of left atrial function and heart failure worsening

Background: Two-dimensional speckle tracking evaluation (2D-STE) is a useful tool to evaluate the complexity of atrial function by the analysis of the different phases of atrial deformation and by the combination with Doppler measurements of diastolic function. Aim of the study: To evaluate the role of the left atrial (LA) strain parameters to predict worsening chronic heart failure (CHF). Methods: We enrolled outpatients affected by CHF referred to our heart failure unit. Each patient underwent a medical visit, an electrocardiogram (ECG), and an echocardiographic examination. LA function was assessed by 2D-STE. The three phases of LA strain, that is, the reservoir (LAr), the conduit (LAcd), and the contraction (LAct)—were evaluated. Moreover, the ratio between E and LAr (E/LAr) and those between LAr and septal (LAr/Ees), lateral (LAr/Eel), and septal-lateral (LAr/Eem) E/e’ were measured. During follow-up, the events related to worsening of heart failure were evaluated. Results: Two hundred eleven patients were enrolled. During a mean follow-up of 14 ± 7 months, 37 patients showed at least one event related to heart failure worsening. At univariate Cox regression analysis, LAr, LAcd, LAct, E/LAr, LAr/Ees, LAr/Eel, and LAr/Eem were all associated with events related to heart failure worsening, but at multivariate regression analyses, only LAr (Hazard Ratio, HR:.95; 95% Confidence Interval, CI:.92–.99; p:.031), LAct (HR: 1.06; 95% CI: 1.01–1.12; p:.027), E/LAr (HR: 1.10; 95%CI: 1.0–1.16; p <.001), LAr/Ees (HR:.57; 95% CI:.37–.87; p:.010), and LAr/Eem (HR:.71; 95% CI:.53–.96; p:.026) remained significantly associated with the events. Finally, in a predictive model including the other relevant echocardiographic parameters LAr < 18%, LAct > −10.0%, LAr/Ees < 1.28, and E/LAr > 3.70 were associated with a statistically significant overall net reclassification improvement. Conclusions: In CHF patients, the measure of the LA reservoir and contraction by 2D-STE is independently associated with heart failure worsening, but the accuracy in predicting the events is even greater when the reservoir is combined with the Doppler measures of diastolic function

Factors associated with cerebrospinal fluid leak after a retrosigmoid approach for cerebellopontine angle surgery

Background: The retrosigmoid approach represents a crucial surgical route to address different lesions in the cerebellopontine angle but cerebrospinal fluid (CSF) leak still remains the most frequent complication after this approach. Here, we analyzed the impact of different factors in CSF leak development after a retrosigmoid approach. Identifying risk factors related to a specific approach may help the surgeon to tailor the perioperative management and to appropriately counsel patients regarding their risk profile. Methods: We retrospectively reviewed the clinical, surgical, and outcome data of 103 consecutive patients (M/F, 47/56; mean follow-up 35.6 ± 23.9 months) who underwent a retrosigmoid approach for different cerebellopontine angle pathologies and studied the impact of different factors on the occurrence of a CSF leak to univariate and multivariate analysis. Results: Seventy-nine patients (76.7%) were operated for tumors growing in the cerebellopontine angle. Twenty-four patients (23.2%) underwent microvascular decompression to treat a drug-resistant trigeminal neuralgia. Sixteen patients (15.5%) developed CSF leak in the postoperative course of which six underwent surgical revision. Performing a craniectomy as surgical procedure (P = 0.0450) and performing a reopening procedure (second surgery; P = 0.0079) were significantly associated to a higher risk of developing CSF leak. Moreover, performing a reopening procedure emerged as an independent factor for CSF developing on multivariate analysis (P = 0.0156). Conclusion: Patients submitted to craniectomy and patients who underwent a second surgery showed an higher CSF leak rate. Ongoing improvement of biomaterial technology may help neurosurgeons to prevent this potentially life-threatening complication