Differentiation between atypical sinonasal non-Hodgkin's lymphoma and inverted papilloma.

AIM: To seek additional magnetic resonance imaging (MRI) features to improve the accuracy of differentiation between atypical sinonasal non-Hodgkin's lymphoma (NHL) and inverted papilloma (IP) using conventional MRI and apparent diffusion coefficient (ADC) maps. MATERIALS AND METHODS: MRI examinations from 44 atypical cases (21 NHLs and 23 IPs) in sinonasal regions were reviewed retrospectively. Imaging features included tumour laterality, extension, T1-weighted imaging (WI)/T2WI signal intensity homogeneity and ratios, enhancement homogeneity and ratios, and ADCmean. RESULTS: In cases of NHL, homogeneous signal intensity was often observed on T2WI, which was homogeneous and significantly less enhanced than the turbinate, with lower ADCmean. Whereas in IPs, heterogeneous signal intensity was seen on T2WI, which was heterogeneous and of comparable enhancement to the turbinate, and higher ADCmean values were commonly seen. An ADCmean cut-off point of 1.10 × 10-3 mm2/s achieved 100% sensitivity, 90% specificity, and 90% accuracy. In addition, special features were observed that support the distinction between the two tumours, including intestinal pattern enhancement in NHL and spot-like appearance on T2WI and enhancement in IP. CONCLUSIONS: ADCmean was the most valuable metric for differentiating between the atypical sinonasal NHLs and IPs.

Estrogenic properties of genistein acting on FSHR and LHR in rats with PCOS.

The purpose of the study was to study the activity of the phytoestrogen genistein (GEN) act- ing on FSHR and LHR in rat ovaries with polycystic ovary syndrome (PCOS). Sixty rats were di- vided into six groups. Rats in the dose group received genistein at a concentration of either 5 (low genistein dose group, L-gen), 10 (middle genistein dose group, M-Gen) or 20 (high genistein dose group, H-Gen) mg per kg of body weight per day. Estrogen group (EG, received 0.5 mg/kg Dieth- ylstilbestrol). Concentration of sex hormones in serum was quantified by enzyme-linked immuno- sorbent assay (ELISA). Expressions of follicle-stimulating hormone receptor (FSHR) and lutein- izing hormone receptor (LHR) protein were determined by immunohistochemistry. Treatment with genistein resulted in a strong stimulation of the concentration of sex hormone in serum. The concentration of progesterone and FSH was significantly higher in H-Gen when compared to the PCOS model control group (MG) (P ⟨ 0.01). In contrast, the concentration of testosterone, LH and the ratio of LH/FSH decreased in GEN treatment groups compared to MG, the effect was statistically significant, tested by the ANOVA test (p⟨0.01). For hormone receptor activity, treat- ment with genistein resulted in an improvement of ovarian function with LHR protein expression being enhanced and FSHR protein expression being suppressed. Our results demonstrate that Genistein played a significant role in regulating FSH and LH receptor expression to improve perimenopausal ovarian and uterine function.

Effect of genistein on the gene expressions of androgen generating key enzymes StAR, P450scc and CYP19 in rat ovary.

In this investigation, the effects of genistein (GEN) on the expression of steroidogenic genes such as steroidogenic acute regulatory protein (StAR), side-chain cleavage enzymes (P450scc) and cytochrome P450 aromatase (CYP19) were assessed. For this study, forty young female Sprague Dawley (SD) rats at aged 2-3 months (200±20 g) and forty aged female SD rats aged 10-12 months (490±20 g) were selected. Also, based on weight they were divided into a negative control group (NC), three different GEN dose groups, which received GEN of 15, 30, 60 mg/kg, and a positive control group (PC). The experiment lasted 30 days. Concentrations of serum hormones were determined by Enzyme-linked immunosorbent assay (ELISA). Gene and protein expressions of StAR, P450scc and CYP19 were determined by Real-Time PCR and western blot techniques. It was observed that 30-60 mg/kg GEN could increase the expression of androgen generating key enzymes in the young rat ovary. GEN also significantly increased progesterone and E2 levels in the serum of aged rats and reduced the levels of LH and FSH in the serum of both young and aged rats. Compared with young rats, the effect of GEN on the ovary of aged rats was stronger and a lower dose of GEN (15 mg/kg) showed an obvious effect on these indicators. GEN influenced both estrogen level and indicators associated with estrogen and androgen transformation processes, which indicates that GEN can impair the growth and maturation of the ovary.

Alterations of single potassium channel activity in CA1 pyramidal neurons after transient forebrain ischemia.

Selective neuronal injury in the CA1 zone of hippocampus following transient cerebral ischemia has been well documented. Extracellular potassium concentration markedly increases during ischemia/hypoxia. Accumulating evidence has indicated that the outward potassium currents, including delayed rectifier potassium current, not only influence membrane excitability but also mediate apoptosis. It has been shown that the amplitude of delayed rectifier potassium current in CA1 neurons significantly increased after cerebral ischemia. To elucidate the mechanisms underlying the changes of potassium currents following ischemia, single potassium channel activities of rat CA1 neurons were compared before and after transient forebrain ischemia. Using cell-attached configuration, depolarizing voltage steps activated outward single channel events. The channel properties, the kinetics and pharmacology of these events resemble the delayed rectifier potassium current. After ischemia, the unitary amplitude of single channels significantly increased, the open probability, mean open time and open time constant also significantly increased while the conductance remained unchanged. These data indicate that the increase of single channel activity is responsible, at least in part, for the increase of delayed rectifier potassium current in CA1 neurons after cerebral ischemia.

Differential expression of neurexin mRNA in CA1 and CA3 hippocampal neurons in response to ischemic insult.

A short period of cerebral ischemia will trigger a cascade of events leading to neuronal death. In an effort to elucidate molecular mechanisms underlying differential vulnerability of CA1 and CA3 hippocampal neurons to neurodegeneration, we performed a transcriptional analysis of rat hippocampal neurons following transient global ischemia. In response to 15-min ischemia, the mRNA level of neurexins II alpha and III alpha was elevated in CA1 neurons and CA3 neurons, respectively. Interestingly, the up-regulated neurexin III alpha mRNA in postischemic CA3 consisted of the insert corresponding to the fourth splicing site, while the transcripts in postischemic CA1 neurons and control CA3 neurons lacked the insert. The observed tissue specific expression and the splicing pattern suggest functional importance of neurexins in postischemic degeneration of hippocampal neurons.

[Changes of K+ channel current in cerebellar cortical neuron of apoptosis induced with H2O2].

The neurons dissociated from the cerebellar cortex of neonatal SD rat were cultured, while the growth of non-neuron cells were suppressed by Ara-c. Apoptosis of the neurons were induced with H2O2. The changes of Ik were studied during apoptosis using the patch clamp technique in cell-attached configurations. The results are as follows: (1) the Ik amplitudes of the neurons were lower than that of normal at various corresponding clamp voltages; (2) the conductances, mean open time, open probability, long and short opening time constants were all lower, as compared with normal neurons. All these results indicate that the activities of K+ channels on cerebellar neurons decrease during apoptosis.

[A study on location of vocalization centres in hawfinch (Coccothraustes coccothraustes)].

Vocal-control nuclei in hawfinch (Coccothraustes coccothraustes) were studied by HRP retrograde tracing and electrophysiological methods. Vocal control centres in hawfinch consist of four discrete nuclei. Hyperstriatum ventral, pars caudale (HVc) is the highest nucleus, with its efferent fibers projecting to the rubust nucleus of archistriatum (RA), which in turn projects to the nucleus intercollicularis (ICo) of midbrain and the nucleus intermedius (IM) of medulla oblongata IM innervating vocal organ (syrinx) also receives input from ICo. The both vocal control pathways are not strictly unilateral. ICo plays a relative independent role in vocal control. The stereotaxic coordinates for HVc RA, ICo, IM are tabulated in Table 2.

Differential changes of potassium currents in CA1 pyramidal neurons after transient forebrain ischemia.

CA1 pyramidal neurons are highly vulnerable to transient cerebral ischemia. In vivo studies have shown that the excitability of CA1 neurons progressively decreased following reperfusion. To reveal the mechanisms underlying the postischemic excitability change, total potassium current, transient potassium current, and delayed rectifier potassium current in CA1 neurons were studied in hippocampal slices prepared before ischemia and at different time points following reperfusion. Consistent with previous in vivo studies, the excitability of CA1 neurons decreased in brain slices prepared at 14 h following transient forebrain ischemia. The amplitude of total potassium current in CA1 neurons increased approximately 30% following reperfusion. The steady-state activation curve of total potassium current progressively shifted in the hyperpolarizing direction with a transient recovery at 18 h after ischemia. For transient potassium current, the amplitude was transiently increased approximately 30% at approximately 12 h after reperfusion and returned to control levels at later time points. The steady-state activation curve also shifted approximately 20 mV in the hyperpolarizing direction, and the time constant of removal of inactivation markedly increased at 12 h after reperfusion. For delayed rectifier potassium current, the amplitude significantly increased and the steady-state activation curve shifted in the hyperpolarizing direction at 36 h after reperfusion. No significant change in inactivation kinetics was observed in the above potassium currents following reperfusion. The present study demonstrates the differential changes of potassium currents in CA1 neurons after reperfusion. The increase of transient potassium current in the early phase of reperfusion may be responsible for the decrease of excitability, while the increase of delayed rectifier potassium current in the late phase of reperfusion may be associated with the postischemic cell death.