Ultrasound-based detection of glucocorticoid-induced impairments of muscle mass and structure in Cushing's disease.

PURPOSE: To investigate the glucocorticoid-induced impairments of muscle mass and structure in patients presenting different stages of steroid myopathy progression. METHODS: Thirty-three patients (28 women) affected by active (N = 20) and remitted (N = 13) Cushing's disease were recruited and the following variables were assessed: walking speed, handgrip strength, total body and appendicular muscle mass by bioelectrical impedance analysis (BIA), thickness and echo intensity of lower limb muscles by ultrasonography. RESULTS: The two groups of patients showed comparable values of both handgrip strength [median (interquartile range) values: active disease: 27.4 (7.5) kg vs. remitted disease: 26.4 (9.4) kg; P = 0.58] and walking speed [active disease: 1.0 (0.2) m/s vs. remitted disease: 1.1 (0.3) m/s; P = 0.43]. Also, the thickness of the four muscles and all BIA-derived sarcopenic indices were comparable (P > 0.05 for all comparisons) between the two groups. On the contrary, the echo intensity of vastus lateralis, tibialis anterior (lower portion), and medial gastrocnemius was significantly (P < 0.05 for all comparisons) higher in patients with active disease compared to patients with remitted disease. Finally, significant negative correlations were found in the whole group of patients between muscle echo intensity and muscle function assessments. CONCLUSIONS: We provided preliminary evidence that the ultrasound-derived measurements of muscle thickness and echo intensity can be useful to detect and track the changes of muscle mass and structure in patients with steroid myopathy and we suggest that the combined assessment of muscle mass, strength, and performance should be systematically applied in the routine examination of steroid myopathy patients.

Characterization and implications of thyroid dysfunction induced by immune checkpoint inhibitors in real-life clinical practice: a long-term prospective study from a referral institution.

PURPOSE: Autoimmune diseases are typically associated with immune checkpoints blockade. This study aims at assessing, in real-life clinical practice, the prevalence and impact of thyroid disorders induced by immune checkpoint inhibitors. METHODS: 52 patients (30 F; age 61 ± 13 years) with advanced melanoma treated with ipilimumab (3 mg/kg i.v./3 weeks; 4 doses) were included. For disease progression, 29 (16 F) of them received nivolumab (3 mg/kg i.v./2 weeks) or pembrolizumab (2 mg/kg i.v./3 weeks). Thyroid function and autoimmunity were assessed before, after 6 weeks, at the end of ipilimumab, as well as before and every 3 months during nivolumab/pembrolizumab treatment. RESULTS: During ipilimumab, 7 (4 F) patients developed thyroid dysfunction (4 thyroiditis, 1 associated with hypothyroidism; 2 thyrotoxicosis in a previously euthyroid multinodular goiter; 1 hypothyroidism worsened). During PD1 inhibitors, 7 patients (3 F) developed hypothyroidism with severe manifestations in 6 of them; 3 patients suffered from euthyroid autoimmune thyroiditis from baseline, one after ipilimumab; 2 patients developed after transient thyrotoxicosis. Mean follow-up after anti-CTLA4 inhibitors treatment was 36 ± 28 months. Thyroid disorders occurred 45.1 ± 20.8 and 151 ± 67 days after the initiation of CTLA4 and PD1 inhibitors, respectively. Autoimmune disorders and BRAF mutation were associated with a better clinical response to CTLA4 followed by PD1 treatment. CONCLUSIONS: Immune checkpoint blockade is burdened by a high incidence of autoimmune thyroid dysfunction, which is often severe. Therefore, early and careful monitoring and, eventually, treatment are crucial to prevent the negative impact of thyroid dysfunction on the clinical outcome.

Localization of neuroglobin in the brain of R6/2 mouse model of Huntington's disease.

Neuroglobin (Ngb) is expressed in the central and peripheral nervous system, cerebrospinal fluid, retina, and endocrine tissues where it is involved in binding O2 and other gasotransmitters. Several studies have highlighted its endogenous neuroprotective function. Huntington's disease (HD), a dominant hereditary disease, is characterized by the gradual loss of neurons in discrete areas of the central nervous system. We analyzed the expression of Ngb in the brain tissue of a mouse model of HD, in order to define the role of Ngb with respect to individual cell type vulnerability in HD and to gender and age of mice. Our results showed different expressions of Ngb among neurons of a specific region and between different brain regions. We evidenced a decreased intensity of Ngb at 13 weeks of age, compared to 7 weeks of age. The double immunofluorescence and fluorescence resonance energy transfer (FRET) experiments showed that the co-localization between Ngb and huntingtin at the subcellular level was not close enough to account for a direct interaction. We also observed a different expression of Ngb in the striatum, depending on the sex and age of animals. These findings provide the first experimental evidence for an adaptive response of Ngb in HD, suggesting that Ngb may exert neuroprotective effects in HD beyond its role in reducing sensitivity to oxidative stress.

The acute effect of a mineralocorticoid receptor agonist on corticotrope secretion in Addison's disease.

PURPOSE: Mineralocorticoid receptors (MR) in the hippocampus display an important role in the control of hypothalamic-pituitary-adrenal (HPA) axis, mediating the ''proactive'' feedback of glucocorticoids (GC). Fludrocortisone (FC), a potent MR agonist, has been shown to decrease HPA activity through a hippocampal mechanism. Since it has been demonstrated that FC shows a significant inhibition of the HPA axis response to hCRH stimulus in normal subjects, also at doses usually administered as replacement therapy in patients with Addison's disease, an FC effect at MRs in human pituitary or a GR-pituitary agonism stronger than believed until now has been postulated. METHODS: Ten patients affected by autoimmune Addison's disease received: (1) placebo p.o. + placebo i.v., (2) hydrocortisone (H) 10 mg p.o. + placebo i.v., (3) FC 0.1 mg p.o. + placebo i.v., (4) FC 0.1 mg and H 10 mg p.o. + placebo i.v. to verify a possible GR FC-mediated effect that might display a repercussion on the GC-replacement therapy. RESULTS: H reduced ACTH (p < 0.01) and increased cortisol levels (p < 0.01) with respect to the placebo session, while FC did not affect either ACTH or cortisol levels compared to placebo, and higher ACTH and lower cortisol levels (p < 0.03 and p < 0.01) were observed compared with the H session; furthermore the co-administration of FC + H showed ACTH and cortisol profiles similar to that observed during H alone. CONCLUSIONS: Our study showed a lack of FC effect on corticotrope secretion in Addison's disease, thus making unlikely the hypothesis of its GR pituitary agonism and the risk of glucocorticoid excess in primary adrenal insufficiency.

Effect of rMnSOD on survival signaling in pediatric high risk T-cell acute lymphoblastic leukaemia.

Manganese superoxide dismutase (MnSOD) is a mitochondrial enzyme that defends against oxidative damage due to reactive oxygen species (ROS). A new isoform of MnSOD with cytotoxic activity was recently discovered in liposarcoma cells. Here, we tested the effectiveness of a recombinant form of this isoform (rMnSOD) on leukemic T cells, Jurkat cells, and lymphocytes. Our results confirm that leukemic T cells can internalize rMnSOD and that rMnSOD causes apoptosis of 99% of leukemic cells without showing toxic effects on healthy cells. Using light and electron microscopy, we determined that an rMnSOD concentration of 0.067 µM most effective on apoptosis induction. Western blot analysis showed that treatment with 0.067 µM rMnSOD resulted in high expression of the pro-apoptotic protein Bax and low expression of the anti-apoptotic protein Bcl-2 in leukemia cells. Concerning signal transduction pathway no influence was observed after treatment except for Jurkat cells showing a slightly decreased expression of ERK phosphorylation. These results suggest that rMnSOD may be an effective and non-toxic treatment option for T-cell leukemia.

PDE10A and PDE10A-dependent cAMP catabolism are dysregulated oppositely in striatum and nucleus accumbens after lesion of midbrain dopamine neurons in rat: a key step in parkinsonism physiopathology.

Loss of dopamine neurons in experimental parkinsonism results in altered cyclic nucleotide cAMP and cGMP levels throughout the basal ganglia. Our objective was to examine whether expression of phosphodiesterase 10A (PDE10A), an isozyme presenting a unique distribution in basal ganglia, is altered after unilateral injection of 6-hydroxydopamine in the medial forebrain bundle, eliminating all midbrain dopaminergic neurons, such that cyclic nucleotide catabolism and steady state could be affected. Our study demonstrates that PDE10A mRNA levels were decreased in striatal neurons 10 weeks after 6-hydroxydopamine midbrain lesion. Such changes occurred in the striatum ipsilateral to lesion and were paralleled by decreased PDE10A protein levels and activity in striatal neurons and in striato-pallidal and striato-nigral projections. However, PDE10A protein and activity were increased while PDE10A mRNA was unchanged in the nucleus accumbens ipsilateral to the 6-hydroxydopamine midbrain lesion. Accordingly, cAMP levels were down-regulated in the nucleus accumbens, and up-regulated in the striatum ipsilateral to the lesion, but they were not significantly changed in substantia nigra and globus pallidus. Unlike cAMP, cGMP levels were decreased in all dopamine-deafferented regions. The opposite variations of cAMP steady state in striatum and nucleus accumbens are concordant and likely dependent, at least in part, on the down-regulation of PDE10A expression and activity in the former and its up-regulation in the latter. On the other hand, the down-regulation of cGMP steady state in the striato-nigral and striato-pallidal complex is not consistent with and is likely independent from the concomitant down-regulation of PDE10A. Therefore, dopamine loss inversely regulates PDE10A gene expression in the striatum and PDE10A post-transcription in the nucleus accumbens, therein differentially modulating PDE10A-dependent cAMP catabolism.

Association between cavernous angioma and cerebral glioma. Report of two cases and literature review of so-called angiogliomas.

The association between vascular malformations and cerebral gliomas is unusual. While the association between cavernous angioma with gliomatous lesions is even more rare, it is considered by certain authors to be a particular pathological entity termed angioglioma. The authors report on two cases of association of a cavernous angioma with a ganglioglioma and an oligodendroglioma respectively. Subsequent review of the literature on the so-called angiogliomas was conducted. In the author's opinion, the entity of angiogliomas represents a general spectrum of angiomatous neoplasms that include gliomatous tumors, in the majority low-grade gliomas, associated with a major vascular component.

Lowered cAMP and cGMP signalling in the brain during levodopa-induced dyskinesias in hemiparkinsonian rats: new aspects in the pathogenetic mechanisms.

Dysregulation of dopamine receptors is thought to underlie levodopa-induced dyskinesias in experimental models of Parkinson's disease. It is unknown whether an imbalance of the second messengers, cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP), is involved in the alterations of levodopa/dopamine signal transduction. We examined cAMP and cGMP signalling in the interconnected cortico-striatal-pallidal loop at the peak of levodopa-induced dyskinesias in rats with 6-hydroxydopamine lesions in the substantia nigra. In addition, we examined the role of phosphodiesterase (PDE) and the rate of cAMP and cGMP degradation on the severity of levodopa-induced dyskinesias in animals pretreated with PDE inhibitor, zaprinast. Unilateral lesion of substantia nigra led to an increase in cAMP but a decrease in cGMP levels in the ipsilateral basal ganglia. After chronic levodopa treatment, cAMP and cGMP were differentially regulated in eukinetic animals: the cAMP level increased in the cortex and striatum but decreased in the globus pallidus of both hemispheres, whereas the cGMP decreased below baseline levels in the contralateral cortico-striatal-pallidal regions. In dyskinetic animals chronic levodopa treatment led to an absolute decrease in cAMP and cGMP levels in cortico-striatal-pallidal regions of both hemispheres. Pretreatment with zaprinast reduced the severity of levodopa-induced dyskinesias, and partly prevented the decrease in cyclic nucleotides compared with pretreatment with saline-levodopa. In conclusion, using a rat model of hemiparkinsonism, we observed a significant reduction in the levels of cyclic nucleotides in both hemispheres at the peak of levodopa-induced dyskinesias. We propose that such a decrease in cyclic nucleotides may partly result from increased catabolism through PDE overactivity.

Anti-ulcer, anti-inflammatory and antioxidant activities of the n-butanol fraction from Pteleopsis suberosa stem bark.

Pteleopsis suberosa Engl. et Diels (Combretaceae) is a tree distributed in many African countries. The decoction from the stem bark is orally administered for the treatment of gastric ulcers in traditional medicine. Previous pharmacological studies reported the anti-ulcer activity of extracts from P. suberosa stem bark. In the present study, the anti-ulcer and anti-inflammatory effects of the n-butanol fraction (RBuOH) obtained from a methanol extract of P. suberosa bark were investigated on ethanol-induced gastric ulcers in rats and carrageenan-induced paw oedema in mice. Misoprostol (0.50 mg/kg, p.o.) and indomethacin (8.00 mg/kg, p.o.) were used as positive controls for anti-ulcer and anti-inflammatory activities, respectively. Results showed that RBuOH treatment significantly reduced the incidence of gastric lesions (50 mg/kg, P<0.05; 100 and 200 mg/kg, P<0.01) and restored the decreased levels of total sulfhydryl groups (T-SH) and non-protein sulfhydryl groups (NP-SH) (50, 100 mg/kg, P<0.05; 200 mg/kg, P<0.01) in the stomach homogenate. Moreover, RBuOH treatment attenuated MDA levels as index of lipid peroxidation in gastric mucosa. Administration of RBuOH at the same dosage (50, 100 and 200 mg/kg) reduced significantly (P<0.01) carrageenan-induced paw oedema in dose-dependent manner (from 42.81% to 87.81% inhibition, 5h after carrageenan injection). The anti-inflammatory effect of RBuOH at 200 mg/kg was comparable with that of indomethacin. Finally, RBuOH proved to possess elevated free radical scavenger capacity on 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay (IC(50) 23.48 microg/ml) which may contribute to the observed anti-ulcer and anti-inflammatory activities.

Polyphenolic profile and biological activities of black carrot crude extract (Daucus carota L. ssp. sativus var. atrorubens Alef.).

Black carrot (Daucus carota L. ssp. sativus var. atrorubens Alef.) is a valuable source of carbohydrates, minerals and vitamins and contains also high amounts of anthocyanins giving the characteristic deep-purple color. These latter compounds are known as natural dyes used in the food and pharmaceutical industry that have recently attracted much attention for their healthful properties. The aim of this work was to investigate for the first time the polyphenolic profile and biological properties of a black carrot crude extract (BCCE) through an in-depth analysis of the main polyphenolic classes evaluating its antioxidant, cytoprotective and anti-angiogenic properties. Twenty five polyphenols were quantified by LC-DAD-FLD-MS/MS analysis (anthocyanins 78.06%, phenolic acids 17.89% and other flavonoids 4.06%) with polyglycosylated cyanidins as major components. In addition, BCCE showed a strong antioxidant and free radical scavenging activity particularly in the hydrogen transfer-based assays (ORAC and ß-carotene bleaching) and a significant increase in the cell viability. Furthermore, BCCE exhibited a strong anti-angiogenic activity at the highest concentration assayed on the chick chorioallantoic membrane (50µg/egg). In conclusion, the obtained results demonstrated the antioxidant, cytoprotective and anti-angiogenic properties of BCCE, which highlight that the higher biological activity of BCCE is probably due to the synergic effects exerted by various polyphenolic classes.

Manganese intoxication decreases the expression of manganoproteins in the rat basal ganglia: an immunohistochemical study.

Manganese (Mn) is a cofactor for some metalloprotein enzymes, including Mn-superoxide dismutase (Mn-SOD), a mitochondrial enzyme predominantly localized in neurons, and glutamine synthetase (GS), which is selectively expressed in astroglial cells. The detoxifying effects of GS and Mn-SOD in the brain, involve catabolizing glutamate and scavenging superoxide anions, respectively. Mn intoxication is characterized by impaired function of the basal ganglia. However, it is unclear whether regional central nervous system expression of manganoproteins is also affected. Here, we use immunocytochemistry in the adult rat brain, to examine whether Mn overload selectively affects the expression of GS, Mn-SOD, Cu/Zn-SOD, another component of the SOD family, and glial fibrillary acid protein (GFAP), a specific marker of astrocytes. After chronic Mn overload in drinking water for 13 weeks, we found that the number and immunostaining intensity of GS- and Mn-SOD-positive cells was significantly decreased in the striatum and globus pallidus, but not in the cerebral frontal cortex. In addition, we found that GS enzymatic activity was decreased in the strio-pallidal regions but not in the cerebral cortex of Mn-treated animals. In contrast, Cu/Zn-SOD- and GFAP-immunoreactivity was unchanged in both the cerebral cortex and basal ganglia of Mn-treated rats. Thus, we conclude that in response to chronic Mn overload, a down-regulation of some manganoproteins occurs in neurons and astrocytes of the striatum and globus pallidus, probably reflecting the vulnerability of these regions to Mn toxicity.

Spectroscopic, diffusion and perfusion magnetic resonance imaging at 3.0 Tesla in the delineation of glioblastomas: preliminary results.

Recent advances in magnetic resonance imaging (MRI) have allowed the evaluation of metabolic, diffusion and hemodynamic features of malignant gliomas. The aim of this study was to evaluate whether such information provided useful, complementary information to conventional MRI for improving the evaluation of glioblastoma extent. Ten patients with glioblastoma multiforme underwent conventional MRI, proton MR spectroscopic imaging (1H-MRSI), perfusion-weighted imaging (PWI) and diffusion-weighted imaging (DWI). Metabolite signals, including normalized choline, N-acetylaspartate, creatine and lactate/lipids, were obtained by 1H-MRSI; apparent diffusion coefficient (ADC) by DWI; and relative cerebral blood volume (rCBV) by PWI. In edematous-appearing areas, 3 multiparametric patterns were identified: infiltrating tumor, with abnormal metabolite ratios, lower ADC and higher rCBV; pure edema, with normal metabolite ratios, higher ADC and lower rCBV; and tumor-infiltrated edema, with abnormal metabolite ratios and intermediate ADC and rCBV. In normal-appearing areas, 2 multiparametric patterns were identified: tumor-infiltrated tissue, with abnormal metabolite ratios and higher rCBV; and normal tissue, with normal MR parameters. The combination of 1H-MRSI, DWI and PWI features contributed to delineation of glioblastomas, offering information not available with conventional MRI. This approach may enhance the assessment of brain gliomas, providing useful information for guiding stereotactic biopsies, surgical resection and radiation treatment.

Evaluation of the antioxidant properties and bioavailability of free and bound phenolic acids from Trichilia emetica Vahl.

Trichilia emetica Vahl. is commonly used in folk medicine of Mali for the treatment of various diseases. In this study, the content and the antioxidant activity of phenolic acids from Trichilia emetica root were evaluated. Free phenolic acids were extracted with a mixture of methanol and 10% acetic acid. Bound phenolic acids were released using first alkaline and then acid hydrolysis. All fractions were quantified separately by HPLC. After alkaline hydrolysis, a remarkable increase in caffeic acid, ferulic acid, p-coumaric acid, syringic acid, vanillic acid, protocathecuic acid and gallic acid content was observed, showing that most of phenolic acids in the drug are present as bound forms. Moreover, the extracts submitted to alkaline hydrolysis showed high antioxidant properties in two in vitro assays: autooxidation of methyl linoleate (MeLo) and ascorbate/Fe(2+)-mediated lipid peroxidation in rat microsomes. An in vivo study was also performed to investigate the intestinal absorption of phenolic acids after oral administration of Trichilia emetica extracts. Results showed high levels of phenolic acids, free or conjugated to glucuronide, in the plasma of rats treated with the hydrolyzed extract. Due to the absence of chlorogenic acid in plasma samples, the presence of caffeic acid seems to be derived from hydrolysis of chlorogenic acid in the gastrointestinal tract.

Hepatoprotective and antibacterial effects of extracts from Trichilia emetica Vahl. (Meliaceae).

Trichilia emetica Vahl. (Meliaceae) is a tree widely distributed in Tropical Africa. It has been used in Mali folk medicine for the treatment of various illnesses. The aim of this work was to study the hepatoprotective and antibacterial effects of a crude aqueous extract from Trichilia emetica root. An ethyl ether fraction from the aqueous extract was also prepared and studied. We have examined the hepatoprotective activity of the extracts on CCl4-induced damage in rat hepatocytes, their toxicity using the brine shrimp bioassay and their antibacterial activity against clinical isolated bacterial strains, which are commonly responsible for respiratory infections. A preliminary phytochemical analysis showed a high polyphenolic content in the aqueous extract and the presence of limonoids in the ethyl ether fraction. These latter compounds may be considered responsible for the good activity against the bacterial strains tested. Trichilia emetica extracts exerted also a significant (P<0.05) hepatoprotective effect at a dose of 1000 microg/ml both on plasma membrane and mitochondrial function as compared to silymarin used as a positive control. These activities may be a result of the presence of either polyphenols or limonoids. Finally, both the aqueous extract and its ethyl ether fraction did not show toxicity (LC50>1000 microg/ml) in the brine shrimp bioassay.

EZH2 is increased in paediatric T-cell acute lymphoblastic leukemia and is a suitable molecular target in combination treatment approaches.

BACKGROUND: T-cell Acute Lymphoblastic Leukemia (ALL) represents about 10-15 % of pediatric ALL cases. EZH2, one of the components of Polycomb group proteins (PRC2) complex, catalyzes the trimethylation of histone H3 lysine 27 that is associated with transcriptional repression and tumor development. METHODS: We examined the expression levels of PRC2 complex in primary samples of T cells ALL at diagnosis by western blotting and real time PCR. We evaluated the effect of 3-deazaneplanocin-A (DZNep), an EZH2 inhibitor, alone and in combination with Daunoblastine on cell viability, apoptotic death and cell cycle distribution of T cell established Jurkat cell line. RESULTS: EZH2 was expressed in 75 % samples at different extents mainly with high expression level. SUZ12 was expressed in 60 % samples and EED in all samples, respectively. The Kaplan-Meier analysis shows that T-ALL expressing EZH2 had a lower probability of disease-free survival (DFS) compared to T-ALL negative for EZH2 (23 % vs 100 %) (p = 0.01). The EZH2 inhibitor DZNep used in combination with Daunoblastine was synergistic in inducing growth inhibition and increasing the apoptosis in T-ALL Jurkat cells at 48 and 72 h paralleled by EZH2 decreased expression. Moreover, the combination decreased the activity of Erk-1/2 proliferation enzymes with no effects on Akt survival pathway. CONCLUSIONS: The evaluation of EZH2 expression in pediatric T-ALL can be useful in predict the clinical outcome of the patients and EZH2 can be a useful target to improve the efficacy of conventional chemotherapy in this subset of patients with bad prognosis.

In vivo visualization of pituitary dopaminergic receptors by iodine-123 methoxybenzamide (IBZM) correlates with sensitivity to dopamine agonists in two patients with macroprolactinomas.

We performed in two patients with macroprolactinoma, pituitary scintigraphy with 123 iodine-methoxybenzamide (IBZM), a dopaminergic antagonist that specifically binds to the D2 dopaminergic receptors. In a 34-yr-old woman with basal PRL levels of about 2000 ng/mL, 7.5 mg/day of Bromocriptine (Br) for a month neither reduced PRL levels nor affected tumor size; in this patient single photon emission tomography SPECT failed to show any pituitary accumulation of the tracer. In the other patient, a 27-yr-old man presenting with cerebrospinal fluid rhinorrhea, basal PRL levels were at 5000 ng/mL; magnetic resonance imaging (MRI) demonstrated a huge pituitary tumor, and SPECT showed a very intense concentration of IBZM at the level of the adenoma. PRL levels fell dramatically to 530 ng/mL with only 2.5 mg/day of Br after 4 days; after 6 days with 7.5 mg/day Br, PRL levels were 63 ng/mL, and the patient underwent surgery to correct cerebrospinal fluid leakage. We conclude that, in these two patients, the pituitary scintigraphy with IBZM has given information on the density of dopamine receptors on the adenoma and has correlated with the inhibitory effect of Br on PRL secretion. Whether this tool might be of value in identifying patients with pituitary tumors potentially responsive to Br treatment is still to be investigated.

NADPH-diaphorase neurons contacting the cerebrospinal fluid in the ventricles of rat brain.

Two populations of scattered neurons containing nitric oxide synthase activity were detected in the wall of the third and lateral cerebral ventricles of rat brain, using histochemistry for NADPH-diaphorase activity. One type was multipolar and lay supraependymally, with dendrites oriented in the plane of the ependymal layer. The second type was bipolar and was situated subependymally, with dendrites extending in opposite directions, either into the surrounding brain tissue or to the ventricular surface. Moreover, multipolar neurons, situated in the corpus callosum and in the subcortical white matter, had long varicose dendrites extending toward the roof of the lateral ventricles. As a result, numerous NADPH-diaphorase neurites spread out on the free surface of the ependymal layer in contact with the CSF. These observations raise the possibility that periventricular nitrergic neurons play an essential role in registering the composition of the CSF and in modulating subcortical cerebral blood flow. A further possibility is that supraependymal nitrergic neuronal processes are effectors regulating activity of ependymal cells.

Determination of the in vivo effects of prednisone on Bcl-2 family protein expression in childhood acute lymphoblastic leukemia.

Glucocorticoid resistance is often associated with treatment failure in children with acute lymphoblastic leukaemia (ALL) but the underlying molecular mechanisms are still unclear. In 30 consecutive children with ALL treated with prednisone we determined changes in the expression of Bcl-2, Bax and Bcl-xl proteins in leukemic lymphoblasts and related these to clinical features and rate of prednisone-induced apoptosis. The apoptotic index increased after prednisone therapy in 24 of the 30 patients. At diagnosis, we detected expression of Bcl-2 and Bcl-xl protein in 28 samples, while Bax expression protein was detected in 21 of the 30 patients. Prednisone treatment induced a decrease in Bcl-2 and Bcl-xl levels in 17 and 16 of the 28 patients, respectively, while Bax protein increased in 14 of the 21 patients. Twenty of the 30 patients studied were considered to be good prednisone responders, whereas 10 were poor responders. We observed a statistically significant decrease only for Bcl-xl protein expression in T phenotype ALL, in the poor responder group and in patients with >20000/mm(3) white cell count (WBC) at diagnosis. These data suggest a role of Bcl-xl in the mechanisms of protection of leukemic cells from apoptosis induced by glucocorticoids (GCs).

Losses of hemifield contrast sensitivity in patients with pituitary adenoma and normal visual acuity and visual field.

OBJECTIVE: To detect early losses of contrast sensitivity (CS) in patients with pituitary adenomas, before the occurrence of visual acuity and visual field defects. METHODS: CS has been evaluated in both hemifields of 28 patients with different kinds of pituitary adenoma (mainly intrasellar) and normal visual acuity and visual field, as well as in 15 age-matched controls. Two different stimuli were used: a coarse (0.3 c/deg) dynamic (10 Hz) grating and a finer (2 c/deg) static grating. RESULTS: On average, CS and/or hemifield asymmetry were reduced in patients, whereas perimetric sensitivity was normal. CS losses were more frequent for 2 c/deg static-, as compared with 0.3 c/deg, 10 Hz stimuli. However selective losses for either stimuli were also found. CS losses did not correlate with anatomical measurements (size, chiasm involvement) of tumors as established by MRI scans. CONCLUSIONS: CS evaluation may provide a simple and effective tool for early detection and monitoring of visual dysfunction in patients with pituitary adenoma. The lack of correlation between CS losses and chiasm involvement suggests causes different from chiasmal compression for visual dysfunction.