A candidate for lung cancer treatment: arsenic trioxide.

Arsenic trioxide (ATO), a highly effective drug in treating acute promyelocytic leukemia with low toxicity, demonstrates a significant effect on lung cancer. The anti-cancer mechanisms of ATO include inhibition of cancer stem-like cells, induction of apoptosis, anti-angiogenesis, sensitization of chemotherapy and radiotherapy, anti-cancer effects of hypoxia, and immunoregulation properties. In addition, some studies have reported that different lung cancers respond differently to ATO. It was concluded on numerous studies that the rational combination of administration and encapsulation of ATO have promising potentials in increasing drug efficacy and decreasing adverse drug effects. We reviewed the efficacy of ATO in the treatment of lung cancer in recent years to provide some views for further study.

Predictors of Vitamin D deficiency in predialysis patients with stage 3-5 chronic kidney diseases in Southern China.

OBJECTIVE: Vitamin D status and risk factors of Vitamin D deficiency in chronic kidney disease (CKD) patients in China have been seldom reported before. In this study, we aim to investigate serum 25-hydroxyvitamin D [25(OH)D] status and find the predictors of Vitamin D deficiency in predialysis patients with Stage 3-5 CKDs in Southern China. METHODS: In this retrospective cross-sectional study, hospitalized predialysis patients who were diagnosed of Stage 3-5 CKD and had taken measurement of serum 25(OH)D in a single center from January 2014 to June 2015 were included. Patients were divided into Vitamin D deficiency group and nondeficiency group depending on the cutoff serum 25(OH)D value of 37 nmol/L. Clinical and biochemical parameters were collected and evaluated for predictors of Vitamin D deficiency by logistic regression. RESULTS: One hundred and fifty-two patients were included in this study, of which 87 (57.2%) were in Vitamin D insufficiency state while 60 (39.5%) were in Vitamin D deficiency state. Serum 25(OH)D levels of patients in Stage 4 and Stage 5 CKD were lower than that of patients in Stage 3 CKD (P = 0.002). It was discovered that female gender (odds ratio [OR] = 3.674; 95% confidence interval [CI], 1.607-8.396; P = 0.002), serum albumin level <30.0 g/L (OR = 6.816; 95% CI, 2.634-17.633; P < 0.001), and estimated glomerular filtration rate (eGFR) <30 ml/min/1.73 m2 (OR = 4.761; 95% CI, 1.353-16.754; P = 0.015) were independent predictors of Vitamin D deficiency. CONCLUSIONS: Vitamin D insufficiency and deficiency are common in predialysis patients with Stage 3-5 CKD in Southern China. Female gender, hypoalbuminemia with serum albumin level <30.0 g/L, and severe damaged renal function with eGFR <30 ml/min/1.73 m2 are independent predictors of Vitamin D deficiency in predialysis patients with Stage 3-5 CKD.

Comparative efficacy of whole-brain radiotherapy with and without elemene liposomes in patients with multiple brain metastases from non-small-cell lung carcinoma.

PURPOSE: We explored and compared the clinical effects of whole-brain radiotherapy (wbrt) with and without elemene liposomes in patients with multiple brain metastases from non-small-cell lung carcinoma (nsclc). METHODS: We retrospectively analyzed 62 patients with multiple brain metastases from nsclc who received wbrt (30 Gy in 10 fractions) at Shengjing Hospital of China Medical University from January 2012 to May 2013. In 30 patients, elemene liposomes (400 mg) were injected intravenously via a peripherally inserted central catheter for 21 consecutive days from the first day of radiotherapy. Overall survival (os) and nervous system progression-free survival (npfs) for the two groups were compared by Kaplan-Meier analysis. Factors influencing npfs were examined by Cox regression analysis. Chi-square or Fisher exact tests were used for group comparisons. RESULTS: The median os was 9.0 months in the wbrt plus elemene group and 7.8 months in the wbrt-alone group (p = 0.581); the equivalent median npfs durations were 5.2 months and 3.7 months (p = 0.005). Patient treatment plan was an independent factor associated with npfs (p = 0.002). Tumour response and disease-control rates in the wbrt plus elemene group were 26.67% and 76.67% respectively; they were 18.75% and 62.5% in the wbrt group (p = 0.452). Compared with the patients in the wbrt-alone group, significantly fewer patients in the wbrt plus elemene group developed headaches (p = 0.04); quality of life was also significantly higher in the wbrt plus elemene group both at 1 month and at 2 months (p = 0.021 and p = 0.001 respectively). CONCLUSIONS: The addition of elemene liposomes to wbrt might prolong npfs in patients with multiple brain metastases from nsclc, while also reducing the incidence of headache and improving patient quality of life.

Radiation-enhancing effect of sodium glycididazole in patients suffering from non-small cell lung cancer with multiple brain metastases: A randomized, placebo-controlled study.

PURPOSE: Median survival of patients with brain metastases from non-small cell lung cancer is poor. This study was to investigate the radiation-enhancing effect of sodium glycididazole combined with whole-brain radiotherapy of multiple brain metastases from non-small cell lung cancer. PATIENTS AND METHODS: Sixty-four patients with multiple brain metastases from non-small cell lung cancer were included: the study group (n=32) received whole-brain radiotherapy combined with sodium glycididazole at a dose of 700mg/m(2) intravenous infusion 30minutes before radiotherapy, three times a week; the control group (n=32) only received whole-brain radiotherapy. The primary end point was central nervous system (CNS) progression-free survival and overall survival. The treatment-related toxicity was also recorded. RESULTS: The CNS disease control rate was better (90.6% vs 65.6%, P=0.016) in the study group than in the control group at 3 month of follow-up. The median CNS progression-free survival time was longer in the study group than in the control group (7.0 months vs 4.0 months, P=0.038). There was no significant difference of the median overall survival time between the study group and the control group (11.0 months vs 9.0 months, P=0.418). On the other hand, the treatment-related toxicity showed no statistically significant difference between these two groups (P>0.05). CONCLUSIONS: The study indicated that sodium glycididazole was an effective, promising radiation-enhancing agent that improved CNS disease control rate, extended the median CNS progression-free survival time and was well tolerated in patients suffering from non-small cell lung cancer with multiple brain metastases.

Serum C-reactive protein predicts poor prognosis in patients with locoregionally advanced nasopharyngeal carcinoma treated with chemoradiotherapy.

BACKGROUND: We aimed to evaluate the association of serum C-reactive protein (crp) with prognosis in patients with locoregionally advanced nasopharyngeal carcinoma treated with chemoradiotherapy. METHODS: We retrospectively reviewed 79 patients with locoregionally advanced nasopharyngeal carcinoma (cT3-4N0-3M0) treated with chemoradiotherapy. Chemoradiotherapy consisted of external-beam radiotherapy to the nasopharynx (70-80 Gy), the lymph node-positive area (60-70 Gy), and the lymph node-negative area (50-60 Gy) combined with 3 cycles of various platinum-based regimens delivered at 3-week intervals. Elevated crp was defined as more than 8 mg/L. The survival rate was calculated using the Kaplan-Meier method, and univariate and multivariate analyses (Cox proportional hazards model) were used to identify factors significantly associated with prognosis. RESULTS: During the median follow-up of 3.9 years (range: 1-5.5 years), 23 patients died from nasopharyngeal cancer. The 5-year cancer-specific survival (css) rate was 62.90%. Before chemoradiotherapy, 18 patients had high serum crp; the css rate in that subgroup was significantly worse than the rate in the remaining patients (p = 0.0002). Multivariate analysis showed that crp was an independent prognostic indicator of css, with a hazard ratio of 3.04 (95% confidence interval: 1.22 to 7.55; p = 0.017). Among the 18 patients with elevated serum crp, 9 achieved normal serum crp after chemoradiotherapy, of whom 5 remained living with no evidence of recurrence or metastasis during follow-up. By contrast, the remaining 9 patients in whom serum crp did not normalize after chemoradiotherapy died within 4.2 years. CONCLUSIONS: Elevated serum crp before treatment predicts poor prognosis in patients with locoregionally advanced nasopharyngeal carcinoma treated with chemoradiotherapy.

Neuroprotective effects of argatroban and C5a receptor antagonist (PMX53) following intracerebral haemorrhage.

Intracerebral haemorrhage (ICH) is a subtype of stroke that associated with neurological dysfunction and inflammation, which may be ameliorated by a neuroprotective strategy targeting the complement cascade. The protective effect of C5a-receptor antagonist (PMX53) solely and in combination with thrombin antagonist (argatroban) was investigated in the ICH mouse model, respectively. Adult male C57BL/6J wild-type (WT) mice and C3(-/-) mice were randomized to receive PMX53/argatroban 1, 3 and 5 days after ICH. A double injection technique was used to infuse 25 µl of autologous whole blood into the right striatum. Mice in the sham group received only needle insertion. Brain water content and mRNA of inflammatory factors were measured on the first, third and fifth days after ICH, respectively. Neurological dysfunction was assessed using a 28-point neurological scoring system in the three cohorts, namely, on days 1, 3 and 5 following ICH. Animals treated with PMX53/argatroban demonstrated significant improvements in neurological function and fewer neurological apoptosis detected by TUNEL [terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end-labelling] and ßIII-tubulin dual-staining compared with vehicle-treated animals. Compared with sham-treated mice, the brain water content in argatroban/PMX53-treated mice was decreased significantly in both the ipsilateral cortex and ipsilateral striatum. Administration of PMX53/argatroban provided a synergistic neuroprotective effect via reducing inflammatory factors and brain oedema, leading to improvements in neurofunctional outcome. The results of this study indicated that simultaneous blockade of the thrombin and C5a receptors represent a promising neuroprotective strategy in haemorrhagic stroke.

Screening and identification of various components in Thalictrum fortunei using a combination of liquid chromatography/time-of-flight tandem mass spectrometry.

An approach for screening and identification of various components in a traditional Chinese medicine (TCM), using a combination of LC/TOF-MS technique was described in this paper. The chemical profile of Thalictrum fortunei, well-known in TCM, was studied using the established method. The possibilities of screening and identifying non-target components inside TCM with modern data acquisition methods of acceleration time of flight mass spectrometers, such as data-dependent MS to MS/MS switching were investigated. As a result, 27 components were identified. This study was aimed to screen and identify the main components of T. fortunei using LC/TOF-MS, expecting to provide a rapid, sensitive, economical and systematical method for the identification and further quality evaluation of TCM preparation.

Serum levels of selenium in patients with brain metastases from non-small cell lung cancer before and after radiotherapy.

PURPOSE: This study was to evaluate the influence of radiotherapy on the selenium serum levels of non-small cell cancer patients with brain metastases. PATIENTS AND METHODS: This prospective study included 95 non-small cell cancer patients with brain metastases treated by radiotherapy from December 2007 until November 2010. Plasma selenium levels were determined before and at the end of the radiotherapy. Age, body mass index (BMI), prior chemotherapy, pathological type and personal habits (smoking and alcoholism) were recorded for each patient. RESULTS: The mean age was 63 years; the mean BMI was 27.6. Seventy-six patients (80%) were non-smokers. Sixty-two patients (65.3%) showed no drinking habits and 8 (8.4%) have no prior chemotherapy. Thirty-nine patients (41.1%) were adenocarcinoma, 51 (53.7%) were squamous cell carcinoma and five (5.3%) were large cell carcinoma. At the beginning of radiotherapy, the mean selenium level for all patients was 90.4 µg/l and after radiation this value dropped to 56.3 µg/l. Multivariate analysis showed statistically significant difference in the plasma selenium concentration before and after radiotherapy for age (P<0.001), BMI (P<0.001), smoking (P<0.001), alcoholism (P<0.001), prior chemotherapy (P<0.001) and pathological type (P<0.001). CONCLUSION: Significant reduction in plasma levels of selenium was recorded in patients undergoing radiotherapy, suggesting attention to the nutritional status of this micronutrient and other antioxidant agents.

Safety and radiation-enhancing effect of sodium glycididazole in locoregionally advanced laryngeal cancers previously treated with platinum-containing chemotherapy regimens: A preliminary report.

PURPOSE: To determine the safety and radiation-enhancing effect of sodium glycididazole in laryngeal squamous cell carcinoma (stage T3-4,N0-3,M0) with conventional radiotherapy. PATIENTS AND METHODS: Patients with locoregional advanced laryngeal cancer (stage T3-4,N0-3,M0) were included: group 1(control, n=30)were not administered of sodium glycididazole; group 2 (test, n=30) received sodium glycididazole at a dose of 700 mg/m(2) intravenous infusion 30 minutes before radiotherapy three times a week. Surrogate end-points of efficacy were tumor and nodal size. Safety parameters were vomiting, nausea, mucositis, laryngeal edema, esophagus and skin reaction, dysphagia, dyspnea, neurological deficit. Patients were evaluated weekly during treatment for 7 weeks and thereafter monthly for 3 months. RESULTS: In the test, the overall response rate was 88.89% (95%CI, 71.00-97.00%) at 7 weeks and 92.59% (95%CI, 76.00 to 99.00%) at 1 month of follow-up. In the control, the overall response rate was 62.5% (95%CI, 41.00 to 81.00%) at 7 weeks and 58.33% (95%CI, 37.00 to 78.00%) at 1 month of follow-up. The short-term locoregional response rate was better in the test group at 7 weeks (p=0.027) and at 1 month (p=0.005) of follow-up. The test group had significantly more nausea and vomiting in weeks 1 (p=0.047), 2 (p=0.007), and 3 (p=0.01) of treatment. CONCLUSIONS: The study indicates sodium glycididazole is an effective radiation-enhancing agent that improves short-term locoregional control and is well tolerated in patients with locoregionally advanced laryngeal cancer.

Differential anesthetic activity of ketamine and the GABAergic neurosteroid allopregnanolone in mice lacking progesterone receptor A and B subtypes.

Progesterone affects the function of the brain by multiple mechanisms. The physiological effects of progesterone are mediated by the interaction of the hormone with progesterone receptors (PRs), which are widely expressed in the hypothalamus, hippocampus and limbic areas. The PR is composed of two protein isoforms, PR-A and PR-B, which are expressed from a single PR gene. In addition, progesterone influences neuronal activity through its conversion to allopregnanolone, a neurosteroid that acts as a positive allosteric modulator of GABA(A) receptors. However, the role of PRs in the sedative-hypnotic action of neurosteroids is unclear. In this study, PR knockout (PRKO) mice were used as model to study the sedative-anesthetic actions of the progesterone-derived neurosteroid allopregnanolone and the noncompetitive NMDA receptor antagonist ketamine. Mice were confirmed to be PR deficient by genotyping and immunohistochemistry of PR expression in the brain. Anesthetic potency was evaluated by the loss of the righting reflex paradigm. Allopregnanolone-induced anesthetic activity was similar in PRKO mice and their wild-type littermates, suggesting that PRs are not involved in the anesthetic response to allopregnanolone. However, the noncompetitive NMDA receptor antagonist ketamine has significantly reduced anesthetic potency in PRKO mice, suggesting a possible developmental plasticity of glutamate receptors. There was no marked gender-related difference to ketamine response in both genotypes. In conclusion, these results suggest that the neurosteroid allopregnanolone and ketamine produce differential anesthetic response in mice lacking PRs.

HIV-1 infected mononuclear phagocyte secretory products affect neuronal physiology leading to cellular demise: relevance for HIV-1-associated dementia.

Viral and cellular products from HIV-1-infected and/or immune competent mononuclear phagocytes (MP) (brain macrophages and microglia) affect neuronal function during HIV-1-associated dementia (HAD). Neurotoxic MP factors include, but are not limited to, pro-inflammatory cytokines, chemokines, platelet activating factor, arachidonic acid and its metabolites, nitric oxide, progeny virions and viral structural and regulatory proteins. The mechanisms for immune-mediated neural injury in HAD, only now, are being unraveled. In this regard, we reviewed the current knowledge of how postmitotic neurons, which can neither divide nor be replaced, are damaged by MP secretory activities. Linking neuronal function with brain MP activation was made possible by placing viral and/or immune products onto neurons and measuring cell signaling events or through ex vivo electrophysiological tests on MP-treated brain slices. Such linkages are shown, in this report, by select demonstrations of MP factors which cause neuronal dysfunction in HAD.

Soluble HIV-1 infected macrophage secretory products mediate blockade of long-term potentiation: a mechanism for cognitive dysfunction in HIV-1-associated dementia.

It is generally accepted that viral and cellular products from immune competent mononuclear phagocytes (MP) (brain macrophages and microglia) underlie the neuropathogenesis of HIV-1-associated dementia (HAD). What remains unanswered, however, is the composition of and mechanisms for such MP-induced neurological dysfunctions. In attempts to address these issues culture fluids from HIV-1ADA-infected monocyte-derived macrophages (MDMs) (depleted or enriched with progeny virus) were placed onto the CA1 area of rat hippocampal brain slices (the site of mammalian learning and memory) and neuronal long-term potentiation (LTP) assayed. LTP was induced by high frequency stimulation (HFS). Lipopolysaccharide (LPS) served as a surrogate macrophage activator. Synaptic strength was assayed by the initial slope of evoked field excitatory postsynaptic potentials (EPSPs). Synaptic potentiation following HFS was observed in slices incubated with uninfected (control) MDM culture fluids. The magnitude of the LTP response was 150.2 +/- 21.10% compared to basal levels (n=6). Synaptic strength was enhanced in virus-infected (135.7+/-28.9%, n=8) and LPS-activated MDM (123.3+/-5.1%, n=7) but at lower levels than controls. The lowest levels of LTP were in brain slices incubated with virus-infected and LPS-activated MDM fluids at (109.5+/-9.9% n=12). Interestingly, bath application of progeny HIV-1 virions showed minimal LTP effects. Virus-infected, LPS-activated MDM fluids, with progenyvirus, reduced synaptic strength but were not statistically different than replicate culture fluids depleted of virus. In contrast, IL-1beta and quinolinic acid, significantly diminished synaptic strength. These results, taken together, suggest that soluble HIV-1-infected MDM secretory products, but not virus per se, significantly affect LTP. This electrophysiological system, which monitors neuronal function following cell exposure to HIV-1 infected materials could provide a novel testing ground for therapeutics designed to protect brain function in HAD.

Intracellular CXCR4 signaling, neuronal apoptosis and neuropathogenic mechanisms of HIV-1-associated dementia.

The mechanism(s) by which HIV-1 affects neural injury in HIV-1-associated dementia (HAD) remains unknown. To ascertain the role that cellular and viral macrophage products play in HAD neurotoxicity, we explored one potential route for neuronal demise, CXCR4. CXCR4, expressed on lymphocytes and neurons, is both a part of neural development and a co-receptor for HIV-1. Its ligand, stromal cell-derived factor-1alpha (SDF-1alpha), affects neuronal viability. GTP binding protein (G-protein) linked signaling after neuronal exposure to SDF-1alpha, virus-infected monocyte-derived macrophage (MDM) secretory products, and virus was determined. In both human and rat neurons, CXCR4 was expressed at high levels. SDF-1alpha/beta was detected predominantly in astrocytes and at low levels in MDM. SDF-1beta/beta was expressed in HAD brain tissue and upregulated in astrocytes exposed to virus infected and/or immune activated MDM conditioned media (fluids). HIV-1-infected MDM secretions, virus and SDF-1beta induced a G inhibitory (Gi) protein-linked decrease in cyclic AMP (cAMP) and increase inositol 1,4, 5-trisphosphate (IP3) and intracellular calcium. Such effects were partially blocked by antibodies to CXCR4 or removal of virus from MDM fluids. Changes in G-protein-coupled signaling correlated, but were not directly linked, to increased neuronal synaptic transmission, Caspase 3 activation and apoptosis. These data, taken together, suggest that CXCR4-mediated signal transduction may be a potential mechanism for neuronal dysfunction during HAD.

Neuroprotective effects of riluzole: an electrophysiological and histological analysis in an in vitro model of ischemia.

The protective effects of riluzole against the neuronal damage caused by O2 and glucose deprivation (ischemia) was investigated in rat cortical slices by recording electrophysiologically the cortico-cortical field potential and by evaluating histologically the severity of neuronal death. Five minutes of ischemia determined an irreversible depression of the amplitude of the field potential. In addition, this insult caused a clear enhancement of the number of death cells that were specifically colored with trypan blue (a vital colorant which stains altered cells). We found that riluzole, which by itself depressed the synaptic transmission, neuroprotected when perfused 15-20 min before and during ischemia. In fact, due to the treatment with riluzole, the ischemia-induced irreversible depression of the field potential recovered and less cells were stained with trypan blue. These findings demonstrate that riluzole prevents neuronal death in an in vitro model of ischemia and suggest a therapeutic use of this drug in order to reduce the pathophysiological outcomes of stroke.

Purification to homogeneity and properties of plant glucosidase I.

Glucosidase I was purified about 3600-fold to apparent homogeneity from the microsomal fraction of mung bean seedlings. The purified enzyme removed the terminal alpha1,2-linked glucose from Glc3Man9GlcNAc2-peptide or the endoglucosaminidase H (Endo H)-released oligosaccharide. Glucosidase I activity was inhibited by kojibiose [Glc(alpha1-2)Glc], but not by other glucose disaccharides. Removal of up to four mannose residues from the N-linked oligosaccharide had little effect on its utilization as a substrate for glucosidase I. The enzyme had a subunit molecular weight of 97 kDa on SDS gels and this was shifted to 94 kDa after treatment with Endo H or Endo F, suggesting that glucosidase I is an N-glycoprotein having one oligomannose-type oligosaccharide. Amino acid sequences of this enzyme showed considerable identity to the enzyme cloned from a human hippocampus cDNA library. The enzyme was inhibited by castanospermine, deoxynojirimycin, MDL, and trehazolin, but not by australine or kifunensine. On the other hand, the other processing glucosidase, glucosidase II, is sensitive to inhibition by australine, but not by trehazolin. Thus, these two inhibitors are useful to distinguish glucosidase I from glucosidase II. The mung bean glucosidase I is quite sensitive to the histidine modifying reagent diethyl pyrocarbonate, whereas the pig liver glucosidase I is not. On the other hand, pig liver and pig brain glucosidase I preparations are sensitive to the sulfhydryl reagent NEM (N-ethylmaleimide), whereas the plant enzyme is not. These sensitivities to amino acid modifiers suggest significant differences between the plant and animal glucosidase I, in terms of catalytic site or protein conformation.

Opposite modulation of 4-aminopyridine and hypoxic hyperexcitability by A1 and A2 adenosine receptor ligands in rat hippocampal slices.

The effects of the adenosine receptor antagonist 1,3-dipropyl-8-cyclopentylxanthine (DPCPX), and of the adenosine agonists N6-cyclopentyladenosine (CPA), N6-(2-phenylisopropyl)adenosine (R-PIA), and 2-[p-(carboxyethyl)phenylethylamino]-5'-N-ethylcarboxamidoadenosin e (CGS 21680) were investigated on the hyperexcitability induced in the CA1 area of rat hippocampal slices by hypoxia or the epileptogenic agent 4-aminopiridine. Slice perfusion with the mixed adenosine receptor agonist R-PIA (0.2 microM) significantly (P < 0.05) decreased: (i) the number of slices showing a transient CA1 epileptiform bursting during the hypoxic period; (ii) the duration of the hypoxia-induced epileptiform bursting. Conversely, slice perfusion with the selective A1 adenosine receptor antagonists DPCPX (0.2 microM) or with the selective A2 adenosine receptor agonist CGS 21680 significantly (P < 0.05) increased the number of slices showing a transient CA1 epileptiform bursting during the hypoxic period but did not affect the duration of the hypoxia-induced epileptiform bursting. Neither drug significantly affected the number of slices showing functional recovery after hypoxia. Slice perfusion with DPCPX (0.2 microM) also significantly increased (P < 0.05) the number of slices showing a persistent CA1 epileptiform bursting during the reoxygenation period, while the other drugs failed to affect it. Slice perfusion with the selective A1 adenosine receptor agonist CPA (2 microM) or R-PIA (5 microM) significantly (P < 0.05) decreased the duration of the CA1 epileptiform bursting induced by 100 microM 4-aminopyridine. CGS 21680 (5 microM) perfused together with CPA (2 microM) significantly (P < 0.05) counteracted the inhibitory effects of the A1 adenosine receptor agonist on 4-aminopyridine epileptiform bursting, while it failed by itself to directly affect the 4-aminopyridine epileptiform bursting duration. The results produce evidence for a selective opposite modulation by A1 and A2 adenosine agonists in the control of hippocampal hyperexcitability induced by hypoxia or 4-aminopyridine but not in the post-hypoxic functional recovery.

Microanatomical and electrophysiological changes of the rat dentate gyrus caused by lesions of the nucleus basalis magnocellularis.

The effect of unilateral or bilateral lesions of the nucleus basalis magnocellularis (NBM) on the dentate gyrus of the hippocampus were assessed using microanatomical and electrophysiological techniques. NBM is the main cholinergic basal forebrain nucleus that supplies the fronto-parietal cortex. Lesions were induced using the neurotoxin ibotenic acid or a radio-frequency system and did not affect glutamic acid decarboxylase activity both in the frontal cortex and in the hippocampus. At 4 weeks after lesioning, a loss of choline acetyltransferase (ChAT) activity and of ChAT-immunoreactive fibres was observed in the frontal cortex but not in the hippocampus and no changes in the density of granule neurons of the dentate gyrus or in the hippocampal long-term potentiation (LTP) were noticeable. At 8 weeks after lesioning the loss of both ChAT activity and of ChAT-immunoreactive fibres persisted in the frontal cortex of NBM-lesioned rats. Moreover, at this time a significant decrease in the density of granule neurons in the dentate gyrus accompanied by a reduced probability of dentate LTP induction were observed in both ibotenic acid- and radio-frequency-lesioned rats. These findings have shown that although NBM does not send direct cholinergic projections to the hippocampus, lesions of this cholinergic nucleus are accompanied by delayed neurodegenerative changes involving the dentate gyrus. This suggests the occurrence of indirect connections between NBM and the hippocampus, the functional relevance of which should be explored.

Effect of long-term treatment with L-deprenyl on the age-dependent microanatomical changes in the rat hippocampus.

Chronic treatment with L-deprenyl increases both mean and maximum life span and improves cognitive functions in the aged rat. The present study was designed to evaluate whether long-term treatment with L-deprenyl at a dosage not inhibiting the monoamine oxidase-B (MAO-B) (1.25 mg/kg/day) or inhibiting the enzyme activity (5 mg/kg/day) had any effect on the age-dependent microanatomical changes in the rat hippocampus. The hippocampus was chosen in view of its key role in learning and memory functions. Treatment with L-deprenyl started at 19 months and lasted until the 24th month of age. Age-matched untreated rats were used as a control, whereas 11-month-old rats were used as an adult reference group. The number of nerve cell and glial fibrillary acidic protein-immunoreactive astrocyte profiles in the CA1 and CA3 fields of the hippocampus and in the dentate gyrus was decreased and increased, respectively in aged compared with adult rats. Treatment with 5 mg/kg/day, but not with 1.25 mg/kg/day L-deprenyl increased the number of neuronal profiles and decreased the number of astrocytes in the hippocampus of aged rats. The density of zinc stores in the associative intrahippocampal pathway of mossy fibres, which was decreased in aged animals, was increased after treatment with the two doses of L-deprenyl. Lipofuscin accumulation within the cytoplasm of pyramidal neurons of the hippocampus was reduced dose dependently by L-deprenyl treatment. These results suggest that long-term treatment with L-deprenyl is able to counter the expression of age-dependent microanatomical changes in the rat hippocampus. These effects seem only partially correlated with the MAO-B inhibitory activity of L-deprenyl.

Age-related changes in brain microanatomy: sensitivity to treatment with the dihydropyridine calcium channel blocker darodipine (PY 108-068).

The influence of aging and of treatment with the dihydropyridine Ca2+ antagonist darodipine (PY 108-068) on the age-related microanatomical changes of rat brain were studied in male Wistar rats treated from the 18th to the 24th month of age with an oral dose of 5 mg/kg/day of darodipine. Twelve-month-old untreated rats were used as an adult reference group. A decreased number of nerve cells and of alkaline phosphatase-positive capillaries and an increased lipofuscin deposition were observed in the frontal and occipital cortex, in the hippocampus, and in the cerebellar cortex of rats of 24 months in comparison with 12-month-old animals. The number of nerve cells was higher in the occipital cortex and in the hippocampus, but not in the frontal cortex and in the cerebellar cortex, of darodipine-treated rats in comparison with age-matched untreated animals. Lipofuscin deposition is reduced in all the brain areas investigated. The density of alkaline phosphatase-reactive capillaries is also increased in the frontal and occipital cortex and in the hippocampus of aged rats treated with darodipine. The above results suggest that treatment with darodipine is able to counter some microanatomical changes occurring in the brain of aged rats and involving not only microvascular parameters. The occipital (visual) cortex and the hippocampus were the cerebral areas more sensitive to treatment with darodipine. The possible relevance of these findings is discussed.

Muscarinic cholinergic receptors in the hippocampus of aged rats: influence of choline alphoscerate treatment.

The present study was designed to investigate age-dependent changes of muscarcinic M1 and M2 cholinergic receptors in the rat hippocampus using radioreceptor assay and autoradiographic techniques with [3H]pirenzepine and [3H]AF-DX 116 as ligands. The analysis was performed on 2-, 12- and 27-month-old male Wistar rats, considered young, adult and old, respectively. Moreover, the influence of a 6-month treatment with choline alphoscerate on the density and pattern of M1 and M2 cholinergic receptors was assessed. Choline alphoscerate (L-alpha-glyceryl phosphorylcholine) is a precursor in the biosynthesis of several brain phospholipids which increases the availability of acetylcholine in various tissues. Muscarinic M1 cholinergic receptors were significantly decreased with increasing age whereas M2 cholinergic receptors did not show changes. Choline alphoscerate treatment countered, in part, the loss of muscarinic M1 receptor sites in old rats. Light microscope autoradiography revealed a loss of silver grains developed after exposure of sections of hippocampus to [3H]pirenzepine in the stratum oriens of CA1 and CA3 fields in rats of 12 and 27 months in comparison with young animals. Choline alphoscerate restored, in part, the decrease of silver grains noted in old rats. Quantitative analysis of the density of silver grains developed in the cell body of pyramidal neurons of CA1 and CA3 fields processed for the demonstration of muscarinic M1 receptor sites revealed a decrease of these grains in rats of 27 months in comparison with younger cohorts. These findings suggest that the reduction in muscarinic M1 sites noticeable between 2- and 12-month rats is probably dependent on the loss of nerve cells and/or terminals in these hippocampal fields rather than to a reduction of their density per neuron. Treatment with choline alphoscerate increased the expression of muscarinic M1 cholinergic receptors within the cell body of pyramidal neurons of CA1 and CA3 fields compared to age-matched control old rats. Consistent with radioreceptor assay data, no changes in the density of muscarinic M2 cholinergic receptors in the animal groups examined were demonstrated by light microscope autoradiography. The possible pharmacological relevance of the increased expression of muscarinic M1 cholinergic receptors elicited by choline alphoscerate in the hippocampus of aged rats is discussed.