Electrophysiological differences in cortical excitability in different forms of dementia: A transcranial magnetic stimulation and laboratory biomarkers study

BACKGROUND

The aim of the present study was to identify neurophysiologic markers to differentiate between Alzheimer dementia (AD), Vascular dementia (VaD), and Parkinson's disease dementia (PDD), and to examine their relationship to levels of transforming growth factor β1 (TGFβ1).

METHODS

The study included 15 patients with each type of dementia (AD, VaD, PDD) and 25 control subjects. Dementia patients were diagnosed according to the DiagnosticandStatisticalManualofMentalDisorders4thedition-revised(DSM-IV-R). Modified Mini Mental State Examination (MMMSE), motor cortex excitability including resting and active motor thresholds (rMT, aMT), input-output (I/O) curve, contralateral and ipsilateral silent periods (cSP, iSP), short-interval intracortical inhibition (SICI) at 1,2 and 4ms, and serum levels of TGFβ1 were examined.

RESULTS

There were no significant differences between groups with regards to age, sex, education or socioeconomic level. There was significant neuronal hyperexcitability in the form of reduced rMT and aMT and a shallower I/O curve in all three groups of dementia compared with the control group. The durations of cSP and iSP were longer in AD and PDD groups compared with the control group, whereas there were no significant differences in VaD. SICI was less effective in the three dementia groups than in the control group at intervals of 4ms. Serum levels of TGFβ1 were significantly elevated in all dementia groups in comparison with the control group. There was a significant negative correlation between serum level of TGFβ1 and cSP, iSP, and SICI across all patients and a significant negative correlation between serum level of TGFβ1 and iSP duration in AD.

CONCLUSION

Although motor thresholds were reduced in all patients, measures of SICI, cSP and iSP could distinguish between dementia groups. Serum level of TGFβ1 negatively correlated with iSP specifically in the AD group. This suggests that levels of TGFβ1 may relate to GABAergic dysfunction in dementia.

Ingenines A and B, Two New Alkaloids from the Indonesian Sponge Acanthostrongylophora ingens

As a continuation of the work on EtOAc fraction of the Indonesian sponge Acanthostrongylophora ingens, 2 new alkaloids: one pyrimidine-β-carboline alkaloid named ingenine A (2) and one pyrimidine-γ-carboline alkaloid named ingenine B (3), along with annomontine (1) were isolated. Their structures were unambiguously established on the basis of NMR spectroscopy ((1) H, (13)C, (1) H-(1) H COSY, HMQC, and HMBC) and mass spectral data. This is the first report of isolation pyrimidine-γ-carboline alkaloid from natural source. Compounds 1 and 3 showed pronounced cytotoxicity against the murine lymphoma L5178Y cancer cell line with ED50 7.8 and 9.1 μg/mL respectively, while compound 2 showed weak activity.

Stigmasterol Tetracosanoate, a New Stigmasterol Ester from the Egyptian Blepharis ciliaris

A new stigmasterol ester: stigmasterol tetracosanoate (3), along with 7 compounds: β-sitosterol (1), stigmasterol (2), (2S,3S,4R)-2[(2'R)-2'-(hydroxyeicosanoyl amino) octadecane-1,3,4-triol (4), apigenin (5), β-sitosterol-3-O-β-D-glucopyranoside (6), stigmasterol-3-O-β-D-glucopyranose (7), and apigenin-7-O-β-D-glucopyranoside (8) were isolated from Blepharis ciliaris aerial parts. Compounds 1, 2, and 5-7 are reported here for the first time from the plant and 4 for the first time from the family. GCMS analysis revealed the presence of 45 fatty acids, 53 hydrocarbons, and 24 sterols. The different fractions exhibited mild cytotoxic in brine shrimp assay and anti-hyperglycaemic activities. The EtOAc fraction and TME (total MeOH extract) showed weak anti-malarial activity against P. falciparum. The CHCl3 fraction gave potent -anti-inflammatory activity compared with indomethacin.

Type 2 diabetes-associated androgen alteration in patients with erectile dysfunction

Our objective was to assess the pattern of type-2 diabetes-associated androgen alteration in patients with erectile dysfunction (ED). A total of 127 diabetic male patients with ED were enrolled in this study. Erectile function was assessed using the International Index of Erectile Function (IIEF). At the time of assessment, patients were also interviewed and assessed for socio-demographic and medical history that includes duration and severity of diabetes mellitus (DM). Patients underwent routine laboratory investigations, in addition to total testosterone (T), dehydroepiandrosterone sulphate (DHEA-S) and insulin assessment. The mean age +/- SD was 53.8 +/- 9.3 years. Of patients 25.2% (n = 32/127), 6.3% (n = 8/127) and 31.5% (n = 40/127) had low total T, low DHEA-S and hyperinsulinaemia respectively. There were significant association between the increase in age and body mass index and the presence of low T level. Of the patients 37.5% (n = 12/32) with low T level had glycosylated haemoglobin (HbA1c) >7% while, 22.1% (n = 21/95) of the patients with normal T level had HbA1c >7% (p < 0.05). There were significant associations between the number of patients with low level of total T or DHEA-S and poor control of DM. Patients with low T level were two times more likely (56.3%, n = 18/32) to have severe ED than patients with normal T level (27.4%, n = 26/95) (p < 0.01). There were significant differences between the mean levels of total T or DHEA-S and poor control of DM. No significant associations were detected between hyperinsulinaemia and the level of fasting blood sugar, duration of DM, metabolic control of DM or ED severity. Patients with low T level were three times as likely to have hyperinsulinaemia as those patients with normal T level (p < 0.05). The current study clearly demonstrated that there were significant associations between low level of total T or DHEA-S and poor control of DM.

Two new chlorinated amides from Nicotiana glauca R. Graham

Two new chlorinated amides, N-(2',6'-diethyl phenyl)-2-chloroacetamide (1) and N-(butyloxymethyl)-N-(2',6'-diethyl phenyl)-2-chloroacetamide (2) were isolated for the first time from the ethanolic extract of the leaves of Nicotiana glauca R. Graham in addition to triacontanol (3), scopoletin (4) and stigmasterol-3-beta-O-D-gluco-pyranoside (5). The structures of the isolated compounds were elucidated by spectroscopic analysis (1D, 2D NMR, EIMS, HR-EIMS, IR and UV).