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Biomedical subjects

A Thomas

Publications and source records attributed to A Thomas.

At least 55 records · Page 3Linked to original sources

Improvement of motor function in early Parkinson disease by safinamide.

A median safinamide (SAF) dose of 70 mg/day (range 40 to 90 mg/day) increased the percentage of parkinsonian patients improving their motor scores by > or =30% from baseline (responders) after 3 months from 21.4% (placebo) to 37.5% (p < 0.05, calculated by logistic regression analysis). In a subgroup of 101 patients under stable treatment with a single dopamine agonist, addition of SAF magnified the response (47.1% responders, mean 4.7-point motor score decrease; p > or = 0.05). These results suggest that doses of SAF exerting ion channel block and glutamate release inhibition add to its symptomatic effect and warrant exploration of higher doses.

Adult↗

Experimental check of the Gerasimov-Drell-Hearn sum rule for 1H.

For the first time we checked the fundamental Gerasimov-Drell-Hearn (GDH) sum rule for the proton experimentally in the photon energy range from 0.2-2.9 GeV with the tagged photon facilities at MAMI (Mainz) and ELSA (Bonn). New data of the doubly polarized total cross section difference are presented in the energy range from 1.6 to 2.9 GeV. The contribution to the GDH integral from 0.2-2.9 GeV yields [254+/-5(stat)+/-12(syst)] microb with negative contributions in the Regge regime at photon energies above 2.1 GeV. This trend supports the validity of the GDH sum rule.

Journal Article↗

Photoproduction of eta-mesic 3He.

The photoproduction of eta-mesic 3He has been investigated using the TAPS calorimeter at the Mainz Microtron accelerator facility MAMI. The total inclusive cross section for the reaction gamma3He-->etaX has been measured for photon energies from threshold to 820 MeV. The total and angular differential coherent eta cross sections have been extracted up to energies of 745 MeV. A resonancelike structure just above the eta production threshold with an isotropic angular distribution suggests the existence of a resonant quasibound state. This is supported by studies of a competing decay channel of such a quasibound eta-mesic nucleus into pi(0)pX. A binding energy of (-4.4+/-4.2) MeV and a width of (25.6+/-6.1) MeV is deduced for the quasibound eta-mesic state in 3He.

Journal Article↗

Altered neurometabolite development in HIV-infected children: correlation with neuropsychological tests.

BACKGROUND: HIV-infected children have abnormal cerebral metabolites, measured by proton MR spectroscopy ((1)H-MRS), but how these abnormalities relate to brain function is unclear. METHODS: Metabolite concentrations in five brain regions of 20 HIV-infected and 13 control children were measured, and these findings were correlated with age, log(10) plasma viral load, CD4 count, and neuropsychological scores. RESULTS: Compared with control subjects, HIV patients had decreased choline concentration [Cho] in left frontal white matter (LFW) (-12%; p = 0.04); those with high viral load (>5,000 HIV RNA copies/mL) had decreased right basal ganglia (RBG) [Cho] (-15%; p = 0.005), and [Cr] (-13%; p = 0.02). Patients with high viral load also had higher [Cho] in the midfrontal gray matter (MFG) (+25%; p = 0.002) and lower myo-inositol [Ins] in the RBG (-18%; p = 0.04) than patients with low HIV viral load. N-Acetyl aspartate concentration ([NAA]) correlated with age in right frontal white matter (RFW) (r = 0.59, p = 0.04), LFW (r = 0.66, p = 0.02), and right hippocampus (RHIP) (r = 0.69, p = 0.02) only in control subjects. In contrast, [Ins] correlated with age in both RFW and LFW (r = 0.71, p = 0.0006; r = 0.65, p = 0.006) only in the HIV patients. Log(10) plasma viral load correlated positively with [Ins] in RFW (r = 0.54, p = 0.02) and [Cho] in MFG (r = 0.49, p = 0.04). Compared with control subjects, HIV patients had poorer spatial memory (p = 0.045) and delayed spatial memory correlated with [Cho] in RHIP (r = 0.68, p = 0.02). CONCLUSIONS: These data suggest that normal brain development may be affected in children infected with HIV at birth, particularly evidenced by the lack of age-related increases in the neuronal marker [NAA]. Early, aggressive treatment of infants with HIV before development of encephalopathy is warranted.

Adolescent↗

Combining entacapone with levodopa/DDCI improves clinical status and quality of life in Parkinson's Disease (PD) patients experiencing wearing-off, regardless of the dosing frequency: results of a large multicentre open-label study.

The efficacy of entacapone and its impact on patient quality of life (QOL) was investigated in an open-label study of 899 patients with idiopathic Parkinson's Disease (PD) experiencing wearing-off fluctuations. Patients were divided into 3 groups (3, 4 or 5 doses daily) based on their current levodopa dosage frequency. Patients received 200 mg entacapone with each levodopa/dopa-decarboxylase inhibitor (DDCI) dose, while continuing their same levodopa/DDCI dosage regimen for 4 weeks. Primary efficacy measure was the Investigators' Clinical Global Impression of Change (CGIC). Patient QoL was assessed using the validated 8-item Parkinson's Disease Questionnaire (PDQ-8). Investigators' CGIC revealed that 76.5% of entacapone treated patients experienced an improvement in global status after 4 weeks. Treatment with entacapone was also associated with improvement in patient QoL, with a mean reduction (improvement) in PDQ-8 score of 1.8 from baseline. This study confirms and extends the results of earlier studies demonstrating that, independent of dosing frequency, completing levodopa/DDCI therapy with entacapone provides clinically relevant improvements in global status and QoL in PD patients experiencing wearing-off on their current levodopa dosing frequency.

Aged↗

Effects of corticosterone on place conditioning to ethanol.

RATIONALE AND OBJECTIVE: Effects of corticosterone on place conditioning to ethanol were investigated in mice using two conditioning schedules; the conventional method and a rapid conditioning schedule in which exposure to the CS+ followed immediately on exposure to the CS-. METHODS: Effects of administration of corticosterone, 10 mg/kg, on the acquisition of place conditioning produced by ethanol, 1-2.5 g/kg, were investigated using the conventional method of conditioning, with exposure to the CS+ and the CS- on alternate days, and also using the rapid conditioning method. Total and free blood corticosterone concentrations were measured after administration of ethanol and corticosterone. RESULTS: In the conventional, alternate day, conditioning schedule, ethanol produced significant place preference at 2 and at 2.5 g/kg, but when these alcohol doses were given with corticosterone 10 mg/kg, significant place conditioning was not seen. In contrast, in the rapid, same day, conditioning schedule corticosterone significantly decreased the dose at which ethanol produced an apparent place preference, with significant place conditioning being seen with ethanol at 1 and 1.5 g/kg in combination with corticosterone, 10 mg/kg. Total and free corticosterone concentrations were increased after ethanol, 1.5 g/kg, compared with controls, and administration of corticosterone, 10 mg/kg, caused a significantly greater increase. There were no significant differences in spontaneous locomotor activity or brain alcohol concentrations between any of the treatment groups. CONCLUSIONS: The effects of corticosterone on ethanol-induced place conditioning are substantially affected by the conditioning schedule used.

Animals↗

hIan5: the human ortholog to the rat Ian4/Iddm1/lyp is a new member of the Ian family that is overexpressed in B-cell lymphoid malignancies.

The family of immune associated nucleotide binding proteins (Ian) is a distinct family of GTP-binding proteins conserved in plants, mice, rats and humans that are associated with immune functions, suggesting involvement in conserved defense mechanisms. Recently, the rat Ian4 (rIan4) was cloned and it appears to be identical to the gene Iddm1/lyp responsible for severe lymphopenia and the development of insulin-dependent diabetes in the BB-DP rat. Here we describe the characterization of a new human member of the Ian family: hIan5. hIan5 is highly homologous to rIan4, has a predicted molecular weight of 35 kDa and contains distinct G motifs of GTP-binding proteins (G-1 to G-4) in the N-terminus. Human Ian5 is anchored to the mitochondria by the hydrophobic COOH-terminal domain. Human Ian5 is highly expressed in lymph node and spleen. Different blood fractions show high hIan5 expression in CD4- and CD8-positive T cells and monocytes, but not in B lymphocytes. In contrast, in B-CLL (chronic lymphocytic leukemia) and mantle cell lymphoma samples, hIan5 mRNA was upregulated. The current data underline the role of hIan5 in T-lymphocyte development and function, and for the first time suggest that upregulation of Ian proteins is associated with B-cell malignancy, possibly by inhibiting apoptosis.

Amino Acid Sequence↗

Early postoperative ultrasound of kidney transplants: evaluation of contrast medium dynamics using time-intensity curves.

OBJECTIVE: To evaluate kidney recipients in the early posttransplant phase by semiquantitative analysis of the arterial arrival of ultrasound (US) contrast medium using time-intensity curves. PATIENTS AND METHODS: Twenty-two kidney recipients underwent US examination after intravenous bolus administration of 2.4 ml of US contrast medium (SonoVue, Bracco Altana) 5 to 7 days after transplantation. The examinations were performed with the Aplio US system (Toshiba) and a 3.5-MHz wideband transducer using contrast harmonic imaging at a low mechanical index of 0.1. Arterial arrival was documented digitally over 60 sec (image repetition rate: 10 images per sec) for subsequent evaluation of contrast medium kinetics in the main renal artery, interlobar artery, subcapsular area, and renal vein using the system's integrated time-intensity curve (TIC) software. The increase, decrease, and percentage enhancement factor were calculated from the curves. Four patients were excluded from analysis because of perirenal hematoma (n = 3) or a polar perfusion loss demonstrated by power Doppler (n = 1). RESULTS: Twelve of the remaining 18 patients assigned to the nonrejection group showed an uneventful clinical course. These had uniform TICs with an early and steep increase of similar magnitude in the main renal artery (11.7 +/- 4.5 intensity units/sec), interlobar artery (8.7 +/- 4.6 intensity units/sec), and subcapsular area (8.3 +/- 3.7 intensity units/sec) followed by a washout and subsequent plateau phase. Six patients showed histologically proven acute rejection on day 5 or 6 after transplantation (rejection group). This group had a delayed (time to peak in the subcapsular area: 32.9 +/- 8.3 sec in the rejection group versus 20.9 +/- 4.7 sec in the nonrejection group, p < 0.05) and smaller subcapsular percentage increase (41.2 +/- 21.9 % versus 114.4 +/- 59.8 %, p < 0.05). In the rejection group the subcapsular area (3.8 +/- 2.3 intensity units/sec) showed a less pronounced increase than the main renal artery (7.9 +/- 5.9 intensity units/sec) and interlobar artery (8.7 +/- 3.8 intensity units/sec). The RI in the rejection group was in the normal range at the time of contrast-enhanced US (day 5: 0.78 +/- 0.06) and increased to abnormal levels in the further course (day 7: 0.94 +/- 0.09). CONCLUSIONS: Quantitative determination of arterial arrival of an US contrast medium in the early phase after kidney transplantation is possible. This new US procedure might identify acute rejection earlier than conventional techniques.

Adult↗

Distribution of hydrophobic residues is crucial for the fusogenic properties of the Ebola virus GP2 fusion peptide.

The lipid-destabilizing properties of the N-terminal domain of the GP2 of Ebola virus were investigated. Our results suggest that the domain of Ebola virus needed for fusion is shorter than that previously reported. The fusogenic properties of this domain are related to its oblique orientation at the lipid/water interface owing to an asymmetric distribution of the hydrophobic residues when helical.

Amino Acids↗

The Football Association Medical Research Programme: an audit of injuries in professional football--analysis of hamstring injuries.

OBJECTIVE: To conduct a detailed analysis of hamstring injuries sustained in English professional football over two competitive seasons. METHODS: Club medical staff at 91 professional football clubs annotated player injuries over two seasons. A specific injury audit questionnaire was used together with a weekly form that documented each clubs' current injury status. RESULTS: Completed injury records for the two competitive seasons were obtained from 87% and 76% of the participating clubs respectively. Hamstring strains accounted for 12% of the total injuries over the two seasons with nearly half (53%) involving the biceps femoris. An average of five hamstring strains per club per season was observed. A total of 13 116 days and 2029 matches were missed because of hamstring strains, giving an average of 90 days and 15 matches missed per club per season. In 57% of cases, the injury occurred during running. Hamstring strains were most often observed during matches (62%) with an increase at the end of each half (p<0.01). Groups of players sustaining higher than expected rates of hamstring injury were Premiership (p<0.01) and outfield players (p<0.01), players of black ethnic origin (p<0.05), and players in the older age groups (p<0.01). Only 5% of hamstring strains underwent some form of diagnostic investigation. The reinjury rate for hamstring injury was 12%. CONCLUSION: Hamstring strains are common in football. In trying to reduce the number of initial and recurrent hamstring strains in football, prevention of initial injury is paramount. If injury does occur, the importance of differential diagnosis followed by the management of all causes of posterior thigh pain is emphasised. Clinical reasoning with treatment based on best available evidence is recommended.

Adolescent↗

Clinically evidenced unilateral dissociation of saccades and pursuit eye movements.

A patient affected by an ischaemic lesion of the right medial thalamic nucleus presented with a uniocular dissociation of upward vertical saccades and pursuit movement, with absent upward vertical saccades in the left eye. Clinical observations were confirmed by magnetic field scleral search coils analysis. During the vertical eye movement the patient denied any diplopia, thus suggesting a transient visual suppression in the left eye.

Antibodies, Antiphospholipid↗

Novel neuroimaging findings in a patient with cerebral Whipple's disease: a magnetic resonance imaging and positron emission tomography study.

The authors report a 43-year-old patient with histopathologically proven cerebral Whipple's disease. Magnetic resonance imaging (MRI) revealed a multilayered left frontal lesion without mass effect, no perifocal brain edema, no contrast enhancement, and a thin shell of fluid signal that presented as an incomplete, open ring. An [11C]methionine positron emission tomography (PET) study showed low uptake below the threshold that is characteristic for brain tumors. In precise co-registration to the MR images, the PET data showed that increased uptake was mainly located in the direct adjacent part of the MRI lesion. The fluid signal on MRI corresponded to the extensive outflow of fluid from the lesion, which was observed during neurosurgical resection, and also to the neuropathological findings. The authors conclude that this cerebral manifestation of Whipple's disease made a unique and hitherto undescribed appearance on MRI; uptake pattern of PET amino acid tracer may help in the preoperative distinction of inflammatory from neoplastic lesions.

Adult↗

Variations in the insecticide-resistance spectrum of Anopheles stephensi after selection with deltamethrin or a deltamethrin-piperonyl-butoxide combination.

When the larvae of Anopheles stephensi, a malaria vector, were selected with deltamethrin for 40 successive generations, there was a 60-fold increase in larval resistance to deltamethrin but no increase in the resistance of the adult mosquitoes. This result, and the observation that deltamethrin selection of adults for 40 generations resulted in only a six-fold increase in adult resistance to deltamethrin, indicated some stage specificity. When F(24) deltamethrin-resistant larvae were selected with 1:5 deltamethrin-piperonyl butoxide (deltamethrin-PBO), instead of deltamethrin alone, for 16 generations, the level of resistance to deltamethrin in the F(40) larvae was reduced by 6%-21%. Similarly, selection with deltamethrin-PBO of adults of the parental strain for 20 generations reduced the speed of the development of resistance to deltamethrin, compared with that seen using selection with deltamethrin alone. Deltamethrin selection appears to select initially a monooxygenase-based mechanism. When the monooxygenase-based mechanism is blocked, by treatment with PBO, selection of a kdr-type mechanism is accelerated, as is evident from increased cross-resistance to 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) in the adults selected with deltamethrin-PBO. The implications of these results are discussed in terms of the management of the larval and adult stages of An. stephensi .

Animals↗

Duration of amantadine benefit on dyskinesia of severe Parkinson's disease.

BACKGROUND: Recent short-term studies suggested that amantadine (Ama) might ameliorate dyskinesia in patients with Parkinson's disease. A double-blind study programmed over 12 months was designed to assess the duration of the antidyskinetic effect of amantadine on levodopa induced dyskinesia. METHODS: 40 patients treated for 7.5 (2.2) years with levodopa (729.3 (199.4) mg/day) and dopaminoagonists, having peak dose or dyphasic dyskinesia with or without pain, were assessed with the Unified Parkinson's Disease Rating Scale subscale IV, Items 32-34, the Dyskinesia Rating Scale and Investigator Global Assessment. Twenty patients received amantadine chloridrate (100 mg) and 20 received a placebo. The Ama or placebo could be withdrawn when scores indicated worsening of dyskinesia, after agreement with the patient. RESULTS: After 15 days of amantadine treatment there was a reduction by 45% in the total dyskinesia scores. All patients in the placebo group were withdrawn in 1-3 months and all patients in the Ama group were withdrawn in 3-8 months (p = 0.01, p<0.001). Ama withdrawal induced a rebound with increase of dyskinesia by 10-20% in 11 patients. CONCLUSION: 300 mg amantadine reduces dyskinesia in Parkinson's disease by approximately 45% but the benefit lasted less than eight months.

Aged↗

Gender disparities in tuberculosis: report from a rural DOTS programme in south India.

SETTING: Tiruvallur District, south India. OBJECTIVES: To examine gender differences in tuberculosis among adults aged >14 years with respect to infection and disease prevalence, health care service access, care seeking behaviour, diagnostic delay, convenience of directly observed treatment (DOT), stigma and treatment adherence. METHODS: Data were collected from 1) community survey, 2) self-referred out-patients seeking care at governmental primary health institutions (PHIs), 3) tuberculosis suspects referred for sputum microscopy at PHIs, and 4) tuberculosis patients notified under DOTS. Community survey results were compared with those for patients notified at PHIs. RESULTS: In the community, 66% of males and 57% of females had tuberculosis infection. The prevalence of smear-positive tuberculosis was 568 and 87/100,000, respectively, among males and females. Fewer males than females attended PHIs (68 men for every 100 women). Females constituted 13% of all smear-positive patients detected in the community survey, and 20% of those detected at PHIs (P < 0.05). The probability of notification decreased significantly with age among both males and females. Significantly more females than males felt inhibited discussing their illness with family (21% vs. 14%) and needed to be accompanied for DOT (11% vs. 6%). Males had twice the risk of treatment default than females (19% vs. 8%; P < 0.01). CONCLUSIONS: Despite facing greater stigma and inconvenience, women were more likely than men to access health services, be notified under DOTS and adhere to treatment. Men and elderly patients need additional support to access diagnostic and DOT services.

Adolescent↗