What does the object decision task measure? Reflections on the basis of evidence from semantic dementia.

The authors investigated the impact of semantic knowledge on visual object analysis by assessing the performance of patients with semantic dementia on a different-views object matching test and on 2 object decision tests differing, for example, in whether the nonreal items were nonsense objects or chimeras of 2 real objects. On average, the patients scored normally on both the object matching and the object decision test including nonsense objects but were impaired on the object decision test including chimeras; this latter was also the only visual object test that correlated significantly with degree of semantic impairment. These findings demonstrate that object decision is not a single task or ability and that it is not necessarily independent of conceptual knowledge. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

In vitro and in vivo ligand binding to the 5HT(3) serotonin receptor characterised by time-resolved fluorescence spectroscopy

The binding of the fluorescein-labelled antagonist GR-flu ([1,2,3,9-tetrahydro-3-[(5-methyl-1H-imidazol-4-yl)methyl]-9-(3-amino-(N-fluoresceinthiocarbamoyl)propyl)-4H-carbazol-4-one]) to a purified, detergent-solubilised ligand-gated ion channel, the type-3 serotonin (5-hydroxytryptamine, 5HT) receptor (5HT(3)R), was characterised by frequency-domain time-resolved fluorescence spectroscopy (TRFS). Detailed understanding of how ligands interact with the homopentameric receptor was obtained. While a 1:1 stoichiometry was observed for the GR-flu-receptor complex, the agonist quipazine bound cooperatively to the receptor, suggesting multiple binding sites for this ligand. The GR-flu-binding site of the receptor was proven to provide an acidic environment as shown by determining the fraction of bound GR-flu in the protonated state. Fluorescence anisotropy relaxation experiments indicated a hindered but still high mobility for the receptor-bound GR-flu. Hence, the binding site is expected to present a wide opening to the ligand. Finally, we succeeded in measuring the binding of GR-flu to 5HT(3) receptors in live cells. These results show that the purified and the native receptor behave identically and demonstrate that time-resolved fluorescence measurements are suited to selectively investigate biomolecular interactions in live cells.     

Psychomotor development in children with triphalangeal thumbs. A preliminary study

A double-blind, randomized, clinical field trial was designed to test the efficacy and tolerance of a specific drug treatment in children in the indeterminate phase of infection by Trypanosoma cruzi. Children were treated with benznidazole at a dose of 5 mg/kg/day for 60 days or placebo and followed-up for 48 months. The treated children showed a significant decrease in geometric mean titers of antibodies against T. cruzi measured by indirect hemagglutination, indirect immunofluorescence, and ELISA. After a four year follow-up, 62% of the benznidazole-treated children and no placebo-treated child were seronegative for T. cruzi when tested by an ELISA using a T. cruzi flagellar calcium-binding protein (F29). Xenodiagnosis carried out after 48 months of follow-up was positive in 4.7% of the benznidazole-treated children and in 51.2% of the placebo-treated children. These results show the tolerance to and efficacy of benznidazole against T. cruzi in seropositive children six to 12 years of age. We used an early serologic marker of cure after treatment, consisting of a recombinant antigen implemented in a rapid, conventional serologic procedure.     

Connections between the tendons of the musculus flexor digitorum profundus involving the synovial sheaths in the carpal tunnel

We earlier described a model of fulminant hepatic failure (FHF) in the rat where partial hepatectomy is combined with induction of right liver lobes necrosis. After this procedure, lack of regenerative response in the residual viable liver tissue (omental lobes) was associated with elevated plasma hepatocyte growth factor (HGF) and transforming growth factor beta (TGF-beta1) levels and delayed expression of HGF and c-met mRNA in the remnant liver. Here, we investigated whether syngeneic isolated hepatocytes transplanted in the spleen will prolong survival and facilitate liver regeneration in FHF rats. Inbred male Lewis rats were used. Group I rats (n = 46) received intrasplenic injection of 2 x 10(7) hepatocytes and 2 days later FHF was induced. Group II FHF rats (n = 46) received intrasplenic injection of saline. Rats undergoing partial hepatectomy of 68% (PH; n = 30) and a sham operation (SO; n = 30) served as controls. In 20 FHF rats (10 rats/group), survival time was determined. The remaining 72 FHF rats (36 rats/group) were used for physiologic studies (liver function and regeneration and plasma growth factor levels). In Group I rats survival was longer than that of Group II controls (73 +/- 22 hr vs. 33 +/- 9 hr; P < 0. 01). During the first 36 hr, Group I rats had lower blood ammonia, lactate, total bilirubin, PT, and PTT values, lower activity of liver enzymes, and higher monoethylglycinexylidide (MEGX) production than Group II rats. In Group I rats, livers increased in weight at a rate similar to that seen in PH controls and showed distinct mitotic and DNA synthetic activity (incorporation of bromodeoxyuridine and proliferation cell nuclear antigen expression). Plasma HGF and TGF-beta1 levels in these rats decreased and followed the pattern seen in PH rats; additionally, c-met expression in the remnant liver was accelerated. Hepatocyte transplantation prolonged survival in FHF rats and facilitated liver regeneration. Even though the remnant liver increased in weight four times reaching 30% of the original liver mass, the transplant-bearing rats expired due to inability of the regenerating liver to support the rat.     

Long-term reproducibility of phantom signal intensities in nonuniformity corrected STIR-MRI examinations of skeletal muscle

Object  Nerve regeneration could be monitored by comparing MRI image intensities in time, as denervated muscles display increased signal intensity in STIR sequences. In this study long-term reproducibility of STIR image intensity was assessed under clinical conditions and the required image intensity nonuniformity correction was improved by using phantom scans obtained at multiple positions. Methods  Three-dimensional image intensity nonuniformity was investigated in phantom scans. Next, over a three-year period, 190 clinical STIR hand scans were obtained using a standardized acquisition protocol, and corrected for intensity nonuniformity by using the results of phantom scanning. The results of correction with 1, 3, and 11 phantom scans were compared. The image intensities in calibration tubes close to the hands were measured every time to determine the reproducibility of our method. Results  With calibration, the reproducibility of STIR image intensity improved from 7.8 to 6.4%. Image intensity nonuniformity correction with 11 phantom scans gave significantly better results than correction with 1 or 3 scans. Conclusions  The image intensities in clinical STIR images acquired at different times can be compared directly, provided that the acquisition protocol is standardized and that nonuniformity correction is applied. Nonuniformity correction is preferably based on multiple phantom scans.     

Identification of four Borrelia burgdorferi sensu lato species in Ixodes ricinus ticks collected from Dutch dogs

A child with afibrinogenemia was evaluated for prophylactic cryoprecipitate transfusion due to recurrent episodes of traumatic bleeding. The parents would only consider ongoing transfusion therapy if a limited donor program could be established. Automated plasmapheresis was performed on a regular basis on the patient's parents and a limited number of selected donors. Studies on the initial units collected demonstrated that a single 500 mL plasmapheresis yielded a mean of 606 mg fibrinogen in the cryoprecipitate, which was stored in two bags. A total of 166 U of cryoprecipitate from 84 individual plasmapheresis donations were transfused prophylactically every 2-3 weeks over a 16-month period. Compared to transfusions from random donors, the use of a limited number of apheresis donors resulted in a donor exposure reduction of 87%. Clinically, the patient has had minimal bleeding during this period.