Brain somatic representation of phantom and intact limb: a fMRI study case report

Reports on phantom limb patients concerning neuronal reorganization using non-invasive methods have focused mainly on the cortical regions and suggest the presence of pain as the cause of this reorganization. The phantom limb, however, includes other somatic and motor sensations other than pain. Here we describe the results of non-painful stimulation in cortical and subcortical lateralization and reorganization and also examine the involvement of subcortical structures in phantom limb telescoping perception. We describe an enlarged contralateral cortical representation of the stump, a cortical and thalamic bilateral representation of the remaining leg, and a neuronal correlate of a telescoping perception of the phantom limb. The missing leg produces an enlarged cortical representation due to abnormal information and the remaining leg has a bilateral SII representation, which could be related to new, compensatory functions. The telescoping perception of a phantom limb by the stimulation of misallocation points was correlated with lenticular nuclei, thalamic and cingulate gyrus activation. We therefore propose that the reorganization concept of a phantom limb, applied mainly to the cortex, must extend to the thalamic and the somatosensory and motor systems (pathways and relay nuclei).

Noninvasive cerebrovascular assessment of Takayasu arteritis

BACKGROUND AND PURPOSE

Despite prominent neurological symptoms reported in Takayasu arteritis (TA), a complete evaluation of the cerebral circulation has not been consistently performed. The purpose of this study is to describe MR angiography (MRA), color Doppler flow imaging, and transcranial Doppler (TCD) findings in the extracranial and intracranial cerebral arteries in TA.

METHODS

MRA, color Doppler flow imaging, and TCD were performed in 21 patients with TA. Intima-media thickness was measured in the common carotid artery. The correlation between noninvasive studies and panaorto-arteriography was examined for supraortic vessels. Cerebral angiography findings were compared with the noninvasive methods in 7 patients. Intracranial hemodynamic changes detected by TCD were compared with extracranial circulation lesions assessed by panaorto-arteriography.

RESULTS

Noninvasive vascular techniques showed at least 1 abnormality in the extracranial and/or intracranial cerebral arteries in 20 of 21 patients (95%). Both MRA and color Doppler flow imaging showed a substantial correlation in the ability to detect obstructive lesions in supra-aortic vessels compared with panaorto-arteriography. High-resolution ultrasonography displayed common carotid artery wall thickening in 5 vessels that were considered normal by arteriography. In 24% of patients, MRA and TCD showed abnormalities consistent with stenosis of the basal cerebral arteries. In 10 patients with severe extracranial circulation involvement (detected by arteriography), TCD displayed intracranial hemodynamic changes consisting of dampened or blunted waveforms with low pulsatility.

CONCLUSIONS

The comprehensive assessment of cerebral circulation in TA patients by noninvasive methods allowed the detection of a high rate of diverse vascular abnormalities in both extracranial and intracranial circulation.

Immunochemical studies on gastric and intestinal digestion of soybean glycinin and beta-conglycinin in vivo

Two experiments were conducted to study gastric and small intestinal digestion of soybean glycinin and beta-conglycinin in preruminant calves fed milk replacers containing a mixture of skim milk powder and antigenic heated soybean flour. In experiment 1, duodenal passage of immunoreactive beta-conglycinin lasted for a much longer time after the morning meal than that of glycinin. Western blotting revealed the early abomasal outflow of glycinin subunits that associated nearly intact basic polypeptides to partially degraded acidic polypeptides. Intact beta-conglycinin was evidenced at most sampling times. In experiment 2, intact basic glycinin (M(r) = 21000) associated with partially digested acidic glycinin (7000 < M(r) < 25000) was demonstrated in ileal digesta up to 8-10 h after the meal. beta-Conglycinin immunoreactivity could not be evidenced by Western blotting in ileal digesta.

Ecotoxicological assessment of ashes and particulate matter from fluidized bed combustion of coal

Toxicity of ash and particulate matter from the gases generated in coal fluidized bed combustion (FBC) has been determined by the Microtox assay according to the standard leachate procedure. Results are compared with the polycylic aromatic hydrocarbon (PAH) content of the particulate matter, which was determined by fluorescence spectroscopy. Although PAHs are considered highly toxic compounds, the low ecotoxicity values obtained could be explained by the low solubility of the compounds in water. The Microtox assay may underestimate the toxicity of water-insoluble compounds unless they are previously extracted with an organic solvent. Nevertheless, this type of assay can be very useful for measuring the potential toxicity of residues when exposed to water sources such as rain water and the risk of the components being dissolved and transported by runoff water.

Cysticercosis. Clinical classification based on imaging studies

Cysticercosis is a pleomorphic disease in which the diagnosis, treatment, and prognosis greatly vary in relation to the location, number, and stage of the lesions. A new classification is proposed that includes the information gathered by magnetic resonance imaging and computed tomography, supplemented by immunodiagnostic studies and clinical data. The different clinical entities produced by cysticercosis are grouped by the frequency and location of the parasites, including valuable data as the number and stage of the lesions as well as the degree of the inflammatory response from the host to the parasite. In this way, the disease can be individualized to define the reliability of diagnostic studies and to design specific therapeutic approaches that depend on the characteristics that the disease acquires in every location.

Antiserum for insulin radioimmunoassay generated by an insulin derivative devoid of hypoglycemic activity

A tetraiodinated derivative of bovine insulin, prepared at pH 1 with stable iodine, was unable to cause signs of hypoglycemia in doses up to 2.4 micrograms/g in fasting mice, when native insulin caused 100% mortality. In neutral and acidic solutions, in absence of chaotropic agents, it behaved as the monomer, and could be separated from less iodinated, active species, that appeared as dimers, by conventional gel filtration. To generate antibodies in guinea-pigs, the tetraiodinated insulin was injected in doses three times higher than native insulin, without any harm to recipient animals. The induced antiserum was compared with antiserum generated by conventional methods in radioimmunoassay (RIA) of native insulin, and parallel curves were obtained.

Medulloblastoma presenting as blindness of rapid evolution. A case report

An 18-year-old man reported rapid decrease of visual acuity that progressed to total blindness in 1 month. Computed tomographic scanning showed two neoplastic masses: a large one, intra- and suprasellar, and a smaller cerebellar nodule. Histologically, the former proved to be a large metastasis of the small cerebellar medulloblastoma, which infiltrated and compressed the chiasm. Direct compression of the optic pathways by metastasis of a medulloblastoma is a rare event.

Intracranial tuberculoma: MR imaging

MR studies of 6 patients with intracranial tuberculoma are reviewed. All patients also underwent CT scans which showed hypo- or isodense lesions with abnormal enhancement following contrast administration. MR showed lesions with prolongation of the T1 relaxation time in every case. On the T2-weighted sequences, the signal properties of the tuberculoma varied according to the stage of evolution of the lesion. Incipient tuberculomas appeared as scattered areas of hypointensity surrounded by edema. Mature tuberculomas were composed of a dark necrotic center surrounded by an isointense capsule which was, in turn, surrounded by edema. In one patient, the center of the lesion was hyperintense probably because of liquefaction and pus formation (tuberculous abscess). While both, CT and MR, were equally sensitive in visualizing the intracranial tuberculoma in every patient, MR was slightly superior in demonstrating the extent of the lesion, especially for brainstem tuberculomas. Nevertheless, the potential role for MR diagnosis of intracranial tuberculoma is limited by the fact that other infectious or neoplasic diseases may present similar findings. The diagnosis of intracranial tuberculoma should rest on a proper integration of data from clinical manifestations, cerebrospinal fluid analysis, and neuroimaging studies.

The acute encephalitic phase of neurocysticercosis: computed tomographic manifestations

Brain infestation by Cysticercus cellulosae, the larval form of Taenia solium, is a common disorder in Mexico and other Latin American countries, Asia, Africa, and some Eastern European countries. Recent immigration has caused an increase in the number of cases of neurocysticercosis in the United States. This work describes the acute encephalitic form of neurocysticercosis in 26 cases. The clinicopathologic and neuroradiologic manifestations are discussed with particular emphasis on the use of computed tomography as a main diagnosis modality which demonstrates multiple diffuse (85%) or localized (15%) enhancing nodules associated with severe edema.

Replication of the Achievement Place model in California

Attempting to replicate procedures from Achievement Place, token reinforcement procedures were used to modify savings, conversational interruptions, and table-setting of delinquent boys residing in a home-style, community based, treatment setting. The tokens (points) were redeemable for various privileges and could be earned for specified appropriate behaviors and lost for specified inappropriate behaviors. Contingent point fines reduced the frequency of interruptions. Point rewards improved table-setting, but even large point rewards did not substantially increase savings. Baseline data indicated that lateness to dinner was not a problem, as it was in Achievement Place. Withdrawal of contingent points and back-up rewards did not disrupt the clean-up behavior of two boys.