Distribution of 125I-ferrotransferrin binding sites in the mesencephalon of control subjects and patients with Parkinson's disease

Iron is abnormally accumulated in the substantia nigra pars compacta of patients with Parkinson's disease (PD). Because neuronal and glial iron uptake seems to be mediated by the binding of ferrotransferrin to a specific high-affinity receptor on the cell surface, the number of transferrin receptors could be altered in this disease. The regional distribution of specific binding sites for human 125I-diferric transferrin has been studied in the mesencephalon, on cryostat-cut sections from autopsy brains of control subjects and parkinsonian patients by in vitro autoradiography. Densities of binding sites were highest in the central gray substance (approximately 10 fmol/mg of tissue equivalent), intermediate in the catecholaminergic cell group A8, superior colliculus, and ventral tegmental area, and almost nonexistent in the substantia nigra. The density of 125I-transferrin binding sites was not significantly different between parkinsonian and control brains in any region analyzed. These results show that in the mesencephalon the regional density of transferrin binding sites is lowest in the dopaminergic cell groups, which are the most vulnerable to PD, and suggest that iron does not accumulate through an increased density of transferrin receptors at the level of the substantia nigra.

Infarcts in the middle cerebral artery territory. Pathological study of the mechanisms of death

Correlates of the size of infarcts, the time from stroke to death, and the mechanisms of death were studied in 77 consecutive patients who died from infarction in the middle cerebral artery territory. The area of infarcts was assessed by planimetry on schemas of representative brain levels and the results were expressed as a ratio of infarcted area on the whole MCA territory. No clear relationship was found between the size of infarcts in the MCA territory, and any of the characteristics of the patients, but extensive infarcts were more frequent when the internal carotid artery was occluded. No evidence was found of an adverse effect of age, diabetes or initial hyperglycemia on the size of infarcts. The mechanisms of death were not linked to sex, age, high blood pressure, diabetes, blood glucose level at admission, presence and location of an arterial occlusion, or etiology of the infarct. On the contrary, they varied as a function of interval from stroke to death. Transtentorial herniation, the main cerebral cause of death, occurred mainly in the first week and was related to the large size of infarcts. Rare recurrences of stroke and frequent extracerebral mechanisms of death (mainly pneumonia, pulmonary embolism and cardiopathy) occurred later on.

Time course of degeneration and regeneration of myelinated nerve fibres following chronic loose ligatures of the rat sciatic nerve: can nerve lesions be linked to the abnormal pain-related behaviours?

This study of a mononeuropathy of 1-15 weeks (W) duration was induced in rats by setting 4 loose ligatures around the common sciatic nerve. This chronic lesion, in which the continuity of the nerve was maintained, has been introduced as a model for experimental pain. Quantitative analyses of teased nerve fibres and a morphometric analysis of semi-thin transverse sections, were performed and completed by electron microscopic examination. Morphological changes were observed mainly distal, but also proximal, to the ligatures, indicating significant axonopathy with simultaneous degeneration and regeneration. The lesions were analysed in parallel with the time course of the pain-related behaviours. Both were at their maximum 2 weeks after ligature with progressive recovery beginning between W3 and W4. However, the largest fibres had not totally recovered by W15, contrasting with the disappearance of abnormal nociceptive reactions between W8 and W10. Although the damage to unmyelinated fibres is of importance, the abnormal pain-related behaviours seen in these rats appeared to be closely linked to the presence of both degenerative and regenerative changes in the A delta-range fibres, which did not necessarily correspond to initial A delta fibres.

Dementia in Parkinson's disease: biochemical evidence for cortical involvement using the immunodetection of abnormal Tau proteins

In order to elucidate the neurochemical basis of the dementia of Parkinson's disease, we compared samples of cerebral cortex from 24 nondemented parkinsonian patients and parkinsonian patients with various degrees of dementia, with those from patients with Alzheimer's disease and control subjects, using a quantitative Western blot analysis. An anti-paired helical filaments antibody was used for the immunodetection of the abnormally phosphorylated Tau proteins 55, 64, and 69, which are known to be specific and reliable biochemical markers of Alzheimer-type neurofibrillary degeneration. The frequency and intensity of immunodetection of the abnormal Tau triplet were higher in the demented parkinsonian subgroups than in the nondemented parkinsonian subgroup in the prefrontal area, temporal cortex, and entorhinal cortex but not in either the occipital or the cingular cortex. A quantification of abnormal Tau triplet by densitometry showed that unlike the results obtained in Alzheimer patients, the intensity of lesions in the cerebral cortex of the most demented parkinsonian patients was more severe in the prefrontal area versus the temporal area. This study (1) gives biochemical evidence for Alzheimer-type changes in the cortex of demented parkinsonian patients and (2) suggests that lesions of the prefrontal cortex may significantly contribute to the occurrence of cognitive changes at least in some patients with Parkinson's disease.

Heterogeneity and selectivity of the degeneration of cholinergic neurons in the basal forebrain of patients with Alzheimer's disease

Cholinergic neurons were studied by immunohistochemistry, with an antiserum against choline acetyltransferase (ChAT), in the basal forebrain (Ch1 to Ch4) of four patients with Alzheimer's disease (AD) and four control subjects. ChAT-positive cell bodies were mapped and counted in Ch1 (medial septal nucleus), Ch2 (vertical nucleus of the diagonal band), Ch3 (horizontal nucleus of the diagonal band) and Ch4 (nucleus basalis of Meynert). Compared to controls, the number of cholinergic neurons in AD patients was reduced by 50% on average. The interindividual variations in cholinergic cell loss were high, neuronal loss ranging from moderate (27%) to severe (63%). Despite the small number of brains studied, a significant correlation was found between the cholinergic cell loss and the degree of intellectual impairment. To determine the selectivity of cholinergic neuronal loss in the basal forebrain of AD patients, NPY-immunoreactive neurons were also investigated. The number of NPY-positive cell bodies was the same in controls and AD patients. The results (1) confirm cholinergic neuron degeneration in the basal forebrain in AD and the relative sparing of these neurons in some patients, (2) indicate that degeneration of cholinergic neurons in the basal forebrain contributes to intellectual decline, and (3) show that, in AD, such cholinergic cell loss is selective, since NPY-positive neurons are preserved in the basal forebrain.

Alterations of glial fibrillary acidic protein mRNA level in the aging brain and in senile dementia of the Alzheimer type

The GFAP mRNA levels were compared to the density of the senile plaques (SP) in postmortem brain samples of 8 cases, either non-demented or affected by senile dementia of the Alzheimer type. In the frontal neocortex, the GFAP mRNA level is not affected, even if SP are present. In the temporal neocortex, a positive correlation between GFAP mRNA level and SP density was highly significant. This shows that in this area, astrocytes are altered at transcriptional or post-transcriptional levels, or both. The different responses of this astrogliosis marker in each area may be related to the loss of specific neurotransmitter system.

Beta A4 deposits are constant in the brain of the oldest old: an immunocytochemical study of 20 French centenarians

beta A4 deposits occur in the brain of some individuals over 50 years of age. It could be a part of the aging process or indicate a disease found frequently in the elderly. To address this question, beta A4 immunocytochemistry was performed on the brain of 15 nondemented and 5 demented centenarians, some of whom were affected by Alzheimer's disease. We found beta A4 deposits in the parahippocampal and the superior temporal gyri of all the cases, whatever the clinical state. The hippocampus was frequently spared. The lesion density was not correlated with the severity of the mental deterioration. The constant deposition of beta A4 protein in the brain of very old people indicates that this process does not spare a large proportion of this population. This result favors beta A4 accumulation in the brain being an ineluctable age-related process.

Mitochondrial encephalomyopathies

Molecular genetic studies are now bringing a new classification and new insights into already recognized mitochondrial encephalomyopathies. There are, however, numerous reports on an overlap pattern between mitochondriopathies. In addition, the link between the defect in oxidative phosphorylation (OXPHOS) in the brain and the specific neuropathological pattern is unclear. A better knowledge of nuclear mutations in mitochondriopathies and of the interactions between nuclear and mitochondrial genomes will probably allow new developments.

Does loss of nerve growth factor receptors precede loss of cholinergic neurons in Alzheimer's disease? An autoradiographic study in the human striatum and basal forebrain

The mechanism by which cholinergic neurons degenerate in Alzheimer's disease is not known. Some of these neurons depend, however, on trophic support from NGF via a membrane receptor. We have analyzed the state of these receptors by autoradiography, with 125I-NGF as the ligand, in the caudate nucleus, putamen, ventral striatum, nucleus basalis of Meynert, and nucleus tegmenti pedunculopontinus of six patients with Alzheimer's disease and five controls, matched for age and postmortem delay. The binding characteristics were similar in the striatum (including caudate nucleus, putamen, and ventral striatum) and basal forebrain of control subjects and patients with Alzheimer's disease (Kd = 2.5-4 x 10(-11) M). In control brains, high levels of 125I-NGF binding were observed in the basal forebrain and striatum (0.32-0.49 fmol/mg tissue equivalent), but no specific binding was detected in the nucleus tegmenti pedunculopontinus. NGF binding sites were distributed heterogeneously in the striatum with patches of low density, corresponding to AChE-poor striosomes, surrounded by a matrix in which receptor density was significantly greater. In Alzheimer's disease, the density of NGF receptors was markedly decreased in the caudate nucleus, putamen, ventral striatum, and nucleus basalis of Meynert. In contrast, AChE staining decreased less in the nucleus basalis of Meynert in all Alzheimer's disease patients, and in the ventral striatum of those most severely affected. These results indicate that if NGF receptors are located on cholinergic neurons, receptor loss and the consequent decrease in trophic support may precede cell degeneration in Alzheimer's disease. The relationship between the loss of these receptors and the pathogenesis of the disease remains to be determined.

Morphology of demyelination in the human central nervous system

The principles of the neuropathological classification of disorders of central nervous system myelin are recalled. They are illustrated by a few selected examples. Dysmyelination is characterized by the production of an abnormal and unstable myelin sheath; it is often associated with hypomyelination (paucity of myelin formation) and is due to metabolic disorders. It is the main process in leukodystrophies. Storage of different lipids (e.g. sulfatides, long-chain fatty acids) or associated pathology of various cell types (in Alexander's disease, for example) are used for classifying these disorders. Biochemical and genetic characterizations are presently ongoing. Demyelination is the destruction of apparently normal myelin. It is often followed by remyelination. Our present knowledge on the neuropathology of multiple sclerosis, the most common demyelinating disease, is summarized. Cell-mediated demyelination affects the myelin sheaths for an obscure reason. The causes of the multifocal and sharply demarcated plaques, and of the fading of the remyelination process at the edge of some plaques, are not clear. A few examples of demyelinating diseases of known etiology and of various mechanisms are given. The similarities between acute disseminated leukoencephalitis and experimental autoimmune encephalitis are stressed. In progressive multifocal leukoencephalopathy, chronic infection of oligodendrocytes by JC virus induces poorly defined areas of demyelination. In AIDS, the pathogenesis of the myelin change is unclear. Macrophages may be responsible. Toxic and vascular disorders provide also good models for the understanding of mechanisms of demyelination.

Neuropathology of the spinal cord in the acquired immunodeficiency syndrome

The neuropathologic findings in the spinal cord were reviewed in 138 consecutive autopsies of patients with the acquired immunodeficiency syndrome. In all cases both the brain and spinal cord were examined by conventional histologic techniques, and in 63 cases immunohistochemistry was used to detect human immunodeficiency virus (HIV), Toxoplasma gondii, cytomegalovirus, and JC papovavirus antigens. The most common observation was a normal spinal cord (60%). Vacuolar myelopathy (VM) was observed in 23 (17%) cases. Human immunodeficiency virus myelitis was evident in 8% of cases. Human immunodeficiency virus myelitis was associated with HIV encephalitis in 65% of the cases. Opportunistic infections of the spinal cord were uncommon, consisting of cryptococcosis (five cases), cytomegalovirus (four cases), toxoplasmosis (one case), and progressive multifocal leukoencephalopathy (one case), and almost always were seen with cerebral and/or systemic infection by these agents. Malignant lymphoma rarely involved the spinal cord (four cases); all were B-cell lymphomas and were associated with cerebral and/or systemic lymphoma. Other abnormalities rarely observed were Wallerian degeneration of the corticospinal tracts or posterior columns (6%) and focal microinfarcts. Most cases of VM (78%) were not associated with HIV myelitis, and in the five patients with both VM and HIV myelitis, HIV-infected cells were not found in the regions affected by VM. In contrast, 65% of cases with VM were associated with HIV encephalitis. The pathogenesis of VM remains unknown; it is probably not due to direct infection by HIV.

Ganglioside GD1b is the target antigen for a biclonal IgM in a case of sensory-motor axonal polyneuropathy: involvement of N-acetylneuraminic acid in the epitope

We report on a 54-year-old man with a sensory-motor polyneuropathy associated with a biclonal IgM-kappa gammopathy, which reacted with the ganglioside GD1b. Examination of nerve biopsy specimens showed some reduction in the density of myelinated fibers and axonal degeneration with a loss of large fibers and a relative increase in the density of small fibers. Immunodetection on thin-layer chromatography of the glycolipid antigens showed strong reactivity of the patient's serum IgM-kappa with GD1b ganglioside and weak binding to GD1a. biclonal IgM antibodies did not react with GM1, asialo-GM1, GT1b, GD2, or GD3. Indirect immunofluorescence staining showed binding of IgM-kappa mainly in a crescent-like pattern on the internal side of myelin sheaths, which could correspond either to an enlarged periaxonal (adaxonal) space or to the internal mesaxon or to both. The immunostaining was abolished after absorption of the serum with GD1b.

Establishment and characterization of a mouse Schwann cell line which produces myelin in vivo

A Schwann cell line (MSC 80) was established from purified mouse Schwann cell cultures using large doses of serum. MSC 80 cell line is an aneuploid cell line which has a doubling time of 17 hr and has been maintained through more than 110 passages. Most of MSC 80 cells are of bipolar or stellate (3-5 processes) shape. A few others are irregular in shape, gigantic, and multinucleated. All MSC 80 cells express antigens of myelin-forming Schwann cells such as S-100, 224/58, laminin, and other glycoproteins of the extracellular matrix. However, they also express the non-myelin-forming Schwann cell antigen GFAP. By time-lapse cinematography, MSC 80 cells exhibit the Schwann cell characteristic rhythmical undulations. When induced to form aggregates in agar, they form intercellular junctions and basement membrane-like structures. In addition, after transplantation in or at a distance from a lysolecithin induced lesion, MSC 80 cells form myelin around the host demyelinated axons. MSC 80 cells thus express, when isolated in vitro, some of the normal myelin-forming Schwann cell phenotype. In addition, they present the major advantage of forming myelin when associated with axons in vivo.

Increase in omega 3 (peripheral-type benzodiazepine) binding site densities in different types of human brain tumours. A quantitative autoradiography study

The density of omega 3 (peripheral type benzodiazepine) binding sites, a marker of reactive and tumoural cells, has been measured in different types of human brain tumours; omega 3 sites were quantified autoradiographically in sections from biopsy or autopsy specimens labelled with the specific radioligand 3H-PK 11195. Compared to normal brain parenchyma, up to 12-fold increase in omega 3 site densities were found in apparently viable areas of high grade astrocytoma and glioblastoma specimens, whereas more limited increases (2 to 3-fold) in this marker were observed in areas of necrosis. Low grade gliomas (astrocytomas) and meningiomas exhibited only moderate increases (2 to 3-fold) in this autoradiographic marker. Metastases of lung or kidney origin were characterized by greatly elevated (up to 20-fold) omega 3 site densities as compared to normal brain parenchyma. In every case, there was a good spatial correspondence between the histopathological limits of the tumour and the anatomical location of the increase in omega 3 site densities. These results suggest that omega 3 site densities in human brain tumours reflect their proliferative activity and point to a possible future usefulness of positron or gamma-ray emitting omega 3 site ligands for the clinical investigation and detection of human brain proliferative diseases.

Lymphoma-induced polyradiculopathy in AIDS: two cases

Progressive polyradiculopathy is a rare, well-documented complication of the acquired immunodeficiency syndrome in man. It has been commonly attributed to a cytomegalovirus (CMV) infection. We report two HIV-infected patients with clinical and electrophysiological features of a unique, subacute, progressive polyradiculopathy. Post-mortem examination in case 1 disclosed an infiltration of the leptomeninges, the lumbar spinal cord, and the anterior and posterior roots by a B-cell immunoblastic lymphoma. Immunochemistry for HIV1 and CMV was negative in the peripheral and the central nervous system. Case 2 showed bone-marrow involvement by a Burkitt type lymphoma. Specific chemotherapy was followed by both clinical improvement of the polyradiculopathy and complete remission on a second bone-marrow biopsy. These findings may indicate that a lymphoma must also be considered a possible cause of polyradiculopathy in AIDS.

Fragmentation of the Golgi apparatus of motor neurons in amyotrophic lateral sclerosis

The Golgi apparatus (complex) is at the center stage of important functions of processing and transport of plasma membrane, lysosomal, and secreted proteins. The involvement of the Golgi apparatus in the pathogenesis of chronic degenerative diseases of neurons is virtually unknown. In the present study, fragmentation and atrophy of the Golgi apparatus of motor neurons in amyotrophic lateral sclerosis (ALS), has been detected with organelle specific antibodies. Approximately 30% of motor neurons in five ALS patients showed a fragmented Golgi apparatus whereas only about 1% of motor neurons from seven controls with neurologic or systemic disease showed a similar change. Morphometric studies are consistent with the hypothesis that the alteration of the Golgi apparatus is an early event in the pathogenesis of the neuronal degeneration in ALS. Immunocytochemical studies with antibodies against alpha tubulin, tau, and phosphorylated subunits of neurofilament polypeptides did not disclose differences in the staining of neurons with fragmented or normal Golgi apparatus, suggesting that the alteration of the organelle is not secondary to a gross lesion of the cytoskeleton. However, these observations do not rule out the hypothesis that the fragmentation of the Golgi apparatus is secondary to subtle changes of the polypeptides involved in the attachment of membranes of the organelle to the cytoskeleton.

Fatal familial insomnia: clinical and pathologic study of five new cases

In 1986, we reported two anatomoclinical observations of a familial condition that we called "fatal familial insomnia" (FFI). We now present the pedigree as well as the clinical and neuropathologic findings in five new subjects. The pedigree includes 288 members from six generations. Men and women are affected in a pattern consistent with an autosomal dominant inheritance. The age of onset of the disease varies between 37 and 61 years; the course averages 13 months with a range of 7 to 25 months. Progressive insomnia (polygraphically proven in two cases); autonomic disturbances including hyperhidrosis, hyperthermia, tachycardia, and hypertension; and motor abnormalities including ataxia, myoclonus, and pyramidal dysfunction, were present in every case, but with variable severity and time of presentation. Sleep and autonomic disorders were the earliest signs in two subjects, motor abnormalities were dominant in one, and others had intermediate clinical patterns. Pathologically, all the cases had severe atrophy of the anterior ventral and mediodorsal thalamic nuclei. Other thalamic nuclei were less severely and inconsistently affected. In addition, most of the cases had gliosis of the cerebral cortex, a moderate degree of cerebellar atrophy with "torpedoes," and severe atrophy of the inferior olivary nuclei. One case also showed spongy degeneration of the cerebral cortex. We conclude that all the lesions were primary, and that FFI is a multisystem disease in which the different structures are primarily affected with different severity. The insomnia appears to correlate best with the major thalamic pathology. The possibility that FFI belongs to the group identified as prion diseases or diseases transmitted by unconventional agents is examined.

The prevalence of ulcerated plaques in the aortic arch in patients with stroke

BACKGROUND AND METHODS

The cause of cerebral infarction is obscure in up to 40 percent of patients with this disorder who are studied prospectively. In this investigation, we determined the frequency of ulcerated plaques in the aortic arch and explored the part they may play in the formation of cerebral emboli. Using an autopsy data bank, we studied the prevalence of ulcerated plaques in the aortic arch in 500 consecutive patients with cerebrovascular and other neurologic diseases who were studied at autopsy.

RESULTS

Ulcerated plaques were present in 26 percent of the 239 patients with cerebrovascular disease but in only 5 percent of the 261 patients with other neurologic diseases (P less than 0.001). After we controlled for age and heart weight, the adjusted rates were 16.9 percent and 5.1 percent, respectively (adjusted odds ratio, 4.0; 95 percent confidence interval, 2.1 to 7.8; P less than 0.001). Among the patients with cerebrovascular disease, the prevalence of ulcerated plaques in the aortic arch was 28 percent in the 183 patients with cerebral infarcts and 20 percent in the 56 patients with brain hemorrhage. The prevalence of ulcerated plaques was 61 percent among the 28 patients with no known cause of cerebral infarction, as compared with 22 percent among the 155 patients with a known cause of cerebral infarction (P less than 0.001). After adjustment for covariates, the prevalence was 57.8 percent among patients with no known cause of cerebral infarction and 20.2 percent among those with a known cause (adjusted odds ratio, 5.7; 95 percent confidence interval, 2.4 to 13.6; P less than 0.001). The presence of ulcerated plaques in the aortic arch was not correlated with the presence of extracranial internal-carotid artery stenosis, suggesting that these were two independent risk factors for stroke.

CONCLUSIONS

Ulcerated plaques in the aortic arch may play a part in causing cerebral infarction, especially in patients in whom cerebral infarction has no known cause.

Endogenous and exogenous alpha-fetoproteins as differential markers of cultured neonatal mouse Schwann cells and fibroblasts

alpha-Fetoprotein (AFP) and AFP-gene transcripts were demonstrated in vitro in Schwann (S) cell and fibroblast (F) cell cultures of neonatal mouse origin. All S and F cells of primary cultures and of established cell lines expressed the AFP gene. AFP mRNA was detected by an in situ hybridization technique using a 35S-AFP-cDNA probe. AFP was localized by immunocytoperoxidase labelling using purified anti-AFP antibodies. The amounts of stained endogenous AFP, estimated semiquantitatively, were about 3-fold higher in S cells than in F cells. After incubating the cultures with exogenous mouse AFP, both S and F cells showed significant ability to take up the protein; the amount of internalized protein was found to be higher in F cells than in S cells. Moreover, the uptake of AFP fluorescein conjugates (FITC-AFP), estimated quantitatively by fluorometry, also gave higher values for F cells. The cytoplasm of F cells exhibited a characteristic fluorescence pattern, strongly illuminated and dispersed grains; the cytoplasm of S cells was regularly labelled. If exogenous FITC-AFP uptake could be used to distinguish labelled F cells from S cells (with application for identification and selection of F cells), the immunocytochemically stained endogenous AFP could allow S cells to be distinguished from F cells (using the dilutions of antibodies still staining the S cells but which lead to the absence of F-cell labelling). The two procedures, which can be used independently or together, may constitute differential markers for S cell and F cultures in, i.e., nerve regeneration of neurofibroma studies using the model of mixed S and F culture also containing other types of cells.

Neuropathological diagnoses in epidemiologic studies

This paper discusses the potential interest of including neuropathological examination in epidemiologic studies of Alzheimer's disease (AD). Neuropathological studies could provide estimates of both false-positive and false-negative error rates of clinical diagnosis in prevalence or incidence studies on AD. To reach this objective, large and representative autopsy samples are required. Another objective could be to analyse distributions of the various modifications of the brain tissue according to age. The validity of the neuropathological examination, and particularly the level of inter- and intra-observer agreement, must be further assessed before undertaking large autopsy studies in a population.

Glial cell localization of acidic fibroblast growth factor-like immunoreactivity in the optic nerve of young adult and aged mammals

The number of axons in the optic nerve decreases with age and this degeneration is greater in patients suffering from Alzheimer's disease. Alterations in the role of neurotrophic factors could lead to this degeneration. Acidic fibroblast growth factor (aFGF)-like immunoreactivity was examined by indirect immunofluorescence on cryostat sections incubated with a rabbit polyclonal antiserum specific for aFGF. Staining was observed by photonic microscopy on optic nerves of Wistar rats (1- to 25-month-old), bovine animals (0.5- to 7-year-old) and normal human adults (24-, 34-, 54- and 84-year-old). In the three species studied, the results show that (1) glial cells were stained in the nuclear region and (2) aFGF-like immuno-reactivity was present over a large age span in adult subjects. Endogenous aFGF may have trophic effects on retinal ganglion cells and their axons throughout the adult life span.

Progressive supranuclear palsy: loss of choline-acetyltransferase-like immunoreactive neurons in the pontine reticular formation

We performed a quantitative immunocytochemical study using a polyclonal antibody directed against choline acetyltransferase (ChAT) in the lower pontine reticular formation in four control subjects and three patients with progressive supranuclear palsy (PSP). In the normal brains, there was detectable ChAT-like immunoreactivity in the nucleus papillioformis, a precerebellar reticular nucleus, and in the nucleus pontis centralis caudalis. In PSP patients, the mean estimated total number of ChAT-like immunoreactive cells was 54% of controls in nucleus papillioformis and 40% of controls in nucleus pontis centralis caudalis. The demonstration of ChAT-like immunoreactivity in nucleus papillioformis is consistent with studies suggesting an extrinsic cholinergic innervation of the cerebellar cortex. Loss of cholinergic cells in nucleus pontis centralis caudalis that corresponds largely to the paramedian pontine reticular formation may be related to disturbances of horizontal saccades in PSP patients.

PET study of carbon-11-PK 11195 binding to peripheral type benzodiazepine sites in glioblastoma: a case report

The utility of the peripheral type benzodiazepine site ligand 11C-PK 11195, for imaging human glioma in conjunction with Positron Emission Tomography, relies on a high specific binding of the tracer to tumoral peripheral type benzodiazepines sites. In a patient with glioblastoma, we found that 11C-PK 11195 binding was two-fold higher in the tumor than in normal gray matter and that 30% of tumoral binding could be displaced by a large excess of unlabeled drug. These findings suggest that tumoral retention of the ligand is due, in part, to specific binding.