Thalamic dementia: an example of primary astroglial dystrophy of Seitelberger.

Pure thalamic dementia is highly uncommon and typically demonstrates widespread loss of neurons throughout the thalamus associated with reactive gliosis. This report describes an autopsy case in which there is widespread gliosis of subcortical white matter, focal hippocampal sclerosis and a unique proliferation of protoplasmic astrocytes in the thalamus, with limited bilateral focal loss of neurons. The alterations of the protoplasmic astrocytes consist of proliferation of perivascular feet surrounding blood vessels and velate sheets which surround individual neurons.

Pituitary adenoma: a DNA flow cytometric study of 192 clinicopathologically characterized tumors.

A clinically, immunohistochemically and ultrastructurally characterized series of 192 pituitary adenomas was analyzed for DNA content by flow cytometry. Results were assessed not only relative to tumor immunotype, size, and invasiveness, but also with frequency of recurrence. Case selection was non-random; males predominated (1.

Dementia: the University of Oklahoma autopsy experience.

The brain from 98 consecutive patients with the clinical diagnosis of dementia were examined at autopsy in a standardized fashion. Alzheimer's Disease was present in 79 of the cases, 76%, but represented the only diagnosis in 41%. Thus, almost 60% had another associated pathologic disorder.

Medullomyoblastoma: case report.

This 7-year-old boy presented with a 2-week history of headache, nausea, vomiting, anorexia, lethargy, and unsteadiness of gait. Brain magnetic resonance imaging (MRI) revealed a cystic mass within the vermis of the cerebellum. A suboccipital craniectomy was performed to remove a tumor that contained primitive neuroectodermal cells with florid skeletal muscle differentiation.

Importance of sequences adjacent to the terminal tripeptide in the import of a peroxisomal Candida tropicalis protein in plant peroxisomes.

The peroxisome targeting signal (PTS) required for import of the rat acyl-CoA oxidase (AOX; EC 1.3.3.

Chloroplast acclimation in leaves of Guzmania monostachia in response to high light.

Acclimation of leaves to high light (HL; 650 micromol m(-2) s(-1)) was investigated in the long-lived epiphytic bromeliad Guzmania monostachia and compared with plants maintained under low light (LL; 50 micromol m(-2) s(-1)). Despite a 60% decrease in total chlorophyll in HL-grown plants, the chlorophyll a/b ratio remained stable. Additionally, chloroplasts from HL-grown plants had a much lower thylakoid content and reduced granal stacking.

The distinctive roles of five different ARC genes in the chloroplast division process in Arabidopsis.

ARC (accumulation and replication of chloroplasts) genes control different aspects of the chloroplast division process in higher plants. In order to establish the hierarchy of the ARC genes in the chloroplast division process and to provide evidence for their specific roles, double mutants were constructed between arc11, arc6, arc5, arc3 and arc1 in all combinations and phenotypically analysed. arc11 is a new nuclear recessive mutant with 29 chloroplasts compared with 120 in wild type.

Pediatric eighth cranial nerve schwannoma without evidence of neurofibromatosis.

Schwannomas of the eighth cranial nerve are rare in children. We report a 4 10/12 - year-old girl with no evidence of neurofibromatosis who presented with facial droop. Radiographic studies revealed a large cerebellopontine angle tumor.

Synthesis of medium-chain-length polyhydroxyalkanoates in arabidopsis thaliana using intermediates of peroxisomal fatty acid beta-oxidation.

Polyhydroxyalkanoate (PHA) is a family of polymers composed primarily of R-3-hydroxyalkanoic acids. These polymers have properties of biodegradable thermoplastics and elastomers. Medium-chain-length PHAs (MCL-PHAs) are synthesized in bacteria by using intermediates of the beta-oxidation of alkanoic acids.

Alzheimer's disease as a defect of neuronal autotrophism: a hypothetical analogy with amateur radio operation.

Amyloid precursor protein appears to be a signaling protein that plays a role in neuronal autotrophism, indicating integrity of the nerve terminal and synapse. Analogous to amateur radio operation with a damaged antenna in which further attempts to improve signal propagation can result in damage to the radio equipment, abnormal signaling by the secreted amyloid precursor protein stimulates compensatory metabolic activity in the neuron that ultimately leads to paired helical filament formation (neurofibrillary tangles) and further neuronal dysfunction and death.

Primary intracerebellar osteosarcoma arising within an epidermoid cyst.

The authors report a case of a primary extraskeletal osteosarcoma arising within an epidermoid cyst in the parenchyma of the cerebellum in a 64-year-old woman. On initial presentation, the tumor involved the midline cerebellum without attachment to the surrounding dura mater or calvarium. Complete medical and radiologic evaluation failed to reveal a primary skeletal or other extraskeletal osteosarcoma.

Agenesis of cerebellum associated with arrhinencephaly.

Complete cerebellar agenesis or aplasia is an extremely rare condition with few previously reported cases. We identified a 38-week gestation infant with microcephaly who had complete cerebellar agenesis associated with arrhinecephaly. There was complete lack of the efferent and afferent limbs of the cerebellum, including the nuclei of the basis pontis, the inferior olivary nuclei, ascending spinal and medullary afferents, deep cerebellar nuclei and their afferents, and the red nucleus.

Immunofluorescent quantitation of chloroplast proteins.

Using scanning light microscopy software to detect and measure immunofluorescence in leaf sections Rubisco concentration in situ in chloroplasts has been accurately determined throughout development. The fluorescence measurements were calibrated by comparison with values for Rubisco accumulation obtained from rocket immuno-electrophoresis profiles of soluble protein from isolated cells and from chloroplasts using a purified sample of Rubisco as the standard. It has been shown that in situ immunofluorescence can be used for cytoquantitation of proteins within individual chloroplasts to a sensitivity of 1fg and also for the comparison of the protein levels in adjacent chloroplasts and cells.

Castor bean isocitrate lyase lacking the putative peroxisomal targeting signal 1 ARM is imported into plant peroxisomes both in vitro and in vivo.

To understand and manipulate plant peroxisomal protein targeting, it is important to establish the universality or otherwise of targeting signals. Contradictory results have been published concerning the nature and location of the glyoxysomal/peroxisomal targeting signal of isocitrate lyase (ICL). L.

Characterization of chloroplast division using the Arabidopsis mutant arc5.

arc5 is a chloroplast division mutant of Arabidopsis thaliana. To identify the role of ARC5 in the chloroplast replication process we have followed the changes in arc5 chloroplasts during their perturbed division. ARC5 does not affect proplastid division but functions at a later stage in chloroplast development.

A putative Mg chelatase subunit from Arabidopsis thaliana cv C24. Sequence and transcript analysis of the gene, import of the protein into chloroplasts, and in situ localization of the transcript and protein.

We have isolated and sequenced a cDNA from Arabidopsis thaliana cv C24 that encodes a putative Mg chelatase subunit. The deduced amino acid sequence shows a very high level of identity to a gene previously characterized from Antirrhinum majus (olive and also high similarity to bchH, a bacterial gene involved in the Mg chelatase reaction of bacteriochlorophyll biosynthesis. We suggest that this gene be called CHL H.

Subcellular Visualization of Gene Transcripts Encoding Key Proteins of the Chlorophyll Accumulation Process in Developing Chloroplasts.

The coordination of the synthesis of chlorophyll (Chl) and light-harvesting Chl proteins was determined by observing the sequence of appearance of the specific mRNAs for the nuclear genes CHLH, Por, and Lhcb1*2 (AB180). CHLH encodes a magnesium protoporphyrin chelatase subunit that is involved in the first committed step in Chl biosynthesis; Por encodes protochlorophyllide oxidoreductase, which catalyzes the penultimate and only light-dependent step in Chl biosynthesis; and Lhcb1*2 encodes light-harvesting Chl a/b binding protein of the type-1 light-harvesting complex of photosystem II. Using digoxigenin-labeled antisense and sense RNA probes and a highly sensitive in situ hybridization technique, we have visualized the first appearance of the specific mRNAs in postmitotic mesophyll cells of developing 7-d-old wheat leaves (Triticum aestivum cv Maris dove).

Rhabdomyolysis following electrical injury.

Severe electrical injury is often associated with acute rhabdomyolysis, evident from massively elevated serum creatine (CK) levels, along with presence of other muscle fiber constituents in the serum and urine, resulting specifically in hyperkalemia, hyperphosphatemia, and myoglobinuria. The acute medical care of the patient with electrical injury must include addressing supportive therapy for the rhabdomyolysis (more fully reviewed in other articles in this issue of Seminars), but understanding the underlying pathophysiology of rhabdomyolysis may allow for the future development of improved therapeutic modalities.

arc6, an extreme chloroplast division mutant of Arabidopsis also alters proplastid proliferation and morphology in shoot and root apices.

The arc6 (accumulation and replication of chloroplasts) mutant of Arabidopsis has only two greatly enlarged chloroplasts per mature leaf mesophyll cell compared with ninety chloroplasts per cell in the wild type. The mutation is a single nuclear gene and the plant phenotype is normal. Shoot and root apical meristems of arc6 plants have been examined to determine how early during plastid development the mutant arc6 phenotype can be recognised.

Mitochondria Increase Three-Fold and Mitochondrial Proteins and Lipid Change Dramatically in Postmeristematic Cells in Young Wheat Leaves Grown in Elevated CO2.

A dramatic stimulation in mitochondrial biogenesis during the very early stages of leaf development was observed in young wheat plants (Triticum aestivum cv Hereward) grown in elevated CO2 (650 [mu]L L-1). An almost 3-fold increase in the number of mitochondria was observed in the very young leaf cells at the base of the first leaf of a 7-d-old wheat plant. In the same cells large increases in the accumulation of a mitochondrial chaperonin protein and the mitochondrial 2-oxoglutarate dehydrogenase complex and pyruvate dehydrogenase complex were detected by immunolabeling.