Proteomic analysis of the genotoxicant methylazoxymethanol (MAM)-induced changes in the developing cerebellum.

The genotoxicant methylazoxymethanol (MAM) is a widely used developmental neurotoxin, and its glucoside is an etiological factor for western Pacific amyotrophic lateral sclerosis-parkinsonism-dementia complex (ALS/PDC). Identification of global protein expression changes that occur in response to MAM in the developing cerebellum could provide valuable insight into the potential mechanisms involved in the neurodegeneration process. We have utilized fluorescence 2-dimensional differential gel electrophoresis (2D-DIGE), to determine the protein expression changes that occur during normal cerebellar development and in response to MAM. Three day-old postnatal C57BL/6 mice (PND3) received a single injection of MAM, and the cerebella of postnatal day 4 (PND4) and day 22 (PND22) were analyzed. Approximately, 1400 unique spots were matched and quantified in all samples. Comparison of PND4 and PND22 developing cerebellum showed that a significant fraction of the proteome (approximately 68%) changes at this stage. The immediate response of the developing cerebellum to MAM was minimal (approximately 10%). However, significant differences (27%) were noted 14 days after MAM exposure. In contrast, the transcriptome changes were more pronounced at 24 h compared to 14 days. MAM targeted several proteins networks including transport (e.g., alpha-synuclein), cytoskeletal (e.g., beta-tubulin, vimentin), and mitochondrial (e.g., Atp5b) proteins. Immunochemistry confirmed several of the changes in protein expression (alpha-synuclein). Comparison with gene expression changes revealed that the temporal changes observed in the transcriptome and proteome are not correlative. These studies demonstrate for the first time the potential networks involved during neuronal development and neurodegenerative processes that are perturbed by MAM.

Molecular networks perturbed in a developmental animal model of brain injury.

Methylazoxymethanol (MAM) is widely used as a developmental neurotoxin and exposure to its glucoside (i.e., cycasin) is associated with the prototypical neurological disorder western Pacific ALS/PDC. However, the specific molecular targets that play a key role in MAM-induced brain injury remain unclear. To reveal potential molecular networks targeted by MAM in the developing nervous system, we examined characteristic phenotypic changes (DNA damage, cytoarchitecture) induced by MAM and their correlation with gene expression differences using microarray assays (27,648 genes). Three day-old postnatal C57BL/6 mice (PND3) received a single injection of MAM and the cerebellum and cerebral cortex of PND4, 8, 15, and 22 mice were analyzed. DNA damage was detected in both the cerebellum (N7-mGua, TUNEL labeling) and cerebral cortex (N7-mGua) of PND4 mice, but progressive disruption of the cytoarchitecture was restricted to the cerebellum. A majority (>75%) of the genes affected (cerebellum 636 genes, cortex 1080 genes) by MAM were developmentally regulated, with a predominant response early (PND4) in the cerebellum and delayed (PND8 and 15) in the cerebral cortex. The genes and pathways (e.g., proteasome) affected by MAM in the cerebellum are distinct from cortex. The genes perturbed in the cerebellum reflect critical cellular processes such as development (17%), cell cycle (7%), protein metabolism (12%), and transcriptional regulation (9%) that could contribute to the observed cytoarchitectural disruption of the cerebellum. This study demonstrates for the first time that specific genes and molecular networks are affected by MAM during CNS development. Further investigation of these targets will help to understand how disruption of these developmental programs could contribute to chronic brain injury or neurodegenerative disease.

Initial treatment of patients with acute ischemic heart disease hospitalized in a community hospital.

During the 1980s, tremendous advances occurred in understanding the pathophysiology of ischemic heart disease. Numerous clinical trials were performed to help clinicians formulate treatment plans and diagnostic schemes to care for patients with coronary artery disease. To see how these studies affect the evaluation and treatment of patients with acute coronary syndromes today, we reviewed the hospital records of patients admitted to our community hospital during September 1990. We found that such patients generally have a good short-term prognosis. Most can be stabilized using modern medical means, and in-hospital mortality is low. Antithrombotic and antianginal therapies are used liberally. Thrombolytic therapy is administered commonly, even to elderly patients. Invasive and noninvasive diagnostic testing procedures are both used frequently, and most acute myocardial infarction and unstable angina patients undergo revascularization.

Coronary angioplasty using new 6 French guiding catheters.

Coronary angioplasty (PTCA) was performed with specially constructed 6-French guiding catheters with an internal lumen of 0.051 inches. In 154 patients these guiding catheters were used in a variety of configurations in conjunction with miniature balloon-on-a-wire dilatation catheters in 1.5 to 3.5 mm sizes to perform PTCA. Overall patient success was 94%. PTCA was attempted in 24 totally occluded arteries with a success rate of 83% and 174 stenoses with a success rate of 97%. 6 French guiding catheters can be used to successfully perform PTCA.

Randomized comparison of over-the-wire and fixed-wire balloon devices for coronary angioplasty.

One hundred and fifteen consecutive patients undergoing coronary angioplasty (PTCA) were randomized to low profile over-the-wire (OTW, e.g., Mini, Sulp II) or fixed-wire (FW, e.g., Ace, Orion, Probe) PTCA balloon wire devices. Overall success, ability to begin and finish with the same balloon device, fluoroscopy time, physician time, and amount of contrast media used were prospectively assessed. Overall final success rate was excellent regardless of which type of system was used first (OTW 92%; FW 96%). In 6 patients no wire would cross, in another, the stenosis would not dilate despite high pressure ( greater than 18 atm). When an OTW device was used first, it was initially successful in 69% of patients and was changed with success to a second OTW balloon in 4 (cumulative 76%). An OTW balloon was changed to FW in 11 patients (success 9 patients, 82%). This was because of inability to cross with balloon of the OTW system after a steerable wire had crossed in 9 of the patients. When a FW device was used first, it was initially successful in 89%. A change to another FW device led to success in 4 additional patients (cumulative 96%). In no patient was a FW changed to an OTW device. Thus, a FW device was more likely to be successful (either 54 of 56 patients initially randomized to FW, or 63 of 67 total patient number in whom a FW device was used) than an OTW device (45 of 59 patients) p less than .05.(ABSTRACT TRUNCATED AT 250 WORDS)