Extracellular signal-regulated kinase (MAP kinase) immunoreactivity in the rhesus monkey brain

Phosphorylation of both tyrosine and serine residues of focal adhesion kinase (FAK) was stimulated by the adhesion of BALB/c mouse 3T3 cells to fibronectin, but phosphorylation of threonine was not detectable. Acidic and basic fibroblast growth factors also stimulated the phosphorylation of serine and tyrosine of FAK in cells adhered to poly-L-lysine, but epidermal growth factor and platelet-derived growth factor did not. A fusion protein of fibronectin and basic fibroblast growth factor effectively induced the phosphorylation of FAK. Phosphorylation of FAK in the rat myoblast L-6 cell line, which lacks fibroblast growth factor receptors, was not stimulated by fibroblast growth factors, suggesting that the interaction of fibroblast growth factors with their receptors might cause the phosphorylation of FAK.     

Enzyme-linked immunosorbent assay, using staphylococcal protein A for detecting virus antibodies

A modification of the indirect enzyme-linked immunosorbent assay (ELISA) was developed which used staphylococcal protein A linked to horseradish peroxidase. Virus antibodies in equine, bovine, porcine, feline, canine, lagomorphic (rabbit), and human sera were detected, using the indirect ELISA in which the antiglobulin enzyme conjugate was replaced by protein A linked to horseradish peroxidase. Results of the ELISA were compared with the results of the serum-virus neutralization test. The application of the test in laboratories performing serologic assays with sera from diverse animal species is discussed.     

Primary nonampullary/periampullary adenocarcinoma of the duodenum

Primary duodenal adenocarcinoma not involving the ampullary region is rare. Our aim was to review the outcome of these patients and determine the factors that affect survival. We performed a retrospective review of all patients with primary, nonampullary duodenal adenocarcinoma at the Cleveland Clinic Foundation from January 1986 through December 1996. Twenty-six patients with primary, nonampullary duodenal malignancies were identified. There were 16 adenocarcinomas, 3 gastrinomas, 3 stromal tumors, 3 leiomyosarcomas, and 1 carcinoid tumor. Patients with adenocarcinoma had symptoms present an average of 6.1 months. Tumors were identified by upper gastrointestinal contrast study and esophagogastroduodenoscopy in 90 per cent and 87 per cent of patients, respectively. Twelve of 13 (93%) cancers found in the third or fourth portion of the duodenum were adenocarcinomas. Seven of the 16 adenocarcinomas were resectable on exploration. Those that were contained within the serosa have not recurred (mean, 6 years); one of the two patients with locally invasive adenocarcinoma remains disease free. The average survival for patients with unresectable disease was 6.7 months. The 5-year survival rates were: all adenocarcinoma, 38 per cent; resectable, 86 per cent; and unresectable, 0 per cent. All patients presenting with weight loss or obstructive symptoms died of disease; those with melena survived long term. Patients with tumors other than adenocarcinoma had a 90 per cent 5-year survival. We conclude that patients typically present with a long history of symptoms. Distal duodenal malignancies are most frequently adenocarcinomas. Upper gastrointestinal contrast study or endoscopy is often diagnostic. Patients with weight loss and/or obstructive symptoms had invasive disease and a morbid prognosis. Aggressive surgery is warranted, and most with resectable disease (86%) had long-term survival.     

Correlation of fine needle aspiration biopsy and fluoride-18 fluorodeoxyglucose positron emission tomography in the assessment of locally recurrent and metastatic head and neck neoplasia

OBJECTIVE: Patients with primary head and neck neoplasia can present during follow-up with suspected recurrence, and both fine needle aspiration biopsy (FNAB) and fluoride-18 fluorodeoxyglucose positron emission tomography (FDG-PET) scan are available methodologies for evaluating these patients. Our objective was to retrospectively correlate patients who underwent both FNAB and FDG-PET scan in order to assess the possibility of recurrent neoplasia. STUDY DESIGN: The cytopathology files at Saint Louis University Health Sciences Center were retrospectively searched for patients with known primary head and neck malignancies beginning in 1995. Suspected recurrence and local metastases evaluated by both FNAB and FDG-PET scan were correlated. RESULTS: Twenty-eight patients received a combined total of 37 FNABs with concurrent FDG-PET scans. The majority of patients had primary oropharyngeal squamous cell carcinoma with intermixed, single cases of other primary head and neck neoplasms. Thirty of the 32 aspirates with recurrent or locally metastatic disease had combined positive findings by both FNAB and FDG-PET scan, yielding a sensitivity of 94%. One nonspecific and one negative FDG-PET scan came from a patient who had disease confirmed by FNAB. Five patients had negative findings by both methods that were supported by the subsequent clinical course. CONCLUSION: FNAB can provide confirmatory evidence of disease in a clinically suspicious abnormality with nonspecific FDG-PET results. FNAB and FDG-PET are highly sensitive for tumors in cases of clinically suspected recurrence and locally metastatic disease.     

Tyrosine hydroxylase expression in primary cultures of olfactory bulb: role of L-type calcium channels

Sensory activity mediates regulation of tyrosine hydroxylase (TH), the first enzyme in the dopamine biosynthetic pathway, in the rodent olfactory bulb. The current studies established for the first time primary cultures of neonatal mouse olfactory bulb expressing TH and tested whether L-type calcium channels mediate the activity-dependent regulation of the dopamine phenotype. After 1 d in vitro (DIV), a small population of TH-immunostained neurons that lacked extensive processes could be demonstrated. After an additional 2 DIV in serum-free medium, the number of TH neurons had doubled, and they exhibited long interdigitating processes. Membrane depolarization for 48 hr with 50 mM KCl produced a further 2.4-fold increase in the number of TH-immunoreactive neurons compared with control cultures. Increased TH neuron number required at least 36 hr of exposure to KCl. Forskolin, which increases intracellular cAMP levels, induced a 1.5- to 1.6-fold increase in the number of TH-immunostained neurons. Combined treatment with KCl and forskolin was not additive. Nifedipine, an L-type calcium channel blocker, completely prevented the depolarization-mediated increase in TH expression but did not block the response to forskolin. Treatment with Bay K8644, an L-type calcium channel agonist, also significantly increased the number of TH-expressing neurons. Depolarization also induced alterations in neuritic outgrowth, resulting in a stellate versus an elongate morphology that, in contrast, was not prevented by nifedipine. These results are the first demonstration that in vitro, as in vivo, depolarization increases TH expression in olfactory bulb and that L-type calcium channels mediate this activity-dependent regulation of the dopamine phenotype.     

Distinct roles for sodium, chloride, and calcium in excitotoxic dendritic injury and recovery

The postsynaptic neuronal dendrite is selectively vulnerable to hypoxic-ischemic brain injury and glutamate receptor overactivation. We explored the glutamate receptor pharmacology and ionic basis of rapid, reversible alterations in dendritic shape which occur in cultured neurons exposed to glutamate. Dendrite morphology was assessed with the fluorescent membrane tracer, DiI, or immunofluorescence labeling of the somatodendritic protein, MAP2. Cortical cultures derived from 15-day-old mouse embryos underwent segmental dendritic beading when exposed to NMDA, AMPA, or kainate, but not to metabotropic glutamate receptor agonists. Varicosity formation in response to NMDA or kainate application was substantially attenuated in reduced sodium buffer (substituted with N-methyl-D-glucamine). Furthermore, veratridine-induced sodium entry mimicked excitotoxic alterations in dendrites and additionally caused varicosity formation in axons. Solutions deficient in chloride (substituted with Na methylsulfate) and antagonists of chloride-permeable GABA/glycine receptors reduced NMDA- or kainate-induced varicosity formation. An increase in dendrite volume was observed as varicosities formed, and varicosity formation was attenuated in sucrose-supplemented hypertonic media. Despite marked structural changes affecting virtually all neurons, dendrite shape returned to normal within 2 h of terminating glutamate receptor agonist application. Neurons exposed to kainate recovered more rapidly than those exposed to NMDA, and neurons exposed to NMDA in calcium-free buffer recovered more rapidly than cells treated with NMDA in normal buffer. While sodium, chloride, and water entry contribute to excitotoxic dendritic injury acutely, calcium entry through NMDA receptors results in lasting structural changes in damaged dendrites.