ANALYSIS OF THE INITIAL STAGES.OF ENZYME IMMOBILIZATION IN POROUS SOLIDS

This work considers the initial stages of enzyme immobilization in solids with pores of much greater diameter than the enzyme molecule. The enzyme immobilization rate is assumed during this time to be first-order with respect to the enzyme concentration in the pore fluid. An analytical solution for this model is obtained using finite Sturm-Liouville integral transforms. Asymptotic expressions for the case of large reservoirs of immobilizing fluid are also determined by application of a multiscale perturbation analysis.     

Neuropsychometric changes in patients after carotid endarterectomy

BACKGROUND AND PURPOSE: One hundred twelve patients undergoing elective carotid endarterectomy for symptomatic and asymptomatic carotid artery stenosis were enrolled in a prospective study to evaluate the incidence of change in postoperative cerebral function. METHODS: Patients were evaluated preoperatively and postoperatively before hospital discharge and at follow-up 1 and 5 months later with a battery of neuropsychometric tests. The results were analyzed by both event-rate and group-rate analyses. For event-rate analysis, change was defined as either a decline or improvement in postoperative neuropsychometric performance by 25% or more compared with a preoperative baseline. RESULTS: Approximately 80% of patients showed decline in one or more test scores, and 60% had one or more improved test scores at the first follow-up examination. The percentage of declined test scores decreased and the percentage of improved test scores increased with subsequent follow-up examinations. Group-rate analysis was similar for group performance on individual tests. However, a decline in performance was seen most commonly on verbal memory tests, and improved performance was seen most commonly on executive and motor tests. CONCLUSIONS: Neuropsychometric evaluation of patients undergoing carotid endarterectomy for significant carotid artery stenosis demonstrates both declines and improvements in neuropsychometric performance. The test changes that showed decreased performance may be associated with ischemia from global hypoperfusion or embolic phenomena, and the improvement seen may be related to increased cerebral blood flow from removal of stenosis.     

Acid secretion from an esophageal inlet patch demonstrated by ambulatory pH monitoring

Heterotopic gastric mucosa may occur throughout the gastrointestinal tract, including the upper esophagus. The capability of this ectopic mucosa to secrete acid has been suggested in different reports. We report for the first time a case of heterotopic gastric mucosa in the upper esophagus complicated by a stricture with secretion of acid demonstrated by prolonged ambulatory pH monitoring. Lansoprazole, 30 mg twice daily, produced symptom resolution, and repeat ambulatory pH showed complete acid suppression in the proximal esophagus.     

Selection of an adjuvant for vaccination with the malaria antigen, MSA-2

Various formulations of the Plasmodium falciparum merozoite surface antigen, MSA-2, were made and tested in animals in order to select one for use in human vaccine trials. Recombinant constructs representing both major allelic forms of MSA-2 were formulated with a range of adjuvants and used to immunize rabbits, mice and sheep. After immunization, antibody responses obtained with the most potent adjuvants were at least tenfold greater than responses obtained with the least potent adjuvant Alhydrogel, which was used as the reference standard, although its lower potency indicated against its further use in clinical trials. Based on broadly similar results obtained with the three animal species, several adjuvants, including the water-in-oil adjuvant Montanide ISA 720, the oil-in-water adjuvant SAF-1, and liposomes containing lipid A formulated with Alhydrogel were demonstrated to be potent and potentially suitable for the clinical evaluation of MSA-2 as a candidate malaria vaccine antigen. Of these, ISA 720 was selected for further trial.     

Biopsy-negative malignant esophageal stricture: diagnosis by endoscopic ultrasound

Endoscopic ultrasound (EUS) of the esophagus has been used primarily in staging biopsy-proven cancers. Its use as a primary diagnostic modality for esophageal malignancy has not been previously described. We report our recent experience in four patients with dysphagia and endoscopic biopsies negative for malignancy, including one patient with clinical and manometric features suggestive of achalasia. In all cases, EUS revealed a large infiltrating tumor invading through the esophageal wall into the surrounding tissues, and in one case into the aorta. Computed tomography suggested the possibility of a tumor in only one of the cases. Two patients underwent esophagectomy and were found to have adenocarcinoma. Two patients underwent repeat biopsy with alternative aggressive biopsy techniques and were found to have squamous cell carcinoma. We conclude that EUS is useful in the diagnosis of esophageal cancer and should be performed in selected patients with esophageal strictures whose biopsies are negative for malignancy; i.e., those with suspicious endoscopic or radiographic appearance, atypical presentation (e.g., profound weight loss, short duration of symptoms, or advanced age), and failure to respond to treatment.     

Involvement of protein tyrosine phosphorylation in the effect of green tea polyphenols on Ehrlich ascites tumor cells in vitro

Recently, elucidation has progressed on a crucial role played by dendritic cells (DCs) in the induction of primary antigen-specific immune reactions. Although mature DCs exhibit potent antigen presenting function, DCs are scattered in nonlymphoid organs throughout the body as immature cells that have only minimum antigen presenting function. When they are stimulated to maturate, they increase their expression of class II major histocompatibility (MHC) antigen and several co-stimulatory molecules, resulting in the augmentation of antigen presenting function. Furthermore, these maturated DCs move to the T-dependent areas of secondary lymphoid organs to sensitize naive T cells for these antigens. Therefore, it is important to understand the mechanism to induce the maturation of DCs. Recent progress in the study of DC biology depicts various factors, such as cytokines, bacterial products and haptens, which are responsible for DC maturation. In this paper, the mechanism of DC maturation induced by cytokines and chemicals is described.