Stomach implant for long-term erythropoietin expression in rats

Caveolae are small microdomains of the plasma membrane that are thought to play important roles in signal transduction processes. In this work, we have investigated the association of Rho proteins with caveolae-enriched membrane domains isolated from cultured endothelial cells. Fractionation of ECV304 cells by sucrose gradient density centrifugation in the absence of detergent resulted in the co-sedimentation of a significant proportion of RhoA and Cdc42 with known caveolae marker proteins, including caveolin, but not with other non-caveolae membrane proteins such as the angiotensin-converting enzyme. Immunoprecipitation experiments carried on crude endothelial cell lysates as well as with solubilized caveolae-enriched membrane domains showed the coimmunoprecipitation of caveolin with RhoA but not with Cdc42. Incubation of endothelial cell lysates with a glutathione-S-transferase (GST)-RhoA fusion protein resulted in the specific precipitation of caveolin, while addition of GST-caveolin-1 to the lysates promoted the precipitation of RhoA. Moreover, incubation of bacterially expressed RhoA with GST-caveolin-1 resulted in the precipitation of RhoA, indicating that RhoA directly interacts with caveolin-1. This interaction was found to be nucleotide-independent and was not affected by prior modification of RhoA with the C3 exoenzyme from C. botulinium or with the cytotoxic necrotinizing factor from E. coli. Taken together, these results suggest the association of RhoA with endothelial caveolae-enriched membrane domains, likely through physical interaction with caveolin-1. These findings may provide new insights into the functions played by Rho proteins and caveolae in signal transduction events.     

Anatomy of the cranial nerves

The anatomy of cranial nerves I and III through XII are presented. Each nerve is diagrammatically illustrated from its nuclear or its sensory origin and correlated with magnetic resonance and computed tomography images. The important identifying anatomical landmarks are demonstrated along the course of each nerve. Peripheral motor and sensory components are also discussed.     

Systemic hypothermia after spinal cord compression injury in the rat: does recorded temperature in accessible organs reflect the intramedullary temperature in the spinal cord?

This article addresses one basic issue regarding the use of systemic hypothermia in the acute management of spinal cord injury, namely, how to interpret temperature recordings in accessible organs such as the rectum or esophagus with reference to the spinal cord temperature. Thirty-six rats, divided into six groups, were randomized to laminectomy or to severe spinal cord compression trauma, and were further randomized to either a cooling/rewarming procedure or continuous normothermia (esophageal temperature 38 degrees C) for 90 min. The first procedure comprised normothermia during the surgical procedure, followed by lowering of the esophageal temperature from 38 degrees C to 30 degrees C (the hypothermic level), a 20-min steady-state period at 30 degrees C, rewarming to 38 degrees C, and finally a 20-min steady-state period at 38 degrees C. The esophageal, rectal, and epidural temperatures were recorded in all animals. The intramedullary temperature was also recorded invasively in four of the six groups. We conclude that the esophageal temperature is safe and easy to record and, in our setting, reflects the epidural temperature. The differences registrated may reflect a true deviation of the intramedullary temperature due to initial environmental exposure and secondary injury processes. Our results indicate that the esophageal temperature exceeds the intramedullary temperature during the initial recording and final steady state following rewarming, but not during the most crucial part of the experiment, the hypothermic period. The core temperature measured in the esophagus can therefore be used to evaluate the intramedullary temperature during alterations of the systemic temperature and during hypothermic periods.     

Chronobiology and chronotherapy of asthma

There is no doubt that many pathophysiologic conditions change over a 24-hour period and thus therapy needs to be directed at these changes. In particular, asthma has been one of the better-studied disease processes in regard to circadian changes in pathophysiology. As we continue to learn more about circadian changes, better approaches to treating the disease with the same medications will emerge. It should be remembered that many asthmatics do not perceive their degree of bronchoconstriction. This was brought forth in Turner-Warwick's epidemiologic study in that less than one half of the asthmatic individuals who had problems with their asthma every night describe their asthma as being severe. The majority stated they either had mild or moderate asthma. Therefore, it is important that we use objective criteria such as peak flow meters in determining an individual patient's day-to-night changes in lung function. Then, any therapeutic intervention can be objectively determined at home with both the patient and physician gaining knowledge about the ongoing asthmatic process.     

N-terminal heterogeneity of parenchymal and cerebrovascular Abeta deposits

The goals of this study were twofold: to determine whether species differences in Abeta N-terminal heterogeneity explain the absence of neuritic plaques in the aged dog and aged bear in contrast to the human; and to compare Abeta N-terminal isoforms in parenchymal vs cerebrovascular Abeta (CVA) deposits in each of the species, and in individuals with Alzheimer disease (AD) vs nondemented individuals. N-terminal heterogeneity can affect the aggregation, toxicity, and stability of Abeta. The human, polar bear, and dog brain share an identical Abeta amino acid sequence. Tissues were immunostained using affinity-purified polyclonal antibodies specific for the L-aspartate residue of Abeta at position one (AbetaN1[D]), D-aspartate at N1 (AbetaN1[rD]), and pyroglutamate at N3 (AbetaN3[pE]) and p3, a peptide beginning with leucine at N17 (AbetaN17[L]). The results demonstrate that each Abeta N-terminal isoform can be present in diffuse plaques and CVA deposits in AD brain, nondemented human, and the examined aged animal models. Though each Abeta N-terminal isoform was present in diffuse plaques, the average amyloid burden of each isoform was highest in AD vs polar bear and dog (beagle) brain. Moreover, the ratio of AbetaN3(pE) (an isoform that is resistant to degradation by most aminopeptidases) vs AbetaN17(L)-x (the potentially nonamyloidogenic p3 fragment) was greatest in the human brain when compared with aged dog or polar bear. Neuritic plaques in AD brain typically immunostained with antibodies against AbetaN1(D) and AbetaN3(pE), but not AbetaN17(L) or AbetaN1(rD). Neuritic deposits in nondemented individuals with atherosclerotic and vascular hypertensive changes could be identified with AbetaN1(D), AbetaN3(pE), and AbetaN1(rD). The presence of AbetaN1(rD) in neuritic plaques in nondemented individuals with atherosclerosis or hypertension, but not in AD, suggests a different evolution of the plaques in the two conditions. AbetaN1(rD) was usually absent in human CVA, except in AD cases with atherosclerotic and vascular hypertensive changes. Together, the results demonstrate that diffuse plaques, neuritic plaques, and CVA deposits are each associated with distinct profiles of Abeta N-terminal isoforms.     

Comparative evaluation of National Committee for Clinical Laboratory Standards broth macrodilution and agar dilution screening methods for testing fluconazole susceptibility of Cryptococcus neoformans

A simple screening method for fluconazole susceptibility of Cryptococcus neoformans using 2% dextrose Sabouraud dextrose agar (SabDex) with fluconazole was compared to the National Committee for Clinical Laboratory Standards (NCCLS) broth macrodilution method. By this method, fluconazole-susceptible C. neoformans isolates are significantly smaller on medium with fluconazole than on fluconazole-free medium. Isolates with decreased susceptibility have normal-size colonies on medium containing fluconazole. The 48-h NCCLS broth macrodilution MICs (NCCLS MICs) for isolates with normal-size colonies on 8- or 16-microg/ml fluconazole plates were predicted to be > or =8 or > or =16 microg/ml, respectively. On medium with 16 microg of fluconazole per ml, all strains (84 of 84) for which the NCCLS MICs were <16 microg/ml were correctly predicted, as were all isolates (7 of 7) for which the MICs were > or =16 microg/ml. Agar dilution appears to be an effective screening method for fluconazole resistance in C. neoformans.     

An office approach to the diagnosis of chronic cough

BACKGROUND: Some cancer patients require invasive techniques for control of chronic cancer pain. Many patients have benefited from local administration of opioids and anesthetics through an epidural catheter. However, epidural abscess and meningitis are side effects of epidural catheters that have serious morbidity and mortality. METHODS: In a retrospective study, the charts of all patients who received an epidural catheter for the management of chronic cancer pain in a 3-year period (1993-1996) were reviewed. Patients with nervous system infections were identified and pertinent clinical, radiologic (magnetic resonance imaging), and bacteriologic data were analyzed. RESULTS: Ninety-one patients received 137 epidural catheters for a total of 4326 catheter days. All but four patients had died at the time of the final analysis. The median survival after placement of the first epidural catheter was 38 days (range, 1 day--> 1000 days). Seventy-two patients received a percutaneous port whereas 19 patients were treated with an implanted subcutaneous port. Adequate pain relief was obtained in 76% of the 58 patients with nociceptive pain and in 73% of 33 patients with neuropathic pain. All neuropathic pain was associated with active tumor and could be classified as nociceptive nerve pain. Technical complications and superficial infections occurred in as many as 43% of patients. Deep infections occurred in 12 patients, 11 of whom had a spinal epidural abscess. CONCLUSIONS: Deep infection is a frequent complication of epidural analgesia and is associated with a high morbidity and mortality. Only cancer patients with a short life expectancy (< or =3 months) should be treated with epidural analgesia.     

Epidemiology, laboratory detection, and therapy of penicillin-resistant streptococcal infections

The excitatory effect of presynaptically released glutamate is tightly regulated and terminated by high affinity sodium-dependent glutamate transporters. The regulation of the glial glutamate transporter GLT-1 is potentially important in synaptic modulation. Using astroglial cultures prepared from the rat cerebral cortex, we found that the delta-opioid receptor agonist [D-pen2,D-pen5]-enkephalin decreases and glutamate increases the expression of the GLT-1 transporter mRNA. Corresponding changes in the uptake kinetics were found after incubation for 48 h with the respective agonists when glial glutamate uptake was measured in primary astroglial cultures. The data suggest that long-term receptor activation induces alterations in glial glutamate uptake properties.