Identification of domains in apoA-I susceptible to proteolysis by mast cell chymase. Implications for HDL function

When stimulated, rat serosal mast cells degranulate and secrete a cytoplasmic neutral protease, chymase. We studied the fragmentation of apolipoprotein (apo) A-I during proteolysis of HDL(3) by chymase, and examined how chymase-dependent proteolysis interfered with the binding of eight murine monoclonal antibodies (Mabs) against functional domains of apoA-I. Size exclusion chromatography of HDL(3) revealed that proteolysis for up to 24 h did not alter the integrity of the alpha-migrating HDL, whereas a minor peak containing particles of smaller size with prebeta mobility disappeared after as little as 15 min of incubation. At the same time, generation of a large (26 kDa) polypeptide containing the N-terminus of apoA-I was detected. This large fragment and other medium-sized fragments of apoA-I produced after prolonged treatment with chymase were found to be associated with the alphaHDL; meanwhile, small lipid-free peptides were rapidly produced. Incubation of HDL(3) with chymase inhibited binding of Mab A-I-9 (specific for prebeta(1)HDL) most rapidly (within 15 min) of the eight studied Mabs. This rapid loss of binding was paralleled by a similar reduction in the ability of HDL(3) to induce high-affinity efflux of cholesterol from macrophage foam cells, indicating that proteolysis had destroyed an epitope that is critical for this function. In sharp contrast, prolonged degradation of HDL(3) by chymase failed to reduce the ability of HDL(3) to activate LCAT, even though it led to modification of three epitopes in the central region of apoA-I that are involved in lecithin cholesterol acyltransferase (LCAT) activation. This differential sensitivity of the two key functions of HDL(3) to the proteolytic action of mast cell chymase is compatible with the notion that, in reverse cholesterol transport, intactness of apoA-I is essential for prebeta(1)HDL to promote the high-affinity efflux of cellular cholesterol, but not for the alpha-migrating HDL particles to activate LCAT.

Effect of hypercholesterolemia on the sequential changes of apoptosis and proliferation after balloon injury to rabbit iliac artery

To evaluate the effect of hypercholesterolemia on apoptosis and proliferation after vascular injury, iliac arteries of hypercholesterolemic (HC) and normocholesterolemic (NC) rabbits were examined after balloon injury using TUNEL, immunohistochemical staining of PCNA, macrophages, smooth muscle actin and p53. In media, apoptosis occurred massively early after injury and then decreased. HC did not affect this early post-injury apoptosis but significantly increased apoptosis 14 days later (D14). Immediate apoptosis in media was followed by active proliferation. HC sustained a high activity of proliferation until D14. The changes of immunoreactivity to p53 over the same 14 day period parallel that of apoptosis. In intima, where cells were scarce initially, proliferative activity reached a peak at D7 and then decreased. HC significantly enhanced proliferation at D14. In intima proliferation was accompanied by a later low-level apoptosis. HC significantly enhanced this low-level apoptosis at D14. These effects of HC resulted in significantly increased areas of intima and media. The fundamental difference between HC and NC was the infiltration of macrophages in HC. In conclusion, balloon injury induces early massive p53-associated apoptosis followed by proliferation in media, whereas in intima, it induces active proliferation followed by a low-level apoptosis. Hypercholesterolemia does not affect the early post-injury apoptosis but enhances proliferation and low-level apoptosis at a later stage, which in turn results in intimal and medial hyperplasia.

Effect of ethanol on thromboxane and prostacyclin production in the human placenta

Fetal alcohol syndrome (FAS) is frequently associated with intrauterine growth retardation (IUGR). One cause of ethanol-induced IUGR is thought to be related to increased pressor activity in the human placenta, resulting in decreased oxygenation and nutrient transport to the fetus. Thus, we have investigated the effect of ethanol on paracrine substances, such as thromboxane and prostacyclin, that act as vasoregulators within the intrauterine tissues. In these studies we have utilized the perfused single human cotyledon system to study the effect of ethanol on placental prostanoid production. We assessed the effect of longer (240 min) and more acute (60 min) exposure to ethanol on release of thromboxane B(2) (TxB(2)) and 6-keto-prostaglandin F(1 alpha) (6-keto-PGF(1 alpha)) at the maternal and fetal sides of the placenta. Thromboxane was increased by both longer and shorter ethanol exposure, especially on the fetal side of the placenta. Prostacyclin was essentially unchanged with exposure to ethanol. The thromboxane:prostacyclin ratio also tended to increase with both 60- and 240-min ethanol exposure, but a statistically significant increase was seen only at a few time points. In the 60-min ethanol exposure, an increase in thromboxane was observed both during and following exposure to ethanol. The increase in the thromboxane milieu observed with ethanol exposure may lead, at least in part, to the IUGR which is frequently associated with FAS. Prevention of this effect of ethanol on thromboxane production might be a beneficial intervention for FAS.

Effective inhibition of human cytomegalovirus gene expression and replication by a ribozyme derived from the catalytic RNA subunit of RNase P from Escherichia coli

A sequence-specific ribozyme (M1GS RNA) derived from the catalytic RNA subunit of RNase P from Escherichia coli was used to target the overlapping exon 3 region of the mRNAs encoding the major transcription regulatory proteins IE1 and IE2 of human cytomegalovirus. A reduction of more than 80% in the expression levels of IE1 and IE2 and a reduction of about 150-fold in viral growth were observed in human cells that stably expressed the ribozyme. In contrast, a reduction of less than 10% in the IE1/IE2 expression and viral growth was observed in cells that either did not express the ribozyme or produced a "disabled" ribozyme that carried mutations that abolished its catalytic activity. Examination of the expression of several other viral early and late genes in the cells that expressed the M1GS ribozyme further revealed an overall reduction of at least 80% in their expression. These results are consistent with the notion that the antiviral effects in these cells are due to the fact that the ribozyme specifically inhibits the expression of IE1 and IE2 and, consequently, abolishes the expression of viral early and late genes as well as viral growth. Our study is the first, to our knowledge, to use M1GS ribozyme for inhibiting human cytomegalovirus replication and demonstrates the utility of this ribozyme for antiviral applications.

Discrepancies in diagnoses of neuroepithelial neoplasms: the San Francisco Bay Area Adult Glioma Study

BACKGROUND

Valid and reliable diagnoses of disease are key both to meaningful epidemiologic and clinical investigations and to decision-making about appropriate treatment. One previous study highlighted the lack of precision in diagnosing primary brain tumors in a neuropathology referral practice. The current study explores diagnostic discrepancies in a population-based adult glioma series by hospital of origin, specialty training of the original diagnosing pathologist, and clinical significance.

METHODS

To confirm patients' eligibility for the San Francisco Adult Glioma Study, the authors obtained participants' pathology specimens and conducted a uniform secondary neuropathology review. Eligible patients were all adults age 20 years or older newly diagnosed with glioma between August 1, 1991, and March 31, 1994, who resided in 1 of 6 San Francisco Bay Area counties.

RESULTS

Overall, the original and secondary diagnoses were the same (concordant) for 352 (77%) of the 457 cases available for study. Twenty-six percent of the cases from community hospitals were discordant, compared with 12% of the cases from academic hospitals P= 0.004. Of the 105 discordant diagnoses, 17 (16%) were determined to be clinically significant, defined as a difference that could significantly alter patient management and/or prognosis. Sixteen of these 17 cases originated at community hospitals, and only 1 originated at a hospital with a neuropathologist. Based on the distribution of review diagnoses, subjects presenting at nonacademic hospitals were more likely than those presenting at academic hospitals to have glioblastoma (61% vs. 52%; P = 0.07).

CONCLUSIONS

The percentage of cases with discrepant original and review diagnoses was higher among those originally diagnosed at community hospitals without a neuropathologist than among those originally diagnosed at an academic hospital with a neuropathologist. Clinically significant discrepancies were much more likely to have originated at a community hospital without a neuropathologist. These data highlight the importance of review of brain tumors by a neuropathologist prior to decision-making regarding treatment. A separate implication of this study is that glioma cases selected exclusively from academic or nonacademic institutions in a particular geographic area are unlikely to be representative of all cases occurring in that area.

Characterisation of acyl-ACP desaturases from Macadamia integrifolia Maiden & Betche and Nerium oleander L

The seed oil in Macadamia integrifolia contains about 30% palmitoleic acid (16:1(Delta9)) and Nerium oleander about 12% isoricinoleic acid (Delta9-hydroxy-18:1(Delta12)). It has been shown that palmitoleic acid can be produced by acyl-acyl carrier protein (ACP) desaturases and it has also been shown that fatty acid hydroxylation can occur via direct substitution of a hydrogen atom. Therefore it seemed possible that the enzymes responsible for the making of these unusual fatty acids in M. integrifolia and N. oleander were of acyl-ACP desaturase type. Extracts from developing M. integrifolia developing seeds showed a relative ratio of 16:0-ACP to 18:0-ACP desaturation that was about 13 times higher than in sunflower seeds. N. oleander seed extracts catalysed conversion of 18:0-ACP to 18:1(Delta9) but only trace amounts of Delta9-hydroxy fatty acids were formed. A total of four cDNAs were isolated from developing seeds, of both species, using a fragment isolated with PCR amplification. The M. integrifolia acyl-ACP desaturase cDNA was expressed in Escherichia coli. A partly purified fraction of the enzyme showed a 16:0-ACP to 18:0-ACP desaturation ratio about 90-fold less than that in the Macadamia extracts. Expressed N. oleander acyl-ACP desaturase cDNAs showed predominantly 18:0-ACP desaturase activity and no hydroxylase activity. Thus it is not likely that any of the four acyl-ACP desaturases cloned from M. integrifolia or N. oleander is involved in the production of unusual fatty acids.

Functional characterization of a gene encoding a fourth ATP sulfurylase isoform from Arabidopsis thaliana

ATP sulfurylase (ATP: sulfate adenylyl transferase, EC 2.7.7.4), the first enzyme of the sulfate assimilation pathway, is present in the chloroplast and cytosol of plants. In Arabidopsis thaliana cDNA cloning revealed the existence of three ATP sulfurylase isoforms (APS1, -2, and -3) all of which appear to be localized in plastids. In the present study the cytosolic isoform was sought by searching the expressed sequence tag (EST) database and by screening A. thaliana genomic libraries. A fourth isoform, APS4, was identified, but it also encodes a plastid-localized isoform. The APS genes all contain four introns. The introns are located at identical positions within the coding sequence of each of the APS genes. A putative TATA box was identified in the promoter of the APS3 and APS4 genes, but no regions of sequence similarity were found among the other promoters. Combined analysis of an APS4 cDNA and genomic clone revealed that the deduced protein is 469 amino acids and is most homologous to the A. thaliana APS1 subclass. The APS4 cDNA was able to functionally complement a yeast ATP sulfurylase (met3) mutant and the recombinant enzyme displayed ATP sulfurylase activity. The APS4 protein exhibits a plastid targeting peptide at its amino terminus that, when fused to green fluorescent protein, was able to target the reporter to chloroplasts. APS4 mRNA was detected at a similar steady-state level in roots and leaves, and its expression was not induced by sulfur starvation or by O-acetylserine treatment. Having identified a fourth plastid-localized ATP sulfurylase, the origin of cytosolic isoform in A. thaliana remains unclear. Based on sequence analysis, it is hypothesized that APS2 may encode the cytosolic ATP sulfurylase.

Immunohistochemical localization of phospholipase D1 in rat central nervous system

Phospholipase D (PLD) is one of the intracellular signal transduction enzymes and plays an important role in a variety of cellular functions. We investigated the distribution of PLD isozyme, PLD1 in the rat brain and spinal cord using an immunological approach. Western blot analysis showed the presence of PLD1 protein in all tissues studied, with significantly higher levels in the brainstem and spinal cord, which was correlated with the results obtained from PLD activity assay. Prominent and specific signals of PLD1 were observed in many functionally diverse brain areas, including the olfactory bulb, medial septum-diagonal band complex, cerebral cortex, brainstem, cerebellum, and spinal cord. In the brainstem, the red nucleus, substantia nigra, interpeduncular nucleus, cranial motor nuclei (trigeminal motor, abducent, facial, and hypoglossal), sensory cranial nerve nuclei (spinal trigeminal, vestibular, and cochlear), as well as nuclei of the reticular formation, all showed intense immunoreactivity. Purkinje cells and deep cerebellar nuclei of the cerebellum were also labeled intensely. However, no significant labeling was found in the thalamus, epithalamus, and basal ganglia. Although many of the PLD1 immunoreactive cells were neurons, PLD1 was also expressed in glial cells such as presumed astrocytes and tanycytes. These findings suggest that PLD1 may play an important role in the central nervous system of the adult rat.

Growth hormone deficiency as the only identifiable cause for primary amenorrhea

Background: There is much evidence that growth hormone plays an important role in the development and function of the reproductive system of both males and females. Growth hormone exerts its effects on the ovarian follicular cycle directly or by local production of insulin-like growth factor 1 (IGF-1). It is known that growth hormone deficiency during childhood may delay pubertal development, but there is limited data about primary amenorrhea in GH-deficient girls with sufficient stimulated gonadotropin levels.Methods: Case series.Results: In the evaluation of primary amenorrhea and delayed puberty, 3 cases of adolescent females aged 17-19 years were identified as isolated GH-deficiency. Among the 3 patients, 2 had history of intracranial surgery due to hydrocephalus (shunt operation) or prolactin-secreting pituitary macro-adenoma (transphenoidal surgery, one year before). 17-year-old patient with shunted hydrocephalus and 19-year-old patient with primary amenorrhea showed short statue (< 5%) and delayed bone maturation. The patient undertaken transphenoidal surgery for prolactinoma showed normal height and bone maturation. There was no familial history of delayed puberty. On physical examination, 3 patients showed variable degree of breast development from Tanner stage II to IV without sex-steroid replacement. In sella MRI, small pituitary gland were identified in 2 patients with short statue and delayed bone maturation. All of the 3 patients underwent combined pituitary function test. After insulin-induced hypoglycemia, peak growth hormone levels of the 3 patients were 0.08, 1.4 and 1.4 ng/ml and were compatible with growth hormone deficiency. Peak LH after intravenous gonadrelin (FACTREL) were 19.0 to 56.1 mIU/ml and LH % responses were 217 to 1100% and were hence defined as not being gonadotropin deficiency. Other anterior pituitary functions were normal in all of the 3 patients.Conclusions: We found isolated growth hormone deficiency as the only identifiable cause for primary amenorrhea in three patients with sufficient gonadotropins secretion. These findings suggest a complementary role of GH to gonadotropins in the occurrence of menarche.

Effects of enzyme inducers and inhibitor on the pharmacokinetics of intravenous 2-(allylthio)pyrazine, a new chemoprotective agent, in rats

In order to find what types of hepatic cytochrome P450 (CYP) isozymes are involved in the metabolism of 2-(allylthio)pyrazine (2-AP) in rats, enzyme inducers, such as phenobarbital, 3-methylcholanthrene, dexamethasone, or isoniazid, and an enzyme inhibitor, such as SKF 525-A were pretreated. After 1-min intravenous administration of 2-AP, 50 mg/kg, to rats pretreated with SKF 525-A (a non-specific CYP inhibitor in rats), the plasma concentrations were significantly higher, and the area under plasma concentration-time curve from time zero to time infinity (AUC) was significantly greater (1365 compared with 1034 microg min/mL) as a result of significantly slower total body clearance (Cl) (36.6 compared with 48.3 mL/min/kg) than those in control rats, indicating that 2-AP was metabolized by CYP isozymes. After 1-min intravenous administration of 2-AP, 50 mg/kg, to rats pretreated with dexamethasone (an inducer of CYP3A in rats), phenobarbital (an inducer of CYP2B1/2, 2C6, 2C7, and 3A1/2 in rats), and 3-methylcholanthrene (an inducer of CYP1A1/2 and 2A1 in rats), the plasma concentrations were significantly lower, and AUC was significantly smaller (27, 41 and 60% decrease, respectively, compared with respective control rats) owing to faster Cl [37 (p>0.05), 70 (p<0.001), and 150% (p<0.001) increase, respectively, compared with respective control rats].

The motor cortex shows adaptive functional changes to brain injury from multiple sclerosis

Although multiple sclerosis (MS) is an inflammatory demyelinating disease, there can be substantial axonal injury and loss. We therefore hypothesized that adaptive cortical changes may contribute to limiting functional impairment, particularly in the early stages of the disease. To test our hypothesis, we used functional magnetic resonance imaging (MRI) to characterize the localization and volumes of activation in the motor cortex during simple flexion-extension finger movements. There were differences in the patterns of cortical activation with movement between the 12 MS patients and the 12 normal controls. All patients showed greater relative supplementary motor area activation than did the normal controls. The relative hemispheric lateralization of sensorimotor cortex (SMC) activation decreased in direct proportion to the total cerebral T2-weighted MRI hyperintense lesion load. This appeared to be due primarily to increases in ipsilateral SMC activation with increasing lesion load in white matter of the hemisphere contralateral to the limb moved. The center of activation in the contralateral SMC was shifted a mean of 8.8 mm posterior in patients relative to controls, providing additional evidence for cortical adaptive responses to injury. The magnitude of this posterior shift in the SMC activation increased with greater T2 lesion loads. These observations demonstrate that cortical recruitment for simple finger movements can change both quantitatively and qualitatively in the SMCs of MS patients, suggesting that cortical reorganization or "unmasking" of latent pathways can contribute to functional recovery. These adaptive changes are another factor potentially limiting the strength of the relationship between MRI measures of pathology and clinical measures of disability.

Apoptosis of primary-culture rat microglial cells induced by pathogenic Acanthamoeba spp

To determine whether trophozoites and lysates of pathogenic Acanthamoeba spp. induce apoptosis in primary-culture microglial cells, transmission electron microscopic (TEM) examinations, assessment of DNA fragmentation by agarose gel electrophoresis, and the TdT-mediated dUTP nick-end labeling assay were performed. When a trophozoite of pathogenic Acanthamoeba culbertsoni came in contact with a microglial cell, the digipodium was observed by TEM. Nuclear chromatin condensation was observed in 10% of microglial cells, while it was not revealed when they were cocultured with weakly pathogenic Acanthamoeba royreba trophozoites. DNA fragmentation in microglial cells cocultured with the A. culbertsoni lysate was detected by electrophoresis, showing DNA ladder formation, whereas it was hardly observed in microglial cells cocultured with A. royreba. DNA fragmentation of microglial cells was also confirmed by flow cytometry analysis. The fluorescence of TdT-stained apoptotic bodies became intensely visible with microglial cells cocultured with the A. culbertsoni lysate. In contrast, with microglial cells cocultured with the A. royreba lysate, only a background level of fluorescence of TdT-stained apoptotic bodies was detected. These results suggest that some rat microglial cells cocultured with pathogenic A. culbertsoni undergo cytopathic changes which show the characteristics of the apoptotic process, such as nuclear condensation and DNA fragmentation.

Pharmacokinetics and tissue distribution of ipriflavone, an isoflavone derivative, after intravenous administration to rabbits

Pharmacokinetic parameters of ipriflavone and its main metabolites, M1 and M5, after intravenous administration of spray-dried ipriflavone, SIP (10, 20, and 30 mg/kg as ipriflavone) and tissue distribution of ipriflavone, M1, and M5 after intravenous administration of SIP (20 mg/kg as ipriflavone) were evaluated in rabbits. Saturable metabolism of ipriflavone were observed after intravenous administration; at an ipriflavone dose of 30 mg/kg, the dose-normalized (based on 10 mg/kg) AUC was significantly greater (72.4 and 64.0 versus 103 microg min/mL), Cl was significantly slower (138 and 156 versus 97.6 mL/min/kg), and terminal half-life (94.8 and 129 versus 211 min) and mean residence time (91.3 and 116 versus 186 min) were significantly longer than those at 10 and 20 mg/kg. The AUC of M1 was also significantly greater at ipriflavone dose of 30 mg/kg. The terminal half-life, AUC, and renal clearance of M5 were also significantly different at ipriflavone dose of 30 mg/kg than those at 10 and 20 mg/kg. Ipriflavone was widely distributed in most rabbit tissues studied and the tissue-to-plasma (T/P) ratios of ipriflavone were greater than unity in all tissues (or organs) studied except spleen, indicating that ipriflavone has high affinity to rabbit tissues studied, and this could be supported by considerably high values of the apparent volume of distribution of ipriflavone at steady state (11 400-16 900 mL/kg). M1 and M5 were also detected in most rabbit tissues with considerable amount of M1 (T/P ratio of 9.43) and M5 (T/P ratio of 4.66) in the kidney.

The efficacy of pentoxifylline as an anti-inflammatory agent in experimental Escherichia coli meningitis in the newborn piglet

This study was done to evaluate the anti-inflammatory effect and the ensuing neuroprotective effect of pentoxifylline in neonatal experimental bacterial meningitis. Newborn piglets were divided into three groups: 10 in the control group (CG), 13 in the meningitis group (MG), and 13 in the meningitis with pentoxifylline group (PG). Meningitis was induced by intracisternal injection of 10(8) colony-forming units of Escherichia coli in 100 microl of saline. In PG, 20 mg/kg of pentoxifylline was given as a bolus intravenous injection 30 min before induction of meningitis and 6 mg/kg/h was given continuously throughout the experiment. In PG, the increase of CSF TNF-alpha level observed in MG was abolished. Reduced brain glucose and ATP concentrations observed in MG were significantly increased in PG. However, other parameters of inflammatory responses such as increased intracranial pressure, reduced glucose and increased lactate concentrations in the CSF observed in MG were not significantly down-modulated. The extent of CSF leukocytosis was even higher in PG than in MG. Increased cerebral cortical cell membrane lipid peroxidation products and decreased Na(+),K(+)-ATPase activity observed in MG, indicative of meningitis-induced brain cell membrane dysfunction, tended to improve without statistical significance in PG. In summary, although some anti-inflammatory effects have been observed, the overall anti-inflammatory effects of pentoxifylline was very weak, and it failed to significantly reduce the brain damage in experimental neonatal bacterial meningitis.

Utilization of parenteral nutrition in patients receiving peripheral blood stem cell transplantation

A paucity of information is available on the use of parenteral nutrition (PN) in patients undergoing peripheral blood stem cell transplantation (PBSCT). To characterize the utilization of PN in patients undergoing PBSCT, we conducted a retrospective chart review study on adult patients receiving autologous and allogeneic PBSCT. Data collection included nutritional parameters such as indications for PN, days of PN administration, and PN-associated complications (i.e., metabolic, infectious, and mechanical). Outcome parameters assessed included length of hospitalization, days to engraftment, graft versus host disease (GVHD), and veno-occlusive disease (VOD). A total of twenty-one consecutive patients were evaluated with 12 receiving allogeneic PBSCT and 9 receiving autologous PBSCT. The allogeneic group received PN for a mean of 25 days compared to 21 days for the autologous group. The rate of metabolic abnormalities was significantly higher in the allogeneic group compared to the autologous group (1.02 abnormalities/PN days vs 0.61 abnormalities/PN day, p < 0.05), but mechanical and infectious complications were similar between the two groups. Length of hospitalization, days to engraftment, incidence of GVHD and VOD did not differ significantly between the two groups. However, mortality prior to discharge was significantly higher in the allogeneic vs autologous group (58% vs 0%, p < 0.05). We conclude that allogeneic PBSCT patients appear to be at a greater risk for metabolic complications while receiving PN as compared to autologous PBSCT patients. As nausea and vomiting are two primary reasons for initiation of PN in this patient population, further studies of aggressive antiemetic therapy may prove to decrease the need for PN in PBSCT patients.

Direct and indirect costs associated with the onset of seropositive rheumatoid arthritis. Western Consortium of Practicing Rheumatologists

OBJECTIVE

To examine the direct and indirect costs of rheumatoid arthritis (RA) during the first year of disease.

METHODS

As part of a longitudinal observational study, 150 patients with seropositive RA of 5.9 +/- 2.9 mo duration were recruited through the Western Consortium of Practicing Rheumatologists. Subjects completed questionnaires about health care services and resources utilized and about the number of days of usual activity lost as a result of RA during the 6 month period prior to enrolment.

RESULTS

Study participants had active RA as evidenced by mean tender and swollen joint counts of 24.9 +/- 13.5 and 20.6 +/- 11.6, respectively, and moderate functional impairment reflected by a mean Health Assessment Questionnaire (HAQ) score of 1.24 +/- 0.7. The average total direct cost of RA was $200/month. Health care visits, medications, and radiographs accounted for 78% of the total direct cost, while expenditures for hospitalizations accounted for only 3.5% of the total. The average number of days of usual activity lost per month because of RA was 3.8 +/- 7.7, translating into an average indirect cost of $281/month. Of the 95 subjects who were gainfully employed prior to disease onset, 12 were disabled and 5 were on sick leave as a result of RA, corresponding to a work disability rate of 18%. Work disabled subjects reported significantly lower total household incomes and higher HAQ disability and global disease activity scores than subjects who continued working.

CONCLUSION

In this group of patients with seropositive RA substantial costs, both direct and indirect, were incurred during the first year of disease.

Immune deviation and Fas-mediated deletion limit antitumor activity after multiple dendritic cell vaccinations in mice

Genetic immunization with a single injection of dendritic cells (DCs) expressing a model melanoma antigen generates antigen-specific, MHC-restricted, protective immune responses. After initiating the immune response, additional vaccinations may increase the protection or conversely downregulate the immune response. Groups of mice were vaccinated several times with DCs transduced with the MART-1 gene, and the anti-tumor protection was compared with that of mice receiving a single vaccination. C3H mice had poorer protection from a syngeneic MART-1-expressing tumor challenge with multiple vaccinations. This was accompanied by lower levels of splenic CTL effectors and a shift from a type 1 to a type 2 cytokine profile. On the contrary, multiple vaccinations in C57BL/6 mice generated greater in vivo antitumor protection with no decrease in splenic CTLs and no cytokine shift. Antiadenoviral humoral or cellular immune responses did not seem to contribute to these effects. When studies were performed in Fas receptor-negative C3H.(lpr) mice, the adverse effect of multiple vaccinations disappeared, and there was no cytokine shift pattern. In conclusion, C3H mice but not C57BL/6 mice receiving multiple vaccinations with DCs expressing the MART-1 tumor antigen show decreased protection associated with deviation from a type 1 to a type 2 cytokine response attributable to a Fas-receptor mediated clearance of antigen-specific IFN-gamma-producing cells.

A phase I trial of solubilized DR2:MBP84-102 (AG284) in multiple sclerosis

OBJECTIVE

To assess the safety, tolerability, and biologic and clinical activity of a solubilized complex comprised of human leukocyte antigen-DR2 with myelin basic protein84-102 (AG284)in patients with secondary progressive MS.

BACKGROUND

Soluble species-specific major histocompatibility complex myelin basic protein91-103 complexes ameliorate disease in a dose-dependent manner when administered to SJL/J mice with chronic relapsing experimental allergic encephalomyelitis. Preincubation with AG284 reduces the proliferative response of a DR2-restricted, myelin basic protein84-102-reactive T cell clone, derived from a MS patient, to myelin basic protein84-102 in the presence of autologous antigen-presenting cells.

METHODS

Thirty-three patients with secondary progressive MS were randomly assigned to receive three alternate day IV doses of AG284 or placebo in a double-masked dose escalation study. The primary outcome was safety and tolerability. Secondary outcomes included a comparison of pre- and post-treatment gadolinium-enhanced brain MRI activity, Kurtzke Expanded Disability Status Scale, and Nine Hole Peg Test scores.

RESULTS

The frequency of adverse events was similar in the AG284 and placebo recipients. No significant treatment effect was detected by Expanded Disability Status Scale, Nine Hole Peg Test, or number of new gadolinium-enhancing MRI lesions.

CONCLUSIONS

AG284 as administered during this study was safe and well tolerated. Further studies are warranted to determine the biologic activity and clinical efficacy of this potential treatment for MS.

Comparison of vignettes, standardized patients, and chart abstraction: a prospective validation study of 3 methods for measuring quality

CONTEXT

Better health care quality is a universal goal, yet measuring quality has proven to be difficult and problematic. A central problem has been isolating physician practices from other effects of the health care system.

OBJECTIVE

To validate clinical vignettes as a method for measuring the competence of physicians and the quality of their actual practice.

DESIGN

Prospective trial conducted in 1997 comparing 3 methods for measuring the quality of care for 4 common outpatient conditions: (1) structured reports by standardized patients (SPs), trained actors who presented unannounced to physicians' clinics (the gold standard); (2) abstraction of medical records for those same visits; and (3) physicians' responses to clinical vignettes that exactly corresponded to the SPs' presentations. Setting Outpatient primary care clinics at 2 Veterans Affairs medical centers.

PARTICIPANTS

Ninety-eight (97%) of 101 general internal medicine staff physicians, faculty, and second- and third-year residents consented to be randomized for the study. From this group, 10 physicians at each site were randomly selected for inclusion.

MAIN OUTCOME MEASURES

A total of 160 quality scores (8 cases x 20 physicians) were generated for each method using identical explicit criteria based on national guidelines and local expert panels. Scores were defined as the percentage of process criteria correctly met and were compared among the 3 methods.

RESULTS

The quality of care, as measured by all 3 methods, ranged from 76.2% (SPs) to 71.0% (vignettes) to 65.6% (chart abstraction). Measuring quality using vignettes consistently produced scores closer to the gold standard of SP scores than using chart abstraction. This pattern was robust when the scores were disaggregated by the 4 conditions (P<.001 to <.05), by case complexity (P<.001), by site (P<.001), and by level of physician training (P values from <.001 to <.05). The pattern persisted, although less dominantly, when we assessed the component domains of the clinical encounter--history, physical examination, diagnosis, and treatment. Vignettes were responsive to expected directions of variation in quality between sites and levels of training. The vignette responses did not appear to be sensitive to physicians' having seen an SP presenting with the same case.

CONCLUSIONS

Our data indicate that quality of health care can be measured in an outpatient setting by using clinical vignettes. Vignettes appear to be a valid and comprehensive method that directly focuses on the process of care provided in actual clinical practice. Vignettes show promise as an inexpensive case-mix adjusted method for measuring the quality of care provided by a group of physicians.

2-Acetylaminofluorene suppresses immune response through the inhibition of nuclear factor-kappaB activation during the early stage of B cell development

2-Acetylaminofluorene (AAF), an arylamide carcinogen, has been known to inhibit humoral and cell-mediated immune response by lipopolysaccharide (LPS). In the current study we demonstrate that AAF induced the down-regulation of protein kinase C (PKC) that is a key enzyme in the pathways leading to LPS-induced B-cell proliferation, while having no inhibitory effect on intracellular cAMP in spleen cells. Additionally, to identify the mechanism of action of AAF during B-cell development, we determined the effects of AAF on LPS-induced nuclear factor-kappaB (NF-kappaB) activation in 70Z/3 murine pre-B cells, CH12 murine mature B cells and S194 murine plasmacytoma cells. LPS-induced NF-kappaB activation, which is dependent on PKC, was inhibited by pretreatment with AAF for 2 h in the nuclei of 70Z/3 murine pre-B cells by detection of NF-kappaB specific DNA-protein binding. Conversely, AAF barely inhibited the constitutive NF-kappaB binding activity in mature B-cells, S194 and CH12. To confirm the effect of AAF on NF-kappaB activation, a chloramphenicol acetyl transferase (CAT) expression vector containing multiple copies of the NF-kappaB element (pCAT(kappaB)(3)) was transiently transfected into 70Z/3 or S194 cells, and assessed for inducible CAT activity. AAF treatment of 70Z/3 cells resulted in a significant inhibition of CAT activity induced by LPS. However, AAF exhibited no inhibitory effect on constitutive CAT activity in mature B cells, S194, indicating that AAF no longer has suppressive effects on the immune response in differentiated B cells. Taken together, these results suggest that AAF may act to suppress immune response by blocking the activation of PKC and nuclear expression of NF-kappaB at the early stage of B cell development.

Hippuryl-alpha-methylphenylalanine and hippuryl-alpha-methylphenyllactic acid as substrates for carboxypeptidase A. Syntheses, kinetic evaluation and mechanistic implication

(R)- and (S)-Hippuryl-alpha-methylphenylalanine [(R)- and (S)-Hipp-alpha-MePhe] and (S)-hippuryl-alpha-methylphenyllactic acid [(S)-Hipp-alpha-MeOPhe] were synthesized and evaluated as substrates for carboxypeptidase A (CPA) in an effort to shed further light on the catalytic mechanism of the enzyme. The rate of CPA-catalyzed hydrolysis of (S)-Hipp-alpha-MePhe was reduced by 105-fold compared with that of (S)-Hipp-Phe, but the hydrolysis rate of (S)-Hipp-OPhe was lowered by only 6.8-fold by the introduction of a methyl group at the alpha-position. (R)-Hipp-alpha-MePhe failed to be hydrolyzed initially, then started to undergo hydrolysis in about 2 h at a much reduced rate. The results of present study may be envisioned on the basis of the proposition that while peptide substrate is hydrolyzed via a tetrahedral transition state formed by the attack of the zinc-bound water molecule at the peptide carbonyl carbon, ester hydrolysis takes the path that involves an anhydride intermediate generated by the attack of the carboxylate of Glu-270 at the ester carbonyl carbon.

Sources of phytoestrogen exposure among non-Asian women in California, USA

OBJECTIVE

We recently described the development of a comprehensive database for assessing phytoestrogen exposure in epidemiologic studies. This paper describes the first application of this database and the primary sources of phytoestrogen consumption in non-Asian women.

METHODS

Four hundred and forty-seven randomly selected African-American, Latina, and white women, ages 50-79 years, residing in California's San Francisco Bay Area and participating as controls in an ongoing population-based case-control study of breast cancer, were included in the present analysis. Average daily consumption of each of seven phytoestrogenic compounds was determined for each woman by combining the values from the new database with food consumption reported on a food-frequency questionnaire.

RESULTS

Phytoestrogens in the non-Asian Bay Area diet appear to come primarily from: (1) traditional soy-based foods (e.g. tofu and soy milk); (2) "hidden" sources of soy (e.g. foods containing added soy protein isolate, soy concentrate, or soy flour, e.g. many brands of doughnuts and white bread); and (3) a variety of foods which contain only low to moderate amounts of phytoestrogens per 100 grams but which are frequently consumed (e.g. coffee and orange juice).

CONCLUSIONS

In the absence of a comprehensive assessment of various phytoestrogens in a wide variety of foods, epidemiologic studies could suffer from the effects of uncontrolled confounding by unmeasured sources of phytoestrogen exposure potentially leading to biased estimates of effect and misinterpretation of findings.