Encephalitogenicity of murine, but not bovine, DM20 in SJL mice is due to a single amino acid difference in the immunodominant encephalitogenic epitope

Myelin proteolipid protein (PLP) contains 2 immunodominant encephalitogenic epitopes in SJL mice, namely PLP residues 139-151 and 178-191. DM20, a minor isoform of PLP, lacks residues 116-150 and consequently contains only the single major encephalitogenic epitope 178-191. However, it has been found previously that bovine DM20 is not encephalitogenic in SJL mice. Since residue 188 within peptide 178-191 is phenylalanine (F) in murine DM20 and alanine (A) in bovine DM20, we tested the effect of this difference on the immune responses and induction of EAE. SJL mice were immunized with either highly purified murine or bovine DM20. Residues 178-191 were found to be immunodominant for each, but only murine and not bovine DM20 was encephalitogenic. A synthetic peptide corresponding to the murine 178-191 sequence (F188) was also encephalitogenic, whereas the peptide corresponding to the bovine sequence (A188) was not. Both F188 and A188 bind with high affinity to I-A(s) and both are recognized by the SJL T cell repertoire. A188-specific T cell lines reacted to both A188 and F188, but F188-specific T cell lines were not stimulated by A188. F188-specific T cell lines produced mRNA for the Th1 cytokines IL2 and IFN gamma and, in passive transfer experiments, were encephalitogenic upon stimulation with F188, but not A188. In contrast, A188-specific T cell lines produced mRNA for IL4, IL5 and IL10, in addition to IL2 and IFN gamma, and were not encephalitogenic after stimulation with either F188 or A188. Cotransfer of A188-specific T cell lines with F188-specific T cell lines resulted in protection from EAE. Thus, A188 induces a functionally different phenotype of T cells from that induced by F188. Taken together these data suggest that the failure of bovine DM20 to induce EAE may be attributable to induction of protective rather than pathogenic T cells by the immunodominant epitope.

Lipid content and fatty acid composition of 11 species of Queensland (Australia) fish

The fatty acid composition of 11 species of fish caught off the northeast coast of Australia was determined. No fatty acid profiles have been previously published for fish from this area nor for nine of these species. Although the percentage of polyunsaturated fatty acid (PU FA) was the same as the calculated average for Australian fish (42.3%), the percentage of n-3 fatty acids was lower (24.4 +/- 5.4% vs. 30.7 +/- 10.1%) and the n-6 fatty acids higher (16.5 +/- 4.5% vs. 11.2 +/- 5.9%), P < 0.001 in each case. The major n-3 PUFA were docosahexaenoic (15.6 +/- 6.3%) and eicosapentaenoic acid (4.3 +/- 1.1%) while the major n-6 PUFA were arachidonic (8.3 +/- 3.2%) and n-6 docosatetraenoic acid (3.1 +/- 1.3%). The second-most abundant class of fatty acid was the saturates (31.6 +/- 3.5%) while the monounsaturates accounted for 17.4 +/- 4.3% of the total fatty acids. The monounsaturate with the highest concentration was octadecenoic acid (11.8 +/- 2.6%). There was a positive correlation between the total lipid content and saturated and monounsaturated fatty acids (r = 0.675 and 0.567, respectively) and a negative correlation between the total lipid content and PUFA(r = 0.774).

Immediate early gene expression and delayed cell death in limbic areas of the rat brain after kainic acid treatment and recovery in the cold

Systemic injection of kainic acid (KA) results in characteristic behaviors and programmed cell death in some regions of the rat brain. We used KA followed by recovery at 4 degrees C to restrict damage to limbic structures and compared patterns of immediate early gene (IEG) expression and associated DNA binding activity in these damaged areas with that in spared brain regions. Male Wistar rats were injected with BA (12 mg/kg, ip) and kept at 4 degrees C for 5 h. This treatment reduced the severity of behaviors and restricted damage (observed by Nissl staining) to the CA1 and CA3 regions of the hippocampus and an area including the entorhinal cortex. DNA laddering, characteristic of apoptosis, was first evident in the hippocampus and the entorhinal cortex 18 and 22 h after RA, respectively. The pattern of IEG mRNA induction fell into three classes: IEGs that were induced in both damaged and spared areas (c-fos, fos B, jun B, and egr-1), IEGs that were induced specifically in the damaged areas (fra-2 and c-jun), and an IEG that was significantly induced by saline injection and/or the cold treatment (jun D). The pattern of immunoreactivity closely followed that of mRNA expression. Binding to the AP-1 and EGR DNA consensus sequences increased in all three regions studied. This study describes a unique modification of the animal model of ICA-induced neurotoxicity which may prove a useful tool for dissecting the molecular cascade that ultimately results in programmed cell death. (C) 1997 Academic Press.

Synthesis, identification, characterization, stability, solubility, and protein binding of ester derivatives of salicylic acid and diflunisal

O-Acyl esters were prepared from salicylic acid and diflunisal by esterification with the appropriate acyl anhydride (in the presence of sulfuric acid at 80 degrees C) or acyl chloride (in the presence of pyridine at 0 degrees C). Synthesis, identification and characterization of these compounds is described. In vitro hydrolysis, solubility and protein binding studies of these O-acyl esters were performed. For the diflunisal esters, the melting points fell as the side chain was increased from ethyl to pentyl. The melting points showed no significant difference as the length of the side chain was increased from pentyl to heptyl. The aspirin analogues showed a similar trend, The relationship between solubility and carbon chain length agreed closely with that for the melting points with carbon chain length. In vitro non-enzymatic hydrolysis studies concluded that: (1) hydrolysis rate constants generally decreased with carbon chain length; (2) the diflunisal esters have shorter half lives compared with their salicylate counterparts; and (3) the in vitro hydrolysis of these compounds was retarded by the presence of bovine serum albumin. Protein binding experiments showed that the strength of binding of the aspirin and diflunisal analogues to bovine serum albumin increased with carbon chain length. (C) 1997 Elsevier Science B.V.

Potential GABAB receptor antagonists .9. The synthesis of 3-amino-3-(4-chlorophenyl)propanoic acid, 2-amino-2-(4-chlorophenyl)ethylphosphonic acid and 2-amino-2-(4-chlorophenyl)ethanesulfonic acid

This paper describes the synthesis of 3-amino-3-(4-chlorophenyl)propanoic acid and the corresponding phosphonic and sulfonic acids, lower homologues of baclofen, phaclofen and saclofen respectively. The chlorinated acids were all weak specific antagonists of GABA at the GABAB receptor, with the sulfonic acid (pA(2) 4.0) being stronger than the phosphonic acid (pA(2) 3.8) and carboxylic acid (pA(2) 3.5).

Macrocycle formation through carbon acid-formaldehyde condensation reactions of bis(propane-1,2-diamine)- and bis (2-methylpropane-1,2-diamine)-copper(II) ions

The reaction of the bis(1,2-diamine) copper(II) complexes of racemic propane-1,2-diamine (pn) and 2-methylpropane-1,2-diamine (dmen) with formaldehyde and nitroethane in methanol under basic conditions yields minor macrocyclic condensation products in addition to the major acyclic products. Where C-pendant methyl groups on the pair of coordinated diamines are in cis dispositions, the first -NH-CH2-C(CH3)(NO2)-CH2-NH- ring formation occurs at amine pairs distant from these C-methyl substituents, and further reaction to yield a macrocycle is not observed. However, where the C-methyl substituents are in trans dispositions, the chemistry proceeds to yield the macrocycle. Commencing with pn, trans-(6,13-diammonio-2,6,9,13-tetramethyl-1,4,7,10-tetraazacyclotetradecane)copper(II) perchlorate formed and crystallized in the space group P2(1)/n, with a 9.782(2), b 9.2794(6), c 17.017(4) Angstrom, beta 103.24(1)degrees. The copper ion is found in a square-planar environment, with the two methyl groups of the pn residues and the pairs of introduced pendant groups all in trans arrangements.

Preoperative Gastric Acid Secretion and the Risk to Develop Barrett`s Esophagus After Esophagectomy for Chagasic Achalasia

The aim of this study was to determine the contribution of preoperative gastric secretory and hormonal response, to the appearance of Barrett`s esophagus in the esophageal stump following subtotal esophagectomy. Thirty-eight end-stage chagasic achalasia patients submitted to esophagectomy and cervical gastric pull-up were followed prospectively for a mean of 13.6 +/- 9.2 years. Gastric acid secretion, pepsinogen, and gastrin were measured preoperatively in 14 patients who have developed Barrett`s esophagus (Group I), and the results were compared to 24 patients who did not develop Barrett`s esophagus (Group II). In the group (I), the mean basal and stimulated preoperative gastric acid secretion was significantly higher than in the group II (basal: 1.52 vs. 1.01, p = 0.04; stimulated: 20.83 vs. 12.60, p = 0.01). Basal and stimulated preoperative pepsinogen were also increased at the Group I compared to Group II (Basal = 139.3 vs. 101.7, p = 0.02; stimulated = 186.0 vs. 156.5, p = 0.07. There was no difference in preoperative gastrin between the two groups. Gastritis was present during endoscopy in 57.1% of the Group I, while it was detected in 16.6% of the Group II, p = 0.014. Barrett`s esophagus in the esophageal stump was associated to high preoperative levels of gastric acid secretion, serum pepsinogen, and also gastritis in the transposed stomach.

The rms1 mutant of pea has elevated indole-3-acetic acid levels and reduced root-sap zeatin riboside content but increased branching controlled by graft-transmissible signal(s)

Rms1 is one of the series of five ramosus loci in pea (Pisum sativum L.) in which recessive mutant alleles confer increased branching at basal and aerial vegetative nodes. Shoots of the nonallelic rms1 and rms2 mutants are phenotypically similar in most respects. However, we found an up to 40-fold difference in root-sap zeatin riboside ([9R]Z) concentration between rms1 and rms2 plants. Compared with wild-type (WT) plants, the concentration of [9R]Z in rms1 root sap was very low and the concentration in rms2 root sap was slightly elevated. To our knowledge, the rms1 mutant is therefore the second ramosus mutant (rms4 being the first) to be characterized with low root-sap [9R]Z content. Like rms2, the apical bud and upper nodes of rms1 plants contain elevated indole-3-acetic acid levels compared with WT shoots. Therefore, the rms1 mutant demonstrates that high shoot auxin levels and low root-sap cytokinin levels are not necessarily correlated with increased apical dominance in pea. A graft-transmissible basis of action has been demonstrated for both mutants from reciprocal grafts between mutant and WT plants. Branching was also largely inhibited in rms1 shoots when grafted to rms2 rootstocks, but was not inhibited in rms2 shoots grafted to rms1 rootstocks. These grafting results are discussed, along with the conclusion that hormone-like signals other than auxin and cytokinin are also involved.

Differences Between ""Classical"" Risk Factors for Infections Caused by Methicillin-Resistant Staphylococcus aureus (MRSA) and Risk Factors for Nosocomial Bloodstream Infections Caused by Multiple Clones of the Staphylococcal Cassette Chromosome mec Type IV MRSA Strain

OBJECTIVE. To identify risk factors associated with nosocomial bloodstream infections caused by multiple clones of the staphylococcal cassette chromosome mec (SCCmec) type IV strain of methicillin-resistant Staphylococcus aureus (MRSA). DESIGN. An unmatched case-control study (at a ratio of 1 : 2) performed during the period from October 2002 through September 2003. SETTING. A 2,000-bed tertiary care teaching hospital affiliated with the University of Sao Paulo in Sao Paulo, Brazil. METHODS. Case patients (n = 30) were defined either as patients who had a bloodstream infection due to SCCmec type IV strains of MRSA diagnosed at least 48 hours after hospital admission or as neonates with the infection who were born in the hospital. Control patients (n = 60) were defined as patients with SCCmec type III MRSA infection diagnosed at least 48 hours after hospital admission. Genes n = 60 encoding virulence factors were studied in the isolates recovered from case patients, and molecular typing of the SCCmec type IV MRSA isolates was also done by pulsed-field gel electrophoresis and multilocus sequence typing. RESULTS. In multivariate analysis, the following 3 variables were significantly associated with having a nosocomial bloodstream infection caused by SCCmec type IV strains of MRSA: an age of less than 1 year, less frequent use of a central venous catheter (odds ratio [OR], 0.07 [95% confidence interval {CI}, 0.02-0.28]; P = .001), and female sex. A second analysis was performed that excluded the case and Pp. 001 control patients from the neonatal unit, and, in multivariate analysis, the following variables were significantly associated with having a nosocomial bloodstream infection caused by SCCmec type IV strains of MRSA: less frequent use of a central venous catheter (OR, 0.12 [95% CI, 0.03-0.55]; P = .007), lower Acute Physiology and Chronic Health Evaluation II score on admission (OR, 0.14 [95% CI, 0.03-0.61];), less frequent surgery (OR, 0.21 [95% CI, 0.06-0.83];), and female sex (OR, 5.70 [95% CI, 1.32-24.66]; P =.020). P = .009 Pp. 025 Pp). Of the 29 SCCmec type IV MRSA isolates recovered from case patients, none contained the Panton-Valentine leukocidin, gamma-hemolysin, enterotoxin B or C, or toxic shock syndrome toxin-1. All of the isolates contained genes for the LukE-LukD leukocidin and alpha-hemolysin. Genes for enterotoxin A were present in 1 isolate, and genes for beta-hemolysin were present in 3 isolates. CONCLUSIONS. ""Classical"" risk factors do not apply to patients infected with the SCCmec type IV strain of MRSA, which is an important cause of nosocomial bacteremia. This strain infects a patient population that is less ill and has had less frequent invasive procedures than a patient population infected with the multidrug-resistant strain of SCCmec type III MRSA. We found that virulence factors were rare and that Panton-Valentine leukocidin was absent. There were multiple clones of the SCCmec type IV strain in our hospital. Children under 1 year of age were at a higher risk. There was a predominant clone ( sequence type 5) in this patient population.

Characterization of Leishmania (Leishmania) amazonensis promastigotes resistant to pentamidine

Pentamidine is a second-line agent used in the treatment of leishmaniasis and its mode of action and mechanism of resistance is not well understood. It was previously demonstrated that transfection of promastigotes and amastigotes with the ABC transporter PRP1 gene confers resistance to pentamidine. To further clarify this point, we generated Leishmania amazonensis mutants resistant to pentamidine. Our results indicated that this ABC transporter is not associated with pentamidine resistance in lines generated by drug pressure through amplification or overexpression mechanisms of PRP1 gene. (C) 2008 Elsevier Inc. All rights reserved.

Ampicillin/sulbactam compared with polymyxins for the treatment of infections caused by carbapenem-resistant Acinetobacter spp.

Background: There has been an increase in worldwide infections caused by carbapenem-resistant Acinetobacter. This poses a therapeutic challenge as few treatment options are available. Objectives: The aim of this study was to evaluate the efficacy and safety of polymyxins and ampicillin/sulbactam for treating infections caused by carbapenem-resistant Acinetobacter spp. and to evaluate prognostic factors. Methods: This was a retrospective review of patients from two teaching hospitals who had nosocomial infections caused by carbapenem-resistant Acinetobacter spp. from 1996 to 2004. Diagnosis of infection was based on CDC criteria plus the isolation of Acinetobacter from a usually sterile site or from bronchoalveolar lavage. Urinary tract infections were not included. Data on demographic and clinical features and treatment were collected from medical records. Prognostic factors associated with two outcomes (mortality during treatment and in-hospital mortality) were evaluated. Results: Eighty-two patients received polymyxins and 85 were treated with ampicillin/sulbactam. Multiple logistic regression analysis revealed that independent predictors of mortality during treatment were treatment with polymyxins, higher Acute Physiological and Chronic Health Evaluation II (APACHE II) score, septic shock, delay in starting treatment and renal failure. On multivariate analysis, prognostic factors for in-hospital mortality were older age, septic shock and higher APACHE II score. Conclusions: This is the first study comparing current therapeutic options for infections due to carbapenem-resistant Acinetobacter. The most important finding of the present study is that ampicillin/sulbactam appears to be more efficacious than polymyxins, which was an independent factor associated with mortality during treatment.

Outbreak of vancomycin-resistant enterococci in a tertiary hospital: The lack of effect of measures directed mainly by surveillance cultures and differences in response between Enterococcus faecium and Enterococcus faecalis

To describe the effect of active surveillance to control vancomycin-resistant enterococci (VRE) after an outbreak, 549 surveillance rectal cultures were performed in 308 patients (35% positive). An educational intervention to prevent transmission was implemented. Infection and colonization by VR-Enterococcus faecalis decreased, but Enterococcus faecium persisted despite control measures. Infections by VR-E faecalis fell to zero in 2008. We observed difficulties in controlling colonization with measures directed mainly by surveillance cultures and differences between responses of E faecium and E faecalis.

Development of an animal model for endometrial ablation using trichloroacetic acid

Objective: To develop an animal model of endometrial ablation, and to evaluate the histologic effects of trichloroacetic acid (TCA) in the uterine cavity. Design: Experimental prospective. Setting: Department of gynecology. Patient(s): Thirty female adult rats. Intervention(s): Animals were submitted to injection of TCA in one uterine horn and saline solution in the other. Group 1 was sacrificed the day after the procedure. Group 2 was sacrificed in phase of diestrus. Superficial epithelia of the endometrium, stromal thickness, endometrial glands, and myometrium thickness were compared among the uterine horns of the same rats of group 1. The same evaluation was performed in group 2. Endometrial regeneration was evaluated. Main Outcome Measure(s): Histologic effects. Result(s): In group 1, histologic parameters showed endometrial destruction on TCA injected uterine horn. In group 2, four rats died after the procedure, and six rats had no viable material. In the rest of the group, TCA-injected uterine horns showed endometrial destruction. Superficial epithelia of the endometrium and stromal thickness were similar between TCA uterine horn from groups. However, the number of endometrial glands was higher in group 1. Conclusion(s): The study developed an experimental model for endometrial ablation. TCA acid is a potent agent for endometrial ablation in rat model. No endometrial regeneration was observed after recovery of cycle. (Fertil Steril (R) 2011; 95: 2418-21. (C) 2011 by American Society for Reproductive Medicine.)