Prompt fragmentation of disulfide-linked peptides during matrix-assisted laser desorption ionization mass spectrometry

During the analysis of an Asp-N digest of a recombinant hematopoietic growth factor by matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS), we observed pseudomolecular ions corresponding to reduced forms of peptides known to be present only in single disulfide linkages. Chromatographic fractionation of the peptide digest, followed by MALDI-MS and electrospray ionization (ESI) MS, confirmed that the reduced peptides were not present in the map. Fragmentation of the disulfide-linked peptides into their reduced forms occurred upon ionization from different matrices (alpha-cyano-4-hydroxycinnamic acid,2,5-dihydroxybenzoic acid, and in some instances sinapinic acid) but only after increasing the laser fluence to above threshold. Analysis of the disulfide-linked peptide fractions by ESI-MS, before and after mixing and drying with matrix, indicated that the matrix did not cause reduction. In a low-energy tandem mass spectrometric experiment with one of the cystinyl peptides, fragmentation did not occur preferentially at the disulfide bond. The pseudomolecular ions exhibited the same m/z values by MALDI-MS as their chemically reduced counterparts, indicating that they arose due to prompt fragmentation or "in-source decay" rather than "post-source decay". This finding is important for MALDI-MS analysis of peptide maps of proteins and peptide fractions with intact disulfides.     

Human behavioral flexibility: a psychogenetic study

Forty-seven two-children families from Moscow were used in a study to assess genetic determination of behavior flexibility, which was measured by eight laboratory tests. Flexibility is regarded as a temperament trait. There was no age- or sex-specific differentiation of human behavioral flexibility. Genetic determination of indices was used as a criterion for construct validization of flexibility tests. Factor analysis produced two principal components of flexibility: "operational flexibility" and "afferent flexibility." The study showed that a considerable part of the phenotypic variability of the flexibility indices included in different factors is under approximately equal genetic control. The flexibility factors differ in their genetic determination. In the inheritance of the first factor the leading role belongs to the additive component, whereas the dominance effects are more prominent in the second factor of flexibility.     

Differential DNA Methylation in Prostate Tumors from Puerto Rican Men

In 2020, approximately 191,930 new prostate cancer (PCa) cases are estimated in the United States (US). Hispanic/Latinos (H/L) are the second largest racial/ethnic group in the US. This study aims to assess methylation patterns between aggressive and indolent PCa including DNA repair genes along with ancestry proportions. Prostate tumors classified as aggressive (n = 11) and indolent (n = 13) on the basis of the Gleason score were collected. Tumor and adjacent normal tissue were annotated on H&E (Haemotoxylin and Eosin) slides and extracted by macro-dissection. Methylation patterns were assessed using the Illumina 850K DNA methylation platform. Raw data were processed using the Bioconductor package. Global ancestry proportions were estimated using ADMIXTURE (k = 3). One hundred eight genes including AOX1 were differentially methylated in tumor samples. Regarding the PCa aggressiveness, six hypermethylated genes (RREB1, FAM71F2, JMJD1C, COL5A3, RAE1, and GABRQ) and 11 hypomethylated genes (COL9A2, FAM179A, SLC17A2, PDE10A, PLEKHS1, TNNI2, OR51A4, RNF169, SPNS2, ADAMTSL5, and CYP4F12) were identified. Two significant differentially methylated DNA repair genes, JMJD1C and RNF169, were found. Ancestry proportion results for African, European, and Indigenous American were 24.1%, 64.2%, and 11.7%, respectively. The identification of DNA methylation patterns related to PCa in H/L men along with specific patterns related to aggressiveness and DNA repair constitutes a pivotal effort for the understanding of PCa in this population.     

Development and population study of an eight-locus short tandem repeat (STR) multiplex system

Amplification of short tandem repeat (STR) loci has become a useful tool for human identification applications. To improve throughput and efficiency for such uses, the polymorphic STR loci CSF1PO, TPOX, TH01, vWA, D16S539, D7S820, D13S317, D5S818, F13A01, FESFPS, F13B, and LPL have been evaluated, developed, and configured into fluorescently labeled multiplex systems. Eight of these STR loci were combined to generate the PowerPlex System, a two-color multiplex system that supports rapid, accurate, reliable analysis and designation of alleles. The remaining four loci comprise the FFFL System, a one-color multiplex system. The PowerPlex System may be evaluated alternatively as two one-color, four-locus multiplex systems, CTTv Multiplex and GammaSTR Multiplex. The products of multiplex amplification may be analyzed with a variety of fluorescence detection instruments. Determination of genotypes of over 200 individuals from each of three different population/ethnic groups revealed independence of inheritance of the loci and allowed calculation of matching probability, typical paternity index, and power of exclusion for each multiplex.     

Expression of receptors for C5a anaphylatoxin (CD88) on human bronchial epithelial cells: enhancement of C5a-mediated release of IL-8 upon exposure to cigarette smoke

Results are presented that demonstrate a heightened responsiveness of human bronchial epithelial cells (HBECs) toward the complement-derived anaphylatoxin C5a when these cells are exposed to cigarette smoke. This C5a response is possible because we show at both the protein and mRNA levels that HBECs constitutively express receptors for C5a (C5aR, CD88). Control (untreated) HBECs responded to C5a (50 nM) by releasing the proinflammatory cytokine IL-8 at low but significant levels. However, exposure of HBECs to 5% cigarette smoke extract (CSE) for at least 15 min resulted in an increase in the ability of an anti-human C5aR Ab to bind to the cell surface. CSE-treated HBECs responded in a dose-dependent fashion to human recombinant C5a and to a conformationally biased decapeptide agonist of C5a (YSFKPMPLaR) by releasing IL-8. The levels of IL-8 released in response to C5a were significantly greater in CSE-treated HBECs than in control HBECs. Moreover, this C5a-mediated release of IL-8 from CSE-treated HBECs was significantly reduced in the presence of the anti-human C5aR Ab. These results indicate that HBECs constitutively express C5aRs and that exposure to environmental irritants such as cigarette smoke modulates the expression and responsiveness of these C5aRs toward the C5a-mediated release of IL-8.     

Domain-specific gender comparisons in identity development among college youth: ideology and relationships

Gender comparisons were conducted in six social domains of identity development on 210 college students: occupation, religion, politics, dating, sex roles, and friendship. The identity research literature often combines domains to create more global estimates of identity development. Such an approach may obscure differences among the domains, each of which may have different implications for different societal contexts, and for males and females. Analyses were made for each domain, and for the combined ideological, interpersonal, and overall domain scores. Several gender differences were apparent when domain-specific analyses were examined. Males were more likely to explore and commit in politics, whereas females were more likely to explore in sex roles and to commit in religion and dating. In politics, fewer males were in the diffused status; in contrast, for dating and sex roles, there were fewer females in the diffused status. However, when combined scores were examined, there were no gender differences in identity status. The results suggest that some gender differences still remain in specific domains. The utility of including domain-specific analyses is suggested when gender comparisons are examined. Regardless of gender, more youth were diffused in political identity than in any other domain, suggesting political apathy among today's college youth.     

Administration of dehydroepiandrosterone sulfate retards onset but not progression of autoimmune disease in NZB/W mice

A series of silica gels and mesoporous molecular sieves differing in both the range of particle size and mean pore size were derivatized with the p-[R,S-alpha-[1-(9H-fluoren-9-yl)-methoxyformamido]-2,4-di methoxybenzyl]- phenoxyacetic acid linker and their loading capacities were measured. Loading capacities ranging between 0.4-0.6 mmol Fmoc/g were achieved. Several of these silica based materials were derivatized with the hydroxymethyl benzoic acid linker and used as supports for the solid phase Claisen rearrangement of a support bound phenyl allyl ether. Both the silica gel and mesoporous supports were heated at 225 degrees C for 3 h to effect the Claisen rearrangement. The results showed that, compared to the same reaction run homogeneously, the silica gel support achieved similar total product yields and ratios for two Claisen products. The mesoporous supports were found to selectively produce one of the Claisen products over the other. Analysis shows that the molecules bound to the mesoporous support are physically further separated from each other as compared to those bound to the silica gel support. A mechanism is presented which accounts for the selectivity of the mesoporous support in forming one Claisen product over the other. The Claisen product was further derivatized to the resulting phenyl ethyl either through a solid phase Mitsunobu reaction on the mesoporous support.     

Accreditation: who's counting?

Active physician involvement and leadership in their accreditation process can produce a cubic win for patients, payors, and providers. For health care quality to improve and everyone win, physicians need to understand the accountability system, the what and why of data collection, and be involved in short- and long-term performance assessments.     

Impact of imported beverages on fluoridated and nonfluoridated communities

In the last 10 years an increasing number of cases of group A streptococcal toxic shock syndrome have appeared in various clinical settings. The manifestation of this syndrome includes rapidly progressive multiorgan failure and soft-tissue necrosis. This report presents a case of streptococcal toxic shock syndrome caused by Streptococcus pyogenes with severe necrotizing fasciitis of the abdominal wall following hysterectomy. Aggressive surgical intervention with debridement of all necrotic tissue necessitated resection of the complete abdominal wall (skin, subcutaneous tissue, muscle and peritoneum). The abdominal wall defect was covered with free myocutaneous flaps and split-skin grafts. Optimal treatment, including adequate antibiotic therapy and radical surgical intervention, is an indispensable prerequisite of successful outcome.     

Chronic posttraumatic stress disorder and chronic pain in Vietnam combat veterans

A study was conducted to investigate chronic pain patterns in Vietnam veterans with posttraumatic stress disorder (PTSD). Combat veterans with PTSD completed standardized PTSD severity, pain, somatization, and depression measures. Of 129 consecutive out-patient combat veterans with PTSD, 80% reported chronic pain. In descending order were limb pain (83%), back pain (77%), torso pain (50%), and headache pain (32%). Compared to PTSD combat veterans without chronic pain, PTSD veterans who reported chronic pain reported significantly higher somatization as measured by the Minnesota Multiphasic Inventory 2 hypochondriasis and hysteria subscales. In the sample of 103 combat veterans with PTSD and chronic pain, MMPI 2 hypochondriasis scores and B PTSD symptoms (reexperiencing symptoms) were significantly related to pain disability, overall pain index, and current pain level MMPI 2 hypochondriasis and depression scores were also significantly related to percent body pain. These results are discussed in the context of current conceptualizations of PTSD.