Optimized determination of T cell epitope responses

Pools of overlapping peptides corresponding to specific antigens are frequently used to identify T cell immune responses to vaccines or pathogens. While the response to the entire pool of peptides provides important information, it is often desirable to also know to which individual peptides within the pool the immune responses are directed. In this report, we analyzed various ways of deconvoluting an immune response to a pool of peptides to determine the number of different peptides to which the T cells are responding. We used a Monte Carlo simulation to optimize the construction of peptide pools that could identify responses to individual peptides using the fewest numbers of assays and patient material. We find that the number of assays required to deconvolute a pool increases by the logarithm of the number of peptides within the pool; however, the optimum configuration of pools changes dramatically according to the number of responses to individual peptides that are expected to be in the sample. Our simulation will help in the design of clinical trials in which the breadth of the response is being measured, by allowing a calculation for the minimum amount of blood that needs to be collected. In addition, our results guide the design and implementation of the experiments to deconvolute the responses to individual peptide epitopes.     

Should donors have the right to decide who receives their gametes?

A continuing feature of gamete donation is the scarcity of availabledonors. A strategy to improve the meagre supply of gametes wouldbe to adjust the donation procedure to the wishes and desiresof the donors. However, giving donors the right to direct theirgametes to certain groups of recipients goes against the generalrule that donors relinquish all rights and duties. Moreover,allocation by the donor might very well run counter to the rulesof distributional justice. On the other hand, the allocationright can be supported by the principle of autonomy and by thedonor's interest in and contribution to the process. The positionis taken that the donors should have the right to direct theirgametes to categories accepted as relevant by the moral andreligious communities in their society. They should not be giventhe right to add their own categories to the exclusion list.If donors are not allowed to allocate their gift, they shouldat least be informed as to which categories of recipient aretreated by the hospital to enable them to decide whether theywant to donate gametes.     

53例慢性髓系白血病细胞遗传学和bcr/abl融合基因检测

目的了解我院慢性粒细胞白血病(慢粒)染色体变异及融合基因表达与临床诊断和分期间的关系。方法染色体制备采用骨髓或外周血短期培养法,G显带,分析核型;融合基因检测则用逆转录-聚合酶链反应法(PCR法)。结果发现慢粒急变期的染色体,除具典型的Ph染色体外,还有 8、 9、i(16)q、i(17)q、-18等其它染色体改变。bcr/ab l融合基因显示慢粒急变期的患者,同时具有165bp和90bp扩增带。结论我们宜将细胞遗传学和PCR法结合,对慢粒白血病进行检测,即有助于对其诊断、预测急变、判断疗效及预后情况的深入了解。     

Two neutrophil populations in human blood with different chemotactic activities: separation and chemoattractant binding.

Normal human blood contains a population of neutrophils that migrates to various chemoattractants and a population that fails to migrate. The percentage of neutrophils migrating to optimal concentrations of chemoattractants was quantified: 20 to 40% migrated to N-formylmethionyl-leucyl-phenylalanine, 30 to 50% migrated to human C5a, 25 to 35% migrated to human leukocyte-derived chemotactic factors, 20 to 30% migrated to casein, 15 to 20% migrated to pepstatin, and 1 to 5% migrated to medium alone. Neutrophil migration to the most active chemoattractant was not increased when other chemoattractants were added, indicating that the population of neutrophils migrating to the most active attractant was the same population that was migrating to the other attractants. The percentage of neutrophils migrating to a chemoattractant was not altered by prolonging the assay incubation period or by replacing the attractant with new chemoattractant during the assay, and the percentage was independent of the neutrophil concentration added to the chemotaxis chamber. Nonmigrating neutrophils were isolated with a chemotaxis collection chamber, and they were examined for radiolabeled chemotactic peptide binding. The binding of radiolabeled N-formylmethionyl-leucyl-phenylalanine by nonmigrating and migrating neutrophils was identical.     

Immunotherapy for neurological diseases

The burden of neurological diseases in western societies has accentuated the need to develop effective therapies to stop the progression of chronic neurological diseases. Recent discoveries regarding the role of the immune system in brain damage coupled with the development of new technologies to manipulate the immune response make immunotherapies an attractive possibility to treat neurological diseases. The wide repertoire of immune responses and the possibility to engineer such responses, as well as their capacity to promote tissue repair, indicates that immunotherapy might offer benefits in the treatment of neurological diseases, similar to the benefits that are being associated with the treatment of cancer and autoimmune diseases. However, before applying such strategies to patients it is necessary to better understand the pathologies to be targeted, as well as how individual subjects may respond to immunotherapies, either in isolation or in combination. Due to the powerful effects of the immune system, one priority is to avoid tissue damage due to the activity of the immune system, particularly considering that the nervous system does not tolerate even the smallest amount of tissue damage.     

Saliva-binding region of Streptococcus mutans surface protein antigen.

A 190-kDa surface protein antigen (PAc) of Streptococcus mutans binds to human salivary components. For detection of specific binding of the PAc protein to human salivary components, a simple sandwich assay was used. Microtiter plates precoated with recombinant PAc (rPAc), PAc fragments, or S. mutans whole cells were allowed to react with human whole saliva and then were incubated with biotinylated rPAc. The biotinylated rPAc bound to salivary components was detected by use of alkaline phosphatase-conjugated streptavidin and p-nitrophenylphosphate. In this assay, the binding of whole cells of S. mutans and purified rPAc to salivary components was confirmed. For determination of a saliva-binding region of the PAc molecule, 14 truncated PAc fragments were constructed by use of the polymerase chain reaction and an expression vector, pAX4a+. The binding of these truncated PAc fragments to human salivary components was determined by the sandwich assay. Among the truncated PAc fragments, fragments corresponding to residues 39 to 864 and residues 39 to 1000 of PAc showed a high ability to bind to salivary components. Shorter recombinant fragments corresponding to residues 39 to 217, residues 200 to 481, residues 470 to 749, and residues 688 to 864 did not exhibit any binding ability. The fragment that corresponds to a proline-rich repeating region (residues 828 to 1000) bound directly to the PAc protein. These results suggest that residues 39 864 of the PAc molecule are important in the binding of the surface protein to human salivary components, and the proline-rich repeating region of the PAc protein may contribute to spontaneous self-aggregation of the PAc protein.     

Essentially Winnicott: Creating Psychic Health

The authors of this paper recognize the paradox of identifying with the body of work of D. W. Winnicott as it was essential to his view that each analyst has to become the analyst s/he is or can be. This is to avoid the dead hand of conformity and falsity. Nevertheless his work continues to inspire creative use with its concern with health and those conditions for its development. Both authors find themselves committed to history taking, to needing and taking time, to a willingness to wait before interpreting, to a recognition that the self derives originally from a bodily state of unintegration, that the body remains significant for the expression of self‐states, to an understanding of aggression as not primarily associated with destructiveness, to attending to the state of mind in the analyst that encourages the establishment and maintenance of the analytic setting. Clinically their intention is to maintain a continuity within which psychic change can be facilitated, through an attention to the ongoing exchanges between both parties of the analytic relation. Several clinical examples are given from different settings to illustrate the presence of these tenets in their work.     

Role of adherent T cells and of B cells in the immune response to purified protein derivative of tuberculin.

The role of monocytes, B cells, and adherent and nonadherent T cells in the response of purified protein derivative of tuberculin (PPD) as measured by [3H]thymidine uptake in vitro has been explored. The response to PPD was found to be highly dependent on monocytes, to approximately the same extent as previously found for the responses to concanavalin A (Con A) and phytohemagglutinin. The response to PPD was also found to be highly dependent on a population of adherent T cells different from the adherent T cell population involved in the response to Con A. In the case of PPD, the effect was additive, as opposed to the potentiating effect seen for Con A. Further, the adherent T cells involved in the response to PPD were much more sensitive to hypotonic shock than those in the response to Con A. B cells were also found to be important in the response to PPD, although only to a slight extent.     

Modal profiles for the Luria-Nebraska Neuropsychological Battery.

Modal Profile Analysis was used to cluster subjects on the clinical scales of the Luria-Nebraska Neuropsychological Battery, Form I (LNNB). The analysis produced 22 modal profile types, of which seven were replicated in multiple samples of subjects with single criterion diagnoses. Subjects who had been assigned to modal types according to their correlations with the modal profiles were more similar to the modal profile of their assigned groups than to other modal profiles. Assigned subjects were more likely to belong to their assigned group than to other groups and were more similar to other subjects who had been assigned to the same group than to subjects assigned to other groups. Eighty-two percent of subjects in the derivation sample were assigned empirically to a modal profile group; 77% of subjects in a cross-validation sample were assigned to a modal profile group. The discussion focuses on the potential research and clinical use of the modal LNNB profiles.     

Immunogenicity of synthetic peptides of Haemophilus influenzae type b outer membrane protein P1.

To identify the B- and T-cell epitopes of P1 of Haemophilus influenzae type b, 13 peptides covering 90% of the protein were chemically synthesized. Mouse, guinea pig, and rabbit antisera raised against purified native P1 were tested for their reactivities against the peptides in peptide-specific enzyme-linked immunosorbent assays (ELISAs). Six immunodominant linear B-cell epitopes were mapped to residues 103 to 137, 189 to 218, 248 to 283, 307 to 331, 384 to 412, and 400 to 437 of the mature P1 protein. When P1 peptides were screened for their reactivities with three human convalescent-phase serum specimens, peptides corresponding to residues 39 to 64, 226 to 253, and 400 to 437 reacted strongly with the antisera. Four regions (residues 39 to 64, 226 to 253, 339 to 370, and 400 to 437) contained murine T-cell epitopes. Rabbit antipeptide antisera were tested for their reactivities with the immunizing peptides and P1 protein by ELISA and immunoblots. All anti-P1 peptide antisera except those raised against peptide HIBP1-8 (residues 279 to 312) or HIBP1-8-keyhole limpet hemocyanin conjugate were shown to be specific for their respective immunizing peptides by ELISA. In addition, rabbit antisera raised against the synthetic peptides corresponding to residues 1 to 29, 39 to 64, 103 to 137, 189 to 218, 226 to 253, 248 to 283, 307 to 331, and 400 to 437 of the mature P1 protein recognized the P1 protein from both typeable and nontypeable isolates. These results suggest that these peptides contain epitopes highly conserved among typeable and nontypeable strains of H. influenzae. However, none of the antipeptide antisera have bactericidal activity, nor were they protective against H. influenzae type b in the infant rat model of bacteremia.     

A Proposed Feedback Method For Studying the Inhibition of EEG Responses to Visual Stimuli

A new method for studying inhibition of an electroencephalographic component of the OR to visual stimuli is described. The EEG response is suppression of the occipital alpha following visual stimulation. By a controlled feedback contingency, two stimuli are made to occur in sequence with a controlled time delay after the onset of alpha in the EEG. Inhibition is defined as a lack of EEG response to the first stimulus followed by a response to the second, delayed stimulus. Because the stimuli are feedback with regard to the occurrence of alpha, the dynamics of the alpha - alpha suppression system are different when a response is made to the first stimulus (elicitation of OR to first stimulus) compared to not responding to the first stimulus but responding to the second delayed stimulus (inhibition of OR to the first stimulus).     

Maternal exposure to influenza and cold in pregnancy and electrodermal activity in offspring: The Mauritius study

Data are in conflict concerning whether a mother's exposure to influenza in pregnancy gives rise to an increased probability that her offspring will develop schizophrenia. In Northern Hemisphere studies, exposure to influenza and cold tend to be confounded. The present study, carried out in Mauritius, examines the effect of maternal exposure to the virus and separately to cold on aspects of electrodermal activity that have been shown in other studies to be related to schizophrenia. The findings are that maternal exposure to influenza in the second and third trimesters gives rise to children who at the age of 3 years show electrodermal hyperresponsivity, whereas exposure to cold in the same periods gives rise to children who tend to be hyporesponsive. In both instances, exposure tends to produce lower levels of tonic activity than in those not exposed to the virus or to cold.     

Effect of the Aldehyde Dehydrogenase Inhibitor, Cyanamide, on the Ex Vivo Sensitivity of Murine Multipotent and Committed Hematopoietic Progenitor Cells to Mafosfamide (Asta Z 7557)

The ex vivo sensitivity of murine multipotent (CFU-GEMM) and committed (CFU-Mk, CFU-GM, BFU-E and CFU-E) hematopoietic progenitor cells to mafosfamide was quantified with and without concurrent exposure to cyanamide, an inhibitor of aldehyde dehydrogenase activity. In the absence of cyanamide, CFU-GEMM, CFU-Mk and CFU-GM were approximately equisensitive to mafosfamide while the erythroid progenitors were more sensitive to the drug. Cyanamide potentiated the cytotoxicity of mafosfamide toward CFU-GEMM and CFU-Mk, but not toward CFU-GM, BFU-E and CFU-E. Cellular aldehyde dehydrogenases are known to catalyze the oxidation of 4-hydroxycyclophos-phamide/aldophosphamide, the major intermediate in cyclophosphamide and mafosfamide activation, to the relatively nontoxic acid, carboxyphosphamide. Thus, our findings indicate that 1) murine CFU-GEMM contain the relevant aldehyde dehydrogenase activity, and 2) the relevant aldehyde dehydrogenase activity is retained upon differentiation to progenitors committed to the megakaryocytoid lineage, but lost upon differentiation to progenitors committed to the granulocytoid/monocytoid and erythroid lineages. The relative insensitivity of CFU-GM to mafosfamide is apparently due to a cellular determinant that influences their sensitivity to all cross-Unking agents since CFU-GM were found to be relatively insensitive to non-oxazaphosphorine cross-linking agents as well.     

Effects of hypothalamic knife cuts on the ingestive responses to glucose and insulin.

Parasagittal knife cuts through the perifornical hypothalamus either medial or lateral to the fornix produced hyperphagia and obesity and altered the rat's ingestive responses to dilute glucose solutions. The lateral knife cut rats drank less dilute glucose solution under both nondeprived and food deprived conditions and displayed less of a feeding suppressive response to glucose ingestion compared to controls. The lateral cut rats were also deficient in their feeding response to insulin-induced hypoglycemia, although their altered sensitivity to glucose and insulin did not appear to be causally related. The medial knife cuts decreased the responsivity to glucose, but less so than the lateral cuts, and did not alter the ingestive response to insulin. Both the medial and lateral knife cuts did not appear to change the rat's responsivity to concentrated blucose solutions. The neuroanatomical and functional nature of the disorder responsible for these effects and its relationship to the hyper-phagia-obesity syndrome are discussed.     

Splenic and granuloma T-lymphocyte responses to fractionated soluble egg antigens of Schistosoma mansoni-infected mice.

Soluble egg antigens (SEA) secreted by the eggs of Schistosoma mansoni worms induce a T-cell-mediated granulomatous response that is principally responsible for the pathology of the disease. In the present study sodium dodecyl sulfate-polyacrylamide gel electrophoresis-separated SEA proteins were divided into nine fractions (less than 21, 25 to 30, 32 to 38, 40 to 46, 50 to 56, 60 to 66, 70 to 90, 93 to 125, and greater than 200 kDa), electroeluted, and utilized in in vitro lymphoproliferation assays. T-cell-enriched spleen cells from acutely infected mice responded to all nine fractions, while those from chronically infected mice responded to only the 50- to 56- and the 60- to 66-kDa fractions. Depletion of the CD4+ T-cell subset among acute and chronic-infection spleen cells abrogated the response. Depletion of the CD8+ T-cell population resulted in increased proliferation in response to fractions by acute-infection T cells and facilitated responsiveness to hitherto-inactive SEA fractions in chronic-infection T cells. Acute-infection CD4+ granuloma T cells responded to the 40- to 46-, 50- to 56-, 70- to 90-, 93- to 125-, and greater than 200-kDa fractions, while the chronic-infection granuloma T cells responded only to the greater than 200-kDa fraction of SEA. Selective depletion of the CD4+ T-cell subset when acute-infection granuloma lymphocytes were tested abrogated proliferation, whereas subset depletions when chronic-infection granuloma cells were tested indicated that both CD4+ and CD8+ T cells respond to the greater than 200-kDa fraction. The present study reveals differences between acute- and chronic-infection splenic and granuloma T cells in the pattern of T-cell blastogenic responses to fractionated SEA.     

An Upsurge in early childhood mortality in Kenya: A search for explanations

This study seeks to document recent trends in early childhood mortality in the country and to offer some plausible explanations for the upsurge in the trends. Data and information from various sources are used in this paper to achieve this purpose. The results obtained show that infant, child and under-five mortality rates had declined in the 1960s and 1970s but were taking an upward trend since early 1990s. This situation is attributable to a combination of factors, including increased poverty, adverse effects of economic hardships and cost recovery programs associated with structural adjustment programs, increased childhood malnutrition, decreased use of certain maternity care services, decline in the coverage of child immunisations, inability of the public health system to provide services, and the HIV / AIDS epidemic and the recent ethnic clashes that rocked some parts of the Rift Valley, Coast, Nyanza and Western province. In order to reverse the upward trend in mortality, there is an urgent need to intensify efforts to reduce poverty, to enable most people to have adequate food supply, improve the public health sector so that it can deliver health care to all people; to make greater efforts to raise the living standards of rural populations and improve the quality of housing, sanitary and sewerage conditions in urban slums. In addition, concerted efforts must continue to be made to contain the spread of HIV/AIDS, to assist Aids orphans and to eliminate completely and to avoid recurrence of ethnic clashes and cattle rustling.     

Evidence of Different Cell Populations in the Mouse Thymus Releasing and Responding to Mitogenic Factor

The thymocyte population of mice treated with cortisone was examined at various times with respect to its relative capacity to be triggered to DNA synthesis by soluble phytomitogens or mitogenic factors (MF) released by lymph node cells exposed to phytomitogens. The capacity of the thymocyte population to produce MF in response to phytomitogen exposure was also examined. We found that the relative blastogenic activity of both phytomitogens and MF on thymocytes increased as the cell number of the thymus was reduced by the cortisone treatment. However, the reactivity to phytomitogens increased to a higher extent. During the subsequent regeneration of the organ the stimulability of the cells by phytomitogen decreased far below that of MF. The relative capacity of thymocytes to produce MF seemed to parallel their phytomitogen reactivities Onepossible explanation of the results is that there exists one subpopulation of cells in the thymus more responsive to phytomitogens than to MF and another more responsive to MF than to phytomitogen. It is possible that the cells that are phytomitogen-responsive are those that can produce MF.     

Kinetic analysis of pepsin digestion of chicken egg white ovomucoid and allergenic potential of pepsin fragments

BACKGROUND: The allergenic potential of chicken egg white ovomucoid (OVM) is thought to depend on its stability to heat treatment and digestion. Pepsin-digested fragments have been speculated to continue to exert an allergenic potential. OVM was digested in simulated gastric fluid (SGF) to examine the reactivity of the resulting fragments to IgE in sera from allergic patients. METHODS: OVM was digested in SGF and subjected to SDS-PAGE. The detected fragments were then subjected to N-terminal sequencing and liquid chromatography/mass spectrometry/mass spectrometry analysis to confirm the cleavage sites and partial amino acid sequences. The reactivity of the fragments to IgE antibodies in serum samples from patients allergic to egg white was then determined using Western blotting (n=24). RESULTS: The rate of OVM digestion depended on the pepsin/OVM ratio in the SGF. OVM was first cleaved near the end of the first domain, and the resulting fragments were then further digested into smaller fragments. In the Western blot analysis, 93% of the OVM-reactive sera also bound to the 23.5- to 28.5-kDa fragments, and 21% reacted with the smaller 7- and 4.5-kDa fragments. CONCLUSION: When the digestion of OVM in SGF was kinetically analyzed, 21% of the examined patients retained their IgE-binding capacity to the small 4.5-kDa fragment. Patients with a positive reaction to this small peptide fragment were thought to be unlikely to outgrow their egg white allergy. The combination of SGF-digestibility studies and human IgE-binding experiments seems to be useful for the elucidation and diagnosis of the allergenic potential of OVM.     

FMRI evidence for a 'parietal reach region' in the human brain

Event-related functional magnetic resonance imaging was used to examine activation in the posterior parietal cortex when subjects made pointing movements or saccades to the same spatial location. One region, well positioned to be homologous to the monkey parietal reach region (PRR), responded preferentially during memory-delay trials in which the subject planned to point to a specific location as compared to trials in which the subject planned to make a saccade to that same location. We therefore conclude that activation in this region is related to specific motor intent; i.e. it encodes information related to the subject's intention to make a specific movement to a particular spatial location.     

Modulation of the immune response by passive antibodies. I. Anti-hapten antibodies enhanced delayed hypersensitivity to the carrier and depressed antibody synthesis to the hapten.

The modulating effects of passive antibodies on both delayed hypersensitivity to the carrier and antibody synthesis to carrier and hapten determinants were studied in guinea pigs. Animals were injected with antibodies directed against either the carrier or the hapten prior to immunization with the hapten-carrier conjugate in Freund's complete adjuvant. Anti-hapten antibodies have been shown to have an enhancing effect on delayed hypersensitivity to the carrier and a suppressive effect on antibody synthesis to the hapten. In this experiment, anti-carrier anti-bodies seemed to have had no effect on delayed hypersensitivity to the carrier and on antibody synthesis to the hapten.