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Biomedical subjects

J M Curtis

Publications and source records attributed to J M Curtis.

At least 37 records · Page 2Linked to original sources
PubMed1995

Protective vaccination with promastigote surface antigen 2 from Leishmania major is mediated by a TH1 type of immune response.

Leishmania major promastigote surface antigen-2 complex (PSA-2) comprises a family of three similar but distinct polypeptides. The three PSA-2 polypeptides were purified from cultured promastigotes by a combination of detergent phase separation and monoclonal antibody affinity chromatography. Intraperitoneal vaccination of C3H/He mice with PSA-2 with Corynebacterium parvum as an adjuvant resulted in complete protection from lesion development after challenge infection with virulent L. major. Significant protection was also obtained in the genetically susceptible BALB/cH-2k and BALB/c mice. One of the PSA-2 genes was cloned and expressed in both Escherichia coli and Leishmania mexicana promastigotes. Vaccination with the recombinant PSA-2 purified from E. coli did not confer protection, in contrast to the L. mexicana-derived recombinant PSA-2, which provided excellent protection. CD4+ T cells isolated from the spleens of vaccinated mice produced large amounts of gamma interferon but no detectable interleukin 4 upon stimulation with PSA-2 in vitro. Limiting dilution analysis showed a marked increase in the precursor frequency of PSA-2-specific gamma interferon-secreting CD4+ T cells. No substantial change in precursor frequency was observed for interleukin 4-secreting T cells in the vaccinated mice. A CD4+ PSA-2 specific T-cell line generated from splenocytes of a vaccinated mouse produces a cytokine pattern consistent with a TH1 phenotype. Intravenous injection of this line into naive mice reduced significantly the parasite burden upon challenge infection. Taken together, the data suggest that vaccination with PSA-2 induces a TH1 type of immune response which protects mice from L. major infection. Moreover, a single recombinant PSA-2 polypeptide derived from a genomic clone can also vaccinate, provided that the structural form of the antigen is near native.

Animals↗
PubMed1995

Elements of critical incident debriefing.

The present paper lists a number of specific therapeutic steps involved in critical incident debriefing. These therapeutic suggestions, while by no means exhaustive, include (a) identification, (b) labeling, (c) articulation, (d) expression, (e) externalization, (f) ventilation, (g) validation, and (h) acceptance. More careful attention to these specific elements--regardless of debriefers' training and backgrounds--might improve therapeutic consistency for trauma victims afflicted with stress-related symptoms. Further applications of these therapeutic steps were also suggested for other types of behavioral problems.

Adaptation, Psychological↗
PubMed1994

Epitope mapping of monoclonal antibodies directed against lipophosphoglycan of Leishmania major promastigotes.

Monoclonal antibodies (MAbs) were generated against Leishmania major promastigote lipophosphoglycan (LPG) to use as tools in defining functional epitopes of this major cell surface glycoconjugate. Epitope mapping of four MAbs, designated 4A2-A2, 2G11-A3, 5E6-D10 and 5E10-F2, revealed that the phosphorylated oligosaccharide repeat unit PO4-6[Gal(beta 1-3)]Gal(beta 1-4)Man alpha 1-, P3, is a highly immunogenic epitope which has previously been demonstrated, by chemical analyses, to be a repeat unit specific to L. major. Two antibodies, 4A2-A2 and 5E10-F2, also recognised the repeat unit PO4-6[Ara(beta 1-2)Gal(beta 1-3)]Gal(beta 1-4)Man alpha 1-, 4Pa, with less affinity than P3, while 2G11-A3 recognised P4a with greater affinity than for P3. The L. major metacyclic-specific antibody 3F12 only recognised repeat units terminating with arabinose residues. In particular, 3F12 recognised P4a, which is upregulated in metacyclic LPG compared to the procyclic form of the molecule. The oligosaccharides P3, P4a and P5a are specific to L. major LPG. The epitopes of 4A2-A2, 2G11-A3, 5E6-D10 and 5E10-F2 were found on the cell surface and in the flagellar pocket of both procyclic and metacyclic V121 promastigotes, but were only detected at very low levels on amastigotes. The repeat unit P3 is able to inhibit attachment of procyclic promastigotes to the midgut of the sandfly vector, but neither Fab fragments of the four antibodies nor purified P3 could inhibit attachment of metacyclic promastigotes to the macrophage cell line J774. It was also shown that human sera from patients with cutaneous leishmaniasis recognised purified P3. The data suggests that while P3 is an immunogen in the natural course of infection of the human host, P3 plays no role in attachment and internalisation of promastigotes into the macrophages of the mammalian host.

Animals↗
PubMed1994

Ricin-resistant mutants of Leishmania major which express modified lipophosphoglycan remain infective for mice.

Glycosylation variants of the virulent Leishmania major clone V121 were generated by mutagenesis with N-methyl-N-nitroso-N-nitroguanidine and selected using the galactose-specific lectin Ricinus communis II (RCA II). Three mutants, 4B9, 1D1 and 1C12, which failed to bind RCA II, were found to have an altered expression of lipophosphoglycan (LPG), a molecule implicated in the attachment to host macrophages and survival within the phagolysosome. There were differences in the antigenicity, molecular weight and localization of LPG from mutant parasites as compared to V121. Expression of gp63, a surface molecule also implicated in attachment to macrophages, was unaltered. All 3 mutants caused disease when injected into genetically susceptible BALB/c mice but lesions developed at a much slower rate than those caused by the virulent V121 clone. This slow rate of lesion development did not correlate with promastigotes' ability to invade macrophages in vitro. Karyotype analysis showed that there was a reduction in the size of chromosome band number 2 in all 3 mutants. The differences in LPG and chromosome band 2 were retained by mutant clones following passage through mice, suggesting that these phenotypes are stable. Although the mutant parasites were infective and caused lesions, the changed structure of the LPG appeared to influence the virulence of the parasites.

Agglutination↗
PubMed1994

Considerations in misdiagnosis of narcissistic personality disorder.

The present paper identified some diagnostic considerations which might be responsible for misdiagnoses of narcissistic personality disorder. Although conventional diagnostic criteria, e.g., DSM-III-R, for narcissistic personality disorder have suggested a rather homogeneous set of features including, e.g., inflated grandiosity, excessive omnipotence, overt arrogance, diminished empathic capacities, onanistic behavior, pathological self-centeredness, and propensities toward self-indulgence, many narcissistic conditions are misdiagnosed because the symptoms are less obvious if not altogether camouflaged. Diagnostic miscalculations can often mislead clinicians from focusing on verifiable and essential aspects of the disorder and lead to unnecessary therapeutic detours and eventual failures. Improved recognition of the heterogeneity of such patients might improve diagnostic consistency and eventual therapeutic outcome.

Diagnostic Errors↗
PubMed1994

Factors related to fear of marriage.

The present paper identified elements which seem to influence fear of marriage or certain avoidant patterns associated with marital commitment. Because census bureau data suggest that increasing numbers of individuals have either delayed marital commitment or avoided it entirely, further research has become necessary to ascertain possible influences. Although the literature suggests men have traditionally had more problems making marital commitments, more women are also avoiding marriage. Some related factors were fears about loss of identity, control, or finances and about accepting adult responsibility. Careful attention to such fears might help clinicians focus more consistently on previously unlabeled impediments to marital commitment.

Fear↗
PubMed1993

Electron ionization-tandem mass spectrometry of glycosphingolipids. Part II. The identification of a carbohydrate sequence corresponding to a novel repetitive blood group A heptaglycosylceramide.

In a previous paper, the presence in human kidney vein tissue of a novel blood group A heptaglycosylceramide based on the type-3 carbohydrate chain GalNAc alpha 1-3(Fuc alpha 1-2)Gal beta 1-3GalNAc alpha 1-3(Fuc alpha 1-2)Gal beta 1-4Glc beta 1-1 Ceramide, was suggested based on thin-layer immunostaining and electron ionization mass spectrometry. Ions corresponding to a structure containing two deoxyhexoses, two hexosamines and three hexoses were identified, but no information was obtained from mass spectrometry concerning the carbohydrate sequence. In the present paper, we report the identification of carbohydrate sequence ions corresponding to a type-3 chain A heptaglycosylceramide by electron ionization-tandem mass spectrometry of a permethylated-reduced glycosphingolipid mixture isolated from human kidney vein tissue. The use of a microchannel-plate-array detector increased the sensitivity for collision-induced dissociation spectra by a factor of at least ten over a conventional electron multiplier.

Blood Group Antigens↗
PubMed1993

Relation of birth order and scores on measures of pathological narcissism.

To study the relationship between birth order and pathological narcissism, it was predicted that firstborn and only children would score significantly higher on standardized measures of pathological narcissism. Two such measures, the Millon Clinical Multiaxial Inventory and the Narcissistic Personality Inventory, were administered to 50 randomly selected subjects from a metropolitan mental health and family treatment agency. Subjects were asked to indicate their ordinal birth positions, e.g., first, middle, last, or only, and then were administered both instruments. Analysis supported the initial prediction by indicating that firstborn and only children had higher mean scores on the measures of pathological narcissism. It might be advisable for clinicians to identify patients' ordinal positions while appraising relevant diagnostic criteria and eventual treatment planning.

Adult↗
PubMed1993

Factors related to susceptibility and recruitment by cults.

Unprecedented escalation of secular and religious cults has necessitated further inquiry into more precise conditions under which individuals develop vulnerability and become converted by these groups. The present discussion focuses on a number of factors which seem to influence individuals' susceptibility and recruitment by cults. These variables include (a) generalized ego-weakness and emotional vulnerability, (b) propensities toward dissociative states, (c) tenuous, deteriorated, or nonexistent family relations and support systems, (d) inadequate means of dealing with exigencies of survival, (e) history of severe child abuse or neglect, (f) exposure to idiosyncratic or eccentric family patterns, (g) proclivities toward or abuse of controlled substances, (h) unmanageable and debilitating situational stress and crises, and (i) intolerable socioeconomic conditions. Also presented are methods utilized by cults, e.g., intimidation, coercion, and indoctrination, for systematically recruiting, initiating, and influencing inductees. More careful attention to these factors might help health care providers, educators, clergy, and concerned family and friends determine more precisely individuals at greater risk for recruitment into cults.

Adolescent↗
PubMed1992

In-line Kevlar filters for microfiltration of transuranic-containing liquid streams.

The Department of Energy Rocky Flats Plant has numerous ongoing efforts to minimize the generation of residue and waste and to improve safety and health. Spent polypropylene liquid filters held for plutonium recovery, known as "residue," or as transuranic mixed waste contribute to storage capacity problems and create radiation safety and health considerations. An in-line process-liquid filter made of Kevlar polymer fiber has been evaluated for its potential to: (1) minimize filter residue, (2) recover economically viable quantities of plutonium, (3) minimize liquid storage tank and process-stream radioactivity, and (4) reduce potential personnel radiation exposure associated with these sources. Kevlar filters were rated to less than or equal to 1 mu nominal filtration and are capable of reducing undissolved plutonium particles to more than 10 times below the economic discard limit, however produced high back-pressures and are not yet acid resistant. Kevlar filters performed independent of loaded particles serving as a sieve. Polypropylene filters removed molybdenum particles at efficiencies equal to Kevlar filters only after loading molybdenum during recirculation events. Kevlars' high-efficiency microfiltration of process-liquid streams for the removal of actinides has the potential to reduce personnel radiation exposure by a factor of 6 or greater, while simultaneously achieving a reduction in the generation of filter residue and waste by a factor of 7. Insoluble plutonium may be recoverable from Kevlar filters by incineration.

Pilot Projects↗
PubMed1991

Diatomic monocations and dications containing germanium and a rare gas atom.

Diatomic dications and monocations GeY2+ and GeY+, where Y = Ne, Ar, Kr or Xe, have been detected on the microsecond time scale. They are characterized via appearance energies, charge stripping of GeY+ ions, and mass-analysed ion kinetic energy spectroscopy. The formation of GeAr+ is found to involve an excited state of Ar in a Hornbeck-Molnar process.

Cations, Divalent↗