Isotype-specific characterization of antibody responses to Onchocerca volvulus in putatively immune individuals

Isotypejsubclass-specific antibody responses to adult Onchocerca volvulus extract (OvAg) were assessed by both ELISA and immunoblotting for a group of putatively immune individuals (PIs, n = 29) from a hyperendemic area in Ecuador and for a group of infected individuals (INFs, n = 47) from the same region. As a group, the Pis have been previously shown to possess lower levels of OvAg specific IgG1, IgG2, IgG3 and IgG4 than INFs but semiquantitative analysis revealed that the relative proportions of these subclasses differs between the two groups. The IgG of the PI group contained a higher proportion of IgG3 and a lower proportion of IgG4 than the INF group. The frequency distribution of IgG3 responses was similar for the PI and INF groups. The frequency distributions for IgG1, IgG4 and IgE were significantly different between the PI and INF groups. A subgroup of the Pis were identified from frequency distributions and multivariate plots of individual isotype responses as having antibody responses (mainly IgG4) possibly indicative of cryptic infection. High IgE responses were exclusive to INF individuals, and a rare response type of high IgG3 with negligible levels of other isotypes/subclasses was seen only in the PI group. However, the majority of the Pis had negligible responses for all antibody classes. Immunoblots demonstrated no obvious differences in qualitative recognition between the PIs and INFs.     

Peptide synthesis on SepharoseTM beads

NHS-activated Pharmacia HiTrap Sepharose^TM was modified with 1,3-diaminopropane to give an amino-functionalized support suitable for solid-phase peptide synthesis. The amide linker p-[(R,S)-α-[1-(9H-fluoren-9-yl)-methoxyformamido]-2,4-dimethoxybenzyl]phenoxyacetic acid was incorporated and the acyl carrier protein sequence 65-74 was synthesized manually on this support by the Fmoc procedure under controlled conditions with monitoring of the coupling reactions. The performance of the support in automated multiple synthesis in open reactors, with an Abimed AMS 422 according to standard protocols, was evaluated by the synthesis of the acyl carrier protein sequence 65-74 and two other 15-mer and 18-mer peptides. The quality of the resulting crude peptides was determined by HPLC and MALDI-MS, and compared with the same sequences synthesized in parallel on the commercial peptide synthesis resin TentaGel S RAM. The modified HiTrap material was found to be particularly suited for Fmoc solid-phase peptide synthesis and should be advantageous for the utilization of immobilized peptides and peptide libraries in biological assays. © Munksgaard 1997.     

Duodenal ulcer healing and acid secretory responses to modified sham feeding and pentagastrin stimulation

The effect of duodenal ulcer healing on the acid secretory responses to modified sham feeding and maximal pentagastrin stimulation has been studied in 17 patients treated successfully with ranitidine (n = 9) and sucralfate (n = 8). Parietal cell sensitivity was calculated as the ratio of the modified sham feeding response to the peak pentagastrin response, expressed as a percentage. Ulcer healing after sucralfate therapy resulted in significant falls in modified sham feeding stimulated acid output (P less than 0.02), from 9.4 (1.8-17.0) (median + range) to 3.7 (0.2-9.4) mmol/h; in peak acid output (P less than 0.05) from 42.8 (23.0-61.4) to 27.7 (7.2-51.0) mmol/h; and in the parietal cell sensitivity (P less than 0.05) from 19.2 (4.4-42.6) to 14.3 (2.8-19.7)%. No significant falls in any of these parameters were noted following ulcer healing with ranitidine. Duodenal ulcer healing with sucralfate results in decreased acid secretory responses to vagal and pentagastrin stimulation.     

The Morphological Identity of Maternal Cells in Newborn Mice

The placenta has been considered ananatomical barrier which prevents maternal rejection of the fetal allograft. Thisview is no longer tenable since, in oneparticular inbred strain of mouse, maternal blood cells have been identified bymeans of radioisotope labels in newbornmice. Both maternal red cells and lymphocytes labeled, respectively, with radiochromium and tritiated thymidinehave been detected in newborn mice.This phenomenon appears independentof the trauma of normal delivery and,what is more, occurs before term.

Submitted on February 17, 1970 Revised on April 29, 1970 Accepted on May 18, 1970     

Secondary syphilis: a clinico-pathological review

The histological appearances found in biopsies from fifty-seven patients with secondary syphilis have been correlated with the clinical morphology of the eruptions. Considerable variation of histological pattern was encountered, and the frequency with which some of the classically described changes were found to be absent or inconspicuous is stressed. Of particular interest were the findings that, in nearly one-quarter of the biopsies, plasma cell infiltration was either absent or very sparse, and that vascular damage was seen in less than half. Where present, the vessel changes were almost entirely confined to swelling of the endothelial cells. Proliferation of the endothelial cells was most uncommon. The epidermis was very frequently involved in the inflammatory process. Exocytosis, spongiosis, parakeratosis, and acanthosis were the most frequent changes. No consistent histological difference between papular and papulo-squamous lesions could be found but macular lesions demonstrated more superficial and less intense dermal infiltration as well as less severe epidermal involvement. In late secondary lesions, the infiltrate became granulomatous, but in other respects the duration of the exanthem could not be correlated with the pathology. The differential diagnosis from pityriasis lichenoides and other inflammatory dermatoses is discussed and the value of histopathology in the diagnosis of secondary syphilis is emphasized.