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S Goldenberg

Publications and source records attributed to S Goldenberg.

143 records · Page 8Linked to original sources
PubMedDate not supplied

Ubiquity of cysteine- and metalloproteinase activities in a wide range of trypanosomatids.

We have analysed the proteinase profiles of 11 species from 7 different genera of trypanosomatids by in situ detection of enzyme activities on SDS-PAGE gels containing co-polymerized gelatin as substrate, and the use of specific proteinase inhibitors. Our survey indicates that while cysteine- and metalloproteinases are distributed ubiquitously among trypanosomatids, there are marked differences between the enzyme profiles from the monogenetic (Crithidia, Herpetomonas, Leptomonas) and digenetic (Trypanosoma, Endotrypanum, Phytomonas, Leishmania) species. The detected metalloproteinase activities, ranging in size from 50-100 kDa, partitioned into the detergent-phase after Triton X-114 extraction, while most of cysteine proteinases, of three distinct molecular mass ranges (30-50 kDa, 80-100 kDa and 116-205 kDa), partitioned into the aqueous phase. Thus, within this group of organisms, the metalloproteinase activities seem to be predominantly membrane-associated proteins. We also show that the plant parasites of the genus Phytomonas exhibit a distinctive cysteine proteinase profile that might be exploited further as a criterion for taxonomy of the genus.

Animals↗
PubMedDate not supplied

Biological aspects of the Dm 28c clone of Trypanosoma cruzi after metacyclogenesis in chemically defined media.

The biological characterization of the Trypanosoma cruzi clone Dm 28c in terms of its growth in LIT medium, cell-cycle, infectivity to mice and interaction with professional and non-professional phagocytic cells shows that it behaves as a bona fide T. cruzi representant. The biological properties of this myotropic clone do not change according to the origin of the trypomastigote forms (i. e., from triatomines, infected mice, cell-culture or from the chemically defined TAUP and TAU3AAG media). In addition Dm 28c metacyclic trypomastigotes from TAU3AAG medium display a high infectivity level to fibroblasts and muscle cells. Experiments on binding of cationized ferritin to trypomastigotes surface show the existence of cap-like structures of ferritin in regions near the kinetoplast, however the nature and role of these anionic sites remain to be determined. The results indicate that metacyclic trypomastigotes from the Dm 28c clone obtained under chemically defined conditions reproduce the biological behaviour of T. cruzi, rendering this system very suitable for the study of cell-parasite interactions and for the isolation of trypanosome relevant macromolecules.

Animals↗
PubMedDate not supplied

Ciliary ultrastructure in primary ciliary dyskinesia and other chronic respiratory conditions: the relevance of microtubular abnormalities.

Twenty-eight subjects with chronic respiratory disease were investigated for clinical data, ciliary beat frequency of nasal mucosa (10 cases), and ciliary ultrastructure. The cases were divided into two groups: those considered compatible with primary ciliary dyskinesia (genetic), and those not fitting into this category (others). A case was defined as genetic if one or more of the following were present: dextrocardia, ciliary beat frequency less than 10 Hz, or an average dynein arm count (outer, inner, or both) of less than two per ciliary cross-section. In each of the genetic cases at least two of these parameters were present. The percentage of malformed microtubules was calculated from the total number of evaluated cross-sections for each case. Ciliary microtubular abnormalities of any kind were no more frequent in cases of primary ciliary dyskinesia than in other cases. The same was true for transposition and radial spoke defects.

Adolescent↗
PubMedDate not supplied

Effects of small bowel exclusion on intestinal myoelectrical activity pattern: comparison between innervated and denervated (transplanted) Thiry-Vella loops in rats.

Small bowel transplantation (SBT) leads to several changes in normal intestinal physiology with special reference to lymphatic disruption and graft denervation. Intestinal myoelectrical activity (MA) has been studied in different conditions, but little is known about MA in excluded bowel segments without the influence of nutrients. We performed this study to evaluate the effects of bowel exclusion on MA pattern. Fifteen Wistar rats were divided into two groups: five were used as donors and five as recipients for SBT; the remaining five underwent isolation of a jejunal segment as Thiry-Vella loop (TVL). On the 20th postoperative day, four bipolar electrodes were implanted in the small bowel of each rat: proximally and distally on the transplanted and the native intestine (SBT group); proximally and distally on the TVL and across the jejunal anastomosis (TVL group). On the 30th postoperative day, MA was recorded for 30 min after a 12 h fast. MA pattern was not altered by the exclusion of innervated jejunal segments (TVLs) with maintenance of high amplitude and migrating myoelectric complex (MMC) occurrence independent of MA in the continuity bowel. The characteristic regular spiking activity was not observed in transplanted grafts and MA analysis showed slow waves containing superimposed irregular spiking activity.

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