Apolipoprotein E is enriched in dense deposits and is a marker for dense deposit disease in C3 glomerulopathy.

C3 glomerulopathy (C3G) is a rare disease resulting from dysregulation of the alternative pathway of complement. C3G includes C3 glomerulonephritis (C3GN) and dense deposit disease (DDD), both of which are characterized by bright glomerular C3 staining on immunofluorescence studies. However, on electron microscopy (EM), DDD is characterized by dense osmiophilic mesangial and intramembranous deposits along the glomerular basement membranes (GBM), while the deposits of C3GN are not dense. Why the deposits appear dense in DDD and not in C3GN is not known. We performed laser microdissection (LCM) of glomeruli followed by mass spectrometry (MS) in 12 cases each of DDD, C3GN, and pretransplant kidney control biopsies. LCM/MS showed marked accumulation of complement proteins C3, C5, C6, C7, C8, C9 and complement regulating proteins CFHR5, CFHR1, and CFH in C3GN and DDD compared to controls. C3, CFH and CFHR proteins were comparable in C3GN and DDD. Yet, there were significant differences. First, there was a six-to-nine-fold increase of C5-9 in DDD compared to C3GN. Secondly, an unexpected finding was a nine-fold increase in apolipoprotein E (ApoE) in DDD compared to C3GN. Most importantly, immunohistochemical and confocal staining for ApoE mirrored the dense deposit staining in the GBM in DDD but not in C3GN or control cases. Validation studies using 31 C3G cases confirmed the diagnosis of C3GN and DDD in 80.6 % based on ApoE staining. Overall, there is a higher burden of terminal complement pathway proteins in DDD compared to C3GN. Thus, our study shows that dense deposits in DDD are enriched with ApoE compared to C3GN and control cases. Hence, ApoE staining may be used as an adjunct to EM for the diagnosis of DDD and might be valuable when EM is not available.

Acid-Base Status Disturbances in Patients on Chronic Hemodialysis at High Altitudes.

BACKGROUND: Acid-base disorders have been previously described in patients with chronic hemodialysis, with metabolic acidosis being the most important of them; however, little is known about the potential changes in acid-base status of patients on dialysis living at high altitudes. METHODS: Cross-sectional study including 93 patients receiving chronic hemodialysis on alternate days and living in Bogotá, Colombia, at an elevation of 2,640 meters (8,661 feet) over sea level (m.o.s.l.). Measurements of pH, PaCO2, HCO3, PO2, and base excess were made on blood samples taken from the arteriovenous fistula (AVF) during the pre- and postdialysis periods in the midweek hemodialysis session. Normal values for the altitude of Bogotá were taken into consideration for the interpretation of the arterial blood gases. RESULTS: 43% (n= 40) of patients showed predialysis normal acid-base status. The most common acid-base disorder in predialysis period was metabolic alkalosis with chronic hydrogen ion deficiency in 19,3% (n=18). Only 9,7% (n=9) had predialysis metabolic acidosis. When comparing pre- and postdialysis blood gas analysis, higher postdialysis levels of pH (7,41 versus 7,50, p<0,01), bicarbonate (21,7mmol/L versus 25,4mmol/L, p<0,01), and base excess (-2,8 versus 2,4, p<0,01) were reported, with lower levels of partial pressure of carbon dioxide (34,9 mmHg versus 32,5 mmHg, p<0,01). CONCLUSION: At an elevation of 2,640 m.o.s.l., a large percentage of patients are in normal acid-base status prior to the dialysis session ("predialysis period"). Metabolic alkalosis is more common than metabolic acidosis in the predialysis period when compared to previous studies. Paradoxically, despite postdialysis metabolic alkalosis, PaCO2 levels are lower than those found in the predialysis period.

Proteomic and transcriptomic analysis of saliva components from the hematophagous reduviid Triatoma pallidipennis.

Species belonging to the Triatominae subfamily are commonly associated with Chagas disease, as they are potential vectors of the parasite Trypanosoma cruzi. However, their saliva contains a cocktail of diverse anti-hemostatic proteins that prevent blood coagulation, vasodilation and platelet aggregation of blood; components with indisputable therapeutic potential. We performed a transcriptomic and proteomic analyses of salivary glands and protein spots from 2DE gels of milked saliva, respectively, from the Mexican Triatoma pallidipennis. Massive sequencing techniques were used to reveal this protein diversity. A total of 78 out of 233 transcripts were identified as proteins in the saliva, divided among 43 of 55 spots from 2DE gels of saliva, identified by LC-MS/MS analysis. Some of the annotated transcripts putatively code for anti-hemostatic proteins, which share sequence similarities with proteins previously described for South American triatomines. The most abundant as well as diverse transcripts and proteins in the saliva were the anti-hemostatic triabins. For the first time, a transcriptomic analysis uncovered other unrelated but relevant components in triatomines, including antimicrobial and thrombolytic polypeptides. Likewise, unique proteins such as the angiotensin-converting enzyme were identified not just in the salivary gland transcriptome but also at saliva proteome of this North American bloodsucking insect. BIOLOGICAL SIGNIFICANCE: This manuscript is the first report of the correlation between proteome and transcriptome of Triatoma pallidipennis, which shows for the first time the presence of proteins in this insect that have not been characterized in other species of this family. This information contributes to a better understanding of the multiple host defense mechanisms that are being affected at the moment of blood ingestion by the insect. Furthermore, this report gives a repertoire of possible therapeutic proteins.

An Insight into the Triabin Protein Family of American Hematophagous Reduviids: Functional, Structural and Phylogenetic Analysis.

A transcriptomic analysis of the saliva of T. pallidipennis together with a short proteomic analysis were carried out to reveal novel primary structures of the lipocalin/triabin protein families in this reduviid. Although triabins share some structural characteristics to lipocalins and they are classified as in the calcyn/lipocalin superfamily, triabins differ from lipocalins in the direction of ß-strands in the general conformation of the ß-barrel. The triabin protein family encompasses a wide variety of proteins, which disrupt the hemostasis of warm-blooded animals. Likewise, the function of proteins classified as triabins includes proteins that are carriers of small molecules, protease inhibitors, binders of specific cell-surface receptors as well as proteins that form complexes with other macromolecules. For example, triabin and pallidipin from the saliva of T. pallidipennis are thrombin and platelet aggregation inhibitors, respectively; triplatin from T. infestans binds to thromboxane A2; and nitrophorin from Rhodnius prolixus carries nitric oxide. Therefore, based on 42 new transcriptome sequences of triabins from the salivary glands of T. pallidipennis reported at present, and on triabin sequences of other American hematophagous reduviids already reported in the literature, subfamilies of triabins were proposed following phylogenetic analyses and functional characterization of triabin members. Eight subfamilies of proteins were recognized with known functions, which were the nitrophorin and amine binding proteins, Rhodnius prolixus aggregation inhibitor, triafestin, triatin, dipetalodipin and pallidipin, triplatin and infestilin, dimiconin and triabin, and procalin subfamilies. Interestingly, 70% of the analyzed sequences came from these eight subfamilies because there was no biological function associated with them, implying the existence of a vast number of proteins with potential novel biological activities.

Developing an acceptability assessment of preventive dental treatments.

OBJECTIVES: Early childhood caries (ECC) is very prevalent among young Hispanic children. ECC is amenable to a variety of preventive procedures, yet many Hispanic families underutilize dental services. Acceptability research may assist in health care planning and resource allocation by identifying patient preferences among efficacious treatments with the goal of improving their utilization. The purposes of this study were (a) to develop a culturally competent acceptability assessment instrument, directed toward the caregivers of young Hispanic children, for five preventive dental treatments for ECC and (b) to test the instrument's reliability and validity. METHODS: An instrument of five standard treatments known to prevent ECC was developed, translated, reviewed by focus groups, and pilot tested, then tested for reliability The instrument included illustrated cards, brief video clips, and samples of the treatments and was culturally appropriate for low-income Hispanic caregivers. In addition to determining the acceptability of the five treatments individually, the treatments were also presented as paired comparisons. RESULTS: Focus groups and debriefing interviews following the pilot tests established that the instrument has good face validity. The illustrated cards, product samples, and video demonstrations of the five treatments resulted in an instrument possessing good content validity. The instrument has good to excellent test-retest reliability, with identical time 1-time 2 responses for each of the five treatments 92 percent of the time (range 87 to 97 percent), and the same treatment of the paired comparisons preferred 75 percent of the time (range 61 to 90 percent). CONCLUSIONS: The acceptability instrument described is reliable and valid and may be useful in program planning efforts to identify and increase the utilization of preferred ECC preventive treatments for target populations.