Integration and Application of Multimodal Measurement Techniques: Relevance of Photogrammetry to Orthodontics.

Multimodal imaging, including 3D modalities, is increasingly being applied in orthodontics, both as a diagnostic tool and especially for the design of intraoral appliances, where geometric accuracy is very important. Laser scanners and other precision 3D-imaging devices are expensive and cumbersome, which limits their use in medical practice. Photogrammetry, using ordinary 2D photographs or video recordings to create 3D imagery, offers a cheaper and more convenient alternative, replacing the specialised equipment with handy consumer cameras. The present study addresses the question of to what extent, and under what conditions, this technique can be an adequate replacement for the 3D scanner. The accuracy of simple surface reconstruction and of model embedding achieved with photogrammetry was verified against that obtained with a triangulating laser scanner. To roughly evaluate the impact of image imperfections on photogrammetric reconstruction, the photographs for photogrammetry were taken under various lighting conditions and were used either raw or with a blur-simulating defocus. Video footage was also tested as another 2D-imaging modality feeding data into photogrammetry. The results show the significant potential of photogrammetric techniques.

Impact of delayed umbilical cord clamping on public cord blood donations: can we help future patients and benefit infant donors?

BACKGROUND: Cord blood (CB) is a widely accepted stem cell source and its clinical utilization depends, to a great extent, on its cell content. Birth-to-clamping (BTC) time of umbilical cord determines placental transfusion to the newborn, and the remaining blood that can be collected and banked. The 2017 Committee Opinion of the American College of Obstetrics and Gynecologists (ACOG) recommends a delay of "at least 30-60 seconds" before clamping the cord for all newborns to ensure adequate iron stores. The impact of delayed cord clamping (DCC) on public CB banking can be substantial. STUDY DESIGN AND METHODS: Cord blood units (CBUs) collected from 1210 mothers at one hospital were evaluated for total nucleated cells (TNCs) and weight/volume based on time to clamping. Bank staff recorded BTC time in seconds as reported by obstetricians; collections were performed ex utero. Immediate clamping was defined as BTC of less than 30 seconds, whereas DCC was defined as BTC of 30 seconds or more. RESULTS: Cord clamping was immediate in 903 (75%) and delayed in 307 (25%) deliveries. Successful recovery (% clinical CBUs) decreased 10-fold with DCC of more than 60 seconds (22% vs. 2.4%, p < 0.001). CBUs collected after DCC of more than 60 seconds had significantly lower TNC counts than those after DCC of less than 60 seconds (p < 0.0001). Furthermore, 38% to 46% of CBUs after DCC of more than 60 seconds had volume of less than 40 mL. CONCLUSION: Our study indicates that DCC of 30 to 60 seconds has a small negative impact on collection of high-TNC-count CBUs. However, increasing BTC to more than 60 seconds decreases significantly both TNC content and volume, reducing drastically the chances of obtaining clinically useful CBUs.

Cytomegalovirus viral load in cord blood and impact of congenital infection on markers of hematopoietic progenitor cell potency.

BACKGROUND: The low incidence of cytomegalovirus (CMV) infection in neonates decreases the risk of viral transmission with cord blood transplantation. Cord blood donors are screened by testing the maternal sample for total antibodies to CMV. Some cord blood banks also screen cord blood for CMV-DNA. The aim of this study was to develop and validate a multiplex real-time polymerase chain reaction assay to measure CMV viral load in cord blood from asymptomatic infants with congenital CMV infection and to assess the impact of CMV infection on cord blood hematopoietic progenitor cell concentrations and colony-forming unit functionality. STUDY DESIGN AND METHODS: CMV infection was evaluated in two groups of cord blood donors: 1) 30,308 neonates prospectively screened by saliva culture, including 41 positive cases (0.14%), all from mothers with total antibodies to CMV; and 2) 4712 newborns from mothers with total antibodies to CMV who were screened retrospectively by polymerase chain reaction, including 18 positive cases (0.38%). All 59 infants with CMV were asymptomatic at birth. RESULTS: Among the 59 positive cases, the average CMV viral load in cord blood was 20.6 × 104 viral copies (vc)/mL; seven of 59 mothers (12%) had CMV-DNA detected, however, with no association to their newborns' CMV viral load. Levels of colony-forming units, CD34+ /CD45+ cells, and total nucleated cells measured in a cohort of CMV-positive cord blood samples were higher than those in the matched control group. CONCLUSION: We developed and validated a multiplex real-time polymerase chain reaction assay to detect CMV-DNA in cord blood. In our study, maternal total antibodies to CMV or CMV-DNA at birth were poor predictors of infection in cord blood donors. Furthermore, our results suggest that CMV congenital infection impacts CD34+ /CD45+ cells and some hematopoietic progenitor cells toward higher proliferation.

Detection of blood group genes using multiplex SNaPshot method.

BACKGROUND: The determination of blood group antigens in patients and donors is of primary importance in transfusion medicine. Blood group antigens are inherited and are polymorphic in nature. The majority of polymorphic blood group antigens arise from single-nucleotide polymorphisms (SNPs) in the blood group genes. Many DNA-based assays, such as species-specific polymerase chain reaction (PCR), PCR-restriction fragment length polymorphism, and microchips, have been described to study variant blood group genes. In this study, the SNaPshot (Applied Biosystems) method was adapted to detect SNPs in 10 common blood group systems. STUDY DESIGN AND METHODS: DNA regions of interest were amplified in multiplex PCR and annealed to specific oligonucleotide probe primers of different lengths. AmpliTaq DNA polymerase extended the primers by adding only a single fluorescent ddNTP to its 3' end and was detected by differential mobility in capillary electrophoresis in a genetic analyzer. Results were analyzed using computer software in SNaPshot default analysis method. RESULTS: Seventeen SNP sites in 29 blood samples, previously phenotyped and/or genotyped, were used to test the accuracy and reproducibility of multiplex SNaPshot assays. The results were compared with the previously analyzed types. SNaPshot analyses predicted the 17 SNP sites accurately for all the 29 blood samples. Both homozygous and heterozygous blood groups were detected with equal confidence. CONCLUSION: Blood group detection by SNaPshot method is a practical alternative to antibody-dependent phenotype prediction. Starting with DNA, this method is fast with a turnaround time of 24 hours with mean reagent cost around $2 per SNP detected.

Immunogold study of altered expression of some interendothelial junctional molecules in the brain blood microvessels of diabetic scrapie-infected mice.

Quantitative immunogold procedure was used to study the distribution of molecular components of interendothelial junctions in blood-brain barrier (BBB) microvessels of scrapie infected SJL/J hyperglycemic mice showing obesity and reduced glucose tolerance. Samples of brain (fronto-parietal cerebral cortex and thalamo-hypothalamic region) obtained from hyperglycemic (diabetic) mice and from non- infected, normoglycemic (non-diabetic) SJL/J mice, were processed for immunocytochemical examination. The localization of the following tight junction (TJ)-associated proteins was studied: occludin as an integral membrane (transmembrane) protein, and zonula occludens one (ZO-1) as a peripheral protein. The localization of beta-catenin as a representative of the cadherin/catenin complex that is typical for adherens junctions (AJs) also was studied. Morphometric analysis revealed that the density of immunosignals for occludin, represented by colloidal gold particles (GPs), was significantly lower in the brain microvessels of diabetic than in non-diabetic mice. No significant differences in the density of immunosignals for ZO-1 and beta-catenin between both experimental mouse groups were observed. It indicates that abnormal glucose metabolism affects mostly occludin which is believed to play a fundamental role in the maintenance of the tightness of endothelial lining in brain microvascular network and thereby in the preservation of its barrier function. These results also support the previously expressed opinion that occludin, detected with the applied morphological method, can be considered a sensitive indicator of altered molecular architecture of the interendothelial junctions due to the action of some metabolic or pathological insults.

Structural and functional studies of interaction between Plasmodium falciparum knob-associated histidine-rich protein (KAHRP) and erythrocyte spectrin.

Plasmodium falciparum dramatically modifies the structure and function of the membrane of the parasitized host erythrocyte. Altered membrane properties are the consequence of the interaction of a group of exported malaria proteins with host cell membrane proteins. KAHRP (the knob-associated histidine-rich protein), a member of this group, has been shown to interact with erythrocyte membrane skeletal protein spectrin. However, the molecular basis for this interaction has yet to be defined. In the present study, we defined the binding motifs in both KAHRP and spectrin and identified a functional role for this interaction. We showed that spectrin bound to a 72-amino-acid KAHRP fragment (residues 370-441). Among nine-spectrin fragments, which encompass the entire alpha and beta spectrin molecules (four alpha spectrin and five beta spectrin fragments), KAHRP bound only to one, the alpha N-5 fragment. The KAHRP-binding site within the alpha N-5 fragment was localized uniquely to repeat 4. The interaction of full-length spectrin dimer to KAHRP was inhibited by repeat 4 of alpha spectrin. Importantly, resealing of this repeat peptide into erythrocytes mislocalized KAHRP in the parasitized cells. We concluded that the interaction of KAHRP with spectrin is critical for appropriate membrane localization of KAHRP in parasitized erythrocytes. As the presence of KAHRP at the erythrocyte membrane is necessary for cytoadherence in vivo, our findings have implications for the development of new therapies for mitigating the severity of malaria infection.

Shift from fibrillar to nonfibrillar Abeta deposits in the neocortex of subjects with Alzheimer disease.

A morphometric study of amyloid-beta-positive plaques in the neocortex of eight non-demented people from 68 to 82 years of age and 17 subjects with late-stage Alzheimer disease (GDS stage 7/FAST stages 7a-f) from 73 to 93 years of age shows a shift from prevalence of fibrillar plaques to prevalence of nonfibrillar plaques. In the aged, non-demented subjects, about 4/mm^2 plaques are detectable in the neocortex, and the majority are fibrillar plaques. Specifically, 64% found to be classical fibrillar and Thioflavin-S-positive bright primitive plaques. A lower percentage of pale primitive plaques (35%) relatively small proportion of plaques that are poor in thioflavin S-positive fibrils. The numerical density of plaques in the severe stage of AD increases to about 41/mm^2. Severely demented subjects appear to maintain an active process of fibrillar plaque formation. This is reflected in the presence of 3% bright primitive plaques. Severely demented subjects also manifest plaque degradation, reflected in the presence of 22% and 48% percentages of classical fibrillar plaques in non-demented subjects and in the end stage of disease suggest that once activated, the process of fibrillar plaque formation persists at a somewhat stable rate during the whole course of brain amyloidosis.