Urinary excretion and blood concentrations of trace elements and electrolytes during total parenteral nutrition in crohn's disease

Urinary excretion of trace elements (Cr, Co, Cu, Fe, Mn, Se, Zn, Sb, Cs, Rb), electrolytes (Na, K, Ca, Mg, phosphate), and nitrogen were determined during days 1–5 and 54–79 of total parenteral nutrition (TPN, nil per os) given to six patients with Crohn's disease. Whole-blood concentrations of Cr, Fe, Zn, Cs, and Rb and serum concentrations of electrolytes were determined before the TPN and on days 54–79 of TPN. The 24-hr urinary excretion of zinc was lower on days 54–79 than on days 1–5, but the rates of excretion of the other essential trace elements during TPN displayed no significant change. The urinary excretion of Cu, Fe, and Mn was numerically lower than the intravenous administration of these elements during days 1–5 and 54–79 of TPN, whereas the urinary excretion of zinc was lower than the supply only during days 54–79. The whole-blood concentration of zinc was low but constant during TPN, whereas the initially low levels of Cr and Fe were normalized on days 54–79. The results suggest that the supply of the essential trace elements Cr, Co, Cu, Fe, Mn, and Zn was largely adequate during two to three months of TPN and that the human body may adapt to a somewhat low supply of zinc, 20–30 mol/24 hr.     

Parenterally administered salivary tissue extracts reduce outputs of Na+ and K+ associated with bile salt-induced damage of rat oxyntic mucosa

Extirpation of the major salivary glands in rats has been shown to exacerbate the ionic fluxes associated with pharmacologically-induced damage to the gastric mucosal barrier. In the present study we have investigated the effect of the administration of a crude extract of submandibular-sublingual salivary glands on gastric secretion and gastric mucosal barrier integrity in the rat. The extract was administered in a dose (4 mg protein) which would reduce established acid secretion by 30%. Chronic parenteral (intraperitoneal) administration of salivary gland extract but not phosphate buffer resulted in a reduction in the luminal appearance of Na⁺ and K⁺ associated with bile salt-induced damage (5 mM sodium taurocholate in 150 mM HCl) to the gastric mucosa of sialoadenectomized animals. Oral administration of the extract depressed its protective action. Boiling the extract prior to parenteral administration also abolished its ability to protect the mucosa. Acute administration of the extract by intraperitoneal injection only 30 min prior to bile salt treatment was also ineffective. These results suggest that chronic parenteral but not enteral treatment with a crude salivary gland extract aids in the maintenance of the gastric mucosal barrier in sialoadenectomized rats. The inability of acute administration of the extract to reduce the net fluxes of Na⁺ and K⁺ suggests that its mode of action is not entirely dependent upon an inhibition of gastric acid secretion.This study was funded by a grant from the Medical Research Council of Canada, Grant no. MA-6426     

The use of a rigid disc to protect exposed structures in wounds treated with negative pressure wound therapy: Effects on wound bed pressure and microvascular blood flow

There are increasing reports of deaths and serious complications associated with the use of negative pressure wound therapy (NPWT). Bleeding may occur in patients when NPWT is applied to a wound with exposed blood vessels or vascular grafts, possibly due to mechanical deformation and hypoperfusion of the vessel walls. Recent evidence suggests that using a rigid barrier disc to protect underlying tissue can prevent this mechanical deformation. The aim of this study was to examine the effect of rigid discs on the tissue exposed to negative pressure with regard to tissue pressure and microvascular blood flow. Peripheral wounds were created on the backs of eight pigs. The pressure and microvascular blood flow in the wound bed were measured when NPWT was applied. The wound was filled with foam, and rigid discs of different designs were inserted between the wound bed and the foam. The discs were created with or without channels (to accommodate exposed sensitive structures such as blood vessels and nerves), perforations, or a porous dressing that covered the underside of the discs (to facilitate pressure transduction and fluid evacuation). When comparing the results for pressure transduction to the wound bed, no significant differences were found using different discs covered with dressing, whereas pressure transduction was lower with bare discs. Microvascular blood flow in the wound bed decreased by 49 ± 7% when NPWT was applied to control wounds. The reduction in blood flow was less in the presence of a protective disc (e.g., ?6 ± 5% for a dressing‐covered, perforated disc, p = 0.006). In conclusion, NPWT causes hypoperfusion of superficial tissue in the wound bed. The insertion of a rigid barrier counteracts this effect. The placement of a rigid disc over exposed blood vessels or nerves may protect these structures from rupture and damage.     

Influence of a Nanoporous Zirconia Implant Surface of on Cell Viability of Human Osteoblasts

Purpose : The dense nonretentive surface of zirconia implants was modified into a nanoporous surface using selective infiltration etching surface treatment. The aim of this study was to investigate the influence of such a nanoporous modified zirconia surface on the attachment of human osteoblasts. Materials and Methods : Human osteoblasts were cultured for 21 days on (i) selective infiltration etched zirconia (nanoporous surface), (ii) polished zirconia, (iii) polished titanium, or (iv) airborne particle abraded acid etched (SLA) titanium disks. After the culture period the following parameters were assessed: number of cells, the morphology of the cells, the attachment of the cells, alkaline phosphatase activity, and the level of total protein (α= 0.05). Results : Statistical analysis revealed a significantly higher cell count on the third (F = 17.4, p < 0.001) and eighth day (F = 163, p < 0.001) for nanoporous zirconia and SLA titanium surfaces compared to polished specimens. The number of cells (nanoporous zirconia 160 ± 20/mm², SLA titanium 133 ± 15/mm²) and cell size (nanoporous zirconia 50.7 ± 3 μm, SLA titanium 42.5 ± 4 μm) were significantly higher than polished specimens. Nanoporous zirconia specimens demonstrated comparable alkaline phosphatase activity (0.0036 ± 0.0035 ng/μl) and intracellular protein content (72.7 ± 0.9 ng/μl) compared to other tested groups. Scanning electron microscopy revealed that cells attached on the polished surface using finger‐like processes, whereas on the nanoporous surface, finger‐like processes were not observed, as the cell membrane appeared to be in close proximity to the underlying surface. Conclusion : The findings of this study suggest that a nanoporous zirconia surface favors cell growth and attachment compared to a polished surface. It was proposed that a nanoporous zirconia surface may improve clinical performance of zirconia implants.     

Micro–Computed Tomography Analysis of the Root Canal Anatomy and Prevalence of Oval Canals in Mandibular Incisors

Introduction

This study aimed to describe the anatomy of the mandibular incisors by using micro–computed tomography.

Methods

Mandibular incisors (n = 340) were scanned at 19-μm voxel size resolution, and the numbers of canals were classified according to Vertucci classification, as well as the major and minor diameters of the root and root canals, presence of oval canals, and three-dimensional analysis of the apical third were also measured. Data were presented in terms of median and range for each anatomic classification.

Results

Overall, the specimens had 1 root canal (N = 257). The second most prevalent anatomy was Vertucci type III (N = 56). These anatomies represent 92% of the sample. The medians of the major diameter at the 1-, 2-, and 3-mm level of the most prevalent anatomies were 0.36, 0.39, and 0.47 mm for type I and 0.41, 0.51, and 0.66 mm for type III, respectively. The apical volume appears to be constant among these anatomies (0.63 and 0.59 mm³). Oval canals were found at the 1-mm apical level, with a prevalence of 16.7% for Vertucci type I and 37.5% for Vertucci type III. The presence of oval canals increased at the 3-mm apical level to 32.4% and 76.2% for Vertucci type I and III classifications, respectively.

Conclusions

Type I and III configurations represent 92% of the mandibular incisors studied. Within these anatomic configurations, oval-shaped canals in the apical third were not uncommon and more prevalent in the type III anatomy.     

Portable fixed dynamometry to quantify ankle dorsiflexion force

Introduction: Quantifying muscle strength is critical in clinical and research settings. A rapid and objective method is ideal. The primary objective of this study was to examine the reliability of a novel device, the rapid objective quantification― tibialis anterior (ROQ-TA), which quantifies the dorsiflexion force of the tibialis anterior, and to assess its validity against isokinetic dynamometry (IKD). Methods: Ankle dorsiflexion of 20 healthy subjects was assessed by 3 modalities, ROQ-TA, manual muscle testing, and isokinetic dynamometry, over 2 testing sessions. Results: The intraclass correlation coefficient [ICC_(2,1)] for reliability was 0.872 (0.677–0.949) for the ROQ-TA and 0.892 (0.728–0.957) for IKD. For validity, the ICC_(2,1) values for the ROQ-TA and IKD were in good agreement, with 0.672 (0.17–0.87) in the first testing session and 0.769 (0.42–0.91) in the second session. Discussion: The ROQ-TA is a valid and reliable device to test ankle dorsiflexion force in a healthy population. Muscle Nerve, 2018