The purpose of the current study was to investigate the effect of different diameters of cylindrical titanium channels on human osteoblasts. Titanium samples having continuous drill channels with diameters of 300, 400, 500, 600, and 1000 microm were put into osteoblast cell cultures that were isolated from 12 adult human trauma patients. Cell migration into the drill channels was investigated by transmitted-light microscopy. The DNA content in the drill channels was measured photometrically, collagen type I production was analyzed by enzyme-linked immunosorbent assay (ELISA) and osteocalcin gene expression by reverse transcriptase-polymerase chain reaction (RT-PCR). Formation of mineralized tissue was assessed by microradiographs of histological sections. Within 20 days, cells grew an average of 838 microm (+/-128 microm) into the drill channels with a diameter of 600 microm and were significantly faster (p < 0.05) than in all other channels. Cells produced significantly more osteocalcin messenger RNA (mRNA) in 600-microm channels (p < 0.05) than they did in 1000-microm channels and demonstrated the highest osteogenic differentiation. The channel diameter did not influence collagen type I production. The highest cell density was found in 300-microm channels (p < 0.05). The DNA content of the channels linearly decreased with increasing channel diameters. After 40 days of culture, the proportion of mineralized tissue at the mouth section amounted to 6% in 300-microm channels and to 9-11% in 400-600-microm channels. In 1000-microm channels, only traces of mineralization were detected. Our data suggest that the diameter of cylindrical titanium channels has a significant effect on migration, gene expression, and mineralization of human osteoblasts.
The goal of this study was to characterize growth, mineralization and bone formation of osteoblast-like cells in titanium pore channels of defined diameter. Titanium implants with continuous drill channels of diameters of 300, 400, 500, 600 and 1,000 µm were inserted into human osteoblast-like cell cultures. The ingrowth of the cells into the drill channels was investigated by transmitted-light microscopy and scanning electron microscopy. Immunofluorescence and histological analysis of 15-channel sections of each diameter were used to investigate the growth behavior and the matrix protein patterns. Mineralization was evidenced by Alizarin red staining and high-resolution microradiography. The ingrowth of human osteoblast-like cells in the drill channels occurred in a sequence of four characteristic stages. In stage 1, osteoblast precursor cells adhered to the wall of the channel and migrated three-dimensionally into the channel by forming foot-like protoplasmic processes. For all 15 sample drill channels that were investigated, the cell ingrowth over 20 days amounted on average to 793 µm (± 179) into 600-µm-diameter channels, where they migrated significantly faster than in all the other channels. In stage 2, approximately on day 5–7, the osteoblast-like cells began to anchor on the substrate wall by matrix proteins and to build up a dense network of matrix proteins in the drill channel. The mineralization of the extracellular matrix, while depending on cell stimulation, was initiated in stage 3, on average after 4 weeks. In drill channels of a diameter of 1,000 µm the cell growth was incomplete and no mineralization was found by radiological assessment. Starting in week 6, in the drill channels of diameters ranging from 300 to 600 µm, the network of extracellular matrix proteins and osteoblast-like cells began to form an osteon-like structure. Neither the highly developed migration behavior of osteoblastic cells nor the reorganization from a fiber-like matrix to a lamellar structure have so far been described for cell cultures.
This article mainly reviews urinary tract injuries in patients with multiple trauma. Approximately 10% of all traumatic injuries resulting from an external force will involve the genitourinary system. The article discusses mechanisms of injury, diagnosis, and therapeutical approaches for renal, ureteral, bladder, and urethral trauma. Due to the complexity of such injuries--despite several attempts to provide a standard strategy in trauma patients with urinary tract involvement--an individual and patient-specific-therapeutic approach is mandatory in most cases. However, the availability of classified guidelines may help the surgeon to reach the most accurate decision. Because of the similarity of American and European guidelines on urological trauma, this article adapts injury severity scales and classification from the American Association for the Surgery of Trauma.
The goal of this study was to assess the osseointegration of porous titanium implants by means of coating with autologous osteoblasts.
In a prospective controlled study, carpal tunnel tissue pressures were determined in a group of 56 patients with distal dislocated fractures of the radius at initial presentation, immediately prior to and after reduction, and 1, 2, 4, 12, and 24 h after reduction. Depending on the severity of the trauma and delay to presentation at the hospital, initial measurements revealed raised pressure averaging 23 mm Hg, which further increased during reduction to 44 mm Hg. After 4 h the average pressure was 37 mm Hg, and it then dropped to 26 mm Hg after 12 h. For anatomical reasons the median nerve is quite vulnerable in the region of the wrist joint. Chronic pressure here may cause carpal tunnel syndrome. Acute pressure in the carpal tunnel, which according to our investigations represents a distinct compartment, results in an overt compartment syndrome. The possibility of a direct relationship between markedly elevated tunnel pressure and the development of Sudeck's dystrophy is discussed.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.