Fetal wound healing has drawn the attention of many researchers from diverse background and specialties. Fetal wound healing is unique and differs from postnatal healing in that fetal skin wounds heal rapidly without scar formation. If the mechanism underlying such phenomenon can be elucidated, it will be serve as a significant milestone in the study of wound healing. Furthermore, the implications for therapeutic applications in wound management and in diseases where scarring is the basic pathogenetic mechanism would be immense. Rather than to list the results and conflicting data of numerous studies, this article hopes to provide a general overview of the recent developments.
Animal ; Cell Adhesion Molecules/physiology ; Collagen/physiology ; Extracellular Matrix/physiology ; Fetus/*physiology ; Growth Substances/physiology ; Human ; *Wound Healing

Human alveolar bone cells were isolated from alveolar bone fragments obtained from normal individual undergoing third molar extractions. Alveolar bone fragments were cultured as explant. Cells began to migrate in the first 5~7 day and were confluent in 5~7 week. Matrix mineralization was observed by 4 week. Our studies utilize established protocols for the characterization of these cells as osteoblasts by means of alkaline phosphatase activity determination, identification of osteocalcin antigens, establishing the presence of cells expressing type I collagen and determining the ability of cells to produce calcification. Transmission electron microscopic observations confirmed the presence of a collagen matrix undergoing a mineralization process. This new model, using human alveolar bone cells, may provide a tool to investigate alveolar bone development and physiology and to set up new therapeutic approaches.
Alkaline Phosphatase ; Bone Development ; Collagen ; Collagen Type I ; Humans* ; Molar, Third ; Osteoblasts ; Osteocalcin ; Physiology

gp130-mediated signaling is involved in both chondrogenesis and osteogenesis, but its direct role in the formation of embryonic Meckel's cartilage and associated mandibular development has not yet been elucidated. In this study, we examined the influence of gp130 ablation on the developing mandibular Meckel's cartilage by evaluating the morphological and histological changes as well as the gene expression patterns in developing embryonic gp130-/- mice. The ablation of the gp130 gene showed no change in region-specific collagen mRNA expression except for a slight delay in its expression but caused shortened embryonic Meckel's cartilage, delayed hypertrophic chondrocyte maturation and subsequent bony replacement with characteristic bending of the intramandibular Meckel's cartilage. The bending of Meckel's cartilage led to a narrow mandibular arch at the rostral area with poor cortical plate formation. These findings indicate that gp130-mediated signaling is important for the normal morphogenesis of Meckel's cartilage and subsequent mandibular development.
Animals ; Body Patterning ; Cartilage/embryology/metabolism/*physiology ; Collagen ; Cytokine Receptor gp130/genetics/*physiology ; Mandible/embryology/metabolism/*physiology ; Mice ; Mice, Knockout

OBJECTIVETo investigate the effect on intramuscular connective tissue and passive range of joint motion by the stress produced in limb lengthening.

METHODSAn animal model of limb lengthening was established in the tibia of rabbits. Distraction was initiated at a rate of 1 mm/d and 2 mm/d in two steps respectively, and both proceeded until 10% and 20% of the tibia length was achieved. Muscle samples were harvested at the time when distraction ended and at the 4th week of consolidation after the distraction. Scanning electron microscope was applied to observe the morphological changes of the perimysium. The goniometer, which we made for this study, was used to measure the passive range of joint motion.

RESULTSThe collagen fibers were partitioned in bundles, crimped and interconnected closely and orderly. In the regime of 1 mm/d distraction with 10% lengthening, no apparent changes of the collagen fiber and passive range of joint motion was demonstrated. When tibia was increased to 20%, the crimped fibers showed a tendency of being straightened while the passive range of joint motion was reduced. The findings remained the same at the 4th week of consolidation. In the regime of 2 mm/d distraction with 10% lengthening, the crimped structure of the collagen fibers in the perimysium disappeared and the fibers were almost straightened. Additionally, the interconnection of the collagen fibers became loosened and interstice was presented among the fibers. At the 4th week of consolidation, the restoration to the original crimped structure was not completed. When the lengthening ratio was increased to 20%, the collagen fibers were straightened completely. This condition remained unchanged throughout all 4 weeks. The passive range of joint motion was reduced dramatically in the regime of 2 mm/d distraction.

CONCLUSIONThe ultrastructure of perimysium and the passive range of joint motion in the regime of 1mm/d lengthening shows the condition closest to the normal ones. The regime of 2 mm/d lengthening may cause an apparent change in the ultrastructure of perimysium and passive range of joint motion.

Animals ; Bone Lengthening ; Collagen ; ultrastructure ; Connective Tissue ; injuries ; physiology ; ultrastructure ; Male ; Osteogenesis, Distraction ; Rabbits ; Range of Motion, Articular ; physiology ; Regeneration ; physiology

OBJECTIVETo observe the effects of supernatants of normal skin keratinocytes(NK) and scar keratinocytes(SK) on proliferation and collagen synthesis of hypertrophic scar fibroblasts(HSFB).

METHODSThe supernatant, collected from cultured NK and SK, was added to the cultivated HSFB. The MTT-method, 3H-proline incorporation and radioimmunoassay were employed to measure the cell proliferation, collagen synthesis and secretion.

RESULTSNK supernatant could inhibit HSFB proliferation and increase the collagen synthesis, but inhibit collagen secretion, as compared with the control group. On the contrary, SK supernatant could increase collagen synthesis and secretion, which had little effects on HSFB proliferation.

CONCLUSIONKeratinocytes derived from normal skin and hypertrophic scar show different effects on hypertrophic scar fibroblasts.

Cell Division ; Cells, Cultured ; Cicatrix, Hypertrophic ; metabolism ; pathology ; Collagen ; biosynthesis ; Culture Media, Conditioned ; Fibroblasts ; physiology ; Humans ; Keratinocytes ; physiology

OBJECTIVETo probe into the mechanism of acupuncture analgesia.

METHODSType-I collagenase was injected to destroy the structure of collagen fibers in the acupoint. Paw withdrawing latency and mast cell degranulation rate in the acute adjuvant arthritis rat were investigated. Effects of acupuncture at "Zusanli" (ST 36) with twirling or thrusting-lifting manipulation on acupuncture analgesia and mast cells were compared when the structures of collagen fibers in the acupoint were destroyed or not.

RESULTSWhen the structures of collagen fiber were destroyed, the analgesic effects of both acupuncture manipulations were attenuated and the degranulation rate of mast cells caused by acupuncture were significantly inhibited.

CONCLUSIONCollagen fibers and mast cells in the acupoint play an important role in acupuncture analgesia. Collagen fibers participate in transmission and transform process of acupuncture signs from the acupoint to the target organ, and the degranulation of mast cells is positively correlated with acupuncture analgesia.

Acupuncture Analgesia ; Acupuncture Points ; Animals ; Cell Degranulation ; Collagen ; physiology ; Male ; Mast Cells ; physiology ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo study the effect of integrin alpha2beta1 on invasion and migration of SK-N-SH neuroblastoma cells.

METHODSNeuroblastoma SK-N-SH cell line was cultured in the modified eagle's medium. The effects of monoclonal antibodies to integrin alpha2 and integrin beta1 on migration and invasion were measured by inclined test and polycarbonate filters incorporated in modified Transwell chambers respectively. The migration and invasion cells were stained with Gimsa staining and counted under a 200 multiplied microscope. The blocking rate of migration and invasion of cells was calculated.

RESULTSThe number of migrated SK-N-SH cells in the anti-alpha2 and anti-beta1 treatment groups (50.9+/-10.5 and 54.3+/-9.0 respectively) was significantly less than that in the control group without monoclonal antibody treatment (98.1+/-7.4) (P<0.01), with a blocking rate of cell migration of 48.1% and 44.5% respectively. The invasion to matrigel of SK-N-SH cells exposed monoclonal antibodies to integrin alpha2 and integrin beta1 was significantly blocked compared with the control SK-N-SH cells, with the number of invasion cells in the anti-alpha2 and anti-beta1 treatment groups of 25.3 +/- 4.4 and 18.8 +/- 3.9 respectively vs 41.5 +/- 4.8 in the control group (P<0.01). The blocking rate of cell invasion in the anti-alpha2 and anti-beta1 treatment groups was 39.0% and 54.7% respectively.

CONCLUSIONSIntegrin alpha2beta1 may promote migration and invasion of neuroblastoma cells.

Cell Line, Tumor ; Cell Movement ; Collagen Type I ; physiology ; Humans ; Integrin alpha2beta1 ; physiology ; Neoplasm Invasiveness ; Neuroblastoma ; pathology

OBJECTIVEThe aim of this study was to investigate the expression of collagen in the process of masseter muscle reattachment to the cortical and cancellous bones of mandible.

METHODSA total of nine adult goats were used in the study. One was the control. The other eight were treated with bilateral detachment of the masseter muscles. The biopsies of bone and muscle were taken at 2, 4, 8 and 12 weeks after the operation. The characteristics of the healing muscle-bone interfaces were examined using immunohistochemical techniques.

RESULTSImmunohistochemical analysis illustrated that the locations of collagen type I, II and III were different during the healing process, but similar in the cortical and cancellous bones.

CONCLUSIONThis study demonstrates that the distribution of the three types of collagens at the muscle-bone interfaces is associated with time, but not related with their locations.

Animals ; Collagen ; biosynthesis ; genetics ; Collagen Type I ; biosynthesis ; genetics ; Collagen Type II ; biosynthesis ; genetics ; Collagen Type III ; biosynthesis ; genetics ; Female ; Goats ; Male ; Mandible ; metabolism ; pathology ; surgery ; Masseter Muscle ; metabolism ; pathology ; surgery ; Wound Healing ; physiology

OBJECTIVETo immortalize human articular chondrocytes (HACs) using gene transfection and to maintain stable phenotype of transformed HACs after induction.

METHODSHACs were transfected with the retroviral vector pLXSN encoding human papillomavirus 16E7 (HPV16E7), and the transformed clones were sorted and proliferated. Karyotype analysis, clone forming tests and nude mice tumor forming tests were applied to check the characteristics of the transformation. Type II collagen of transformed chondrocytes was inducted with free serum medium (FSM) supplemented with nutridoma-sp and ascorbate.

RESULTSImmortalized HACs were isolated with fifty passages achieved. The HPV16E7 transformed cells were confirmed to be benign. Induction of FSM with nutridoma-sp and ascorbate promoted type II collagen of transformed chondrocytes to the high levels of normal chondrocytes.

CONCLUSIONHACs transformed with HPV16E7 survive for long periods in vitro, and type II collagen can maintain stability after induction.

Cells, Cultured ; Chondrocytes ; physiology ; Collagen Type II ; analysis ; Fetus ; Humans ; Knee Joint ; cytology ; Phenotype ; Transfection

This experiment was aimed to shed light on the correlation and quantitative relationships between the width of bovine periodontal ligament (PDL) and the elastic modulus and, more over, between the width of bovine PDL and the capacity ratio of collagen fibers. The width and length of periodontal ligament of PDL were determined by stereomicroscope, and the elastic modulus by the materials testing systems. The collagen fibers in cross section of the specimen were stained with 1% Sirius Red F3B in saturated carbazotic acid, and the photo of stained PDL was collected by stereomicroscope. Image pro plus6.0 image analysis software was used to measure and calculate the capacity ratio of collagen fibers. It was found that there is a negative correlation between the width of bovine periodontal ligament and elastic modulus. The correlation coefficient is -0.21 and the simple linear regression model is Y = 71. 681-0.021x (Width of PDL); there is a positive correlation between capacity ratio of collagen fibers and elastic modulus. The coefficient correlation is 1.583 and the simple linear regression model is Y = -34.944 + 1.583x (The percentage of collagen fibers). Thus, the elastic modulus of bovine PDL increases while the width of bovine PDL decreases, and it increases while the capacity ratio of collagen fibers increases.
Animals ; Cattle ; Collagen ; chemistry ; Elastic Modulus ; Periodontal Ligament ; physiology ; Tensile Strength ; Tooth Root ; anatomy & histology