Rodent animal models for vital pulp therapy are commonly used in dental research because their tooth anatomy and cellular processes are similar to the anatomy and processes in humans. However, most ...studies have been conducted using uninfected sound teeth, which makes it difficult to adequately assess the inflammatory shift after vital pulp therapy. In the present study, we aimed to establish a caries-induced pulpitis model based on the conventional rat caries model and then evaluate inflammatory changes during the wound-healing process after pulp capping in a model of reversible pulpitis induced by carious infection. To establish the caries-induced pulpitis model, the pulpal inflammatory status was investigated at different stages of caries progression by immunostaining targeted to specific inflammatory biomarkers. Immunohistochemical staining revealed that both Toll-like receptor 2 and proliferating cell nuclear antigen were expressed in moderate and severe caries-stimulated pulp, indicating that an immune reaction occurred at both stages of caries progression. M2 macrophages were predominant in moderate caries-stimulated pulp, whereas M1 macrophages were predominant in the severe caries-stimulated pulp. Pulp capping in teeth with moderate caries (i.e., teeth with reversible pulpitis) led to complete tertiary dentin formation within 28 d after treatment. Impaired wound healing was observed in teeth with severe caries (i.e., teeth with irreversible pulpitis). During the wound-healing process in reversible pulpitis after pulp capping, M2 macrophages were predominant at all time points; their proliferative capacity was upregulated in the early stage of wound healing compared with healthy pulp. In conclusion, we successfully established a caries-induced pulpitis model for studies of vital pulp therapy. M2 macrophages have an important role in the early stages of the wound-healing process in reversible pulpitis.
Background
Visceral obesity is one of the risk factors for clinically relevant pancreatic fistula after pancreatic resection. The objective of this study was to evaluate the impact of intraperitoneal ...lipolysis on postoperative pancreatic fistula.
Methods
The degree of intraperitoneal lipolysis was investigated by measuring the free fatty acid concentration in drain discharge in patients after pancreatic resection. An experimental pancreatic fistula model was prepared by pancreatic transection, and the impact of intraperitoneal lipolysis was evaluated by intraperitoneal administration of triolein (triglyceride) with, or without orlistat (lipase inhibitor).
Results
Thirty‐three patients were included in the analysis. The free fatty acid concentration in drain discharge on postoperative day 1 was significantly associated with the development of a clinically relevant pancreatic fistula (P = 0·004). A higher free fatty acid concentration in drain discharge was associated with more visceral adipose tissue (P = 0·009). In the experimental model that included 98 rats, intraperitoneal lipolysis caused an increased amount of pancreatic juice leakage and multiple organ dysfunction. Intraperitoneal administration of a lipase inhibitor reduced lipolysis and prevented deterioration of the fistula.
Conclusion
Intraperitoneal lipolysis significantly exacerbates pancreatic fistula after pancreatic resection. Inhibition of lipolysis by intraperitoneal administration of a lipase inhibitor could be a promising therapy to reduce clinically relevant postoperative pancreatic fistula.
Surgical relevance
Clinically, there are two types of pancreatic fistula after pancreatic resections: harmless biochemical leak and harmful clinically relevant pancreatic fistula. Visceral obesity is one of the known risk factors for clinically relevant pancreatic fistula; however, the underlying mechanisms remained to be elucidated.
Patients with clinically relevant pancreatic fistula had a higher free fatty acid concentration in the drain discharge, suggesting a relationship between intraperitoneal lipolysis and pancreatic fistula. The experimental model of pancreatic fistula demonstrated that intraperitoneal lipolysis caused deterioration in pancreatic fistula, suggesting that intraperitoneal lipolysis is one of the mechanisms that drives biochemical leakage to clinically relevant pancreatic fistula.
Intraperitoneal administration of a lipase inhibitor prevented lipolysis as well as pancreatic fistula deterioration in the experimental model, suggesting a future clinical application for lipase inhibitors in prevention of clinically relevant pancreatic fistula.
Patients with clinically relevant pancreatic fistula had a significantly higher free fatty acid concentration in drain discharge, suggesting a relationship between intraperitoneal lipolysis and pancreatic fistula. The investigation in rat pancreatic fistula models demonstrated that intraperitoneal lipolysis caused deterioration of pancreatic fistula, indicating that intraperitoneal lipolysis is one of the mechanisms that drives biochemical leakage to clinically relevant pancreatic fistula.
Potential target for prevention
The condition for the occurrence of stick-slip motion is examined analytically based on a 1-DOF system with Coulomb friction which includes seven independent parameters. There exist two dimensionless ...parameters which control the occurrence of stick-slip motion, one denotes the easiness for the occurrence of stick-slip motion and the other is the damping ratio acting to suppress the motion. A simple non-occurrence inequality of stick-slip motion is derived with the two dimensionless parameters through dimensionless analysis and numerical simulation, which has both high accuracy and high usability. Its validity is confirmed by the comparison with the experimental results reported by Singh.
In this paper, the authors study the behavior of the sheaf cohomology functors
R
●
ind
B
G
−
where
G
is an algebraic group scheme corresponding to a simple classical Lie superalgebra and
B
is a BBW ...parabolic subgroup as defined in GGNW. We provide a systematic treatment that allows us to study the behavior of these cohomology groups
R
●
ind
B
G
L
f
λ
where
L
f
λ
is an irreducible representation for the detecting subalgebra
f
.
In particular, we prove an analog of Kempf's vanishing theorem and the Bott-Borel-Weil theorem for large weights.
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