Evidence for the existence of intraepithelial nerve endings in the junctional epithelium of rat molars: an immunohistochemical study using protein gene product 9.5 (PGP 9.5) antibody

Innervation of the junctional epithelium was investigated in rat molars by means of immunohistochemistry for protein gene product 9.5 (PGP 9.5) at light and electron microscopic levels. In comparison with our previous study on same tissues using neurofilament protein (NFP)-antibody, the PGP 9.5-immuno-staining further disclosed numerous nerve fibers in the gingiva of rat molars and revealed the existence of a well-developed plexus of PGP 9.5-positive nerve fibers. The interproximal portion also contained numerous nerve fibers.
Observation of horizontal sections revealed a denser innervation toward the inner junctional gingival epithelium than the outer marginal epithelium. The nerve fibers, beaded in appearance and extending from the nerve bundles in the lamina propria, penetrated into the junctional epithelial layer and were distributed throughout the junctional epithelium, with some nerves being located near the epithelial surface. Non-neuronal cells showing PGP 9.5-immunoreactivity were absent in the junctional epithelium. In immunoelectron microscopy, the axoplasm of nerves in the gingiva was filled with electron-dense reaction products of PGP 9.5, except for the cell organellae. The nerve fibers were devoid of Schwann cell investment and terminated among the epithelial cells in the junctional epithelium, frequently beneath the epithelial surface. The intraepithelial nerve endings contained various kinds of vesicles including large-cored ones, supporting the presence of peptidergic innervation shown by previous studies. These findings confirmed the usefulness of PGP 9.5-immunohisto-chemistry for the identification of delicated nerve fibers in dental tissue, and suggested the dense network of nerve fibers that may serve as sensory receptor and other functions in the junctional epithelium.     

Effects of Self Washout Structure on the Antithrombogenicity and the Hemolytic Properties of a Centrifugal Pump

Abstract: Antithrombogenicity in an initial type (Nl) of a centrifugal pump (CP) developed in our institute is provided by the central balancing hole of an impeller. A new CP (N2) was modified to obtain better antithrombogenicity, in which the balancing hole was widened to improve self washout flow velocity (Vsf), and an edge of the thrust bearing was rounded off to minimize flow separation. Effects of the modifications were assessed in vitro and in vivo studies. The Vsf of the Nl and the N2 evaluated by a Doppler velocimeter were 12.8 and 22.1 cm/s, respectively. Flow around the thrust bearing, which was visualized by a light cutting method, confirmed less flow stagnation in the N2. The hemolytic indices of the Nl and the N2 were 0.023 and 0.008 mg/dl, respectively. In vivo antithrombogenicity and the hemolytic properties of the N2 and the Nl were investigated without anticoagulation therapy in 3 goats. In each goat the N2 was driven for 1 week and exchanged for the Nl, which was driven for the same period. Red thrombi at the thrust bearing were found in 2 Nls, and 2 small thrombi were on the impeller of another Nl, whereas a thrombus of less than 1 mm³ at the TB was noted in 1 N2. Plasma free hemoglobin was not increased in either CP. These results indicate that the N2 has better antithrombogenicity and hemolytic properties than the Nl.     

Detection of mutant adenine phosphoribosyltransferase genes by polymerase chain reaction-single strand conformation polymorphism analysis]

Polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) analysis is a rapid and sensitive method to identify point mutations in a given sequence of genomic DNA. We tried to apply the PCR-SSCP to the diagnosis of adenine phosphoribosyltransferase (APRT) deficiency, which is an autosomal recessive hereditary disease leading to 2,8-dihydroxyadenine urolithiasis. Genomic APRT genes, with or without mutations, were amplified and labeled simultaneously with 32P-dCTP by PCR. When run in a 6% polyacrylamide gel containing 10% glycerol, two types of mutant genes, APRT*Q0 and APRT*J, gave bands clearly distinct from those of the respective normal APRT genes. Since heterozygotes as well as homozygotes for these mutant APRT genes can be detected in 2 days, PCR-SSCP should be a valuable method in the diagnosis of APRT deficiency and in screening a large population for APRT mutant genes.     

Fundus hemorrhage in patients with intracranial hemorrhage caused by cerebrovascular disease--its clinical significance]

To clarify the significance of fundus hemorrhage in the acute stage of intracranial hemorrhage due to cerebrovascular disease (HCVD), the incidence of such hemorrhage (retinal, preretinal, and subhyaloid hemorrhage) was examined and its correlations with the severity of the disturbance of consciousness and the prognosis were investigated. Two hundred sixteen HCVD patients with intracranial hemorrhage were the subjects of this study, including 87 cases of subarachnoid hemorrhage (SAH), 60 cases of hypertensive intracerebral hemorrhage (HICH), 54 cases of arteriovenous malformation (AVM), and 15 cases of Moyamoya disease. Fundus hemorrhage was recognized in 41 cases of SAH (47%), 5 cases of HICH (8%), 3 cases of AVM (6%), and 2 cases of Moyamoya disease (13%). The incidence of fundus hemorrhage was significantly higher in SAH than in the other type of HCVD associated with intracranial hemorrhage. Among patients with severe disturbance of consciousness (JCS 100-300), fundus hemorrhage was recognized in 69% with SAH, 13% with HICH, 17% with AVM, and none with Moyamoya disease. Therefore, patients with both fundus hemorrhage and severe disturbance of consciousness in the acute stage are most likely to have SAH, but HICH and AVM should be also taken into consideration. In patients with slight disturbance of consciousness (JCS 0-30), fundus hemorrhage was only noted in SAH (27%) and not in other types of HCVD associated with intracranial hemorrhage. Thus, SAH is highly likely to be the primary HCVD associated with intracranial hemorrhage, if we recognize fundus hemorrhage in patients with slight disturbance of consciousness in the acute stage.(ABSTRACT TRUNCATED AT 250 WORDS)     

A study of the right ventricular load at the unilateral pulmonary artery occlusion test after pneumonectomy

After pneumonectomy, it is recognized that the absolute reduction of the pulmonary vascular bed makes the right ventricular afterload increase and can cause right heart failure in patients with low cardiopulmonary reserve. Therefore, we investigated how the right ventricular load was predicted by UPAO test, comparing hemodynamics at the time of the test with those after pneumonectomy in patients with lung cancer. At the test, the absolute reduction of the pulmonary vascular bed made the right ventricular afterload increase but the right ventricular pump function was maintained at the preoperative level by the increase of the right ventricular work load, namely, by the contraction of the right ventricle. After pneumonectomy, the absolute reduction of the vascular bed did not always make the afterload increase and in spite of the decreased preload the pump function was maintained at the preoperative level by increased heart rate. Additionally, the increase of the right ventricular work load improved during early postoperative days. It was concluded that UPAO test was apt to overestimate the right ventricular load of the postoperative day because it was done under the condition of the different compensatory function from the postoperative hypovolemic change.     

Interference by adrenaline with chondrogenic differentiation through suppression of gene transactivation mediated by Sox9 family members

In contrast to osteoblasts, little attention has been paid to the functional expression of adrenergic signaling machineries in chondrocytes. Expression of mRNA was for the first time demonstrated for different adrenergic receptor (AdR) subtypes in chondrogenic ATDC5 cells and mouse metatarsals isolated before vascularization in culture, but not for other molecules related to adrenergic signaling. In neonatal mouse tibial sections, β₂AdR and α_2aAdR mRNA expression was found in chondrocytes at different developmental stages by in situ hybridization. Exposure to adrenaline significantly suppressed expression of several maturation markers through the cAMP/protein kinase A pathway activated by β₂AdR without affecting cellular proliferation in both cultured ATDC5 cells and metatarsals. Adrenaline also significantly inhibited gene transactivation by sry-type HMG box 9 (Sox9) family members essential for chondrogenic differentiation in a manner prevented by the general βAdR antagonist propranolol, with a concomitant significant decrease in the levels of Sox6 mRNA and corresponding protein, in ATDC5 cells and primary cultured mouse costal chondrocytes. Systemic administration of propranolol significantly promoted the increased expression of mRNA for collagen I and collagen X, but not for collagen II, in callus of fractured femur in mice. These results suggest that adrenaline may interfere with chondrogenic differentiation through downregulation of Sox6 expression for subsequent suppression of gene transactivation mediated by Sox9 family members after activation of β₂AdR expressed by chondrocytes.