Shark pit organs: enhancement of mechanosensitivity by potassium ions.

The mandibular pit organs of pelagic sharks, which respond sensitively to monovalent cations, often show neural discharges synchronized with respiratory gill movement. The mechanosensitivity of the organs is remarkably enhanced by application of potassium ions on the same end organ, respiratory movement remaining constant. In view of their michanosensitivity to an incr-ease of potassium ions in the cell environment, as well as their chemosensitivity,the pit organs of sarks, rather than the canal organs which have no chemosensitivity, may be designated as a better model of the inner ear of higher animals.

Tetraethylammonium and tetrodotoxin: effects on cochlear potentials.

Tetraethylammonium chloride, which is believed to decrease potassium conductance, and tetrodotoxin, which apparently decreases sodium conductance in nerve fibers, were introduced iontophoretically into the organ of Corti or the scala media of guinea pig cochlea. The former depressed the direct-current endocochlear potential and also the alternating-current cochlear microphonics (the receptor potential of the ear), but tetrodotoxin was ineffective except on the nerve impulses.

Shark pit organs: response to chemicals.

Nerve fibers from pit organs and canal neuromasts are distinguished by the nature of their electrophysiological response to mechanical and chemical stimulation. Pit organs respond to touch but have a relatively high threshold compared with canal neuromasts. They respond readily to sodium and potassium chloride solutions, the rate of discharge increasing with the concentration of the solution. Order of effectiveness with 1 molar solutions of monovalent cations is as follows: potassium, rubidium > sodium, ammonium > cesium, lithium. Anions are ineffective. Divalent cations such as calcium and magnesium are inhibitory. Responses to acid, sugar, and quinine are either very slight or inhibitory.

E-cadherin expression in the subepithelial nevus cells of the giant congenital nevocellular nevi (GCNN) correlates with their migration ability in vitro.

BACKGROUND: Giant congenital nevocellular nevi (GCNN) are histologically characterized by the broad distribution of nevus cells in the epidermis and dermis. OBJECTIVE: To characterize E-cadherin in GCNN and define its role in nevic cell migrations. METHODS: Twenty-four cases were immunohistochemically examined and in five cases cells were isolated for primary culture for migration assays. RESULTS: The nevus cells in the superficial region showed the immunoreactivity of E-cadherin in a membranous pattern, but those in the deep part of dermis had little immunoreactivity. Ultra-structural analysis of the superficial nevus cells revealed that E-cadherin immunodeposits in the fibrillar processes around the cell body in a spotted pattern. This distribution pattern is quite different from that in the adherens junction of skin squamous epithelial cells. Boyden chamber experiments were performed using primary cultures of intradermal nevus cells. EDTA pretreatment reduced cell migration to the E-cadherin positive side when the E-cadherin positive population was relatively large in the primary cultures. CONCLUSIONS: These results indicate that E-cadherin in the nevus cells may affect nevus cell motility rather than intercellular attachment.

Appropriate hinge position for prevention of unstable lateral hinge fracture in open wedge high tibial osteotomy.

AIMS: Open wedge high tibial osteotomy (OWHTO) for medial-compartment osteoarthritis of the knee can be complicated by intra-operative lateral hinge fracture (LHF). We aimed to establish the relationship between hinge position and fracture types, and suggest an appropriate hinge position to reduce the risk of this complication. PATIENTS AND METHODS: Consecutive patients undergoing OWHTO were evaluated on coronal multiplanar reconstruction CT images. Hinge positions were divided into five zones in our new classification, by their relationship to the proximal tibiofibular joint (PTFJ). Fractures were classified into types I, II, and III according to the Takeuchi classification. RESULTS: Among 111 patients undergoing OWHTOs, 22 sustained lateral hinge fractures. Of the 89 patients without fractures, 70 had hinges in the zone within the PTFJ and lateral to the medial margin of the PTFJ (zone WL), just above the PTFJ. Among the five zones, the relative risk of unstable fracture was significantly lower in zone WL (relative risk 0.24, confidence interval 0.17 to 0.34). CONCLUSION: Zone WL appears to offer the safest position for the placement of the osteotomy hinge when trying to avoid a fracture at the osteotomy site. Cite this article: Bone Joint J 2017;99B10:1313-18.

The validity of the classification for lateral hinge fractures in open wedge high tibial osteotomy.

The objective of this study was to validate the efficacy of Takeuchi classification for lateral hinge fractures (LHFs) in open wedge high tibial osteotomy (OWHTO). In all 74 osteoarthritic knees (58 females, 16 males; mean age 62.9 years, standard deviation 7.5, 42 to 77) were treated with OWHTO using a TomoFix plate. The knees were divided into non-fracture (59 knees) and LHF (15 knees) groups, and the LHF group was further divided into Takeuchi types I, II, and III (seven, two, and six knees, respectively). The outcomes were assessed pre-operatively and one year after OWHTO. Pre-operative characteristics (age, gender and body mass index) showed no significant difference between the two groups. The mean Japanese Orthopaedic Association score was significantly improved one year after operation regardless of the presence or absence of LHF (p = 0.0015, p < 0.001, respectively). However, six of seven type I cases had no LHF-related complications; both type II cases had delayed union; and of six type III cases, two had delayed union with correction loss and one had overcorrection. These results suggest that Takeuchi type II and III LHFs are structurally unstable compared with type I. Cite this article: Bone Joint J 2015;97-B:1226-31.

Effects of dienogest, a synthetic steroid, on experimental endometriosis in rats.

OBJECTIVE: Dienogest, a synthetic steroid with progestational activity, is used as a component of oral contraceptives and is currently being evaluated clinically for the treatment of endometriosis. The present study was conducted to confirm the effects of dienogest on experimental endometriosis in rats and to elucidate its mechanism of action. DESIGN: Experimental endometriosis induced by autotransplantation of endometrium in rats. METHODS: Endometrial implants, immune system, and bone mineral were investigated after 3 weeks of medication. RESULTS: Dienogest (0.1-1 mg/kg per day, p.o.) reduced the endometrial implant volume to the same extent as danazol (100 mg/kg per day, p.o.). Simultaneously, dienogest ameliorated the endometrial implant-induced alterations of the immune system: i.e. it increased the natural killer activity of peritoneal fluid cells and splenic cells, decreased the number of peritoneal fluid cells, and decreased interleukin-1beta production by peritoneal macrophages. In contrast, danazol (100 mg/kg per day, p.o.) and buserelin (30 microg/kg per day, s.c.) had none of these immunologic effects. Additionally, combined administration of dienogest (0.1 mg/kg per day) plus buserelin (0.3 microg/kg per day) suppressed the bone mineral loss induced by buserelin alone, with no reduction of the effect on endometrial implants. In vitro studies on dienogest revealed an antiproliferative effect on rat endometrial cells due to inhibition of protein kinase C activity plus a partial progestational effect. CONCLUSIONS: Dienogest appears to be a potent agent with mechanisms of action different from those of danazol and GnRH agonists currently available for the treatment of endometriosis.

Successful heterotransplantation of human endometrium in SCID mice.

OBJECTIVE: To establish an experimental system useful for long-term evaluation of human endometrial tissue by its heterotransplantation to SCID mice. METHODS: Human endometrium was transplanted subcutaneously into SCID mice, nude mice, or nude mice given anti-asialo GM1 antibody, a natural killer activity suppressor. The transplant was observed by ultrasonography for up to 10 weeks and then morphologically. To assess the drug susceptibility of the transplant, danazol (10-100 mg/kg/day orally), buserelin (0.01 mg/kg/day subcutaneously), or estradiol (0.5 mg/kg/day intraperitoneally) was administered to the host mice for up to 10 weeks after the transplantation. Multiple-comparison procedures were used for statistical evaluation. RESULTS: The heterotransplant was accepted 100% in SCID mice and natural killer activity-suppressed nude mice, but was significantly inferior (40%) in nude mice at 10 weeks after the transplantation. The transplant size was volumetrically measurable noninvasively by ultrasonography. Using this SCID mouse model, we could evaluate drug effects on the transplanted endometrium. CONCLUSION: This system in SCID mice may be useful for evaluating drug actions on human endometrium and endometriotic tissues.

Role of urinary trypsin inhibitor in the maintenance of pregnancy in mice.

OBJECTIVE: To investigate the mechanisms whereby urinary trypsin inhibitor prevents lipopolysaccharide-induced preterm delivery in mice. METHODS: On day 15 of pregnancy, C3H/HeNCrg female mice impregnated by Crg:B6D2F1 male mice were treated intraperitoneally with lipopolysaccharide (50 micrograms/kg, twice at a 3-hour interval) to induce preterm delivery. Urinary trypsin inhibitor (2.5 x 10(4), 7.5 x 10(4), or 25 x 10(4) units/kg, ten times at 1-hour intervals) or saline solution was administered intraperitoneally to the animals. RESULTS: The incidence of preterm delivery was significantly decreased on a dose-related basis by urinary trypsin inhibitor treatment. Urinary trypsin inhibitor prevented the morphologic and functional changes in fetal membranes and cervical ripening preceding the onset of preterm delivery. Urinary trypsin inhibitor also suppressed the increase in plasma and amniotic fluid concentrations of interleukin-1 alpha, interleukin-6, and tumor necrosis factor-alpha after the lipopolysaccharide dosing in this animal model for preterm delivery. CONCLUSION: Urinary trypsin inhibitor prevents the pathogenicity of preterm delivery through the suppression of cytokine production.

Trophoblastic apoptosis in mice with preterm delivery and its suppression by urinary trypsin inhibitor.

OBJECTIVE: To investigate histopathologic changes of the placenta in mice with preterm delivery induced by lipopolysaccharide and the effect of urinary trypsin inhibitor. METHODS: Female C3H/HeN mice impregnated by male B6D2F1 mice were treated with lipopolysaccharide (50 micrograms/kg, intraperitoneally) or lipopolysaccharide plus urinary trypsin inhibitor (25 x 10(4) U/kg, intraperitoneally). At 3, 6, 9, and 18 hours after the second dose of lipopolysaccharide, and at delivery in the control and urinary trypsin inhibitor-treated groups, the concentrations, of interleukin-1 alpha and tumor necrosis factor-alpha were determined in serum and amniotic fluid. Subsequently, the placentas were examined. In the same manner, we examined mice treated with interleukin-1 alpha (250 micrograms/kg, subcutaneously) on day 15 of pregnancy and intact mice on days 15 and 18 of pregnancy as well as at delivery. To assess the direct action of cytokines, we cultured placental slices with tumor necrosis factor-alpha, interleukin-1 alpha, or tumor necrosis factor-alpha plus urinary trypsin inhibitor and examined them morphologically. RESULTS: Control mice were characterized by trophoblastic apoptosis and increased serum levels of tumor necrosis factor-alpha and interleukin-1 alpha. In contrast, urinary trypsin inhibitor-treated mice showed suppression of apoptosis and lower cytokine levels. Interleukin-1 alpha induced trophoblastic apoptosis and increased the serum level of tumor necrosis factor-alpha. The in vitro study showed that tumor necrosis factor-alpha directly induced trophoblastic apoptosis in placental slices. CONCLUSION: We demonstrated that trophoblastic apoptosis occurs in the placentas of a mouse model with preterm delivery induced by lipopolysaccharide. We postulated that apoptosis may lead to placental abruption, and its development may be prevented by treatment with urinary trypsin inhibitor.

Dienogest, a synthetic steroid, suppresses both embryonic and tumor-cell-induced angiogenesis.

Orally administered dienogest (17alpha-cyanomethyl-17beta-hydroxy-estra-4,9-diene-3-one) is efficacious against human hormone-dependent cancer xenografts in severely immunodeficient mice and in rats with experimental endometriosis, but its mechanisms of action remain unclear. We assessed the effect of dienogest on angiogenesis, because these two diseases that are sensitive to dienogest are known to be angiogenesis-dependent. Topical dienogest treatment dose-dependently inhibited embryonic angiogenesis, the ID(50) value being 6.4 nmol/egg. Oral administration of dienogest (1 mg kg(-1) day(-1)) for 5 consecutive days significantly suppressed angiogenesis induced by S-180 mouse tumor cells in the mouse dorsal air sac assay. In vitro experiments showed that dienogest at concentrations up to 10 microM had little or no effect on the proliferation of plasminogen activator activity or formation of tube-like structures by microvascular endothelial cells. These results suggest that dienogest is a new, orally active antagonist of angiogenesis, and that its anti-angiogenic action may be involved in its therapeutic effects on cancer xenografts and endometriosis that we observed previously.

Evidence for "response to injury" hypothesis.

Role of platelet-derived growth factor (PDGF) in myointimal thickening described in "response to injury" hypothesis was investigated with artery of rats in culture and with air-injured artery of rats. PDGF promoted cell growth in ring preparation of carotid artery in culture denuded with citrate. It did not promote any cell growth in preparations without denudation. Trapidil, a PDGF antagonist, inhibited the cell growth promoted by PDGF in the denuded arterial ring. Systemic injection of PDGF was performed for 8 days to rats with thrombocytopenia induced by injections of anti-platelet serum. This treatment caused myointimal thickening of carotid artery 10 days after denudation by means of air injury. Trapidil at oral intake levels of 1, 3 and 30 mg/kg/day inhibited this change observed in denuded site of artery. Trapidil at oral intake of 6 mg/kg/day also inhibited myointimal thickening observed 15 days after denudation of carotid artery by air injury in normotensive and spontaneous hypertensive rats both with normal platelet counts. These results evidenced the role of PDGF in myointimal thickening described in "response to injury" hypothesis and clinical use of trapidil may be a new approach to the treatment of atherosclerosis.

Effect of dienogest on bleeding time, coagulation, fibrinolysis, and platelet aggregation in female rats.

We investigated the effect of dienogest on bleeding time, coagulation, fibrinolysis, and platelet aggregation in female rats compared with that of medroxyprogesterone acetate (MPA) and danazol, in order to elucidate the reason for relatively high incidence of bleeding in dienogest-treated patients with endometriosis. Dienogest caused no change in the bleeding time at a single dose of 100 mg/kg or at a repeated dose of 10 mg/kg per day for 2 weeks. The drug increased the fibrinogen level, coagulation factor II and V activities, and antithrombin III activity, but had no effect on fibrinolysis or on platelet aggregation at repeated doses of 1 and 10 mg/kg per day for 4 weeks. MPA significantly shortened the bleeding time at the same doses as dienogest. MPA increased the fibrinogen level and plasminogen activity, potentiated the platelet aggregation, and increased the platelet cholesterol-to-phospholipid ratio at a repeated dose of 10 mg/kg per day for 4 weeks. Danazol significantly shortened the bleeding time like MPA. Danazol increased the fibrinogen level, coagulation factor II, V, VII, VIII, IX, X, XI, and XII activities, and antithrombin III activity, but had no influence on the platelet aggregation at repeated doses of 10 and 100 mg/kg per day for 4 weeks. In comparison with MPA and danazol, dienogest may induce a relatively high incidence of bleeding in patients with endometriosis partially because of its minimal effect on hemostasis.

Effects of dienogest (a synthetic steroid) on coagulation, fibrinolysis, and platelet aggregation in female monkeys.

We investigated the effects of dienogest (0.1-10 mg/kg per day, p.o.) on coagulation, fibrinolysis and platelet aggregation in female rhesus monkeys. Then, we also examined those of medroxyprogesterone acetate (MPA, 10 mg/kg per day, p.o.) or danazol (10-1000 mg/kg per day, p.o.) on these parameters in the same species. In addition, we assessed the effects of dienogest (1 and 3 mg/kg per day, p.o.) or MPA (10 mg/kg per day, p.o.) on platelet aggregation and platelet lipids in female cynomolgus monkeys. At doses of 0.3 mg/kg or greater, dienogest increased the levels of several coagulation and anticoagulation factors, but had no effect on the prothrombin time, activated partial thromboplastin time, fibrinolysis, or platelet aggregation. MPA (10 mg/kg) had no effect on coagulation or fibrinolysis, but significantly potentiated platelet aggregation in response to ADP and collagen and also increased the platelet cholesterol-to-phospholipid ratio. Danazol (10 mg/kg or more) increased the activities of coagulation factors V, VII, VIII, X, XI, and XII in comparison to dienogest and MPA. Consequently, dienogest caused less potentiation of platelet aggregation than MPA and less potentiation of coagulation than danazol.

The receptive mechanism of various metallic ions in the lateral-line organ of the tadpoles of Rana catesbeiana.

The stimulating effect on the receptor organ of various mono-and divalent metallic ions on the lateral-line nerve of tadpoles was studied. The orders of the effectiveness were Ag + greater than T1+ greater than K+==Na+ greater than Li for monovalent ions and Sr2+ greater than Mg2+ greater than or equal too Ba2+ greater than Cd2+ greater than or equal too Co2+ greater than Mn2+ greater than Zn2+ for divalent ions. Both agree well with the order of Pearson's softness parameter for monovalent ions and Edwards' modified parameter for divalent ones. All sorts of divalent cations exhibited suppressive effects on the stimulating effect of the monovalent cations when they were applied together with the monovalent cations. A simple selection rule was found for the suppressive effect. The stimulating effect of Na+ or K+ was suppressed by all sorts of divalent cations. But the effect of Ag+ was suppressed by Cd2+, but not by Mg2+ nor by Ca2+. In order to remove the Ag+ effect, a dilute solution of DTT was used, although the effect of K+ or Na+ was removed easily by rinsing with distilled water. From these results the receptive mechanism of the endorgan was thought to be chemical adsorption of ions in the receptor cell membrane. Based on the principle of "hard and soft acid and base", it is suggested that there are two types of binding sites for the ions on the membrane, a soft site and a hard one.

The chemical receptive mechanism in the lateral-line organ.

Stimulating effects of various mono- and divalent cations on the lateral-line organ were theoretically analysed by use of the site binding chemical adsorption model with the principle of "hard and soft acids and bases." A linear relation between the softness parameter and the logarithmic value of the intrinsic association constant was obtained for the cations of Na, K, Tl, Ag, Ca, Mg, and Cd. The order of effectiveness of these cations agreed with that of the intrinsic association constant. Using these values for various cations, the critical concentration of divalent cations necessary to supress the effect of monovalent cations was calculated and compared with the experimental values. The calculated concentration of the hard divalent cations (Ca2+, Mg2+), which suppressed the effect of the hard monovalent cations (K+, Na+), agreed with the experimental concentration. The same relations were obtained between the suppressive effect of a soft divalent and a soft monovalent cation. The chemical adsorption of Ag+ on the lateral-line organ of Xenopus laevis was investigated by using a transmission electron microscope equipped with an X-ray microprobe analyser in order to get further confirmation of this model. Silver applied to the lateral-line organ was found around a kinocilium but not in the hair cells of the lateral-line organ. Thus chemical adsorption of the cation on the surface of the receptor membrane was directly proved.

Electrical potentials of the subtectorial space in the guinea pig cochlea.

Precipitation of cobalt ions and iontophoretic marking by Alcian Blue were utilized in examination of physiological properties of the subtectorial space in the guinea pig cochlea. Cobalt ions injected into the scala media were sulfurated and observed as a black precipitation in cross sections. Precipitation was seen on the upper and the lower surface of the tectorial membrane, and on the reticular membrane. Alcian Blue was the most suitable dye for marking in the organ of Corti. Recording sites of potentials in the subtectorial space were identified by Alcian Blue marking. The potentials were similar to those measured in the scala media. These facts verify that the subtectorial space communicates with the scala media through the outermost margin of the tectorial membrane. Thus the sensory hairs of hair cells are bathed in the endolymph of high potassium concentration, and the condition for optimum sensitivity of their receptor function is maintained.

Good's syndrome presenting with cytomegalovirus pneumonia.

A 61-year-old woman who had undergone an operation for thymoma 17 years previously suddenly became dyspneic and showed bilateral pulmonary infiltrates on a chest radiograph. In the bronchoalveolar lavage fluid cells contained characteristic cytomegalic inclusion bodies, as well as cytomegalovirus DNA demonstrated by a polymerase chain reaction. Immunological findings included hypogammaglobulinemia, deficient numbers of circulating B cells, and impaired blast transformation of peripheral blood T cells in response to mitogens in vitro. Considering all of the findings, the patient was diagnosed with Good's syndrome presenting with cytomegalovirus pneumonia.

Animal studies on the endocrinological profile of dienogest, a novel synthetic steroid.

Dienogest is an orally active synthetic steroid that is used for contraception and is currently being studied for the possible treatment of endometriosis. Earlier we demonstrated that dienogest had therapeutic effects on experimental endometriosis in rats and that its mechanisms of action were different from those of drugs currently on the market for the treatment of endometriosis. We also reported preclinically that dienogest showed a potential anticancer action against hormone-dependent cancers that was different from that of progestins. Accordingly, we obtained preclinical background data for the above-described clinical applications and extension of the clinical use of the drug in the near future by investigating the endocrinological profile of dienogest in rabbits and rats. Dienogest was characterized by having a moderate binding affinity for progesterone receptors and by progestational activities: it stimulated endometrial proliferation (> or = 0.01 mg/kg) that was only partially inhibited by RU-486, and induced carbonic anhydrase activity in endometrium (> or = 0.01 mg/kg). Also, it was slightly uterotrophic (> or = 1 mg/kg) with very low binding affinity for oestrogen receptors but without biological androgenic and anabolic activities (100 mg/kg), with neither glucocorticoid activity nor mineralocorticoid activity (100 mg/kg), and with very slight binding affinity for human sex hormone-binding globulin. These findings suggest that dienogest is not a pure progestin and appears to induce fewer side effects than drugs currently on the market for the treatment of endometriosis.