Effects of the potassium channel openers cromakalim and pinacidil on catecholamine secretion and calcium mobilization in cultured bovine adrenal chromaffin cells

The effects of two K+ channel openers, cromakalim and pinacidil, on voltage-dependent and receptor-mediated catecholamine secretion and Ca2+ mobilization in bovine adrenal chromaffin cells were studied to determine the role of membrane K+ channels in the regulation of a Ca(2+)-dependent secretory process. Both cromakalim and pinacidil stimulated the efflux of 86Rb (used to monitor K+ permeability) from preloaded cells. Cromakalim and pinacidil did not affect the catecholamine secretion induced by excessive depolarization with 56 mM K+, but inhibited that induced by moderate depolarization with 31 mM K+ in a concentration-dependent manner (1 microM-100 microM). The 31 mM K(+)-induced 45Ca2+ influx and increase in intracellular free Ca2+ concentration [Ca2+]i were also inhibited by these agents at similar concentrations to those for inhibition of catecholamine secretion. Cromakalim and pinacidil inhibited catecholamine secretion, 45Ca2+ influx and increase in [Ca2+]i induced by stimulation of nicotinic acetylcholine (ACh) receptors with carbamylcholine. Furthermore, both cromakalim and pinacidil inhibited the increase in [Ca2+]i induced by carbamylcholine in the absence of extracellular Ca2+, which is thought to be mediated by muscarinic ACh receptors. On the other hand, they did not affect catecholamine secretion induced by Bay-K 8644, Ba2+, A23187, histamine or bradykinin. These results indicate that the K+ channel openers, cromakalim and pinacidil, selectively inhibit catecholamine secretion induced by moderate depolarization or by nicotinic ACh receptor stimulation by inhibiting Ca2+ influx and increase in [Ca2+]i. Furthermore, the results suggest that these K+ channel openers-sensitive membrane K+ channels are involved in the regulation of catecholamine secretion mainly indirectly through effects on the voltage-dependent membrane Ca2+ channels.

Significance of oral examination in chronic graft-versus-host disease

Fourteen patients who received allogeneic bone marrow transplantation (BMT) were examined 100 to 220 days after BMT. Ten out of 14 patients were diagnosed as having chronic graft-versus-host disease (cGVHD) in skin, liver, eyes and other organs. These cGVHD patients also had objective evidence of oral involvement. Subjective xerostomia was experienced by 7 cGVHD patients and decreased whole saliva flow was observed in 4 cGVHD patients. However, no patient had a history of parotid swelling or notable abnormality in parotid sialography. Labial salivary glands (LSG) or 9 cGVHD patients showed atrophy and/or destruction in association with diffusely infiltrating lymphocytes. The infiltrating lymphocytes were mainly CD3+ T cells with a predominance of CD8+ cells over CD4+ cells. Lichenoid lesions on the oral mucosa were also observed in 5 cGVHD patients. Thus, thus study indicated that oral examination, including LSG biopsy, is useful in the diagnosis of cGVHD.

Long-term changes in the haversian systems following high-dose irradiation. An ultrastructural and quantitative histomorphological study

The effects of high-dose irradiation on the morphology of haversian bone were studied, over a fifty-two-week period, in seventy-seven adult rabbits, after the administration of a single dose of radiation (therapeutic x-ray; twenty-five, fifty, or 100 gray) to one knee joint. The specimens of bone were examined with microangiography, light and transmission electron microscopy, and histomorphometry. Analysis was performed on the haversian bone in the subchondral bone plate of weight-bearing portions of the femoral condyles. Microangiography demonstrated dilatation of the microvasculature four weeks after irradiation. Beginning at twelve weeks, there was a marked decrease in vascularity; no obvious recovery of the subchondral bone had occurred by fifty-two weeks. At four weeks, morphological analysis revealed two changes in the haversian canals: simple occlusion of the haversian vessels with loss of cells in the canal, and dilatation of the capillaries with abnormal resorption of the perivascular bone matrix by osteoclasts. The abnormal bone resorption was not coupled with subsequent new-bone formation, resulting in increased porosity. Beginning at four weeks, a progressive decrease in the number of haversian vessels and in cellularity became prominent. The decrease in cellularity involved all types of cells, including endothelial cells, pericytes, perivascular mesenchymal cells, osteoblasts, osteocytes, and osteoclasts. The loss of perivascular cells was often but not always associated with occlusion of the haversian vessels. Histomorphometry revealed both time-dependent and dose-dependent decreases in capillary density (the number of intraosseous capillaries per unit area) and in the number of osteocytes in the subchondral bone plate. The porosity of the same areas showed a significant increase by four weeks (p < 0.001 after administration of twenty-five gray and p < 0.01 after administration of both fifty and 100 gray), but between twelve and fifty-two weeks, there was only a slight additional increase. Statistical analysis revealed significant correlations between capillary density and osteocyte survival (p < 0.001) and between capillary density and porosity (p < 0.001). The portion of the subchondral bone plate that was located farthest from the non-irradiated normal bone showed progressive damage and no sign of recovery at fifty-two weeks.

Lack of relationship between gamma-glutamyl transpeptidase and tyrosine transport in cultured bovine adrenal chromaffin cells

Effect of gamma-glutamyl transpeptidase (GGTP) inhibitor acivicin on tyrosine transport was investigated in cultured bovine adrenal chromaffin cells. Tyrosine transport into the cells was inhibited by acivicin at the low concentration range. This drug also caused the inhibition of GGTP in the cell lysates, but the concentration required for the inhibition of the enzyme was evidently different from that producing the inhibition of tyrosine transport into the cells. In addition, tyrosine transport was not affected by a GGTP activator hippurate even at the high concentration. These results seem to provide the evidence that GGTP may not be involved in the transport of tyrosine into the adrenal chromaffin cell.

Repair of osteochondral defects with grafts of cultured chondrocytes. Comparison of allografts and isografts

Isogeneic and allogeneic chondrocytes cultured in collagen gel were transplanted into osteochondral defects in knee joints of inbred strains of rats. At 12 weeks, all eight isografted defects had healed successfully, compared with only four of eight allografted defects (p < 0.05). At 26 and 52 weeks, all defects except one had healed successfully and there was no significant difference in the success rate between the isografted and allografted groups. Control defects that had been implanted with only collagen gel did not heal successfully.

Calcium efflux from cultured bovine adrenal chromaffin cells induced by bradykinin

The effect of bradykinin on Ca2+ efflux from cultured bovine adrenal chromaffin cells was examined. Bradykinin enhanced the efflux of 45Ca2+ from the cells in a concentration dependent manner (10(-9)-10(-6) M). This effect was inhibited by a specific bradykinin B2-receptor antagonist, but not by a B1-receptor antagonist. Nifedipine, Co2+ and Cd2+ did not inhibit the bradykinin-stimulated 45Ca2+ efflux from the cells. 12-O-Tetradecanoyl phorbol 13-acetate, an activator of protein kinase C, also had no effect on the efflux of 45Ca2+ from the cells. The increase in bradykinin-stimulated 45Ca2+ efflux was reduced by removal of extracellular Na+. These results suggest that bradykinin stimulates Na+/Ca2+ exchange in cultured bovine adrenal chromaffin cells.

Morphological alterations of gap junctions in phalloidin-treated rat livers

Morphological alterations in the pattern of liver cell gap junctions were examined in phalloidin-treated rats to assess the role of gap junctions in experimental intrahepatic cholestasis. Double-labelled fluorescent staining of gap junctions and F-actin were performed using a monoclonal antibody against rat hepatocyte connexin 32 and rhodamine-phalloidin. Immunoelectron microscopy, using the anti-connexin 32 antibody, freeze-fracture replica electron microscopy, and conventional electron microscopy were also performed. In phalloidin-treated rat livers, the specific immunofluorescent staining of connexin 32 was markedly decreased in the pericentral area after 1 day of phalloidin treatment and, after 5 days of phalloidin treatment, there was a decrease in connexin 32 staining in the entire hepatic lobule. On the other hand, F-actin staining at the cell periphery and at the bile canaliculi was markedly increased in the pericentral area of the hepatic lobule after 1 day of phalloidin treatment and in the entire lobule after 5 days of treatment. Immunoelectron microscopy showed that both sides of the cytoplasmic domains of gap junctions were stained with anti-connexin 32 antibody in controls, whereas, in cholestatic rats, only one side of the cytoplasmic domain of some gap junctions was stained with anti-connexin 32 antibody after 1 or 3 days of phalloidin treatment. No gap junctions were observed after 5 days of phalloidin treatment either by freeze-fracture replica electron microscopy or by conventional electron microscopy. These results indicate that with phalloidin treatment, hepatocyte gap junctions decrease, first in the pericentral area, and finally throughout the entire lobule.

Intravenous extended infusion of recombinant human soluble thrombomodulin prevented tissue factor-induced disseminated intravascular coagulation in rats

This study demonstrated that intravenous infusion of recombinant human soluble thrombomodulin (rhs-TM) could inhibit disseminated intravascular coagulation (DIC) caused by 4 hr infusion of tissue factor (TF) in rats. Extended infusion of TF reduced fibrinogen and platelet counts and elevated serum FDP level. Pretreatment and coinfusion of rhs-TM could block changes of these DIC-parameters without prolongation of APTT. Heparin, which is a potent anti-DIC drug, could also inhibit these changes with extra prolongation of APTT and PT. Thus, these results suggest thrombomodulin prevent DIC less bleeding tendency than heparin.

An immunohistochemical study of the extracellular matrix in oral squamous cell carcinoma and its association with invasive and metastatic potential

The expression of extracellular matrices (ECMs) laminin (LN), type IV collagen (IV C), heparan-sulphate proteoglycan (HS-PG), fibronectin (FN), tenascin (TN), decorin and vitronectin (VN) was examined immunohistochemically in 112 primary tumours and 29 metastatic cervical lymph nodes in oral squamous cell carcinoma (OSCC). In highly invasive primary tumours, the expression of LN, IV C and HS-PG in the basement membrane along the tumour-stroma borderline and the expression of decorin and VN in the tumour stroma at the invasive site were all significantly decreased. The expression of FN and TN in the tumour stroma at the same site was markedly increased. In peritumour stroma in metastatic lymph nodes, LN, IV C, HS-PG, decorin and VN were weakly expressed, while FN and TN were strongly expressed. Thus, the staining pattern of the ECMs in the metastatic lymph nodes was similar to that in highly invasive primary tumours. Furthermore, in primary tumours of metastatic cases, the expression of LN, IV C, HS-PG, decorin and VN obviously decreased, while the expression of FN and TN increased when compared with those of the non-metastatic cases. The investigation of ECMs in OSCC was valuable in predicting tumour behaviour.

Pathophysiologic significance of free and conjugated dopamines in congestive heart failure

sulfoconjugated dopamine constitutes the major portion of circulating or excreted dopamine, but its physiologic significance is still unknown. To test whether conjugated dopamine serves as a source of free dopamine in response to acute stress, plasma concentrations of free and conjugated dopamine were measured during an acute exacerbation of heart failure. The plasma concentration of conjugated dopamine decreased significantly during the acute phase of heart failure, whereas that of free dopamine increased. The plasma concentration of free dopamine decreased, whereas the concentration of conjugated dopamine increased as heart failure improved. An infusion of dopamine increased the plasma concentration of conjugated dopamine, suggesting that at least part of the excess active dopamine was detoxified through conjugation. The results of these tests with both conjugated and free dopamine are interconvertible and indicate that conjugated dopamine can serve as a reservoir of active dopamine.

Expression of wild-type p53 during the cell cycle in normal human mammary epithelial cells

In this study, we compare the expression patterns of p53 mRNA and protein in normal human mammary epithelial cells following synchronization to different points in the cell cycle using two independent methods. When treated with lovastatin, the cells were blocked in G1 and appeared to express increased levels of wild-type p53 when examined by immunostaining. Upon reversal of the metabolic block, the number of nuclei that stained positively for p53 declined dramatically during mid-G1 and increased again concomitant with the entry of cells into S phase. In contrast to the immunostaining results, Northern and Western blot analyses revealed little change in p53 mRNA and protein levels in the lovastatin-synchronized cells. When normal human mammary epithelial cells were made quiescent by removal of growth factors, the mRNA for p53 showed a biphasic distribution. p53 mRNA levels were increased during growth arrest, decreased during the G1 phase, and rose again concomitant with the entry of cells into S phase. The immunostaining pattern of p53 also showed a biphasic distribution similar to the pattern of mRNA expression. Despite an increase in p53 mRNA and immunostaining levels, growth factor-arrested cells actually had less total p53 protein. Upon stimulation to proliferate, p53 protein levels remained low throughout G1 and increased concomitant with the entry of cells into S phase. Taken together, the results from these studies demonstrate that p53 immunostaining patterns do not correlate with the overall levels of p53 protein at different times during the cell cycle. Therefore, the distinct changes observed in p53 immunostaining patterns are likely due to posttranslational modifications, conformational changes, or interactions of p53 with other cellular proteins during the cell cycle.

Complications of miniplate osteosynthesis for mandibular fractures

Postoperative complications of delayed osteosynthesis with stainless steel miniplates were examined in 110 patients with mandibular fractures. The miniplates were removed in 91 of the patients, even if symptom-free, once sufficient bony union was obtained, and the healing conditions and the surrounding tissues were examined. Malocclusion, exposure of miniplates, delayed union, and infection were observed in 3.6%, 3.6%, 1.8%, and 1.0% of the patients, respectively. The complication rates were within acceptable limits even when treatment was performed later than 24 hours after injury. The healing conditions and the surrounding tissues did not show any serious problems. Thus, at least in short-term retention, stainless steel miniplates seem to be effective and suitable for osteosynthesis of mandibular fractures.

Intraarterial combined immunochemotherapy for unresectable hepatocellular carcinoma: preliminary results

An important objective for patients with unresectable hepatocellular carcinoma (HCC) is the development of effective chemotherapy. We administered a combination of biological response modifiers and anticancer agents to 24 patients with unresectable HCC. Each case had an implanted infuser port which was connected to a catheter placed in the hepatic artery for the intraarterial (i.a.) administration of chemotherapy. The following agents were administered to each patient: recombinant interleukin-2 (800,000 JRU/day infused i.a. continuously for 6 days/week); OK-432 (5 KE injected i.a. twice in 4 weeks and i.m. three times per week); Adriamycin (10 mg injected i.a. twice in 4 weeks); cyclophosphamide (300 mg injected i.a. twice in 4 weeks), and famotidine (40 mg/day administered orally). Objective response was assessed according to tumor size measured by computed tomography and angiography before and after treatment. We observed a complete response (CR) in 4, partial response (PR) in 3, minor response (MR) in 7, no change (NC) in 7, and progressive disease (PD) in 3. The response rate (CR+PR+MR) was 58.3%. The overall 2-year survival rate was 52%. The 2-year survival rate of the responders (CR+PR+MR) was 80%, while that of the non-responders (NC+PD) was 0%. There was a significant difference between the responders and non-responders in respect to survival rate (P < 0.05). The percentages of CD25+ cells, CD56+ cells, and Leu7-CD16+ cells and NK activity in the peripheral blood showed a significant increase following the regimen. Serum levels of tumor necrosis factor alpha TNF alpha rose after the initiation of OK-432. TNF alpha levels were higher in the responders than in the non-responders. Adverse effects included high fever (all patients) and severe transient hypotension (15 patients) that was controlled by conservative therapy. Combined immunochemotherapy administered intraarterially may be a new strategy for treating unresectable HCC.

Chromaffin cells express Alzheimer amyloid precursor protein in the same manner as brain cells

Amyloid precursor protein (APP) 695 is remarkably expressed in the brain as compared with APP751 and APP770 which are dominant in other tissues. This study showed that human and bovine adrenal medullae dominantly expressed mRNA of APP695 as do brain nerve cells, while the adrenal cortexes expressed mRNAs of APP751 and APP770 as in other non-neural tissues. In immunohistochemistry, chromaffin cells of young rat adrenal medullae and primary cultured bovine chromaffin cells were significantly stained with a monoclonal antibody (mAb) against the common domain of the amino-terminal side of human APPs. At higher magnification, the immunostained cells revealed that APP was granularly distributed not only in the perikaryon but also in the cell processes. These results suggest that primary cultured chromaffin cells representing the state of adrenal medulla in vivo are a useful model for studying the pathophysiological functions of APPs and the mechanism of processing of APPs as a model of neuronal systems.

Prostaglandin E2 levels and lymphocyte subsets in portal venous drainage of colorectal cancers

Local immunosurveillance may play an important role in the growth and spread of tumors. To investigate the local immune response, we determined prostaglandin E2 (PGE2) levels (n = 23) and lymphocyte subsets (n = 10) in the portal vein draining the tumors of patients with colorectal cancer. PGE2 levels in the portal vein were significantly higher than those in the radial artery. Portal PGE2 levels in patients with advanced stage tumors (Duke's C and D) and lymph node metastases were significantly higher than those of patients with Duke's A and B tumors without lymph node metastases. Moreover, four of the nine patients with portal PGE2 levels greater than 100 pg/mL had liver metastases within 2 years of surgery. There were no differences in lymphocyte subsets between the portal vein and the radial artery. PGE2 levels in the portal vein draining colorectal tumor may thus be closely related to tumor progression and recurrence and may serve as a predictor of tumor recurrence in patients with colorectal cancer.

Radiologically occult lung cancer in the peripheral region

A rare case of radiologically occult lung cancer in the peripheral region beyond bronchoscopic visibility is reported. A 69-year-old female was referred because of positive sputum cytology. Despite detailed bronchoscopic and otorhinoralyngologic examinations, the source of malignant cells was not localized. During the follow-up period, squamous cell carcinoma of the lung periphery was detected radiologically three years after its presence was detected in sputum. Awareness of the existence of this type of cancer and careful follow-up are important in the management of patients with positive sputum cytology and no evidence of cancer.

A novel method for generating nested deletions using the in vitro bacteriophage T3 DNA packaging system

To sequence a DNA segment inserted into a cosmid vector under the directed sequencing strategy, we established a simple and rapid method for generating nested deletions which uses the in vitro packaging system of bacteriophage T3 DNA. The principle is based on the previous finding that this system can translocate any linear double-stranded DNA up to 40 kb into the phage capsid in a time-dependent manner and the encapsulated DNA becomes DNase-resistant. For this purpose, we constructed a cosmid vector that carries two different antibiotic selection markers at both sides of the multiple cloning site, and after insertion of a DNA segment, the clone was linearized by lambda-terminase at the cos site. After the packaging reaction in vitro followed by DNase treatment, the encapsulated DNA was introduced into Escherichia coli cells to give clones with unidirectional deletions by differential antibiotic selection. Restriction and sequence analyses of deletion clones demonstrated that an ordered set of clones with nested deletions, ranging from less than 1 kb to 25 kb, was created from either the end of the DNA segment. Thus, nested deletion clones that cover the entire region of a approximately 40-kb cosmid insert can be obtained by a single packaging reaction, and its restriction map can be simultaneously obtained.

Prostacyclin (PGI) receptor binding and cyclic AMP synthesis activities of PGI1 analogues, SM-10906 and its methyl ester, SM-10902, in mastocytoma P-815 cells

The prostacyclin I1 (PGI1) analogue, SM-10906 and its methyl ester, SM-10902, have been compared with the PGI2 analogue, iloprost, with respect to binding to the PGI2 receptor, stimulation of adenylate cyclase activity and inhibition of thrombin-induced Ca2+ mobilization in mastocytoma P-815 cells. SM-10906 displaced [3H]iloprost binding to the membrane fraction, the IC50 value being 100 nM, but showed very low affinity for the prostaglandin E (PGE) receptor. SM-10906 dose-dependently stimulated GTP-dependent adenylate cyclase activity in the membrane fraction, the EC50 value being 35 nM. Furthermore, SM-10906 prevented a thrombin-induced increase in the intracellular Ca2+ concentration, the IC50 value being 300 nM. These IC50 and EC50 values are much lower than those of SM-10902. These results demonstrate that SM-10906, a stable PGI1 derivative, is an agonist for the [3H]iloprost-binding (PGI2) receptor, and that it prevents thrombin-induced Ca2+ mobilization through stimulation of the adenylate cyclase system in mastocytoma cells. On the other hand, a methyl ester derivative of PGI1, SM-10902, was inactive in the binding assay, but it seems to be a partial agonist for adenylate cyclase activity [corrected].

Anti-shock effect of pituitary adenylate cyclase activating polypeptide (PACAP) on experimental endotoxin shock in dogs

Effects of pituitary adenylate cyclase activating polypeptide with 38 amino acid residues (PACAP-38) on both cardiovascular functions and plasma hormone levels during endotoxin shock were studied in anesthetized dogs. When PACAP-38 (a bolus 420 pmol/kg injection or a bolus 420 pmol/kg injection followed by a continuous 30 pmol/kg/min infusion for 60 min) was administered intravenously 5 min after application of endotoxin, both mean arterial pressure and cardiac output were restored at 10 min. The continuous administration of PACAP-38 was more effective in improving the symptoms of shock. Plasma adrenalin and cortisol levels were significantly increased by both regimens. These results clearly indicate that the anti-shock properties of PACAP-38 may be attributed to its abilities to increase plasma cortisol and adrenalin levels and to stimulate cardiac function.

Treatment of osteomyelitis by antibiotic impregnated porous hydroxyapatite block

A novel drug delivery system was developed for osteomyelitis using porous hydroxyapatite blocks (HA-b) that were impregnated with antibiotics by a centrifuge method. For the experimental study, a 10 mm3 HA-b was placed in a container, mixed with an antibiotic solution and centrifuged at 1500 rpm for 15 min for the purpose of impregnating antibiotics into the pores. The slow release activity of antibiotic (Arbekacin sulfate [1-N-(S)-4 amino-2-hydroxybutyryl dibekacin]) from the HA-b was tested. An evaluation was made of the slow-releasing capabilities of the ABK from HA-b which was still maintained at 0.5 microgram/ml within 21 exchanges of PBS after 42 days. Consequently, seven patients with osteomyelitis, including one with tuberculosis and two with infected hip arthroplasty, have been treated. On a follow-up study, all of the foci had completely healed by the end of the follow-up period without complications. This new method is simple and can be performed safety as a one-stage operation.

Bone formation and remodeling around implanted materials under load-bearing conditions

Bone formation and remodeling around implanted materials are influenced by the load-bearing conditions. In this study, three types of material were implanted into dog femoral condyles and bone formation and remodeling were observed for 24 weeks thereafter. Even thickening of lamellar bone was observed around bead-coated alumina implants, whereas thick fibrous tissue surrounded by corticalized bone formed around those made of smooth alumina. With an implant made of an artificial osteo-chondral composite material, abundant bone ingrowth into the titanium fibers was observed 8 weeks after the operation and this ingrowth resulted in firm attachment of this composite material to the host bone site. The tibial joint surface against the polyvinyl alcohol (PVA)-hydrogel articular surface of this implant remained intact, which suggests this artificial osteochondral composite material is a very promising joint prosthetic material.

Cementless total hip replacement. Bio-active glass ceramic coating studied in dogs

We studied 2 types of a cementless total hip prosthesis in dogs. Both were coated with titanium plasma-spray. In both components, the pores in the deep layer of 1 group were further coated with apatite and wollastonite containing glass-ceramic (AW glass-ceramic). 50 dogs underwent unilateral total hip replacements, and were killed at 1, 3, or 6 months postoperatively. We evaluated the femoral and the acetabular components mechanically and histologically. At 1 month, the detaching load and bone ingrowth of the AW glass-ceramic-coated femoral and acetabular components were higher than those of the control implants. At 3 and 6 months there were no differences between the 2 types of components. Thus, AW glass-ceramic enhanced the early phase of cementless implant fixation.

New antiviral antibiotics, kistamicins A and B. II. Structure determination

The structures of antiviral antibiotics kistamicins A and B have been determined by a combination of chemical degradation and spectral analysis. They are commonly composed of D-tyrosine, 3,5-dihydrophenylglycine, a biphenyl ether bis-amino acid, and a diphenyl substituted indole tris-amino acid, forming a tricyclic ring structure. Kistamicin B possessed a phenethylamide at the amino terminal of kistamicin A. They are structurally related to the nuclei of the vancomycin group antibiotics particularly to antibiotic complestatin.

Multimodality imaging of cervicofacial actinomycosis

Actinomycosis is an uncommon chronic disease usually caused by Actinomyces israelii. It affects the soft tissue mainly but sometimes spreads to involve salivary glands, bone, or even the skin of the face and neck. Five cases have been seen in our department. Several imaging modalities were used to assist in making the diagnosis. The cases are presented and the literature reviewed. Ultrasonography was found to be a useful diagnostic tool especially in developing the differential diagnosis.