Activation of protein kinase C and specific phosphorylation of a Mr 90,000 membrane protein of promotable BALB/3T3 and C3H/10T1/2 cells by tumor promoters

The activation of protein kinase C and protein phosphorylation by tumor promoters were examined using quiescent cultures of BALB/3T3 and C3H/10T1/2 cells, because in these cells tumor promoters enhance chemically induced transformation and also induce DNA synthesis and ornithine decarboxylase. The cytosol and membrane fractions were partially purified, and the activity of protein kinase C was assayed. In quiescent cells, protein kinase C activity was found only in the cytosol fraction. Treatment with 100 ng of 12-O-tetradecanoylphorbol-13-acetate or teleocidin B per ml caused rapid translocation of protein kinase C from the cytosol to the membrane fraction. The activity in the cytosol disappeared almost completely after 15 min when the activity in the membrane reached a peak. The membrane activity gradually decreased to the control level after 6 h, while no activity reappeared in the cytosol within 6 h. Under these circumstances, a membrane protein with a molecular weight of 90,000 and pl of 4.0-4.4 (termed p90) was specifically phosphorylated, possibly by the activated protein kinase C, in both cell-free and intact-cell systems. On treatment of quiescent BALB/3T3 cells with 100 ng of 12-O-tetradecanoylphorbol-13-acetate, p90 phosphorylation increased 2-fold in 1 min, reaching a peak in 15 min of 3.4-fold the initial value. The phosphorylation of p90 increased with increase in the concentrations of 12-O-tetradecanoylphorbol-13-acetate between 0.1 and 10 ng/ml and reached a plateau at 10 ng/ml. p90 phosphorylation also occurred on exposure of the cells to non-phorbol ester tumor promoters (mezerein and teleocidin B) and growth factors, such as platelet-derived growth factor and fibroblast growth factor. p90 was not immunoprecipitated by antibody against the insulin receptor. Phosphorylation of p90 occurred at a serine residue. The present study suggests that activation of protein kinase C and phosphorylation of p90 by it are early events leading to tumor promotion.     

In vivo observation of crystalline lens changes in the early post-vitrectomy stage]

Crystalline lens changes of 17 cases of eye undergoing simple vitrectomy were observed from the post-operative 1st to 21st month. Changes in the crystalline lenses were detected through a slitlamp microscope or by methods of image analysis, the Opacity Lensmeter and the laser scattering spectroscopy. Increases of the scattering light intensity of the anterior and posterior deep cortical layers were observed from the early post-operative stage in 9 cases. Seven cases progressed to nuclear opacification during the observation period, however, one case showed no nuclear changes even at the 12 post-operative month. No relationships were observed between the early cortical changes and surgical invasion, patient age, or cause of vitreous opacification. Quantitative evaluation by image analysis revealed early post-operative crystalline lens changes in cases undergoing vitreous surgery.     

Bronchial hyperresponsiveness to acetylcholine during acute pulmonary congestion in guinea pigs]

To understand the precise mechanism of bronchial hyperresponsiveness in patients with congestive heart failure, we studied the effect of mild pulmonary congestion on bronchial responsiveness to inhaled acetylcholine (ACh) in guinea pigs. We induced mild pulmonary congestion by inflation of a balloon placed in the left atrium, and maintained the left atrial pressure (Pla) at 10 mmHg for 30 minutes with continuous monitoring of lung resistance (RL) and dynamic compliance (Cdyn). Furthermore, we determined the provocative concentration of ACh producing 100% increase in RL (PC100-ACh), before and during balloon inflation. In animals with propranolol pretreatment, but not in animals without propranolol pretreatment, mild pulmonary congestion caused slight increase in RL (N.S.) and significant decrease in Cdyn (p less than 0.01) and PC 100-ACh (p less than 0.01). Cutting of bilateral vagal nerves partially inhibited the decrease of PC100-ACh, but pretreatment with either phenoxybenzamine, indomethacin, AA-861 or OKY-046 had not effect. These results suggest that blockade of beta-adrenergic receptors and the vagal reflex, but not of alpha-adrenergic receptors or arachidonates, contributes to bronchial hyperresponsiveness during acute pulmonary congestion.     

Pathological effects on mice by gambierol, possibly one of the ciguatera toxins

Gambierol was isolated from Gambierdiscus toxicus, which causes ciguatera fish poisoning. The acute toxicological effects induced in mice by synthesized gambierol were studied. The lethal doses were about 80 μg/kg by i.p. and i.v., and 150 μg/kg by p.o. The main injury by this toxin was observed in the lung, and secondary in the heart, resulting in systemic congestion. Another toxic effect was seen in the stomach, inducing hypersecretion and ulceration. With survival from the severe stage during the initial 3 h, recovery was favorable, especially after 4 days. Additional effects were not evident during 1-week post-administration observation.     

Dissecting aneurysm of the posterior cerebral artery treated with proximal ligation.

A rare case of a dissecting aneurysm of the P3 segment of the right posterior cerebral artery is presented that seems to have occurred in association with mild head injury. The patient was treated surgically because of repeated intramural hemorrhage and enlargement of the aneurysm. Proximal ligation produced thrombosis of the aneurysm without resulting in infarction in the region of the posterior cerebral artery. The mechanisms of the dissection, diagnosis, and treatment are briefly discussed.     

Long-term survival of a pulmonary artery sarcoma produced by aggressive surgical resection and adjuvant chemoradiotherapy.

Malignant pulmonary artery tumors represented by sarcomas are rare, but fatal. Early diagnosis and radical surgical resection offer the only chance for survival. However, surgical intervention has some challenging aspects, and prognosis is poor even after tumor resection. We report a case of a pulmonary artery sarcoma between the right ventricular outflow tract and the pulmonary artery branches. The tumor was aggressively extracted with reconstruction using a cryopreserved pulmonary valved allograft, followed by adjuvant chemoradiotherapy. At 56 months after surgery, the patient is well without any evidence of recurrence, demonstrating that aggressive surgical resection with adjuvant chemoradiotherapy can prolong survival.     

Enhancing effect of combining two pyrrolidone vehicles on transdermal drug delivery

The enhancing effect of combining 1-methyl-2-pyrrolidone (MP) and 1-lauryl-2-pyrrolidone (LP) as the vehicles for transdermal penetration of phenolsulphonphthalein (phenol red) has been investigated by using an in-vitro technique with excised rat skin. LP had a higher enhancing effect on the penetration of phenol red than MP, but there was a long lag time before steady-state penetration was attained. A potent effect with a shorter lag time was obtained when MP and LP were used together. This potentiation was maintained when the concentration of MP was decreased by 95%. The combined vehicle also enhanced the skin accumulation of phenol red. MP promoted the rapid penetration of LP into the skin and potentiated the enhancing effect of LP on the penetration of phenol red and thereby shortened the lag time. The combined vehicle also enhanced the penetration of the hydrophilic anticancer agent, 5-fluorouracil.     

The Sistrunk median cervical cyst operation using a cecal foramen pointer

The cecal foramen pointer was invented for a Sistrunk median cervical cyst operation. The instrument consists of three elements, namely: The cecal foramen holder, the giraffe shaped connector and the pointer needle. First of all, the cecal foramen is held by the holder which is reconstructed from hemostatic forceps. The one end of the connector is joined to the holder's handle. Then the other end of the connector comes along the patient's chin, in front of the neck. The cyst and mid-portion of the hyoid bone are dissected, followed by coring out of the thyroglossal duct toward the cecal foramen. In the coring out process, the pointer needle is pierced through the tunnel of the connector's opposite end, so that the needle top reaches to the bottom of operative wound. Then the needle shows exactly the direction to the cecal foramen and the distance from the bottom of the wound to the cecal foramen. By using this instrument the operation was successfully performed for a case of a recurrent median cervical cyst with a complete fistula to the cecal foramen.     

KW-4679-induced inhibition of tachykininergic contraction in the guinea-pig bronchi by prejunctional inhibition of peripheral sensory nerves.

1. Sensory mechanisms play an important role in the vagal regulation of tracheobronchial smooth muscle tone. We examined the effect of KW-4679, an anti-allergic drug, on guinea-pig tachykinin-mediated contractile responses induced by electrical field stimulation (EFS) in guinea-pig bronchial muscles. 2. EFS (8 Hz, 0.5 ms, 15 V, for 15 s) evoked biphasic contractile responses in the guinea-pig isolated main bronchus in the presence of 5 microM indomethacin. The contractions consisted of a fast phase of an atropine-sensitive transient contraction and a slow phase of a sustained contraction which was inhibited by a combination of the tachykinin NK1 receptor antagonist, (+/-)-CP-96,345 (1 microM) and the NK2 receptor antagonist, SR 48969 (0.1 microM). 3. KW-4679 preferentially inhibited the slow phase in a concentration-dependent manner by 43.2 +/- 7.7% at 10 microM, whereas the drug had no effect on the fast phase at concentrations up to 10 microM. KW-4679, at a concentration of 100 microM, inhibited not only the slow phase by 49.2 +/- 11.4%, but also the fast phase by 36.8 +/- 9.3% [corrected]. 4. KW-4679 (10 microM and 100 microM) did not affect the substance P-induced or neurokinin A-induced contraction. Against the acetylcholine-induced contractile responses, 100 microM KW-4679 had a marked effect producing a 10.2 fold shift to the right in the curve. 5. The inhibitory effect of KW-4679 (10 microM) on the slow phase contraction was not influenced by treatment with naloxone (100 nM), propranolol (1 microM), thioperamide (1 microM), saclofen (50 microM), yohimbine (1 microM), methiothepin (1 microM) or methysergide (1 microM). 6. The inhibitory effect of KW-4679 (10 microM) on the slow phase contraction was not influenced by treatment with intermediate or large conductance Ca(2+)-activated K+ channel blockers (charybdotoxin (10 nM) or iberiotoxin (10 nM)), but suppressed by treatment with small conductance Ca(2+)-activated K+ channel blockers, apamin (500 nM) or scyllatoxin (300 nM). Apamin or scyllatoxin per se did not influence the slow phase contractions. 7. The results suggest that KW-4679 preferentially inhibits the release of tachykinins from the bronchial sensory nerves through activation of small conductance Ca(2+)-activated K+ channels.     

Regeneration of periodontal ligament and cementum by BMP-applied tissue engineering

Previously, we demonstrated that the inductive properties of bone morphogenetic protein (BMP) highly depend on the nature of the carrier material used for implantation. In this paper, we show that administration of BMP incorporated in a fibrous collagen membrane can help to regenerate periodontal ligament and cementum both in cat canines and in monkey molars. The partially purified bovine BMP was combined with one or two layers of a fibrous collagen membrane. Although the single layer approach showed partial regeneration of periodontal defects, it also quite often led to ankylosis. The double layer technique in artificially prepared class III furcation defects in monkey molars gave favorable results. After 12 wk, not only the alveolar process but also the periodontal ligament and cementum had regenerated along the entire treated dentin surface. Collagen fibers were arranged more or less perpendicular to the surface of the new cementum. Ankylosis was not seen. It is concluded that the double-layer approach is superior to the single-layer technique in regenerating cementum.