Enhancement of Newcastle disease virus-induced fusion of mouse L cells by sodium vanadate

Sodium vanadate enhanced Newcastle disease virus (NDV)-induced cell fusion in L cells, and there was a direct correlation between the degree of cell fusion and the dose of vanadate added. When anti-F protein of NDV monospecific antiserum was added to the culture fluid of L cells infected with NDV, the enhancement of cell fusion was suppressed. In contrast, neither anti-HN nor anti-M protein monospecific antiserum inhibited the enhancement. Incubation at low temperature (4 C) and addition of sodium azide to the culture fluid suppressed the enhancement. The suppression by azide was seen only when the drug was added within 5 min after the beginning of incubation of NDV-infected L cells with vanadate. On the other hand, incubation at low temperature inhibited the enhancement at any time during incubation with vanadate. Cytochalasin D also inhibited the enhancement if it was added at any time during incubation with vanadate.

Calcium and cardioplegia. The optimal calcium content for the St. Thomas' Hospital cardioplegic solution

The relationship between the calcium content of the St. Thomas' Hospital cardioplegic solution and the degree of tissue protection it affords has been characterized by means of an isolated working rat heart preparation subjected to normothermic ischemic arrest. With a 3 minute period of preischemic infusion of solutions containing calcium chloride concentrations of 0, 0.6, 1.0, 1.1, 1.2, 1.3, 1.4, and 2.4 mmol/L and 35 minutes of normothermic ischemic arrest, postischemic creatine kinase leakage was 562.3 +/- 26.7, 64.8 +/- 12.1, 63.3 +/- 9.9, 37.5 +/- 5.4, 33.4 +/- 3.1, 41.2 +/- 4.1, 58.6 +/- 7.4, and 65.7 +/- 9.1 IU/15 min/gm dry weight, respectively. The postischemic recovery of aortic flow was 0%, 29.2% +/- 6.8%, 29.0% +/- 3.3%, 45.8% +/- 4.9%, 55.5% +/- 1.4%, 38.5% +/- 2.7%, 27.8% +/- 8.6%, and 19.5 +/- 7.1%, respectively. The results indicate optimal protection with a calcium concentration of 1.2 mmol/L and a rapid decline in protection with even small changes in concentration either side of the optimum. The hazard of total absence of calcium was confirmed by the induction of the calcium paradox. This study shows that under normothermic conditions a calcium concentration of 1.2 mmol/L is optimal for the St. Thomas' Hospital solution. This study reinforces the importance of undertaking dose-response studies for all components of all cardioplegic solutions.

Neuronal pathway from floccular caudal zone contributing to vertical eye movements in cats--role of group y nucleus of vestibular nuclei

In ketamine-anesthetized cats, electric microstimulation of the group y nucleus of the vestibular nuclei evoked a slow and smooth upward eye movement. Destruction of the group y nucleus eliminated a slow and smooth downward eye movement evoked by stimulation of the caudal zone of the flocculus. These data support the interpretation that Purkinje cell activity in the caudal zone of the flocculus can evoke vertical eye movements by inhibiting the activity of neurons of the group y nucleus.

Isolation of transforming sequences of two human lung carcinomas: structural and functional analysis of the activated c-K-ras oncogenes

Human lung tumors PR310 and PR371 maintained in nude mice contain activated c-K-ras oncogenes detectable by the ability of their DNAs to induce the morphological transformation of NIH 3T3 mouse fibroblasts. Using phage libraries constructed with DNA from NIH 3T3 mouse fibroblast transformants, we have isolated human sequences that span greater than 40 kilobase pairs of the c-K-ras oncogene. Based on the conservation of these human sequences in mouse fibroblast transformants, we conclude that the transforming ability of the oncogene activated in these tumors resides within a 43- to 46-kilobase-pair DNA region. No clear differences were observed between the structures of the PR310 and PR371 cloned oncogene sequences. Nucleotide sequence analysis in concert with DNA transfection experiments suggests that the PR371 oncogene has been activated by a single base change in the first exon, which results in the substitution of cysteine for glycine in position 12 of the predicted amino acid sequence. The genetic alteration responsible for the transforming activity of the PR310 oncogene, however, does not reside in the first exon. These results indicate that the activation of the c-K-ras oncogene in human lung cancer can occur by different mutational events.

Calcium antagonists and myocardial protection: diltiazem during cardioplegic arrest

Using an isolated rat heart preparation as a model of cardiopulmonary bypass and ischemic arrest, the effects of the addition of the calcium antagonist, diltiazem, to St. Thomas' cardioplegic solution were investigated. Under conditions of normothermic ischemic arrest (37 degrees C, 35 min), the addition of diltiazem improved the protective properties of the St. Thomas' cardioplegic solution. Moreover, studies with varying concentrations produced a bell-shaped dose-response curve for diltiazem with its optimal concentration at 0.5 mumoles/liter (0.21 mg/liter) when postischemic recovery of aortic flow was improved from 53.2 +/- 4.3% to 79.2 +/- 4.4% (p less than 0.01) and postischemic creatine kinase leakage was reduced by approximately 40%. Despite this marked additional protection when ischemic arrest was normothermic, diltiazem afforded no improvement in protection under conditions of hypothermic (20 degrees C, 180 min) ischemic arrest.

Nifedipine and cardioplegia: rat heart studies with the St Thomas' cardioplegic solution

The ability of nifedipine to enhance myocardial protection was assessed using an isolated rat heart model of cardiopulmonary bypass and ischaemic cardiac arrest. With normothermic ischaemic arrest (35 min, 37 degrees C), nifedipine addition improved the protective properties of the St Thomas' cardioplegic solution. Optimal protection was observed with 0.075 mumol nifedipine X litre-1, where post-ischaemic recovery of aortic flow was improved from 47.9 +/- 5.2% to 76.7 +/- 2.9% (P less than 0.001) and creatine kinase leakage was reduced by approximately 50%. Despite the marked additional protection under normothermic conditions the drug was unable to improve contractile recovery after a period of hypothermic ischaemic arrest (150 min, 20 degrees C) although it did allow a significant reduction (22%) in creatine kinase leakage. In other studies, the ability of nifedipine to replace the cardioplegic solution was examined. Under normothermic conditions, it showed a good ability to protect against ischaemia, but this protection did not match that afforded by the St Thomas' cardioplegic solution. Under hypothermic conditions the drug failed to substitute for the cardioplegic solution, suggesting that a common modality between hypothermia and nifedipine-induced protection.

Cardioplegia and slow calcium-channel blockers. Studies with verapamil

The ability of dl-verapamil to enhance myocardial protection when given before, during, or after myocardial ischemia was assessed with the use of an isolated working rat heart model of cardiopulmonary bypass and ischemic cardiac arrest. Under conditions of normothermic ischemic arrest (30 minutes at 37 degrees C), the addition of verapamil enhanced the protective properties of the St. Thomas' Hospital cardioplegic solution. Optimal protection was observed with verapamil concentrations of 0.5 mg/L (1.09 mumol/L) of cardioplegic solution. Under these conditions, postischemic enzyme leakage was reduced by 32.2% and the postischemic recovery of aortic flow was improved by 18.7%. Despite the additional protection at normothermia, the drug at several concentrations appeared unable to improve functional recovery after an extended period of hypothermic arrest (150 minutes at 20 degrees C), although under these conditions its inclusion in the cardioplegic solution could substantially reduce enzyme leakage. In other studies, the ability of various doses of verapamil alone as a substitute for the cardioplegic solution was examined. At the optimal dose (again 0.5 mg/L), and under normothermic conditions, verapamil alone was a good protection against ischemic injury, although this protection did not match that afforded by the St. Thomas' Hospital cardioplegic solution. In similar studies under hypothermic conditions, the drug failed to afford tissue protection, perhaps indicating some common modality between hypothermia and verapamil-induced protection. Pretreatment with verapamil (0.1 mg/L) prior to ischemia offered moderate additional protection, but its use during reperfusion failed to enhance overall recovery.

Detection of cellular receptors for Sendai virus in mouse tissue sections

We have established a method for detecting virus receptors in the tissue sections and have been able to clarify the distribution of cellular receptors for Sendai virus in various mouse organs, including trachea, esophagus, large intestine and cerebrum. The virus receptors were detected in ciliated cells of the trachea, as to be expected for a pneumotropic virus. The lamina propria and connective tissue of the mouse esophagus and large intestine, immediately under the epithelium, contained an abundance at virus receptors, but very few were detected in the epithelium of these organs. In mouse cerebrum, the cells lining the ventricles had a large number of virus receptors.

Occurrence of uronic acid in lipopolysaccharides of Vibrionaceae

The occurrence of uronic acid as a sugar constituent of lipopolysaccharides (LPS) in Vibrionaceae was demonstrated for the first time. More than 100 strains were examined. Of five genera constituting Vibrionaceae, i.e., Vibrio, Aeromonas, Plesiomonas, Photobacterium, and Lucibacterium, the latter three contained uronic acid in LPS of all of their constituting members examined, while it was totally lacking in Aeromonas LPS so far tested. Only the members of genus Vibrio were found to be divided into uronic acid-containing and -lacking groups; V. parahaemolyticus, V. alginolyticus, V. fisheri, V. costicola, Beneckea ('Vibrio'), and V. fluvialis belonged to the former, while all four biotypes of V. cholerae regardless of their serotypes, V. vulnificus and V. anguillarum, belonged to the latter group. The uronic acid content of V. parahaemolyticus O1 to O12 LPS ranged from 1.6 to 4.2%. The uronic acid residue released from V. parahaemolyticus O1, O4, O10, and O12 LPS by heating in 5% acetic acid at 100 C for 2 hr was identified as galacturonic acid; in particular, that from O12 LPS was characterized as D-galacturonic acid.

The 'pricking' method. A new efficient technique for mechanically introducing foreign DNA into the nuclei of culture cells

Using the thymidine kinase gene-containing plasmid pTK-1 and the mouse fibroblast thymidine kinase-deficient LTK- cell line, we obtained results indicating that the plasmid molecules suspended in the external medium were introduced into the nuclei by pricking cells on the nuclei with a microneedle. Approx. 25% of the cells pricked in the presence of the plasmid pTK-1 showed TK gene expression, and 2% of the cells became stable TK+ transformants. This 'pricking' method is applicable for introducing DNA into cell nuclei and is more efficient than the conventional calcium phosphate transformation method.

Comparative studies on the distribution mode of orthomyxo-virus and paramyxo-virus receptor possessing cells in mice and birds

Many experimental studies have shown that orthomyxo- and para-myxoviruses may be pneumotropic, but not enterotropic in mammals. On the other hand, these viruses are both pneumotropic and enterotropic in avian species. We have devised a new method for detecting virus receptor possessing cells (VRPC) in tissue sections. VRPC could be detected in the cells lining the airways of both mice and birds. The mode of distribution of VRPC in mouse digestive system differed remarkedly from that in avian digestive system. VRPC were not found in the epithelium of mouse digestive systems whereas the epithelium of bird digestive system were abundant in VRPC. When the large intestines from mice or duck undergoing laparotomy and inoculated directly into intestine with influenza virus were examined, viral antigen was detected in the epithelial cell of duck colon, but not in mouse intestines. From the study utilizing the new method, it could be concluded that the distribution mode of VRPC is one of the most important factors determining the virus tissue specificity.

Structure of thymidine kinase gene introduced into mouse Ltk- cells by a new injection method

Pricking, a new injection method developed by Yamamoto et al. (1981), can be used to introduce DNA into cultured cells with high efficiency. Closed circular plasmid DNA containing the cloned HSV-TK gene (pTK-1) was introduced by this method and the structure of DNA in stable transformants was examined. In most clones, the introduced DNA was integrated into the mouse genome in a tandemly repeated form. The possibility of multiple integration via mouse middle repetitive sequences was also examined using the chimeric plasmid with TK genes and middle repetitive sequences (pMRTK-1). Digestion with restriction enzymes showed that the middle repetitive sequence used in this experiment had no effect on the efficiency of transformation, suggesting that this sequence is unable to mediate homologous recombination with mouse genomes.

Contribution of prostaglandin to the contraction induced by catecholamines in the isolated gallbladder of the guinea-pig

Possible contribution of prostaglandins to the mechanical response produced by catecholamines was investigated in the isolated strips of the guinea-pig gallbladder. The contraction by catecholamine was blocked by an alpha-blocker, phentolamine (10(-6)M and relaxation was blocked by a beta-blocker, propranolol (10(-6)M. The rhythmic spontaneous motility and intrinsic tone were markedly inhibited by a prostaglandin synthesis inhibitor, indomethacin (10(-7)M. Furthermore, exogenous prostaglandins F2 alpha, E1 and E2 produced potent stimulant actions on gallbladder and the order of potency was found to be E2 > E1 > F2 alpha. The contractile response of catecholamines was abolished almost completely by indomethacin (10(-7)M. Even after the muscle tone was elevated by exogenous prostaglandin after treatment with indomethacin, catecholamine produced no contractile response, although it still relaxed the preparation through activation of beta-receptor. Based on these results, it was suggested that endogenous prostaglandins appear to be contributed to the alpha-action of catecholamines in the isolated guinea-pig gallbladder.

Intranasal flunisolide in the treatment of perennial rhinitis: Correlation with immunologic parameters

The effectiveness and safety of 200 micrograms/day of intranasal flunisolide in the treatment of perennial rhinitis was studied in 56 patients in a 6 wk double-blind parallel vehicle controlled clinical trial. In addition, patients failing to respond to placebo were entered into a 6 wk open trial with the active drug. Forty-six percent of the flunisolide-treated patients achieved total or substantial control of their nasal symptoms compared to 11% of the placebo-treated group in the double-blind study (p = 0.031). Eighty percent of patients achieved total or substantial control of their nasal symptoms in the 6 wk open study. No adverse effects attributable to flunisolide were observed. Parameters of IgE-mediated reactivity, including immediate-type skin test reactivity, total serum and nasal secretion IgE, specific serum and nasal secretion IgE, and nasal eosinophilia, were also assessed in these patients. Although benefit from flunisolide significantly correlated with all of these parameters except specific serum IgE, the absence of these findings did not preclude significant benefit from the drug. This study demonstrates the efficacy and safety of intranasal flunisolide in the treatment of perennial rhinitis, especially but not exclusively in those patients with evidence of IgE-mediated reactivity.

Steroid-dependent asthma treated with inhaled beclomethasone dipropionate in children

The efficacy of beclomethasone diproprionate aerosal (BDA) was studied in 27 steroid-dependent asthmatic children. In the double-blind portion of the study BDA was found to be superior to placebo. The benefits of BDA therapy were sustained through the two-year, open-label portion of the study. Adverse effects were few and minor. Transfer from oral corticosteroid therapy to BDA was carried out uneventfully and was not associated with untoward effects.

Administration of local anesthetics to patients with a history of prior adverse reaction

The clinical histories of 71 patients evaluated for suspected local anesthetic (LA) allergy were reviewed retrospectively. The clinical histories were classified into (1) immediate generalized reactions (15%), (2) localized swelling at the injection site (25%), (3) nonspecific systemic symptoms (42%), and (4) other histories (17%). Serial dilutional intradermal skin tests were performed with mepivacaine, lidocaine, and procaine in 59 patients. There were 5 skin test--positive patients found, and each had a positive reaction to an LA to which, by history, they had not reacted. In 50 patients, when an LA was subsequently required, a subcutaneous challenge was performed with an LA chosen for chemical nonsimilarity. No significant reactions were observed in this group. Three patients tolerated a challenge with an LA to which they were skin test--positive. These data indicate (1) the low incidence of reactions compatible with a systemic IgE-mediated mechanism by history in patients referred for evaluation of LA allergy, (2) the lack of specific and clinically relevant information provided by dilutional skin tests, and (3) the apparent safety and usefulness of careful challenge with an alternative LA.

A new approach to absorptive function of gallbladder

To investigate the mechanism of concentration of bile, the normal canine gallbladders were cannulated through the cystic duct into the gallbladder neck with polyethylene tube, and hypotonic, isotonic and hypertonic salines as well as hepatic and gallbladder biles were placed in the gallbladder. Low molecular electrolytes such as Na+ and Cl- were transported across the epithelial membrane against water flux. The hepatic bile was decreased markedly in volume and each level of electrolytes including bile acids approached that in the gallbladder bile. The different results were obtained by concentration of the hepatic bile in the gallbladder with chemically induced cholecystitis.