Search

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.

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.

The ability of nifedipine, verapamil, and diltiazem to enhance cardioplegic protection has been assessed using an isolated rat heart preparation as a model of cardiopulmonary bypass and ischemic arrest. With normothermic ischemia (30 or 35 min at 37 degrees C), the addition of these compounds enhanced the protective properties of the St. Thomas' cardioplegic solution. All these compounds showed bell-shaped dose-response characteristics, with the optimal concentrations in terms of functional recovery and enzyme leakage of verapamil being 1.0 mumole/liter; nifedipine, 0.075 mumole/liter; and diltiazem, 0.5 mumole/liter. However, under conditions of hypothermia (150 or 180 min at 20 degrees C), none of these compounds improved postischemic functional recovery, although there was some reduction in enzyme leakage. From these results, further experiments were undertaken to investigate the relationship between calcium antagonists and temperature. Verapamil improved functional recovery at 34, 31 and 29 degrees C, but not at 27, 25, and 20 degrees C. These results suggest a common site of action between hypothermia and calcium antagonists in promoting functional recovery after ischemia.

In 17 cats anesthetized by Ketalar, neuronal activities were recorded extracellularly by a tungsten microelectrode placed in the group y nucleus of the vestibular nuclei. Forty-seven of 139 neurons tested were activated antidromically by stimulation of the superior rectus and inferior oblique subdivisions of the oculomotor nucleus. Twenty-five of these 47 neurons ceased their spontaneous discharges after stimulation of the caudal zone of the flocculus. In addition, 18 out of these 25 units responded polysynaptically to stimulation of the vestibular nerve.

The promoter of the human c-K-ras gene has been characterized by deletion mutagenesis in concert with stable and transient expression gene transfer experiments. The transcription initiation sites were determined by S1 mapping and RNase A protection experiments. The c-K-ras promoter region is rich in G + C, lacks TATA and CCAAT boxes and contains sequence similarities with other house-keeping genes such as the dihydrofolate reductase (DHFR) and the epidermal growth factor (EGF) receptor genes. The promoter of the c-K-ras gene consists of multiple elements and initiation of transcription occurs at multiple sites. A 54 bp DNA fragment immediately upstream from the 5' end untranslated exon controls the position of many of the transcription initiation sites and direct sufficient transcription for transformation of NIH3T3 cells. However, these sequences can be replaced by other upstream sequences which are required for optimal gene expression. In addition, sequences overlapping with the 5' end untranslated exon and therefore downstream from the major transcription initiation sites are important (although not sufficient) for transcription because their deletion greatly impairs the promoter activity of the upstream elements.

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.

We reported five cases of children with spinal injuries. Spinal injuries are rare in children, and most common from the occiput to C3 in children younger than 8 years. In our cases, two younger children had upper cervical lesions and two older children had lower lesions. These differences result from anatomical characteristics, such as special histological architecture of the growth zones in younger children. One patient had a delayed onset paraplegia without radiographic abnormality. This phenomenon seems to be one of the characteristics of the spinal injuries in children. Because of this, all children with head or neck injuries should be fully investigated. A nine-month-old child who suffered from a fracture of the odontoid process with atlantoaxial dislocation was treated by immobilization only, and the result was good. Generally, fracture of the odontoid process in young children can be treated by proper immobilization. One patient with fracture dislocation of the cervical spine died as a result of cord injury. So immediate surgical decompression is mandatory for patients with evidence of cord compression.

Ninety-one patients with tetralogy of Fallot underwent intracardiac repair between 1978 and 1981. One patient died from left-sided heart failure. Retrospective analyses of this death revealed a significant decrease of the left ventricular (LV) end-diastolic volume index (EDVI) of 21 ml/m2 (36% of normal). Results of early postoperative hemodynamic studies after total correction of this anomaly suggested that an EDVI of 30 ml/m2 is the minimal requirement for adequate cardiac output postoperatively. Based on these data, 3 patients with decreased LV volume with EDVI of around 30 ml/m2 were challenged with the primary repair with success, although they required atrial pacing and catecholamine support postoperatively to maintain adequate left atrial pressure and cardiac output. From these results, it is recommended that patients with tetralogy of Fallot and an EDVI of 30 ml/m2 or more can be considered as candidates for the primary repair, but that patients with an EDVI of less than 30 ml/m2 should be palliated once by systemic-to-pulmonary arterial shunt procedures. Subsequent total correction should be performed after sufficient LV growth for those patients.

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.

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.

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.

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.

Four arginine ester hydrolases, ME-1, 2, 3 and 4 from the venom of Trimeresurus mucrosquamatus had been isolated and characterized by Sugihara et al. (1980, 1981, 1982, 1983). Immunologically, ME-1, 2, 3 and 4 are identical. The four enzymes hydrolyzed Pro-Phe-Arg-MCA and z-Phe-Arg-MCA. Furthermore, ME-2 slightly hydrolyzed Boc-Val-Pro-Arg-MCA, Boc-Phe-Ser-Arg-MCA and Boc-Ile-Glu-Gly-Arg-MCA. ME-1 cleaved almost simultaneously the Arg(22)-Gly(23) and Phe(25)-Tyr(26) bond of oxidized insulin B chain. ME-2 and 3 also hydrolyzed the same bond of insulin B chain, but the activity was not as potent as ME-1. ME-4 did not cleave the substrate. The four enzymes hydrolyzed C-terminal of arginine in the biologically active peptides. Four arginine ester hydrolases showed fibrinogenolytic activity. ME-1 and 2 first cleaved B beta-chain and then A alpha-chain. On the contrary, ME-3 and 4 cleaved A alpha- and B beta-chain simultaneously. The four enzymes also hydrolyzed fibrinogen in plasma cleaving B beta- and gamma-chain and slightly digesting A alpha-chain. The various inhibitors affected TAME (tosyl-arginine-methylester) and the fibrinogen hydrolytic activity of the four enzymes. All four enzymes had fibrinolytic activity.

MK412A (0.2% chlorhexidine in 70% ethanol) and MK412B (0.2% benzalkonium chloride in 70% ethanol), which are rapid drying and rubbing antiseptic preparations, have been evaluated for hand sterilization over a month by ICU nurses. They have been shown to have effective skin decontaminant efficacy under practical conditions in a busy ICU. There were no adverse reactions except for two cases of mild erythema in the MK412A treatment group. In a comparative in vitro study with Pseudomonas cepacia, 0.2% chlorhexidine solution alone and 0.2% benzalkonium chloride solution alone were less bactericidal than MK412A and MK412B.

To study the effects of extracorporeal circulation on the post operative infections, the relationship between the influences of the immunologic change during cardiopulmonary bypass (CPB) and post operative change of neutrophilia was evaluated in 52 patients. These patients were divided into two groups: group A (non-infected), 19 patients whose neutrophil count increased within 15,000/microliters in peripheral blood after operation. Group B (infected), 33 patients whose neutrophil count increased 15,000/microliters or more within one week after operation. Immunoglobulins (IgG, IgA, IgM) and complement fraction (C3, C4, CH50) levels decreased significantly during CPB, but there was no significant difference between the two groups. The amount of lymphocyte subsets of helper/inducer T cell and suppressor/cytotoxic T cell showed similar change in both groups. On the contrary the amount of lymphocyte subset of Natural Killer cell showed significant increase in A group during CPB when compared with B group, suggesting immunological activation, however, in the group which showed less than 40% increase of NK cell during CPB, there was significant increase of neutrophils after operation compared with the other group which showed high increase of NK cell. These findings suggested the increased activation of the Natural Killer cell during CPB is a favorable response, especially for preventing infections after operation.

Up to now light and dark adaptation are considered as of minor importance when recording the pattern electroretionogram (P-ERG) which in man reflects cone vision. In order to test this supposition transient P-ERGs were recorded in six healthy subjects to a reversing checkerboard pattern produced by a pivoted mirror system after two minutes of pre-exposure to darkness (1), to the pattern reversal stimulus (2), and to uniform illumination of 3.3 log cd/m2 (3). Field size was 18 x 20 degrees, check size 69 min of arc, reversal frequency 3.5/s, contrast 0.95. When recording the P-ERG within the first 30 s after pre-exposure, the amplitude/luminance function of the p-q and the q-r component was shifted along the luminance axis without changing the maximum amplitude. For a criterion response of 1.5 microV there was a sensitivity difference of 1.3 log units between measurements after pre-exposure to darkness and after strong illumination. Furthermore, the P-ERG latencies of the q and the r component displayed significantly shorter values after pre-exposure to strong light than after darkness, whereas no change of p-latency was recorded. We conclude that pre-exposure to darkness and strong illumination has no effect on the P-ERG elicited at high luminance levels. However, pre-adaptation should be considered when recording the P-ERG at luminance levels near threshold.

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.

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.

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.

Normal guinea-pig serum (GPS) lacking detectable antiviral antibody efficiently neutralized the infectivity of influenza B virus grown in chick embryos or MDCK cells. The inhibitor was heat-labile and sensitive to trypsin digestion. This beta-like inhibitor required Ca2+ and the complement components C1 and C4 for its activity. In contrast, GPS did not inactivate influenza A virus. Influenza B virus from which the neuraminidase activity of the spikes on the viral envelope had been eliminated by trypsin digestion was also inactivated to a level comparable to untreated virus. Complement component C1 alone bound directly to influenza B virus and inhibited its haemagglutinin activity. We suggest that the beta-like inhibitor in GPS is a component of the classical complement pathway which is triggered by the protein moiety of influenza B virus haemagglutinin, leading to virus neutralization.

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 significant percentage of human tumors contain activated ras oncogenes that have acquired oncogenic potential as a result of somatic point mutations at codon 12 or 61 of the encoded ras gene product. We report here a method to detect and characterize mutations in ras genes that is based on the ability of pancreatic ribonuclease (RNase A; EC 3.1.27.5) to cleave RNA heteroduplexes containing single-base mismatches. Using this method, we show that certain human tumor cells contain mutant c-Ki-ras genes, and we define the nature and position of these mutations. At the same time, we describe the presence and estimate the expression of both normal and mutant c-Ki-ras alleles in the same tumor cells. This method should be useful for the diagnostic detection and characterization of single point mutations in expressed genes.

In our hospital, 22 patients with severe coronary arterial lesion after Kawasaki disease underwent coronary artery bypass grafting (CABG) since 1982. The age of the cases at surgery ranged from 1 year to 19 years. Mean age was 8.3 years. Fifteen cases were bypassed using internal mammary artery (IMA) and 5 cases using IMA and autologous saphenous vein (SVG). Two cases were bypassed using only SVG. They have been examined until now by catheterization, by Treadmill test, and by Tl-201 myocardial imaging, around 1 month (Study 1) and around 1 year (Study 2) after surgery for the evaluation of results of CABG. One patient died from acute myocardial infarction 3 months after surgery and one patient shows return of anginal attack due to graft stenosis. Other patients are almost uneventful. In the study 1,20 (100%) IMA were patent, and 7 (88%) SVG were patent. In the study 2, 11 (92%) IMA and 6 (67%) SVG remained patent. Development of left anterior descending artery distal to IMA anastomosis was shown in 8 cases in the study 2. On the follow-up study with TI-201 myocardial imaging, disappearance or decrease of perfusion defect was seen in 7 cases (59%) in the study 1 and 9 cases (75%) in the study 2. On the Treadmill test, disappearance or improvement of ischemic change was seen in 15 cases (88%) in the study 1 and 10 cases (84%) in the study 2. These results suggest that IMA is more preferable for than SVG for young children who has an indication of CABG after Kawasaki disease.