[Ventricular arrhythmias in the acute stage of experimental swine myocardial infarct; effect of the beta blocker pindolol and the calcium antagonist Ro 11-1781]

A study was designed to examine ventricular arrhythmias in the acute phase of experimental myocardial infarction in the pig and to evaluate possible antiarrhythmogenic influence of the beta-adrenergic blocking drug pindolol (Visken) and the calcium antagonist Ro 11-1781. Ventricular fibrillation (VF) occurred in 17 of 18 animals, in 4 almost immediately after coronary occlusion and in 12 with a delay of about 17 min. VF was almost always induced by episodes of ventricular tachycardia (VT) which were started by single ventricular premature beats (VPBs). VPBs occurred in 3 phases, whereas VT and VF coincided only with phase 1 and phase 3. The prematurity index QR/QT of single VPBs decreased significantly with time after coronary occlusion. The beta-adrenergic blocking drug pindolol and the calcium antagonist Ro 11-1781 did not prevent VT or VF.

[Experimental coronary ligation in swine: reduction of myocardial infarct and hemodynamic and metabolic changes by means of the calcium antagonist RO 11-1781]

In a comparative study the effect of the new calcium antagonist Ro 11-1781 on experimental infarct size and left ventricular function in the pig has been investigated. The calcium antagonist was administered 30 min prior to ligation of the left anterior descending coronary artery and twice daily on the following 4 days. For morphometric assessment of infarct size the ventricular myocardium was cut into slices and stained with nitro-benztoluene. There was a significant reduction in infarct size of about 25% in the calcium antagonist-treated group in comparison with the control group. After coronary occlusion left ventricular function is equally depressed in both groups, as is myocardial lactate extraction, which becomes negative.

Purification and properties of methanol dehydrogenase from Hyphomicrobium x

(1) A method for the isolation of methanol dehydrogenase (alcohol:(acceptor) oxidoreductase, EC 1.1.99.8) from Hyphomicrobium X is decribed. The purified enzyme was resolved by polyacrylamide gel electrophoresis into one main and two minor active bands. Iron and manganese were the only detected metals in the enzyme preparation. (2) The substrate, methanol, was oxidized to formic acid by a stoichiometric amount of artificial electron acceptor. During the reaction, no free formaldehyde could be detected. Other primary alcohols were oxidized to the corresponding aldehydes were a poor substrate or no substrate at all. (3) Some new and efficient one-electron acceptors were found. With these electron acceptors, the enzyme had a high pH optimum and ammonia was still required in the assay system. (4) ESR spectroscopy showed the presence of an enzyme-bound organic free radical. With X-band ESR the signal had a peak-to-peak linewidth of about 0.7 mT. The signal was further resolved by Q-band ESR and the values gparallel = 2.0024 and gperpendicular = 2.0056 were derived. (5) Under denaturing conditions the ESR signal and enzymatic activity disappeared at the same time as fluorescence appeared. Enzymatic activity is not restored when extracted cofactor and apoenzyme are brought together under normal conditions. Some properties of the unusual prosthetic group are presented in a preliminary form.

Ioglycamide (Biligram) studies in man. Radiological opacification of the bile duct. A comparison of a number of different methods

Intravenous cholangiography was carried out in 80 anicteric patients using ioglycamide (Biligram). Twenty patients were given a 30 ml ampoule of 35% ioglycamide as a slow hand injection over ten minutes; the remainder were given ioglycamide by one hour slow drip infusion at a rate of 2, 3, or 4 mg per kg body weight per minute. The radiological opacification of the bile duct was then assessed independently by two radiologists. There was a statistically significant difference between the bile duct opacification found in patients given either 3 or 4 mg/kg/min of ioglycamide for one hour compared with those given ioglycamide either by ten minute injection or by 2 mg/kg/min drip infusion.

Ioglycamide (Biligram) studies in man--relation between plasma concentration and billary excretion

Plasma ioglycamide concentration was linearly related to the rate of intravenous infusion over a dose range of from 1 to 4 mg per kg per min. The relation between plasma and biliary concentration of ioglycamide was studied in 15 anicteric patients with a T-tube in situ. Peak biliary concentrations and excretory rates of ioglycamide were seen when the plasma concentration was greater than 1500 micrograms per ml. The mean biliary transport maximum (Tm) for ioglycamide in man was 31.6 mg/min (range 22.0-40.4). The results suggest that near optimal concentrations of iodine in the bile duct can be obtained during intravenous cholangiography if ioglycamide is infused for one hour at a rate of about 4 mg per kg per min.

A phase II study of phenesterin (NSC-104469)

Phenesterin was evaluated in 222 patients with two different dosage regimens, one by daily treatment and the other with an intermittent schedule. Toxicity was moderate with both programs. The largest group of patients treated had breast cancer; they experienced a 10% response rate. Of interest was a higher percentage of responses in ovarian cancer (36%). An expanded study of patients with ovarian cancer would be of interest.

Reconstruction of glutamine synthetase using computer averaging

The axial projection of the glutamine synthetase molecule has been reconstructed from electron micrographs of a stained preparation by using a new method of correlation search and averaging. The average over 50 individual molecules appears as a radial pattern with sixfold symmetry. The handedness evident in the average is attributed to nonuniformity of the negative stain.

The incidence of cervical cancer and duration of oral contraceptive use

In a prospective study carried out on a cohort of 17,942 women belonging to the Kaiser Foundation Health Plan and living in suburban communities of the San Francisco Bay Area, a positive association was found between the incidence of cervical carcinoma and total duration of oral contraceptive use. The association was established while controlling for the effects of age, education, and selected infections. The association persists when incident cases of dysplasia are added to those of carcinoma. A further study, in which covariates relating to sexual behavior will also be taken into account, is in progress.

Oral contraceptives and blood pressure

Both cross-sectional and longitudinal analysis of data from 13,358 women showed that oral contraceptive use is associated with a slight but statistically significant (P lesser than .05) rise in mean blood pressure, which is reversible. The age-adjusted proportion of oral contraceptive users with a blood pressure over 140/90 mm Hg was about three times that on nonusers. These findings are caused by a uniform upward shift in the blood pressure distribution of oral contraceptive users compared to nonusers. Women continuing oral contraceptive use had no appreciably greater change in blood pressure between two visits than persistent nonusers. The clinical implications of a mild contraceptive-induced blood pressure elevation (systolic, 5 to 6 mm Hg; diastolic, 1 to 2 mm Hg) remain unsettled but disturbing.

Motif detection in quantum noise-limited electron micrographs by cross-correlation

The use of cross-correlation to detect randomly positioned low-dose realizations of a motif in an image field is quantitatively evaluated. For both the bright- and dark-field cases, we derive theoretical expressions for the minimum dose allowing detection in terms of motif size, resolution, and contrast. Model computations on simulated low-dose images of a spherical virus particle give results that agree with our theoretical formulas and demonstrate the feasibility of this approach.

IR spectrophotometric assay of carbachol solutions

Carbachol ophthalmic solutions can be assayed by evaporating a measured volume, dissolving the residue in methanol, and scanning the carbonyl stretching frequency in an IR spectrophotometer using a cell with calcium fluoride windows. Methylcellulose and other formulation vehicle components do not interfere. The method is stability indicating with respect to hydrolysis. It affords a recovery of 99.5+/-0.51% (RSD).

The 11q -- syndrome

An eighth case of terminal deletion of the long arm of chromosome eleven (11q--) is reported to emphasize both the distinctive facies, but otherwise non-specific nature of this disorder, and the female preponderance of affected patients. Growth and mental retardation, congenital heart disease and telecanthus are the other most constant features. The authors' experience with 3 unrelated cases in less than 2 years suggests that this syndrome is underdiagnosed.

Preservation of cross-modal transfer of a rate discrimination in the bushbaby (Galago senegalensis) with lesions of posterior neocortex

The effect of lesions of posterior neocortex was assessed, using a test method that permits the demonstration of cross-modal transfer in intact bushbabies. Eight bushbabies were trained to discriminate light flashes of 18/sec and 3/sec in a go-no-go shock-avoidance task. On completion of training, four bushbabies received lesions of posterior neocortex by aspiration. After 6 wk both lesion and intact animals were returned to training in the visual discrimination. On the day following criterion performance on the visual tests, auditory clicks off the same rate and contingencies were substituted and maintained to criterion. All eight bushbabies demonstrated rapid transfer and the lesion animals were not retarded as compared with intact subjects. The cross-modal transfer of a specific rate discrimination was thus preserved in the absence of posterior intersensory neocortex. The results are discussed in terms of a hypothetical subcortical system capable of the amodal coding of simple stimulus dimensions.