Drug-induced vasodilation in an in vitro and in vivo study: the effects of nicardipine, papaverine, and lidocaine on the rabbit carotid artery

Extreme arterial vasoconstriction (vasospasm) is a common problem encountered in microvascular surgery. An ideal pharmacologic tool able to counteract ischemia during microsurgery should be easy to apply and exert its action both locally and distally in the microcirculation of the flap. We have compared in vitro and in vivo vascular properties of nicardipine, papaverine, and lidocaine in the rabbit carotid artery. In vitro, rings from the rabbit carotid artery (n = 7) were bathed in Krebs-Ringers solution and stretched progressively to an optimal tension of 3.7 to 4.2 g. The specimens were contracted with norepinephrine (1 microM), and a cumulative dose response curve was established. In vivo, microvascular anastomoses were performed bilaterally in the rabbit carotid artery in 35 animals using 9-0 nylon suture and standard microsurgical techniques. During and after the anastomoses, nicardipine (0.1, 0.01 mg topical, or 0.1 mg/hour IV), papaverine (30 mg/cc topical), and lidocaine (2% with and without epinephrine) were applied (blinded) at the anastomotic site in five rabbits each. Heparinized sodium chloride was used as topical irrigation for control and to clean the anastomosis. Blood flow changes were monitored continuously with the transonic Doppler for 30 minutes after the procedure. The systemic blood pressure was also monitored in a group of pilot experiments. A documented decrease in blood flow was noted in all animals after the microvascular anastomosis. Nicardipine and papaverine evoked a concentration-dependent relaxation to precontracted rings to norepinephrine. Nicardipine was greater than papaverine in inducing relaxation. Lidocaine demonstrated a biphasic response with low concentrations potentiating contraction. Systemic nicardipine and papaverine significantly increased the blood flow in the rabbit carotid artery. Topical application of nicardipine and lidocaine did not significantly alter the blood flow; however, the application of nicardipine demonstrates a trend toward increased flow. Lidocaine with epinephrine significantly decreased the blood flow. No drug was found to alter the blood pressure of the animals. Our results demonstrate that nicardipine and papaverine seem to be pharmacologic tools able to increase the blood flow in anastomotic arteries. In contrast, the use of 2% lidocaine as a spasmolytic agent should be re-evaluated, since this substance may act as a partial agonist.     

DNA-protein interactions in CpG islands and DNAse I sensitive chromatin]

DNA-protein interactions were studied in the chromatin preparations obtained according to different procedures by means of nucleoprotein-celite chromatography. Three discrete fractions dissociating in 1M, 2M and 3M NaCl were observed in all preparations. The 1M fraction prevails in DNaseI-sensitive chromatin and the 2M fraction--in the resistant. Chromatin solubilized by MspI restrictase (the active chromatin) contains the 1M and 3M fractions, one solubilized by AluI (inactive)--the 2M fraction. Distribution of the fractions is different in proliferating and quiescent cells.     

Differential accumulation and tissue distribution of mosquito hexamerins during metamorphosis

We report on 30 cases where we have used cortical stimulation mapping to define the areas representing sensorimotor, language and speech functions under local anesthesia to facilitate resection of space-occupying lesions near these areas. Under the simplistic concept that Broca's area lies in the frontal operculum (inferior frontal gyrus) and that Wernicke's area is located in the posterior perisylvian area (superior temporal, angular and supramarginal gyri), we found language and speech function to be represented outside these areas in up to 4 stimulation sites of 15 patients. The results of cortical stimulation mapping were therefore essential to decide on the optimal access route to the lesions that were located subcortically and on the optimal resection plane in gliomas. After the limits of these areas and of the lesions had been established with stimulation mapping and with intrasurgical microscopic smear preparations, respectively, lesions were safely removed under continuous monitoring of sensorimotor, language and speech function. Immediately after surgery we encountered language and speech deficits in 9 patients (30%), which resolved completely in 5 and incompletely in 4 instances. Thus, language functions were normal in 26 patients (87%) at the end of the follow-up period. It is concluded that use of this technique allows safe and extensive resection of lesions that would otherwise have been considered hazardous to remove or inexcisable.     

Incidence of leukemias in people aged 0 to 24 in north Cotentin

Multifocal electroretinograms were recorded from twelve subjects on three separate days using the Visual Evoked Response Imaging System (VERIS). The subjects were 18-40 years-of-age. Each recording session was separated by an interval of between one and 16 weeks. Four electrode types were compared: the JET contact lens electrode, the gold foil electrode, the DTL thread electrode and the carbon fibre (c-glide) electrode. The b-wave amplitude density (nV/sq.deg) recorded with each electrode was measured. The mean amplitude density recorded at each session for each subject and each electrode was calculated and compared. There were no significant differences in amplitude density for the ERGs recorded with each type of electrode over the three days. The coefficient of variation for each electrode and each subject was then calculated using the results for the three days. The coefficients of variation for each electrode showed significant differences (One-way ANOVA: F = 4.51, d.f. = 3.44, P < 0.008). The c-glide electrode results had the highest variability and post hoc tests showed that its coefficient of variation was significantly different from those of the JET and gold foil electrodes but not from that of the DTL thread electrode.     

New data on the etiological factors in acute pyelonephritis

Spectrum of microbe agents of acute pyelonephritis has been studied. It is shown that Mycoplasma hominis plays an important role in etiology of acute pyelonephritis besides the already known enterobacteria and Gram-positive cocci. It is also established that mycoplasmal pyelonephritis more often develops in patients with the diseases of urinary blade (cystitis) and genital organs. Results of serological investigations which confirm etiological role of isolated microorganisms in the initiation of acute pyelonephritis are presented.     

Variance components analysis of carotid and femoral intima-media thickness measurements. REGRESS Study Group, Interuniversity Cardiology Institute of The Netherlands, Utrecht, The Netherlands. Regression Growth Evaluation Statin Study

B-mode ultrasound intima-media thickness (IMT) measurements of carotid and femoral arterial walls are used in atherosclerosis studies. In this study, the components contributing to IMT measurement variability in males with coronary artery disease were investigated by means of repeated B-mode ultrasound scans and repeated off-line video image analyses. For statistical analysis, a mixed-model analysis of variance was used. From sonographer data, it was shown that human subjects and their arterial wall segments contributed 75% of the total IMT measurement variability in this population. Inter-sonographer variance contributed 25%. The intra-sonographer variance was negligible (<1%). In off-line image analysis, variance components due to subjects and segments, inter-analyst variance, and residual fluctuation were 88%, < 1% and 11%, respectively. Intra-analyst variance was negligible (<1%). The major source of B-mode ultrasound IMT measurement variability finds its origin in subjects and their arterial walls. Although sonographers proved a lesser source of variability, in comparative studies they should enter a study well trained and should be randomly assigned to subjects. Follow-up examinations should preferably be done by the same sonographer. Off-line image analysis contributed little to IMT measurement variability.     

Preservation and peeling of the inferior mesenteric artery in the anterior resection for complicated diverticular disease

The authors, on the basis of 3 cases of complicated diverticular disease, discuss the indications to surgery, considering the advantages and disadvantages of the various surgical techniques and examining in particular the rules for a correct operation with resection and primary or secondary anastomosis. As they performed a rectosigmoidectomy with primary high colorectal anastomosis, they report the reasons why they adopted the preservation and peeling of the inferior mesenteric artery (IMA).