Abstract: Injections of cyclic AMP (cAMP) and 8-Br-cAMP into Paramecium and external application of isobutylmethylxanthine (IBMX), an inhibitor of cAMP breakdown, to these cells increased the frequency of ciliary beating and hyperpolarized the membrane potential. When the membrane potential was held equal to the resting potential under voltage clamp, the same experimental conditions which serve to increase intracellular cAMP did not raise the ciliary frequency. We conclude that cAMP is presumably not the direct mediator of the hyperpolarization-induced ciliary activation, although it may be associated with this motor response.

Abstract: The surface of monomolecular layers of fatty acids prepared by Langmuir-Blodgett methods on polycrystalline silver has been studied by High Resolution Electron Energy Loss Spectroscopy (HREELS). Results demonstrate HREELS sensitivity to large molecules in molecular organizates on polycrystalline substrates. Spectra are interpreted in comparison with infrared vibrational data; results allow differentiation of degrees of unsaturation. The carbonyl vibration loss is observed as a weak feature, explained as due to the orientation of the fatty acid heads “down” on the subtrate surface approximately 20 A from the scattering interaction.

Abstract: Preparation des complexes mixtes de type M(η 2 -olefine)(η 2 -alcyne)(S 2 CNR 2 ) 2 (M=Mo et W). Structure cristalline de W(η 2 -anhydride maleique)(η 2 -PhC 2 H)(S 2 CNMe 2 ) 2

Abstract: It has been reported that patients suffering from azotemia attributable to urinary obstruction required significantly less thiopental for induction and maintenance of general anesthesia than did a comparable group of patients with normal blood urea concentrations. Moreover, the thiopental requirements of normal subjects could be reduced by urea administration. In rats, experimental renal dysfunction was associated with reduced concentrations of phenobarbital (PB) in serum, serum water, brain and cerebro-spinal fluid at onset of a defined hypnotic effect (loss of righting reflex) produced by a slow i.v. infusion of PB. To determine the mechanism of this effect, these studies have now been repeated in normal rats made azotemic (approximately 170 mg of urea nitrogen/100 ml of serum) by intra-arterial infusion of urea and in control animals infused with saline solution. The total dose of thiopental required to produce loss of righting reflex was significantly reduced in the rats infused with urea. confirming the clinical observations. Similar results were obtained with PB and heptabarbital, two barbiturates that (unlike thiopental) are not racemic mixtures and are therefore more suitable for this investigation. On the other hand, urea infusion had no apparent effect on the concentrations of PB and heptabarbital in serum, brain and cerebrospinal fluid at onset of loss of righting reflex. Urea apparently affects the distribution kinetics of barbiturates and this, rather than increased receptor sensitivity, appears to be responsible for the decreased barbiturate dose requirements in acute experimental azotemia produced by urea infusion.

Abstract: In adult male Wistar rats (Rattus norvegicus albinus) gingival irritation provided by means of wire silk ligatures around the cervix of first left lower molars, for a duration of 77 days, caused gingival inflammatory changes. In the rats receiving also daily one i.p. injection of sodium 5,5-diphenythydantoinate (phenytoin), during 70 days, there was no macroscopical change of the gingiva of non-ligated first right lower molars. However, in the first left lower molars, the association of silk ligature-plus-phenytoin administration elicited gingival overgrowth. The rat was seen as a satisfactory animal model for studies of phenytoin-induced gingival changes.

Abstract: Cinetique des reactions de substitution de Fe 3 (CO) 12 et Os 3 (CO) 12 par L=PPh 3 , PBu 3 , P(OPh) 3 et P(OMe) 3 en solution d'hydrocarbure. Comparaison des reactivites des agregats a celle de l'analogue Ru

Abstract: The microwave spectrum of chloromethylphosphonic difluoride, ClCH2P(O)F2, has been investigated in the region from 26.5 to 39 GHz. The a‐type R branch transitions have been assigned for both the 35Cl and 37Cl isotopic species for the trans conformer on the basis of the rigid rotor model. For the ground vibrational state the rotational constants for the 35Cl isotope were found to be A = 4392.4±2.3, B=1543.36±0.01, and C=1512.30±0.01 MHz and for the 37Cl isotope: A=4395.3±2.7, B=1502.04±0.01, and C=1472.54±0.01 MHz. With reasonably assumed structural parameters for the C–H and P=0 distances as well as the HCH angle, a diagnostic least‐squares adjustment was utilized to obtain the other six structural parameters. The dipole moment components were determined from the Stark effect to be ‖μa‖ =2.28±0.05, ‖μb‖ =0.75±0.02, and ‖μt‖ =2.40±0.02 D. The infrared (3500–40 cm−1) and Raman (3500–20 cm−1) spectra of the gas and solid have been recorded. Additionally, the Raman spectrum of the liquid has been recorded and...

Abstract: We have isolated Neurospora trehalaseless mutants and mapped the trehalase structural gene to linkage group I. The structural gene mutations not only affect thermostability and other characteristics of the enzyme but also affect the production of an inhibitor of the wild-type trehalase. The inhibitor appears to be the mutant trehalase. We suggest that the mutant subunits act as inhibitors by entering into the multimeric forms of the enzyme and altering the ability of the normal wild-type subunits to catalyze the cleavage of trehalose.—Wild type trehalase has been purified to near homogeneity, and its characteristics have been studied. It was purified as a tetramer, with each subunit having a molecular weight of 88,000.—We have studied the regulation of trehalase and found the production of trehalase to be glucose repressible. Cells begin to produce trehalase 60 min after being transferred to glucose-free medium.

Abstract: On a mesh-connected computer, moving data across the mesh is the most time-consuming operation in many algorithms. This time can be reduced by using a mesh with smaller diameter, i.e., with fewer processing elements. To accomodate inputs of the same size, this requires that the processors have more memory. For image processing and graph theoretic algorithms we analyze the time as a function of the mesh diameter and problem size. We show that for many problems, smaller diameters can yield faster algorithms, and that there is a choice of diameter that is simultaneously best for several of these problems. Further, for these problems and this number of processing elements (or any smaller number), the mesh is an optimal interconnection scheme.

Abstract: A search for structural and numerical chromosomal aberrations was made on metaphases obtained by culturing in vitro skin fibroblasts of 16 leprosy patients (10 lepromatous, 2 borderline, and 4 tuberculoid cases) and 2 healthy individuals used as controls. The data were analyzed taking into account sex, age, race, form of leprosy, bacterial index, type of therapy, and age of the fibroblast cultures. Structural chromosomal aberrations are the only type of chromosomal abnormality that may be accepted as significantly increased in the skin fibroblasts of leprosy patients who are under treatment with dapsone alone or with combined therapy.

Abstract: This investigation was designed to determine if the acute hypnotic activity of a barbiturate is altered by advanced pregnancy. Twenty-day-pregnant rats and nonpregnant rats of the same age received an i.v. infusion of phenobarbital, 0.824 mg/min/rat, until they lost their righting reflex. The concentrations of total and free phenobarbital in serum at that time were significantly lower in pregnant than in nonpregnant animals. However, pregnancy had no effect on the concentrations of phenobarbital in the brain and cerebrospinal fluid at onset of loss of righting reflex. The difference of the serum phenobarbital concentrations was due to the slower rate of phenobarbital infusion received by the pregnant rats when normalized for body weight. The lack of difference of phenobarbital concentrations in cerebrospinal fluid, a site that reflects the concentration of the free drug at the sites of action, indicates that advanced pregnancy has no apparent effect on the central nervous system response to phenobarbital.

Abstract: To determine if the pharmacodynamics of ethanol are altered in advanced pregnancy, 20-days pregnant Lewis rats and nonpregnant rats of the same age received an i.v. infusion of ethanol, 96 mg/min/kg, until they lost their righting reflex. The concentrations of ethanol at that time in adult and fetal serum, and in the cerebrospinal fluid (CSF) and brain of the adult animals were determined. Ethanol concentrations in the pregnant rats were only slightly (less than 10%) but statistically significantly lower than in nonpregnant controls. Brain/serum, CSF/serum, and CSF/brain concentration ratios of ethanol were essentially identical in pregnant and nonpregnant rats, indicating no apparent effect of pregnancy on the distribution kinetics of ethanol. The serum concentrations of ethanol in mothers and their fetuses were similar and significantly correlated. The results of this investigation show that the central nervous system depressant effect of ethanol is not appreciably altered by pregnancy.