Augmentation of pentylenetetrazol induced seizures by tricyclic antidepressants

The effect of a brief appointment reminder for mental-health center applicants is reported. A standardized phone message was delivered by an administrative staff member one to three days before the appointment and a sequential experimental design alternating baseline and phone message conditions was used to assess the effects of the procedure. The no-show rate averages were 32%, 11%, 25%, and 14% respectively. The cost of the procedure was $162.00, which was totally recovered when only six appointments were kept. Since over 1000 patients were involved in the study, the return on the investment of +162.00 is considerable. Implications for this procedure are discussed for other community mental-health centers and for other community care-giving agencies.     

Chemical kindling induced by pentylenetetrazol changes cholecystokinin mRNA and peptide levels in rat frontal cortex

Kindling model is useful to study the mechanism of learning and memory. Cholecystokinin (CCK) mRNA and CCK-like immunoreactivity (CCK-LI) levels in the hippocampus and frontal cortex of chemically kindled rats were determined at different time points. In the frontal cortex, chronic treatment with pentylenetetrazol (PTZ) (40 mg/kg per day for 8 days) increased CCK mRNA level at 7 days, and decreased CCK-LI level at 2 and 7 days after the last injection. However, neither CCK mRNA nor CCK-LI levels in the hippocampus changed. These results suggest that PTZ-induced kindling increases CCK mRNA expression and CCK-LI release in the frontal cortex.     

Myotonic dystrophy: relative sensitivity of symptoms signs and abnormal investigations

Twenty-five symptoms, signs, and abnormal investigations were looked for in 20 patients with clinically-definite myotonic dystrophy. Weakness of facial muscles, neck flexors, and arm external rotators was found in all patients (sensitivity = 100%). Arm external rotation has not been reported as a frequently involved muscle in previous clinical studies on myotonic dystrophy. Careful examination of muscle strength may therefore predict which patients may or may not carry the abnormal gene for myotonic dystrophy.     

The effect of propionyl L-carnitine on skeletal muscle metabolism in renal failure

The effect of propionyl L-carnitine on skeletal muscle metabolism in chronic renal failure. Carnitine deficiency, resulting in defective oxidative ATP synthesis, has been implicated in the myopathy of chronic renal failure. Using 31P magnetic resonance spectroscopy we examined calf muscle metabolism in 10 dialysed patients before and after 8 weeks of propionyl L-carnitine (PLC) 2 g.p.o. daily. Resting phosphocreatine/ATP (4.41 +/- 0.20 [SEM]) decreased to normal control levels on PLC (3.98 +/- 0.14; controls 4.00 +/- 0.06). In contrast, there was no effect of PLC on aerobic and anaerobic metabolism of muscle during or following 2-10 min exercise. The maximal calculated oxidative capacity (Qmax) remained below normal (28 +/- 3 mM/min before and 24 +/- 3 mM/min after PLC; controls 49 +/- 3 mM/min). Qmax correlated positively with hemoglobin concentration ([Hb]) after PLC (p < 0.03). Oxidative capacity assessed by phosphocreatine recovery T significantly improved with PLC administration (0.93 +/- 0.1 to 0.74 +/- 0.08 min) in those patients (n = 6) with [Hb] > 10 g/dl. [Hb] was rate limiting to oxidative metabolism in recovery from exercise but only following treatment with PLC. Patients with anemia or those subjects who use relatively more non-oxidatively synthesized ATP during exercise, do not respond to PLC. Oxidative metabolism did not normalize on PLC suggesting that anemia and carnitine deficiency are not the only causes of mitochondrial dysfunction in renal failure.     

Enhancing effect of nonionic surfactant on the inactivation of lipopolysaccharide by steam-heat treatment II

n-alkylpolyoxyethylene surfactants (CnH2n+1O(CH2CH2O)mH; CnEm) showed a strong enhancing effect on the inactivation of lipopolysaccharide (LPS) by heat treatment over a wide range of temperatures. The effect of CnE8 (n = 10-16) was observed above the critical micelle concentration (CMC) and above the cloud point, and was influenced by the length of the alkyl chains. The efficacy of the surfactants was in the order C10E8 < C12E8, C16E8 < C14E8. However, the hydrophilic moiety seemed to have no influence. An 80-95% solution of n-butanol showed a similar effect, indicating that LPS was more effectively inactivated in the oily phase of the surfactants than in water. The effect of surfactant on the hydrodynamic diameter of LPS was the same before and after steam-heat treatment for 20 minutes at 121 degrees C. Each surfactant disaggregated LPS without alteration of the activity of LPS before the heat treatment. We consider that the surfactants interact with LPS in the region of lipid A in a manner that favors loss of the activities of LPS during heating.     

Impaired fatty acid oxidation in children on valproic acid and the effect of L-carnitine

Fatty acid oxidation was studied in 12 patients (aged 3 to 19 years) receiving valproic acid (VPA), predominantly as monotherapy, before and after 1 month of L-carnitine supplementation (50 mg/kg/day po) in order to determine whether L-carnitine plays a role in preventing the hepatotoxic effects of this drug. Five of these patients were also studied prior to VPA treatment. Only one patient taking VPA had an abnormally low plasma free carnitine. Acyl-/free carnitine ratios were elevated in five patients on VPA and normalized after L-carnitine supplementation. Mean plasma concentrations of free fatty acids, beta-OH-butyrate, and cumulative excretion of 13CO2 after administration of 1-13C-octanoic acid were not changed by VPA or L-carnitine treatment. Urinary dicarboxylic acids, acylglycines, and octanoylcarnitine were elevated during VPA therapy and unaltered by L-carnitine. These results suggest that, in patients at low risk for VPA-induced hepatotoxicity (patients aged > 2 years and taking VPA as monotherapy), VPA causes metabolic abnormalities resembling those found in inborn errors of mitochondrial beta-oxidation which are not corrected by L-carnitine.     

Further investigation on the radiation induced inactivation of ribonuclease and the radioprotective effect of some selenium-containing compounds

Steady state inactivation data on dilute aqueous solutions of RNase show that all water radicals, e-aq, OH, and H are responsible for the inactivation, but the most efficient radical is H atom, only about 4 of them being required for one inactivating event. The data are, therefore, more in agreement with the conclusions of Mee et al. (1972). In the transient absorption spectra of pulse irradiated ribonuclease different components derived by the individual radicals are observed. Organic and inorganic selenium-containing compounds offer a great protection of the enzyme activity, in agreement with the data obtained in other chemical and biological systems. In particular the effects of two new secondary radicals (CNSe)-2 and SeO-3 are in good accord with the known structure of ribonuclease.     

Histone redistribution and conformational effect on chromatin induced by formaldehyde

Histone redistributions between endogenous DNA in calf thymus chromatin and exogenous DNA from Clostridium perfringens (69% A + T) or from Micrococcus luteus (30% A + T) induced by 0.6 M NaCl or by 2% formaldehyde were studied by thermal denaturation. The observed redistribution occurred on histone Hl when the exogenous DNA was (A + T)-richer than the DNA in chromatin, and when the mixture was exposed to 0.6 M NaCl or formaldehyde. When a (G + C)-richer DNA was added as the acceptor for histones, no substantial transfer of histones from chromatin DNA to exogenous DNA was found. Thus the activation energy of histone dissociation from chromatin DNA seems to be substantially lowered by 0.6 M NaCl or formaldehyde such that histones (mostly histone Hl) can be dissociated and bind the (A + T)-richer DNA and form a more stable complex. It is suggested that the formaldehyde effect on histones may be due to the loss of positive charges on lysine and arginin residues (probably more on lysine than on arginine) in histones after their rapid reaction with formaldehyde. Formaldehyde treatment of chromatin also distorts the DNA conformation, as revealed by circular dichroism (CD) studies. This structural effect occurs mainly on those base pairs bound by histones other than Hl, or within the chromatin subunit. Histone redistribution is treated as a thermodynamic phenomenon of histone binding to DNA. The validity of using formaldehyde to study chromatin structure is discussed.     

Cellular effects induced by some synthetic prostaglandins obtained at ICCF-Bucharest

Four prostaglandin compounds synthetized at ICCF [chloprostenol triacetate (a), the isopropylic ester of the chloprostenol analogue (b), a PGA2 sulprostone analogue (c) and a PGE2 analogue (d)] were tested with respect to the cytotoxic effect, by successive studies on chicken embryo fibroblasts (CEF) and on human cells (HeLa). It was established that (b) and (d) display a high cytotoxicity, while (a) and (c) were relatively well tolerated by the cell layer. The spectrofluorometric determinations showed that these drugs did not induce modifications at the cell membrane level. The treatment with 4 micrograms/ml PGs (a) and (c) of HeLa cells inoculated with Sendai virus produced a significant decrease of TCID50/ml 24 hrs after drug introduction into the culture medium, from 10(6.5) to 10(4.5) and to 10(3.25), respectively.     

Enhancing effect of interleukin-2 on production of parathyroid hormone-related protein by adult T-cell leukemia cells

Leukemic cells from patients with adult T-cell leukemia (ATL) can produce a calcium-regulating protein, parathyroid hormone-related protein (PTHrP). Moreover, it has been reported that ATL cells produce some cytokines besides PTHrP and that these cells respond to the T-cell growth factors, interleukin-2 (IL-2) and interleukin-4 (IL-4). To elucidate whether PTHrP produced by ATL cells is regulated by IL-2 or IL-4, we investigated the in vitro effects of IL-2 and IL-4 on the release of PTHrP. IL-2 increased the release of PTHrP into the conditioned medium from leukemic cells in some, but not all, ATL patients; however, IL-4 did not affect the PTHrP release. PTHrP messenger RNA (mRNA) levels were increased in ATL cells cultured in the presence of IL-2. These data suggest that IL-2 plays a role in the regulation of hypercalcemia by enhancing the production of PTHrP in ATL patients.     

Testing the validity of some theoretical signs of vocational decision-making ability.

Examined the validity of some theoretically derived vocational diagnostic signs to learn whether a person's self-knowledge, occupational knowledge, and decision making ability were predictable. 1,005 high school juniors, 692 college juniors, and 140 employed adults were administered the Self-Directed Search (SDS, the source of the diagnostic signs) and the criteria for validating the signs (the Career Maturity Inventory, a decision making task, questionnaire items about vocational choice, and scales measuring identity, anomy, originality, and interpersonal competency). The theoretical signs of good decision making ability (consistency and differentiation of the SDS profiles) predicted scores on the decision making task more efficiently than any rival predictors. In contrast, the theoretical signs of self-knowledge and occupational knowledge did not show convergent or discriminant validity. The positive results imply some practical applications and the need for further theoretical investigation. (19 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Protective effect of l-cis-diltiazem on hypercontracture of rat myocytes induced by veratridine

The protective effect of l-cis-diltiazem, the stereoisomer of d-cis-diltiazem, was studied against the veratridine-induced hypercontracture of rat myocytes. Veratridine increased both [Na+]i and [Ca2+]i, but did not cause hypercontracture in the absence of extracellular Ca2+. Both l-cis-diltiazem (0.1-10 microM) and d-cis-diltiazem (10-30 microM) inhibited the hypercontracture and the increase in [Ca2+]i in a concentration-dependent manner. However, l-cis-diltiazem did not exert a negative inotropic effect in K+ (20 mM)-depolarized rat papillary muscles even at a dose of 10 microM. As seen in the case of tetrodotoxin, l-cis-diltiazem and d-cis-diltiazem also suppressed the increase in [Na+]i. The results show that l-cis-diltiazem prevents the veratridine-induced hypercontracture of myocytes by suppression of the [Ca2+]i increase. The attenuation of the [Ca2+]i increase by l-cis-diltiazem was not dependent on inhibition of Ca2+ channels, but was partly due to inhibition of excessive Na+ entry via veratridine-modified Na+ channels.     

The effect of deformation on abnormal grain growth in tungsten ingots

This paper reports a study of abnormal grain growth in tungsten ingots that had been deformed in compression at elevated temperatures. The results show that very large grains form in these samples directly from the polygonized structure when the deformed samples are annealed. A critical amount of deformation is required to begin this process. Beyond that point, the resulting grain size decreases with increasing amounts of deformation and decreasing test temperature. Abnormal grain growth occurs first in the regions of the sample that have undergone the most strain. Two factors appear to provide the driving force for the formation of these large grains. One is the elimination of grain boundary area. This effect would be present in any system undergoing regular or abnormal grain growth. The other is the elimination of grains that are more highly strained by grains that are less strained. In this way, this process is similar to the large grain growth resulting from strain annealing.