Effects of LTP-inducing tetanic stimulations of the perforant path on the commissural inhibition and facilitation of dentate granule cell discharge

Effects of diazepam (1 mg/kg, i.p.) on the commissural influences on granule cells were first examined to further assess its GABAergic inhibitory mechanism. Whereas the commissural inhibition at an interval of 5–8 ms of the contralateral dentate-perforant path (CP) combined stimulus was not enhanced by diazepam, the commissural facilitation at a CP interval of 11–20 ms was reduced, suggesting that the GABAergic inhibition is involved in rather a part of the commissural facilitation at a CP interval of 11–20 msec than a part of the ‘commissural’ inhibition at a shorter CP interval. Based on the results of diazepam, effects of high-frequency stimulations of the perforant path on the commissural inhibition of dentate granule cells were then examined, in relation to their effects on the dentate paired-pulse depression. These stimulations produced the long-term potentiation of the perforant path-dentate excitatory synapse and significant reduction of the paired-pulse depression. The commissural inhibition at a CP interval of 5–8 ms remained unchanged following tetanization. The commissural facilitation at a CP interval of 11–20 ms was, however, slightly enhanced by tetanic stimulations and a statistical significance was obtained at a CP interval of 19 ms. These results imply that tetanic stimulations of the perforant path selectively reduce the GABAergic component of the commissural inhibition, as well as that of the paired-pulse depression.     

Clinical experience of enoxacin complicated urinary tract infection

Enoxacin (ENX) was administered to 69 patients with complicated urinary tract infections (UTI). Clinical efficacy and safety were evaluated by the criteria proposed by the UTI Committee, Japan. The overall clinical efficacy was excellent in 60.9%, moderate in 10.1% and poor in 29% of the patients. Of the 76 strains isolated from the patients 61 strains (80.3%) were eradicated. Subjective side effect was observed in one patient who complained of slight nausea. No drug-related aggravation in the laboratory test was observed. These results showed that ENX was effective and safety for the treatment of complicated urinary tract infection.     

Effects of Endosulfan and Aldrin on Muscle Coordination and Conditioned Avoidance Response in Rats

Abstract: The deteriorative effects after chronic endosulfan exposure on muscle coordination, learning and memory of rats were compared with that produced by aldrin which has been reported to have similar effects in experimental animals. A rota-rod apparatus was used to study the muscle coordination and learning and memory were tested by recording the response to unconditioned and conditioned stimuli using a pole-climbing apparatus. Aldrin but not endosulfan inhibited motor coordination in both sexes. A greater motor deterioration occurred in male group. This finding, together with the previous data which shows inhibition by its metabolite of motor activity, suggests that its metabolic product is responsible for this action. Like aldrin, endosulfan inhibited both learning ability and conditioned avoidance response. A change in the activities of brain monoamines or inhibition of perception and reflexes or both were proposed for these behavioural effects, since the former was reported to be produced by both compounds and the latter was found to occur in aldrin treated rats.     

Formation of reactive oxygen species and of 8-hydroxy-2'-deoxyguanosine in DNA in vitro with betel-quid ingredients

Using a chemiluminescence technique, superoxide anion (O2-.) and H2O2 were shown to be formed in vitro, above pH 9.5, from betel-quid (BQ) ingredients, such as areca-nut extract and catechu. The formation of O2-. was enhanced by Fe2+, Fe3+ and Cu2+ and inhibited by Mn2+. Saliva was found to inhibit both O2-. and H2O2 formation from BQ ingredients. Upon incubation of DNA at alkaline pH with areca-nut extract or catechu, in the presence or absence of Fe3+, 8-hydroxy-2'-deoxyguanosine was formed, as quantified by high-performance liquid chromatography. The data suggest a possible role of reactive oxygen species (ROS) in the etiology of oral cancer in betel quid chewers.     

Frequency of consumption and nutrient composition of composite dishes commonly consumed by South Asians originating from Gujerat and the Punjab

Information regarding the most common dishes consumed by South Asians originating from the Punjab (Sikhs) or Gujerat (Hindus) and living in London, was obtained from weighed records collected as part of three separate dietary surveys. For each common dish the content of energy and selected nutrients was calculated from the ingredients and cooked weight as described in the diet records. There was considerable variation in the fat and energy contents of similar recipes both within and between groups, suggesting that reduction in fat (and hence energy) intakes could be achieved, without loss of palatability, by recommending use of the lower fat versions.     

Constitutive expression of the granulocyte-macrophage colony-stimulating factor gene in human solid tumors

We detected constitutive expression of the granulocyte-macrophage colony-stimulating factor (GM-CSF) gene in 3 human solid tumors by Northern blot analysis. Two of them were also found to secrete the GM-CSF protein by colony forming unit-culture assay. Southern blot analysis of each tumor DNA showed no gross rearrangement of the GM-CSF gene. This is the first report that demonstrates expression of the GM-CSF gene in solid tumors at the mRNA level.     

Microcomputer-controlled laboratory system for field potential experiments

A microcomputer-controlled laboratory system for hippocampal field potential experiments was constituted. This system realized the quasi-simultaneous processing of execution of stimulation, data acquisition, data display and data analysis by means of a microcomputer for the first time. To attain this quasi-simultaneous processing, a new algorithm for drawing a tangent on the wave-form of the potential was contrived, which enabled rapid analysis of an arbitrary population spike even in the case of generation of double spikes. The system has the following functions: (1) execution of the programmed stimulation paradigm, (2) analog/digital (A/D) conversion of the evoked field potential with a sampling interval of more than 50 microseconds per channel, (3) display of the A/D converted wave-form data on a CRT and storage of the data on a floppy disk, (4) on-line analysis of the population excitatory postsynaptic potential (EPSP) and population spike, (5) more detailed off-line analysis of the field potentials, and (6) output of the wave-form data and measured values through a printer and an X-Y plotter.