Cocaine kindling in mice

Previous studies proposed the involvement of theN-methyl-D-aspartate (NMDA) type of glutamate receptors in the development of sensitization to the convulsive effect of cocaine (cocaine kindling). The present study was undertaken to determine, first, if cocaine kindling is associated with enhanced sensitivity of the NMDA receptor to the convulsive response ofN-methyl-D,L-aspartate (NMDLA), and second, whether in vivo modulation of nitric oxide synthase (NOS) function regulates the development of cocaine kindling. The following results were observed:

1. Cocaine-kindled animals were significantly more susceptible to the convulsive effect of the NMDA receptor agonist NMDLA than saline controls;
2. Pretreatment with the NOS inhibitor N^G-nitro-L-arginine methyl ester (L-NAME; 100 mg/kg; ip) blocked the development of cocaine kindling;
3. The protective effect of L-NAME was partially reversed with the coadministration of the NOS substrate,L-arginine (300 mg/kg; ip), but notD-arginine; and
4. L-Arginine (300 mg/kg; ip), but notD-arginine, amplified the development of cocaine kindling. Taken together, these findings suggest that supersensitivity of the NMDA receptor and activation of NOS may underlie the development of cocaine kindling.

     

Purification and properties of the alkaline phosphatase ofSerratia marcescens

1. A hypothesis based on the Hill-Bendall-model of photosynthetic electron transport is proposed to explain positive and negative photo-phobotaxis inPhormidium uncinatum. In the non-cyclic electron chain a pool is located into which photosystem II (e. g. by absorption by C-phycoerythrin, 561 nm) feeds electrons while photosystem I (e.g. 723 nm) drains electrons out of it.
2. Interruption of the electron flow into the pool causes a sudden decrease of the pool size and thus a positive phobic response. This happens e.g. when an organism leaves a trap which is illuminated by a wavelength absorbed by photosystem II pigments (e. g. 561 nm).
3. A negative reaction takes place when electrons are suddenly drained out of the pool; again the pool size decreases. This is the case when an organism enters a light trap illuminated by photosystem I light (723 nm).
4. The net flow of electrons into or out of the pool—and thus the reaction sense—can be manipulated by the relative excitation of the two photosystems or by blocking the electron influx by DCMU.

     

Effects of prenatal cocaine exposure in the prefrontal cortex of the rat

This work was undertaken in order to assess the organization of the prelimbic area of the medial prefrontal cortex of rats exposed prenatally to cocaine. Pregnant Wistar rats were assigned to the following groups:

1. Cocaine—60 mg/kg body wt/d sc, from gestational days 8–22; 0131
2. Saline;
3. Pair-fed; and
4. Nonmanipulated.

Male offspring were perfused on postnatal days 14 and 30. Six brains per group and per age were embedded in celloidin to calculate the volumes of the prelimbic area; sections from the other six brains were embedded in resin and processed for electron microscopy. Using semithin sections (2 μm) of layers II–III and V–VI, the following parameters were calculated:

1. The fraction of the neuropil occupied by neurons (V_V);
2. The packing (N_A) density; and
3. The numerical (N_V) density.

Qualitative alterations consisted of dispersed profiles of degenerated neurons and dendrites in the medial prefrontal cortex. No significant differences were found in the gross morphometric parameters when the cocaine group was compared with the other groups. A high interanimal variation was shown in the prelimbic volumes of postnatal day (PND) 14 cocaine-treated rats, and a decrease in volumes was detected at PND30. Although there are some alterations in the main afferent cortical target area for dopaminergic input, its gross morphometric parameters do not seem to be sufficiently affected to account for the behavioral alterations referred to as being dependent on this brain region.     

Growth of a floating aquatic weed,Salvinia under standard conditions

1. Growth of the floating aquatic weed, Salvinia, in sterile culture was exponential for at least 2 weeks under standardized conditions.
2. Increase in light intensity or in CO₂ resulted in increases in growth rate, but did not extend the exponential period of growth.
3. This aquatic plant, like many others, discriminates against calcium relative to strontium.
4. In culture Salvinia exhibited luxury consumption of N and P.
5. Because of high C/N ratios, Salvinia may not be a favorable source of animal food, but might be useful in nutrient removal schemes.
6. In sterile culture, S. molesta produced fewer leaves than S. minima, but maintained a significant increase in leaf area and dry weight. This may be correlated with the ability of the first species to rapidly spread over tropical waterways.

     

Mycotoxins and fungi accompanying wheat head fusariosis in Poland

The occurrence of wheat head fusariosis in various regions of Poland was observed in 1985 and 1986. The incidence of fusariosis was usually low — about 0,01% — only on South — East in some localities reached 5 – 20%. The most important species isolated from infected heads were :Fusarium culmorum F.grami nearurn,F.ni vale andF.avenaceum, in addition to whichF.crookwel1ense,F.eqiseti,F.subqluti nans andF.tricinctum (sensu Nelson et al.1983) were observed. Deoxynivalenol was present in 100% examined kernels subsamples at level 5–18 mg/kg and 3-acetyl deoxyn i val enol in 70% at level 1–3 mg/kg. The mycotoxins amount in chaff was 1,4 to 2,6 and 1,4 to 11 times higher (DON and 3AcD0N resp.) than in kernels.     

A study on the rate of water transport of the clam katelysia opima in relation to environmental conditions

1. The neutral red technique was employed to study the rate of filtration in Katelysia opima.
2. The weight specific water filtration was found to be greater for younger clams compared to the older ones.
3. The rate of water filtration increased with decreasing salinity.
4. Water filtration was found to increase as temperature increased, reaching a maximum at 35°C. but then sharply decreasing at 39°C.
5. Light had no significant effect on the rate of filtration.
6. Suspended matter was found to affect the rate of water filtration.
7. The rate of filtration was low at high pH and high in low pH.
8. The rate of water filtration was found to be faster during high tide than during low tide.
9. The presence of the parasitic crab, Pennotheris sp., in the mantle cavity of clams had a marked effect on the particle filtration.
10. Accidental cut of the siphon tips had no effect on the rate of filtration.

     

Seasonal variation in the biochemical composition of Mytilus viridis at Ratnagiri on the West Coast of India

1. The seasonal variation in the water, protein, fat and glycogen contents of the mussel, Mytilus viridis has been studied for the year March, 1974 to March, 1975.
2. The water level increased during the monsoon season and decreased in summer.
3. The level of protein, fat and glycogen showed correlation with the reproductive cycle of the mussel.
4. The protein level was high when the mussels were mature and dropped during the breeding period.
5. During sex change from male to female in May the protein level remained high whereas during sex change from female to male in October and November it was low.
6. The fat level was high in mature mussels and declined on spawning.
7. The glycogen level was at its peak in immature mussels and low in mature.

     

The reproductive cycle in a typical estuarine mollusc Nausitora hedleyi Schepman based on a study of the Gonad Index

1. Previous work on the methods employed for the determination of the breeding season of shipworms is briefly reviewed.
2. The method adopted for studying the reproductive cycle by using the “gonad index” is described.
3. The reproductive cycle of Nausitora hedleyi is described in detail based on a study of the gonad index of different sexes collected at monthly intervals from the estuarine environment of Cochin harbour.
4. The fact that breeding is restricted as marked by seasonal activity is shown from the size and activity of the gonad during the different months of the year.
5. The environment, and the hydrographic conditions prevailing in the habitat of N. hedleyi in the Cochin harbour are described.

     

Diurnal variation in Sagar Lake,Sagar (India) I studies in the deep water area

1. A diurnal study of inland fresh water lake has been made with respect to physical and chemical properties and the plankton.
2. Chlorides have followed the total carbonates while dissolved oxygen and pH have shown no relation.
3. Microcystis has followed no definite pattern of diurnal movement.
4. All crustaceans, some of the rotifers andTrachelomonas perform considerable diurnal movement in the course of a twenty four hour period.

     

Oxygen consumption and respiratory behaviour of three Nile fishes

1. The respiratory behaviour and patterns of oxygen consumption of three Nile species have been investigated.
2. Tilapia nilotica showed a typical pattern of oxygen consumption with an ambient region, adaptive plateau and lethal region (Fig. 2).
3. Specimens of Polypterus senegalus and Clarias lazera (body weights 20–30 and 30–45 g respectively) showed patterns of consumption comparable to that of Tilapia (Fig. 3a and 4a). In larger specimens of the two species the adaptive plateau was either insignificant or completely absent.
4. Specimens of Polypterus and Clarias (20–30 g and 30–45 g respectively) could survive in waters saturated with oxygen (7.4 mg/l) but their tolerance to lower oxygen concentrations was limited. Larger specimens of Polypterus and Clarias failed to survive in oxygen saturated waters.
5. The tolerance of Tilapia nilotica to extremely low oxygen concentration is an adaptation of a tropical and completely aquatic species. Polypterus and Clarias resort to their compensatory mechanisms only when the aquatic respiratory surface fails to satisfy their oxygen requirements.

     

Succession in Zoo- and phytoplankton in a sewage stabilization pond

The investigations pertaining to zoo- and phytoplankton succession during prestabilization and stabilization of domestic waste water in a facultative pond operating at 1.22 meters depth with an average BOD loading of 336.3 kg per hectare per day and a retention period of 10 days revealed the following:

1. A photosynthetic sulphur bacterium Thiocystis violacea has been recorded during the second and third day along with a considerable population of ciliate protozoa and algae.
2. Chlorophytes were followed by euglenoids in the ecological succession and the latter became predominant after the pond stabilized.
3. Of the twelve protozoan species Halteria grandinella, Bursaria truncatella and Perispira ovum were associated with peaks of algae and vigorous photosynthesis in the stabilized pond water.
4. There ia a gradual improvement in the quality of the waste water with respect to reduction in bacteria and biochemical oxygen demand and enhancement in changes in physico-chemical factors till a relatively stable community is evolved.

     

The anaerobic metabolism of malate of Saccharomyces bailii and the partial purification and characterization of malic enzyme

1. The main pathway of the anaerobic metabolism of l-malate in Saccharomyces bailii is catalyzed by a l-malic enzyme.
2. The enzyme was purified more than 300-fold. During the purification procedure fumarase and pyruvate decarboxylase were removed completely, and malate dehydrogenase and oxalacetate decarboxylase were removed to a very large extent.
3. Manganese ions are not required for the reaction of malic enzyme of Saccharomyces bailii, but the activity of the enzyme is increased by manganese.
4. The reaction of l-malic enzyme proceeds with the coenzymes NAD and (to a lesser extent) NADP.
5. The K _m-values of the malic enzyme of Saccharomyces bailii were 10 mM for l-malate and 0.1 mM for NAD.
6. A model based on the activity and substrate affinity of malic enzyme, the intracellular concentration of malate and phosphate, and its action on fumarase, is proposed to explain the complete anaerobic degradation of malate in Saccharomyces bailii as compared with the partial decomposition of malate in Saccharomyces cerevisiae.

     

EPR characterization of oxide supported transition metal ions: Relevance to catalysis

EPR spectroscopy is a powerful tool to identify at a molecular level, the different steps of catalyst preparation, and of catalytic reactions:

1. Deposition of paramagnetic transition metal ions onto a support is monitored, and the coordination sphere of the metallic center is characterized by EPR.
2. The catalyst is also characterized after activation (thermal oxidation or reduction):

- the distribution among the different sites in zeolites can be determined;

- the dispersion of the active phase may be appreciated;

- the unsaturation degree of the active site may be evaluated using probe molecules such as water or¹³C enriched carbon monoxide.

1. The catalytic mechanisms can be investigated by studying the elementary steps of the catalytic reaction, as illustrated for methanol oxidation over Mo/SiO₂ catalysts whose EPR results have extended the reaction mechanism proposed on the basis of kinetic data. In addition, reaction intermediates may be isolated inquasi-in situ conditions as in the case of olefin oligomerization catalyzed by Ni/SiO₂ systems.

     

Effects of Environmental Perturbations on Short-Term Phytoplankton Production off Lawson's Bay,A Tropical Coastal Embayment

1. The phytoplankton cycle off Lawson's Bay, Waltair follows a bimodal pattern with a major peak during March–May; a minor peak during October–November months and with a low production during the summer months i.e., June–August.
2. During the summer months of 1957, 1958, 1960 and 1962 dumping of dredged spoil from the entrance channel of the harbour into the sea resulted in a natural enrichment of waters.
3. Following this enrichment, there was a qualitative and quantitative increase in the phytoplankters thus leading to the development of a bloom.
4. Only Thalassiosira subtilis and Chaetoceros curvisetus commonly bloomed during the four years.
5. The increase in gross production which varied from 3–13 fold and the high photosynthesis-respiration ratios 5.1 to 10.5 indicated that the bloom populations were in a healthy state.
6. The decrease of the populations to the initial levels suggests that some unknown factor, other than those investigated must have been operating.
7. Consequences of eutrophication of different origins on stimulation of phytoplankton production are briefly discussed.

     

A study of the relationship between mechanical characteristics and the coastal vegetation among several broad-leaf trees in Miura Peninsula in Japan

The mechanical properties of broad-leaf tree species in a maritime-wind exposed habitat in central Japan were examined. The broad-leaf trees studied were Celtis sinensis var. japonica, Ilex integra, Eurya japonica, Pittosporum tobira, Euonymus japonicus and Cinnamomum japonicum. The results obtained can be summarized briefly as follows:

1. At places with weaker wind, the number of species increased and the height of the canopy increased.
2. The fracture strength σ_m showed no dependence on tree part or branch thickness, but was constant.
3. The order of strength was Celtis sinensis var. japonica > Ilex integra > Eurya japonica > Pittosporum tobira > Euonymus japonicus > Cinnamomum japonicum, and these six species could best adapt to the wind pressure in the study area.
4. Within species, fracture strength varied directly with wind strength.
5. The strain ε_m decreased as the trunk became thicker.
6. Within species, strain energy U_m varied directly with wind strength.

     

Charakterisierung eines phagenähnlichen Partikels aus Zellen von Nitrobacter

1. Polyhedral particles were isolated from cells of Nitrobacter winogradskyi and of Nitrobacter strains K₁, K₄ and α₁. Their physical and biological properties are characterized.
2. The investigated strains contain polyhedral particles, 1000–1200 Å in size. With increasing age of the culture more particles are found in cells of Nitrobacter. Simultaneously the number of colony producing nitritoxidants decreases.
3. In strain α₁ the loss of the capability to form colonies is connected with partial lysis of the cell and release of particles.
4. A homogeneous fraction of particles was obtained by zone density gradient centrifugation in Tris-Mg-SH-buffer.
5. The polyhedral particles have a sedimentation coefficient of s _w,20 ⁰ =825S and a CsCl-buoyant density of ?²⁵ g/cm³.
6. Based on the determined properties the particles are classified as phage-like Nitrobacter particles Nb₁.

     

An ecological study of the Ponggol Estuary in Singapore

1. An ecological study of the Ponggol Estuary was conducted from July 1965 to June 1966 and the seasonal data on physical, chemical and biological characteristics were presented.
2. The Ponggol River represents a short, narrow and shallow estuary in Singapore. The river mouth is open throughout the year and water from eastern Johore Straits drains in twice a day at high tide. The upper reach, however, is left exposed at low tide.
3. The Ponggol River was classified as a vertically and laterally homogeneous estuary and was found to exhibit a mesohaline to polyhaline environment.
4. Significant hydrological gradients from the river mouth 10 the upper reach were noted in the river system. Salinity, dissolved oxygen and pH increased towards the mouth of the river and other parameters such as nutrients, dissolved organic matter and turbidity increased towards the source.
5. Although the river received organic pollutants at the upper reach the estuary was able to discharge them fairly rapidly through regular flushing by the tides. The transient rise of organic matter did not appear to impart any serious affect on the biota in the estuary.
6. Over 98% of the phytoplankton consisted of diatoms, most of which were brought into the estuary from eastern Johore Straits. Freshwater forms were relatively few.
7. Phytoplankton biomass was considerably higher than the adjoining waters. and was reduced at the upper reach due to high turbidity of the water.
8. 80% of the zooplankton was composed of dinoflagellates,Difflugia, copepods and bivalve larvae dominating at all sections of the estuary.
9. Percentage composition of the zooplankton showed that dinoflagellates and copepod nauplii predominated at high tide whileDifflugia and bivalve larvae were abundant at low tide.
10. Zooplankton standing crop, in general, was higher towards the source at high tide but the reverse was found at low tide, i.e. standing crop increased towards the river mouth. This was attributed to the process of concentration.
11. Species composition of zooplankton was found to be more or less similar to that of the eastern Johore Straits.
12. The nekton consisted predominantly of small and juvenile fish. Close correlation of fish and copepods was found to be statistically valid and it was concluded that the fish entered the estuary to feed rather than to spawn.
13. The squids formed an important catch of the beach seine unit and were caught throughout the year.
14. The fish population could be grouped into four categories: estuarine components, euryhaline components, marine components and migratory components.
15. Benthic invertebrates were abundant. Commercially important species consisted of prawns,Metapenaeus andPenaeus, and crabs,Neptunus pelagicus andScylla serrata.
16. The river bed was inhabited predominantly by molluscs and the distribution resembled that of the sheltered shore of muddy-sand type.

     

Uptake of radionuclides by some aquatic macrophytes of Ismailia Canal,Egypt

1. Uptake of the radionuclides Co-60, Cs-134, Sr-89 and P-32 by different aquatic plants present in Ismailia Canal was found to increase at increasing initial concentrations of the radionuclides in the water.
2. Maximum uptake was reached by most of the aquatic plants after different periods of contamination, ranging from 1 to 4 days.
3. Ceratophyllum was found to be the most favourable biological indicator for strontium radioisotopes in concentrations ranging from 0.5 to 10 µCi/1 and for contamination periods up to 16 days.
4. Elodea was found to serve as a biological indicator for either strontium or phosphorus radioisotopes for limited contamination periods of 2 to 16 days for Sr and to 2 days for P isotopes.
5. Potamogeton was also found to serve as a biological indicator for limited contamination periods for strontium, phosphorus and cesium radioisotopes: 0 to 2 days for Sr, 2 to 16 days for P. and 0 to 2 days for Cs isotopes.

     

Die rezente Verbreitung der Flusskrebse in Hessen (Decapoda: Astacidae)

1. This investigation demonstrates the presence of three different species in Hessen (West Germany). By means of three maps the recent distribution is demonstrated.
2. Astacus astacus is still present in Hessen in small populations.
3. Austropotamobius torrentium is the rarest species and was recorded only in the Taunus-, Spessart- und Odenwald mountains.
4. Oronectes limosus, in the rivers Rhein and Main numerous before 1950, has become scarce. In the river Fulda there have been only two recordings in 1958.

     

The influence of EDTA on the composition of alginate synthesized by Azotobacter vinelandii

1. During an investigation of the physiology of Azotobacter vinelandii with particular reference to polysaccharide formation, a suitable medium which was precipitate-free was developed by adding EDTA at a concentration of 50 mg/l to a basal medium containing one of eight different carbohydrates as sole carbon source.
2. Acetylated alginate was always produced by the organism when cultured under defined conditions, regardless of the carbohydrate source incorporated in the basal medium.
3. When EDTA was added to the medium, the bacteria produced acetylated polyuronides with a preponderance of mannuronic acid residues.
4. A comparison of the infrared spectra of the alginate produced by Azotobacter vinelandii and the affect of EDTA upon the mannuronic acid/guluronic acid ratios of the alginate are reported.