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PubMed1996

Intravenous morphine increases glucose utilization in the shell of the rat nucleus accumbens.

The [14C]2-deoxyglucose method was applied to measure the effects of the acute intravenous administration of morphine sulphate (0.2-0.4 mg/kg) on cerebral glucose utilization in rats. Morphine produced dose-dependent increases of glucose metabolism in the shell of the nucleus accumbens, without affecting functional activity in any other brain area. These results provide further evidence for the preferential effects of intravenously abused substances in the shell of the nucleus accumbens.

Animals↗
PubMed1984

Ca2+- and Mg-ATP-dependent shape change of human erythrocyte ghosts and triton shells.

Human erythrocyte membranes (ghosts) prepared from fresh blood changed in shape from spherical to crenated, when suspended in 10(-7)-10(-6) M Ca2+-EGTA buffers. Although the ghosts from long-stored ACD blood (10 weeks) were less sensitive to 10(-7)-10(-6) M Ca2+, the ghosts obtained from this blood after it had been preincubated with adenine and inosine for 3 h at 37 degrees C were highly sensitive to Ca2+. When these highly sensitive ghosts were incubated in 10 mM Tris-Cl buffer (pH 7.4) or 1 mM MgCl2 (pH 7.4) at 0 degrees C, they gradually lost Ca2+ sensitivity within 60 min, but they recovered Ca2+ sensitivity again after re-incubation with 2 mM Mg-ATP for 20 min at 37 degrees C followed by washing with 1 mM MgCl2 (pH 7.4). The shape of these highly Ca2+-sensitive ghosts immediately changed from crenate to disc on addition of 1 mM Mg-ATP even at 6 degrees C in the presence of 10(-7)-10(-6) M Ca2+. A similar shape change was also observed when ghosts treated with 0.5% Triton X-100 (Triton shells) were used. Triton shells from fresh blood ghosts or from long-stored blood ghosts which had been preincubated with 2 mM Mg-ATP for 20 min at 37 degrees C shrank immediately in the presence of 10(-6) M Ca2+ and then swelled on addition of 1 mM Mg-ATP. The specificity to ATP and the dependency on ATP concentration are in agreement with those of the ghost shape change at step 2 (Jinbu, Y. et al., Biochem biophys res commun 112 (1983) 384-390) [18]. These results suggest that cytoskeletal protein phosphorylation enhances sensitivity to Ca2+ and induces erythrocyte shape change in the presence of physiological concentrations of ATP and Ca2+.

Adenosine Triphosphate↗
PubMed1986

Circadian rhythms in serotonin, norepinephrine, and epinephrine contents of the pineal-paraphyseal complex of the soft-shelled turtle (Lissemys punctata punctata).

Diurnal variations in pineal serotonin, norepinephrine, and epinephrine levels were measured at four different time intervals (06:00, 12:00, 18:00, and 24:00 hr) in adult male soft-shelled turtles. The serotonin level increased during day and decreased during night. But the norepinephrine and epinephrine levels showed reverse changes. The findings reveal that there is a distinct circadian rhythm in serotonin, norepinephrine, and epinephrine contents of the pineal-paraphyseal complex in adult male soft-shelled turtles.

Animals↗
PubMed1987

Influence of age on diurnal rhythms of adrenal norepinephrine, epinephrine, and corticosterone levels in soft-shelled turtles (Lissemys punctata punctata).

An investigation was made of what role aging plays on diurnal rhythms of norepinephrine, epinephrine, and corticosterone contents in the adrenal gland of soft-shelled turtles. To resolve this problem, juvenile and adult soft-shelled turtles were sacrificed at four different time intervals (0600, 1200, 1800, and 2400 hr) and adrenal hormonal levels were measured by spectrofluorometer. The findings revealed that peak norepinephrine, epinephrine, and corticosterone values were observed at 2400, 0600, and 2400 hr, respectively, and trough values for all the hormones were found at 1200 hr in both juvenile and adult animals. Thus, diurnal rhythms for all the hormones studied exist in both juvenile and adult animals. It is suggested that aging apparently has no influence on diurnal variations of adrenal hormones in turtles.

Adrenal Glands↗
PubMed1989

Effect of ambient temperature on serotonin, norepinephrine, and epinephrine contents in the pineal-paraphyseal complex of the soft-shelled turtle (Lissemys punctata punctata).

The aim of the present investigation was to ascertain the influence of ambient temperature on serotonin, norepinephrine, and epinephrine contents in the pineal-paraphyseal complex of soft-shelled turtles. Turtles were exposed to low (10 degrees) and high (32 degrees) temperatures for 7 days in an incubator with the same photoperiod (12L:12D). Control animals were also kept in the same incubator at 25 degrees for similar duration with the same photoperiod. The findings revealed that ambient temperatures significantly altered serotonin, norepinephrine, and epinephrine content in the pineal-paraphyseal complex of turtles. The results thus indicate that ambient temperature has some influence on pineal serotonin, norepinephrine, and epinephrine contents in soft-shelled turtles.

Animals↗
PubMed1983

Structure and inherent properties of the bacteriophage lambda head shell. III. Spectroscopic studies on the expansion of the prohead.

The head shell of bacteriophage lambda expands by about 20% in diameter when it packages the DNA molecule in vivo. The expansion reaction is essentially a conformational change of the major head protein molecules to a state of lower free energy and can also be triggered in vitro by treatment with 4 M-urea. In order to investigate the conformational change, we have measured the circular dichroism, fluorescence and difference absorption spectra of the lambda head shell before and after the expansion by the treatment with urea. The far-ultraviolet circular dichroism spectra and the fluorescence spectra show that the expansion is not accompanied by a great change in the secondary structure (29% alpha-helix, 23% beta-structure) and the environment (non-polar) of the tryptophan residues of the major head protein molecule. On the other hand, by measurements of the circular dichroism and difference absorption spectra in the near-ultraviolet region as well as by chemical modification experiments with tetranitromethane, we have found that one or two tyrosine residues of the major head protein are transferred from a polar, solvent-exposed to a non-polar, solvent-unexposed environment during the expansion. Judging from these results, the conformational change seems to be mainly intermolecular or interdomainal rather than intradomainal.

Bacteriophage lambda↗
PubMed1989

The orbital shell: an aid in positioning the ocular component and verifying margin contours for oculofacial prostheses.

The correct location of the orientation (conversational gaze) of the ocular component is vital to esthetically pleasing oculofacial prostheses. This location should be verified before time and energy are spent on sculpturing the oculofacial prosthesis. A technique is described that uses a clear acrylic resin shell as a matrix and Play-doh material as a support medium to position and support the ocular component to verify the orientation. In addition, the thin acrylic resin shell can be used to refine border inaccuracies that may exist clinically.

Acrylic Resins↗
PubMed1991

The egg-shell of Drosophila melanogaster. VI, Structural analysis of the wax layer in laid eggs.

Utilizing freeze-fracturing conventional electron microscopy and scanning electron microscopy methods, a wax layer was identified, sealing the oocyte of Drosophila melanogaster. In mature egg-shells wax forms a hydrophobic layer surrounding the oocyte and lying between, and in very close contact with the vitelline membrane (interiorly) and the crystalline intermediate chorionic layer (exteriorly). In cross-fractured views it is less than 50 A thick whereas in longitudinal fracturing it reveals smooth fracture faces of a multilayered material in the form of hydrophobic areas or plaques (0.5-1 microns in diameter) which are partially overlapping and highly compressed between the vitelline membrane and the innermost chorionic layer. The evidence for this layer being a wax are the facts that a) it is not preserved in conventional fat-extracting electron microscopy methods, b) it directs laterally the fracture planes during freeze-fracturing and reveals smooth fracture faces. Analysis of the structural features of wax in mature egg-shell in various species of Drosophilidae have shown that the wax layer exhibits indistinguishable (among the species) hydrophobic plaques, which have the same size and thickness with Drosophila melanogaster. These data provide structural evidence explaining the physiological resistance of the insect eggs studied, against water loss or water uptake, whenever they are laid on substrates with extreme environmental conditions. In addition, the data demonstrate how an extracellular substance can be organized to perform that function.

Animals↗
PubMed1984

Occurrence of tetrodotoxin in the gastropod mollusk Tutufa lissostoma (frog shell).

Paralytic toxicity was detected in gastropod mollusk Tutufa lissostoma (frog shell) specimens collected from Suruga Bay, Shizuoka Prefecture, Japan. Seventeen of the 22 digestive glands removed were toxic; the highest toxicity, expressed as tetrodotoxin (TTX), being as high as 700 mouse units (MU) per gram. Attempts were made to isolate the toxin from pooled digestive glands by activated charcoal treatment and column chromatography on Amberlite IRC-50, CM-Sephadex C-25 and Bio-Rex 70. The toxin showed a specific toxicity (as TTX) of 4200 MU/mg. It exhibited the same thin-layer chromatographic and electrophoretic behaviors and 1H-NMR spectrum as TTX. The toxin gave the same pattern as the TTX standard when alkali-hydrolyzed and analyzed by GC--MS, indicating that it contains the quinazoline skeleton specific to TTX. From these results the frog shell toxin was identified as TTX.

Animals↗
PubMed1981

Enhancement of the immunogenicity of the maize rough dwarf virus outer shell with the cross-linking reagent dithiobis(succinimidyl)propionate.

Injection into rabbits of native or glutaraldehyde (GA)-treated intact particles of the fijivirus maize rough dwarf virus (MRDV) failed to yield antibodies to the outer shell of the virus. After fixation of the particles with the cross-linking reagent dithiobis(succinimidyl)propionate (DSP), antisera were obtained reacting with the outer shell of MRDV (both DSP-fixed and unfixed) to a titre of 1/1024 in immunoelectron microscopic decoration tests, but giving no reaction with another fijivirus, oat sterile dwarf virus, whose subviral particles are known to be unrelated to those of MRDV. Further fixation of the DSP-fixed particles with GA did not appear to enhance immunogenicity. Stabilization with DSP could have further application with viruses the instability of which renders them poor immunogens.

Animals↗
PubMed1989

Increased sensitivity for rapid detection of cytomegalovirus by shell vial centrifugation assay using mink lung cell cultures.

A comparative study was made of various human and non-human cell cultures to determine their sensitivity for cytomegalovirus (CMV) as detected by the production of CMV early antigen using the shell vial centrifugation assay. Mink lung cell cultures, frequently used for detection of herpes simplex virus in clinical specimens, were found to be significantly more sensitive to infection by CMV than other cell cultures tested. Using the shell vial centrifugation assay, the mink lung cell cultures were more sensitive than human diploid fibroblasts for the detection of the Davis strain of human CMV and CMV from clinical specimens.

Animals↗
PubMed1995

Differential localization of mRNAs encoding dopamine D1 or D2 receptors in cholinergic neurons in the core and shell of the rat nucleus accumbens.

By combining immunocytochemistry for ChAT and in situ hybridization for dopamine D1 or D2 receptor mRNA in the striatum, it was found that (1) the percentage of ChAT/D2 mRNA co-localization is higher in the caudate-putamen than in the shell and core of the nucleus accumbens, (2) in the shell the degree of ChAT/D2 mRNA co-localization is higher rostrally than caudally, and 3) no significant regional differences exist in the degree of co-localization of ChAT and D1 mRNA.

Animals↗
PubMed1995

Cocaine alters glutamic acid decarboxylase differentially in the nucleus accumbens core and shell.

The effects of acute and repeated daily cocaine on the levels of mRNA coding for glutamic acid decarboxylase (GAD), preproenkephalin (PPE), preprotachykinin (PPT), and the dopamine D2 receptor were determined in the striatum, nucleus accumbens core and shell areas (NAcore, NAshell), and medial prefrontal cortex. Rats were given repeated saline or cocaine for 6 days. A cocaine challenge administered 24 h later resulted in an augmented locomotor response in daily cocaine-pretreated rats. Six h after the challenge, rats were sacrificed and Northern blot analysis revealed that acute cocaine increased GAD mRNA levels by 44% in the NAshell, while repeated cocaine prevented the acute cocaine-induced increase. These data suggest that cocaine may differentially regulate GABA release at NA core and shell projection fields.

Analysis of Variance↗
PubMed1995

Recovery of a population of the flame shell, Lima hians, in an Irish bay previously contaminated with TBT.

The flame shell, Lima hians, is dominant in the shallows of the Moross Channel in Mulroy Bay, Co. Donegal. Its interwoven byssal threads form an extensive 'carpet' covering shell-sand. Laminarians attach to this 'carpet' and provide a canopy acting both as a substratum and shelter for several species. The population was first studied in 1980, a year prior to the use of TBT. From 1981-1985 TBT was used within Mulroy Bay as an antifoulant on salmon cages and there was a noticeable decline in the population of Lima. This led to the loss of the byssal carpet and laminarian cover and ultimately exposed the sand, which became unstable and formed waves. TBT usage was discontinued in 1985 and legally controlled in 1987. The Moross Channel was re-visited in 1994; the population has recovered and a canopy of laminarians was present as in 1980.

Journal Article↗
PubMed1994

Chlorinated hydrocarbons and shell thinning in eggs of (Accipiter) hawks in Ontario, 1986-1989.

Eggs of sharp-shinned hawks (Accipiter striatus), Cooper's hawks (A. cooperii), and northern goshawks (A. gentilis) were collected from nests in south-central Ontario from 1986 to 1989. Detectable levels of the chlorinated hydrocarbons DDE, DDT, DDD, mirex, photomirex, cis-nonachlor, trans-nonachlor, oxychlordane, dieldrin, heptachlor expoxide, HCB and PCB were present in all the eggs analyzed. Mean contaminant levels were highest in sharp-shinned hawks, slightly lower in Cooper's hawks, and significantly lower in goshawks; for example, mean DDE values were 7.23, 4.48 and 0.90 mg kg(-1) (wet weight), respectively. Total PCB levels were generally less than 1.5 mg kg(-1), lower than those associated with reproductive effects in field and laboratory studies with other species. Mean shell thicknesses of sharp-shinned and Cooper's hawk eggs were significantly less than mean pre-DDT era thicknesses (-10 and -8%, respectively), reductions that were probably not relevant to reproductive success. Goshawk eggs exhibited no significant reduction in shell thickness. Contaminant levels among the three species probably reflect differing food habits and migratory patterns.

Journal Article↗
PubMed1995

Characterization of organic matrix macromolecules from the shells of the Antarctic scallop, Adamussium colbecki.

The highly acidic soluble organic matrix (SM) isolated from shells of the Antarctic scallop, Adamussium colbecki, was shown to consist of 1.5% carbohydrate by weight and 12.8% phosphate by weight. Total SM is composed of approximately 31% Asx, 29% Ser, and 18% Gly. Separation of the SM using RP-HPLC yielded a minimum of six protein fractions labeled RP-1 through RP-6 in order of elution off the column. The first fraction, RP-1, was found to be an effective inhibitor of calcium carbonate crystal nucleation in vitro suggesting a role for this protein in the regulation of shell mineralization. A less acidic fraction, RP-3, showed less inhibitory activity and dephosphorylation of RP-1 resulted in almost complete loss of inhibitory activity. Automated Edman degradation was used to sequence peptides generated by chemical cleavage of RP-1. Mild acid hydrolysis yielded peptides with sequences of N-S-G-D-D-D-D-G-G-OH, N-S-G-G-(S,G)-G-OH, and N-S-G-R-G-OH. Cleavage with hydroxylamine yielded peptides of N-D-D-D-D-D-D-D-D-OH, N-L-Y-Y-OH, and N-A-V-G-E-S-D-OH. These data suggest biochemical similarities between this SM and other SM proteins isolated from both calcium carbonate and calcium phosphate biominerals, and presents evidence of a primary domain structure similar to that described for oyster SM and phosphophoryn isolated from rat dentin.

Amino Acid Sequence↗
PubMed1989

The value of treatment planning using CT and an immobilizing shell in radiotherapy for paranasal sinus carcinomas.

This article describes a method which uses CT scans and immobilizing shells radiation treatment planning (CT-assisted planning) for paranasal sinus carcinomas and the value of this method on the treatment outcome. Results of the treatment for 82 patients who had CT-assisted planning were compared with that of 88 patients who had no such treatment planning. It has been concluded that the combined use of CT and the shell in treatment planning permitted a 3-dimensional localization of both the tumor and critical normal structures with great accuracy, leading to an improved long-term survival and a reduced complication rate. The multivariate regression analysis for predicting significant prognostic factors also confirmed the valuable role of CT in terms of survival and primary tumor control. The actuarial 5-year survival rate was 51% in all patients, whereas, by using CT-assisted planning, it was improved to 61%. The improved survival was observed among the patients with tumors of the suprastructures where tumors were located adjacent to the critical organs (brain and eye). Major complications attributable to radiation have included instances of brain and ocular damage. CT-assisted planning, however, has been proven effective in avoiding brain necrosis and preserving eye sight.

Adult↗