Significance of scrotal afferents within the general thermoafferent system

• 1.1.|Switching neurons, in the past referred to as a special scrotal afferent system, intergrate information not only from the scrotum, but from various body areas.
• 2.2.|They are present in male and female rats, as well as in guinea-pigs.
• 3.3.|They are present in midbrain, thalamus, hypothalamus and cortical areas.
• 4.4.|Information processing from the scrotum, is not a special system, but part of the general thermo-and noci-afferent system.
• 5.5.|Switching neurons seem to interact with behavioral, perhaps with autonomic thermoregulatory mechanisms, too.

     

Immunocytochemical localisation of vitellogenic and non-vitellogenic yolk proteins in the ovary of leptinotarsa decemlineata

• 1.1. Two vitellogenins and chromoprotein 2 are selectively accumulated by the oocyte and cannot be detected either in follicle cells or in the germarium.
• 2.2. At the start of their accumulation in terminal oocytes they are asymmetrically distributed.
• 3.3. Endocytosis of vitellogenin 1 starts somewhat later than the uptake of vitellogenin 2 and chromoprotein 2.
• 4.4. In follicle cells of young follicles, a protein (DLP), immunologically related to diapause protein 1, is highly concentrated.
• 5.5. During vitellogenesis DLP is sequestered by the oocytes.
• 6.6. The protein rich globules in terminal oocytes contain the vitellins as well as chromoprotein 2 and DLP.

     

Deleterious effects of disulfiram on the respiratory electron transport system of liver mitochondria

• 1.1. The mechanism of action of disulfiram on the respiratory electron transport system of the liver mitochondria was studied in vitro.
• 2.2. Disulfiram inhibited the respiration supported by malate-glutamate as well as succinate.
• 3.3. Mitochondrial respiration inhibition was dependent upon alteration of —SH groups.
• 4.4. The inhibitory action of disulfiram might be related to the crosslinking of several proteins of the inner mitochondrial membrane.
• 5.5. The effects described above could be attributed to disulfiram per se and not to the main metabolite diethyldithiocarbamate.

     

Amino acid substitutions within the analogous nucleotide binding loop (P-loop) of aminoglycoside 3'-phosphotransferase-II

• 1.1. Oligonucleotide-directed mutagenesis of APH(3')-II was used to investigate the functions of key amino acids in the P-loop analogous motif of the enzyme.
• 2.2. The mutations of Gly205 → Glu, Gly210 → Ala and Arg211 → Pro considerably reduced the resistance of the resulting strains to KM and to related drugs, e.g. G418.
• 3.3. Similarly, enzyme activity in the crude extracts of these mutants was substantially reduced as well as the enzyme's affinity for Mg²⁺ ATP.
• 4.4. Alternatively substitutions at a highly conserved basic residue (Arg211 → Lys and Arg211 → His) were not sufficient for the enzyme to sustain the activity at a level comparable to that of the wildtype.
• 5.5. Moreover, an Arg211 → His mutation drastically reduced affinity of the enzyme for Mg²⁺ ATP.
• 6.6. This argues the importance of Arg211 residue in contributing to the formation of the P-loop structure in addition to its involvement in phosphoryl transfer reaction.
• 7.7. Computer analysis of the secondary structure predicted that the APH(3')-II loop connects a β -strand to an α-helix and that the above mutations caused varying degrees of structural distortions at the corresponding regions of the protein.

     

Identification of the major annexins in Ehrlich ascites tumor cells

• 1.1. Three calcium-binding proteins have been purified from Ehrlich ascites tumor cells.
• 2.2. They were identified by amino acid sequence analysis on selected fragments obtained by tryptic digestion.
• 3.3. The proteins belong to the annexin family and were identified as annexins II, III and V.
• 4.4. Antibodies raised against the proteins were used to examine for their presence in a number of murine tissues.
• 5.5. The occurrence was found to be in reasonable accordance with earlier reports.

     

Structural and functional effects of heavy metals on the nervous system,including sense organs,of fish

• 1.1. Today, fish in the environment are inevitably exposed to chemical pollution. Although most hazardous substances are present at concentrations far below the lethal level, they may still cause serious damage to the life processes of these animals.
• 2.2. Fish depend on an intact nervous system, including their sense organs, for mediating relevant behaviour such as food search, predator recognition, communication and orientation.
• 3.3. Unfortunately, the nervous system is most vulnerable and injuries to its elements may dramatically change the behaviour and consequently the survival of fish.
• 4.4. Heavy metals are well known pollutants in the aquatic environment. Their interaction with relevant chemical stimuli may interfere with the communication between fish and environment.
• 5.5. The affinity for a number of ligands and macromolecules makes heavy metals most potent neurotoxins.
• 6.6. The present Mini-Review highlights some aspects of how trace concentrations of mercury, copper and lead affect the integrity of the fish nervous system; structurally, physiologically and biochemically.

     

Kinetic analysis of reversible closed bicyclic enzyme cascades covering the whole course of the reaction

A kinetic analysis of the closed bicyclic enzyme cascades is presented.

• 1.1. It includes the dependence on time from the onset of the reaction, of the concentration of the modified and unmodified enzyme species involved and the time course equations of the modificational fractions of the interconvertible enzymes.
• 2.2. The transient phase equations obtained allow the definition of new regulatory modification properties.
• 3.3. The expressions for concentrations of the unmodified and modified forms of the interconvertible enzymes, as well as those of the fractional modifications in the steady state are derived as particular cases of the general equations.
• 4.4. These steady state expressions coincide with those obtained by other authors.
• 5.5. The analytical results obtained are discussed in relation to the Escherichia coli glutamine syntethase cascade.

     

The role of lipoproteins in the delivery of tumour-targeting photosensitizers

• 1.I. Serum lipoproteins play an important role in the in vivo transport of several porphyrinoid derivatives having a moderate or high degree of hydrophobicity.
• 2.2. There appears to exist a correlation between the extent of photosensitizer association with low-density lipoproteins (LDL) and the efficiency of tumour targeting by some classes of photosensitizers, such as differently sulphonated porphyrins and phthalocyanines, haematoporphyrin dialkylethers and unsubstituted phthalocyanines and naphthalocyanines.
• 3.3. In all cases, LDL-carried photosensitizers are preferentially released to malignant cells; hence, direct cell damage appears to be the major determinant of tumour damage consequent to photodynamic therapy.
• 4.4. Present evidence suggests that the LDL-associated photosensitizer is accumulated by tumour cells largely via a receptor-mediated endocytotic process.
• 5.5. Thus, the use of delivery systems for orientating a systemically injected photosensitizer towards lipoproteins has been explored; promising results have been obtained by incorporation of the dye into liposomal vesicles, oil emulsions or inclusion complexes, as well as by precomplexation of the dye with LDL.
• 6.6. Moreover, a suitable choice of the chemical constituents of the delivery system and the experimental conditions allows one to modulate the photosensitizer distribution among the different lipoproteins.
• 7.7. The occurrence of tumour-targeting strategies other than the LDL pathway is briefly discussed.

     

Company news

Including information on:

• ScanSoft
• SpeechWorks International
• Viisage Technology
• Firstec
• BIO-key International
• HP
• ZN Vision Technologies
• Unisys
• US Government’s
• Communication Intelligence Corporation
• Infinity Technologies

     

Company news

• Daon
• Musicrypt
• EMI Music Canada
• Digital Broadband Networks
• FaceKey Corporation
• Eystar Media Inc (EMI)
• Temasya Wira
• Animated Electronic Industries
• BIO-key International
• Entryport Corporation

     

Influence of environmental factors on the deep and skin temperature in the European bison,Bison bonasus (L.)

• 1.1. In 43 European bison divided into three groups (Group A, 3–8-month-old calves; Group B, 18-month-7-year-old young bison; Group C, 12–24-year-old bison) the rectal, humerus region and abdomen region temperatures were measured.
• 2.2. The experiments were carried out in winter months, from mid-December to mid-March.
• 3.3. The mean rectal temperatures changed from 38.55°C in calves to 38.15°C in the oldest bison.
• 4.4. The mean temperatures of the humerus region changed from 20.69°C in calves to 21.49°C in older bison.
• 5.5. The mean temperatures of the abdomen region changed from 20.79°C in calves to 22.17°C in older bison (Gr. B).
• 6.6. The cluster analysis divided the bison into four groups named hot, warm, cool and cold bison.
• 7.7. Only air temperature measured 2 m above the ground and snow cover influenced the integrated bison temperature. Age, sex and mass as well as some environmental factors had no influence.
• 8.8. Measurements made 1 to nearly 4hr after a bison's death showed a drop in rectal temperature and mostly increases in temperatures of the humerus and abdomen regions.

     

Evidence for two isoforms of carbonic anhydrase II in the leech (Hirudo medicinalis) central nervous system

• 1.1. We dissected, homogenized and prepared ganglia and connectives from the central nervous system of medicinal leeches for SDS gel electrophoresis. The isolated proteins were transferred to nitrocellulose and incubated with affinity column-purified antibodies.
• 2.2. The immunoblots showed a strong positive reaction of a bovine carbonic anhydrase standard at a molecular weight of 29 kDa, and a distinct double-bond at the same molecular weight in the analyzed material.
• 3.3. We demonstrated with rat antibodies that carbonic anhydrase II is detectable in the leech central nervous system as the main isoenzyme.
• 4.4. The biochemical knowledge of carbonic anhydrase reported here agrees well with the immunocytochemical locations, thus affirming the validity of specific staining.

     

Application news

Including information on:

• Martin State Airport
• Bioscrypt
• Saflink
• Office of the Secretary of Defense
• Department of Defense
• Boeing Corporation
• Bell ID, Gemplus
• Siemens
• Foreign Ministry

     

Kinetic analysis of the michaelis-menten mechanism in which the substrate and the product are unstable

• 1.1. A kinetic analysis of the Michaelis-Menten mechanism for the case in which both the substrate and the product are unstable, either spontaneously or as the result of the addition of a reagent, has been made.
• 2.2. The explicit time course equations of the immediate product and the species into which it subsequently is transformed have been derived under the conditions of rapid equilibrium and limiting substrate concentration.
• 3.3. The validity of these equations has been checked using numerical simulations.
• 4.4. The kinetic data analysis which we suggest is based on the time progress curves of the product or, in the case in which the product accumulation cannot be monitored experimentally, on the time progress curve of the species into which the immediate product is transformed.
• 5.5. This analysis allows the determination of the rate and the equilibrium constants if adequate experimental results are available.
• 6.6. We have chosen a numerical example, with which we illustrate the procedure of the kinetic data analysis by simulating some curves with assumed experimental errors.

     

In brief

• Bioscrypt
• Saflink
• Dell
• Fujitsu Microelectronics America
• Identix
• Viisage
• Acsys Biometrics
• US Government

     

Neutrophil mediated myocardial injury

• 1.1. Activated polymorphonuclear neutrophils (PMN) were shown to exacerbate ischemic myocardial injury and their activation is modulated by complement system, platelet activating factor, arachidonic acid metabolites, adenosine and nitric oxide.
• 2.2. Mechanisms of injurious PMN effect on ischemic myocardium are related to both mechanical and biochemical processes.
• 3.3. Activated PMN aggregate and adhere to endothelium that results in capillary plugging and subsequent impairment of coronary blood flow as well as participating in the development of endothelial cell edema.
• 4.4. PMN-related biochemical damage of ischemic myocardium is a result of the release of cytotoxic free oxygen radicals and proteolytic enzymes as well as vasoconstrictor leukotriene B4 and leukotoxin.

     

Biomines-stimulated phosphorylation and (Na+, K+-ATPase in the gills of the chinese crab,Eriocheir sinensis

• 1.1. Subcellular distribution of (NA⁺, K⁺-ATPase and ouabain-insensitive ATPase (Mg²⁺-ATPase) are compared in branchial tissues of the euryhaline crab, Eriocheir sinensis, acclimated to fresh water.
• 2.2. Both the anterior and posterior gills contain cAMP-dependent protein kinase and endogenous protein substrate for phosphorylation.
• 3.3. Phosphorylation occurs in both “particulate” and “soluble” subcellular fractions but its stimulation by cAMP is restricted to the “soluble” fraction.
• 4.4. serotonin (5-HT) and dopamine receptors are present only in the “light particulate” fraction isolated from the posterior gills.

• 1.(a) Serotonin and dopamine have no effect on the phosphorylation observed in a subcellular fraction alone.
• 2.(b) Activation of the phosphorylation by serotonin and dopamine is found when the soluble fraction (source of cAMP-dependent protein kinase) is added to the fraction P₃ from the posterior gills.
• 3.(c) No activation occurs with the fractions P₃ as well as P₁ or P₂ (not shown) from anterior gills of fresh water crab.
• 4.(d) Cyproheptadine, a serotonin receptor antagonist, inhibits the 5-HT dependent increase in phosphorylation.
• 5.(e) The dopamine receptor antagonist, chlorpromazine, inhibits dopamine-stimulated phosphorylation.
• 6.5. Ouabain mimics the effect of cyproheptadine on the serotonin-stimulated phosphorylation found in the posterior gills.

     

Cumene hydroperoxide-induced chemiluminescence in human erythrocytes: Effect of antioxidants and sulfhydryl compounds

• 1.1. The time-course of cumene hydroperoxide-induced changes in lipid peroxidation, protein sulfhydryl groups and chemiluminescence intensity was determined in human erythrocytes.
• 2.2. Increase in lipid peroxidation was maximal within 60 min of incubation and was paralleled by a decrease in protein sulfhydryl groups and an increase in chemiluminescence formation.
• 3.3. A standard assay system was established to investigate the protective effects of antioxidants and scavenger compounds on cumene hydroperoxide-induced chemiluminescence formation.
• 4.4. Chain-breaking antioxidants (i.e. butylated hydroxytoluene) and sulfhydryl compounds (i.e. dithiothreitol) were able to suppress chemiluminescence formation.
• 5.5. Our results suggested that secondary free radicals, as well as sulfhydryl groups of proteins are involved in cumene hydroperoxide-induced chemiluminescence formation.

     

Apparent low free magnesium levels in blue crab vas deferens determined by 31P NMR

• 1.1. ³¹P NMR examination of blue crab vas deferens reveals an α-β ATP chemical shift differences on average of 9.8 ppm.
• 2.2. This implies a free magnesium concentration well below 100 μM.
• 3.3. Thus crab vas deferens represents a new model for a low free magnesium system.
• 4.4. These results also point to a feature of carcine metabolism not previously recognized.