Structural-functional aspects of the postischemic recovery of the hepatocyte endoplasmic network in rats

The experiments on rats have shown that total hepatic ischemia reduces the content of microsomal cytochromes P-450 and b5 and causes amidopyrine and aniline disturbances over a 2-3-week post-ischemic period. The analysis of hepatocyte ultrastructure has revealed the interdependence of structural and functional changes in endoplasmic reticulum during recovery period. The damage of monooxygenase inducibility correlated with stable decline in the number of fixed ribosomes in post-ischemic period.     

Polymorphism in Two Parasitoids Detected Using Random Amplified Polymorphic DNA Polymerase Chain Reaction

We used Chelex 100 chelating resin to prepare DNA for the polymerase chain reaction (PCR) from two species of Hymenopteran parasitoids, Trioxys pallidus and Diglyphus begini. Chelex 100 produces consistent DNA yields for both species, as measured with Hoescht dye fluorometry. Approximately twice as much DNA was obtained from individual D. begini wasps than from T. pallidus wasps, but there were no differences in yield between sexes. We used this DNA to perform random amplified polymorphic DNA (RAPD) analysis, a PCR technique that amplifies various regions of the genome using arbitrarily chosen 10-base primers. Of the 120 primers tested using T. pallidus, 92 produced a total of 342 scorable bands, 118 of which exhibited presence/absence polymorphism. Of the 25 primers tested using D. begini, 18 produced a total of 53 scorable bands, 30 of which exhibited presence/absence polymorphism. The level of genetic variation detected using this technique was greater than any found in Hymenoptera using allozymes. Scorable bands segregated as dominant Mendelian traits. Potential uses of RAPD-PCR in genetic analyses on parasitic Hymenoptera are discussed.     

Reactivity of neurons of the orbito-frontal cortex of the cat during exposure to the scent or sight of food

Reactivity of neurones in orbitofrontal cortex of the cat to the action of light or sound was studied in consecutive stages of alimentary behaviour conditioned by the smell and then the sight of food. Changes were found of the character of neuronal reactions to the light and sound stimuli at the change of smell to the sight of food. A conclusion is drown, that polysensory properties of the neurones of the orbitofrontal cortex provide integral organization of brain sensory function at separate stages of alimentary behaviour.     

Identification of a gene, closely linked to dnaK, which is required for high-temperature growth of Escherichia coli.

We have constructed four deletion derivatives of the cloned dnaK gene. Plasmid pDD1, in which the last 10 amino acids of the DnaK protein have been replaced by three different amino acids derived from the pBR322 vector, was as effective as plasmid pKP31, from which it was derived, in restoring the ability of a dnaK null mutant, Escherichia coli BB1553, to plate lambda phage and to grow at high temperatures. The other three mutations, involving much larger deletions of the dnaK gene, did not restore the ability to plate lambda phage or the ability to grow at high temperatures. Plasmid pKUC2, which contains the whole dnaK gene and its promoters, was capable of restoring the ability of E. coli BB1553 to plate lambda phage but, surprisingly, it did not restore the ability to grow at high temperatures, even though it was shown that the DnaK protein was efficiently expressed in these cultures. By transposon mutagenesis and sub-cloning, we have shown the presence of a second gene in plasmid pKP31 which is required for high-temperature growth of E. coli BB1553. This gene, which we call htg A, is presumably also defective in the dnaK null mutant E. coli BB1553. We have also demonstrated that the inability of E. coli K756 to grow above 43.5 degrees C is complemented by sub-clones which contain the htg A gene, but not by plasmid pKUC2.     

Purification of hepatitis B virus gene X product synthesized in Escherichia coli and its detection in a human hepatoblastoma cell line producing hepatitis B virus

A fused gene containing 94% of the hepatitis B virus (HBV) open reading frame X was expressed in Escherichia coli, and its 17-kDa product was purified by ion-exchange chromatography. Antibody elicited against the X-gene product reacted with materials proximal to the nuclear membrane of a human hepatoblastoma cell line producing HBV particles. No such reaction was observed with the same cell line that did not produce HBV particles.     

The postnatal histology of the epididymis in buffalo (Bubalus bubalis).

The epididymis of buffalo is differentiated into 6 regions. The head represents the first 3 regions, the body the 4th region and the tail the 5th and 6th region. At 3-30 weeks, the epithelium is simple high columnar with few basal cells in region I, simple low columnar with few basal cells in region II, pseudostratified low columnar in regions III, IV, V, and pseudostratified low columar in region VI. As age advances, the epithelium increases in height and shows a tendency toward advanced pseudostratification. The basal cells are greater in number in regions III, IV and V than in the other regions of the epididymis. The epithelial cells contain stereocilia in region I at 3 weeks and regions III, IV and V at 30 weeks, whereas they are absent in regions II and VI. The tubules in region I are the smallest in diameter while the tubules in region VI have the largest diameter.     

Effects of high and low molecular soluble factors of the bone marrow on antibody formation and pain sensitivity in animals

In addition to the immunostimulating activity, bone marrow mediators, myelopeptides (MP) show the dose-dependent effect on the development of pain sensitivity in mice. When injected in nanogram amounts, MP induce hyperalgesia and 3-9 fold higher production of antibodies against SREC. When injected in milligram amounts, they exhibit hypoalgesic effect and no influence on antibody production. Immunostimulating effect in MP (mol, mass less than 1 KD, fraction 3) is accompanied with hypoalgesia. Bone marrow factors of mol. masses 40-150 KD (fraction 1) eluted at Sephadex G-25 gel-filtration before MP enhance the pain sensitivity tHreshold and show a potent immunodepressive effect. Thus the bone marrow factors are capable of exhibiting the opposite effects on the immune system in the pain control system that evidences the tight interrelation between these systems.     

Early endosteal bone response to incorporated plutonium-238 in mice

Ten Swiss albino ICR SPF female mice 110 days old (weight about 30 g) were exposed for 48 hours to a solution of plutonium-238 nitrate (spec. act. 5 MBq/1 m1, pH 2.7) injected in amounts of 0.01 ml into the popliteal area of the right femur, each thus receiving about 500 kBq per 30 g body weight. Of the injected activity, 50% was retained in the right femur, 2% in the left femur and approximately 2-3% in the excrements collected separately from each animal during the whole exposure period. Ultrastructurally, electron micrographs revealed a variety of changes, including hypertrophy and destruction of endosteal cell organelles (primary damage), deformation and hypertrophy of osteocytes (secondary damage) and the irregularities in the osteocyte self-burial process leading to an abnormal formation of bone tissue structure (tertiary damage). Qualitatively, these changes in the irradiated bone ultrastructure were analogous to those occurring with age. This was confirmed by comparing two groups of control mice 110 and 330 days old. Assessed quantitatively, changes due to irradiation were more pronounced than those associated with aging.