Effects of gall volume on survival and fecundity of gall-making aphidsAdelges japonicus (Homoptera: Adelgidae)

The number of larvae reaching maturity within the gall of Adelges japonicus was positively related to gall volume, and the relationship between the number of mature larvae and gall volume did not change with different densities of colonized larvae. The population changes in the bud galls of A. japonicus were surveyed by collecting the galls, which did not suffer predation or parasitism within the galls, from young artificial plantations of Picea jezoensis over two years. In the year when the density of colonized larvae was high, they suffered a 42% mortality within the galls, whereas mortality was nearly zero in the low density year. The numbers of larvae per gall were positively correlated with gall volume. The regression lines of the number of colonized larvae on gall volume did not differ significantly in the regression coefficients between the two years, whereas the intercept was significantly higher in the year when the density of colonized larvae was higher. However, different within-gall mortality nullified this difference, and the regression lines of the number of mature larvae on gall volume had no significant difference both in the regression coefficients and the intercepts. This suggests that the number of mature larvae per gall was limited by available resources within the gall which were positively related to gall volume. In 25% of the galls in which mature larvae inhabited, the space within the galls were completely filled by the larvae, indicating that space was one of the limiting resources. Gall volume also affected the number of adults that emerged from the gall and the potential number of their progeny.     

Functional expression of the genes of Escherichia coli in gram-positive Corynebacterium glutamicum

Summary Hybrid plasmids were constructed by combining in vitro the Escherichia coli plasmid pGA22, which carries the genes determining resistance to kanamycin, tetracycline, chloramphenicol and ampicillin, with the cryptic plasmids, pCG1 and pCG2, of Corynebacterium glutamicum. The hybrid plasmids were introduced into C. glutamicum and E. coli and replicated in both hosts. They expressed all the E. coli resistance phenotypes except ampicillin resistance in C. glutamicum. The levels of antibiotic inactivating enzymes encoded on these plasmids were about four to ten times lower in C. glutamicum than in E. coli. Despite the lack of expression of ampicillin resistance, -lactamase activity was detected in C. glutamicum carrying hybrid plasmids.     

Specificity of Tn5 insertions into a 36-bp DNA sequence repeated in tandem seven times

The target junction sequences of six independent Tn5 insertions into a 36-bp tandemly repeated DNA segment have been determined. In all instances Tn5 preferentially inserts near one end of the tandem repeat, but in four out of six cases the insertion is between different nucleotides. The target sequence shares some similarity (8 out of 11 bp) with the ends of Tn5. All six insertions are accompanied by duplication of 9 bp of target DNA. The data imply that, even though Tn5 appears to insert randomly on a macro scale, at the nucleotide sequence level insertion into target DNA, which has limited similarity to the Tn5 end reactive sequences, may be a preferred event.     

New medium for isolating propionibacteria and its application to assay of normal flora of human facial skin.

The conditions for isolation and cultivation of Propionibacterium acnes and related propionibacteria were studied in detail. Triton X-100 added to the diluent inhibited the growth of propionibacteria in concentrations of 0.05 to 0.1%. However, such was not the case with Tween 80; rather, growth of the bacteria was further enhanced by this agent. Consequently, Tween 80 was considered to be a suitable surfactant for addition to the diluent for isolation of propionibacteria. A new medium for isolating propionibacteria from human skin was developed. Comparative studies with colonies of P. acnes, Propionibacterium granulosum, and Staphylococcus epidermidis showed morphological differences among the colonies; thus, the medium was very useful for differentiating and identifying species of the microbes. The new medium was used for studies on the distribution of propionibacteria on the foreheads of 30 Japanese volunteers. Among 447 strains of P. acnes and 86 strains of P. granulosum isolated from the volunteers, all strains of the former were positive for indole, nitrate, milk, and gelatin hydrolysis, whereas all strains of the latter were negative for all of the tests.     

Spread of varicella in hospitalized children having no direct contact with an indicator zoster case and its prevention by a live vaccine

Varicella spread from a child with zoster to a total of 3 susceptible infants in another room in a children's ward, although they had been strictly isolated. To prevent spread of the disease, the staffs and patients were doing their own washing and no source of natural infection could be found. The cases indicate that it is difficult to predict nosocomial varicella infection or to prevent spread of the disease simply by isolation in a children's ward. A total of 11 other children without history of varicella in the ward were given live varicella vaccine before or immediately after this event. None of these children developed symptoms of varicella and all the susceptible children who were vaccinated showed an antibody response.     

An anomaly in the resonance Raman spectra of cytochrome P-450cam in the ferrous high-spin state.

Resonance Raman spectra of cytochrome P-450cam (P-450cam) and its enzymatically inactive form (P-420) in various oxidation and spin states were measured for the first time. The Raman spectrum of reduced P-450cam was unusual in the sense that the "oxidation-state marker" appeared at an unexpectedly lower frequency (1346 cm-1) in comparison with those of other reduced hemoproteins (approximately 1355-approximately 1365 cm-1), whereas that of oxidized P-450cam was located at a normal frequency. This anomaly in the Raman spectrum of reduced P-450cam can be explained by assuming electron delocalization from the fifth ligand, presumably a thiolate anion, to the antibonding pi orbital of the porphyrin ring. The corresponding Raman line of reduced P-420 appeared at a normal frequency (1360 cm-1), suggesting a status change or replacement of the fifth ligand upon conversion from P-450cam to P-420. The Raman spectrum of reduced P-450cam-metyrapone complex was very similar to that of ferrous cytochrome b5.     

Different sensitivities of avian- and mammalian-haemoglobin synthesis to elevated temperatures

Molecular Biology Reports - Avian- and mammalian-haemoglobin synthesis show different sensitivities to elevated temperatures. Temperature-dependent, reversible polyribosome disaggregation in avian...     

Fluorometric assay of microsomal aldehyde oxygenase activity: 9-anthraldehyde as a substrate.

With regard to hepatic microsomal oxidation of 9-anthraldehyde (9-AA), a fluorometric method for determination of 9-anthracene carboxylic acid (9-ACA) is described. 9-AA was incubated with hepatic microsomes prepared from male ddN mice. 9-ACA formed was fluorometrically (excitation and emission wavelengths of 255 and 458 nm, respectively) quantitated after the separation from 9-AA by an alkali extraction and ethyl acetate reextraction. Hepatic microsomes less than 0.1 mg protein were enough to assay the microsomal aldehyde oxidation. The enzyme in the microsomes that catalyzes the oxidation of 9-AA to 9-ACA has been characterized by this method.     

Alterations of GABA metabolism and seizure susceptibility in the substantia nigra of the kindled rat acclimating to changes in osmotic state

Seizure susceptibility and GABA metabolism were altered in the substantia nigra [SN] of adult male Sprague Dawley rats when these animals were acclimating to an altered plasma osmolality. Changes in GABA metabolism were measured in vivo in SN of the freely moving rat. Suitable precautions were taken to avoid any post-mortem flux of glutamate to GABA and to correct for the underestimation of GABA build up in SN due to the finite diffusion rate of -vinyl GABA [GVG] after stereotaxic injection of small amounts into one side of the brain. Control experiments provided evidence that changes in osmolality, within a normal physiological range, did not affect significantly -aminobutyric acid transaminase [GABA-T]. Also kindling via the medial septum [MS], in the absence of electrical stimulation did not alter GABA metabolism in SN, thus providing a stable baseline for studies of osmotic effects. Hyperosmolality was associated with a rise in seizure thresholds, with a marked reduction of the rate of GABA synthesis in SN, and with a substantial increase in turnover time of the GABA pool. Hypoosmolality, of a degree known to be associated with mild cerebral edema and swelling localized to astrocytes, markedly reduced seizure threshold, and reduced GABA pool size in SN, but did not alter the rate of GABA synthesis significantly. These results demonstrate by new and independent means the relationship between GABA metabolism in the SN and seizure susceptibility in vivo.Special issue dedicated to Dr. Eugene Roberts.