A molecular genetic linkage map of mouse chromosome 19, including thelpr,Ly-44, andTdt genes

The mouselpr gene, which is an autosomal recessive gene causing autoimmune disease with features of human systemic lupus erythematosus and eventually death from severe immune-complex glomerulonephritis, has been mapped on chromosome 19. To determine its exact chromosomal location, a three-point backcross was carried out by mating (MRL/MpJ-lpr/lpr × MOL-MIT)F₁ × MRL/MpJ-lpr/lpr using the genesLy-44 (lymphocyte differentiation antigen-44) andTdt (terminal deoxynucleotidyl transferase) as markers. The following order of genes is proposed, with the distances between genes given in parentheses: centromere-Ly-44 (19.3 cM)-lpr (6.1 cM)-Tdt-telomere. TheLy-44 ^a andTdt ^a alleles are found in all laboratory strains and in the wild Western European subspecies,domesticus andbrevirostris. In contrast, theLy-44 ^b andTdt ^b alleles are found in some Asian subspecies, Chinese mice of wild origin,yamashinai andmolossinus. Furthermore the thirdTdt allele,Tdt ^c , is detected incastaneus.Some of the data in this study were previously presented at the 4th Mouse Gene Mapping Workshop, Annapolis, Maryland, in November 1990.     

Circadian Rhythm and Seasonal Variations in Basal cAMP Content of Rat Heart Ventricles

The cAMP content in rat heart ventricles was studied at 3-hr intervals during 24hr at different times of the year. A significant circadian rhythm in cAMP content was found. Time of the year reproducibly influenced the 24-hr mean, the amplitude as well as the peak value in cAMP in relation to circadian time.     

Delineation of the frequency and boundary of chromosomal copy number variations in paediatric neuroblastoma

Neuroblastoma, the most common solid tumour in early childhood, is characterized by very frequent chromosomal copy number variations (CNVs). While chromosome 2p amplification, 17q gain, 1p and 11q deletion in human neuroblastoma tissues are well-known, the exact frequencies and boundaries of the chromosomal CNVs have not been delineated. We analysed the publicly available single nucleotide polymorphism (SNP) array data which were originally generated by the Therapeutically Applicable Research to Generate Effective Treatments (TARGET) initiative, defined the frequencies and boundaries of chromosomes 2p11.2 – 2p25.3 amplification, 17q11.1-17q25.3 gain, 1p13.3-1p36.33 deletion and 11q13.3-11q25 deletion in neuroblastoma tissues, and identified chromosome 7q14.1 (Chr7:38254795-38346971) and chromosome 14q11.2 (Chr14:21637401-22024617) deletion in blood and bone marrow samples from neuroblastoma patients, but not in tumour tissues. Kaplan Meier analysis showed that double deletion of Chr7q14.1 and Chr14q11.2 correlated with poor prognosis in MYCN gene amplified neuroblastoma patients. In conclusion, the oncogenes amplified or gained and tumour suppressor genes deleted within the boundaries of chromosomal CNVs in tumour tissues should be studied for their roles in tumourigenesis and as therapeutic targets. Focal deletions of Chr7q14.1 and Chr14q11.2 together in blood and bone marrow samples from neuroblastoma patients can be used as a marker for poorer prognosis and more aggressive therapies.     

Seasonal changes in bacterial and phytoplankton biomass in a subantarctic coastal area (Kerguelen Islands)

The seasonal variations of bacterial and phytoplanktonic biomass were studied during several pluri-annual surveys in the subantarctic Morbihan Bay (Kerguelen Islands, 49 ° 20 S; 70 ° 10 E). Large interannual variation was observed. Phytoplanktonic biomass showed moderate values during winter and autumn. They increased sharply in spring, reaching a maximum value of about 1 mg C l^–1 corresponding to an important depletion of nutrients. A second phytoplanktonic bloom of similar amplitude occurred in late summer. During algal blooms which were roughly associated with optimal values of solar irradiation for the first one and with the highest temperatures for the second one, phytoplanktonic material represented near 100% of particulate and living carbon. Bacteria showed maximal abundance (0.2 to 0.7 mg C l^–1) during summer or autumn. Their relative abundance, which represented less than 1% of the living biomass in spring and summer, can reach more than 95% in autumn and winter.     

Seasonal variations in nitrous oxide losses from managed grasslands in The Netherlands

Seasonal and interannual variations in nitrous oxide (N₂O) losses from agricultural soils hamper the accurate quantification of the N₂O source strength of these soils. This study focuses on a quantification of seasonal and interannual variations in N₂O losses from managed grasslands. Special attention was paid to N₂O losses during the growing season and off-season as affected by grassland management. Fluxes of N₂O from grasslands with three different types of management and on four different soil types in the Netherlands were measured weekly during two consecutive years, using flux chambers. There were distinct seasonal patterns in N₂O losses, with large losses during spring, summer, and autumn but relatively small losses during the winter. These seasonal variations were related to fertilizer N application, grazing and weather conditions. Measurements of N₂O concentrations in soil profiles showed that a rise in groundwater level was accompanied by increased N₂O concentrations in the soil. Disregarding off-season losses would underestimate total annual losses by up to 20%, being largest for unfertilized grassland and smallest for N-fertilized grazed grassland. Total annual N₂O losses ranged from 0.5 to 12.9 kg N ha^-1 yr^-1 for unfertilized grasslands to 7.3 to 42.0 kg N ha^-1 yr^-1 for N-fertilized grazed grasslands. Despite the considerable interannual variations in N₂O losses, this study indicates that the results of measurements carried out in one year have predictive power for estimating N₂O losses in other years.     

Effects of Depressed Affect on Diurnal and Ultradian Variations in Mood in a Healthy Sample

The study investigated diurnal and ultradian variations in cheerful and depressed mood in a healthy sample, and examined whether these variations were related to severity of depressed affect. Thirty employed volunteers used a pocket computer to complete self-rating scales of depression and cheerfulness every 2 h for 14 days except during sleep periods. They also completed the Beck Depression Inventory (BDI) and the General Health Questionnaire (GHQ). Analysis of variance of depressed mood showed a significant interaction between time of day and BDI/GHQ, in which only the mood of the high BDI/GHQ groups got worse during the day. The low BDI group showed a diurnal variation in cheerful mood in which mood was at its best in the early evening. Cosinor and “binfit” analysis of raw and residual time-series showed that more than half of the participants had significant fitting ultradian rhythms in mood in the range 3-9 h. However, only the number of significant fits for residual cheerful mood was substantially above the level of chance. The amplitudes of the ultradian rhythms in raw depressed mood were greater in participants scoring higher on the BDI/GHQ scales, but this seemed to reflect an increase in serial dependency between depressed mood states. The results are discussed in relation to circadian rhythms in mood and depression.     

Seasonal changes in phagocytic capacity and superoxide anion production of blood phagocytes from tench (Tinca tinca,L.)

Seasonal variations in the ex vivo phagocytic function of blood cells from tench, including ingestion capacity of inert particles and its destruction (microbicide capacity) assessed by measurement of superoxide anion production, were studied. Tench were maintained under natural conditions throughout the year, and the different assays of samples taken during each season were initially performed in vitro at 22°C and the results compared. Subsequently, assays were performed at the same temperature as that of the water ponds in which the fish were kept (“seasonal temperature”: 12°C in winter, 22°C in spring and autumn and 30°C in summer) and the results compared seasonally. The results at 22°C showed that phagocytic capacity was greatest in spring and summer and lowest in winter. However, when phagocytic capacity was measured at seasonal temperature, highest values appeared in winter and lowest in summer and autumn. Nitroblue tetrazolium reduction by tench phagocytes after phagocytosing latex beads demonstrated a similar seasonal behaviour at both 22°C in each season and at seasonal temperature. The highest values appeared in summer, which suggests a better microbicide capacity in this season. The results obtained in this study suggest that for a correct interpretation of ex vivo phagocytic capacity of fish through the year it is necessary to use the same assay temperature as that of the water in which the fish is kept.     

Expression characteristics of pokeweed antiviral proteins (PAPs): Two distinct types of proteins

Pokeweed antiviral proteins (PAPs) become novel therapeutic agents in relation to application in human viral diseases and cancer, as well as potent tools in plant system for defending viral infection. We have studied the expression characteristics of PAPs in pokeweed plants by western blot analysis. PAP-I was constitutively expressed in leaves, stems and roots of the pokeweed plant, while PAP-II was not expressed in roots. The expression of PAP-II began in May and then gradually increased with development of the plants. The PAP-II expression was induced and/or stimulated not only by biotic stresses, such as insect pests and viral infection, but also by abiotic stresses, like drought. Interestingly, low-light intensity was found to be more effective than high-light in the expression of both PAP-I and PAP-II. Our results suggest that PAP-II appears to have an additive effect in terms of protection of the plant against pathogens during summer-time when the plant actively grows and is attacked by various pathogens.     

Seasonal Variations in the Presence of Antibodies against Coxiella burnetii in Dairy Cattle in Hokkaido,Japan

The prevalence and seasonal variations of infection by Coxiella burnetii in cattle were investigated seroepidemiologically on a farm in Hokkaido, Japan, by an immunofluorescent antibody test. A total of 364 serum samples from 28 cows were collected from August 1993 to October 1995 in two barns on the farm. It was found that the number of antibody-positive cows and their antibody titers were significantly elevated in winter and decreased in summer. In addition, antibodies were detectable in seroconverted cows for about five months.